bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphology-dependent field emission properties and wetting behavior of ZnO nanowire arrays
Authors: Yao Lujun , Zheng Maojun , Ma Li , Li Wei , Li Mei , Shen Wenzhong
Published: February 2011

The fabrication of three kinds of ZnO nanowire arrays with different structural parameters over Au-coated silicon (100) by facile thermal evaporation of ZnS precursor is reported, and the growth mechanism are proposed based on structural analysis. Field emission (FE) properties and wetting behavior were revealed to be strongly morphology dependent. The nanowire arrays in small diameter and high aspect ratio exhibited the best FE performance showing a low turn-on field (4.1 V/μm) and a high field-enhancement factor (1745.8). The result also confirmed that keeping large air within the films was an effective way to obtain super water-repellent properties. This study indicates that the preparation of ZnO nanowire arrays in an optimum structural model is crucial to FE efficiency and wetting behavior.
The relationship between indoleamine 2,3-dioxygenase activity and post-stroke cognitive impairment
Authors: Gold Allison B , Herrmann Nathan , Swardfager Walter , Black Sandra E , Aviv Richard I , Tennen Gayla , Kiss Alexander , Lanctôt Krista L
Published: February 2011

Background

Activation of indoleamine 2,3-dioxygenase (IDO) and higher concentrations of several kynurenine metabolites have been observed post-stroke, where they have been associated with increased mortality. While lower tryptophan or a higher ratio of kynurenine/tryptophan (K/T) in peripheral blood have been associated with dementia and the severity of cognitive symptoms in Alzheimer's disease, the association between K/T ratios and post-stroke cognitive impairment (PSCI) has not been investigated.

Methods

Patients were recruited from the acute stroke unit of a general hospital within 1 month post-stroke. Assessments included the Standardized Mini-Mental State Examination (sMMSE) for cognition, the National Institutes of Health Stroke Scale (NIHSS) for stroke severity, and the Center for Epidemiological Studies-Depression Scale (CES-D) for depressive symptoms. Tryptophan and kynurenine concentrations were determined by high-performance liquid chromatography.

Results

A total of 41 patients with ischemic stroke ([mean ± SD] age 72.3 ± 12.2 years, 53.7% male, sMMSE 25.6 ± 4.1, NIHSS 7.27 ± 5.55) were recruited. Higher K/T ratios were associated with lower post-stroke global cognition (i.e. sMMSE scores; β = -.327, P = .037). A backward stepwise elimination linear regression (F1,40=6.15, P=.005, adjusted R2=.205) showed that the highest K/T ratio tertile (β = -.412, P = .006) predicted lower sMMSE scores, controlling for age (β = -.253, p = .081), with NIHSS (β = -.027, P = 0.859), and lesion volume (β = -.066, P = 0.659) removed from the model. In receiver operating characteristic analysis, a K/T ratio of 78.3 μmol/mmol (top tertile) predicted significant cognitive impairment (sMMSE score ≤ 24) with 67% sensitivity and 86% specificity (area under the curve = 0.730, p = .022).

Conclusions

These data suggest an inflammatory response characterized by IDO activation may be relevant to the development of PSCI. Since the neuroactivity of kynurenine metabolites may be amenable to pharmacotherapeutic intervention, the K/T ratio may be a clinically important biomarker.
Highly conserved serine residue 40 in HIV-1 p6 regulates capsid processing and virus core assembly
Authors: Votteler Jörg , Neumann Liane , Hahn Sabine , Hahn Friedrich , Rauch Pia , Schmidt Kerstin , Studtrucker Nicole , Solbak Sara MØ , Fossen Torgils , Henklein Peter , Ott David E , Holland Gudrun , Bannert Norbert , Schubert Ulrich
Published: February 2011

Background

The HIV-1 p6 Gag protein regulates the final abscission step of nascent virions from the cell membrane by the action of two late assembly (L-) domains. Although p6 is located within one of the most polymorphic regions of the HIV-1 gag gene, the 52 amino acid peptide binds at least to two cellular budding factors (Tsg101 and ALIX), is a substrate for phosphorylation, ubiquitination, and sumoylation, and mediates the incorporation of the HIV-1 accessory protein Vpr into viral particles. As expected, known functional domains mostly overlap with several conserved residues in p6. In this study, we investigated the importance of the highly conserved serine residue at position 40, which until now has not been assigned to any known function of p6.

Results

Consistently with previous data, we found that mutation of Ser-40 has no effect on ALIX mediated rescue of HIV-1 L-domain mutants. However, the only feasible S40F mutation that preserves the overlapping pol open reading frame (ORF) reduces virus replication in T-cell lines and in human lymphocyte tissue cultivated ex vivo. Most intriguingly, L-domain mediated virus release is not dependent on the integrity of Ser-40. However, the S40F mutation significantly reduces the specific infectivity of released virions. Further, it was observed that mutation of Ser-40 selectively interferes with the cleavage between capsid (CA) and the spacer peptide SP1 in Gag, without affecting cleavage of other Gag products. This deficiency in processing of CA, in consequence, led to an irregular morphology of the virus core and the formation of an electron dense extra core structure. Moreover, the defects induced by the S40F mutation in p6 can be rescued by the A1V mutation in SP1 that generally enhances processing of the CA-SP1 cleavage site.

