bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite Element Analysis Examining the Effects of Cam FAI on Hip Joint Mechanical Loading Using Subject-Specific Geometries during Standing and Maximum Squat
Authors: Ng K. C. Geoffrey , Rouhi Gholamreza , Lamontagne Mario , Beaulé Paul E.
Published: January 2013

Background

Cam femoroacetabular impingement (FAI) can impose elevated mechanical loading in the hip, potentially leading to an eventual mechanical failure of the joint. Since in vivo data on the pathomechanisms of FAI are limited, it is still unclear how this deformity leads to osteoarthritis.

Purpose

The purpose of this study was to examine the effects of cam FAI on hip joint mechanical loading using finite element analysis, by incorporating subject-specific geometries, kinematics, and kinetics.

Questions

The research objectives were to address and determine: (1) if hips with cam FAI demonstrate higher maximum shear stresses, in comparison with control hips; (2) the magnitude of the peak maximum shear stresses; and (3) the locations of the peak maximum shear stresses.

Methods

Using finite element analysis, two patient models were control-matched and simulated during quasi-static positions from standing to squatting. Intersegmental hip forces, from a previous study, were applied to the subject-specific hip geometries, segmented from CT data, to evaluate the maximum shear stresses on the acetabular cartilage and underlying bone.

Results

Peak maximum shear stresses were found at the anterosuperior region of the underlying bone during squatting. The peaks at the anterosuperior acetabulum were substantially higher for the patients (15.2 ± 1.8 MPa) in comparison with the controls (4.5 ± 0.1 MPa).

Conclusions

Peaks were not situated on the cartilage, but instead located on the underlying bone. The results correspond with the locations of initial cartilage degradation observed during surgical treatment and from MRI.

Clinical Relevance

These findings support the pathomechanism of cam FAI. Changes may originate from the underlying subchondral bone properties rather than direct shear stresses to the articular cartilage.
The Accuracy of the Use of Functional Hip Motions on Localization of the Center of the Hip
Authors: Speirs Andrew D , Benoit Daniel L , Beaulieu Mélanie L , Lamontagne Mario , Beaulé Paul E.
Published: January 2013

Background

The hip joint is generally considered a ball-and-socket joint, the center of which is used as an anatomic landmark in functional analyses and by surgical navigation systems. The location of the hip center has been estimated using functional techniques using various limb motions. However, it is not clear which specific motions best predicted the functional center.

Purpose

This study aims to compare the predicted functional center of the hip evaluated from multiplanar circumduction and star motions, and to compare this functional center with the geometric center.

Methods

Eight hips in four fresh–frozen cadavers were used and verified as morphologically normal in CT scans. Three-dimensional motion of each lower limb was recorded using arrays of reflective markers rigidly attached to the femur and pelvis. Each hip was manipulated to produce circumduction or star motion, i.e., abduction–adduction and flexion extension. The hip was then dissected and the bearing surface traced with a probe, from which a best-fit sphere was calculated. The functional center was calculated from the motion data and compared to the geometric technique.

Results

There was no difference between the functional hip center predicted by circumduction or star motions, although this was offset from the geometric hip center by up to 14 mm. For all except two hips, the functional center was less than 6 mm from the geometric hip in each anatomic direction. Test–retest differences were smaller for circumduction than for star motions.

Conclusions

Estimation of the hip center based on motion of the femur relative to the pelvis could localize the geometric center of the joint within 14 mm and circumduction motions were more repeatable.

Clinical Relevance

Many surgical navigation systems make use of the functional hip center as a landmark for alignment or reconstruction. Errors associated with this would have a very minor influence in lower limb alignment, e.g., for knee reconstruction, but could affect proximal femoral geometry relevant to hip reconstruction.
Groin Pain after Metal on Metal Hip Resurfacing: Mid-Term Follow-Up of a Prospective Cohort of Patients
Authors: Illical Emmanuel , Belanger Heather , Kim Paul R. , Beaulé Paul E.
Published: January 2013

Background and Purpose

Groin pain after metal on metal hip resurfacing has been previously reported. The purpose of this study was to determine the natural history of a cohort of patients with groin pain after hip resurfacing previously reported on and incidence of revision surgery.

