bluuebunny/crossref_metadata_2025 huggingface dataset:
The Heritability of Life Events: An Adolescent Twin and Adoption Study
Authors: Bemmels Heather R. , Burt S. Alexandra , Legrand Lisa N. , Iacono William G. , McGue Matt
Published: May 2008

Although life events are often conceptualized as reflecting exogenous risk factors for psychopathology, twin studies have suggested they are heritable. We undertook a mixed twin/adoption study to further explore genetic and environmental contributions to individual differences in the experience of life events. Specifically, a sample of 618 pairs of like-sex adolescent twins, 244 pairs of like-sex adopted adolescent and young adult siblings, and 128 pairs of like-sex biological siblings completed a life events interview. Events were classified as independent (not likely to have been influenced by respondent's behavior), dependent (likely to have been influenced by respondent's behavior), or familial (experienced by a family member), and then summed to form three life event scales. Variance on the scales was assumed to be a function of four factors: additive genetic effects (a2), shared environmental effects (c2), twin-specific effects (t2), and nonshared environmental effects (e2). Data were analyzed using standard biometrical models. Shared environmental effects were found to be the largest contributor to variance in familial events (c2 = .71; 95% confidence interval of .65, .76); additive genetic effects were the largest contributor to dependent events (a2 = .45; CI = .31, .58); and nonshared environmental effects were found to be the largest contributor independent events (e2 = .57; CI = .51, .64). A significant twin-specific effect was also found for independent life events, indicating that twins are more likely to be exposed to such events than non-twin biological siblings. Findings are discussed in terms of their implication for understanding the nature of psychosocial risk.
Sex Differences in Genetic and Environmental Contributions to Depression Symptoms in South Korean Adolescent and Young Adult Twins
Authors: Hur Yoon-Mi
Published: May 2008

It has been reported that prevalence estimates, symptom presentation, and sociocultural risk and protective factors for depression differ between Caucasian and East Asian populations. But, nonetheless, as the vast majority of twin studies of depression symptoms have been carried out using Caucasians, genetic and environmental influences on depression symptoms in East Asians remain poorly understood. In the present study, the Center for Epidemiologic Studies — Depression Scale (CES-D) was administered to 490 pairs of South Korean adolescent and young adult twins (ages: 13–23 years) by telephone interview. In males, monozygotic (MZ) and dizygotic (DZ) twin correlations were similar (.44 vs. .41), suggesting the importance of shared environmental factors in depression symptoms. In females, however, MZ twin correlation was much greater than DZ twin correlation (.40 vs. .23), indicating the importance of genetic influences. The total phenotypic variance for the CES-D was greater in females than in males. Variance components model confirmed sex differences in the magnitude of genetic and environmental influences on depression symptoms: Additive genetic, shared environmental, and individual specific environmental effects in the full model were, res pectively, 12% (95% CI: 0–54%), 32% (95% CI: 0–53%), and 56% (95% CI: 44–70%) in males, and 41% (95% CI: 0–52%), 0% (95% CI: 0–36%), and 59% (95% CI: 48–72%) in females. Similar results were observed when ‘culturally biased’ items of the CES-D were separately analyzed. These variance components estimates for depression symptoms in East Asians overlap those observed in Caucasians.
Sex Differences in Genetic and Environmental Influences on Obsessive–Compulsive Symptoms in South Korean Adolescent and Young Adult Twins
Authors: Hur Yoon-Mi , Jeong Hoe-Uk
Published: May 2008

Recent molecular genetic studies provide suggestive evidence for sexual dimorphism in genetics of obsessive-compulsive disorder. However, only a few twin studies have addressed the question of sex differences in genetic and environmental contributions to variation of obsessive–compulsive symptoms. The aim of the present study was to estimate genetic and environmental influences on obsessive–compulsive symptoms in South Korean twins, with a special emphasis on sex difference. In total, 751 adolescent and young adult twin pairs (ages: 13–23 years) completed a Korean version of the 30 items of the Maudsley Obsessional — Compulsive Inventory (MOCI) through a mail survey. A sum of the answers for the 30 items was calculated to represent a total score for obsessive–compulsive symptoms (hereafter, the MOCIT). Males had significantly higher variance of the MOCIT than did females. In males, monozygotic (MZ) twin correlation was significantly higher than dizygotic (DZ) twin correlations (.56 vs. .24), whereas in females, MZ and DZ twin correlations were not significantly different from each other (.39 vs. .36). The general sex-limitation model was applied to the twin data. The results of model-fitting analyses indicated that the unstandardized genetic variance as well as heritability estimate (53% vs. 41%) for the MOCIT was higher in males than in females. However, shared environmental influences did not attain statistical significance perhaps due to insufficient statistical power.
Multivariate Genetic Analyses of the 2D:4D Ratio: Examining the Effects of Hand and Measurement Technique in Data from 757 Twin Families
Authors: Medland Sarah E. , Loehlin John C.
Published: May 2008

