On the divisibility of characteristic classes of non-oriented surface bundles

In this note we introduce a construction which assigns to an arbitrary manifold bundle its fiberwise orientation covering. This is used to show that the zeta classes of unoriented surface bundles are not divisible in the stable range.Comment: 6 pages, to appear in Topology and its Applications. v2: changes in expositio

Sex-specific pathways of parental age effects on offspring lifetime reproductive success in a long-lived seabird

The conditions under which individuals are reared vary and sensitivity of offspring to such variation is often sex-dependent. Parental age is one important natal condition with consequences for aspects of offspring fitness, but reports are mostly limited to short-term fitness consequences and do not take into account offspring sex. Here we used individual-based data from a large colony of a long-lived seabird, the common tern Sterna hirundo, to investigate longitudinal long-term fitness consequences of parental age in relation to both offspring and parental sex. We found that recruited daughters from older mothers suffered from reduced annual reproductive success. Recruited sons from older fathers were found to suffer from reduced life span. Both effects translated to reductions in offspring lifetime reproductive success. Besides revealing novel sex-specific pathways of transgenerational parental age effects on offspring fitness, which inspire studies of potential underlying mechanisms, our analyses show that reproductive senescence is only observed in the common tern when including transgenerational age effects. In general, our study shows that estimates of selective pressures underlying the evolution of senescence, as well as processes such as age-dependent mate choice and sex allocation, will depend on whether causal transgenerational effects exist and are taken into account

TGFβ signaling is associated with changes in inflammatory gene expression and perineuronal net degradation around inhibitory neurons following various neurological insults.

Brain damage due to stroke or traumatic brain injury (TBI), both leading causes of serious long-term disability, often leads to the development of epilepsy. Patients who develop post-injury epilepsy tend to have poor functional outcomes. Emerging evidence highlights a potential role for blood-brain barrier (BBB) dysfunction in the development of post-injury epilepsy. However, common mechanisms underlying the pathological hyperexcitability are largely unknown. Here, we show that comparative transcriptome analyses predict remodeling of extracellular matrix (ECM) as a common response to different types of injuries. ECM-related transcriptional changes were induced by the serum protein albumin via TGFβ signaling in primary astrocytes. In accordance with transcriptional responses, we found persistent degradation of protective ECM structures called perineuronal nets (PNNs) around fast-spiking inhibitory interneurons, in a rat model of TBI as well as in brains of human epileptic patients. Exposure of a naïve brain to albumin was sufficient to induce the transcriptional and translational upregulation of molecules related to ECM remodeling and the persistent breakdown of PNNs around fast-spiking inhibitory interneurons, which was contingent on TGFβ signaling activation. Our findings provide insights on how albumin extravasation that occurs upon BBB dysfunction in various brain injuries can predispose neural circuitry to the development of chronic inhibition deficits

Telomere length is repeatable, shortens with age and reproductive success, and predicts remaining lifespan in a long-lived seabird

Telomeres are protective caps at the end of chromosomes, and their length is positively correlated with individual health and lifespan across taxa. Longitudinal studies have provided mixed results regarding the within-individual repeatability of telomere length. While some studies suggest telomere length to be highly dynamic and sensitive to resource-demanding or stressful conditions, others suggest that between-individual differences are mostly present from birth and relatively little affected by the later environment. This dichotomy could arise from differences between species, but also from methodological issues. In our study, we used the highly reliable Terminal Restriction Fragment analysis method to measure telomeres over a 10-year period in adults of a long-lived seabird, the common tern (Sterna hirundo). Telomeres shortened with age within individuals. The individual repeatability of age-dependent telomere length was high (>0.53), and independent of the measurement interval (i.e., one vs. six years). A small (R-2 = .01), but significant part of the between-individual variation in telomere length was, however, explained by the number of fledglings produced in the previous year, while reproduction in years prior to the previous year had no effect. We confirmed that age-dependent telomere length predicted an individual's remaining lifespan. Overall, our study suggests that the majority of between-individual variation in adult telomere length is consistent across adult life, and that a smaller part of the variation can be explained by dynamic factors, such as reproduction

Digital Equity in the Time of COVID: Student Use of Technology for Equitable Outcomes

This issue brief is the third and final in a series published by the Metropolitan Educational Research Consortium (MERC) addressing digital equity in K-12 schools. It examines research regarding students’ use of and outcomes related to technology. Research finds that inequities exist in use and outcomes for students based on gender, language, ability, race, SES and other sociocultural factors. Based on these inequities, theoretical and practical recommendations are discussed

Design of a comprehensive Alzheimer’s disease clinic and research center in Spain to meet critical patient and family needs

AbstractObjectivesAlzheimer's disease (AD) affects people worldwide, and the prevalence is increasing as the population ages. There is an international effort to understand the biology of AD to develop primary and secondary prevention strategies, and to develop effective therapeutic interventions for individuals who are already symptomatic. One of the critically important pieces of all national plans to address AD is the call for the development of service models to deliver quality, effective care based on the best evidence available.MethodsWe describe one type of care model developed by the Fundacio ACE, Institut Catala de Neurociencies Aplicades (Fundacio ACE, Barcelona, Spain) that integrates diagnosis, therapy, follow-up care, daycare, and a day hospital, and does so in the context of an active clinical research and educational program.ResultsThere were 13,048 individuals newly evaluated and diagnosed in Fundacio ACE between 1996 and 2011. Of these, 6132 had AD (47.0%), 3871 had mild cognitive impairment (MCI) (29.7%), and 1958 had no cognitive impairment (15.0%). Follow-up information is available on 4735 (47.3%) AD and MCI patients, and these data indicate that MCI develops into dementia at a rate of 222.6/1000 person-years. Apolipoprotein E (APOE) genotyping was available in 22.4% of the patients. The ε4 allele occurred in 45.7% of the AD patients, in 37.8% of the MCI subjects, and in 31.6% of those without cognitive impairment.ConclusionsFundació ACE can serve as a model system that can be adapted to other settings within their specific cultural, governmental, and legal constraints

The Exchange of Orientifold Two-Planes in M-theory

We propose an M-theory lift picture of the exchange among type IIA orientifold two-planes. This consists in wrapping a M5-brane on a three-cycle in the transverse space of the M-theory orientifold plane OM2. A flux quantization condition for the three-form self-dual field strength, on the worldvolume of the M5-brane is computed. This condition establishes the value which explains the relative charge between two different OM2-planes. Also, we find that the exchange of the four types of orientifold two-planes in string theory, has a common picture in M-theory. Moreover, we find that the assignment of the extra charge is fixed by cohomology and by the flux quantization of the field strength G in M-theory. We conclude that cohomology is sufficient to describe some orientifold properties in M-theory, that at string theory level, only K-theory is able to explain.Comment: 23+1 pages, 6 figures. v2: typos corrected, references adde