Showing papers by "University of Peradeniya published in 2000"
TL;DR: The degree of aggregation in the distribution of 1768 tree species is examined based on the average density of conspecific trees in circular neighborhoods around each tree, and it is found that nearly every species was more aggregated than a random distribution.
Abstract: Fully mapped tree census plots of large area, 25 to 52 hectares, have now been completed at six different sites in tropical forests, including dry deciduous to wet evergreen forest on two continents. One of the main goals of these plots has been to evaluate spatial patterns in tropical tree populations. Here the degree of aggregation in the distribution of 1768 tree species is examined based on the average density of conspecific trees in circular neighborhoods around each tree. When all individuals larger than 1 centimeter in stem diameter were included, nearly every species was more aggregated than a random distribution. Considering only larger trees (≥ 10 centimeters in diameter), the pattern persisted, with most species being more aggregated than random. Rare species were more aggregated than common species. All six forests were very similar in all the particulars of these results.
1,117 citations
TL;DR: Rates of multiple feeding were associated positively with temperature and negatively with mosquito size in Thailand, but not in Puerto Rico, and may be associated with variation in patterns of dengue virus transmission.
Abstract: We used a histologic technique to study multiple blood feeding in a single gonotrophic cycle by engorged Aedes aegypti (L.) that were collected weekly for 2 yr from houses in a rural village in Thailand (n = 1,891) and a residential section of San Juan, Puerto Rico (n = 1,675). Overall, mosquitoes from Thailand contained significantly more multiple meals (n = 1,300, 42% double meals, 5% triple meals) than mosquitoes collected in Puerto Rico (n = 1,156, 32% double meals, 2% triple meals). The portion of specimens for which frequency of feeding could not be determined was 31% at both sites. We estimated that on average Ae. aegypti take 0.76 and 0.63 human blood meals per day in Thailand and Puerto Rico, respectively. However, frequency of multiple feeding varied among houses and, in Puerto Rico, the neighborhoods from which mosquitoes were collected. In Thailand 65% of the mosquitoes fed twice on the same day, whereas in Puerto Rico 57% took multiple meals separated by > or = 1 d. At both sites, the majority of engorged specimens were collected inside houses (Thailand 86%, Puerto Rico 95%). The number of blood meals detected was independent of where mosquitoes were collected (inside versus outside of the house) at both sites and the time of day collections were made in Puerto Rico. Feeding rates were slightly higher for mosquitoes collected in the afternoon in Thailand. Temperatures were significantly higher and mosquitoes significantly smaller in Thailand than in Puerto Rico. At both sites female size was negatively associated with temperature. Rates of multiple feeding were associated positively with temperature and negatively with mosquito size in Thailand, but not in Puerto Rico. Multiple feeding during a single gonotrophic cycle is a regular part of Ae. aegypti biology, can vary geographically and under different climate conditions, and may be associated with variation in patterns of dengue virus transmission.
453 citations
TL;DR: This study has shown for the first time that significant proportions of the Sri Lankan female population may be Se deficient (24, 24 and 40% in the NIDD, MIDD and HIDD villages, respectively) and a combination of iodine and Se deficiency could be involved in the pathogenesis of goitre in Sri Lanka.
119 citations
TL;DR: In this article, the thermal properties of polyaniline (PANI) have been studied to identify the optimum processing and maximum application temperatures for non-protonated emeraldine base form.
Abstract: Among conducting polymers with metallic characteristics, polyaniline (PANI) is claimed to have one of the highest environmental stability. From an industrial point of view it would be useful to be able to thermally process this material into useful products using conventional techniques such as extrusion, stretching, rolling, etc., which generally are carried out at elevated temperatures. Somewhat surprisingly, relatively few studies have addressed the thermal stability of PANI, in particular that of the non-protonated emeraldine base form. Therefore, a study of the thermal properties was performed to examine the thermal stability of this material and to identify the optimum processing and maximum application temperatures.
