bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibiting Unwanted Redox Reactions with Valve Metal Oxide Topcoats on Dimensionally Stable Anodes
Authors: Moats Michael , Hardee Kenneth
Published: February 2007

It has been recently discovered that the application of valve metal oxide topcoats to dimensionally stable anodes can inhibit redox reactions. Typically, tantalum oxide is coated over an existing IrO2-Ta2O5 coating using a thermal decomposition method. It is believed that the tantalum oxide topcoat produces a porous barrier that inhibits reactants from reaching the electrocatalytic surface of the IrO2-Ta2O5 while allowing water to pass at a rate sufficient to maintain electrolysis. The inhibiting effect has been shown on both a laboratory and commercial scale for reactions such as ferrous oxidation, chloride oxidation, destruction of organic brightener and the deposition of manganese dioxide.
Nanoparticles and Nanoceramics of Y-doped CeO2
Authors: Ruiz-Trejo Enrique , Benítez-Rico Adriana , Gómez-Reynoso Silvia , Angeles-Rosas Melisa
Published: February 2007

In this article we discuss the synthesis of nanoparticles and the preparation of dense nanoceramics of Y-doped CeO2. We prepared the nanoparticles by the combustion method and characterised the nanopowders by XRD, SEM and TEM. The good sintering properties of these nanopowders allowed us to obtain very dense ceramics of Y-doped CeO2 and keep the grain size in some cases around 100 nm using sintering temperatures as low as 1250 {degree sign}C and very short times of 5 to 60 min. The microstructure of these nanoceramics was analysed by AFM and SEM. The most interesting feature of these nanoceramics is that the electrical measurements in N2 carried out by the 4-point dc technique showed a considerable increase in conductivity in comparison with the measurements in air or oxygen in the range 700-900 {degree sign}C. This might be associated with electronic conduction.
Characterization and Growth Mechanism of Filamentous Zinc Electrodeposits
Authors: Wang Rainey Y. , Kirk Donald W. , Zhang Gregory X.
Published: February 2007

The morphology of mossy zinc deposits from alkaline zincate solutions was investigated using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The composition and orientation of the mossy deposits were examined using powder X-ray diffraction (XRD), and selected area XRD (SAD). Morphologically, the deposits appear as spongy at the micrometer scale, but filamentous at the nanometer scale. Filamentous mossy zinc was determined to consist of pure metallic zinc. Individual deposit filaments were found to be single crystals which grow in the <0001> direction. The BET specific surface area of filamentous deposits was determined to be 5-11 m2 g-1 (BET). This high surface area makes filaments highly active and can spontaneously oxidize in the air.
Transport Properties of Proton Exchange Membranes
Authors: Roy Abhishek , Hickner Michael A. , Lee Hae-Seung , Badami Anand , Yu Xiang , Li Yanxiang , Glass Thomas , McGrath James E.
Published: February 2007

Disulfonated poly(arylene ether sulfone) random copolymers have shown promise as potential candidates for proton exchange membranes. The chemical structure of these copolymers has served as a basis for the molecular design of new random and multiblock copolymers. In random copolymers the sulfonic acid is distributed statistically, while in the multiblock copolymers the chemical structure is designed to have co continuous hydrophilic and hydrophobic domains. The effect of these variables on the transport properties of the membranes was investigated. For the random copolymers, high proton conductivity was observed at higher IEC along with high methanol permeability. But for the multiblock copolymers, it was possible to combine high proton conductivity with low methanol permeability. Improved proton conductivity was observed under partially hydrated conditions for samples with higher block lengths. Self diffusion coefficient of water was also measured by NMR which provided better understanding of the transport process.
Porous Crystalline Organosilica Materials as High Surface Area Support in Proton Exchange Membranes for Fuel Cells
Authors: Holmberg Brett A.
Published: February 2007

Crystalline organosilica mesoporous materials (OMMs) have been directly synthesized with mercaptopropyl side chains and framework ethylene, benzene, and biphenyl groups. Preliminary OMMs with benzene framework groups and propylsulfonic acid side chains have exhibited proton conductivity as high as 8.97×10-3 S/cm. The optimization of organosilica material proton conductivity for fuel cell applications is ongoing.
β-Cell “rest” accompanies reduced first-pass hepatic insulin extraction in the insulin-resistant, fat-fed canine model
Authors: Kim Stella P. , Ellmerer Martin , Kirkman Erlinda L. , Bergman Richard N.
Published: February 2007

