Mitochondrial DNA diversity and maternal origins of Pakistani donkey / Diversidade de DNA mitocondrial e origens maternas do burro do Paquistão

Domestic donkey plays a key role as a draft animal in rural economy of Pakistan where its population is increasing every year. The complete mtDNA control region of forty randomly sampled donkeys was PCR- amplified and sequenced bi-directionally using specific primers. Distinct mtDNA haplotypes obtained in the current study (KY446001−KY446011) were subjected to haplotype (h) and nucleotide diversity (π) measures using DnaS as well as to phylogenetic, Network, and AMOVA analyses. There were a total 27 polymorphic sites present within 11 unique mtDNA haplotypes from the studied 40 animals from different regions. Neighbor-joining network and median-joining network both illustrated the splitting of all these haplotypes into two well-defined Nubian and Somali lineages, confirming African maternal origin of Pakistani domestic donkey. Diversity parameters h (0.967± 0.037) and π (0.02917± 0.00307) were found to reveal high levels of genetic diversity in Pakistani donkeys. AMOVA demonstrated only 1% of genetic differences between two mtDNA maternal lineages, pointing to lack of population substructure in Pakistani donkeys as is the case with worldwide domestic donkey population. Pakistani donkeys have African maternal origin and high levels of mtDNA diversity. High genetic diversity may be due to non-selective breeding and heteroplasmy. We herein provide the first report on mtDNA diversity of control region in Pakistani domestic donkey.

O burro doméstico possui um papel fundamental como animal de tração na economia rural do Paquistão, onde a população desse animal está aumentando a cada ano. A região de controle de mtDNA completa de 40 burros amostrados aleatoriamente foi ampliada por PCR e sequenciada bidirecionalmente por intermédio de primers específicos. Haplótipos distintos de mtDNA obtidos no estudo atual (KY446001 − KY446011) foram submetidos a medidas de haplótipo (h) e diversidade de nucleotídeos (π) por meio de DnaS, bem como análises filogenéticas, de rede e AMOVA. Havia um total de 27 sítios polimórficos presentes em 11 haplótipos de mtDNA exclusivos dos 40 animais estudados de diferentes regiões. A rede de união de vizinhos e a rede de união mediana ilustram a divisão de todos esses haplótipos em duas linhagens núbias e somalis bem definidas, confirmando a origem materna africana do burro doméstico do Paquistão. Os parâmetros de diversidade h (0,967 ± 0,037) e π (0,02917 ± 0,00307) revelaram altos níveis de diversidade genética em burros paquistaneses. AMOVA demonstrou apenas 1% de diferenças genéticas entre as duas linhagens maternas de mtDNA, apontando a falta de subestrutura populacional em burros paquistaneses, como é o caso da população mundial de burros domésticos. Os burros paquistaneses têm origem materna africana e altos níveis de diversidade de mtDNA. A alta diversidade genética pode ser por causa da reprodução não seletiva e de heteroplasmia. Aqui, fornecemos o primeiro relatório sobre a diversidade do mtDNA da região de controle em burros domésticos do Paquistão

Mitochondrial DNA diversity and maternal origins of Pakistani donkey

Abstract Domestic donkey plays a key role as a draft animal in rural economy of Pakistan where its population is increasing every year. The complete mtDNA control region of forty randomly sampled donkeys was PCR- amplified and sequenced bi-directionally using specific primers. Distinct mtDNA haplotypes obtained in the current study (KY446001KY446011) were subjected to haplotype (h) and nucleotide diversity () measures using DnaS as well as to phylogenetic, Network, and AMOVA analyses. There were a total 27 polymorphic sites present within 11 unique mtDNA haplotypes from the studied 40 animals from different regions. Neighbor-joining network and median-joining network both illustrated the splitting of all these haplotypes into two well-defined Nubian and Somali lineages, confirming African maternal origin of Pakistani domestic donkey. Diversity parameters h (0.967± 0.037) and (0.02917± 0.00307) were found to reveal high levels of genetic diversity in Pakistani donkeys. AMOVA demonstrated only 1% of genetic differences between two mtDNA maternal lineages, pointing to lack of population substructure in Pakistani donkeys as is the case with worldwide domestic donkey population. Pakistani donkeys have African maternal origin and high levels of mtDNA diversity. High genetic diversity may be due to non-selective breeding and heteroplasmy. We herein provide the first report on mtDNA diversity of control region in Pakistani domestic donkey.

