Appearance and disappearance of the second Born effects in the (e,3e) reaction in He

We demonstrate, both experimentally and theoretically, clear manifestation of the second Born effects in the angular distributions of two ejected electrons produced by a 500 eV electron impact on the He atom in the so-called (e,3e) reaction. The second Born contribution, due to subsequent interaction of the projectile with the target, is most prominent for glancing collisions with small momentum transfer. However, these effects are absent for hard knock-out collisions with large momentum transfer

Phylogeographic reconstruction of the marbled crayfish origin

The marbled crayfish (Procambarus virginalis) is a triploid and parthenogenetic freshwater crayfish species that has colonized diverse habitats around the world. Previous studies suggested that the clonal marbled crayfish population descended as recently as 25 years ago from a single specimen of P. fallax, the sexually reproducing parent species. However, the genetic, phylogeographic, and mechanistic origins of the species have remained enigmatic. We have now constructed a new genome assembly for P. virginalis to support a detailed phylogeographic analysis of the diploid parent species, Procambarus fallax. Our results strongly suggest that both parental haplotypes of P. virginalis were inherited from the Everglades subpopulation of P. fallax. Comprehensive whole-genome sequencing also detected triploid specimens in the same subpopulation, which either represent evolutionarily important intermediate genotypes or independent parthenogenetic lineages arising among the sexual parent population. Our findings thus clarify the geographic origin of the marbled crayfish and identify potential mechanisms of parthenogenetic speciation

Functional magnetic resonance imaging outcomes from a comprehensive magnetic resonance study of children with fetal alcohol spectrum disorders

A comprehensive neuropsychological/psychiatric, MR imaging, (MRI), MR spectroscopy (MRS), and functional MRI (fMRI) assessment was administered to children with fetal alcohol spectrum disorders (FASD) to determine if global and/or focal abnormalities could be identified, and distinguish diagnostic subclassifications across the spectrum. The four study groups included: 1. FAS/Partial FAS; 2. Static Encephalopathy/Alcohol Exposed (SE/AE); 3. Neurobehavioral Disorder/Alcohol Exposed (ND/AE); and 4. healthy peers with no prenatal alcohol exposure. fMRI outcomes are reported here. The neuropsychological/psychiatric, MRI, and MRS outcomes are reported separately. fMRI was used to assess activation in seven brain regions during performance of N-back working memory tasks. Children across the full spectrum of FASD exhibited significant working memory deficits and altered activation patterns in brain regions that are known to be involved in working memory. These results demonstrate the potential research and diagnostic value of this non-invasive MR tool in the field of FASD

Cyclin H expression is increased in GIST with very-high risk of malignancy

<p>Abstract</p> <p>Background</p> <p>Risk estimation of gastrointestinal stromal tumours (GIST) is based on tumour size and mitotic rate according to the National Institutes of Health consensus classification. The indication for adjuvant treatment of patients with high risk GIST after R₀resection with small molecule inhibitors is still a controversial issue, since these patients represent a highly heterogeneous population. Therefore, additional prognostic indicators are needed. Here, we evaluated the prognostic value of cyclin H expression in GIST.</p> <p>Methods</p> <p>In order to identify prognostic factors of GIST we evaluated a single centre cohort of ninety-five GIST patients. First, GISTs were classified with regard to tumour size, mitotic rate and localisation according to the NIH consensus and to three additional suggested risk classifications. Second, Cyclin H expression was analysed.</p> <p>Results</p> <p>Of ninety-five patients with GIST (53 female/42 male; median age: 66.78a; range 17-94a) risk classification revealed: 42% high risk, 20% intermediate risk, 23% low risk and 15% very low risk GIST. In patients with high risk GIST, the expression of cyclin H was highly predictive for reduced disease-specific survival (p = 0.038). A combination of cyclin H expression level and high risk classification yielded the strongest prognostic indicator for disease-specific and disease-free survival (p ≤ 0.001). Moreover, in patients with tumour recurrence and/or metastases, cyclin H positivity was significantly associated with reduced disease-specific survival (p = 0.016) regardless of risk-classification.</p> <p>Conclusion</p> <p>Our data suggest that, in addition to high risk classification, cyclin H expression might be an indicator for "very-high risk" GIST.</p

