598 research outputs found
Observations on the exploitation of sea turtles along the Tuticorin coast, Tamil Nadu, India
Aqueous extract of seven species of marine macroalgae were screened for their antimicrobial
potency against ten pathogenic bacterial strains. Ulva fasciata, Gracilaria corticata, Sargassum
wightii and Padina tetrastromatica showed significantly higher activity against 70% of the
tested bacterial isolates. The maximum zone of inhibition was noted for the red alga G.corticata
against Proteus mirabilis (17mm) and brown alga P. tetrastromatica against the pathogens
Staphylococcus aureus and Vibrio harveyi (15mm). The general trend of inhibitory activity
was higher towards Gram negative bacteria
Association of molluscan fauna with the coral reefs of Gulf of Mannar
Coral reefs are one of the important ecosystems in India. Major coral families of Gulf of mannar
such as Acroporidae, Pocilloporidae, Poridae were collected. The above reef building corals
harboured 51 numbers of molluscan species during this study. Pteria chinensis, Ostrea sp,
Nerita rumphi and Cypraea tigris were noted from the study area. The gastropods are mostly
associated with the coral reefs than the bivalves. The present study will reveal the diversity of
molluscan fauna harbored in the different habitat of corals
Spawning, intracapsular development and production potential of viable juveniles of a murex Chicoreus virgineus var. ponderosa Sowerby under laboratory conditions
Muricids are commercially important gastropods and are exploited primarily for shell craft industries. They also occupy a niche in ornamental keeping. Studies on the larval development of muricids in Indian waters are few. Hence, an attempt was made to study with a focus on the optimum requirements for captive brood maintenance; regional variation in egg laying, intracapsular development and to estimate production potential of individual brooder (the length/ weight ranged from 80 - 110 mm/49 - 169 g (average 94.875 ± 3.980 mm/111.625 ± 14.870 g) of Chicoreus virgineus var. ponderosa collected off Tuticorin coast, Gulf of Mannar. Experimental airlift water circulation system fitted in 1 t FRP tanks having an overturn of 300% water is found suitable for long term maintenance and maturation of brooders with near cent percent survival over a year. Spontaneous breeding commenced from June ’09. Eggs cases were ‘vase’ shaped and measured 1.2 - 1.5 cm in height. Egg case numbers varied between 110 and 140 and got reduced to 10 - 40 during October and increased in Nov & December. Number of eggs within the egg case was highly variable ranging from 100 - 380. Eggs were spherical, embedded in jelly mass within the egg case and measured 510 - 608 μ (578 μ). Intra capsular development is detailed and compared with the earlier report on this species from other areas of Indian coast. Development took nearly 20 days and only few free living juveniles measuring between 1.7 - 1.9 mm emerged and the rest of the eggs have functioned as “Nurse eggs”. Average net production potential of a single viable egg case was estimated to be 6.7 nos for Chicoreus virgineus var. ponderosa of Tuticorin coast of Gulf of Mannar
Ovicidal, oviposition deterrent and larvicidal response of Anopheles stephensi Liston, 1901 to Lobophora variegata Lamouroux, 1817 from Tuticorin coast, Gulf of Mannar, India
The objective of the present study was to investigate the mosquito ovicidal, oviposition deterrent and larvicidal efficacy of hexane, benzene, chloroform, ethyl acetate and methanol extracts of, Lobophora variegata against malarial vector Anopheles stephensi. Among the five extract tested, the methanol extract was notable, which attained the 100 percent mortality at the concentration of 200.0 ppm and the hatchability rate ranged from 71.3 to 36.3 percent. In laboratory oviposition deterrent test, the extract of L. variegata greatly reduced the number of eggs deposited by gravid An. stephensi. The maximum and significant diminished fecundity in An. stephensi was observed with methanol extract which caused 76.15–97.69% effective deterrence. Larvicidal response of An. stephensi was more susceptible in methanol extract. The LC50 Âvalue of methanol extract was 61.63 ppm and the Chi-square value were significant at p<0.05 level. It is concluded, that the extract of L. variegata could be used in control of malarial vector An. stephensi
Orange IV stabilizes silk fibroin microemulsions
