Growth, biomass, carbon storage and nutrient distribution in Gmelina arborea Roxb. stands on red lateritic soils in central India

Growth, biomass, carbon storage and nutrient (N, P and K) variations in 1 to 6-year-old chronosequence plantations of Gmelina arborea were studied in three degraded red lateritic sites in central India. Growth parameters (dbh, total height and number of branches) varied significantly due to difference in age and site quality, but tree density showed non-significant variation. Stand biomass ranged from 3.94 (1-year-old) to 53.67 Mgha(-1) (6-year-old) and stand carbon in 6-year-old plantations ranged from 24.12 to 31.12 Mgha(-1) at different sites. Among the tree components, the stem wood accounted for maximum C (56.25% at site 1) followed by branches (19.8% at site 3), roots (18.51% at site 2) and foliage (7.01% at site 3). Mean annual C accretion at 6 years age of plantation was highest in site 3 and it was 0.35, 2.66, 0.965 and 0.87 Mgha(-1) for leaf, stem, branches and roots, respectively. Quantity of nutrients increased with age. Total nitrogen accumulation in 6-year-old stands at the three sites ranged from 212.9 to 279.5 kgha(-1) with a mean annual storage of 238.43 kgha(-1) and total K ranged from 170.8 to 220.5 kgha(-1) with a mean annual storage of 189.93 kgha(-1). Phosphorous accumulation was lowest with a mean storage of 16.75 kgha(-1). The organic carbon and nutrients in the soils improved significantly after 6 years of G. arborea planting. Soil organic carbon increased from 8.46 to 14.02 Mgha(-1) within 6 years. At soil depths 0-20 cm, 21-40 cm and 41-60 cm, available N enhanced by 14.85%, 11.98% and 11.25%, K by 10%, 9.13% and 10.63%, whereas phosphorous declined by 26%, 23% and 20%, respectively. At 6 years, G. arborea stands sequestered 31.37 Mgha(-1) carbon. The nutrient management strategies in relation to carbon accretion in G. arborea stands on degraded lateritic sites are discussed.

Nonequilibrium dynamics in the complex Ginzburg-Landau equation

Results from a comprehensive analytical and numerical study of nonequilibrium dynamics in the two-dimensional complex Ginzburg-Landau equation have been presented. In particular, spiral defects have been used to characterize the domain growth law and the evolution morphology. An asymptotic analysis of the single-spiral correlation function shows a sequence of singularities-analogous to those seen for time-dependent Ginzburg-Landau models with O(n) symmetry, where n is even.

Effect of intravenous contrast for left ventricular opacification and border definition on sensitivity and specificity of dobutamine stress echocardiography compared with coronary angiography in technically difficult patients

BACKGROUND

The study evaluates whether Optison used during dobutamine stress echocardiography (DSE) will improve endocardial border definition and whether this will translate to an improvement in sensitivity and specificity of the test in patients with poor echocardiographic windows. DSE is extremely valuable in the workup of patients with coronary artery disease. The test is limited in patients with suboptimal endocardial border visualization. Frequent studies have demonstrated improved endocardial border visualization with intravenous contrast agents at rest.

METHODS AND RESULTS

We studied 229 patients: 112 had good rest echocardiography with no contrast and 117 had poor rest echocardiography with Optison injection during DSE. Percentage of endocardial border visualization, wall thickening, sensitivity, and specificity were compared in both groups, as was interobserver variability. Both groups were matched with respect to age, percentage of previous myocardial infarctions, resting wall motion abnormality, percentage of coronary stenosis, and number of diseased coronary arteries. Optison significantly improved endocardial border visualization, especially at peak stress. The ability to measure wall thickening was significantly higher in the contrast DSE group with suboptimal images versus the noncontrast group with optimal images (89% ability to measure wall thickening vs 71%, P =.01). This resulted in a comparable sensitivity (79% vs 71%, P = not significant [NS]), specificity (76% vs 82%, P = NS), and diagnostic accuracy (80% vs 76%, P = NS). Agreement on test interpretation was higher among 3 observers in contrast DSE versus noncontrast DSE groups (79% vs 69%, P =.01).

