Aircraft with increasingly high performance were important to the war effort in World War II. Changes in technology allowed aircraft to reach faster speeds and to complete missions at higher altitudes. With these changes came new obstacles for pilots who had to tolerate these stresses. Of primary concern to the U.S. War Department was the loss of consciousness that often occurred with high-speed maneuvers and especially during pull-up after dive-bombing missions. In some cases, pilots would experience up to 9G of (...) force during rapid ascent, much more than the 6G threshold that typically leads to loss of consciousness. In 1941, a research team in Red Wing, MN, proposed experiments to elucidate the mechanism .. (shrink)

Patients with schizophrenia have a higher risk of cardiovascular diseases and higher mortality from them than does the general population; however, the underlying mechanism remains unclear. Impaired cerebral autoregulation is associated with cerebrovascular diseases and their mortality. Increased or decreased cerebral blood flow in different brain regions has been reported in patients with schizophrenia, which implies impaired cerebral autoregulation. This study investigated the cerebral autoregulation in 21 patients with schizophrenia and 23 age- and sex-matched healthy controls. None of (...) the participants had a history of cardiovascular diseases, hypertension, or diabetes. All participants underwent 10-min blood pressure and cerebral blood flow recording through finger plethysmography and Doppler ultrasonography, respectively. Cerebral autoregulation was assessed by analyzing two autoregulation indices: the mean blood pressure and cerebral blood flow correlation coefficient (Mx), and the phase shift between the waveforms of blood pressure and cerebral blood flow determined using transfer function analysis. Compared with the controls, the patients had a significantly higher Mx (0.257 vs. 0.399, p = 0.036) and lower phase shift (44.3° vs. 38.7° in the 0.07–0.20 Hz frequency band, p = 0.019), which indicated impaired maintenance of constant cerebral blood flow and a delayed cerebrovascular autoregulatory response. Impaired cerebral autoregulation may be caused by schizophrenia and may not be an artifact of coexisting medical conditions. The mechanism underlying impaired cerebral autoregulation in schizophrenia and its probable role in the development of cerebrovascular diseases require further investigation. (shrink)

Ischemic stroke involves numerous and complex pathophysiological mechanisms including blood flow reduction, ionic exchanges, spreading depressions and cell death through necrosis or apoptosis. We used a mathematical model based on these phenomena to study the influences of intensity and duration of ischemia on the final size of the infarcted area. This model relies on a set of ordinary and partial differential equations. After a sensibility study, the model was used to carry out in silico experiments in various ischemic (...) conditions. The simulation results show that the proportion of apoptotic cells increases when the intensity of ischemia decreases, which contributes to the model validation. The simulation results also show that the influence of ischemia duration on the infarct size is more complicated. They suggest that reperfusion is beneficial when performed in the early stroke but may be either inefficacious or even deleterious when performed later after the stroke onset. This aggravation could be explained by the depolarisation waves which might continue to spread ischemic damage and by the speeding up of the apoptotic process leading to cell death. The effect of reperfusion on cell death through these two phenomena needs to be further studied in order to develop new therapeutic strategies for stroke patients. (shrink)

BACKGROUND: Through their action on the locus coeruleus, ␣ 2-adrenoceptor agonists induce rapidly reversible sedation while partially preserving cognitive brain functions. Our goal in this observational study was to map brain regions whose activity is modified by clonidine infusion so as to better understand its loci of action, especially in relation to sedation. METHODS: Six ASA I–II right-handed volunteers were recruited. Electroencephalogram (EEG) was monitored continuously. After a baseline H215O activation scan, clonidine infusion was started at a rate ranging from (...) 6 to 10 ␮g ⅐ kgϪ1 ⅐ h Ϫ1. A sequence of 11 similar scans was then performed at 8 min intervals. Plasma clonidine concentration was measured. Using statistical parametric mapping, we sought linear correlations between normalized regional cerebral blood flow (rCBF), an indicator of regional brain activity, and plasma clonidine concentration or spindle EEG activity. RESULTS: Clonidine induced clinical sedation and EEG patterns (spindles) comparable to early stage nonrapid eye movement sleep. A significant negative linear correlation between clonidine concentration and rCBF or spindle activity was observed in the thalamus, prefrontal, orbital and parietal association cortex, posterior cingulate cortex, and precuneus. CONCLUSIONS: The EEG patterns and decreases in rCBF of specific brain regions observed during clonidine-induced sedation are similar to those of early stage nonrapid eye movement sleep. Patterns of deactivated brain regions are also comparable to those observed during general anesthesia or vegetative state, reinforcing the hypothesis that alterations in the activity of a common network occur during these modified conscious states. (shrink)

Brain mapping studies using dynamic imaging methods demonstrate areas regional cerebral blood flow (rCBF) decreases, as well as areas where increases, during performance of various experimental tasks. Task holds for both sets of cerebral blood flow changes (CBF), providing the opportunity to investigate areas that become and “activated” in the experimental condition relative to control state. Such data yield the intriguing observation that in areas in emotional processing, such as the amygdala, the posteromedial cortex, and the (...) ventral anterior cingulate cortex, although flow as expected during specific emotion-related tasks, flow decreases performance of some attentionally demanding, cognitive tasks. Conversely, in some of the areas that appear to subserve cognitive functions, as the dorsal anterior cingulate and the dorsolateral prefrontal cortices, increases while performing attentionally demanding cognitive tasks, but during some experimentally induced and pathological emotional Although the specific nature of such reciprocal patterns of regional remains unclear, they may reflect an important cross-modal interaction during mental operations. The possibility that neural activity is less in areas required in emotional processing during some higher cognitive processes holds implications for the mechanisms underlying interactions cognition and emotion. Furthermore, the possibility that neural in some cognitive-processing areas is suppressed during intense states suggests mechanisms by which extreme fear or severe may interfere with cognitive performance. (shrink)

IntroductionDeep brain stimulation is an effective treatment for advanced Parkinson’s disease with the targeting bilateral subthalamic nucleus or globus pallidus internus. So far, detailed studies on the efficacy of unilateral STN-DBS for motor symptoms have been reported, but few studies have been conducted on unilateral GPi-DBS.Materials and MethodsSeventeen patients with Parkinson’s disease who underwent unilateral GPi-DBS were selected. We conducted comparison analyses between scores obtained 6–42 months pre- and postoperatively using the following measurement tools: the Movement Disorder Society Unified Parkinson’s (...) Disease Rating Scale part III, the Hoehn and Yahr stage, the presence/absence of dyskinesia, Mini-Mental State Examination, Frontal Assessment Battery, Geriatric Depression Scale, levodopa equivalent dose, and cerebral blood flow by single photon emission computed tomography. Patient backgrounds were compared between four cohorts with favorable and unfavorable postoperative outcome.ResultsSignificant improvement was observed postoperatively in the following: total MDS-UPDRS Part III scores during the off period, contralateral scores, ipsilateral scores, and axial scores. Similarly, the Hoehn and Yahr stages during the off period, and GDS also showed significant decrease. In contrast, LED, MMSE, and FAB remained unchanged while the number of patients who scored positive for dyskinesia decreased by 40%. Abnormal cerebral blood flow preoperatively seen in the cerebral cortex had normalized in the total score-based good responder cohort. In the ipsilateral score-based good responder cohort, cerebral blood flow increased in the contralateral frontal lobe including in the premotor cortex, contralateral to the DBS. Compared to the poor responders, postoperative good responders demonstrated significantly higher preoperative MMSE scores.DiscussionUnilateral GPi-DBS therapy was effective in improving contralateral, ipsilateral, and axial motor symptoms of patients with advanced PD; in particular, it was found to be especially beneficial in PwPD whose cognitive function was unimpaired; the treatment efficacy rivaled that of bilateral counterparts up till at least 6 months postoperatively. Finally, normalization of preoperative abnormalities in cerebral blood flow and increased cerebral blood flow in the contralateral frontal lobe indicated the beneficial potential of this therapy on ipsilateral motor symptoms. (shrink)

Blood coagulation is regulated through a complex network of biochemical reactions of blood factors. The main acting enzyme is thrombin whose propagation in blood plasma leads to fibrin clot formation. Spontaneous clot formation is normally controlled through the action of different plasma inhibitors, in particular, through the thrombin binding by antithrombin. In the current study we develop a mathematical model of clot formation both in quiescent plasma and in blood flow and determine the analytical conditions (...) on the antithrombin concentration corresponding to different regimes of blood coagulation. (shrink)

Blood coagulation is regulated through a complex network of biochemical reactions of blood factors. The main acting enzyme is thrombin whose propagation in blood plasma leads to fibrin clot formation. Spontaneous clot formation is normally controlled through the action of different plasma inhibitors, in particular, through the thrombin binding by antithrombin. In the current study we develop a mathematical model of clot formation both in quiescent plasma and in blood flow and determine the analytical conditions (...) on the antithrombin concentration corresponding to different regimes of blood coagulation. (shrink)

The present study addresses the fluid transport behaviour of the flow of gold -copper /biomagnetic blood hybrid nanofluid in an inclined irregular stenosis artery as a consequence of varying viscosity and Lorentz force. The nonlinear flow equations are transformed into dimensionless form by using nonsimilar variables. The finite-difference technique is involved in computing the nonlinear transport dimensionless equations. The significant parameters like angle parameter, the Hartmann number, changing viscosity, constant heat source, the Reynolds number, and nanoparticle volume (...) fraction on the flow field are exhibited through figures. Present results disclose that the Lorentz force strongly lessens the hybrid nanofluid velocity. Elevating the Grashof number values enhances the rate of blood flow. Growing values of the angle parameter cause to reduce the resistance impedance on the wall. Hybrid nanoparticles have a superior wall shear stress than copper nanoparticles. The heat transfer rate is amplifying at the axial direction with the growing values of nanoparticles concentration. The applied Lorentz force significantly reduces the hybrid and unitary nanofluid flow rate in the axial direction. The hybrid nanoparticles expose a supreme rate of heat transfer than the copper nanoparticles in a blood base fluid. Compared to hybrid and copper nanofluid, the blood base fluid has a lower temperature. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Bibliography of Resources by and about André E. Hellegers*Compiled by Doris Mueller Goldstein (bio)This bibliography is derived from the holdings of the National Reference Center for Bioethics Literature and the BIOETHICSLINE© database (both of which are at the Kennedy Institute of Ethics and supported by the National Library of Medicine); the archives of Lauinger Library, Georgetown University; the Medline databases of the National Library of Medicine; the WorldCat database (...) of OCLC, Dublin, Ohio, and selected Internet sites.Primarily comprised of writings by Dr. Hellegers, the list also includes interviews and media programs in which he participated, as well as writings about him that were written following his death. The arrangement within each section is by date. The 231 authored pieces reflect the transition from Dr. Hellegers’s early career as a researcher in fetal physiology at Johns Hopkins Medical School, where he published his first research report at the age of 29, to the early years of the Kennedy Institute, where he produced so many provocative columns on bioethical issues that influenced the growth of the field.Due to the diversity of sources and the 40-year time span covered, there are some variations in bibliographic style. Time and availability constraints precluded verifying all of the citations with the original documents. Any additions or corrections should be submitted to the compiler.Works Authored by André E. HellegersNo Date Ethical Issues in Sterilization of the Retarded. Unpublished paper.1956Vitamin B12 Serum Level and Pregnancy. American Journal of Clinical Nutrition 4: 440+, 1956. [With Bacon F. Chow and Kunio Okuda] [End Page 89]1957Vitamin B12 Absorption in Pregnancy and in the Newborn. American Journal of Clinical Nutrition 5: 327+, 1957. [With Bacon F. Chow, Robert E. L. Nesbitt, Kunio Okuda, and David W. Smith]1958The Effects of Acute Hypoxia on the Osmotic Pressure of the Plasma. Quarterly Journal of Experimental Physiology 43: 197+, 1958. [With Donald H. Barron, Frederick C. Battaglia, and Giacomo Meschia]Studies on the Absorption of Vitamin B12 in Human Pregnancy with Especial Reference to the Effect of D-Sorbitol. American Journal of Obstetrics and Gynecology 76: 91+, 1958. [With Bacon F. Chow, Harry Prystowsky, and Vernon Wong]1959The Alveolar PCO2 and PO2 in Pregnant and Nonpregnant Women at Altitude. Proceedings of the Society for Clinical Investigation 38: 1010+, 1959. [With Donald Barron, William Huckabee, Giacomo Meschia, James Metcalfe, and Harry Prystowsky]A Comparison of the Oxygen Dissociation Curves of the Bloods of Maternal and Fetal Goats at Various pHs. Quarterly Journal of Experimental Physiology 44: 215–21, July 1959. [With Donald Barron, Giacomo Meschia, Harry Prystowsky, and A. Stark Wolkoff]Fetal Blood Studies. XII. On the Relationship Between the Position of the Oxygen Dissociation Curve of Human Fetal Blood and Adult Fetal Hemoglobin. American Journal of Obstetrics and Gynecology 77: 585+, 1959. [With Paul D. Bruns, Julian Cotter, and Harry Prystowsky]Fetal Blood Studies. XIV. A Comparative Study of the Oxygen Dissociation Curve of Nonpregnant, Pregnant and Fetal Human Blood. American Journal of Obstetrics and Gynecology 78: 489–93, September 1959. [With Paul D. Bruns and Harry Prystowsky]Fetal Blood Studies. XVI. On the Changes in Total Osmotic Pressure and Sodium and Potassium Concentration of Amniotic Fluid During the Course of Human Gestation. Surgery, Gynecology and Obstetrics 109: 509–12, October 1959. [With Frederick Battaglia, Paul D. Bruns, Harry Prystowsky, and Clayton Smisson]Further Observations on the Metabolism of Vitamin B12 in Human Pregnancy. American Journal of Obstetrics and Gynecology 77: 1+, 1959. [With Bacon F. Chow, Harry Prystowsky, Bruno Ranke, and Elma Ranke]The Oxygen Dissociation Curves of the Bloods of Adult and Fetal Llamas. Federation Proceedings 18, 1959. [With Donald Barron, William Huckabee, Giacomo Meschia, James Metcalfe, and Harry Prystowsky] [End Page 90]Transfer of Oxygen Across the Sheep Placenta at High Altitude. Federation Proceedings 18, 1959. [With Donald Barron, William Huckabee, Giacomo Meschia, and Harry Prystowsky]Uterine Blood Flow and Metabolism in Pregnant Sheep at High Altitude. Federation Proceedings 18, 1959. [With Donald Barron, William Huckabee, Giacomo Meschia, James Metcalfe, and Harry Prystowsky]Uterine Blood Flow and Metabolism in Unanesthetized Pregnant Sheep. Federation Proceedings 18, 1959. [With Donald Barron, William Huckabee, Giacomo... (shrink)

