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1.
Bull Environ Contam Toxicol ; 111(3): 44, 2023 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-37715801

RESUMO

Moyna of Purba Medinipur district is widely known as an aquaculture hub of West Bengal, India. Though very good production is achievable from this fish culture system, management practices are inappropriate, which could create the sustainability problem of this culture system. The present study was thus undertaken for the estimation of plankton population, water quality, carbon footprint and carbon sequestration of this intensive aquaculture practices. Information on spawn to fry, fry to fingerlings and grow-out culture were collected through the structured questionnaire from the fish farmers. The plankton density, primary productivity, carbon footprint and carbon sequestration were analyzed using standard procedures. The phytoplankton, zooplankton and primary productivity were maximum at the stocking period and minimum during the middle of culture period. The lowest feed conversion ratio (FCR) was noticed with the minimum amount of feed applied in the pond. The CO2-e emission ranged from 0.56 to 4.89 kg CO2-e/kg fish (av. 2.13) for the production levels of 5.0 to 10.7 t/ha/yr. The pond water developed salinity and ammonium-N increased from 0.01 to 0.50 mg/l. The ponds with high feed loading (28 to 32 t/ha/yr) had the highest average sediment accumulation rate (11.0 ± 3.0 cm/yr) and carbon sequestration (704 ± 30 g C/m2/yr).


Assuntos
Pegada de Carbono , Sequestro de Carbono , Animais , Dióxido de Carbono , Aquicultura , Índia , Plâncton
2.
Mymensingh Med J ; 28(4): 762-766, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31599238

RESUMO

Stroke is one of the leading cause of disability worldwide. Motor function deficits due to stroke contribute to overall low quality of life. The objective was of this study is to observe functional motor outcome after stroke with low dose Levodopa therapy. This prospective follow up study was carried out in the Department of Neurology, Mymensingh Medical College Hospital, Mymensingh, Bangladesh from July 2014 to June 2016 to see the effect of low dose of Levodopa (110mg) on motor outcome after stoke disability. Motor deficit was measured by Medical Research Council (MRC) grading and Rivermead Mobility Index (RMI) score. Two groups were selected by simple random method, consisted of both ischemic and hemorrhagic stroke. All the patients of both the groups were suffering from at least some post stroke motor disability and attended full course of physiotherapy. The group (L) received 110mg Levodopa with physiotherapy. On the other hand (NL) group received only physiotherapy. They were all followed up for four times within two months of time and were assessed for recovery of motor function. Mean age was 59.03±11.56 years in Levodopa (L) group and 57.10±12.41 years in the Non Levodopa (NL) group; Males were predominant in both groups. Ninety three (77.50%) cases had ischemic stroke and 27(22.50%) cases had hemorrhagic stroke. Most common risk factors were hypertension and smoking. No known risk factor was detected in 8 (6.67%) patients. Single or multiple risk factors were confirmed in 112 patients (93.33%). MRC score was significantly higher both in affected upper and lower limb in Levodopa group comparing non Levodopa group at 4th visit. RMI score was also significantly higher in Levodopa group comparing non Levodopa group at 4th visit. The Levodopa (L) group showed better recovery pattern than Non Levodopa (NL) group. It can be concluded that motor recovery was better with administration of a single low dose of Levodopa in combination with physiotherapy. Motor outcome was significantly higher in levodopa group than non-levodopa group.


Assuntos
Pessoas com Deficiência , Dopaminérgicos/uso terapêutico , Levodopa/uso terapêutico , Transtornos Motores/tratamento farmacológico , Acidente Vascular Cerebral/tratamento farmacológico , Idoso , Bangladesh , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida
3.
In. The University of the West Indies, Faculty of Medical Sciences. Faculty of Medical Sciences, Research Day. St. Augustine, Caribbean Medical Journal, March 21, 2019. .
Não convencional em Inglês | MedCarib | ID: biblio-1025217

