475 research outputs found
Summing the strokes: energy economy in northern elephant seals during large-scale foraging migrations.
BackgroundThe energy requirements of free-ranging marine mammals are challenging to measure due to cryptic and far-ranging feeding habits, but are important to quantify given the potential impacts of high-level predators on ecosystems. Given their large body size and carnivorous lifestyle, we would predict that northern elephant seals (Mirounga angustirostris) have elevated field metabolic rates (FMRs) that require high prey intake rates, especially during pregnancy. Disturbance associated with climate change or human activity is predicted to further elevate energy requirements due to an increase in locomotor costs required to accommodate a reduction in prey or time available to forage. In this study, we determined the FMRs, total energy requirements, and energy budgets of adult, female northern elephant seals. We also examined the impact of increased locomotor costs on foraging success in this species.ResultsBody size, time spent at sea and reproductive status strongly influenced FMR. During the short foraging migration, FMR averaged 90.1 (SE = 1.7) kJ kg(-1)d(-1) - only 36 % greater than predicted basal metabolic rate. During the long migration, when seals were pregnant, FMRs averaged 69.4 (±3.0) kJ kg(-1)d(-1) - values approaching those predicted to be necessary to support basal metabolism in mammals of this size. Low FMRs in pregnant seals were driven by hypometabolism coupled with a positive feedback loop between improving body condition and reduced flipper stroking frequency. In contrast, three additional seals carrying large, non-streamlined instrumentation saw a four-fold increase in energy partitioned toward locomotion, resulting in elevated FMRs and only half the mass gain of normally-swimming study animals.ConclusionsThese results highlight the importance of keeping locomotion costs low for successful foraging in this species. In preparation for lactation and two fasting periods with high demands on energy reserves, migrating elephant seals utilize an economical foraging strategy whereby energy savings from reduced locomotion costs are shuttled towards somatic growth and fetal gestation. Remarkably, the energy requirements of this species, particularly during pregnancy, are 70-80 % lower than expected for mammalian carnivores, approaching or even falling below values predicted to be necessary to support basal metabolism in mammals of this size
Factors Influencing Crisis Management: A systematic review and synthesis for future research
The purpose of this study is to provide a comprehensive systematic literature review (SLR) of factors influencing crisis management (CM). The study attempts to assess the main areas that have been linked to and studied CM, and the research outlets that have been provided these research. The study adopts a qualitative approach and uses SLR method to collect relevant data. The study surveyed 223 studies from different research outlets, including the most reputed publishers; Emerald, Wiley, Elsevier, Springer, Taylor & Francis, SAGE, and Inderscience. The extracted articles are categorized into 8 areas based on their effect on CM. The most important factors are communication and social media, which have 66 studies with 4039 citations, leadership which have 40 studies with 2315 citations, followed by knowledge, governance, information technology, strategic planning, and professional entities, which have 38, 24, 23, 16, and 16 manuscripts with 2109, 1738, 301, 548, and 160 citations, respectively. The current study provides an open insight for academicians and researchers on the main areas of CM investigated by prior studies. It provides a novel contribution and comprehensive understating through highlighting what has been done and what is left to be done in respect to crisis management
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Principles of Glomerular Organization in the Human Olfactory Bulb – Implications for Odor Processing
Olfactory sensory neurons (OSN) in mice express only 1 of a possible 1,100 odor receptors (OR) and axons from OSNs expressing the same odor receptor converge into ,2 of the 1,800 glomeruli in each olfactory bulb (OB) in mice; this yields a convergence ratio that approximates 2:1, 2 glomeruli/OR. Because humans express only 350 intact ORs, we examined human OBs to determine if the glomerular convergence ratio of 2:1 established in mice was applicable to humans. Unexpectedly, the average number of human OB glomeruli is .5,500 yielding a convergence ratio of ,16:1. The data suggest that the initial coding of odor information in the human OB may differ from the models developed for rodents and that recruitment of additional glomeruli for subpopulations of ORs may contribute to more robust odor representation
Serum Fatty Acid Binding Protein 4 (FABP4) Predicts Pre-eclampsia in Women with Type 1 Diabetes
OBJECTIVE
To examine the association between fatty acid binding protein 4 (FABP4) and pre-eclampsia risk in women with type 1 diabetes.
