bluuebunny/crossref_metadata_2025 huggingface dataset:
Farming Systems and Rural Out‐Migration in Nang Rong, Thailand, and Chitwan Valley, Nepal
Authors: Piotrowski Martin , Ghimire Dirgha , Rindfuss Ronald
Published: January 2013

Using data from two postfrontier rural settings, Nang Rong, Thailand (N = 2,538), and Chitwan Valley, Nepal (N = 876), this article examines agricultural push factors determining the out‐migration of young people age 15 to 19. We focus on different dimensions of migration, including distance and duration. Our study examines a wide array of agricultural determinants, each with its own potential effect on migration. These determinants include land tenure, crop portfolios, animal husbandry activities, and use of farm inputs. We link these proximal causes to two underlying mechanisms: risk and amenities. We examine these determinants using separate models across settings. Our results indicate that agricultural factors are significant determinants of migration in both contexts. However, different factors operate in different settings, indicating the importance of contextual variation in explaining the manner in which risks and amenities influence agricultural determinants of migration.
The Relationship between Marcellus Shale Gas Development in Pennsylvania and Local Perceptions of Risk and Opportunity
Authors: Schafft Kai A. , Borlu Yetkin , Glenna Leland
Published: January 2013

Recent advances in gas and oil drilling technology have led to dramatic boomtown development in many rural areas that have endured extended periods of economic decline. In Pennsylvania's Marcellus gas fields, the recent development of unconventional shale gas resources has not been without controversy. It has been variously framed as a major opportunity for economic revitalization at the local and regional levels and energy independence at the national level, but also as a significant environmental risk, with uncertain and uneven economic benefits. We use data from a survey conducted in 309 school districts located within Pennsylvania's Marcellus Shale region to study the ways local stakeholders perceive both risk and opportunity associated with gas extraction from Marcellus Shale. Our analyses indicate that there is a strong positive association between perceptions of risk and opportunity associated with gas extraction. Further, the intensity of perception of both risk and opportunity is directly associated with the amount of local drilling, suggesting the complexity of local contexts within which local stakeholders evaluate rapid boomtown‐associated community change. In total, these findings complicate the framing of unconventional gas extraction in the Marcellus Shale region, and indeed boomtown growth overall, as fundamentally polarizing issues.
Vascular Access Surveillance: Case Study of a False Paradigm
Authors: Paulson William D. , Moist Louise , Lok Charmaine E.
Published: January 2013

The hemodialysis vascular access surveillance controversy provides a case study of how enthusiasm for a new test or treatment can lead to adoption of a false paradigm. Paradigms are the beliefs and assumptions shared by those in a field of knowledge, and are commonly included in clinical practice guidelines. The guidelines of the National Kidney Foundation Kidney Disease Outcomes Quality Initiative recommend that arteriovenous vascular accesses undergo routine surveillance for detection and correction of stenosis. This recommendation is based on the paradigm that surveillance of access blood flow or dialysis venous pressure combined with correction of stenosis improves access outcomes. However, the quality of evidence that supports this paradigm has been widely criticized. We tested the validity of the surveillance paradigm by applying World Health Organization (WHO) criteria for evaluating screening tests to a literature review of published vascular access studies. These criteria include four components: undesired condition, screening test, intervention, and desired outcome. The WHO criteria show that surveillance as currently practiced fails all four components and provides little or no significant benefit, suggesting that surveillance is a false paradigm. Once a paradigm is established, however, challenges to its validity are usually resisted even as new evidence indicates the paradigm is not valid. Thus, it is paramount to apply rigorous criteria when developing guidelines. Regulators may help promote needed changes in paradigms when cost and safety considerations coincide.
Human herpesvirus‐6 encephalitis during hematopoietic stem cell transplantation leads to poor prognosis
Authors: Shimazu Y. , Kondo T. , Ishikawa T. , Yamashita K. , Takaori‐Kondo A.
Published: January 2013

Introduction

Indications for the application of hematopoietic stem cell transplantation (HSCT) from alternative donors have remarkably broadened in scope; however, the incidence of infections that lead to failure of HSCT, such as human herpesvirus‐6 (HHV‐6) encephalitis, has also increased.

Methods

We analyzed risk factors for symptomatic HHV‐6 reactivation and the development of HHV‐6 encephalitis in 140 consecutive adult patients who received allogeneic HSCT at our institution. Stem cell sources for the recipients were as follows: related‐donor bone marrow in 40, related‐donor peripheral blood in 5, unrelated bone marrow in 67, and unrelated cord blood in 28.

Results

Symptomatic HHV‐6 reactivation occurred in 22 patients (16%), and 11 patients manifested encephalitis. Multivariate Cox proportional hazards regression analysis identified cord blood cell transplantation (CBT) as an independent predictor of HHV‐6 reactivation (P = 0.008). Hyponatremia or hypernatremia at the time of HHV‐6 reactivation was detected before the development of HHV‐6 encephalitis in 2 or 4 patients, respectively. Two patients died of HHV‐6 encephalitis and 6 patients died of relapse of underlying diseases. Survival analysis identified higher risk of the disease (P = 0.021) and HHV‐6 encephalitis (P = 0.003) as independent risk factors for reduced overall survival.