Conclusions

Overall, these data support a so far unrecognized function of p6 mediated by Ser-40 that occurs independently of the L-domain function, but selectively affects CA maturation and virus core formation, and consequently the infectivity of released virions.
Efficacy and safety of a multifactor intervention to improve therapeutic adherence in patients with chronic obstructive pulmonary disease (COPD): protocol for the ICEPOC study
Authors: Barnestein-Fonseca Pilar , Leiva-Fernández José , Vidal-España Francisca , García-Ruiz Antonio , Prados-Torres Daniel , Leiva-Fernández Francisca
Published: February 2011

Background

Low therapeutic adherence to medication is very common. Clinical effectiveness is related to dose rate and route of administration and so poor therapeutic adherence can reduce the clinical benefit of treatment. The therapeutic adherence of patients with chronic obstructive pulmonary disease (COPD) is extremely poor according to most studies. The research about COPD adherence has mainly focussed on quantifying its effect, and few studies have researched factors that affect non-adherence. Our study will evaluate the effectiveness of a multifactor intervention to improve the therapeutic adherence of COPD patients.

Methods/Design

A randomized controlled clinical trial with 140 COPD diagnosed patients selected by a non-probabilistic method of sampling. Subjects will be randomly allocated into two groups, using the block randomization technique. Every patient in each group will be visited four times during the year of the study. Intervention: Motivational aspects related to adherence (beliefs and behaviour): group and individual interviews; cognitive aspects: information about illness; skills: inhaled technique training. Reinforcement of the cognitive-emotional aspects and inhaled technique training will be carried out in all visits of the intervention group.

Discussion

Adherence to a prescribed treatment involves a behavioural change. Cognitive, emotional and motivational aspects influence this change and so we consider the best intervention procedure to improve adherence would be a cognitive and emotional strategy which could be applied in daily clinical practice. Our hypothesis is that the application of a multifactor intervention (COPD information, dose reminders and reinforcing audiovisual material, motivational aspects and inhalation technique training) to COPD patients taking inhaled treatment will give a 25% increase in the number of patients showing therapeutic adherence in this group compared to the control group.

We will evaluate the effectiveness of this multifactor intervention on patient adherence to inhaled drugs considering that it will be right and feasible to the clinical practice context.

Trial registration

Current Controlled Trials ISCTN18841601
Contributions of Cardiorespiratory Fitness and Visceral Adiposity to Six-Year Changes in Cardiometabolic Risk Markers in Apparently Healthy Men and Women
Authors: Rhéaume Caroline , Arsenault Benoit J. , Dumas Marie-Pierre , Pérusse Louis , Tremblay Angelo , Bouchard Claude , Poirier Paul , Després Jean-Pierre
Published: February 2011

Context:

Both excess visceral adipose tissue (VAT) and low cardiorespiratory fitness (CRF) levels are associated with a deteriorated cardiometabolic risk profile.

Objective:

The aim of the study was to examine the respective contributions of changes in VAT accumulation vs. changes in CRF to 6-yr longitudinal changes in cardiometabolic risk markers.

Design, Settings, and Participants:

We conducted a prospective, population-based study with an average follow-up of 5.9 ± 0.8 yr. We followed 132 middle-aged participants from the Quebec Family Study (mean age, 35.3 ± 13.9 yr). VAT was measured by computed tomography, whereas the level of CRF was assessed by a submaximal physical working capacity test at baseline and at follow-up. A complete cardiometabolic risk profile, including systolic and diastolic blood pressure, fasting glucose and insulin levels, C-reactive protein (n = 72), as well as a standard lipoprotein-lipid profile, was obtained at baseline and at follow-up.

Main Outcome Measures:

We measured changes in CRF, VAT, and cardiometabolic risk profile over 6 yr.

Results:

After adjusting for age and sex, 6-yr changes in VAT were negatively correlated with changes in CRF (r = −0.38; P < 0.001). In a multivariate model that included age, sex, changes in VAT, changes in CRF, as well as baseline levels of the above cardiometabolic risk factors, 6-yr changes in VAT were the most important predictor of the change in the metabolic syndrome score (R2 = 13.2%; P < 0.001). Adding 6-yr changes in CRF levels significantly improved the predictability of the model (R2 = 19.7%; P = 0.002).

Conclusions:

Changes in both VAT and CRF levels observed over 6 yr are associated with changes in parameters of the lipoprotein-lipid profile, glucose-insulin homeostasis, and inflammatory markers. Thus, maintaining a low level of VAT and a high level of CRF are important targets for maintenance of cardiometabolic health.
Back to “Oriental” Africa: Islamicism and Becoming African in the Early Black Atlantic
Authors: Knadler Stephen
Published: February 2011