RESUMO

Objectives: The objective of the study was to assess the extent to which the Chronic Disease Assistance Programme (CDAP)was able to meet the needs of different risk groups within the Trinidad and Tobago population. The study sought to answer the research question how does the healthcare strategy of risk group segmentation (RGS) interact with the country context to create legitimacy for CDAP. It was hypothesised that the implementation of a RGS strategy improves CDAP's legitimacy to allocate and manage resources. Design and Methodology: A sample of 161 pharmacists were surveyed via face to face interviews and telephone calls using a convenient sampling method. The instrument determined the extent to which the six dimensions of RGS were utilized in CDAP and three performance construct were assessed. Two pharmacists from each pharmacy were interviewed to reduce common method bias. Descriptive measures such as mean, standard deviation and Pearson bivariate correlations for the purpose of simple summaries of the dominant views and relationships were done and hypothesis testing was conducted using three-stage hierarchical regression analysis. Results: RSG was seen as an empowering tool for the patients and was needed, but not addressed. It was found to be desirable but not implemented. Its non implementation reduced the socio-political legitimacy of the program. Conclusions: CDAP in its current form does not address the risk faced by various groups in Trinidad and Tobago. This has led to the socio-political legitimacy of the program being reduced. It may be inferred its ability to create true health equality is compromised.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Acesso a Medicamentos Essenciais e Tecnologias em Saúde , Serviços de Saúde , Trinidad e Tobago , Região do Caribe/etnologia
4.
Mymensingh Med J ; 27(4): 685-692, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30487481

RESUMO

Stroke is leading cause of death world wide, after coronary artery disease and cancer. A high proportion of patients suffering from an acute stress such as stroke or myocardial infarction may develop hyperglycemia, even in the absence of a preexisting diagnosis of diabetes. An observational comparative study was carried out at the Department of Neurology and Medicine, Mymensingh Medical College, Mymensingh, Bangladesh from July 2011 to June 2013 among purposively selected ninety-three patients with a view to assess the outcome of stress hyperglycemia on acute stroke. Data were collected through interview, physical examinations & laboratory investigations by using case record form. Statistical analysis was performed using SPSS (Statistical package for social science) version 17. The mean age of this study was 59.04±15.01 years in the hyperglycemic group and 62.06±13.81 years in the normoglycemic group. The male female ratio in the Hyperglycemic and normoglycemic group was 2.12:1 and 2.44:1 respectively. Smoker was 48.8% in the hyperglycemic group and 52% in the normoglycemic group. 70% of the Hyperglycemic group and 66% of the normoglycemic were found hypertensive. Mean±SD blood glucose level was found 11.86±0.58mmol/L in the Hyperglycemic group and 6.50±1.55mmol/L in the normoglycemic group. Mean HbAlc were 6.14±0.56 in hyperglycemic group and 5.29±0.54 in normoglycemic group. Stroke severity score were 21.79±11.85 in Hyperglycemic and 28.64±9.53 in normoglycemic group on admission. Functional outcome was measured on discharge & at the end of 4th weeks of every patient by Glasgo Outcome Scale (GOS). The study also suggests that stress hyperglycemia is an important risk factor of poor stroke outcome.


Assuntos
Diabetes Mellitus , Hiperglicemia , Acidente Vascular Cerebral , Adulto , Idoso , Bangladesh , Glicemia , Feminino , Humanos , Hiperglicemia/complicações , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Acidente Vascular Cerebral/complicações
5.
Mymensingh Med J ; 27(2): 229-236, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29769483