Conclusion

In cases involving CBT or unrelated‐donor transplantation, patients should be carefully monitored for the symptomatic reactivation of HHV‐6.
Evaluation of risk factors for cytomegalovirus infection and disease occurring within 1 year of liver transplantation in high‐risk patients
Authors: Katsolis J.G. , Bosch W. , Heckman M.G. , Diehl N.N. , Shalev J.A. , Pungpapong S. , Gonwa T.A. , Hellinger W.C.
Published: January 2013

Background

Recent studies have demonstrated that cytomegalovirus (CMV) infection and disease are associated with increased risk of graft loss and death in high‐risk (donor CMV seropositive/recipient CMV seronegative) liver transplant recipients (LTR) despite effective antiviral chemoprophylaxis. Predictors of CMV infection and disease in this important population are incompletely defined.

Methods

A retrospective cohort study of 227 high‐risk first LTR who received primary anti‐CMV chemoprophylaxis during the first 100 days after transplant was performed. A large number of patient, donor, operative, and post‐transplant potential risk factors were collected. Associations of potential risk factors for CMV infection or disease that occurred during the first year after transplant were assessed using Cox regression models. After Bonferroni adjustment for multiple testing, P‐values ≤0.00125 (associations with CMV infection) and ≤0.00122 (associations with CMV disease) were considered as statistically significant.

Results

CMV infection and disease occurred in 91 (40%) and 43 (19%) of LTR, respectively. In multivariable analysis, increased risk of CMV infection was observed for patients with lower model for end‐stage liver disease (MELD) score (P = 0.025), lower total bilirubin (P = 0.014), and longer operative time (P = 0.038), whereas increased risk of CMV disease was seen in patients with lower MELD score (P = 0.026), lower total bilirubin (P = 0.044), and lower international normalized ratio (P = 0.043). However, after adjustment for multiple testing, none of these findings approached statistical significance.

Conclusion

Our results suggest that interventions designed to prevent CMV infection and disease should be applied to all high‐risk LTR until more definitive predictors of these complications are identified.
Ureteral stent placement and BK viremia in kidney transplant recipients
Authors: Kayler L. , Zendejas I. , Schain D. , Magliocca J.
Published: January 2013

Introduction

BK virus (BKV) infection is an important cause of kidney transplant dysfunction. A possible association of double‐J ureteral stent placement and BK viremia has been suggested in previous studies; however, risk factors for BK are incompletely understood. We aimed to determine if stent placement is an independent risk factor for BK viremia.

Methods

Data were collected on consecutive kidney‐only transplant recipients between December 1, 2006 and June 30, 2010. All patients had at least 12 months of follow‐up.

Results

Of 600 consecutive kidney transplants, BK viremia within the first post‐transplant year was detected in 93 patients (15.5%); in 70 of these cases, the peak BKV polymerase chain reaction was ≥10,000 copies/mL. By multivariate analysis, significant risk factors for BK viremia were recipient age (P = 0.02) and stent placement (P = 0.03). Stents were placed in 49.2% and removed at a median of 46 days (range: 11–284) post transplantation; removals occurred within 0–30, 30–60, 60–90, 90–120, 120–150, and >150 days post transplantation in 18.4%, 67.2%, 10.5%, 2.4%, 1.0%, and 0.3% of cases, respectively. No association was found of BK viremia with stent duration >46 days (P = 0.70) or by the 6‐level groupings (P = 0.92).

Conclusions

Although we observed a significant association of BK viremia with stent placement, no dose‐dependent effect was seen.
Impact of Perfect Drug Adherence on Immunopathogenic Mechanism for Dynamical System of Psoriasis
Authors: Roy Priti Kumar , Datta Abhirup
Published: January 2013

Psoriasis is a frequent autoimmune chronic skin disease differentiated by T-Cells agreeable hyperproliferation of epidermal Keratinocytes. The feature of TCells held up Psoriatic scratches is the epidermal penetration of basically oligoclonal CD8+ T-Cells and also of CD4+ T-Cells in the dermis. Psoriatic lesions are sharply distinguished, red and enlarged scratches together with whitish silver scales. In this research article, we propose a mathematical depiction for Psoriasis, involving a set of differential equations, regarding T-Cells, Dendritic Cells, CD8+ T-Cells and epidermal Keratinocytes. Here, we specially introduce the interaction between Dendritic Cells and CD8+ T-Cells to monitor the impact of this interaction upon the system dynamics. We also analyze the mathematical model both in presence and absence of effectiveness of two drugs. We study the system analytically and numerically to comprehend the significance of effectiveness of the drugs, integrated in the model system. Here, we reduce the Keratinocyte population to restrict Psoriasis by applying the combination of two drugs and able to enlighten the perspective of the disease dynamics for Psoriasis.
Rough Sets in Biomedical Informatics
Authors: Popov Antony , Stoykov Simeon
Published: January 2013

The intent of this paper is to face the essentials of granular computing and in its major component - the rough sets theory, introduced by Pawlak, since any rough set represents an information granule. As a part of modern soft computing paradigm, rough sets have been introduced as an interval-like extension of the usual sets with main applications in the intelligent systems. The proposed rough approach provides efficient algorithms for finding hidden patterns in data, finds minimal sets of data (data reduction), evaluates significance of data. Applications in medicine via DICOM standard are presented, as well as ideas for applications to microbiology.
Modeling of Transient Transport of Soluble Proteins in the Connecting Cilium of a Photoreceptor Cell
Authors: Kuznetsov A. V.
Published: January 2013

