Mechanisms and functional significance of aberrant seizure-induced hippocampal neurogenesis

Studies of experimental mesial temporal lobe epilepsy (mTLE) indicate that prolonged seizures in the adult not only damage the hippocampal formation but also dramatically stimulate neurogenesis. Endogenous neural progenitor cells (NPCs) located in the adult rodent dentate gyrus and striatal subventricular zone are stimulated by experimental status epilepticus (SE) to generate increased numbers of dentate granule cells (DGCs) and olfactory interneurons, respectively ( Bengzon et al., 1997 ; Parent et al., 1997, 2002 ; Scott et al., 1998 ). In this review, we discuss current knowledge regarding the consequences of seizure activity on NPC proliferation, focusing on the hippocampus, and on the migration and integration of adult-born hippocampal neurons. We also describe the effects of seizure-induced neurogenesis on hippocampal network function and the potential relevance of aberrant neurogenesis to human mTLE.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65409/1/j.1528-1167.2008.01634.x.pd

Is neurogenesis reparative after status epilepticus?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65863/1/j.1528-1167.2007.01355.x.pd

Gender gaps in the path to adulthood for young females and males in six African countries from the 1990s to the 2010s

In this paper, we study on a comparative basis the school-to-work transition of young women and young men in six countries in sub-Saharan Africa, and we examine how this has evolved over recent years, based on the data collected by Demographic and Health Surveys. We examine educational attainments and the nature of early jobs young people are able to obtain, as well as considering their relationship to marriage and fertility outcomes, factors which are likely to be particularly relevant for young women. A pooled regression analysis shows that educational levels have increased substantially and gender gaps have narrowed in most countries. Access to better jobs has improved much more slowly with unchanging gender gaps in most countries, so that agriculture is still the dominant sector of employment for most young men and women. We model correlates of key educational outcomes and access to different types of jobs those controlling for individual- and household-level characteristics, including marital status, presence of children and wealth. Attaining a high level of education is unsurprisingly critical for access to the best jobs and is also associated with young women delaying marriage and childbearing

Analysis of adequacy levels for human resources improvement within primary health care framework in Africa

Human resources in health care system in sub-Saharan Africa are generally picturing a lack of adequacy between expected skills from the professionals and health care needs expressed by the populations. It is, however, possible to analyse these various lacks of adequacy related to human resource management and their determinants to enhance the effectiveness of the health care system. From two projects focused on nurse professionals within the health care system in Central Africa, we present an analytic grid for adequacy levels looking into the following aspects: - adequacy between skills-based profiles for health system professionals, quality of care and service delivery (health care system /medical standards), needs and expectations from the populations, - adequacy between allocation of health system professionals, quality of care and services delivered (health care system /medical standards), needs and expectations from the populations, - adequacy between human resource management within health care system and medical standards, - adequacy between human resource management within education/teaching/training and needs from health care system and education sectors, - adequacy between basic and on-going education and realities of tasks expected and implemented by different categories of professionals within the health care system body, - adequacy between intentions for initial and on-going trainings and teaching programs in health sciences for trainers (teachers/supervisors/health care system professionals/ directors (teaching managers) of schools...). This tool is necessary for decision-makers as well as for health care system professionals who share common objectives for changes at each level of intervention within the health system. Setting this adequacy implies interdisciplinary and participative approaches for concerned actors in order to provide an overall vision of a more broaden system than health district, small island with self-rationality, and in which they operate

Postglacial expansion of the arctic keystone copepod calanus glacialis

Calanus glacialis, a major contributor to zooplankton biomass in the Arctic shelf seas, is a key link between primary production and higher trophic levels that may be sensitive to climate warming. The aim of this study was to explore genetic variation in contemporary populations of this species to infer possible changes during the Quaternary period, and to assess its population structure in both space and time. Calanus glacialis was sampled in the fjords of Spitsbergen (Hornsund and Kongsfjorden) in 2003, 2004, 2006, 2009 and 2012. The sequence of a mitochondrial marker, belonging to the ND5 gene, selected for the study was 1249 base pairs long and distinguished 75 unique haplotypes among 140 individuals that formed three main clades. There was no detectable pattern in the distribution of haplotypes by geographic distance or over time. Interestingly, a Bayesian skyline plot suggested that a 1000-fold increase in population size occurred approximately 10,000 years before present, suggesting a species expansion after the Last Glacial Maximum.GAME from the National Science Centre, the Polish Ministry of Science and Higher Education Iuventus Plus [IP2014 050573]; FCT-PT [CCMAR/Multi/04326/2013]; [2011/03/B/NZ8/02876

