Trading Fast and Slow: Fish Marketing Networks Provide Flexible Livelihood Opportunities on an East African Floodplain

Domestic marketing networks in inland small-scale fisheries (SSF) provide food and income to millions of the rural poor globally. Yet these contributions remain undervalued, as most trade is informal and unmonitored, and inland fisheries overlooked in research and policy. Taking a commodity chain approach, we provide a case study of access arrangements governing how people come to enter and benefit from the freshwater fish trade on Tanzania's Rufiji River floodplain. We conducted a repeat market survey, interviews, and participant observation with actors at all levels of the district trade over 15 months. Gender, age, and social capital structured participation patterns, with younger men dominating the more lucrative but riskier fresh trade, older men prioritizing steady income from smoked fish, and women culturally constrained to selling a “cooked” product (i.e., fried fish). Nearly all participants were local, with traders drawing on a complex web of relationships to secure supplies. The majority of market vendors cited the trade as their household's most important income source, with women's earnings and consumption of unsold fish likely to have substantial benefits for children's well-being. Our findings reveal a resilient and pro-poor trade system where, starting with small initial investments, people overcame considerable environmental, financial, regulatory, and infrastructural challenges to reliably deliver fish to rural and urban consumers. Preserving the ecological integrity of Rufiji wetlands in the face of hydro-power development and climate change should be a priority to safeguard the livelihoods and well-being of local inhabitants

Transient aspects of impinging shock-wave/boundary layer interactions

Measurements of wall pressure fluctuations and the flow-field were performed to understand the transient behavior of a shock-wave interacting with a Mach 3 boundary layer. Ramps of 10◦, 15◦, 17.5◦ and 20◦ turn angles were used to generate the incident shock-waves. The mean and fluctuating wall pressures were measured underneath the interaction region using flush-mounted high-speed pressure sensors. Schlieren videos with high spatial and temporal resolution were also recorded for each interaction. The mean static pressure profile shows good agreement with theoretical results, and single point statistics of the unsteady pressure signal clearly resolves the impact of the various flow features on the wall pressure. The mean flow features and shock structures are well defined in Schlieren images, and the setup shows strong potential for detailed analysis of unsteady aspects of the flow

The Effect of Pressure Gradient on the Aeroacoustics and WakDynamics of a Finite Wall-Mounted Square Cylinder

This paper reports an experimental investigation of the wake flow structures and noise production of a square finite-wall-mounted cylinder (FWMC) with an aspect ratio of 2.4. The cylinder was immersed in flows with favourable-, near-zero-and adverse-pressure gradients at a Reynolds number of 48000, based on cylinder width. Acoustic and particle image velocimetry measurements were taken simultaneously using the newly developed open-jet pressure gradient test rig in the UNSW Anechoic Wind Tunnel. An adverse pressure gradient was found to enhance the cylinder junction upwash, weaken the free-end downwash and suppress the primary tonal noise at a Strouhal number of approximately 0.1. Conversely, a favourable-pressure gradient promotes downwash over the free-end and leads to a higher tonal noise level. Wake flow structures that correlated with the far-field sound pressure were identified to understand noise generation or suppression mechanisms

Interplay of Mre11 Nuclease with Dna2 plus Sgs1 in Rad51-Dependent Recombinational Repair

The Mre11/Rad50/Xrs2 complex initiates IR repair by binding to the end of a double-strand break, resulting in 5′ to 3′ exonuclease degradation creating a single-stranded 3′ overhang competent for strand invasion into the unbroken chromosome. The nuclease(s) involved are not well understood. Mre11 encodes a nuclease, but it has 3′ to 5′, rather than 5′ to 3′ activity. Furthermore, mutations that inactivate only the nuclease activity of Mre11 but not its other repair functions, mre11-D56N and mre11-H125N, are resistant to IR. This suggests that another nuclease can catalyze 5′ to 3′ degradation. One candidate nuclease that has not been tested to date because it is encoded by an essential gene is the Dna2 helicase/nuclease. We recently reported the ability to suppress the lethality of a dna2Δ with a pif1Δ. The dna2Δ pif1Δ mutant is IR-resistant. We have determined that dna2Δ pif1Δ mre11-D56N and dna2Δ pif1Δ mre11-H125N strains are equally as sensitive to IR as mre11Δ strains, suggesting that in the absence of Dna2, Mre11 nuclease carries out repair. The dna2Δ pif1Δ mre11-D56N triple mutant is complemented by plasmids expressing Mre11, Dna2 or dna2K1080E, a mutant with defective helicase and functional nuclease, demonstrating that the nuclease of Dna2 compensates for the absence of Mre11 nuclease in IR repair, presumably in 5′ to 3′ degradation at DSB ends. We further show that sgs1Δ mre11-H125N, but not sgs1Δ, is very sensitive to IR, implicating the Sgs1 helicase in the Dna2-mediated pathway

