Poverty - dynamic and sustainability perspectives: Implications for welfare and policy with reference to India

After outlining some comparative features of poverty in India, this article reviews critically recent literature on the dynamics of poverty. On economic efficiency grounds, it rejects the view that the chronically poor are more deserving than the non-chronic poor of poverty assistance. Mechanisms of households and communities for coping with poverty are discussed. The possibility is raised that where poverty has been persistent that rational methods for coping with it are likely to be well established, and less suffering may occur than for households and communities thrown temporarily into poverty. However, situations can also be envisaged where such rational behaviours deepen the poverty trap and create unfavourable externalities for poverty alleviation. Conflict can arise between programmes to alleviate poverty in poor communities and the sustainability of these communities and their local cultures. Problems posed by this are discussed. Furthermore, the impact of market extension on poor landholders is considered. In contrast to the prevailing view that increased market extension and liberalisation is favourable to poor farmers, it is argued that inescapable market transaction cost makes it difficult for the poor to survive as landholders in a fluid and changing market system. The likelihood of poor landholders joining the landless poor rises, and if they migrate from the countryside to the city they face further adjustment hurdles. Consequently, poor landholders may be poorer after the extension of the market system and only their offspring may reap benefits from market reforms.

What role does knowledge of wildlife play in providing support for species' conservation?

Conservation of biodiversity is a complex issue. Apart from the creation of nature reserves, there is a plethora of other factors that are part of this complex web. One such factor is the public knowledge of species. Since public funding is imperative for the conservation of species and creation of reserves for them it is important to determine the public’s awareness of species and their knowledge about them. In the absence of such awareness and knowledge, it is possible that the public may misallocate their support. In other words, resources may be provided for species that do not need support urgently. We show how availability of balanced information about species helps the public to make rational decisions and to allocate support (e.g. monetary) to species that need it most. Other implications of a ‘wildlife knowledgeable’ public are also discussed.

Pharmacokinetics of ingested fluoride: Lack of effect of chemical compound

Fluoride in drinking water may be present from natural sources or added as sodium fluoride (NaF), sodium silicofluoride (Na2SiF6) or fluorosilicic acid (H2SiF6). Results from an early study with rats suggested that, when ingested as Na2SiF6, the absorption and excretion of fluoride were greater than when ingested as NaF. Objective: The present single-blind, crossover study with 10 adults was done to determine three key pharmacokinetic parameters: the maximum plasma fluoride concentrations (C-max), the elapsed time to reach the maximum concentrations (T-max) and the 6-h areas under the time-plasma concentration curves (AUCs) after ingestion of 500 ml, of water containing 0.67 or 5.45 mg F/L present naturally or added as NaF or H2SiF6. Design: Blood was collected prior to and at nine time points during 6 h after ingestion of the test solutions. Plasma was analysed by electrode after HMDS-facilitated diffusion and the data were analysed for statistically significant differences using repeated measures ANOVA. Results: The C-max, T-max and AUC values after ingestion of the solutions containing natural fluoride, NaF or H2SiF6 did not differ significantly at either dose level. Further, the Tmax values associated with the 0.67 and SAS mg/L solutions did not differ significantly indicating that the absorption, distribution and elimination rates were not affected by the dose size. Conclusions: Considered together with published reports, the present findings support the conclusion that the major features of fluoride metabolism are not affected differently by the chemical compounds commonly used to fluoridate water nor are they affected by whether the fluoride is present naturally or added artificially. (C) 2008 Elsevier Ltd. All rights reserved.

The 434(G > C) polymorphism in the eosinophil cationic protein gene and its association with tissue eosinophilia in oral squamous cell carcinomas

