Comparison of Inorganic and Organic Matter Sedimentation in a Natural Laboratory: A One-Year Study at Lough Hyne Marine Reserve, Ireland

Measuring sedimentation rates may provide useful information on the habitat preferences of marine organisms. To understand the effect of flow rates and meteorological conditions on sedimentation in the absence of other confounding factors, sedimentation of organic (OM) and inorganic (IOM) matters was measured at 6 sites in Lough Hyne Marine Reserve (a semienclosed marine lake) over the course of 13 months. During winter, both OM and IOM were imported to the Lough, peaking in December at Whirlpool, the site nearest to the Lough entrance, likely as a result of extreme weather conditions causing resuspension of matter outside the Lough. Highest inorganic matter (IOM) sedimentation occurred in December (47.36 gm−2d−1 at Whirlpool Cliff) and was related to November wind speeds (, ). Decreasing current speed also caused a decline in IOM sedimentation. Highest OM sedimentation occurred in December at Whirlpool (5.59 gm−2d−1), but was not related to meteorological conditions. No single environmental factor strongly influenced organic matter (OM) sedimentation. One-way ANOVAs on OM and log-transformed IOM data showed that sedimentation differed significantly amongst the six sites within the Lough. Increased plankton production in the Lough during summer led to increased OM sedimentation in areas of low current speed away from the entrance of the Lough

The impact of a mosquito net voucher subsidy programme on incremental ownership: The case of the Tanzania National Voucher Scheme.

The subsidisation of mosquito nets has been widely used to increase ownership in countries where malaria represents a public health problem. However, an important question that has not been addressed empirically is how far net subsidy programmes increase ownership above the level that would have prevailed in the absence of the subsidy (i.e., incremental ownership). This study addresses that gap by investigating the impact of a large-scale mosquito net voucher subsidy--the Tanzania National Voucher Scheme (TNVS)--on short-term demand for unsubsidised commercial nets, estimating a household demand model with nationally representative household survey data. The results suggest that, despite the TNVS using a categorical targeting approach that did not discriminate by wealth, it still led to a large increase in incremental ownership of mosquito nets, with limited evidence of displacement of unsubsidised sales. Although no evidence is found of an additional TNVS voucher decreasing the number of unsubsidised sales in the same period, results indicate that an additional TNVS voucher reduced the probability of purchasing any unsubsidised net in the same period by 14%. The findings also highlight the critical role played by social learning or campaign messaging in increasing mosquito net ownership

Impact of Mask Wearing on Post-Exercise Hemodynamics

As the guidelines regarding COVID-19 regressed, many fitness centers established regulations requiring mask-wearing during exercise. Data suggest that the impact of a mask during exercise has minimal effects on exercise hemodynamics. The post-exercise period has been described as a window of opportunity to lower blood pressure, a phenomenon called post-exercise hypotension. The impact of wearing a mask on post-exercise hemodynamics is unknown. PURPOSE: The purpose of this study was to examine the impact of mask-wearing during exercise on post-exercise hemodynamics. METHODS: Nine total participants aged 18-30 yr were recruited for this experimental cross-over study. This within-subject design involved six randomized conditions; control no mask, no exercise (CON-NE), control-surgical mask, no exercise (CON-SUR), control-exercise, no mask (CON-E), exercise surgical mask (EXS-SUR), exercise N95 mask (EXS-N95), and exercise cloth mask (EXS-CL). The exercise protocol was a HIIT 4 x 4 on a cycle ergometer. Participants exercised at 85% of VO2max for four minutes, followed by a three-minute rest period, repeated four times. Measurements of cardiac output (Q), stroke volume (SV), heart rate (HR), systemic vascular resistance (SVR), and brachial blood pressure (BP) were measured pre-exercise for 20-min, during exercise, and postexercise for 60-min. RESULTS: Exercising at high intensity with the surgical, cloth, and N95 masks showed no statistically significant differences in HR, systolic BP, diastolic BP, SV, SVR, and RPE during exercise when compared to the CON-E condition (all p \u3e 0.05). Post-exercise data revealed no statistical differences in systolic BP or diastolic BP compared to the CON-E condition (both p \u3e 0.05). HR was significantly lower (roughly 4-5 ± 1.8 bpm p \u3c 0.01) in the CON-E group compared to all exercise mask-wearing groups following exercise. Additionally, SV (p\u3c0.001) and Q (p=0.002) were significantly lower in the EXS-N95 group compared to the other exercise groups. CONCLUSION: This study is consistent with current literature in suggesting that mask-wearing during exercise, even at high intensity, has no effect physiologically during exercise and on post-exercise hemodynamics. The impact of wearing a mask during exercise may alter the mechanisms of post-exercise hypotension

Local search: A guide for the information retrieval practitioner

There are a number of combinatorial optimisation problems in information retrieval in which the use of local search methods are worthwhile. The purpose of this paper is to show how local search can be used to solve some well known tasks in information retrieval (IR), how previous research in the field is piecemeal, bereft of a structure and methodologically flawed, and to suggest more rigorous ways of applying local search methods to solve IR problems. We provide a query based taxonomy for analysing the use of local search in IR tasks and an overview of issues such as fitness functions, statistical significance and test collections when conducting experiments on combinatorial optimisation problems. The paper gives a guide on the pitfalls and problems for IR practitioners who wish to use local search to solve their research issues, and gives practical advice on the use of such methods. The query based taxonomy is a novel structure which can be used by the IR practitioner in order to examine the use of local search in IR

