Measures of nutrient processes as indicators of stream ecosystem health

To better understand how freshwater ecosystems respond to changes in catchment land-use, it is important to develop measures of ecological health that include aspects of both ecosystem structure and function. This study investigated measures of nutrient processes as potential indicators of stream ecosystem health across a land-use gradient from relatively undisturbed to highly modified. A total of seven indicators (potential denitrification; an index of denitrification potential relative to sediment organic matter; benthic algal growth on artificial substrates amended with (a) N only, (b) P only, and (c) N and P; and delta N-15 of aquatic plants and benthic sediment) were measured at 53 streams in southeast Queensland, Australia. The indicators were evaluated by their response to a defined gradient of agricultural land-use disturbance as well as practical aspects of using the indicators as part of a monitoring program. Regression models based on descriptors of the disturbance gradient explained a large proportion of the variation in six of the seven indicators. Denitrification index, algal growth in N amended substrate, and delta N-15 of aquatic plants demonstrated the best regression. However, the delta N-15 value of benthic sediment was found to be the best indicator overall for incorporation into a monitoring program, as samples were relatively easy to collect and process, and were successfully collected at more than 90% of the study sites

Multi tyrosine kinase inhibitor dasatinib as novel cause of severe pre-capillary pulmonary hypertension?

<p>Abstract</p> <p>Background</p> <p>Pulmonary hypertension (PH) is a life-threatening disease with poor prognosis. Encouraging efforts have been made to target the main vasoproliferative aspects of the disease. Promising emerging therapeutics are tyrosine kinase inhibitors such as imatinib.</p> <p>Case presentation</p> <p>Here, we discuss the relevance of previously published cases and add another well-characterised patient who developed pre-capillary PH under long-term therapy with the multi-tyrosine kinase inhibitor dasatinib approved for therapy of chronic myeloic leukaemia (CML) and Philadelphia chromosome positive acute lymphocytic leukaemia (mean time of all patients on dasatinib: 26 months). Hence, we discuss the possibility of dasatinib itself causing PH after long-term therapy and turn specialist's attention to this possible severe side effect.</p> <p>At present, the true incidence of dasatinib-associated PH remains illusive and systematic data regarding haemodynamics are missing.</p> <p>Conclusion</p> <p>We therefore recommend systematic screening of dasatinib-treated patients for pulmonary hypertension and subsequent collection of haemodynamic data.</p

Properties of Rubble-Pile Asteroid (101955) Bennu from OSIRIS-REx Imaging and Thermal Analysis

Establishing the abundance and physical properties of regolith and boulders on asteroids is crucial for understanding the formation and degradation mechanisms at work on their surfaces. Using images and thermal data from NASA's Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft, we show that asteroid (101955) Bennu's surface is globally rough, dense with boulders, and low in albedo. The number of boulders is surprising given Bennu's moderate thermal inertia, suggesting that simple models linking thermal inertia to particle size do not adequately capture the complexity relating these properties. At the same time, we find evidence for a wide range of particle sizes with distinct albedo characteristics. Our findings imply that ages of Bennu's surface particles span from the disruption of the asteroid's parent body (boulders) to recent in situ production (micrometre-scale particles)

The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements

The top-shaped morphology characteristic of asteroid (101955) Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission. Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, we find a notable transition in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface. As the intersection of the rotational Roche lobe with Bennu’s surface has been most recently migrating towards its equator (given Bennu’s increasing spin rate), we infer that Bennu’s surface slopes have been changing across its surface within the last million years. We also find evidence for substantial density heterogeneity within this body, suggesting that its interior is a mixture of voids and boulders. The presence of such heterogeneity and Bennu’s top shape are consistent with spin-induced failure at some point in its past, although the manner of its failure cannot yet be determined. Future measurements by the OSIRIS-REx spacecraft will provide insight into and may resolve questions regarding the formation and evolution of Bennu’s top-shape morphology and its link to the formation of binary asteroids

Evidence for widespread hydrated minerals on asteroid (101955) Bennu

Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM-type carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of metres observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu’s spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth

Modelling and experimental investigation of engine performance and emissions fuelled with biodiesel produced from Australian Beauty Leaf Tree

