Zero-error Slepian-Wolf Coding of Confined Correlated Sources with Deviation Symmetry

In this paper, we use linear codes to study zero-error Slepian-Wolf coding of a set of sources with deviation symmetry, where the sources are generalization of the Hamming sources over an arbitrary field. We extend our previous codes, Generalized Hamming Codes for Multiple Sources, to Matrix Partition Codes and use the latter to efficiently compress the target sources. We further show that every perfect or linear-optimal code is a Matrix Partition Code. We also present some conditions when Matrix Partition Codes are perfect and/or linear-optimal. Detail discussions of Matrix Partition Codes on Hamming sources are given at last as examples.Comment: submitted to IEEE Trans Information Theor

Erythropoietin inhibits chemotherapy-induced cell death and promotes a senescence-like state in leukemia cells

There are conflicting reports on the adverse effects of erythropoietin (EPO) for the management of cancer-associated anemia. The recognition that erythropoietin receptors (EPORs) are expressed outside the erythroid lineage and concerns that erythropoiesis-stimulating agents (ESAs) may cause tumors to grow and increase the risk of venous thromboembolism have resulted in substantially fewer cancer patients receiving ESA therapy to manage myelosuppressive chemotherapy. In this study, we found that EPO suppresses p53-dependent apoptosis induced by genotoxic (daunorubicin, doxorubicin, and γ-radiation) and non-genotoxic (nutlin-3a) agents and induces a senescence-like state in myeloid leukemia cells. EPO interferes with stress-dependent Mdm2 downregulation and leads to the destabilization of p53 protein. EPO selectively modulates the expression of p53 target genes in response to DNA damage preventing the induction of a number of noncoding RNAs (ncRNAs) previously associated with p53-dependent apoptosis. EPO also enhances the expression of the cyclin-dependent kinase inhibitor p21WAF1 and promotes recruitment of p53 to the p21 promoter. In addition, EPO antagonizes Mcl-1 protein degradation in daunorubicin-treated cells. Hence, EPO signaling targets Mcl-1 expression and the p53-Mdm2 network to promote tumor cell survival.York University Librarie

Pandémie à Severe Acute Respiratory Syndrome-Coranovirus-2 (SARS-COV-2) en Afrique sub-saharienne : Quelles solutions innovantes pour contenir la propagation ? Severe Acute Respiratory Syndrome-Coranovirus-2 (SARS-COV-2) pandemic in sub-Saharan Africa: What innovative solutions to contain the propagation?

