Effects of Water Hardness and Metal Concentration on a Freshwater Tubifex Tubifex Muller

The present investigation was designed to determine the effectsof water hardness and heavy metals concentrations on a freshwaterTubifex tubifex. Very few data concerning the effect of water hardness on the acute toxicity of heavy metals are available on T. tubifex, which has been proposed as a testorganism for ecotoxicological studies. The effect of water hardness on the toxicity of heavy metals is discussed. The acutetoxicity of selected heavy metals to a freshwater T. tubifex Muller was determined in very soft, soft, hard and veryhard (12, 45, 170 and 300 mg CaCO₃ L^-1 total hardness,respectively) water. Percentage mortality of T. tubifex as influenced by heavy metals was studied in water of variable hardness. Water hardness had a significant effect on heavy metalstoxicity. The concentrations of metals necessary to immobilize 50% of the test animals at 24, 48, 72, 96 hr were significantlydifferent in soft and hard water. The 96 hr EC₅₀ valuesfor T. tubifex were higher in hard and very hard watercompared with soft and very soft water. Median effectiveconcentrations (EC₅₀) and their 95% confidence limits weredetermined for cadmium, cobalt, chromium, copper, iron, lead, manganese, mercury, nickel, and zinc during exposure for 24, 48,72 and 96 hr in four different water hardness. Hardness has a muchsmaller effect upon the acute toxicity of mercury than the otherheavy metals tested. The results indicate that Cu, Cd, Hg and Zninduced autotomy of the caudal region and mucus production. It isconcluded that water hardness parameters should be considered inestablishing appropriate water quality criteria and standards forthe protection of aquatic fauna and flora, and ultimately human health.     

Suppression of aging in mice by the hormone Klotho

A defect in Klotho gene expression in mice accelerates the degeneration of multiple age-sensitive traits. Here, we show that overexpression of Klotho in mice extends life span. Klotho protein functions as a circulating hormone that binds to a cell-surface receptor and represses intracellular signals of insulin and insulin-like growth factor 1 (IGF1), an evolutionarily conserved mechanism for extending life span. Alleviation of aging-like phenotypes in Klotho-deficient mice was observed by perturbing insulin and IGF1 signaling, suggesting that Klotho-mediated inhibition of insulin and IGF1 signaling contributes to its anti-aging properties. Klotho protein may function as an anti-aging hormone in mammals.     

Fabrication of Cellulose Nanocrystals from Agricultural Compost

ABSTRACT

Cellulose nanocrystals have emerged as replacements for man-made fibers to fabricate environmentally friendly green products. In this work, cellulose nanocrystals (CNCs) of mixed morphology were synthesized by acid hydrolysis of compost using sulfuric acid. Compost, an agro-based biomass feedstock, procured from water hyacinth (Eichhornia crassipes), cow dung, and saw dust (8:1:1) was utilized for the extraction of cellulose, followed by synthesis of CNCs. Compost was prepared using a rotary drum composter and was utilized for the production of CNCs. A two-step procedure for the extraction of CNCs was studied. Initial chemical treatments, including alkali treatment and bleaching, led to the gradual removal of lignin and hemicellulose, while the subsequent sulphuric acid (40%) hydrolysis step yields CNCs in an aqueous suspension. The synthesized CNCs have been studied by Fourier transform infrared (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and particle size analyzer. The morphology and dimension of nanofibrils were studied by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) techniques, which showed mixed morphology of rectangular cone type and spherical dimensions. Fabrication of such mixed morphology was found to be dependent on the selected biomass. The trace of metal elements present in the biomass was investigated by scanning electron microscopy-energy dispersive X-ray (SEM-EDX). We report a cost effective and feasible approach of utilizing inexpensive bioresources for production of value added products like CNCs, which could find potential application in the fields of healthcare, biomedical engineering, packaging, etc.     

Effect of supplementation of rice straw with biogas residual slurry manure on the yield, protein and mineral contents of oyster mushroom

Popularity of oyster mushroom is increasing for its ease of cultivation, high yield potential as well as its high nutritional value. Laboratory experimentation followed by farm trial with a typical oyster mushroom Pleurotus sajor caju revealed that the yield potential of these mushrooms can be increased significantly when grown on a lignocellulosic crop residue—rice straw supplemented with biogas residual slurry manure in 1:1 ratio as substrate. Residual slurry manures obtained from biogas plants utilising either cattle dung, poultry litter, jute caddis or municipal solid waste as substrates for biogas production were all effective in increasing the yield of Pleurotus sajor caju significantly although to different extents. Disinfection of straw and manure by means of 0.1% KMnO₄ plus 2% formalin solution in hot water caused 42.6% increase in yield of Pleurotus sajor caju over control, i.e., when disinfection done with hot water. In addition to increased yield, the above treatments caused significant increase in protein content, reduction in carbohydrate and increase in essential mineral nutrients in mushroom sporophores. Thus, it is concluded from the study that supplementation of rice straw with biogas residual slurry manure has strong impact in improving the yield potential, protein and mineral nutrient contents of Pleurotus sajor caju mushroom in Indian subcontinent or similar climatic conditions.     

