4,023 research outputs found
Common carp (Cyprinus carpio L.) alters its feeding niche in response to changing food resources: direct observations in simulated ponds
We used customized fish tanks as model fish ponds to observe grazing, swimming, and conspecific social behavior of common carp (Cyprinus carpio) under variable food-resource conditions to assess alterations in feeding niche. Different food and feeding situations were created by using only pond water or pond water plus pond bottom sediment or pond water plus pond bottom sediment and artificial feeding. All tanks were fertilized twice, prior to stocking and 2 weeks later after starting the experiment to stimulate natural food production. Common carp preferred artificial feed over benthic macroinvertebrates, followed by zooplankton. Common carp did not prefer any group of phytoplankton in any treatment. Common carp was mainly benthic in habitat choice, feeding on benthic macroinvertebrates when only plankton and benthic macroinvertebrates were available in the system. In the absence of benthic macroinvertebrates, their feeding niche shifted from near the bottom of the tanks to the water column where they spent 85% of the total time and fed principally on zooplankton. Common carp readily switched to artificial feed when available, which led to better growth. Common carp preferred to graze individually. Behavioral observations of common carp in tanks yielded new information that assists our understanding of their ecological niche. This knowledge could be potentially used to further the development of common carp aquaculture
Antibacterial and Cytotoxic Activities of Capparis zeylanica Linn Roots
Se analizaron extractos crudos y un ácido graso, ácido octadec-7-en-5-ynoic (1), de la corteza de la raíz de Capparis
zeylanica Linn. (familia de las Capparidaceae) para observar sus actividades antibacterianas frente a la bacteria
Gram positiva y Gram negativa. Entre los extractos crudos, el extracto de cloroformo mostró una buena actividad
frente a todos los organismos de prueba. El ácido graso (1) aislado del extracto de cloroformo mostró actividades
antibacterianas frente a todos los organismos de prueba, a excepción de E. coli. Las actividades se compararon con
un antibiótico estándar: la kanamicina. Las concentraciones inhibitorias mínimas (CIH) de 1, determinadas mediante
la técnica de dilución en serie, fueron 64 μg/ml frente a Bacillus subtilis y Shigella dysenteriae. Las actividades
citotóxicas del extracto crudo y del ácido graso (1) se observaron mediante el bioensayo de gambas en salmuera y el valor de LC50 del compuesto fue 6,27 μg/mlCrude extracts and a fatty acid, octadec-7-en-5-ynoic acid (1), from the root bark of Capparis zeylanica Linn. (Fam.
Capparidaceae) were screened for their antibacterial activities against Gram positive and Gram negative bacteria.
Among the crude extracts, chloroform extract showed good activity against all test organisms. The fatty acid (1) isolated
from chloroform extract exhibited antibacterial activities against test organisms except E. coli. The activities were
compared to a standard antibiotic- kanamycin. The minimum inhibitory concentrations (MICs) of 1, determined by
serial dilution technique, were found to be 64 μg/ml against Bacillus subtilis and Shigella dysenteriae. The cytotoxic
activities of crude extract and fatty acid (1) were observed by brine shrimp biassay and LC50 value of the compound was found to be 6.27 μg/m
Arsenic-induced straighthead: An impending threat to sustainable rice production in South and South-East Asia!
Straighthead is a physiological disorder of rice (Oryza sativa L.) that results in sterile florets with distorted lemma and palea, and the panicles or heads may not form at all in extreme cases. Heads remain upright at maturity, hence the name 'straighthead'. The diseased panicles may not emerge from the flag leaf sheath when the disease is severe. Straighthead disease in rice results in poorly developed panicles and significant yield loss. Although other soil physicochemical factors involved, arsenic contamination in soil has also been reported to be closely associated with straighthead of rice. Monosodium methanearsonate has been a popular herbicide in cotton production in the USA, which has shown to cause injuries in rice that are similar to straighthead. Since toxicity of inorganic arsenic (iAs) is higher than other forms of arsenic, it may produce a more severe straighthead disorder in rice. The use of iAs-rich groundwater for irrigation, and the increase of iAs concentrations in agricultural soil in arsenic epidemic South and South-East Asia may cause a high incidence of straighthead in rice, resulting in a threat to sustainable rice production in this region. © 2011 Springer Science+Business Media, LLC
Status of compost usage and its performance on vegetable production in Monga areas of Bangladesh
The present study was carried out to assess the existing status of compost usage on vegetable production and determine the overall effect of household waste compost (HWC) on growth and yield of vegetables and enhancement of soil fertility in the monga areas of Bangladesh. A field survey was conducted on 152 sampled farmers during 2010 to 2011. Questionnaire containing both closed and open-ended questions were used to assess existing production practices of vegetables using compost in both homestead and field conditions. Three field trials at Badargonj and Kawnia upazilas of Rangpur district were conducted taking four treatments i.e. control, recommended doses (RD) of fertilizers, HWC at the rate of 10 tha-1, and HWC 10 t ha-1 plus RD as IPNS based with Lal shak, Palong shak, Pui shak and Tomato. Base line survey results indicated inadequate knowledge of the farmers on use and preparation of the