Since the dawn of time, epidemics have sometimes invaded large areas of the world, decimating entire populations; and this fact has been occurring even before the concept of globalization took on the scale we know nowadays. Millions of people lost their lives, as was the case of the “black plague” which occurred between 1347 and 1352, and the Spanish flu between 1918 and 1919. The COVID-19 pandemic that has started in its first outbreak in the city of Wuhan, China in December 2019, is very peculiar in terms of its contagious nature and the severity of clinical manifestations in vulnerable individuals, with a mortality rate that challenges even the most efficient healthcare systems with well-equipped hospitals in the world. Of course, the whole world has been so overwhelmed by the propagation of this new disease that containment measures taken at individual, community and national levels seem to have been taken too late. Anyway, we had no choice but just trying to limit the human and socioeconomic impacts, as well as the adverse effects which will certainly last beyond the end of the pandemic. Africa was affected a few weeks after other continents; thus, African countries should have learned from both positive and negative experiences of other countries and continents in order to better cope with this infectious threat. The most pessimistic or the most macabre predictions are often made for sub-Saharan Africa (SSA). To date, the scale of the COVID-19 epidemic on the African continent is visibly of less importance, compared to what is observed elsewhere, which does not suggest the way the pandemic is going to evolve in the next days or weeks. This is where the preventive measures advocated overseas deserve to be adopted by means of a “textualization” which must make them acceptable and applicable. Indeed, the “copy-paste” of these measures which demonstrate their effectiveness in Asian and Western countries is often not possible for cultural and economic reasons. And yet prevention remains the best weapon against this corona virus infection. So what confinement? What barriers and social distancing measures? What communication to use for the adoption of behaviors likely to protect individuals and communities? In other words, what prevention in a context of extreme poverty, combined with insufficiency of basic social services in terms of water and electricity supply and means of communication (dilapidated and poor roads, difficulty to have access to new information technologies including internet …). How to make people accept effective preventive measures amidst poor sanitation, poverty, cultural and faith-based obstacles … And this without procrastination which can only be fatal for communities already affected by malaria and other endemics even recognized as “neglected diseases” by the international community. Our thinking is based on the main prevention measures recommended throughout the world in regard to the current COVID-19 pandemic, and observation of their effective application in the community after the official proclamation of those measures in Kinshasa, the capital city of the Democratic republic of the Congo (DRC). A particular attention is paid to the various messages to raise awareness among the populations and the dissemination by the political and health authorities of information on the pandemic via public media and social networks. We have observed the reactions of people in terms of acceptance or refusal to apply the measures that are propagated through both written and audio-visual media. Considering these observations, we can then suggest locale but effective solutions for realistic preventive approach. Considering the socio-economic status of the populations, overcrowding in cities and especially the common faith in miraculous cure in our society, we hereby suggest a number of recommendations for the success of preventive measures against COVID-19 in SSA: Increase awareness among populations of the danger of the SARS-CoV-2 virus, by means of adapted messages which are given to community leaders who are truly trusted and influential. It is time for church leaders, traditional leaders, traditional healers and all those who have a voice to take the lead and pass on awareness messages to their respective communities. Provide basic needs of the population, supplying food items in a spirit of volunteerism by even using state resources and military support. During this time, it is necessary to pay decent salaries and bonuses to workers from all sectors to allow households acquire basic needs and secure autonomy during the lockdown period. Ensure regular supply of water and electric power, and free access to masks for underprivileged populations while making their use compulsory. Ensure that residents visit markets and other places to purchase goods in their respective districts or communes only at daytime. The creation of public canteens for selling food and non-alcoholic beverages at low cost should be encouraged. This has the advantage of reducing contact between people. If necessary, requisition state vehicles belonging to public and cooperative partner agencies for the mobility of hospital staff and policemen. A lockdown should be declared to limit people’s movement and allow them to rest at home during night time as long as necessary for the security and peace of mind. To cope with the closure of schools and universities, distance learning should be encouraged by facilitating access to the internet and the acquisition of lap-tops or even android mobile phones by school children and students. In the media, we should avoid talking only about sensational news regarding COVID-19, as if success no longer existed even in the epidemiological field. We should not follow the media that repeatedly talk about what psychologically traumatizes people. It is not a question here of trivializing the health crisis but one will make barrage with the one and the others in bad popularity to be made visible under pretext to act finally for the poor population. Denounce certain messages that fuel collective psychosis in social networks and, above all, the respect of confidentiality of medical information, even after the death of patients. Train and provide safety equipment to medical staff and encourage healthcare workers at the frontline of the COVID-19 crisis who are more exposed while continuing to serve. To talk about the treatment that remains uncertain in this area of viral diseases, while adopting well-documented treatment regimens that have proven to be effective elsewhere, researchers should be encouraged to draw on the African pharmacopoeia which presumably contains resources that are likely to contribute to solving this global challenge. The use of traditional African medicine should not, however, open a breach for charlatans of all stripes by imposing strict compliance with the rules in this area. Universities and other research institutions should contribute with technological innovations, particularly in the design and development of medical devices and equipment to improve patients care and, even in producing COVID-19 prevention tools. Since the dawn of time epidemics have occasionally invaded large areas of