CONCLUSIONS

In patients with poor echocardiographic windows, the use of Optison during DSE improves endocardial border visualization, which translates to a comparable sensitivity and specificity to noncontrast DSE tests in patients with good echocardiographic windows.

Kinetics of phase separation in ternary mixtures

We present detailed results from Monte Carlo simulations of the kinetics of phase separation in ternary mixtures. We focus on the case of ABV mixtures (where V denotes a vacancy) and investigate segregation kinetics resulting from V-mediated dynamics. We provide heuristic arguments for the existence of different morphologies in various parameter regimes. Furthermore, we present comprehensive numerical results for various characteristic features of the domain growth process, e.g., real-space correlation functions, domain-size distribution functions, and growth laws.

Nonequilibrium dynamics of the complex Ginzburg-Landau equation: analytical results

We present a detailed analytical and numerical study of nonequilibrium dynamics for the complex Ginzburg-Landau equation. In particular, we characterize evolution morphologies using spiral defects. This paper is the first in a two-stage exposition. Here, we present analytical results for the correlation function arising from a single-spiral morphology. We also critically examine the utility of the Gaussian auxiliary field ansatz in characterizing a multispiral morphology. In the next paper of this exposition we will present detailed numerical results.

Affluent adolescent girls of Delhi: eating and weight concerns

Despite a dramatic increase in research on eating-related pathologies, gaps remain in our understanding of the factors responsible for the development and maintenance of dysfunctional attitudes and behaviour related to weight and eating among adolescents. A study was therefore conducted to compare eating and weight concerns among underweight, normal-weight and obese affluent adolescent girls in New Delhi. The sample comprised fifty underweight, fifty normal-weight and thirty obese girls, 16-18 years of age. Information was collected about their body image perception, weight concerns and eating attitudes by a well-structured questionnaire. Dietary intake was determined by 24 h recall and a food-frequency questionnaire. Body size was adjudged by measurements of weight, height, waist, hip and mid upper arm circumferences, and the BMI and waist : hip ratio were determined. Of the subjects, 99.2 % had a gynoid pattern of fat distribution. Concerns about excess weight were prevalent among the adolescent girls, even among those who were normal-weight and underweight. The level of satisfaction with body size decreased with increase in weight. Dieting behaviour was reported in a higher number of obese (76.6 %) compared with normal-weight (38 %) and underweight (14 %) girls. Of the obese girls, 43.3 % were found to be at a significantly (P=0.00109) greater risk of developing anorexia in the future. Characteristic dietary features of adolescence, such as missing meals, snacking and eating out, were observed. While the diets of most of the subjects were adequate in Ca, thiamin, riboflavin and vitamin C, they were found to be deficient in energy, protein, Fe, niacin, vitamin A and fibre. Thus, it is important to recognize that weight concerns and dissatisfaction with body size may pose a threat to a healthy nutritional state, and may develop into precursors of a later eating disturbance.

For left ventricular opacification and endocardial border definition: is it really important which contrast agent we use, or is it the imaging modality we choose?

AIMS

The purpose of this study was to prospectively compare the effect of three imaging modalities (fundamental, harmonics, and power harmonics) on left ventricular opacification and endocardial border definition with two different echo agents, Optison and Albunex.

METHODS

A total of 84 patients who had suboptimal transthoracic images were studied with echo contrast agents Albunex (n=41) and Optison (n=43). Each contrast agent was examined with three different imaging modalities, fundamental, harmonics and power harmonics, respectively. Left ventricular opacification was obtained by videodensitometric analysis. Percentage of endocardial border visualization was determined by indexing circumference of visualized endocardium to total circumference. Variables were compared with respect to three imaging modalities between two different echo agents.

RESULTS

Higher videointensities and higher percentages of endocardial visualization were achieved with Optison compared to Albunex with fundamental and harmonics. However, there was no significant difference between Optison and Albunex with respect to LV opacification and border visualization by power harmonics.

