Analysing the representativeness of local‐scale palaeodiversity measurements: a case from the Lower Cretaceous plant assemblage of Hautrage (Mons Basin,Belgium)

Two plant fossil‐bearing beds from the middle Barremian of Belgium were analysed to ascertain how experimental designs affect conclusions regarding palaeodiversity at a local scale. We analysed eight lateral samples per bed taken regularly every 3 m using an exhaustive sub‐sampling method. The Clench equation was used to evaluate the completeness of the taxonomic inventory of the samples and the sampling effort needed to obtain a reliable representation of diversity. The number of replicates needed to obtain the same representation of diversity from different nearby lateral samples of the same bed ranged from 5 to 19. Richness (S), Evenness (J) and the number of equiprobable taxa (2^H’) greatly varied between samples from the same bed, even over short distances. Only one of the studied samples was representative of the taxonomic inventory of its bed. Our study shows that 1) the selection bias of the sampling area is reduced by increasing the number of lateral samples taken in a bed, enabling more reliable conclusions about local‐scale diversity; 2) intense sub‐sampling methods are needed to account for statistically independent observations of detailed lateral variation; and 3) sampling methods in palaeodiversity analyses must look for a similar degree of representativeness in samples rather than a homogeneous sample size. Using a sampling effort analysis provides evidence for the completeness of the data set, adjusting the amount of work required. Implementing the Clench equation in palaeodiversity analyses improves the performance of data acquisition in palaeoecological studies and provides a quality test of the data sets derived from them.     

Winter sheltering by juvenile brown trout (Salmo trutta) – effects of stream wood and an instream ectothermic predator

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In situ genotyping of a pooled strain library after characterizing complex phenotypes

In this work, we present a proof‐of‐principle experiment that extends advanced live cell microscopy to the scale of pool‐generated strain libraries. We achieve this by identifying the genotypes for individual cells in situ after a detailed characterization of the phenotype. The principle is demonstrated by single‐molecule fluorescence time‐lapse imaging of Escherichia coli strains harboring barcoded plasmids that express a sgRNA which suppresses different genes in the E. coli genome through dCas9 interference. In general, the method solves the problem of characterizing complex dynamic phenotypes for diverse genetic libraries of cell strains. For example, it allows screens of how changes in regulatory or coding sequences impact the temporal expression, location, or function of a gene product, or how the altered expression of a set of genes impacts the intracellular dynamics of a labeled reporter.     

Field preference of Greylag geese <Emphasis Type="Italic">Anser anser</Emphasis> during the breeding season

Few studies address food preference of geese on agricultural land (utilization related to availability) and only a handful so for the breeding season. We studied Greylag geese Anser anser during the breeding season in an intensively farmed area in southern Sweden. Few of 22 available field types were truly preferred. Pastureland was the most consistently preferred, by goslings (with parents) as well as by non-breeders. In some sampling periods, goslings also preferred grazed hay, ley, and carrot fields. Non-breeders exploited a greater variety of crops/fields, feeding also on barley, fallow, grazed hay, lettuce, oats, potatoes, and carrots. Most of these crops were preferred on at least one sampling occasion, except for fallow, grazed hay, and wheat, which were always used less than expected from availability. GLMs revealed that goslings rested more than they fed and preferred shorter vegetation before higher. Moreover, goslings occurred in higher densities in younger age classes than in older and preferred nearshore areas. In contrast, density of non-breeders was only related to field type and sampling occasion (higher densities as the season progressed). The maximum number of broods observed (106) implies a breeding success of 34% based on 311 active nests earlier in the season. Brood size decreased from 3.5 to 2.1 during the study period. Our study shows that goose management during the breeding season should consider goslings and their parents separately from non-breeders, and it implies little potential conflict between Greylag geese and agriculture during the breeding period.     

Multimodal optical analysis of meningioma and comparison with histopathology

Meningioma is the most frequent primary central nervous system tumor. The risk of recurrence and the prognosis are correlated with the extent of the resection that ideally encompasses the infiltrated dura mater and, if required, the infiltrated bone. No device can deliver real‐time intraoperative histopathological information on the tumor environment to help the neurosurgeon to achieve a gross total removal. This study assessed the abilities of nonlinear microscopy to provide relevant and real‐time data to help resection of meningiomas. Nine human meningioma samples (four World Health Organization Grade I, five Grade II) were analyzed using different optical modalities: spectral analysis and imaging, lifetime measurements, fluorescence lifetime imaging microscopy, fluorescence emitted under one‐ and two‐photon excitation and the second‐harmonic generation signal imaging using a multimodal setup. Nonlinear microscopy produced images close to histopathology as a gold standard. The second‐harmonic generation signal delineated the collagen background and two‐photon fluorescence underlined cell cytoplasm. The matching between fluorescence images and Hematoxylin and Eosin staining was possible in all cases. Grade I meningioma emitted less autofluorescence than Grade II meningioma and Grade II meningioma exhibited a distinct lifetime value. Autofluorescence was correlated with the proliferation rates and seemed to explain the observed differences between Grade I and II meningiomas. This preliminary multimodal study focused on human meningioma samples confirms the potential of tissue autofluorescence analysis and nonlinear microscopy in helping intraoperatively neurosurgeons to reach the actual boundaries of the tumor infiltration.

Correspondence between H&E staining (top pictures) and the two‐photon fluorescence imaging (bottom pictures)     

G-protein-coupled receptor Gpr1 and G-protein Gpa2 of cAMP-dependent signaling pathway are involved in glucose-induced pexophagy in the yeast Saccharomyces cerevisiae

In yeast cell, glucose induces various changes of cellular metabolism on genetic and metabolic levels. One of such changes is autophagic degradation of dispensable peroxisomes (pexophagy) which occurs in vacuoles. We have found that in Saccharomyces cerevisiae, defect of G-protein-coupled receptor Gpr1 and G-protein Gpa2, both the components of cAMP-signaling pathway, strongly suppressed glucose-induced degradation of matrix peroxisomal protein thiolase. We conclude that proteins Gpr1 and Gpa2 are involved in glucose sensing and signal transduction during pexophagy process in yeast.     

CFTR mutations in Turkish and North African cystic fibrosis patients in Europe: implications for screening

AIMS: To obtain more insight into the variability of the CFTR mutations found in immigrant cystic fibrosis (CF) patients who are living in Europe now, and to estimate the test sensitivity of different frequently used methods of DNA analysis to detect CF carriers or patients among these Turkish or North African immigrants. METHODS: A survey among 373 European CF centers asking which CFTR mutations had been found in Turkish and North African CF patients. RESULTS: 31 and 26 different mutations were reported in Turkish and North African patients, identifying 64.2% (113/176) and 87.4% (118/135) alleles, respectively (p < 0.001). The mean sensitivity (detection rate) of three most common CFTR mutation panels to detect these mutations differed between Turkish and North African people, 44.9% (79/176) versus 69.6% (94/135) (p < 0.001), and can be increased to 57.4% (101/176) and 79.3% (107/135) (p < 0.001), respectively, by expanding these panels with 13 mutations which have been found on two or more alleles. CONCLUSION: 35.8% and 12.6%, respectively, of CF alleles in Turkish and North African patients living in Europe now had not been identified. Among these populations, the test sensitivity of common CFTR mutation panels is insufficient for use in screening programs in Europe, even after expansion with frequent Turkish and North African mutations. This raises questions about whether and how to implement CF carrier and neonatal screening in a multiethnic society.