bluuebunny/crossref_metadata_2025 huggingface dataset:
Contact lenses: GP guide to choice and the complications
Authors: Terry Patsy
Published: June 2009

Patsy Terry describes the properties of the various contact lenses available and how to manage the complications that can arise with lens wear. Copyright © 2009 Wiley Interface Ltd
Inversion layer electron transport in 4H‐SiC metal–oxide–semiconductor field‐effect transistors
Authors: Tilak Vinayak
Published: June 2009

Silicon carbide is the only compound semiconductor with silicon dioxide as its native oxide and can form metal–oxide–semiconductor field‐effect transistors. In this article, we review the inversion layer electron transport properties of 4H‐SiC/SiO2. The inversion layer electron transport theories developed for the Si/SiO2 system have been reviewed to highlight the behaviour of inversion layer electrons at an ideal interface. The 4H‐SiC/SiO2 interface, is currently far from ideal and so we discuss the inversion layer electron transport for several techniques of oxidation of the (0001) 4H‐SiC including nitridation of thermal oxides and sodium enhanced oxidation of 4H‐SiC. Inversion layer mobility of nitrided oxides is dominated by Coulomb scattering at low surface electric field values and surface roughness scattering at high surface electric field values. In sodium enhanced oxidation samples no trapped charge is found at the interface close to the conduction band edge, but the temperature dependence of mobility shows that the samples are not limited by phonon scattering and therefore not ideal. We also review the results of inversion layer transport on alternate faces of 4H‐SiC. We conclude highlighting the future work remaining in the field and the behaviour of inversion layer electron mobility we expect to see in an ideal 4H‐SiC/SiO2 interface. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Two alternative implementations of the ensemble‐transform (ET) analysis‐perturbation scheme: The ET with extended cycling intervals, and the ET without cycling
Authors: McLay Justin , Reynolds Carolyn A.
Published: June 2009

Four alternative approximate bases for the ensemble transform (ET) are obtained by extending the cycling interval to 24, 48, 72 and 96 h. Another alternative basis is obtained by foregoing cycling and instead drawing randomly generated perturbations from an archive. Experiments based upon 16‐member global ensembles and a diagonal estimate of analysis‐error covariance indicate that the alternative bases are effective at reducing the discrepancy between the ET analysis‐perturbation variance and the estimated analysis‐error variance. Forecast ensembles associated with the alternative bases maintain considerably more energy in the tropics and subtropics than the forecast ensemble associated with the original basis. Forecast ensembles associated with the alternative bases also outperform the original forecast ensemble in terms of the ensemble forecast‐error covariance‐matrix eigenvalue spectrum, the relationship between ensemble variance and observed squared error and the Brier score. The performance gains facilitated by the alternative approximate bases are substantial in some instances, especially in the tropics. The randomly sampled basis is superior to the original basis in most respects. Published in 2009 by John Wiley & Sons, Ltd.
Covariance regularization in inverse space
Authors: Ueno Genta , Tsuchiya Takashi
Published: June 2009

In data assimilation, covariance matrices are introduced in order to prescribe the weights of the initial state, model dynamics, and observation, and suitable specification of the covariances is known to be essential for obtaining sensible state estimates. The covariance matrices are specified by sample covariances and are converted according to an assumed covariance structure. Modelling of the covariance structure consists of the regularization of a sample covariance and the constraint of a dynamic relationship. Regularization is required for converting the singular sample covariance into a non‐singular sample covariance, removing spurious correlation between variables at distant points, and reducing the required number of parameters that specify the covariances. In previous studies, regularization of sample covariances has been carried out in physical (grid) space, spectral space, and wavelet space. We herein propose a method for covariance regularization in inverse space, in which we use the covariance selection model (the Gaussian graphical model). For each variable, we assume neighbouring variables, i.e. a targeted variable is directly related to its neighbours and is conditionally independent of the non‐neighbouring variables. Conditional independence is expressed by specifying zero elements in the inverse covariance matrix. The non‐zero elements are estimated numerically by the maximum likelihood using Newton's method. Appropriate neighbours can be selected with the AIC or BIC information criteria. We address some techniques for implementation when the covariance matrix has a large dimension. We present an illustrative example using a simple 3 × 3 matrix and an application to a sample covariance obtained from sea‐surface height observations. Copyright © 2009 Royal Meteorological Society
Temperature‐dependent release of volatile organic compounds of eucalypts by direct analysis in real time (DART) mass spectrometry
Authors: Maleknia Simin D. , Vail Teresa M. , Cody Robert B. , Sparkman David O. , Bell Tina L. , Adams Mark A.
Published: June 2009

A method is described for the rapid identification of biogenic, volatile organic compounds (VOCs) emitted by plants, including the analysis of the temperature dependence of those emissions. Direct analysis in real time (DART) enabled ionization of VOCs from stem and leaf of several eucalyptus species including E. cinerea, E. citriodora, E. nicholii and E. sideroxylon. Plant tissues were placed directly in the gap between the DART ionization source skimmer and the capillary inlet of the time‐of‐flight (TOF) mass spectrometer. Temperature‐dependent emission of VOCs was achieved by adjusting the temperature of the helium gas into the DART ionization source at 50, 100, 200 and 300°C, which enabled direct evaporation of compounds, up to the onset of pyrolysis of plant fibres (i.e. cellulose and lignin). Accurate mass measurements facilitated by TOF mass spectrometry provided elemental compositions for the VOCs. A wide range of compounds was detected from simple organic compounds (i.e. methanol and acetone) to a series of monoterpenes (i.e. pinene, camphene, cymene, eucalyptol) common to many plant species, as well as several less abundant sesquiterpenes and flavonoids (i.e. naringenin, spathulenol, eucalyptin) with antioxidant and antimicrobial properties. The leaf and stem tissues for all four eucalypt species showed similar compounds. The relative abundances of methanol and ethanol were greater in stem wood than in leaf tissue suggesting that DART could be used to investigate the tissue‐specific transport and emissions of VOCs. Copyright © 2009 John Wiley & Sons, Ltd.
Semi‐quantitative and structural metabolic phenotyping by direct infusion ion trap mass spectrometry and its application in genetical metabolomics
Authors: Koulman Albert , Cao Mingshu , Faville Marty , Lane Geoff , Mace Wade , Rasmussen Susanne
Published: June 2009

The identification of quantitative trait loci (QTL) for plant metabolites requires the quantitation of these metabolites across a large range of progeny. We developed a rapid metabolic profiling method using both untargeted and targeted direct infusion tandem mass spectrometry (DIMSMS) with a linear ion trap mass spectrometer yielding sufficient precision and accuracy for the quantification of a large number of metabolites in a high‐throughput environment. The untargeted DIMSMS method uses top‐down data‐dependent fragmentation yielding MS2 and MS3 spectra. We have developed software tools to assess the structural homogeneity of the MS2 and MS3 spectra hence their utility for phenotyping and genetical metabolomics. In addition we used a targeted DIMS(MS) method for rapid quantitation of specific compounds. This method was compared with targeted LC/MS/MS methods for these compounds. The DIMSMS methods showed sufficient precision and accuracy for QTL discovery. We phenotyped 200 individual Lolium perenne genotypes from a mapping population harvested in two consecutive years. Computational and statistical analyses identified 246 nominal m/z bins with sufficient precision and homogeneity for QTL discovery. Comparison of the data for specific metabolites obtained by DIMSMS with the results from targeted LC/MS/MS analysis showed that quantitation by this metabolic profiling method is reasonably accurate. Of the top 100 MS1 bins, 22 ions gave one or more reproducible QTL across the 2 years. Copyright © 2009 John Wiley & Sons, Ltd.
Long term outcome of organic acidurias: Survey of 105 French cases (1967–1983)
Authors: Rousson R. , Guibaud P.
Published: June 2009

The French experience in the long term follow‐up of 105 cases of organic aciduria (45 maple syrup urine disease, 12 isovaleric acidaemia, 19 propionic acidaemia, 24 methylmalonic aciduria and some rare allied disorders) is reported. Main conclusions drawn from this survey are the poor overall prognosis and the slow improvement in the outcome of such disorders over the last 15 years. In MSUD, while early diagnosis and early management remain a basic requirement, intellectual development did not improve as much as expected. In propionic and methylmalonic acidaemia modern treatment does not prevent a fatal outcome in the classical neonatal forms. It should be also emphasized that in the rare cases where a coenzyme deficiency has been demonstrated, vitamin therapy is very often ineffectivein vivo.
The management and long term outcome of organic acidaemias
Authors: Leonard J. V. , Daish P. , Naughten E. R. , Bartlett K.
Published: June 2009

We review the outcome of patients with maple syrup urine disease (14 classical patients and three variants), biotinidase deficiency (two patients) and non‐cofactor‐responsive variants of methylmalonic acidaemia (eight patients), propionic acidaemia (eight patients) and isolated 3‐methylcrotonyl CoA carboxylase deficiency (three patients). Their survival, growth, intellectual development and other clinical problems are analysed. With the exception of isolated 3‐methylcrotonyl CoA carboxylase deficiency the outcome of patients with disorders that are not cofactor responsive is disappointing. Twelve patients have died (five maple syrup urine disease, two methylmalonic acidaemia, five propionic acidaemia) and many of the survivors are developmentally retarded. The outlook is worst for patients with propionic acidaemia presenting in the neonatal period but a good outcome is possible for patients with maple syrup urine disease if the diagnosis is made early.
Glutaric acidaemia type II (multiple Acyl‐Coa dehydrogenation deficiency)
Authors: Goodman S. I. , Frerman F. E.
Published: June 2009

The clinical and biochemical phenotype of glutaric acidaemia type II (GAII) has led to the suggestion that the defect in the disorder affects electron transfer from primary FAD‐containing dehydrogenases into the respiratory chain. Two proteins are involved in this process, i.e. electron transfer flavoprotein (ETF) and ETF dehydrogenase, an iron‐sulphur flavoprotein with a distinctive EPR signal. Reliable catalytic assays for these proteins are not available, but both proteins have been purified and antisera against them prepared in rabbits.

SDS‐PAG electrophoresis of liver mitochondrial membranes from a GAII infant with congenital anomalies, locating ETF dehydrogenase with specific antiserum, showed no cross‐reactive material. EPR of the same membranes showed a marked decrease in the ETF dehydrogenase signal. These results suggest that the defect in GAII in some patients is indeed in electron transport, and specifically in ETF dehydrogenase.
The differential diagnosis of dicarboxylic aciduria
Authors: Duran M. , De Klerk J. B. C. , Wadman S. K. , Bruinvis L. , Ketting D.
Published: June 2009

Various types of dicarboxylic aciduria are known, most of them are accompanied by non‐ketotic hypoglycaemia. For the differential diagnosis of these conditions several methods of investigation have been used: (1) analysis of urinary organic acids in both native and hydrolysed samples, (2) analysis of free and esterified carnitine, the latter by means of chromatographic separation and identification of acyl moieties, (3) analysis of plasma organic acids, including the so‐called free fatty acids, (4) a prolonged fasting test with serial measurements of the aforementioned parameters and close monitoring of the blood glucose and (5) an oral loading test with medium chain triglycerides accompanied by the same measurements as those named in item (4).

So far differentiation has been made between patients with a metabolite profile most probably characteristic of medium chain acyl‐CoA dehydrogenase deficiency and other dicarboxylic acidurias, among the latter systemic carnitine deficiency. Patients belonging to the first group accumulate octanoate, decanoate andcis‐4‐decenoate in their plasma; they excrete hexanoylglycine, octanoylcarnitine and suberylglycine in addition to the usual C6–C10 dicarboxylic acids. There was a high prevalence of an increased plasma free fatty acid/3‐hydroxybutyrate ratio.
Mitochondrial myopathies: Disorders of the respiratory chain and oxidative phosphorylation
Authors: Clark J. B. , Hayes D. J. , Morgan‐Hughes J. A. , Byrne E.
Published: June 2009

Mitochondrial myopathies are a clinical condition characterized by muscle weakness and fatigue in which the primary defect is localized at the level of the mitochondria. Microscopic examination shows accumulations of mitochondria at the fibre periphery (ragged red fibres) and in some cases mitochondrial paracrystalline inclusions. The spectrum of different mitochondrial defects so far described is reviewed and data from cases investigated in this laboratory are described. The first case was a 17‐year‐old boy with a multisystem disorder whose muscle mitochondria showed low respiratory activity with all substrates, which doubled in the presence of uncouples Further investigation showed that the mitochondrial ATPase activity was only 6 % of normal. The next cases were a mother and daughter who showed a typical lipid storage myopathy. The latter was treated successfully with oral carnitine but the myopathy persisted. Mitochondrial investigations indicated a low respiratory activity with NAD‐linked substrates but normal activity with succinate and ascorbate + TMPD. A defect in the NADH‐CoQ reductase section of the respiratory chain was pinpointed possibly at an iron‐sulphur centre. The fourth and fifth cases were two sisters who exhibited no lipid storage myopathy but whose mitochondrial activity was low with NAD‐linked substrates but normal with succinate. Again a defect in the NADH‐CoQ reductase (complex I) of the respiratory chain was determined. They were also investigated using31P‐NMR. It was found after exercise that their muscle creatine phosphate levels took seven times longer to return to pre‐exercise concentrations than control subjects.

These results are discussed with respect to the synthesis of mitochondrial proteins and the influence that both the mitochondrial and nuclear DNA have on this process.
Organic acids in urine of patients with congenital lactic acidoses: An aid to differential diagnosis
Authors: Chalmers R. A.
Published: June 2009

The differential diagnosis of patients with apparent congenital lactic acidoses poses one of the most intractable problems in the study of patients with disorders of organic acid metabolism. An outline of the factors leading to a lactic acidosis, particularly in infants and young children, together with a brief review of the known causes of congenital lactic acidosis, are presented. Quantitative examination of the organic acids excreted by patients with proven enzyme deficiencies causing congenital lactic acidosis has demonstrated the characteristic patterns that are associated with specific disorders of this kind. After exclusion of uninherited, acquired and secondary metabolic causes of lactic acidosis, these quantitative patterns of organic acid excretion, together with other clinical and biochemical observations, provide valuable indicators of the area of the underlying primary metabolic disorder for subsequent selected, confirmatory, enzymology. The study of organic acids has a key and central role in the approach to the clinical and biochemical investigation and diagnosis of patients with congenital lactic acidoses.
A Comprehensive Evaluation of the Melting Points of Fatty Acids and Esters Determined by Differential Scanning Calorimetry
Authors: Knothe Gerhard , Dunn Robert O.
Published: June 2009

The melting point is one of the most important physical properties of a chemical compound and it plays a significant role in determining possible applications. For fatty acid esters the melting point is essential for a variety of food and non‐food applications, the latter including biodiesel and its cold‐flow properties. In this work, the melting points of fatty acids and esters (methyl, ethyl, propyl, butyl) in the C8–C24 range were determined by differential scanning calorimetry (DSC), many of which for the first time. Data for triacylglycerols as well as ricinoleic acid and its methyl and ethyl esters were also acquired. For some compounds whose melting points have been previously reported, data discrepancies exist and a comprehensive determination by DSC has not been available. Variations in the present data up to several °C compared to data in prior literature were observed. The melting points of some methyl‐branched iso‐ and anteiso‐acids and esters were also determined. Previously unreported systematic effects of compound structure on melting point are presented, including those for ω‐9 monounsaturated fatty acids and esters as well as for methyl‐branched iso and anteiso fatty acids and esters. The melting point of a pure fatty acid or ester as determined by DSC can vary up to approximately 1 °C. Other thermal data, including heat flow and melting onset temperatures are briefly discussed.
Fatty Acid Distribution in the Seed Flour of Wild Vicia Species from Southern Spain
Authors: Pastor‐Cavada Elena , Juan Rocio , Pastor Julio E. , Alaiz Manuel , Vioque Javier
Published: June 2009

The fatty acid distribution in the seed flour from 31 Vicia taxa distributed throughout southern Spain was analyzed by gas chromatography. Fatty acids ranged from myristic acid to araquidic acid. Linoleic acid (from 28.7 to 66.3% of the fatty acids), oleic acid (from 7.2 to 32.5% of the fatty acids) and linolenic acid (from 2.7 to 16.6% of the fatty acids) were the most abundant among unsaturated ones and palmitic acid among saturated ones. The total unsaturated to saturated fatty acids ratio ranged between 2.6 in V. hirsuta and 4.2 in V. hybrida. Polyunsaturated to monounsaturated fatty acids ratio ranged between 1.3 in V. ervilia and 9.0 in V. pyrenaica. The ω‐6 to ω‐3 ratio ranged between 1.7 in V. articulata and 17.3 in V. faba. The fatty acids distribution observed in the Vicia species studied supports the use of these plants as a source of important dietary lipids.
Participation in civil society and political life among young people in Maharashtra: Findings from the Youth in India ‐ Situation and Needs study
Authors: Acharya Rajib , Singh Abhishek , Santhya K.G. , Ram Faujdar , Jejeebhoy Shireen , Ram Usha , Mohanty Sanjay
Published: June 2009

Youth participation in civil society and political life is increasingly recognised to be an important development objective. Nonetheless, research that sheds light on the extent to which youth participate in these arenas, and the factors that facilitate or inhibit such participation remain limited in most developing countries including India. Drawing on data from a representative survey of young people in the state of Maharashtra, India, this paper explores the extent of and the factors associated with youth participation in civil society, their adherence to pro‐social values, and their participation in political processes. Findings suggest that for many youth, particularly for young women, opportunities to engage in civil society and political life are limited, and that pro‐social values are not uniformly observed. Findings underline the importance of education, agency and close parental interaction in facilitating youth participation in civil society and political life and their expression of pro‐social values.
Uniqueness of solutions to degenerate elliptic problems with unbounded coefficients
Authors: Punzo Fabio , Tesei Alberto
Published: June 2009

We study well-posedness of the Dirichlet problem for linear degenerate elliptic equations under mild assumptions on the coefficients (in particular, they can be unbounded). We provide sufficient conditions both for uniqueness and nonuniqueness of solutions, which rely on the construction of suitable sub- and supersolutions to certain auxiliary problems.
Attached to the web — harmful use of the Internet and its correlates
Authors: Korkeila J. , Kaarlas S. , Jääskeläinen M. , Vahlberg T. , Taiminen T.
Published: June 2009

Background and aims

The aim of this study was to test the validity of the Finnish version of the Internet Addiction Test and the correlates of harmful use of the Internet.

Methods

One thousand eight hundred and twenty-five students (45.5% men and 54.5% women, mean age 24.7 years, S.D. = 5.7) filled in a web-based questionnaire including IAT, reasons for use of the Internet, distress, social support, and substance use.

Results

Men had a statistically significantly higher mean score on the IAT than women. Subjects with self-reported use of cannabis had higher mean score on the IAT compared to non-users (39.5 [11.3] vs 35.8 [10.8]). The total IAT score was associated with “adult entertainment” (OR = 1.07, 95%CI: 1.06–1.08,P< 0.001), “playing games” (OR = 1.05, 95%CI: 1.04–1.06,P< 0.001), “chatting” (OR = 1.07, 95%CI: 1.06–1.08,P< 0.001) and “discussion” (OR = 1.08, 95%CI: 1.07–1.09,P< 0.001) as reasons for Internet use. The IAT score had a significant negative correlation with social support (r= −0.24,P< 0.001) and a significant positive correlation with the CAGE score (r= 0.18,P< 0.001). Using factor analysis, we found a single factor solution with a Cronbach'sαof 0.92.

Conclusions

The IAT seems to provide a valid measurement of harmful use of the Internet, as the score was significantly associated with variables tapping psychopathology.
ECT rekindles pharmacological response in schizophrenia
Authors: Hustig H. , Onilov R.
Published: June 2009

Objective

The aim of our naturalistic-observational study was to determine the efficacy and utility of electroconvulsive therapy (ECT) in clinical population of individuals with schizophrenia where pharmacological response was suboptimal.

Methods

The cohort comprised 27 patients suffering from schizophrenia with refractoriness to antipsychotic agents and with severe, disabling symptoms. They only interventional assessing tool was clinical global impression (CGI-S) performed at the baseline and at the end of the treatment.

Results

The administration of ECT resulted in overall clinical improvement reflected in CGI scales and descriptions in clinical notes. On 12 months follow-up period, 10 patients (37.1%) maintained improvement and were able to continue with pharmacological therapy only, suggesting its rekindling effect, especially with Clozapine. Conversely, 17 patients (62.9%) deteriorated and required an additional course of ECT to maintain improvement. In some cases, maintenance ECT treatment was required. The group who engaged in self-harming behaviour at baseline demonstrated they were more likely to relapse into psychosis at the end of the first course of ECT, their self-harming behaviour abated, especially when maintenance ECT was undertaken.

Conclusions

Although limited by lack of control group, small sample size, heterogeneous symptom profiles and various concurrent neuroleptic agents, the ECT proved as valuable and safe augmentative procedure when unsatisfactory response to pharmacological interventions had been demonstrated prior to interventions. This effect was evident despite the chronicity of the illness.
INFANT AND CHILD MORTALITY AMONG CATHOLICS AND LUTHERANS IN NINETEENTH CENTURY POZNAŃ
Authors: LICZBIŃSKA GRAŻYNA
Published: June 2009

The purpose of this study was to show the differences in the mortality rates of children from Catholic and Lutheran families in 19th century Poznań, and to elucidate the causes of these differences. Data from Catholic and Lutheran parish death registers were used. The infant death rate (IDR), neonatal and postneonatal death rates and life table biometric functions were calculated and causes of deaths were characterized. The worst child mortality values (IDR=394.4; neonatal and postneonatal death rates, respectively, 117.1 and 277.4;e0=16.14 years; Crow's Index=2.47) were obtained for the poor Catholic Parish of St Margaret. The lowest infant and neonatal and postneonatal death rates were observed to have occurred in the Catholic Parish of St Maria Magdalena situated in the city's more affluent central area (mortality rates, respectively, 269.9, 93.1 and 176.9;e0=24.63 years; Crow's Index=0.96). The widest range of differences with regard to death rates was found for the Lutheran Parish of St Cross (the infant, neonatal and postneonatal death rates were, respectively, 293.1, 99.1 and 193.9;e0=28.03 years; Crow's Index=0.92). The St Cross Parish encompassed a fairly large area of the city characterized by varying ecological conditions. Among infants and young children from the three studied populations a high frequency of deaths due to infectious diseases, diarrhoeas, dysenteries and tuberculosis were observed. Differences in the mortality of children from Catholic and Lutheran families in 19th century Poznań resulted from ecological conditions, among which water played the most important role, rather than from religious differences.
Determinants of Judicial Independence: Lessons from Three ‘Cases’ of Constitutional Courts in Peru (1982–2007)
Authors: DARGENT EDUARDO
Published: June 2009

The Peruvian Constitutional Tribunal (CT) is currently an independent institutional actor in Peru's politics. By comparing and contrasting the recent history of the CT and two previous ‘cases’ of ‘failed’ constitutional courts – the CT's role during the Fujimori regime and its predecessor, the Tribunal of Constitutional Guarantees – the article tests several theories that aim to explain the emergence of independent courts in democracies. The three cases provide evidence in support of theories that highlight the importance of political pluralism as a necessary condition for the emergence of independent courts, but the cases also show that an institutional design that ‘mirrors’ this pluralism is crucial to attain this outcome. The importance of these political and institutional factors suggests that it is too soon to be optimistic about the likelihood that the present CT can maintain its independence in the future.
Lost Decades? Economic Performance in Post-Independence Latin America
Authors: PRADOS DE LA ESCOSURA LEANDRO
Published: June 2009

In this paper the economic performance of post-independence Latin America is assessed in comparative perspective. The release from the colonial fiscal burden was partly offset by higher costs of self-government, while the opening of independent Latin American countries to the international economy represented a handmaiden of growth. Regional disparities increased after independence, so generalisations about the region's long-run behaviour are not straightforward. However, on average, per capita income grew in Latin America, and although the region fell behind compared with the United States and Western Europe, it improved or maintained its position relative to the rest of the world. Thus the term ‘lost decades’ appears an unwarranted depiction of the period between 1820 and 1870.
The impact of garlic on lipid parameters: a systematic review and meta-analysis
Authors: Reinhart Kurt M. , Talati Ripple , White C. Michael , Coleman Craig I.
Published: June 2009

In order to determine the impact of garlic on total cholesterol (TC), TAG levels, as well as LDL and HDL, and establish if any variables have an impact on the magnitude of this effect, a meta-analysis was conducted. A systematic literature search of MEDLINE, CINAHL and the Cochrane Database from the earliest possible date through to November 2007 was conducted to identify randomised, placebo-controlled trials of garlic that reported effects on TC, TAG concentrations, LDL or HDL. The weighted mean difference of the change from baseline (with 95 % CI) was calculated as the difference between the means in the garlic groups and the control groups using a random-effects model. Subgroup and sensitivity analyses were performed to determine the effects on type, brand and duration of garlic therapy as well as baseline TC and TAG levels, the use of dietary modification, and study quality on the meta-analysis's conclusions. Twenty-nine trials were included in the analysis. Upon meta-analysis garlic was found to significantly reduce TC ( − 0·19; 95 % CI − 0·33, − 0·06 mmol/l) and TAG ( − 0·11; 95 % CI − 0·19, − 0·06 mmol/l) but exhibited no significant effect on LDL or HDL. There was a moderate degree of statistical heterogeneity for the TC and TAG analyses. Garlic reduces TC to a modest extent, an effect driven mostly by the modest reductions in TAG, without appreciable LDL lowering or HDL elevation. Higher baseline line TC levels and the use of dietary modification may alter the effect of garlic on these parameters. Future studies should be conducted evaluating the impact of adjunctive garlic therapy with fibrates or statins on TAG concentrations.
Vitamin D: emerging new roles in insulin sensitivity
Authors: Teegarden Dorothy , Donkin Shawn S.
Published: June 2009