Methods

Our group previously reported an 18% incidence of groin pain at a mean of 18 months post hip resurfacing. This cohort of groin pain patients was prospectively followed. Patients were evaluated using a visual analog pain rating score, the University of California at Los Angeles (UCLA) Physical Activity Index, and the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index. Functional outcome scores were compared from initial to latest follow up using the paired Student's t test. Further diagnostic evaluation and/or intervention or other complication was also recorded.

Results

The latest mean follow up from surgery was 63 ± 15 months. The mean pain rating, UCLA, and WOMAC scores all improved at latest follow up, although WOMAC score improvement was not statistically significant. Mean pain rating score improved from 5.2 ± 2.0 to 2.5 ± 1.4 ( p = 0.0001). UCLA activity score improved from 6.4 ± 2.0 to 6.9 ± 1.6 ( p = 0.03). Total WOMAC score improved from 75.6 ± 20.5 to 84.5 ± 14.8 ( p = 0.15). Only one patient was revised for an adverse local tissue reaction.

Conclusion

Groin pain post hip resurfacing has a multifactorial etiology, and in the vast majority of cases improves over time with no significant functional limitations. However, the surgeon should be aware of the many potential causes, and help minimize the possibility with proper patient selection and surgical technique.
Recurrence of Dislocation following Total Hip Arthroplasty Revision using Dual Mobility Cups was Rare in 180 Hips followed over 7 Years
Authors: Mertl Patrice , Combes Antoine , Leiber-Wackenheim Frédérique , Fessy Michel Henri , Girard Julien , Migaud Henri
Published: January 2013

Background

Dual mobility (DM) cups of mobile polyethylene were introduced to prevent total hip arthroplasty (THA) dislocation, but no large series with this design to treat recurrent instability have been reported.

Purpose

Our retrospective investigation ascertained the efficiency of DM cups in correction of recurrent dislocation and assessed any adverse effects.

Methods

One hundred eighty THAs with recurrent instability were revised to DM cups in 180 patients (mean age, 67.4 ± 11.7 years; range, 19 to 92 years). Thirty-one patients (17.2%) underwent at least one earlier THA revision, and 15 (10.3%) incurred non-union of the greater trochanter. Of the initial group in 2009, 145 patients had completed evaluations which included assessment of the Harris Hip Score and a radiographic assessment at a mean follow-up of 7.7 ± 2.2 years (range, 4 to 14 years). The rate of survival was calculated considering any reason for revision as failure.

Results

At follow-up, Harris hip score was 83.9 ± 16.1 (range, 21 to 100). Dislocation of the large articulation occurred in seven hips (4.8%), and only two recurred (1.4%) (one requiring additional revision). In addition, two intra-prosthetic dislocations of the small articulation (1.4%) were observed and needed revision surgery. The large number of earlier surgeries and non-union of the greater trochanter were related to recurrent instability. Two cups (1.4%) showed signs of definite loosening; six (4.1%) presented signs of possible loosening. Twenty-nine hips manifested femoral or acetabular osteolysis (20%), but only three were severe. Eight-year survival rate considering revision for any reason was 92.6% (95% CI, 85.5–96.4%).

Conclusions

This series indicates that DM cups are a viable option to treat recurrent THA instability. Their design provides a low risk of recurrent instability without increasing mechanical complications.
Neck-Preserving Femoral Stems
Authors: Rajakulendran Karthig , Field Richard E.
Published: January 2013

Background

Surgeons undertaking total hip arthroplasty (THA) routinely perform a distal femoral neck resection. It has been argued that retaining the femoral neck during THA can provide mechanical and biological advantages.

Purposes

The objectives of this study were to review: (1) the current evidence on the advantages of femoral neck preservation during THA and (2) the clinical and radiological outcome of neck-preserving femoral stems.

Methods

A search of the English-language literature on neck-preserving THA and on the individual neck-preserving implants was performed using PubMed, Ovid SP and Science Direct.