RESEARCH DESIGN AND METHODS
Serum FABP4 was measured in 710 women from the Diabetes and Pre-eclampsia Intervention Trial (DAPIT) in early pregnancy and in the second trimester (median 14 and 26 weeks’ gestation, respectively).
RESULTS
FABP4 was significantly elevated in early pregnancy (geometric mean 15.8 ng/mL [interquartile range 11.6–21.4] vs. 12.7 ng/mL [interquartile range 9.6–17]; P < 0.001) and the second trimester (18.8 ng/mL [interquartile range 13.6–25.8] vs. 14.6 ng/mL [interquartile range 10.8–19.7]; P < 0.001) in women in whom pre-eclampsia later developed. Elevated second-trimester FABP4 level was independently associated with pre-eclampsia (odds ratio 2.87 [95% CI 1.24–6.68], P = 0.03). The addition of FABP4 to established risk factors significantly improved net reclassification improvement at both time points and integrated discrimination improvement in the second trimester.
CONCLUSIONS
Increased second-trimester FABP4 independently predicted pre-eclampsia and significantly improved reclassification and discrimination. FABP4 shows potential as a novel biomarker for pre-eclampsia prediction in women with type 1 diabetes.
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Cardiorespiratory Progression Over 5 Years and Role of Corticosteroids in Duchenne Muscular Dystrophy: A Single-Site Retrospective Longitudinal Study
Background:
Duchenne muscular dystrophy (DMD) boys treated with corticosteroids (CS) have prolonged survival and respiratory function when compared to CS-naïve. /\ud
Research question:
The differential impact of frequently used corticosteroids and their regimens on long-term (>5 years) cardiorespiratory progression in DMD children is unknown. /
Study Design and Methods: Retrospective longitudinal study including DMD children followed at Dubowitz Neuromuscular Centre (Great Ormond Street Hospital London), May 2000-June 2017. Patients enrolled in any interventional clinical trials were excluded. We collected patients’ anthropometrics, respiratory (forced vital capacity, FVC% predicted and absolute FVC, non-invasive ventilation requirement, NIV) and cardiac (left ventricular shortening function, LVFS%) function. CS-naïve patients had never received CS. CS-treated took either deflazacort or prednisolone, daily or intermittently (10 days on/10 days off) for >1 month. Average longitudinal models were fitted for yearly respiratory (FVC%P) and cardiac (LVFS%) progression. A time-to-event analysis to FVC%P<50%, NIV start and cardiomyopathy (LVFS<28%) was performed in CS-treated (daily and intermittent) vs CS-naïve patients. /
Results:
There were 270 patients, mean age at baseline 6.2 (±2.3) years. Median follow-up 5.6 (± 3.5) years. At baseline, 263 were ambulant. Sixty-six were CS-daily, 182 CS-intermittent >60% treatment, 22 CS-naïve. Yearly FVC%P declined similarly from 9 years (5.9% and 6.9%/year, p=0.27) in CS-daily and CS-intermittent. CS-daily declined from a higher FVC%P than CS-intermittent (p2 years later than CS-treated. LVFS% declined by 0.53%/year in CS-treated irrespective of CS regimen, significantly slower (p<0.01) than CS-naïve progressing by 1.17%/year. Age at cardiomyopathy was 16.6 in CS-treated (p<0.05) irrespective of regimen and 13.9 years in CS-naïve. /
Interpretation:
CS irrespective of their regimen significantly improved respiratory function and delayed NIV requirement and cardiomyopathy
Relationships of Physical Performance Tests to Military-relevant Tasks in Women
Purpose: This investigation sought to determine the most predictive measures of performance on a repetitive box lifting task (RBLT) and load bearing task (LBT) among 123 women (aged 23±4 years, height 165±7 cm, body mass 64±10 kg).
