Aerodynamically-Actuated Radical Shape-Change Concept

Aerodynamically-actuated radical shape change (AARSC) is a novel concept that enables flight vehicles to conduct a mission profile containing radically different flight regimes while possibly mitigating the typical penalties incurred by radical geometric change. Weight penalties are mitigated by utilizing a primary flight control to generate aerodynamic loads that then drive a shape-change actuation. The flight mission profile used to analyze the AARSC concept is that of a transport aircraft that cruises at a lower altitude than typical transports. Based upon a preliminary analysis, substantial fuel savings are realized for mission ranges below 2000 NM by comparison to a state-of-the-art baseline, with an increasing impact as mission range is reduced. The predicted savings are so significant at short-haul ranges that the shape-change concept rivals the fuel-burn performance of turboprop aircraft while completing missions in less time than typical jet aircraft. Lower-altitude cruise has also been sought after in recent years for environmental benefits, however, the performance penalty to conventional aircraft was prohibitive. AARSC may enable the opportunity to realize the environmental benefits of lower-altitude emissions coupled with mission fuel savings. The findings of this study also reveal that the AARSC concept appears to be controllable, turbulence susceptibility is likely not an issue, and the shape change concept appears to be mechanically and aerodynamically feasible

Osteoblast Recruitment Routes in Human Cancellous Bone Remodeling

It is commonly proposed that bone forming osteoblasts recruited during bone remodeling originate from bone marrow perivascular cells, bone remodeling compartment canopy cells, or bone lining cells. However, an assessment of osteoblast recruitment during adult human cancellous bone remodeling is lacking. We addressed this question by quantifying cell densities, cell proliferation, osteoblast differentiation markers, and capillaries in human iliac crest biopsy specimens. We found that recruitment occurs on both reversal and bone-forming surfaces, as shown by the cell density and osterix levels on these respective surfaces, and that bone formation occurs only above a given cell density. Canopies appeared an important source of osteoprogenitors, because (i) canopy cells proved to be more proliferative and less differentiated than bone surface cells, as shown by the inverse levels of Ki-67 and procollagen-3 N-terminal peptide versus osterix, and (ii) canopy cell densities, found to decline with age, and canopy-capillary contacts above eroded surfaces correlated positively with osteoblast density on bone-forming surfaces. Furthermore, we showed that bone remodeling compartment canopies arise from a mesenchymal envelope surrounding the red bone marrow, which is lifted and hypertrophied on initiation of bone resorption. This study, together with earlier reports, led to a model in which canopies and nearby capillaries are critical for reaching the osteoblast density required for bone formation

Resisting the Coloniality and Colonialism of a Westernized Community Psychology: Toward a Critical Racial Justice Praxis

The institutional violence we are now experiencing, coupled with historical and ongoing waves of oppression, is a result and continuation of the legacy of colonialism. The outward eruptions that we are seeing over the last years are a result of American and Canadian settler nation-states that have taken hold in North America but are now in decline. Yet, the perpetuation of imperialism and white supremacist ideologies via the academe and other noneducational entities reproduced through curricula, pedagogy, and institutional policies and practices must still be addressed. The discipline of community psychology (CP) is no exception. As a part of the imperialist empire, CP, a mainstream academic discipline born at the heart of the empire of the colonial ruling class, continuously asks: What can we do? We, the authors of this paper, are troubled by this question and respond with a question of our own: Can community psychology really be part of the solution if it does not acknowledge that it is part of the problem? Through the lens of five Indigenous, Black, and racialized scholar-activists, educators, and practitioners, we identify three community psychology principles and argue that in practice within Black and Indigenous communities, they are not sufficient. Further, we illustrate that, related to these principles, community psychology is situated within what is termed the industrial complex, and we elucidate the implications of this situating. Lastly, we offer a proposal for how we, as part of the academe and practice, can decolonize community psychology and move it forward to align with current liberation movements and Indigenous sovereignty