Although revisionary work in African American literary history has stretched the borders of the Black Atlantic to include a hemispheric America or a Black Pacific, these transnational paradigms ignore the connection of the Black Atlantic's migrations, cultural exchanges, and cross-racial encounters with an Islamic diaspora. By restoring West Africa as a contact zone within overlapping nineteenth-century Black Atlantic and Islamic diasporic histories, this essay traces a complex, ambivalent “islamicism” (or specific Islamic orientalism) within early pan-African or “back-to-Africa” discourse. In key works shaping nineteenth-century political and psychological identifications with Africa, Black Atlantic writers erased the multistoried hybridity of a mixed Muslim, Arab, and “native” West Africa. To imagine a pan-African solidarity figured around nation building on a primitive frontier, early Black Atlantic writers disavowed an Islamic economic, cultural, and political presence. Islam represented an abjected third term that would overturn the foundational binary logic of Anglo-American exceptionalism. Arab Muslim resistance in Algiers, however, complicated this prevailing islamicist denial as Black Atlantic writers also saw in leaders such as Abdelkader early representatives of postcolonial resistance.
Nana in the World: Novel, Gender, and Transnational Form
Authors: Hill Christopher L.
Published: February 2011

In the decades following the publication of Emile Zola's novel Nana (1880), “Nana figures” resembling Zola's heroine appeared in fiction around the world. The history of the Nana figure contradicts current models for the study of world literature, based on the diffusion of forms unchanged by their movement. The protagonists of the Japanese writer Kosugi Tengai's New Year's Finery and the American Theodore Dreiser's Sister Carrie (both 1900) show Zola's character reduced to a cluster of minimal qualities: performance, mobility, and contagion. Paradoxically, flattening the Nana figure makes her more dynamic, able to address social questions absent from Nana. The history of the Nana figure suggests that a focus on transformation through movement offers new approaches to the history of naturalism, and by extension realism, on a world scale.
Regulation of the NKCC2 ion cotransporter by SPAK-OSR1-dependent and -independent pathways
Authors: Richardson Ciaran , Sakamoto Kei , de los Heros Paola , Deak Maria , Campbell David G. , Prescott Alan R. , Alessi Dario R.
Published: February 2011

Ion cotransporters, such as the Na+/Cl− cotransporter (NCC), control renal salt re-absorption and are regulated by the WNK-signalling pathway, which is over-stimulated in patients suffering from Gordon's hypertension syndrome. Here, we study the regulation of the NKCC2 (SLC12A1) ion cotransporter that contributes towards ~25% of renal salt re-absorption and is inhibited by loop-diuretic hypertensive drugs. We demonstrate that hypotonic low-chloride conditions that activate the WNK1-SPAK and OSR1 pathway promote phosphorylation of NKCC2 isoforms (A, B and F) at five residues (Ser91, Thr95, Thr100, Thr105 and Ser130). We establish that the SPAK and OSR1 kinases activated by WNK interact with an RFQV motif on NKCC2 and directly phosphorylate Thr95, Thr100, Thr105 and, possibly, Ser91. Our data indicate that a SPAK-OSR1-independent kinase, perhaps AMP-activated protein kinase (AMPK), phosphorylates Ser130 and that phosphorylation of Thr105 and Ser130 plays the most important roles in stimulating NKCC2 activity. In contrast with NCC, whose membrane translocation is triggered by SPAK-OSR1 phosphorylation, NKCC2 appears to be constitutively at the membrane. Our findings provide new insights into how NKCC2 is regulated and suggest that inhibitors of SPAK and/or OSR1 for the treatment of hypertension would be therapeutically distinct from thiazide or loop diuretics, as they would suppress the activity of both NCC and NKCC2.
Evaluation of two HbA1c point-of-care analyzers
Authors: Sánchez-Mora Catalina , Rodríguez-Oliva Manuel S. , Fernández-Riejos Patricia , Mateo Joaquín , Polo-Padillo Juan , Goberna Raimundo , Sánchez-Margalet Víctor
Published: February 2011

Background: Measurement of HbA1c is the most important parameter to assess glycemic control in diabetic patients. Different point-of-care devices for HbA1c are available. The aim of this study was to evaluate two point-of-care testing (POCT) analyzers (DCA Vantage from Siemens and Afinion from Axis-Shield). We studied the bias and precision as well as interference from carbamylated hemoglobin.

Methods: Bias of the POCT analyzers was obtained by measuring 53 blood samples from diabetic patients with a wide range of HbA1c, 4%–14% (20–130 mmol/mol), and comparing the results with those obtained by the laboratory method: HPLC HA 8160® Menarini. Precision was performed by 20 successive determinations of two samples with low 4.2% (22 mmol/mol) and high 9.5% (80 mmol/mol) HbA1c values. The possible interference from carbamylated hemoglobin was studied using 25 samples from patients with chronic renal failure.

Results: The means of the differences between measurements performed by each POCT analyzer and the laboratory method (95% confidence interval) were: 0.28% (p<0.005) (0.10–0.44) for DCA and 0.27% (p<0.001) (0.19–0.35) for Afinion. Correlation coefficients were: r=0.973 for DCA, and r=0.991 for Afinion. The mean bias observed by using samples from chronic renal failure patients were 0.2 (range –0.4, 0.4) for DCA and 0.2 (–0.2, 0.5) for Afinion. Imprecision results were: CV=3.1% (high HbA1c) and 2.97% (low HbA1c) for DCA, CV=1.95% (high HbA1c) and 2.66% (low HbA1c) for Afinion.