Results

Studies have indicated that neck preservation offers superior tri-planar implant stability and allows more accurate restoration of the hip geometry and biomechanics. The trend towards tissue sparing surgery has contributed to the development of bone-conserving short-stem implants that offer variable levels of neck preservation. Despite an initial learning curve, these implants have generated promising early clinical results, with low revision rates and high outcome scores. However, radiological evaluation of some neck-preserving implants has detected a characteristic pattern of proximal femoral bone loss with distal cortical hypertrophy. The long-term implications of this finding are not yet known.

Conclusions

Preserving the femoral neck during THA has biomechanical advantages. However, long-term outcome data are needed on neck-preserving femoral stems to evaluate on-going bone remodelling and assess implant performance and survival.
An Algorithmic Approach to Mechanical Hip Pain
Authors: Poultsides Lazaros A. , Bedi Asheesh , Kelly Bryan T.
Published: January 2013

Background

As our understanding of hip pathology evolves, the focus is shifting toward earlier identification of hip pathology. Therefore, it is vitally important to elucidate intra-articular versus extra-articular pathology of hip pain in every step of the patient encounter: history, physical examination, and imaging.

Questions/Purposes

The objective was to address the following research questions: (1) Can an algorithmic approach to physical examination of a painful non-arthritic hip provide a more accurate diagnosis and improved treatment plan? (2) Does an anatomical layered concept of clinical diagnosis improve diagnostic accuracy? (3) What are the diagnostic tools necessary for the accurate application of a four-layer (osteochondral, inert, contractile, and neuromechanical) diagnosis?

Methods

An unrestricted computerized search of MEDLINE was conducted. Different terms were used in various combinations.

Results

An algorithmic approach to physical examination of a painful nonarthritic hip, including history, physical examination (specific tests), and advanced imaging allow for better interpretation of debilitating intra- and extra-articular disorders and their effect on core performance. Additionally, it improves our understanding as to how underlying abnormal joint mechanics may predispose the hip joint and the associated hemipelvis to asymmetric loads. These abnormal joint kinematics (layer I) can lead to cartilage and labral injury (layer II), as well as resultant injury to the musculotendinous (layer III) and neural structures (layer IV) about the hip joint and the hemipelvis. The layer concept is a systematic means of determining which structures about the hip are the source of hip pathology and how to best implement treatment.

Conclusions

A clear understanding of the differential diagnosis of hip pain through a detailed and systematic physical examination, diagnostic imaging assessment, and the interpretation of how mechanical factors can result in such a wide range of compensatory injury patterns about the hip can facilitate the diagnosis and treatment recommendations.
Development of Polymeric Nanocarrier System for Early Detection and Targeted Therapeutic Treatment of Peri-Implant Osteolysis
Authors: Purdue P. Edward , Levin Adam S. , Ren Ke , Sculco Thomas P. , Wang Dong , Goldring Steven R.
Published: January 2013

Background

Extensive research has implicated inflammation as a necessary and causative factor in the development of peri-implant osteolysis, suggesting that such an inflammatory response is the sentinel event for the process. The potential to impact the clinical course of this condition is hampered by the lack of an effective medical therapy, as well as a limited ability for early detection prior to radiographically evident osteolysis. Advances in nanotechnology have allowed for the production of engineered water-soluble nanocarriers, which exploit changes in the microvascular architecture for selective distribution to inflamed tissues. Evaluation of the uptake of the nanocarriers in sites of inflammation has elucidated a novel mechanism of cellular uptake and retention of these particles.

Purpose

The current review discusses the development of a novel, biocompatible, water-soluble nanocarrier utilizing copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA), conjugated to imaging and therapeutic agents for the detection and targeted treatment of inflammatory conditions.

Methods

We performed Medline searches for the terms “periprosthetic osteolysis,” “murine osteolysis model,” “HPMA osteolysis,” and “HPMA inflammation.” These searches identified 631, 306, 1, and 6 articles, respectively. These were then manually searched for articles relevant to the development of mouse models for inflammatory osteolysis and the use of HPMA copolymer technology in mouse models of inflammation.