RESUMO

Stroke is one of the leading causes of death and disability in developed as well as developing countries like Bangladesh. There is a crucial need to identify additional risk factors that are easily measurable and treatable in general population. Role of serum lipids, lipoproteins and lipoprotein related variables in the prediction of stroke is less clear. Abnormalities in plasma lipoproteins are the most firmly established and best understood risk factors for atherosclerosis and they are probable risk factors for ischaemic stroke, largely by their link to atherosclerosis. High serum apolipoprotein-B (Apo-B) levels may predict an increased risk for ischaemic stroke. Aim of the study was to evaluate the association between serum Apo-B level and acute ischaemic stroke and to measure and compare serum Apo-B level in ischaemic stroke and normal subjects. A cross-sectional comparative study was carried out in the department of Neurology, Mymensingh Medical College Hospital, Mymensingh, Bangladesh from July 2013 to June 2015. A total number of 100 subjects within 18-70 years were considered for the study. Fifty (50) subjects with stroke (both clinically as well as CT scan of head or MRI of brain proven) were taken as the cases and 50 age and sex matched nearly healthy individuals without stroke were taken as the controls by using non-probability sampling procedure. Total cholesterol, HDL cholesterol and triglycerides were estimated by enzymatic method using Semiautoanalyser. LDL cholesterol was estimated by Friedewald formula. Apo-B was estimated by immunoturbidimetric method using Semiautoanalyser. Finally collected data were analyzed by using SPSS software Version 20. Student 't' test was used to compare the data between cases and controls. P value was set <0.05. Diagnostic validity tests were conducted to assess the diagnostic efficiency of Apo-B. Total cholesterol, LDL cholesterol and triglycerides are significantly increased in cases compared to controls. HDL-cholesterol was significantly decreased in cases compared to controls. Apo-B was significantly increased in cases compared to controls. The result was statistically significant. Apo-B may be used as predictors of ischaemic stroke components.


Assuntos
Isquemia Encefálica , Colesterol , Acidente Vascular Cerebral , Apolipoproteínas B/sangue , Bangladesh , Isquemia Encefálica/sangue , HDL-Colesterol , LDL-Colesterol , Estudos Transversais , Humanos , Acidente Vascular Cerebral/sangue , Triglicerídeos
6.
Water Res ; 124: 192-201, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28756221

RESUMO

Faecal contamination of groundwater from pit latrines is widely perceived as a major threat to the safety of drinking water for several billion people in rural and peri-urban areas worldwide. On the floodplains of the Ganges-Brahmaputra-Meghna delta in Bangladesh, we constructed latrines and monitored piezometer nests monthly for two years. We detected faecal coliforms (FC) in 3.3-23.3% of samples at four sites. We differentiate a near-field, characterised by high concentrations and frequent, persistent and contiguous contamination in all directions, and a far-field characterised by rare, impersistent, discontinuous low-level detections in variable directions. Far-field FC concentrations at four sites exceeded 0 and 10 cfu/100 ml in 2.4-9.6% and 0.2-2.3% of sampling events respectively. The lesser contamination of in-situ groundwater compared to water at the point-of-collection from domestic wells, which itself is less contaminated than at the point-of-consumption, demonstrates the importance of recontamination in the well-pump system. We present a conceptual model comprising four sub-pathways: the latrine-aquifer interface (near-field); groundwater flowing from latrine to well (far-field); the well-pump system; and post-collection handling and storage. Applying a hypothetical dose-response model suggests that 1-2% of the diarrhoeal disease burden from drinking water is derived from the aquifer, 29% from the well-pump system, and 70% from post-collection handling. The important implications are (i) that leakage from pit latrines is a minor contributor to faecal contamination of drinking water in alluvial-deltaic terrains; (ii) fears of increased groundwater pollution should not constrain expanding latrine coverage, and (iii) that more attention should be given to reducing contamination around the well-head.


Assuntos
Saúde Pública , Toaletes , Poluentes Químicos da Água , Bangladesh , Água Subterrânea , Humanos
7.
Zootaxa ; 4178(2): 257-277, 2016 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-27811723

RESUMO

The Metrocoris fauna of India is reviewed and five new species are described from India: M. murtiensis Basu, Polhemus and Subramanian sp. nov. belonging to the nigrofasciatus species group, M. dinendrai Basu, Polhemus and Subramanian sp. nov. and M. darjeelingensis Basu, Polhemus and Subramanian sp. nov. of the compar species group, M. deceptor Basu, Polhemus and Subramanian sp. nov. (previously treated as M. quynhi Tran & Zettel in Basu et al., 2015) of the anderseni species group, and M. lavitra Basu, Polhemus, Subramanian and Saha sp. nov., which does not fit well into any currently established species group. The new species proposed are compared to all other known species, and a key to all the species of Indian Metrocoris is provided, accompanied by a table for comparison of key morphological characters, and a map and table of distributional details.