96 citations
TL;DR: In this paper, environmental pollution in Sri Lanka has been investigated and the authors propose a method to solve the problem of environmental pollution by using the J.N.S. Foundation Sri Lanka 2000 28(4)
Abstract: Keywords: Environmental pollution, Sri Lanka DOI: http://dx.doi.org/10.4038/jnsfsr.v28i4.2644 J. Natn. Sci. Foundation Sri Lanka 2000 28(4): 301-325
68 citations
TL;DR: Resistance in C. tritaeniorhynchus increased between 1984 and 1998, whereas Cx.
Abstract: Summary
Culex tritaeniorhynchus Giles and Cx. gelidus Theobald (Diptera: Culicidae), both vectors of Japanese encephalitis, were collected in 1984 and 1998 from two disease endemic localities in Sri Lanka: Anaradhapura and Kandy. Using wild-caught adult mosquitoes from light traps, log dosage-probit mortality curves for insecticide bioassays were obtained for three insecticides: malathion (organophosphate), propoxur (carbamate) and permethrin (pyrethroid). LD50 values showed that, in 1998, Cx. tritaeniorhynchus was ∼100-fold more resistant to malathion and 10-fold more resistant to propoxur than was Cx. gelidus. This difference was attributed to Cx. tritaeniorhynchus breeding mostly in irrigated rice paddy fields, where it would have been exposed to pesticide selection pressure, whereas Cx. gelidus breeds in other types of aquatic habitats less prone to pesticide applications. Resistance in Cx. tritaeniorhynchus increased between 1984 and 1998, whereas Cx. gelidus remained predominantly susceptible.
Propoxur inhibition of acetylcholinesterase (AChE) activity (the target site of organophosphates and carbamates) indicated that in 1998, frequencies of insensitive AChE-based resistance were 9% in Cx. gelidus and 2–23% in Cx. tritaeniorhynchus, whereas in 1984 this resistance mechanism was detected only in 2% of the latter species from Anaradhapura. The AChE inhibition coefficient (ki) with propoxur was 1.86 ± 0.24 × 105 m−1 min−1 for Cx. tritaeniorhynchus from Anaradhapura in 1998.
Both species were tested for activity levels of detoxifying glutathione S-trans- ferases (GSTs) and malathion-specific as well as general carboxylesterases. High activities of GSTs and carboxylesterases were detected in Cx. tritaeniorhynchus but not Cx. gelidus. Malathion-specific carboxylesterase was absent from both species.
Native polyacrylamide gel electrophoresis resolved two elevated general carboxylesterases, CtrEstβ1 and CtrEstα1, from Cx. tritaeniorhynchus and none from Cx. gelidus. CtrEstβ1 was the most intensely staining band. Gel inhibition experiments showed that both elevated esterases were inhibited by organophosphates and carbamates but not by pyrethroids.
The major elevated esterase CtrEstβ1 was partially purified (15-fold) by sequential Q-Sepharose and phenyl Sepharose column chromatography. The bimolecular rate constant (ka) and the deacylation rate constant (k3) for the malaoxon/ enzyme interaction were 9.9 ± 1.1 × 103 m−1 min−1 and 3.5 ± 0.05 × 10−4m−1 min−1, respectively, demonstrating that the role of this enzyme in organophosphorus insecticide resistance is sequestration.
67 citations
TL;DR: This infection might be an important cause of abortion in bovids in Sri Lanka, however, there is also evidence of other causes for abortion, repeat breeding and retained placenta that may have contributed to the spread of brucellosis.
65 citations
TL;DR: Use of contraceptive preparations containing oestrogen and progesterone resulted in hormonal changes similar to those seen in pregnancy, associated with increased prevalence of gingivitis.
Abstract: Aims: Women using hormonal contraceptives can be considered to be a ‘risk group’ for periodontal disease, due to prolonged, sustained serum levels of oestrogens and progesterone. This investigation aims to study the effects of hormonal contraceptives on periodontal tissues.
Methods: 32 women using hormonal contraceptives for less than 2 years, 17 for 2–4 years and a matched control group of 39 non-users were selected for the study. They were clinically examined for plaque levels (plaque index: PLI), gingival condition (gingival index: GI) and loss of periodontal attachment (LA).
