bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of a Phosphodiesterase 5 Inhibitor on Pulmonary and Cerebral Arteries of Newborn Piglets with Chronic Hypoxia-Induced Pulmonary Hypertension
Authors: Fike Candice D. , Kaplowitz Mark , Zhang Yongmei , Dantuma Mark , Madden Jane A.
Published: July 2011

Background: The use of phosphodiesterase 5 (PDE5) inhibitors to treat newborns with pulmonary hypertension is increasing. The effect of PDE5 inhibitors on the neonatal cerebral circulation remains unknown. The neonatal piglet model of chronic hypoxia-induced pulmonary hypertension allows the study of the effects of PDE5 inhibitors on both the pulmonary and cerebral circulations. Objectives: To determine whether the PDE5 inhibitor, zaprinast, causes dilation in pulmonary and middle cerebral arteries (MCA) of normoxic newborn piglets and those with chronic hypoxia-induced pulmonary hypertension, and to evaluate whether zaprinast alters responses to increased pressure (autoregulatory ability) of the MCA. Methods: Two-day-old piglets were raised in normoxia or hypoxia for 3 or 10 days. Pulmonary arteries and MCA were isolated and pressurized, after which changes in diameter to zaprinast were measured. MCA pressure-diameter relationships were determined. Results: Dilation to zaprinast was similar in pulmonary arteries from normoxic and hypoxic piglets. Zaprinast dilated MCA from all groups but the response was diminished in MCA from piglets raised in hypoxia for 10 days. MCA pressure-diameter relationships (autoregulation) did not differ between the groups. Conclusions: Pulmonary artery dilation to zaprinast supports the use of PDE5 inhibitors to treat pulmonary hypertension in neonates. PDE5 inhibitors function as MCA dilators but do not impair the pressure-diameter behavior of the cerebral circulation of either normoxic newborn piglets or those with chronic hypoxia-induced pulmonary hypertension. These findings suggest that cerebral autoregulation is likely to be intact with acute PDE5 inhibitor treatment in infants with pulmonary hypertension in conditions associated with chronic hypoxia.
Discrepancies between Arterial Oxygen Saturation and Functional Oxygen Saturation Measured with Pulse Oximetry in Very Preterm Infants
Authors: Rosychuk Rhonda J. , Hudson-Mason Ann , Eklund Dianne , Lacaze-Masmonteil Thierry
Published: July 2011

Background: Discrepancies between pulse oximetry saturation (SpO2) and arterial saturation (SaO2) at low blood oxygenation values have been previously reported with significant variations among instruments and studies. Whether pulse oximeters that attenuate motion artifact are less prone to such discrepancies is not well known. Objective: To prospectively assess the agreement of the Masimo V4 pulse oximeter within the critical 85–95% SpO2 target range. Patients and Methods: For all consecutive babies with gestational age <33 weeks, postnatal age <7 days, and an umbilical arterial line, SpO2 was measured continuously and SaO2 analyzed on an as-needed basis. Bland-Altman techniques provided estimates of the difference (D = SaO2 – SpO2), standard deviation (SD), and 95% limits of agreement (D ± 2*SD). Results: There were 1,032 measurements (114 babies) with SpO2 between 85 and 95%. The 95% limits of agreement were –2.0 ± 5.8, –2.4 ± 9.2, and –1.9 ± 5.3 in the SpO2 categories 85–95, 85–89, and 91–95%, respectively. For the SpO2 categories 85–89% and 91–95%, only 52% (53/101) and 59% (523/886) of SpO2 values, respectively, corresponded to the analogous SaO2 categories. In the 85–89% SpO2 category, SaO2 was lower than 85% in 39 of the 101 (39%) measurements. Conclusion: SaO2 was lower on average than SpO2 with an increased bias at lower saturation. The –2.4 ± 9.2 95% limits of agreement for SaO2 – SpO2 in the 85–89% SpO2 category suggest that SpO2 and SaO2 are not interchangeable and intermittent SaO2 assessments are warranted when the targeted SpO2 is within this range.
Does Admission Hypothermia Predispose to Intraventricular Hemorrhage in Very-Low-Birth-Weight Infants?
Authors: Audeh Safwat , Smolkin Tatiana , Bental Yoram , Haramati Ziv , Blazer Shraga , Litig Eti , Biton Reut , Dolberg Shaul , Makhoul Imad R.
Published: July 2011

Background: The etiology of intraventricular hemorrhage (IVH) in very-low-birth-weight (VLBW) infants is multifactorial and is associated with low gestational age (GA) and severity of neonatal respiratory disease. The role of admission hypothermia (AHT) in the pathogenesis of IVH in VLBW infants has not yet been elucidated. We searched risk factors for IVH in VLBW infants while focusing on AHT. Patients and Methods: VLBW infants ≤33 weeks’ gestation from three participating medical centers were included. From patients’ medical charts we collected variables known to be associated with IVH, focusing on AHT. AHT was defined as rectal temperature ≤35.5°C at admission to the NICU. Head ultrasound was performed at 2–5 and 6–10 days of age and before discharge. Results: 271 VLBW infants were studied. Univariate analysis showed that AHT at ≤35.5°C was not significantly associated with IVH (all grades; p = 0.16), but associated with IVH grade 3–4 (p = 0.034), while AHT at ≤35°C was significantly associated with IVH (p = 0.036) and with IVH grade 3–4 (p = 0.003). Multivariate logistic regression analysis showed that AHT (at ≤35.5 and at ≤35°C) were not associated with IVH. Only four variables were independently significantly associated with IVH: GA, use of nitric oxide, hypocarbia and base deficit >10. Four variables were strongly associated with severe IVH (grades 3–4): GA, hypotension, base deficit >10 and hyponatremia. Conclusions: In VLBW infants, AHT at ≤35.5 and at ≤35.0°C were not significantly associated with IVH. GA, use of nitric oxide, hypocarbia and base deficit >10 were strongly associated with IVH.
Indomethacin Impairs Coronary Perfusion in Infants with Hemodynamically Significant Ductus Arteriosus
Authors: Sehgal Arvind , Ramsden C. Andrew , McNamara Patrick J.
Published: July 2011

