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Ocean acidification but not nutrient enrichment reduces grazing and alters diet preference in Littorina littorea
No full textOcean acidification and eutrophication have direct, positive effects on the growth of many marine macroalgae, potentially resulting in macroalgal blooms and shifts in ecosystem structure and function. Enhanced growth of macroalgae, however, may be controlled by the presence of grazers. While grazing under ocean acidification and eutrophication conditions has variable responses, there is evidence of these factors indirectly increasing consumption. We tested whether a common marine herbivorous snail, Littorina littorea, would increase consumption rates of macroalgae (Ulva and Fucus) under ocean acidification (increased pCO2) and/or eutrophication conditions, via feeding trials on live and reconstituted algal thalli. We found that increased pCO2 resulted in reduced grazing rates on live thalli, with snails feeding almost exclusively on Ulva. However, eutrophication did not impact consumption rates of live tissues. In addition, similarity in consumption of reconstituted Ulva and Fucus tissues across all treatments indicated that physical characteristics of algal tissues, rather than tissue chemistry, may drive dietary shifts in a changing climate. In this system, decreased consumption, coupled with increased growth of macroalgae, may ultimately enhance algal growth and spread
Assessing Durability and Safety of Permethrin Impregnated Uniforms Used by Outdoor Workers to Prevent Tick Bites after One Year of Use
No full textLong lasting permethrin-impregnated (LLPI) clothing can retain permethrin and repel ticks for up to three months and without exceeding EPA-approved safe levels; however, little is known about longer term effects of wearing LLPI clothing. Here, permethrin content was measured in new forester pants soon after initial impregnation (Insect Shield) and again one year later after being repeatedly worn by foresters in the field. Urine samples were collected from foresters for biomonitoring of permethrin metabolites at multiple time intervals (pre-use, one-month, three-to-four-months, and one-year post-use). Lethality against nymphal Ixodes scapularis Say was measured in clothing after one year of wear by foresters. Furthermore, to test potential variability in permethrin impregnation of different batches of clothing, separate sets of clothing were anonymously sent to Insect Shield for permethrin treatment over a period of three months and permethrin was quantified. Results demonstrated 33% of participants\u27 pants had no measurable permethrin after one year of wear and permethrin content and tick mortality varied significantly between clothing. Only two of the participants\u27 clothing resulted in ≥ 30% tick mortality after one year of wear. Significant differences were observed in 3-PBA and trans-DCCA, but not cis-DCCA metabolites in participants over the four measured time points and were higher than general United States population levels. This study provides practical information on the safety (measured by urinary metabolites) over time of LLPI clothing. It also provides snapshots (pre-washing and after one year of wear) of effectiveness of LLPI clothing as personal protective equipment against ticks for outdoor workers
Contribution of Viscoelastic Stress to the Synchronization of Earthquake Cycles on Oceanic Transform Faults
No full textEarthquake clustering can be promoted by local, regional, and remote triggering. The interaction between faults by static and dynamic stress transfer has received much attention. However, the role of quasi-static stress interaction mediated by viscoelastic flow is still poorly understood. Here, we investigate whether the tight synchronization of moment-magnitude 6 earthquakes every about 6 years on distant asperities in the Gofar-Discovery fault system of the East Pacific Rise may be caused by mechanical coupling within the lithosphere-asthenosphere system. We build a three-dimensional numerical model of seismic cycles in the framework of rate- and state-dependent friction with a brittle layer overlaying a viscoelastic mantle with nonlinear rheology to simulate earthquake cycles on separate asperities. The brittle section of the West Gofar fault consists of two frictionally unstable 20 km-long by 5 km-wide asperities separated by a velocity-strengthening barrier, consistent with seismic observations, allowing stress transfer by afterslip and viscoelastic relaxation. We find that viscoelastic stress transfer can promote the synchronization of earthquakes. Even if the asperities are separated by as far as 30 km, synchronization is still possible for a viscosity of the underlying mantle of 1017 Pa s, which can be attained by dislocation creep or transient creep during the postseismic period. Considering the similarities in tectonic and structural settings, viscoelastic stress transfer and earthquake synchronization may also occur at 15’20 (Mid-Atlantic Ridge), George V (Southeast Indian Ridge), Menard and Heezen transform fault (Pacific-Antarctic Ridge)
First Generation Female College Students\u27 Health, Stress and Alcohol Use
Get PDFGoing to college can be a stressful time for many adolescents/emerging adults. For some, this may be the first time they are living on their own, caring for themselves, and managing their time without the direct supervision of parents. Guided by social- ecological theory, this study examined family influences of stress, well-being, and alcohol use among female undergraduate college students, and compared the experiences of first-generation college women (FirstGens) with those whose parents attended college. We hypothesized FirstGens might not experience the same level of anticipatory guidance from parents that could ease the transition to college. This cross- sectional study examined family background, FirstGen status, general health, stress, and alcohol use in female students at the University of Rhode Island and SUNY Binghamton. Data about the fall 2020 semester were collected via an anonymous online survey.