Microguards and micromessengers of the genome

The regulation of gene expression is of fundamental importance to maintain organismal function and integrity and requires a multifaceted and highly ordered sequence of events. The cyclic nature of gene expression is known as ‘transcription dynamics’. Disruption or perturbation of these dynamics can result in significant fitness costs arising from genome instability, accelerated ageing and disease. We review recent research that supports the idea that an important new role for small RNAs, particularly microRNAs (miRNAs), is in protecting the genome against short-term transcriptional fluctuations, in a process we term ‘microguarding’. An additional emerging role for miRNAs is as ‘micromessengers’—through alteration of gene expression in target cells to which they are trafficked within microvesicles. We describe the scant but emerging evidence that miRNAs can be moved between different cells, individuals and even species, to exert biologically significant responses. With these two new roles, miRNAs have the potential to protect against deleterious gene expression variation from perturbation and to themselves perturb the expression of genes in target cells. These interactions between cells will frequently be subject to conflicts of interest when they occur between unrelated cells that lack a coincidence of fitness interests. Hence, there is the potential for miRNAs to represent both a means to resolve conflicts of interest, as well as instigate them. We conclude by exploring this conflict hypothesis, by describing some of the initial evidence consistent with it and proposing new ideas for future research into this exciting topic

Evo-devo of human adolescence: beyond disease models of early puberty

Despite substantial heritability in pubertal development, much variation remains to be explained, leaving room for the influence of environmental factors to adjust its phenotypic trajectory in the service of fitness goals. Utilizing evolutionary development biology (evo-devo), we examine adolescence as an evolutionary life-history stage in its developmental context. We show that the transition from the preceding stage of juvenility entails adaptive plasticity in response to energy resources, other environmental cues, social needs of adolescence and maturation toward youth and adulthood. Using the evolutionary theory of socialization, we show that familial psychosocial stress fosters a fast life history and reproductive strategy rather than early maturation being just a risk factor for aggression and delinquency. Here we explore implications of an evolutionary-developmental-endocrinological-anthropological framework for theory building, while illuminating new directions for research

Cognitive loading affects motor awareness and movement kinematics but not locomotor trajectories during goal-directed walking in a virtual reality environment.

The primary purpose of this study was to investigate the effects of cognitive loading on movement kinematics and trajectory formation during goal-directed walking in a virtual reality (VR) environment. The secondary objective was to measure how participants corrected their trajectories for perturbed feedback and how participants' awareness of such perturbations changed under cognitive loading. We asked 14 healthy young adults to walk towards four different target locations in a VR environment while their movements were tracked and played back in real-time on a large projection screen. In 75% of all trials we introduced angular deviations of ±5° to ±30° between the veridical walking trajectory and the visual feedback. Participants performed a second experimental block under cognitive load (serial-7 subtraction, counter-balanced across participants). We measured walking kinematics (joint-angles, velocity profiles) and motor performance (end-point-compensation, trajectory-deviations). Motor awareness was determined by asking participants to rate the veracity of the feedback after every trial. In-line with previous findings in natural settings, participants displayed stereotypical walking trajectories in a VR environment. Our results extend these findings as they demonstrate that taxing cognitive resources did not affect trajectory formation and deviations although it interfered with the participants' movement kinematics, in particular walking velocity. Additionally, we report that motor awareness was selectively impaired by the secondary task in trials with high perceptual uncertainty. Compared with data on eye and arm movements our findings lend support to the hypothesis that the central nervous system (CNS) uses common mechanisms to govern goal-directed movements, including locomotion. We discuss our results with respect to the use of VR methods in gait control and rehabilitation