Lack of energy dissipation is one of the shortcomings of conventional glass fiber reinforced composites. The addition of steel fibers to the conventional FRP composite to create a hybrid composite ...has been recently investigated as an option to address this limitation. The current literature is limited to composites reinforced with metal and non-metal fibers of the same alignment. In this study, hybrid and nonhybrid FRP composites of different layups, fiber content, and weave type were manufactured and subjected to hysteretic tensile loads. Woven glass fabrics in ±45° orientation were hybridized with unidirectional stainless steel fabrics in 0° and 90° orientations. This put the glass and steel layers in in-plane shear and normal stresses, respectively. The nonlinear stress⁻strain relationship, residual plastic strains, energy dissipation capability, and failure mechanisms of hybrid and nonhybrid composite type were compared. The hybrid composites presented improved energy dissipation, tensile strength, and stiffness when compared to nonhybrid ones. The applicability of an existing constitutive model that was originally developed for in-plane shear of conventional composites was investigated and refinements were proposed to present the hysteretic stress⁻strain relationship after addition of steel fibers. The refined model captured the increased plastic strain values and energy dissipation because of stainless steel fibers in the hybrid composite samples. An Armstrong⁻Frederick plasticity model was implemented to model the stress⁻strain relationship of the stainless steel composite samples.
Le stress prénatal est un sujet d'intérêt éthologique croissant en raison de ses effets sur la santé humaine et le bien-être des animaux. Cette thése de doctorat s’intéresse à la seiche Sepia ...officinalis, un modèle pratique dans lequel la progéniture en développement peut être séparée de leurs mères pour examiner diverses sources potentielles de stress en isolement expérimental. Plusieurs catégories de facteurs de stress ont été appliquées aux embryons et aux juvéniles et la progéniture résultante a été testée dans une série d'épreuves physiologiques et comportementales. L'objectif était de déterminer si différents types de stress prénatal affectent la seiche et, dans l'affirmative, comment ces effets se transmettent. Les données présentées démontrent que les stresseurs appliqués aux femelles reproductrices (stress maternel), ainsi que les stresseurs appliqués directement aux embryons (stress embryonnaire), affectent le comportement postnatal (y compris la structuration corporelle, la latéralisation cérébrale, la prédation et les schémas d'activité) la mémoire et / ou la neurobiologie (y compris les concentrations et le renouvellement de la monoamine, la taille des différents lobes cérébraux et la division cellulaire). Les résultats mettent en évidence la présence de trois voies par lesquelles le stress peut exercer des effets: sur le nombre de descendants produits par la femelle, la transmission de la femelle à sa progéniture et directement sur la progéniture elle-même. Les expériences ont également démontré qu'un facteur de stress complètement artificiel (lumière forte) affectait un éventail plus large de comportements chez la progéniture qu’un stress naturel (odeur de prédateur). Enfin, les données ont montré que l'environnement d'incubation et d’élevage peuvent également affecter la progéniture et méritent donc une attention particulière dans la formulation et l'interprétation des expériences avec cette espèce. Ces découvertes informent à la fois les pratiques de bien-être des seiches et d'autres céphalopodes (par exemple, réduisent la manipulation pour maximiser la reproduction) et élucident et renforcent les principes éthologiques qui s'appliquent au stress animal en général (par exemple la transmission des effets de stress de la mère à la progéniture). Compte tenu des informations fournies ici et dans de nombreuses autres études, la seiche et d'autres céphalopodes devraient continuer à servir de modèles comportementaux en éthologie et en biologie en général.
Prenatal stress is a subject of growing ethological interest due to its effects on human health and animal welfare. This Ph.D. thesis utilizes the cuttlefish Sepia officinalis, a convenient model in which developing offspring can be separated from their mothers to examine various potential sources of stress in experimental isolation. Several categories of stressors were applied to cuttlefish and cuttlefish eggs and the resulting offspring were tested in a range of physiological and behavioral tests. The goal was to determine if various types of prenatal stress affect cuttlefish, and if so, how these effects are transmitted. The data presented demonstrate that both stressors applied to reproducing females (maternal stress), as well as stressors applied directly to embryos (embryonic stress), affected post-natal behavior (including body patterning, brain lateralization, predation and activity patterns), learning, memory and/or neurobiology (including monoamine concentrations and turnover, the size of various brain lobes and cell division). The results highlight the presence of three pathways by which stress can exert effects: on the number of offspring produced by the female, transmission from the female to her offspring and directly on the offspring themselves. The experiments also demonstrated that a completely artificial stressor (bright light) affected a wider range of behaviors in offspring than a natural-occurring one (predator odor). Finally, the data showed that incubation and spawning environment can also affect offspring, and thus deserve attention in the formulation and interpretation of experiments with this species. These findings inform both welfare practices for cuttlefish and other cephalopods (e.g. reduce handling to maximize reproduction) as well as elucidating and reinforcing ethological principles that apply to animal stress in general (e.g. the transmission of stress effects from mother to offspring). Given the insight provided here and in numerous other studies, cuttlefish and other cephalopods should continue to serve as behavioral models in ethology and biology in general.