Results: Contraceptive users of less than 2 years and 2–4 years duration (n=32, n=17 repectively) and non-users (n=39) had similar oral hygiene levels; yet the contraceptive users had a significantly higher level of gingival inflammation, compared to the non-users (p<0.001; 1-way ANOVA). Usage of hormonal contraceptives for 2–4 years (n=17) caused a significantly higher LA (p<0.001) compared to that of controls (n=39).
Conclusions: Usage of contraceptive preparations containing oestrogen and progesterone resulted in hormonal changes similar to those seen in pregnancy, associated with increased prevalence of gingivitis. There was significantly higher LA with prolonged usage of hormonal contraceptives, compared with controls.
60 citations
TL;DR: The stem bark of Microcos paniculata contained a new alkaloid, N-Methyl-6 beta-(deca-1',3',5'-trienyl)-3 beta-methoxy-2 beta-methylpiperidine, which showed good insecticidal activity against Aedes aegypti second instar larvae.
58 citations
TL;DR: In this article, it is shown that the association between increasing blood pressure and the increasing risk of future complications or shortening of life is continuous from lowest to highest values of systolic and diastolic blood pressure.
Abstract: Mercury sphygmomanometry, the most widely used indirect method of blood pressure measurement, derived from the work of Scipione Riva-Rocci and Nicolai Korotkov forms the basis of our knowledge of the epidemiology of high blood pressure. Thus, recognised hypertension was first described as a specific clinical entity associated with an increased risk of strokes in the middle aged and elderly. However, it is now known that hypertension is a quantitative and not a qualitative deviation from the norm, and that there is no natural dividing line between normal and abnormal pressures.1
The main problem with interpreting measured blood pressure is its variability within the same individual and also between individuals, as determined by genetic and environmental factors. In addition, genetic and environmental influences can also vary from time to time within the same individual. Therefore, attempts at standardising blood pressure at a plateau before measurement (for example, British Hypertension Society criteria) have not been very successful because of diurnal variation and environmental influences (such as the “white coat effect”), particularly in children. This led to the tendency to use the mean value of several blood pressure measurements in clinical practice.
Even with this approach there are two basic concerns regarding the interpretation of measured blood pressure in children. The first is the identification of “hypertension” as a disease entity using an epidemiological definition (for example, blood pressure above the 95th centile,2 or two standard deviations above the mean), which is purely a descriptive demarcation without an underlying biological meaning. This is because the association between increasing blood pressure and the increasing risk of future complications or shortening of life is continuous from lowest to highest values of systolic and diastolic blood pressure.3 The second concern relates to the identification of hypertension in children using the above definition, which …
58 citations
TL;DR: The prevalence of Cryptosporidium oocysts in the faeces of 1020 goats in three age categories was examined and these animals are likely to play an important role in the epidemiology of cryptosporidiosis in goat kids and humans.
TL;DR: In this article, the authors used the heat pulse technique to measure transpiration rates of tea plants growing in the field as part of extensive canopies at Talawakelle, Sri Lanka during the period between 1 January and 19 February 1997.
TL;DR: In this paper, the synthesis and properties of the highest oxidation state of polyaniline, pernigraniline in the base as well as the corresponding salt form are discussed.
Abstract: The oxidation state of polyaniline (PANI) can be varied from the fully reduced leucoemeraldine base (LEB) to the half oxidized emeraldine base (EB) and to the fully oxidized form pernigraniline base (PNB). In this work, the synthesis and properties of the highest oxidation state of polyaniline, pernigraniline, in the base as well as the corresponding salt form are discussed.
TL;DR: An overview of clinical variants of oral candidosis is provided, both new and old, and recent advances in the usage of antimycotics in the management of this condition are discussed.
Abstract: The advent of the human immunodeficiency virus and the increasing prevalence of immunocompromised individuals in the community have resulted in a resurgence of opportunistic infections, including oral candidoses. Despite the availability of a number of effective antimycotics for the management of oral candidoses, therapeutic failure is not uncommon. Further, the presence of many clinical variants of oral candidosis, both new and old, may confound the unwary clinician and complicate its management. These problems have been partly circumvented by the introduction of the triazole group of antimycotics, which initially appeared to be highly effective. However, an alarming increase in organisms resistant to triazoles has been reported recently. In this paper we provide an overview of clinical variants of oral candidosis. A second paper will discuss recent advances in the usage of antimycotics in the management of this condition.
