2,641 research outputs found

    Future hydrological extremes: the uncertainty from multiple global climate and global hydrological models

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    Projections of changes in the hydrological cycle from global hydrological models (GHMs) driven by global climate models (GCMs) are critical for understanding future occurrence of hydrological extremes. However, uncertainties remain large and need to be better assessed. In particular, recent studies have pointed to a considerable contribution of GHMs that can equal or outweigh the contribution of GCMs to uncertainty in hydrological projections. Using six GHMs and five GCMs from the ISI-MIP multi-model ensemble, this study aims: (i) to assess future changes in the frequency of both high and low flows at the global scale using control and future (RCP8.5) simulations by the 2080s, and (ii) to quantify, for both ends of the runoff spectrum, GCMs and GHMs contributions to uncertainty using a two-way ANOVA. Increases are found in high flows for northern latitudes and in low flows for several hotspots. Globally, the largest source of uncertainty is associated with GCMs, but GHMs are the greatest source in snow-dominated regions. More specifically, results vary depending on the runoff metric, the temporal (annual and seasonal) and regional scale of analysis. For instance, uncertainty contribution from GHMs is higher for low flows than it is for high flows, partly owing to the different processes driving the onset of the two phenomena (e.g. the more direct effect of the GCMs' precipitation variability on high flows). This study provides a comprehensive synthesis of where future hydrological extremes are projected to increase and where the ensemble spread is owed to either GCMs or GHMs. Finally, our results underline the need for improvements in modelling snowmelt and runoff processes to project future hydrological extremes and the importance of using multiple GCMs and GHMs to encompass the uncertainty range provided by these two sources

    Fever among Children in Calabar, Nigeria: Malaria, the Predominant Precursory Medical Condition

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    The study was aimed at elucidating the yearly total hospital admittances due to fever among children under 13 years and the associated underlying medical conditions between the years 2000 and 2011. Records of cases of fever among children under 13 years who presented with fever-associated medical condition and attended the General Hospital, Calabar between 2000 and 2011 were collated. The causes of the fever, age and sex of children were collected and collated. A total of 3663 children were admitted into the General Hospital Calabar with fever-associated medical condition between the year 2000 and 2011. Of these, males were 1520 (41.5%) while females were 2143 (58.5%). The sex-related difference was significant (x2-test; p < 0.05). The relative proportion of total annual fever cases ranged from 8.7% to 17.0% between 2000 and 2005, and 2.8% to 5.0% between 2006 and 2011. There are significantly higher number of cases between 2000 and 2005 than between 2006 and 2011 in all the categories of sex and age (t-test; p < 0.05 for all the tests). Malaria was associated with more than a third of the fever cases (39.3%) recorded. This was followed by Respiratory Tract Infection (RTI) which was associated with a fifth of all fever cases recorded (20.1%). In all, 25 medical conditions were found to be associated with fever among the children. The control of malaria and RTI would significantly reduce the burden of fever in Calabar. Keywords: Fever, malaria, Hospital attendance, Under 13 years childre

    Effectiveness of GF-120 NF Naturalyte Fruit Fly Bait Spray against Different Ages of Melon Fly (Diptera: Tephritidae) Females When Applied to Border Crops of Various Widths

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    GF-120 NF Naturalyte Fruit Fly Bait was evaluated for its effectiveness to prevent melon fly, Bactrocera cucurbitae (Coquillett), females of various ages from ovipositing in cucumber patches with border crops of different widths. Cohorts of color-marked, protein-fed females, eclosed after 1, 2, or 4 weeks, were released from sites outside sorghum, (Sudax bicolor x S. bicolor var. sudanense) borders 1, 2, or 4 rows deep (30, 90, and 135 cm in width, respectively). Capture rates of female B. cucurbitae were higher for 2- and 4-week-old than for 1-week-old females. Borders sprayed with GF-120 NF Naturalyte Fruit Fly Bait were effective at preventing released sexually- mature 4-wk-old females from reaching the cucumber patches only when in association with the widest border (135 cm) treatment. Our findings suggest that for maximum effectiveness against host-seeking female B. cucurbitae, GF-120 NF Naturalyte Fruit Fly Bait should be applied to broader swaths of sorghum planted as a border crop

    Pan-Africanism: a contorted delirium or a pseudonationalist paradigm? Revivalist critique

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    This essaic-article goes against established conventions that there is anything ethno-cultural (and hence national) about the so-called African tribes. Drawing largely from the culture history of precolonial/prepolitical Africans—that is, the Bantu/Cushitic-Ethiopians (Azanians)—the author has demonstrated vividly that far from being distinct ethno-culture national communities, the so-called tribes of African states are better considered subculture groups, whose regional culture practices erstwhile paid tribute to their nation’s main culture center in Karnak. For example, using the culture symbols and practices of some local groups and linking them to the predynastic and dynastic Pharaonic periods, I argued that there is compelling evidence against qualifying Africa’s tribes as distinct ethno-culture national entities. In genuine culture context, I stressed that the Ritual of Resurrection and its twin culture process of the mummification of deceased indigenous Pharaohs tend to suggest that the object of the Bantu/Cushitic-Ethiopians national culture was life (in its eternal manifestation) and then resurrection later, and that there are recurring (culturally sanctioned) ethical examples among the culture custodians of these subculture groups that generally pay tribute to the overarching culture norm. Furthermore, the fact that the Ritual of Resurrection began in the Delta region and ended at the Sources of the Nile, where the spirit of the deceased indigenous Pharaohs was introduced into the spiritual world of their ancestors, contradicts conventional perceptions that ancient Egypt was a distinct national community isolated from precolonial/prepolitical Africa/Azania