The growing incidence of prediabetes and clinical type 2 diabetes, in part characterised by insulin resistance, is a critical health problem with consequent devastating personal and health-care costs. Vitamin D status, assessed by serum 25-hydroxyvitamin D levels, is inversely associated with diabetes in epidemiological studies. Several clinical intervention studies also support that vitamin D, or its active metabolite 1,25-dihydroxyvitamin D (1,25(OH)2D), improves insulin sensitivity, even in subjects with glucose metabolism parameters classified within normal ranges. The mechanisms proposed which may underlie this effect include potential relationships with improvements in lean mass, regulation of insulin release, altered insulin receptor expression and specific effects on insulin action. These actions may be mediated by systemic or local production of 1,25(OH)2D or by suppression of parathyroid hormone, which may function to negatively affect insulin sensitivity. Thus, substantial evidence supports a relationship between vitamin D status and insulin sensitivity; however, the underlying mechanisms require further exploration.
Stroke: roles of B vitamins, homocysteine and antioxidants
Authors: Sánchez-Moreno Concepción , Jiménez-Escrig Antonio , Martín Antonio
Published: June 2009

In the present review concerning stroke, we evaluate the roles of B vitamins, homocysteine and antioxidant vitamins. Stroke is a leading cause of death in developed countries. However, current therapeutic strategies for stroke have been largely unsuccessful. Several studies have reported important benefits on reducing the risk of stroke and improving the post-stroke-associated functional declines in patients who ate foods rich in micronutrients, including B vitamins and antioxidant vitamins E and C. Folic acid, vitamin B6and vitamin B12are all cofactors in homocysteine metabolism. Growing interest has been paid to hyperhomocysteinaemia as a risk factor for CVD. Hyperhomocysteinaemia has been linked to inadequate intake of vitamins, particularly to B-group vitamins and therefore may be amenable to nutritional intervention. Hence, poor dietary intake of folate, vitamin B6and vitamin B12are associated with increased risk of stroke. Elevated consumption of fruits and vegetables appears to protect against stroke. Antioxidant nutrients have important roles in cell function and have been implicated in processes associated with ageing, including vascular, inflammatory and neurological damage. Plasma vitamin E and C concentrations may serve as a biological marker of lifestyle or other factors associated with reduced stroke risk and may be useful in identifying those at high risk of stroke. After reviewing the observational and intervention studies, there is an incomplete understanding of mechanisms and some conflicting findings; therefore the available evidence is insufficient to recommend the routine use of B vitamins, vitamin E and vitamin C for the prevention of stroke. A better understanding of mechanisms, along with well-designed controlled clinical trials will allow further progress in this area.
A review and meta-analysis of the effect of weight loss on all-cause mortality risk
Authors: Harrington Mary , Gibson Sigrid , Cottrell Richard C.
Published: June 2009

Overweight and obesity are associated with increased morbidity and mortality, although the range of body weights that is optimal for health is controversial. It is less clear whether weight loss benefits longevity and hence whether weight reduction is justified as a prime goal for all individuals who are overweight (normally defined as BMI>25 kg/m2). The purpose of the present review was to examine the evidence base for recommending weight loss by diet and lifestyle change as a means of prolonging life. An electronic search identified twenty-six eligible prospective studies that monitored subsequent mortality risk following weight loss by lifestyle change, published up to 2008. Data were extracted and further analysed by meta-analysis, giving particular attention to the influence of confounders. Moderator variables such as reason for weight loss (intentional, unintentional), baseline health status (healthy, unhealthy), baseline BMI (normal, overweight, obese), method used to estimate weight loss (measured weight loss, reported weight loss) and whether models adjusted for physical activity (adjusted data, unadjusted data) were used to classify subgroups for separate analysis. Intentional weight loss per se had a neutral effect on all-cause mortality (relative risk (RR) 1·01; P = 0·89), while weight loss which was unintentional or ill-defined was associated with excess risk of 22 to 39 %. Intentional weight loss had a small benefit for individuals classified as unhealthy (with obesity-related risk factors) (RR 0·87 (95 % CI 0·77, 0·99); P = 0·028), especially unhealthy obese (RR 0·84 (95 % CI 0·73, 0·97); P = 0·018), but appeared to be associated with slightly increased mortality for healthy individuals (RR 1·11 (95 % CI 1·00, 1·22); P = 0·05), and for those who were overweight but not obese (RR 1·09 (95 % CI 1·02, 1·17); P = 0·008). There was no evidence for weight loss conferring either benefit or risk among healthy obese. In conclusion, the available evidence does not support solely advising overweight or obese individuals who are otherwise healthy to lose weight as a means of prolonging life. Other aspects of a healthy lifestyle, especially exercise and dietary quality, should be considered. However, well-designed intervention studies are needed clearly to disentangle the influence of physical activity, diet strategy and body composition, in order to define appropriate advice to those populations that might be expected to benefit.
The effect of light and number of diurnal temperature fluctuations on germination of Phragmites australis
Authors: Ekstam B. , Johannesson R. , Milberg P.
Published: June 2009

