864 research outputs found
Patterns of energy allocation during energetic scarcity; evolutionary insights from ultra-endurance events.
Exercise physiologists and evolutionary biologists share a research interest in determining patterns of energy allocation during times of acute or chronic energetic scarcity. Within sport and exercise science, this information has important implications for athlete health and performance. For evolutionary biologists, this would shed new light on our adaptive capabilities as a phenotypically plastic species. In recent years, evolutionary biologists have begun recruiting athletes as study participants and using contemporary sports as a model for studying evolution. This approach, known as human athletic palaeobiology, has identified ultra-endurance events as a valuable experimental model to investigate patterns of energy allocation during conditions of elevated energy demand, which are generally accompanied by an energy deficit. This energetic stress provokes detectable functional trade-offs in energy allocation between physiological processes. Early results from this modelsuggest thatlimited resources are preferentially allocated to processes which could be considered to confer the greatest immediate survival advantage (including immune and cognitive function). This aligns with evolutionary perspectives regarding energetic trade-offs during periods of acute and chronic energetic scarcity. Here, we discuss energy allocation patterns during periods of energetic stress as an area of shared interest between exercise physiology and evolutionary biology. We propose that, by addressing the ultimate "why" questions, namely why certain traits were selected for during the human evolutionary journey, an evolutionary perspective can complement the exercise physiology literature and provide a deeper insight of the reasons underpinning the body's physiological response to conditions of energetic stress
Patterns of energy allocation during energetic scarcity; evolutionary insights from ultra-endurance events
Exercise physiologists and evolutionary biologists share a research interest in determining patterns of energy allocation during times of acute or chronic energetic scarcity. Within sport and exercise science, this information has important implications for athlete health and performance. For evolutionary biologists, this would shed new light on our adaptive capabilities as a phenotypically plastic species. In recent years, evolutionary biologists have begun recruiting athletes as study participants and using contemporary sports as a model for studying evolution. This approach, known as human athletic palaeobiology, has identified ultra-endurance events as a valuable experimental model to investigate patterns of energy allocation during conditions of elevated energy demand, which are generally accompanied by an energy deficit. This energetic stress provokes detectable functional trade-offs in energy allocation between physiological processes. Early results from this modelsuggest thatlimited resources are preferentially allocated to processes which could be considered to confer the greatest immediate survival advantage (including immune and cognitive function). This aligns with evolutionary perspectives regarding energetic trade-offs during periods of acute and chronic energetic scarcity. Here, we discuss energy allocation patterns during periods of energetic stress as an area of shared interest between exercise physiology and evolutionary biology. We propose that, by addressing the ultimate “why” questions, namely why certain traits were selected for during the human evolutionary journey, an evolutionary perspective can complement the exercise physiology literature and provide a deeper insight of the reasons underpinning the body's physiological response to conditions of energetic stress
Influence of Nozzle Orifice Geometry and Fuel Properties on Flow and Cavitation Characteristics of a Diesel Injector
Smoke-free homes: what are the barriers, motivators and enablers? A qualitative systematic review and thematic synthesis
Objective: To thematically synthesise primary qualitative studies of the barriers, motivators and enablers of smoke-free homes (SFHs).
Design: Systematic review and thematic synthesis.
Data sources: Searches of MEDLINE, EBM Reviews (Cochrane Database of Systematic Reviews), PsycINFO, Global Health, CINAHL, Web of Science, Informit and EMBASE, combining terms for families, households and vulnerable populations; SFH and secondhand smoke; and qualitative research, were supplemented by searches of PhD theses, key authors, specialist journals and reference lists.
Study selection: We included 22 articles, reporting on 18 studies, involving 646 participants. Inclusion criteria: peer-reviewed; English language; published from 1990 onwards (to week 3 of April 2014); used qualitative data collection methods; explored participants’ perspectives of home smoking behaviours; and the barriers, motivators and enablers to initiating and/or maintaining a SFH.
Data extraction: 1 of 3 authors extracted data with checking by a second.
Data synthesis: A thematic synthesis was performed to develop 7 core analytic themes: (1) knowledge, awareness and risk perception; (2) agency and personal skills/attributes; (3) wider community norms and personal moral responsibilities; (4) social relationships and influence of others; (5) perceived benefits, preferences and priorities; (6) addiction and habit; (7) practicalities.
Conclusions: This synthesis highlights the complexity faced by many households in having a SFH, the practical, social, cultural and personal issues that need to be addressed and balanced by households, and that while some of these are common across study settings, specific social and cultural factors play a critical role in shaping household smoking behaviours. The findings can inform policy and practice and the development of interventions aimed at increasing SFHs.