Wolbachia Induces Male-Specific Mortality in the Mosquito Culex pipiens (LIN Strain)

Background: Wolbachia are maternally inherited endosymbionts that infect a diverse range of invertebrates, including insects, arachnids, crustaceans and filarial nematodes. Wolbachia are responsible for causing diverse reproductive alterations in their invertebrate hosts that maximize their transmission to the next generation. Evolutionary theory suggests that due to maternal inheritance, Wolbachia should evolve toward mutualism in infected females, but strict maternal inheritance means there is no corresponding force to select for Wolbachia strains that are mutualistic in males. Methodology/Principal findings: Using cohort life-table analysis, we demonstrate that in the mosquito Culex pipiens (LIN strain), Wolbachia-infected females show no fitness costs due to infection. However, Wolbachia induces up to a 30% reduction in male lifespan. Conclusions/significance: These results indicate that the Wolbachia infection of the Culex pipiens LIN strain is virulent in a sex-specific manner. Under laboratory situations where mosquitoes generally mate at young ages, Wolbachia strains that reduce male survival could evolve by drift because increased mortality in older males is not a significant selective force

JEFET SCHWILI ERZÄHLT. Hundertneunundsechzig jemenitische Volkserzählungen aufgeszeichnet in Israel 1957 - 1960. Herausgegeben von DOV NOY. Supplement - Serie zu Fabula , Reihe A, Band 4. Walter de Gruyter, Berlin 1963.

Precautionary conservation and cooperative global governance are needed to protect Antarctic blue carbon: the world’s largest increasing natural form of carbon storage with high sequestration potential. As patterns of ice‐loss around Antarctica become more uniform, there is an underlying increase in carbon capture‐to‐storage‐to‐sequestration on the seafloor. The amount of carbon captured per unit area is increasing and the area available to blue carbon is also increasing. Carbon sequestration could further increase under moderate (+1 °C) ocean warming, contrary to decreasing global blue carbon stocks elsewhere. For example, in warmer waters, mangroves and seagrasses are in decline and benthic organisms are close to their physiological limits, so a 1°C increase in water temperature could push them above their thermal tolerance (e.g. bleaching of coral reefs). In contrast, on the basis of past change and current research we expect that Antarctic blue carbon could increase by orders of magnitude.The Antarctic seafloor is biophysically unique and the site of carbon sequestration, the benthos, faces less anthropogenic disturbance than any other ocean continental shelf environment. This isolation imparts both vulnerability to change, and an avenue to conserve one of the world’s last biodiversity refuges. In economic terms, the value of Antarctic blue carbon is estimated at between £0.65 billion and £1.76 billion (~2.27 billion USD), for sequestered carbon in the benthos around the continental shelf. To balance biodiversity protection against society’s economic objectives, this paper builds on a proposal incentivising protection by building a ‘non‐market framework’ via the 2015 Paris Agreement to the United Nations Framework Convention on Climate Change. This could be connected and coordinated through the Antarctic Treaty System to promote and motivate member states to value Antarctic blue carbon and maintain scientific integrity and conservation for the positive societal values ingrained in the Antarctic Treaty System

DNA resection in eukaryotes: deciding how to fix the break

DNA double-strand breaks are repaired by different mechanisms, including homologous recombination and nonhomologous end-joining. DNA-end resection, the first step in recombination, is a key step that contributes to the choice of DSB repair. Resection, an evolutionarily conserved process that generates single-stranded DNA, is linked to checkpoint activation and is critical for survival. Failure to regulate and execute this process results in defective recombination and can contribute to human disease. Here, I review recent findings on the mechanisms of resection in eukaryotes, from yeast to vertebrates, provide insights into the regulatory strategies that control it, and highlight the consequences of both its impairment and its deregulation

Centrosome clustering and Cyclin D1 gene amplification in double minutes are common events in chromosomal unstable bladder tumors