Results

Promising results in a small animal model of osteolysis have demonstrated the capability for detection prior to the development of bone loss, and have highlighted the utility of nanocarriers for selective drug delivery to the affected tissues.

Conclusions

Challenges to the clinical translation of HPMA nanocarriers in peri-implant osteolysis remain, and the future research directions necessary for human clinical application are reviewed.
The Relationship among Health Literacy, Health Knowledge, and Adherence to Treatment in Patients with Rheumatoid Arthritis
Authors: Quinlan Patricia , Price Kwanza O. , Magid Steven K. , Lyman Stephen , Mandl Lisa A. , Stone Patricia W.
Published: January 2013

Background

Patients with poor health literacy often lack the knowledge needed to manage their treatment.

Objective

The aim of this cross-sectional study is to determine whether health literacy is a predictor of health knowledge and/or adherence to medication treatment in patients with rheumatoid arthritis.

Method

The study was completed in an urban, outpatient rheumatology setting. Health literacy was measured using the Test of Functional Health Literacy in Adults. The Arthritis Knowledge Questionnaire was modified to measure medication specific health knowledge, and the Morisky Medication Adherence scale was used to measure adherence. Researchers used regression analyses to determine if health literacy was a predicator of knowledge and/or adherence.

Results

Participants ( N = 125) had high mean health literacy scores. The average medication knowledge score was 0.73. Adherence to medication regimen was 0.84. Controlling for patient covariates, health literacy was positively associated with education, race, and age. In adjusted analyses, health literacy was a significant predictor of health knowledge but not adherence. Race, neighborhood income, and confidence with contacting provider about medications were predictors of adherence.

Conclusion

Study findings indicate that health literacy is independently associated with medication knowledge but not medication adherence in patients with rheumatoid arthritis. These results provide useful information for planning initiatives to support individuals with disease self-management.
Rhabdomyolysis is a Potential Complication of Total Hip Arthroplasty in the Morbidly Obese
Authors: Goodman Susan M. , Figgie Mark , Green Douglas , Memtsoudis Stavros
Published: January 2013

Rhabdomyolysis (RML) can complicate prolonged surgery and may lead to renal failure and death. Obese patients are at high risk for this complication. This complication has been recently described in bariatric surgery and prolonged spine surgery, but it is not well recognized in patients undergoing THA. We present an obese patient (BMI = 50) who developed RML and acute kidney injury after a total hip arthroplasty.
Bilateral Disruption of Soft Tissue Extensor Mechanism of Knee: Functional Outcome and Comparison to Unilateral Injuries
Authors: Monroy Alexa , Urruela Adriana , Egol Kenneth A. , Tejwani Nirmal C.
Published: January 2013

Background

Bilateral ruptures of the extensor mechanism are rare.

Questions/Purpose

The purpose of this study was to compare the clinical outcomes of operatively treated unilateral and bilateral knee soft tissue extensor mechanism injuries and to identify risk factors for bilateral disruption.

Methods

All patients operatively treated for a knee extensor mechanism injury were entered into a database and prospectively followed. Postoperative protocol was standardized for all patients. Demographic data, baseline characteristics, range of motion, complications, pain, and functional status were assessed. The main patient-reported outcome measures used in this study were the SF-36 Health Survey and the Lysholm Scale.

Results

Patients who sustained bilateral injuries were more likely to have one or more systemic medical conditions. There was no statistical difference between the groups with regard to mechanism of injury or body mass index. The average follow-up was 29 months (range 6–60 months). Patient-reported outcomes, in the form of the SF-36 Health Survey and Lysholm scores, were not significantly different between the two groups at final follow-up. Range of motion and quadriceps strength was also similar between the two cohorts. At latest follow-up, 88% of patients with unilateral injuries and 83% of patients with bilateral disruption were able to return to their pre-injury employment.

