bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-use high/low-temperature and pressure compatible portable chamber forin situgrazing-incidence X-ray scattering studies
Authors: Ferrer Pilar , Rubio-Zuazo Juan , Heyman Catherine , Esteban-Betegón Fatima , Castro Germán R.
Published: February 2013

The multipurpose portable ultra-high-vacuum-compatible chamber described in detail in this article has been designed to carry out grazing-incidence X-ray scattering techniques on the BM25-SpLine CRG beamline at the ESRF. The chamber has a cylindrical form, built on a 360° beryllium double-ended conflate flange (CF) nipple. The main advantage of this chamber design is the wide sample temperature range, which may be varied between 60 and 1000 K. Other advantages of using a cylinder are that the wall thickness is reduced to a minimum value, keeping maximal solid angle accessibility and keeping wall absorption of the incoming X-ray beam constant. The heat exchanger is a customized compact liquid-nitrogen (LN2) continuous-flow cryostat. LN2 is transferred from a storage Dewar through a vacuum-isolated transfer line to the heat exchanger. The sample is mounted on a molybdenum support on the heat exchanger, which is equipped with a BORALECTRIC heater element. The chamber versatility extends to the operating pressure, ranging from ultra-high vacuum (<10−10 mbar) to high pressure (up to 3 × 103 mbar). In addition, it is equipped with several CF ports to allocate auxiliary components such as capillary gas-inlet, viewports, leak valves, ion gun, turbo pump,etc., responding to a large variety of experiment requirements. A movable slits set-up has been foreseen to reduce the background and diffuse scattering produced at the beryllium wall. Diffraction data can be recorded either with a point detector or with a bi-dimensional CCD detector, or both detectors simultaneously. The system has been designed to carry out a multitude of experiments in a large variety of environments. The system feasibility is demonstrated by showing temperature-dependence grazing-incidence X-ray diffraction and conductivity measurements on a 20 nm-thick La0.7Ca0.3MnO3thin film grown on a SrTiO3(001) substrate.
Behavior of micropolar lubricated lobe bearings: influence of non‐circularity parameters
Authors: Nekoeimehr M. , Rahmatabadi A.D. , Rashidi R.
Published: February 2013

Purpose

The purpose of this paper is to analyse the static performance characteristics of lobe journal bearings lubricated with a micropolar fluid, considering effect of non‐circularity. Number of lobes and their preload value are the non‐circularity parameters considered in the present study. The bearings undertaken for the investigation are two, three and four‐lobe symmetric journal bearings with finite width.

Design/methodology/approach

For this purpose, modified form of Reynolds equation is derived, based on Eringen's micropolar fluid theory and it is solved numerically using finite element method (FEM). The effect of the non‐circularity parameters of bearings on the steady‐state performance characteristics such as load carrying capacity, attitude angle, coefficient of friction and side leakage flow are presented and discussed.

Findings

The results show that the number of lobes and their preload value can influence the performance of lobe bearings. It is seen that, in order to provide certain improvement over simple cylindrical bearings, the non‐circularity parameters of lobe bearings must be chosen correctly. There is no single optimum profile for multi‐lobe bearing application.

Originality/value

Lobe bearings, compared with simple circular bearings, offer several geometric parameters to designers. These parameters must be chosen correctly, so that the requirements of a specific application can be fulfilled.
Wear behavior of ceramic powder cladded on carbon steel surface by gas tungsten arc welding
Authors: Peng De‐Xing , Kang Yuan , Li Zheng‐Xian , Chang Shih‐Yen
Published: February 2013

Purpose

The purpose of this paper is to test the wear behavior of a carbon steel surface after cladding by gas tungsten arc welding (GTAW) method to enhance wear resistance.

Design/methodology/approach

The microstructures, chemical compositions, and wear characteristics of cladded surfaces were analyzed by scanning electron microscopy (SEM), and energy dispersive X‐ray spectroscopy (EDX). A rotating‐type tribometer was used to evaluate the wear characteristics of cladded specimens under dry sliding conditions at room temperature. The dry sliding wear resistance of the coatings was tested as a function of applied load and sliding time, and wear mechanisms were elucidated by analyzing wear surfaces.

Findings

The experimental results revealed an excellent metallurgical bond between the composite coating and substrate. The coating was uniform, continuous, and almost defect‐free, and particles were evenly distributed throughout the cladding layer. Hardness was increased from 200 HV in the substrate to 650‐800 HV in the modified layer due to the presence of the hard TiC phase. The excellent wear resistance and very low load sensitivity observed in the dry sliding wear test of the intermetallic matrix composite coating were due to the high hardness of TiC and the strong atomic bonds of the intermetallic matrix.

Originality/value

The experiments in this study confirm that, by reducing friction and anti‐wear, the cladding layer prepared using the proposed methods can prolong machinery operating life.
Validation of a META‐RELQUAL construct through a Nordic comparative study
Authors: Svensson Göran , Mysen Tore , Rindell Anne , Billström Anders
Published: February 2013

Purpose

The purpose of this paper is to test the validity and reliability of a META‐RELQUAL construct in Finnish, Norwegian and Swedish business relationships.

Design/methodology/approach

A total of 1,500 companies were involved. The Finnish, Norwegian, and Swedish sampling frames each consisted of the 500 largest companies based upon revenue across multiple industries. The response rate was 38 percent.

Findings

The goodness‐of‐fit measures of the tested measurement model of the META‐RELQUAL construct were all found to be satisfactory within the recommended guidelines. The recommended guidelines for convergent, discriminant and nomological validity, as well as for construct reliability, were all well met. It is concluded that the measurement properties of the META‐RELQUAL construct applied in Finnish, Norwegian and Swedish business relationships indicate acceptable validity and reliability.

Research limitations/implications

The tested META‐RELQUAL construct appears accurate for those Finnish, Norwegian, and Swedish business relationships studied, but only further testing and comparisons will verify whether it can be seen as a valid, reliable measurement for other countries and their companies’ business relationships. Suggestions for further research are provided.

Practical implications

This international study is of managerial interest to executives since it provides a framework of constructs to be considered in corporate efforts to maintain satisfactory levels of relationship quality in Finnish, Norwegian, and Swedish business relationships. It may also be applicable in other business relationships and in other countries.

Originality/value

This Nordic comparative study of a META‐RELQUAL construct contributes to theory since it outlines a higher‐order construct and measurement instrument benefitting other researchers and practitioners. It appears unique in making an international comparison of a tested measurement model of the META‐RELQUAL construct.
A statistical review of mudrock elastic anisotropy
Authors: Horne S.A.
Published: February 2013

Mudrocks, defined to be fine‐grained siliclastic sedimentary rocks such as siltstones, claystones, mudstones and shales, are often anisotropic due to lamination and microscopic alignments of clay platelets. The resulting elastic anisotropy is often non‐negligible for many applications in the earth sciences such as wellbore stability, well stimulation and seismic imaging. Anisotropic elastic properties reported in the open literature have been compiled and statistically analysed. Correlations between elastic parameters are observed, which will be useful in the typical case that limited information on a rock's elastic properties is known. For example, it is observed that the highest degree of correlation is between the horizontal elastic stiffnesses C11 and C66. The results of statistical analysis are generally consistent with prior observations. In particular, it is observed that Thomsen's ɛ and γ parameters are almost always positive, Thomsen's ɛ and γ parameters are well correlated, Thomsen's δ is most frequently small and Thomsen's ɛ is generally larger than Thomsen's δ. These observations suggest that the typical range for the elastic properties of mudrocks span a sub‐space less than the five elastic constants required to fully define a Vertical Transversel Isotropic medium. Principal component analysis confirms this and that four principal components can be used to span the space of observed elastic parameters.
Do Clinical Standards for Diabetes Care Address Excess Risk for Hypoglycemia in Vulnerable Patients? A Systematic Review
Authors: Berkowitz Seth A. , Aragon Katherine , Hines Jonas , Seligman Hilary , Lee Sei , Sarkar Urmimala
Published: February 2013

Objective

To determine whether diabetes clinical standards consider increased hypoglycemia risk in vulnerable patients.

Data Sources

MEDLINE, the National Guidelines Clearinghouse, the National Quality Measures Clearinghouse, and supplemental sources.

Study Design

Systematic review of clinical standards (guidelines, quality metrics, or pay‐for‐performance programs) for glycemic control in adult diabetes patients. The primary outcome was discussion of increased risk for hypoglycemia in vulnerable populations.

Data Collection/Extraction Methods

Manuscripts identified were abstracted by two independent reviewers using prespecified inclusion/exclusion criteria and a standardized abstraction form.

Principal Findings

We screened 1,166 titles, and reviewed 220 manuscripts in full text. Forty‐four guidelines, 17 quality metrics, and 8 pay‐for‐performance programs were included. Five (11 percent) guidelines and no quality metrics or pay‐for‐performance programs met the primary outcome.

Conclusions

Clinical standards do not substantively incorporate evidence about increased risk for hypoglycemia in vulnerable populations.
Severe Hypertriglyceridemia‐Related Acute Pancreatitis
Authors: Stefanutti Claudia , Labbadia Giancarlo , Morozzi Claudia
Published: February 2013

Acute pancreatitis is a potentially life‐threatening complication of severe hypertriglyceridemia. In some cases, inborn errors of metabolism such as lipoprotein lipase deficiency, apoprotein C‐II deficiency, and familial hypertriglyceridemia have been reported as causes of severe hypertriglyceridemia. More often, severe hypertriglyceridemia describes various clinical conditions characterized by high plasma levels of triglycerides (>1000 mg/dL), chylomicron remnants, or intermediate density lipoprotein like particles, and/or chylomicrons. International guidelines on the management of acute pancreatitis are currently available. Standard therapeutic measures are based on the use of lipid‐lowering agents (fenofibrate, gemfibrozil, niacin, Ω‐3 fatty acids), low molecular weight heparin, and insulin in diabetic patients. However, when standard medical therapies have failed, non‐pharmacological approaches based upon the removal of triglycerides with therapeutic plasma exchange can also provide benefit to patients with severe hypertriglyceridemia and acute pancreatitis. Plasma exchange could be very helpful in reducing triglycerides levels during the acute phase of hyperlipidemic pancreatitis, and in the prevention of recurrence. The current evidence on management of acute pancreatitis and severe hypertriglyceridemia, focusing on symptoms, treatment and potential complications is reviewed herein.
Abstinence duration modulates striatal functioning during monetary reward processing in cocaine patients
Authors: Bustamante Juan‐Carlos , Barrós‐Loscertales Alfonso , Costumero Víctor , Fuentes‐Claramonte Paola , Rosell‐Negre Patricia , Ventura‐Campos Noelia , Llopis Juan‐José , Ávila César
Published: February 2013

Pre‐clinical and clinical studies in cocaine addiction highlight alterations in the striatal dopaminergic reward system that subserve maintenance of cocaine use. Using an instrumental conditioning paradigm with monetary reinforcement, we studied striatal functional alterations in long‐term abstinent cocaine‐dependent patients and striatal functioning as a function of abstinence and treatment duration. Eighteen patients and 20 controls underwent functional magnetic resonance imaging during a Monetary Incentive Delay task. Region of interest analyses based on masks of the dorsal and ventral striatum were conducted to test between‐group differences and the functional effects in the cocaine group of time (in months) with no more than two lapses from the first time patients visited the clinical service to seek treatment at the scanning time (duration of treatment), and the functional effects of the number of months with no lapses or relapses at the scanning session time (length of abstinence). We applied a voxel‐wise and a cluster‐wise FWE‐corrected level (pFWE) at a threshold of P < 0.05. The patient group showed lower activation in the right caudate during reward anticipation than the control group. The regression analyses in the patients group revealed a positive correlation between duration of treatment and brain activity in the left caudate during reward anticipation. Likewise, length of abstinence negatively correlated with brain activity in the bilateral nucleus accumbens during monetary outcome processing. In conclusion, caudate and nucleus accumbens show a different brain response pattern to non‐drug rewards during cocaine addiction, which can be modulated by treatment success.
Demystifying Animal Models of Adverse Pregnancy Outcomes: Touching Bench and Bedside
Authors: Bonney Elizabeth A.
Published: February 2013

This represents an overview of the use of animal models to study the adverse pregnancy outcomes seen in humans. The purpose is to entice clinicians to utilize some of this information to seek out the literature and have more meaningful and profitable discussions with their academic colleagues and enhance transdisciplinary research in reproductive health.
Decreased cardiac vagal control in drug‐naive patients with panic disorder: A case‐control study in Taiwan
Authors: Chang Hsin‐An , Chang Chuan‐Chia , Tzeng Nian‐Sheng , Kuo Terry B. J. , Lu Ru‐Band , Huang San‐Yuan
Published: February 2013

Introduction

Cardiac autonomic dysregulation has been proposed in panic disorder (PD), but the results are mixed. Analyses with larger sample sizes and better methodology are needed.

Methods

Forty‐eight drug‐naïve individuals with PD and 202 healthy volunteers were recruited for a case‐control analysis. We used the Hamilton Anxiety Rating Scale and the Beck Anxiety Inventory to assess anxiety severity. Cardiac autonomic function was evaluated by measuring heart rate variability (HRV) parameters. Frequency‐domain indices of HRV were obtained. The obtained results were evaluated in association with personality traits assessed by the Tridimensional Personality Questionnaire.

Results

Patients exhibited reduced mean RR interval (816.94 ± 135.92 versus 873.47 ± 143.36 ms, P = 0.014) and HRV levels (Var 6.37 ± 1.32 versus 7.38 ± 0.95, LF 4.90 ± 1.63 versus5.82 ± 1.11 and HF 4.57 ± 1.53 versus 5.62 ± 1.24 [ln(ms2)], all P < 0.001) as compared to controls, which mainly suggested a reduction in cardiac vagal control in PD. The anxiety severity was negatively correlated with HRV levels (r = −0.29 for Var, r = −0.22 for LF and r = −0.28 for HF, all P < 0.001). The harm avoidance score (which has been suggested to be associated with serotonergic activity) was associated with decreased HRV levels (r = −0.22 for Var, P < 0.01, r = −0.14 for LF, P < 0.05 and r = −0.17 for HF, P < 0.01).

Discussion

This study demonstrates that PD is associated with cardiac autonomic dysregulation, highlighting the importance of assessing HRV in PD patients.
Chewing efficiency and electromyographic activity of masseter muscle with three designs of implant‐supported mandibular overdentures. A cross‐over study
Authors: Elsyad Moustafa A. , Hegazy Salah A. F. , Hammouda Nelly I. , Al‐Tonbary Gilan Y. , Habib Ahmed A.
Published: February 2013

Purpose

The aim of this study was to compare the effect of three designs for implant‐supported mandibular overdenture on the chewing efficiency and electromyographic (EMG) activity of masseter muscles.

Material and methods

Eighteen edentulous patients received new maxillary and mandibular dentures (control, CD) before implant placement. After using the dentures for 3 months, patients were randomly divided into six blocks (three patients/block) and received four implants in canine and first molar areas of the mandible. Following osseointegration period, new duplicate mandibular overdentures were successively connected to the implants with: (i) ball attachment on two implants (2BOD), (ii) bar attachment on two implants (2ROD), and (iii) bar attachments on four implants (4ROD) in a random order. Chewing efficiency was measured using chewing gum, and EMG was recorded during clenching (with or without food). Evaluations were made 3 months after using each of the following prostheses: CD, 2BOD, 2ROD, and 4ROD.

Results

All implant‐supported overdentures showed a significant increase in chewing efficiency and EMG values when compared to CD. These values increased significantly with 4ROD when compared to 2BOD or 2ROD prostheses. There was no significant difference in chewing efficiency and EMG between 2BOD and 2ROD prostheses.