Gene editing for the cure of inborn errors of metabolism (IEMs) has been limited by inefficiency of adult hepatocyte targeting. Here, we demonstrate that in utero CRISPR/Cas9-mediated gene editing in ...a mouse model of hereditary tyrosinemia type 1 provides stable cure of the disease. Following this, we performed an extensive gene expression analysis to explore the inherent characteristics of fetal/neonatal hepatocytes that make them more susceptible to efficient gene editing than adult hepatocytes. We showed that fetal and neonatal livers are comprised of proliferative hepatocytes with abundant expression of genes involved in homology-directed repair (HDR) of DNA double-strand breaks (DSBs), key for efficient gene editing by CRISPR/Cas9. We demonstrated the same is true of hepatocytes after undergoing a regenerative stimulus (partial hepatectomy), where post-hepatectomy cells show a higher efficiency of HDR and correction. Specifically, we demonstrated that HDR-related genome correction is most effective in the replicative phase, or S-phase, of an actively proliferating cell. In conclusion, this study shows that taking advantage of or triggering cell proliferation, specifically DNA replication in S-phase, may serve as an important tool to improve efficiency of CRISPR/Cas9-mediated genome editing in the liver and provide a curative therapy for IEMs in both children and adults.
Salinity tolerance-associated phenotypes of 35 EMS mutagenized wheat lines originating from BARI Gom-25 were compared. Vegetative growth was measured using non-destructive image-based phenotyping. ...Five different NaCl concentrations (0 to 160 mM) were applied to plants 19 days after planting (DAP 19), and plants were imaged daily until DAP 38. Plant growth, water use, leaf Na+, K+ and Cl− content, and thousand kernel weight (TKW) were measured, and six lines were selected for further analysis. In saline conditions, leaf Na+, K+, and Cl− content variation on a dry weight basis within these six lines were ~9.3, 1.4, and 2.4-fold, respectively. Relative to BARI Gom-25, two (OA6, OA62) lines had greater K+ accumulation, three (OA6, OA10, OA62) had 50–75% lower Na+:K+ ratios, and OA62 had ~30% greater water-use index (WUI). OA23 had ~2.2-fold greater leaf Na+ and maintained TKW relative to BARI Gom-25. Two lines (OA25, OA52) had greater TKW than BARI Gom-25 when grown in 120 mM NaCl but similar Na+:K+, WUI, and biomass accumulation. OA6 had relatively high TKW, high leaf K+, and WUI, and low leaf Na+ and Cl−. Phenotypic variation revealed differing associations between the parameters measured in the lines. Future identification of the genetic basis of these differences, and crossing of lines with phenotypes of interest, is expected to enable the assessment of which combinations of parameters deliver the greatest improvement in salinity tolerance.
In response to ESA Voyage 2050 announcement of opportunity, we propose an ambitious L-class mission to explore one of the most exciting bodies in the Solar System, Saturn largest moon Titan. Titan, a ..."world with two oceans", is an organic-rich body with interior-surface-atmosphere interactions that are comparable in complexity to the Earth. Titan is also one of the few places in the Solar System with habitability potential. Titan remarkable nature was only partly revealed by the Cassini-Huygens mission and still holds mysteries requiring a complete exploration using a variety of vehicles and instruments. The proposed mission concept POSEIDON (Titan POlar Scout/orbitEr and In situ lake lander DrONe explorer) would perform joint orbital and in situ investigations of Titan. It is designed to build on and exceed the scope and scientific/technological accomplishments of Cassini-Huygens, exploring Titan in ways that were not previously possible, in particular through full close-up and in situ coverage over long periods of time. In the proposed mission architecture, POSEIDON consists of two major elements: a spacecraft with a large set of instruments that would orbit Titan, preferably in a low-eccentricity polar orbit, and a suite of in situ investigation components, i.e. a lake lander, a "heavy" drone (possibly amphibious) and/or a fleet of mini-drones, dedicated to the exploration of the polar regions. The ideal arrival time at Titan would be slightly before the next northern Spring equinox (2039), as equinoxes are the most active periods to monitor still largely unknown atmospheric and surface seasonal changes. The exploration of Titan northern latitudes with an orbiter and in situ element(s) would be highly complementary with the upcoming NASA New Frontiers Dragonfly mission that will provide in situ exploration of Titan equatorial regions in the mid-2030s.