A minimal mathematical model describing mass transport in the connecting cilium (CC) of a photoreceptor cell in response to a suddenly increased protein concentration at the base of the CC is developed. Dimensionless governing equations and dimensionless parameters are identified. Analytical solutions are obtained for concentrations of free (diffusion-driven) and motor-driven proteins. The obtained solutions make it possible to predict mass transfer in the CC as a function of two dimensionless transport parameters involved in the model: the diffusivity of free soluble proteins and the transition rate from the diffusion-driven to the motor-driven state. Sensitivities of the obtained solutions to these two parameters are discussed.
Vibration Analysis of Single Walled Boron Nitride Nanotube Based Nanoresonators
Authors: Panchal Mitesh B. , Upadhyay S. H. , Harsha S. P.
Published: January 2013

In this paper, the vibration response analysis of single walled boron nitride nanotubes (SWBNNTs) treated as thin walled tube has been done using finite element method (FEM). The resonant frequencies of fixed-free SWBNNTs have been investigated. The analysis explores the resonant frequency variations as well as the resonant frequency shift of the SWBNNTs caused by the changes in size of BNNTs in terms of length as well as the attached masses. The performance of cantilevered SWBNNT mass sensor is also analyzed based on continuum mechanics approach and compared with the published data of single walled carbon nanotube (SWCNT) for fixed-free configuration as a mass sensor. As a systematic analysis approach, the simulation results based on FEM are compared with the continuum mechanics based analytical approach and are found to be in good agreement. It is also found that the BNNT cantilever biosensor has better response and sensitivity compared to the CNT as a counterpart. Also, the results indicate that the mass sensitivity of cantilevered boron nitride nanotube nanomechanical resonators can reach 10−23 g and the mass sensitivity increases when smaller size nanomechanical resonators are used in mass sensors.
Measurements in High Void-Fraction Bubbly Wakes Created by Ventilated Supercavitation
Authors: Wosnik Martin , Arndt Roger E. A.
Published: January 2013

A study of ventilated supercavitation in the reentrant jet regime has been carried out in the high-speed water tunnel at St. Anthony Falls Laboratory as the hydrodynamics part of an interdisciplinary study on stability and control of high-speed cavity-running bodies. The work is aimed at understanding the interaction between a ventilated supercavity and its turbulent bubbly wake, with the goal to provide the information needed for the development of control algorithms. Particle image velocimetry (PIV) measurements in high-void fraction bubbly wakes created by the collapse of ventilated supercavities are reported. Bubble velocity fields are obtained and are shown to submit to the same high Reynolds number similarity scaling as the single-phase turbulent axisymmetric wake. A grayscale technique to measure local average void fraction is outlined. Results of a time-resolved PIV experiment at 2000 Hz, using an adaptive masking scheme based on a sliding intensity threshold filter, are also presented.
Identification of the Cold Flow Perturbation Sources in a Dump Combustor With a Tapered Exit
Authors: Yadav N. P. , Kushari Abhijit
Published: January 2013

This paper reports on the experimental investigation of the flow inside a low aspect ratio (length less than the reattachment length of separated flow) dump combustor with a tapered exit. The flow field in the combustor is evaluated using wall pressure and velocity measurements at varying flow Reynolds numbers. The mean velocity and turbulence variation closer to the wall of the combustor was found to be different from that at other radial locations due to the presence of recirculation and possible thickening of the shear layer caused by a decrease in the strength of the potential core. The power spectral study of the wall pressure and velocity fluctuations suggested the dominant presence of acoustic perturbations with amplitude modulation of such perturbations due to viscous dissipation in the shear layer.
Direct Measurement of the Permeability of Human Cervical Tissue
Authors: Fernandez Michael , Vink Joy , Yoshida Kyoko , Wapner Ronald , Myers Kristin M.
Published: January 2013

The mechanical integrity of the uterine cervix is critical for a pregnancy to successfully reach full term. It must be strong to retain the fetus throughout gestation and then undergo a remodeling and softening process before labor for delivery of the fetus. It is believed that cervical insufficiency (CI), a condition in pregnancy resulting in preterm birth (PTB), is related to a cervix with compromised mechanical strength which cannot resist deformation caused by external forces generated by the growing fetus. Such PTBs are responsible for infant developmental problems and in severe cases infant mortality. To understand the etiologies of CI, our overall research goal is to investigate the mechanical behavior of the cervix. Permeability is a mechanical property of hydrated collagenous tissues that dictates the time-dependent response of the tissue to mechanical loading. The goal of this study was to design a novel soft tissue permeability testing device and to present direct hydraulic permeability measurements of excised nonpregnant (NP) and pregnant (PG) human cervical tissue from women with different obstetric histories. Results of hydraulic permeability testing indicate repeatability for specimens from single patients, with an order of magnitude separating the NP and PG group means (2.1 ± 1.4×10-14 and 3.2 ± 4.8×10-13m4/N·s, respectively), and large variability within the NP and PG sample groups. Differences were found between samples with similar obstetric histories, supporting the view that medical history may not be a good predictor of permeability (and therefore mechanical behavior) and highlighting the need for patient-specific measurements of cervical mechanical properties. The permeability measurements from this study will be used in future work to model the constitutive material behavior of cervical tissue and to develop in vivo diagnostic tools to stage the progression of labor.
A Novel Method for Quantifying Spatial Correlations Between Patterns of Atherosclerosis and Hemodynamic Factors
Authors: Peiffer Véronique , Bharath Anil A. , Sherwin Spencer J. , Weinberg Peter D.
Published: January 2013