TL;DR: In this paper, the identity of the mobile ion has been elucidated for three polypyrrole (PPy) based systems by using the Nernst equation to interpret the dependence of the peak potentials in voltammograms on electrolyte concentration.
TL;DR: For the first time, the absolute configuration of a tropane alkaloid (erythrozeylanine A) has been determined by quantum chemical CD calculations.
TL;DR: A newly recognized phenomenon known as the post-antifungal effect implies that antifungals, even at sub-therapeutic concentrations, may suppress the virulent attributes of yeasts, especially intra-orally where topical drug levels fluctuate dramatically during dosing intervals.
Abstract: As both humans and fungi are eukaryotic organisms, antifungal agents affect their cellular metabolism Thus, a relatively few antifungals with minimal toxicity and side-effects are available compared with a plethora of antibacterials These agents currently prescribed in dentistry belong to two major groups, the polyenes (nystatin and amphotericin B) and the azoles (imidazoles and triazoles) A newly recognized phenomenon known as the post-antifungal effect implies that antifungals, even at sub-therapeutic concentrations, may suppress the virulent attributes of yeasts, especially intra-orally where topical drug levels fluctuate dramatically during dosing intervals
TL;DR: Independent of the storage temperature, the survival of A. caulinodans in peat and coir dust was very high during a 12-month period, whereas the bagasse and rice straw carriers showed a serious decline from 3 months onwards, indicating that the bacterial nitrogenase activity is limited by energy supply.
Abstract: Azorhizobium caulinodans strongly colonized the rhizosphere of rice plants after incorporation of Sesbania rostrata in a field trial throughout the growing season and during the fallow period until 19 weeks after incorporation of S. rostrata. A. caulinodans became well established in the rhizosphere (7.17 log cfu g–1 dry rice root) and colonized subsequent S. rostrata test plants. Three traditional and three improved high-yielding rice varieties were inoculated with A. caulinodans under gnotobiotic conditions. In none of the combinations did acetylene reduction activity significantly increase. Ethylene production on colonized rice roots only started after the growth medium had been supplemented with an extra C source (0.1 to 0.25% Na-lactate). This indicates that the bacterial nitrogenase activity is limited by energy supply. Four possible inoculant-carriers (peat, coir dust, bagasse, rice straw) were compared for long-term survival of the bacterial strain. Independent of the storage temperature (26 °C or 4 °C), the survival of A. caulinodans in peat and coir dust was very high during a 12-month period (>8 log cfu g–1 dry carrier), whereas the bagasse and rice straw carriers showed a serious decline from 3 months onwards.
TL;DR: Two copper-ion conducting solid-polymer electrolyte systems based on polyacrylonitrile (PAN) have been synthesized and characterized using DC polarization tests and impedance measurements as mentioned in this paper.
TL;DR: In this paper, Kolikuttu bananas were packed under modified atmosphere (M.A.) conditions using low density polyethylene (LDPE) bags and stored at 14°C and 94% r.h.d.
Abstract: SummaryMature `Kolikuttu' bananas were packed under modified atmosphere (M.A.) conditions using low density polyethylene (LDPE) bags and stored at 14°C and 94% r.h. The effect of ethylene scavengers on storage life of banana was examined. The in-package concentrations of oxygen, carbon dioxide and ethylene were measured during storage. Percentage weight loss, changes in firmness, total soluble solids (TSS), pH and sugar: acid during storage were also determined. Based on the in-package gaseous composition, the optimum storage period was defined. After termination of storage, bananas were allowed to ripen naturally, and the physico-chemical properties of ripened banana were analysed. `Kolikuttu' bananas could be packed in LDPE (0.075 mm) and stored at 14°C and 94% r.h. for 24.d. Storage life could be further extended up to 30.d by using ethylene scavengers. Physico-chemical properties of M.A. stored banana after ripening were similar to those held under ambient conditions. Therefore, packaging of `Kolikutt...
