A permeabilized cell model for studying cell division: a comparison of anaphase chromosome movement and cleavage furrow constriction in lysed PtK1 cells.

After lysis in a Brij 58-polyethylene glycol medium, PtK1 cells are permeable to small molecules, such as erythrosin B, and to proteins, such as rhodamine-labeled FAB, myosin subfragment-1, and tubulin. Holes are present in the plasma membrane, and the mitochondria are swollen and distorted, but other membrane-bounded organelles of the lysed cell model are not noticeably altered. After lysis, the mitotic apparatus is functional; chromosomes move poleward and the spindle elongates. Cells lysed while in cytokinesis will continue to divide for several minutes. Addition of crude tubulin extracts, MAP-free tubulin, or taxol to the lysis medium retards anaphase chromosome movements but does not affect cleavage. On the other hand, N-ethylmaleimide-modified myosin subfragment-1, phalloidin, and cytochalasin B inhibit cleavage but have no effect on anaphase chromosome movements under identical lysis conditions. These results suggest that actomyosin plays no functional role in anaphase chromosome movement in mammalian tissue culture cells and that microtubule depolymerization is a rate-limiting step for chromosome-to-pole movements

Differentiated Threat and the Genesis of Prejudice: Group-Specific Antecedents of Homonegativity, Islamophobia, Anti-Semitism, and Anti-Immigrant Attitudes

In this article we argue that an exclusive focus on the generalized aspect of prejudice limits understanding of the structure and genesis of prejudice towards particular out-groups. In order to conceptualize the specific nature of particular prejudices, we propose the differentiated threat approach. This framework postulates that different out-groups challenge diverse realistic and symbolic interests, and that these out-group specific threats affect various socio-economic strata and cultural groups differentially. The differentiated threat approach is applied to analyse majority-group Belgians’ attitudes towards immigrants, Muslims, Jews and homosexuals. The results show that a common denominator of prejudice can be distinguished, but that the prejudices towards the various out-groups contain substantively relevant unique components that are influenced by socio-demographic and attitudinal predictors in diverging ways. Gender traditionalism is found to reinforce homonegativity and temper Islamophobia at the same time. Feelings of relative deprivation are more strongly related to Islamophobia than to other forms of prejudice, and are unrelated to homonegativity. Religious involvement plays a more decisive role in the formation of antiSemitism and homonegativity than it does in the other forms of prejudice. Anti-immigration attitudes show a class gradient that is absent in attitudes towards other out-groups. Our results evidence that the concrete realization of attitudes towards a specific out-group cannot be understood without paying attention to structural and contextual factors, such as social positions, the nature of inter-group relations, power balances and elite discourses

Gedifferentieerde dreiging en de verklaring van vooroordelen: Anti-immigranten attitudes, islamofobie, antisemitisme en homonegativiteit vergeleken

Deze bijdrage stelt dat een te eenzijdige aandacht voor de veralgemeende component van vooroordelen een obstakel vormt om de structuur en genese van vooroordelen tegenover specifeke groepen te begrijpen. We stellen een model van gedifferentieerde dreiging voor dat toelaat het particuliere karakter van specifeke vooroordelen te conceptualiseren en te toetsen. Deze benadering postuleert dat verschillende uitgroepen diverse economische en culturele belangen uitdagen, en dat deze specifeke bedreigingen diverse socio-economische lagen en culturele segmenten van de bevolking in verschillende mate treffen. Vervolgens passen we het model van gedifferentieerde dreiging toe om de houdingen van autochtone Belgen tegenover immigranten, moslims, joden en homoseksuelen te analyseren. De resultaten tonen aan dat het inderdaad mogelijk is om een gemeenschappelijke component in de diverse vooroordelen te onderscheiden. Maar tegelijkertijd bevatten de onderscheiden vooroordelen elk een relevante, unieke component die op verschillende wijze samenhangt met structurele kenmerken en attitudes. Traditionele genderopvattingen, bijvoorbeeld, hebben tegelijkertijd een versterkend effect op homonegativiteit en een temperende invloed op islamofobie. Gevoelens van relatieve deprivatie zijn dan weer sterker gerelateerd met islamofobie dan met andere vormen van vooroordeel en hebben helemaal geen impact op homonegativiteit. Religiositeit speelt een meer beslissende rol in de formatie van antisemitisme en homonegativiteit dan het geval is bij andere vooroordelen

Experimental studies of bubbly flow in a pseudo-2D micro-structured bubble column reactor using digital image analysis

A novel micro-structured bubble column reactor(MSBC) is studied experimentally in this work. Micro-structuring is realized by using a wire mesh inserted in a pseudo-2D bubble column reactor. Different flow configurations of the wire mesh are evaluated by means of visual observation. Three different regimes with bubble cutting, bubble cutting followed by re-coalescence and gas pocket formation was observed for different wire meshes for superficial gas velocities ranging from 5 to 50 mm/s. An advanced Digital Image Analysis technique (DIA) was used to determine the effect of wire mesh on the bubble size distribution, gas holdup and interfacial area. Detailed experiments were performed for wire meshes with mesh openings of 3.3 mm, 3.7 mm and 5.6 mm for superficial gas velocities ranging from 5 to 30 mm/s. Bubble cutting is observed at 3.7 mm mesh opening for superficial gas velocities up to 15 mm/s. At higher superficial gas velocities,the bubble breaks up to very small bubbles and bypasses the wire mesh unaffected

The N-terminal intrinsically disordered domain of mgm101p is localized to the mitochondrial nucleoid.

