3,328 research outputs found

    Population demography of an endangered lizard, the Blue Mountains Water Skink.

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    BACKGROUND: Information on the age structure within populations of an endangered species can facilitate effective management. The Blue Mountains Water Skink (Eulamprus leuraensis) is a viviparous scincid lizard that is restricted to < 40 isolated montane swamps in south-eastern Australia. We used skeletochronology of phalanges (corroborated by mark-recapture data) to estimate ages of 222 individuals from 13 populations. RESULTS: These lizards grow rapidly, from neonatal size (30 mm snout-vent length) to adult size (about 70 mm SVL) within two to three years. Fecundity is low (mean 2.9 offspring per litter) and is affected by maternal body length and age. Offspring quality may decline with maternal age, based upon captive-born neonates (older females gave birth to slower offspring). In contrast to its broadly sympatric (and abundant) congener E. tympanum, E. leuraensis is short-lived (maximum 6 years, vs 15 years for E. tympanum). Litter size and offspring size are similar in the two species, but female E. leuraensis reproduce annually whereas many E. tympanum produce litters biennially. Thus, a low survival rate (rather than delayed maturation or low annual fecundity) is the key reason why E. leuraensis is endangered. Our 13 populations exhibited similar growth rates and population age structures despite substantial variation in elevation, geographic location and swamp size. However, larger populations (based on a genetic estimate of effective population size) contained older lizards, and thus a wider variance in ages. CONCLUSION: Our study suggests that low adult survival rates, as well as specialisation on a rare and fragmented habitat type (montane swamps) contribute to the endangered status of the Blue Mountains Water Skink

    Effect of Fodder Demonstrations in Rainfed Multi-location Conditions of Uttar Pradesh and Uttarakhand

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    Presently green fodder availability is 64.66 M tons and dry fodder (64.23 M tons.) in Uttar Pradesh, India., the green fodder deficit is 28.3% and dry fodder surplus by 14.1% respectively. Whereas, in Uttrakhand. Green fodder availability is 4.07 M tons and dry fodder 2.83 M tons, green fodder deficit is 48.1% and dry fodder 42.1%. There are many limitations affecting the forage production such as small holding of farmers and preferential need of food grains crops, limited availability of quality seed of improved varieties of fodder crops, low priority for investment in fodder production by the farmers. There is varied problem soils (acid, salt affected and water logged) prevailing in the area, lack of post harvest management for surplus fodder, no priority for fodder seed production by the farmers/seed producing agencies, no MSP for any of the fodder crops and lack of mechanization in fodder farming. Therefore, Nation Initiative on Fodder Technology Demonstrations will focus on increasing productivity through adoption of improved and appropriate technology best suited to the agro-climatic conditions in the zone in both arable and non-arable land. The objective of the technology demonstration is i). Accelerating production of fodder through promotion of fodder production, conservation and utilization enhancing the availability of the fodder throughout the year ii). Developing seed and planting material demonstrations units at KVK for fulfill the requirements of their vicinity. iii). Establishing back ward and forward linkages with different stake holders for profitable forage based life style husbandry

    Identification of nitric oxide synthase in human and bovine oviduct

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    Nitric oxide synthase (NOS) is responsible for the biological production of nitric oxide (NO) in several organs. NOS activity has also been localized in the reproductive tract, although direct evidence for its presence in the human or bovine oviduct is still lacking. In the present study, four different techniques were used to identify the presence of NOS activity in human (n = 11) and bovine (n = 9) oviduct: (i) conversion of [3H]-L-arginine to [3H]-L-citrulline; (ii) production of nitrite/nitrate (NO2/NO3; stable NO metabolites); (iii) identification of NADPH-diaphorase activity; and (iv) immunostaining with antiserum to endothelial NOS. Cytosolic extracts from human ampullary segments of the Fallopian tube, obtained from post-partum patients (n = 4), converted [3H]-L-arginine to [3H]-L-citrulline (21.0 ± 8.8 fmol/mg protein/min). This conversion rate was significantly (P <0.05) reduced in the presence of either EDTA or N-monomethyl-L-arginine monoacetate (L-NMMA), an inhibitor of NOS activity. When bovine (n = 3) ampullary segments were incubated for 36 h in Hanks' balanced salt solution, the concentration of NO2/NO3 in the medium was increased (P <0.05) if segments were pretreated with lipopolysaccharide (LPS; an inducer of inducible NOS), but not after treatment with LPS + L-NMMA. Additionally, epithelial cells cultured from ampullary segments showed positive staining both for NADPH-diaphorase activity and with antiserum to endothelial NOS. The results of the present study provide direct evidence for the presence of both the Ca2+ -dependent constitutive form of NOS, as well as the inducible form of NOS activity in human and bovine oviduct. Since the oviduct plays a key role in the reproductive process, it is possible that the two forms of NOS may be involved in the physiological regulation of oviduct functio

