The problem of stability in population dynamics concerns many domains of application in demography, biology, mechanics and mathematics. The problem is highly generic and independent of the population considered (human, animals, molecules,…). We give in this paper some examples of population dynamics concerning nucleic acids interacting through direct nucleic binding with small or cyclic RNAs acting on mRNAs or tRNAs as translation factors or through protein complexes expressed by genes and linked to DNA as transcription factors. The networks made of (...) these interactions between nucleic acids (considered respectively as edges and nodes of their interaction graph) are complex, but exhibit simple emergent asymptotic behaviours, when time tends to infinity, called attractors. We show that the quantity called attractor entropy plays a crucial role in the study of the stability and robustness of such genetic networks. (shrink)

Building a meaningful model of biological regulatory network is usually done by specifying the components and their interactions, by guessing the values of parameters, by comparing the predicted behaviors to the observed ones, and by modifying in a trial-error process both architecture and parameters in order to reach an optimal fitness. We propose here a different approach to construct and analyze biological models avoiding the trial-error part, where structure and dynamics are represented as formal constraints. We apply the method to (...) Hopfield-like networks, a formalism often used in both neural and regulatory networks modeling. The aim is to characterize automatically the set of all models consistent with all the available knowledge. The available knowledge is formalized into formal constraints. The latter are compiled into Boolean formula in conjunctive normal form and then submitted to a Boolean satisfiability solver. This approach allows to formulate a wide range of queries, expressed in a high level language, and possibly integrating formalized intuitions. In order to explore its potential, we use it to find cycles for 3-nodes networks and to determine the flower morphogenesis regulatory network of Arabidopsis thaliana. Applications of this technique are numerous and concern the building of models from data as well as the design of biological networks possessing specified behaviors. (shrink)

ḥeleḳ rishon. Sheʼelot u-teshuvot be-ʻinyanim shonim mi-toratenu ha-ḳedoshah shebi-khetav ṿeshe-be-ʻal peh -- ḥeleḳ sheni. Leḳet mikhtavim u-maʼamarim le-ḥizuḳ ṿe-hitʻorerut ba-ʻavodat ha-Shem yitbarakh -- ḥeleḳ shelishi. Leḳet mikhtavim me-a.m. ṿe-r. ha-Rav Ḥayim Shaʼul z. l.l. h.h. Grainiman baʻal ha-ḥidushim u-veʼurim".

[ḥeleḳ 1]. Al hilkhot meḳaḥ ṭaʻut, onaʼah u-matanah, Ḥ m. 227-249 -- ḥeleḳ 2. ʻAl Hilkhot avedah u-metsiʼah, hefḳer, periḳah u-ṭeʻinah, genevah u-gezelah, Ḥ. m. 259-275, 348-377.

[1] Hagadah shel Pesaḥ -- [2] Pirḳe Avot -- [3] Mishle -- [4] Shir ha-shirim -- [5] Megilat Ḳohelet -- 6. Megilat Ekhah -- [7] Megilat Rut -- [8] Sefer Tehilim.

1. Moʻadim -- 2. Moʻadim 2. -- 3. Moʻadim 3.

Kerekh 1. shaʼar 1 pereḳ 1-6 -- Kerekh 2. shaʻar 1 pereḳ 7-22.

Committee decision making is examined in this study focusing on the role assigned to the committee members. In particular, we are concerned about the comparison between committee performance under specialization and non-specialization of the decision makers. Specialization (in the context of project or public policy selection) means that the decision of each committee member is based on a narrow area, which typically results in the acquirement and use of relatively high expertise in that area. When the committee members’ expertise is (...) already determined, specialization only means that the decision of each committee member is based solely on his/her relatively high expertise area. This form of specialization is potentially inferior relative to non-specialization under which the decision of each committee member is based on different areas, not just his/her relatively high expertise area. Given that the expertise of the committee members is already determined but unknown, our analysis focuses on non-specializing individuals whose decision is based on a decision rule that does not require information on the decision-making skills. Under these realistic assumptions, non-specialization is shown to be preferable over specialization, depending on the aggregation rule applied by the committee. The significance of our approach is not limited to the specific results that we obtain. Rather, it should be viewed as a first step toward a deeper examination of the role of individual decision makers in enhancing the performance of collective decision making. (shrink)

pereḳ 1. ʻOśeh fele -- pereḳ 2. Ḥidud be-divre Torah -- pereḳ 3. Ḥidud be-mile de-ʻalma -- pereḳ 4. Ḳetsat shut śikhliyot ṿe-ʻimahem shene derushim le-midrash Talmud Torah.

This policy report arises from the research project Augmented Reality: Ethics, Perception, Metaphysics, conducted at the University of Glasgow’s Centre for the Study of Perceptual Experience between November 2021 and November 2023. It was funded by a grant from the Royal Society of Edinburgh. The project brought together experts in various academic fields, with partners from industry and regulatory bodies, to explore the nature of augmented and mixed reality technology, the theories underpinning them, and the ethical and legal questions prompted (...) by new technology in this domain. (shrink)