Smc5/6 coordinates formation and resolution of joint molecules with chromosome morphology to ensure meiotic divisions

During meiosis, Structural Maintenance of Chromosome (SMC) complexes underpin two fundamental features of meiosis: homologous recombination and chromosome segregation. While meiotic functions of the cohesin and condensin complexes have been delineated, the role of the third SMC complex, Smc5/6, remains enigmatic. Here we identify specific, essential meiotic functions for the Smc5/6 complex in homologous recombination and the regulation of cohesin. We show that Smc5/6 is enriched at centromeres and cohesin-association sites where it regulates sister-chromatid cohesion and the timely removal of cohesin from chromosomal arms, respectively. Smc5/6 also localizes to recombination hotspots, where it promotes normal formation and resolution of a subset of joint-molecule intermediates. In this regard, Smc5/6 functions independently of the major crossover pathway defined by the MutLγ complex. Furthermore, we show that Smc5/6 is required for stable chromosomal localization of the XPF-family endonuclease, Mus81-Mms4Eme1. Our data suggest that the Smc5/6 complex is required for specific recombination and chromosomal processes throughout meiosis and that in its absence, attempts at cell division with unresolved joint molecules and residual cohesin lead to severe recombination-induced meiotic catastroph

Psycho-social outcomes and mechanisms of self-help groups in Ethiopia

Tearfund has implemented a programme of establishing and facilitating a network self-help groups (SHG) comprising the poorest people in Ethiopian Society since 2002. The SHGs follow a carefully defined philosophy based initially on the self-help group movement run by MYRADA India and adapted to the Ethiopian Context with the assistance of Tearfund Ireland, Tearfund Netherlands, The Dutch Ministry of Foreign Affairs (BuZa) and Irish Aid. Previous research has examined the cost-benefit of Ethiopian self-help groups and found a very positive cost benefit ratio (Venton, et. al., 2013). However, this research has not documented, other than anecdotally, the social and psychological benefits experienced by the individuals participating in SHGs or the mechanisms involved in bringing about these benefits This research aims to: ? Evaluate the impact of SHGs on the psycho-social wellbeing of their members ? Elucidate the features of SHGs which promote, and those that may hamper, achieving this impact Ten SHGs from Wolaita (SNNPR) and Adama (Oromiya) were selected for this study ? five young (less than two years) and five more mature (more than five years). The SHGs were chosen to include high- (5), low- (1) and average- (4) functioning groups. A survey of individual members, a focus group with the SHG as a whole and interviews with key informants served to gather qualitative and quantitative data about both the individual and the SHG. Quantitative analysis was complemented by a thematic analysis of the open-ended questions in the survey and focus groups. We found that, as well as having a clear impact on the financial circumstances, SHGs are also impacting members? lives in a variety of ways. Older SHGs assessed the impact of the SHG as being greater and they scored more highly on measures of psychological and social wellbeing, indicating that the impact of the SHG increases over time. Themes that emerged from the members? discussion of the impact of the SHG were increased finances, moving from poverty to provider, moving from dependence to independence, education gained through the SHG, moving from social isolation to participation, social development, personal development and spiritual development. We identified several key elements of SHGs that seem to be critical in achieving these positive outcomes. The defined rules and bylaws of each SHG provide a strong structure for members to interact with clear expectations and boundaries. For of members who, in their own words, have come from lives with no structure, no role, no one to meet, no process to follow, the ?hard? fixed aspects of the SHG are very empowering. These are complemented by a set of values and principles ? of equality, sharing, mutual support and forgiveness. The evidence is strong that the SHGs manage to develop an environment in which all members are valued and get to participate, where dominance by one or two individuals is rare and where conflicts are, generally, effectively dealt with within the group. These ?soft? aspects of the SHGs are to some extent built into the structure, but there is a strong indication that facilitators are a critical part of promoting this culture by providing strong models of the values and attitudes that are reported as being characteristic of the SHGs ? acceptance, love, forgiveness. A strong theme in both the impact and mechanism sections above is education or training. It is clear that this is an aspect of the SHG that participants find very empowering. Given the low education level that most of the participants are coming from, the opportunity to gain knowledge and skills in areas as diverse as financial management and hygiene is very empowering

How does climate change affect the response of cyanobacteria to nutrients?

See pdf attache

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L-1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4 degrees C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature.Peer reviewe

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L−1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4°C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature

Data Descriptor: A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins

Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment