Development of non-stress baseline of crop water stress index for wheat in humid sub-tropical climate in India

Aim: A study was conducted to develop a new approach of non-stress baseline and evaluate different approach of determining non stress baseline for Crop Water Stress Index (CWSI).Methodology: To observe maximum and minimum canopy temperature, two plots with three replications were maintained at fully stress (no irrigation) and no stress (fully irrigated) conditions, respectively. Portable weather station with data logger was installed at the middle of field to record continuous data at half an hour interval. Gypsum block soil moisture sensor were buried at 20 cm interval up to 100 cm and connected with data logger. Infrared radiometer was used to measure canopy temperature. Results: The evaluation was based on five statistical indicators; correlation coefficient (R2), root mean square error (RMSE), mean absolute error (MAE), mean bias error (MBE) and Wilmot index of agreement (d). It was found that new regression base line performed better than other existing approaches. The calculated value of RMSE, MAE, MBE, d and R2 were 0.65, 0.51, 0.02, 0.79 and 0.83, respectively, for new baseline approach. Interpretation: The newly developed multiple regression equation (incorporating three weather parameters (Rn, VPD and u) and two crop growth parameters (h and CC)) helped to reduce error in the calculation of non-stress baseline for wheat crop in humid subtropical climate

Fine root growth and soil nutrient dynamics during shifting cultivation in tropical semi-evergreen forests of northeast India

Aim: The present study aimed to understand the periodical changes in fine root biomass, production, turnover and carbon and nitrogen return in forest fallows following shifting agriculture in Mizoram, Northeast India. Methodology: Root biomass was determined using sequential coring method in different fallow lands (FL-3, FL-5 and FL-10) following shifting agriculture. Annual fine root production was calculated as the sum of differences between annual maximum and minimum root biomass of different diameter classes. Concentrations of carbon and nitrogen in soil and roots were determined using CHN auto-analyzer, and their accumulations and returns were computed as the product of mass and element concentrations. Results: Total root biomass was maximum (561 g m-2) at FL-10, which decreased to 141 g m-2 at FL-3 with greater accumulation of fine roots in upper soil layer (0-10 cm) and coarse roots in lower depths. Root biomass was maximum (1499 g m-2) at the time of slashing which decreased to about one fourth just after burning. The amount of organic matter, carbon and nitrogen return to soil through fine root death was significantly regulated by soil moisture, microbial biomass carbon and total nitrogen in different fallow lands. Interpretation: Addition of organic matter, carbon and nitrogen to soil through death and decomposition of fine roots is an important mechanism responsible for sustaining soil fertility and crop productivity in different fallow lands. The output of the study has implications for the management of fallow lands following shifting cultivation and modeling global cycles of carbon and nitrogen.

Evidence of Late Palaeocene-Early Eocene equatorial rain forest refugia in southern Western Ghats, India.

Equatorial rain forests that maintain a balance between speciation and extinction are hot-spots for studies of biodiversity. Western Ghats in southern India have gained attention due to high tropical biodiversity and endemism in their southern most area. We attempted to track the affi nities of the pollen fl ora of the endemic plants of Western Ghat area within the fossil palynofl ora of late Palaeocene-early Eocene (~55–50 Ma) sedimentary deposits of western and northeastern Indian region. The study shows striking similarity of extant pollen with twenty eight most common fossil pollen taxa of the early Palaeogene. Widespread occurrences of coal and lignite deposits during early Palaeogene provide evidence of existence of well diversifi ed rain forest community and swampy vegetation in the coastal low lying areas all along the western and northeastern margins of the Indian subcontinent. Prevalence of excessive humid climate during this period has been seen as a result of equatorial positioning of Indian subcontinent, superimposed by a long term global warming phase (PETM and EECO) during the early Palaeogene. The study presents clear evidence that highly diversifi ed equatorial rain forest vegetation once widespread in the Indian subcontinent during early Palaeogene times, are now restricted in a small area as a refugia in the southernmost part of the Western Ghat area. High precipitation and shorter periods of dry months seem to have provided suitable environment to sustain lineages of ancient tropical vegetation in this area of Western Ghats in spite of dramatic climatic changes subsequent to the post India-Asia collision and during the Quaternary and Recent times.

A study on drug use in a district hospital of West Bengal.