the world, decimating entire populations, and this even before the concept of globalization took on the scale we have known in recent decades. The deaths were sometimes counted by millions of people as was the case with the black plague which ranged from 1,347 to 1,352 or the Spanish flu from 1918 to 1919. The COVID-19 pandemic that appeared in its first outbreak in Wuhan, China is very particular in terms of its contagiousness and the seriousness of the clinical picture in fragile people, with a mortality rate challenging even the most efficient health systems with the most hospitals equipped with the world. No doubt surprised by the great contagiousness of this new pathology, the whole world is taken aback so that the national and individual containment measures seem to have been taken too late, in any case we have come to resign ourselves to limiting the human, social and economic damage, the harmful effects of which will certainly last beyond the end of the pandemic. Africa was affected a few weeks after the other continents; which should allow the countries of the continent to benefit from both positive and negative experiences from other countries and continents to better cope with this infectious danger. The most pessimistic if not the most macabre forecasts are regularly made for sub-Saharan Africa (SSA). To date, the scale of the epidemic on the African continent is visibly of less importance, compared to what is observed elsewhere; which does not suggest the evolution of the pandemic in the next days or weeks. This is where the prevention measures advocated elsewhere deserve to be adopted by means of a “textualization” which must make them acceptable and applicable. Indeed, the “copy-pasted” of these measures which demonstrate their effectiveness in Asian and Western countries is often not possible for cultural and economic reasons. And yet prevention remains the best weapon against this corona virus infection. So what confinement? What barriers and social distancing measures? What communication for the adoption of consistent behavior likely to protect individuals and communities? In other words, what prevention in a context of poverty of people, lack / weakness of basic social services in terms of water and electricity supply, see means of communication (dilapidated and deficit urban roads, access to new information technologies / internet …). How to make people accept (make themselves appropriate) effective preventive measures, despite insalubrity, poverty, cultural and religious burdens … And this without procrastination which can only be fatal for  communities already affected by malaria and other endemics sometimes even recognized as “neglected diseases” by the international community. Our thinking is based on the main prevention measures recommended throughout the world in the face of the current COVID-19 pandemic; and to observe their effectiveness in the community after their proclamation in the capital city of Kinshasa in the DRC. Particular attention is paid to the various messages to raise awareness among the population and the dissemination by the political and health authorities of information on the pandemic via public media and social networks. We have observed the reactions of people in terms of acceptance or difficulty / refusal to apply these measures decreed by the public and health authorities, through both written and audio-visual media. We can then, on the strength of these observations, suggest possible solutions for realistic prevention, “local in fact” but which retains certain effectiveness. Taking into account the socio-economic level of the population, the promiscuity in the agglomerations and especially the beliefs in miracle cures which it is enough to find in the good therapist in the broad sense of the term, here are some conditions for the success of the measures of prevention against realistic COVID-19 in SSA: Make the population sufficiently aware of the danger of the Corona virus, by means of adapted messages which are received by community leaders who are truly recognized and influential. It is here where church leaders, traditional leaders, traditional healers and all those who have a voice must carry for the cause if necessary “well motivated”, with obligation to pass messages in the community with results. Ensure the basic needs of the population, where it is, by supplying agglomerations with food supplies, in a voluntarism manner by resorting in particular to the means of the State and the army. During this time, workers and workers, in order and in all sectors, are guaranteed wages and bonuses to enable them to secure autonomy in essential goods during confinement time. We will ensure a regular supply of water and electricity where the agreement exists. A free distribution of the masks will be made for the underprivileged population, while making their wearing compulsory. Ensure that residents only use daily markets and other places to acquire goods in their respective districts or communes for daily shopping. The creation of popular canteens for the low-cost sale of food and non-alcoholic beverages will be encouraged. This has the advantage of avoiding the mixing of populations. We will sometimes have to requisition state vehicles (ministries, specialized programs) and cooperation partners for the mobility of hospital staff and police. A curfew will be decided forever to limit movement and promote the night rest so necessary for the security and peace of mind. To cope with the closure of schools and universities, distance education will be encouraged, by facilitating access to the Internet and the acquisition by pupils and students of lap-tops or even Android phones. In the media, we should avoid talking only about the sensational, as if success no longer existed even in the epidemiological field. Do not do as in the media which only repeat what traumatizes more. It is not a question here of trivializing the health crisis but one will make barrage with the one and the others in bad popularity to be made visible under pretext to act finally for the poor population. Denounce certain messages that fuel collective psychosis in social networks, and above all respect the confidentiality of medical information, even after the disappearance of the persons concerned. Measures to rehabilitate and equip medical training and to encourage health workers at the forefront of the crisis more exposed to danger while continuing to serve. To talk about the treatment that remains uncertain in this area of viral diseases, while adopting well-documented treatment regimens that have proven themselves elsewhere, researchers will be encouraged to draw on the African pharmacopoeia which presumably contains resources which are likely to face this global challenge. The use of traditional African medicine should not, however, open a breach for charlatans of all stripes by imposing strict compliance with the rules in this area. Universities and other research institutions will contribute to the building of technological innovations, particularly in the design and development of medical equipment for the hospital care of patients, and even in COVID-19 prevention tools. Pandémie à Severe Acute