257 research outputs found

    FOOD HABITS OF ASIAN ELEPHANT (Elephas maximus maximus) IN HANDAPANAGALA , SOUTH EAST SRI LANKA

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    Handapanagala tank area is home for the largest Elephant aggregation(Elephas maxim us maxim us) in Wellawaya area during the dry season. Mostof these Elephants come from different areas mainly from adjacent protectedareas such as Yala, Udawalawe and Lunugamwehera National parks. Themain traditional migratory route lies across the study area connecting Yala -through Demodara. The local migration is mainly due to lack of food andwater within the protected areas.The study attempted to find the food habits of elephants in Handapanagalaarea during dry season. This study was carried out for six months. The mainobjectives were to determine both food availability and feeding habits inrelation to the habitats. Food availability and their Relative ImportanceValues (RIV) were estimated using line transect and direct observationmethod within study area. Relative importance values were comparativelyhigh in species like Bauhinia racemosa (12.39 %), Fleuggea leucocarpa(17.32 %), Securinrega leucopyrus (14.3 %). Relative frequency valueindicated that most common species distributed in the study area wereBauhinia racemosa, Dichrostachys cinera, Phyllanthus sp., Premna sp. Themicro histological analysis was done to determine food habits of elephants.The major food plant parts in dung samples were analyzed to identify thecategories of plants consumed by elephants. This study revealed that themajor food items consumed by elephant during dry season were themonocotyledon leaves (65 %), Culm (12 %), Sheath (6 %) and DicotylidensBark (7 %) and, Woody fiber (2%). The predominant grasses identified indung samples were Imperata cylindrica (Gini grass) and Panicum maximum(Illuk). The field observations revealed that the elephants were mainlyconsuming plants in families such as Leguminosae, Graminae,Euphorbiaceae and Verbenaceae. Majority of bark damages were seen inplants such as Bauhinia racemosa (RIV - 12.39), Treminalia arjuna(Kumbuk) and Phyllanthus spp. A total of 112 plant species were identifiedand 35 species (31% of the available plants) were consumed by elephants.The results indicate that the Elephants in the Handapanagala are grazers andmainly feed on tall grasses during the dry season. Results also indicated that there is an impact on forest tree species like Bauhinia racemosa, Fleuggealeucocarpa and Securinrega leucopyrus, which have high RIV. Since thepresent study was carried out during dry season, this should be continuedduring wet season to get a hroad idea about the seasonal changes in foodhabits of Elephants.

    IMPACT OF SAMBAR DEER(Cervus unicoior unicoior) ON THE VEGETATION AT THE HORTON PLAINS NATIONAL PARK

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    A survey was carried out at the Horton Plains National Park to investigate the influenceof sambar deer on grassland and fares' vegetation. The method adopted was, comparisonof the dominant grassland communities and seedlings in the forested areas with andwithout the effect of deer. Three enclosures (20 m x 5 m) were erected in the grasslandand four enclosures (20 In x 15 m) were erected in the forest to serve as controls (nograzing). Similar areas adjoining the plots were marked with pegs as test areas (withgrazing). Field surveys were carried ou. during the years 1997 and 1998. Incidence andextent of bark damage by sambar deer \Y<JS also examined using a scoring method on sixtransects each measuring 250 lJ1. GSN (Grazing Susceptibility Number) was used as anindicator of the the phytosociological behaviour of sambar in the grassland SummedDominance Ratio (SDR)) was used to calculate the GSN. During the months of January,March. July and October 1997, GSN values for dominant species in the grassland vizPennicetum and Chrysopogon were 184,20,23.75, -3.06 and 18.6,8.1, 17.23, 19.0respectively. The minus GSN value of ).06 indicates that during October Pcnnicctumgrass was not damaged by deer which coincided with the flowering period of thatspecies. Grazing presusure values obtained during the periods July-Sep 97, Sep-Nov 97 .Nov-Jan 98, Jan-Mar 98 for Pennicetum and Chrysopogon were 17, 5.6, -17.6, 5.8 andI, I I, -0.5, 0.9 respectively. Here the minus values indicates heavy grazing. During theperiods of less rain and also during peak lactation periods of sambar, the grazingpressure is high (July-September and November-January) compared to positive values ofgrazing pressure which coincides well with the comparatively high rainfall periods Studiesof the forest vegetation revealed that after a period of two years (1997-1999) 88'% ofseedlings survived (N=1499) in the enclosure but only 73% of the seedlings survived(N= 1488) in the open area. Bark damage is distinct on plants like Cinnamomumovalifolium, Neolitsea fucata, Calopiiyllum walkeri, Eurya japonica, Eleocarpussubvillosus, Syzigium revolutum and rJedyotis lawsoniae all of which have high IV)(Importance Value Indices). Trees with average gbh 28 cm and average height 7 m weremore prone to damage by deer. Only S% of a total of 921 trees were dead due to barkdamage

    Infectious Disease Ontology

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    Technological developments have resulted in tremendous increases in the volume and diversity of the data and information that must be processed in the course of biomedical and clinical research and practice. Researchers are at the same time under ever greater pressure to share data and to take steps to ensure that data resources are interoperable. The use of ontologies to annotate data has proven successful in supporting these goals and in providing new possibilities for the automated processing of data and information. In this chapter, we describe different types of vocabulary resources and emphasize those features of formal ontologies that make them most useful for computational applications. We describe current uses of ontologies and discuss future goals for ontology-based computing, focusing on its use in the field of infectious diseases. We review the largest and most widely used vocabulary resources relevant to the study of infectious diseases and conclude with a description of the Infectious Disease Ontology (IDO) suite of interoperable ontology modules that together cover the entire infectious disease domain

    Seeking legitimacy through CSR: Institutional Pressures and Corporate Responses of Multinationals in Sri Lanka

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    Arguably, the corporate social responsibility (CSR) practices of multinational enterprises (MNEs) are influenced by a wide range of both internal and external factors. Perhaps most critical among the exogenous forces operating on MNEs are those exerted by state and other key institutional actors in host countries. Crucially, academic research conducted to date offers little data about how MNEs use their CSR activities to strategically manage their relationship with those actors in order to gain legitimisation advantages in host countries. This paper addresses that gap by exploring interactions between external institutional pressures and firm-level CSR activities, which take the form of community initiatives, to examine how MNEs develop their legitimacy-seeking policies and practices. In focusing on a developing country, Sri Lanka, this paper provides valuable insights into how MNEs instrumentally utilise community initiatives in a country where relationship-building with governmental and other powerful non-governmental actors can be vitally important for the long-term viability of the business. Drawing on neo-institutional theory and CSR literature, this paper examines and contributes to the embryonic but emerging debate about the instrumental and political implications of CSR. The evidence presented and discussed here reveals the extent to which, and the reasons why, MNEs engage in complex legitimacy-seeking relationships with Sri Lankan institutions

    Testing in Mice the Hypothesis That Melanin Is Protective in Malaria Infections

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    Malaria has had the largest impact of any infectious disease on shaping the human genome, exerting enormous selective pressure on genes that improve survival in severe malaria infections. Modern humans originated in Africa and lost skin melanization as they migrated to temperate regions of the globe. Although it is well documented that loss of melanization improved cutaneous Vitamin D synthesis, melanin plays an evolutionary ancient role in insect immunity to malaria and in some instances melanin has been implicated to play an immunoregulatory role in vertebrates. Thus, we tested the hypothesis that melanization may be protective in malaria infections using mouse models. Congenic C57BL/6 mice that differed only in the gene encoding tyrosinase, a key enzyme in the synthesis of melanin, showed no difference in the clinical course of infection by Plasmodium yoelii 17XL, that causes severe anemia, Plasmodium berghei ANKA, that causes severe cerebral malaria or Plasmodium chabaudi AS that causes uncomplicated chronic disease. Moreover, neither genetic deficiencies in vitamin D synthesis nor vitamin D supplementation had an effect on survival in cerebral malaria. Taken together, these results indicate that neither melanin nor vitamin D production improve survival in severe malaria