During insulin resistance, glucose homeostasis is maintained by an increase in plasma insulin via increased secretion and/or decreased first-pass hepatic insulin extraction. However, the relative importance of insulin secretion vs. clearance to compensate for insulin resistance in obesity has yet to be determined. This study utilizes the fat-fed dog model to examine longitudinal changes in insulin secretion and first-pass hepatic insulin extraction during development of obesity and insulin resistance. Six dogs were fed an isocaloric diet with an ∼8% increase in fat calories for 12 wk and evaluated at weeks 0, 6, and 12 for changes in 1) insulin sensitivity by euglycemic-hyperinsulinemic clamp, 2) first-pass hepatic insulin extraction by direct assessment, and 3) glucose-stimulated insulin secretory response by hyperglycemic clamp. We found that 12 wk of a fat diet increased subcutaneous and visceral fat as assessed by MR imaging. Consistent with increased body fat, the dogs exhibited a ∼30% decrease in insulin sensitivity and fasting hyperinsulinemia. Although insulin secretion was substantially increased at week 6, β-cell sensitivity returned to prediet levels by week 12. However, peripheral hyperinsulinemia was maintained because of a significant decrease in first-pass hepatic insulin extraction, thus maintaining hyperinsulinemia, despite changes in insulin release. Our results indicate that when obesity and insulin resistance are induced by an isocaloric, increased-fat diet, an initial increase in insulin secretion by the β-cells is followed by a decrease in first-pass hepatic insulin extraction. This may provide a secondary physiological mechanism to preserve pancreatic β-cell function during insulin resistance.
Beta Rhythms (15–20 Hz) Generated by Nonreciprocal Communication in Hippocampus
Authors: Bibbig Andrea , Middleton Steven , Racca Claudia , Gillies Martin J. , Garner Helen , LeBeau Fiona E. N. , Davies Ceri H. , Whittington Miles A.
Published: February 2007

Generation of gamma rhythms in reciprocally connected areas of cortex produces synchronous neuronal firing, although little is known about the consequences of gamma rhythms when generated in nonreciprocally connected regions. This nonreciprocity exists in hippocampus, where gamma rhythms are generated in area CA3 in vitro and in vivo and nonreciprocally projected to area CA1 by the Schaffer collateral pathway. Here we demonstrate how this CA3 gamma rhythm generates two different patterns of local CA1 oscillation dependent on the degree of output from area CA1. 1) In conditions where activity projected to area CA1 produces only very low principal cell recruitment the local population rhythm mimics the gamma rhythm projected from CA3. This activity is generated predominantly by recruitment of CA1 basket cells in a manner dependent on phasic, feedforward excitation of this interneuron subclass. Interneurons in stratum oriens, not receiving CA3 feedforward input, fired at theta frequencies. 2) In the presence of serotonin CA1 principal cell recruitment was appreciably enhanced, resulting in dual activation of CA1 basket cells through both feedforward and feedback excitations. Feedback excitation to CA1 stratum oriens interneurons was also enhanced. The resulting change in interneuron network dynamics generated a beta-frequency CA1 rhythm (as a near-subharmonic of the gamma rhythm projected from CA3). These findings demonstrate that in nonreciprocally connected networks, the frequency of population rhythms in target areas serves to code for degree of principal cell recruitment by afferent input.
Antibacterial Effect of Chlorhexidine- Containing Glass Ionomer Cement in vivo: A Pilot Study
Authors: Frencken J.E. , Imazato S. , Toi C. , Mulder J. , Mickenautsch S. , Takahashi Y. , Ebisu S.
Published: February 2007

This in vivo pilot study was carried out to test the antibacterial effect of glass ionomer containing chlorhexidine (test group) in comparison to conventional glass ionomer (control group). Fifty 6- to 11-year-old children with one occlusal lesion in a molar were randomly allocated to test and control groups in a parallel-group design. The cavity walls and one half of the floor were cleaned and restored with one of the materials without dentine conditioning. The restorations were removed after 7 days. Dentine samples were taken from the cleaned (affected dentine) and noncleaned area (infected dentine) at baseline and at day 7. Samples were anaerobically and aerobically cultivated for mutans streptococci, lactobacilli and total viable bacterial count (TVC) following common laboratory procedures. ANCOVA was used to test for treatment effects. Seven days after treatment, a significant decrease in anaerobic and aerobic bacterial counts (p = 0.0001) was shown. Lower numbers of anaerobic lactobacilli (p = 0.02), TVC (p = 0.008) and aerobic lactobacilli and TVC (p = 0.03), but not of mutans streptococci, were indicated in the test group compared to the control group. A significant reduction in aerobic lactobacilli from infected dentine treated with the glass ionomer containing chlorhexidine (p = 0.05) was observed whereas in affected dentine, anaerobic mutans streptococci, lactobacilli and TVC and aerobic TVC and mutans streptococci were significantly lower in the test group 7 days after treatment (p = 0.01). We conclude that the present pilot study revealed lower microorganism counts in chlorhexidine-containing glass ionomers than in conventional glass ionomers for both affected and infected dentine over a 7-day period.
Efficacy of Waiting Periods and Topical Fluoride Treatment on Toothbrush Abrasion of Eroded Enamel in situ
Authors: Ganss C. , Schlueter N. , Friedrich D. , Klimek J.
Published: February 2007

The aim of this study was to investigate the effectiveness of both waiting periods between acid exposure and tooth brushing and fluoride applications in preventing toothbrush abrasion of acid-softened enamel surfaces. The study, on 5 subjects, had an in situ crossover design with experimental periods of 5 days each. Human enamel samples were recessed in mouth appliances and at the end of each experimental period, enamel loss was determined profilometrically. Specimens were eroded extraorally (2 × 20 min per day; 0.05 M citric acid), standardized brushing (2 × 30 s per sample per day; powered toothbrush) was performed in situ. The groups were: (1) erosion only, (2) brushing with fluoride-free toothpaste directly after, (3) 2 h after, or (4) before erosion; fluoride application was either (5) brushing with a fluoride toothpaste or (6) brushing with a fluoride toothpaste or gel, and rinsing with a fluoride mouth rinse. Enamel loss was (1) 45.2 ± 10.8, (2) 79.3 ± 7.8, (3) 81.7 ± 9.5, (4) 69.7 ± 13.8, (5) 51.5 ± 13.0, and (6) 41.2 ± 1.8 µm. Brushing without fluoride increased the enamel loss significantly (p ≤ 0.001), waiting for 2 h had no protective effect, and brushing before erosion decreased enamel loss values only by 12% (n.s.). In the fluoride groups, enamel loss was significantly lower than after brushing with the fluoride-free toothpaste and comparable to values after erosion only (n.s.). Waiting periods had only a minor effect, whilst the application of fluoride appeared promising.
Changes in Electrical Resistance of Sound Fissure Enamel in First Molars for 66 Months from Eruption
Authors: Kataoka S. , Sakuma S. , Wang J. , Yoshihara A. , Miyazaki H.
Published: February 2007

The purposes of this study were to investigate the enamel maturation process in the occlusal pit of sound first molars by measuring electrical resistance. Ninety-nine sound first molars in 34 children (mean age of 6.47 ± 0.51 years) were measured electrically once every 6 months and were monitored for a maximum of 66 months. Electrical resistance increased during the posteruptive period. However, the results suggest that posteruptive enamel maturation in the occlusal pits may not be completed even 66 months after tooth eruption.
Effects of a Low-Fat versus a Low-Carbohydrate Diet on Adipocytokines in Obese Adults
Authors: de Luis D.A. , Aller R. , Izaola O. , Gonzalez Sagrado M. , Bellioo D. , Conde R.
Published: February 2007

Background and Aims: There are few studies addressing the effect of weight loss on circulating levels of adipocytokines. The aim of our study was to determine whether different diets would have different weight loss effects and to examine the changes in adipocytokine levels. Methods: A population of 90 obesity non-diabetic outpatients was analyzed in a prospective way. The patients were randomly allocated to two groups: (a) diet I (low-fat diet), and (b) diet II (low-carbohydrate diet). At baseline and after 3 months on the diet, adipocytokines were evaluated. Results: 43 patients were randomized to group I and 47 patients to diet group II. No differences were detected between weight loss in either group (3.3 ± 0.51 vs. 4.4 ± 0.6 kg; n.s.). In group I, a significant decrease in leptin levels was found. In group II, leptin and C-reactive protein (CRP) levels also decreased. The decrease in leptin levels was lower with diet I than II (16.4 vs. 22.8%; p < 0.05). Conclusion: The serum leptin concentration decreased due to the 3-month intervention with low-fat and low-carbohydrate diets, without changes in other adipocytokines. The decrease in leptin and CRP levels were higher with a low-carbohydrate diet than a low-fat diet.
Evaluation of Peritoneal Transport and Membrane Status in Peritoneal Dialysis: Focus on Incident Fast Transporters
Authors: Rodrigues Anabela S. , Martins Margarida , Korevaar Johanna C. , Silva Sandra , Oliveira José C. , Cabrita Antonio , Castro e Melo João , Krediet Raymond T.
Published: February 2007

Background/Aim: The determinants of baseline fast solute transport are still unclear. We prospectively investigated the relationship of peritoneal solute transport with markers of inflammation, angiogenesis, and membrane status, with a focus on fast transporters. Methods: Seventy-one incident peritoneal dialysis patients were assessed with baseline and annual peritoneal equilibration tests, using a 3.86% glucose dialysis solution. Residual renal function and markers of inflammation, including systemic and intraperitoneal interleukin-6 (IL-6), effluent cancer antigen 125 (CA-125), and vascular endothelial growth factor (VEGF) appearance rates (ARs), were investigated. The time course of the dialysate-to-plasma ratio of creatinine (D/P creatinine ratio) and its relationship with the biomarkers were investigated by a mixed linear model. Results: Incident fast/fast average transporters had a similar age, diabetes prevalence, and serum and effluent IL-6 levels, but significantly higher levels of CA-125 and VEGF ARs than the slow/slow average group; the D/P creatinine ratio was not correlated with systemic IL-6, but was correlated with effluent CA-125 AR (r = 0.45, p < 0.0001) and VEGF AR (r = 0.52, p < 0.0001). The D/P creatinine ratio decreased with a U-shaped profile (p = 0.02). Intraperitoneal IL-6 was the significant and positive determinant of the time course of the D/P creatinine ratio (p < 0.0001). Effluent CA-125 decreased with time on peritoneal dialysis (p = 0.013). Conclusions: Baseline peritoneal fast transport was not associated with systemic inflammation, but was related to peritoneal locally produced substances able to mediate transitory hyperpermeability. The D/P creatinine ratio changed during the follow-up period with a U-shaped profile. This was associated with effluent IL-6 and partly with VEGF. CA-125 decreased throughout the follow-up period.
Trust in Complex Decision-Making Networks
Authors: Edelenbos Jurian , Klijn Erik-Hans
Published: February 2007

This article explores some theoretical notions of trust in complex interorganizational networks, especially public-private partnerships. The article begins with a theoretical exploration of the value of trust in complex interorganizational processes. Next, the role of trust in a public-private partnership “Sijtwende” is analyzed. The authors analyze the cooperation process and the organizational arrangements that have been used, as well as the outcomes thus far. They then trace the existence and development of trust in these processes and their influence on the process and outcomes. The authors close with some preliminary conclusions and hypotheses on the manageability of trust.
Wetlands in drylands: geomorphological and sedimentological characteristics, with emphasis on examples from southern Africa
Authors: Tooth Stephen , McCarthy Terence S.
Published: February 2007

Wetlands are poorly documented features of many landscapes, and there is often little understanding of the geomorphological controls on their origin, development and characteristics. This paper addresses the apparent paradox of wetlands in drylands, focusing particularly on the geomorphology and sedimentology of wetlands in southern Africa. Drylands are characterized by high (but variable) levels of aridity, reflecting low ratios between precipitation and potential evapotranspiration, so wetlands can only exist where there are locally positive surface water balances for all or part of the year. Most moderate to large wetlands in drylands are thus maintained by river inflows that combine with other factors that serve to impede drainage or reduce infiltration, including faulting, rock outcrops, swelling soils, and ponding by tributary or aeolian sediments. Together with variations in sediment supply, vegetation communities, and levels of animal activity, this promotes a diverse range of wetlands that span a continuum from permanently inundated, to seasonally inundated, to ephemerally inundated. In detail, every wetland has a unique range of geomorphological and sedimentological characteristics but, at a general level, the dryland setting can be shown to impart some distinctive features. By comparison with humid region (tropical and temperate) wetlands, we propose that many wetlands in drylands are characterized by: 1) more frequent and/or longer periods of desiccation; 2) channels that commonly decrease in size and even disappear downstream; 3) higher levels of chemical sedimentation; 4) more frequent fires that reduce the potential for thick organic accumulations and promote aeolian activity; and 5) longer timescales of development that may extend far back into the Pleistocene. Additional studies of wetlands in different drylands may reveal other distinctive characteristics. Correct identification of the factors giving rise to wetlands, and improved understanding of the geomorphological and sedimentological processes governing their development, is vital for the design of sustainable management guidelines for these diverse yet fragile habitats.
Genital-Shrinking Panic in Ghana: A Cultural Psychological Analysis
Authors: Adams Glenn , Dzokoto Vivian Afi
Published: February 2007

The present article applies the theoretical framework of mutual constitution (MC)—the dialectical process by which ‘culture and psyche make each other up’—to analyze an occurrence of genital-shrinking panic (GSP). Although media reports promote interpretation of this event in terms of ignorance and superstition, the MC framework affords a less pathologizing analysis. The first part of this analysis, one that resonates with classic ethnographic perspectives, emphasizes the cultural grounding of psychological experience: how episodes of GSP make sense given local constructions of reality. However, an adequate analysis requires attention not only to cultural realities in which incidents of GSP make sense, but also to the role of psychological activity in reproducing, maintaining and extending those realities. Accordingly, the second part of this analysis emphasizes the less articulated, dynamic-construction side of the MC framework: the role of psychological activity in the reproduction of cultural worlds.
Parties and Accountable Government in New Democracies
Authors: Carey John , Reynolds Andrew
Published: February 2007

Political scientists have long associated accountability with strong political parties, and have also frequently noted the weakness of parties in new democracies. This article disaggregates the strong party ideal into two components - legislative discipline and programmatic platforms - and suggests that the former in the absence of the latter can undermine accountability. We describe levels of discipline in parties in various new democracies. Then we provide a taxonomy of political party origins, according to how origins affect the proclivity of parties toward both programmatic policy and legislative discipline.
Consent in severely disabled children: informed or an infringement of their human rights?
Authors: Rowse Vicki L.
Published: February 2007

In this article the issue of consent in children is examined with particular reference to disabled children and young people. It is demonstrated that gaining informed consent from disabled children is still a long way off and that the issues are not clear. The law delivers contradictory rulings, parents and families are becoming more vocal in challenging doctors, and the courts are becoming increasingly involved in decision-making on treatment options. The Human Rights Act 1998 is becoming more prominent in informing these decisions. The article concludes that these developments may not be in the best interests of disabled children and that strategies are needed to help them communicate their views.
Bones of Contention: Thoughts on the Study of Animation
Authors: Darley Andrew
Published: February 2007

Within the academy, animation is still a relatively under-studied subject field - though, clearly, this is beginning to change. This article is a polemical response to the nascent field of animation studies. It explores some implications of the marginalization of animation and confronts what it views as significant obstacles (and cul-de-sacs) with respect to the progress and consolidation of the subject as a legitimate field of scholarship. An overall approach is suggested which - in certain respects - is at odds with what has been undertaken in the field in the past and with what is professed as legitimate and epistemologically productive in the present.
Inhibition of PC cell-derived growth factor (PCDGF)/granulin-epithelin precursor (GEP) decreased cell proliferation and invasion through downregulation of cyclin D and CDK 4 and inactivation of MMP-2
Authors: Liu Yulan , Xi Ling , Liao Guoning , Wang Wei , Tian Xun , Wang Beibei , Chen Gang , Han Zhiqiang , Wu Mingfu , Wang Shixuan , Zhou Jianfeng , Xu Gang , Lu Yunping , Ma Ding
Published: February 2007

Background

PC cell-derived growth factor (PCDGF), also called epithelin/granulin precursor (GEP), is an 88-kDa secreted glycoprotein with the ability to stimulate cell proliferation in an autocrine fashion. In addition, some studies indicated that PCDGF participated in invasion, metastasis and survival of cancer cells by regulating cell migration, adhesion and proliferation. Yet the effects of PCDGF on proliferation and invasion of ovarian cancer cells in vitro and the mechanisms by which PCDGF mediates biological behaviors of ovarian cancer have rarely been reported. In the present study we investigated whether and how PCDGF/GEP mediated cell proliferation and invasion in ovarian cancer.