Conclusions: Both POCT analyzers for HbA1c show good correlation with the laboratory method and acceptable precision.
Soxhlet Extraction Determination of Composition of Synthetic Soils
Authors: Bardet Jean-Pierre , Sanchez Joseandres
Published: February 2011

Synthetic soils are gradually replacing natural soils, e.g., sandy loams, in various types of sport and recreational surfaces, including horseracing tracks. Synthetic soils are made of a mixture of sand, binder (e.g., wax and polymer), fibers and rubber chips, which optimize the mechanical and hydraulic properties of natural soils so that they drain faster after rains, decrease risks of sport injuries, and improve sport performances. Synthetic surfaces are in early stages of development and often do not behave as intended mainly due to uncontrollable variation in composition. Until now, there was no laboratory procedure to determine the composition of these mixtures. Hereafter a laboratory method is proposed to determine the composition of synthetic soils, including (1) water content; (2) polymeric binder content; and (3) fiber and filler content. The main laboratory procedure uses Soxhlet extraction to determine binder content, and a solvent, e.g., Toluene, to dissolve the binder and separate it from other constituents. The Soxhlet extraction procedure was successfully applied to all tested types of synthetic soils in horseracing tracks.
A prospective study of sex steroids, sex hormone-binding globulin, and non-vertebral fractures in women and men: the Tromsø Study
Authors: Bjørnerem Åshild , Ahmed Luai Awad , Joakimsen Ragnar Martin , Berntsen Gro K Rosvold , Fønnebø Vinjar , Jørgensen Lone , Øian Pål , Seeman Ego , Straume Bjørn
Published: February 2011

The authors apologise for errors in the results reported in their above titled article published in the European Journal of Endocrinology 2007 157 119–125.

Due to a technical error, a number of fractures were not included in the database. In the cohort of 2750 participants, a total of 487 suffered a non-vertebral fracture (not 386 as stated in the article), and the incidence was 30.0 in women and 11.8 in men per 1000 person-years, respectively.

The main results were unchanged after re-analysis and no significant association was present between sex steroids and risk of non-vertebral fractures after adjustment for age in both sexes. Each 1 S.D. higher SHBG increased the risk of non-vertebral fracture by about 20% in women (HR 1.15; 95% CI 1.03–1.29) and men (HR 1.18; 95% CI 0.99–1.41) after adjustment for age, height, weight, smoking and physical activity. After adjustment for BMD, the increased risk was attenuated and no longer statistical significant in women (HR 1.07; 95% CI 0.96–1.21) and men (HR 1.12; 95% CI 0.94–1.34) respectively.
Metabolic syndrome and the effect of testosterone treatment in young men with congenital hypogonadotropic hypogonadism
Authors: Sonmez A , Haymana C , Bolu E , Aydogdu A , Tapan S , Serdar M , Altun B , Barcin C , Taslipinar A , Meric C , Uckaya G , Kutlu M
Published: February 2011

Objective

The relationship between metabolic syndrome (MS) and hypogonadism has always been investigated in study groups confounded with aging, obesity or chronic metabolic disorders. So far, there has been no data about the presence of MS in young hypogonadal patients. Also, there is controversial data about the metabolic effects of testosterone replacement therapy. We investigated the frequency of MS in treatment-naïve, young men with congenital hypogonadal hypogonadism (CHH). We also searched for the effect of testosterone replacement on the metabolic profiles of this specific patient group.

Design

Retrospective analysis.

Methods

A total of 332 patients (age 21.68±2.09 years) were enrolled. The control group included 395 age- and body mass index (BMI)-matched healthy young men (age 21.39±1.49 years). Standard regimen of testosterone esters (250 mg/3 weeks) was given to 208 patients.

Results

MS was more prevalent in CHH (P<0.001) according to healthy controls. The patients had higher arterial blood pressure, waist circumference (WC), triglyceride (P<0.001 for all), fasting glucose (P=0.02), fasting insulin (P=0.004), homeostatic model assessment of insulin resistance (HOMA-IR) (P=0.002) and lower high density lipoprotein (HDL) cholesterol (P<0.001) levels. After 5.63±2.6 months of testosterone treatment, the BMI, WC (P<0.001 for both), systolic blood pressure (P=0.002) and triglyceride level (P=0.04) were increased and the total and HDL cholesterol levels were decreased (P=0.02 andP<0.001 respectively).

Conclusions

This study shows increased prevalence of MS and unfavorable effects of testosterone replacement in young patients with CHH. Long-term follow-up studies are warranted to investigate the cardiovascular safety of testosterone treatment in this specific population.
The 19 Genomes of Drosophila: A BAC Library Resource for Genus-Wide and Genome-Scale Comparative Evolutionary Research
Authors: Song Xiang , Goicoechea Jose Luis , Ammiraju Jetty S S , Luo Meizhong , He Ruifeng , Lin Jinke , Lee So-Jeong , Sisneros Nicholas , Watts Tom , Kudrna David A , Golser Wolfgang , Ashley Elizabeth , Collura Kristi , Braidotti Michele , Yu Yeisoo , Matzkin Luciano M , McAllister Bryant F , Markow Therese Ann , Wing Rod A
Published: February 2011

The genus Drosophila has been the subject of intense comparative phylogenomics characterization to provide insights into genome evolution under diverse biological and ecological contexts and to functionally annotate the Drosophila melanogaster genome, a model system for animal and insect genetics. Recent sequencing of 11 additional Drosophila species from various divergence points of the genus is a first step in this direction. However, to fully reap the benefits of this resource, the Drosophila community is faced with two critical needs: i.e., the expansion of genomic resources from a much broader range of phylogenetic diversity and the development of additional resources to aid in finishing the existing draft genomes. To address these needs, we report the first synthesis of a comprehensive set of bacterial artificial chromosome (BAC) resources for 19 Drosophila species from all three subgenera. Ten libraries were derived from the exact source used to generate 10 of the 12 draft genomes, while the rest were generated from a strategically selected set of species on the basis of salient ecological and life history features and their phylogenetic positions. The majority of the new species have at least one sequenced reference genome for immediate comparative benefit. This 19-BAC library set was rigorously characterized and shown to have large insert sizes (125–168 kb), low nonrecombinant clone content (0.3–5.3%), and deep coverage (9.1–42.9×). Further, we demonstrated the utility of this BAC resource for generating physical maps of targeted loci, refining draft sequence assemblies and identifying potential genomic rearrangements across the phylogeny.
Alternative Rehydration Methods: A Systematic Review and Lessons for Resource-Limited Care
Authors: Rouhani Shada , Meloney Laura , Ahn Roy , Nelson Brett D. , Burke Thomas F.
Published: February 2011

OBJECTIVE:

Dehydration is a significant threat to the health of children worldwide and a major cause of death in resource-scarce settings. Although multiple studies have revealed that oral and intravenous (IV) methods for rehydration in nonsevere dehydration are nearly equally effective, little is known about effectiveness beyond these 2 techniques. With this systematic review we analyzed the effectiveness of nonoral and nonintravenous methods of rehydration.

METHODS:

The Medline, Cochrane, Global Health, Embase, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases were searched for articles on intraosseous (IO), nasogastric (NG), intraperitoneal (IP), subcutaneous (hypodermoclysis), and rectal (proctoclysis) rehydration through December 2009. Only human pediatric studies that included data on the effectiveness or complications of these methods were included.

RESULTS:

The search identified 38 articles that met the inclusion criteria: 12 articles on NG, 16 on IO, 7 on IP, 3 on subcutaneous, and none on rectal rehydration. NG rehydration was as effective as IV rehydration for moderate-to-severe dehydration. IO rehydration was effective and easy to obtain, although only 1 randomized trial was identified. IP rehydration had some benefit for moderate dehydration, although none of the trials had control groups. Limited data were available on subcutaneous rehydration, and only 1 case series showed benefit.

CONCLUSIONS:

NG rehydration should be considered second-line therapy, after oral rehydration, particularly in resource-limited environments. IO rehydration seems to be an effective alternative when IV access is not readily obtainable. Additional evidence is needed before IP and subcutaneous rehydration can be endorsed.
Prediction of Neurodevelopmental and Sensory Outcome at 5 Years in Norwegian Children Born Extremely Preterm
Authors: Leversen Katrine Tyborg , Sommerfelt Kristian , Rønnestad Arild , Kaaresen Per Ivar , Farstad Theresa , Skranes Janne , Støen Ragnhild , Bircow Elgen Irene , Rettedal Siren , Egil Eide Geir , Irgens Lorentz M , Markestad Trond
Published: February 2011

OBJECTIVE:

To examine the prevalence of neurodevelopmental disability and the predictive value of pre-, peri-, and postnatal data on neurologic, sensory, cognitive, and motor function in children born extremely preterm.

METHODS:

This was a prospective observational study of all infants born in Norway between 1999 and 2000 with gestational ages between 22 and 27 weeks or birth weights between 500 and 999 g. Cognitive function was assessed with the Wechsler Preschool and Primary Scale of Intelligence–Revised, motor function with the Movement Assessment Battery for Children, and severity of cerebral palsy with the Gross Motor Function Classification for Cerebral Palsy. Disabilities were described as mild, moderate, or severe.

RESULTS:

Of 371 eligible children, 306 (82%) were examined at a mean (SD) age of 5 years and 10 (4) months. For gestational age less than 28 weeks (n = 239), 26 (11%) children had cerebral palsy alone (n = 21) or in combination with blindness (n = 3) or deafness (n = 2); 1 was blind and 1 was deaf. Of the remaining children, the mean full-scale IQ was 94 ± 15, and significant predictors were (values given as the difference in IQ points [95% confidence intervals]) high maternal education (9.6 [5.7–13.4]), preeclampsia (−7.7 [−12.7 to −2.7]), and retinopathy of prematurity higher than grade 2 (−17.5 [−27.1 to −8.0]). Movement Assessment Battery for Children scores were positively associated with gestational age and prenatal steroids and negatively associated with being small for gestational age, male gender, and having retinopathy of prematurity. Moderate to severe neurodevelopmental disability was more common for gestational ages 25 weeks or less (28 of 87 children) than for 26 to 27 weeks (12 of 152 children; P < .001) and 28 weeks or more (7 of 67 children; P = .001).

CONCLUSIONS:

The outcome was poorer for children with gestational ages of 25 weeks or less compared with those with gestational ages between 26 and 27 weeks. For those without cerebral palsy, blindness, or deafness, however, gestational age had a limited association with cognitive and motor function.
Pericarditis as the Presenting Feature of Adrenoleukodystrophy
Authors: Taxter Alysha J. , Bellin Melena D. , Binstadt Bryce A.
Published: February 2011

X-linked adrenoleukodystrophy is characterized by elevated levels of very long chain fatty acids in the serum, brain, and adrenal glands that can lead to neurodevelopmental impairment and decreased adrenal function. We report here the case of a pediatric patient with pericarditis who was found to have adrenoleukodystrophy. More common causes of pericarditis (such as infectious, autoimmune, and metabolic) were excluded. On the basis of the examination finding of cutaneous hyperpigmentation, hypocortisolism was discovered. Further evaluation revealed elevated serum levels of very long chain fatty acids and a partial deletion of the ABCD1 gene, consistent with the diagnosis of X-linked adrenoleukodystrophy. Two of the index patient's brothers were subsequently found to have the same disease. Although pericarditis has been reported previously in association with autoimmune diseases that affect the adrenal glands, this is the first reported case (to our knowledge) of pericarditis in association with hypocortisolism from a nonautoimmune cause. Therefore, we suggest that hypocortisolism itself may lead to pericarditis in some patients.
Principles of Drug Literature Evaluation for Observational Study Designs
Authors: Shields Kelly M. , DiPietro Natalie A. , Kier Karen L.
Published: February 2011

Clinical pharmacists must often interpret and use data derived from observational studies when making clinical decisions and recommendations, answering drug information questions, and educating patients about drug therapy. This is the third article in a three‐part series intended to enhance clinical pharmacists' understanding of methods frequently used in such research and their application to patient care. Principles for critical evaluation of published observational studies are presented. Issues of bias and confounding that must be taken into account when assessing the data derived from observational studies are explained. Finally, examples of applications in pharmacy practice are presented.
Risk Assessment of Glyphosate Resistance in Western Canada
Authors: Beckie Hugh J. , Harker K. Neil , Hall Linda M. , Holm Frederick A. , Gulden Robert H.
Published: February 2011

With increasing incidence of glyphosate-resistant weeds worldwide, greater farmer awareness of the importance of glyphosate stewardship and proactive glyphosate-resistance management is needed. A Web-based decision-support tool (http://www.weedtool.com) comprising 10 questions has been developed primarily for farmers in western Canada to assess the relative risk of selection for glyphosate-resistant weeds on a field-by-field basis. We describe the rationale for the questions and how a response to a particular question influences the risk rating. Practices with the greatest risk weighting in western Canadian cropping systems are lack of crop-rotation diversity (growing mainly oilseeds) and a high frequency of glyphosate-resistant crops in the rotation. Three case scenarios are outlined—low, moderate, and high risk of glyphosate-resistance evolution. Based on the overall risk rating, three best-management practices are recommended to reduce the risk of glyphosate resistance in weeds.
Weed Management in a Furrow-Irrigated Imidazolinone-Resistant Hybrid Rice Production System
Authors: Norsworthy Jason K. , Scott Robert C. , Bangarwa Sanjeev K. , Griffith Griff M. , Wilson Michael J. , McCelland Marilyn
Published: February 2011

Research was conducted in 2007 and 2008 to evaluate weed-control options in an imazethapyr-resistant rice production system. Raised beds were formed, and imidazolinone-resistant hybrid rice ‘CL 730’ was drill-seeded on beds. Five herbicide programs applied up to the four- to six-leaf stage of rice were evaluated with and without additional “as-needed” herbicide at later stages. All the herbicide combinations and as-needed herbicides tested in this research were labeled for rice, and only minor transient injury (< 5%) was initially observed. Weeds emerged throughout the growing season, and as-needed herbicides were applied after the four- to six-leaf stage of rice to control these late-emerging weeds and weeds not effectively controlled with earlier applications, primarily Palmer amaranth. Most of the Palmer amaranth at this site was insensitive to imazethapyr (possibly acetolactate synthase resistant). Therefore, application of as-needed herbicides with different modes of action, such as 2,4-D, were used to improve Palmer amaranth control. Rice yields were often numerically higher in plots that received additional herbicide after the six-leaf stage of rice, but yields were not significantly improved.
The Next Stage for Multiphase Meters — Generating More Detailed Flow Rate Knowledge and Widening the Operating Envelope
Authors: Tol Martijn , Brandt Morten
Published: February 2011

Multiphase meters must change and adapt to meet operator challenges. Such challenges include more geologically complex and remote fields, environmental concerns on the gamma sources in multiphase meters, and the need to manage costs at the same time as optimizing production.

The paper will tackle the question of how multiphase meters can meet these challenges, generate more detailed knowledge on flow rates and complex flow patterns, be more compact and flexible, and also meet the environmental concerns of nucleonic sources.

Referencing a number of test results, the paper will chart the development of a new measurement principle for multiphase meters based on voxel-based signal processing, a new electrode geometry sensor and new field electronics to generate more combinations and more accurate fraction measurements and velocities for each segment, as well as the incorporation of both rotational near wall measurements and cross-volume measurements.