Recently, we identified myeloid‐derived growth factor (MYDGF) as a blood flow‐induced angiocrine signal that promotes human and mouse hepatocyte proliferation and survival. Here, we review literature reporting changes in blood flow after partial organ resection in the liver, lung, and kidney, and we describe the angiocrine signals released by endothelial cells (ECs) upon blood flow alterations in these organs. While hepatocyte growth factor (HGF) and MYDGF are important angiocrine signals for liver regeneration, by now, (...) angiocrine signals have also been reported to stimulate hyperplasia and/or hypertrophy during the regeneration of lungs and kidneys. In addition, angiocrine signals play a critical role in tumor growth. Understanding the mechano‐elastic properties and flow‐mediated alterations in the organ‐specific microvasculature is crucial for therapeutic approaches to maintain organ health and initiate organ renewal. (shrink)

We have studied a number of long-term meditators in previous studies. The purpose of this study was to determine if there are differences in baseline brain function of experienced meditators compared to non-meditators. All subjects were recruited as part of an ongoing study of different meditation practices. We evaluated 12 advanced meditators and 14 non-meditators with cerebral blood flow SPECT imaging at rest. Images were analyzed with both region of interest and statistical parametric mapping. The CBF of (...) long-term meditators was significantly higher compared to non-meditators in the prefrontal cortex, parietal cortex, thalamus, putamen, caudate, and midbrain. There was also a significant difference in the thalamic laterality with long-term meditators having greater asymmetry. The observed changes associated with long-term meditation appear in structures that underlie the attention network and also those that relate to emotion and autonomic function. (shrink)

Modern readers view ancient theories of blood flow through the lens of circulation. Since the nineteenth century, scholarly work on the ancient understanding of the vascular system has run the gamut from attempting to prove that an ancient author had in fact, to some extent or another, pre-empted Harvey's discovery of the circulation of the blood or towards attempting, often with some empathetic embarrassment, to explain the failure on the part of an ancient author to notice something (...) that seems so obvious to the modern eye. Thus C.R.S. Harris's 1973 book The Heart and Vascular System in Ancient Greek Medicine, which remains the standard on the topic, opens with a sentence in which he marvels at how the otherwise admirable ancient Greek physicians could have ‘failed entirely to arrive at any conception of the circulation of the blood’. This modern vantage point has had an unfortunate effect. In the case of Aristotle in particular, understanding of his cardiovascular system has been diminished by a tendency to define it in contradistinction to our own modern understanding of circulation. By deliberately uncoupling from the framework of modern physiology, this paper will offer a richer and more accurate picture of his views. (shrink)

ObjectiveTo explore the effect of independently developed transcranial pulsed current stimulation on alleviating athlete’s mental fatigue.MethodsA total of 60 college athletes were randomly divided into the active stimulation group and the sham stimulation group. Subjective questionnaires, behavior test, and functional near-infrared spectroscopy test were conducted before and after the experiment. Two-way ANOVA with repeated measures was used to compare the differences in mental fatigue indexes before and after the two experimental conditions.ResultsAfter 7 days of exercise training, there was a significant (...) difference in the main effect of the time factor in all indexes of the two groups. The scores of rated perceived exertion scale, positive and negative affect schedule, critical flicker frequency, and reaction time, in the tPCS treatment group, were better than those in the sham stimulation group. After 7 days of exercise training, all the subjects had different degrees of athlete’s mental fatigue; the subjects in the active stimulation group have a good evaluation of the tPCS developed by the research group without adverse actions.ConclusiontPCS intervention can improve emotional state, reduce the subjective evaluation of fatigue, improve behavioral levels such as attention and reaction time and increase cerebral prefrontal blood flow and oxygen supply. (shrink)

In this paper, we report on an experiment with The Walking Dead (TWD), which is a narrative-driven adventure game with morally charged decisions set in a post-apocalyptic world filled with zombies. This study aimed to identify physiological markers of moral decisions and non-moral decisions using infrared thermal imaging (ITI). ITI is a non-invasive tool used to capture thermal variations due to blood flow in specific body regions that might be caused by sympathetic activity. Results show that moral decisions (...) seem to elicit a significant decrease in temperature in the chin region 20 seconds after participants are presented with a moral decision. However, given the small sample involved, and the lack of significance in other regions, future studies might be needed to confirm the results obtained in this work. (shrink)

Concepts and experimental results taken frombehavioral pharmacology, functional brain imaging,brain physiology, and behavioral neuroscience, wereused to develop the hypothesis that behavioraltolerance can, in part, be attributed to cellulartolerance. It is argued that task specific activationof circumscribed neuronal populations gives rise tocorresponding increases in regional cerebral bloodflow such that neurons related to task performance areexposed to higher effective doses of blood-borne drugthan neuronal groups not highly activated by thebehavioral task. Through this cerebral hemodynamicregulatory mechanism cellular tolerance phenomena canat least partially (...) account for behavioral tolerance(i.e., tolerance conferred through drugged practice). (shrink)

Experiential and behavioural aspects of emotions can be measured readily but developing a contactless measure of emotions’ physiological aspects has been a major challenge. We hypothesised that different emotion-evoking films can produce distinctive facial blood flow patterns that can serve as physiological signatures of discrete emotions. To test this hypothesis, we created a new Transdermal Optical Imaging system that uses a conventional video camera to capture facial blood flows in a contactless manner. Using this and deep machine (...) learning, we analysed videos of the faces of people as they viewed film clips that elicited joy, sadness, disgust, fear or a neutral state. We found that each of these elicited a distinct blood flow pattern in the facial epidermis, and that Transdermal Optical Imaging is an effective contactless and inexpensive tool to the reveal physiological correlates of discrete emotions. (shrink)

Biobanks are increasingly being linked together into global networks in order to maximise their capacity to identify causes of and treatments for disease. While there is great optimism about the potential of these biobank networks to contribute to personalised and data-driven medicine, there are also ethical concerns about, among other things, risks to personal privacy and exploitation of vulnerable populations. Concepts drawn from theories of globalisation can assist with the characterisation of the ethical implications of biobank networking across borders, which (...) can, in turn, inform more ethically sophisticated responses. Using the China Kadoorie Biobank as a case study, we show how distinguishing between the subnational, transnational, supranational and extranational spheres of operation and influence can help researchers, institutions and regulators to understand and manage the ethical issues raised by the globalisation of biobanking. (shrink)