Biological evaluation of pearl millet protein: effect of different treatments and storage

Whole grain flour of one variety (HC-4) of pearl millet (Pennisetum americanum L. Leeke) after giving different treatments (defatting, butylated hydroxyanisole, ascorbic acid and thermal) was stored in earthen pots at prevailing room temperature (28–34°C) and relative humidity (70–80%) for 30 days. The flour samples were evaluated for protein quality using rats. Storage of flour for 30 days markedly reduced the protein quality. The values of protein efficiency ratio, true digestibility, biological value, net protein retention and net protein utilisation were significantly (P<0.05) higher in fresh and treated flour than untreated flour. Among treated flours, defatted flour showed best growth followed by butylated hydroxyanisole, thermal and ascorbic acid treated flour.     

Yield characteristics and morphometric relationships of giant freshwater prawn,Macrobrachium rosenbergii (de Man, 1879)

Meat yield of 233 individuals of giant freshwater prawn, Macrobrachium rosenbergii (de Man, 1879), and their morphometric relationships were examined. Morphometric parameters of different length and weight measurements were recorded for both the sexes separately and subjected to analysis. The meat yield of prawns was size and sex dependent with females showing significantly greater (P < 0.05) tail meat yield than males. The tail meat as a body weight percentage ranges from 26.12 to 40.75 and 32.97 to 42.11 in males and females, respectively. Much of the differences in yield are related to the size and weight of the head and claws. The head weight of males was observed to be higher compared to females in all the size classes. Regression slopes of total length versus body weight and total length versus head weight were significantly higher than critical isometric value indicating high positive allometric growth in both the sexes, with males showing significantly higher (P < 0.05) slope than females. The relationship parameters of total length versus tail weight and total length versus tail meat showed a positive allometric growth in females, whereas it is isometry and negative allometry in males. The morphometric relationship of tail length versus all weight measurements showed positive allometry and negative allometry in females and males, respectively.     

Horvath-Kawazoe Model Based Evaluation of Pore Volume of Nanoporous Clinoptilolite

A liquid nitrogen (N₂) adsorption isotherm was employed to understand the differential pore-volume distribution (PVD) patterns of commercial Clinoptilolite (zeolite) fractions (<125 µ (Z8; fine or micro), 125–250 µ (Z9; medium) and >250 µ (Z10; coarse). The differential PVD of the fractions were calculated from the original Horvath-Kawazoe (HK) model. A full spectrum of pore volume distribution has exhibited “curves symmetric around the origin” irrespective of the Clinoptilolite fractions. However, the fractions exhibited a definite pattern of curves for each of the micro, meso and macropore region. Although, ultramicropores couldn’t be seen in any of the fractions, super micropore region exhibited uni-modal distribution curve with mono-disperse pores for all the fractions with varying pore volumes, while multimodal and tri-modal for meso and macro pore region respectively. Irrespective of the pore region, fine fraction (Z8) exhibited higher differential pore volume than other fractions. It was evident from the differential PVD that particle size has a major role in determining the textural properties of Clinoptilolite fractions.     

A combined Taguchi and response surface approach to improve electret charge in corona-charged fibrous electrets

In this work, an attempt was made to model, analyze, and optimize corona charging process for production of fibrous electrets using a combined Taguchi and response surface approach. The key process variables determining the magnitude and duration of electret charge were screened out using Taguchi approach and optimized using response surface approach. The simultaneous optimization of magnitude as well as duration of electret charge led to an initial surface potential of 1.6 kV and half-decay time of 11.18 min.     

Isolation and culture of preantral follicles for retrieving oocytes for the embryo production: present status in domestic animals

The development of efficient ovarian preantral follicle (PF) isolation and culture systems provide a large number of oocytes for the manipulation and embryo production. It also helps for understanding the mechanisms of follicle and oocyte development. Isolation and culture protocols for PFs were developed for many domestic species like cattle, buffalo, sheep, goat, pig, horse, camel, dog and cats; however, embryo production from oocytes derived from in vitro grown PFs was reported only in pigs, buffalo, sheep and goat. The rate of oocyte maturation from PFs grown in vitro is low and requires considerable research. This paper presents an overview of isolation and culture systems of PFs that have been developed for domestic species (cattle, buffalo, sheep, goat, pigs, horse, camel, dog and cat) along with the current status of progress achieved in the direction of producing embryos using PFs as the source of oocyte in these species.     

Properties and functional impact of termite sheetings

Termites are considered soil engineers and key bioturbators in tropical and subtropical soils. A large number of studies have described the specific properties of the aboveground mounds that termites construct to protect their colonies from environmental hazards. However, there is a paucity of information on properties of soil sheetings; more temporary but often extensive structures are covering over or inserted within substrates on the ground such as leaves and woody materials or components of arboreal runways. Such sheetings are conspicuously produced not only by the Macrotermitinae but also by many other unrelated taxa. Here, we review the available literature and discuss (i) the relationship between rainfall and soil sheeting production and (ii) how termites affect the clay and C contents in soil sheetings. This reveals that sheeting production is highly variable and site specific. We also found that soil sheetings are always enriched in clay, but their impacts on soil C content are variable and related to the C content of the parent soil and to the quality of the substrates consumed by termites.