CONCLUSION

These results indicate that left ventricular opacification and endocardial border visualization is significantly improved by using power harmonic imaging as compared to harmonics or fundamental imaging following both echo contrast agents. Furthermore, although Optison is clearly superior to Albunex in opacifying left ventricle, power harmonic imaging compensates for the less robust agent.

Kinetics of phase separation in polymer-solvent mixtures

We investigate the kinetics of phase separation in systems with a strong asymmetry in the mobility. This simple model system mimics the segregation kinetics of polymer-solvent mixtures, where the polymer-rich phase forms a low-mobility gel. We obtain detailed numerical results for this model, both without and with thermal noise. In the absence of thermal noise, we find that domain growth is slowed down drastically when the low-mobility phase percolates the system. However, thermal noise restores rapid domain growth through a Brownian coalescence mechanism.

Determination of vaporization enthalpies of polychlorinated biphenyls by correlation gas chromatography

The vaporization enthalpies of 16 polychlorinated biphenyls have been determined by correlation gas chromatography. This study was prompted by the realization that the vaporization enthalpy of the standard compounds used in previous studies, octadecane and eicosane, were values measured at 340 and 362 K, respectively, rather than at 298 K. Adjustment to 298 K amounts to a 7-8 kJ/mol increment in the values. With the inclusion of this adjustment, vaporization enthalpies evaluated by correlation gas chromatography are in good agreement with the values determined previously in the literature. The present results are based on the vaporization enthalpies of several standards whose values are well established in the literature. The standards include a variety of n-alkanes and various chlorinated hydrocarbons. The vaporization enthalpies of PCBs increased with the number of chlorine atoms and were found to be larger for meta- and para-substituted polychlorinated biphenyls.

Kinetics of domain growth in systems with local barriers

We study domain growth in spin-1 lattice models having nonconserved spin-flip kinetics with local barriers. Our primary motivation is to model the relaxational behavior of physical systems in which molecular motion is impeded by local kinetic barriers. The kinetic constraint is such that a spin from an up (down) state can flip to a down (up) state only via the zero state, which has a higher energy. We examine how the usual curvature-driven domain growth is affected by these local barriers, and whether the single-spin barriers have a collective effect. This paper presents comprehensive numerical results for phase ordering dynamics in this model using Monte Carlo simulations. We demonstrate dynamical scaling for domain-size distribution functions and spatial correlation functions. We also present results for the time dependence of characteristic length scales and autocorrelation functions. The length-scale behavior is interpreted in terms of the random walk of steps on domain boundaries. Furthermore, we present a simple stochastic model to derive an analytic expression for the autocorrelation function, which exhibits a stretched-exponential behavior over an extended regime-in agreement with our numerical simulations.

Surface-directed spinodal decomposition in binary fluid mixtures

We consider the phase separation of binary fluids in contact with a surface, which is preferentially wetted by one of the components of the mixture. We review the results available for this problem and present numerical results obtained using a mesoscopic level simulation technique for the three-dimensional problem.

Power laws and crossovers in off-critical surface-directed spinodal decomposition

We study the dynamics of phase separation in binary mixtures near a surface with a preferential attraction for one of the components of the mixture. We obtain detailed numerical results for a range of mixture compositions. In the case where the minority component is attracted to the surface, wetting layer growth is characterized by a crossover from a surface-potential-dependent growth law to a universal law. We formulate a simple phenomenological model to explain our numerical results.

Hysteresis effects in spin systems with quenched disorder

We present detailed numerical results for hysteresis effects in spin-glass systems. In particular, we focus on the dependence of hysteresis loop area on (a) disorder amplitude and (b) frequency of the applied magnetic field.

Tuberculous abdominal lymphadenopathy causing reversible renovascular hypertension

Renovascular hypertension is an important but not so common cause of hypertension. Rarely the extrinsic compression of renal arteries by retroperitoneal structures may be responsible for hypertension. Lymphadenopathy due to metastasis has been reported to cause renovascular hypertension. The present case reports hypertension which resulted from tubercular abdominal lymphadenopathy in a twenty one years male. The patient was treated with antitubercular medication with which his hypertension also got controlled. An unusual cause of hypertension and a rare complication of tuberculosis is reported.