Background: A haemodynamically significant ductus arteriosus (HSDA) is commonly associated with morbidity in preterm infants. Aim: To study the effect of the first dose of indomethacin on coronary blood flow in preterm neonates diagnosed with an HSDA. Method: A prospective observational echocardiographic study was performed on preterm infants. A single study dose of intravenous indomethacin (0.1 mg/kg) was administered over 1 h. Serial echocardiography was performed before and after indomethacin treatment to study the effect on coronary artery perfusion and cardiovascular performance. Results: Eighteen infants born at a median gestation of 25.8 (24.2, 28.1) weeks and a birth weight of 773 g (704, 1,002) were evaluated. The median age at indomethacin administration was 7.5 days (4, 17). There was no significant change in arterial pressure or ventilatory indices. Left anterior descending artery diastolic velocity and time integral declined from 0.3 ± 0.1 and 3.19 ± 1.2 m/s to 0.22 ± 0.08 and 2.01 ± 0.9 m/s, respectively, within 10 min of completion of infusion. These indices showed partial recovery when reassessed after 60 min. There were no changes in left ventricular output or transductal flow. Conclusions: Intravenous indomethacin was followed by a decline in coronary arterial diastolic blood flow.
Risk Factors for Pulmonary Artery Hypertension in Preterm Infants with Moderate or Severe Bronchopulmonary Dysplasia
Authors: Kim Do-Hyun , Kim Han-Suk , Choi Chang Won , Kim Ee-Kyung , Kim Beyong Il , Choi Jung-Hwan
Published: July 2011

Background: Despite the potential importance of pulmonary artery hypertension (PAH) in preterm infants with bronchopulmonary dysplasia (BPD), little is known about the risk factors for PAH. Objectives: To investigate the risk factors for PAH in preterm infants with BPD. Methods: Infants diagnosed with BPD were assigned to the PAH group or non-PAH group except for infants with mild BPD who had no PAH. PAH was diagnosed on the basis of echocardiograms demonstrating elevated right ventricle pressure beyond the postnatal age of 2 months. Logistic regression analysis was done for the multivariate assessment of the risk factors for PAH in preterm infants with moderate or severe BPD. Results: A total of 98 infants among 145 infants with BPD were divided into a PAH group (n = 25) or non-PAH group (n = 73), while the remaining 47 infants had mild BPD with no PAH. Among the study patients, survival rate of the PAH group was significantly lower than that of the non-PAH group. Infants with PAH had more severe cases of BPD and underwent longer durations of oxygen therapy, conventional or high-frequency ventilation, and hospitalization compared to those without PAH. Low 5-min Apgar scores (≤6; relative risk (RR) 6.2; 95% confidence interval (CI) 1.4–28.0; p = 0.017) and oligohydramnios (RR 7.7; 95% CI 2.0–29.6; p = 0.030) were found to be significant risk factors for PAH according to multivariate analysis. Conclusions: The present study shows that oligohydramnios is a specific risk factor for PAH in preterm infants with moderate or severe BPD.
Optimal Techniques for mRNA Extraction from Neonatal Salivary Supernatant
Authors: Dietz Jessica A. , Johnson Kirby L. , Wick Heather C. , Bianchi Diana W. , Maron Jill L.
Published: July 2011

Background: Gene expression profiling of the salivary supernatant is emerging as a new and important source of real-time, systemic, biological information. However, existing technologies prevent RNA extraction of small quantities found in neonatal salivary supernatant. Objective: The aim of this study was to develop techniques to enhance extraction of cell-free RNA from neonatal salivary supernatant. Methods: Two saliva samples (10–100 µl) were serially collected from newborns (36–41 weeks’ gestation) (n = 13) and stabilized. Total RNA was extracted from salivary supernatant with the use of two modified extraction techniques: Qiagen RNAprotect® Saliva Mini Kit (method 1) and the QIAamp Viral RNA Mini Kit (method 2). Quantitative RT-PCR amplification for GAPDH was performed on extracted salivary samples. Statistical analyses were performed on mean threshold cycle (Ct) levels to compare RNA yield from each protocol. Paired microarray analyses were made between neonatal whole saliva and supernatant (n = 3) to discern gene expression differences between these biolayers. Results: mRNA was successfully extracted and amplified from all salivary supernatant samples. Extraction with method 2 yielded more RNA than with method 1 (p = 0.008). There was a 7.5% discordance between paired gene expression analyses for whole saliva and supernatant. Genes that were statistically significantly upregulated in supernatant highlighted 16 distinct biological functions not seen in whole saliva. Conversely, only two biological functions were unique to whole saliva. Conclusion: Neonatal cell-free salivary supernatant mRNA may be readily extracted and utilized on downstream applications. These technical enhancements allow for further exploration of the diagnostic potential of the neonatal salivary transcriptome.
Bcar3 Is Expressed in Sertoli Cells and Germ Cells of the Developing Testis in Mice
Authors: Pennekamp P. , Feldner S. , Seesing F.J. , Psathaki O.E. , Schöler H.R. , Wieacker P. , Dworniczak B.
Published: July 2011