Background: Aneuploidy, centrosome abnormalities and gene amplification are hallmarks of chromosome instability (CIN) in cancer. Yet there are no studies of the in vivo behavior of these phenomena within the same bladder tumor. Methods: Twenty-one paraffin-embedded bladder tumors were analyzed by conventional comparative genome hybridization and fluorescence in situ hybridization (FISH) with a cyclin D1 gene (CCND1)/centromere 11 dual-color probe. Immunofluorescent staining of α, β and γ tubulin was also performed. Results: Based on the CIN index, defined as the percentage of cells not displaying the modal number for chromosome 11, tumors were classified as CIN-negative and CIN-positive. Fourteen out of 21 tumors were considered CIN-positive. All T1G3 tumors were included in the CIN-positive group whereas the majority of Ta samples were classified as CIN-negative tumors. Centrosome clustering was observed in six out of 12 CIN-positive tumors analyzed. CCND1 amplification in homogeneously staining regions was present in six out of 14 CIN-positive tumors; three of them also showed amplification of this gene in double minutes. Conclusions: Complex in vivo behavior of CCND1 amplicon in bladder tumor cells has been demonstrated by accurate FISH analysis on paraffin-embedded tumors. Positive correlation between high heterogeneity, centrosome abnormalities and CCND1 amplification was found in T1G3 bladder carcinomas. This is the first study to provide insights into the coexistence of CCND1 amplification in homogeneously staining regions and double minutes in primary bladder tumors. It is noteworthy that those patients whose tumors showed double minutes had a significantly shorter overall survival rate (p < 0.001)

High-Density Microwell Chip for Culture and Analysis of Stem Cells

With recent findings on the role of reprogramming factors on stem cells, in vitro screening assays for studying (de)-differentiation is of great interest. We developed a miniaturized stem cell screening chip that is easily accessible and provides means of rapidly studying thousands of individual stem/progenitor cell samples, using low reagent volumes. For example, screening of 700,000 substances would take less than two days, using this platform combined with a conventional bio-imaging system. The microwell chip has standard slide format and consists of 672 wells in total. Each well holds 500 nl, a volume small enough to drastically decrease reagent costs but large enough to allow utilization of standard laboratory equipment. Results presented here include weeklong culturing and differentiation assays of mouse embryonic stem cells, mouse adult neural stem cells, and human embryonic stem cells. The possibility to either maintain the cells as stem/progenitor cells or to study cell differentiation of stem/progenitor cells over time is demonstrated. Clonality is critical for stem cell research, and was accomplished in the microwell chips by isolation and clonal analysis of single mouse embryonic stem cells using flow cytometric cell-sorting. Protocols for practical handling of the microwell chips are presented, describing a rapid and user-friendly method for the simultaneous study of thousands of stem cell cultures in small microwells. This microwell chip has high potential for a wide range of applications, for example directed differentiation assays and screening of reprogramming factors, opening up considerable opportunities in the stem cell field

Fellowship training:a qualitative study of scope and purpose across one department of medicine

BACKGROUND: Fellowship training follows certification in a primary specialty or subspecialty and focusses on distinct and advanced clinical and/or academic skills. This phase of medical education is growing in prevalence, but has been an &quot;invisible phase of postgraduate training&quot; lacking standards for education and accreditation, as well as funding. We aimed to explore fellowship programs and examine the reasons to host and participate in fellowship training, seeking to inform the future development of fellowship education. METHODS: During the 2013-14 academic year, we conducted interviews and focus groups to examine the current status of fellowship training from the perspectives of division heads, fellowship directors and current fellows at the Department of Medicine, University of Ottawa, Canada. Descriptive statistics were used to depict the prevailing status of fellowship training. A process of data reduction, data analysis and conclusions/verifications was performed to analyse the quantitative data. RESULTS: We interviewed 16 division heads (94%), 15 fellowship directors (63%) and 8 fellows (21%). We identified three distinct types of fellowships. Individualized fellowships focus on the career goals of the trainee and/or the recruitment goals of the division. Clinical fellowships focus on the attainment of clinical expertise over and above the competencies of residency. Research fellowships focus on research productivity. Participants identified a variety of reasons to offer fellowships: improve academic productivity; improve clinical productivity; share/develop enhanced clinical expertise; recruit future faculty members/attain an academic position; enhance the reputation of the division/department/trainee; and enhance the scholarly environment. CONCLUSIONS: Fellowships serve a variety of purposes which benefit both individual trainees as well as the academic enterprise. Fellowships can be categorized within a distinct taxonomy: individualized; clinical; and research. Each type of fellowship may serve a variety of purposes, and each may need distinct support and resources. Further research is needed to catalogue the operational requirements for hosting and undertaking fellowship training, and establish recommendations for educational and administrative policy and processes in this new phase of postgraduate education