Pre-Clinical Grades Predict Clinical Performance in the MBBS Stage II Examination at the University of the West Indies, Mona Campus

Summary: In the preclinical sciences, statistically significant predictive values have been reported between the performances in one discipline and the others, supporting the hypothesis that students who perform well in one discipline were likely to perform well in the other disciplines. We  therefore decided to conduct a retrospective study to investigate the  predictive effects of preclinical subjects on clinical subjects from 87 students of The University of the West Indies (UWI), Mona Campus who took the MBBS Stage II examination at various times between May 2000 and May 2002. The grade in Pathology was significantly predicted by scores in  Anatomy and Pharmacology; Medicine by Physiology and Pharmacology scores; Surgery by Anatomy and Social and Preventive Medicine scores;  while, the Obstetrics and Gynecology grade was predicted by the Anatomy score. The results support the hypothesis that the scores in some  preclinical subjects can predict the performance in specific clinical subjects, which could be interpreted to suggest that poor performance in specific  preclinical disciplines could be a warning sign of future poor performance in the related clinical disciplines.Keywords: Medical education, preclinical grades, clinical grades, predictors of performanc

Ribosomal S6K1 in POMC and AgRP Neurons Regulates Glucose Homeostasis but Not Feeding Behavior in Mice.

SummaryHypothalamic ribosomal S6K1 has been suggested as a point of convergence for hormonal and nutrient signals in the regulation of feeding behavior, bodyweight, and glucose metabolism. However, the long-term effects of manipulating hypothalamic S6K1 signaling on energy homeostasis and the cellular mechanisms underlying these roles are unclear. We therefore inactivated S6K1 in pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, key regulators of energy homeostasis, but in contrast to the current view, we found no evidence that S6K1 regulates food intake and bodyweight. In contrast, S6K1 signaling in POMC neurons regulated hepatic glucose production and peripheral lipid metabolism and modulated neuronal excitability. S6K1 signaling in AgRP neurons regulated skeletal muscle insulin sensitivity and was required for glucose sensing by these neurons. Our findings suggest that S6K1 signaling is not a general integrator of energy homeostasis in the mediobasal hypothalamus but has distinct roles in the regulation of glucose homeostasis by POMC and AgRP neurons

A kilobit hidden SNFS discrete logarithm computation

We perform a special number field sieve discrete logarithm computation in a 1024-bit prime field. To our knowledge, this is the first kilobit-sized discrete logarithm computation ever reported for prime fields. This computation took a little over two months of calendar time on an academic cluster using the open-source CADO-NFS software. Our chosen prime $p$ looks random, and $p--1$ has a 160-bit prime factor, in line with recommended parameters for the Digital Signature Algorithm. However, our p has been trapdoored in such a way that the special number field sieve can be used to compute discrete logarithms in $\mathbb{F}\_p^*$ , yet detecting that p has this trapdoor seems out of reach. Twenty-five years ago, there was considerable controversy around the possibility of back-doored parameters for DSA. Our computations show that trapdoored primes are entirely feasible with current computing technology. We also describe special number field sieve discrete log computations carried out for multiple weak primes found in use in the wild. As can be expected from a trapdoor mechanism which we say is hard to detect, our research did not reveal any trapdoored prime in wide use. The only way for a user to defend against a hypothetical trapdoor of this kind is to require verifiably random primes

Large Representation Recurrences in Large N Random Unitary Matrix Models

In a random unitary matrix model at large N, we study the properties of the expectation value of the character of the unitary matrix in the rank k symmetric tensor representation. We address the problem of whether the standard semiclassical technique for solving the model in the large N limit can be applied when the representation is very large, with k of order N. We find that the eigenvalues do indeed localize on an extremum of the effective potential; however, for finite but sufficiently large k/N, it is not possible to replace the discrete eigenvalue density with a continuous one. Nonetheless, the expectation value of the character has a well-defined large N limit, and when the discreteness of the eigenvalues is properly accounted for, it shows an intriguing approximate periodicity as a function of k/N.Comment: 24 pages, 11 figure