This study first experimentally investigates the performance and exhausts emissions of a compression ignition (CI) engine fuelled with biodiesel produced from Australian beauty leaf tree (BLT) oil and compares these results with that of petroleum diesel. Then, an engine combustion model is developed using computational fluid dynamics (CFD) software, AVL Fire, to predict the engine performance and emission of those biodiesels and petroleum diesel. Experiments were done according to ISO 8178 standard enginetest procedure using B5 biodiesel (5% BLT blend), B10 (10% BLT blend) and petroleum diesel in a 4-cylinderengine test-bed equipped with necessary dynamometer and sensors. The measurements were done for engine power, torque, specific fuel consumption and engine emissions. The combustion model is validated with the experimentally measured data, which shows very good agreement between them, more specifically variation of only up to 4.4% in power, 4.0% in torque and 3.3% in specific fuel consumption was found. The experimental results show that overall B10 biodiesel provides significantly reducedengine emissions, up to 18% compared to petroleum diesel. The validated model is then used to optimise the engine performance and emissions as a function of operating parameters such as ignition timing, crank angles and compression ratios. The simulation results show that B10 provides a slight improvement in performance and significant reduction in emission. It is believed that this paper provides a solid base of new knowledge towards achieving a sustainable BLT biodiesel industry

Das Ausmaß und die Determinanten von Empathie bei Medizinstudenten aus arabischsprachigen Ländern: Eine systematische Überprüfung

Aim: This systematic review aims to investigate the level of empathy among medical students in Arabic speaking countries and analyze its determinants. Methods: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2022 (PRISMA), the authors conducted a systematic research of studies investigating the level and determinants of empathy among medical students in Arabic speaking countries. The databases PubMed, Scopus, web of science and google scholar were searched. Results: Ten studies from six countries were included. Nine of which had a cross-sectional study design. Level of empathy was assessed using the Jefferson scale in seven studies and using the Interpersonal Reactivity Index in two studies. The mean of empathy scale ranges between 97.65±14.10 to 106.55±19.16 in studies used the Jefferson scale of empathy. The associated factors with empathy were gender; high levels of empathy were reported in female students. Other factors are explored in relation with empathy such as specialty preference (surgery or medicine, "people-orientated" specialties or ''technology-oriented specialties''), family factors (marital status of parents, satisfactory relationship with parents, parents level of education and household income) and factors related to medical education (academic performance, year of study and type of curriculum) but the results are heterogeneous. Conclusion: This is the first systematic review, which illustrated the determinants of empathy in Arabic medical students. Our results revealed varied results on empathy determinants. Further studies may guarantee a full exploration of this ability in order to improve the doctor-patient relationship and patient management in the Arab world.Ziel: Diese systematische Übersichtsarbeit zielt darauf ab, das Maß an Empathie unter Medizinstudenten in arabischsprachigen Ländern zu untersuchen und seine Determinanten zu analysieren. Methoden: In Übereinstimmung mit den Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2022 (PRISMA) führten die Autoren eine systematische Recherche von Studien durch, die das Ausmaß und die Determinanten von Empathie unter Medizinstudenten in arabischsprachigen Ländern untersuchten. Es wurden die Datenbanken PubMed, Scopus, Web of Science und Google Scholar durchsucht. Ergebnisse: Es wurden zehn Studien aus sechs Ländern einbezogen. Neun davon hatten ein Querschnittsstudiendesign. Der Grad der Empathie wurde in sieben Studien mit der Jefferson-Skala und in zwei Studien mit dem Interpersonal Reactivity Index gemessen. Der Mittelwert der Empathieskala lag zwischen 97,65±14,10 und 106,55±19,16 in den Studien, die die Jefferson-Skala für Empathie verwendeten. Die mit Empathie assoziierten Faktoren waren das Geschlecht; bei weiblichen Studenten wurde ein hohes Maß an Empathie festgestellt. Andere Faktoren wurden im Zusammenhang mit Empathie untersucht, z. B. die Präferenz für ein Fachgebiet (Chirurgie oder Medizin, "menschenorientierte" Fachgebiete oder "technologieorientierte Fachgebiete"), familiäre Faktoren (Familienstand der Eltern, zufriedenstellende Beziehung zu den Eltern, Bildungsniveau der Eltern und Haushaltseinkommen) und Faktoren im Zusammenhang mit der medizinischen Ausbildung (akademische Leistung, Studienjahr und Art des Lehrplans), aber die Ergebnisse sind uneinheitlich.Schlussfolgerung: Dies ist die erste systematische Übersichtsarbeit, die die Determinanten von Empathie bei arabischen Medizinstudenten illustriert. Unsere Ergebnisse zeigten unterschiedliche Ergebnisse zu den Determinanten der Empathie. Weitere Studien könnten eine umfassende Erforschung dieser Fähigkeit gewährleisten, um die Arzt-Patienten-Beziehung und das Patientenmanagement in der arabischen Welt zu verbessern