Molecular cloning of the cDNA encoding pp36, a tyrosine-phosphorylated adaptor protein selectively expressed by T cells and natural killer cells.

Activation of T and natural killer (NK) cells leads to the tyrosine phosphorylation of pp36 and to its association with several signaling molecules, including phospholipase Cgamma-1 and Grb2. Microsequencing of peptides derived from purified rat pp36 protein led to the cloning, in rat and man, of cDNA encoding a T- and NK cell-specific protein with several putative Src homology 2 domain-binding motifs. A rabbit antiserum directed against a peptide sequence from the cloned rat molecule recognized tyrosine phosphorylated pp36 from pervanadate-treated rat thymocytes. When expressed in 293T human fibroblast cells and tyrosine-phosphorylated, pp36 associated with phospholipase Cgamma-1 and Grb2. Studies with GST-Grb2 fusion proteins demonstrated that the association was specific for the Src homology 2 domain of Grb-2. Molecular cloning of the gene encoding pp36 should facilitate studies examining the role of this adaptor protein in proximal signaling events during T and NK cell activation

Methodological approaches for the selection of genotypes in a progeny trial of Dacryodes edulis (G. Don) H. J. Lam in Cameroon

The World Agroforestry Centre (ICRAF) initiated a program in Cameroon for the selection of improved genotypes of Dacryodes edulis for domestication. There are major challenges in such selection because superior performance of individual trees may be based on site conditions rather than on genetic differences. Open-pollinated seeds were collected from mother trees in four provenances in Cameroon and planted in a progeny trial at Minkoameyos, Cameroon. Progeny from the same mother tree are referred to as family. After one year of growth in the field, growth traits were measured annually for five years and fruit traits were measured in two successive years. Three methodological approaches were investigated: family and within-family selection (combined selection), ranking for phenotypic selection and correlation for multi-trait and early selection. Variation in growth and fruit traits among families was not significant for most provenances, indicating that family selection would not be effective for the selection of genotypes in the trial. Phenotypic selection resulted in the retention of a small number of individuals of all families in the trial. There were strong positive correlations between fruit traits and between fruit and growth traits, while negative correlations were found between fruit traits and yield. The correlations indicate that selecting for one fruit trait may also improve the other fruit traits but reduce fruit yield. Positive and significant juvenile-mature correlations for growth were also found in this trial, indicating that early selection may be possible based ongrowth. Based on these results, phenotypic selection is recommended in the progeny trial for the domestication program in Cameroon and further research on early selection is needed as the trial advances in age

Neurovascular manifestations of COVID-19

Even early at the beginning of the coronavirus disease 2019 (COVID‑19) pandemic, stroke was described as a manifestation or complication of infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current meta-analyses reported a stroke rate of approximately 1.5%. Stroke in COVID‑19 positive patients occurs more frequently in severe courses of the infection and in older patients with cardiovascular comorbidities; however, young patients without cardiovascular risk factors are also not uncommonly affected. The mechanisms of stroke are predominantly embolic. The thrombi frequently occlude large intracranial vessels and in more than 20% affect multiple vascular territories, whereas infarctions due to small vessel disease are uncommon. The exact source of the embolism remains cryptogenic in more than 40% of patients. The mortality caused by the co-occurrence of a SARS-CoV‑2 infection and a stroke exceeds 15–30%. While acute stroke treatment was severely affected in some European regions, the rates of recanalization treatment in Germany largely remained stable during the first pandemic wave; however, 20–30% fewer patients with minor stroke and transient ischemic attacks (TIA) presented to hospitals during the first wave in spring 2020. The present narrative review summarizes the current evidence regarding the epidemiology and pathogenesis of stroke associated with COVID‑19 and describes the effect of the pandemic so far on the provision of acute stroke treatment

Strength of Correlations in electron and hole doped cuprates

High temperature superconductivity was achieved by introducing holes in a parent compound consisting of copper oxide layers separated by spacer layers. It is possible to dope some of the parent compounds with electrons, and their physical properties are bearing some similarities but also significant differences from the hole doped counterparts. Here, we use a recently developed first principles method, to study the electron doped cuprates and elucidate the deep physical reasons why their behavior is so different than the hole doped materials. We find that electron doped compounds are Slater insulators, e.g. a material where the insulating behavior is the result of the presence of magnetic long range order. This is in sharp contrast with the hole doped materials, where the parent compound is a Mott charge transfer insulator, namely a material which is insulating due to the strong electronic correlations but not due to the magnetic order.Comment: submitted to Nature Physic

Community trust reduces myopic decisions of low-income individuals

Why do the poor make shortsighted choices in decisions that involve delayed payoffs? Foregoing immediate rewards for larger, later rewards requires that decision makers (i) believe future payoffs will occur and (ii) are not forced to take the immediate reward out of financial need. Low-income individuals may be both less likely to believe future payoffs will occur and less able to forego immediate rewards due to higher financial need; they may thus appear to discount the future more heavily. We propose that trust in one’s community—which, unlike generalized trust, we find does not covary with levels of income—can partially offset the effects of low income on myopic decisions. Specifically, we hypothesize that low-income individuals with higher community trust make less myopic intertemporal decisions because they believe their community will buffer, or cushion, against their financial need. In archival data and laboratory studies, we find that higher levels of community trust among low-income individuals lead to less myopic decisions. We also test our predictions with a 2-y community trust intervention in rural Bangladesh involving 121 union councils (the smallest rural administrative and local government unit) and find that residents in treated union councils show higher levels of community trust and make less myopic intertemporal choices than residents in control union councils. We discuss the implications of these results for the design of domestic and global policy interventions to help the poor make decisions that could alleviate poverty.This research was made possible in part by a Cambridge Judge Business School small grant, the research facilities provided by the Center for Decision Sciences at Columbia University, and the support of the German National Academic Foundatio