Access Anglesey 2018: Lessons from an inclusive field course

Abstract. Traditional methods of fieldwork delivery can present learners with a range of physical, cognitive and social challenges which may subsequently hinder their ability to engage effectively with learning. We developed a residential geoscience field course designed to be physically accessible to, and socially inclusive of, a diverse range of learners including those with limited physical mobility and neurodiverse conditions. This paper presents the logistical and pedagogical challenges involved in delivering such a field course. In terms of pedagogic design scheduling, pace and timing, and the ability to access content in multiple ways were critical to ensuring that all students were included in the learning. The most effective mitigations were the simplest and benefitted the whole group. Practical interventions found to support access and inclusion for the benefit of all participants included using an audio tour-guide system to communicate with students at field locations, using a four-wheel drive vehicle to improve access to specific locations, providing alternative exercises such as prepared photomicrographs and rock specimens, providing electronic tablets with suitable apps, and selecting accommodation with accessible common-room spaces, and a dedicated quiet room. </jats:p

The holistic phase model of early adult crisis

The objective of the current study was to explore the structural, temporal and experiential manifestations of crisis episodes in early adulthood, using a holistic-systemic theoretical framework. Based on an analysis of 50 interviews with individuals about a crisis episode between the ages of 25 and 35, a holistic model was developed. The model comprises four phases: (1) Locked-in, (2) Separation/Time-out, (3) Exploration and (4) Rebuilding, which in turn have characteristic features at four levels—person-in-environment, identity, motivation and affect-cognition. A crisis starts out with a commitment at work or home that has been made but is no longer desired, and this is followed by an emotionally volatile period of change as that commitment is terminated. The positive trajectory of crisis involves movement through an exploratory period towards active rebuilding of a new commitment, but ‘fast-forward’ and ‘relapse’ loops can interrupt Phases 3 and 4 and make a positive resolution of the episode less likely. The model shows conceptual links with life stage theories of emerging adulthood and early adulthood, and it extends current understandings of the transitional developmental challenges that young adults encounter

A neo-W chromosome in a tropical butterfly links colour pattern, male-killing, and speciation

PublishedJournal Article© 2016, Royal Society of London. All rights reserved.Sexually antagonistic selection can drive both the evolution of sex chromosomes and speciation itself. The tropical butterfly the African Queen, Danaus chrysippus, shows two such sexually antagonistic phenotypes, the first being sex-linked colour pattern, the second, susceptibility to a male-killing, maternally inherited mollicute, Spiroplasma ixodeti, which causes approximately 100% mortality in male eggs and first instar larvae. Importantly, this mortality is not affected by the infection status of the male parent and the horizontal transmission of Spiroplasma is unknown. In East Africa, male-killing of the Queen is prevalent in a narrow hybrid zone centred on Nairobi. This hybrid zone separates otherwise allopatric subspecies with different colour patterns. Here we show that a neo-W chromosome, a fusion between the W (female) chromosome and an autosome that controls both colour pattern and malekilling, links the two phenotypes thereby driving speciation across the hybrid zone. Studies of the population genetics of the neo-W around Nairobi showthat the interaction between colour pattern and male-killer susceptibility restricts gene flow between two subspecies of D. chrysippus. Our results demonstrate how a complex interplay between sex, colour pattern, malekilling, and a neo-W chromosome, has set up a genetic ‘sink’ that keeps the two subspecies apart. The association between the neo-W and male-killing thus provides a ‘smoking gun’ for an ongoing speciation process.Matt McClements (Blink Studios Ltd) designed the figures, Bernard Rono assisted with fieldwork, and Samuel Katoi provided specimens from Watamu. Fieldwork at Silole Sanctuary (Kitengela) was sanctioned by Nani Croze, Eric Krystall, John Keen, and Mark van Rampelberg. Simon Martin scrutinized the first draft of the manuscript and made valuable suggestions for its improvement. Spiroplasma screening was carried out at icipe. D.A.S.S. thanks the Linnean Society of London and the Outreach Fund of the Royal Entomological Society of London for funding. I.J.G., D.A.S.S., W.T., and K.S. are Research Affiliates of the National Museums of Kenya