We identified Bcar3 in the course of a screen for developmentally regulated genes at early developmental stages in mouse embryos. In this study, we explored the spatio-temporal expression pattern of Bcar3 during the critical time period of sex determination using in situ hybridization, real-time RT-PCR, and immunohistochemistry. We found that Bcar3 is expressed in XY gonads during early stages of gonad development and that BCAR3 localizes to Sertoli cells and germs cells. In addition, we identified a new alternative Bcar3 transcript in which exons 4–7 are deleted. This deletion could result in the generation of a truncated BCAR3 protein lacking functional domains including the SH2 domain. The data presented here suggest that Bcar3 could play a role in gonad development.
Ontogenesis of Ap-2γ Expression in Rat Testes
Authors: Hou M. , Stukenborg J.-B. , Nurmio M. , Andersson M. , Toppari J. , Söder O. , Jahnukainen K.
Published: July 2011

Searching for useful markers of spermatogonial stem cells and their differentiation, we used rat testes from ages representing different stages of testicular maturation to investigate the expression profile of transcription factor activation protein-2γ (Ap-2γ). The immunohistochemical and immunocytochemical evaluation using Ap-2γ and promyelocytic leukemia zinc finger in combination with sorting of CD9 and CD90 positive cells (undifferentiated spermatogonia) by fluorescence-activated cell sorting was performed. Our experiments revealed that Ap-2γ is detectable in testes of late fetal age and up to 60 days postnatally and is expressed in gonocytes and spermatogonia from late fetal age throughout all maturational stages. Restricted nuclear expression of Ap-2γ to undifferentiated male germ cells was verified by coexpression of Ap-2γ with promyelocytic leukemia zinc finger in sections of paraffin-embedded testes as well as in cells sorted positive for CD9 and CD90 expression. Our study demonstrated clearly that nuclear expression of Ap-2γ is a useful marker for identifying undifferentiated male germ cells, although its functional role is yet to be fully explored.
Activation of the Renin-Angiotensin System in Hyperoxia-Induced Lung Fibrosis in Neonatal Rats
Authors: Jiang Jiunn-Song , Lang Yaw-Dong , Chou Hsiu-Chu , Shih Chwen-Ming , Wu Meng-Ying , Chen Chung-Ming , Wang Leng-Fang
Published: July 2011

Background: Oxygen toxicity plays an important role in lung injury and may lead to bronchopulmonary dysplasia. We previously demonstrated that hyperoxia activated the renin-angiotensin system (RAS) in cultured human fetal lung fibroblasts. Objective: To examine whether the upregulation of RAS components is associated with hyperoxia-induced lung fibrosis in neonatal Sprague-Dawley rats. Methods: Experimental rat pups were exposed to 1 week of >95% O2 and a further 2 weeks of 60% O2. Control pups were exposed to room air over the same periods. Lung tissues were taken for biochemical and histochemical assays on postnatal days 7 and 21. Results: Hyperoxia significantly increased total collagen content and the expression of type I collagen and alpha smooth muscle actin when compared to control rats. RAS components including angiotensinogen, angiotensin-converting enzyme, angiotensin II, and angiotensin II type 1 receptor were significantly upregulated by hyperoxia. The results also demonstrated that only the extracellular signal-regulated kinase (ERK) signaling pathway was activated by hyperoxia exposure. p38 mitogen-activated protein kinase and c-Jun N-terminal kinase were not activated. Conclusions: Local RAS activation is involved in the pathogenesis of hyperoxia-induced lung fibrosis in neonatal rats. ERK phosphorylation might mediate angiotensin II type 1 receptor activation.
Conditional Knockout of Lgr4 Leads to Impaired Ductal Elongation and Branching Morphogenesis in Mouse Mammary Glands
Authors: Oyama K. , Mohri Y. , Sone M. , Nawa A. , Nishimori K.
Published: July 2011

We have analyzed the function of LGR4 in the development of various mouse epithelial tissues. Here we first report the retarded invasion of mammary ducts into the fat pad observed in Lgr4K5 KO mice at 4 weeks, compared with that of age-matched Lgr4K5 ctrl. Furthermore, we demonstrate a significant decrease in mammary ductal branching in Lgr4K5 KO at several stages (4, 6 and 8 weeks). On the other hand, immunohistochemical analysis of the mammary gland of Lgr4K5 KO using anti-αSMA, anti-K18 and anti-laminin antibodies showed structures similar to those of Lgr4K5 ctrl mammary glands. In addition, we did not detect significant differences in the expression of ERα, which was suggested to be a downstream molecule of LGR4, and Lgr4K5 KO showed no retarded invasion in the response to 17β-estradiol administration. Furthermore, the phosphorylated form of Smad1/5/8 was normally detected in the mammary gland of Lgr4K5 KO.
Association of Adiponectin with Carotid Arteriosclerosis in Predialysis Chronic Kidney Disease
Authors: Hayashi Mutsuharu , Shibata Rei , Takahashi Hiroshi , Ishii Hideki , Aoyama Toru , Kasuga Hirotake , Yamada Shigeki , Ohashi Koji , Maruyama Syoichi , Matsuo Seiichi , Ouchi Noriyuki , Murohara Toyoaki , Toriyama Takanobu
Published: July 2011