Resumo O burro doméstico possui um papel fundamental como animal de tração na economia rural do Paquistão, onde a população desse animal está aumentando a cada ano. A região de controle de mtDNA completa de 40 burros amostrados aleatoriamente foi ampliada por PCR e sequenciada bidirecionalmente por intermédio de primers específicos. Haplótipos distintos de mtDNA obtidos no estudo atual (KY446001 KY446011) foram submetidos a medidas de haplótipo (h) e diversidade de nucleotídeos () por meio de DnaS, bem como análises filogenéticas, de rede e AMOVA. Havia um total de 27 sítios polimórficos presentes em 11 haplótipos de mtDNA exclusivos dos 40 animais estudados de diferentes regiões. A rede de união de vizinhos e a rede de união mediana ilustram a divisão de todos esses haplótipos em duas linhagens núbias e somalis bem definidas, confirmando a origem materna africana do burro doméstico do Paquistão. Os parâmetros de diversidade h (0,967 ± 0,037) e (0,02917 ± 0,00307) revelaram altos níveis de diversidade genética em burros paquistaneses. AMOVA demonstrou apenas 1% de diferenças genéticas entre as duas linhagens maternas de mtDNA, apontando a falta de subestrutura populacional em burros paquistaneses, como é o caso da população mundial de burros domésticos. Os burros paquistaneses têm origem materna africana e altos níveis de diversidade de mtDNA. A alta diversidade genética pode ser por causa da reprodução não seletiva e de heteroplasmia. Aqui, fornecemos o primeiro relatório sobre a diversidade do mtDNA da região de controle em burros domésticos do Paquistão.

Prolonged neuraxial block following spinal anaesthesia in a patient with carnitine palmitoyl transferase II deficiency undergoing caesarean section.

Carnitine palmitoyl transferase II (CPT II) deficiency is a rare disorder of fatty acid metabolism in cell mitochondria. There is limited information about the disease process and complications of anaesthesia, particularly in the obstetric population. Due to the increased risks of general anaesthesia in patients with CPT II deficiency, neuraxial anaesthesia is the preferred method of anaesthesia. We describe a patient with CPT II deficiency who had spinal anaesthesia for caesarean section. Subsequently, the patient had prolonged neuraxial blockade, a previously undescribed complication in a patient with CPT II deficiency.

Deep learning based diagnostic quality assessment of choroidal OCT features with expert-evaluated explainability.

Various vision-threatening eye diseases including age-related macular degeneration (AMD) and central serous chorioretinopathy (CSCR) are caused due to the dysfunctions manifested in the highly vascular choroid layer of the posterior segment of the eye. In the current clinical practice, screening choroidal structural changes is widely based on optical coherence tomography (OCT) images. Accordingly, to assist clinicians, several automated choroidal biomarker detection methods using OCT images are developed. However, the performance of these algorithms is largely constrained by the quality of the OCT scan. Consequently, determining the quality of choroidal features in OCT scans is significant in building standardized quantification tools and hence constitutes our main objective. This study includes a dataset of 1593 good and 2581 bad quality Spectralis OCT images graded by an expert. Noting the efficacy of deep-learning (DL) in medical image analysis, we propose to train three state-of-the-art DL models: ResNet18, EfficientNet-B0 and EfficientNet-B3 to detect the quality of OCT images. The choice of these models was inspired by their ability to preserve the salient features across all the layers without information loss. To evaluate the attention of DL models on the choroid, we introduced color transparency maps (CTMs) based on GradCAM explanations. Further, we proposed two subjective grading scores: overall choroid coverage (OCC) and choroid coverage in the visible region(CCVR) based on CTMs to objectively correlate visual explanations vis-à-vis DL model attentions. We observed that the average accuracy and F-scores for the three DL models are greater than 96%. Further, the OCC and CCVR scores achieved for the three DL models under consideration substantiate that they mostly focus on the choroid layer in making the decision. In particular, of the three DL models, EfficientNet-B3 is in close agreement with the clinician's inference. The proposed DL-based framework demonstrated high detection accuracy as well as attention on the choroid layer, where EfficientNet-B3 reported superior performance. Our work assumes significance in bench-marking the automated choroid biomarker detection tools and facilitating high-throughput screening. Further, the methods proposed in this work can be adopted for evaluating the attention of DL-based approaches developed for other region-specific quality assessment tasks.