Assuntos
Heterópteros/anatomia & histologia , Heterópteros/classificação , Animais , Feminino , Heterópteros/crescimento & desenvolvimento , Índia , Masculino , Ninfa/anatomia & histologia , Especificidade da Espécie
8.
Indian J Lepr ; 87(1): 1-16, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26591845

RESUMO

A cross sectional observational study was conducted to assess knowledge, attitude and practices about leprosy among leprosy patients in six districts of West Bengal. Total patients selected for the study were 300; of them 185 patients were from three high prevalent districts and 115 from three low prevalent districts of West Bengal. 56.33% patients were male and 43.67% were female. Most of the patients (85.67%) belonged to Hindu community and 60% from socially backward group. 64.33% patients lived below poverty line. Thirty five percentage of patients had correct knowledge that leprosy is caused by a bacteria. Patients from high prevalent districts (41.62%) have better knowledge than those from low prevalent areas (26.09%). Difference was found to be statistically significant (p = 0.006). Correct knowledge about spread of leprosy through cough & sneezing, of the patients from high prevalent districts (30.81%) was more than those from low prevalent districts (14.78%) (p = 0.001). 74.05% patients from high prevalent districts could tell one or other forms of clinical presentation of a leprosy patients, while 56.52% from low prevalent areas could mention it correctly (p = 0.01). About infectiousness, duration of treatment, complications, patients from high prevalent districts showed better knowledge that those from low prevalent districts. Similarly, Attitude of the patients towards leprosy was found to be more adverse in low prevalent areas. 90% patients have idea that leprosy was curable, but only 51.67% patients heard about MDT. Place of residence (high prevalent districts) & level of education (secondary & above) attributed to better knowledge score of the patients, whereas Place of residence (high prevalent districts) & age (younger age group) attributed to better attitude score of the patients.


Assuntos
Hanseníase/epidemiologia , Hanseníase/psicologia , Percepção , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Religião , Adulto Jovem
9.
Neotrop Entomol ; 44(4): 374-84, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26174962

RESUMO

In tropical freshwaters, different species of water bugs (Heteroptera) constitute a guild sharing similar prey resources including chironomid and mosquito larvae. Assuming possibilities of intraguild predation (IGP) among the constituent members, an attempt was made to evaluate the effects of prey and predator density on the mortality of mosquito and chironomid larvae (shared prey), using Laccotrephes griseus Guérin-Méneville (Hemiptera: Nepidae) and Ranatra filiformis Fabricius (Hemiptera: Nepidae) as IG predators and Anisops bouvieri Kirkaldy (Hemiptera: Notonectidae) as IG prey. The predation on mosquito and chironomid larvae varied with the density and combinations of the predators. When present as conspecific IG predators, L. griseus exhibited greater effect on the prey mortality than R. filiformis. The effects on shared prey suggest that the two predators are not substitutable in terms of the effect on the shared prey mortality. The mortality of A. bouvieri (IG prey) at low shared prey density was significantly different (p < 0.05) from high shared prey density. In view of predatory effect of the heteropteran predators on the dipteran larvae, the results suggest possible interference by the presence of A. bouvieri as an intermediate predator. It seems that the presence of heteropteran predators including A. bouvieri as IG prey may benefit the dipteran prey under situations when the density is low in tropical waters. The intensity of the predatory effect may differ based on the species composition at IG predator level. For mosquito biological control, the interactions between the predators may not be substitutable and are independent in their effects.


Assuntos
Heterópteros/fisiologia , Comportamento Predatório , Animais , Culicidae , Larva , Densidade Demográfica
10.
Zootaxa ; 3904(3): 415-20, 2015 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-25660792

RESUMO

A new stenopodaine reduviid, Aulacogenia darjeelingensis sp. nov. belonging to the "corniculata species group" from India is described and illustrated. A key to the Indian species of the genus Aulacogenia Stål is provided. 


