SOil ORGANIC MAneR AND NUTRIENT STATUS OF SOME VEGETABLE GROWING SOilS IN MATARA DISTRICT

The main function of a soil from an agricultural perspective is to produce a bountifulcrop with minimum mputsrTherefore, the maintenance of soil fertility and productivityis important to obtain a sustainable yield. Though, farmers prefer that their soil support •ideal crop growth, poor soil management practices adopted by them have caused adecreasing trend of yield continuously. Therefore, it is important to investigate thenutrient status of such soils and make recommendation for sustainable land management.This study was conducted to assess organic matter and nutrient status of selectedvegetable growing soils in the Matara District, Sri Lanka.Ten vegetable growing fields were selected and soil samples were drawn randomly fromO-15cmdepth. Soil samples were analyzed to determine N, P, K and organic mattercontent using standard methods and soil samples were also taken from a forest on thesame soil type to compare cultivated and undisturbed soils.Results revealed that the average soil N, P and K contents for the vegetable growing soilwere 0.14%, 404 mglKg of soil and 106 mgIKg of soil respectively, and thecorresponding figures for the forest soil were 0.17%, 65 mg/Kg of soil and 30 mglKg ofsoil. The average organic matter content of the vegetable growing soils was 0.65%,whereas the corresponding figure for the reference forest soil was 2.5%. Results revealedthat the average P and K contents of Vegetable growing soils were higher than the forestsoil and possible reason may be the regular application of synthetic fertilizer to vegetablegrowing soils. Results further indicated that more than 50% samples collected fromvegetable growing soils had N and organic matter contents below the average value.According to the results, it can be concluded the most of the vegetable growing soils inMatara District are considerably low in N and organic matter contents. Hence preventingsoil erosion and sustaining or increasing soil organic matter levels by adding cropresidues, compost and organic manures may be the most important practices that growerscan adopt in managing soil nutrients status.

AN ASSESSMENT ON NATURAL REGENERATION OF Gymnema sylvestre, A RARE MEDICINAL PLANT

Gymnema sylvestre R.Br. belonging to family Asclepiadaceae, is naturallyfound in tropical forests of India and in some parts of Sri Lanka. This herb isbest known for its ability to abolish the taste of sugar and has been used inthe treatment of diabetes. A number of commercial herbal products are nowavailable that contain varying amounts of gymnemic acids, the componentresponsible for the action against diabetes. Though the demand for thespecies is increasing rapidly, the commercial cultivation of the species is yetto be expanded. On the other hand it is felt that the natural regeneration ofthis important herb is poor and this study was carried out in Matara Districtof Southern Sri Lanka to assess the natural regeneration of the species.An extensive survey was conducted in order to find the natural habitats andauthenticity was confirmed for the mother plants found in the area.Flowering, fruiting and other important physiological phases of the plantwere monitored and observations were made under natural conditions.Results revealed that Gymnema is propagated naturally by means of seedgermination only. Flowering commences late in the year and mature podsrelease seeds from early February each year. The low moisture content of theseeds at the time of release together with dry environmental conditions resultin very low germination and thus the natural regeneration of the species ispoor though a single mother plant produces thousands of seeds at a season.Therefore, an alternative mode of multiplication should be made available inorder to propagate and to conserve genetic stock of this useful plant

Effect of physiological status on rooting of Masbedda (Gymnema sylvestre) cuttings

Vegetative propagation by means of cuttings is an important method for starting new plants identicalto the parent plants. Many plants can be propagated with good results by cutting, though the successdepends upon the propagator's circumstances, the time of year, and the plant to be propagated. Thepresent study was carried out to investigate the effect of physiological stage on rooting of Gymnemasylvestre stem cuttings.Healthy, double nodded cuttings were made from the mature plant stock established at the Faculty ofAgriculture, University of Ruhuna. The cuttings taken from pre-flowering (Tl), flowering (T2) andpost-flowering (T3) stages were stuck into preformed holes in poly bags filled with moistened rootingmedium which consisted of sand, top soil and compost (1 :1: 1 by volume). They were placed in a shadehouse and watered once a day. The Completely Randomized Design (CRD) was used with tenreplicates. Assessment was done 75 days after for rooting. The percentage survival was not significantly(p ~ 0.05) different between cuttings taken from the pre-flowering (92%) and post-flowering (87%)stages. No significant (p ~ 0.05) differences also in the percentage of callused and rooted cuttingswere recorded between T I and T3. However, number of roots and length of the longest root percutting were significantly (p ~ 0.05) higher in Tl than any other. Furthermore, T2 showed the lowestfigures for all the parameters assessed, indicating that the physiological status of the stock plant at thetime the cuttings are excised is of great importance for the rooting process.

Assessing Tuberculosis Case Fatality Ratio: A Meta-Analysis

Background: Recently, the tuberculosis (TB) Task Force Impact Measurement acknowledged the need to review the assumptions underlying the TB mortality estimates published annually by the World Health Organization (WHO). TB mortality is indirectly measured by multiplying estimated TB incidence with estimated case fatality ratio (CFR). We conducted a meta-analysis to estimate the TB case fatality ratio in TB patients having initiated TB treatment. Methods: We searched for eligible studies in the PubMed and Embase databases through March 4(th) 2011 and by reference listing of relevant review articles. Main analyses included the estimation of the pooled percentages of: a) TB patients dying due to TB after having initiated TB treatment and b) TB patients dying during TB treatment. Pooled percentages were estimated using random effects regression models on the combined patient population from all studies. Main Results: We identified 69 relevant studies of which 22 provided data on mortality due to TB and 59 provided data on mortality during TB treatment. Among HIV infected persons the pooled percentage of TB patients dying due to TB was 9.2% (95% Confidence Interval (CI): 3.7%-14.7%) and among HIV uninfected persons 3.0% (95% CI: 21.2%-7.4%) based on the results of eight and three studies respectively providing data for this analyses. The pooled percentage of TB patients dying during TB treatment was 18.8% (95% CI: 14.8%-22.8%) among HIV infected patients and 3.5% (95% CI: 2.0%-4.92%) among HIV uninfected patients based on the results of 27 and 19 studies respectively. Conclusion: The results of the literature review are useful in generating prior distributions of CFR in countries with vital registration systems and have contributed towards revised estimates of TB mortality This literature review did not provide us with all data needed for a valid estimation of TB CFR in TB patients initiating TB treatmen

Biochemical­­– and biophysical–induced barriergenesis in the blood brain barrier: a review of barriergenic factors for use in in vitro models

Central nervous system (CNS) pathologies are a prevalent problem in aging populations, creating a need to understand the underlying events in these diseases and develop efficient CNS‐targeting drugs. The importance of the blood‐brain barrier (BBB) has become evident, acting both as a physical barrier to drug entry into the CNS, and potentially as the cause or aggravator of CNS diseases. The development of a biomimetic BBB in vitro model is required for the understanding of BBB‐related pathologies and in the screening of drugs targeting the CNS. There is currently a great interest in understanding the influence of biochemical and biophysical factors, as these have the potential to greatly improve the barrier function of brain microvascular endothelial cells (BMECs). Recent advances in understanding how these may regulate barriergenesis in BMECs can help promote the development of improved BBB in vitro models, and therefore novel interventional therapies for pathologies related to its disruption. This review provides an overview of specific biochemical and biomechanical cues in the formation of the BBB, with a focus on in vitro models and how these might recapitulate BBB function