Imaging of human tooth enamel using ultrasound

This paper reports the results of a complete circumferential scan of a human tooth and its underlying dentino-enamel junction using ultrasound at frequencies in the 10-MHz range. The imagery shows clearly a two-dimensional contour of the dentinoenamel junction with a depth and lateral resolution of approximately 100 microm and 750 microm, respectively. The resulting sonograph is compared with an optical micrograph of the same tooth to verify the accuracy of the ultrasonic technique. The results are a significant step toward the biolocation of submillimeter size features within the tooth volume.

Validation of two air quality models for Indian mining conditions

All major mining activity particularly opencast mining contributes to the problem of suspended particulate matter (SPM) directly or indirectly. Therefore, assessment and prediction are required to prevent and minimize the deterioration of SPM due to various opencast mining operations. Determination of emission rate of SPM for these activities and validation of air quality models are the first and foremost concern. In view of the above, the study was taken up for determination of emission rate for SPM to calculate emission rate of various opencast mining activities and validation of commonly used two air quality models for Indian mining conditions. To achieve the objectives, eight coal and three iron ore mining sites were selected to generate site specific emission data by considering type of mining, method of working, geographical location, accessibility and above all resource availability. The study covers various mining activities and locations including drilling, overburden loading and unloading, coal/mineral loading and unloading, coal handling or screening plant, exposed overburden dump, stock yard, workshop, exposed pit surface, transport road and haul road. Validation of the study was carried out through Fugitive Dust Model (FDM) and Point, Area and Line sources model (PAL2) by assigning the measured emission rate for each mining activity, meteorological data and other details of the respective mine as an input to the models. Both the models were run separately for the same set of input data for each mine to get the predicted SPM concentration at three receptor locations for each mine. The receptor locations were selected such a way that at the same places the actual filed measurement were carried out for SPM concentration. Statistical analysis was carried out to assess the performance of the models based on a set measured and predicted SPM concentration data. The value of coefficient of correlation for PAL2 and FDM was calculated to be 0.990-0.994 and 0.966-0.997, respectively, which shows a fairly good agreement between measured and predicted values of SPM concentration. The average index of agreement values for PAL2 and FDM was found to be 0.665 and 0.752, respectively, which represents that the prediction by PAL2 and FDM models are accurate by 66.5 and 75.2%, respectively. These indicate that FDM model is more suited for Indian mining conditions.

Inflammatory pseudotumour of the lung : report of a case and review of literature

A case of unusual benign tumour of the lung is described. The patient presented with a history of prolonged cough with expectoration, and fever with generalised weakness of shorter duration. Radiological examination of the chest revealed a large non-homogeneous opacity with calcification in the left lower zone. Fine needle aspiration cytology (FNAC) was inconclusive. Therefore, surgical exploration and a left lower lobectomy was performed. The diagnosis of inflammatory pseudotumour was made on histopathological examination.

In vitro regeneration of Hypericum patulum Thunb.--a medicinal plant

A protocol was developed for high frequency plant regeneration in H. patulum by shoot-tip culture. H. patulum plants were collected from a wild source growing at high altitude in the eastern Himalayas. Multiple buds were initiated from shoot-tips cultured on Murashige and Skoog's medium supplemented with BAP, kinetin. Addition of thiamin HCI, Ca-pantothenate and biotin enhanced multiple shoot formation. Upon transfer to phytohormone free liquid medium following a brief exposure to auxin, root formation occurred from the micro shoots . Rooted plants were hardened and transferred to soil. Regeneration potentiality was found to be constant throughout the year in long term cultures.

Monitoring of bacteria growth using a wireless, remote query resonant-circuit sensor: application to environmental sensing

A new technique is presented for in-vivo remote query measurement of the complex permittivity spectra of a biological culture solution. A sensor comprised of a printed inductor-capacitor resonant-circuit is placed within the culture solution of interest, with the impedance spectrum of the sensor measured using a remotely located loop antenna; the complex permittivity spectra of the culture is calculated from the measured impedance spectrum. The remote query nature of the sensor platform enables, for example, the in-vivo real-time monitoring of bacteria or yeast growth from within sealed opaque containers. The wireless monitoring technique does not require a specific alignment between sensor and antenna. Results are presented for studies conducted on laboratory strains of Bacillus subtilis, Escherichia coli JM109, Pseudomonas putida and Saccharomyces cerevisiae.

