Range safety signal propagation through the SRM exhaust plume of the space shuttle

Theoretical predictions of plume interference for the space shuttle range safety system by solid rocket booster exhaust plumes are reported. The signal propagation was calculated using a split operator technique based upon the Fresnel-Kirchoff integral, using fast Fourier transforms to evaluate the convolution and treating the plume as a series of absorbing and phase-changing screens. Talanov's lens transformation was applied to reduce aliasing problems caused by ray divergence

Plume RF interference calculations for space shuttle

During a static ground test of a full-scale SRM, measurements of attenuation of the UHF 416.5 MHz Range Safety Signal, the VHF voice link (230 MHz), and of S-band (c. 2.2. GHz) communications links were undertaken. Analyses of these results indicate that measurable attenuation did occur at all test frequencies. The measured attenuation levels are compared with a simple model in which the received signal is identified as that diffracted about the edge of the highly absorbing plume and the signal level in the shadow zone is evaluated using the formula for diffraction at a straight edge. The comparison is satisfactory at VHF and UHF frequencies, and slightly less so at S-band. Reasons for the discrepancies found at higher frequencies are discussed. A revised procedure which appears to relieve the accuracy problem was developed. This procedure is discussed along with applications to high altitude SRM plume attenuation

Histopathological prognostic factor comparison of endometrial cancer patients in a tertiary hospital in India

Background: The objective of this study was to describe the histopathological features of patients with endometrial cancer in a tertiary hospital in South India.Methods: This retrospective study included cases diagnosed and operated in a tertiary hospital in the period of 3 years. Histopathological data was retrieved from records and analyzed. The study included both endometrial biopsy and post hysterectomy specimens of which prognostic factor comparison was performed on the latter following TNM and FIGO staging systems.Results: The sample consisted of 43 patients which includes 28 resected and 15 biopsy specimens. Age ranged from a minimum of 27 years to a maximum of 75 years (Mean around 52 years). Endometrioid adenocarcinoma was the predominant histological subtype (80 – 85%), while other types included papillary serous adenocarcinoma, stromal sarcoma and malignant mixed mullerian tumour (MMMST). Grade I tumours were 19 in number constituting 79.16% and stage IB tumours were the commonest. Pelvic nodal involvement, lymphatic invasion and recurrence were individually noted in one patient each.Conclusions: This study highlights the prognostic characteristics of endometrial cancer patients with most of them presenting in early stages thereby having a good prognostic outcome

Identification of lunar volcanic tubes, a potential site for human settlement using 3D Chandrayaan-1 TMC data

This article does not have an abstract

Prospective, randomized double blind comparative study of safety and efficacy of carvedilol versus atenolol in patients of mild to moderate hypertension

Background: Carvedilol is a new cardiovascular compound with the combined pharmacologic properties of nonselective ß-blockade and vasodilation. The Aim of the study was to compare the safety and antihypertensive efficacy of 25mg Carvedilol once daily with 50mg atenolol once daily in patients with mild to moderate essential hypertension.Methods: This was a single center study conducted in Rangaraya Medical College, Kakinada. 80 eligible patients with mild to moderate hypertension were randomized to receive 25mg Carvedilol once daily (40 patients) or 50mg atenolol (40 patients) in a double-blind 12-week treatment phase. At each visit 0, 4, 8 and 12 weeks of treatment, sitting Blood Pressure (BP) and heart rate were measured. The effect on BP reduction within the group is compared by paired “t”test and the effect on reduction of BP between two study groups compared by unpaired “t”test.Results: After 12 weeks of treatment, the mean reduction of SBP (Systolic Blood Pressure) with carvedilol is 22.33±8.31mmHg with no Significant difference (p >0.05) compared to atenolol group mean reduction in SBP of 21.37±10mm Hg. The mean reduction in DBP (Diastolic Blood Pressure) after completion of the study in carvedilol group is 6.75±4.82mm Hg with no Significant difference (p >0.05) compared to atenolol group mean reduction in DBP of 8.55±5.25mm Hg. No significant difference seen in the efficacy parameters of both the drugs. The incidence of adverse effects such as bradycardia, headache, nausea, vomiting, hypotension and rash is less with carvedilol.Conclusions: In patients with mild to moderate hypertension, there was no statistically significant difference between efficacy of carvedilol or atenolol with regard to the degree of reduction in BP or the percentage of patients achieving a response to therapy but carvedilol showed a better safety profile when compared to atenolol

Proteolytic Activity in the Midgut of Helicoverpa armigera (Noctuidae: Lepidoptera) Larvae Fed on Wild Relatives of Chickpea, Cicer arietinum

