bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linkages between environmental conditions and recreational king mackerel (Scomberomorus cavalla) catch off west‐central Florida
Authors: WALL CARRIE C. , MULLER‐KARGER FRANK E. , ROFFER MITCHELL A. 
Published: May 2009

AbstractCatch statistics for the king mackerel (Scomberomorus cavalla) recreational fishery off west‐central Florida were derived from angler interviews conducted during 19 seasonal tournaments held in April–May and October–November of 2004 and 2005. Fishing location, number of fish per line per hour (catch per unit effort), and presence of baitfish from the tournament data were examined in the context of bathymetric gradients and other benthic features (e.g., wrecks or artificial reefs), and the location and persistence of oceanic fronts mapped using satellite imagery of sea surface temperature (AVHRR) and ocean color (MODIS and SeaWiFS). Generalized linear models were applied to identify the relationship between king mackerel catch rates and environmental data. The distance of fishing activity to the nearest front varied substantially, particularly when winds and front position were variable. However, baitfish presence with proximity to water clarity fronts (as defined by water‐leaving radiance at 443 nm) significantly influenced successful king mackerel catch. Positive catch rates were significantly influenced by chlorophyll values and period (season and year). Additionally, intermediate water clarity (in the range 0.7–1.0 mW cm−2μm−1 sr−1) led to higher catch rates. Decreased water quality, primarily associated with a large Karenia brevis red tide, led to a lower number of catch and lower catch rates (122 king mackerel, 0.13 catch per unit effort) in fall 2005, compared to spring 2004 (179, 0.14), fall 2004 (360, 0.17) and spring 2005 (296, 0.21), despite a consistent seasonal effort.
Atmospheric nitrogen‐deposition may intensify phosphorus limitation of shallow epilithic periphyton in unproductive lakes
Authors: LIESS A. , DRAKARE S. , KAHLERT M. 
Published: May 2009

Summary1. We tested whether increasing atmospheric nitrogen (N) deposition along a north–south gradient intensifies epilithic phosphorus (P) limitation in oligotrophic Swedish lakes from the north to the south. We examined the epilithic community at a shallow depth from seven northern and six southern Swedish lakes, and also compared the results with a lake located geographically between the two groups. We determined lake nutrient state, epilithic nutrient ratios and epilithic algal composition, as well as grazer N : P ratios, grazer‐epilithon N : P imbalance, and N : P cycling ratios.2. Epilithic communities appear to be generally more N‐limited in the northern lakes and more P‐limited in the southern lakes. Lake water total N (Tot‐N) and epilithic N : P ratios were lower in northern than in southern lakes and the proportion of N2‐fixing cyanobacteria was higher in northern than in southern lakes.3. Gastropod grazers had lower N : P imbalances and cycled less N relative to P in northern than in southern lakes.4. Atmospheric N‐deposition showed a strong positive correlation with lake water Tot‐N and a much weaker positive correlation with epilithon N : P ratios. Atmospheric N‐deposition also correlated negatively with the proportion of N2‐fixing cyanobacteria.5. There are indications that increased atmospheric N‐deposition towards the south might intensify P‐limitation of epilithic algae and invertebrate grazers, although more studies are needed to show the strength and generality of our findings.
Contingent productivity responses to more extreme rainfall regimes across a grassland biome
Authors: HEISLER‐WHITE JANA L. , BLAIR JOHN M. , KELLY EUGENE F. , HARMONEY KEITH , KNAPP ALAN K. 
Published: May 2009

