CHEMISTRY OF LEAF LINER OF SOME AGRO-FORESTRY SPECIES IN SRI LANKA

Dl'l'llillpmilion or k:l! litter ix a major process in the nutrient dyn.nnicx of agroccosystcm»,which is intricnlly gOVL'lllcd hv the liner chemistry, The chemistry of leaf litter dctcrrnincshOlh the umc course of decomposition and the nutrient rcIC:1SCpaucrn. There arc many:I,~rIllorc'strv Spl'l'leS in Sri 1.:1111-::1h.ili information nvailahk- Oil their liner chcmixirv ISxc.uuv. Such information provcx useful ill idelltifying :1J'[1ropri:ltl' agrofon'stry spccie,s Iordnl'lopillg xuxtainahlr agrol'U)systl'IllS, Therefore studies were carried out to dcrcrm incIhe l'lllll'l'lltr:I1iolls Ill' nutricius II.; N. P. K, Ca and Mg ), ligllill .md ccllulnxr or nine:1~J()fmeslry spl'l'ies ill Sri Lanka. vii .. Acacia auriculijonnis, Acacia mangium. Giriridia,\('I'lllll!, Maccnan;« !1ciIUIU (Kallde J. Altoni« srholaris (Alstonia). Artocurnus il/lcgrU(J/iarluk J, Aruuntpu» altilis (bread truin. 11'/lIIiI/0//(/ ('(11111/10 (Indian almond), and MOI/.~It('r'lindica (m:1I1goI.Considerable interspecific variation in the above parameters was observed in the leaf litter.Ax rl'g:lI'<ls the per ccntx of ",y, K. C:I and Mg. the values observed varied from 0,39'1 -1(12, OJ)2'i - 0,171. () 16 - 0,9'1. 1.76 - 2,'17 and (I.n - 0.'1 I. respectively. The highestconcentration of N W:IS in (; scpittm while A altilis, A. altilis. A. il/lcgrifiJ/iil and A.sclioars had the highest conccutrarion of P. K. Ca and Mg. respectively. This underlinesIhl' importance of introducinu diverse species (hiological diversity) ill order to cxrablish abalanced Icrtility regime. Milldim and A. ntangiurn had the highest concentration oflignin (22.9l) %) and cellulose 132.76 %). respectively. A salient feature in the leaf litter inM. indica W:IS that. it had the lowest concentration of N (0.39'1 %) and cellulose (14.59 %)and the highest concentration of lignin (n.99%). These data prove useful in identifying asuitable combination of agroforcsuy species for sustainable soil fertility management.

EFFECT OF AGRICULTURE ON ENVIRONMENT

The burgeoning population in this country is making increasing demands on agriculture.Consequently, there is mounting pressure on the natural resource base, particularly on landfor increased food production. Failure to adopt appropriate soil and water conservationpractices in agriculture has resulted in considerable soil erosion and land degradation,rendering a large extent of agricultural lands marginal and unproductive. Due todemographic pressure, agriculture is being extended even to sloping lands, causing heavysoil erosion. Moreover, shifting cultivation has continued unabated, further dwindling theforest cover, which has already reached a threshold value. With the advent of improvedvarieties, large quantities of agrochemicals such as inorganic fertilizers, insecticides,herbicides, fungicides etc. are being released to the environment. Many of farmers usepesticides indiscriminately polluting the soil, water and the food they produce, causingserious environmental and health problems.Some major consequences of improper agricultural practices are the loss of soil fertility,land degradation, siltation of rivers and reservoirs, occurrence of flash floods,eutrophication of water bodies with attendant reduction in hydro-power generation, loss ofbiodiversity, emissions of green house gases such as CO2 and NO", which have far-reachingenvironmental, social, economic and political implications. The major causes ofagriculture-related environmental problems, their effects and consequences and measuresto mitigate them are discussed

THE SEED BANK DYNAMICS OF TWO DIFFERENT FOREST TYPES IN SOUTHERN SRI LANKA

The floristic composition and regeneration potential of natural forests in wet zone(Wilpita) and dry zone (Hambanthota) was investigated by sampling in the top IOcm ofthe soil using special desigri samples (30cm*30cm* lOcm) along the transects andenumerating the number of seedlings emerge from the soil during the period of twomonths. The seedlings were transferred into poly bags once a week and allowed to grow forfew months to determine the floristic composition.The mean number of seeds germinated per square meter in Wilpita in Hambanthota were162 and 146 respectively. The composition of the seedlings from Wilpita and Hambanthotaforests was not similar, though the population density was generally higher in the Wilpitaforests. The floristic composition at the Wilpita forests was observed and Alstoniamacrophy/a (Hawarinuga), Macaranga Pe/teta (Kande), Trema orienta/is (Gedumba) andMelastoma malabathricum (Bovitiya) were prominent species among the tree species.Affinity analysis showed that the Alstonia was the most prominent tree species in Wilpitaforest There was no significant difference observed in the number of seedlings per squaremeter among the samples collected along tbe transects.This study shows that the regeneration potential of the rain forests in the wet zone(Wilpita) is much higher than forests in the dry zone.