TL;DR: Feldspar, among many natural substances such as termitemount-clay, saw-dust, kaolinite and dolomite, offers asignificant removal ability for sulfate, phosphate, and colored substances as discussed by the authors.
Abstract: Feldspar, among many natural substances such as termitemount-clay, saw-dust, kaolinite and dolomite, offers asignificant removal ability for sulfate, phosphate, and coloredsubstances. Optimization of experimental parameters such assolution pH and flow rate reveals, that the maximum efficiency forremoval of phosphate, sulfate, and colored substances is about42, 52, and 73% respectively. X-ray diffraction, adsorptionisotherm and recovery studies suggest, that the removal processof anions occurs via ion exchange in conjunction with surfaceadsorption. Furthermore, reaction rate studies indicate thatthe removal of the selected pollutants by feldspar follows first-order kinetics. Although the percent removal, under the optimized conditions, is higher for laboratory prepared solutions, efficiency is a little less for industrial effluentsdue to interferent effects.
TL;DR: Three new naphthylisoquinoline alkaloids, ancistrolikokines A-C (1-3), have been isolated and structurally assigned from Ancistrocladus likoko, as well as the known compound korupensamine A (4), and their 5,8'-coupling hints at a close biogenetic relationship of A. likoko.
Abstract: Three new naphthylisoquinoline alkaloids, ancistrolikokines A-C (1-3), have been isolated and structurally assigned from Ancistrocladus likoko, as well as the known compound korupensamine A (4). Their 5,8'-coupling hints at a close biogenetic relationship of A. likoko to other Central African Ancistrocladus species. Compounds 1-4 showed good to moderate antimalarial activities when evaluated in vitro against the NF54 and K1 strains of Plasmodium falciparum.
TL;DR: The study indicated that the effective catchment area of a village treatment center will be influenced by the degree of initial support from key individuals in the communities, the selection procedure and training of assistants, and the history of the relationships between different villages to be served by the center.
Journal Article•
TL;DR: La perte de poids, les changements d'extraits secs solubles (ESS), d'acidite titrable (AT), de pH, de fermete, du rapport [sucre/acidite] and de couleur de the peau, pendant / ou apres le stockage, ont ete determines.
Abstract: Introduction. Au Sri Lanka, les bananes du cultivar indigene Kolikuttu' sont vendues plus cheres que celles des autres cultivars en raison de leur gout agreable. Leur maturation precoce, caractere inherent de ces fruits, raccourcit leur duree de vie apres recolte. Materiel et methodes. Des mains de bananes Kolikuttu' mures, introduites dans des sachets en poly-ethylene de faible densite (LDPE) de 75 μm d'epaisseur creant les conditions de AM, ont ete stockees a 25 ± 2 °C et 85 ± 1 % d'humidite relative. L'efficacite de briques d'argile imbibees de permanganate de potassium utilisees comme AE a ete etudiee. Pendant le stockage, les concentrations en CO 2 , O 2 et C 2 H 4 ont ete mesurees dans les sachets. Apres stockage en AM, les sachets ont ete ouverts et les bananes ont muri naturellement dans les conditions ambiantes. La perte de poids, les changements d'extraits secs solubles (ESS), d'acidite titrable (AT), de pH, de fermete, du rapport [sucre/acidite] et de couleur de la peau, pendant / ou apres le stockage, ont ete determines. Resultats. Compares aux echantillons emballes sans AE, ceux emballes avec AE ont eu, a l'interieur des sacs, des concentrations en C 2 H 4 et en CO 2 sensiblement inferieures, des taux plus eleves en O 2 et des changements minimes de fermete et de teneur en ESS; leur perte de poids, AT et pH ont peu change pendant le stockage en AM. L'AM creee a l'interieur des sacs en LDPE munis d'AE a prolonge la vie verte des bananes du cultivar Kolikuttu' jusqu' a 20 d. Les fruits ont muri naturellement en moins de 4 d apres la fin du stockage. Discussion. L'emballage de bananes Kolikuttu', sous forme de mains individuelles, dans des sacs en LDPE munis d'AE, pourrait etre recommande pour prolonger leur duree de conservation a la temperature ambiante. Cette technologie, apte a presenter une importance economique considerable dans les pays ou le stockage au froid est cher ou peu facile, n'est pas compliquee. Elle pourrait etre facilement adoptee par les planteurs pour reduire au minimum les pertes apres recolte des bananes.