Conclusion

Four‐implant‐supported overdentures seem to present a functional advantage vs. two‐implant‐supported overdentures, independent of the chosen attachment system.
Auditor Independence and Auditor Bargaining Power: Some Spanish Evidence Concerning Audit Error in the Going Concern Decision
Authors: Barnes Paul , Renart Marcos Antón
Published: February 2013

It is well known that where an auditor's relative bargaining power is high, this may help its independence and prevent a Type II error (no qualification but corporate failure). It is less well known that this may also lead to a lack of independence in the form of over‐conservatism and an unjustified inclination by an auditor to qualify to protect its reputation leading to a Type I error (a qualification but no corporate failure). We therefore hypothesize that there is a positive relationship between the auditor's relative bargaining power and Type I errors (‘H1’) and a negative relationship between it and Type II errors (‘H2’). The empirical study supports H1 but rejects H2. Taken together, these results suggest that Spanish auditors have a high propensity to qualify to protect their reputation, undeterred by pressure from client companies, in order to protect their reputation – ‘over‐conservatism’ as we have called it.
Does exercise intensity affect blood pressure and heart rate in obese adolescents? A 6‐month multidisciplinary randomized intervention study
Authors: Farah B. Q. , Ritti‐Dias R. M. , Balagopal P. (B.) , Hill J. O. , Prado W. L.
Published: February 2013

What is already known about this subject

Aerobic exercise training is frequently used to reduce risk factors for cardiovascular disease in obese adolescents.

However, there is no consensus on how the intensity of exercise affects blood pressure and heart rate variability (HRV).

What this study adds

The current study shows that high‐intensity exercise training is able to decrease heart rate and enhance HRV likely playing a role in improving cardiac autonomic modulation.

However, it does not influence the reduction in blood pressure.

Background

Aerobic exercise improves cardiovascular health in general, but whether the impact varies with exercise intensity is not clear.

Objective

The aim of the current study was to compare the effects of a high‐intensity aerobic exercise training (HIT) vs. a low‐intensity aerobic exercise training (LIT) on blood pressure (BP), heart rate (HR) and heart rate variability (HRV) in obese adolescents.

Methods

Forty‐three (13–18 years) Tanner stage (III–IV) matched obese adolescents were studied in a randomized trial of either HIT (corresponding to the ventilatory threshold I; n = 20) or LIT (corresponding to 20% below the ventilatory threshold I; n = 23) programme for a period of 6 months. All participants also received a multidisciplinary therapy that included nutritional, psychological and clinical counselling. Both HIT and LIT sessions were isocaloric, with energy expenditure set at 350 kcal. BP, HR and HRV were measured along with markers of body adiposity and insulin resistance before and after the respective interventions.

Results

The participants in both groups had similar physical and clinical characteristics. After the 6‐month intervention, systolic, diastolic and mean BP decreased (P < 0.05, for all) similarly in both groups, whereas waist circumference, HR and HRV showed beneficial changes only in the HIT group (P < 0.05).

Conclusion

Aerobic exercise training set at a high intensity compared with the low intensity appears to have additional benefits on abdominal obesity and cardiovascular health in that it enhances the parasympathetic and autonomic modulation of the heart in obese adolescents.
In situ Diamond Anvil Cell–Raman Spectroscopy and Nanoindentation Study of the Pressure‐Induced Phase Transformation in Pure and Zinc‐Doped β‐Eucryptite
Authors: Ramalingam Subramanian , Packard Corinne E. , Reimanis Ivar E.
Published: February 2013

β‐eucryptite (LiAlSiO4), a member of the family of lithium aluminum silicates, is known to undergo a reversible pressure‐induced phase transformation at ~0.8 GPa to ε‐eucryptite. This study correlates the results between two techniques, in situ diamond anvil cell–Raman spectroscopy and nanoindentation experiments, to explore how doping (substituting Zn for Li) influences this pressure‐induced phase transformation. Diamond anvil cell tests carried up to 3 GPa hydrostatic stress under Raman spectroscopy were compared with nanoindentation results, which provide a more localized, multiaxial stress state. The results indicate that the magnitude of hysteresis observed (difference between the pressures required for the forward and reverse transformation) is lower for Zn‐doped β‐eucryptite; however, the onset of the phase transformation is unchanged by doping with Zn. Furthermore, calculations of activation volume from nanoindentation experiments yield similar values (~0.1 nm3) for pure and Zn‐doped β‐eucryptite, suggesting that the nucleation event that establishes the onset of the phase transformation is the same for both materials.
Bisphenol A in relation to behavior and learning of school‐age children
Authors: Hong Soon‐Beom , Hong Yun‐Chul , Kim Jae‐Won , Park Eun‐Jin , Shin Min‐Sup , Kim Boong‐Nyun , Yoo Hee‐Jeong , Cho In‐Hee , Bhang Soo‐Young , Cho Soo‐Churl
Published: February 2013

Background

Bisphenol A (BPA) has been shown to affect brain and behavior in rodents and nonhuman primates, but there are few studies focusing on its relationship to human neurobehavior. We aimed to investigate the relationship between environmental exposure to BPA and childhood neurobehavior.

Methods

Urinary BPA concentrations and behavioral and learning characteristics were assessed in a general population of 1,089 children, aged 8–11 years. The main outcome measures were the Child Behavior Checklist (CBCL) and the Learning Disability Evaluation Scale (LDES).

Results

Urinary levels of BPA were positively associated with the CBCL total problems score and negatively associated with the learning quotient from the LDES. The linear association with the CBCL anxiety/depression score and the quadratic association with the LDES listening score were significant after correction for multiple comparisons.

Conclusions

Environmental exposure to BPA might be associated with childhood behavioral and learning development. The results suggest possible nonmonotonic relationships.
Prevalence and associated factors of gingival recession in Greek adults
Authors: Chrysanthakopoulos Nikolaos A.
Published: February 2013

Aim

The aim of the present cross‐sectional study was to estimate gingival recession (GR) prevalence and associated risk factors in young Greek adults.

Methods

The study population consisted of 420 young adults (200 males and 220 females). All individuals were clinically examined and answered questions regarding their smoking status, educational level, and oral hygiene practices. In addition, the association between GR and the following aspects was assessed: sex, smoking status, educational level, plaque index, gingival index, calculus presence, and plaque control methods. Statistical analysis of data was accomplished using the multivariate linear regression analysis model.

Results

The average number of GR overall was 1.38 mm (standard deviation: 0.18 mm). Gingival index (P = 0.000) and smoking (P = 0.01) were the most important associated risk factors of GR, while sex, oral hygiene practices, presence of supragingival calculus, educational level, and plaque index were not significantly associated with it.

Conclusion

Gingival inflammation, as determined by the gingival index, and smoking were the most important associated risk factors of GR.
Failed Governance: A Comment on Baker and Griffith's Ensuring Corporate Misconduct
Authors: Heimer Carol A.
Published: February 2013

This essay evaluates Baker and Griffith's book, Ensuring Corporate Misconduct, as a contribution to the social science literatures on regulation and governance, risk, and insurance. Previous social science work on insurance often took an “insurance on the ground” perspective comparing how insurance actually works with the theory of insurance and scrutinizing the actions of insurers as well as the actions of their policyholders. In line with this perspective, Baker and Griffith find that directors and officers (D&O) insurers do not actually charge premiums that vary with risk or monitor the actions of the officers and directors covered by the insurance. Because insurers and governments share governance tasks (a point Baker makes elsewhere), insurers' failures in fact amount to “failed governance” of the corporate world.
Design Principles for Flexible Systems
Authors: Andradóttir Sigrún , Ayhan Hayriye , Down Douglas G.
Published: February 2013

A fundamental aspect of designing systems with dedicated servers is identifying and improving the system bottlenecks. We extend the concept of a bottleneck to networks with heterogeneous, flexible servers. In contrast with a network with dedicated servers, the bottlenecks are not a priori obvious, but can be determined by solving a number of linear programming problems. Unlike the dedicated server case, we find that a bottleneck may span several nodes in the network. We then identify some characteristics of desirable flexibility structures. In particular, the chosen flexibility structure should not only achieve the maximal possible capacity (corresponding to full server flexibility), but should also have the feature that the entire network is the (unique) system bottleneck. The reason is that it is then possible to shift capacity between arbitrary nodes in the network, allowing the network to cope with demand fluctuations. Finally, we specify when certain flexibility structures (in particular chaining, targeted flexibility, and the “N” and “W” structures from the call center literature) possess these desirable characteristics.
5‐HTTLPR and anxiety modulate brain‐heart covariation
Authors: Mueller Erik M. , Stemmler Gerhard , Hennig Jürgen , Wacker Jan
Published: February 2013

To date, little is known about genes affecting the interplay of brain and heart activity. Because serotonin (5‐HT) is involved in corticovagal neurotransmission, we tested whether the 5‐HT transporter polymorphism 5‐HTTLPR affects brain‐heart covariation. Further, associations with neuroticism/anxiety (NANX) were tested, as anxiety is related to 5‐HT and neurogenic changes of heart period (HP). N = 168 participants performed a time‐estimation task while EEG and HP were recorded. Brain‐heart covariation was measured using time‐lagged within‐subject correlations of centromedial feedback‐evoked single‐trial EEG at 300 ms and subsequent changes of HP. EEG‐HP correlations were higher in 5‐HTTLPR long allele carriers. Moreover, after negative feedback, EEG‐HP correlations and feedback‐related negativity amplitudes independently correlated with NANX. The results indicate that individual differences in brain‐heart covariation relate to 5‐HT and NANX.
Marfan syndrome: a review of the literature and case report
Authors: Tsang Annetta K. L. , Taverne Aart , Holcombe Trevor
Published: February 2013

Marfan syndrome (MFS) is a connective tissue disorder of variable inheritance that affects multiple organ systems. Cardiovascular, ocular, and skeletal abnormalities are cardinal features of the syndrome. Orofacially, MFS patients typically exhibit skeletal class II malocclusion, dolichofacial growth pattern, mandibular retrognathia, malar hypoplasia, high arched palate, dental crowding, and root anomalies. The purpose of this paper is to provide a review of the literature, as well as describe an 11‐year‐old female with MFS diagnosed at the age of 10.5 years. This report emphasizes the orofacial findings in MFS and highlights particularities of dental treatment when social deficits and intellectual disabilities are also implicated.
The Continuing Challenge of Understanding, Preventing, and Treating Neural Tube Defects
Authors: Wallingford John B. , Niswander Lee A. , Shaw Gary M. , Finnell Richard H.
Published: February 2013

Prevention or Repair

Neural tube defects, such as spina bifida, remain remarkably common, despite widespread efforts to prevent them through supplementing maternal diets with folic acid. Surgery early in development has seen some success, but problems often remain.