household waste compost. Yield data of all vegetables i.e. Tomato, Lal shak, Palong shak and Pui shak indicated that the combined application of nutrients using organic and inorganic sources were significantly better than that of solitary application of inorganic fertilizers. The potential of household waste compost applied @ 10 t ha-1 along with inorganic fertilizers applied was found highly satisfactory in producing Tomato, where yield was recorded 75 t ha-1 in the study area. The fresh yield of Palong shak was found 16 t ha-1 when recommended doses of inorganic fertilizers were applied, but it was about 19 t ha-1 under combined application of HWC @ 10 t ha-1 and inorganic fertilizers following IPNS concept. The fresh yield of Pui shak was found about 49 t ha-1 under combined application of organic and inorganic nutrients. Considering the availability and costs of different composts, it is evinced that HWC contained good amount of NPK which indicates its potentiality to be used as a soil amendment, improving soil fertility and crop productivity. It can be an alternative to chemical fertilizer to increase soil microbial populations and enzyme activities and to promote the soil nutrient for horticultural crops in the unfertile areas especially in the monga areas of Bangladesh. DOI: http://dx.doi.org/10.3329/ijarit.v4i2.22640 Int. J. Agril. Res. Innov. & Tech. 4 (2): 22-28, December, 201
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Neuromuscular junction transmission is effected by quantum entanglement of ion transition states
Neuromuscular Junction (NMJ) is the place where the neuron meets with muscle fiber crating a synapse to propagate the electrochemical signals. The infolds of the endplate of sodium channels in contraction of NMJ transmission mechanism. We have studied here the entanglement of sodium channel activation particle ('m' particle). Through the simulation results we confirm that the entanglement of 'm' particle effects the initiation time, amplitude and the rate of change of membrane potential
Ever-increasing Caesarean section and its economic burden in Bangladesh
BACKGROUND: Cesarean Section (CS) delivery has been increasing rapidly worldwide and Bangladesh is no exception. In Bangladesh, the CS rate has increased from about 3% in 2000 to about 24% in 2014. This study examines trend in CS in Bangladesh over the last fifteen years and implications of this increasing CS rates on health care expenditures. METHODS: Birth data from Bangladesh Demographic and Health Survey (BDHS) for the years 2000–2014 have been used for the trend analysis and 2010 Bangladesh Maternal Mortality Survey (BMMS) data were used for estimating health care expenditure associated with CS. RESULTS: Although the share of institutional deliveries increased four times over the years 2000 to 2014, the CS deliveries increased eightfold. In 2000, only 33% of institutional deliveries were conducted through CS and the rate increased to 63% in 2014. Average medical care expenditure for a CS delivery in Bangladesh was about BDT 22,085 (USD 276) in 2010 while the cost of a normal delivery was BDT 3,565 (USD 45). Health care expenditure due to CS deliveries accounted for about 66.5% of total expenditure on all deliveries in Bangladesh in 2010. About 10.3% of Total Health Expenditure (THE) in 2010 was due to delivery costs, while CS costs contribute to 6.9% of THE and rapid increase in CS deliveries will mean that delivering babies will represent even a higher proportion of THE in the future despite declining crude birth rate. CONCLUSION: High CS delivery rate and the negative health outcomes associated with the procedure on mothers and child births incur huge economic burden on the families. This is creating inappropriate allocation of scarce resources in the poor economy like Bangladesh. Therefore it is important to control this unnecessary CS practices by the health providers by introducing litigation and special guidelines in the health policy
Characterization of antibiotic resistant Salmonella spp isolated from chicken eggs of Dhaka city
Phytotoxicity of arsenate and salinity on early seedling growth of rice (oryza sativa l.): A threat to sustainable rice cultivation in South and South-East Asia
Arsenic (As) contamination is an important environmental consequence in some parts of salinity-affected South (S) and South-East (SE) Asia. In this study, we investigated the individual and combined phytotoxicity of arsenic (As) [arsenate; As(V)] and salinity (NaCl) on early seedling growth (ESG) of saline-tolerant and non-tolerant rice varieties. Germination percentage (GP), germination speed (GS) and vigor index (VI) of both saline-tolerant and non-tolerant rice varieties decreased significantly (p[0.01) with increasing As(V) and NaCl concentrations. The highest GP(91%) was observed for saline non-tolerant BRRI dhan28 and BRRI dhan49, while the lowest (62%) was for salinetolerant BRRI dhan47. The ESG parameters, such as weights and relative lengths of plumule and radicle, also decreased significantly (p\0.01) with increasing As(V) and NaCl concentrations. Relative radicle length was more affected than plumule length by As(V) and NaCl. Although VI of saline-tolerant and non-tolerant rice seedlings showed significant variation (p\0.05), weights and lengths of plumule and radicle of different rice varieties did not show significant variation for As(V) and NaCl treatments. Results reveal that the combined phytotoxicity of As(V) and NaCl on rice seed germination and ESG are greater than their individual toxicities, and some saline-tolerant rice varieties are more resistant to the combined phytotoxicity of As(V) and NaCl than the saline non-tolerant varieties. © Springer Science+Business Media, LLC 2012
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