Studies investigating the relation between the focal nature of atherosclerosis and hemodynamic factors are employing increasingly rigorous approaches to map the disease and calculate hemodynamic metrics. However, no standardized methodology exists to quantitatively compare these distributions. We developed a statistical technique that can be used to determine if hemodynamic and lesion maps are significantly correlated. The technique, which is based on a surrogate data analysis, does not require any assumptions (such as linearity) on the nature of the correlation. Randomized sampling was used to ensure the independence of data points, another basic assumption of commonly-used statistical methods that is often disregarded. The novel technique was used to compare previously-obtained maps of lesion prevalence in aortas of immature and mature cholesterol-fed rabbits to corresponding maps of wall shear stress, averaged across several animals in each age group. A significant spatial correlation was found in the proximal descending thoracic aorta, but not further downstream. Around intercostal branch openings the correlation was borderline significant in immature but not in mature animals. The results confirm the need for further investigation of the relation between the localization of atherosclerosis and blood flow, in conjunction with appropriate statistical techniques such as the method proposed here.
Strategies Utilized to Transfer Weight During Knee Flexion and Extension With Rotation for Individuals With a Total Knee Replacement
Authors: Ferris Lauren A. , Denney Linda M. , Maletsky Lorin P.
Published: January 2013

Functional activities in daily life can require squatting and shifting body weight during transverse plane rotations. Stability of the knee can be challenging for people with a total knee replacement (TKR) due to reduced proprioception, nonconforming articular geometry, muscle strength, and soft tissue weakness. The objective of this study was to identify strategies utilized by individuals with TKR in double-stance transferring load during rotation and flexion. Twenty-three subjects were recruited for this study: 11 TKR subjects (age: 65 ± 6 years; BMI 27.4 ± 4.1) and 12 healthy subjects (age: 63 ± 7; BMI 24.6 ± 3.8). Each subject completed a novel crossover button push task where rotation, flexion, and extension of the knee were utilized. Each subject performed two crossover reaching tasks where the subject used the opposite hand to cross over their body and press a button next to either their shoulder (high) or knee (low), then switched hands and rotated to press the opposite button, either low or high. The two tasks related to the order they pressed the buttons while crossing over, either low-to-high (L2H) or high-to-low (H2L). Force platforms measured ground reaction forces under each foot, which were then converted to lead force ratios (LFRs) based on the total force. Knee flexion angles were also measured. No statistical differences were found in the LFRs during the H2L and L2H tasks for the different groups, although differences in the variation of the loading within subjects were noted. A significant difference was found between healthy and unaffected knee angles and a strong trend between healthy and affected subject's knee angles in both H2L and L2H tasks. Large variations in the LFR at mid-task in the TKR subjects suggested possible difficulties in maintaining positional stability during these tasks. The TKR subjects maintained more of an extended knee, which is a consistent quadriceps avoidance strategy seen by other researchers in different tasks. These outcomes suggest that individuals with a TKR utilize strategies, such as keeping an extended knee, to achieve rotary tasks during knee flexion and extension. Repeated compensatory movements could result in forces that may cause difficulty over time in the hip joints or low back. Early identification of these strategies could improve TKR success and the return to activities of daily living that involve flexion and rotation.
Microscale Fiber Network Alignment Affects Macroscale Failure Behavior in Simulated Collagen Tissue Analogs
Authors: Hadi Mohammad F. , Barocas Victor H.
Published: January 2013

A tissue's microstructure determines its failure properties at larger length scales, however, the specific relationship between microstructure and macroscopic failure in native and engineered soft tissues (such as capsular ligaments, aortic aneurysms, or vascular grafts) has proven elusive. In this study, variations in the microscale fiber alignment in collagen gel tissue analogs were modeled in order to understand their effects on macroscale damage and failure outcomes. The study employed a multiscale finite-element (FE) model for damage and failure in collagen-based materials. The model relied on microstructural representative volume elements (RVEs) that consisted of stochastically-generated networks of discrete type-I collagen fibers. Fiber alignment was varied within RVEs and between layers of RVEs in a macroscopic FE model of a notched dogbone geometry. The macroscale stretch and the microscale response of fibers for each of the differently aligned cases were compared as the dogbone was uniaxially extended to failure. Networks with greater fiber alignment parallel to the direction of extension failed at smaller strains (with a 6–22% reduction in the Green strain at failure), however, at greater grip forces (a 28–60% increase) than networks with fibers aligned perpendicular to the extension. Alternating layers of crisscrossed network alignments (aligned ±45 deg to the direction of extension) failed at smaller strains but at greater grip forces than those created using one fiber alignment type. In summary, variations in microscale structure via fiber alignment produced different macroscale failure trends. To conclude, these findings may be significant in the realm of tissue engineering and in soft tissue biomechanics.
Mechanical Properties of Viscoelastic Media by Local Frequency Estimation of Divergence-Free Wave Fields
Authors: Clayton Erik H. , Okamoto Ruth J. , Bayly Philip V.
Published: January 2013

