Criticality Analysis of Activity Networks under Interval Uncertainty

Dedicated to the memory of Professor Stefan Chanas - The extended abstract version of this paper has appeared in Proceedings of 11th International Conference on Principles and Practice of Constraint Programming (CP2005) ("Interval Analysis in Scheduling", Fortin et al. 2005)International audienceThis paper reconsiders the Project Evaluation and Review Technique (PERT) scheduling problem when information about task duration is incomplete. We model uncertainty on task durations by intervals. With this problem formulation, our goal is to assert possible and necessary criticality of the different tasks and to compute their possible earliest starting dates, latest starting dates, and floats. This paper combines various results and provides a complete solution to the problem. We present the complexity results of all considered subproblems and efficient algorithms to solve them

Controlled overexpression of Pax6 in vivo negatively autoregulates the Pax6 locus, causing cell-autonomous defects of late cortical progenitor proliferation with little effect on cortical arealization

Levels of expression of the transcription factor Pax6 vary throughout corticogenesis in a rostro-lateral(high) to caudo-medial(low) gradient across the cortical proliferative zone. Previous loss-of-function studies have indicated that Pax6 is required for normal cortical progenitor proliferation, neuronal differentiation, cortical lamination and cortical arealization, but whether and how its level of expression affects its function is unclear. We studied the developing cortex of PAX77 YAC transgenic mice carrying several copies of the human PAX6 locus with its full complement of regulatory regions. We found that PAX77 embryos express Pax6 in a normal spatial pattern, with levels up to three times higher than wild type. By crossing PAX77 mice with a new YAC transgenic line that reports Pax6 expression (DTy54), we showed that increased expression is limited by negative autoregulation. Increased expression reduces proliferation of late cortical progenitors specifically, and analysis of PAX77↔wild-type chimeras indicates that the defect is cell autonomous. We analyzed cortical arealization in PAX77 mice and found that, whereas the loss of Pax6 shifts caudal cortical areas rostrally, Pax6 overexpression at levels predicted to shift rostral areas caudally has very little effect. These findings indicate that Pax6 levels are stabilized by autoregulation, that the proliferation of cortical progenitors is sensitive to altered Pax6 levels and that cortical arealization is not

Buildings as landscapes: The analysis of corporate designed landscapes of the 1970s and 1980s

This dissertation uses a case-study approach to examine the design rationale for landscapes associated with corporate architecture of the 1970s and 1980s, and determines whether their design was influenced by government policies or the designers' contextual response to the site

Výskyt slunečních shluků jako součást termoregulace lesních mravenců Formica polyctena

The occurrence of sunning clusters in red wood ants is a remarkable phenomenon and it is a ubiquitous behavior observed in all nests we studied. This specific behavior is supposed to play an important role in the nest thermoregulation; namely in the rapid heating of the ant nest after winter. This doctoral thesis investigates the occurrence of sunning clusters in nests of red wood ants Formica polyctena in relation to environmental factors and their contribution to the spring nest heating. In early spring, the frequency of sunning clusters was low and increased as the internal nest temperature and the duration of daylight increased. A breaking point of the nest internal temperature is at 7 řC and 13 hours and 24 minutes of daylight. After this the cluster frequency decreased. The daily occurrence of clusters in early spring correlated positively with the air temperature, but as the nest temperature increased, this correlation of cluster occurrence with the air temperature gradually decreased and eventually became negative at the nest temperature more than 20 řC. The increase in sunning cluster frequency results in the increase of internal nest temperature over the day. This can be applied only on nests which are not heated on temperature above 20 řC. The frequency of daily occurrence of sunning...Výskyt slunečních shluků u lesních mravenců je pozoruhodný jev a je to všudypřítomné chování pozorované ve všech námi studovaných hnízdech. Toto specifické chování by mělo hrát důležitou roli v termoregulaci hnízda; konkrérně při rychlém zahřívání mraveniště po zimě. Tato dizertační práce se zabývá studiem výskytu slunečních shluků v hnízdech lesních mravenců Formica polyctena ve vztahu k faktorům prostředí a jejich podílu na jarním zahřívání hnízda. Brzy na jaře byla frekvence slunečních shluků nízká a zvyšovala se s rostoucí vnitřní teplotou hnízda a délkou denního světla. Bod zlomu vnitřní teploty hnízda nastává při 7 řC a 13 hodinách a 24 minutách denního světla. Poté se frekvence shluků snižovala. Denní výskyt shluků brzy na jaře pozitivně koreloval s teplotou vzduchu, avšak se zvyšující sa teplotou hnízda tato korelace mezi výskytem shluků a teplotou vzduchu postupně klesala, až se nakonec stala negativní při teplotě hnízda nad 20 řC. Nárůst četnosti slunečních shluků má za následek zvýšení vnitřní teploty hnízda během dne. Toto lze aplikovat pouze na hnízda, která nejsou vyhřívaná na teplotu nad 20 řC. Četnost denního výskytu slunečních shluků významně pozitivně korelovala s denním zvyšováním vnitřní teploty hnízda. To přináší jasný statistický důkaz o tom, že sluneční shluky přispívají k...Institute for Environmental StudiesÚstav pro životní prostředíFaculty of SciencePřírodovědecká fakult

Regulation of nestin expression by thrombin and cell density in cultures of bone mesenchymal stem cells and radial glial cells

BACKGROUND: Bone marrow stromal cells and radial glia are two stem cell types with neural phenotypic plasticity. Bone marrow mesenchymal stem cells can differentiate into osteocytes, chondrocytes and adipocytes, but can also differentiate into non-mesenchymal cell, i.e. neural cells in appropriate in vivo and in vitro experimental conditions. Likewise, radial glial cells are the progenitors of many neurons in the developing cortex, but can also generate astrocytes. Both cell types express nestin, an intermediate filament protein which is the hallmark of neural precursors. RESULTS: In this study, we demonstrate that thrombin, a multifunctional serine protease, stimulates the growth of radial glial cells (RG) and mesenchymal stem cells (MSCs) in a dose-dependent manner. In RG, the mitogenic effect of thrombin is correlated with increased expression of nestin but in MSCs, this mitogenic effect is associated with nestin down-regulation. Both cell types express the PAR-1 type receptor for Thrombin and the effect of Thrombin on both cell types can be mimicked by its analogue TRAP-6 activating specifically this receptor subtype or by serum which contains various amount of thrombin. Moreover, we also demonstrate that serum deprivation-induced expression of nestin in MSCs is inhibited by high cell density (> 50,000 cells/cm2). CONCLUSION: This work shows that thrombin stimulates the growth of both RG and MSCs and that nestin expression by MSCs and RG is regulated in opposite manner by thrombin in vitro. Thrombin effect is thus associated in both cell types with a proliferating, undifferentiated state but in RG this involves the induction of nestin expression, a marker of immaturity for neural progenitors. In MSCs however, nestin expression, as it corresponds to a progression from the mesenchymal "undifferentiated", proliferating phenotype toward acquisition of a neural fate, is inhibited by the mitogenic signal

« Des collections en partage » au musée de Bretagne. Quand la notion de « commun » entre au musée

L’objectif du projet présenté ici était de faire connaître, partager, permettre la réutilisation gratuite, dans le respect des droits des collections et ressources patrimoniales du musée de Bretagne grâce à un outil numérique simple et intuitif pour les utilisateurs. Les responsables présentent les différentes étapes de mise en place et dressent un premier bilan d’utilisation de ce portail qui s’inscrit dans une démarche militante d’ouverture des données culturelles

DNaseI Hypersensitivity and Ultraconservation Reveal Novel, Interdependent Long-Range Enhancers at the Complex Pax6 Cis-Regulatory Region

The PAX6 gene plays a crucial role in development of the eye, brain, olfactory system and endocrine pancreas. Consistent with its pleiotropic role the gene exhibits a complex developmental expression pattern which is subject to strict spatial, temporal and quantitative regulation. Control of expression depends on a large array of cis-elements residing in an extended genomic domain around the coding region of the gene. The minimal essential region required for proper regulation of this complex locus has been defined through analysis of human aniridia-associated breakpoints and YAC transgenic rescue studies of the mouse smalleye mutant. We have carried out a systematic DNase I hypersensitive site (HS) analysis across 200 kb of this critical region of mouse chromosome 2E3 to identify putative regulatory elements. Mapping the identified HSs onto a percent identity plot (PIP) shows many HSs correspond to recognisable genomic features such as evolutionarily conserved sequences, CpG islands and retrotransposon derived repeats. We then focussed on a region previously shown to contain essential long range cis-regulatory information, the Pax6 downstream regulatory region (DRR), allowing comparison of mouse HS data with previous human HS data for this region. Reporter transgenic mice for two of the HS sites, HS5 and HS6, show that they function as tissue specific regulatory elements. In addition we have characterised enhancer activity of an ultra-conserved cis-regulatory region located near Pax6, termed E60. All three cis-elements exhibit multiple spatio-temporal activities in the embryo that overlap between themselves and other elements in the locus. Using a deletion set of YAC reporter transgenic mice we demonstrate functional interdependence of the elements. Finally, we use the HS6 enhancer as a marker for the migration of precerebellar neuro-epithelium cells to the hindbrain precerebellar nuclei along the posterior and anterior extramural streams allowing visualisation of migratory defects in both pathways in Pax6(Sey/Sey) mice

Essential genes for astroglial development and axon pathfinding during zebrafish embryogenesis

The formation of the central nervous system depends on the coordinated development of neural and glial cell types that arise from a common precursor. Using an existing group of zebrafish mutants generated by viral insertion, we performed a “shelf-screen” to identify genes necessary for astroglial development and axon scaffold formation. We screened 274 of 315 viral insertion lines using antibodies that label axons (anti-Acetylated Tubulin) and astroglia (anti-Gfap) and identified 25 mutants with defects in gliogenesis, glial patterning, neurogenesis, and axon guidance. We also identified a novel class of mutants affecting radial glial cell numbers. Defects in astroglial patterning were always associated with axon defects, supporting an important role for axon-glial interactions during axon scaffold development. The genes disrupted in these viral lines have all been identified, providing a powerful new resource for the study of axon guidance, glio- and neurogenesis, and neuron-glial interactions during development of the vertebrate CNS.National Institutes of Health (U.S.) (Grant T32MH020051)National Institutes of Health (U.S.) (Grant F32NS043872