AbstractClimate models predict, and empirical evidence confirms, that more extreme precipitation regimes are occurring in tandem with warmer atmospheric temperatures. These more extreme rainfall patterns are characterized by increased event size separated by longer within season drought periods and represent novel climatic conditions whose consequences for different ecosystem types are largely unknown. Here, we present results from an experiment in which more extreme rainfall patterns were imposed in three native grassland sites in the Central Plains Region of North America, USA. Along this 600 km precipitation–productivity gradient, there was strong sensitivity of temperate grasslands to more extreme growing season rainfall regimes, with responses of aboveground net primary productivity (ANPP) contingent on mean soil water levels for different grassland types. At the mesic end of the gradient (tallgrass prairie), longer dry intervals between events led to extended periods of below‐average soil water content, increased plant water stress and reduced ANPP by 18%. The opposite response occurred at the dry end (semiarid steppe), where a shift to fewer, but larger, events increased periods of above‐average soil water content, reduced seasonal plant water stress and resulted in a 30% increase in ANPP. At an intermediate mixed grass prairie site with high plant species richness, ANPP was most sensitive to more extreme rainfall regimes (70% increase). These results highlight the inherent complexity in predicting how terrestrial ecosystems will respond to forecast novel climate conditions as well as the difficulties in extending inferences from single site experiments across biomes. Even with no change in annual precipitation amount, ANPP responses in a relatively uniform physiographic region differed in both magnitude and direction in response to within season changes in rainfall event size/frequency.
Population trends of European common birds are predicted by characteristics of their climatic niche
Authors: JIGUET FRÉDÉRIC , GREGORY RICHARD D. , DEVICTOR VINCENT , GREEN RHYS E. , VOŘÍŠEK PETR , VAN STRIEN ARCO , COUVET DENIS 
Published: May 2009

AbstractTemperate species are projected to experience the greatest temperature increases across a range of modelled climate change scenarios, and climate warming has been linked to geographical range and population changes of individual species at such latitudes. However, beyond the multiple modelling approaches, we lack empirical evidence of contemporary climate change impacts on populations in broad taxonomic groups and at continental scales. Identifying reliable predictors of species resilience or susceptibility to climate warming is of critical importance in assessing potential risks to species, ecosystems and ecosystem services. Here we analysed long‐term trends of 110 common breeding birds across Europe (20 countries), to identify climate niche characteristics, adjusted to other environmental and life history traits, that predict large‐scale population changes accounting for phylogenetic relatedness among species. Beyond the now well‐documented decline of farmland specialists, we found that species with the lowest thermal maxima (as the mean spring and summer temperature of the hottest part of the breeding distribution in Europe) showed the sharpest declines between 1980 and 2005. Thermal maximum predicted the recent trends independently of other potential predictors. This study emphasizes the need to account for both land‐use and climate changes to assess the fate of species. Moreover, we highlight that thermal maximum appears as a reliable and simple predictor of the long‐term trends of such endothermic species facing climate change.
Demographic effects of temperature‐dependent sex determination: will tuatara survive global warming?
Authors: MITCHELL NICOLA J. , ALLENDORF FRED W. , KEALL SUSAN N. , DAUGHERTY CHARLES H. , NELSON NICOLA J. 
Published: May 2009

AbstractGlobal climate change is of particular concern for small and isolated populations of reptiles with temperature‐dependent sex determination because low genetic variation can limit adaptive response in pivotal temperatures, leading to skewed sex ratios. We explore the demographic consequences of skewed sex ratios on the viability of a tuatara population characterized by low genetic diversity. We studied the rare species of tuatara (Sphenodon guntheri) on the 4 ha North Brother Island in New Zealand over two nesting seasons and captured 477 individuals, with a 60% male bias in the adult population. Females first breed at 15 years and have extremely low rates of gravidity, producing clutches of three to eight eggs every 9 years. Simulations of the population using population viability analysis showed that the current population is expected to persist for at least 2000 years at hatchling sex ratios of up to 75% male, but populations with 85% male hatchlings are expected to become extinct within approximately 300 years (some eight generations). Incorporation of inbreeding depression increased the probability of extinction under male biased sex ratios, with no simulated populations surviving at hatchling sex ratios >75% male. Because recent models have predicted that climate change could lead to the production of all male S. guntheri hatchlings by 2085, we examined whether periodic intervention to produce mixed or female biased sex ratios would allow the population to survive if only males were produced in natural nests. We show that intervention every 2–3 years could buffer the effects of climate change on population sex ratios, but translocation to cooler environs might be more cost‐effective. Climate change threatens tuatara populations because neither modified nesting behaviour nor adaptive response of the pivotal temperature can modify hatchling sex ratios fast enough in species with long generation intervals.
Optimizing resiliency of reserve networks to climate change: multispecies conservation planning in the Pacific Northwest, USA
Authors: CARROLL CARLOS , DUNK JEFFREY R. , MOILANEN ATTE 
Published: May 2009