Wallingford
et al.

(
10.1126/science.1222002
) review normal and abnormal neural tube development and suggest that discovering the genetic risk factors for these serious birth defects could provide ways to prevent and treat neural tube defects.
New U.S. Rules Increase Oversight of H5N1 Studies, Other Risky Science
Authors: Malakoff David , Enserink Martin
Published: February 2013

Scientists interested in doing experiments involving the H5N1 avian influenza virus and 14 other potentially dangerous biological agents face new requirements to get funding from the U.S. government.
Astronomers Lend Know-How to Cleanup
Authors: Normile Dennis
Published: February 2013

The Fukushima radioactivity cleanup is getting an assist from an unexpected source: Japanese astronomers.
Pollutants Capture the High Ground in the Himalayas
Authors: Qiu Jane
Published: February 2013

In high alpine areas once thought pristine, dust and soot appear to be accelerating glacier melting and may alter monsoon patterns.
Evaluation of the Safety and Immunogenicity of a Candidate Tuberculosis Vaccine, MVA85A, Delivered by Aerosol to the Lungs of Macaques
Authors: White A. D. , Sibley L. , Dennis M. J. , Gooch K. , Betts G. , Edwards N. , Reyes-Sandoval A. , Carroll M. W. , Williams A. , Marsh P. D. , McShane H. , Sharpe S. A.
Published: February 2013

Tuberculosis (TB) is a reemerging disease. The only available vaccine,Mycobacterium bovisBCG, is delivered intradermally and confers highly variable efficacy against pulmonary disease. There is an urgent need for improved vaccination strategies. Murine studies suggest that immunizations delivered directly to the respiratory mucosa might be a more effective route of vaccination. This study compared the immunogenicity of a leading candidate tuberculosis (TB) vaccine, modified vaccinia virus Ankara expressing antigen 85A (MVA85A), in rhesus macaques, delivered either as an aerosol or as an intradermal boost immunization 12 weeks after an intradermal BCG prime vaccine. Aerosol vaccination was well tolerated. MVA85A delivered by aerosol or by intradermal injection induced antigen-specific immune responses in the periphery and the lung, with a trend toward the highest response when the compartment and route of delivery were matched. The ability of poxvirus-vectored vaccines delivered by the systemic route to induce responses in the mucosal immune compartment in macaques is in contrast to the independent compartmentalization of mucosal and systemic immune systems described in mice. Unlike intradermal vaccination, aerosol vaccination did not induce a detectable serum anti-vector antibody response. The delivery of vaccines to the lungs might provide an immunization strategy that limits the induction of systemic anti-vector immunity, which would be extremely useful in the development of improved vaccine strategies. This is the first study to show a recombinant MVA-vectored vaccine to be highly immunogenic when delivered by the aerosol route to nonhuman primates. These results provide important safety and proof-of-concept data for further evaluation of this route of immunization for use in human clinical trials.
Optimized Method for Acinetobacter Species Carbapenemase Detection and Identification by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry
Authors: Álvarez-Buylla Adela , Picazo Juan J. , Culebras Esther
Published: February 2013

The use of matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) for rapid detection and identification of the enzymes responsible for carbapenem resistance in
Acinetobacter
spp. appears as a promising option, but it will be necessary to have a standardized protocol that facilitates routine use. Based on the results reported herein and comparisons of several previously published reports, we identified the significant peaks for imipenem detection. Optimal bacterial inoculum and incubation time were established, and results obtained with and without dipicolinic acid (DPA) and Zn
2+
allowed us to distinguish between metallo-beta-lactamases and oxacillinases.
School closures and influenza: systematic review of epidemiological studies
Authors: Jackson Charlotte , Vynnycky Emilia , Hawker Jeremy , Olowokure Babatunde , Mangtani Punam
Published: February 2013

Objective

To review the effects of school closures on pandemic and seasonal influenza outbreaks.

Design

Systematic review.

Data sources

MEDLINE and EMBASE, reference lists of identified articles, hand searches of key journals and additional papers from the authors' collections.

Study selection

Studies were included if they reported on a seasonal or pandemic influenza outbreak coinciding with a planned or unplanned school closure.

Results

Of 2579 papers identified through MEDLINE and EMBASE, 65 were eligible for inclusion in the review along with 14 identified from other sources. Influenza incidence frequently declined after school closure. The effect was sometimes reversed when schools reopened, supporting a causal role for school closure in reducing incidence. Any benefits associated with school closure appeared to be greatest among school-aged children. However, as schools often closed late in the outbreak or other interventions were used concurrently, it was sometimes unclear how much school closure contributed to the reductions in incidence.