    Physiological basis and image processing in functional magnetic resonance imaging: Neuronal and motor activity in brain

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    Functional magnetic resonance imaging (fMRI) is recently developing as imaging modality used for mapping hemodynamics of neuronal and motor event related tissue blood oxygen level dependence (BOLD) in terms of brain activation. Image processing is performed by segmentation and registration methods. Segmentation algorithms provide brain surface-based analysis, automated anatomical labeling of cortical fields in magnetic resonance data sets based on oxygen metabolic state. Registration algorithms provide geometric features using two or more imaging modalities to assure clinically useful neuronal and motor information of brain activation. This review article summarizes the physiological basis of fMRI signal, its origin, contrast enhancement, physical factors, anatomical labeling by segmentation, registration approaches with examples of visual and motor activity in brain. Latest developments are reviewed for clinical applications of fMRI along with other different neurophysiological and imaging modalities

    Trends in life science grid: from computing grid to knowledge grid

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    BACKGROUND: Grid computing has great potential to become a standard cyberinfrastructure for life sciences which often require high-performance computing and large data handling which exceeds the computing capacity of a single institution. RESULTS: This survey reviews the latest grid technologies from the viewpoints of computing grid, data grid and knowledge grid. Computing grid technologies have been matured enough to solve high-throughput real-world life scientific problems. Data grid technologies are strong candidates for realizing "resourceome" for bioinformatics. Knowledge grids should be designed not only from sharing explicit knowledge on computers but also from community formulation for sharing tacit knowledge among a community. CONCLUSION: Extending the concept of grid from computing grid to knowledge grid, it is possible to make use of a grid as not only sharable computing resources, but also as time and place in which people work together, create knowledge, and share knowledge and experiences in a community

    Brain Structural Networks Associated with Intelligence and Visuomotor Ability

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    Increasing evidence indicates that multiple structures in the brain are associated with intelligence and cognitive function at the network level. The association between the grey matter (GM) structural network and intelligence and cognition is not well understood. We applied a multivariate approach to identify the pattern of GM and link the structural network to intelligence and cognitive functions. Structural magnetic resonance imaging was acquired from 92 healthy individuals. Source-based morphometry analysis was applied to the imaging data to extract GM structural covariance. We assessed the intelligence, verbal fluency, processing speed, and executive functioning of the participants and further investigated the correlations of the GM structural networks with intelligence and cognitive functions. Six GM structural networks were identified. The cerebello-parietal component and the frontal component were significantly associated with intelligence. The parietal and frontal regions were each distinctively associated with intelligence by maintaining structural networks with the cerebellum and the temporal region, respectively. The cerebellar component was associated with visuomotor ability. Our results support the parieto-frontal integration theory of intelligence by demonstrating how each core region for intelligence works in concert with other regions. In addition, we revealed how the cerebellum is associated with intelligence and cognitive functions

    Possible Brucellosis in an Early Hominin Skeleton from Sterkfontein, South Africa

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    We report on the paleopathological analysis of the partial skeleton of the late Pliocene hominin species Australopithecus africanus Stw 431 from Sterkfontein, South Africa. A previous study noted the presence of lesions on vertebral bodies diagnosed as spondylosis deformans due to trauma. Instead, we suggest that these lesions are pathological changes due to the initial phases of an infectious disease, brucellosis. The macroscopic, microscopic and radiological appearance of the lytic lesions of the lumbar vertebrae is consistent with brucellosis. The hypothesis of brucellosis (most often associated with the consumption of animal proteins) in a 2.4 to 2.8 million year old hominid has a host of important implications for human evolution. The consumption of meat has been regarded an important factor in supporting, directing or altering human evolution. Perhaps the earliest (up to 2.5 million years ago) paleontological evidence for meat eating consists of cut marks on animal remains and stone tools that could have made these marks. Now with the hypothesis of brucellosis in A. africanus, we may have evidence of occasional meat eating directly linked to a fossil hominin
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