Constituents of Asteracantha longifolia

The isolation of two aliphatic esters and betulin from the aerial parts of Asteracantha longifolia is reported.

Sex gene pool evolution and speciation: a new paradigm

In this paper, we review the literature on the growing body of data demonstrating the rapid evolution of sex and reproduction related (SRR) genes and show how a paradigm shift to the study of SRR genes can provide new approaches to solving some of the old problems in evolutionary biology. The argument is based on (1) the growing scope and importance of sexual selection in evolution, (2) the growing number of case studies showing rapid evolution of sexual traits in a wide variety of taxa, (3) the faster rate of DNA sequence divergence in genes affecting sexual function and fertility, (4) the evidence for the involvement of novel traits/genes in sexual functions, and (5) a proposed sex/non-sex dichotomy of the gene pool affecting viability versus fertility. It is argued that the adoption of the sex/non-sex dichotomy of genes/traits can provide new perspectives on such problems as species concepts, modes (allopatric/sympatric) of speciation, Haldane's rule, reinforcement, and the founder effect. It is proposed that the evolutionary study of genes affecting viability versus fertility is the key to understanding the genetic basis of speciation.

Aliphatics from Peristrophe bicalyculata

The isolation and spectral data of the new 14-methyl-tritriacont-14-en-15-ol (1) and 35-hydroxynonatriacontanal (2) from the aerial parts of Peristrophe bicalyculata are reported.

A biogeographic genetic approach for testing the role of reinforcement: the case of Drosophila pseudoobscura and D. persimilis

The role of reinforcement in speciation can be explained by two distinct models. In model I, two diverged populations hybridize and produce fertile hybrids that successfully backcross (hybridization with gene flow). In model II, two populations hybridize but succeeding backcrosses are unproductive (hybridization without gene flow). Using Drosophila persimilis and D. pseudoobscura, we have tested model I by comparing the extent of heterospecific introgression in sympatric versus allopatric populations. We show that certain expectations of this particular model of reinforcement, which is based on hybridization and gene flow between divergent populations after secondary contact, are not realized in these two species. The evidence consists of the similarity of genetic distances as well as proportions of unique/rare alleles between sympatric and allopatric heterospecific populations and a negative correlation between genetic distance and geographical distance between heterospecific populations, which suggests ecological differentiation. This approach in quantifying differential gene flow has important consequences to studies that compare sympatric and allopatric isolation using genetic distance. Following model I, one would expect a pattern of higher prezygotic isolation in sympatric species compared to allopatric species of the same genetic distance simply as a result of an underestimation of genetic distance due to introgression between sympatric populations. We suggest more parsimonious explanations such as reinforcement without genetic exchange (model II) and ecological differentiation, which require high levels of preexisting reproductive isolation between populations.

A comparison of esmolol and diltiazem for heart rate control during coronary revascularisation on beating heart

This prospective study compared control of heart rate and haemodynamics during coronary artery revascularization without cardiopulmonary bypass using either esmolol or diltiazem. Sixty adult patients with one or two vessel coronary artery disease, were randomly divided into 2 groups. Group A (n=30) received a 50 microg/kg/ loading dose of esmolol followed by a 100 microg/kg/hr infusion, for control of heart rate during surgical anastomosis of the coronary vessel. Group-B (n=30) received 0.15 mg/kg of diltiazem as a loading dose followed by a 5 mg/hr infusion for heart rate control, during the anastomosis. It was seen that heart rate control was better in group A, 51.4 +/- 1.3 beats/min, (p <0.01) than in group B, 69.6 +/- 3.0 beats/min (p <0.05), as compared to baseline values of 80.6 +/- 12.1 beats/min in group A and 82.4 +/- 10.6 beats/min in group B respectively. Systemic vascular resistance and pulmonary artery wedge pressure were unchanged in group A but mean pulmonary artery pressure and pulmonary vascular resistance were significantly raised. Group B patients had decreased systemic vascular resistance, mean pulmonary artery pressure and pulmonary artery wedge pressure, and reduced right ventricular stroke work index at the time of distal coronary anastomosis. We concluded that although esmolol provided dramatically slower heart rates, during surgery, the resulting elevations in mean pulmonary artery pressure and pulmonary vascular resistance would require caution if used in patients with underlying right ventricular dysfunction from ischaemia or infarction. Diltiazem by virtue of its effects on systemic vascular resistance, cardiac output, and lowering of mean arterial pressure may be a better choice in hypertensive patients.