Magnetic resonance elastography (MRE) is an imaging modality with which mechanical properties can be noninvasively measured in living tissue. Magnetic resonance elastography relies on the fact that the elastic shear modulus determines the phase velocity and, hence the wavelength, of shear waves which are visualized by motion-sensitive MR imaging. Local frequency estimation (LFE) has been used to extract the local wavenumber from displacement wave fields recorded by MRE. LFE -based inversion is attractive because it allows material parameters to be estimated without explicitly invoking the equations governing wave propagation, thus obviating the need to numerically compute the Laplacian. Nevertheless, studies using LFE have not explicitly addressed three important issues: (1) tissue viscoelasticity; (2) the effects of longitudinal waves and rigid body motion on estimates of shear modulus; and (3) mechanical anisotropy. In the current study we extend the LFE technique to (1) estimate the (complex) viscoelastic shear modulus in lossy media; (2) eliminate the effects of longitudinal waves and rigid body motion; and (3) determine two distinct shear moduli in anisotropic media. The extended LFE approach is demonstrated by analyzing experimental data from a previously-characterized, isotropic, viscoelastic, gelatin phantom and simulated data from a computer model of anisotropic (transversely isotropic) soft material.
Investigation of the Magnus Effect of a Generic Projectile at Mach 3 Up to 16 Degrees Angle of Attack
Authors: Klatt D. , Hruschka R. , Leopold F.
Published: January 2013

The Magnus effect on a generic 6.37 diameter long tangential-ogive-cylinder type projectile was studied by means of 3D Reynolds-averaged Navier–Stokes (RANS) simulations and wind tunnel measurements. The nominal Mach number was 3 and the Reynolds number, based on the model length, was 1.09 × 107. The simulations provided a profound insight into the flow structure and revealed a shift of the cross-flow separation lines as a consequence of the spin. This was shown to be the primary source of the Magnus side force for the higher angles of attack in the investigated range. The nonlinear dependence of the Magnus side force on the angle of attack was analyzed and reached a maximum value between 10 and 15 deg before decreasing again. The occurrence of secondary vortices in this range of angles of attack is presented as an explanation for a locally negative Magnus side force portion acting on the model.
Biochemomechanics of Intraluminal Thrombus in Abdominal Aortic Aneurysms
Authors: Wilson J. S. , Virag L. , Di Achille P. , Karšaj I. , Humphrey J. D.
Published: January 2013

Most computational models of abdominal aortic aneurysms address either the hemodynamics within the lesion or the mechanics of the wall. More recently, however, some models have appropriately begun to account for the evolving mechanics of the wall in response to the changing hemodynamic loads. Collectively, this large body of work has provided tremendous insight into this life-threatening condition and has provided important guidance for current research. Nevertheless, there has yet to be a comprehensive model that addresses the mechanobiology, biochemistry, and biomechanics of thrombus-laden abdominal aortic aneurysms. That is, there is a pressing need to include effects of the hemodynamics on both the development of the nearly ubiquitous intraluminal thrombus and the evolving mechanics of the wall, which depends in part on biochemical effects of the adjacent thrombus. Indeed, there is increasing evidence that intraluminal thrombus in abdominal aortic aneurysms is biologically active and should not be treated as homogeneous inert material. In this review paper, we bring together diverse findings from the literature to encourage next generation models that account for the biochemomechanics of growth and remodeling in patient-specific, thrombus-laden abdominal aortic aneurysms.
An Electromyogram-Driven Musculoskeletal Model of the Knee to Predict in Vivo Joint Contact Forces During Normal and Novel Gait Patterns
Authors: Manal Kurt , Buchanan Thomas S.
Published: January 2013

Computational models that predict internal joint forces have the potential to enhance our understanding of normal and pathological movement. Validation studies of modeling results are necessary if such models are to be adopted by clinicians to complement patient treatment and rehabilitation. The purposes of this paper are: (1) to describe an electromyogram (EMG)-driven modeling approach to predict knee joint contact forces, and (2) to evaluate the accuracy of model predictions for two distinctly different gait patterns (normal walking and medial thrust gait) against known values for a patient with a force recording knee prosthesis. Blinded model predictions and revised model estimates for knee joint contact forces are reported for our entry in the 2012 Grand Challenge to predict in vivo knee loads. The EMG-driven model correctly predicted that medial compartment contact force for the medial thrust gait increased despite the decrease in knee adduction moment. Model accuracy was high: the difference in peak loading was less than 0.01 bodyweight (BW) with an R2 = 0.92. The model also predicted lateral loading for the normal walking trial with good accuracy exhibiting a peak loading difference of 0.04 BW and an R2 = 0.44. Overall, the EMG-driven model captured the general shape and timing of the contact force profiles and with accurate input data the model estimated joint contact forces with sufficient accuracy to enhance the interpretation of joint loading beyond what is possible from data obtained from standard motion capture studies.
The effect of speakers' sex on voice onset time in Mandarin stops
Authors: Li Fangfang
Published: January 2013

