A number of improvement proposals and corrections of the German Rili-BAEK (Guideline of the German Medical Association on Quality Assurance in Medical Laboratory Examinations) are discussed with ...special focus on the internal and external quality assurance (IQA/EQA) as well as reference intervals for quantitative results. Particular attention is paid to reconsider the retrospective analysis of control measurements. Such an analysis can be very useful to monitor establishing errors of measurement even before they become critical. The present method “Quadratischer Mittelwert der Messabweichung (QMMA)” has proved to be ineffective. Furthermore, the current idea of a common limit for single control measures and the retrospective statistics must be revised. As a more sophisticated concept, the novel Adaptive Retrospective Monitoring (ARM) has been developed. ARM is recommended as the new minimum requirement for the entire internal quality assurance. Further proposals to enhance clarity are given concerning the release decisions of medical devices and the EQA. Individualized medicine begins with a patient-specific interpretation of analytic results. This requires standardized subgroup-specific reference intervals with smooth age-related adaptations. Only large laboratories are able to ensure the desired specificity and a sufficient statistical significance of self-developed in-laboratory reference intervals. Hence, the need of a central database for harmonized reference intervals is discussed and recommended. Suitable and consistent reference intervals are also an essential prerequisite for unitless laboratory values like the zlog value.
We present the first record of Leptophis ahaetulla for the State of Rio Grande do Sul, Brazil. Between November and December 2014, and February 2015, three specimens were found, respectively: one ...male dead on a highway at the Parque Estadual do Espinilho, a conservation unit located at the municipality of Barra do Quaraí; and two females collected in an anthropic landscape of Salso farm at the municipality of Uruguaiana, Rio Grande do Sul, Brazil. Meristic data and coloration enables the identification of these specimens as Leptophis ahaetulla marginatus.
Importance of the field: Current computational docking methods are often effective in predicting accurate drug-binding geometries in cases of relatively rigid target structures. However, binding of ...drug-like ligands to protein receptor molecules frequently involves or even requires conformational adaptation. Realistic prediction of ligand-receptor binding geometries and complex stability needs in many cases an appropriate inclusion of conformational changes, not only for the ligand, but also for the receptor molecule.
Areas covered in this review: Recent approaches to efficiently account for target receptor flexibility during docking simulations are reviewed.
What the reader will gain: The reader will gain insights into methods to efficiently treat protein side-chain flexibility and approaches for continuous adaptation of backbone conformations in pre-calculated essential or soft collective degrees of freedom. In addition, molecular dynamics or Monte Carlo based methods providing simultaneous inclusion of receptor and ligand flexibility are discussed as well as promising new developments to generate conformationally diverse ensembles of a protein structure. The large variety of possible conformational changes in proteins on ligand binding is illustrated for the enzyme reverse transcriptase of HIV-1, which is an important drug target.
Take home message: If the backbone conformation of the binding site does not change, current docking programs can perform well by taking side-chain reorientations into account only. Future progress to account for full target flexibility in docking requires both accurate prediction of the essential modes of backbone motion and improvements in scoring to enhance selectivity. Thus, the scoring function should realistically cover energetic and particularly entropic contributions to binding, which would allow more realistic estimates of binding free energies.
Increasing evidence demonstrates a role for the cross-habitat spillover process in the maintenance of biodiversity in managed agricultural landscapes. However, the mechanisms that drive this process ...are less well understood. In particular, it is critical to know how landscape structure modulates spillover movements, and whether species are moving through the matrix to acquire resources or simply to disperse between habitat fragments. We tested landscape effects and food resource use within cattle pasture matrices. We used mist-nets to collect data on avian communities across 51 sampling sites, spanning a forest cover gradient. We additionally integrated stable isotopic analysis (δ13C signature) to determine the provenance of resources used (either forest - dominated by C3 plants; or pasture, dominated by C4). Bird movement across pasture matrices was extremely reduced, and bird occupation was concentrated near forest edges. There was a clear distinction of resource use according to species’ habitat preferences, with forest-species foraging predominantly in-forests, open-area species in pastures, and generalist species having more varied diets, but still relying on a large proportion of C3 sources. Forest cover was unrelated to avian spillover from forests into pastures, but positively related to C3 signatures for both forest and open-area associated species. Finally, we found that most birds moving from forests to pastures were habitat generalists (63%), and that pastures work as a barrier for forest-associated species movement. Landscapes dominated by pasture are very unfavorable to the conservation of forest species, but potentially can maintain ecosystem services from the spillover of generalist species.