Volumetric quantification of choroid and Haller's sublayer using OCT scans: An accurate and unified approach based on stratified smoothing.

BACKGROUND AND OBJECTIVE: The choroid, a dense vascular structure in the posterior segment of the eye, maintains the health of the retina by supplying oxygen and nutrients, and assumes clinical significance in screening ocular diseases including age-related macular degeneration (AMD) and central serous chorioretinopathy (CSCR). As a technological assist, algorithmic estimation of choroidal biomarkers has been suggested based on sectional (B-scan) optical coherence tomography (OCT) images. However, most such 2D estimation techniques are compute-intensive, yet enjoy limited accuracy and have only been validated on OCT image datasets of healthy eyes. Not surprisingly, fine-scale analyses, including those involving Haller's sublayer, remain relatively rare and unsophisticated. Against this backdrop, we propose an efficient algorithm to quantify desired biomarkers with improved accuracy based on volume OCT scans. Specifically, we attempted an accurate, computationally light volumetric segmentation method involving stratified smoothing to detect choroid and Haller's sublayer. METHODS: For detecting the various boundaries of the choroid and the Haller's sublayer, we propose a common volumetric method that performs suitable exponential enhancement and maintains smooth spatial continuity across 2D B-scans. Further, we achieve suitable volumetric smoothing by primarily deploying light-duty linear regression, and sparingly using compute-intensive tensor voting, and hence significantly reduce overall complexity. The proposed methodology is tested on five health and five diseased OCT volumes considering various metrics including volumetric Dice coefficient and corresponding quotient measures to facilitate comparison vis-à-vis intra-observer repeatability. RESULTS: On five healthy and five diseased OCT volumes, respectively, the proposed method for choroid segmentation recorded volumetric Dice coefficients of 93.53 % and 93.30 %, which closely approximate the respective reference observer repeatability values of 95.60 % and 95.49 %. In terms of related quotient measures, our method achieved more than 50 % improvement over a recently reported method. In detecting Haller's sublayer as well, our algorithm records statistical performance closely matching that of reference manual method. CONCLUSION: Advancing the state-of-the-art, the proposed volumetric segmentation, tested on both healthy and diseased datasets, demonstrated close match with the manual reference. Our method assumes significance in accurate screening of chorioretinal diseases including AMD, CSCR and pachychoroid. Further, it enables generating accurate training data for developing deep learning models for improved detection of choroid and Haller's sublayer.

Mitochondrial DNA diversity and maternal origins of Pakistani donkey.

Domestic donkey plays a key role as a draft animal in rural economy of Pakistan where its population is increasing every year. The complete mtDNA control region of forty randomly sampled donkeys was PCR- amplified and sequenced bi-directionally using specific primers. Distinct mtDNA haplotypes obtained in the current study (KY446001-KY446011) were subjected to haplotype (h) and nucleotide diversity (π) measures using DnaS as well as to phylogenetic, Network, and AMOVA analyses. There were a total 27 polymorphic sites present within 11 unique mtDNA haplotypes from the studied 40 animals from different regions. Neighbor-joining network and median-joining network both illustrated the splitting of all these haplotypes into two well-defined Nubian and Somali lineages, confirming African maternal origin of Pakistani domestic donkey. Diversity parameters h (0.967± 0.037) and π (0.02917± 0.00307) were found to reveal high levels of genetic diversity in Pakistani donkeys. AMOVA demonstrated only 1% of genetic differences between two mtDNA maternal lineages, pointing to lack of population substructure in Pakistani donkeys as is the case with worldwide domestic donkey population. Pakistani donkeys have African maternal origin and high levels of mtDNA diversity. High genetic diversity may be due to non-selective breeding and heteroplasmy. We herein provide the first report on mtDNA diversity of control region in Pakistani domestic donkey.

Adaptation of MacArthur Communicative Development Inventory in rural Pakistan - useful tool for early childhood studies.

BACKGROUND: Given the significance of early language for later academic achievement, language development can be an important outcome measure in evaluation of early childhood intervention programmes. Language development may be challenging to assess in settings where trained personnel are hard to find; therefore, maternal report can be a reliable alternative measure. AIM: The aim of this study was to adapt a maternal report measure, the MacArthur Communicative Development Inventory II-Short Form, in the Sindhi language and to examine its psychometric properties as a measure of language outcome in 2-year-old children in rural Pakistan. METHODS: A three-phase process was followed to produce a Sindhi adaptation of the tool comprising 100 words. The first phase was a review of the original 258 words through a focus group discussion with a team familiar with the context; the second phase was testing 258 words to compile a 100-word list of easy, moderate and difficult words. The third phase was a pilot of the 100-word list followed by administration in a larger intervention study population. RESULTS: On administration with 1381 children, concurrent validity with the Bayley Scale of Infant Development III using the Pearson's correlation test showed a moderate association for comprehension (r = 0.45, p = 0.01, n = 1381) and good association for expression (r = 0.51, p = 0.01, n = 1381). Internal consistency was high with alphas of 0.98 for comprehension items and 0.96 for expression items. CONCLUSION: The authors conclude that the Sindhi adaptation of the MacArthur Communicative Development Inventory followed a feasible and rigorous methodology to create a reliable and sensitive tool to assess young children's language development for use in a child assessment battery for early childhood health, nutrition and development studies.

Evaluation of Reference Genes for RT-qPCR Studies in the Seagrass Zostera muelleri Exposed to Light Limitation.

Seagrass meadows are threatened by coastal development and global change. In the face of these pressures, molecular techniques such as reverse transcription quantitative real-time PCR (RT-qPCR) have great potential to improve management of these ecosystems by allowing early detection of chronic stress. In RT-qPCR, the expression levels of target genes are estimated on the basis of reference genes, in order to control for RNA variations. Although determination of suitable reference genes is critical for RT-qPCR studies, reports on the evaluation of reference genes are still absent for the major Australian species Zostera muelleri subsp. capricorni (Z. muelleri). Here, we used three different software (geNorm, NormFinder and Bestkeeper) to evaluate ten widely used reference genes according to their expression stability in Z. muelleri exposed to light limitation. We then combined results from different software and used a consensus rank of four best reference genes to validate regulation in Photosystem I reaction center subunit IV B and Heat Stress Transcription factor A- gene expression in Z. muelleri under light limitation. This study provides the first comprehensive list of reference genes in Z. muelleri and demonstrates RT-qPCR as an effective tool to identify early responses to light limitation in seagrass.

The development and reliability of an observational tool for assessing mother-child interactions in field studies- experience from Pakistan.

BACKGROUND: This study describes the development and reliability testing of an observational tool to measure mother-child interactions with toddlers aged 2 years in a rural low-income country setting. METHODS: The development protocol comprised five phases with iterative revisions: (1) identification of the theoretical framework for responsive behaviours and selection of items; (2) field testing; (3) expert review; (4) training of the data collection team; and (5) piloting. The final tool was a structured live observational measure assessing a 5-min interaction of a shared picture-book-reading activity. Maternal behaviours assessed included affect, touch, verbal statements and language stimulation; child behaviours assessed included affect, communication and attention. RESULTS: Following development, the mother-child interaction tool was administered on a cohort of 1390 children at 2 years of age. Using a video strategy, inter-observer reliability assessed by the Bland-Altman test for mother-child dyads suggested moderate agreement between expert and field assessors on total scores (r = 0.681**, P < 0.001, n = 154). Significant associations of the total interaction score correlations using Pearson's' correlations were found with the Responsiveness (r = 0.271**, P < 0.001, n = 1345) and Involvement (r = 0.325**, P < 0.001, n = 1345) subscales of the Home Observation for Measurement of Environment-Infant Toddler Inventory, maternal knowledge (r = 0.203**, P < 0.001, n = 1345), maternal depression (r = .-063**, P < 0.001, n = 1345), child cognitive development (r = 0.392**, P < 0.001, n = 1345) and language development (r = 0.620**, P < 0.001, n = 1345) assessed using the Bayley Scales for Infant and Toddler Development, Third Edition. CONCLUSION: The authors conclude that this tool can be reliably used by trained assessors to measure mother-child interactions in field studies.