Methods: To determine the relationship of various predictors to performance on the RBLT and LBT, multiple regression analysis was conducted on body mass, height, leg cross-sectional area, upper and lower body muscular strength, lower body explosive power, upper and lower body local muscular endurance, and aerobic capacity.
Results: The mean±SD (range) number of repetitions for the RBLT was 86±23 (20-159). The mean±SD (range) time to complete the LBT was 2,054±340 seconds (1,307-3,447). The following equations were generated: RBLT (number of repetitions)=57.4 + 0.2(peak jump power) + 0.4(number of pushups in 2 minutes) + 0.15(number of repetitions during the squat endurance test) + 1.39(one repetition maximal strength boxlift (kg)) – 0.04(2-mile run time (2MR) in seconds), R=0.81; standard error of the estimate (SEE)=14; LBT (in seconds)=1,831 – 4.28(number of repetitions during the squat endurance test) + 0.95(2MR in seconds) – 13.4(body mass), R=0.73; SEE=232.
Conclusions: We found that the 2MR and squat endurance test were signifi cant predictive factors for performance on both load carriage tasks. These data also imply that women’s performance in combat-related tasks can be improved with training that targets muscular strength, power, and local muscular endurance in addition to aerobic capacity
Rationale and preclinical efficacy of a novel anti-EMP2 antibody for the treatment of invasive breast cancer
Despite significant advances in biology and medicine, the incidence and mortality due to breast cancer worldwide is still unacceptably high. Thus, there is an urgent need to discover new molecular targets. In this article, we show evidence for a novel target in human breast cancer, the tetraspan protein epithelial membrane protein-2 (EMP2). Using tissue tumor arrays, protein expression of EMP2 was measured and found to be minimal in normal mammary tissue, but it was upregulated in 63% of invasive breast cancer tumors and in 73% of triple-negative tumors tested. To test the hypothesis that EMP2 may be a suitable target for therapy, we constructed a fully human immunoglobulin G1 (IgG1) antibody specific for a conserved domain of human and murine EMP2. Treatment of breast cancer cells with the anti-EMP2 IgG1 significantly inhibited EMP2-mediated signaling, blocked FAK/Src signaling, inhibited invasion, and promoted apoptosis in vitro. In both human xenograft and syngeneic metastatic tumor monotherapy models, anti-EMP2 IgG1 retarded tumor growth without detectable systemic toxicity. This antitumor effect was, in part, attributable to a potent antibody-dependent cell-mediated cytotoxicity response as well as direct cytotoxicity induced by the monoclonal antibody. Together, these results identify EMP2 as a novel therapeutic target for invasive breast cancer.Fil: Fu, Maoyong. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados UnidosFil: Maresh , Erin L.. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados UnidosFil: Helguera, Gustavo Fernando. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de BiologÃa y Medicina Experimental (i); Argentina. Universidad de Buenos Aires; ArgentinaFil: Kiyohara, Meagan. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados UnidosFil: Qin, yu. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados UnidosFil: Ashki, Negin. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados UnidosFil: Daniels Wells, Tracy R.. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados UnidosFil: Aziz, Najib. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados UnidosFil: Gordon, Lynn K.. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados UnidosFil: Braun, Jonathan. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados UnidosFil: Elshimali, Yahya. Charles Drew University. Department of Pathology; Estados UnidosFil: Soslow, Robert A.. Memorial Sloan-Kettering Cancer Center. Department of Pathology; Estados UnidosFil: Penichet, Manuel L.. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados UnidosFil: Goodglick, Lee. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados UnidosFil: Wadehra, Madhuri. University of California Los Angeles. David Geffen School of Medicine at UCLA; Estados Unido
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