Sustainability of home gardens in Masemulla forest area in Matara district

Home-gardens are meant to be sustainable land use systems that provide a variety of products andservices to the people. This study was undertaken to evaluate the sustainability of home-gardens inMasemulla forest area in Matara district. Ullala, which is a small village closed to Masernulla forestarea, was selected for the study. A survey was conducted using a random sample of 40 home-gardensin the area. Average land area ranged from 0.25 to 0.5 acres with an average family size of 2-8 andalmost all the families belonged to the low income group.Majority of home gardens (90%) consisted of three canopy layers-near the ground surface herbaceouslayer, followed by an intermediate layer of shrubs and a tree layer at the upper level. Tree densityranged from low to medium with a combination of mixed species arranged in a random way. Canopycoverage was about 15 to 50% and there were more than 50% of unutilized land areas. Speciesdiversity in the selected home-gardens was low ranging from 20-25 species and the no of woody taxa was about 5-10. Dominant tree species included jak (Artocarpus heterophvilus [; coconut (Cocosnuciferai, mango (Mangifer a indica), areca nut (Areca catechu), mahogany (Swieteniamacrophvllai etc. Majority of house holders (90%) considered cinnamon (Cinnamomum verum) asan additional income source. All the householders consumed the products of the home-gardens asfood.Less than 10% of house-holders rare animals and although there is a good potential for bee keeping,less than I% of householders practiced this. Wild-boar and wild-rat attack was one of the mainproblems in crop production. Soil erosion was also a problem in this area and less than 30% ofhouseholders practiced some form of soi I conservation methods. Half of the householders fu Ifi Iledtheir energy requirement from their home-gardens. Although there are many advantages in homegardening.householders don't pay adequate attention as they don't fully understand the various benefitsof proper home-garden ing

A novel mode of capping protein-regulation by Twinfilin

Cellular actin assembly is controlled at the barbed ends of actin filaments, where capping protein (CP) limits polymerization. Twinfilin is a conserved in vivo binding partner of CP, yet the significance of this interaction has remained a mystery. Here, we discover that the C-terminal tail of Twinfilin harbors a CP-interacting (CPI) motif, identifying it as a novel CPI-motif protein. Twinfilin and the CPI-motif protein CARMIL have overlapping binding sites on CP. Further, Twinfilin binds competitively with CARMIL to CP, protecting CP from barbed-end displacement by CARMIL. Twinfilin also accelerates dissociation of the CP inhibitor V-1, restoring CP to an active capping state. Knockdowns of Twinfilin and CP each cause similar defects in cell morphology, and elevated Twinfilin expression rescues defects caused by CARMIL hyperactivity. Together, these observations define Twinfilin as the first \u27pro-capping\u27 ligand of CP and lead us to propose important revisions to our understanding of the CP regulatory cycle

Product Development Partnerships: Case studies of a new mechanism for health technology innovation

There is a continuing need for new health technologies to address the disease burdens of developing countries. In the last decade Product Development Partnerships (PDP) have emerged that are making important contributions to the development of these technologies. PDPs are a form of public private partnerships that focus on health technology development. PDPs reflect the current phase in the history of health technology development: the Era of Partnerships, in which the public and private sectors have found productive ways to collaborate. Successful innovation depends on addressing six determinants of innovation. We examine four case studies of PDPs and show how they have addressed the six determinants to achieve success

Derivation and validation of a risk-factor model for detection of oral potentially malignant disorders in populations with high prevalence

Background:Oral and pharyngeal cancers constitute the sixth most common type of cancer globally, with high morbidity and mortality. In many countries, most cases of oral cancer arise from long-standing, pre-existing lesions, yet advanced malignancies prevail. A new approach to early detection is needed. We aimed to validate a model for screening so that only high-risk individuals receive the clinical examination.Methods:A community-based case-control study (n1029) in rural Sri Lanka assessed risk factors and markers for oral potentially malignant disorders (OPMD) by administering a questionnaire followed by an oral examination. We then developed a model based on age, socioeconomic status and habits of betel-quid chewing, alcohol drinking and tobacco smoking, with weightings based on odds ratios from the multiple logistic regression. A total, single score was calculated per individual. Standard receiver-operator characteristic curves were plotted for the total score and presence of OPMD. The model was validated on a new sample of 410 subjects in a different community.Results:A score of 12.0 produced optimal sensitivity (95.5%), specificity (75.9%), false-positive rate (24.0%), false-negative rate (4.5%), positive predictive value (35.9%) and negative predictive value (99.2%).Conclusion:This model is suitable for detection of OPMD and oral cancer in high-risk communities, for example, in Asia, the Pacific and the global diaspora therefrom. A combined risk-factor score of 12.0 was optimal for participation in oral cancer/OPMD screening in Sri Lanka. The model, or local adaptations, should have wide applicability

Lung transplantation for pulmonary fibrosis in dyskeratosis congenita: Case Report and systematic literature review

<p>Abstract</p> <p>Background</p> <p>Dyskeratosis congenita (DC) is a progressive, multi-system, inherited disorder of telomere biology with high risks of morbidity and mortality from bone marrow failure, hematologic malignancy, solid tumors and pulmonary fibrosis. Hematopoietic stem cell transplantation (HSCT) can cure the bone marrow failure, but it does not eliminate the risks of other complications, for which life-long surveillance is required. Pulmonary fibrosis is a progressive and lethal complication of DC.</p> <p>Case presentation</p> <p>In this report, we describe a patient with DC who developed pulmonary fibrosis seven years after HSCT for severe aplastic anemia, and was successfully treated with bilateral lung transplantation. We also performed a systematic literature review to understand the burden of pulmonary disease in patients with DC who did or did not receive an HSCT. Including our patient, we identified 49 DC patients with pulmonary disease (12 after HSCT and 37 without HSCT), and 509 with no reported pulmonary complications.</p> <p>Conclusion</p> <p>Our current case and literature review indicate that pulmonary morbidity is one of the major contributors to poor quality of life and reduced long-term survival in DC. We suggest that lung transplantation be considered for patients with DC who develop pulmonary fibrosis with no concurrent evidence of multi-organ failure.</p

The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation