10 research outputs found

    Falcons using orchard nest boxes reduce fruit-eating bird abundances and provide economic benefits for a fruit-growing region

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    1. Suppression of pest species via a native predator is a regulating ecosystem service that has the potential to limit crop damage and produce economic benefits. American kestrels Falco sparverius are widespread, highly mobile, generalist predators that hunt in human-dominated habitats and have the potential to provide previously undocumented ecosystem services in agricultural landscapes. 2. We hypothesized that kestrel activity associated with nest boxes and artificial perches acts to increase perceived predation risk that, in combination with direct predation, can reduce fruit-eating bird abundances in orchards. We used counts and observations of fruit-eating birds from fixed-width transect surveys to investigate variation in bird abundances and to estimate sweet cherry loss in cherry orchards with and without active kestrel boxes. We also conducted a benefit–cost analysis of nest box installation and used regional economic modelling to estimate macroeconomic impacts of increased sweet cherry production in Michigan, an important US fruit production region. 3. Fruit-eating bird counts were significantly lower at orchards with active kestrel boxes. Although kestrels used the perches in young orchard blocks and may benefit from them, the presence of perches did not have a significant effect on bird counts. 4. Benefit–cost ratios for kestrel nest boxes indicated that for every dollar spent on nest boxes, 84to84 to 357 of sweet cherries would be saved from fruit-eating birds. Regional economic modelling predicted that increased sweet cherry production from reduced bird damage would result in 46–50 jobs created and 2.2millionto2.2 million to 2.4 million in increased income for the state of Michigan over a 5-year period. 5. Synthesis and applications. Kestrel nest boxes in sweet cherry orchards provide a highly cost-effective ecosystem service with potential reverberating benefits for a regional economy. Box occupancy rates will undoubtedly vary across landscapes and regions. However, costs to install and maintain boxes are small and, even if box occupancy rates are low, boxes can direct kestrel activity to particular places in agricultural landscapes where they can deter pest birds. Thus, the potential benefits for fruit crops greatly outweigh the costs of this pest management strategy

    Stimulus-specific functional remodeling of the left ventricle in endurance and resistance-trained men

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    Left ventricular (LV) structural remodeling following athletic training has been evidenced through training-specific changes in wall thickness and geometry. Whether the LV response to changes in hemodynamic load also adapts in a training-specific manner is unknown. Using echocardiography, we examined LV responses of endurance-trained (n = 15), resistance-trained (n = 14), and nonathletic men (n = 13) to 1) 20, 40, and 60% one repetition-maximum (1RM), leg-press exercise and 2) intravascular Gelofusine infusion (7 mL/kg) with passive leg raise. While resting heart rate was lower in endurance-trained participants versus controls (P = 0.001), blood pressure was similar between groups. Endurance-trained individuals had lower wall thickness but greater LV mass relative to body surface area versus controls, with no difference between resistance-trained individuals and controls. Leg press evoked a similar increase in blood pressure; however, resistance-trained participants preserved stroke volume (SV; −3 ± 8%) versus controls at 60% 1RM (−15 ± 7%, P = 0.001). While the maintenance of SV was related to the change in longitudinal strain across all groups (R = 0.537; P = 0.007), time-to-peak strain was maintained in resistance-trained but delayed in endurance-trained individuals (1 vs. 12% delay; P = 0.021). Volume infusion caused a similar increase in end-diastolic volume (EDV) and SV across groups, but leg raise further increased EDV only in endurance-trained individuals (5 ± 5 to 8 ± 5%; P = 0.018). Correlation analysis revealed a relationship between SV and longitudinal strain following infusion and leg raise (R = 0.334, P = 0.054); however, we observed no between-group differences in longitudinal myocardial mechanics. In conclusion, resistance-trained individuals better maintained SV during pressure loading, whereas endurance-trained individuals demonstrated greater EDV reserve during volume loading. These data provide novel evidence of training-specific LV functional remodeling. NEW & NOTEWORTHY Training-specific functional remodeling of the LV in response to different loading conditions has been recently suggested, but not experimentally tested in the same group of individuals. Our data provide novel evidence of a dichotomous, training-specific LV adaptive response to hemodynamic pressure or volume loading