The present study examined deep gray matter perfusion in neonates with congenital heart disease (CHD) with arterial spin labeling magnetic resonance imaging preoperatively. We found that neonates with cyanotic CHD showed lower right thalamus compared with controls and lower right basal ganglia perfusion compared with acyanotic CHD. When the CHD group was assessed as a whole, it showed slightly decreased left thalamus perfusion compared with controls. The results suggest that cardiac physiology plays a crucial part in changes in regional cerebral (...) perfusion. Perfusion with arterial spin labeling may be a useful marker of high risk for impaired cerebral blood flow auto-regulation and cerebral hypoperfusion in neonates with CHD. (shrink)

Although it is commonly believed that the concept of brain death was developed to benefit organ transplants, it evolved independently. Transplantation owed its development to advances in surgery and immunosuppressive treatment; BD owed its origin to the development of intensive care. The first autotransplant was achieved in the early 1900s, when studies of increased intracranial pressure causing respiratory arrest with preserved heartbeat were reported. Between 1902 and 1950, the BD concept was supported by the discovery of EEG, Crile’s definition of (...) death, the use of EEG to demonstrate abolition of brain potentials after ischaemia, and Crafoord’s statement that death was due to cessation of blood flow. Transplantation saw the first xenotransplant in humans and the first unsuccessful kidney transplant from a cadaver. In the 1950s, circulatory arrest in coma was identified by angiography, and the death of the nervous system and coma dépassé were described. Murray performed the first successful kidney transplant. In the 1960s, the BD concept and organ transplants were instantly linked when the first kidney transplant using a brain-dead donor was performed; Schwab proposed to use EEG in BD; the Harvard Committee report and the Sydney Declaration appeared; the first successful kidney, lung and pancreas transplants using cadaveric donors were achieved; Barnard performed the first human heart transplant. This historical review demonstrates that the BD concept and organ transplantation arose separately and advanced in parallel, and only began to progress together in the late 1960s. Therefore, the BD concept did not evolve to benefit transplantation. (shrink)

SignificanceElectrical burns can cause severe damage to the nervous system, resulting in autonomic dysfunction with reduced cerebral perfusion. However, few studies have investigated these consequences.AimTo elucidate changes in prefrontal cerebral hemodynamics using functional near-infrared spectroscopy (fNIRS) during the head-up tilt table test (HUT) for patients with electrical burns.ApproachWe recruited 17 patients with acute electrical burns within 1 week after their accidents and 10 healthy volunteers. The NIRS parameters acquired using an fNIRS device attached to the forehead were analyzed in five (...) distinct HUT phases.ResultsBased on their HUT response patterns, patients with electrical burns were classified into the group with abnormal HUT results (APG, n = 4) or normal HUT results (NPG, n = 13) and compared with the healthy control (HC, n = 10) participants. We found trends in hemodynamic changes during the HUT that distinguished HC, NPG, and APG. Reduced cerebral perfusion and decreased blood oxygenation during the HUT were found in both the NPG and APG groups. Patients with electrical burns had autonomic dysfunction compared to the HC participants.ConclusionsUsing fNIRS, we observed that acute-stage electrical burn injuries could affect cerebral perfusion. (shrink)

_Background:_ Preterm infants are still at an increased risk for suboptimal neurodevelopmental outcomes when compared with term born infants. The development of a child born preterm can be jeopardized by suboptimal conditions during pregnancy, in addition to the suboptimal growth environment postnatally compared to the normal in utero environment. This review summarizes the literature on the role of chorioamnionitis, placental insufficiency, and maternal smoking on the developmental outcomes of preterm infants. _Methods:_ A systematic database search was performed to identify all (...) original articles published on or before September 12, 2018 that evaluated the impact of clinical or histological chorioamnionitis, abnormal prenatal fetal and placental blood flow, and prenatal smoking exposure on the neuropsychological and cognitive outcomes of preterm infants. We identified a total of 54 studies. Thirty five original articles evaluated the effects of clinical or histological chorioamnionitis; 15 studies evaluated the effects of abnormal blood flow patterns; and four studies evaluated the effects of maternal smoking during pregnancy. _Results:_ The studies on prenatal risk factors showed conflicting results about the impact on the neurodevelopment of preterm infants. The majority of the studies did not show that chorioamnionitis poses a direct risk to the development of preterm infants. The role of abnormal prenatal placental and fetal blood flow on the development of preterm infants remained inconclusive because the sample sizes were often small and methodological problems complicated the interpretation of the data. Maternal smoking during pregnancy was assessed only in one cohort which showed that maternal smoking is a risk for suboptimal cognitive and neuropsychological development in preterm infants. _Conclusions:_ This review summarizes the data on several prenatal risk factors which play a role in the developmental outcomes of preterm infants. To optimize the developmental outcomes, we need to first optimize the fetal wellbeing before birth. More research that extends from the fetal life to long-term developmental outcomes is needed. (shrink)

A subtitle for this paper might have been ‘The ugly face ofVerstehen’, for it asks whether the theory ofVerstehenhas, to switch metaphors, ‘dirty hands’. By the theory ofVerstehen, I mean the constellation of concepts—life, experience, expression, interpretative understanding—which, according to Wilhelm Dilthey, are essential for the study of human affairs, thereby showing that ‘the methodology of the human studies[Geisteswissenschafteri]is … different from that of the physical sciences’ :1 for in the latter, these concepts have no similar place. Even critics of (...) Dilthey tend to agree that his heart, if not his head, was in the right place: thatVerstehenwas designed as an antidote to ‘dehumanizing’ attempts by positivists to reduce the categories used in explaining human behaviour to just those equally operative in the physical sciences. As Dilthey himself put it, ‘there is no real blood flowing in the veins’ of human beings as examined by the positivists and their precursors: they do not treat of ‘the whole man’. The idea ofVerstehen, it seems, is doubly humane: a humanizing approach to the humane studies. (shrink)

The blood oxygen level dependent effect that provides the contrast in functional magnetic resonance imaging has been demonstrated to affect the linewidth of spectral peaks as measured with magnetic resonance spectroscopy and through this, may be used as an indirect measure of cerebral blood flow related to neural activity. By acquiring MR-spectra interleaved with frames without water suppression, it may be possible to image the BOLD effect and associated metabolic changes simultaneously through changes in the linewidth of (...) the unsuppressed water peak. The purpose of this study was to implement this approach with the MEGA-PRESS sequence, widely considered to be the standard sequence for quantitative measurement of GABA at field strengths of 3 T and lower, to observe how changes in both glutamate and GABA levels may relate to changes due to the BOLD effect. MR-spectra and fMRI were acquired from the occipital cortex of 20 healthy participants whilst undergoing intrascanner visual stimulation in the form of a red and black radial checkerboard, alternating at 8 Hz, in 90 s blocks comprising 30 s of visual stimulation followed by 60 s of rest. Results show very strong agreement between the changes in the linewidth of the unsuppressed water signal and the canonical haemodynamic response function as well as a strong, negative, but not statistically significant, correlation with the Glx signal as measured from the OFF spectra in MEGA-PRESS pairs. Findings from this experiment suggest that the unsuppressed water signal provides a reliable measure of the BOLD effect and that correlations with associated changes in GABA and Glx levels may also be measured. However, discrepancies between metabolite levels as measured from the difference and OFF spectra raise questions regarding the reliability of the respective methods. (shrink)

