1,206 research outputs found

    Genetic Connectivity in Scleractinian Corals across the Northern Gulf of Mexico: Oil/Gas Platforms, and Relationship to the Flower Garden Banks

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    The 3,000 oil/gas structures currently deployed in the northern Gulf of Mexico (GOM) provide hard substratum for marine organisms in a region where such has been rare since the Holocene. The major exception to this are the Flower Garden Banks (FGB). Corals are known to have colonized oil/gas platforms around the FGB, facilitating biogeographic expansion. We ask the question, what are the patterns of genetic affinity in these coral populations. We sampled coral tissue from populations of two species occurring on oil and gas platforms: Madracis decactis (hermatype) and Tubastraea coccinea (invasive ahermatype). We sampled 28 platforms along four transects from 20 km offshore to the continental shelf edge off 1) Matagorda Island, TX; 2) Lake Sabine, TX; 3) Terrebonne Bay, LA; and 4) Mobile, AL. The entire population of M. decactis was sampled between depths of 5 m and 37 m. T. coccinea populations were sub-sampled. Genetic variation was assessed using the PCR-based Amplified Fragment Length Polymorphisms (AFLPs). Data were analyzed via AFLPOP and STRUCTURE. Genetic connectivity among M. decactis platform populations was highest near the FGB and decreased to the east. Connectivity increased again in the eastern sector, indicating isolation between the populations from different sides of the Mississippi River (Transects 3 and 4). A point-drop in genetic affinity (relatedness) at the shelf edge south of Terrebonne Bay, LA indicated a population differing from all others in the northern GOM. Genetic affinities among T. coccinea were highest in the west and decreased to the east. Very low genetic affinities off Mobile, AL indicated a dramatic difference between those populations and those west of the Mississippi River, apparently a formidable barrier to larval dispersal

    Establishing a New Paradigm in Engineering and Technology education: An Experimental Analysis of Multiple Learning Methodologies and Examination of Cognitive Profiles of Continuing Education Students

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    This study consisted of two inter-related components. The first part compared three instructional methods for delivering a Computer Aided Design (CAD) course for adult Continuing Education (CE) students. The second part established a comprehensive cognitive profile matrix of adult continuing education students entering careers in technology. The first part examined the use of three delivery methods, using three randomly selected groups of students. The three methods were as following: Traditional classroom-based training. Instructor-facilitated course presented online. Independent study, using a CD-ROM tutorial. The experimental design consisted of three randomly selected sample groups’ of20 students. The independent variable in the study was the instructional method. The dependent variables were the academic achievement scores and the satisfaction levels of the participants. As a second component, the study determined a cognitive profile of adult continuing education students. This analysis involved the same group of 60 students and presented a quantitative matrix of learning styles (by way of the bi-polar cognitive profile matrix. After obtaining all of the statistical data, a correlation analysis was performed, comparing cognitive profiles students versus the instructional methodology. The academic achievement analysis yielded the following results: There was a significant difference between in-class and online course, where in-class method showed higher academic achievement results. There was a significant difference between online course and the CD-ROM based course. In this case the CD method was more effective than the online method. There was no statistically significant difference between the in-class and the independent CD-ROM methods. The correlation analysis established that no significant correlation existed between the achievement and learning styles of the students. The results indicated that overall academic achievement within the subject of CAD are equal for all cognitive profile categories, allowing people with different learning styles to achieve their desired levels of academic success, as well as to meet their educational goals. The results of the Objective Course Satisfaction and indicated that there was no significant difference among the three groups. It was, therefore concluded that the objective course satisfaction was equal among the three methods of instruction described in this study