The goal of the present study is to examine the effect of speakers' gender on voice onset time in Mandarin speakers' stop productions. Word-initial lingual stops were elicited from 10 male and 10 female Mandarin speakers using a word-repetition task. The results revealed differentiated voice onset time (VOT) patterns between the two genders for all four lingual stops on raw VOT values. After factoring out speech rate variation, gender-related differences remained for voiced stops only with females' VOTs being shorter than males. The results, together with previous findings from other languages, suggest a sociolinguistic/stylistic account on the relation between gender and VOT that vary in a language-specific manner.
Paramyxovirus V Proteins Disrupt the Fold of the RNA Sensor MDA5 to Inhibit Antiviral Signaling
Authors: Motz Carina , Schuhmann Kerstin Monika , Kirchhofer Axel , Moldt Manuela , Witte Gregor , Conzelmann Karl-Klaus , Hopfner Karl-Peter
Published: January 2013

Parainfluenza 5 and MDA5

Our immune system and the viruses that infect us are in a constant arms race, with one side always trying to outwit the other. One example is the inhibition of host protein MDA5, a member of the retinoic acid–inducible gene 1 (RIG-I)–like receptor (RLR) family of innate immune sensors, by the V protein expressed by parainfluenza virus 5 (PIV5). To better understand how this inhibition is accomplished,

Motz
et al.

(p.
690
, published online 17 January) solved the crystal structure of PIV5 V protein bound to the adenosine triphosphatase (ATPase) domain of porcine MDA5. This analysis, together with mutational studies using mouse and human versions of MDA5, revealed that the V protein unfolds the ATPase domain of MDA5 and replaces two β strands of this domain's structural core. These changes disrupt the ATPase hydrolysis site and prevent the formation of filaments by MDA5, which are important for transmitting downstream signals that activate antiviral immunity. Mutation of just two amino acids in RLR family member RIG-I also rendered this receptor susceptible to V protein–mediated inhibition.
Kallmann syndrome and paranoid schizophrenia: a rare combination
Authors: Verhoeven Willem M A , Egger Jos I M , Hovens Johannes E , Hoefsloot Lies
Published: January 2013

Kallmann syndrome (KS) is a genetically heterogeneous and rare disorder characterised by the combination of hypothalamic hypogonadism and anosmia/hyposmia, a variable degree of intellectual disability and several somatic anomalies. In about one-third of the patients, mutations have been identified in at least seven different genes. Virtually no data are available about possible neuropsychiatric symptoms in KS. Here, a young adult male is described with a previous clinical diagnosis of KS and recent paranoid schizophrenia of which positive, but not negative symptoms, fully remitted upon treatment with antipsychotics. Neither genome-wide array analysis nor mutation analyses disclosed imbalances or mutations in any of presently known KS disease genes. This is the first report on a patient with KS and paranoid schizophrenia in whom extensive genetic analyses were performed. It is concluded that further studies are warranted in order to elucidate a possible increased risk for psychiatric symptoms in patients with KS.
Surgical-orthodontic management of bilateral multiple impactions in non-syndromic patient
Authors: Agrawal Jiwanasha Manish , Agrawal Manish Suresh , Nanjannawar Lalita Girish
Published: January 2013

Several surgical and orthodontic treatment options are available to disimpact the impacted teeth. But the closed eruption technique has the best long-term prognosis. The tooth is surgically exposed, an attachment is bonded to it, flap is resutured over it and an orthodontic extrusive force is delivered to bring the tooth into occlusion. This case report presents a case with multiple impacted teeth in which no syndrome or systemic conditions were detected. A 20-year-old female patient reported for orthodontic treatment with chief complaint of multiple unerupted permanent teeth and retained primary teeth. Radiographic examination revealed impacted 14, 15, 24, 25, 33, 34, 43 and 44. Surgical exposure of the impacted teeth was done after extraction of retained primary teeth. Forced eruption of these teeth was done by applying traction with closed eruption technique. After careful treatment planning followed by guided eruption of impacted teeth, patient finished with a significantly improved functional and aesthetic result.
Leucocytoclastic vasculitis as a late complication of clopidogrel therapy
Authors: Shetty Ranjan K , Madken Mohit , Naha Kushal , Vivek G
Published: January 2013

We describe a case of leucocytoclastic vasculitis manifested as exanthematous rash in a 57-year-old woman on long-term therapy with clopidogrel. The diagnosis was confirmed by skin biopsy. The patient was managed symptomatically with oral antihistaminics and topical steroids in consultation with dermatologists. Clopidogrel therapy was discontinued on suspicion of drug-induced vasculitis. The rash resolved completely within 2 weeks of withdrawal of clopidogrel, satisfying criteria for a probable adverse drug reaction. Leucocytoclastic vasculitis is an unusual adverse effect of clopidogrel therapy and even rarer as a late complication.
First reported case of posterior reversible encephalopathy syndrome occurring in a weightlifter
Authors: Strzelecki Ryan , Ramlackhansingh Anil , Baldwin Tom , Sturman Stephen
Published: January 2013