    Connexins and Pannexins in Bone and Skeletal Muscle

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    PURPOSE OF REVIEW: To discuss current knowledge on the role of connexins and pannexins in the musculoskeletal system. RECENT FINDINGS: Connexins and pannexins are crucial for the development and maintenance of both bone and skeletal muscle. In bone, the presence of connexin and more recently of pannexin channels in osteoblasts, osteoclasts, and osteocytes has been described and shown to be essential for normal skeletal development and bone adaptation. In skeletal muscles, connexins and pannexins play important roles during development and regeneration through coordinated regulation of metabolic functions via cell-to-cell communication. Further, under pathological conditions, altered expression of these proteins can promote muscle atrophy and degeneration by stimulating inflammasome activity. In this review, we highlight the important roles of connexins and pannexins in the development, maintenance, and regeneration of musculoskeletal tissues, with emphasis on the mechanisms by which these molecules mediate chemical (e.g., ATP and prostaglandin E2) and physical (e.g., mechanical stimulation) stimuli that target the musculoskeletal system and their involvement in the pathophysiological changes in both genetic and acquired diseases

    The influence of riparian woodland on the spatial and temporal variability of stream water temperatures in an upland salmon stream

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    International audienceThe spatio-temporal variability of stream water temperatures was investigated at six locations on the Girnock Burn (30km2 catchment), Cairngorms, Scotland over three hydrological years between 1998 and 2002. The key site-specific factors affecting the hydrology and climatology of the sampling points were investigated as a basis for physical process inference. Particular emphasis was placed on assessing the effects of riparian forest in the lower catchment versus the heather moorland riparian zones that are spatially dominant in the upper catchment. The findings were related to river heat budget studies that provided process detail. Gross changes in stream temperature were affected by the annual cycle of incoming solar radiation and seasonal changes in hydrological and climatological conditions. Inter-annual variation in these controlling variables resulted in inter-annual variability in thermal regime. However, more subtle inter-site differences reflected the impact of site-specific characteristics on various components of the river energy budget. Inter-site variability was most apparent at shorter time scales, during the summer months and for higher stream temperatures. Riparian woodland in the lower catchment had a substantial impact on thermal regime, reducing diel variability (over a period of 24 hours) and temperature extremes. Observed inter-site differences are likely to have a substantial effect on freshwater ecology in general and salmonid fish in particular. Keywords: temperature, thermal regime, forest, salmon, hydrology, Girnock Burn, Cairngor

    The effect of colour vision status on the detection and selection of fruits by tamarins (Saguinus spp.)

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    The evolution of trichromatic colour vision by the majority of anthropoid primates has been linked to the efficient detection and selection of food, particularly ripe fruits among leaves in dappled light. Modelling of visual signals has shown that trichromats should be more efficient than dichromats at distinguishing both fruits from leaves and ripe from unripe fruits. This prediction is tested in a controlled captive setting using stimuli recreated from those actually encountered by wild tamarins (Saguinus spp.). Dietary data and reflectance spectra of Abuta fluminum fruits eaten by wild saddleback (Saguinus fuscicollis) and moustached (Saguinus mystax) tamarins and their associated leaves were collected in Peru. A. fluminum leaves, and fruits in three stages of ripeness, were reproduced and presented to captive saddleback and red-bellied tamarins (Saguinus labiatus). Trichromats were quicker to learn the task and were more efficient at selecting ripe fruits than were dichromats. This is the first time that a trichromatic foraging advantage has been demonstrated for monkeys using naturalistic stimuli with the same chromatic properties as those encountered by wild animal

    Hercules X-1: Empirical Models of UV Emission Lines

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    The UV emission lines of Hercules X-1, resolved with the HST GHRS and STIS, can be divided into broad (FWHM 750 km/s) and narrow (FWHM 150 km/s) components. The broad lines can be unambiguously identified with emission from an accretion disk which rotates prograde with the orbit. The narrow lines, previously identified with the X-ray illuminated atmosphere of the companion star, are blueshifted at both phi=0.2 and phi=0.8 and the line flux at phi=0.2 is 0.2 of the flux at phi=0.8. Line ratio diagnostics show that the density of the narrow line region is log n=13.4+/-0.2 and the temperature is T=1.0+/-0.2x10^5 K. The symmetry of the eclipse ingress suggests that the line emission on the surface of the disk is left-right symmetric relative to the orbit. Model fits to the O V, Si IV, and He II line profiles agree with this result, but fits to the N V lines suggest that the receding side of the disk is brighter. We note that there are narrow absorption components in the N V lines with blueshifts of 500 km/s.Comment: To be published in the Astrophysical Journa

    Story in health and social care

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    This paper offers a brief consideration of how narrative, in the form of people‟s own stories, potentially figures in health and social care provision as part of the impulse towards patient-centred care. The rise of the epistemological legitimacy of patients‟ stories is sketched here. The paper draws upon relevant literature and original writing to consider the ways in which stories can mislead as well as illuminate the process of making individual treatment care plans
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