Neuroimaging has been to neuroethics what free will and determinism has been, albeit for much longer, to philosophy: pillars for scholarly inquiry and curiosity, and entries to dialogue, debate, and discovery. With interest piqued by reproducible measures of regional blood flow in the human brain under well-defined conditions such as existential problem solving, decision-making, and trust, this article meticulously documents emerging trends involving functional MRI studies. The article builds on that work and examines the hypothesis that almost twenty (...) years after the first wave of such studies, the focus on neuroimaging and its application to complex and profoundly personal human behaviors has not abated. Neuroimaging studies remain an unwavering source of energy for the field. It reviews some of the reasons that they have provoked so much attention in neuroethics and elsewhere, presenting a 2002–2008 update to the trends that documented for 1991–2001, comparing this second generation of data to the first. (shrink)

Pericytes, like vascular smooth muscle cells, are perivascular cells closely associated with blood vessels throughout the body. Pericytes are necessary for vascular development and homeostasis, with particularly critical roles in the brain, where they are involved in regulating cerebral blood flow and establishing the blood-brain barrier. A role for pericytes during neurovascular disease pathogenesis is less clear—while some studies associate decreased pericyte coverage with select neurovascular diseases, others suggest increased pericyte infiltration in response to hypoxia or (...) traumatic brain injury. Here, we used an endothelial loss-of-function Recombination signal binding protein for immunoglobulin kappa J region (Rbpj)/Notch mediated mouse model of brain arteriovenous malformation (AVM) to investigate effects on pericytes during neurovascular disease pathogenesis. We tested the hypothesis that pericyte expansion, via morphological changes, and Platelet-derived growth factor B/Platelet-derived growth factor receptor β (Pdgf-B/Pdgfrβ)-dependent endothelial cell-pericyte communication are affected, during the pathogenesis of Rbpj mediated brain AVM in mice. Our data show that pericyte coverage of vascular endothelium expanded pathologically, to maintain coverage of vascular abnormalities in brain and retina, following endothelial deletion of Rbpj. In Rbpj-mutant brain, pericyte expansion was likely attributed to cytoplasmic process extension and not to increased pericyte proliferation. Despite expanding overall area of vessel coverage, pericytes from Rbpj-mutant brains showed decreased expression of Pdgfrβ, Neural (N)-cadherin, and cluster of differentiation (CD)146, as compared to controls, which likely affected Pdgf-B/Pdgfrβ-dependent communication and appositional associations between endothelial cells and pericytes in Rbpj-mutant brain microvessels. By contrast, and perhaps by compensatory mechanism, endothelial cells showed increased expression of N-cadherin. Our data identify cellular and molecular effects on brain pericytes, following endothelial deletion of Rbpj, and suggest pericytes as potential therapeutic targets for Rbpj/Notch related brain AVM. (shrink)

WHO II low grade glioma evolves inevitably to anaplastic transformation. Magnetic resonance imaging is a good non-invasive way to watch it, by hemodynamic and metabolic modifications, thanks to multinuclear spectroscopy 1H/31P. In this work we study a multi-scale minimal model of hemodynamics and metabolism applied to the study of gliomas. This mathematical analysis leads us to a fast-slow system. The control of the position of the stationary point brings to the concept of domain of viability. Starting from this system, the (...) equations bring to light the parameters that push glioma cells out of their domain of viability. Four fundamental factors are highlighted. The first two are cerebral blood flow and the rate of lactate transport through monocarboxylate transporters, which must be reduced in order to push glioma out of its domain of viability. Another factor is the intra arterial lactate, which must be increased. The last factor is pH, indeed a decrease of intra cellular pH could interfere with glioma growth. These reflections suggest that these four parameters could lead to new therapeutic strategies for the management of low grade gliomas. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Earth-O-Meter: Color Studies OchreElpitha Tsoutsounakis (bio)Ochre is always in a state of becoming—becoming color, becoming blood. Ancient, stellar death becoming current, terrestrial life; geological making. Design becomes epistemic tool beyond aesthetic representation.I join a body of academic and community scholars around the globe who think with Ochre from a variety of disciplines. How have we evolved through and with Ochre? What future does Ochre bring as art or (...) technology? How can Ochre remediate legacies of extraction? How can we return to the material from our current abstraction and commodification of color? How can we relate to terrestrial beings beyond anonymous resource? How can Ochre reveal plural realities of time and place through erased or forgotten narratives?This exploration has become the Field Studio Geontological Survey (FSGS), a design research collective assembling and extending Ochre dimensions to expand human/nonhuman inter-subjectivity. The collective is inspired by the United States Geological Survey (USGS), which has surveyed, mapped, and catalogued the U.S.—and the world—extensively and completely, translating earth matter into anonymous “natural” resources. Through its manipulation of geopower, USGS mediates our human relation to the more-than-human. The Geontological Survey diverts USGS tactics—survey, map, catalog, archive—towards a future feminist Ochre imaginary though collective practice in field, community, and studio operations. Ochre bodies, pigments, swatches, and the maps and artifacts produced with/by them, are archived at UnknownProspect.org.Earth-O-Meter 231101 (see Fig. 1) is assembled with thirty-six Ochres from FSGS Folio 2301,1 all surveyed in field operations at Temple Mountain Mining District in the San Rafael Swell, Utah. The swell is a geological anomaly at the edge of the Colorado Plateau, an anticline pushed up 60 million years ago during the Laramide Orogeny. It measures roughly 64 [End Page 109] Click for larger view View full resolutionFigure 1.Earth-O-Meter 231101: Ochre bodies from Folio 2301 and their respective swatches made with pigment in gum arabic and water. Full-scale color image and more on Ochres from Folio 2301 can be seen at unknownprospect.org.km wide and 121 km long. Erosion has revealed millions of years of geological time exposed to the desert sun along the reef edge where so-called Temple Mountain emerges from the southeast flank. An ancient marine environment left us the Chinle Formation in the Triassic Period—a formation marked by colorful instances of oxidation or reduction based on [End Page 110] fluctuating sea levels and water conditions. The meter begins and ends with Ochre that appears “green” (28.006) alongside Ochre that appears “violet” (18.003). They arrive next to one another just as they are found in the landscape: green nestled in violet, reminding us of lapping waters so long ago.Folio 2301 and the Earth-O-Meter are lines of flight for a material color theory, one in which color is not an abstract, perceived characteristic observed by physics, or a trick debating its place in or out of the mind. Color, or chroma, are material signs in the universe. Folio 2301 archives Ochre bodies from Temple Mountain alongside their respective pigments and the registry of community members who prepared them. The pigments were swatched to produce eight plates containing color studies or “palettes of place.” In Ochre, heat moves iron from yellow to red, water differentiates green from violet. Fluctuations of heat, time, pressure, electromagnetic field, and energy all play a part in the matter of color.While it is inspired by the cyanometer, a tool made to measure the blueness of the sky,2 the Earth-O-Meter is not a tool for measuring color, or earth-ness. It is a portal and a sign where the energy and intelligence of iron is flowing and evolving—all around us, before us, and after us. The cyanometer is made using Prussian blue, which is an oxidation of ferrous ferrocyanide salts. Prussian blue is known as the “first synthetic pigment.” By tinting Prussian blue to create the spectrum of the sky, technics modify iron to produce a divergent color in order to measure an ephemeral effect of atmosphere. The sky’s blueness is our experience of... (shrink)