Conclusion

Operatively treated bilateral knee extensor mechanism disruptions fare similar to unilateral injuries with regard to ultimate functional outcome. The presence of one of more preexisting medical conditions was identified as a risk factor for bilateral tendinous disruption.
Autograft and Allograft Unite Similarly in Lateral Column Lengthening for Adult Acquired Flatfoot Deformity
Authors: Vosseller J. Turner , Ellis Scott J. , O'Malley Martin J. , Elliott Andrew J. , Levine David S. , Deland Jonathan T. , Roberts Matthew M.
Published: January 2013

Background

Lateral column lengthening (LCL) is used to address the forefoot abduction associated with the adult acquired flatfoot. This opening wedge osteotomy can be filled with either allograft or autograft bone.

Questions/Purposes

The investigators sought to determine union rates and any loss of correction in patients undergoing LCL with autograft versus allograft.

Methods

Over a 3-year period, 126 LCLs performed by five surgeons in 120 patients were reviewed. Autograft was used in 51 patients, allograft in 75 patients. Times to clinical and radiographic union were established for these patients. Any loss of correction of forefoot abduction as manifested by talonavicular uncoverage was recorded for those grafts that healed. Failure was defined as nonunion or loss of 50% or greater correction. The size of the implanted graft was assessed as a risk factor for failure.

Results

There were 20 total failures: seven in patients with autograft and 13 in patients with allograft ( p = 0.63). The size of the implanted graft was larger in those patients that did fail ( p = 0.04).

Conclusions

The rate of nonunion and loss of correction for LCL was not significantly different between allograft and autograft. The overall rate of nonunion may be higher than has previously been reported.
Surgical Dislocation of the Hip: Evolving Indications
Authors: Ross James R. , Schoenecker Perry L. , Clohisy John C.
Published: January 2013

Background

Femoroacetabular impingement (FAI) is a condition that has become increasingly identified as abnormal, repetitive abutment of the proximal femur and acetabular rim. Safe surgical dislocation of the hip has been popularized as a technique that allows surgeons to not only improve joint preservation procedures but also understand disease patterns more clearly.

Questions/Purposes

We describe the technique of surgical dislocation as well as review the indications, results, and complications that are associated with the procedure. We also present various case examples to highlight this technique.

Search Strategies

We performed a systematic review of the literature to define the indications, clinical outcomes, and complications associated with surgical dislocation of the hip for the treatment of FAI.

Results

Clinical success rates vary in the literature between 64% and 96% of patients with good results, and conversion to total hip arthroplasty ranging between 0% and 30% in patients who underwent FAI treatment with surgical dislocation. Reported major complication rates have ranged from 3.3% to 6%, most commonly in the form of trochanteric nonunion, neurapraxia, or heterotopic ossification.

Conclusions

FAI deformities encompass a wide spectrum of disease patterns. Surgical dislocation allows full access to the hip in addition to observing its pathomechanics. Strict adherence to proper technique allows the surgeon to minimize complication rates while treating the deformity at hand.
Incidence of Radiographic Cam-Type Impingement in Young Patients (<50) after Femoral Neck Fracture Treated with Reduction and Internal Fixation
Authors: Wendt Matthew C. , Cass Joseph R. , Trousdale Robert R.
Published: January 2013

Background

Cam-type femoral impingement is caused by structural abnormalities of the hip and is recognized as a cause of degenerative hip arthritis. Identifiable etiologies of this structural abnormality include congenital malformation, pediatric hip disease, and malunion of femoral neck fractures after internal fixation.

Purpose

The purpose of this study was to determine the prevalence of radiographic impingement in healed Orthopaedic Trauma Association (OTA) type 31B fractures treated with reduction and internal fixation.

Methods

Seventy OTA 31B hip fractures treated with internal fixation were identified from our institutional trauma database and radiographs were retrospectively reviewed for signs of impingement. Mean follow-up was 53 months after fracture. Alpha angle, Mose templates, and femoral head retroversion were the measurements used to determine impingement.

