2,281 research outputs found

    Red Lionfish (Pterois volitans) Invade San Salvador, Bahamas: No Early Effects on Coral and Fish Communities

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    The red lionfish, Pterois volitans, was first reported at San Salvador, Bahamas in January 2006; by 2009 they were common in waters 2 to 40 m deep around the island. Among the 5,078 fish observed on shallow patch reefs in 2007, only two were P. volitans; they were much more prevalent in deeper water along San Salvador’s platform wall. Captured P. volitans ranged in size from 19-32 cm, all longer than maturity length. Pallid goby (Coryphopterus eidolon), blackcap basslet (Gramma melacara) and red night shrimp (Rynchocienetes rigens) were the most commonly identified stomach contents. Our study in 2007 also collected data on coral and fish communities at three, near-shore patch reef complexes (Rice Bay, Rocky Point, Lindsay Reef, and compared the results to a similar study done in 2001, before P. volitans was discovered at San Salvador. Scleractinian and, therefore, total coral species richness decreased significantly from 2001 to 2007; however, coral percentage cover increased significantly by approximately 50% during the same period, probably due to a more precise estimation procedure rather than a real increase. Even after adjustment for CPUE (2.25 more effort in 2007 than in 2001), significantly more fish were observed in 2007 than in 2001. Continued monitoring of lionfish numbers and potentially associated changes in patch reef ecology is recommended

    MISSE-11 Ground Experiment Control

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    Back during the Apollo missions, when astronauts were being sent to the moon to explore and further scientific knowledge by conducting experiments and collecting samples for scientists back on Earth, they were faced with a surprising problem. It was discovered that the moons surface is covered with dust that has electrostatic properties, which would stick to suit and equipment. This hindered the functionality of the astronauts space suits, solar panels, optical instruments, among other exposed surfaces due to the jagged geometry of the dust which would damage said equipment. To resolve this issue, the Electrostatics and Surface Physics Laboratory (ESPL) came up with the solution of using an Electrodynamic Dust Shield (EDS)1 that uses electrostatic forces to move particles across a surface. Varieties of this dust shield have been developed for different applications. The purpose of the Materials International Space Station Experiments 11 (MISSE-11) is to experiment a payload that contains the dust mitigation technology to be flown to space for one year and an identical payload will be on earth, under vacuum, in the Electrostatics and Surface Physics Laboratory. The space payload was prepared prior to our arrival and shipped to fly on the International Space Station (ISS). The payload staying on the ground is going to act as a control for the experiment so that we may compare it to the payload that was flown in space. During our time at Kennedy Space Center, we were tasked with building and start testing the ground control unit of the MISSE-11 payload. To complete our task for the ground control unit, we constructed a new vacuum chamber setup and added automated aspects, procured the necessary flight electronics, designed and communicated for the machining of the payload frame, and performed functional and thermal testing on the electronics to the same original operational standards. Some modifications were made where possible, without affecting the performance of the samples, to be efficient with the production of the control unit while keeping important aspects identical. The experiment is now nearly complete, and testing will be starting within the next few weeks

    Repeated Sprint Performance in Male and Female College Athletes Matched for VO2max Relative to Fat Free Mass

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    The purpose of this study was to examine gender differences in repeated sprint exercise (RSE) performance among male and female athletes matched for VO2max relative to FFM (VO2max FFM). Thirty nine male and female college athletes performed a graded exercise test for VO2max and hydrostatic weighing to determine FFM. From the results, 11 pairs of males and females matched for VO2max FFM (mean ± SD; 58.3 ± 4.3 and 58.9 ± 4.6 ml.kg FFM-1.min-1; men and women, respectively) were identified. On a separate day, matched participants performed a RSE protocol that consisted of five 6-sec cycle sprints with 30-sec recovery periods, followed by 5-min active recovery and a 30-sec all-out sprint. Repeated 6-sec sprint performance did not differ between men and women; both maintained power output (PO) until sprint 4. POFFM (W.kg-1 FFM) did not differ between men and women during the five sprints. During the 30-sec sprint, men achieved a lower peak POFFM than women (11.7 ± 1.5 vs 13.2 ± 1.2); however, the decline in POFFM over 30 sec was greater in women. VO2 (ml.kg FFM-1.min-1) was lower in men during recovery (24.4 ± 3.8 vs 28.7 ± 5.7) and at the beginning (29.2 ± 4.0 vs 34.7 ± 4.9and end (49.4 ± 5.0 vs 52.3 ± 4.0) of the 30-sec sprint. These data indicate that men and women with similar aerobic capacities do not respond differently to short repeated sprints but may differ in their ability to recover and perform sprints of longer duration