The ratio of the lengths of the second to fourth digits of the hand (2D:4D) is a sexually dimorphic trait that has been proposed as a measure of prenatal testosterone exposure and a putative correlate of a variety of later behavioral and physiological outcomes including personality, fitness and sexual orientation. We present analyses of 2D:4D ratios collected from twins (1413 individuals) and their nontwin siblings (328 individuals) from 757 families. In this sample 2D:4D was measured from photocopies using digital calipers, and for a subset of participants, computer-aided measurement. Multivariate modeling of the left- and right-hand measurements revealed significant genetic and environmental covariation between hands. The two methods yielded very similar results, and the majority of variance was explained by factors shared by both measurement methods. Neither common environmental nor dominant genetic effects were found, and the covariation between siblings could be accounted for by additive genetic effects accounting for 80% and 71% of the variance for the left and right hands, respectively. There was no evidence of sex differences in the total variance, nor in the magnitude or source of genetic and environmental influences, suggesting that X-linked effects (such as the previously identified association with the Androgen receptor) are likely to be small. However, there were also nonshared environmental effects specific to each hand, which, in addition to measurement error, may in part explain why some studies within in the literature find effects for the 2D:4D ratio of one hand but not the other.
Discordant Prenatal Phenotype and Karyotype of Monozygotic Twins Characterized by the Unequal Distribution of Two Cell Lines Investigated by Different Methods: A Review
Authors: Gentilin Barbara , Guerneri Silvana , Bianchi Vera , Natacci Federica , Colombo Augusto , Fogliani Roberto , Fortuna Renato , Coviello Domenico A. , Curcio Cristina , Lalatta Faustina
Published: May 2008

We present the case of a monozygotic twin pregnancy discordant for phenotype and karyotype. A chorionic villus sample was performed at the 11th week of gestation in a primigravida because of cystic hygroma detected by ultrasound in one twin of a monochorionic, biamniotic pregnancy. Rapid testing by means of quantitative fluorescence polymerase chain reaction and conventional karyotyping, obtained by both short- and long-term culture, revealed a homogeneous monosomy X (45,X). Amniocentesis was performed separately for both twins before termination and showed an homogeneous monosomy X in one sample and a 46,X,del(X)(p11.1) karyotype in the other one. Postmortem fetal tissues culture confirmed the discordant karyotype between the two embryos. Placental samples obtained after termination revealed the cell line which was not detected at chorionic villus sampling. Based on this and previous reports, we suggest that in cases of a phenotypic discordance detected at ultrasound in the first trimester, it is advisable to perform a karyotype analysis on amniocytes because it better reflects fetal constitution rather than chorionic villi or lymphocytes in case of heterokaryotipic monosomy X monochorionic twins.
Elizabeth M. Bryan: Tributes From Home and Abroad; Research Reviews: Anorexia Nervosa in Opposite-Sex Twins, Twin Study of Self-Esteem, DNA Differences in Monozygotic Twins; Twins and More Twins: Twins Living Apart, Twins Playing Together, Twins Working Together, Twins Playing Apart, Multiple Birth Odds
Authors: Segal Nancy L.
Published: May 2008

Elizabeth M. Bryan: Tributes From Home and Abroad

May 13, 1942 – February 21, 2008

The life and work of Dr Elizabeth M. Bryan, our late distinguished twin studies colleague, are remembered. Tributes come from colleagues in the United States and the United Kingdom, where Elizabeth lived and worked. This section is followed by reviews of twin research on anorexia nervosa, self-esteem and DNA differences in monozygotic twins. The lives of some noteworthy twins are also briefly chronicled, both for their scientific value and human interest. An update on current twinning rates follows.
The World of Port-Royal: The Jansenist Movement in the Catholic Church, 17th–18th Centuries
Authors: Palmer Douglas
Published: May 2008

The seventeenth and eighteenth century Catholic reform movement known as Jansenism is best recognized by historians of the period as a primarily French phenomenon. Indeed, it was in France where the neo-Augustinism teaching of the University of Louvain theologian and Bishop of Ypres Cornelius Jansen made its most widespread and dramatic impact. Hated equally in France by supporters of absolutism, papal infallibility, and the
Strategies for Building Digitized Collections
Authors: Smith Abby
Published: May 2008

Libraries have been digitizing collections for a decade or more. Their collective experience has produced a depth of technical expertise and a set of tested practices. That information is widely shared among library staffs and has been well reported at meetings and in publications. This ongoing experiment with representing research collections online has resulted in the codification of technical practices and the emergence of clear trends in selection policies. This paper reviews existing selection practices in libraries, identifies selection policies and best practices where they exist, and discusses the long-term implications of the opportunities and constraints that shape digital-conversion programs. This is not a systematic review of what all research libraries are doing, but an analysis of significant achievements that will make it possible to identify good practices and benchmarks for success. Every library, regardless of size or mission, will need to determine for itself how and when digitization will move from being an experiment to becoming a collection-development strategy that is well integrated into its daily practice.
Evaluation of endocrine testing of Leydig cell function using extractive and recombinant human chorionic gonadotropin and different doses of recombinant human LH in normal men
Authors: Cailleux-Bounacer Anne , Reznik Yves , Cauliez Bruno , Menard Jean François , Duparc Céline , Kuhn Jean Marc
Published: May 2008

Background

The functional testing of endocrine testis uses extractive human chorionic gonadotropin (ehCG). Recombinant human hCG (rhCG), avoiding any contamination, should replace ehCG. Moreover, a functional evaluation with recombinant human LH (rhLH) would be closer to physiology than a pharmacological testing with hCG.