The mitochondrial genome maintenance gene, MGM101, is essential for yeasts that depend on mitochondrial DNA replication. Previously, in Saccharomyces cerevisiae, it has been found that the carboxy-terminal two-thirds of Mgm101p has a functional core. Furthermore, there is a high level of amino acid sequence conservation in this region from widely diverse species. By contrast, the amino-terminal region, that is also essential for function, does not have recognizable conservation. Using a bioinformatic approach we find that the functional core from yeast and a corresponding region of Mgm101p from the coral Acropora millepora have an ordered structure, while the N-terminal domains of sequences from yeast and coral are predicted to be disordered. To examine whether ordered and disordered domains of Mgm101p have specific or general functions we made chimeric proteins from yeast and coral by swapping the two regions. We find, by an in vivo assay in S.cerevisiae, that the ordered domain of A.millepora can functionally replace the yeast core region but the disordered domain of the coral protein cannot substitute for its yeast counterpart. Mgm101p is found in the mitochondrial nucleoid along with enzymes and proteins involved in mtDNA replication. By attaching green fluorescent protein to the N-terminal disordered domain of yeast Mgm101p we find that GFP is still directed to the mitochondrial nucleoid where full-length Mgm101p-GFP is targeted

Effect of Intensive Training on Mood With No Effect on Brain-Derived Neurotrophic Factor

Purpose Monitoring mood state is a useful tool for avoiding non-functional overreaching (NFOR). Brain derived neurotrophic factor (BDNF) is implicated in stress-related mood disorders. The purpose of the present study was to investigate the impact of intensified training-induced mood disturbance on plasma BDNF concentrations at rest and in response to exercise.  Methods Eight cyclists performed 1 week of normal (NT), 1 week of intensified (INT) and 1 week of recovery (REC) training. Fasted blood samples were collected before and after exercise, on day 7 of each training week and were analyzed for plasma BDNF and cortisol concentrations. A 24-item Profile Of Mood State questionnaire was administered on day 7 of each training week and global mood score (GMS) was calculated. Results Time trial performance was impaired during INT (p=0.01) and REC (p=0.02) compared with NT. Basal plasma cortisol (NT=153±16 ng/ml, INT=130±11 ng/ml, REC=150±14 ng/ml) and BDNF (NT=484±122 pg/ml, INT=488±122 pg/ml, REC=383±56 pg/ml) concentrations were similar between training conditions. Likewise, similar exercise-induced increases in cortisol and BDNF concentrations were observed between training conditions. GMS was 32% greater during INTvs.NT (P<0.001). Conclusion Consistent with a state of functional overreaching (FOR), impairments in performance and mood state with INT were restored after one week of REC. These results support evidence that mood changes before plasma BDNF concentrations as a biochemical marker of FOR and that cortisol is not a useful marker for predicting FOR

Recovery and performance in sport: Consensus statement

© 2018 Human Kinetics, Inc. The relationship between recovery and fatigue and its impact on performance has attracted the interest of sport science for many years. An adequate balance between stress (training and competition load, other life demands) and recovery is essential for athletes to achieve continuous high-level performance. Research has focused on the examination of physiological and psychological recovery strategies to compensate external and internal training and competition loads. A systematic monitoring of recovery and the subsequent implementation of recovery routines aims at maximizing performance and preventing negative developments such as underrecovery, nonfunctional overreaching, the overtraining syndrome, injuries, or illnesses. Due to the inter- and intraindividual variability of responses to training, competition, and recovery strategies, a diverse set of expertise is required to address the multifaceted phenomena of recovery, performance, and their interactions to transfer knowledge from sport science to sport practice. For this purpose, a symposium on Recovery and Performance was organized at the Technical University Munich Science and Study Center Raitenhaslach (Germany) in September 2016. Various international experts from many disciplines and research areas gathered to discuss and share their knowledge of recovery for performance enhancement in a variety of settings. The results of this meeting are outlined in this consensus statement that provides central definitions, theoretical frameworks, and practical implications as a synopsis of the current knowledge of recovery and performance. While our understanding of the complex relationship between recovery and performance has significantly increased through research, some important issues for future investigations are also elaborated

On the Estimation Stability of Efficiency and Economies of Scale in Microfinance Institutions

This paper uses a panel data set of microfinance institutions (MFI) across the world to compare several identification strategies of cost efficiency and economies of scale. Concretely, we contrast the non-parametric Data Envelopment Analysis (DEA) with the Stochastic Frontier Analysis (SFA) and a distribution-free identification based on time-invariant heterogeneity estimates. Furthermore, we analyze differences of production functions across regions and investigate the relevance of accounting for unobserved heterogeneity across countries. The results suggest that efficiency rankings of MFIs are robust across identification strategies, but highlight the relevance of accounting for unobserved heterogeneity. We further find substantial economies of scale for a pure financial production process. However, accounting for the multi-dimensional production process of MFIs by including a measure of outreach lowers the estimated extent of economies of scale for the parametric estimations, suggesting that producing outreach creates high transaction costs and requires exploitation of local knowledge