Zapalenie mięśnia sercowego u dzieci i młodzieży — przegląd piśmiennictwa

Myocarditis is defined by the World Health Organization as an inflammatory disease involving cardiomyocytes, interstitial tissue, vessels and occasionally the pericardium. In this article, literature from the past 5 years regarding epidemiology, diagnostic tests, treatment and prognosis in myocarditis in young children and adolescents was analyzed. For this purpose the Pubmed database was screened using the key words “myocarditis” and “children”, yielding 117 articles. This list of was narrowed down to those in which the study group consisted of at least 5 people and included information about: symptoms and signs, abnormalities in additional tests, etiology, treatment, length of hospitalization and mortality. Finally, the review included 17 studies, describing 1891 children with a diagnosis of myocarditis. The analysis shows that myocarditis is a rare disease. Two peaks of the disease are observed: the first in newborns and infants, the second one in adolescents. Age less than 2 years is a predictor of severe prognosis. In reported cases the most common symptoms were: fatigue, chest pain, palpitations or irregular heart rhythm. Tachycardia, tachypnoe, hypotension and hepatomegaly dominated among findings in physical examination. The interview, the result of physical examination and additional tests (troponin levels, electrocardiogram, echocardiogram) are helpful in making a diagnosis. Cardiac magnetic resonance imaging is used to confirm the diagnosis. In the analyzed group, 65–90% of children were treated in the Intensive Care Unit. Extracorporeal membrane oxygenation was used in 168 cases, a ventricular assist device was implanted in 35 children and 38 children underwent heart transplantation. The mortality rate in myocarditis remains high (25–35% in analyzed studies). Up to 25% of children may develop chronic heart failure. Due to the unpredictable course of this disease, patients in the acute period of the disease should be hospitalized, and after being discharge from the hospital undergo further cardiological check-up.Zapalenie mięśnia sercowego (ZMS) według Światowej Organizacji Zdrowia definiuje się jako chorobę zapalną obejmującą kardiomiocyty, tkankę śródmiąższową, naczynia, a czasem również osierdzie. W poniższym opracowaniu przeanalizowano piśmiennictwo z ostatnich 5 lat dotyczące epidemiologii, badań diagnostycznych, leczenia i rokowania w ZMS u dzieci i młodzieży. W tym celu dokonano przeglądu medycznej bazy danych Pubmed, używając słów/zwrotów kluczowych: „dzieci” (ang. ‘children’), „zapalenie mięśnia sercowego” (ang. ‘myocarditis’) — strategia ta pozwoliła uzyskać łącznie 117 artykułów. Spośród nich wyodrębniono prace, w których badana grupa obejmowała co najmniej 5 dzieci, a w opisie zawarto dane dotyczące objawów klinicznych, odchyleń w badaniach laboratoryjnych oraz badaniach obrazowych, identyfikacji czynników etiologicznych, zastosowanego leczenia oraz czasu hospitalizacji i liczby zgonów. Do analizy końcowej włączono 17 artykułów; zestawienie obejmuje łącznie 1891 dzieci, u których rozpoznano ZMS. Z analizy wynika, że ZMS jest chorobą rzadką. Obserwuje się dwa szczyty zachorowań: w wieku noworodkowym i wczesnoniemowlęcym oraz w okresie dojrzewania, przy czym wiek poniżej 2. rż. jest niekorzystnym czynnikiem rokowniczym. W raportowanych przypadkach najczęstszymi objawami podmiotowymi były: osłabienie, ból w klatce piersiowej, kołatania serca. Wśród objawów przedmiotowych dominowały: tachypnoe, tachykardia, hipotensja, hepatomegalia. Wywiad, wynik badania przedmiotowego oraz wyniki badań dodatkowych (stężenia troponin, elektrokardiogram, echokardiogram) przybliżają do rozpoznania, natomiast „złotym standardem” do ustalenia diagnozy jest badanie rezonansu magnetycznego serca. W analizowanej grupie 65–90% dzieci wymagało leczenia na oddziale intensywnej terapii, u 168 dzieci zastosowano ciągłe pozaustrojowe natlenianie krwi, a 35 dzieciom wszczepiono tak zwane sztuczne komory. U 38 pacjentów wykonano przeszczepienie serca. Śmiertelność w ZMS jest wysoka (w przeanalizowanym piśmiennictwie wyniosła 25–35%). U około 25% dzieci dysfunkcja mięśnia sercowego pozostała trwała. Ze względu na nieprzewidywalny przebieg choroby pacjent w ostrym okresie choroby powinien być hospitalizowany, a po wypisaniu ze szpitala podlegać dalszej kontroli kardiologicznej