Assuntos
Reduviidae/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Ecossistema , Feminino , Índia , Masculino , Tamanho do Órgão , Reduviidae/anatomia & histologia , Reduviidae/crescimento & desenvolvimento
11.
Acta Biomater ; 10(12): 5178-5192, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25159371

RESUMO

This paper systematically examines the thermomechanical properties and phase transformation behaviour of slightly Ni-rich Ni-Ti biomedical shape memory wires containing homogeneously distributed nanoscale precipitates induced by stress-assisted ageing. In contrast to previous studies, particular attention is paid to the role of precipitates in impeding twin boundary movement (TBM) and its underlying mechanisms. The size and volume fraction of precipitates are altered by changing the ageing time. The martensitic transformation temperatures increase with prolonged ageing time, whereas the R-phase transformation temperature remains relatively unchanged. The stress-strain behaviour in different phase regions during both cooling and heating is comprehensively examined, and the underlying mechanisms for the temperature- and thermal-history-dependent behaviour are elucidated with the help of the established stress-temperature phase diagram. The effect of precipitates on TBM is explored by mechanical testing at 133K. It is revealed that the critical stress for TBM (σcr) increases with increasing ageing time. There is a considerable increase of 104MPa in σcr in the sample aged at 773K for 120min under 70MPa compared with the solution-treated sample, owing to the presence of precipitates. The Orowan strengthening model of twinning dislocations is insufficient to account for this increase in σcr. The back stress generation is the predominant mechanism for the interactions between precipitates and twin boundaries during TBM that give rise to the increase in σcr. Such results provide new insights into the thermomechanical properties of precipitate containing Ni-Ti biomedical shape memory wires, which are instructive for developing high-performance biomedical shape memory alloys.


Assuntos
Nanofios/química , Nanofios/ultraestrutura , Níquel/química , Titânio/química , Precipitação Química , Módulo de Elasticidade , Temperatura Alta , Teste de Materiais , Tamanho da Partícula , Estresse Mecânico , Resistência à Tração
12.
Zootaxa ; 3795: 578-84, 2014 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24870501

RESUMO

A new genus, Neoschidium was erected with the type genus, Neoschidium phasma (Distant). It was earlier described under Ghilianella Spinola 1850 as G. phasma Distant and later under Schidium Bergroth 1916 as Schidium phasma (Distant) by Bergroth (1916). Because it exhibits characters not only of Ghilianella and Schidium but also intermediate specific characters that are not found in both the genera, the type genus Neoschidium phasma (Distant) is redescribed with additional taxonomic details, morphometrics, and illustrations. It is also recorded for the first time from India.


Assuntos
Biodiversidade , Reduviidae/classificação , Animais , Ecossistema , Índia , Masculino , Reduviidae/anatomia & histologia
13.
Med Vet Entomol ; 28(1): 1-9, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23437887

RESUMO

Wetlands are potential sites for mosquito breeding and are thus important in the context of public health. The use of chemical and microbial controls is constrained in wetlands in view of their potential impact on the diverse biota. Biological control using generalist aquatic insects can be effective, provided a preference for mosquito larvae is exhibited. The mosquito prey preferences of water bugs and larvae of odonate species were evaluated using chironomid larvae, fish fingerlings and tadpoles as alternative prey. Manly's selectivity (αi ) values with 95% confidence intervals (CIs) were estimated to judge prey preference patterns. Multivariate analysis of variance (manova) and standardized canonical coefficients were used to test the effects of density on prey selectivity. The αi values indicated a significant preference (P < 0.05) in all of the insect predators tested for mosquito larvae over the alternative prey as a density-dependent function. On a comparative scale, chironomid larvae had the highest impact as alternative prey. In a multiple-prey experiment, predators showed a similar pattern of preference for mosquito larvae over alternative prey, reflecting a significant (P < 0.05) niche overlap. The results suggest that, in a laboratory setting, these insect predators can effectively reduce mosquito density in the presence of multiple alternative prey.