Conclusions

School closures appear to have the potential to reduce influenza transmission, but the heterogeneity in the data available means that the optimum strategy (eg, the ideal length and timing of closure) remains unclear.
Investigation into water retention behaviour of deformable soils
Authors: Salager Simon , Nuth Mathieu , Ferrari Alessio , Laloui Lyesse
Published: February 2013

The paper presents an experimental and modelling approach for the soil-water retention behaviour of two deformable soils. The objective is to investigate the physical mechanisms that govern the soil-water retention properties and to propose a constitutive framework for the soil-water retention curve accounting for the initial state of compaction and deformability of soils. A granular soil and a clayey soil were subjected to drying over a wide range of suctions so that the residual state of saturation could be attained. Different initial densities were tested for each material. The soil-water retention curves (SWRCs) obtained are synthesized and compared in terms of water content, void ratio, and degree of saturation, and are expressed as a function of the total suction. The studies enable assessment of the effect of the past and present soil deformation on the shape of the curves. The void ratio exerts a clear influence on the air-entry value, revealing that the breakthrough of air into the pores of the soil is more arduous in denser states. In the plane of water content versus suction, the experimental results highlight the fact that from a certain value of suction, the retention curves corresponding to different densities of the same soil are convergent. The observed features of behaviour are conceptualized into a modelling framework expressing the evolution of the degree of saturation as a function of suction. The proposed retention model makes use of the theory of elastoplasticity and can thus be generalized into a hysteretic model applicable to drying–wetting cycles. The calibration of the model requires the experimental retention data for two initial void ratios. The prediction of tests for further ranges of void ratios proves to be accurate, which supports the adequacy of formulated concepts.
COMPUTATIONAL MODELING STUDY ON METABOLISM MECHANISM OF OSELTAMIVIR
Authors: LI RUI , WANG YENG-TSENG , CHEN CHENG-LUNG
Published: February 2013

Oseltamivir (OTV) is widely used in the treatment of both influenza virus A and B infections. Additionally, OTV is an effective antiviral drug in treating the 2009 A ( H1N1 ) influenza virus. Clinical studies concluded that OTV is readily extensively converted to the active carboxylate metabolite after oral administration. In order to investigate the metabolism mechanism of OTV, we carried out density functional theory (DFT) quantum mechanical calculations. The molecule orbital (MO) theory and natural population analysis (NPA) were also employed to help understanding the reaction mechanism. All possible reaction pathways for OTV metabolism are considered, involving hydrolysis of ester and amide. Two mechanisms were considered in this work, viz. concerted mechanism and stepwise mechanism. Our results indicate the stepwise mechanism is more favorable in both hydrolysis reactions and the rate-determining stage is the formation of the tetrahedral intermediate. In addition, the hydrolysis reactions can be assisted by substrate NH2 group and solvent water molecules. The substrate-assisted mechanism for the formation of the carboxylate metabolite is the most favorable one.
Bone morphogenetic protein 2 decreases TRPC expression, store-operated Ca2+ entry, and basal [Ca2+]i in rat distal pulmonary arterial smooth muscle cells
Authors: Zhang Yi , Lu Wenju , Yang Kai , Xu Lei , Lai Ning , Tian Lichun , Jiang Qian , Duan Xin , Chen Minsheng , Wang Jian
Published: February 2013

Recent studies indicate that multiple bone morphogenetic protein (BMP) family ligands and receptors are involved in the development of pulmonary arterial hypertension, yet the underlying mechanisms are incompletely understood. Although BMP2 and BMP4 share high homology in amino acid sequence, they appear to exert divergent effects on chronic hypoxic pulmonary hypertension (CHPH). While BMP4 promotes vascular remodeling, BMP2 prevents CHPH. We previously demonstrated that BMP4 upregulates the expression of canonical transient receptor potential channel (TRPC) proteins and, thereby, enhances store-operated Ca2+ entry (SOCE) and elevates intracellular Ca2+ concentration ([Ca2+]i) in pulmonary arterial smooth muscle cells (PASMCs). In this study, we investigated the effects of BMP2 on these variables in rat distal PASMCs. We found that treatment with BMP2 (50 ng/ml, 60 h) inhibited TRPC1, TRPC4, and TRPC6 mRNA and protein expression. Moreover, BMP2 treatment led to reduced SOCE and decreased basal [Ca2+]i in PASMCs. These alterations were associated with decreased PASMC proliferation and migration. Conversely, knockdown of BMP2 with specific small interference RNA resulted in increased cellular levels of TRPC1, TRPC4, and TRPC6 mRNA and protein, enhanced SOCE, elevated basal [Ca2+]i, and increased proliferation and migration of PASMCs. Together, these results indicate that BMP2 participates in regulating Ca2+ signaling in PASMCs by inhibiting TRPC1, TRPC4, and TRPC6 expression, thus leading to reduced SOCE and basal [Ca2+]i and inhibition of cell proliferation and migration.
Prolonged high fat/alcohol exposure increases TRPV4 and its functional responses in pancreatic stellate cells
Authors: Zhang L. P. , Ma F. , Abshire S. M. , Westlund K. N.
Published: February 2013

