Calcareous dinoflagellate cyst distributions in surface sediments from upwelling areas off NW Africa, and their relationships with environmental parameters of the upper water column

Only very few studies have focussed on the spatial distribution and ecology of calcareous dinoflagellate cysts (dinocysts) in upwelling areas. Here, distributions of individual calcareous dinocyst species in surface sediment samples from the coastal upwelling zone off NW Africa and their relationships with known environmental parameters of the (sub-)surface waters have been analysed in order to enhance our knowledge on their modern distribution patterns and to determine the ecological significance and palaeoenvironmental reconstruction potential of each calcareous dinocyst species within this exemplary high-productivity region. In addition to calculating relative cyst abundances, well-constrained sedimentation rates have allowed the calculation of dinocyst accumulation rates (cysts cm^− 2 ka^− 1) for most of the surface sample positions, thus providing a much more accurate estimation of actual calcareous dinocyst production in the upper water column than could be warranted in similar studies so far. Distinct differences in the geographic distribution patterns of nine species were observed. In general, high accumulation rates of calcareous dinocysts were found around and south of 29°N and offshore the westernmost Canary Island La Palma, with slightly lower accumulation rates in the upwelling-influenced areas off Cape Yubi and in the upwelling filament area off Cape Ghir. Multivariate ordination techniques were applied in order to compare the cyst accumulation rates of individual species with physical parameters (temperature, salinity, density, mixed layer depth) and the trophic state (nitrate, phosphate and chlorophyll concentrations) of the overlying (sub-)surface waters. All species were found to relate significantly to one or more of the environmental parameters, partly confirming previous results on cyst ecology but also providing new information which will be useful for future palaeoenvironmental reconstructions within upwelling areas.     

Differential recombination dynamics within the MHC of macaque species

A panel of 15 carefully selected microsatellites (short tandem repeats, STRs) has allowed us to study segregation and haplotype stability in various macaque species. The STRs span the major histocompatibility complex (MHC) region and map in more detail from the centromeric part of the Mhc-A to the DR region. Two large panels of Indian rhesus and Indonesian/Indochinese cynomolgus macaques have been subjected to pedigree analysis, allowing the definition of 161 and 36 different haplotypes and the physical mapping of 10 and 5 recombination sites, respectively. Although most recombination sites within the studied section of the Indian rhesus monkey MHC are situated between the Mhc-A and Mhc-B regions, the resulting recombination rate for this genomic segment is low and similar to that in humans. In contrast, in Indonesian/Indochinese macaques, two recombination sites, which appear to be absent in rhesus macaques, map between the class III and II regions. As a result, the mean recombination frequency of the core MHC, Mhc-A to class II, is higher in Indonesian/Indochinese cynomolgus than in Indian rhesus macaques, but as such is comparable to that in humans. The present communication demonstrates that the dynamics of recombination ‘hot/cold spots’ in the MHC, as well as their frequencies, may differ substantially between highly related macaque species.     

4-Phenylbutyrate Inhibits Tunicamycin-Induced Acute Kidney Injury via CHOP/GADD153 Repression

Different forms of acute kidney injury (AKI) have been associated with endoplasmic reticulum (ER) stress; these include AKI caused by acetaminophen, antibiotics, cisplatin, and radiocontrast. Tunicamycin (TM) is a nucleoside antibiotic known to induce ER stress and is a commonly used inducer of AKI. 4-phenylbutyrate (4-PBA) is an FDA approved substance used in children who suffer from urea cycle disorders. 4-PBA acts as an ER stress inhibitor by aiding in protein folding at the molecular level and preventing misfolded protein aggregation. The main objective of this study was to determine if 4-PBA could protect from AKI induced by ER stress, as typified by the TM-model, and what mechanism(s) of 4-PBA''s action were responsible for protection. C57BL/6 mice were treated with saline, TM or TM plus 4-PBA. 4-PBA partially protected the anatomic segment most susceptible to damage, the outer medullary stripe, from TM-induced AKI. In vitro work showed that 4-PBA protected human proximal tubular cells from apoptosis and TM-induced CHOP expression, an ER stress inducible proapoptotic gene. Further, immunofluorescent staining in the animal model found similar protection by 4-PBA from CHOP nuclear translocation in the tubular epithelium of the medulla. This was accompanied by a reduction in apoptosis and GRP78 expression. CHOP^−/− mice were protected from TM-induced AKI. The protective effects of 4-PBA extended to the ultrastructural integrity of proximal tubule cells in the outer medulla. When taken together, these results indicate that 4-PBA acts as an ER stress inhibitor, to partially protect the kidney from TM-induced AKI through the repression of ER stress-induced CHOP expression.     

Genotypic selection shapes patterns of within-species diversity in experimental plant populations

1.  An increasing body of evidence suggests that within-species diversity plays an important role for community and ecosystem functioning, alters complex trophic interactions and affects patterns of species diversity and coexistence. Nonetheless, we lack a good understanding of how genotypic trait variation translates into shifts in the relative abundance of genotypes within populations.
2.  In this study, we show that genotypic selection strongly alters dominance relationships among genotypes over a period of 5 years. This resulted in remarkably consistent changes in the proportional representation of genotypes, and in a concomitant decline of diversity and evenness in our experimental populations.
3.  High growth rates and the production of large offspring were positively associated with genotypic performance. Vegetative abundances of genotypes translated monotonically into flowering frequencies.
4.   Synthesis . We conclude that genotypic selection markedly affects patterns of diversity and consistently alters genotypic abundance and mean trait distributions in plant populations over a relatively short period of time.     

Cultural Identity Among Afghan and Iraqi Traumatized Refugees: Towards a Conceptual Framework for Mental Health Care Professionals

Cultural identity in relation with mental health is of growing interest in the field of transcultural psychiatry. However, there is a need to clarify the concept of cultural identity in order to make it useful in clinical practice. The purpose of this study is to unravel the complexity and many layers of cultural identity, and to assess how stress and acculturation relate to (changes in) cultural identity. As part of a larger study about cultural identity, trauma, and mental health, 85 patients from Afghanistan and Iraq in treatment for trauma-related disorders were interviewed with a Brief Cultural Interview. The interviews were analysed through qualitative data analysis using the procedures of grounded theory. The analysis resulted in three domains of cultural identity: personal identity, ethnic identity and social identity. Within each domain relationships with stress and acculturation were identified. The results offer insight into the intensity of changes in cultural identity, caused by pre-and post-migration stressors and the process of acculturation. Based on the research findings recommendations are formulated to enhance the cultural competency of mental health workers.