Induction of tissue plasminogen activator secretion from rat heart microvascular cells by fM 1,25(OH)(2)D(3)

We investigated the effects of 1,25-dihydroxyvitamin D(3) [25(OH)(2)D(3)] on tissue plasminogen activator (tPA) secretion from primary cultures of rat heart microvascular cells. After an initial 5-day culture period, cells were treated for 24 h with 1,25(OH)(2)D(3) and several of its analogs. The results showed that 1,25(OH)(2)D(3) induced tPA secretion at 10(-10) to 10(-16) M. A less calcemic analog, Ro-25-8272, and an analog that binds the vitamin D receptor but is ineffective at perturbing Ca(2+) channels, Ro-24-5531, were approximately 10% as active as 1,25(OH)(2)D(3). An analog that binds the vitamin D receptor poorly but is an effective Ca(2+) channel agonist, Ro-24-2287, required approximately 10(-13) M to induce tPA secretion. Combinations of Ro-24-5531 and Ro-24-2287 were approximately as potent as 1,25(OH)(2)D(3). Treatment of the cells with BAY K 8644 or thapsigargin also increased tPA secretion, suggesting that increased cytosolic calcium concentration ([Ca(2+)]) induces tPA secretion. The results suggested that the sensitivity of the tPA secretory response of microvascular cells to 1,25(OH)(2)D(3) was due in part to generation of a vitamin D-depleted state in vitro and in part to synergistic effects of 1,25(OH)(2)D(3) on two different induction pathways of tPA release.

Abnormal coronary flow velocity reserve after coronary artery stenting in patients: role of relative coronary reserve to assess potential mechanisms

BACKGROUND

Absolute coronary flow velocity reserve (CVR) after stenting may remain abnormal as a result of several different mechanisms. Relative CVR (rCVR=CVR(target)/CVR(reference)) theoretically normalizes for global microcirculatory disturbances and facilitates interpretation of abnormal CVR.

METHODS AND RESULTS

To characterize potential mechanisms of poststent physiology, CVR was measured using a Doppler-tipped angioplasty guidewire in 55 patients before and after angioplasty, after stenting, and in an angiographically normal reference vessel. For the group, the percent diameter stenosis decreased from 75+/-13% to 40+/-18% after angioplasty and to 10+/-9% (all P<0.05) after stent placement. After angioplasty, CVR increased from 1.63+/-0.71 to 1.89+/-0.55 (P<0.05) and after stent placement, to 2.48+/-0.75 (P<0.05 versus pre- and postangioplasty). After angioplasty, rCVR increased from 0.64+/-0.26 to 0.75+/-0.23 and after stent placement to 1.00+/-0.34. In 17 patients with CVR(stent) < or = 2.0, increased basal coronary flow, rather than attenuated hyperemia, was responsible in large part for the lower CVR(stent) compared with patients having CVR(stent) >2.0. In 8 patients with CVR(stent) <2.0, a normal rCVR supported global microvascular disease. The subgroup of 9 patients with CVR(stent) <2.0 and abnormal rCVR (16% of the studied patients) may require a pressure-derived fractional flow reserve to differentiate persistent obstruction from diffuse atherosclerotic disease or microvascular stunning.

CONCLUSIONS

Although a majority of patients after stenting normalize CVR for the individual circulation (ie, normal CVR or normal rCVR), in those with impaired CVR(stent), the analysis of coronary flow dynamics suggests several different physiological mechanisms. Additional assessment may be required to fully characterize the physiological result for such patients to exclude remediable luminal abnormalities.

Disruption of the relationship between renin and atrial natriuretic peptide early in the course of ventricular dysfunction

BACKGROUND

Plasma renin activity is normal in left ventricular dysfunction in the absence of diuretic therapy. In health there is a reciprocal relationship between renin and atrial natriuretic peptide (ANP) but a positive correlation in advanced heart failure. The relationship between renin and ANP in mild left ventricular dysfunction is unknown.