Methods

PCDGF/GEP expression level in three human ovarian cancer cell lines of different invasion potential were detected by RT-PCR and western blot. Effects of inhibition of PCDGF expression on cell proliferation and invasion capability were determined by MTT assay and Boyden chamber assay. Expression levels of cyclin D1 and CDK4 and MMP-2 activity were evaluated in a pilot study.

Results

PCDGF mRNA and protein were expressed at a high level in SW626 and A2780 and at a low level in SKOV3. PCDGF expression level correlated well with malignant phenotype including proliferation and invasion in ovarian cancer cell lines. In addition, the proliferation rate and invasion index decreased after inhibition of PCDGF expression by antisense PCDGF cDNA transfection in SW626 and A2780. Furthermore expression of CyclinD1 and CDK4 were downregulated and MMP-2 was inactivated after PCDGF inhibition in the pilot study.

Conclusion

PCDGF played an important role in stimulating proliferation and promoting invasion in ovarian cancer. Inhibition of PCDGF decreased proliferation and invasion capability through downregulation of cyclin D1 and CDK4 and inactivation of MMP-2. PCDGF could serve as a potential therapeutic target in ovarian cancer.
Reliable allele detection using SNP-based PCR primers containing Locked Nucleic Acid: application in genetic mapping
Authors: Nakitandwe Joy , Trognitz Friederike , Trognitz Bodo
Published: February 2007

Background

The diploid, Solanum caripense, a wild relative of potato and tomato, possesses valuable resistance to potato late blight and we are interested in the genetic base of this resistance. Due to extremely low levels of genetic variation within the S. caripense genome it proved impossible to generate a dense genetic map and to assign individual Solanum chromosomes through the use of conventional chromosome-specific SSR, RFLP, AFLP, as well as gene- or locus-specific markers. The ease of detection of DNA polymorphisms depends on both frequency and form of sequence variation. The narrow genetic background of close relatives and inbreds complicates the detection of persisting, reduced polymorphism and is a challenge to the development of reliable molecular markers. Nonetheless, monomorphic DNA fragments representing not directly usable conventional markers can contain considerable variation at the level of single nucleotide polymorphisms (SNPs). This can be used for the design of allele-specific molecular markers. The reproducible detection of allele-specific markers based on SNPs has been a technical challenge.

Results

We present a fast and cost-effective protocol for the detection of allele-specific SNPs by applying Sequence Polymorphism-Derived (SPD) markers. These markers proved highly efficient for fingerprinting of individuals possessing a homogeneous genetic background. SPD markers are obtained from within non-informative, conventional molecular marker fragments that are screened for SNPs to design allele-specific PCR primers. The method makes use of primers containing a single, 3'-terminal Locked Nucleic Acid (LNA) base. We demonstrate the applicability of the technique by successful genetic mapping of allele-specific SNP markers derived from monomorphic Conserved Ortholog Set II (COSII) markers mapped to Solanum chromosomes, in S. caripense. By using SPD markers it was possible for the first time to map the S. caripense alleles of 16 chromosome-specific COSII markers and to assign eight of the twelve linkage groups to consensus Solanum chromosomes.

Conclusion

The method based on individual allelic variants allows for a level-of-magnitude higher resolution of genetic variation than conventional marker techniques. We show that the majority of monomorphic molecular marker fragments from organisms with reduced heterozygosity levels still contain SNPs that are sufficient to trace individual alleles.
Modulation of the Homocysteine-Betaine Relationship by Methylenetetrahydrofolate Reductase 677 C->T Genotypes and B-Vitamin Status in a Large-Scale Epidemiological Study
Authors: Holm Pål I. , Hustad Steinar , Ueland Per Magne , Vollset Stein Emil , Grotmol Tom , Schneede Jørn
Published: February 2007

Context: Betaine is formed from the essential nutrient choline or is supplied from the diet. It serves as a substrate in the betaine-homocysteine methyltransferase reaction and thereby provides methyl groups for the homocysteine-methionine cycle, which is regulated by enzymes dependent on folate, vitamin B12, riboflavin (vitamin B2), or vitamin B6.

Objective: We investigated how betaine affected total homocysteine (tHcy) concentration within the frame of variable B-vitamin status and according to the methylenetetrahydrofolate reductase (MTHFR) 677C->T genotype.

Design/Setting/Patients: This is a population-based study with a cross-sectional design. It includes 10,601 healthy men and women aged 50–64 yr.

Outcome Measures: Plasma samples were analyzed for tHcy, betaine, choline, dimethylglycine, riboflavin, and vitamin B6, whereas folate and vitamin B12 were analyzed in serum.