Finally, the paper will also look at the challenge of desiging a multiphase meter which improves flow measurement accuracy but provides cost savings in terms of installation, maintenance and deck space. Environmental concerns will be addressed by examining how an X-ray based densitometer can replace the multiphase meter’s gamma source by utilising the attenuation measurements of the same photon energies as a low energy gamma-ray source. The importance of a field replaceable insert venturi will also be examined.

The findings from the paper will be of interest to any operator or well testing company wanting to increase the production optimization capabilities of multiphase meters, while at the same time addressing cost, flexibility and environmental concerns.
An Improved Water Coning Calculation for Horizontal Wells
Authors: Permadi P. , Jayadi T.
Published: February 2011

Actual coning behavior in a horizontal well is not fully understood. Lacks of knowledge of fluids distribution within the reservoir and the heterogeneity as well lead to either over-predicting or under-predicting performance of the well implemented. The prediction done then needs to be revised in the effort to re-evaluate the economic of the well.

This paper presents a semi-empirical method for predicting post breakthrough performance of horizontal wells. The method was developed based on straight forward Darcy equation for linear flow and the principle of material balance. An iterative procedure of calculation is provided for predicting production performance. Based on results of the parametric study conducted using a numerical reservoir simulator, corrections necessary for the linear flow model proposed were established. Water cresting efficiency is defined in this study by inverting the correction factor and was found systematically to relate with factors that influence the coning behavior.

The applicability of the proposed method was validated using two sets of field data. The first data set is the case having practically initial zero water cut, while the other set represents cases with high water cut since the production start up. Results of prediction for both cases are in very good agreement with the field data.
Oil Recovery Enhancement from Low-Permeable Reservoirs on Base of Reservoir Simulation with Well-Testing and Production Logging
Authors: Gulyaev D.N. , Ipatov A.I. , Chernoglazova N.N.
Published: February 2011

Tight reservoirs start to play increasingly more important role in petroleum industry. However, quality of the most part of the 3D reservoir models created in Russia does not allow a trustworthy reservoir characterization and their development optimization. This circumstance is one of the causes for rather low recovery factors in the territory of the RF. To significantly improve the quality of those models production logging data is to be more widely used in reservoir simulation. Recovery enhancement activities become much more efficient when based on reliable reservoir development models.

With specific reference to simulation of one of the “Gazprom neft” tight fields, the paper shows how the integration of welltest data in 3D simulation results in more confident modeling and improves the current oil production and ultimate oil recovery. In addition, some particular features were identified in the course of the work and new approaches were developed to solve tight reservoir simulation issues.
A Completions Guide Book to Shale-Play Development: A Review of Successful Approaches Towards Shale-Play Stimulation in the Last Two Decades
Authors: Chong K. K. , Grieser W. V. , Passman A. , Tamayo C. H. , Modeland N. , Burke B.
Published: February 2011

Almost three decades have passed since the early exploration of the north Texas, Barnett shale. The Barnett serves as an example study for the shale life cycle. Operators in North America have used the Barnett-shale development as a roadmap for the exploration of new shale plays like the Marcellus, Haynesville, and Eagle Ford, as well as others. Each new shale play is unique in nature with respect to geologic setting, lithology, and production mechanism. It is useful to have a defined strategy for the discovery, development, and decline phases of each individual shale play. The roadmap to shale well-completion designs should include the following key factors: Fracability: capability of the reservoir to be fracture stimulated effectivelyProducibility: capability of the completion plan to sustain commercial productionSustainability: capability of the field development to meet both economic and environmental constraints

This paper reviews the evolution and development of completion practices of the major US shale reservoirs in the last two decades and presents a roadmap for effective completion practices for shale stimulation. The completion roadmap uses the history of 16,000 shale frac stages in the Barnett, Woodford, Haynesville, Antrim, and Marcellus shales. Following the map through specific decision points will alter the path for individual shales. These decision points will be influenced by geologic, geochemical, and geomechanical information gathered along the way. The path toward a commercially viable shale play from the early asset- evaluation phase to the late asset maintenance-and-remediation phase evolves from a series of decision trees throughout the process.

Information presented in this paper provides a completion engineer with better understanding of the factors involved in shale- play stimulation and provides a methodical approach to select appropriate and optimum solutions that have evolved during the last two decades.
Remote Monitoring and Optimization of Electrical Submersible Pumps Utilizing Control Algorithms
Authors: Haapanen B. E. , Gagner M. G.
Published: February 2011

The Proportional, Integral, Derivative (PID) control algorithm has been used in industry for many years. The proper application and tuning of this algorithm has been the topic of much research and many papers. Its use with ESPs has been underutilized, yet its benefit is significant when employed properly for many reasons. Monitoring and benchmarking the system's performance while in PID mode can be hap-hazard unless employing a remote monitoring system that provides visibility for tuning and optimizing of the control algorithm.