METHODS AND RESULTS

Patients with left ventricular dysfunction (n = 35, 18 without diuretic therapy) were compared to 20 age-matched healthy subjects. Plasma concentrations of active renin (PARC), ANP and norepinephrine were measured after 20 min rest and 45 min after an infusion of normal saline (10 ml/kg body wt.). Basal plasma ANP was increased in patients with left ventricular dysfunction compared to healthy subjects, whether or not they were receiving diuretics. PARC was similar in healthy controls and patients untreated with diuretics but was increased in diuretic treated patients. After saline loading in healthy subjects PARC fell while ANP rose. Patients with left ventricular dysfunction had a smaller decline in PARC, that did not achieve statistical significance, but had a greater increase in plasma ANP compared to healthy subjects (P<0.05). The close reciprocal relationship between PARC and ANP observed in healthy subjects before and after saline loading (r = 0.8, P<0.001 and r = 0.6, P<0.01) was weakened in those not receiving diuretics (r = 0.4, P<0.05 and r = 0.24, ns) and lost in those receiving diuretics (r = 0.1 and r = 0.08).

CONCLUSIONS

Patients with left ventricular dysfunction have a disturbance of the normal reciprocal relationship between PARC and ANP which antedates diuretic treatment. This should be taken into account when interpreting plasma neuroendocrine measurements in patients with ventricular dysfunction.

Impaired pulmonary diffusion during exercise in patients with chronic heart failure

BACKGROUND

Pulmonary diffusion is impaired at rest in patients with chronic heart failure (CHF) and has been implicated in the generation of symptoms and exercise intolerance. The aim of this study was to determine whether pulmonary diffusion is impaired during exercise in CHF, to examine its relationship to pulmonary blood flow, and to consider its functional significance in relation to metabolic gas exchange.

METHODS AND RESULTS

Carbon monoxide transfer factor (TLCO) and pulmonary blood flow (Q(C)) were measured by a rebreathe technique at rest and during steady-state cycling at 30 W in 24 CHF patients and 10 control subjects. Both patients and control subjects were able to raise TLCO and Q(C) during exercise. However, the patient group had a lower diffusion for a given blood flow (TLCO/Q(C)) both at rest (3.6+/-0.16 and 4.8+/-0.23 mL x L(-1) x mm Hg(-1); P<0.001) and during exercise (2.8+/-0.16 and 3.4+/-0.13 mL x L(-1) x mm Hg(-1) for CHF patients and control subjects, respectively; P<0.05). TLCO/Q(C) was related to the ventilatory equivalent for carbon dioxide (VEVCO(2)) production at 30 W (TLCO/Q(c) versus VEVCO(2), r = -0.58, P<0.01) and to peak exercise oxygen consumption measured during a progressive test (TLCO/Qc versus VO(2peak), r = 0.57, P<0.01) in these patients.

CONCLUSIONS

Patients with CHF are able to recruit reserves of TLCO and Q(C) during exercise. However, the TLCO/Q(C) ratio is consistently impaired in these patients and relates to both exercise hyperpnea and peak exercise oxygen consumption. Whether this impairment in alveolar gas exchange is reversible in CHF and therefore is a potential target for therapy has yet to be determined.

Calcitonin inhibits anterior pituitary cell proliferation in the adult female rats

