Ziziphus mauritiana Lam. is an important fruit crop of the Thar Desert of India. About 330 accessions and cultivars collected from various parts of India are currently being maintained at a farm in the Central Institute for Arid Horticulture. Utilization of such a large collection of germplasm for breeding and crop improvement is difficult. Therefore, in the present study, using a heuristic approach based on phenotypic characters, we identified 52 accessions that represented a core collection, with a coverage of 100% and a coincidence rate of 98.1%. No significant difference was observed with respect to either the Shannon–Weaver or the Nei diversity index for qualitative traits, mean values and ranges for quantitative traits or clustering patterns between the core and whole collections. The core collection represents the entire range of diversity with minimum redundancy and should be useful for the conservation and utilization of Z. mauritiana germplasm.

Field experiments were made during the rainy seasons of 1979 and 1980 at Hissar, India, to study the effect of time of weed removal on the yield of groundnut. Removing weeds from 2 to 8 weeks after sowing led to significantly larger yields than that of plots which were not weeded. Maximum pod yield in both years was obtained when weeds were removed 4 weeks after crop sowing.

Field experiments were done during the rainy seasons of 1980 and 1981 at Hissar, India; they studied the effects of time of weed removal on the yield of mung beans. Removing weeds at 10, 20 or 30 days after sowing led to significantly larger yields than that of the weedy check. Maximum seed yields in booth years were obtained when weeds were removed 20 days after sowing

Four depth of tillage treatments were given by ploughing to 7 cm. depth by bullock-drawn plough and 14, 21 and 28 cm. depth with a tractor-drawn mouldboard plough in 1962–63. A significant decrease in bulk density was observed with the 21 and 28 cm. ploughing, negatively correlated with dry matter of crop roots and yield of grain. The effectiveness of 28 cm. tillage in reducing the population and dry matter of weeds was significant when compared to tillage at 7 and 14 cm. and there were significant relations between dry matter of weeds and yield of grain. Crop roots under tractor tillage were significantly greater than with 7 cm. tillage. Grain yield was maximum under 28 cm. tillage followed by 21, 14 and 7 cm. deep tillage in that order. The higher grain yields were associated with a greater number of fertile tillers per metre of row and higher yields per tiller.

The aim of the present study was to explore whether mice fed a diet low in Zn (2·0 mg Zn/kg diet) for a relatively short period of time were more prone to severe Streptococcus pneumoniae infection than mice fed a normal diet (25 mg elemental Zn/kg). The Zn-deficient mice were compared with mice in two Zn-adequate control groups; one pair-fed and another with free access to the diet. After 2 weeks feeding, the mice were infected intranasally under anaesthesia with a suspension containing about 107 pneumococci. Clinical status was observed every day and blood samples were examined for S. pneumoniae every second day for a week. All infected mice examined carried the infecting strain intranasally. The survival time and time before positive blood culture were significantly shorter in the Zn-depleted group than in the pair-fed Zn-adequate group (hazard ratios 15·6 and 3·2, P<0·0001 and P=0·045 respectively). At the end of the observation period, ten of the twelve mice in the Zn-deficient group were dead while one of twelve and two of twelve were dead in the two Zn-adequate control groups. This study shows that even acutely-induced Zn deficiency dramatically increases the risk of serious pneumococcal infection in mice.

Malnutrition increases morbidity and mortality and affects physical growth and development, some of these effects resulting from specific micronutrient deficiencies. While public health efforts must be targeted to improve dietary intakes in children through breast feeding and appropriate complementary feeding, there is a need for additional measures to increase the intake of certain micronutrients. Food-based approaches are regarded as the long-term strategy for improving nutrition, but for certain micronutrients, supplementation, be it to the general population or to high risk groups or as an adjunct to treatment must also be considered. Our understanding of the prevalence and consequences of iron, vitamin A and iodine deficiency in children and pregnant women has advanced considerably while there is still a need to generate more knowledge pertaining to many other micronutrients, including zinc, selenium and many of the B-vitamins. For iron and vitamin A, the challenge is to improve the delivery to target populations. For disease prevention and growth promotion, the need to deliver safe but effective amounts of micronutrients such as zinc to children and women of fertile age can be determined only after data on deficiency prevalence becomes available and the studies on mortality reduction following supplementation are completed. Individual or multiple micronutrients must be used as an adjunct to treatment of common infectious diseases and malnutrition only if the gains are substantial and the safety window sufficiently wide. The available data for zinc are promising with regard to the prevention of diarrhea and pneumonia. It should be emphasized that there must be no displacement of important treatment such as ORS in acute diarrhea by adjunct therapy such as zinc. Credible policy making requires description of not only the clinical effects but also the underlying biological mechanisms. As findings of experimental studies are not always feasible to extrapolate to humans, the biology of deficiency as well as excess of micronutrients in humans must continue to be investigated with vigour.