    Falcons using orchard nest boxes reduce fruit-eating bird abundances and provide economic benefits for a fruit-growing region

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    1. Suppression of pest species via a native predator is a regulating ecosystem service that has the potential to limit crop damage and produce economic benefits. American kestrels Falco sparverius are widespread, highly mobile, generalist predators that hunt in human-dominated habitats and have the potential to provide previously undocumented ecosystem services in agricultural landscapes. 2. We hypothesized that kestrel activity associated with nest boxes and artificial perches acts to increase perceived predation risk that, in combination with direct predation, can reduce fruit-eating bird abundances in orchards. We used counts and observations of fruit-eating birds from fixed-width transect surveys to investigate variation in bird abundances and to estimate sweet cherry loss in cherry orchards with and without active kestrel boxes. We also conducted a benefit–cost analysis of nest box installation and used regional economic modelling to estimate macroeconomic impacts of increased sweet cherry production in Michigan, an important US fruit production region. 3. Fruit-eating bird counts were significantly lower at orchards with active kestrel boxes. Although kestrels used the perches in young orchard blocks and may benefit from them, the presence of perches did not have a significant effect on bird counts. 4. Benefit–cost ratios for kestrel nest boxes indicated that for every dollar spent on nest boxes, 84to84 to 357 of sweet cherries would be saved from fruit-eating birds. Regional economic modelling predicted that increased sweet cherry production from reduced bird damage would result in 46–50 jobs created and 2.2millionto2.2 million to 2.4 million in increased income for the state of Michigan over a 5-year period. 5. Synthesis and applications. Kestrel nest boxes in sweet cherry orchards provide a highly cost-effective ecosystem service with potential reverberating benefits for a regional economy. Box occupancy rates will undoubtedly vary across landscapes and regions. However, costs to install and maintain boxes are small and, even if box occupancy rates are low, boxes can direct kestrel activity to particular places in agricultural landscapes where they can deter pest birds. Thus, the potential benefits for fruit crops greatly outweigh the costs of this pest management strategy

    Occupancy modeling reveals territory-level effects of nest boxes on the presence, colonization, and persistence of a declining raptor in a fruit-growing region

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    <div><p>Nest boxes for predators in agricultural regions are an easily implemented tool to improve local habitat quality with potential benefits for both conservation and agriculture. The potential for nest boxes to increase raptor populations in agricultural regions is of particular interest given their positions as top predators. This study examined the effects of cherry orchard nest boxes on the local breeding population of a declining species, the American Kestrel (<i>Falco sparverius</i>), in a fruit-growing region of Michigan. During the 2013–2016 study, we added a total of 23 new nest boxes in addition to 24 intact boxes installed previously; kestrels used up to 100% of our new boxes each season. We conducted temporally-replicated surveys along four roadside transects divided into 1.6 km × 500 m sites. We developed a multi-season occupancy model under a Bayesian framework and found that nest boxes had strong positive effects on first-year site occupancy, site colonization, and site persistence probabilities. The estimated number of occupied sites increased between 2013 and 2016, which correlated with the increase in number of sites with boxes. Kestrel detections decreased with survey date but were not affected by time of day or activity at the boxes themselves. These results indicate that nest boxes determined the presence of kestrels at our study sites and support the conclusion that the local kestrel population is likely limited by nest site availability. Furthermore, our results are highly relevant to the farmers on whose properties the boxes were installed, for we can conclude that installing a nest box in an orchard resulted in a high probability of kestrels occupying that orchard or the areas adjacent to it.</p></div

    Multi-season occupancy modeling results for kestrel presence.

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    <p>Multi-season occupancy modeling results for kestrel presence.</p

    Predictions of the relationship between Julian date and kestrel detection probability <i>p</i>.