Resisting the Coloniality and Colonialism of a Westernized Community Psychology: Toward a Critical Racial Justice Praxis

The institutional violence we are now experiencing, coupled with historical and ongoing waves of oppression, is a result and continuation of the legacy of colonialism. The outward eruptions that we are seeing over the last years are a result of American and Canadian settler nation-states that have taken hold in North America but are now in decline. Yet, the perpetuation of imperialism and white supremacist ideologies via the academe and other noneducational entities reproduced through curricula, pedagogy, and institutional policies and practices must still be addressed. The discipline of community psychology (CP) is no exception. As a part of the imperialist empire, CP, a mainstream academic discipline born at the heart of the empire of the colonial ruling class, continuously asks: What can we do? We, the authors of this paper, are troubled by this question and respond with a question of our own: Can community psychology really be part of the solution if it does not acknowledge that it is part of the problem? Through the lens of five Indigenous, Black, and racialized scholar-activists, educators, and practitioners, we identify three community psychology principles and argue that in practice within Black and Indigenous communities, they are not sufficient. Further, we illustrate that, related to these principles, community psychology is situated within what is termed the industrial complex, and we elucidate the implications of this situating. Lastly, we offer a proposal for how we, as part of the academe and practice, can decolonize community psychology and move it forward to align with current liberation movements and Indigenous sovereignty

Use, microbiological effectiveness and health impact of a household water filter intervention in rural Rwanda-A matched cohort study.

Unsafe drinking water is a substantial health risk contributing to child diarrhoea. We investigated impacts of a program that provided a water filter to households in rural Rwandan villages. We assessed drinking water quality and reported diarrhoea 12-24 months after intervention delivery among 269 households in the poorest tertile with a child under 5 from 9 intervention villages and 9 matched control villages. We also documented filter coverage and use. In Round 1 (12-18 months after delivery), 97.4% of intervention households reported receiving the filter, 84.5% were working, and 86.0% of working filters contained water. Sensors confirmed half of households with working filters filled them at least once every other day on average. Coverage and usage was similar in Round 2 (19-24 months after delivery). The odds of detecting faecal indicator bacteria in drinking water were 78% lower in the intervention arm than the control arm (odds ratio (OR) 0.22, 95% credible interval (CrI) 0.10-0.39, p<0.001). The intervention arm also had 50% lower odds of reported diarrhoea among children <5 than the control arm (OR=0.50, 95% CrI 0.23-0.90, p=0.03). The protective effect of the filter is also suggested by reduced odds of reported diarrhoea-related visits to community health workers or clinics, although these did not reach statistical significance

Resisting the Coloniality and Colonialism of a Westernized Community Psychology: Toward a Critical Racial Justice Praxis

The institutional violence we are now experiencing, coupled with historical and ongoing waves of oppression, is a result and continuation of the legacy of colonialism. The outward eruptions that we are seeing over the last years are a result of American and Canadian settler nation-states that have taken hold in North America but are now in decline. Yet, the perpetuation of imperialism and white supremacist ideologies via the academe and other noneducational entities reproduced through curricula, pedagogy, and institutional policies and practices must still be addressed. The discipline of community psychology (CP) is no exception. As a part of the imperialist empire, CP, a mainstream academic discipline born at the heart of the empire of the colonial ruling class, continuously asks:&nbsp;What can we do?&nbsp;We, the authors of this paper, are troubled by this question and respond with a question of our own:&nbsp;Can community psychology really be part of the solution if it does not acknowledge that it is part of the problem?&nbsp;Through the lens of five Indigenous, Black, and racialized scholar-activists, educators, and practitioners, we identify three community psychology principles and argue that in practice within Black and Indigenous communities, they are not sufficient. Further, we illustrate that, related to these principles, community psychology is situated within what is termed the industrial complex, and we elucidate the implications of this situating. Lastly, we offer a proposal for how we, as part of the academe and practice, can decolonize community psychology and move it forward to align with current liberation movements and Indigenous sovereignty

