Duration of stunting impacts compensatory growth and carcass quality of farmed milkfish, Chanos chanos (Forsskal, 1775) under field conditions.

An 18-months field trial was performed to explore the effect of duration of stunting on growth, digestive enzymes and carcass quality in Chanos chanos. Milkfish fry (weight of 1.25 ± 0.03 g and length of 5.53 ± 0.03 cm) were stocked in earthen ponds of 0.02 ha, in triplicate, for different duration of stunting, viz., 4 months (Treatment-1; T4), 8 months (Treatment-2; T8) and 12 months (Treatment-3; T12) and a normal seed (Control; C) separately. In the stunting phase, fish were stocked at higher stocking density (0.2 million/ha) and fed de-oiled rice bran at sub-optimal level. Post-stunting or re-feeding phase commenced immediately after completion of respective stunting duration and fish were reared for the rest of the period to complete the total rearing period of 18 months. In post-stunting, fish stocking density was adjusted to (5000 pieces/ha) and fed at an optimum level (3%). At the end of stunting phase, the study found a significant reduction in growth, survival, digestive enzymes activity, except protease in the T4 group, and carcass nutrients composition of stunted fish. However, in the initial phase of post-stunting, T8 group exhibited an elevated specific growth rate (5.00 ± 0.092%/day), body weight gain (80.82 ± 1.28 g), amylase (0.585 ± 0.021 U/mg protein), protease (5.48 ± 0.13 U/mg protein), and lipase activity (7.92 ± 0.32 U/mg protein). All stunted fish groups displayed a compensatory growth response in post-stunting, but a complete growth compensation was observed in T8 group, which resulted in better feed conversion ratio (3.03 ± 0.04) feed efficiency ratio (0.33 ± 0.01), protein efficiency ratio (1.91 ± 0.03), survival (91.38 ± 0.07%) and digestive enzyme activities. Similarly, at the end of post-stunting, carcass analysis revealed a complete restoration of nutrients in stunted fish and significantly higher protein content in T8 group. Further, the study found lower meat and higher bone contents in normally reared fish than the post-stunted fish which revealed the carcass quality improvement in post-stunted fish thus indicates superiority of the stunting process over normal rearing. Overall, the study suggests that stunting of milkfish, for 8 months (T8), positively affects its growth, survival, digestive enzyme activities and carcass quality which in turn, shall help to overcome the contemporary challenges in milkfish culture.

Expression and activity of key lipases during the larval development of walking catfish (Clarias magur).

The study was conducted to investigate the expression and activity of key lipolytic enzymes during the ontogenetic development of Clarias magur. After partial characterization, the messenger RNA (mRNA) expression analysis of lipoprotein lipase (LPL), pancreatic triacylglycerol lipase (PL), and bile salt-activated lipase (BAL) genes along with the specific lipase activity were performed in larvae from Day 1 after hatching till 34-day posthatch (dph). Heterogeneous patterns of mRNA expression were shown by the important lipolytic enzymes and were detected before first exogenous feeding during the yolk-sac stage. LPL started increasing from 13 dph and peaked at 16 dph followed by a declining trend till 34 dph. However, the PL observed to be peaking at 9, 22, and 30 dph. Similarly, BAL showed an increasing trend from 11 to 22 dph with a significantly high level of mRNA expression at 16 dph. Later, the specific lipase activity was evaluated which appears at Day 1 after hatching with a progressive increase from 7 to 16 dph and a further declining trend afterwards with a peak at 22 dph. The results indicated the development of exocrine pancreas at 16 dph. Furthermore, the transcript levels and the activity of lipases were regulated with the age. Hence, the present study can be helpful in devising different strategies containing optimum lipid levels at a suitable stage of development for improving the survival during larval rearing. Furthermore, the study could be a baseline for elucidating the optimized dietary lipid levels of this catfish during its larval rearing.

Hairpins in the conformations of a confined polymer.

If a semiflexible polymer confined to a narrow channel bends around by 180°, the polymer is said to exhibit a hairpin. The equilibrium extension statistics of the confined polymer are well understood when hairpins are vanishingly rare or when they are plentiful. Here, we analyze the extension statistics in the intermediate situation via experiments with DNA coated by the protein RecA, which enhances the stiffness of the DNA molecule by approximately one order of magnitude. We find that the extension distribution is highly non-Gaussian, in good agreement with Monte-Carlo simulations of confined discrete wormlike chains. We develop a simple model that qualitatively explains the form of the extension distribution. The model shows that the tail of the distribution at short extensions is determined by conformations with one hairpin.

Needle necropsy in AIDS.