Impact of mask-wearing during high-intensity interval training on exercise hemodynamics

As the guidelines regarding the COVID-19 pandemic regressed, allowing the re-opening of health centers, many established regulations required mask-wearing during exercise to limit transmission of the virus. Current literature suggests that the impact of a mask during exercise has minimal effects on exercise hemodynamics. However, limited data exists measuring blood pressure, cardiac output, and systemic vascular resistance during high-intensity exercise. PURPOSE: The purpose of this study was to examine the impact of mask-wearing on exercise hemodynamics. METHODS: Nine total participants aged 18-30 yr were recruited for this experimental cross-over study. This within subject design involved six randomized conditions; control no mask, no exercise (CON-NE), control-surgical mask, no exercise (CON-SUR), control-exercise, no mask (CON-E), exercise surgical mask (EXS-SUR), exercise N95 mask (EXS-N95), and exercise cloth mask (EXS-CL). The exercise protocol used was a HIIT 4 x 3 on a cycle ergometer. Participants exercised at 85% of VO2max for 4 minutes followed by a 3-minute rest period, repeated 4 times. Measurements of cardiac output (Q), stroke volume (SV), heart rate (HR), systemic vascular resistance (SVR), and brachial/central blood pressure (BP) was measured during exercise. RESULTS: There was no statistically significant difference between any exercise group on outcomes of HR ( CON-E: 172 ± 11, EXS-SUR: 171 ± 13, EXS-CL: 178 ± 9, EXS-N95: 177 ± 10, P=0.564), SBP (CON-E: 160 ± 26, EXS-SUR: 160 ± 23, EXS-CL: 166 ± 24, EXS-N95: 157 ± 22, P=0.913), DBP (CON-E: 70 ± 13, EXS-SUR: 69 ± 9, EXS-CL: 67 ± 11, EXS-N95: 75 ± 7, P=0.986), SV (CON-E: 102 ± 43, EXS-SUR: 85 ± 48, EXS-CL: 107 ± 44, EXS-N95: 100 ± 42, P=0.073), or SVR (CON-E: 1942 ± 4425, EXS-SUR: 3175 ± 6486, EXS-CL: 1270 ± 2601, EXS-N95: 1311 ± 4034, P=0.123). CONCLUSION: This study is consistent with current literature in suggesting that mask-wearing during exercise, even at high intensity has no effect physiologically during exercise

The interplay between extrinsic and intrinsic factors in determining migration decisions in brown trout (Salmo trutta): An experimental study

Many species are capable of facultative migration, but the relative roles of extrinsic versus intrinsic factors in generating diverse migratory tactics remain unclear. Here we explore the proximate drivers of facultative migration in brown trout in an experimental laboratory setting. The effects of reduced food, as a putative environmental cue, were examined in two populations: one that exhibits high rates of anadromy (sea-migration) in nature, and one that does not exhibit anadromy in nature. Juveniles derived from wild-caught parents were reared for two years under four environmental treatments: low food in years 1 and 2 (Low-Low); high food in years 1 and 2 (High-High), low food in year 1 and high in year 2 (Low-High), and vice versa (High-Low). Food restriction had a significant effect on migratory tactics, with the frequency of smolts (juveniles choosing migration) highest in the Low-Low treatment in both populations. No individuals became smolts in the High-High treatment, and intermediate smolting rates were observed in the Low-High and High-Low treatments. Higher overall smolting rates in the naturally anadromous population suggested an inherited component to anadromy/migration decisions, but both populations showed variability in migratory tactics. Importantly, some fish from the naturally non-anadromous population became smolts in the experiment, implying the capacity for migration was lying ‘dormant’, but they exhibited lower hypo-osmoregulatory function than smolts from the naturally anadromous population. Tactic frequencies in the naturally anadromous population were more affected by food in the 2nd year, while food in the 1st year appeared more important for the naturally non-anadromous population. Migratory tactics were also related to sex, but underpinned in both sexes by growth in key periods, size and energetic state. Collectively these results reveal how migration decisions are shaped by a complex interplay between extrinsic and intrinsic factors, informing our ability to predict how facultatively migratory populations will respond to environmental change

Extreme oxygen dynamics in shallow water of a fully marine Irish sea lough

The benthos of Lough Hyne (Europe’s first marine reserve) in SW Ireland has changed dramatically in the past decade with declining invertebrate communities and proliferating ephemeral macroalgae. In summer 2011 and 2012, we measured dissolved oxygen (DO) levels on shallow subtidal rocky shores of the lough and recorded both benthic hypoxia (<2 mg O2 L−1) and hyperoxia (∼10–16 mg O2 L−1). In late summer 2013, we systematically characterized the spatial and temporal patterns of DO in the lough seawater. Daytime DO levels were hyperoxic either at or near the rocky shore, declined with increased distance for the first 5 m offshore, then stabilized at normoxic levels (∼8 mg O2 L−1). DO levels above and below rocks were variable and often showed large differences (max. difference of 15.6 mg O2 L−1), particularly at rocky shore sites with low current flow. At night, the DO in shallow water declined, becoming hypoxic to anoxic during calm weather. These extreme oxygen fluctuations (i) are amongst the first records to report severe conditions within Irish coastal waters and (ii) could contribute to the known recent decline in benthic invertebrate diversity within the marine reserve