Silk fibroin (SF) is a natural biopolymer that has been extensively studied in various applications due to its impressive mechanical properties and biocompatibility. Recently, SF-based particles have been proposed as controlled drug delivery systems. A new and efficient method to prepare SF microemulsions (SF-MEs) was developed by oil-in-water emulsions using high-pressure homogenization to promote emulsification. During SF-ME production, the secondary structure of SF changed to a more stable conformation (from random coil to -sheets), thus allowing the formation of small and stable (140.7 ± 1.9 nm; polydispersity index, 0.25) SF microparticles (SF-MPs). The efficiency of SF-MP formation was 60%. Orange IV was used as a model compound for incorporation and release studies, although its incorporation into the SF-MEs significantly improved particle size and size distribution over at least 4 wk compared to traditional stabilizers (e.g., poloxamer 407, transcutol, Tween 80, and SDS). This should be a call of attention when using dyes as model compounds since they can influence particle properties and lead to misinterpretation of the results. Orange IV showed an incorporation efficiency of 91% and a controlled release over time. Stable SF-MP formulations, further enhanced by orange IV incorporation, provide an innovative method with potential application in pharmaceutical development due to its associated high biocompatibility and release profile.The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the project "BioHealth - Biotechnology and Bioengineering Approaches to Improve Health Quality," Ref. NORTE-07-0124-FEDER-000027, cofunded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER. We would also like to acknowledge CRA - Unita di Ricerca di Apicoltura and Bachicoltura Padova (Italy) for the supply of B. mori silkworm cocoons, and Andreia Vasconcelos for technical support
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Factors Influencing Profit Chain of Little Millet by Farmer Producer Organization Farmers, Processors and Marketers in Tamil Nadu, India
Little millet, a significant part of the Indian diet known for its health benefits. The study focuses the factors influencing Profit chain of little millet by FPO farmers, processor and retailers. The research focuses on Northern Tamil Nadu, analysing profitability for producers (75), processors (10), and marketers (10). A total sample of 95 respondents were surveyed using structured interview schedule. Key factors influencing profit chain were identified using multiple linear regression model. For producers, Nitrogen and Potash fertilizer positively impact profits, while labour and seed exhibit negative effects. Processors benefit from positive associations with labour and transport, and marketers' profits are linked to labour, transportation, and storage. The findings stress the need for strategic interventions to enhance the millet value chain, emphasizing the importance of efficient logistics. The study recommends policy measures to increase farmers' productivity and profits through incentives, farmer support extension, and innovative technologies, promoting a balanced diet, weight maintenance, and overall well-being while addressing economic aspects of millet production and distribution
Vitamin D Deficiency and Exogenous Vitamin D Excess Similarly Increase Diffuse Atherosclerotic Calcification in Apolipoprotein E Knockout Mice
Background: Observational data associate lower levels of serum vitamin D with coronary artery calcification, cardiovascular events and mortality. However, there is little interventional evidence demonstrating that moderate vitamin D deficiency plays a causative role in cardiovascular disease. This study examined the cardiovascular effects of dietary vitamin D deficiency and of vitamin D receptor agonist (paricalcitol) administration in apolipoprotein E knockout mice.
Methods: Mice were fed atherogenic diets with normal vitamin D content (1.5IU/kg) or without vitamin D. Paricalcitol, or matched vehicle, was administered 3× weekly by intraperitoneal injection. Following 20 weeks of these interventions cardiovascular phenotype was characterized by histological assessment of aortic sinus atheroma, soluble markers, blood pressure and echocardiography. To place the cardiovascular assessments in the context of intervention effects on bone, structural changes at the tibia were assessed by microtomography.