Background/Aims: Adiponectin is an adipocyte-derived protein with antiatherogenic properties. Chronic kidney disease (CKD) is one of the risk factors for cardiovascular disease. We investigated the potential association between adiponectin and carotid arteriosclerosis in patients with predialysis CKD. Methods: We enrolled 95 CKD patients without dialysis and 81 non-CKD patients. Intima-media thickness (IMT) and plaque score (PS) in the common carotid artery were measured using an ultrasound system. Carotid arteriosclerosis was defined as IMT >1.2 mm and/or PS >5.0 mm. Results: The prevalence of CKD was independently associated with carotid arteriosclerosis after adjustment for other risk factors. Higher adiponectin levels were observed in CKD patients compared with non-CKD patients. Adiponectin levels were not independently correlated with the presence of carotid arteriosclerosis in all subjects. To evaluate the association between adiponectin and carotid arteriosclerosis among a CKD population, we divided the CKD patients into 2 groups according to a cutoff level of adiponectin determined by ROC analysis. The prevalence of carotid arteriosclerosis was significantly higher in the low-adiponectin group than in the high-adiponectin group among CKD patients. After adjusting for other risk factors, low levels of adiponectin were independently correlated with carotid arteriosclerosis in CKD patients. Conclusion: Our data document that adiponectin is associated with increased risk of carotid atherosclerosis in a predialysis CKD population.
Risks of thromboembolism and bleeding with thromboprophylaxis in patients with atrial fibrillation: A net clinical benefit analysis using a ‘real world’ nationwide cohort study
Authors: Lip Gregory , Lindhardsen Jesper , Lane Deirdre , Ahlehoff Ole , Hansen Morten , Raunsø Jakob , Tolstrup Janne , Hansen Peter , Gislason Gunnar , Torp-Pedersen Christian , Olesen Jonas
Published: July 2011

It was the aim of this study to determine the efficacy and safety of vitamin K antagonists (VKAs) and acetylsalicylic acid (ASA) in patients with non-valvular atrial fibrillation (AF), with separate analyses according to predicted thromboembolic and bleeding risk. By individual levellinkage of nationwide registries, we identified all patients discharged with non-valvular AF in Denmark (n=132,372). For every patient, the risk of stroke and bleeding was calculated by CHADS2, CHA2DS2-VASc, and HAS-BLED. During follow-up, treatment with VKA and ASA was determined time-dependently. VKA consistently lowered the risk of thromboembolism compared to ASA and no treatment; the combination of VKA+ASA did not yield any additional benefit. In patients at high thromboembolic risk, hazard ratios (95% confidence interval) for thromboembolism were: 1.81 (1.73–1.90), 1.14 (1.06–1.23), and 1.86 (1.78–1.95) for ASA, VKA+ASA, and no treatment, respectively, compared to VKA. The risk of bleeding was increased with VKA, ASA, and VKA+ASA compared to no treatment, the hazard ratios were: 1.0 (VKA; reference), 0.93 (ASA; 0.89–0.97), 1.64 (VKA+ASA; 1.55–1.74), and 0.84 (no treatment; 0.81–0.88), respectively. There was a neutral or positive net clinical benefit (ischaemic stroke vs. intracranial haemorrhage) with VKA alone in patients with a CHADS2 score of ≥ 0, and CHA2DS2-VASc score of ≥ 1. This large cohort study confirms the efficacy of VKA and no effect of ASA treatment on the risk of stroke/thromboembolism. Also, the risk of bleeding was increased with both VKA and ASA treatment, but the net clinical benefit was clearly positive, in favour of VKA in patients with increased risk of stroke/thromboembolism.
Competing Risks for Death and Cardiac Transplantation in Children With Dilated Cardiomyopathy
Authors: Alvarez Jorge A. , Orav E. John , Wilkinson James D. , Fleming Lora E. , Lee David J. , Sleeper Lynn A. , Rusconi Paolo G. , Colan Steven D. , Hsu Daphne T. , Canter Charles E. , Webber Steven A. , Cox Gerald F. , Jefferies John L. , Towbin Jeffrey A. , Lipshultz Steven E. ,   for the Pediatric Cardiomyopathy Registry Investigators
Published: July 2011

Background

Pediatric dilated cardiomyopathy (DCM) is the leading indication for heart transplantation after 1 year of age. Risk factors by etiology at clinical presentation have not been determined separately for death and transplantation in population-based studies. Competing risks analysis may inform patient prioritization for transplantation listing.

Methods and Results

The Pediatric Cardiomyopathy Registry enrolled 1731 children diagnosed with DCM from 1990 to 2007. Etiologic, demographic, and echocardiographic data collected at diagnosis were analyzed with competing risks methods stratified by DCM etiology to identify predictors of death and transplantation. For idiopathic DCM (n=1192), diagnosis after 6 years of age, congestive heart failure, and lower left ventricular (LV) fractional shortening
z
score were independently associated with both death and transplantation equally. In contrast, increased LV end-diastolic dimension
z
score was associated only with transplantation, whereas lower height-for-age
z
score was associated only with death. For neuromuscular disease (n=139), lower LV fractional shortening was associated equally with both end points, but increased LV end-diastolic dimension was associated only with transplantation. The risks of death and transplantation were increased equally for older age at diagnosis, congestive heart failure, and increased LV end-diastolic dimension among those with myocarditis (n=272) and for congestive heart failure and decreased LV fractional shortening among those with familial DCM (n=79).