Results: Betaine was a strong determinant of plasma tHcy in subjects with low serum folate and the MTHFR TT genotype. The association was further strengthened at low levels in the circulation of the other B-vitamins (B2, B6, and B12). Thus, in subjects with the combination of serum folate in the lowest quartile, low vitamin B2, B6, and B12 status, and the MTHFR TT genotype, the difference in tHcy (mean, 95% confidence interval) across extreme plasma betaine quartiles was 8.8 (1.3–16.2) μmol/liter.

Conclusion: Betaine may thus be an important one-carbon source, particularly in MTHFR 677 TT subjects with inadequate B-vitamin status.
Impaired Sexual and Reproductive Outcomes in Women with Classical Forms of Congenital Adrenal Hyperplasia
Authors: Gastaud F. , Bouvattier C. , Duranteau L. , Brauner R. , Thibaud E. , Kutten F. , Bougnères P.
Published: February 2007

Objectives: The objectives of the study were 2-fold: 1) a detailed description of sexual and reproductive outcomes in adult women with congenital adrenal hyperplasia (CAH) of different phenotypic severity at birth; and 2) comparisons of these outcomes among CAH subtypes and between CAH women and non-CAH control women.

Design: This was a cross-sectional study using a face-to-face interview, a written questionnaire, the Female Sexual Function Index, and a gynecological examination.

Patients: Patients included 35 women with CAH, representing Prader stages I–V at birth, aged 18–43 yr, who had been treated from birth to adolescence in the same pediatric endocrine clinics. Sixty-nine non-CAH healthy control women were selected from hospital-staff families.

Results: None of the CAH women expressed doubts about their gender assignment. Twenty percent (seven of 35) had homosexual inclinations; 23% (eight of 35) were married; three reported a complete lack of sexual activity; and 37% (13 of 35) said they never had heterosexual intercourse with vaginal penetration. Sexual functioning as assessed by the Female Sexual Function Index was much lower in CAH women than controls and lowest in CAH women with high Prader stages. Eighty-one percent (18 of 22) experienced pain during vaginal penetration. Only eight women became pregnant, and 17% (six of 35) had children.

Conclusions: Despite expert medical and surgical care by physicians dedicated to this rare disease, women with CAH still suffer major limitations in their sexual function and reproductive life.
Androgens in Women with Anorexia Nervosa and Normal-Weight Women with Hypothalamic Amenorrhea
Authors: Miller K. K. , Lawson E. A. , Mathur V. , Wexler T. L. , Meenaghan E. , Misra M. , Herzog D. B. , Klibanski A.
Published: February 2007

Context: Anorexia nervosa and normal-weight hypothalamic amenorrhea are characterized by hypogonadism and hypercortisolemia. However, it is not known whether these endocrine abnormalities result in reductions in adrenal and/ or ovarian androgens or androgen precursors in such women, nor is it known whether relative androgen deficiency contributes to abnormalities in bone density and body composition in this population.

Objective: Our objective was to determine whether endogenous androgen and dehydroepiandrosterone sulfate (DHEAS) levels: 1) are reduced in women with anorexia nervosa and normal-weight hypothalamic amenorrhea, 2) are reduced further by oral contraceptives in women with anorexia nervosa, and 3) are predictors of weight, body composition, or bone density in such women.

Design and Setting: We conducted a cross-sectional study at a general clinical research center.

Study Participants: A total of 217 women were studied: 137 women with anorexia nervosa not receiving oral contraceptives, 32 women with anorexia nervosa receiving oral contraceptives, 21 normal-weight women with hypothalamic amenorrhea, and 27 healthy eumenorrheic controls.

Main Outcome Measures: Testosterone, free testosterone, DHEAS, bone density, fat-free mass, and fat mass were assessed.

Results: Endogenous total and free testosterone, but not DHEAS, were lower in women with anorexia nervosa than in controls. More marked reductions in both free testosterone and DHEAS were observed in women with anorexia nervosa receiving oral contraceptives. In contrast, normal-weight women with hypothalamic amenorrhea had normal androgen and DHEAS levels. Lower free testosterone, total testosterone, and DHEAS levels predicted lower bone density at most skeletal sites measured, and free testosterone was positively associated with fat-free mass.

Conclusions: Androgen levels are low, appear to be even further reduced by oral contraceptive use, and are predictors of bone density and fat-free mass in women with anorexia nervosa. Interventional studies are needed to confirm these findings and determine whether oral contraceptive use, mediated by reductions in endogenous androgen levels, is deleterious to skeletal health in such women.
Cranial Irradiation and Growth Hormone Neurosecretory Dysfunction: A Critical Appraisal
Authors: Darzy Ken H. , Pezzoli Suzan S. , Thorner Michael O. , Shalet Stephen M.
Published: February 2007

Context: It has been suggested that radiation-induced GH neurosecretory dysfunction exists in children; however, the pathophysiology is poorly understood, and it is unknown if such a phenomenon exists in adult life.

Study Subjects: Twenty-four-hour spontaneous GH secretion was studied by 20-min sampling both in the fed state (n = 16; six women) and the last 24 h of 33-h fast (n = 10; three women) in adult cancer survivors of normal GH status defined by two GH provocative tests, 13.1 ± 1.6 (range, 3–28) yr after cranial irradiation (18–40 Gy) for nonpituitary brain tumors (n = 12) or leukemia (n = 4) in comparison with 30 (nine women) age- and body mass index-matched normal controls (fasting, 11 men and three women).