Broad-sense sexual selection, sex gene pool evolution, and speciation

Studies of sexual selection have traditionally focused on explaining the extreme sexual dimorphism in male secondary sexual traits and elaborate mating behaviors displayed by males during courtship. In recent years, two aspects of sexual selection have received considerable attention in the literature: an extension of the sexual selection concept to other traits (i.e., postcopulatory behaviors, external and internal genital morphology, gametes, molecules), and alternative mechanistic explanations of the sexual selection process (i.e., coevolutionary runaway, good-genes, sexual conflicts). This article focuses on the need for an extension of sexual selection as a mechanism of change for courtship and (or) mating male characters (i.e., narrow-sense sexual selection) to all components of sexuality not necessarily related to courtship or mating (i.e., broad-sense sexual selection). We bring together evidence from a wide variety of organisms to show that sex-related genes evolve at a fast rate, and discuss the potential role of broad-sense sexual selection as an alternative to models that limit speciation to strict demographic conditions or treat it simply as an epiphenomenon of adaptive evolution.Key words: sexual selection, sex-related genes, speciation.

Purulent pericarditis: clinical profile and outcome following surgical drainage and intensive care in children in Chandigarh

Purulent pericarditis, though rare in developed countries, is not uncommon in developing countries. However, the type of pericardial drainage required and the risk of subsequent constrictive pericarditis has not been clearly defined. Thirty children between the ages of 3 months and 12 years with a diagnosis of purulent pericarditis were studied retrospectively. Pericardial effusion was confirmed in all by echocardiography and the diagnosis of bacterial pericarditis was based on aspiration of purulent fluid with leucocytosis and high proteins. Purulent pericarditis was a part of the disseminated sepsis in 25 (83%) children. Fever was present in all, hepatomegaly in 28 and breathlessness in 25, whereas muffled heart sounds, raised JVP and pericardial rub were found in only 18, 16 and 7, respectively. The ECG was abnormal in only 16 children. Staphylococcus aureus was the causative organism in 24 (96%). Open surgical drainage was done in 26 children, 23 of whom underwent anterior pericardiectomy. Two children died of disseminated sepsis. None of the 21 who returned for follow-up for periods of between 4 and 24 months had any long-term sequelae.

Broad-sense sexual selection, sex gene pool evolution, and speciation

Studies of sexual selection have traditionally focused on explaining the extreme sexual dimorphism in male secondary sexual traits and elaborate mating behaviors displayed by males during courtship. In recent years, two aspects of sexual selection have received considerable attention in the literature: an extension of the sexual selection concept to other traits (i.e., postcopulatory behaviors, external and internal genital morphology, gametes, molecules), and alternative mechanistic explanations of the sexual selection process (i.e., coevolutionary runaway, good-genes, sexual conflicts). This article focuses on the need for an extension of sexual selection as a mechanism of change for courtship and (or) mating male characters (i.e., narrow-sense sexual selection) to all components of sexuality not necessarily related to courtship or mating (i.e., broad-sense sexual selection). We bring together evidence from a wide variety of organisms to show that sex-related genes evolve at a fast rate, and discuss the potential role of broad-sense sexual selection as an alternative to models that limit speciation to strict demographic conditions or treat it simply as an epiphenomenon of adaptive evolution.