Conclusions

Risk factors for death and transplantation in children varied by DCM etiology. For idiopathic DCM, increased LV end-diastolic dimension was associated with increased transplantation risk but not mortality. Conversely, short stature was significantly related to death but not transplantation. These findings may present an opportunity to improve the transplantation selection algorithm.
Association of Sodium and Potassium Intake With Left Ventricular Mass
Authors: Rodriguez Carlos J. , Bibbins-Domingo Kirsten , Jin Zhezhen , Daviglus Martha L. , Goff David C. , Jacobs David R.
Published: July 2011

High salt intake may affect left ventricular mass (LVM). We hypothesized that urinary sodium (UNa) and sodium/potassium ratio (UNa/K) are associated with LVM in a predominantly normotensive cohort of young adults. The Coronary Artery Risk Development in Young Adults (CARDIA) Study is a multicenter cohort of black and white men and women aged 30±3.6 years at the time of baseline echocardiographic examination (1990–1991). 2D guided M-mode LVM indexed to body size (grams per meter
2.7
) was calculated, and UNa and potassium excretion assessed (average of three 24-hour urinary samples, n=1042). Linear and logistic regression analysis was used. Participants were 57% women and 55% black. Only 4% were hypertensive. UNa, urinary potassium, and UNa/K ratios were (mean±SD) 175.6±131.0, 56.4±46.3, and 3.4±1.4 mmol/24 h, respectively. Participants in the highest versus the lowest UNa excretion quartile had the greatest LVM (37.5 versus 34.0 g/m
2.7
;
P
<0.001). Adjusted for age, sex, education, and race, LVM averaged 0.945 g/m
2.7
higher per SD of UNa/K (
P
=0.001). The relationship between UNa/K and LVM persisted among 399 participants with repeat echocardiographic measures 5 years later. In logistic regression analysis adjusted for age, sex, education, and race, each SD higher baseline UNa/K was associated with 23% and 38% greater chances of being in the highest quartile of LVM at baseline (odds ratio: 1.23;
P
=0.005) and 5 years later (odds ratio: 1.38;
P
=0.02). A higher sodium/potassium excretion ratio is significantly related to cardiac structure, even among healthy young adults.
Facilitating Student Learning Through Contextualization
Authors: Perin Dolores
Published: July 2011

This is a review of evidence for contextualization, defined here as an instructional approach connecting foundational skills and college-level content. Two forms of contextualization are identified, contextualized and integrated instruction. Despite methodological limitations, the available studies suggest that contextualization has the potential to accelerate the progress of academically underprepared college students.
Organization as an (Imbricated) Configuring of Transactions
Authors: Taylor James R.
Published: July 2011

This paper argues that taking communication as a primary focus of theory and research leads to new insights on the nature of organization, as currently displayed in studies of strategy, institutionalization, boundary objects, discourse and materiality. Communicatively, an organization is both a configuring of practices, each with its own interactive modes of exchange, and a corporate legal person whose ‘voice’ becomes, paradoxically, a component of that same discursive geography. The ‘paradox’ dissolves, however, in a communicative theory, which argues that organizational identity, and its personhood, are established in the same way as those of individuals. The article then presents an original vision of organization as an ‘imbrication’ of domains of discourse out of which layers of identity emerge. The primary mechanism responsible for coherence of purpose and identity is authority, in that the persons of both organization and members must be continually “authored” for them to exist. The article concludes with a brief discussion of the implications of taking a communicative approach for future research.
Marital and Family Satisfaction as a Function of Work–Family Demands and Community Resources
Authors: Hostetler Andrew J. , Desrochers Stephan , Kopko Kimberly , Moen Phyllis
Published: July 2011

This study uses individual- and couple-level analyses to examine the influence of work–family demands and community resources on marital and family satisfaction within a sample of dual-earner parents with dependent children ( N = 260 couples, 520 individuals). Total couple work hours were strongly negatively associated with marital satisfaction for both fathers and mothers. Work hours may be best studied as a couple-level demand, and working shorter combined hours, if possible, may be a central component of a broader adaptive strategy. Negative work-to-family spillover was negatively associated with parents’ family satisfaction, but for mothers this relationship was mediated by negative affect and (marginally) by couple disagreements. Finally, fathers’ neighborhood friends emerged as an important resource for both fathers and mothers, suggesting gender differences in the role of community in the work–family interface and highlighting the need for further research of community-level resources.
May the Circle Be Unbroken
Authors: Blodgett Amy T. , Schinke Robert J. , Peltier Duke , Fisher Leslee A. , Watson Jack , Wabano Mary Jo
Published: July 2011

This study was conducted by university and Aboriginal coresearchers in Canada, utilizing a participatory action research (PAR) approach akin to a decolonizing methodology. The purpose was to empower nine Aboriginal coresearchers to share their recommendations for meaningful research practice, grounded in their cultural perspectives and lived experiences. Data were collected through conversational interviews. The overarching intent was to (a) challenge the Eurocentric research paradigms that are prevalent within the sport sciences by bringing forward Indigenous voices; and (b) delineate applied strategies for research aimed at social transformation within other marginalized communities. The project provides one example of how participatory action research can be put into action so that positive relations may be restored between academics and marginalized community members and social justice may be achieved.
Does physiotherapy based on the Bobath concept, in conjunction with a task practice, achieve greater improvement in walking ability in people with stroke compared to physiotherapy focused on structured task practice alone? A pilot randomized controlled trial
Authors: Brock Kim , Haase Gerlinde , Rothacher Gerhard , Cotton Susan
Published: July 2011

Objective: To compare the short-term effects of two physiotherapy approaches for improving ability to walk in different environments following stroke: (i) interventions based on the Bobath concept, in conjunction with task practice, compared to (ii) structured task practice alone.

