Comparison of two histological techniques for age determination in small cetaceans

Peer reviewedPreprin

Proteostasis failure in neurodegenerative diseases: focus on oxidative stress

Protein homeostasis or proteostasis is an essential balance of cellular protein levels mediated through an extensive network of biochemical pathways that regulate different steps of the protein quality control, from the synthesis to the degradation. All proteins in a cell continuously turn over, contributing to development, differentiation, and aging. Due to the multiple interactions and connections of proteostasis pathways, exposure to stress conditions may cause various types of protein damage, altering cellular homeostasis and disrupting the entire network with additional cellular stress. Furthermore, protein misfolding and/or alterations during protein synthesis results in inactive or toxic proteins, which may overload the degradation mechanisms. The maintenance of a balanced proteome, preventing the formation of impaired proteins, is accomplished by two major catabolic routes: The ubiquitin proteasomal system (UPS) and the autophagy-lysosomal system. The proteostasis network is particularly important in nondividing, long-lived cells, such as neurons, as its failure is implicated with the development of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. These neurological disorders share common risk factors such as aging, oxidative stress, environmental stress, and protein dysfunction, all of which alter cellular proteostasis, suggesting that general mechanisms controlling proteostasis may underlay the etiology of these diseases. In this review, we describe the major pathways of cellular proteostasis and discuss how their disruption contributes to the onset and progression of neurodegenerative diseases, focusing on the role of oxidative stress

Amphicarpic Legumes for Tropical Pasture Persistence

Amphicarpy, by which a plant produces underground seeds in addition to aerial fruits, is found in many plant families and in species of at least 15 legume genera. First studies on the tropical Centrosema rotundifolium and subtropical Macroptilium panduratum revealed for both species, besides their stoloniferous growth habit, two important mechanisms for survival under unfavorable conditions: (1) Underground meristems and reserve organs, and (2) regeneration from a soil seed reserve based on underground, aerial-flowering independent, seed production. Underground seed production was for both species particularly high on very sandy soils, but amphicarpy enables the plants to exhibit a plasticity response to unfavourable soil conditions by changing resource allocation from underground to above-ground reproduction. The latter, which seems to be influenced by cross-pollination and thus aids gene-recombination, favours spreading of plant populations whereas underground reproduction ensures population survival on-site. Preliminary information on the agronomic potential of both species is given and several research needs are highlighted