    CRYPTOSPORIDIUM CANIS N. SP. FROM DOMESTIC DOGS

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    Seizures and disturbed brain potassium dynamics in the leukodystrophy megalencephalic leukoencephalopathy with subcortical cysts

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    OBJECTIVE: Loss of function of the astrocyte-specific protein MLC1 leads to the childhood-onset leukodystrophy "megalencephalic leukoencephalopathy with subcortical cysts" (MLC). Studies on isolated cells show a role for MLC1 in astrocyte volume regulation and suggest that disturbed brain ion and water homeostasis is central to the disease. Excitability of neuronal networks is particularly sensitive to ion and water homeostasis. In line with this, reports of seizures and epilepsy in MLC patients exist. However, systematic assessment and mechanistic understanding of seizures in MLC are lacking. METHODS: We analyzed an MLC patient inventory to study occurrence of seizures in MLC. We used two distinct genetic mouse models of MLC to further study epileptiform activity and seizure threshold through wireless extracellular field potential recordings. Whole-cell patch-clamp recordings and K+-sensitive electrode recordings in mouse brain slices were used to explore the underlying mechanisms of epilepsy in MLC. RESULTS: An early onset of seizures is common in MLC. Similarly, in MLC mice, we uncovered spontaneous epileptiform brain activity and a lowered threshold for induced seizures. At the cellular level, we found that although passive and active properties of individual pyramidal neurons are unchanged, extracellular K+dynamics and neuronal network activity are abnormal in MLC mice. INTERPRETATION: Disturbed astrocyte regulation of ion and water homeostasis in MLC causes hyperexcitability of neuronal networks and seizures. These findings suggest a role for defective astrocyte volume regulation in epilepsy. Ann Neurol 2018;83:636-649

    Additional Haplogroups of Toxoplasma gondii out of Africa: Population Structure and Mouse-Virulence of Strains from Gabon

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    Prevalence of human toxoplasmosis in tropical African countries usually exceeds 50%. Its role as a major opportunistic infection of AIDS patients is regularly described. Due to the lack of investigation, congenital infection is certainly underestimated in Africa. Incidence of Toxoplasma ocular disease is higher in Africa and South America than in Europe. Severe cases in immunocompetent patients were described after infection acquired in Amazonia, but nothing is known about such cases in Africa. Several studies argued for a role of genotypes in the clinical expression of human toxoplasmosis, and for a geographical structuration of Toxoplasma across continents. Genetic data concerning isolates from Africa are scarce. Here, apart from the worldwide Type III, we described two main haplogroups, Africa 1 and 3. We detected genetic exchanges between urban centers favored by trade exchange and transportation. It shows how important human influence is, even in shaping the genetic structure of a zoonotic disease agent. Finding of identical haplogroups in South America suggested that these African and American strains share a common ancestor. As a higher pathogenicity in human of South American genotypes has been described, this similarity of genotypes should encourage further clinical studies with genotype analysis in Africa

    Interventions of Sodic Soil Reclamation Technologies and Constraints in their Adoption

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    ABSTRACT Salt affected soils are an important ecological entity in India and around 8.09 million ha is affected with menace of salinity in different climatic regions. Of this, 1.183 million ha area is in Rajasthan alone where soil reclamation programme is less effective as groundwater is of poor quality. As regards to underground water quality in Rajasthan state, only 16% is good, 16% marginal and 68% is of poor quality. Further, under poor quality water category, distribution of saline, sodic and saline sodic waters are about 16, 35 and 49%, respectively (Sen, 2003). Due to unavailability of good quality water for irrigation, use of poor quality underground water for irrigation has deteriorated the soil properties and reduced crop yields. Rajasthan state has developed several water projects for irrigation and drinking purposes. Galwa, Moti and Mansi dams for rain water conservation were developed in Tonk district. These dams are used to supply irrigation water through canals at critical stages of crops. Expansion of irrigation facilities through inter-basin transfer of water has created problems in different command areas through out the country, either in the form of water-logging, or a combination of water-logging and salinity in different irrigation commands. Moreover, sodicity problem in command areas is created due to indiscriminate irrigation with sodic under-ground water, as several times canals fail to supply irrigation water when needed. Further, undulated topography, low rainfall and high evaporation rate have also contributed to salt accumulation, deterioration of soil condition and low crop-yields. It calls for management of such soils to improve their physico-chemical condition for attaining higher sustainable crop production in command areas. The present study of farmers&apos; participatory research was accordingly carrie
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