The present study investigated transient receptor potential vanilloid type 4 (TRPV4) ion channels in pancreatic stellate cells (PSCs) isolated from rats with high-fat and alcohol diet (HFA)-induced chronic pancreatitis. TRPV4 is a calcium-permeable nonselective ion channel responsive to osmotic changes, alcohol metabolites arachidonic acid, anandamide, their derivatives, and injury-related lipid mediators. Male Lewis rats were fed HFA for 6–8 wk before isolation and primary culture of PSCs. Control PSCs were harvested from rats fed standard chow. Immunoreactivity for cytoskeletal protein activation product α-smooth muscle actin (α-SMA) and platelet-derived growth factor receptor-β subunit (PDGFR-β) characterized the cells as PSCs. TRPV4 expression increased in PSCs of HFA-fed rats and control cultures after alcohol treatment (50 mM). Cell responses to activation of inducible TRPV4 were assessed with live cell calcium imaging. Threefold increased and sustained intracellular calcium mobilization responses occurred in 70% of pancreatic stellate cells from HFA-fed rats in response to TRPV4 activators arachidonic acid, lipid second messenger, phorbol ester 4 α-phorbol 12,13-didecanoate (4αPDD), and 50% hypoosmotic media compared with relatively unresponsive PSCs from control rats. Activation responses were attenuated by nonselective TRPV channel blocker ruthenium red. Tumor necrosis factor-α (TNF-α, 1 ng/ml, 16 h) increased responses to 4αPDD in control PSCs. These findings implicate TRPV4-mediated calcium responses inducible after HFA exposure and inflammation in reactive responses of activated PSCs that impair pancreatic function, such as responsiveness to cytokines and the deposition of collagen fibrosis that precipitates ductal blockage and pain.
Dominant negative PPARγ promotes atherosclerosis, vascular dysfunction, and hypertension through distinct effects in endothelium and vascular muscle
Authors: Pelham Christopher J. , Keen Henry L. , Lentz Steven R. , Sigmund Curt D.
Published: February 2013

Agonists of the nuclear hormone receptor peroxisome proliferator-activated receptor γ (PPARγ) have potent insulin-sensitizing effects and inhibit atherosclerosis progression in patients with Type II diabetes. Conversely, missense mutations in the ligand-binding domain of PPARγ that render the transcription factor dominant negative (DN) cause early-onset hypertension and Type II diabetes. We tested the hypothesis that DN PPARγ-mediated interference of endogenous wild-type PPARγ in the endothelium and vascular smooth muscle exacerbates atherosclerosis in apolipoprotein E-deficient (ApoE−/−) mice. Endothelium-specific expression of DN PPARγ on the ApoE−/− background unmasked significant impairment of endothelium-dependent relaxation in aortic rings, increased systolic blood pressure, altered expression of atherogenic markers (e.g., Cd36, Mcp1, Catalase), and enhanced diet-induced atherosclerotic lesion formation in aorta. Smooth muscle-specific expression of DN PPARγ, which induces aortic dysfunction and increased systolic blood pressure at baseline, also resulted in enhanced diet-induced atherosclerotic lesion formation in aorta on the ApoE−/− background that was associated with altered expression of a shared, yet distinct, set of atherogenic markers (e.g., Cd36, Mcp1, Osteopontin, Vcam1). In particular, induction of Osteopontin expression by smooth muscle-specific DN PPARγ correlated with increased plaque calcification. These data demonstrate that inhibition of PPARγ function specifically in the vascular endothelium or smooth muscle may contribute to cardiovascular disease.
Changes in task parameters during walking prism adaptation influence the subsequent generalization pattern
Authors: Alexander M. Scott , Flodin Brent W. G. , Marigold Daniel S.
Published: February 2013

An understanding of the transfer (or generalization) of motor adaptations between legs and across tasks during walking has remained elusive due to limited research and mixed results. Here, we asked whether stepping sequences or task constraints introduced during walking prism-adaptation tasks influence generalization patterns. Forty subjects adapted to prism glasses in precision-walking or obstacle-avoidance tasks that required a specific stepping sequence to the center of two/three targets or laterally over an obstacle. We then tested for generalization, reflected by aftereffects in the nonadapted task. Our previous study using these tasks found that only one leg generalized. Here, we reversed the stepping sequence and found that only the opposite leg generalized in the subject group that adapted in a precision-walking task. The combination of stepping sequence and direction of prism shift caused subjects in two groups to collide with the obstacle early during adaptation, thus making the step prior to going over the obstacle more important. Both legs subsequently generalized. A fourth subject group experienced a three-target, precision-walking task, resulting in a balanced, right-left, left-right stepping sequence, meant to induce bilateral generalization. While only one leg generalized, foot placement aftereffects before stepping over the obstacle would have caused subjects to collide with it. Together with our previous study, the results suggest a contribution of stepping sequence during the adapted task on generalization patterns, likely driven by proprioceptive feedback. The results also support the idea that negative consequences during adaptation and/or perceived threat can influence generalization.
Spreaders and Sponges Define Metastasis in Lung Cancer: A Markov Chain Monte Carlo Mathematical Model
Authors: Newton Paul K. , Mason Jeremy , Bethel Kelly , Bazhenova Lyudmila , Nieva Jorge , Norton Larry , Kuhn Peter
Published: February 2013

The classic view of metastatic cancer progression is that it is a unidirectional process initiated at the primary tumor site, progressing to variably distant metastatic sites in a fairly predictable, although not perfectly understood, fashion. A Markov chain Monte Carlo mathematical approach can determine a pathway diagram that classifies metastatic tumors as “spreaders” or “sponges” and orders the timescales of progression from site to site. In light of recent experimental evidence highlighting the potential significance of self-seeding of primary tumors, we use a Markov chain Monte Carlo (MCMC) approach, based on large autopsy data sets, to quantify the stochastic, systemic, and often multidirectional aspects of cancer progression. We quantify three types of multidirectional mechanisms of progression: (i) self-seeding of the primary tumor, (ii) reseeding of the primary tumor from a metastatic site (primary reseeding), and (iii) reseeding of metastatic tumors (metastasis reseeding). The model shows that the combined characteristics of the primary and the first metastatic site to which it spreads largely determine the future pathways and timescales of systemic disease. Cancer Res; 73(9); 2760–9. ©2013 AACR.