Results demonstrated that FirstGens reported lower levels of overall health (p = .018) compared to others; 54% rated their health as poor or fair. FirstGens also reported higher levels of stress related to managing money (p = .004) and family relationships (p = .001), with no differences reported for academics, roommate issues, and COVID- related stress. However, FirstGens were less likely to report that parents provided them with alcohol for their dorm or apartment compared to peers with college-educated parents (8.4% vs. 17.4%; p = .02). They were also less likely to reside in a sorority or off-campus apartment (p = .003). FirstGens also reported drinking and binge drinking on fewer days than peers (p = .001, p = .04, respectively). Female FirstGen college students may have different early college experiences and challenges compared to peers with college-educated parents. Some differences may be protective (e.g., less alcohol use) while others may be important stressors to consider when designing health promotion programs for college students
Ballasting System for an Autonomous Underwater Vehicle
Get PDFNOURA RAYES (Mechanical Engineering); Ballasting System for an Autonomous Underwater Vehicle Sponsor: Bahram Nassersharif (Mechanical Engineering)
Over the last year, our Mechanical Engineering Capstone team, Nautilus, has been working to design a ballasting system for various Autonomous Underwater Vehicles (AUVs) sponsored by Raytheon Technologies. Common AUV systems are used for a wide range of applications from environmental monitoring, oceanic exploration, to data collection. AUVs also have many technical advantages that make underwater tasks more efficient, cost-effective, and generally safer. Raytheon Technology, specifically, is looking to improve their existing ballasting mechanism for their AUVs to use for military defense. For this project, Raytheon Technology has set a standard for this design to improve upon current space, weight, and power efficiencies. The end goal of this design is to create a modular ballasting system, to meet the specific requirements set by Raytheon, to be designed for a Type B AUV. Ballasting systems are known to drive the vertical motion of AUV systems based on density control. To control the desired depth of such devices, ballast is used to create negative, neutral, or positive buoyancy based on Archimedes Principle. Predominantly, the vehicle should be able to remove .6lbs of water and reach a depth of 14ft, having a variable ballasting time no longer than 10 minutes and a mission length of at least 30 minutes. A syringe-type ballast system design was established to meet the desired criteria. After the team’s proof of concept, the design was evaluated for improvement. Currently, the system has been made to utilize two linear actuators, to act as the devices trim tanks, that each have feedback control. The feedback on this design is necessary to precisely regulate the density of the vehicle. Composing this project includes methods of sketching, mechatronics control, machining, CAD modeling, 3D printing, waterproof testing, and teamwork collaboration
Distinctive Collections Sexennial Report, 2016-2022
Get PDFReport of the Distinctive Collections Unit (formerly known as Special Collections and University Archives, University Libraries, University of Rhode Island covering 2016-2022. Covers history and mission of the unit, staffing, accomplishments, and future goals
The impact of media and information literacy on students’ acquisition of the skills needed to detect fake news
Get PDFThis research investigated the impact of media and information literacy (MIL) on education faculty students’ acquisition of the skills needed to detect fake news. A one-group experimental design was employed with a randomly selected sample of 100 Jordanian undergraduate students. The participants completed one pre-test and two post-tests, each of which consisted of 10 closed-ended questions and one open-ended question on how to detect fake news. The results indicated that studying MIL has an impact on students’ acquisition of the skills needed to detect fake news. The findings also suggested that the methods students employed to identify and detect fake news after studying the MIL course were scientific and well-reasoned. Based on the results, several recommendations are made that will be of value to researchers and workers in this field
Free-energy landscapes and insertion pathways for peptides in membrane environment
Get PDFFree-energy landscapes for short peptides—specifically for variants of the pH low insertion peptide (pHLIP)—in the heterogeneous environment of a lipid bilayer or cell membrane are constructed, taking into account a set of dominant interactions and the conformational preferences of the peptide backbone. Our methodology interprets broken internal H-bonds along the backbone of a polypeptide as statistically interacting quasiparticles, activated from the helix reference state. The favored conformation depends on the local environment (ranging from polar to nonpolar), specifically on the availability of external H-bonds (with H2O molecules or lipid headgroups) to replace internal H-bonds. The dominant side-chain contribution is accounted for by residue-specific transfer free energies between polar and nonpolar environments. The free-energy landscape is sensitive to the level of pH in the aqueous environment surrounding the membrane. For high pH, we identify pathways of descending free energy that suggest a coexistence of membrane-adsorbed peptides with peptides in solution. A drop in pH raises the degree of protonation of negatively charged residues and thus increases the hydrophobicity of peptide segments near the C terminus. For low pH, we identify insertion pathways between the membrane-adsorbed state and a stable trans-membrane state with the C terminus having crossed the membrane
Success or growth? Distinctive roles of extrinsic and intrinsic career goals in high-performance work systems, job crafting, and job performance
No full textDespite the increasing evidence that has demonstrated the strengths of high-performance work systems (HPWS), there is no consensus on the relation between HPWS and job performance. By integrating HPWS theory with the model of career goals, we developed a mediated moderation model to explain the way career goals moderate the relation between employee-experienced HPWS and job performance, and whether job crafting mediates these interactive effects. Based upon a multi-phase, multi-source sample of 398 employees and their direct supervisors, we found that employee-experienced HPWS is related positively and significantly to job performance only when intrinsic career goals are high or when extrinsic career goals are low, and the results showed that job crafting mediates these moderated relations. Theoretical contributions, practical implications, and limitations are discussed as well
The Experiences of Sexually Abused Women with Disabilities Who Consulted Services in Zimbabwe: The Intersection of Disability, Gender, and Poverty
Get PDFWomen have experienced sexual abuse, and very few of them report to the police or seek other services, such as medical attention. This study aims to gain insight into the barriers women with disabilities face when accessing police, health, and counseling services after experiencing sexual abuse. Barriers such as long distances, physical barriers at service sites, communication barriers, gender issues, lack of confidence in the service providers, and an overall lack of resources were reported. In a study undertaken in Zimbabwe, women with disabilities encountered intersecting barriers such as the intersection of disability, and gender, poverty, unemployment, and low levels of education aggravated structural and social impediments for women with disabilities when seeking services after sexual abuse