Posterior reversible encephalopathy syndrome (PRES) is an increasingly well recognised clinical and radiological condition. Here we report on the first known published case of PRES in a weightlifter. We present a 34-year-old man with acute onset visual disturbance and expressive dysphasia which occurred after an intensive gym session.
Disappearance of a small intracranial aneurysm as a result of vessel straightening and in-stent stenosis following use of an Enterprise vascular reconstruction device
Authors: Takemoto Koichiro , Tateshima Satoshi , Rastogi Sachin , Gonzalez Nestor , Jahan Reza , Duckwiler Gary , Vinuela Fernando
Published: January 2013

In-stent stenosis after stent-assisted coil embolization is a rare but well-known complication. A 32-year-old woman with an unruptured wide-necked left internal carotid artery (ICA) terminus aneurysm and an ipsilateral very small anterior choroidal artery aneurysm underwent stent-assisted coil embolization for the ICA terminus aneurysm. The 4-month follow-up angiography revealed diffuse in-stent stenosis and disappearance of the untreated anterior choroidal artery aneurysm, retaining the patency of the anterior choroidal artery. To our knowledge, this is the first report to demonstrate the course of in-stent stenosis and disappearance of an untreated small intracranial aneurysm as a result. We report this unique case and discuss the interesting mechanism underlying this phenomenon, and also provide a review of the relevant literature.
A prospective study of downhill mountain biking injuries
Authors: Becker Johannes , Runer Armin , Neunhäuserer Daniel , Frick Nora , Resch Herbert , Moroder Philipp
Published: January 2013

Background

Downhill mountain biking (DMB) has become an increasingly popular extreme sport in the last few years with high velocities and bold manoeuvres. The goal of this study was to provide information on the pattern and causes of injuries in order to provide starting points for injury prevention measures.

Methods

We performed a monthly e-mail-based prospective survey of 249 riders over one summer season ranging from April until September 2011.

Results

A total of 494 injuries occurred during the 29 401 h of downhill exposure recorded, of these 65% were mild, 22% moderate and 13% severe, of which 41% led to a total restriction greater than 28 days. The calculated overall injury rate was 16.8 injuries per 1000 h of exposure. For experts it was 17.9 injuries per 1000 h of exposure, which is significantly higher than the 13.4 for professional riders (OR 1.34; 95% CI, 1.02 to 1.75; p=0.03). A significantly higher rate of injury was reported during competition (20 per 1000 h) than during practice (13 per 1000 h) (OR 1.53; 95% CI, 1.16 to 2.01; p=0.0022). The most commonly injured body site was the lower leg (27%) followed by the forearm (25%). Most frequent injury types were abrasions (64%) and contusions (56%). Main causes of injury reported by the riders were riding errors (72%) and bad trail conditions (31%).

Conclusions

According to our data DMB can be considered an extreme sport conveying a high risk of serious injury. Strategies of injury prevention should focus on improvements in riders’ technique, checking of local trail conditions and protective equipment design.
Coping after recurrent miscarriage: uncertainty and bracing for the worst
Authors: Ockhuijsen Henrietta D L , Boivin Jacky , van den Hoogen Agnes , Macklon Nickolas S
Published: January 2013

Background

The aim of this study was to understand how women with single or recurrent miscarriages cope during the waiting periods after miscarriage – waiting for pregnancy or waiting for pregnancy confirmation – and to investigate their perception of a ‘positive reappraisal’ coping intervention designed for these waiting periods. Positive reappraisal is a cognitive strategy to change the meaning of a situation, specifically reinterpreting the situation in a more positive way.

Methods

A qualitative methodology was used. Data were obtained from two focus groups comprising nine women with one or more miscarriages.

Results

Two core categories, ‘uncertainty’ and ‘bracing’, were highlighted during the waiting period for confirmation of an ongoing pregnancy. Women who had experienced a single miscarriage appraised this waiting period as benign and used distraction and coping by social support. Women with recurrent miscarriages could not confidently appraise the waiting period as one that would bring hope or joy and used bracing for the worst as their coping strategy to manage this ambivalence. With this strategy, women tried to control their current emotions, and looked into the future to try to minimise their distress if a further miscarriage occurred. Although all women thought that a ‘positive reappraisal’ coping intervention would be practical and applicable during waiting periods, only women with recurrent miscarriages actually wanted to use such an intervention.

Conclusions

Coping interventions targeting reappraisal of the waiting period stressor situation could help women to cope as they wait for a subsequent pregnancy to be confirmed as ongoing. Coping interventions may need to be tailored, but before any strategy is introduced, further study is needed to identify the most appropriate approach.
A moderate dose of caffeine ingestion does not change energy expenditure but decreases sleep time in physically active males: a double-blind randomized controlled trial
Authors: Júdice Pedro B. , Magalhães João P. , Santos Diana A. , Matias Catarina N. , Carita Ana Isabel , Armada-Da-Silva Paulo A.S. , Sardinha Luís B. , Silva Analiza M.
Published: January 2013