Abstract Objective Protein-pacing (P; 5
–
6 meals/day @ 2.0 g/kg BW/day) and multi-mode exercise (RISE; resistance, interval, stretching, endurance) training (PRISE) improves muscular endurance, ...strength, power and arterial health in exercise-trained women. The current study extends these findings by examining PRISE on fitness, growth hormone (GH), insulin-like growth factor-1 (IGF-1), and brain-derived neurotrophic factor (BDNF) response, cardiometabolic health, and body composition in exercise-trained men. Design Twenty active males (> 4 days exercise/week) completed either: PRISE (n = 11) or RISE (5
–
6 meals/day @ 1.0 g/kg BW/day; n = 9) for 12 weeks. Muscular strength (1-repetition maximum bench and leg press, 1-RM BP, and 1-RM LP), endurance (sit-ups, SU; push-ups, PU), power (squat jump, SJ, and bench throw, BT), flexibility (sit-and-reach, SR), aerobic performance (5 km cycling time-trial, TT), GH, IGF-1, BDNF, augmentation index, (AIx), and body composition, were assessed at weeks 0 (pre) and 13 (post). Results At baseline, no differences existed between groups except for GH (RISE, 230 ± 13 vs. PRISE, 382 ± 59 pg/ml, p < 0.05). The exercise intervention improved 1-RM, SJ, BT, PU, SU, SR, 5 km-TT, GH, AIx, BP, and body composition in both groups (time, p < 0.05). However, PRISE elicited greater improvements in 1-RM BP (21 vs. 10 ∆ lbs), SJ (171 vs. 13 ∆ W
), 5 km-TT (
− 37 vs.
− 11 ∆ s
), and sit-and-reach (5.3 vs. 1.2 ∆ cm) over RISE alone (p < 0.05) including increased IGF-1 (12%,
p < 0.05). Conclusions Exercise-trained men consuming a P diet combined with multi-component exercise training (PRISE) enhance muscular power, strength, aerobic performance, and flexibility which are not likely related to GH or BDNF but possibly to IGF-1 response.
In response to ESA Voyage 2050 announcement of opportunity, we propose an ambitious L-class mission to explore one of the most exciting bodies in the Solar System, Saturn largest moon Titan. Titan, a ..."world with two oceans", is an organic-rich body with interior-surface-atmosphere interactions that are comparable in complexity to the Earth. Titan is also one of the few places in the Solar System with habitability potential. Titan remarkable nature was only partly revealed by the Cassini-Huygens mission and still holds mysteries requiring a complete exploration using a variety of vehicles and instruments. The proposed mission concept POSEIDON (Titan POlar Scout/orbitEr and In situ lake lander DrONe explorer) would perform joint orbital and in situ investigations of Titan. It is designed to build on and exceed the scope and scientific/technological accomplishments of Cassini-Huygens, exploring Titan in ways that were not previously possible, in particular through full close-up and in situ coverage over long periods of time. In the proposed mission architecture, POSEIDON consists of two major elements: a spacecraft with a large set of instruments that would orbit Titan, preferably in a low-eccentricity polar orbit, and a suite of in situ investigation components, i.e. a lake lander, a "heavy" drone (possibly amphibious) and/or a fleet of mini-drones, dedicated to the exploration of the polar regions. The ideal arrival time at Titan would be slightly before the next northern Spring equinox (2039), as equinoxes are the most active periods to monitor still largely unknown atmospheric and surface seasonal changes. The exploration of Titan northern latitudes with an orbiter and in situ element(s) would be highly complementary with the upcoming NASA New Frontiers Dragonfly mission that will provide in situ exploration of Titan equatorial regions in the mid-2030s.
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