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    <p>Black line shows posterior mean, and gray lines show the relationship based on a random posterior sample of size 200 to visualize estimation uncertainty [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0185701#pone.0185701.ref034" target="_blank">34</a>].</p

    Data from: Falcons using orchard nest boxes reduce fruit-eating bird abundances and provide economic benefits for a fruit-growing region

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    1. Suppression of pest species via a native predator is a regulating ecosystem service that has the potential to limit crop damage and produce economic benefits. American kestrels (Falco sparverius) are widespread, highly-mobile, generalist predators that hunt in human-dominated habitats and potentially provide previously undocumented ecosystem services in agricultural landscapes. 2. We hypothesized that kestrel activity associated with nest boxes and artificial perches acts to increase perceived predation risk that, in combination with direct predation, can reduce fruit-eating bird abundances in orchards. We used counts and observations of fruit-eating birds from fixed-width transect surveys to investigate variation in bird abundances and to estimate sweet cherry loss in cherry orchards with and without active kestrel boxes. We also conducted a benefit-cost analysis of nest box installation and used regional economic modelling to estimate macroeconomic impacts of increased sweet cherry production in Michigan, an important US fruit-production region. 3. Fruit-eating bird counts were significantly lower at orchards with active kestrel boxes. Although kestrels used the perches in young orchard blocks and may benefit from them, the presence of perches did not have a significant effect on bird counts. 4. Benefit-cost ratios for kestrel nest boxes indicated that for every dollar spent on nest boxes, 84to84 to 357 of sweet cherries are saved from fruit-eating birds. Regional economic modelling predicted that increased sweet cherry production from reduced bird damage would result in 46 to 50 jobs created and 2.2millionto2.2 million to 2.4 million in increased income for the state of Michigan over a five-year period. 5. Synthesis and application. Kestrel nest boxes in sweet cherry orchards provide a highly cost-effective ecosystem service with potential reverberating benefits for a regional economy. Box occupancy rates will undoubtedly vary across landscapes and regions. However, costs to install and maintain boxes are small and, even if box occupancy rates are low, boxes can direct kestrel activity to particular places in agricultural landscapes where they can deter pest birds. Thus, the potential benefits in fruit crops greatly outweigh the costs of this pest management strategy

    The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure

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    BACKGROUND: Exercise training is recommended for chronic heart failure (HF) patients to improve functional status and reduce risk of adverse outcomes. Elevated plasma levels of amino-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (hs-CRP), and cardiac troponin T (cTnT) are associated with increased risk of adverse outcomes in this patient population. Whether exercise training leads to improvements in biomarkers and how such improvements relate to clinical outcomes are unclear. METHODS AND RESULTS: Amino-terminal pro-brain natriuretic peptide, hs-CRP, and cTnT levels were assessed at baseline and 3 months in a cohort of 928 subjects from the HF-ACTION study, a randomized clinical trial of exercise training versus usual care in chronic HF patients with reduced left ventricular ejection fraction (<35%). Linear and logistic regressions were used to assess 3-month biomarker levels as a function of baseline value, treatment assignment (exercise training vs usual care), and volume of exercise. Linear regression and Cox proportional hazard modeling were used to evaluate the relations between changes in biomarker levels and clinical outcomes of interest that included change in peak oxygen consumption (peak VO(2)), hospitalizations, and mortality. Exercise training was not associated with significant changes in levels of NT-proBNP (P = .10), hs-CRP (P = .80), or detectable cTnT levels (P = .83) at 3 months. Controlling for baseline biomarker levels or volume of exercise did not alter these findings. Decreases in plasma concentrations of NT-proBNP, but not hs-CRP or cTnT, were associated with increases in peak VO(2) (P < .001) at 3 months and decreased risk of hospitalizations or mortality (P ≤ .04), even after adjustment for a comprehensive set of known predictors. CONCLUSIONS: Exercise training did not lead to meaningful changes in biomarkers of myocardial stress, inflammation, or necrosis in patients with chronic HF. Only improvements in NT-proBNP translated to reductions in peak VO(2) and reduced risk of clinical events
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