Guiding principles for the improved governance of port and shipping impacts in the Great Barrier Reef.

The Great Barrier Reef (GBR) region of Queensland, Australia, encompasses a complex and diverse array of tropical marine ecosystems of global significance. The region is also a World Heritage Area and largely within one of the world's best managed marine protected areas. However, a recent World Heritage Committee report drew attention to serious governance problems associated with the management of ports and shipping. We review the impacts of ports and shipping on biodiversity in the GBR, and propose a series of guiding principles to improve the current governance arrangements. Implementing these principles will increase the capacity of decision makers to minimize the impacts of ports and shipping on biodiversity, and will provide certainty and clarity to port operators and developers. A 'business as usual' approach could lead to the GBR's inclusion on the List of World Heritage in Danger in 2014.

Carbon isotope fractionation studies of bacterial strain Rhodococcus rhodochrous MTCC 291.

Carbon isotope fractionation associated with the aerobic consumption of propane (C3) were determined using Rhodococcus rhodochrous MTCC 291 bacterial strain to estimate the amount of hydrocarbon oxidized using GC, fractionation of delta13C carbon isotopes of propane and CO2 using GC-C-IRMS and growth of bacteria by UV-Visible Spectrophotometer. The initial delta13C isotopic value of propane was -34 per thousand and after incubation the changes of the isotopic values have been determined on 6th, 10th, 14th, and 17th days. The propane isotopic fractionation value was found to be maximum of -38.0 per thousand with an average value of -36.5 per thousand and a standard deviation of -1.22 per thousand. The initial delta13C isotopic value of CO2 was -19.601 per thousand. The CO2 isotopic fractionation value was found to be maximum of -29.153 per thousand with an average value of -26.859 per thousand and a standard deviation of -28.338 per thousand. The consumption of propane gas was estimated using Gas Chromatograph. The initial concentration of propane in control was found to be 53 ppm. On incubation, the consumption of the propane gas was observed to be of 26 ppm. The carbon isotope fractionation presented here may be applied to estimate the extent of C1-C4 oxidation in natural gas samples, and should prove useful in further studying the microbial oxidation of these compounds in the natural environment.

Characterization of light gaseous hydrocarbons of the surface soils of Krishna-Godavari basin, India.

Several techniques are used for the exploration of hydrocarbons, of which; the geochemical techniques involving the microbiological technique use the principle of detecting the light hydrocarbon seepage activities for indication of sub-surface petroleum accumulations. Asurvey was carried out to characterize the light gaseous hydrocarbons seeping in oil and gas fields of Krishna-Godavari basin ofAndhra Pradesh. Aset of 50 sub-soil samples were collected at depths of about 3 m for geochemical analyses and 1m for microbiological analysis. The microbial prospecting studies showed the presence of high bacterial population for methane 2.5 x 10(2) to 6.0 x 10(6) cfu g(-1), propane 1x10(2) to 8.0 x 10(6) cfu g(-1) in soil samples. The adsorbed soil gas analysis showed the presence of moderate to low concentrations of methane (26 to 139 ppb), ethane (0 to 17 ppb), propane (0 to 8 ppb), butane (0 to 5 ppb) and pentane (0 to 2 ppb) in the soil samples of the study area. Carbon isotope analysis for methane ('13C1) ranging from -36.6 to -22.7 per hundred Pee Dee Belemnite (PDB) suggests these gases are of thermogenic origin. Geo-microbial prospecting method coupled with adsorbed soil gas and carbon isotope ratio analysis have thus shown good correlation with existing oil/gas fields of Krishna-Godavari basin.

Evaluation of potable groundwater quality in some villages of Adilabad in Andhra Pradesh, India.