Objective: The aim of this study was to investigate the prevalence of the Eosinophil cationic protein (ECP)-gene polymorphism 434(G > C) in oral squamous cell carcinoma (OSCC) patients and its association with tumor-associated tissue eosinophilia (TATE), demographic, clinical, and microscopic variables. Methods: The ECP genotypes of 165 healthy individuals and 157 OSCC patients were detected by PCR-RFLP analysis after cleavage of the amplified DNA sequence with enzyme PstI. TATE was obtained by morphometric analysis. Chi-square test or Fisher`s exact test was used to analyze the association of ECP-gene polymorphism 434(G > C) with TATE, demographic, clinical, and microscopic variables in OSCC patients. Disease-free survival and overall survival were calculated by the Kaplan-Meier product-limit actuarial method and the comparison of the survival curves were performed using log rank test. Results: Most of healthy individuals (53.33%) and OSCC patients (57.97%) were heterozygous for the ECP 434(G > C) polymorphism. Based on numerical differences, our results showed that OSCC patients with intense TATE and at least one C allele had a higher frequency of bilateral neck dissection, local recurrence, vascular embolization, involved resection margins, and postoperative radiotherapy. No statistically significant differences on survival rates were found in OSCC patients presenting different ECP 434(G > C) genotypes. Conclusions: These results suggest a tendency towards a poor clinical outcome in OSCC patients with intense TATE and 434GC/CC genotypes, probably due to an ECP genetic variant with altered cytotoxic activity.

Monolithic CAD/CAM Lithium Disilicate Versus Veneered Y-TZP Crowns: Comparison of Failure Modes and Reliability After Fatigue

Purpose: The aim of this research was to evaluate the fatigue behavior and reliability of monolithic computer-aided design/computer-assisted manufacture (CAD/CAM) lithium disilicate and hand-layer-veneered zirconia all-ceramic crowns. Materials and Methods: A CAD-based mandibular molar crown preparation, fabricated using rapid prototyping, served as the master die. Fully anatomically shaped monolithic lithium disilicate crowns (IPS e.max CAD, n = 19) and hand-layer-veneered zirconia-based crowns (IPS e.max ZirCAD/Ceram, n = 21) were designed and milled using a CAD/CAM system. Crowns were cemented on aged dentinlike composite dies with resin cement. Crowns were exposed to mouth-motion fatigue by sliding a WC-indenter (r = 3.18 mm) 0.7 mm lingually down the distobuccal cusp using three different step-stress profiles until failure occurred. Failure was designated as a large chip or fracture through the crown. If no failures occurred at high loads (> 900 N), the test method was changed to staircase r ratio fatigue. Stress level probability curves and reliability were calculated. Results: Hand-layer-veneered zirconia crowns revealed veneer chipping and had a reliability of < 0.01 (0.03 to 0.00, two-sided 90% confidence bounds) for a mission of 100,000 cycles and a 200-N load. None of the fully anatomically shaped CAD/CAM-fabricated monolithic lithium disilicate crowns failed during step-stress mouth-motion fatigue (180,000 cycles, 900 N). CAD/CAM lithium disilicate crowns also survived r ratio fatigue (1,000,000 cycles, 100 to 1,000 N). There appears to be a threshold for damage/bulk fracture for the lithium disilicate ceramic in the range of 1,100 to 1,200 N. Conclusion: Based on present fatigue findings, the application of CAD/CAM lithium disilicate ceramic in a monolithic/fully anatomical configuration resulted in fatigue-resistant crowns, whereas hand-layer-veneered zirconia crowns revealed a high susceptibility to mouth-motion cyclic loading with early veneer failures. Int J Prosthodont 2010; 23: 434-442.

Fatigue and damage accumulation of veneer porcelain pressed on Y-TZP

Objectives: This study compared the reliability and fracture patterns of zirconia cores veneered with pressable porcelain submitted to either axial or off-axis sliding contact fatigue. Methods: Forty-two Y-TZP plates (12 mm x 12 mm x 0.5 mm) veneered with pressable porcelain (12 mm x 12 mm x 1.2 mm) and adhesively luted to water aged composite resin blocks (12 mm x 12 mm x 4 mm) were stored in water at least 7 days prior to testing. Profiles for step-stress fatigue (ratio 3:2:1) were determined from single load to fracture tests (n = 3). Fatigue loading was delivered on specimen either on axial (n = 18) or off-axis 30 degrees angulation (n = 18) to simulate posterior tooth cusp inclination creating a 0.7 mm slide. Single load and fatigue tests utilized a 6.25 mm diameter WC indenter. Specimens were inspected by means of polarized-light microscope and SEM. Use level probability Weibull curves were plotted with 2-sided 90% confidence bounds (CB) and reliability for missions of 50,000 cycles at 200 N (90% CB) were calculated. Results: The calculated Weibull Beta was 3.34 and 2.47 for axial and off-axis groups, respectively, indicating that fatigue accelerated failure in both loading modes. The reliability data for a mission of 50,000 cycles at 200 N load with 90% CB indicates no difference between loading groups. Deep penetrating cone cracks reaching the core-veneer interface were observed in both groups. Partial cones due to the sliding component were observed along with the cone cracking for the off-axis group. No Y-TZP core fractures were observed. Conclusions: Reliability was not significantly different between axial and off-axis mouth-motion fatigued pressed over Y-TZP cores, but incorporation of sliding resulted in more aggressive damage on the veneer. (C) 2009 Elsevier Ltd. All rights reserved.

Thermal/mechanical simulation and laboratory fatigue testing of an alternative yttria tetragonal zirconia polycrystal core-veneer all-ceramic layered crown design

This study evaluated the stress levels at the core layer and the veneer layer of zirconia crowns (comprising an alternative core design vs. a standard core design) under mechanical/thermal simulation, and subjected simulated models to laboratory mouth-motion fatigue. The dimensions of a mandibular first molar were imported into computer-aided design (CAD) software and a tooth preparation was modeled. A crown was designed using the space between the original tooth and the prepared tooth. The alternative core presented an additional lingual shoulder that lowered the veneer bulk of the cusps. Finite element analyses evaluated the residual maximum principal stresses fields at the core and veneer of both designs under loading and when cooled from 900 degrees C to 25 degrees C. Crowns were fabricated and mouth-motion fatigued, generating master Weibull curves and reliability data. Thermal modeling showed low residual stress fields throughout the bulk of the cusps for both groups. Mechanical simulation depicted a shift in stress levels to the core of the alternative design compared with the standard design. Significantly higher reliability was found for the alternative core. Regardless of the alternative configuration, thermal and mechanical computer simulations showed stress in the alternative core design comparable and higher to that of the standard configuration, respectively. Such a mechanical scenario probably led to the higher reliability of the alternative design under fatigue.

Effect of framework design on crown failure

This study evaluated the effect of core-design modification on the characteristic strength and failure modes of glass-infiltrated alumina (In-Ceram) (ICA) compared with porcelain fused to metal (PFM). Premolar crowns of a standard design (PFMs and ICAs) or with a modified framework design (PFMm and ICAm) were fabricated, cemented on dies, and loaded until failure. The crowns were loaded at 0.5 mm min(-1) using a 6.25 mm tungsten-carbide ball at the central fossa. Fracture load values were recorded and fracture analysis of representative samples were evaluated using scanning electron microscopy. Probability Weibull curves with two-sided 90% confidence limits were calculated for each group and a contour plot of the characteristic strength was obtained. Design modification showed an increase in the characteristic strength of the PFMm and ICAm groups, with PFM groups showing higher characteristic strength than ICA groups. The PFMm group showed the highest characteristic strength among all groups. Fracture modes of PFMs and of PFMm frequently reached the core interface at the lingual cusp, whereas ICA exhibited bulk fracture through the alumina core. Core-design modification significantly improved the characteristic strength for PFM and for ICA. The PFM groups demonstrated higher characteristic strength than both ICA groups combined.

Reliability of Metalloceramic and Zirconia-based Ceramic Crowns

Despite the increasing utilization of all-ceramic crown systems, their mechanical performance relative to that of metal ceramic restorations (MCR) has yet to be determined. This investigation tested the hypothesis that MCR present higher reliability over two Y-TZP all-ceramic crown systems under mouth-motion fatigue conditions. A CAD-based tooth preparation with the average dimensions of a mandibular first molar was used as a master die to fabricate all restorations. One 0.5-mm Pd-Ag and two Y-TZP system cores were veneered with 1.5 mm porcelain. Crowns were cemented onto aged (60 days in water) composite (Z100, 3M/ESPE) reproductions of the die. Mouth-motion fatigue was performed, and use level probability Weibull curves were determined. Failure modes of all systems included chipping or fracture of the porcelain veneer initiating at the indentation site. Fatigue was an acceleration factor for all-ceramic systems, but not for the MCR system. The latter presented significantly higher reliability under mouth-motion cyclic mechanical testing.

Nanoscale Oxidative Patterning of Metallic Surfaces to Modulate Cell Activity and Fate

In the field of regenerative medicine, nanoscale physical cuing is clearly becoming a compelling determinant of cell behavior. Developing effective methods for making nanostructured surfaces with well-defined physicochemical properties is thus mandatory for the rational design of functional biomaterials. Here, we demonstrate the versatility of simple chemical oxidative patterning to create unique nanotopographical surfaces that influence the behavior of various cell types, modulate the expression of key determinants of cell activity, and offer the potential of harnessing the power of stem cells. These findings promise to lead to a new generation of improved metal implants with intelligent surfaces that can control biological response at the site of healing.

Selective down-regulation of the astrocyte glutamate transporters GLT-1 and GLAST within the medial thalamus in experimental wernicke's encephalopathy

Although earlier studies on thiamine deficiency have reported increases in extracellular glutamate concentration in the thalamus, a vulnerable region of the brain in this disorder, the mechanism by which this occurs has remained unresolved. Treatment with pyrithiamine, a central thiamine antagonist, resulted in a 71 and 55% decrease in protein levels of the astrocyte glutamate transporters GLT-1 and GLAST, respectively, by immunoblotting in the medial thalamus of day 14 symptomatic rats at loss of righting reflexes. These changes occurred prior to the onset of convulsions and pannecrosis. Loss of both GLT-1 and GLAST transporter sites was also confirmed in this region of the thalamus at the symptomatic stage using immunohistochemical methods. In contrast, no change in either transporter protein was detected in the non-vulnerable frontal parietal cortex. These effects are selective; protein levels of the astrocyte GABA transporter GAT-3 were unaffected in the medial thalamus. In addition, astrocyte-specific glial fibrillary acidic protein (GFAP) content was unchanged in this brain region, suggesting that astrocytes are spared in this disorder. Loss of GLT-1 or GLAST protein was not observed on day 12 of treatment, indicating that down-regulation of these transporters occurs within 48 h prior to loss of righting reflexes. Finally, GLT-1 content was positively correlated with levels of the neurofilament protein alpha -internexin, suggesting that early neuronal drop-out may contribute to the down-regulation of this glutamate transporter and subsequent pannecrosis. A selective, focal loss of GLT-1 and GLAST transporter proteins provides a rational explanation for the increase in interstitial glutamate levels, and may play a major role in the selective vulnerability of thalamic structures to thiamine deficiency-induced cell death.

Binding and functional studies with the growth hormone receptor antagonist, B2036-PEG (pegvisomant), reveal effects of pegylation and evidence that it binds to a receptor dimers

GH actions are dependent on receptor dimerization. The GH receptor antagonist, B2036-PEG, has been developed for treating acromegaly. B2036 has mutations in site 1 to enhance receptor binding and in site 2 to block receptor dimerization. Pegylation (B2036-PEG) increases half-life and lowers immunogenicity, but high concentrations are required to control insulin-like growth factor-I levels. We examined antagonist structure and function and the impact of pegylation on biological efficacy. Unpegylated B2036 had a 4.5-fold greater affinity for GH binding protein (GHBP) than GH but similar affinity for membrane receptor. Pegylation substantially reduced membrane binding affinity and receptor antagonism, as assessed by a transcription assay, by 39- and 20-fold, respectively. GHBP reduced antagonist activity of unpegylated B2036 but did not effect antagonism by B2036-PEG. B2036 down-regulated receptors, and membrane binding sites doubled in the presence of dimerization-blocking antibodies, suggesting that B2036 binds to a receptor dimer. It is concluded that the high concentration requirement of B2036-PEG for clinical efficacy relates to pegylation, which decreases binding to membrane receptor but has the advantages of reduced clearance, immunogenicity, and interactions with GHBP. Our studies suggest that B2036 binds to a receptor dimer and induces internalization but not signaling.

Vascular smooth muscle relaxation mediated by nitric oxide donors: a comparison with acetylcholine, nitric oxide and nitroxyl ion

I Vasorelaxant properties of three nitric oxide (NO) donor drugs (glyceryl trinitrate, sodium nitroprusside and spermine NONOate) in mouse aorta (phenylephrine pre-contracted) were compared with those of endothelium-derived NO (generated with acetylcholine), NO free radical (NO; NO gas solution) and nitroxyl ion (NO-; from Angeli's salt). 2 The soluble guanylate cyclase inhibitor, ODQ (1H-(1,2,4-)oxadiazolo(4,3-a)-quinoxalin-1-one; 0.3, 1 and 10 muM), concentration-dependently inhibited responses to all agents. 10 muM ODQ abolished responses to acetylcholine and glyceryl trinitrate, almost abolished responses to sodium nitroprusside but produced parallel shifts (to a higher concentration range; no depression in maxima) in the concentration-response curves for NO gas solution, Angeli's salt and spermine NONOate. 3 The NO scavengers, carboxy-PTIO, (2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-indazoline-1-oxyl-3-oxide; 100 muM) and hydroxocobalamin (100 muM), both inhibited responses to NO gas solution and to the three NO donor drugs, but not Angeli's salt. Hydroxocobalamin, but not carboxy-PTIO, also inhibited responses to acetylcholine. 4 The NO- inhibitor, L-cysteine (3 mm), inhibited responses to Angeli's salt, acetylcholine and the three NO donor drugs, but not NO gas solution. 5 The data suggest that, in mouse aorta, responses to all three NO donors involve (i) activation of soluble guanylate cyclase, but to differing degrees and (ii) generation of both NO and NO-. Glyceryl trinitrate and sodium nitroprusside, which generate NO following tissue bioactivation, have profiles resembling the profile of endothelium-derived NO more than that of exogenous NO. Spermine NONOate, which generates NO spontaneously outside the tissue, was the drug that most closely resembled (but was not identical to) exogenous NO.

Familial hyperaldosteronism

Primary aldosteronism (PAL) may be as much as ten times more common than has been traditionally thought, with most patients normokalemic. The study of familial varieties has facilitated a fuller appreciation of the nature and diversity of its clinical, biochemical, morphological and molecular aspects. In familial hyperaldosteronism type I (FH-I), glucocorticoid-remediable PAL is caused by inheritance of an ACTH-regulated, hybrid CYP11B1/CYP11B2 gene. Genetic testing has greatly facilitated diagnosis. Hypertension severity varies widely, demonstrating relationships with gender, affected parent's gender, urinary kallikrein level, degree of biochemical disturbance and hybrid gene crossover point position. Analyses of aldosterone/PRA/cortisol 'day-curves' have revealed that (1) the hybrid gene dominates over wild type CYP11B2 in terms of aldosterone regulation and (2) correction of hypertension in FH-I requires only partial suppression of ACTH, and much smaller glucocorticoid doses than those previously recommended. Familial hyperaldosteronism type II is not glucocorticoid-remediable, and is clinically, biochemically and morphologically indistinguishable from apparently sporadic PAL. In one informative family available for linkage analysis, FH-II does not segregate with either the CYP11B2, AT1 or MEN1 genes, but a genome-wide search has revealed linkage with a locus in chromosome 7. As has already occurred in FH-I, elucidation of causative mutations is likely to facilitate earlier detection of PAL and other curable or specifically treatable forms of hypertension. (C) 2001 Elsevier Science Ltd. All rights reserved.

Quantitative analysis of the time courses of enzyme-catalyzed reactions

The catalytic properties of enzymes are usually evaluated by measuring and analyzing reaction rates. However, analyzing the complete time course can be advantageous because it contains additional information about the properties of the enzyme. Moreover, for systems that are not at steady state, the analysis of time courses is the preferred method. One of the major barriers to the wide application of time courses is that it may be computationally more difficult to extract information from these experiments. Here the basic approach to analyzing time courses is described, together with some examples of the essential computer code to implement these analyses. A general method that can be applied to both steady state and non-steady-state systems is recommended. (C) 2001 academic Press.