Methods

The study was conducted in normal men. We first evaluated the dose–effect of ehCG on plasma testosterone and estradiol levels, before and after injection of either hCG or vehicle. Secondly, the responses to the optimal dose of ehCG were compared with those of rhCG. Thirdly, we investigated the dose–effect of rhLH, on steroid hormone secretion. LH, testosterone, and estradiol plasma levels were measured after the injection of either rhLH or placebo.

Results

ehCG induced dose-dependent increases in plasma estradiol and testosterone levels. They respectively peaked at 24 and 72 h after the injection. The most potent dose of ehCG (5000 IU) induced results similar to those observed with 250 μg (6500 IU) rhCG. By comparison with placebo, rhLH induced a significant and dose-dependent increase in plasma testosterone levels 4 h after the injection. Peak response of testosterone to rhLH and rhCG was significantly correlated. rhLH did not induce significant change in plasma estradiol level.

Conclusions

In normal men, a single i.v. injection of 150 IU rhLH induces a 25% rise in plasma testosterone levels by comparison with placebo. At the moment, the dynamic evaluation using hCG remains the gold standard test to explore the Leydig cell function. The use of 250 μg rhCG avoiding any contamination should be recommended.
Normalization of catecholamine production following resection of phaeochromocytoma positively influences carotid vascular remodelling
Authors: Bernini Giampaolo , Galetta Fabio , Franzoni Ferdinando , Bardini Michele , Taurino Chiara , Moretti Angelica , Bernini Matteo , Berti Piero , Miccoli Paolo , Salvetti Antonio
Published: May 2008

Objective

To evaluate the influence of plasma catecholamines on the vascular structure in humans, the effects of catecholamine normalization on the carotid wall of patients with phaeochromocytoma (PHEO) were investigated. A prospective study in patients with PHEO before and after (first follow-up: 20.5±1.8 months, second follow-up: 31.5±2.2 months) successful surgery was conducted in the University Referral Center for Blood Pressure Diseases. Ten consecutive patients with PHEOs and ten age- and blood pressure-matched controls were investigated. Intima–media thickness (IMT) by two-dimensional conventional ultrasonography and corrected ultrasonic integrated backscatter signal (C-IBS) analysis of carotid arteries were investigated in basal conditions and after mass removal.

Results

In PHEOs, at variance with the expected reduction in metanephrines and catecholamines, no variation in body weight, blood pressure and lipid profile was observed after operation. IMT and C-IBS values in patients with PHEO were greater (at least P<0.01) than in controls. At long-term follow-up after surgery, a significant reduction in mean carotid IMT (P<0.0009) and C-IBS (P<0.009) values was observed. A significant correlation (r=0.54, P<0.03) was found between absolute reduction in C-IBS values and absolute decrement in urinary normetanephrine levels.

Conclusions

Our study shows that normalization of catecholamine levels after the removal of PHEO improves carotid IMT and reduces carotid wall fibrosis even without influencing blood pressure and lipid profile. These findings confirm that high catecholamine tone in humans directly influences vascular remodelling of carotid arteries.
The association of thyroid function with carotid artery plaque burden and strokes in a population-based sample from a previously iodine-deficient area
Authors: Dörr Marcus , Empen Klaus , Robinson Daniel M , Wallaschofski Henri , Felix Stephan B , Völzke Henry
Published: May 2008

Background

Thyroid dysfunction is associated with detrimental cardiovascular effects. We analyzed whether thyroid status is related to carotid artery plaques and prevalent strokes.

Design, patients and measurements

Data from 2128 subjects (1157 men and 971 women) aged ≥45 years without thyroid diseases participating in the Study of Health in Pomerania were analyzed. The presence of carotid plaques was assessed by B-mode ultrasound and prevalent stroke was assessed by interview. The sample was divided according to the reference range of serum TSH levels into decreased (<0.25 mIU/l), normal (0.25–2.12 mIU/l), and elevated (>2.12 mIU/l). Logistic regression models were adjusted for common confounders including age, sex, BMI, hypertension, diabetes mellitus, smoking, school education, plasma fibrinogen and serum cholesterol levels, and statins.

Results

The prevalence of carotid plaques at any site was higher in subjects with decreased serum TSH levels (81.7%) compared with normal serum TSH levels (70.2%) and elevated serum TSH levels (65.6%; P<0.001). Fully adjusted logistic regression models revealed increased odds for carotid plaques (odds ratio (OR) 1.67; 95% confidence interval (CI) 1.11–2.51; P<0.05) as well as for prevalent strokes (OR 1.98; 95% CI 1.05–3.73; P<0.05) in subjects with decreased serum TSH levels, while there was no association between elevated serum TSH levels and carotid plaques or stroke respectively.