TL;DR: In this article, the authors proposed a method to simultaneously determine optimal placements for multiple actuators, sensors, and appropriate output feedback gains of the controller, which allows lower sampling rates to be used at the implementation stage.
Abstract: Lightweight floor systems are susceptible to excessive levels of vibration caused by occupant activities such as walking, dancing, and aerobics. Ongoing research utilizes active control to reduce vibration. Placement of multiple actuators and sensors for effective vibration control of flexible systems such as floors is a challenging task. The method proposed in this paper simultaneously determines optimal placements for multiple actuators, sensors, and appropriate output feedback gains of the controller. Instead of carrying out the controller design in the analog domain and then applying a transformation to arrive at a digital implementation, the proposed algorithm provides a digital controller directly. This allows lower sampling rates to be used at the implementation stage. To obtain faster settling times in the presence of external disturbances, a performance index that penalizes system states exponentially is utilized. The nonlinearities associated with actuator saturation due to force/stroke limitations is considered explicitly in the optimization. The proposed algorithm uses an interpolation scheme in case only partial knowledge of the mode shape is available. Hence it is applicable to a wider class of 2D structures that do not possess closed-form expressions for modal shapes and for which one has to resort to finite-element or experimental modal analysis.
TL;DR: Additional mechanisms by which polyene antimycotics may operate in vivo to suppress candidal pathogenicity are elucidated.
Abstract: Post-antifungal effect (PAFE) is defined as the suppression of growth that persists following limited exposure of fungi to antimycotics and subsequent removal of the drug. The fungal pathogen Candida albicans is the major aetiologic agent of oral candidosis, and the cell surface hydrophobicity (CSH) of this yeast is considered a critical factor contributing to its colonisation potential. As the concentration of topically prescribed antifungals reach sub-therapeutic levels at dosage intervals, the study of the polyene-induced PAFE and its impact on the CSH of oral C. albicans should be of clinical relevance. Hence the aims of this investigation were to measure the PAFE and CSH of 12 isolates of C. albicans following limited exposure (1 h) to nystatin and amphotericin B and also to investigate the ultrastructural features of yeast cells following such antifungal exposure. The yeasts were exposed to sub-lethal concentrations of nystatin (x2 MIC) and amphotericin B (x2 MIC) for a period of 1 h. Following subsequent removal of the drug, the PAFE and the CSH of the isolates were assessed by a turbidometric measurement of growth and a biphasic aqueous-hydrocarbon assay, respectively. The mean duration of PAFE of nystatin and amphotericin B were 5.99 (+/-0.49) h and 8.73 (+/-0.93) h, respectively, while the reduction in CSH following exposure to these drugs were 17.32% (P<0.05 for 83% of the isolates) and 14.26% (P<0.05 for 66% of the isolates), respectively. On scanning electron microscopy the exposed cells were seen to undergo collapse of the internal cell membrane, leaving an intact cell wall, while a proportion of cells were deflated. Some cells showed intense puckering of the cell wall, resulting in a mulberry appearance. Taken together, these data elucidate additional mechanisms by which polyene antimycotics may operate in vivo to suppress candidal pathogenicity.
TL;DR: Biogenic graphite has been used as a geomarker for trace sites of sedimentary basins and subsequent ocean closures that may have resulted in geosutures as mentioned in this paper.
TL;DR: This study demonstrated the presence of cellulitis in Sri Lanka and this report describes some of the phenotypic characteristics of the E. coli isolates.