    Grain Physics and Rosseland Mean Opacities

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    Tables of mean opacities are often used to compute the transfer of radiation in a variety of astrophysical simulations from stellar evolution models to proto-planetary disks. Often tables, such as Ferguson et al. (2005), are computed with a predetermined set of physical assumptions that may or may not be valid for a specific application. This paper explores the effects of several assumptions of grain physics on the Rosseland mean opacity in an oxygen rich environment. We find that changing the distribution of grain sizes, either the power-law exponent or the shape of the distribution, has a marginal effect on the total mean opacity. We also explore the difference in the mean opacity between solid homogenous grains and grains that are porous or conglomorations of several species. Changing the amount of grain opacity included in the mean by assuming a grain-to-gas ratio significantly affects the mean opacity, but in a predictable way.Comment: 19 pages, 6 figures, accepted for publication in Ap

    Pediatric medication use experiences and patient counseling in community pharmacies: Perspectives of children and parents

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    AbstractObjectivesThis study aimed to explore the perspectives of children and parents regarding: 1) pediatric patients' knowledge and medication use experiences for chronic conditions; 2) how they want to learn about medicines; and 3) perceptions of community pharmacist–provided counseling.DesignQualitative study using semistructured interviews and thematic analyses.SettingThree community pharmacies in 2 eastern states: one in rural western North Carolina, and 2 in an urban region of western Pennsylvania.ParticipantsA total of 39 study participants: 20 children using medications for chronic conditions and 19 parents interviewed July-December 2015.Main outcome measuresChild and parent perspectives regarding pediatric medication use, knowledge, experiences, and pharmacist-provided patient counseling.ResultsChildren and parents had similar perspectives on pediatric medication use and pharmacist counseling experiences. Six themes emerged: 1) child's knowledge, self-management, and medication use experiences; 2) essential medication information and sources; 3) child's frequent absence from the pharmacy; 4) patient counseling needs and recommendations; 5) use of interactive technologies to facilitate learning about medicines; and 6) perceptions of pharmacists. Participants reported that children were independently managing their medications, although they had minimal knowledge about medicines. Children and parents stated that the child's absence during medication pick-up at pharmacies was a barrier to receiving counseling by pharmacists. Children were comfortable and receptive to pharmacists educating them about their medicines, particularly how medications affect the human body, how they were manufactured, and research studies on their medications. Parents and children recommended the use of interactive and educational technologies for pediatric counseling.ConclusionChildren are frequently not present at pharmacies during prescription pick-up; however, children and parents are comfortable with and receptive to pediatric medication counseling by pharmacists. Interactive and educational technologies need to be developed and used by pharmacists to facilitate counseling and educate children about the effective and safe use of medicines

    Using Unoccupied Aerial Vehicles to estimate availability and group size error for aerial surveys of coastal dolphins

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    Aerial surveys are frequently used to estimate the abundance of marine mammals, but their accuracy is dependent upon obtaining a measure of the availability of animals to visual detection. Existing methods for characterizing availability have limitations and do not necessarily reflect true availability. Here, we present a method of using small, vessel-launched, multi-rotor Unoccupied Aerial Vehicles (UAVs, or drones) to collect video of dolphins to characterize availability and investigate error surrounding group size estimates. We collected over 20 h of aerial video of dive-surfacing behaviour across 32 encounters with Australian humpback dolphins Sousa sahulensis off north-western Australia. Mean surfacing and dive periods were 7.85 sec (se = 0.26) and 39.27 sec (se = 1.31) respectively. Dolphin encounters were split into 56 focal follows of consistent group composition to which example approaches to estimating availability were applied. Non-instantaneous availability estimates, assuming a 7 sec observation window, ranged between 0.22 and 0.88, with a mean availability of 0.46 (CV = 0.34). Availability tended to increase with increasing group size. We found a downward bias in group size estimation, with true group size typically one individual more than would have been estimated by a human observer during a standard aerial survey. The variability of availability estimates between focal follows highlights the importance of sampling across a variety of group sizes, compositions and environmental conditions. Through data re-sampling exercises, we explored the influence of sample size on availability estimates and their precision, with results providing an indication of target sample sizes to minimize bias in future research. We show that UAVs can provide an effective and relatively inexpensive method of characterizing dolphin availability with several advantages over existing approaches. The example estimates obtained for humpback dolphins are within the range of values obtained for other shallow-water, small cetaceans, and will directly inform a government-run program of aerial surveys in the region