This paper looks at two ESP systems where operation was benchmarked before the PID algorithm was implemented. The operation was then compared after the PID control mode was implemented with the aid of a downhole gauge unit. The resulting effect on the pumping system was then quantified through the use of remote monitoring and analysis systems. Significant benefits in the pumping system were shown, such as increased run life (from cooler operation), lower operating temperatures in the ESP motor, lower operating frequency resulting in lower power consumption, and stable downhole pressures with the ability to manage free gas during operation. Production and efficiency gains were realized through increased drawdown, stable operation, and immediate feedback from key operational information. Finally, the importance of proper tuning of the control algorithm is critical for the success of the implementation.
Simulation of a Complex Fluvial-Deltaic Reservoir to Identify Opportunities to Improve Oil Recovery in a Mature Oil Field: A Case History
Authors: Urdaneta M.C. , Angel F.J. , Askoul Y.E. , Guevara J. , González E.R.
Published: February 2011

A meandering system where sandbodies produced are complex, so that fluvial deltaic reservoir consist of channel belt sandbodies with highly variable permeability patterns pose a significant challenge for further development of a mature oil field in the Southwest Venezuela. To obtain an optimal strategy a multi-disciplinary reservoir characterization study was carried out.

This study combined all available data (geophysics, geology, petrophysics, and engineering) into a 3D stochastic geo-model to build a reservoir simulation model, many sensitivities with grid size and reservoir description in fluvially dominated deltaic facies were undertaken. These sensitivities included various assumptions on sand content of main producing horizons, sandbody dimensions, permeability distribution, and continuity of flood plain acting as vertical barriers in some reservoir areas.

All these sensitivities were tested during history matching as alternatives to reach a history match. Drilling locations and some exploitation strategies were made in order to improve the oil recovery factor through closing some wells for several periods (3 months - 6 months) and then opening those wells, this technique helped to decrease the water production rate and increased slightly the oil production rate. The associated economic evaluations were based on simulated forecasts while connected volume calculation was made for the chosen realization.
Experience of Commercial Hydrocarbons Forecasting in Pre-Jurassic Series of Western Siberia Region
Authors: Shkurakov V. , Groman M.
Published: February 2011

This particular study has shown high efficiency of the Recog-12 seismic data geological interpretation technology to solve the problem of forecasting oil and gas accumulation zones in the pre-Jurassic series of Western Siberia region and forecasting “commercial inflow” as well.
Wellbore Dynamics of Acid Gas Injection Well Operation
Authors: Mireault R. A. , Stocker R. , Dunn D. W. , Pooladi-Darvish M.
Published: February 2011

This paper presents insights gained from analyzing and modeling acid gas (H2S and CO2) injection well performance over the last 13 years. As the world increasingly develops oil and gas reservoirs that contain significant concentrations of H2S and CO2, the number and size of acid gas injection facilities and their associated acid gas injection wells will increase. A methodology to estimate wellhead operating pressures satisfies a key requirement for design of the injection wells and sizing of the acid gas injection compressors. It may also help inform engineering and operations personnel, and regulatory agencies, of the complex behaviour of acid gas injection wells.

The initial impetus for this work was an operator who increased the acid gas injection rate on a well yet saw virtually no change in wellhead operating pressure, which is inconsistent with water injection well operations. To predict wellhead pressures, a numerical simulation model integrates a modified Peng-Robinson equation-of-state for fluid phase behaviour with a wellbore model and a multi-step adaptation of the Cullender and Smith method to account for the friction and hydrostatic pressure changes associated with flow in the wellbore.

Pressure gradients in aquifers or reservoirs suitable for acid gas sequestration may range from a normal hydrostatic gradient to extremely sub-normal in depleted hydrocarbon reservoirs. Two injection cases present wellbore pressure profiles for injection into a depleted and a normally pressured reservoir at rates of 20, 100 and 280 103m3/d. Three sensitivity studies illustrate the impact of bottomhole sandface pressure, fluid composition and wellhead temperature on wellhead pressure. Depending on conditions, injected acid gas may undergo phase transitions from a gaseous or two-phase mixture at the wellhead to liquid at the sandface and back to gaseous or supercritical out in the reservoir. The complex interactions between temperature, phase behavior, fluid density and pressure can lead to unusual operating characteristics including an increased injection rate or sandface pressure with little or no change in wellhead pressure.
Fast Semianalytical Layered Geomechanical Model Applied to a Parametric Study of Hydraulic Fracture Reorientation in a Water-Flooded Field
Authors: Chertov M. , Siebrits E. , Butula K.
Published: February 2011

Mathematically formulating and implementing a semianalytical-layered geomechanical model by simplifying assumptions about field configuration and properties allows fast numerical estimation of production-induced displacements and stress changes in a reservoir. The developed fast semianalytical model was applied to a parametric study of hydraulic fracture reorientation in a water-flooded field in western Siberia. Results of the study indicate that for the typical conditions in the field, the perturbation of pressure induced by the injection pattern is sufficient to initiate considerable rotations of hydraulic fracture planes. The angle of rotation is very sensitive to anisotropy of initial stress; thicker pay zones result in larger swing angles. This software tool is fast, both in terms of calculation time and time required to set up a numerical task, and is very convenient for preliminary quick-look studies before constructing a detailed 3D reservoir model. The speed of the software tool makes it applicable for parametric, optimization, or sensitivity studies, which require multiple trial simulations in a reasonable amount of time.