Current neuroimaging techniques with high spatial resolution constrain participant motion so that many natural tasks cannot be carried out. The aim of this paper is to show how a time-locked correlation-analysis of cerebral blood flow velocity (CBFV) lateralization data, obtained with functional TransCranial Doppler (fTCD) ultrasound, can be used to infer cerebral activation patterns across tasks. In a first experiment we demonstrate that the proposed analysis method results in data that are comparable with the standard Lateralization Index (LI) (...) for within-task comparisons of CBFV patterns, recorded during cued word generation (CWG) at two difficulty levels. In the main experiment we demonstrate that the proposed analysis method shows correlated blood-flow patterns for two different cognitive tasks that are known to draw on common brain areas, CWG, and Music Synthesis. We show that CBFV patterns for Music and CWG are correlated only for participants with prior musical training. CBFV patterns for tasks that draw on distinct brain areas, the Tower of London and CWG, are not correlated. The proposed methodology extends conventional fTCD analysis by including temporal information in the analysis of cerebral blood-flow patterns to provide a robust, non-invasive method to infer whether common brain areas are used in different cognitive tasks. It complements conventional high resolution imaging techniques. (shrink)

Although it is commonly believed that the concept of brain death was developed to benefit organ transplants, it evolved independently. Transplantation owed its development to advances in surgery and immunosuppressive treatment; BD owed its origin to the development of intensive care. The first autotransplant was achieved in the early 1900s, when studies of increased intracranial pressure causing respiratory arrest with preserved heartbeat were reported. Between 1902 and 1950, the BD concept was supported by the discovery of EEG, Crile’s definition of (...) death, the use of EEG to demonstrate abolition of brain potentials after ischaemia, and Crafoord’s statement that death was due to cessation of blood flow. Transplantation saw the first xenotransplant in humans and the first unsuccessful kidney transplant from a cadaver. In the 1950s, circulatory arrest in coma was identified by angiography, and the death of the nervous system and coma dépassé were described. Murray performed the first successful kidney transplant. In the 1960s, the BD concept and organ transplants were instantly linked when the first kidney transplant using a brain-dead donor was performed; Schwab proposed to use EEG in BD; the Harvard Committee report and the Sydney Declaration appeared; the first successful kidney, lung and pancreas transplants using cadaveric donors were achieved; Barnard performed the first human heart transplant. This historical review demonstrates that the BD concept and organ transplantation arose separately and advanced in parallel, and only began to progress together in the late 1960s. Therefore, the BD concept did not evolve to benefit transplantation. (shrink)

Since its development about 15 years ago, functional magnetic resonance imaging (fMRI) has become the leading research tool for mapping brain activity. The technique works by detecting the levels of oxygen in the blood, point by point, throughout the brain. In other words, it relies on a surrogate signal, resulting from changes in oxygenation, blood volume and flow, and does not directly measure neural activity. Although a relationship between changes in brain activity and blood flow (...) has long been speculated, indirectly examined and suggested and surely anticipated and expected, the neural basis of the fMRI signal was only recently demonstrated directly in experiments using combined imaging and intracortical recordings. In the present paper, we discuss the results obtained from such combined experiments. We also discuss our current knowledge of the extracellularly measured signals of the neural processes that they represent and of the structural and functional neurovascular coupling, which links such processes with the hemodynamic changes that offer the surrogate signal that we use to map brain activity. We conclude by considering applications of invasive MRI, including injections of paramagnetic tracers for the study of connectivity in the living animal and simultaneous imaging and electrical microstimulation. D 2004 Elsevier Inc. All rights reserved. (shrink)

Although it is commonly believed that the concept of brain death was developed to benefit organ transplants, it evolved independently. Transplantation owed its development to advances in surgery and immunosuppressive treatment; BD owed its origin to the development of intensive care. The first autotransplant was achieved in the early 1900s, when studies of increased intracranial pressure causing respiratory arrest with preserved heartbeat were reported. Between 1902 and 1950, the BD concept was supported by the discovery of EEG, Crile’s definition of (...) death, the use of EEG to demonstrate abolition of brain potentials after ischaemia, and Crafoord’s statement that death was due to cessation of blood flow. Transplantation saw the first xenotransplant in humans and the first unsuccessful kidney transplant from a cadaver. In the 1950s, circulatory arrest in coma was identified by angiography, and the death of the nervous system and coma dépassé were described. Murray performed the first successful kidney transplant. In the 1960s, the BD concept and organ transplants were instantly linked when the first kidney transplant using a brain-dead donor was performed; Schwab proposed to use EEG in BD; the Harvard Committee report and the Sydney Declaration appeared; the first successful kidney, lung and pancreas transplants using cadaveric donors were achieved; Barnard performed the first human heart transplant. This historical review demonstrates that the BD concept and organ transplantation arose separately and advanced in parallel, and only began to progress together in the late 1960s. Therefore, the BD concept did not evolve to benefit transplantation. (shrink)

Magnetic resonance imaging (MRI) can provide a number of measurements relevant to sport-related concussion (SRC) symptoms; however, most studies to date have used a single MRI modality and whole-brain exploratory analyses in attempts to localize concussion injury. This has resulted in highly variable findings across studies due to wide ranging symptomology, severity and nature of injury within studies. A multimodal MRI, symptom-guided region-of-interest (ROI) approach is likely to yield more consistent results. The functions of the cerebellum and basal ganglia transcend (...) many common concussion symptoms, and thus these regions, plus the white matter tracts that connect or project from them, constitute plausible ROIs for MRI analysis. We performed diffusion tensor imaging (DTI), resting-state functional MRI, quantitative susceptibility mapping (QSM), and cerebral blood flow (CBF) imaging using arterial spin labeling (ASL), in youth aged 12-18 years following SRC, with a focus on the cerebellum, basal ganglia and white matter tracts. Compared to controls similar in age, sex and sport (N= 20), recent SRC youth (N= 29; MRI at 8 ± 3 days post injury) exhibited increased susceptibility in the cerebellum (p= 0.032), decreased functional connectivity between the caudate and each of the pallidum (p= 0.035) and thalamus (p= 0.021), and decreased diffusivity in the mid-posterior corpus callosum (p< 0.038); no changes were observed in recovered asymptomatic youth (N= 16; 41 ± 16 days post injury). For recent symptomatic-only SRC youth (N= 24), symptom severity was associated with increased susceptibility in the superior cerebellar peduncles (p= 0.011) and reduced activity in the cerebellum (p= 0.013). Fewer days between injury and MRI were associated with reduced cerebellar-parietal functional connectivity (p< 0.014), reduced activity of the pallidum (p= 0.002), increased CBF in the caudate (p= 0.005), and reduced diffusivity in the central corpus callosum (p< 0.05). Youth SRC is associated with acute cerebellar inflammation accompanied by reduced cerebellar activity and cerebellar-parietal connectivity, as well as structural changes of the middle regions of the corpus callosum accompanied by functional changes of the caudate, all of which resolve with recovery. Early MRI post-injury is important to establish objective MRI-based indicators for concussion diagnosis, recovery assessment and prediction of outcome. (shrink)