Results

The overall prevalence of any sign of radiographic impingement was 75%. Alpha angle was elevated in 32 hips (46%), asphericity was present in 46 femoral heads (65%), and femoral head retroversion was present in 26 hips (37%). The rates were highest in displaced subcapital fractures (OTA 31B-3) with a 63% (13/19) prevalence of elevated alpha angle, 68% (14/19) prevalence of asphericity, and 47% (10/19) prevalence of retroversion.

Conclusions

Prevalence of radiographic signs of impingement in this population is higher than expected based on population-based controls. Surgeons must be vigilant about reduction and fixation of femoral neck fractures. Malunion should be recognized as early intervention may be beneficial in improving long-term outcomes.
Biomechanical Analysis of Knotless Flexor Tendon Repair Using Large-Diameter Unidirection Barbed Suture
Authors: Lin Toni E. , Lakhiani Chrisovalantis , Lee Michael R. , Saint-Cyr Michel , Sammer Douglas M.
Published: January 2013

Purpose

In traditional flexor tendon repairs, suture knots can be sites of weakness, impair tendon healing, stimulate an inflammatory response, and increase the bulk of the tendon repair. Because of this, there has been an increased interest in knotless flexor tendon repair using barbed suture. Since knots are not required, it may be possible to increase the strength of the tendon repair by using a large-diameter barbed suture. The purpose of this study was to biomechanically compare a traditional four-strand tendon repair using 3–0 braided polyester with a similar knotless four-strand tendon repair using 0 unidirectional barbed suture.

Methods

Twenty-two matched cadaveric flexor digitorum profundus tendons were lacerated and assigned to repair by a four-strand modified Kirchmayr–Kessler technique using 3–0 braided polyester ( n=11) or knotless four-strand modified Kirchmayr–Kessler repair using 0 unidirectional barbed suture ( n=11). Repaired tendons were linearly distracted to failure at 20 mm/min after 1 N preload. Maximum load and load at 2-mm gap formation were recorded. Maximum load and load at 2-mm gap formation were compared with the Student's t test, and p values≤0.05 were considered significant.

Results

The mean maximum load of the barbed, knotless suture repair was higher than that of the traditional repair (52 vs. 42 N). There was no difference between the two groups in the mean load required to produce a 2-mm gap.

Conclusions

The four-strand knotless tendon repairs using a large-diameter unidirectional barbed suture were stronger than the traditional four-strand repairs using 3-0 braided polyester, and had similar 2-mm gap resistance.
The History and Advances of Reversible Terminators Used in New Generations of Sequencing Technology
Authors: Chen Fei , Dong Mengxing , Ge Meng , Zhu Lingxiang , Ren Lufeng , Liu Guocheng , Mu Rong
Published: January 2013

DNA sequencing using reversible terminators, as one sequencing by synthesis strategy, has garnered a great deal of interest due to its popular application in the second-generation high-throughput DNA sequencing technology. In this review, we provided its history of development, classification, and working mechanism of this technology. We also outlined the screening strategies for DNA polymerases to accommodate the reversible terminators as substrates during polymerization; particularly, we introduced the “REAP” method developed by us. At the end of this review, we discussed current limitations of this approach and provided potential solutions to extend its application.
Midcarpal Joint Loose Body, Where does it Come from?
Authors: Arthur Ma King-Hay , Ping-Tak Chan , Yuk-Yin Chow
Published: January 2013

We report a case of intra-articular loose body in the midcarpal joint following the fracture of the distal radius. The patient fell from a height of 5 ft. The radiographs and computed tomography scan showed a bony fragment in the midcarpal joint. It was associated with dorsal scapholunate ligament tear. The intra-articular bony fragment originated from the fracture distal radius. The possible relationship of the intrusion of the bony fragment and SL ligament injury is discussed.
The nub of an automorphism of a totally disconnected, locally compact group
Authors: WILLIS GEORGE A.
Published: January 2013