AbstractThe effectiveness of a system of reserves may be compromised under climate change as species' habitat shifts to nonreserved areas, a problem that may be compounded when well‐studied vertebrate species are used as conservation umbrellas for other taxa. The Northwest Forest Plan was among the first efforts to integrate conservation of wide‐ranging focal species and localized endemics into regional conservation planning. We evaluated how effectively the plan's focal species, the Northern Spotted Owl, acts as an umbrella for localized species under current and projected future climates and how the regional system of reserves can be made more resilient to climate change. We used the programmaxentto develop distribution models integrating climate data with vegetation variables for the owl and 130 localized species. We used the programzonationto identify a system of areas that efficiently captures habitat for both the owl and localized species and prioritizes refugial areas of climatic and topographic heterogeneity where current and future habitat for dispersal‐limited species is in proximity. We projected future species' distributions based on an ensemble of contrasting climate models, and incorporating uncertainty between alternate climate projections into the prioritization process. Reserve solutions based on the owl overlap areas of high localized‐species richness but poorly capture core areas of localized species' distribution. Congruence between priority areas across taxa increases when refugial areas are prioritized. Although core‐area selection strategies can potentially increase the conservation value and resilience of regional reserve systems, they accentuate contrasts in priority areas between species and over time and should be combined with a broadened taxonomic scope and increased attention to potential effects of climate change. Our results suggest that systems of fixed reserves designed for resilience can increase the likelihood of retaining the biological diversity of forest ecosystems under climate change.
Physiological and environmental regulation of interannual variability in CO2 exchange on rangelands in the western United States
Authors: POLLEY H. WAYNE , EMMERICH WILLIAM , BRADFORD JAMES A. , SIMS PHILLIP L. , JOHNSON DOUGLAS A. , SALIENDRA NICANOR Z. , SVEJCAR TONY , ANGELL RAYMOND , FRANK ALBERT B. , PHILLIPS REBECCA L. , SNYDER KEIRITH A. , MORGAN JACK A. 
Published: May 2009

AbstractFor most ecosystems, net ecosystem exchange of CO2 (NEE) varies within and among years in response to environmental change. We analyzed measurements of CO2 exchange from eight native rangeland ecosystems in the western United States (58 site‐years of data) in order to determine the contributions of photosynthetic and respiratory (physiological) components of CO2 exchange to environmentally caused variation in NEE. Rangelands included Great Plains grasslands, desert shrubland, desert grasslands, and sagebrush steppe. We predicted that (1) week‐to‐week change in NEE and among‐year variation in the response of NEE to temperature, net radiation, and other environmental drivers would be better explained by change in maximum rates of ecosystem photosynthesis (Amax) than by change in apparent light‐use efficiency (α) or ecosystem respiration at 10 °C (R10) and (2) among‐year variation in the responses of NEE, Amax, and α to environmental drivers would be explained by changes in leaf area index (LAI). As predicted, NEE was better correlated with Amax than α or R10 for six of the eight rangelands. Week‐to‐week variation in NEE and physiological parameters correlated mainly with time‐lagged indices of precipitation and water‐related environmental variables, like potential evapotranspiration, for desert sites and with net radiation and temperature for Great Plains grasslands. For most rangelands, the response of NEE to a given change in temperature, net radiation, or evaporative demand differed among years because the response of photosynthetic parameters (Amax, α) to environmental drivers differed among years. Differences in photosynthetic responses were not explained by variation in LAI alone. A better understanding of controls on canopy photosynthesis will be required to predict variation in NEE of rangeland ecosystems.
Electromyographic study of ejaculatory mechanism
Authors: Shafik A. , Shafik A. A. , El Sibai O. , Shafik I. A. 
Published: May 2009