    Salt marsh pond biogeochemistry changes hourly-to-yearly but does not scale with dimensions or geospatial position

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    Author Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Biogeosciences 125(10), (2020): e2020JG005664, doi:10.1029/2020JG005664.Shallow ponds are expanding in many salt marshes with potential impacts on ecosystem functioning. Determining how pond characteristics change over time and scale with physical dimensions and other spatial predictors could facilitate incorporation of ponds into projections of ecosystem change. We evaluated scaling relationships across six differently sized ponds in three regions of the high marshes within the Plum Island Ecosystems‐Long Term Ecological Research site (MA, USA). We further characterized diel fluctuations in surface water chemistry in two ponds to understand short‐term processes that affect emergent properties (e.g., habitat suitability). Primary producers drove oxygen levels to supersaturation during the day, while nighttime respiration resulted in hypoxic to anoxic conditions. Diel swings in oxygen were mirrored by pH and resulted in successive shifts in redox‐sensitive metabolisms, as indicated by nitrate consumption at dusk followed by peaks in ammonium and then sulfide overnight. Abundances of macroalgae and Ruppia maritima correlated with whole‐pond oxygen metabolism rates, but not with surface area (SA), volume (V), or SA:V. Moreover, there were no clear patterns in primary producer abundances, surface water chemistry, or pond metabolism rates across marsh regions supplied by different tidal creeks or that differed in distance to upland borders or creekbanks. Comparisons with data from 2 years prior demonstrate that plant communities and biogeochemical processes are not in steady state. Factors contributing to variability between ponds and years are unclear but likely include infrequent tidal exchange. Temporal and spatial variability and the absence of scaling relationships complicate the integration of high marsh ponds into ecosystem biogeochemical models.Thanks to S. McNichol, S. Jayne, E. Neel, and PIE‐LTER (NSF‐OCE1238212) for field assistance; I. Forbrich for meteorological data (Giblin & Forbrich, 2018); J. Jennings for dissolved nutrient analyses; J. Seewald for ion chromatograph access; and G. Mariotti for elevation data. C. Wilson and an anonymous reviewer provided comments that greatly improved our manuscript. A. C. S. was supported by NSF (OCE1233678), NOAA (NA14NOS4190145), and Sea Grant (NA14OAR4170104) awards, and A. D. by the MIT Undergraduate Research Opportunities Program.2021-03-1

    Dengue Virus-Induced Inflammation of the Endothelium and the Potential Roles of Sphingosine Kinase-1 and MicroRNAs

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    Copyright © 2015 Amanda L. Aloia et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.One of the main pathogenic effects of severe dengue virus (DENV) infection is a vascular leak syndrome. There are no available antivirals or specific DENV treatments and without hospital support severe DENV infection can be life-threatening. The cause of the vascular leakage is permeability changes in the endothelial cells lining the vasculature that are brought about by elevated vasoactive cytokine and chemokines induced following DENV infection. The source of these altered cytokine and chemokines is traditionally believed to be from DENV-infected cells such as monocyte/macrophages and dendritic cells. Herein we discuss the evidence for the endothelium as an additional contributor to inflammatory and innate responses during DENV infection which may affect endothelial cell function, in particular the ability to maintain vascular integrity. Furthermore, we hypothesise roles for two factors, sphingosine kinase-1 and microRNAs (miRNAs), with a focus on several candidate miRNAs, which are known to control normal vascular function and inflammatory responses. Both of these factors may be potential therapeutic targets to regulate inflammation of the endothelium during DENV infection

    Versatile routes to functional RAFT chain transfer agents through the Passerini multicomponent reaction

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    The widespread adoption of RAFT polymerization stems partly from the ease and utility of installing a functional chain transfer agent onto the ends of the generated polymer chains. In parallel, the Passerini multicomponent reaction offers great versatility in converting a wide range of easily accessible building blocks to functional materials. In this work, we have combined the two approaches such that a single, commonly available, RAFT agent is used in Passerini reactions to generate a variety of multifunctional RAFT chain transfer agents containing ester linkages. Reactions to generate the multifunctional RAFT agents took place under mild conditions and in good yields. The resulting Passerini-RAFT agents were able to exert control over radical polymerization to generate materials of well-defined molecular weights and dispersity. Furthermore, the presence in these polymer cores of ester and amide functionality through the Passerini chemistries, provided regions in the materials which are inherently biodegradable, facilitating any subsequent biomedical applications. The work overall thus demonstrates a versatile and facile synthetic route to multi functional RAFT chain transfer agents and biodegradable polymers
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