Results: Vitamin D deficient diet induced significant reductions in plasma vitamin D (p<0.001), trabecular bone volume (p<0.01) and bone mineral density (p<0.005). These changes were accompanied by an increase in calcification density (number of calcifications per mm2) of von Kossa-stained aortic sinus atheroma (461 versus 200, p<0.01). Paricalcitol administration suppressed parathyroid hormone (p<0.001), elevated plasma calcium phosphate product (p<0.005) and induced an increase in calcification density (472 versus 200, p<0.005) similar to that seen with vitamin D deficiency. Atheroma burden, blood pressure, metabolic profile and measures of left ventricular hypertrophy were unaffected by the interventions.
Conclusion: Vitamin D deficiency, as well as excess, increases atherosclerotic calcification. This phenotype is induced before other measures of cardiovascular pathology associated clinically with vitamin D deficiency. Thus, maintenance of an optimal range of vitamin D signalling may be important for prevention of atherosclerotic calcification
Znf202 Affects High Density Lipoprotein Cholesterol Levels and Promotes Hepatosteatosis in Hyperlipidemic Mice
Background: The zinc finger protein Znf202 is a transcriptional suppressor of lipid related genes and has been linked to hypoalphalipoproteinemia. A functional role of Znf202 in lipid metabolism in vivo still remains to be established. Methodology and Principal Findings: We generated mouse Znf202 expression vectors, the functionality of which was established in several in vitro systems. Next, effects of adenoviral znf202 overexpression in vivo were determined in normo- as well as hyperlipidemic mouse models. Znf202 overexpression in mouse hepatoma cells mhAT3F2 resulted in downregulation of members of the Apoe/c1/c2 and Apoa1/c3/a4 gene cluster. The repressive activity of Znf202 was firmly confirmed in an apoE reporter assay and Znf202 responsive elements within the ApoE promoter were identified. Adenoviral Znf202 transfer to Ldlr-/- mice resulted in downregulation of apoe, apoc1, apoa1, and apoc3 within 24 h after gene transfer. Interestingly, key genes in bile flux (abcg5/8 and bsep) and in bile acid synthesis (cyp7a1) were also downregulated. At 5 days post-infection, the expression of the aforementioned genes was normalized, but mice had developed severe hepatosteatosis accompanied by hypercholesterolemia and hypoalphalipoproteinemia. A much milder phenotype was observed in wildtype mice after 5 days of hepatic Znf202 overexpression. Interestingly and similar to Ldl-/- mice, HDL-cholesterol levels in wildtype mice were lowered after hepatic Znf202 overexpression. Conclusion/Significance: Znf202 overexpression in vivo reveals an important role of this transcriptional regulator in liver lipid homeostasis, while firmly establishing the proposed key role in the control of HDL levels
Design, development, calibration, and testing of indigenously developed strain gauge based dynamometer for cutting force measurement in the milling process
In this work, a milling dynamometer based on strain gauge with an octagonal and square ring was designed and tested. Strain gauges were attached with the mechanical rings to detect the deformation, during the machining process. Wheatstone bridge circuit was equipped with gauges to acquire the strain as voltage owing to the deformation of mechanical rings when machining takes place. The finite element analysis (FEA) was used to identify the location of maximum deformation and stress. The direction of rings and location of gauges were decided to increase the sensitivity and decrease the cross-sensitivity. Then, the cutting force was acquired through NI 6221 M series data acquisition (DAQ) card. The dynamometer had undergone a cycle of tests to verify its static and dynamic characteristics. The metrological characterization was performed according to the calibration procedure based on ISO 376 – 2011 standard. The cutting force was measured with both the dynamometers through milling experiments based on Taguchi’s L9 orthogonal array and the results were recorded. The measured cutting force varied from 300 N to 550 N. The obtained results depicted that low-cost milling dynamometer was reliable to measure the three component machining force. Overall, the square ring based dynamometer provides the better static and dynamic characteristics in terms of linearity, cross-sensitivity (4%), uncertainty (0.054%), and natural frequency (362.41 rev/s)
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