Seed germination of the wetland emergent perennial Phragmites australis is stimulated by diurnally fluctuating temperatures. A germination experiment in darkness and light at different temperature regimes showed that P. australis germinated as well in darkness as in light over most of the temperature regimes tested. The germination requirements could partly explain why this species, despite a large annual production of small seeds, does not accumulate a persistent soil seed bank. A second experiment examined the effect of one to four diurnal temperature cycles with amplitude of fluctuations ranging from 0 to 30°C; diurnal mean temperature of 15°C. Germination in the absence of fluctuations was low, and logistic model estimates showed a positive effect of number of temperature cycles which was strongly influenced by amplitude size. For seeds that have fallen on moist ground during the winter, these laboratory results predict that a few large diurnal temperature fluctuations could be sufficient for onset of germination in the subsequently warmer spring period. Seeds that are located under water, however, are predicted to remain ungerminated until the water level falls. Hence, we suggest that the requirement for fluctuating temperature, in addition to being a sensor for ‘exposed’ seed sites, is also effectively acting as a germination timing mechanism.
Melencolia §I – der „angelo terrestre” und sein gleichzeitiges doppeltes Sehvermögen
Authors: Mayer Ernst Th.
Published: June 2009

Zusammenfassung. Das am meisten mathematische Bild Dürers hat eine Trostwirkung, deren Ursache kunsthistorisch, kunstpsychologisch und ikonologisch untersucht wird. Es wird die These vertreten, dass die Trost-Wirkung auf der „visuellen Geometrie” beruht, die Dürer seiner Bildkonstruktion zu Grunde gelegt hat. Der Betrachter sieht das „Selbst”, er ist – wie der Schöpfer des Bildes – „voller Figur”, wie Dürer seine eigene Kreativität beschrieben hat, und beginnt, das Bild zu lesen. Der Betrachter folgt dabei intuitiv oder bewusst den sinnführenden Perspektiven. Dazu wird die These aufgestellt, Dürer sei inspiriert von dem kontemplativen Aufstieg zum „angelo terrestre”, der von Giovanni Pico della Mirandola in seinem Commento sopra una canzone d’amore 1486, beschrieben wurde.
Seasonal variability in the salinity and oxygen isotopic composition of seawater from the Cariaco Basin, Venezuela: Implications for paleosalinity reconstructions
Authors: McConnell Martha C. , Thunell Robert C. , Lorenzoni Laura , Astor Yrene , Wright James D. , Fairbanks Richard
Published: June 2009

Oxygen isotope measurements (δ18Ow) were made on seawater samples collected monthly between May 1996 and February 1997 and between December 2005 and May 2006 at various water depths at the Cariaco Basin ocean time series station (10°30N, 64°40W). The δ18Ow values are compared with concurrent salinity measurements to assess the δ18Ow:salinity relationship in this tropical region and to determine if significant seasonal variability exists in the relationship. The δ18Ow values range from 0.88 to 1.19‰ SMOW in the upper 250 m. Our results indicate that the strongest positive linear correlation between δ18Ow and salinity in the upper 250 m occurred during the February and April 2006 upwelling season (R2 = 0.95 and 0.94, respectively). The salinity: δ18Ow relationship displays significant seasonal variability which is attributed to seasonal changes in freshwater input from the Tuy, Neverí, and Unare rivers into the Cariaco Basin. Specifically, an inverse correlation (R2 = 0.77) exists between monthly Neverí River discharge and sea surface salinity. Our results demonstrate that significant seasonal changes in the δ18Ow:salinity relationship occur in the tropics. The data also show a distinct difference between the surface water δ18Ow:salinity relationship during the upwelling season (R2 = 0.96) and the nonupwelling season (R2 = 0.93) revealing zero‐salinity end‐members of −28.53 (SE ± 3.04) and −8.77 (SE ± 1.33), respectively. The seasonal mixing lines are an important consideration when utilizing the salinity:oxygen isotope relationship for paleosalinity reconstructions. The oxygen isotope composition (δ18Oc) was also measured in two surface‐dwelling planktonic foraminiferal species, Globigerinoides ruber and Globigerina bulloides, from biweekly sediment trap samples collected in the Cariaco Basin between November 1996 and February 1997 and May 2003 through May 2006. The large range in δ18Oc during the study period, 1.4‰ for G. ruber and 1.5‰ for G. bulloides, is attributed to changes in calcification depths of the species from 1996–1997 to 2005–2006. Using the surface water δ18Ow:salinity equations generated for the upwelling and nonwelling seasons in the Cariaco Basin, we compare measured seawater salinity with the calculated seawater salinity at various depths of calcification. The δ18Ow:salinity equation generated from surface waters during the upwelling months yields salinity estimates that best agree with measured salinities.
New observations of HF‐induced optical emissions from the ionospheric E region
Authors: Pedersen T. , Mishin E. , Esposito R.
Published: June 2009

A new independent instance of highly localized artificial 557.7 nm optical emissions induced by high‐power HF waves incident upon a precipitation‐produced E layer at High Frequency Active Auroral Research Program (HAARP) confirms the original discovery of this phenomenon and adds a number of new observational facts. The features are excited by O mode transmissions but not X mode transmissions and disappear entirely during deliberate off periods. The specific transmitter pulsing period does not appear to be a critical factor, ruling out ULF resonances as a possible mechanism. The observed locations of the enhanced emissions are consistent with a small number of long‐lived inhomogeneities traveling steadily across the field of view over several minutes. These persistent regions are preferentially excited even at a small fraction of peak power well away from the beam center and can reappear along the same trajectory after gaps of more than 1 min. The absence of any detectable enhancements in directly coincident 630.0 nm data or side‐looking 557.7 and 630.0 nm images focused on the F region portion of the field line conclusively locates these artificial emissions in the ionospheric E region. We suggest possible hypotheses that might explain the new observations and the earlier results.
Physical properties of aerosol particles at a Himalayan background site in India
Authors: Komppula M. , Lihavainen H. , Hyvärinen A.‐P. , Kerminen V.‐M. , Panwar T. S. , Sharma V. P. , Viisanen Y.
Published: June 2009