Previous studies have shown that CT-like immunoreactive peptide(s) (pit-CT) is synthesized by the anterior pituitary (AP) gland, and exogenously added salmon(s) CT inhibits PRL release and PRL gene transcription in cultured AP cells. Anti-sCT serum, which immunoreacts with pit-CT, stimulates PRL secretion, suggesting pit-CT is a physiologically relevant PRL-inhibiting hormone. Using proliferating cell nuclear antigen (PCNA) staining and 5-bromo-2'deoxyuridine (BrdU) incorporation into newly replicated DNA, the effect of calcitonin (CT) on cellular proliferation in the rat anterior pituitary gland (AP) was examined. CT significantly attenuated PCNA-immunopositive as well as BrdU-positive AP cell populations in dispersed rat AP cells. A second series of experiments tested the effects of CT on AP cell proliferation in vivo. OVX + E2 rats were injected with 200 microg CT (iv), the rats killed at various time points, and the APs were processed for BrdU staining. CT inhibited BrdU incorporation at all time points up to 15 h after the injection, and this inhibitory effect was reversed at later time points. The effect of CT was concentration dependent, and a maximal inhibition was observed 10 h after the CT injection. Subsequent experiments identified CT-responsive AP cell populations using double immunofluorescence for BrdU and either PRL or FSH. The number of BrdU-labeled lactotropes in the AP gland declined by 74% in the CT-treated rats. Neutralization of endogenous pit-CT by passive immunization with anti-sCT serum caused a 2-fold increase in AP cell proliferation. These results suggest an important role for the endogenous pit-CT in regulation of lactotrope population of the AP gland.

Hereditary pancreatitis

Hereditary pancreatitis is a rare cause of chronic pancreatitis and has been mainly reported in western literature. It is inherited in an autosomal dominant manner. In this report, we present our data on two affected members in a family from Punjab, North India.

Acute saline infusion reduces alveolar-capillary membrane conductance and increases airflow obstruction in patients with left ventricular dysfunction

BACKGROUND

Impaired alveolar-capillary membrane conductance is the major cause for the reduction in pulmonary diffusing capacity for carbon monoxide (DLCO) in heart failure. Whether this reduction is fixed, reflecting pulmonary microvascular damage, or is variable is unknown. The aim of this study was to assess whether DLCO and its subdivisions, alveolar-capillary membrane conductance (DM) and pulmonary capillary blood volume (Vc), were sensitive to changes in intravascular volume. In addition, we examined the effects of volume loading on airflow rates.

METHODS AND RESULTS

Ten patients with left ventricular dysfunction (LVD) and 8 healthy volunteers were studied. DM and Vc were determined by the Roughton and Forster method. The forced expiratory volume in 1 second (FEV1), vital capacity, and peak expiratory flow rates (PEFR) were also recorded. In patients with LVD, infusion of 10 mL. kg-1 body wt of 0.9% saline acutely reduced DM (12.0+/-3.3 versus 10.4+/-3.5 mmol. min-1. kPa-1, P<0.005), FEV1 (2.3+/-0.4 versus 2.1+/-0.4 L, P<0.0005), and PEFR (446+/-55 versus 414+/-56 L. min-1, P<0.005). All pulmonary function tests had returned to baseline values 24 hours later. In normal subjects, saline infusion had no measurable effect on lung function.

CONCLUSIONS

Acute intravascular volume expansion impairs alveolar-capillary membrane function and increases airflow obstruction in patients with LVD but not in normal subjects. Thus, the abnormalities of pulmonary diffusion in heart failure, which were believed to be fixed, also have a variable component that could be amenable to therapeutic intervention.

Prospective study of outcome in antenatally diagnosed renal pelvis dilatation

AIMS

To ascertain the outcome associated with antenatal renal pelvis dilatation; to recommend guidelines for postnatal investigation and determine an upper limit of normal for the anterioposterior dimensions of the fetal renal pelvis.

METHODS

Infants whose antenatal ultrasound scan showed a fetal renal pelvis of 5 mm or greater were investigated using postnatal renal tract ultrasound and a micturating cystogram. Isotope studies were also performed, where appropriate.

RESULTS

Vesicoureteric reflux (VUR), the most common diagnosis, was evident in 23/104 (22%). In 14 infants with VUR the postnatal ultrasound scan was normal. There was no evidence of renal scarring or dysplasia in any of the refluxing kidneys. Other diagnoses were pelviureteric junction obstruction, renal dysplasia, and idiopathic dilatation. Antenatal counselling and parental information facilitated postnatal assessment.

CONCLUSIONS

Infants with antenatal renal pelvis measurements of 5 mm or greater should be investigated postnatally, as a significant percentage will have VUR. A normal postnatal ultrasound scan does not preclude the presence of VUR.