Results: Using previously published diagnostic thresholds, all patients had stimulated peak GH responses in the normal range to both the insulin tolerance test and the combined GHRH plus arginine stimulation test, as well as normal individual mean profile GH levels during the fed and fasting states. However, gender-specific comparisons revealed marked reduction (by 40%) in the overall peak GH responses to both provocative tests but similar GH secretory profiles; no differences were seen in the pulsatile attributes of GH secretion (cluster analysis) or the profile absolute and mean GH levels in the fed state or when the hypothalamic-pituitary axis was stimulated by fasting.

Conclusions: Radiation-induced GH neurosecretory dysfunction either does not exist or is a very rare phenomenon in irradiated adult cancer survivors. The normality of physiological GH secretion in the context of reduced maximum somatotroph reserve suggests compensatory overdrive of the partially damaged somatotroph axis and constitutes a relative argument against somatotroph dysfunction being explained purely by hypothalamic damage with secondary atrophy due to GHRH deficiency. It is therefore possible that radiation in doses less than 40 Gy causes dual damage to both the pituitary and the hypothalamus.
Influence of an Interactive Computer-Based Inhaler Technique Tutorial on Patient Knowledge and Inhaler Technique
Authors: Navarre Matt , Patel Hiral , Johnson Cary E , Durance Ann , McMorris Marc , Bria William , Erickson Steven R
Published: February 2007

Background:

Patient knowledge of correct inhaler technique is essential in the treatment of pulmonary disease. Computer delivery of educational content may augment existing teaching efforts.

Objective:

To determine whether a computer-based tutorial on inhaler technique could improve patients' knowledge and ability to correctly demonstrate inhaler technique.

Methods:

A total of 34 adults with pulmonary disease and experience using inhalers were randomized into the control or intervention groups. The intervention group viewed the tutorial, after which they demonstrated their inhaler technique and completed an Inhaler Technique Knowledge Test. Control group patients, who did not view the tutorial, were also evaluated on their demonstrated inhaler technique and technique knowledge. Additional information obtained included demographics, illness and treatment history, and patients' use of computers. Lastly, all patients who viewed the tutorial completed a brief questionnaire eliciting tutorial feedback. Control group patients were invited to view the tutorial after other data collection was complete. The 2 principal outcomes were the observed inhaler technique score and the inhaler technique knowledge test score. Comparisons between groups were conducted using Student's t-test and χ2 test, with a p value less than 0.05 considered statistically significant.

Results:

Eighteen subjects were enrolled in the computer group; 16 were in the control group. The intervention group demonstrated significantly better inhaler technique, with a mean Observed Inhaler Technique Score of 88.3 ± 12.3 compared with 67.4 ± 19.2 for the control group (p = 0.001). The intervention group also scored significantly higher on the Inhaler Technique Knowledge Test, with a score of 80.9 ± 17.0 versus 67.4 ± 11.8 for the control group (p = 0.01). Overall, the program appeared acceptable to patients.

Conclusions:

Patients in the tutorial group demonstrated better inhaler technique and scored higher on the Inhaler Technique Knowledge Test compared with those in a control group. This tutorial may be a useful educational tool to enhance patient education regarding inhaler technique.
Pyridostigmine in the Treatment of Orthostatic Intolerance
Authors: Gales Barry J , Gales Mark A
Published: February 2007

Objective:

To review the efficacy of pyridostigmine bromide for the treatment of orthostatic intolerance.

Data Sources:

MEDLINE and International Pharmaceutical Abstracts were searched (1966–December 2006) using the terms pyridostigmine, acetylcholinesterase inhibitor, orthostatic intolerance, orthostatic hypotension, neurogenic orthostatic hypotension, postural tachycardia syndrome, tachycardia, and orthostatic tachycardia.

Study Selection and Data Extraction:

Pertinent English-language human clinical trials, case reports, and background material were evaluated for safety and efficacy data. The references of reviewed articles were reviewed and used to identify additional sources.

Data Synthesis:

Pyridostigmine bromide has been associated with improved baroreceptor sensitivity and presents a novel approach to treatment of orthostatic intolerance. Four single-dose trials and a follow-up survey encompassing a total of 106 patients were identified. One open-label and one placebo-controlled single-dose trial in patients with neurogenic orthostatic hypotension (NOH) found statistically significant improvement in standing diastolic blood pressures (DBP). Absolute improvements in standing DBP were 3.7 and 6.4 mm Hg in the open-label and controlled trials, respectively. Long-term data consist of a single survey of patients receiving open-label pyridostigmine bromide. Twenty-nine percent of patients who initiated maintenance pyridostigmine bromide discontinued therapy. Concomitant NOH medications were taken by 75% of patients, and 85% of patients reported receiving benefit from pyridostigmine bromide. When evaluated for postural tachycardia syndrome, pyridostigmine bromide significantly reduced standing heart rate (10%). Pyridostigmine bromide significantly reduced symptom scores when compared with baseline but not placebo. The majority of patients included in these trials did not have supine hypertension.