A cross-sectional study at Howrah General Hospital, West Bengal for prescription analysis and assessment of drug dispensing in 341 patients revealed that the average number of drugs prescribed per encounter was 2.98 +/- 1.69, 38.2% drugs were in generic name and majority were from essential drugs list. 18.6% and 5.2% encounters used antibiotics and injections respectively. Average consultation and dispensing time were short. Majority of drugs were dispensed but unlabeled. 46.8% patients knew correct dosage of drugs. Only 4.7% patients were treated without drugs. Average drug cost per encounter was Rs. 31.32+30.89 where antibiotics and injections shared 36.5% and 4.6% respectively.

Prescribing and dispensing activities at the health facilities of a non-governmental organization.

BACKGROUND: Prescribing and dispensing surveys are pre-requisites to achieving rational drug use. There is a dearth of such studies in India, particularly in the non-governmental organization sector. METHODS: We carried out a survey at the outpatient facilities maintained by the Southern Health Improvement Samity, a non-governmental organization in the South 24 Parganas district of West Bengal. Data were collected prospectively by interviewing patients immediately after patient-physician and patient-dispenser encounters. Pre-designed forms were used to collect data pertaining to World Health Organization drug-use indicators and some additional indices. The calculations of cost of therapy involved some approximation. RESULTS: Of the 312 prescriptions analysed, the majority were signed, legible and complete with respect to age/gender data; 95.5% used Latin abbreviations and 7.7% mentioned neither signs and symptoms nor diagnosis. The average number of drugs per encounter was 3.2; only 2 patients were treated without drugs; 46.2% of drugs were prescribed by generic name. Use of antibiotics (72.8% of encounters) and irrational fixed dose combinations (45.6% of prescribed drugs) were frequent, but injection use (3.9% of prescriptions) was low. The average drug cost per encounter was Rs 74.19, of which antibiotics comprised 37.1%. The availability of first-line antitubercular drugs was adequate but other key drugs were in limited supply. Essential drugs lists and formularies were not followed. Only 45.7% of prescribed drugs conformed to the World Health Organization model list of essential drugs. Only 12 preparations accounted for 70.9% of the prescribed drugs, including therapeutically doubtful ones such as cough syrups, multivitamins and carminative syrups. For the dispensing survey, 301 prescriptions were analysed separately. All the prescribed drugs were supplied for only 11.6% of prescriptions. There were no serious errors in dispensing but 43.8% of dispensed products were inadequately labelled. Patients knew the correct mode of use for 64.5% of dispensed drugs. The average consultation and dispensing times were 3.7 and 3.1 minutes, respectively. CONCLUSION: Frequent use of antibiotics, irrational fixed dose combinations and preparations of uncertain efficacy, inadequate labelling of dispensed drugs and lack of access to standard tools for rational drug use such as locally adapted essential drugs list, formularies and standard treatment guidelines were some of the problematic prescribing and dispensing trends identified through this survey. Educational interventions are required to rectify these problems.

Evaluation of antimuscarinic activity in human volunteers: a teaching aid in clinical pharmacology.

The antimuscarinic activity of oxyphenonium bromide, diphenhydramine hydrochloride and astemizole were evaluated in six volunteers. The parameters used were salivary secretion, heart rate and pupillary size. The results indicated that the changes in heart rate and pupillary size and measurements were not convenient parameters for class room demonstration. However, salivary secretion and dryness of mouth were found to be reliable parameters for measurement. It was concluded that simple procedures like evaluation of antimuscarinic activity could be introduced as teaching aids in clinical pharmacology for undergraduate students.

Effect of fatty diet on pharmacokinetics and pharmacodynamics of a liquid theophylline preparation in volunteers.

The effect of a standard breakfast and a fatty breakfast on the pharmacokinetics and pharmacodynamics of a theophylline liquid preparation (160 mg-single dose) was examined in 6 healthy, non-smoking male volunteers. The plasma theophylline concentrations after both standard and fatty diet were found to be comparable at each point of time and pharmacokinetic parameters like Cmax, Tmax, T1/2a, T1/2 beta and AUC0-alpha, were also comparable. However, the time taken to attain the therapeutic plasma concentration was earlier and sustained along with the standard breakfast in comparison to that with fatty breakfast. Peak change in PEFR and pulse rate was also observed earlier with the standard diet than with fatty diet. The plasma theophylline concentrations produced after both diets were insufficient to produce any detectable change in subjective symptoms like tremor palpitation, heart burn, nausea, restlessness and tenseness. However, theophylline after fatty breakfast was better tolerated than that after a standard breakfast.