Conclusions

Thyroid function was associated with the presence of carotid artery plaques and prevalent strokes in this population-based sample. Periodical screening and early treatment of atherosclerotic risk factors should be performed in subjects with decreased serum TSH levels.
Recombinant human GH replacement increases CD34+ cells and improves endothelial function in adults with GH deficiency
Authors: van der Klaauw Agatha A , Pereira Alberto M , Rabelink Ton J , Corssmit Eleonora P M , Zonneveld Anton-Jan , Pijl Hanno , de Boer Hetty C , Smit Johannes W A , Romijn Johannes A , de Koning Eelco J P
Published: May 2008

Objective

Adult patients with GH deficiency (GHD) are at increased risk for cardiovascular morbidity and mortality. Endothelial function, vascular stiffness, and loss of circulating CD34+ cells are considered biomarkers for cardiovascular disease. The aim of this study was to assess vascular structure and function in relation to circulating CD34+ cells in adults with GHD before and during 1 year of recombinant human GH (rhGH) replacement.

Design

One-year intervention with rhGH.

Patients and methods

Vascular function (flow-mediated dilatation (FMD)) and structure (pulse wave velocity (PWV) and analysis) were assessed in 14 adult patients (nine men) with GHD (mean age 57 years, range 27–71 years). In addition, the number of CD34+ cells was evaluated using flow cytometric analysis. Study parameters were analyzed at baseline, and after 6 months and 1 year of rhGH replacement.

Results

rhGH replacement increased IGF-I levels from 10.4±4.5 mmol/l at baseline to 18.4±10.1 mmol/l, and 20.5±8.0 mmol/l, at 6 months, and 1 year respectively (P=0.001). FMD increased from 3.5±1.8% to 6.0±2.5% and 5.1±2.5% during 1 year of rhGH replacement (P=0.008). There was no beneficial effect on PWV, central pulse pressure, central systolic pressure, and augmentation index. The number of CD34+ cells increased from 794.9±798.8 to 1270.7±580.1 cells/ml and to 1356.9±759.0 cells/ml (P=0.010).

Conclusion

One year of rhGH replacement in adults with GHD improves endothelial function and increases the number of circulating CD34+ cells.
Irrigation Canals as Sink Habitat for Trout and Other Fishes in a Wyoming Drainage
Authors: Roberts James J. , Rahel Frank J.
Published: May 2008

Irrigation canals can be a major source of mortality for fish in the Rocky Mountain region. Our study looked at how fish were affected by the irrigation canal system in the Smiths Fork, a tributary to the Bear River in western Wyoming. There are two native species of conservation concern in the Smiths Fork drainage: Bonneville cutthroat trout Oncorhynchus clarkii utah and northern leatherside chub Lepidomeda copei. Our objectives were to determine the relative abundance of each species within the canals and the fate of trout (Bonneville cutthroat trout and brown trout Salmo trutta) that enter canals. During the summer of 2003 we sampled 30 sites within the Covey Canal system, which is the largest canal system withdrawing water from the Smiths Fork. Because fish were observed to accumulate at certain spots in the canal system, we developed a sampling scheme that incorporated both random sample sites and sites known to attract fish. We estimated that between 6,300 and 10,400 fish encompassing 10 species were entrained in this canal system. The two most abundant species were speckled dace Rhinichthys osculus (29% of all fish) and mountain sucker Catostomus platyrhynchus (37% of all fish). Bonneville cutthroat trout and northern leatherside chub each comprised 2% of the total entrained fish. We implanted 30 Bonneville cutthroat trout and 13 brown trout with radio transmitters to determine whether entrained trout could leave the canal system when water levels were reduced in late summer. We found that 77% of the transmitter‐implanted fish died within the canals, indicating that this system functions as sink habitat for Bonneville cutthroat trout and brown trout. Based on this mortality rate, we estimated that 120 Bonneville cutthroat trout (95% confidence interval, 75‐165) and 299 brown trout (280‐317) perished in the Covey Canal system during the summer of 2003.
Metastatic Pancreatic Cancer 2008: Is the Glass Less Empty?
Authors: Nieto Jacqueline , Grossbard Michael L. , Kozuch Peter
Published: May 2008

Editor's Note

This article is not available for CME.
Cardiac corticosteroid receptors mediate the enlargement of the ovine fetal heart induced by chronic increases in maternal cortisol
Authors: Reini Seth A , Dutta Garima , Wood Charles E , Keller-Wood Maureen
Published: May 2008

Previous studies have demonstrated that modest, physiologically relevant increases in maternal cortisol in late gestation result in enlargement of the fetal heart. In this study, we investigated the role of mineralocorticoid receptor (MR) or glucocorticoid receptor (GR) in this enlargement. Ewes with single fetuses were randomly assigned at ∼120 days of gestation to one of four groups: maternal cortisol infusion (1 mg/kg per day, cortisol); maternal cortisol infusion with fetal intrapericardial infusion of the MR antagonist (MRa) potassium canrenoate (600 μg/day; cortisol+MRa); maternal cortisol infusion with fetal intrapericardial infusion of the GR antagonist (GRa) mifepristone (50 μg/day, cortisol+GRa); and maternal saline infusion (control). At ∼130 days of gestation, fetal heart to body weight ratio and right ventricular (RV) and left ventricular (LV) free wall thicknesses were increased in the cortisol group when compared with control group. Fetal hearts from the cortisol+MRa group weighed significantly less, with thinner LV, RV, and interventricular septum walls, when compared with the cortisol group. Fetal hearts from the cortisol+GRa group had significantly thinner RV walls than the cortisol group. Fetal arterial pressure and heart rate were not different among groups at 130 days. Picrosirius red staining of fetal hearts indicated that the increased size was not accompanied by cardiac fibrosis. These results suggest that physiologic increases in maternal cortisol in late gestation induce fetal cardiac enlargement via MR and, to a lesser extent, by GR, and indicate that the enlargement is not secondary to an increase in fetal blood pressure or an increase in fibrosis within the fetal heart.
Back to the future: a new look at ‘old’ vitamin D
Authors: Chun Rene F , Adams John S , Hewison Martin
Published: May 2008