A deep search for planets in the inner 15 au around Vega

We present the results of a deep high-contrast imaging search for planets around Vega. Vega is an ideal target for high-contrast imaging because it is bright, nearby, and young with a face-on two-belt debris disk which may be shaped by unseen planets. We obtained $J-$ and $H-$band data on Vega with the coronagraphic integral-field spectrograph Project 1640 (P1640) at Palomar Observatory. Two nights of data were obtained in 2016, in poor seeing conditions, and two additional nights in more favorable conditions in 2017. In total, we obtained 5.5 hours of integration time on Vega in moderate to good seeing conditions (<1.5"). We did not detect any low mass companions in this system. Our data present the most sensitive contrast limits around Vega at very small separations (2-15 au) thus far, allowing us to place new constraints on the companions which may be sculpting the Vega system. In addition to new constraints, as the deepest data obtained with P1640, these observations form the final legacy of the now decommissioned instrument.Comment: Accepted for publication in A

Sex specific effects of pre-pubertal stress on hippocampal neurogenesis and behaviour

Experience of traumatic events in childhood is linked to an elevated risk of developing psychiatric disorders in adulthood. The neurobiological mechanisms underlying this phenomenon are not fully understood. The limbic system, particularly the hippocampus, is significantly impacted by childhood trauma. In particular, it has been hypothesised that childhood stress may impact adult hippocampal neurogenesis (AHN) and related behaviours, conferring increased risk for later mental illness. Stress in utero can lead to impaired hippocampal synaptic plasticity, and stress in the first 2–3 weeks of life reduces AHN in animal models. Less is known about the effects of stress in the post-weaning, pre-pubertal phase, a developmental time-point more akin to human childhood. Therefore, we investigated persistent effects of pre-pubertal stress (PPS) on functional and molecular aspects of the hippocampus. AHN was altered following PPS in male rats only. Specifically males showed reduced production of new neurons following PPS, but increased survival in the ventral dentate gyrus. In adult males, but not females, pattern separation and trace fear conditioning, behaviours that rely heavily on AHN, were also impaired after PPS. PPS also increased the expression of parvalbumin-positive GABAergic interneurons in the ventral dentate gyrus and increased glutamic acid decarboxylase 67 expression in the ventral hilus, in males only. Our results demonstrate the lasting effects of PPS on the hippocampus in a sex- and time-dependent manner, provide a potential mechanistic link between PPS and later behavioural impairments, and highlight sex differences in vulnerability to neuropsychiatric conditions after early-life stres

Microsatellite diversity and broad scale geographic structure in a model legume: building a set of nested core collection for studying naturally occurring variation in Medicago truncatula

BACKGROUND: Exploiting genetic diversity requires previous knowledge of the extent and structure of the variation occurring in a species. Such knowledge can in turn be used to build a core-collection, i.e. a subset of accessions that aim at representing the genetic diversity of this species with a minimum of repetitiveness. We investigate the patterns of genetic diversity and population structure in a collection of 346 inbred lines representing the breadth of naturally occurring diversity in the Legume plant model Medicago truncatula using 13 microsatellite loci distributed throughout the genome. RESULTS: We confirm the uniqueness of all these genotypes and reveal a large amount of genetic diversity and allelic variation within this autogamous species. Spatial genetic correlation was found only for individuals originating from the same population and between neighbouring populations. Using a model-based clustering algorithm, we identified four main genetic clusters in the set of individuals analyzed. This stratification matches broad geographic regions. We also identified a set of "admixed" individuals that do not fit with this population structure scheme. CONCLUSION: The stratification inferred is discussed considering potential historical events like expansion, refuge history and admixture between neighbouring groups. Information on the allelic richness and the inferred population structure are used to build a nested core-collection. The set of inbred lines and the core collections are publicly available and will help coordinating efforts for the study of naturally occurring variation in the growing Medicago truncatula community