Lessons from monochorionic twin delivery

The presence of acute peripartum anaemia in a monochorionic twin pregnancy represents a clinical challenge requiring prompt recognition and management. Twin-to-twin transfusion syndrome (TTTS) is a major complication of these pregnancies and a medical emergency in its acute form. Acute intrapartum fetoplacental transfusion (AIFT) has been reported infrequently. The authors present a case of a probable acute TTTS in an uneventful monochorionic monoamnionic twin pregnancy, where typical ultrasound criteria for long-standing TTTS were absent. The first twin was born pale, hypotonic and developed hypovolemic shock due to acute anaemia. Soon after birth, she presented with seizures and a cerebral ultrasound detected a large parieto-occipital infarction. The second twin, although plethoric, was clinically well. The risk of acute TTTS and AIFT, although infrequent and unpredictable, should be kept in mind when planning delivery of monochorionic twins, because the consequences for one or both twins can be disastrous

Exploitation promotes earlier sex change in a protandrous patellid limpet, Patella aspera Röding, 1798

Exploitation of organisms can prompt the reduction in the number and size of target populations consequently affecting reproductive output and replenishment. Here, we investigated the effects of exploitation on the population structure of a protandrous patellid limpet, Patella aspera, an overexploited Macaronesian endemic. Timed dives were used to collect animals across eleven islands of Macaronesia. Individuals were inspected for sex, size, and gonad stage. Using catch effort (time per person) per island coastal perimeter as a surrogate for exploitation intensity, we found that limpet abundance (CPUE) and mean size tended to decrease with exploitation intensity. When considering the sex of animals separately, the size of the largest male, but not females, decreased with exploitation. In contrast, the size of the smallest male remained relatively consistent, whereas the size of the smallest female decreased significantly with exploitation. As exploitation is mostly targeting larger individuals, results suggest that males are compensating the removal of larger females, by undergoing sex change at smaller and presumably earlier sizes. These results have wider implications for the conservation of P. aspera, as a reduction in female size will likely affect the numbers of oocytes produced, hence fecundity. Regulations promoting the protection of the larger-sized animals should be enforced to safeguard the replenishment of the population

Treadmill walking differently affects body composition and metabolic parameters of female rats from normal or small litters

This work assessed whether walking affects bodily development and metabolic parameters of female rats raised in small litters (three pups, group S) or control litters (nine pups, group C). After weaning, some of the rats had five sessions per week of a 30-min treadmill walking (CE and SE), while the others remained sedentary (CS and SS) until the age of 120 days. Exercise caused a reduction of body weight (CS/CE = 1.18), Lee index (CS/CE = 1.04), fasting blood glucose (CS/CE = 1.35), mesenteric (CS/CE = 1.23), and ovarian fat (CS/CE = 1.33) in CE, but only glucose was decreased in SE (SS/SE = 1.16). The diameter of adipocytes decreased to a half in the small-litter groups. Exercise increased subcutaneous (CS/CE = 0.88 and SS/SE = 0.71), but decreased retroperitoneal adipocytes (CS/CE = 1.2 and SS/SE = 1.3). Litter size reduction had little impact on females at the age of 120 days, but the light physical activity seemed insufficient to counteract all the effects of lactational overfeeding. On the other hand, pups from exercised mothers had a decrease in their biometric and glycemic indexes, demonstrating the transgenerational action of regular, although light, exercise

SHOC2 scaffold protein modulates daunorubicin-induced cell death through p53 modulation in lymphoid leukemia cells

SHOC2 scaffold protein has been mainly related to oncogenic ERK signaling through the RAS-SHOC2-PP1 phosphatase complex. In leukemic cells however, SHOC2 upregulation has been previously related to an increased 5-year event-free survival of pediatric pre-B acute lymphoid leukemia, suggesting that SHOC2 could be a potential prognostic marker. To address such paradoxical function, our study investigated how SHOC2 impact leukemic cells drug response. Our transcriptome analysis has shown that SHOC2 can modulate the DNA-damage mediated by p53. Notably, upon genetic inhibition of SHOC2 we observed a significant impairment of p53 expression, which in turn, leads to the blockage of key apoptotic molecules. To confirm the specificity of DNA-damage related modulation, several anti-leukemic drugs has been tested and we did confirm that the proposed mechanism impairs cell death upon daunorubicin-induced DNA damage of human lymphoid cells. In conclusion, our study uncovers new insights into SHOC2 function and reveals that this scaffold protein may be essential to activate a novel mechanism of p53-induced cell death in pre-B lymphoid cells