Our perception of the vitamin D system continues to evolve. Recent studies have re-evaluated the parameters for adequate vitamin D status in humans, revealing a high prevalence of insufficiency in many populations throughout the world. Other reports have highlighted the potential consequences of vitamin D insufficiency beyond established effects on bone homeostasis. Most notably, there is now strong evidence of a role for vitamin D in modulating innate and adaptive immunities, with insufficiency being linked to infectious disease and other immune disorders. To date, signaling pathways for these new responses to vitamin D have been based on established endocrine models for active 1,25-dihydroxyvitamin D, despite present evidence for more localized, intracrine modes of action. In the following review, we provide a fresh perspective on vitamin D signaling in non-classical target cells such as macrophages by highlighting novel factors associated with the transport and action of this pluripotent secosteroid.
Stage-dependent differences in effects of carbaryl on population growth rate in Japanese medaka (Oryzias latipes)
Authors: Kashiwada Shosaku , Tatsuta Haruki , Kameshiro Maiko , Sugaya Yoshio , Sabo-Attwood Tara , Chandler G. Thomas , Ferguson P. Lee , Goka Koichi
Published: May 2008

Fish embryo toxicology is important because embryos are considered more susceptible than adult fish to the effects of toxic chemicals. Recently, fish embryo bioassay was proposed to replace the conventional fish acute toxicity chemical test of the Organization for Economic Cooperation and Development guidelines because it offers the advantages of fewer reagents, easy handling, and efficient data production. To accelerate the establishment of a chemical toxicity database for the protection of environmental and human health, we need to determine whether the conventional toxicity test can safely be replaced by such fish embryo toxicity tests. For instance, it is unclear how the presence of the chorion moderates the toxic effects of some chemicals. If such chemical toxicities do differ between embryos and, for example, the larval stage, then different toxic effects should appear in later life. We tested the later-life effects of the neurotoxic insecticide carbaryl at sublethal concentrations (0 [control] and 5 and 10 mg/L) in embryos and posthatch larvae of the freshwater fish medaka, Oryzias latipes. Although embryos exposed until hatching showed multiple developmental malformations and reductions in subsequent survival rates over three months, no significant reduction was observed in tolerance to starvation for 7 d and in intrinsic population growth rate (r). Exposure of larvae for 96 h resulted in dose-responsive vertebral fracture, significant reduction in tolerance to starvation for 7 d, and reduced three-month survival rate; r was reduced significantly and consistently. These results suggested that posthatch larvae were more susceptible than embryos to carbaryl exposure and that the toxic cascades may differ between larvae and embryos. The influences of carbaryl exposure on population growth rate differed significantly with developmental stage.
Evidence for Radiation Hormesis after In Vitro Exposure of Human Lymphocytes to Low Doses of Ionizing Radiation
Authors: Rithidech Kanokporn Noy , Scott Bobby R.
Published: May 2008

Previous research has demonstrated that adding a very small gamma-ray dose to a small alpha radiation dose can completely suppress lung cancer induction by alpha radiation (a gamma-ray hormetic effect). Here we investigated the possibility of gamma-ray hormesis during low-dose neutron irradiation, since a small contribution to the total radiation dose from neutrons involves gamma rays. Using binucleated cells with micronuclei (micronucleated cells) among in vitro monoenergetic-neutron-irradiated human lymphocytes as a measure of residual damage, we investigated the influence of the small gamma-ray contribution to the dose on suppressing residual damage. We used residual damage data from previous experiments that involved neutrons with five different energies (0.22–, 0.44–, 1.5–, 5.9–, and 13.7-million electron volts [MeV]). Corresponding gamma-ray contributions to the dose were approximately 1%, 1%, 2%, 6%, and 6%, respectively. Total absorbed radiation doses were 0, 10, 50, and 100 mGy for each neutron source. We demonstrate for the first time a protective effect (reduced residual damage) of the small gamma-ray contribution to the neutron dose. Using similar data for exposure to gamma rays only, we also demonstrate a protective effect of 10 mGy (but not 50 or 100 mGy) related to reducing the frequency of micronucleated cells to below the spontaneous level.
Acetal Resins
Authors: Dolce Thomas J. , Grates John A.
Published: May 2008

Acetal resins are the family of polymers derived primarily from formaldehyde and therefore have a repeat unit, (CH
2
—O)

n

. The homopolymers are completely characterized by this repeat unit and the name polyoxymethylene is more structurally descriptive. Acetal copolymers have the oxymethylene structure occasionally interrupted by the comonomer unit. The designation aldehyde polymers generally refers to polymers of aldehydes larger than formaldehyde. The term polyacetal should be reserved for polymeric products of the reactions of aldehydes and polyhydric alcohols.

