Shadow Enhancers Foster Robustness of Drosophila Gastrulation

SummaryCritical developmental control genes sometimes contain “shadow” enhancers that can be located in remote positions, including the introns of neighboring genes [1]. They nonetheless produce patterns of gene expression that are the same as or similar to those produced by more proximal primary enhancers. It was suggested that shadow enhancers help foster robustness in gene expression in response to environmental or genetic perturbations [2, 3]. We critically tested this hypothesis by employing a combination of bacterial artificial chromosome (BAC) recombineering and quantitative confocal imaging methods [2, 4]. Evidence is presented that the snail gene is regulated by a distal shadow enhancer located within a neighboring locus. Removal of the proximal primary enhancer does not significantly perturb snail function, including the repression of neurogenic genes and formation of the ventral furrow during gastrulation at normal temperatures. However, at elevated temperatures, there is sporadic loss of snail expression and coincident disruptions in gastrulation. Similar defects are observed at normal temperatures upon reductions in the levels of Dorsal, a key activator of snail expression (reviewed in [5]). These results suggest that shadow enhancers represent a novel mechanism of canalization whereby complex developmental processes “bring about one definite end-result regardless of minor variations in conditions” [6]

Ecology and management history drive spatial genetic structure in Scots pine

Forest management practices that remove trees from stands can promote substantial changes in the distribution of genetic diversity within and among populations at multiple spatial scales. In small and isolated populations, elevated inbreeding levels might reduce fitness of subsequent generations and threaten forest resilience in the long term. Comparing fine-scale spatial genetic structure (SGS) between life stages (e.g. adult and juvenile cohorts) can identify when populations have undergone disturbance, even in species with long generation times. Here, we studied the effects of historical and contemporary forest management, characterized by intense felling and natural regeneration respectively, on genetic diversity and fine-scale SGS in adult and juvenile cohorts. We examined fragmented Scots pine (Pinus sylvestris L.) stands in the Scottish Highlands, and compared them with a remote, unmanaged stand. A total of 777 trees were genotyped using 12 nuclear microsatellite markers. No difference was identified in allelic richness or gene diversity among stands or life stages, suggesting that historical and contemporary management have not impacted levels of genetic variation. However, management appears to have changed the spatial distribution of genetic variation. Adult genotypes from managed stands were more spatially structured than in the unmanaged stand, a difference mediated by contrasts in tree density, degree of fragmentation of stands at the time of establishment and rate of gap creation. Surprisingly, juveniles were less spatially structured than adults in the managed stands, suggesting an historical erosion of the structure of the adult cohort but contemporary recovery to natural dynamics, and indicating a high capacity of the species to recover after disturbance. Here we showed that using the spatial component of genetic diversity can help to detect both historical and contemporary effects of disturbance in tree populations. Evaluation of successional change is important to adequately detect early responses of tree populations to forest management practices. Overall, our study suggests that combining sustainable management with forest conservation practices that ensure larger effective population sizes is key to successfully maintaining genetic diversity in Scots pine

Prevalencia serológica a Coxiella burnetti en ovinos por la prueba de fijación del complemento

Se examinaron 2.501 muestras de suero de ovinos pertenecientes a las principales áreas de explotación de ovinos en Colombia para estudiar la presencia de anticuerpos contra fiebre Q, usando la microtécnica de fijación del complemento. En los ovinos criollos y los ovinos de razas seleccionadas (2.099) ya adaptadas al país se encontró una prevalencia ajustada entre 4.5% (106) y que fluctúa entre 3,5 - 5,5 (P 0,05). En contraste para los 402 ovinos Blackface importados recientemente, 91 (23%) dieron reacción positiva a la prueba. Se discute la importancia de la enfermedad en salud pública y se sugiere mantener la vigilancia epidemiológica para evitar la entrada de reactores positivos.A total of 2.501 sera were collected from the principal sheep rearing areas of Colombia to determine the prevalence of antibodies against Q-ferver using the micro complement fixation test. The indigenous and imported breed that had acclimated (2.099 to Colombia showed an adjusted prevalence between 3,5 - 5,5%(106) in contrast to the 402 recently imported Blackface ewes, 91(2317o) of which were positive to the test. The importance of the disease in public health is discussed and it is suggested that careful control should be maintained to avoid the importation of positive animals.Ovinos-Ganado ovino - Ovis arie

Observaciones sobre un tratamiento estratégico contra fasciolasis ovina en áreas de páramo en Boyacá.

La fasciolacis ovina es de gran importancia económica en el páramo del norte de Boyacá. Por tal razón se realizó un ensayo práctico de control con el objeto de mostrar la reducción de la mortalidad y la infestación del rebaño debido a fasciolasis, mediante la aplicación de un programa de dosificación estratégica con rafoxanide, un antihelmíntico. Se seleccionaron tres rebaños de 200 animales cada uno y se trataron con rafoxanide en la siguiente forma: el rebaño 1, cada 6 semanas, el rebaño 2, cada 4 semanas y el rebaño 3 se dejó como control. No hubo diferencias significaticas en la tasa de excreción de huevos entre los rebaños 1 y 2 (promedio total 18.7 y 19.8 por ciento respectivamente), pero hubo diferencias altamente significativas entre los anteriores y el control cuyo promedio total de excreción de huevos fué de 37 por ciento. Los caracoles identificados como huéspedes intermediarios fueron clasificados por técnicos del Museo Británico de Ciencias Naturales como pertenecientes a la especie Lymnae viatrix. Se discute la efectividad del tratamiento y sobre algunos aspectos epidemiológicos de la infección en el área