Assuntos
Culicidae/fisiologia , Peixes/fisiologia , Preferências Alimentares , Insetos/fisiologia , Controle de Mosquitos , Comportamento Predatório , Animais , Anuros/fisiologia , Cadeia Alimentar , Índia , Larva , Densidade Demográfica , Áreas Alagadas
15.
J Med Eng Technol ; 32(6): 456-65, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18663636

RESUMO

The first step towards detection of valvular heart diseases from heart sound signal (phonocardiogram) is segmentation. A segmentation algorithm provides the location of the first and second heart sounds which in turn helps to locate and analyse the murmur. Established phonocardiogram based segmentation methods use an electrocardiographic (ECG) signal as a continuous auxiliary input in a complex instrumentation setup. This paper proposes an automatic segmentation method that does not require any such auxiliary signal. Compared to other approaches without auxiliary signal, this work extensively utilizes biomedical domain features for reduction of time and computational complexities and is more accurate. The performance of the algorithm is evaluated for nine commonly occurring pathological cases and normal heart sound for various sampling frequencies, recording environments and age group of subjects. The proposed algorithm yields an overall accuracy of 97.47% and is compared with two competing techniques. In addition, the robustness of the algorithm is shown against additive white Gaussian noise contamination at various SNR levels.


Assuntos
Algoritmos , Doenças das Valvas Cardíacas/diagnóstico , Fonocardiografia/métodos , Ruídos Cardíacos/fisiologia , Humanos
16.
J Med Eng Technol ; 32(2): 122-32, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18297503

RESUMO

Auscultation, the technique of listening to heart sounds, remains a primary detection tool for diagnosing heart valve disorders. Other techniques, e.g. electrocardiography, ultrasound, etc, are accurate as well as informative; but expensive. With major advancement in the speed of computers, heart sound signals can be processed with ease by memory efficient digital signal processing and pattern recognition algorithms. This paper presents a digital signal processor (DSP) implementation of such a technique by using new threshold criteria. The proposed work can detect whether a heart sound recording belongs to a person suffering from valvular heart disease or not by giving 'diseased' or 'not diseased' decisions. The algorithm is tested for nine commonly occurring pathological problems and normal heart sound. The robustness of the algorithm is also checked against synthetically injected additive white Gaussian noise (AWGN) with different SNR levels. It is found to give an accuracy of 96.67% up to SNR values of 15 dB and 93.33% up to SNR values of 5 dB.


Assuntos
Algoritmos , Diagnóstico por Computador/métodos , Sopros Cardíacos/diagnóstico , Doenças das Valvas Cardíacas/diagnóstico , Fonocardiografia/métodos , Processamento de Sinais Assistido por Computador , Espectrografia do Som/métodos , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
Arch Environ Contam Toxicol ; 52(3): 332-8, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17354031

RESUMO

Volatile arsenic species are found in gases released from natural environments as a result of natural ambient-temperature biomethylation of arsenic conducted by yeast, fungi, and bacteria. This process is part of arsenic transport in the arsenic geocycle. It is important to determine the flux of gasified arsenic released by microorganisms to determine the quantitative flux of arsenic cycle clearly and also to understand the effect of microorganisms on the transport and distribution of arsenic in the contaminated environment. In this study, biologic gasification potential of natural soil was determined by enumeration of arsenic methylating bacteria (AsMB). Enumeration of AsMB was conducted for 10 contaminated sites in Bangladesh where AsMB concentration varies from 0.2 x 10(4) to 7.8 x 10(4) most probable number (MPN) kg(-1) dry soil. The specific gasification rate of arsenic by microorganisms was estimated as 1.8 x 10(-7) microg As MPN(-1) d(-1) by incubation of soil in a laboratory soil column setup. Natural biologic gasification potential of arsenic was then calculated by multiplying the specific rate by the number of AsMB in different soils. The attempt of this study is a fundamental step in determining the volatilization flux of arsenic from land surface contributed by microorganisms.