Acetal resins are important engineering resins used in industrial, transportation, agricultural, construction, and consumer markets. They possess excellent chemical, thermal, and mechanical properties and as a result have replaced metals in many applications. These properties are discussed.

This article gives data on the properties and manufacture of formaldehyde and its polymerization into acetal resins. Production of these resins is limited to a few companies worldwide. Ticona (Germany) DuPont (U.S.) and Mitsubishi (Japan) are the three top producers worldwide. DuPont's Delrin and Ticona's Celcon are the examples given here. Their processing, grades, health and safety issues as well as detailed uses are given.
Estimation of serum protein binding of compounds metabolized in serum using matrix inhibition
Authors: Uchimura Takahide , Kato Motohiro , Shiokawa Rie , Nabuchi Yoshiaki , Saito Kimitoshi , Kinoshita Haruki
Published: May 2008

It is difficult to evaluate the serum protein binding of compounds that are metabolized in rat serum, even when using ultrafiltration. Protein binding was estimated using matrix inhibition, a method that uses the change in metabolic velocity achieved by changing the free fraction of a compound in the incubation mixture by diluting the serum with phosphate buffered saline. The T1/2 of phenyl nicotinate, benzyl nicotinate, octyl nicotinate, hexyl nicotinate, butyl nicotinate and [3H] compound A were 0.165, 0.780, 2.62, 3.94, 5.22 and 135 min, respectively, with protein binding values of 82.1%, 91.6%, 98.8%, 98.5%, 85.5% and 96.9%. The protein binding value of compound A estimated by ultrafiltration was 93.4%, indicating that the two methods give similar values. The matrix inhibition method is thus applicable for the evaluation of compounds metabolized in serum, and provides a simple, useful method to determine protein binding. Copyright © 2008 John Wiley & Sons, Ltd.
KazrinA is required for axial elongation and epidermal integrity in Xenopus tropicalis
Authors: Sevilla Lisa M. , Rana Amer A. , Watt Fiona M. , Smith James C.
Published: May 2008

Kazrin is a recently described desmosomal protein that binds the cornified envelope precursor periplakin. In this study, we have examined kazrin isoform A expression during the development of Xenopus tropicalis and investigated the consequences of its depletion. Whole mount in situ hybridisation revealed that kazrinA mRNA is expressed throughout the embryo at least until tadpole stages. Xenopus tropicalis embryos that had been injected with antisense morpholino oligonucleotides directed against kazrinA failed to elongate properly and showed defects in development of the head, eye, notochord, and somites. We also observed that the epidermis became disorganised and frequently separated from the underlying mesoderm, causing the formation of epidermal blisters. Together, our results suggest that loss of kazrinA causes defects in cell adhesion that affect axial elongation, cell differentiation, and epidermal morphogenesis. Developmental Dynamics 237:1718‐1725, 2008. © 2008 Wiley‐Liss, Inc.
Retinoic acid controls heart anteroposterior patterning by down‐regulating Isl1 through the Fgf8 pathway
Authors: Sirbu Ioan Ovidiu , Zhao Xianling , Duester Gregg
Published: May 2008

Distinct progenitor cell populations exist in cardiac mesoderm important for patterning of the heart. During heart tube formation in mouse, Tbx5 is expressed in progenitors located more laterally, whereas Isl1 and Fgf8 are expressed in progenitors located more medially. Signals that drive mesodermal progenitors into various cardiac lineages include Fgf8, which functions to induce Isl1. Studies in chick and zebrafish have shown that retinoic acid restricts the number of cardiac progenitors, but its role in mammalian cardiac development is unclear. Here, we demonstrate that Raldh2−/− mouse embryos lacking retinoic acid signaling exhibit a posterior expansion of the cardiac Fgf8 expression domain as well as an expansion of Isl1 expression into mesoderm lying posterior to the cardiac field. We provide evidence that retinoic acid acts specifically in the posterior‐medial region of the cardiac field to establish the heart posterior boundary potentially by reducing Fgf8 expression which restricts the Isl1 domain. Developmental Dynamics 237:1627–1635, 2008. © 2008 Wiley‐Liss, Inc.
Occurrence of cluster microforms in mountain rivers
Authors: Strom K. B. , Papanicolaou A. N.
Published: May 2008

The occurrence of cluster microforms in natural rivers is examined using data collected from three mountain streams. The study was conducted under the premise that the occurrence of clusters is strongly tied to local reach‐scale conditions, and that prediction of clustered sites therefore can be made through identification of particular reach conditions that are conducive to cluster development. For the study, reach‐scale variables were measured at 50 sites and the presence or absence of clusters at each of these sites was recorded. A statistical analysis using logistic regression was performed to examine the correlation between the occurrence of clusters and various combinations of reach‐scale parameters. It was found that clustering was best predicted by the bankfull channel width scaled with the d84 of the bed sediment, w/d84, and the non‐dimensional parameter wQ2/gd. It is thought that these variables work best at predicting the presence of clusters because they are descriptive of the reach hydraulic and sedimentary conditions and work well at discriminating between reach morphology types. It was found that clustering was most strongly tied to riffle–pool type reaches. Observations from this study suggest that clusters can be described as bed features that form out of the structural organization of grains in cobble‐size sediment within depositional mountain reaches, for which the majority of the sediment can become mobilized by yearly peak flows. Copyright © 2008 John Wiley and Sons, Ltd.
Predictors of ovarian cancer survival: A population‐based prospective study in Sweden
Authors: Yang Ling , Klint Åsa , Lambe Mats , Bellocco Rino , Riman Tomas , Bergfeldt Kjell , Persson Ingemar , Weiderpass Elisabete
Published: May 2008