Respiratory Syndrome-Coranovirus-2 (SARS-COV-2) en Afrique sub-saharienne : Quelles solutions innovantes pour contenir la propagation ? Severe Acute Respiratory Syndrome-Coranovirus-2 (SARS-COV-2) pandemic in sub-Saharan Africa: What innovative solutions to contain the propagation? Depuis la nuit des temps des épidémies ont de temps en temps envahi des larges territoires du monde en décimant des populations entières, et ceci bien avant même que le concept de mondialisation ne prenne l’ampleur qu’on lui connait ces dernières décennies. Les morts se sont parfois comptés par millions de personnes comme ce fut le cas avec la peste noire qui sévissait de 1347 à 1352 ou la grippe espagnole de 1918 à 1919. La pandémie à COVID-19 qui est apparue dans son premier foyer de Wuhan en Chine est bien particulière par sa contagiosité et la gravité des tableaux cliniques chez les personnes fragiles, avec un taux de mortalité défiant même les systèmes sanitaires performants avec les hôpitaux les plus équipés du monde. Sans doute surpris par la grande contagiosité de cette nouvelle pathologie, le monde entier est pris de court de telle sorte que les mesures de confinement nationales et individuelles semblent avoir été prises trop tard, en tout cas on en est arrivé à se résigner à limiter les dégâts humains, sociaux et économiques dont les effets néfastes dureront certainement au-delà de la fin de la pandémie. L’Afrique a été touchée quelques semaines après les autres continents ; ce qui devrait permettre aux Pays du continent de profiter tant des expériences positives et que négatives des autres pays et continents pour mieux faire face à ce péril infectieux. Les prévisions les plus pessimistes pour ne pas dire les plus macabres sont régulièrement faites pour l’Afrique au sud du Sahara. A ce jour l’ampleur de l’épidémie sur le continent africain est visiblement de moindre importance, comparées à ce qui s’observe ailleurs ; ce qui ne laisse pas présager sur l’évolution de la pandémie dans les jours ou les semaines à venir. C’est ici où les mesures de préventions préconisées ailleurs méritent d’être adoptées moyennant une « contextualisation » qui doit les rendre acceptables et applicables. En effet, la « copie-collée » de ces mesures qui démontrent leur efficacité dans les pays asiatiques et occidentaux n’est souvent pas possible pour des raisons culturelles et économiques. Et pourtant, la prévention reste la meilleure arme contre cette infection à corona virus. Alors quel confinement ? Quelles mesures barrières et de distanciation sociale ? Quelle communication pour l’adoption d’un comportement conséquent de nature à protéger les individus et les communautés ? En d’autres termes quelle prévention dans un contexte de pauvreté des personnes, de manque /faiblesse des services sociaux de base en terme de fourniture d’eau et d’électricité, voir des moyens de communication (voirie urbaine délabrée et déficitaire, accès aux nouvelles technologies de l’information/internet …). Comment faire accepter (se faire approprier) des mesures efficaces de prévention, malgré l’insalubrité, la pauvreté, les pesanteurs culturelles et religieuses…. Et ceci sans atermoiement qui ne peut être que funeste pour les communautés déjà meurtries par le paludisme et d’autres endémies parfois même reconnues comme « maladies négligées » par la communauté internationale. Notre réflexion se base sur les mesures principales de prévention préconisées à travers le monde face à la présente pandémie de la COVID-19 ; et de constater leur effectivité dans la communauté après leur proclamation dans la ville capitale de Kinshasa en République démocratique du Congo (RDC). Une attention particulière est accordée aux différents messages de sensibilisation de la population et de diffusion par l’autorité politique et sanitaire de l’information sur la pandémie via les média publiques et les réseaux sociaux. Nous avons observé les réactions des personnes en termes d’acceptation ou de difficulté/refus d’application desdites mesures décrétées par l’autorité publique et sanitaire, à travers les média tant écrits qu’audio-visuels. Nous pouvons par la suite, fort de ces observations, proposer des pistes de solution pour une prévention réaliste, à « couleur locale » mais qui garde une certaine efficacité. Tenant compte du niveau socio-économique de la population, de la promiscuité dans les agglomérations et surtout des croyances en des remèdes miracles qu’il suffit de trouver chez le bon thérapeute au sens large du terme, voici quelques conditions pour le succès des mesures de prévention contre la COVID-19 réalistes en Afrique au sud du Sahara : Conscientiser suffisamment la population devant le danger du Corona virus, par des messages adaptés qui soient reçus par les leaders communautaires réellement reconnus et influents. C’est ici où les responsables d’Eglises, les chefs traditionnels, les tradithérapeutes et tous ceux qui ont une voix qui porte doivent être acquis pour la cause s’il le faut « bien motivés », avec obligation de passer les messages dans la communauté avec des résultats. Assurer les besoins de base de la population, là où elle est, en approvisionnant les agglomérations en vivres alimentaires, de manière volontariste en recourant notamment aux moyens de l’Etat et de l’armée. Pendant ce temps il est assuré aux travailleurs, dans l’ordre et tous secteurs confondus, des salaires et primes pour leur permettre de s’assurer une autonomie en biens de première nécessité pendant le temps de confinement. On veillera à un approvisionnement régulier en eau et en électricité là où l’accordement existe. Une distribution gratuite des masques sera faite pour la population déshéritée, tout en rendant leur port obligatoire. Faire en sorte que les habitants ne recourent pour les courses journalières qu’aux marchés et autres lieux d’acquisition de biens dans leurs quartiers ou communes respectifs. Il sera encouragé la création des cantines populaires pour la vente à bas prix des aliments et des boissons non alcooliques. Ceci a l’avantage d’éviter le brassage des populations. On sera parfois amené à réquisitionner les véhicules de l’Etat (ministères, programmes spécialisés) et des partenaires de coopération pour la mobilité du personnel des hôpitaux et des forces de l’ordre. Il sera décidé d’un couvre-feu pour toujours pour limiter les déplacements et favoriser le repos nocturne tant nécessaire pour la sécurité et la tranquillité des esprits. Pour faire face à la fermeture des écoles et des Universités, l’enseignement à distance sera encouragé, en facilitant l’accès à l’internet et l’acquisition par les élèves et les étudiants des lap-tops ou même des téléphones androïdes. Dans les médias on devra éviter de ne parler que du sensationnel, comme si le succès n’existait plus même dans le domaine épidémiologique. Ne pas faire comme dans les médias qui ne font que passer en boucle ce qui traumatise d’avantage. Il ne s’agit pas ici de banaliser la crise sanitaire mais on fera barrage aux uns et aux autres en mal de popularité de se faire visibles sous prétexte d’agir enfin pour la pauvre population. Dénoncer certains messages qui alimentent la psychose collective dans les réseaux sociaux, et surtout respect