Wild relatives of crops are an important source of resistance genes against insect pests. However, it is important to identify the accessions of wild relatives with different mechanisms of resistance to broaden the basis and increase the levels of resistance to insect pests. Therefore, we evaluated 15 accessions of wild relatives of chickpea belonging to seven species and five genotypes of cultivated chickpea for their resistance to pod borer, Helicoverpa armigera, which is the most damaging pest of chickpea. The test genotypes were evaluated for resistance to H. armigera using detached pod assay. Data were also recorded on activity of the digestive enzymes in the midgut of the larvae fed on different wild relatives of chickpea. All the wild chickpea genotypes suffered lower pod damage and weight gained by the third-instar larvae of H. armigera was lower when fed on them compared with the cultivated chickpea. The accessions, IG 69979 (Cicer cuneatum), PI 599066, IG 70006, IG 70018, IG 70022 (Cicer bijugum), IG 599076 (Cicer chrossanicum), and IG 72933, IG 72953 (Cicer reticulatum), showed high levels of resistance to H. armigera. There were significant differences in protease activity in larval gut of H. armigera fed on different wild relatives of chickpea. Total protease, trypsin, and chymotrypsin activities were lowest in larva fed on PI 599066 (C. bijugum) compared with that in the larvae fed IG 69979 (C. cuneatum) and IG 70022 (C. bijugum). Aminopeptidase activity was highest in the larvae fed on IG 70022 (C. bijugum) and IG 599076 (C. chrossanicum), whereas lowest activity was recorded in the larvae fed on ICC 3137 and KAK 2 (susceptible checks). The variation in protease activities may be due to the presence of protease inhibitors in the wild relatives or hyperproduction of enzymes by the larvae as result of protease inhibitor activity of the wild relatives, resulting in low weight gain by larvae. The results suggested that wild relatives of chickpea with diverse mechanisms of resistance can be exploited to increase the levels and diversify the basis of resistance to H. armigera in cultivated chickpea

Cardiovascular risk profile and management of atrial fibrillation in India: Real world data from RealiseAF survey

BACKGROUND: Atrial fibrillation (AF) is the most common sustained arrhythmia with high risk for many cardiovascular (CV) complications. Adherence to recommended management guidelines is important to avoid complications. In India, there is little knowledge on how AF is managed in real world. METHODS: This is a cross-sectional study of patients in India enrolled in RealiseAF survey between February 2010 and March 2010 with a diagnosis of AF within the last 12 months. RESULTS: From 15 centers, 301 patients {mean age 59.9 years (14.4); 52.5% males} were recruited. AF was controlled in 50% of patients with 77 (26.7%) in sinus rhythm and 67 (23.3%) with heart rate <80beats/min. Hypertension (50.8%), valvular heart disease (40.7%), heart failure (25.9%), and diabetes (20.4%) were the most common underlying CV diseases. Increased risk for stroke (CHADS2 score≥2) was present in 36.6%. Most of the patients (85%) were symptomatic. AF was paroxysmal, persistent, and permanent in 28.7%, 22.7%, and 34.3% respectively. In 14%, AF was diagnosed as first episode. Forty-six percent of patients had rate control, 35.2% rhythm control, 0.3% both strategies, and 18.4% received no therapy for AF before the visit. At the end of the visit, adoption to rate control strategy increased to 52.3% and patients with no therapy decreased to 7%. CONCLUSION: AF in India is not adequately controlled. Concomitant CV risk factors and risk of stroke are high. The study underscores the need for improved adoption of guideline-directed management for optimal control of AF and reducing the risk of stroke

Influence of antioxidant (L- ascorbic acid) on tolbutamide induced hypoglycaemia/antihyperglycaemia in normal and diabetic rats

BACKGROUND: Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycaemia. Increased oxidative stress and decreased antioxidant levels are the leading cause of diabetes and diabetic complications. So it is felt that supplementation of antioxidants may be useful in controlling the glucose levels and to postpone the occurrence of diabetic complications. The objective of our study is to find the influence of antioxidant supplementation (L-ascorbic acid) on tolbutamide activity in normal and diabetic rats. METHODS: L- ascorbic acid/tolbutamide/L-ascorbic acid + tolbutamide were administered orally to 3 different groups of albino rats of either sex in normal and diabetic condition. Blood samples were collected from retro-orbital puncture at different time intervals and were analyzed for blood glucose by GOD-POD method. Diabetes was induced by alloxan 100 mg/kg body weight administered by I.P route. RESULTS: L-ascorbic acid/ tolbutamide produced hypoglycaemic activity in a dose dependant manner in normal and diabetic condition. In the presence of L-ascorbic acid, tolbuatmide produced early onset of action and maintained for longer period compared to tolbutamide matching control. CONCLUSION: Supplementation of antioxidants like L-ascorbic acid was found to improve tolbutamide response in normal and diabetic rats