Ovarian cancer is the leading cause of death from gynecologic malignancies among women worldwide. Little is known about reproductive factors or lifestyle determinants and ovarian cancer prognosis. The objective of this study was to examine whether ovarian cancer survival is influenced by reproductive history, anthropometric characteristics, prediagnostic life‐style factors and family history of breast or ovarian cancer. The study population consisted of 635 epithelial ovarian cancer (EOC) cases derived from a nationwide population‐based case‐control study conducted in Sweden between 1993 and 1995. Exposure data on prediagnostic factors of interest were collected through questionnaires at the beginning of the parent study. Clinical data were abstracted from medical records. Cases were followed‐up by means of record linkage to nationwide registers until December 31, 2002. Cox proportional hazard regression model was used to estimate the prognostic effect of each factor in terms of hazard ratios (HR) and 95% confidence intervals (CI), following adjustment for age at diagnosis, FIGO tumor stage and WHO grade of tumor differentiation. Tumor characteristics significantly influenced the risk of death from EOC. After adjustment for these, no clear associations were detected between reproductive history (parity, age at first or last birth, oral contraceptive use, age at menarche or menopause), anthropometric characteristics (body size and shape in different periods of life), lifestyle factors before diagnosis (alcohol consumption, smoking and physical activity over lifetime), nor family history of breast cancer or ovarian cancer and EOC survival. Our findings indicate that these prediagnostic factors do not influence the EOC survival. Nevertheless, among women with early stage disease (FIGO stage I and II), there was some indication that overweight in young adulthood or recent years increased the risk of death, while physical activity in young adult life appeared to reduce the risk of death due to EOC. © 2008 Wiley‐Liss, Inc.
Pluralistic inquiry for the history of community psychology
Authors: Kelly James G. , Chang Janet
Published: May 2008

The authors present the case not only for studying the history of community psychology but also of adopting a pluralistic approach to historical inquiry, using multiple methods and access to resources from other disciplines (e.g., historians of science and social historians). Examples of substantive topics and methods, including social network and citation analyses, oral histories and narratives, larger cultural forces, and investigative reporting, that can illuminate historical issues are discussed. Current resources for the study of the history of community psychology are identified. Recommendations for the continued study of the history of community psychology are also presented. © 2008 Wiley Periodicals, Inc.
Community psychology in Australia and Aotearoa/New Zealand
Authors: Fisher Adrian T. , Gridley Heather , Thomas David R. , Bishop Brian
Published: May 2008

Community psychology in Australia and Aotearoa/New Zealand reflect interesting parallels and convergences. While both have a strong educational basis influenced by North American publications, they have developed foci and forms of practice reflecting the cultural, political, and historic underpinnings of these two countries. In New Zealand, community psychology developed from academic researchers and teachers moulding and adapting approaches to suit the needs of their local communities. In Australia, two processes of practitioners establishing a professional home and academics developing a field of education have come together to form the basis of the field. At the core of community psychology in both countries is the place of social justice—with a strong emphasis on the position and plight of the Indigenous peoples. © 2008 Wiley Periodicals, Inc.
Kinetics of syntrophic acetogenesis in a saline medium
Authors: Huiliñir César , Roa Erick , Vargas Daniela , Roeckel Marlene , Aspé Estrella
Published: May 2008

BACKGROUND: The anaerobic degradation kinetics of volatile fatty acids (VFA) in a saline (24 g NaCl dm−3) and mesophilic (37 °C) medium was studied under batch test conditions. The acetate production kinetics without inhibition by propionic, butyric and valeric acids was determined. The inhibition of acetate production during syntrophic acetogenesis by VFA and pH was studied. The acetogenesis without inhibition was modelled using a Monod equation. The pH inhibition was represented by a Michaelis pH function, while the inhibition by acetic acid (HAc) was represented by a non‐competitive model.

RESULTS: The specific maximum degradation rate and saturation constant (kmax, VFA, KS, max) values were (5.89, 15.95), (7.97, 25.99) and (7.75 g VFA g−1 volatile suspended solids day−1, 11.52 mg VFA dm−3) for propionic, butyric and valeric acids respectively, with maximum velocity at pH 7. The inhibition constants (KI, HAc) were 1295, 671 and 572 mg HAc dm−3 for propionic, butyric and valeric acids respectively.

