Dinoflagellate cyst biostratigraphy of the Opalinuston Formation (Middle Jurassic) in the Aalenian type area in southwest Germany and north Switzerland

Feist‐Burkhardt, S. & Pross, J. 2010: Dinoflagellate cyst biostratigraphy of the Opalinuston Formation (Middle Jurassic) in the Aalenian type area in southwest Germany and north Switzerland. Lethaia, Vol. 43, pp. 10–31. In order to provide a detailed dinoflagellate cyst stratigraphy of the Lower Aalenian Opalinuston Formation from the Aalenian type area, 68 samples from four boreholes and one outcrop section were analysed. The sample localities are Hausen an der Fils and Wittnau in southwest Germany, Weiach in north Switzerland and Mont Russelin in the Swiss Jura Mountains. Dinoflagellate cyst assemblages were recovered from the Late Toarcian Aalensis Zone to the Late Aalenian Murchisonae Zone. The samples yielded rich, well‐preserved and diverse assemblages with 51 dinoflagellate cyst taxa identified in total. The dinoflagellate cyst distribution data obtained from this study allow a high‐resolution biostratigraphical subdivision of the lowermost Middle Jurassic Opalinuston Formation into four palynostratigraphical units. First and last occurrences, acmes and consistent presence of the species Batiacasphaera sp. A, Evansia cf. granochagrinata, Kallosphaeridium praussii, Nannoceratopsis triangulata, Phallocysta? frommernensis and Wallodinium laganum were selected as the criteria for defining these units. The obtained high‐resolution palynostratigraphical scheme provides a basis for establishing and further refining early Middle Jurassic biostratigraphy in the Boreal and Tethyan realms. □Aalenian, biostratigraphy, dinoflagellate cysts, Germany, Jurassic, Switzerland, Toarcian.     

Prevalencia del consumo de fármacos psicoactivos en una población de obesos

ObjectiveTo establish the prevalence of psychoactive drug consumption in an obese population.Material and methodsWe collected data from the clinical records of obese patients attending the Endocrinology and Nutrition Department and Psychiatry Department of Hospital del Mar between June 2005 and May 2006 (n=259). We recorded anthropometric, epidemiological and toxicological data. We also investigated the prevalence of concomitant diseases in this population.ResultsPsychoactive drugs were consumed by 37% of obese patients, mainly antidepressants (27%), anxiolytics, sedatives and hypnotics, and anticonvulsants. Moreover, 15% of all patients received combination treatment with two or more psychoactive drugs, mostly the association of an antidepressant and an antiepileptic drug.ConclusionThe prevalence of psychoactive drug consumption in our sample was higher than prevalence data observed in the general population, with antidepressant consumption being three-fold higher.     

Analysis of the mitochondrial genome of Schistocerca gregaria gregaria (Orthoptera: Acrididae)

In the present study, we present the full sequence of the mitochondrial genome of the African desert locust Schistocerca gregaria gregaria. The size of 15625 bp reported matches very well with mitochondrial genomes of other Orthopteriodea. The mitochondrial genome comprises 13 protein‐coding genes, two ribosomal RNAs and 22 t‐RNAs with two t‐RNA (trnD and trnK) rearrangements that are typical for the taxon Caelifera. We compared the sequence with 12 mitochondrial genes of Schistocerca gregaria flaviventris and Schistocerca americana and used some of these data to construct phylogenetic trees, which confirm the close relationship between the two subspecies S. g. flaviventris and S. g. gregaria. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 296–305.     

Genetic variation and structure in the Mediterranean shrubs Myrtus communis and Pistacia lentiscus in different landscape contexts

Studies concerning different habitat configurations can provide insights into the complex interactions between species’ life‐history traits and the environment and can help to predict patterns in population genetics. In this study, we compared patterns of genetic variation in two Mediterranean shrub species (Myrtus communis and Pistacia lentiscus) that co‐occur in populations within three contrasting landscape contexts: continuous, fragmented‐connected and fragmented‐isolated populations. Analysing variation at microsatellites loci, our results revealed weak responses to the landscape contexts. We rather found a population‐specific response in both study species. However, despite both study species sharing similar levels of genetic diversity, Myrtus displayed higher levels of homozygosity and genetic differentiation among populations, stronger patterns of within‐population spatial genetic structure, lower values of mutation‐scaled effective population size and stronger evidence for recent genetic bottlenecks than Pistacia. This result highlights the influence of past events (e.g. historical connectivity, fluctuations in population size) and local factors (e.g. microhabitat availability for recruitment, habitat quality, plant density, native fauna) and that the landscape configuration per se (i.e. fragment size and/or isolation) might not completely determine the species’ genetic patterns.     