SummaryCavernosus muscle (CM), seminal vesicle (SV) and vasal ampullary (VA) contractions at ejaculation are said to be reflex mechanisms (ejaculatory reflex), which have been scarcely dealt with in the literature. We investigated the hypothesis that contraction of the CMs, SVs and VA at ejaculation is a reflex action. The electromyographic (EMG) activity of CM, SV and VA during ejaculation was recorded in 28 healthy men. The test was repeated after separate anaesthetization of the glans penis (GP), CMs, SVs, and VA in the pre‐ejaculatory period. Latent ejaculatory time (LET) was calculated. CMs showed no EMG activity until rigid erection phase was reached. SVs and VA exhibited resting EMG activity which increased gradually with different stages of erection. At ejaculation, CMs, SVs and VA showed two to four intermittent contractions. The mean LET was 1.3 ± 0.2 sec. GP anaesthetization led to the disappearance of CM, SV and VA EMG activity at ejaculation, while bland gel did not affect EMG activity. CMs, SVs and VA when anaesthetized in the pre‐ejaculatory period exhibited no EMG activity at ejaculation, while saline did not affect EMG activity. Increased EMG activity of CM, SV and VA apparently denotes increase in their contractile activity. CM, SV and VA contraction on GP stimulation and ejaculation are assumed to be reflex actions and are mediated through the ‘glans‐cavernosovesicular reflex’ (GCVR) which presumably represents the ejaculatory reflex. Changes in LET or evoked response would indicate a defect in the reflex pathway. The GCVR might act as an investigative tool in diagnosing erectile dysfunction, provided further studies are performed in this respect.
Increased aneuploidy rates in spermatozoa of a male carrier of a trisomy 18 mosaicism
Authors: Perrin A. , Douet‐Guilbert N. , Le Bris M. J. , May‐Panloup P. , Guichet A. , Amice V. , Amice J. , De Braekeleer M. , Morel F. 
Published: May 2009

SummarySemen analysis of a 31‐year‐old infertile man showed a severe oligoteratozoospermia. Karyotyping of peripheral blood lymphocytes showed a 47,XY,+18[13]/46,XY[16] mosaicism. Cultured skin fibroblasts, right and left jugal smears showed 3, 50 and 65% trisomic cells respectively. The aim of the study was to evaluate the aneuploidy rates of chromosomes X, Y, 13, 18 and 21 and the diploidy rate in his spermatozoa by fluorescence in situ hybridization. The rate of disomy 18 was significantly increased in the spermatozoa of the patient (0.68%) compared to the control group (0.06%). A statistically significant difference in the rates of disomy for chromosome 13 (0.46% vs. 0.14%) and the gonosomes (0.78% vs. 0.24%) and diploidy (0.93% vs. 0.34%) was also found between the patient and the control group. However, no significant difference was observed for chromosome 21 (0.34% vs. 0.15%). Our results show evidence of a generalized perturbation of the meiotic mechanism that could lead to an increased risk for a mosaic trisomy 18 infertile male of producing offspring with aneuploidy that is not only on account of the father’s mosaicism, but also more particularly because of severe oligoteratozoospermia.
Perceptions of a service redesign by adults living with type 2 diabetes
Authors: McDowell Joan R.S. , McPhail Kathryn , Halyburton Gillian , Brown Malcolm , Lindsay Grace 
Published: May 2009

AbstractTitle.  Perceptions of a service redesign by adults living with type 2 diabetes. Aim.  This article is a report of a study conducted to explore the perceptions of adults with type 2 diabetes towards the service redesign.Background.  Diabetes is reaching epidemic proportions and the management of this chronic illness is changing in response to this challenge. In the United Kingdom, there is ongoing restructuring of healthcare services for people with chronic illnesses to ensure that their general health and clinical needs are met predominantly in primary care.Method.  An explorative qualitative approach was used. Eight focus groups were conducted with 35 people with type 2 diabetes in one urban location between 2003 and 2004. Five focus groups were conducted with people who had recently experienced the restructured service and three groups with people who had up to 2 years’ experience of the new service. Concurrent data collection and thematic analysis were conducted by three researchers and credibility and verification sought by feedback to participants.Findings.  Five main themes were identified: impact of living with diabetes; understanding diabetes; drivers for organizational change; care in context and individual concerns. Participants identified issues for ongoing development of the service.Conclusion.  People with type 2 diabetes appreciate their care management within the primary care setting where there has been investment in staff to deliver this care. Healthcare resources are required to support the development of staff and the necessary infrastructure to undertake management in primary care. Policy makers need to address the balance of resources between primary and secondary care.
Areas of endemism and spatial diversification of the Muscidae (Insecta: Diptera) in the Andean and Neotropical regions
Authors: Löwenberg‐Neto Peter , De Carvalho Claudio José Barros 
Published: May 2009