•Pasture matrices drastically reduces avian movement in fragmented landscapes•Habitat cover and isolation influences avian resource use in fragmented landscapes•Habitat-generalist bird species compose the majority of movement events across pastures•Habitat-generalists are effective foraging-related ecosystem service agents in high-contrasting matrices•Stable isotopes in landscape-level studies may improve our understanding of ecological processes in fragmented landscapes
Herein we report improved chemo- and enantioselective hydrogenations of 1-(2,2,4-trimethylquinolin-1(2H)-yl)ethan-1-one (1) toward (R)-1-(2,2,4-trimethyl-3,4-dihydroquinolin-1(2H)-yl)ethan-1-one ...(2) using well-defined novel Crabtree-type iridium complexes.
Natural history collections (NHCs) contain valuable information that can be used in different fields of knowledge, and aid in the development of society, science, and technology. The role of curators ...and taxonomists in maintaining and improving biological collections is essential, as these are fundamental for the understanding of biodiversity. However, the role of taxonomists and the importance of NHCs to society have been undervalued in recent years. We, while attending a graduate program on collections at PUCRS, noted a gap in knowledge about scientific collections. Was this gap, which continued from our undergraduate to graduate years, a mere coincidence or widespread in biological science programs in Brazil? We queried 126 Brazilian institutions of higher education to assess the presence of courses related to natural-history collections and taxonomy. A total of 25 private and 37 public universities from 126 institutions searched, have a program of study in biological sciences in the curriculum on their websites. About 16% offer some course related to NHCs or taxonomy, and all of them are public institutions. Despite the budget cutting made by the Brazilian government that make it even more difficult to recognize NHCs and related areas, we believe that there should be more links among researchers from different areas and especially between the levels of basic and higher education, so that students are exposed to this subject early in their education. We, as Brazilian students, believe that more information on NHC-related issues and taxonomic subjects is urgently needed in biological science programs.
ABSTRACT Natural history collections (NHCs) contain valuable information that can be used in different fields of knowledge, and aid in the development of society, science, and technology. The role of ...curators and taxonomists in maintaining and improving biological collections is essential, as these are fundamental for the understanding of biodiversity. However, the role of taxonomists and the importance of NHCs to society have been undervalued in recent years. We, while attending a graduate program on collections at PUCRS, noted a gap in knowledge about scientific collections. Was this gap, which continued from our undergraduate to graduate years, a mere coincidence or widespread in biological science programs in Brazil? We queried 126 Brazilian institutions of higher education to assess the presence of courses related to natural-history collections and taxonomy. A total of 25 private and 37 public universities from 126 institutions searched, have a program of study in biological sciences in the curriculum on their websites. About 16% offer some course related to NHCs or taxonomy, and all of them are public institutions. Despite the budget cutting made by the Brazilian government that make it even more difficult to recognize NHCs and related areas, we believe that there should be more links among researchers from different areas and especially between the levels of basic and higher education, so that students are exposed to this subject early in their education. We, as Brazilian students, believe that more information on NHC-related issues and taxonomic subjects is urgently needed in biological science programs.
Electron paramagnetic resonance (EPR) spectroscopy using site-directed spin-labeling is an appropriate technique to analyze the structure and dynamics of flexible protein regions as well as ...protein-protein interactions under native conditions. The analysis of a set of protein mutants with consecutive spin-label positions leads to the identification of secondary and tertiary structure elements. In the first place, continuous-wave EPR spectra reflect the motional freedom of the spin-label specifically linked to a desired site within the protein. EPR spectra calculations based on molecular dynamics (MD) and stochastic dynamics simulations facilitate verification or refinement of predicted computer-aided models of local protein conformations. The presented spectra simulation algorithm implies a specialized in vacuo MD simulation at 600
K with additional restrictions to sample the entire accessible space of the bound spin-label without large temporal effort. It is shown that the distribution of spin-label orientations obtained from such MD simulations at 600
K agrees well with the extrapolated motion behavior during a long timescale MD at 300
K with explicit water. The following potential-dependent stochastic dynamics simulation combines the MD data about the site-specific orientation probabilities of the spin-label with a realistic rotational diffusion coefficient yielding a set of trajectories, each more than 700
ns long, essential to calculate the EPR spectrum. Analyses of a structural model of the loop between helices E and F of bacteriorhodopsin are illustrated to demonstrate the applicability and potentials of the reported simulation approach. Furthermore, effects on the motional freedom of bound spin-labels induced by solubilization of bacteriorhodopsin with Triton X-100 are examined.
Gray-hooded Gull, Chroicocephalus cirrocephalus (Vieillot, 1818), is distributed across South America and considered a resident, with individuals in their non-breeding period able to disperse over ...long distances. We report the first records of this species from the state of Espírito Santo, the only state on the Brazilian coast without previous records. We suggest that the geographical distribution of this species is expanding along the Brazilian coast, in accordance with what has been previously suggested for Gray-hooded Gull.
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