A study of the cuticle of Gordius robustus, a nematomorph worm. I. Cuticle in the parasitic phase.

1. An investigation on the structure and chemical nature of the cuticle of a nematomorph worm Gordius robustus and its role in the physiology of the endoparasitic phase has been conducted. 2. The cuticle has fundamentally three layers; the cortical, homogeneous and fibrillar layers, differing from one another in physical as well as chemical properties. 3. The cortical layer has organic sulphur and acid mucopolysaccharide; the homogeneous layer has organic sulphur together with collagen-like protein and the fibrillar layer has only collagen. 4. Electrophoretic and chromatographic analyses reveal the presence of four proteins with different amino acid composition; the carbohydrate components of the cuticle are galactose and mannose. 5. Alkaline phosphatase and non-specific esterase are found in the cuticle of the general body surface and these seem to be related to the cutaneous absorption of materials. 6. Using peroxidase as tracer protein, the absorption of materials across the cuticle from outside the body has been demonstrated; this absorption is found to be an active process.     

Peer Reviewed: Assessing Retail Fruit and Vegetable Availability in Urban and Rural Underserved Communities

Introduction

Fruits and vegetables (F&Vs) are important parts of a healthy, balanced diet. Consumption of F&Vs is low among residents of socioeconomically disadvantaged communities. We investigated and compared retail F&V availability in urban and rural underserved communities in New York State.

Methods

All food retail stores and farmers'' markets (N = 263) in downtown Albany and in Columbia and Greene counties in New York State were visited and surveyed. Food stores were classified as F&V stores if they stocked more than the minimum varieties of fresh F&Vs defined by this study and as fruit-for-snack stores if they had ready-to-eat fruits only. Store density per 10,000 residents was calculated as a standardized measure of F&V availability. Adjustment weights were created to incorporate store size and business hours into the analysis.

Results

The weight-adjusted density (per 10,000 residents) of F&V stores was 4.6 in Albany''s minority neighborhood (reference category), 11.4 in Albany''s racially mixed neighborhood (P = .01), 7.8 in Columbia and Greene counties'' rural community (P = .10), and 9.8 in Columbia and Greene counties'' small-town community (P = .02). Significant differences were not found in fruit-for-snack stores, which ranged from 2.0 per 10,000 in the mixed neighborhood to 3.4 per 10,000 in the rural community.

Conclusion

The urban minority neighborhood had the most barriers to fresh F&Vs in retail outlets, even when compared with the rural community. The low availability of retail F&Vs in the minority neighborhood was attributed to the lack of supermarkets and not the absolute lack of food stores. Public health intervention strategies to increase retail F&V availability in urban minority neighborhoods may aid in mitigating these disparities.     

Chitinolytic enzymes from endophytic fungi

Fungal endophytes isolated from leaves of tree species of the forests of Western Ghats, southern India were screened for chitin modifying enzyme production. Thirty-one of the one hundred and sixty two isolates were positive for chitinase, while different isolates produced isoforms of the enzyme. Many isolates produced chitosanase that acted on chitosan with different degrees of acetylation. Modified chitin and different types of chitosans are used in biomedical applications including wound healing, drug delivery, gene delivery, tissue engineering, in the food industry as preservatives and emulsifying agents, and in biocatalysis. Horizontally transmitted endophytes appear to be a good source for a variety of chitin modifying enzymes with the potential to be used in biotechnology. The possibility of chitin modifying enzymes of endophytes in regulating plant defense against pathogens and pests in vivo should also be addressed.     

Jumping in simulated and true microgravity: response to maximal efforts with three landing types

BACKGROUND: Exercise is a promising countermeasure to the physiological deconditioning experienced in microgravity, but has not proven effective in eliminating the ongoing loss of bone mineral, most likely due to the lack of high-impact forces and loading rates during in-flight activity. We wanted to determine lower-extremity response to high-impact jumping exercises in true and simulated microgravity and establish if 1-G force magnitudes can be achieved in a weightless environment. METHODS: Jumping experiments were performed in a ground-based zero-gravity simulator (ZGS) in 1 G, and during parabolic flight with a gravity-replacement system. There were 12 subjects who participated in the study, with 4 subjects common to both conditions. Force, loading rates, jump height, and kinematics were analyzed during jumps with three distinct landings: two-footed toe-heel, one-footed toe-heel, and flat-footed. Gravity replacement loads of 45%, 60%, 75%, and 100% bodyweight were used in the ZGS; because of time constraints, these loads were limited to 60% and 75% bodyweight in parabolic flight. RESULTS: Average peak ground-reaction forces during landing ranged between 1902+/-607 and 2631+/-663 N in the ZGS and between 1683+/-807 and 2683+/-1174 N in the KC-135. No significant differences were found between the simulated and true microgravity conditions, but neither condition achieved the magnitudes found in 1 G. CONCLUSION: Data support the hypothesis that jumping exercises can impart high-impact forces during weightlessness and that the custom-designed ZGS will replicate what is experienced in true microgravity.