Efficient Certified Resolution Proof Checking

We present a novel propositional proof tracing format that eliminates complex processing, thus enabling efficient (formal) proof checking. The benefits of this format are demonstrated by implementing a proof checker in C, which outperforms a state-of-the-art checker by two orders of magnitude. We then formalize the theory underlying propositional proof checking in Coq, and extract a correct-by-construction proof checker for our format from the formalization. An empirical evaluation using 280 unsatisfiable instances from the 2015 and 2016 SAT competitions shows that this certified checker usually performs comparably to a state-of-the-art non-certified proof checker. Using this format, we formally verify the recent 200 TB proof of the Boolean Pythagorean Triples conjecture

Reproductive output, foraging destinations, and isotopic niche of olive ridley and loggerhead sea turtles, and their hybrids, in Brazil

Hybridization is a fundamental evolutionary and ecological process with significant conservation ramifications. Sea turtle hybridization occurs at unusually high frequencies along the northeastern coast of Brazil. To better understand the process, we studied the reproductive output, migration patterns (through satellite telemetry), and isotopic niches of loggerhead turtles Caretta caretta and olive ridley turtles Lepidochelys olivacea and their hybrids. We classified 154 nesting females as loggerhead (n = 91), olive ridley (n = 38), or hybrid (n = 25) based on mitochondrial and nuclear DNA. Further, we compared nesting female morphological data and reproductive parameters (clutch size, emergence success, hatchling production, incubation period) of 405 nests among hybrids and parental species. We found no significant differences among the 3 groups when hatchling production was corrected for female body size, indicating that hybrids and parental species produce similar numbers of hatchlings per clutch. Satellite tracking of 8 post-nesting hybrid females revealed shared foraging grounds with both parental species, as well as neritic migrations between foraging and nesting areas similar to those previously reported for loggerheads and olive ridleys. Analyses of 13C and 15N isotope values (n = 69) further confirmed this pattern, as hybrid isotopic niches overlapped extensively with both parental species. Thus, given the similarities presented between hybrids and their parental species in reproductive, ecological, and behavioral characteristics, we conclude that these hybrids may persist along with other sea turtle nesting populations in the area, with research and conservation implications. © The authors 2021. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are unrestricted. Authors and original publication must be credited

Finite temperature calculations for the bulk properties of strange star using a many-body approach

We have considered a hot strange star matter, just after the collapse of a supernova, as a composition of strange, up and down quarks to calculate the bulk properties of this system at finite temperature with the density dependent bag constant. To parameterize the density dependent bag constant, we use our results for the lowest order constrained variational (LOCV) calculations of asymmetric nuclear matter. Our calculations for the structure properties of the strange star at different temperatures indicate that its maximum mass decreases by increasing the temperature. We have also compared our results with those of a fixed value of the bag constant. It can be seen that the density dependent bag constant leads to higher values of the maximum mass and radius for the strange star.Comment: 21 pages, 2 tables, 12 figures Astrophys. (2011) accepte

An invisibility cloak using silver nanowires

In this paper, we use the parameter retrieval method together with an analytical effective medium approach to design a well-performed invisible cloak, which is based on an empirical revised version of the reduced cloak. The designed cloak can be implemented by silver nanowires with elliptical cross-sections embedded in a polymethyl methacrylate host. This cloak is numerically proved to be robust for both the inner hidden object as well as incoming detecting waves, and is much simpler thus easier to manufacture when compared with the earlier proposed one [Nat. Photon. 1, 224 (2007)].Comment: 7 pages, 4 figures, 2 table

Estimation of the national disease burden of influenza-associated severe acute respiratory illness in Kenya and Guatemala : a novel methodology

Background: Knowing the national disease burden of severe influenza in low-income countries can inform policy decisions around influenza treatment and prevention. We present a novel methodology using locally generated data for estimating this burden. Methods and Findings: This method begins with calculating the hospitalized severe acute respiratory illness (SARI) incidence for children <5 years old and persons ≥5 years old from population-based surveillance in one province. This base rate of SARI is then adjusted for each province based on the prevalence of risk factors and healthcare-seeking behavior. The percentage of SARI with influenza virus detected is determined from provincial-level sentinel surveillance and applied to the adjusted provincial rates of hospitalized SARI. Healthcare-seeking data from healthcare utilization surveys is used to estimate non-hospitalized influenza-associated SARI. Rates of hospitalized and non-hospitalized influenza-associated SARI are applied to census data to calculate the national number of cases. The method was field-tested in Kenya, and validated in Guatemala, using data from August 2009–July 2011. In Kenya (2009 population 38.6 million persons), the annual number of hospitalized influenza-associated SARI cases ranged from 17,129–27,659 for children <5 years old (2.9–4.7 per 1,000 persons) and 6,882–7,836 for persons ≥5 years old (0.21–0.24 per 1,000 persons), depending on year and base rate used. In Guatemala (2011 population 14.7 million persons), the annual number of hospitalized cases of influenza-associated pneumonia ranged from 1,065–2,259 (0.5–1.0 per 1,000 persons) among children <5 years old and 779–2,252 cases (0.1–0.2 per 1,000 persons) for persons ≥5 years old, depending on year and base rate used. In both countries, the number of non-hospitalized influenza-associated cases was several-fold higher than the hospitalized cases. Conclusions: Influenza virus was associated with a substantial amount of severe disease in Kenya and Guatemala. This method can be performed in most low and lower-middle income countries