The value of autopsy in understanding the natural course of any disease is beyond any argument. The reluctance of pathologists to perform autopsy in HIV infected cadavers is justified due to the risks involved to the prosector and the morgue attendants. A relative low risk needle necropsy protocol is proposed using fine needle aspiration cytology, tru-cut biopsies and microbiological examination. Diagnosis could be offered in all the forty-four needle necropsies performed. Disseminated tuberculosis in 18/44 (40.9%) cases, disseminated cryptococcosis in 12/44 (27.2%) cases, poly-microbial infections in 27.2% cases and non-Hodgkin's lymphoma in 9% cases were detected in the study. Infectious agents like Histoplasma capsulatum, Isospora belli, tachyzoites of Toxoplasma gondii, Candida sp and Cryptococcus sp could be demonstrated in the samples obtained in the study. Lack of material for study of gross pathology, inaccessibility of deep-seated lesions and risk of needle stick injury to the prosector though low are the limitations of this procedure.

FINE NEEDLE ASPIRATION CYTOLOGY OF LYMPH NODES IN HIV INFECTED PATIENTS.

Lymphadenopathy is the commonest presentation in HIV positive individuals. Fine needle aspiration cytology of 196 HIV positive patients was studied during six monthly review. 75% paients in this study who were asymptomatic were detected to have lymphadenopathy during the surveillance. 82% had lymph nodes smaller than 1cm size. Lymphadenopathy at more than one site was observed in 46.8% cases. Commonest opportunistic infection noticed was tuberculosis (TB) in 34.2%. Cyto-morphologically reactive pattern with Add fast bacilli (AFB) positivity was observed in 16.4% of TB cases. In 2.9% cases AFB were detected even in the tissue fluid. Negative images of AFB were observed in the macrophages in 3 cases. TB was detected with equal frequency in both asymptomatic and symptomatic groups. Axillary nodes pose problem due to deeper location. False positives were a case of dermatopathic lymphadenopathy and a case of Kimura's disease. False negatives include two cases of TB lymphadenitis. Pathogens should be looked for irrespective of cyto-morphology. Biopsy should be done to confirm cases of lymphomas. Fine needle aspiration cytology should be included in the protocol of six monthly review of HIV infected cases.

Safety performance of gloves using the pressure tolerance of the hand.

Two prototype gloves have been designed and developed at the University of Nebraska-Lincoln. The aim of this study was to evaluate the safety performance of the developed gloves. An experiment was conducted to assess the discomfort threshold level at 12 zones on the palmar surface of the hand for five hand conditions--bare hand, single glove, double glove and two prototype gloves. Prototype I consisted of a glove with an extra layer of glove material applied selectively to critical areas of the hand; while prototype II had up to four layers applied to critical areas. This design increases protection in critical areas without increasing bulk, provides performances comparable with single glove, and improves grip strength. The study was conducted using an algometer device to apply pressure to each of the 12 zones, for all hand conditions. The results indicated that for pressure tolerance, prototype II had the highest pressure-discomfort threshold, while prototype I had a threshold similar to the double layer glove. Pressure discomfort tolerance threshold is greatly increased by the use of gloves, and pressure-discomfort thresholds are raised by 25-65%. The two prototype gloves, although much less bulkier than the double glove, have pressure thresholds that are equal to or superior to that of a double glove. The algometer can be used to assess the safety of glove from mechanical trauma. Hence, the generalizability of the results is somewhat restricted. However, the method of selective protection, without compromising performance appears to be promising and is worth pursuing by glove designers.

The development and evaluation of an ergonomic glove.

The primary intent of this study was to determine if a hand glove could be designed on a criterion of selective protection. Force distribution patterns on the palmar side of hand were obtained from various studies to develop zones of hand that needed protection. A new design for gloves was developed based on the principle of selective protection, where protective material is introduced in varying levels over different parts of the glove, in order to provide protection where it is most needed, and at the same time preserve the desirable dexterity and strength capabilities of the barehand, optimizing the trade-off between protection and performance. Two pairs of prototype gloves incorporating different levels of protection were fabricated and tested using a battery of performance tests and an algometer test for pressure sensitivity. The test battery comprising four dexterity tasks and a maximal voluntary grip strength task was used to assess a number of glove conditions, including the two prototype gloves developed. The results indicate that the performance of the prototype gloves are comparable, and that the performance times for the double glove and the two prototype gloves tested were not significantly different. For the grip strength, the two prototype gloves were better than the double glove. The assembly task performance for the prototype II (laminar glove) was significantly lower than that of the other glove types tested. It appears that gloves of variable thickness can be developed to afford adequate protection at zones of most need. Glove manufacturers are recommended to use an ergonomic approach in the design of gloves. Such an approach, besides protecting the safety objective of gloves, could enhance productivity considerably.