Conditioned stochastic particle systems and integrable quantum spin systems

We consider from a microscopic perspective large deviation properties of several stochastic interacting particle systems, using their mapping to integrable quantum spin systems. A brief review of recent work is given and several new results are presented: (i) For the general disordered symmectric exclusion process (SEP) on some finite lattice conditioned on no jumps into some absorbing sublattice and with initial Bernoulli product measure with density $\rho$ we prove that the probability $S_\rho(t)$ of no absorption event up to microscopic time $t$ can be expressed in terms of the generating function for the particle number of a SEP with particle injection and empty initial lattice. Specifically, for the symmetric simple exclusion process on $\mathbb Z$ conditioned on no jumps into the origin we obtain the explicit first and second order expansion in $\rho$ of $S_\rho(t)$ and also to first order in $\rho$ the optimal microscopic density profile under this conditioning. For the disordered ASEP on the finite torus conditioned on a very large current we show that the effective dynamics that optimally realizes this rare event does not depend on the disorder, except for the time scale. For annihilating and coalescing random walkers we obtain the generating function of the number of annihilated particles up to time $t$, which turns out to exhibit some universal features.Comment: 25 page

Constructing a Stochastic Model of Bumblebee Flights from Experimental Data

PMCID: PMC3592844This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Modeling the scaling properties of human mobility

While the fat tailed jump size and the waiting time distributions characterizing individual human trajectories strongly suggest the relevance of the continuous time random walk (CTRW) models of human mobility, no one seriously believes that human traces are truly random. Given the importance of human mobility, from epidemic modeling to traffic prediction and urban planning, we need quantitative models that can account for the statistical characteristics of individual human trajectories. Here we use empirical data on human mobility, captured by mobile phone traces, to show that the predictions of the CTRW models are in systematic conflict with the empirical results. We introduce two principles that govern human trajectories, allowing us to build a statistically self-consistent microscopic model for individual human mobility. The model not only accounts for the empirically observed scaling laws but also allows us to analytically predict most of the pertinent scaling exponents

Influence of depression and interpersonal support on adherence to antiretroviral therapy among people living with HIV

BackgroundPoor adherence and under-utilization of antiretroviral therapy (ART) services have been major setbacks to achieving 95-95-95 policy goals in Sub-Saharan Africa. Social support and mental health challenges may serve as barriers to accessing and adhering to ART but are under-studied in low-income countries. The purpose of this study was to examine the association of interpersonal support and depression scores with adherence to ART among persons living with HIV (PLWH) in the Volta region of Ghana.MethodsWe conducted a cross-sectional survey among 181 PLWH 18 years or older who receive care at an ART clinic between November 2021 and March 2022. The questionnaire included a 6-item simplified ART adherence scale, the 20-item Center for Epidemiologic Studies Depression Scale (CES-D), and the 12-item Interpersonal Support Evaluation List-12 (ISEL-12). We first used a chi-squared or Fisher’s exact test to assess the association between these and additional demographic variables with ART adherence status. We then built a stepwise multivariable logistic regression model to explain ART adherence.ResultsART adherence was 34%. The threshold for depression was met by 23% of participants, but it was not significantly associated with adherence in multivariate analysis(p = 0.25). High social support was reported by 48.1%, and associated with adherence (p = 0.033, aOR = 3.45, 95% CI = 1.09–5.88). Other factors associated with adherence included in the multivariable model included not disclosing HIV status (p = 0.044, aOR = 2.17, 95% CI = 1.03–4.54) and not living in an urban area (p = 0.00037, aOR = 0.24, 95% CI = 0.11–0.52).ConclusionInterpersonal support, rural residence, and not disclosing HIV status were independent predictors of adherence to ART in the study area