    The Origin of Nitrogen on Jupiter and Saturn from the 15^{15}N/14^{14}N Ratio

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    The Texas Echelon cross Echelle Spectrograph (TEXES), mounted on NASA's Infrared Telescope Facility (IRTF), was used to map mid-infrared ammonia absorption features on both Jupiter and Saturn in February 2013. Ammonia is the principle reservoir of nitrogen on the giant planets, and the ratio of isotopologues (15^{15}N/14^{14}N) can reveal insights into the molecular carrier (e.g., as N2_2 or NH3_3) of nitrogen to the forming protoplanets, and hence the source reservoirs from which these worlds accreted. We targeted two spectral intervals (900 and 960 cm1^{-1}) that were relatively clear of terrestrial atmospheric contamination and contained close features of 14^{14}NH3_3 and 15^{15}NH3_3, allowing us to derive the ratio from a single spectrum without ambiguity due to radiometric calibration (the primary source of uncertainty in this study). We present the first ground-based determination of Jupiter's 15^{15}N/14^{14}N ratio (in the range from 1.4×1031.4\times10^{-3} to 2.5×1032.5\times10^{-3}), which is consistent with both previous space-based studies and with the primordial value of the protosolar nebula. On Saturn, we present the first upper limit on the 15^{15}N/14^{14}N ratio of no larger than 2.0×1032.0\times10^{-3} for the 900-cm1^{-1} channel and a less stringent requirement that the ratio be no larger than 2.8×1032.8\times10^{-3} for the 960-cm1^{-1} channel (1σ1\sigma confidence). Specifically, the data rule out strong 15^{15}N-enrichments such as those observed in Titan's atmosphere and in cometary nitrogen compounds. To the extent possible with ground-based radiometric uncertainties, the saturnian and jovian 15^{15}N/14^{14}N ratios appear indistinguishable, implying that 15^{15}N-enriched ammonia ices could not have been a substantial contributor to the bulk nitrogen inventory of either planet, favouring the accretion of primordial N2_2 from the gas phase or as low-temperature ices.Comment: 33 pages, 19 figures, manuscript accepted for publication in Icaru

    Long-term calorie restriction in humans is not associated with indices of delayed immunologic aging: A descriptive study.

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    BACKGROUND: Delayed immunologic aging is purported to be a major mechanism through which calorie restriction (CR) exerts its anti-aging effects in non-human species. However, in non-obese humans, the effect of CR on the immune system has been understudied relative to its effects on the cardiometabolic system. OBJECTIVE: To examine whether CR is associated with delayed immunologic aging in non-obese humans. METHODS: We tested whether long-term CR practitioners (average 10.03 years of CR) evidenced decreased expression of T cell immunosenescence markers and longer immune cell telomeres compared to gender-, race/ethnicity-, age-, and education-matched "healthy" Body Mass Index (BMI) and "overweight"/"obese" BMI groups. RESULTS: Long-term human CR practitioners had lower BMI (p <  0.001) and fasting glucose (p <  0.001), as expected. They showed similar frequencies of pre-senescent cells (CD8+CD28- T cells and CD57 and PD-1 expressing T cells) to the comparison groups. Even after adjusting for covariates, including cytomegalovirus status, we observed shorter peripheral blood mononuclear cell telomeres in the CR group (p = 0.012) and no difference in granulocyte telomeres between groups (p = 0.42). CONCLUSIONS: We observed no clear evidence that CR as it is currently practiced in humans delays immune aging related to telomere length or T cell immunosenescent markers

    The influence of barefoot and barefoot inspired footwear on the kinetics and kinematics of running in comparison to conventional running shoes.

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    Barefoot running has experienced a resurgence in footwear biomechanics literature, based on the supposition that it serves to reduce the occurrence of overuse injuries in comparison to conventional shoe models. This consensus has lead footwear manufacturers to develop shoes which aim to mimic the mechanics of barefoot locomotion. This study compared the impact kinetics and 3-D joint angular kinematics observed whilst running: barefoot, in conventional cushioned running shoes and in shoes designed to integrate the perceived benefits of barefoot locomotion. The aim of the current investigation was therefore to determine whether differences in impact kinetics exist between the footwear conditions and whether shoes which aim to simulate barefoot movement patterns can closely mimic the 3-D kinematics of barefoot running. Twelve participants ran at 4.0 m.s-1±5% in each footwear condition. Angular joint kinematics from the hip, knee and ankle in the sagittal, coronal and transverse planes were measured using an eight camera motion analysis system. In addition simultaneous tibial acceleration and ground reaction forces were obtained. Impact parameters and joint kinematics were subsequently compared using repeated measures ANOVAs. The kinematic analysis indicates that in comparison to the conventional and barefoot inspired shoes that running barefoot was associated significantly greater plantar-flexion at footstrike and range of motion to peak dorsiflexion. Furthermore, the kinetic analysis revealed that compared to the conventional footwear impact parameters were significantly greater in the barefoot condition. Therefore this study suggests that barefoot running is associated with impact kinetics linked to an increased risk of overuse injury, when compared to conventional shod running. Furthermore, the mechanics of the shoes which aim to simulate barefoot movement patterns do not appear to closely mimic the kinematics of barefoot locomotion

    Primarily neutral effects of river restoration on macroinvertebrates, macrophytes, and fishes after a decade of monitoring

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    Restoring river habitat heterogeneity is expensive and time consuming, yet often has little effect on aquatic biota. Such poor restoration outcomes could be partly caused by the predominance of short‐term studies, which do not account for natural temporal fluctuations nor changes in the effects of restoration through time. Consequently, research that examines the longer‐term dynamics of river restoration is crucial for providing a temporal perspective of restoration outcomes and for informing the effectiveness of restoration methods. We used the Nidda River in Germany as a case study of the temporal effects of river hydromorphological restoration on different aquatic taxa. We surveyed macroinvertebrate, macrophyte, and fish communities across three sites prerestoration (2008) and then monitored changes in one control versus two restored sites across 10 years (2010–2019). Overall, we found few effects of restoration on the macroinvertebrate and macrophyte communities, with no effects whatsoever on fishes. Restoration improved some components of the macroinvertebrate and macrophyte communities; however, these positive effects were temporally inconsistent and did not translate to improvements in river ecosystem health (based on an index of ecological quality). Our findings illustrate how allowing for more time for community development will not necessarily alter the fact that local‐scale river habitat restoration can elicit little to no change in aquatic communities. Combining local‐ with broad‐scale restoration efforts that address the primary drivers of hydroecological decline, in addition to long‐term monitoring, may therefore be required to ensure that river restorations successfully meet their ecological goals

    Long term dietary supplementation with microalgae increases plasma docosahexaenoic acid in milk and plasma but does not affect plasma 13, 14-dihydro-15-keto PGF2α concentration in dairy cows

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    The aims of the study were to determine the long-term effects of dietary supplementation with microalgae (SCIM) on milk and blood fatty acid (FA) composition and reproductive hormones in early lactation dairy cows. Sixty Holstein–Friesian dairy cows (30 per treatment) were unsupplemented (Control) or supplemented with 100 g of SCIM (Schizochytrium limacinum sp.) per cow per day from 25 ± 0.5 d post-partum for 98 d. Intake and milk yield were recorded daily, with milk samples collected at weeks 0, 1, 2, 4, 8 and 14, and blood samples collected from 12 representative pairs per treatment at weeks 0, 2, 4, 8, and 14 for subsequent analysis of FA, β-hydroxybutyrate, non-esterified fatty acids and glucose. At 33 ± 0.9 d postpartum the oestrus cycle of 24 cows (12 per treatment) were synchronized and plasma 13,14-dihydro-15-keto PGF2α (PGFM) concentrations determined following an oxytocin challenge. Data were analysed by repeated measures analysis of variance. There was no effect of treatment on dry matter intake, milk yield or milk fat content, with mean values across treatments of 22.1 and 40.6, and 37.2 g/kg respectively. Milk fat concentration of C22:6 n-3 increased rapidly in cows receiving SCIM, reaching a maximum of 0.38 g/100 g FA by week 14. Similarly, blood concentration of C22:6 n-3 increased to 1.6 g/100 g FA by week 14 in cows fed SCIM. There was no effect of treatment on plasma metabolites, but plasma glucose was lower in cows fed SCIM compared to the Control at week 2, and higher in week 8. There was no effect of treatment on peak plasma PGFM concentration or area under the curve. It is concluded that feeding SCIM rapidly increases blood and milk concentrations of C22:6 n-3 which are maintained over time, but does not improve plasma PGFM in dairy cows