HABILIDADES DE RACIOCÍNIO CRÍTICO DE ALUNOS DE CONTABILIDADE

Educational systems around the world judge student academic performance based upon reading and writing abilities, with evidence of critical thinking playing an essential role. In order to improve business education, a better understanding of students’ critical thinking and communication skill is required. This study aimed at assessing reading, writing, and critical thinking skills of accounting students using validated instruments: (a) Motivated Strategies for Learning Questionnaire, (b) Ennis-Weir Critical Thinking Essay Test, and (c) Flesch Reading Ease (English and Portuguese). Students wrote a short essay that was evaluated for writing quality and critical thinking based on the EW-CTET. Scores provided indications of good writing quality and evidence of high levels of critical thinking. No significant differences (i.e., gender, parenthood, program level, and program stage) of measured reading levels of the written products were found. Elements for improving learners’ performance aligned with their critical thinking skills are discussed along with a deep reflection on how educators would behave as agents of change in the reported scenario. Observed cultural differences in critical thinking related to perception of authority should be examined in further investigations.Sistemas educacionales alrededor del mundo evalúan el desempeño académico de los alumnos con base en habilidades de lectura y redacción, con evidencias sobre el papel esencial del raciocinio crítico. Para mejorar la educación en el área de negocios es necesario mejor entendimiento sobre el raciocinio crítico de los alumnos, así como sobre sus habilidades de comunicación. Esta investigación se centró en la evaluación de habilidades de lectura, redacción y raciocinio crítico de alumnos de contabilidad utilizando instrumentos validados: (a) Cuestionario de Estrategias Motivadoras para Aprendizaje (Motivated Strategies for Learning Questionnaire, MSLQ), (b) Prueba Escrita de Raciocinio Crítico de Ennis-Weir (Ennis-Weir Critical Thinking Essay Test, EW-CTET), y (c) Indicador Flesch de Facilidad de Lectura (Flesch Reading Ease, en Inglés y versión adaptada al Portugués). Los participantes escribieron una pequeña redacción que fue evaluada en términos de calidad de escrita y de raciocinio crítico con base en el EW-CTET. Los resultados mostraron la buena calidad de la escrita e hicieron evidentes los niveles elevados de raciocinio crítico. Diferencias significativas (por ejemplo: género, maternidad / paternidad, nivel de estudios, y nivel en el programa) no fueron observadas en las métricas sobre niveles de facilidad de lectura de los productos escritos generados por los participantes. Elementos para la mejora del desempeño de los participantes alineados con sus habilidades de raciocinio crítico son discutidos juntamente con la reflexión profunda sobre el comportamiento de educadores como agentes de cambio en este escenario. Se sugiere que las diferencias culturales sobre raciocinio crítico observadas en este estudio relacionadas con la percepción de autoridad sean examinadas en futuras investigaciones.Sistemas educacionais ao redor do mundo avaliam o desempenho acadêmico de alunos com base em habilidades de leitura e redação, com evidências sobre o papel essencial do raciocínio crítico. Para aprimorar a educação na área de negócios é necessário melhor entendimento sobre o raciocínio crítico dos alunos, bem como sobre suas habilidades de comunicação. Esta pesquisa focou na avaliação de habilidades de leitura, redação e raciocínio crítico de alunos de contabildiade utilizando instrumentos validados: (a) Questionário de Estratégias Motivadoras para Aprendizagem (Motivated Strategies for Learning Questionnaire, MSLQ), (b) Teste Escrito de Raciocínio Crítico de Ennis-Weir (Ennis-Weir Critical Thinking Essay Test, EW-CTET), e (c) Indicador Flesch de Facilidade de Leitura (Flesch Reading Ease, em Inglês e versão adaptada para o Português). Os participantes escreveram uma pequena redação que foi avaliada em termos de qualidade de escrita e raciocínio crítico com base no EW-CTET. Os resultados trouxeram indicações de boa qualidade de escrita e evidência de níveis elevados de raciocínio crítico. Diferenças significativas (e.g., gênero, maternidade/paternidade, nível de estudos, e estágio no programa) não foram observadas nas métricas sobre níveis de facilidade de leitura dos produtos escritos gerados pelos participantes. Elementos para o aprimoramento de desempenho dos participantes alinhados com suas habilidades de raciocínio crítico são discutidos juntamente com reflexão profunda sobre comportamento de educadores como agentes de mudança neste cenário. Sugere-se que diferenças culturais sobre raciocínio crítico observadas neste estudo relacionadas com a percepção de autoridade sejam examinadas em futuras investigações

The detection of lubricating oil viscosity changes in gearbox transmission systems driven by sensorless variable speed drives using electrical supply parameters

Lubrication oil plays a decisive role to maintain a reliable and efficient operation of gear transmissions. Many offline methods have been developed to monitor the quality of lubricating oils. This work focus on developing a novel online method to diagnose oil degradation based on the measurements from power supply system to the gearbox. Experimental studies based on an 10kW industrial gearbox fed by a sensorless variable speed drive (VSD) shows that measurable changes in both static power and dynamic behaviour are different with lube oils tested. Therefore, it is feasible to use the static power feature to indicate viscosity changes at low and moderate operating speeds. In the meantime, the dynamic feature can separate viscosity changes for all different tested cases

ARC‐1, a sequence element complementary to an internal 18S rRNA segment, enhances translation efficiency in plants when present in the leader or intercistronic region of mRNAs