A comparison of esmolol & diltiazem for heart rate control during coronary revascularisation on beating heart

This prospective study was done to compare the control of heart rate and haemodynamics during coronary artery revascularisation without cardiopulmonary bypass using either esmolol or diltiazem. Sixty adult patients with one or two vessel coronary artery disease, were randomly divided into 2 equal groups. Group A received a 500 micrograms/kg loading dose of esmolol followed by a 100 micrograms/kg/h infusion, for control of heart rate during surgical anastomosis of the coronary vessel. While Group B received 0.15 mg/kg diltiazem as a loading dose followed by a 5 mg/h infusion for heart rate control, during the anastomosis. It was seen that heart rate control was better in Group A, 51.4 (+/- 1.3) beats/min, than in Group B, 69.6 (+/- 3.9) beats/min but the decrease in heart rate was significant in both the groups at peak effect compared to respective predrug values. Group A patients had unchanged systemic resistance and pulmonary artery wedge pressure but mean pulmonary artery pressure and pulmonary vascular resistance were significantly raised. Group B patients had decreased systemic resistance, mean pulmonary artery pressure and pulmonary artery wedge pressure, and reduced right ventricular stroke work index. We concluded that although esmolol provided dramatically slower heart rates, during surgery, the resulting elevations in mean pulmonary artery pressure and pulmonary vascular resistance would require caution if used in patients with underlying right ventricular dysfunction from ischaemia or infarction. Diltiazem by virtue of its effects on systemic vascular resistance, cardiac output, and lowering of mean arterial pressure may be a better choice in hypertensive patients.

Tension pneumocephalus after excision of posterior mediastinal mass

Although paraplegia after a posterolateral thoracotomy has been described as a serious complication, the occurrence of tension pneumocephalus after excision of posterior mediastinal mass has also been reported as another life-threatening complication. We report one such case.

Sex-related genes, directional sexual selection, and speciation

Reproductive isolation and speciation can result from the establishment of either premating or postmating barriers that restrict gene flow between populations. Recent studies of speciation have been dominated by a molecular approach to dissect the genetic basis of hybrid male sterility, a specific form of postmating reproductive isolation. However, relatively little attention has been paid to the evolution of genes involved in premating isolation and genes generally involved in other sex-related functions (e.g., mating behavior, fertilization, spermatogenesis, sex determination). We have assembled DNA sequences from 51 nuclear genes and classified them based on their functional characteristics. The proportion of nonsynonymous to synonymous nucleotide substitutions were compared between Drosophila melanogaster, Drosophila simulans, and Drosophila pseudoobscura, as well as between Caenorhabditis elegans and Caenorhabditis briggsae. We found a high ratio of nonsynonymous to synonymous substitutions for sex-related genes (i.e., genes involved in mating behavior, fertilization, spermatogenesis, or sex determination). The results suggest that directional sexual selection has shaped the evolution of sex-related genes and that these changes have more likely occurred during the early stages of speciation. It is possible that directional selection becomes relaxed after reproductive isolation has been completed between more distantly related species (e.g., D. melanogaster and D. pseudoobscura). However, a saturation in the number of nucleotide substitutions since the time of species separation may mask any sign of directional selection between more distantly related species.

Unusual intrapulmonary foreign body: a pencil

A case of unusual intrapulmonary foreign body in the form of a pencil is described. The penetration occurred following an insignificant fall. The diagnosis was made on CT scan and subsequently surgical removal was undertaken successfully.

Ruptured aneurysm sinus of Valsalva and Gerbode defect with severe tricuspid and aortic regurgitation. A case report and its surgical correction

An unusual early, childhood presentation in a case with reputured non-coronary sinus of Valsalva aneurysm with Gerbode defect and severe pulmonary hypertension is described. The reasons for early rupture are discussed and anatomically important relations of membranous septum, fibroskeleton of heart and conduction system are schematically elucidated. Associated severe tricuspid and aortic regurgitation are explained to be secondary effects following the rupture of aneurysm. A technique of surgical correction of this rare association of anomalies using single PTFE patch is illustrated, cautiously safeguarding the closely related conduction system. Regurgitant aortic and tricuspid valves were also successfully repaired. In retrospect, early repair before rupture of aneurysm and onset of severe pulmonary hypertension may be more beneficial, which would also prevent the leakage of semilunar and atrioventricular valves.