Assuntos
Poluentes Atmosféricos/metabolismo , Arsênio/metabolismo , Arsenicais/metabolismo , Bactérias/metabolismo , Poluentes do Solo/metabolismo , Bactérias/isolamento & purificação , Biodegradação Ambiental , Contagem de Colônia Microbiana , Gases/metabolismo , Metano/metabolismo , Metilação , Microbiologia do Solo
18.
Indian J Exp Biol ; 45(3): 285-90, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17373375

RESUMO

Methanol extract was prepared from the fronds of Pteris biaurita and partial purification was done by solvent partitioning with diethyl ether and ethyl acetate, followed by hydrolysis and further partitioning with ethyl acetate. The three fractions, thus obtained were bioassayed separately against five test fungi--Curvularia lunata, Fomes lamaoensis, Poria hypobrumea, Fuasrium oxysporum and a bacterium--Bacillus pumilus, by spore germination, radial growth and agar cup techniques. Results revealed that ethyl acetate fraction (III) contained the active principle. TLC plate bioassay of the active fraction revealed inhibition zone at an Rf of 0.5-0.65. Silica gel from this region was scraped, eluted in methanol and subjected to UV-spectrophotometric analysis. An absorption maxima of 278 nm was recorded. HPLC analysis of TLC-eluate revealed a single peak with retention time of 8.1 min. GC-MS analysis revealed six major peaks in the retention time range of 7.2-10.9 min. Comparison with GC-MS libraries revealed that the extracts may contain a mixture of eicosenes and heptadecanes.


Assuntos
Anti-Infecciosos/química , Pteris/química , Anti-Infecciosos/farmacologia , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Delgada , Cromatografia Gasosa-Espectrometria de Massas , Pteris/crescimento & desenvolvimento , Pteris/fisiologia , Espectrofotometria Ultravioleta
19.
J Vector Borne Dis ; 42(1): 9-14, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15999455

RESUMO

BACKGROUND & OBJECTIVES: The predatory behaviour with reference to the frequency-dependent prey-selection of the water bugs Sphaerodema annulatum Fabricius and S. rusticum Fabricius was studied in the laboratory using the IV instar larvae and pupae of Armigeres subalbatus as prey to ascertain their efficacy as predator of mosquito immatures. METHODS: Field collected adult morphs of the water bugs were allowed to predate on larvae and pupae provided in different ratios and densities as per the model of Greenwood and Elton' for a fixed time period. The data obtained on their predation rate were analysed with respect to the model parameters, lnV--the frequency independent component and b--the frequency dependent component of selection. RESULTS: It was found that the prey-selection was dependent on the relative numbers of prey available, favouring apostatic selection. The b values and lnV values for S. annulatum were 0.54 +/- 0.01 and 0.92 +/- 1.04 respectively whereas the corresponding values for S. rusticum were 0.71 +/- 0.03 and 0.17 +/- 1.57 respectively. INTERPRETATION & CONCLUSION: The selection of preys by the water bugs was dependent on the relative number of the prey forms and thus they are expected to predate on the form more abundant in a heterogeneous prey population and adversely affect the adult emergence.


Assuntos
Culicidae , Heterópteros/fisiologia , Modelos Biológicos , Comportamento Predatório/fisiologia , Animais , Índia , Larva , Densidade Demográfica , Análise de Regressão
20.
Bioresour Technol ; 95(2): 169-72, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15246441

RESUMO

The daily number of IV instar larva of Culex quinquefasciatus killed, rate of pupation and adult emergence was noted in presence of the predatory water bug Sphaerodema annulatum for a period of seven consecutive days, experimentally, in the laboratory. The rate of IV instar larva killed by the water bugs on an average was 65.17 per day. The rate of pupation ranged between 7.6 and 48 in control while in presence of water bugs it ranged between 6 and 35. The rate of adult emergence in control experiments varied between 1.4 and 4.8 per day, which was reduced to only 0.4-28.8 per day in case of the water bugs. The results clearly indicate that the water bugs on its way of predation reduces the rate of pupation and adult emergence of Cx. quinquefasciatus significantly which calls for an extensive field trials.


Assuntos
Culex/fisiologia , Ecossistema , Heterópteros/fisiologia , Controle de Mosquitos/métodos , Comportamento Predatório/fisiologia , Animais , Água Doce , Índia , Larva/fisiologia , Dinâmica Populacional , Reprodução/fisiologia
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