The sequences of different plant viral leaders with known translation enhancer ability show partial complementarity to the central region of 18S rRNA. Such complementarity might serve as a means to attract 40S ribosomal subunits and explain in part the translation‐enhancing property of these sequences. To verify this notion, we designed β‐glucuronidase (GUS) mRNAs differing only in the nature of 10 nt inserts in the center of their 41 base leaders. These were complementary to consecutive domains of plant 18S rRNA. Sucrose gradient analysis revealed that leaders with inserts complementary to regions 1105-1114 and 1115-1124 (‘ARC‐1') of plant 18S rRNA bound most efficiently to the 40S ribosomal subunit after dissociation from 80S ribosomes under conditions of high ionic strength, a treatment known to remove translation initiation factors. Using wheat germ cell‐free extracts, we could demonstrate that mRNAs with these leaders were translated more than three times more efficiently than a control lacking such a complementarity. Three linked copies of the insert enhanced translation of reporter mRNA to levels comparable with those directed by the natural translation enhancing leaders of tobacco mosaic virus and potato virus Y RNAs. Moreover, inserting the same leaders as intercistronic sequences in dicistronic mRNAs substantially increased translation of the second cistron, thereby revealing internal ribosome entry site activity. Thus, for plant systems, the complementary interaction between mRNA leader and the central region of 18S rRNA allows cap‐independent binding of mRNA to the 43S pre‐initiation complex without assistance of translation initiation factor

Extensive phenotypic plasticity of a Red Sea coral over a strong latitudinal temperature gradient suggests limited acclimatization potential to warming

Global warming was reported to cause growth reductions in tropical shallow water corals in both, cooler and warmer, regions of the coral species range. This suggests regional adaptation with less heat-tolerant populations in cooler and more thermo-tolerant populations in warmer regions. Here, we investigated seasonal changes in the in situ metabolic performance of the widely distributed hermatypic coral Pocillopora verrucosa along 12 degrees latitudes featuring a steep temperature gradient between the northern (28.5 degrees N, 21-27 degrees C) and southern (16.5 degrees N, 28-33 degrees C) reaches of the Red Sea. Surprisingly, we found little indication for regional adaptation, but strong indications for high phenotypic plasticity: Calcification rates in two seasons (winter, summer) were found to be highest at 28-29 degrees C throughout all populations independent of their geographic location. Mucus release increased with temperature and nutrient supply, both being highest in the south. Genetic characterization of the coral host revealed low inter-regional variation and differences in the Symbiodinium clade composition only at the most northern and most southern region. This suggests variable acclimatization potential to ocean warming of coral populations across the Red Sea: high acclimatization potential in northern populations, but limited ability to cope with ocean warming in southern populations already existing at the upper thermal margin for coral

Imaging stress and magnetism at high pressures using a nanoscale quantum sensor

Pressure alters the physical, chemical and electronic properties of matter. The development of the diamond anvil cell (DAC) enables tabletop experiments to investigate a diverse landscape of high-pressure phenomena ranging from the properties of planetary interiors to transitions between quantum mechanical phases. In this work, we introduce and utilize a novel nanoscale sensing platform, which integrates nitrogen-vacancy (NV) color centers directly into the culet (tip) of diamond anvils. We demonstrate the versatility of this platform by performing diffraction-limited imaging (~600 nm) of both stress fields and magnetism, up to pressures ~30 GPa and for temperatures ranging from 25-340 K. For the former, we quantify all six (normal and shear) stress components with accuracy $<0.01$ GPa, offering unique new capabilities for characterizing the strength and effective viscosity of solids and fluids under pressure. For the latter, we demonstrate vector magnetic field imaging with dipole accuracy $<10^{-11}$ emu, enabling us to measure the pressure-driven $\alpha\leftrightarrow\epsilon$ phase transition in iron as well as the complex pressure-temperature phase diagram of gadolinium. In addition to DC vector magnetometry, we highlight a complementary NV-sensing modality using T1 noise spectroscopy; crucially, this demonstrates our ability to characterize phase transitions even in the absence of static magnetic signatures. By integrating an atomic-scale sensor directly into DACs, our platform enables the in situ imaging of elastic, electric and magnetic phenomena at high pressures.Comment: 18 + 50 pages, 4 + 19 figure

Intelligence and ambition are distributed equally around the globe

The impact of freely accessible knowledge distribution platforms is briefly discussed