48 research outputs found
Widespread colonisation of Tanzanian catchments by introduced Oreochromis tilapia fishes: the legacy from decades of deliberate introduction
From the 1950s onwards, programmes to promote aquaculture and improve capture fisheries in East Africa have relied heavily on the promise held by introduced species. In Tanzania these introductions have been poorly documented. Here we report the findings of surveys of inland water bodies across Tanzania between 2011 and 2017 that clarify distributions of tilapiine cichlids of the genus Oreochromis. We identified Oreochromis from 123 sampling locations, including 14 taxa restricted to their native range and three species that have established populations beyond their native range. Of these three species, the only exotic species found was blue-spotted tilapia (Oreochromis leucostictus), while Nile tilapia (Oreochromis niloticus) and Singida tilapia (Oreochromis esculentus), which are both naturally found within the country of Tanzania, have been translocated beyond their native range. Using our records, we developed models of suitable habitat for the introduced species based on recent (1960â1990) and projected (2050, 2070) East African climate. These models indicated that presence of suitable habitat for these introduced species will persist and potentially expand across the region. The clarification of distributions provided here can help inform the monitoring and management of biodiversity, and inform policy related to the future role of introduced species in fisheries and aquaculture
Notas sobre el tratamiento de la histeria : Tesis inaugural
A la cabeza de portada: Universidad de la Capital. Facultad de Ciencias MĂ©dicas. - Incluye nĂłmina de CatedrĂĄticos y Asignatura
Language, exclusion and violent jihad: are they related?
This paper advances the hypothesis that an inability to fully participate in an immigrant parentâs first language as a minority community language, and associated pressures this can put on the individualâs sense of personal identity and self-esteem, can be a contributing factor to the profound alienation that has been implicated in the rise of Islamic extremist violence. Studies of Islamic extremism have sought to identify common factors in the backgrounds of self-styled jihadists; however, they have proved to be a fairly heterogeneous group. One factor that stands out is that, in Europe and North America, the so-called home-grown terrorist is frequently a second- or third-generation immigrant. Education in the majority community language and a desire to assimilate not infrequently lead to an incomplete acquisition, and subsequent attrition of a âhomeâ language. This can separate the second/third-generation immigrant from the minority community, while discrimination forms a barrier to acceptance by the majority community. This paper briefly examines some of the background literature in Applied Linguistics and Counter Terrorism Studies, before turning to sources that tend to support the hypothesis. Finally, a case is made for further study and some possible approaches suggested
Diet of the extinct Lava mouse Malpaisomys insularis from the Canary Islands: Insights from dental microwear
Malpaisomys insularis is a mouse-like rodent endemic to the eastern Canary Islands. It became extinct during the fourteenth century. It was a remarkable species living under hyperarid conditions. A dental microwear analysis was performed in order to determine its former diet. The elevated number of fine scratches found in Malpaisomys molars suggests that it consumed a significant part of Poaceae, grass consumption leaving the most distinctive features on dental wear facets. A graminivorous diet with a high amount of abrasive items is in agreement with the broad teeth of Malpaisomys, considered as adapted to grass consumption. However, in the absence of potential competitors over its native range, it is likely that Malpaisomys also foraged on dicots to meet higher nutrient and energetic requirements. The ecology of Malpaisomys is discussed from these results in the context of the desertic climatic conditions of the eastern Canary Islands and with a special concern on its small body size in contrast to other large-sized island murine species such as the giant rats of the central Canary Islands. © 2010 Springer-Verlag.The present study is a part of the Spanish program N CGL2007-62047/BTE and is contributed by ISE-M (UMR 5554) n 2010-124.Peer Reviewe
Data from: Evolutionary dynamics of the leaf phenological cycle in an oak metapopulation along an elevation gradient
It has been predicted that environmental changes will radically alter the selective pressures on phenological traits. Long-lived species, such as trees, will be particularly affected, as they may need to undergo major adaptive change over only one or a few generations. The traits describing the annual life cycle of trees are generally highly evolvable, but nothing is known about the strength of their genetic correlations. Tight correlations can impose strong evolutionary constraints, potentially hampering the adaptation of multivariate phenological phenotypes. In this study, we investigated the evolutionary, genetic and environmental components of the timing of leaf unfolding and senescence within an oak metapopulation along an elevation gradient. Population divergence, estimated from in situ and common garden data, was compared to expectations under neutral selection, based on microsatellite markers. This approach made it possible (1) to evaluate the influence of genetic correlation on multivariate local adaptation to elevation and (2) to identify traits probably exposed to past selective pressures due to the colder climate at high elevation. The genetic correlation was positive but very weak, indicating that genetic constraints did not shape the local adaptation pattern for leaf phenology. Both spring and fall (leaf unfolding and senescence, respectively) phenology timings were involved in local adaptation, but leaf unfolding was probably the trait most exposed to climate change-induced selection. Our data indicated that genetic variation makes a much smaller contribution to adaptation than the considerable plastic variation displayed by a tree during its lifetime. The evolutionary potential of leaf phenology is, therefore, probably not the most critical aspect for short-term population survival in a changing climate
âHer body was my countryâ: Gender and Cuban-American exile-community nationalist identity in the work of Gustavo PĂ©rez Firmat
Messy moods: Nostalgia and other nagging feelings in Oscar Hijuelos's The Mambo Kings Play Songs of Love
High urinary excretion of kidney injury molecule-1 is an independent predictor of end-stage renal disease in patients with IgA nephropathy
Item does not contain fulltextBACKGROUND: The variable course of immunoglobulin A nephropathy (IgAN) warrants accurate tools for the prediction of progression. Urinary kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) are markers for the detection of early tubular damage caused by various renal conditions. We evaluated the prognostic value of these markers in patients with IgAN. METHODS: We included patients (n = 65, 72% male, age 43 +/- 13 years) with biopsy-proven IgAN, who were evaluated for proteinuria. Urinary KIM-1 and NGAL were measured by enzyme-linked immunosorbent assay. We analysed data using Cox regression for the outcome end-stage renal disease (ESRD). RESULTS: Median serum creatinine was 142 mumol/L and proteinuria 2.2 g/day. During follow-up (median 75 months), 23 patients (35%) developed ESRD. In patients with IgAN median urinary KIM-1 excretion was 1.7 ng/min and NGAL excretion was 47 ng/min, both significantly higher than in healthy controls. KIM-1 and NGAL were correlated with proteinuria (r = 0.40 and 0.34, respectively, P < 0.01) and each other (r = 0.53, P < 0.01) but not with estimated glomerular filtration rate (eGFR). Interestingly, KIM-1 was not significantly correlated with the excretion of alpha(1)-microglobulin (alpha(1)m) and beta(2)-microglobulin (beta(2)m), known markers of tubular injury. Univariate analysis showed that baseline serum creatinine and urinary excretion of total protein, alpha(1)m, beta(2)m, immunoglobulin G, KIM-1 and NGAL were significantly associated with ESRD. By multivariate analysis, serum creatinine and KIM-1 excretion proved to be significant independent predictors of ESRD. CONCLUSION: KIM-1 and NGAL excretion are increased in patients with IgAN and correlate with proteinuria but not with eGFR. Baseline serum creatinine and urinary KIM-1, but not proteinuria, are independent predictors of ESRD