Reconnaissance hydrochemical survey was conducted in some villages of Adilabad district, Andhra Pradesh to assess the quality of groundwater, which is mainly used for drinking purpose. The study consists of the determination of physico-chemical properties, trace metals, heavy metals and rare earth elements in water samples. The data showed the variation of the investigated parameters in samples as follows: pH 6.92 to 8.32, EC 192 to 2706 microS cm(-1), TDS 129.18 to 1813.02 ppm. The pH of the waters was within the permissible limits whereas EC and TDS were above the permissible limits of World Health Organization (WHO). Total 27 elements (Li, Be, B, Na, Mg, Al, Si, K, Ca, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sb, Ba and Pb) were analyzed using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). The concentration of elements in water samples ranged between 0.063 to 0.611 mg l(-1) for B, 11.273 to 392 mg l(-)1 for Na, 5.871 to 77.475 mg l(-1) for Mg, 0.035 to 1.905 mg l(-1) for Al, 0.752 to 227.893 mg l(-1) for K, 11.556 to 121.655 mg l(-1) for Ca and 0.076 to 0.669 mg l(-1) for Fe respectively. The concentrations of Na, Mg, Al, K, Ca, and Fe exceeded the permissible limits of WHO and BIS guidelines for drinking water quality. In the present study, Bhimavaram, Kazipalli, Kannepalli and Chennur areas of the Adilabad are especially prone to geogenic contamination. Overall water quality was found unsatisfactory for drinking purposes.

Polarizing properties of embedded symmetric trilayer stacks under conditions of frustrated total internal reflection.

An all-transparent symmetric trilayer structure, which consists of a high-index center layer coated on both sides by a low-index film and embedded in a high-index prism, can function as an efficient polarizer or polarizing beam splitter under conditions of frustrated total internal reflection over a wide range of incidence angles. For a given set of refractive indices, all possible solutions for the thicknesses of the layers that suppress the reflection of either the p or s polarization at a specified angle, as well as the reflectance of the system for the orthogonal polarization, are determined. A 633 nm design that uses a MgF2-ZnS-MgF2 trilayer embedded in a ZnS prism achieves an extinction ratio (ER) > 40 dB from 50 degrees to 80 degrees in reflection and an ER > 20 dB from 58 degrees to 80 degrees in transmission. IR polarizers that use CaF2-Ge-CaF2 trilayers embedded in a ZnS prism are also considered.

Effect of hydrocarbons and other parameters on hydrocarbon-utilizing Pichia angusta MTCC-225.

Pichia angusta MTCC-225, a catalase-positive yeast that utilizes methanol and lighter hydrocarbons, is the subject of this investigation. An orthogonal experimental design L16 was used to investigate the effects of methanol, a gas mixture, zero air, temperature, agitation, and salts solution on hydrocarbon utilizing P. angusta. QUALITEK-4 Software was used for automatic design and analysis of the experimental results. Among the various parameters tested, agitation contributed the highest influence (56.5%). Zero air, methanol concentration, and gas mixture showed a moderate influence on the growth of P. angusta. Methanol concentration and gas mixture showed a 10.91 and 10.12% influence, respectively, on yeast growth. Zero air played an important role, with a 15.19% influence on the utilization of hydrocarbon.

Single-layer-coated beam splitters for the division-of-amplitude photopolarimeter.

A design procedure is presented for a near-optimal, single-layer-coated prism beam splitter that serves as the key optical element of the division-of-amplitude photopolarimeter (DOAP). For given film and substrate refractive indices, the angle of incidence and film thickness are selected such that the ellipsometric differential phase shifts in reflection and transmission deltar, and deltat, differ by +/- pi/2, and the normalized determinant of the instrument matrix is maximized. The best results are obtained by using high-index films on low-index substrates. This is illustrated by examples of ZnS and GaP films on silica prisms in the visible and Si, Ge, and PbTe films on Irtran 1 substrates in the infrared. A 16 degrees Si-prism DOAP beam splitter at the 1.55-microm lightwave-communications wavelength is also presented. It uses a 163-nm SiO2 coating on the entrance face to satisfy the optimum delta condition at 73 degrees incidence, and the determinant of the instrument matrix is 78.23% of its theoretical maximum. The exit face of the Si prism is antireflection coated with a 208-nm Si3N4 film.