Design: Randomized controlled trial.

Setting: Two rehabilitation centres

Participants: Twenty-six participants between four and 20 weeks post-stroke, able to walk with supervision indoors.

Interventions: Both groups received six one-hour physiotherapy sessions over a two-week period. One group received physiotherapy based on the Bobath concept, including one hour of structured task practice. The other group received six hours of structured task practice.

Outcome measures: The primary outcome was an adapted six-minute walk test, incorporating a step, ramp and uneven surface. Secondary measures were gait velocity and the Berg Balance Scale. Measures were assessed before and after the intervention period.

Results: Following the intervention, there was no significant difference in improvement between the two groups for the adapted six-minute walk test (89.9 (standard deviation (SD) 73.1) m Bobath versus 41 (40.7) m task practice, P = 0.07). However, walking velocity showed significantly greater increases in the Bobath group (26.2 (SD 17.2) m/min versus 9.9 (SD  = 12.9) m/min, P = 0.01). No significant differences between groups were recorded for the Berg Balance Scale ( P = 0.2).

Conclusion: This pilot study indicates short-term benefit for using interventions based on the Bobath concept for improving walking velocity in people with stroke. A sample size of 32 participants per group is required for a definitive study.
Early Risk Behaviors and Adolescent Injury in 25 European and North American Countries
Authors: de Looze Margaretha , Pickett William , Raaijmakers Quinten , Kuntsche Emmanuel , Hublet Anne , Nic Gabhainn Saoirse , Bjarnason Thoroddur , Molcho Michal , Vollebergh Wilma , ter Bogt Tom
Published: July 2011

Injury is a leading cause of mortality and morbidity among adolescents in developed countries. Jessor and Jessor’s Problem Behavior Theory suggests an association between risk behaviors (e.g., smoking, drunkenness, cannabis use, and sexual intercourse) and adolescent injury. The present study examined whether early engagement in risk behaviors would predict injury at age 15. It also examined whether such associations were consistent in strength across countries. Based on the data from the 2005-2006 Health Behaviour in School-aged Children (HBSC) survey, a multigroup logistic regression analysis was conducted. Our findings demonstrate a cross-national consistent association (with relative odds of injury rising to 1.85; 95% CI: 1.70-2.02). Based on the study findings, early engagement in risk behaviors was considered a marker for a trajectory that places adolescents at higher risk for physical injury, independent of their national context.
Structural model for prediction of thermo-mechanical properties of fabric sandwich composites
Authors: Clifton P , Subic A , Mouritz A
Published: July 2011

An applied prediction code has been developed to calculate the thermo-mechanical properties of sandwich composites utilizing common fabric configurations. A well-established unit-cell approach was employed to model the fabric layer geometry. Effective elastic properties were determined using Hashin's cylinder model, together with common coordinate transformations and volumetric averaging methods. Two-dimensional laminate theory was applied to calculate the mechanical properties of the resulting composite structure, with the code allowing for variable width and thickness geometry in the final part. A simple validation has been undertaken for three different composite samples to confirm the accuracy of the developed prediction model.
Modelling of ballraceway contacts in a slewing bearing with non-linear springs
Authors: Gao X H , Huang X D , Wang H , Chen J
Published: July 2011

During the operation, a slewing bearing is always subjected to a set of combined loads. It is the source of deformation of ballraceway contacts, rings, and even supporting structures. In practice, deformation of rings and supporting structures is often neglected for simplification, that is, they are supposed to be ideally stiff. To take elasticity of rings and supporting (fixed) structures into consideration, the finite-element method (FEM) is applied. Due to hundreds of contact pairs and the difference in the scale of contact area and rings or supporting structures, it is difficult to simultaneously model both local ballraceway contacts and the global slewing rings in a slewing bearing. The article developed a simple method to solve the problem, where the contacts are replaced by non-linear springs.
Field investigations into the performance of magnetic track brakes of an electrical multiple unit against slippery tracks. Part 1: Adhesion improvement
Authors: Arias-Cuevas O , Li Z
Published: July 2011

Some rolling stock designed for conventional and high-speed railway operation has magnetic track brakes (MTBs) to have an additional brake independent of the wheel–rail adhesion to be mostly activated in emergency situations. In recent years, interest has grown in some railways towards the possible use of MTB against slippery tracks. However, there seems to be a lack of knowledge on the major benefits and possible side effects of using MTB to overcome low-adhesion conditions. This hinders the realization of a cost-benefit analysis to look at possible implementation. In order to contribute to a better understanding, field tests have been performed with the permanent MTB of an electrical multiple unit in a stabling yard. Low-adhesion conditions have been created by three types of contamination representative of slippery tracks, i.e. leaves, water, and grease. The entire work has been divided in two parts. In this Part I, emphasis is put on the adhesion recovery, in particular the benefit for subsequent wheel (or train) passages. Baseline tests (i.e. no use of MTB) have also been performed with water and leaves. Additionally, an adhesion improver widely used in the Dutch and British railways has also been tested with leaves to allow for a comparison in effectiveness with MTB under similar operating conditions. In each test, the wheel–rail adhesion conditions along the initially contaminated track have been measured to evaluate the adhesion improvement under the different testing conditions.
Field investigations into the performance of magnetic track brakes of an electrical multiple unit against slippery tracks. Part 2: Braking force and side effects
Authors: Arias-Cuevas O , Li Z
Published: July 2011