Research on the effect of caffeine on energy expenditure (EE), physical activity (PA), and total sleep time (TST) during free-living conditions using objective measures is scarce. We aimed to determine the impact of a moderate dose of caffeine on TST, resting EE (REE), physical activity EE (PAEE), total EE (TEE), and daily time spent in sedentary, light, moderate, and vigorous intensity activities in a 4-day period and the acute effects on heart rate (HR) and EE in physically active males. Using a double-blind crossover trial (ClinicalTrials.gov ID: NCT01477294) with two conditions (4 days each with 3-day washout) randomly ordered as caffeine (5 mg/kg of body mass/day) and placebo (maltodextrin) administered twice per day (2.5 mg/kg), 30 nonsmoker males, low-caffeine users (<100 mg/day), aged 20–39, were followed. Body composition was assessed by dual-energy X-ray absorptiometry. PA was assessed by accelerometry, while a combined HR and movement sensor estimated EE and HR on the second hour after the first administration dose. REE was assessed by indirect calorimetry, and PAEE was calculated as [TEE − (REE + 0.1TEE)]. TST and daily food records were obtained. Repeated measures ANOVA and ANCOVA were used. After a 4-day period, adjusting for fat-free mass, PAEE, and REE, TST was reduced (p = 0.022) under caffeine intake, while no differences were found between conditions for REE, PAEE, TEE, and PA patterns. Also, no acute effects on HR and EE were found between conditions. Though a large individual variability was observed, our findings revealed no acute or long-term effects of caffeine on EE and PA but decreased TST during free-living conditions in healthy males.
P2W18O62·24H2O as an efficient and recyclable catalyst for the ecofriendly preparation of β-aminocrotonates
Authors: Sanchez Laura M. , Sathicq Ángel G. , Baronetti Graciela T. , Thomas Horacio J. , Romanelli Gustavo P.
Published: January 2013

H6P2W18O62·24H2O bulk- and silica-supported catalysts were found to be efficient and recyclable catalysts for the synthesis of a series of β-aminocrotonates using toluene as the solvent or under no solvent reaction conditions. Several substituted β-aminocrotonates can be prepared in very good yields and purity by direct reaction of amines and 1,3-dicarbonyl compounds in the presence of a catalytic amount of bulk- and silica-gel-supported H6P2W18O62·24H2O. The title compounds were prepared in very good yields using both methodologies, and no secondary products were detected. The procedure using no reaction solvent resulted in a clean and useful alternative, which has the advantages of a greener methodology with operative simplicity, the use of a reusable and noncorrosive solid catalyst, soft reaction conditions, low reaction times, and good yields.
Theoretical calculations of rate of NDMA formation from gramine
Authors: Shojaie F. , Dehestani M.
Published: January 2013

The first ab initio theoretical study is performed on the ion–molecule reaction of gramine (C11H14N2) with NO+ for the formation of N-nitrosodimethylamine (NDMA). The reaction mechanism is investigated using the B3LYP density functional theory level. The stationary points along the reaction energy profile have been calculated at the B3LYP/6-311+G(d,p) level of the theory in the gas phase and solution phase. In this work, an attempt is made to elucidate the mechanism and so is proposed the efficient reactive pathway for the reaction of gramine with NO+ step by step. A complete reaction mechanism has been established, and the temperature dependence of all rate constants between 23 and 65 °C are reported and analyzed in terms of transition state theory. The percentages of NDMA formation in the 23–65 °C temperature range have been calculated in aqueous solution by transition state theory. The results are in good agreement with experimental results.
The water–boryl radical as a proton-coupled electron transfer reagent for carbon dioxide, formic acid, and formaldehyde — Theoretical approach
Authors: Tantawy Waled , Hashem Ahmed , Yousif Nabil , Flefel Eman
Published: January 2013

The thermochemistry of the hydrogen atom transfer reactions from the H2O–BX2radical system (X = H, CH3, NH2, OH, F) to carbon dioxide, formic acid, and (or) formaldehyde, which produce hydroxyformyl, dihydroxymethyl, and hydroxymethyl radicals, respectively, were investigated theoretically at ROMP2/6–311+G(3DF,2P)//UB3LYP/6–31G(D) and UG3(MP2)-RAD levels of theory. Surprisingly, in the cases of a strong Lewis acid (X = H, CH3, F), the spin transfer process from the water–boryl radical to the carbonyl compounds was barrier-free and associated with a dramatic reduction in the B–H bond dissociation energy (BDE) relative to that of isolated water–borane complexes. Examining the coordinates of these reactions revealed that the entire hydrogen atom transfer process is governed by the proton-coupled electron transfer (PCET) mechanism. Hence, the elucidated mechanism has been applied in the cases of weak Lewis acids (X = NH2, OH), and the variation in the accompanied activation energy was attributed to the stereoelectronic effect interplaying in CO2and HCOOH compared with HCHO. We ascribed the overall mechanism as a SA-induced five-center cyclic PCET, in which the proton transfers across the so-called complexation-induced hydrogen bond (CIHB) channel, while the SOMOB–LUMOC=O′interaction is responsible for the electron migration process. Owing to previous reports that interrelate the hydrogen-bonding and the rate of proton-coupled electron-transfer reactions, we postulated that “the rate of the PCET reaction is expected to be promoted by the covalency of the hydrogen bond, and any factor that enhances this covalency could be considered an activator of the PCET process.” This postulate could be considered a good rationale for the lack of a barrier associated with the hydrogen atom transfer from the water-boryl radical system to the carbonyl compounds. Light has been shed on the water–boryl radical reagent from the thermodynamic perspective.