Advanced architectural descriptors in foams: novel 3D computational methods

This work presents 3D computational strategies aimed at providing foam de-structuration of the basic components of a cellular material (struts and cell walls) offering the possibility of analysing separately the structural elements that play an important role in the physical properties of thee materials. Two different methodologies have been used depending on the topological similarities existing between the struts and cell walls: 3D erosion-dilation procedure (thick struts) and solid classification algorithm (thin struts). In a second step, analysis of cell walls is performed in order to show the advantages of analysing separately the two foams components. Particularly, cell wall thickness distribution reveals differences that could not be found prior to the de-structuration

On the Fractography of Impact-Tested Samples of Al-Si Alloys for Automotive Alloys

Castings were prepared from both industrial and experimental 319.2, B319.2 and A356.2 alloy melts, containing Fe levels of 0.2–1.0 wt%. Stontium-modified (∼200 ppm) melts were also prepared for each alloy/Fe level. Impact testing of heat-treated samples was carried out using an instrumented Charpy impact testing machine. At low Fe levels and high cooling rates (0.4% Fe, dendrite arm spacing (DAS) of 23 μm), crack initiation and propagation in unmodified 319 alloys occur through the cleavage of β-Al5FeSi platelets (rather than by their decohesion from the matrix). The morphology of the platelets (individual or branched) is important in determining the direction of crack propagation. Cracks also propagate through the fracture of undissolved CuAl2 or other Cu intermetallics, as well as through fragmented Si particles. In Sr-modified 319 alloys, cracks are mostly initiated by the fragmentation or cleavage of perforated β-phase platelets, in addition to that of coarse Si particles and undissolved Cu-intermetallics. In A356.2 alloys, cracks initiate mainly through the fracture of Si particles or their debonding from the Al matrix, while crack propagation occurs through the coalescence of fractured Si particles, except when β-Al5FeSi intermetallics are present, in which case the latter takes precedence. In the Sr-modified case, cracks propagate through the linkage of fractured/debonded Si particles, as well as fragmented β-iron intermetallics. In samples exhibiting low-impact energies, crack initiation and propagation occur mainly through cleavage of the β-iron intermetallics

Strong intracellular signal inactivation produces sharper and more robust signaling from cell membrane to nucleus

For a chemical signal to propagate across a cell, it must navigate a tortuous environment involving a variety of organelle barriers. In this work we study mathematical models for a basic chemical signal, the arrival times at the nuclear membrane of proteins that are activated at the cell membrane and diffuse throughout the cytosol. Organelle surfaces within human B cells are reconstructed from soft X-ray tomographic images, and modeled as reflecting barriers to the molecules’ diffusion. We show that signal inactivation sharpens signals, reducing variability in the arrival time at the nuclear membrane. Inactivation can also compensate for an observed slowdown in signal propagation induced by the presence of organelle barriers, leading to arrival times at the nuclear membrane that are comparable to models in which the cytosol is treated as an open, empty region. In the limit of strong signal inactivation this is achieved by filtering out molecules that traverse non-geodesic paths.https://www.biorxiv.org/content/10.1101/2020.01.16.909333v1First author draf