Role of micronutrients namely vitamin A, zinc and folate, as adjunct therapy of illness episodes in children in developing countries have been discussed in the light of health policy. Apart from a selective review, attempts have been made to statistically combine results of several studies to address policy issues. In children, vitamin A supplementation during illness has (a) a profound effect in reducing mortality in measles, (b) possibly a significant effect in reducing persistent diarrhea episodes in children with acute diarrhea, and (c) no benefit in pneumonia.

Use of large dose vitamin A is recommended during measles episodes but not in non-measles pneumonia. Its use in acute diarrhea is debatable but recommended in persistent diarrhea and in severe malnutrition as a component of a micronutrient mixture. Large dose vitamin A supplementation should be used with caution in young infants as there are unresolved concerns about its safety particularly, bulging fontanelle observed in infants when co-administered at immunization. In children, zinc supplementation during illness, (a) had a marked effect in reducing prolonged episodes and a modest effect on episode duration in acute diarrhea, (b) resulted in reduced rate of treatment failure and death in persistent diarrhea, (c) had no effect in measles and non-measles pneumonia, and (d) probably had a detrimental effect of increasing death rate when a large dose was used in severely malnourished children. The desirability of routine zinc supplementation therapy of undernourished children with acute diarrhea should be assessed further. Concerning policy, zinc supplementation as a component of a micronutrient mixture is recommended in the rehabilitation of severely malnourished children and in persistent diarrhea. However, recommendation for its routine use in all cases of acute diarrhea in children needs additional studies on effectiveness, cost, operations and safety. In two randomized controlled trials folate has been evaluated in acute and persistent diarrhea and found to have no beneficial effect. Folate is not recommended as adjunct therapy of diarrhea. Role of folate in preventing severe disease and/or death deserves further evaluation.

We have systematically investigated the effects of addition of sub-ppm levels of boron on the stability of a-Si:H films and p-i-n devices, deposited by PE-CVD technique. The films thus produced with appropriate amounts of boron, show a significant improvement in stability, when soaked under both AM 1.5 (short-term) as well as 10×sun (long-term) illumination conditions. The opto-electronic properties of the films are quite respectable It is concluded that boron compensates the native impurities by forming donor-acceptor pairs, which reduces the “fast” defects and hence the initial degradation of the films. It is also speculated that boron may also be improving the short-term stability, by reducing the recombination of light generated electrons and holes, by converting D° into D+ states. The long-term stability appears to get affected by hydrogen dilution which seems to reduce the amount of “slow” defects. As a result of B doping of i-layer, the initial conversion efficiency of the devices decreases. It is presumed that our devices may contain an enhanced level of boron impurity, than expected, making them as worse material and to degrade less.

We discuss the growth of a-Si:H Materials and devices using a low pressure remote ECR plasma. We show that by using this plasma in an etching mode with a high H flux, we can grow high quality a-Si:H films at high temperatures (325–375 C). These films have significantly improved stability compared to standard a-Si:H films deposited using glow discharge. We can further improve the stability of these films by incorporating minute (sub ppm levels) of boron during growth. We also report on the fabrication of devices at these temperatures using this very reactive plasma. We discuss the precautions taken to obtain good devices, and discuss how the devices can be further improved.

Immunohistochemical staining for keratin proteins may be useful as a diagnostic parameter in head and neck neoplasms. Our study evaluates the keratin antibody staining properties of normal tissues as well as neoplastic and non-neoplastic head and neck lesions from surgical procedures performed on 100 patients. The results indicate that the anti-keratin antibody technique can be helpful in several areas of head and neck pathology.