CONCLUSION: VFA and pH can be inhibitory for acetogenesis under these conditions. Copyright © 2008 Society of Chemical Industry
Reality check on career success and weak paradigms: chance still favors the hearty soul
Authors: Glick William H. , Miller C. Chet , Cardinal Laura B.
Published: May 2008

In an earlier article, we discussed the effects of dissensus and low paradigm development on the lives and scholarly successes of junior scholars. Our analysis painted a somewhat bleak picture, but our advice for moving forward was simple, actionable, and therefore hopeful. Based on the bleak picture that was painted, one particular aspect of our work, career‐level evaluation reliability, was recently critiqued. We respond to that critique here. Copyright © 2008 John Wiley & Sons, Ltd.
ACMEG‐TS: A constitutive model for unsaturated soils under non‐isothermal conditions
Authors: François Bertrand , Laloui Lyesse
Published: May 2008

This paper introduces an unconventional constitutive model for soils, which deals with a unified thermo‐mechanical modelling for unsaturated soils. The relevant temperature and suction effects are studied in light of elasto‐plasticity. A generalized effective stress framework is adopted, which includes a number of intrinsic thermo‐hydro‐mechanical connections, to represent the stress state in the soil. Two coupled constitutive aspects are used to fully describe the non‐isothermal behaviour. The mechanical constitutive part is built on the concepts of bounding surface theory and multi‐mechanism plasticity, whereas water retention characteristics are described using elasto‐plasticity to reproduce the hysteretic response and the effect of temperature and dry density on retention properties. The theoretical formulation is supported by comparisons with experimental results on two compacted clays. Copyright © 2008 John Wiley & Sons, Ltd.
Positive predictive value of ICD‐9 codes 410 and 411 in the identification of cases of acute coronary syndromes in the Saskatchewan Hospital automated database
Authors: Varas‐Lorenzo Cristina , Castellsague Jordi , Stang Mary Rose , Tomas Luis , Aguado Jaume , Perez‐Gutthann Susana
Published: May 2008

Background

Case definitions are essential to epidemiological research.

Objectives

To evaluate ICD‐9 codes 410 and 411 to identify cases of acute coronary syndromes (ACS), and the clinical information availability in the administrative and hospital discharge records of Saskatchewan, Canada.

Methods

In the context of a safety cohort study, we identified hospitalisations with primary discharge codes 410 (2260) and 411 (799). We selected all records with code 411, and a random sample (200) with code 410. Based on information obtained by trained abstractors from hospital records, events were classified by two cardiologists as definite or possible according to adapted AHA/ESC criteria. The validity of 410 and 411 codes was assessed by calculating the positive predictive value (PPV). Completeness of the recorded information on risk factors and use of aspirin was explored.

Results

The PPVs of the codes 410 and 411 for ACS were 0.96 (95%CI: 0. 92–0.98) and 0.86 (95%CI: 0.83–0.88), respectively. The PPV of 410 for acute myocardial infarction (AMI) was 0.95 (95%CI: 0.91–0.98). The PPV of 411 was 0.73 (95%CI: 0.70–0.77) for primary unstable angina (UA) and 0.09 (95%CI: 0.07–0.11) for AMI. Hospital charts review revealed key information for clinical variables, smoking, obesity and use of aspirin at admission.

Conclusions

ICD‐9 410 code has high PPV for AMI cases, likewise 411 for UA cases. Case validation remains important in epidemiological studies with administrative health databases. Given the pathophysiology of ACS, both AMI and UA might be used as study end points. In addition to code 410, we recommend the use of 411 plus validation. Copyright © 2008 John Wiley & Sons, Ltd.
How can a chemical system act purposefully? Bridging between life and non‐life
Authors: Pross Addy
Published: May 2008

One of life's most striking characteristics is its purposeful (teleonomic) character, a character already evident at the simplest level of life – a bacterial cell. But how can a bacterial cell, effectively an aqueous solution of an assembly of biomolecules and molecular aggregates within a membrane (that is itself a macromolecular aggregate), act purposefully? In this review, we discuss this fundamental question by showing that the somewhat vague concept of purpose can be given precise physicochemical characterization, and can be shown to derive directly from the powerful kinetic character of the replication reaction. At the heart of our kinetic model is the idea that the stability that governs replicating systems is adynamic kinetic stability, one that is distinctly different to the thermodynamic stability that dominates the inanimate world. Accordingly, living systems constitute akinetic state of matteras opposed to the thermodynamic states that dominate the inanimate world. Thus, the model is able to unite animate and inanimate within a single conceptual framework, yet is able to account for life's unique characteristics, amongst them its purposeful character. As part of that unification, it is demonstrated that key Darwinian concepts are special examples of more general chemical concepts. Implications of the model with regard to the possible synthesis of living systems are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Excited‐state substituent constants σ from substituted benzenes
Authors: Cao Chenzhong , Chen Guanfan , Yin Zhiqing
Published: May 2008

In this work, 13 compounds of 4,4′‐disubstituted stilbenes and 5 compounds of 3‐methyl‐4′‐substituted stilbenes were prepared and their UV spectra were measured. A new substituent effect constant, namely excited‐state substituent constant, was proposed, which was calculated directly from the UV absorption energy data of substituted benzenes. The investigation result shows that the proposed constant is different from the existing polar substituent constants and radical substituent constants in nature. The availability of the new constant was confirmed by the good correlations with the UV absorption energy of four kinds of compounds, 1,4‐disubstituted benzenes, 4,4′‐disubstituted stilbenes, substituted ethenes, and m‐Y‐substituted aromatic compounds. It is expected that the excited‐state substituent constant can be applied in QSPR study on organic compounds at the excited state. Copyright © 2008 John Wiley & Sons, Ltd.