Part II of the field investigations focuses on the braking force and some possible side effects of the frequent use of magnetic track brakes (MTBs) against slippery tracks. In part I, the adhesion recovery using MTBs along contaminated rails has been presented. Field tests have been performed with the permanent MTB of an electrical multiple unit (EMU) in a stabling yard. Three types of contamination representative of slippery tracks have been employed, e.g. water, leaves, and grease. Tests with dry ‘clean’ rails have also been performed throughout the testing to obtain a reference of the braking force in the speed range 0–40 km/h. Furthermore, the braking performance of the EMU in different braking modes is analysed under the tested conditions. The surfaces of the brake shoes and the rails have been examined to analyse possible changes during the testing. The profile of rails and the mass loss of the brake shoes have also been measured in the tests to quantify the wear caused in the tests. Moreover, the possible negative effect of a passing MTB on the electrical insulation of an insulated rail joint has been examined by means of electrical measurements and visual inspection.
Controls on lake level in the early to mid Holocene, Hawes Water, Lancashire, UK
Authors: Jones R.T. , Marshall J.D. , Fisher E. , Hatton J. , Patrick C. , Anderson K. , Lang B. , Bedford A. , Oldfield F.
Published: July 2011

This study presents a new interpretation of the evidence for Holocene lake-level changes from Hawes Water in NW England constrained by detailed stratigraphic data, radiocarbon chronology and palaeo-environmental evidence. Lake levels are seen to decline gradually from the start of the Holocene through to 9960 cal. yr BP, in response to lake infilling and the prevailing dry climatic conditions. Low lake levels then persist until 6000 cal. yr BP, punctuated by two transgressive phases. Rising sea levels during the Holocene high-level sea stand are thought to be responsible for a major rise in lake level at 6000 cal. yr BP driven by changes in the local water-table. The rise in lake level is coincident with a rise in anthropogenic activity across the site, possibly reflecting the migration of coastal Mesolithic communities inland in response to rising sea levels.
Attentiveness in care: Towards a theoretical framework
Authors: Klaver Klaartje , Baart Andries
Published: July 2011

The purpose of this article is to shape a theoretical framework of attentiveness in care, which may function as a background to study attentiveness in a health care setting empirically. More insight into the functions, forms, and aspects of attentiveness in a particular health care setting is important, as there is a lack of indicators and criteria that enable a sharp picture of the caring side of health provision. The concept of attentiveness and its relation to care have seldom been examined thoroughly and broadly. This article argues that attentiveness is constitutive for good care, as it can create a space in which a relationship may arise.
Educators' and Parents' Perception of What School Nurses Do
Authors: Maughan Erin , Adams Rachael
Published: July 2011

The purpose of this qualitative study was to determine how ratios influenced relationships between school nurses and the educators and parents with whom they work; and how the relationships influenced the understanding and value of the school nurse. A purposeful sampling of 33 participants from four states (New Hampshire, Vermont, Michigan, and Utah) was included in the study. The results indicate both educators and parents perceived the primary role of the school nurse to be medication administration and first aid. The value and understanding of the role of the nurse was not based on the school nurse-to-student ratio. It was influenced by the quality of interactions with school nurses; and the extent to which the nurse was a member of the school team. School nurses must understand the culture of education in order to build professional relationships with administrators and be seen as valuable members of the school team.
Analysis and control of friction-induced oscillations in a continuous system
Authors: Saha Ashesh , Pandey Shashank Shekhar , Bhattacharya Bishakh , Wahi Pankaj
Published: July 2011

We analyse and control friction-induced oscillations in a continuous system due to the drooping characteristics of the friction force. The model consists of a cantilever beam with an end mass that is in frictional contact with a rigid rotating disc. Time-delayed displacement feedback applied normal to the disc surface is used to control the vibrations. Linear stability analysis yields the stability boundary corresponding to the Hopf bifurcation point. Nonlinear analysis is performed to obtain conditions on the control parameters for which the nature of the bifurcation is subcritical such that these values can be avoided. The control parameters for effective quenching of the vibrations are obtained. An interesting regime of control parameters for which the system is stable for low and high velocities but unstable for intermediate velocities is also observed.
Radial oil injection applied to main engine bearings: evaluation of injection control rules
Authors: Estupiñan EA , Santos IF
Published: July 2011

The performance of main bearings in a combustion engine affects key functions such as durability, noise and vibration. Thus, with the aim of reducing friction losses and vibrations between the crankshaft and the bearings, the work reported here evaluates different strategies for applying controllable radial oil injection to main crankshaft journal bearings. In an actively lubricated bearing, conventional hydrodynamic lubrication is combined with controllable hydrostatic lubrication, where the oil injection pressures can be modified depending on the operational conditions. In this study, the dynamic behaviour of the main bearing of a medium-size engine is theoretically analysed when the engine operates with controllable radial oil injection and four different injection control rules. The theoretical investigation is based on a single-cylinder combustion engine model. The performance of the actively lubricated bearing is compared with the performance of the conventional lubricated bearing, giving some insights into the minimum fluid film thickness, maximum fluid film pressure, friction losses and maximum vibration levels.
Arrests for Child Pornography Production
Authors: Wolak Janis , Finkelhor David , Mitchell Kimberly J. , Jones Lisa M.
Published: July 2011