Fluvial sediment supply to a mega-delta reduced by shifting tropical-cyclone activity

© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. The world's rivers deliver 19 billion tonnes of sediment to the coastal zone annually, with a considerable fraction being sequestered in large deltas, home to over 500 million people. Most (more than 70 per cent) large deltas are under threat from a combination of rising sea levels, ground surface subsidence and anthropogenic sediment trapping, and a sustainable supply of fluvial sediment is therefore critical to prevent deltas being 'drowned' by rising relative sea levels. Here we combine suspended sediment load data from the Mekong River with hydrological model simulations to isolate the role of tropical cyclones in transmitting suspended sediment to one of the world's great deltas. We demonstrate that spatial variations in the Mekong's suspended sediment load are correlated (r = 0.765, P < 0.1) with observed variations in tropical-cyclone climatology, and that a substantial portion (32 per cent) of the suspended sediment load reaching the delta is delivered by runoff generated by rainfall associated with tropical cyclones. Furthermore, we estimate that the suspended load to the delta has declined by 52.6 ± 10.2 megatonnes over recent years (1981-2005), of which 33.0 ± 7.1 megatonnes is due to a shift in tropical-cyclone climatology. Consequently, tropical cyclones have a key role in controlling the magnitude of, and variability in, transmission of suspended sediment to the coast. It is likely that anthropogenic sediment trapping in upstream reservoirs is a dominant factor in explaining past, and anticipating future, declines in suspended sediment loads reaching the world's major deltas. However, our study shows that changes in tropical-cyclone climatology affect trends in fluvial suspended sediment loads and thus are also key to fully assessing the risk posed to vulnerable coastal systems

Transkriptionsanalytische und immunhistochemische Untersuchung zellzyklusassoziierter Gene in Gastrointestinalen Stromatumoren unter besonderer Berücksichtigung des prädiktiven Werts von Cyclin H

Background: Lacking better indicators, risk estimation of gastrointestinal stromal tumors (GIST) is still based on tumor size and mitotic rate. The indication for adjuvant treatment of patients with high risk GIST after R0 resection is a controversial issue, since these patients represent a highly heterogeneous population. Therefore, the discovery of additional prognostic markers is of great importance. Aim of the work in hand is to find new indicators by investigating the cyclin-cdk-system as well as the MAPK- and p53-signaling pathways. Methods: In order to detect expression-alterations in the large number of GIST-signaling associated genes, quantitative real-time PCRs (qRT-PCR) of 16 tissue samples were conducted. After evaluation of the results cyclin H was selected for further investigation: Its expression and prognostic value was examined in a single center cohort of 92 GIST patients by immunochemical staining. Results: The qRT-PCRs showed increased transcription levels for several cyclins (A2, B1, B2, E1, H) in the course of tumor progression as well as in tumors with high risk grading. In contrast to these findings, the transcription of inhibitors of the cyclin-cdk-system (CDKN1B & C, CDKN2A & B, RKCA) was reduced. The classification of the immunohistochemistry cohort (n = 92) revealed the following distribution: 41.1% high, 21.1% intermediate, 22.2% low and 15.5% very low risk GIST. In patients with high risk GIST, the expression of cyclin H was highly predictive for reduced disease-specific survival (p = 0.032). A combination of cyclin H expression status and high risk classification yielded the strongest prognostic value for disease-specific and disease-free survival (p kleiner/gleich 0.001). Conclusion: Our data suggest that the cyclin-cdk-system may play an important role in GIST pathophysiology. Moreover, in addition to high risk classification, cyclin H expression might be an indicator for "very-high risk" GIST