A trial to determine the role of placental extract in the treatment of chronic non-healing wounds.

OBJECTIVE: To investigate the effect of topical placental extract in the treatment of non-healing wounds. METHOD: One hundred patients attending the wound clinic at University Hospital, Varanasi, India, with wounds of more than six weeks' duration were recruited. Fifty patients were treated with placental extract, and 50 were controls. Wound biopsy and swab culture and sensitivity were performed and the area surrounding the wound was X-rayed. Wound size was measured and the rate of epithelialisation assessed at weekly follow-ups. In nine cases biopsies were repeated after two weeks of treatment and sent for histopathological examination, including angiogenesis. RESULTS: Thirty patients dropped out, leaving 40 cases in the treatment group and 30 in the control group. Over an eight-week period, 27 patients (67.5%) in the treatment group showed more than 50% epithelialisation, compared with only seven patients (23.3%) in the control group. CONCLUSION: Placental extract has a beneficial role to play as a topical agent in the management of chronic non-healing wounds.

Spectral polarization measurements by use of the grating division-of-amplitude photopolarimeter.

The grating division-of-amplitude photopolarimeter (G-DOAP) is an instrument that exploits the multiple-beam-splitting, polarizing, and dispersive properties of diffraction gratings for the time-resolved measurement of the complete state of polarization of collimated broadband incident light, as represented by the four Stokes parameters as a function of wavelength across the spectrum. It is a compact, high-speed sensor that has no moving parts and is simple to install and operate. These characteristics make the G-DOAP well suited for in situ spectroscopic ellipsometry (SE) applications for monitoring and controlling thin-film processes. The design and performance of a prototype instrument are presented. Precise SE measurements, to +/-0.04 degrees in psi and +/-0.1 degrees in delta, are demonstrated in the 550-940-nm wavelength range.

Symmetrically coated pellicle beam splitters for dual quarter-wave retardation in reflection and transmission.

A trilayer pellicle that consists of a high-index center layer that is symmetrically coated on both sides by a low-index film can be designed to produce differential reflection and transmission phase shifts of +/- 90 degrees at oblique incidence and equal throughput for the p and the s polarizations. Such a device splits a beam of incident linearly polarized light into two orthogonal circularly polarized components that travel in well-separated angular directions. Examples of infrared dual quarter-wave retarders that use a symmetrically coated Ge pellicle at 77 degrees angle of incidence are presented. A 50-50% splitter requires a symmetric pellicle with at least five layers. Error analysis shows that the thicknesses of the high-index layers must be tightly controlled. These circular polarization beam splitters are intended for operation with a well-collimated light source and can be used as the basis of a novel circular polarization Michelson interferometer.

Clinico-epidemiological study of hospitalized cases of severe leptospirosis.

In an attempt to understand the clinical spectrum and pathological and biochemical abnormalities and their prognostic importance in leptospirosis, a prospective study was carried out in Port Blair during September 1996 to August 1997. Out of 80 patients suspected to have leptospirosis, 58 were proved to have current leptospiral infection using serological tests and among these, 14 died giving a case fatality rate of 24.1 per cent. The incidence of the disease showed two separate peaks roughly coinciding with the paddy sowing and harvesting season and the majority of the patients had history of exposure to wet and water logged environment prior to the attack of the disease. The disease presented as two separate clinical syndromes--the hepato-renal form and the pulmonary form though some degree of overlap was present. Hepatic and renal complications occurred in 30 patients each with 26 of them having both. These generally occurred late in the course of the disease and the mortality rate was relatively low. In contrast pulmonary complication occurred quite early and the case fatality rate in those patients was very high (6.7% vs 42.9%). The other complications encountered in the current series of cases were refractory hypotension probably due to myocarditis in 40 per cent and neck stiffness and altered sensorium due to central nervous involvement in 12.1 per cent of the patients. The chances of the patients developing complications were considerably low if treated early and very few of them developed any complications after 2 days of hospitalized treatment. The early occurrence of pulmonary complications indicates a pathogenesis totally different from that responsible for the other complications.