Fragmentation and comparative genetic structure of four mediterranean woody species: complex interactions between life history traits and the landscape context

Aim The effect of habitat fragmentation on population genetic structure results from the interaction between species’ life history traits and the particular landscape context, and both components are inherently difficult to tease apart. Here, we compare the genetic (allozyme) structure of four co‐occurring woody species with contrasting life histories to explore how well their response to the same fragmentation process can be predicted from their functional traits. Location A highly fragmented forest landscape located in the lower Guadalquivir catchment, south‐western Spain. Methods We sampled four species (Cistus salviifolius, Myrtus communis, Pistacia lentiscus and Quercus coccifera) from the same 23 forest fragments known to form a representative array of habitat characteristics in the region. We assessed genetic diversity (A, H_e and N_g) and differentiation (F_IS and F_ST) for each species and explored their potential drivers using a model‐selection approach with four fragment features (size, historical and current connectivity, and stability) as predictor variables. Results Regional‐scale genetic diversity increased from the shortest‐lived to the longest‐lived species, while population differentiation of the self‐compatible species was roughly double that of the three self‐incompatible species. Fragment size was the only feature that did not consistently affect the genetic diversity of local populations across all species. Three species showed signs of being affected by fragmentation, yet each responded differently to the set of fragment features considered. We observed several trends that were at odds with simple life history‐based predictions but could arise from patterns of gene flow and/or local‐scale demographic processes. Main conclusions Our comparative study of various landscape features and species underscores that the same fragmentation process can have very different, and complex, consequences for the population genetic structure of plants. This idiosyncrasy renders generalizations across natural systems very difficult and highlights the need of context‐oriented guidelines for an efficient conservation management of species‐rich landscapes.     

Modeling brewers' yeast flocculation

Flocculation of yeast cells occurs during the fermentation of beer. Partway through the fermentation the cells become flocculent and start to form flocs. If the environmental conditions, such as medium composition and fluid velocities in the tank, are optimal, the flocs will grow in size large enough to settle. After settling of the main part of the yeast the green beer is left, containing only a small amount of yeast necessary for rest conversions during the next process step, the lagering. The physical process of flocculation is a dynamic equilibrium of floc formation and floc breakup resulting in a bimodal size distribution containing single cells and flocs. The floc size distribution and the single cell amount were measured under the different conditions that occur during full scale fermentation. Influences on flocculation such as floc strength, specific power input, and total number of yeast cells in suspension were studied. A flocculation model was developed, and the measured data used for validation. Yeast floc formation can be described with the collision theory assuming a constant collision efficiency. The breakup of flocs appears to occur mainly via two mechanisms, the splitting of flocs and the erosion of yeast cells from the floc surface. The splitting rate determines the average floc size and the erosion rate determines the number of single cells. Regarding the size of the flocs with respect to the scale of turbulence, only the viscous subrange needs to be considered. With the model, the floc size distribution and the number of single cells can be predicted at a certain point during the fermentation. For this, the bond strength between the cells, the fractal dimension of the yeast, the specific power input in the tank and the number of yeast cells that are in suspension in the tank have to be known. Copyright 1998 John Wiley & Sons, Inc.     

Phylogeny of the reptilian Eimeria: are Choleoeimeria and Acroeimeria valid generic names?

Reptiles are the animals with the most described coccidian species among all vertebrates. However, the co‐evolutionary relationships in this host–parasite system have been scarcely studied. Paperna & Landsberg (South African Journal of Zoology, 24, 1989, 345) proposed the independent evolutionary origin of the Eimeria‐like species isolated from reptiles based on morphological and developmental characteristics of their oocysts. Accordingly, they suggested the reclassification of these parasites in two new genera, Choleoeimeria and Acroeimeria. The validity of the genera proposed to classify reptilian Eimeria species remained unresolved due to the lack of species genetically characterized. In this study, we included 18S rRNA gene sequences from seven Eimeria‐like species isolated from five different lizard host families. The phylogenetic analyses confirmed the independent evolutionary origin of the Eimeria‐like species infecting lizards. Within this group, most species were placed into two monophyletic clades. One of them included the species with ellipsoidal oocysts (i.e. Choleoeimeria‐like oocysts), whereas the species with more spheroidal oocysts (i.e. Acroeimeria‐like oocysts) were included in the second one. This result supports the taxonomic validity of the genera Acroeimeria and Choleoeimeria.     

Delphi-consensus weights for ischemic and bleeding events to be included in a composite outcome for RCTs in thrombosis prevention

Background and Objectives

To weight ischemic and bleeding events according to their severity to be used in a composite outcome in RCTs in the field of thrombosis prevention.

Method

Using a Delphi consensus method, a panel of anaesthesiology and cardiology experts rated the severity of thrombotic and bleeding clinical events. The ratings were expressed on a 10-point scale. The median and quartiles of the ratings of each item were returned to the experts. Then, the panel members evaluated the events a second time with knowledge of the group responses from the first round. Cronbach''s a was used as a measure of homogeneity for the ratings. The final rating for each event corresponded to the median rating obtained at the last Delphi round.

Results

Of 70 experts invited, 32 (46%) accepted to participate. Consensus was reached at the second round as indicated by Cronbach''s a value (0.99 (95% CI 0.98-1.00)) so the Delphi was stopped. Severity ranged from under-popliteal venous thrombosis (median = 3, Q1 = 2; Q3 = 3) to ischemic stroke or intracerebral hemorrhage with severe disability at 7 days and massive pulmonary embolism (median = 9, Q1 = 9; Q3 = 9). Ratings did not differ according to the medical specialty of experts.

Conclusions

These ratings could be used to weight ischemic and bleeding events of various severity comprising a composite outcome in the field of thrombosis prevention.