Trial registration number: CRD42014014115
Growth-Adapted Tensegrity Structures: A New Calculus for the Space Economy
We describe a novel approach to create and engineer an economically viable space habitat development technology, for deployment of a lightweight tensegrity habitat structure orbiting at Earth-Moon L2, where onboard robotic assets will use space-based materials to provide water for shielding, irrigation and life support, soil for ecosystem development, and to enable structural maintenance and enhancement. The habitat can become a tourist destination, an economic hub, and a multi-purpose research and support facility for lunar surface development and space ecosystem life sciences
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Diagnostic Performance of Ultrasonography-Based Risk Models in Differentiating Between Benign and Malignant Ovarian Tumors in a US Cohort
Importance: Ultrasonography-based risk models can help nonexpert clinicians evaluate adnexal lesions and reduce surgical interventions for benign tumors. Yet, these models have limited uptake in the US, and studies comparing their diagnostic accuracy are lacking. Objective: To evaluate, in a US cohort, the diagnostic performance of 3 ultrasonography-based risk models for differentiating between benign and malignant adnexal lesions: International Ovarian Tumor Analysis (IOTA) Simple Rules with inconclusive cases reclassified as malignant or reevaluated by an expert, IOTA Assessment of Different Neoplasias in the Adnexa (ADNEX), and Ovarian-Adnexal Reporting and Data System (O-RADS). Design, setting, and participants: This retrospective diagnostic study was conducted at a single US academic medical center and included consecutive patients aged 18 to 89 years with adnexal masses that were managed surgically or conservatively between January 2017 and October 2022. Exposure: Evaluation of adnexal lesions using the Simple Rules, ADNEX, and O-RADS. Main outcomes and measures: The main outcome was diagnostic performance, including area under the receiver operating characteristic (ROC) curve (AUC), sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios. Surgery or follow-up were reference standards. Secondary analyses evaluated the models' performances stratified by menopause status and race. Results: The cohort included 511 female patients with a 15.9% malignant tumor prevalence (81 patients). Mean (SD) ages of patients with benign and malignant adnexal lesions were 44.1 (14.4) and 52.5 (15.2) years, respectively, and 200 (39.1%) were postmenopausal. In the ROC analysis, the AUCs for discriminative performance of the ADNEX and O-RADS models were 0.96 (95% CI, 0.93-0.98) and 0.92 (95% CI, 0.90-0.95), respectively. After converting the ADNEX continuous individualized risk into the discrete ordinal categories of O-RADS, the ADNEX performance was reduced to an AUC of 0.93 (95% CI, 0.90-0.96), which was similar to that for O-RADS. The Simple Rules combined with expert reevaluation had 93.8% sensitivity (95% CI, 86.2%-98.0%) and 91.9% specificity (95% CI, 88.9%-94.3%), and the Simple Rules combined with malignant classification had 93.8% sensitivity (95% CI, 86.2%-98.0%) and 88.1% specificity (95% CI, 84.7%-91.0%). At a 10% risk threshold, ADNEX had 91.4% sensitivity (95% CI, 83.0%-96.5%) and 86.3% specificity (95% CI, 82.7%-89.4%) and O-RADS had 98.8% sensitivity (95% CI, 93.3%-100%) and 74.4% specificity (95% CI, 70.0%-78.5%). The specificities of all models were significantly lower in the postmenopausal group. Subgroup analysis revealed high performances independent of race. Conclusions and relevance: In this diagnostic study of a US cohort, the Simple Rules, ADNEX, and O-RADS models performed well in differentiating between benign and malignant adnexal lesions; this outcome has been previously reported primarily in European populations. Risk stratification models can lead to more accurate and consistent evaluations of adnexal masses, especially when used by nonexpert clinicians, and may reduce unnecessary surgeries.</p
Phenomenological Implications of a Magnetic 5th Force
A 5th force coupling to baryon number has been proposed to account for
the correlations between the acceleration differences of the
samples studied in the E\"{o}tv\"{o}s experiment, and the corresponding
differences in the baryon-to-mass ratios . To date the
E\"{o}tv\"{o}s results have not been supported by modern experiments. Here we
investigate the phenomenological implications of a possible magnetic analog
of the conventional 5th force electric field,
, arising from the Earth's rotation. We demonstrate that,
in the presence of couplings proportional to , both the
magnitude and direction of a possible 5th force field could be quite different
from what would otherwise be expected and warrants further investigation.Comment: 31 pages, 1 figure, ws-ijmpa.cls, minor changes, final version to
appear in International Journal of Modern Physics
BET inhibition as a single or combined therapeutic approach in primary paediatric B-precursor acute lymphoblastic leukaemia
Paediatric B-precursor ALL is a highly curable disease, however, treatment resistance in some patients and the long-term toxic
effects of current therapies pose the need for more targeted therapeutic approaches. We addressed the cytotoxic effect of JQ1,
a highly selective inhibitor against the transcriptional regulators, bromodomain and extra-terminal (BET) family of proteins, in
paediatric ALL. We showed a potent
in vitro
cytotoxic response of a panel of primary ALL to JQ1, independent of their prognostic
features but dependent on high
MYC
expression and coupled with transcriptional downregulation of multiple pro-survival
pathways. In agreement with earlier studies, JQ1 induced cell cycle arrest. Here we show that BET inhibition also reduced c-Myc
protein stability and suppressed progression of DNA replication forks in ALL cells. Consistent with c-Myc depletion and
downregulation of pro-survival pathways JQ1 sensitised primary ALL samples to the classic ALL therapeutic agent dexamethasone.
Finally, we demonstrated that JQ1 reduces ALL growth in ALL xenograft models, both as a single agent and in combination with
dexamethasone. We conclude that targeting BET proteins should be considered as a new therapeutic strategy for the treatment of
paediatric ALL and particularly those cases that exhibit suboptimal responses to standard treatment
Cataract, abnormal electroretinogram and visual evoked potentials in a child with SMA-LED2 - extending the phenotype.
This case report describes a girl who presented antenatal arthrogryposis and postnatal hypotonia, generalized and respiratory weakness, joint deformities particularly affecting the lower limbs and poor swallow. By 5 months, cataracts, abnormal electroretinograms, visual evoked potentials and global developmental impairments were recognized. No causative variants were identified on targeted gene panels. After her unexpected death at 11 months, gene-agnostic trio whole exome sequencing revealed a likely pathogenic de novo BICD2 missense variant, NM_001003800.1, c.593T>C, p.(Leu198Pro), confirming the diagnosis of spinal muscular atrophy lower extremity predominant type 2 (SMA-LED2). We propose that cataracts and abnormal electroretinograms are novel features of SMA-LED2
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