Conclusions:

Single doses of pyridostigmine bromide produced modest but statistically significant improvements in hemodynamic measurements. At this time, long-term data are insufficient to support recommending the routine use of pyridostigmine bromide for treatment of orthostatic intolerance.
Preparing Todayis Teachers of the Deaf and Hard of Hearing to Work With Tomorrowis Students: A Statewide Needs Assessment
Authors: Dodd Evelyn E , Scheetz Nanci A
Published: February 2007

The Individuals with Disabilities Education Act is explicit in its mandate
that students who receive special education services have opportunities to
be involved in and progress in the general education curriculum. Teachers
providing instruction to students who are deaf or hard of hearing are
expected to comply with this federal mandate. To determine if teachers of
students who are deaf or hard of hearing throughout the state of Georgia
felt adequately prepared to educate this population, a statewide needs
assessment survey was conducted. Questionnaires were reviewed from 110
experienced teachers of students who are deaf or hard of hearing. More
that half of the teachers who responded judged their teacher preparation
program to be appropriate. Specific suggestions for modifications to
teacher preparation programs are provided.
Micro-local characterization of quasi-homogeneous singularities
Authors: Xu Yi-Jing , Yau Stephen S.-T.
Published: February 2007

A moduli algebra A ( V ) of hypersurface singularity ( V , 0) is a finite dimensional C -algebra. In 1982, Mather and Yau proved that two germs of complex analytic hypersurfaces of the same dimension with isolated singularities are biholomorphically equivalent if and only if their moduli algebra are isomorphic. It is a natural question to ask for a necessary and sufficient condition for a complex analytic isolated hypersurface singularity to be quasi-homogeneous in terms of its moduli algebra. In this paper we prove that ( V , 0) admits a quasi-homogeneous structure if and only if its moduli algebra is isomorphic to a finite dimensional nonnegatively graded algebra. In 1983, Yau introduced a finite dimensional Lie algebra L ( V ) to an isolated hypersurface singularity ( V , 0). L ( V ) is defined to be the algebra of derivations of the moduli algebra A ( V ) and is finite dimensional. We prove that ( V , 0) is quasi-homogeneous singularity if (1) L ( V ) is isomorphic to a nonnegatively graded Lie algebra without center, (2) There exists E in L ( V ) of degree zero such that [ E, D i ] = i D i for any D i in L ( V ) of degree i , and (3) For any element a ∈ m - m 2 where m is the maximal ideal of A ( V ), aE is not in degree zero part of L ( V ).
Zeros of the Wronskian and renormalized oscillation theory
Authors: Gesztesy F. , Simon B. , Teschl G.
Published: February 2007

For general Sturm-Liouville operators with separated boundary conditions, we prove the following: If E 1,2 ∈ R and if u 1,2 solve the differential equation Hu j = E j u j , j = 1, 2 and respectively satisfy the boundary condition on the left/right, then the dimension of the spectral projection P ( E 1 , E 2 ) ( H ) of H equals the number of zeros of the Wronskian of u 1 and u 2 .
Opérateurs d'entrelacement pour les groupes de lie exponentiels
Authors: Arnal Didier , Fujiwara Hidenori , Ludwig Jean
Published: February 2007

Soit G un groupe de Lie exponentiel, d'algèbre de Lie g. Soit f un point du dual g* de g. Si h 1 et h 2 sont des polarisations en f qui satisfont la condition de Pukanszky, alors les représentations π i = ind G H i χ f ( i = 1, 2, H i = exp h i , χ f ( exp X ) = e if ( X ) pour X dans g) sont irréductibles et équivalentes. Le principal obstacle à la construction d'un opérateur d'entrelacement pour ces représentations est de prouver la convergence d'une certaine intégrale. Dans cet article, nous présentons un opérateur d'entrelacement explicite pour π 1 et π 2 qui évite cette difficulté.
On the topological cyclic homology of the integers
Authors: Tsalidis Stavros
Published: February 2007

This article provides a computation of the mod p homotopy groups of the fixed points of the Topological Hochschild Homology of the ring of integers under the action of any finite subgroup of the cirle group whose order is a power of an odd prime p . This leads to a computation of the Topological Cyclic Homology groups of the ring of integers, and determines also the p -adic completion of the algebraic K -theory of the p -adic integers.
On Cartan's theorem and Cartan's conjecture
Authors: Vojta Paul
Published: February 2007

We give a mild generalization of Cartan's theorem on value distribution for a holomorphic curve in projective space relative to hyperplanes. This generalization is used to complete the proof of the following theorem claimed in an earlier paper by the author: Given hyperplanes in projective space in general position, there exists a finite union of proper linear subspaces such that all holomorphic curves not contained in that union (even linearly degenerate curves) satisfy the inequality of Cartan's theorem, except for the ramification term. In addition, it is shown how these methods can lead to a shorter proof of Nochka's theorem on Cartan's conjecture and (in the number field case) how Nochka's theorem gives a short proof of Wirsing's theorem on approximation of algebraic numbers by algebraic numbers of bounded degree.
Multiparameter operators and sharp weighted inequalities
Authors: Fefferman R. , Pipher J.
Published: February 2007

This article is concerned with the operators from harmonic analysis which are naturally associated to a multiple parameter family of dilations. We are especially interested here in dealing with questions from the theory of such operators whose answers cannot be obtained by a reduction to the case of product operators. We also introduce a new tool in order to carry out this multiparameter analysis which comes from the classical theory. This is the concept of "sharp weighted inequalities," where, for operators such as the Hilbert transform or classical square function, one asks for Hilbert space inequalities which imply the correct estimates of the norm on L p of these operators as p becomes large.