Abstract: Cellulitis caused by Escherichia coli in broilers results in substantial losses to the broiler industry in North America and Europe due to condemnations at slaughter. The objective of this study was to identify cellulitis in broilers in Sri Lanka and to characterize the E. coli from cellulitis and other colibacillosis lesions. Twenty-four farms from the low- and mid-country were selected and bacterial isolations were obtained from 241 birds. Two hundred and ninety-one gross lesions were observed in these 241 birds and 162 E. coli isolates were obtained. Cellulitis was observed in 21% of the birds. Twenty-one per cent of the birds had multiple lesions due to E. coli. The frequency of detection of other disease syndromes was 162 (67%) birds with pericarditis, 26 (11%) airsacculitis, 24 (10%) hepatitis, 12 (5%) perihepatitis, and 16 (7%) polyserositis (a combination of pericarditis, perihepatitis and airsacculitis). Serogroups O78, O2, O85 and O88 were distributed among the 32% of typable E. coli and 81% of isolates were assigned to three biotypes. Forty-four per cent of the E. coli isolates produced aerobactin and 88% demonstrated resistance to the bactericidal effect of normal chicken serum. The majority of the E. coli isolates were resistant to the antibiotics commonly used in poultry. All the E. coli isolates were non-haemolytic and 25% of the isolates produced K1 capsule. This study demonstrated the presence of cellulitis in Sri Lanka and this report describes some of the phenotypic characteristics of the E. coli isolates.
01 Jan 2000
TL;DR: A rapidly expanding literature on candidal adherence attests to the potential importance of understanding the behavior of this ubiquitous yeast and the pathogenesis of infections which it causes in the human host.
Abstract: Increasing recognition of the ecological, medical and economic significance of microbial adhesion has resulted in a vast escalation of research effort in this area. Although studies on bacterial adhesion have predominated, with an extensive body of data, investigations on candidal adherence are comparatively limited.23 Nevertheless, a rapidly expanding literature on candidal adherence attests to the potential importance of understanding the behavior of this ubiquitous yeast and the pathogenesis of infections which it causes in the human host.37,59 Adhesion of Candida to epithelial cells has been investigated to define parameters relevant to the pathogenesis of oral, gastrointestinal, vaginal and urinary candidiasis.24,48,57,58 Further, the attachment of the organism to fibrin, fibrin-platelet matrices and to vascular endothelial cells have been examined to elucidate initial events leading to candidal endocarditis and hematogenously disseminated infection.48,49,60 There is also a growing body of information on the adhesion of Candida to inert/nonbiological surfaces such as denture prostheses, intravascular and urinary catheters, and prosthetic cardiac valves.12,31–33,48,50,51,54,55
TL;DR: Compared to a sole crop of mung bean, most hedgerow intercrops removed greater soil nitrogen, whereas all removed lower soil phosphorus, indicating competitive capture of nutrients by hedges and Gliricidia, which allowed greater mung Bean yields, also allowed greater nutrient capture by mungbean.
Abstract: Annual crops grown in association with contour hedgerows often show yield reductions. This paper quantifies the variation of above- and below-ground environmental factors in hedgerow intercrops involving six different tree species (Calliandra calothyrus, Desmodium ransonii, Flemingia c ongesta, Gliricidia sepium, Cassia spectabilis and Tithonia diversifolia) and thereby shows the effects of tree hedges on mung bean (Vigna radiata). Compared to a sole crop of mung bean, most hedgerow intercrops removed greater soil nitrogen, whereas all removed lower soil phosphorus. Mung bean closer to the hedgerows had lower N and P, indicating competitive capture of nutrients by hedges. Most hedgerow intercrops had greater top-soil water because of their shading effect, especially near hedgerows. However, greater absorption by tree root systems decreased subsoil water near hedgerows late in the season. Soil temperature was lower in most hedgerow intercrops than in the control and increased with increasing distance from hedges. During initial stages of mung bean growth, radiation interception of intercrops was greater than that of the control, especially closer to hedgerows. However, after the first month, radiation interception of the sole crop was either equal to or greater than that of hedgerow intercrops. There was significant variation between tree species in all these environmental factors. Gliricidia, which allowed greater mung bean yields, also allowed greater nutrient capture by mung bean, greater top-soil water availability, lower extraction of subsoil water and lower soil temperatures.