Three years of particle number size distribution measurements were conducted in a remote Himalayan site in Mukteshwar, India. The 1‐h average total number concentrations varied from 220 to 27,300 cm−3. A clear seasonal cycle in measured aerosol properties was identified. The rainy season in July–August was found to decrease particle number concentrations to less than half of that observed in spring, prior to the rainy season. Highest concentrations were found in eastern and northern air masses. The air masses from these sectors arrived from higher altitudes suggesting the presence of long‐range‐transported aerosol. The particle size distributions were mostly unimodal, having a mean diameter larger than 100 nm during the dry seasons and around 100 nm during the rainy season. During the spring, atmospheric new particle formation events produced bimodal shapes for the size distributions. The diurnal variation in the particle number concentration showed slightly different patterns in different seasons. In spring the pattern was driven partly by new particle formation which started normally around midday during about one third of the days. In winter and autumn, particle concentrations increased from morning to evening and settled to lower levels again toward the night. This behavior is thought to be due to the combination of boundary layer evolution and daily behavior patterns/activities, such as cooking and heating, of habitants in the nearby valley. During the rainy season when the rain “cleaned” the atmosphere, particle number concentrations decreased notably, and no clear diurnal pattern could be identified.
Increasing influence of ENSO and decreasing influence of AO/NAO in the recent decades over northwest India winter precipitation
Authors: Yadav R. K. , Rupa Kumar K. , Rajeevan M.
Published: June 2009

The interannual variability of northwest India winter precipitation (NWIWP) is examined in association with the variability of surface temperature, mean sea level pressure, tropospheric geopotential height, and wind patterns over the globe to study the changes in the large‐scale circulation features associated with NWIWP. The data for the study have been considered from 1950 to 2008 (for a period of 59 years). The analysis is based on correlations and composites performed using India Meteorological Department records based on station data. We find that the interannual variability of NWIWP is influenced by Arctic Oscillation/North Atlantic Oscillation (AO/NAO) and El Niño–Southern Oscillation (ENSO) phenomena. Above‐normal NWIWP is associated with the positive phase of AO/NAO and the warm phase of ENSO, but showing strong secular variations. During the recent decades, the influence of ENSO over NWIWP has increased while the influence of AO/NAO has decreased. This conclusion is supported by a consistency across the different observation data sets employed in the study. A physical mechanism for such effect is proposed, by which western disturbances are intensified over NW India by the intensification of Asian westerly jet stream over Middle East during positive phase of AO/NAO and shift and intensification of Asian jet to the lower latitudes during the warm phase of ENSO.
A magnetospheric generator driving ion and electron acceleration and electric currents in a discrete auroral arc observed by Cluster and DMSP
Authors: Echim M. M. , Maggiolo R. , Roth M. , De Keyser J.
Published: June 2009

Simultaneous observations on April 28, 2001 by Cluster and DMSP‐F14 reveal a stable discrete auroral arc and fluxes of field‐aligned accelerated electrons and ions coincident with a magnetospheric plasma interface at an altitude of 4.5 RE in the dusk sector. We compare satellite data with a quasi‐stationary magnetosphere‐ionosphere coupling model based on a Vlasov solution for the magnetospheric generator. The model provides a self‐consistent magnetospheric electric potential matching the Cluster observations. The ionospheric potential is derived from the current continuity equation and gives a field‐aligned potential drop and a flux of precipitating energy in agreement with the DMSP data. Model results and data analysis suggest a quasi‐stationary field‐aligned acceleration of auroral electrons and ions with a magnetospheric generator. We associate the generator with the convergent perpendicular electric field at the interface of the plasma sheet boundary layer with the lobe or at the inner edge of the low latitude boundary layer.
Transport of mercury in the Arctic atmosphere: Evidence for a spring‐time net sink and summer‐time source
Authors: Hirdman D. , Aspmo K. , Burkhart J. F. , Eckhardt S. , Sodemann H. , Stohl A.
Published: June 2009

In the Arctic, atmospheric concentrations of gaseous elemental mercury (GEM) can decrease strongly in spring when mercury is deposited to the snow. Some studies suggest mercury can accumulate in the snow while others suggest rapid reemission after atmospheric mercury depletion events. We have combined measurements of GEM at the Arctic site Zeppelin (Ny Ålesund, Spitsbergen) with the output of the Lagrangian particle dispersion model FLEXPART, for a statistical analysis of GEM source and sink regions. We find that the Arctic is a strong net sink region for GEM in April and May, suggesting that mercury accumulates in the Arctic snow pack. For summer, we find the Arctic to be a GEM source, indicating reemission of previously deposited mercury when the snow and/or ice melts, or evasion from the ocean through sea ice leads and polynyas. Our results are corroborated by a related analysis of ozone source and sink regions.