Stuttering is a disorder characterized by intermittent loss of volitional control of speech movements. This hypothesis and theory article focuses on the proposal that stuttering may be related to an impairment of the energy supply to neurons. Findings from electroencephalography, brain imaging, genetics, and biochemistry are reviewed: Analyses of the EEG spectra at rest have repeatedly reported reduced power in the beta band, which is compatible with indications of reduced metabolism. Studies of the absolute level of regional cerebral blood (...) flow show conflicting findings, with two studies reporting reduced rCBF in the frontal lobe, and two studies, based on a different method, reporting no group differences. This contradiction has not yet been resolved. The pattern of reduction in the studies reporting reduced rCBF corresponds to the regional pattern of the glycolytic index. High regional GI indicates high reliance on non-oxidative metabolism, i.e., glycolysis. Variants of the gene ARNT2 have been associated with stuttering. This gene is primarily expressed in the brain, with a pattern roughly corresponding to the pattern of regional GI. A central function of the ARNT2 protein is to act as one part of a sensor system indicating low levels of oxygen in brain tissue and to activate appropriate responses, including activation of glycolysis. It has been established that genes related to the functions of the lysosomes are implicated in some cases of stuttering. It is possible that these gene variants result in a reduced peak rate of energy supply to neurons. Lastly, there are indications of interactions between the metabolic system and the dopamine system: for example, it is known that acute hypoxia results in an elevated tonic level of dopamine in the synapses. Will mild chronic limitations of energy supply also result in elevated levels of dopamine? The indications of such interaction effects suggest that the metabolic theory of stuttering should be explored in parallel with the exploration of the dopaminergic theory. (shrink)

ABSTRACT The past fifteen years or so have witnessed considerable progress in our understanding of how the human brain works. One of the objectives of the fast-growing field of neuroscience is to deepen our knowledge of how the brain perceives and interacts with the external world. Advances in this direction have been made possible by progress in brain imaging techniques and by clinical data obtained from patients with localized brain lesions. A relatively new field within neuroscience is neuroeconomics, which focuses (...) on individual decision making and aims to systematically classify and map the brain activity that correlates with decision-making that pertains to economic choices. Neuroeconomic studies rely heavily on functional magnetic resonance imaging (fMRI), which measures the haemodynamic response (that is, changes in the blood flow) related to neural activity in the brain. (shrink)

Vertebrate haemoglobin (Hb), the oxygen‐carrying protein of the blood, consists of two α‐ and two β‐subunits, each containing one haem, and shows cooperative oxygen binding known as the haem–haem interaction. The amino‐acid sequences of Hbs found in different species have diverged considerably and the homology in the most distantly related ones is only 40%. How can such varied amino‐acid sequences give rise to similar three‐dimensional structures and functional properties? To what extent do amino‐acid replacements affect the structure of haemoglobin? (...) Which mutations are responsible for the functional differences between haemoglobins from different species? Expression of α‐ and β‐globins in Escherichia coli has enabled us to introduce any mutations in the haemoglobin molecule at will. By X‐ray crystallographic and functional studies of the engineered mutants, we are trying to answer these questions. (shrink)

Studies exploring how students learn and understand science processes such as diffusion and natural selection typically find that students provide misconceived explanations of how the patterns of such processes arise (such as why giraffes’ necks get longer over generations, or how ink dropped into water appears to “flow”). Instead of explaining the patterns of these processes as emerging from the collective interactions of all the agents (e.g., both the water and the ink molecules), students often explain the pattern as (...) being caused by controlling agents with intentional goals, as well as express a variety of many other misconceived notions. In this article, we provide a hypothesis for what constitutes a misconceived explanation; why misconceived explanations are so prevalent, robust, and resistant to instruction; and offer one approach of how they may be overcome. In particular, we hypothesize that students misunderstand many science processes because they rely on a generalized version of narrative schemas and scripts (referred to here as a Direct-causal Schema) to interpret them. For science processes that are sequential and stage-like, such as cycles of moon, circulation of blood, stages of mitosis, and photosynthesis, a Direct-causal Schema is adequate for correct understanding. However, for science processes that are non-sequential (or emergent), such as diffusion, natural selection, osmosis, and heat flow, using a Direct Schema to understand these processes will lead to robust misconceptions. Instead, a different type of general schema may be required to interpret non-sequential processes, which we refer to as an Emergent-causal Schema. We propose that students lack this Emergent Schema and teaching it to them may help them learn and understand emergent kinds of science processes such as diffusion. Our study found that directly teaching students this Emergent Schema led to increased learning of the process of diffusion. This article presents a fine-grained characterization of each type of Schema, our instructional intervention, the successes we have achieved, and the lessons we have learned. (shrink)

Do states have a right to exclude prospective immigrants as they see fit? According to statists the answer is a qualified yes. For these authors, self-determining political communities have a prima facie right to exclude, which can be overridden by the claims of vulnerable groups such as refugees and children born in the state’s territory. However, there is a concern in the literature that statists have not yet developed a theory that can protect children born in the territory from being (...) excluded from the political community. For if the self-determining political community has the right to decide who should form the self in the first place, then that right should count against both newcomers by immigration and newcomers by birth. Or so the concern goes. In this essay, I defend statism against this line of criticism and provide a liberal justification for the inclusion of children born within the state’s borders. My account leads to some surprising implication for citizenship law, as well as immigration arrangements in the area of asylum and unauthorized immigration. (shrink)

In this paper I first address what I consider a central issue in the account of perception in Plato’s Timaeus, namely, how the pathemata pass through the body to reach the soul, and thus become aistheseis. My point in Section 1 is that in tackling this issue Plato aims to provide a firm physiological basis to the notion of perception that starts to emerge in the Theaetetus and the Philebus and is crucial to the late development of his theory of (...) cognition. In the ensuing section I try to put the account of perception in the Timaeus into a historical perspective, aiming to highlight two points: a) Plato’s description of the way in which sensible impressions “travel” inside the body and interact with its parts and other constituents is largely indebted to previous theories, such as those we find, for example, in Empedocles and a few Hippocratic writers; b) The leading role in this story (where internal air plays a significant supporting role) is played by blood flowing through the vascular system and thus performing a crucial cognitive function. Moreover, emphasizing the role of blood as well as analyzing the elaborate way in which perceptions are transmitted through the body to the soul proves vital to appreciate (in Section 3) the cognitive status of the lower parts of the soul (which are more involved in perception) and their relation to reason. Overall, the paper adds further elements to our understanding of Plato’s embodied approach to cognition. I had already written (and submitted) this article when Johansen (2021) was published. The latter’s approach to the role of blood in Plato’s physiology of knowledge in the Timaeus converges in part with mine (as I was pleased to find out), partly due to our overlapping sources and bibliography. (shrink)

“Dumpster diving” is a term generally used for obtaining items, in this case food for consumption, from dumpsters. This study evaluates the prevalence of dumpster diving in two low-income urban communities in Minneapolis, Minnesota. Additionally, attitudes and beliefs of adults who engage in this behavior are reported. Surveys (n=396) were used to collect data including individual dumpster diving behavior, food security, health, and demographic data. Nearly one-fifth of those surveyed had used dumpster diving as a means (...) to obtain food. Focus groups (n=17) were conducted to further evaluate dumpster divers’ attitudes and beliefs about dumpster diving, use of food assistance programs including benefits and barriers, and other strategies used to obtain food such as stealing. Focus group participants were primarily homeless and most were high school educated. Ways to improve delivery of food assistance are suggested. In conclusion, more research on the use of dumpsters as a source of food is needed. Utilizing more of the 96 billion pounds of food wasted each year in the US through food recovery and donation programs could help to provide socially acceptable means for low-income urban dwellers to obtain food. (shrink)

This study introduces destination image, nostalgic feeling, and flow experience into tea estate tourism and constructs a theoretical model that includes destination image, nostalgic feeling, flow experience, cultural identity, and tourists’ behavioral intention. Then, an empirical study is conducted with tourists at Yunling Tea Estate in Anxi, China. The results show that all hypotheses are supported except the hypothesis pertaining to the significance of the influence of flow experience on behavioral intention, which is not supported. The model (...) includes eight mediating effects and one moderating effect that is influenced by cultural memory. (shrink)

While studies on the characteristics of flow states and their relation to peak performance exist, little is known about the dynamics by which flow states emerge and develop over time. The current paper qualitatively explores the necessary pre-conditions to enter flow, and the development of flow over time until its termination. Using an elicitation interview, participants were asked to recall their flow experiences in sports or music performances. The analysis resulted in the identification of the (...) following three phases that athletes and musicians experience during flow: Preparation to enter flow; Entry into the flow state and; Exit from the flow state. These three phases are characterized by several sub-themes contributing to the experience of flow. The function of emotions is crucial, as they play a core role across all three phases and regulate flow over time. The findings provide insights into the phenomenological characteristics of the transition and maintenance of the three proposed phases and the temporal dynamics of flow. (shrink)

This study examines the food flow in Tianjin, divided into three areas (urban, suburban, and rural), as a case study to gain a better understanding of local and regional food flows and ecosystem performance. The study has the following objectives: (1) to evaluate the capacity for self-sufficiency within Tianjin’s administrative boundary by estimating a self-sufficiency ratio (SSR) using statistical data at both the city and local scales, (2) to estimate food flow at the city scale from field surveys (...) of the local markets and statistics provided by the local government, and (3) to examine the real flows of the two primary types of arable crops (cereal grains and vegetables) at the local level by conducting semi-structured household interviews. The results of this study show that Tianjin has experienced a rapid increase of self-sufficiency capacity since the 1980s, and it appears to have the capacity to support the citizens within its borders. Rural areas have had a surplus in all of the studied food categories since the 1980s, and suburban areas have a history of high estimated SSR for vegetables, poultry, and fish. However, a low degree of locally sourced product flow was observed in this study. Most of the local cereal crops were consumed in the agricultural production areas, but 70 % of the vegetables produced in the rural areas flowed outside of Tianjin and did not support Tianjin local consumption. To reduce its vulnerability to food security issues and to promote a more environmentally desirable local food system, Tianjin needs to recognize the high productivity of its local ecosystem and reduce its dependence on other remote ecosystems for its food needs. A stronger relationship between urban and rural areas should also be established. (shrink)

Branching Streams Flow in the Darkness: Zen Talks on the Sandokai. Shunryu Suzuki, edited by Mel Weitsman and Michael Wenger. University of California Press, Berkeley & Los Angeles 1999. viii, 195 pp. $22.50. ISBN 0-52-21982-1.

The subject of this paper is Georg Ernst Stahl's reflections on epilepsy. In the German physician's work, the concept of disease is stratified: it is the morbid idea which causes dysfunctions in the animal economy, as well as irregular motion, overabundance and ultimately an alteration of the corporeal humours. In particular, epilepsy is an affection deriving from an altered functioning of the bodily motions, caused by abnormal blood flow, intestinal worms, anatomical defects, foreign bodies, and the passions of (...) the soul. While a certain medical tradition attributed a nervous origin to epilepsy, Stahl, giving it a humoural genesis, openly shows the theoretical premises on which his physiology rests. So, Stahlian physiology appears to be a non-mechanistic, teleological-inspired, hydraulicism. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:204 Feminist Studies 46, no. 1. © 2020 by Feminist Studies, Inc. Blood on a Blackberry Darlene Taylor The road bends. In a place where a girl was snatched, no one says her name. They talk about the bloody slip, not the lost girl. The blacktop road curves there and drops. Can’t see what’s ahead so, I listen. Insects scratch their legs and wind their wings above their (...) backs. The road sounds safe. Every day I walk alone on the schoolhouse road, keeping my eyes on where I’m going, not where I’ve been. Bruises on my shoulder from carrying books and notebooks, pencils and crayons. Pebbles crunch. An engine grinds, brakes screech. I step into a cloud of pink dust and weeds. The sandy taste of road dust dries my tongue. Older boys, mean boys, cursing beer-drunk boys laugh and bluster—“Rusty Girl.” They drive fast. Their laughter fades. Feathers of a bent blue bird impale the road. Sun beats the crushed bird. Cutting through the tall, tall grass, I pick up a stick to warn. Songs and sticks have power over snakes. Bramble snaps. Wild berries squish under my feet. The ripe scent makes my belly grumble. Briar thorns prick my skin, making my fingertips bleed. Plucking handfuls, I eat. Blood on a blackberry ruins its taste. Pencils, crayons, books spill. Backwards I fall. Pages tear. Lessons brown like sugar, cinnamon, nutmeg. Blackberry stain. Thistles and nettles grate my legs and thighs. Coarse laughter, not from inside me. A boy, a laughing boy, a mean boy presses. Berry black stains my dress. A snake hisses. I run. Home. I kneel. Well water pumps, washing away sin. The sun burns through kitchen windows, warming, baking. I roll my purple-tipped fingers into my palms. Darlene Taylor 205 “Sweetchild,”grandmotherwillsay.“Smartgirl.Whatdid you learn today?” On the schoolhouse road.... (shrink)