AbstractAim  We present a biogeographical analysis of the areas of endemism and areas of diversification in the Muscidae. This analysis searched for geographical patterns in the Muscidae to reconstruct elements of the evolutionary biogeographical history of this insect family.Location  Andean and Neotropical regions.Method  We constructed a geographic database of 728 species from the literature and museum specimens. Areas of endemism were established by parsimony analysis of endemicity (PAE) based on grids of two different sizes: 5° (550 × 550 km) and 2° (220 × 220 km). Areas of diversification were delimited by track analysis that also included phylogenetic information. This process was independently applied to 11 genera. For each genus, we plotted generalized tracks generated by sister species on a map. When these generalized tracks supported inter‐generic nodes they were manually contoured and inferred to be areas of diversification for the Muscidae.Results  Thirteen endemic areas were found using the 5° grid, and eight endemic areas resulted from the 2° grid. Ten areas were in agreement with previous studies, and 11 were new. Amazonian and Atlantic areas of diversification agreed with previous areas for the genus Polietina, and new areas of diversification were found in Panama and in central Chile.Main conclusions  Six spatial patterns in the Muscidae were identified: (1) areas of endemism in both Pampa and Puna provinces were established with species whose distributions had not previously been analysed; (2) a new area of endemism was established in extreme southern South America, in Tierra del Fuego; (3) two new areas of diversification, which include Panama and central Chile, were identified; (4) a spatial association was identified between the separation of Chiloe Island from the continent and the diversification in Andean species; (5) a north–south track axis and latitudinal node intervals were identified, interpreted as spatial responses to glaciation or glacial retreat in the Andes; and (6) a spatial coincidence of areas of endemism, of diversification and high species richness in the Muscidae was discovered. The analysis of a complete database and the recognition of areas of diversification are extremely important in elucidating novel biogeographical patterns, which will in turn contribute to a better understanding of the geographical patterns of evolution in the Muscidae.
Species on the menu of a generalist predator, the eastern red bat (Lasiurus borealis): using a molecular approach to detect arthropod prey
Authors: CLARE ELIZABETH L. , FRASER ERIN E. , BRAID HEATHER E. , FENTON M. BROCK , HEBERT PAUL D. N. 
Published: May 2009

AbstractOne of the most difficult interactions to observe in nature is the relationship between a predator and its prey. When direct observations are impossible, we rely on morphological classification of prey remains, although this is particularly challenging among generalist predators whose faeces contain mixed and degraded prey fragments. In this investigation, we used a polymerase chain reaction and sequence‐based technique to identify prey fragments in the guano of the generalist insectivore, the eastern red bat (Lasiurus borealis), and evaluate several hypotheses about prey selection and prey defences. The interaction between bats and insects is of significant evolutionary interest because of the adaptive nature of insect hearing against echolocation. However, measuring the successes of predator tactics or particular prey defences is limited because we cannot normally identify these digested prey fragments beyond order or family. Using a molecular approach, we recovered sequences from 89% of the fragments tested, and through comparison to a reference database of sequences, we were able to identify 127 different species of prey. Our results indicate that despite the robust jaws of L. borealis, most prey taxa were softer‐bodied Lepidoptera. Surprisingly, more than 60% of the prey species were tympanate, with ears thought to afford protection against these echolocating bats. Moths of the family Arctiidae, which employ multiple defensive strategies, were not detected as a significant dietary component. Our results provide an unprecedented level of detail for the study of predator–prey relationships in bats and demonstrate the advantages which molecular tools can provide in investigations of complex ecological systems and food‐web relationships.