    Identification of a lipid-rich depot in the orbital cavity of the thirteen-lined ground squirrel

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    We discovered a previously undescribed orbital lipid depot in the thirteen-lined ground squirrel during the first ever magnetic resonance image (MRI) of this common experimental model of mammalian hibernation. In animals housed at constant ambient temperatures (5°C or 25°C, 12 h:12 h light:dark photoperiod), the volume of this depot increased in the autumn and decreased in the spring, suggesting an endogenous circannual pattern. Water-fat MRI revealed that throughout the year this depot is composed of ∼40% lipid, similar to brown adipose tissue (BAT). During arousal from torpor, thermal images showed higher surface temperatures near this depot before the rest of the head warmed, suggesting a thermoregulatory function. This depot, however, does not contain uncoupling protein 1, a BAT biomarker, or uncoupling protein 3. Histology shows blood vessels in close proximity to each other, suggesting it may serve as a vascular rete, perhaps to preferentially warm the eye and brain during arousals

    An enhanced functional ability questionnaire (faVIQ) to measure the impact of rehabilitation services on the visually impaired

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    AIM To develop a short, enhanced functional ability Quality of Vision (faVIQ) instrument based on previous questionnaires employing comprehensive modern statistical techniques to ensure the use of an appropriate response scale, items and scoring of the visual related difficulties experienced by patients with visual impairment. METHODS Items in current quality-of-life questionnaires for the visually impaired were refined by a multi-professional group and visually impaired focus groups. The resulting 76 items were completed by 293 visually impaired patients with stable vision on two occasions separated by a month. The faVIQ scores of 75 patients with no ocular pathology were compared to 75 age and gender matched patients with visual im pairm ent. RESULTS Rasch analysis reduced the faVIQ items to 27. Correlation to standard visual metrics was moderate (r=0.32-0.46) and to the NEI-VFQ was 0.48. The faVIQ was able to clearly discriminate between age and gender matched populations with no ocular pathology and visual impairment with an index of 0.983 and 95% sensitivity and 95% specificity using a cut off of 29. CONCLUSION The faVIQ allows sensitive assessm ent of quality-of-life in the visually im paired and should support studies which evaluate the effectiveness of low vision rehabilitation services. © Copyright International Journal of Ophthalmology Press

    A Very Ambiguous Empire:Russia’s Hybrid Exceptionalism

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    Legal rules are often designed to provide different incentives to plaintiffs and defendants. With regard to prejudgment interest, however, it is not clear why there should be a bias in either direction. Absent a convincing argument for leaning toward one party or the other, we conclude that as a normative matter, the ideal rule for prejudgment interest should be neutral with regard to delay: plaintiffs are compensated fully for delay and defendants pay the market rate for the benefits they implicitly derive from holding money that belongs to the plaintiff. This simple “neutrality rule” implies, of course, that all claims should be treated equally with regard to applying prejudgment interest; that there should not be a legislatively-set prejudgment rate or legislative mandating of simple, rather than compound, interest; and that prospective damages should be discounted to the date of injury and not the date of trial. We conclude this Article with another admonition from the Eleventh Circuit: “Symmetrical treatment should be given to the estimated lost earnings both before and after trial so that neither party can benefit by delaying the final judgment.”161 Utah could substantially reduce the problems and inconsistencies that derive from the current legal treatment of prejudgment interest if it were to adopt a simple principle: other than adding prejudgment interest, if a change in the trial date increases or decreases estimated damages, the methodology being used embeds an inconsistency concerning the treatment of time
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