Finance & Stochastic

The study analyses quantitative models for financial markets by starting from geometric Brown process and Wiener process by analyzing Ito’s lemma and first passage model. Furthermore, it is analyzed the prices of the options, Vanilla & Exotic, by using the expected value and numerical model with geometric applications. From contingent claim approach ALM strategies are also analyzed so to get the effective duration measure of liabilities by assuming that clients buy options for protection and liquidity by assuming defaults protection barrier as well. Furthermore, the study analyses interest rate models by showing that the yields curve is given by the average of the expected short rates & variation of GDP with the liquidity risk, but in the case we have crisis it is possible to have risk premium as well, the study is based on simulated modelisation by using the drift condition in combination with the inflation models as expectation of the markets. Moreover, the CIR process is considered as well by getting with modification of the diffusion process the same result of the simulated modelisation but we have to consider that the CIR process is considered in the simulated environment as well. The credit risk model is considered as well in intensity model & structural model by getting the liquidity and risk premium and the PD probability from the Rating Matrix as well by using the diagonal. Furthermore, the systemic risk is considered as well by using a deco relation concept by copula approaches. Moreover, along the equilibrium condition between financial markets is achieved the equity pricing with implications for the portfolio construction in simulated environment with Bayesian applications for smart beta. Finally, Value at Risk is also analyzed both static and dynamic with implications for the percentile of daily return and the tails risks by using a simulated approach

Photometric stereo data for the validation of a structural health monitoring test rig

Photometric stereo uses images of objects illuminated from various directions to calculate surface normals which can be used to generate 3D meshes of the object. Such meshes can be used by engineers to estimate damage of a concrete surface, or track damage progression over time to inform maintenance decisions. This dataset [1] was collected to quantify the uncertainty in a photometric stereo test rig through both the comparison with a well characterised method (coordinate measurement machine) and experiment virtualisation. Data was collected for 9 real objects using both the test rig and the coordinate measurement machine. These objects range from clay statues to damaged concrete slabs. Furthermore, synthetic data for 12 objects was created via virtual renders generated using Blender (3D software) [2]. The two methods of data generation allowed the decoupling of the physical rig (used to light and photograph objects) and the photometric stereo algorithm (used to convert images and lighting information into 3D meshes). This data can allow users to: test their own photometric stereo algorithms, with specialised data created for structural health monitoring applications; provide an industrially relevant case study to develop and test uncertainty quantification methods on test rigs for structural health monitoring of concrete; or develop data processing methodologies for the alignment of scaled, translated, and rotated data

Neurophysiological consequences of synapse loss in progressive supranuclear palsy

Synaptic loss occurs early in many neurodegenerative diseases and contributes to cognitive impairment even in the absence of gross atrophy. Currently, for human disease there are few formal models to explain how cortical networks underlying cognition are affected by synaptic loss. We advocate that biophysical models of neurophysiology offer both a bridge from clinical to preclinical models of pathology, and quantitative assays for experimental medicine. Such biophysical models can also disclose hidden neuronal dynamics generating neurophysiological observations like electro- and magneto-encephalography. Here, we augment a biophysically informed mesoscale model of human cortical function by inclusion of synaptic density estimates as captured by [11C]UCB-J positron emission tomography, and provide insights into how regional synapse loss affects neurophysiology. We use the primary tauopathy of progressive supranuclear palsy (Richardson's syndrome) as an exemplar condition, with high clinicopathological correlations. Progressive supranuclear palsy causes a marked change in cortical neurophysiology in the presence of mild cortical atrophy and is associated with a decline in cognitive functions associated with the frontal lobe. Using parametric empirical Bayesian inversion of a conductance-based canonical microcircuit model of magnetoencephalography data, we show that the inclusion of regional synaptic density-as a subject-specific prior on laminar specific neuronal populations-markedly increases model evidence. Specifically, model comparison suggests that a reduction in synaptic density in inferior frontal cortex affects superficial and granular layer glutamatergic excitation. This predicted individual differences in behaviour, demonstrating the link between synaptic loss, neurophysiology, and cognitive deficits. The method we demonstrate is not restricted to progressive supranuclear palsy or the effects of synaptic loss: such pathology-enriched dynamic causal models can be used to assess the mechanisms of other neurological disorders, with diverse non-invasive measures of pathology, and is suitable to test the effects of experimental pharmacology

Correction to: The Edinburgh Consensus: preparing for the advent of disease-modifying therapies for Alzheimer's disease.

Since the publication of this article [1], it has come to the attention of the authors that information for one of the authors was not included in the competing interests section. Craig Richie has declared potential competing interests with the following companies; Janssen, Eisai, Pfizer, Eli Lilly, Roche Diagnostics, Boeringher Ingleheim, Novartis, AC Immune, Ixico, Aridhia, Amgen, Berry Consultants, Lundbeck, Sanofi, Quintiles (IQVIA) and Takeda. The full competing interests section for this article can be found below

Gene content evolution in the arthropods

Arthropods comprise the largest and most diverse phylum on Earth and play vital roles in nearly every ecosystem. Their diversity stems in part from variations on a conserved body plan, resulting from and recorded in adaptive changes in the genome. Dissection of the genomic record of sequence change enables broad questions regarding genome evolution to be addressed, even across hyper-diverse taxa within arthropods. Using 76 whole genome sequences representing 21 orders spanning more than 500 million years of arthropod evolution, we document changes in gene and protein domain content and provide temporal and phylogenetic context for interpreting these innovations. We identify many novel gene families that arose early in the evolution of arthropods and during the diversification of insects into modern orders. We reveal unexpected variation in patterns of DNA methylation across arthropods and examples of gene family and protein domain evolution coincident with the appearance of notable phenotypic and physiological adaptations such as flight, metamorphosis, sociality, and chemoperception. These analyses demonstrate how large-scale comparative genomics can provide broad new insights into the genotype to phenotype map and generate testable hypotheses about the evolution of animal diversity