This study collected information on arrests for child pornography (CP) production at two points (2000–2001 and 2006) from a national sample of more than 2,500 law enforcement agencies. In addition to providing descriptive data about an understudied crime, the authors examined whether trends in arrests suggested increasing CP production, shifts in victim populations, and challenges to law enforcement. Arrests for CP production more than doubled from an estimated 402 in 2000–2001 to an estimated 859 in 2006. Findings suggest the increase was related to increased law enforcement activity rather than to growth in the population of CP producers. Adolescent victims increased, but there was no increase in the proportion of arrest cases involving very young victims or violent images. Producers distributed images in 23% of arrest cases, a proportion that did not change over time. This suggests that much CP production may be primarily for private use. Proactive law enforcement operations increased, as did other features consistent with a robust law enforcement response.
Merging Developmental and Criminal Career Perspectives
Authors: Cale Jesse , Lussier Patrick
Published: July 2011

Currently, a majority of actuarial risk-assessment tools for sexual recidivism contain static risk factors that measure various aspects of the offender’s prior criminal history in adulthood. The goal of the current study was to assess the utility of extending static risk factors, by using developmental and criminal career parameters of offending, in the actuarial assessment of risk of violent/sexual recidivism. The current study was based on a sample of 204 convicted sexual aggressors of women incarcerated in the province of Quebec, Canada between April 1994 and June 2000. Semistructured interviews were used to gather information on the offender’s antisocial history prior to adulthood, and police records were used to collect data on the criminal career of these offenders in adulthood. For an average follow-up period of approximately 4 years, the violent/sexual recidivism rate for the sample was 23.7%. The results provided support for the inclusion of both developmental and criminal career indicators for the prediction of violent/sexual recidivism. More specifically, recidivists were characterized by an early onset antisocial trajectory and a pattern of escalation of antisocial behavior between childhood and adolescence. The findings suggest that risk assessors should look beyond broad adult criminal history data to include aspects of antisocial development to improve predictive accuracy.
Legitimizing dialogue as textual and ideological goal in academic writing for assessment and publication
Authors: Lillis Theresa
Published: July 2011

The semiotic world that we inhabit (within and outside the academy) is fast changing in terms of the resources that are used and the practices in which many engage. Yet the institutional norms governing highly consequential academic texts – students’ texts assessed as part of their disciplinary-based activity and scholars’ papers submitted for publication – lack engagement with this array of resources and, epistemologically, continue to drive a monologic stance towards academic meaning making. The aim of this article is to argue for a reconfiguring of the textual goal of academic writing, through one simple yet transformative tool, that of juxtaposition. Textual juxtaposition is illustrated in this article, and its intellectual and ideological value discussed, drawing on Bakhtin’s emphasis on dialogue, using several examples from published academic texts. The relevance to scholarly and student writing is explored.
The Emerging Viewertariat and BBC Question Time
Authors: Anstead Nick , O’Loughlin Ben
Published: July 2011

This paper advances the study of microblogging and political events by investigating how one high-profile broadcast acted as a stimulus to real-time commentary from viewers using Twitter. Our case study is a controversial, high-ratings episode of BBC Question Time, the weekly British political debate show, in October 2009, in which Nick Griffin, leader of the far-right British National Party, appeared as a panelist. The “viewertariat” emerging around such a political event affords the opportunity to explore interaction across media formats. We examine both the structural elements of engagement online and the expressions of collective identity expressed in tweets. Although many concerns noted in previous studies of online political engagement remain (inequality in the propensity to comment, coarseness of tone), we find certain notable characteristics in the sample, especially a direct link between the quantity of tweets and events on the screen, an ability to preempt the arguments offered by panelists, and ways in which viewertariat members add new content to the discussion. Furthermore, Twitter users commenting online express a range of overlapping identities. These complexities challenge broadcasting and political institutions seeking to integrate new, more organic models of engagement.
Hypoxia-inducible factor-1 drives annexin A2 system-mediated perivascular fibrin clearance in oxygen-induced retinopathy in mice
Authors: Huang Bihui , Deora Arun B. , He Kai-Li , Chen Kang , Sui Guangzhi , Jacovina Andrew T. , Almeida Dena , Hong Peng , Burgman Paul , Hajjar Katherine A.
Published: July 2011

Oxygen-induced retinopathy (OIR) is a well-characterized model for retinopathy of prematurity, a disorder that results from rapid microvascular proliferation after exposure of the retina to high oxygen levels. Here, we report that the proliferative phase of OIR requires transcriptional induction of the annexin A2 (A2) gene through the direct action of the hypoxia-inducible factor-1 complex. We show, in addition, that A2 stabilizes its binding partner, p11, and promotes OIR-related angiogenesis by enabling clearance of perivascular fibrin. Adenoviral-mediated restoration of A2 expression restores neovascularization in the oxygen-primed Anxa2−/− retina and reinstates plasmin generation and directed migration in cultured Anxa2−/− endothelial cells. Systemic depletion of fibrin repairs the neovascular response to high oxygen treatment in the Anxa2−/− retina, whereas inhibition of plasminogen activation dampens angiogenesis under the same conditions. These findings show that the A2 system enables retinal neoangiogenesis in OIR by enhancing perivascular activation of plasmin and remodeling of fibrin. These data suggest new potential approaches to retinal angiogenic disorders on the basis of modulation of perivascular fibrinolysis.