To any automorphism,$\alpha $, of a totally disconnected, locally compact group,$G$, there is associated a compact,$\alpha $-stable subgroup of$G$, here called thenubof$\alpha $, on which the action of$\alpha $is ergodic. Ergodic actions of automorphisms of compact groups have been studied extensively in topological dynamics and results obtained transfer, via the nub, to the study of automorphisms of general locally compact groups. A new proof that the contraction group of$\alpha $is dense in the nub is given, but it is seen that the two-sided contraction group need not be dense. It is also shown that each pair$(G, \alpha )$, with$G$compact and$\alpha $ergodic, is an inverse limit of pairs that have ‘finite depth’ and that analogues of the Schreier refinement and Jordan–Hölder theorems hold for pairs with finite depth.
A Consideration of Biomarkers to be Used for Evaluation of Inflammation in Human Nutritional Studies
Authors: Calder P.C. , Ahluwalia N. , Albers R. , Bosco N. , Bourdet-Sicard R. , Haller D. , Holgate S.T. , Jönsson L.S. , Latulippe M.E. , Marcos A. , Moreines J. , M'Rini C. , Müller M. , Pawelec G. , van Neerven R.J.J. , Watzl B. , Zhao J.
Published: January 2013

To monitor inflammation in a meaningful way, the markers used must be valid: they must reflect the inflammatory process under study and they must be predictive of future health status. In 2009, the Nutrition and Immunity Task Force of the International Life Sciences Institute, European Branch, organized an expert group to attempt to identify robust and predictive markers, or patterns or clusters of markers, which can be used to assess inflammation in human nutrition studies in the general population. Inflammation is a normal process and there are a number of cells and mediators involved. These markers are involved in, or are produced as a result of, the inflammatory process irrespective of its trigger and its location and are common to all inflammatory situations. Currently, there is no consensus as to which markers of inflammation best represent low-grade inflammation or differentiate between acute and chronic inflammation or between the various phases of inflammatory responses. There are a number of modifying factors that affect the concentration of an inflammatory marker at a given time, including age, diet and body fatness, among others. Measuring the concentration of inflammatory markers in the bloodstream under basal conditions is probably less informative compared with data related to the concentration change in response to a challenge. A number of inflammatory challenges have been described. However, many of these challenges are poorly standardised. Patterns and clusters may be important as robust biomarkers of inflammation. Therefore, it is likely that a combination of multiple inflammatory markers and integrated readouts based upon kinetic analysis following defined challenges will be the most informative biomarker of inflammation.
A comparative study between non-linear regression and artificial neural network approaches for modelling wild oat (Avena fatua) field emergence
Authors: CHANTRE G. R. , BLANCO A. M. , FORCELLA F. , VAN ACKER R. C. , SABBATINI M. R. , GONZALEZ-ANDUJAR J. L.
Published: January 2013

Non-linear regression (NLR) techniques are used widely to fit weed field emergence patterns to soil microclimatic indices using S-type functions. Artificial neural networks (ANNs) present interesting and alternative features for such modelling purposes. In the present work, a univariate hydrothermal-time based Weibull model and a bivariate (hydro-time and thermal-time) ANN were developed to study wild oat emergence under non-moisture restriction conditions using data from different locations worldwide. Results indicated a higher accuracy of the neural network in comparison with the NLR approach due to the improved descriptive capacity of thermal-time and the hydro-time as independent explanatory variables. The bivariate ANN model outperformed the conventional Weibull approach, in terms of RMSE of the test set, by 70·8%. These outcomes suggest the potential applicability of the proposed modelling approach in the design of weed management decision support systems.
Reflection impulsivity and response inhibition in first-episode psychosis: relationship to cannabis use
Authors: Huddy V. C. , Clark L. , Harrison I. , Ron M. A. , Moutoussis M. , Barnes T. R. E. , Joyce E. M.
Published: January 2013

Background

People with psychosis demonstrate impaired response inhibition on the Stop Signal Task (SST). It is less clear if this impairment extends to reflection impulsivity, a form of impulsivity that has been linked to substance use in non-psychotic samples.

Method

We compared 49 patients with first-episode psychosis (FEP) and 30 healthy control participants on two forms of impulsivity measured using the Information Sampling Test (IST) and the SST, along with clinical and IQ assessments. We also compared those patients who used cannabis with those who had either given up or never used.

Results

Patients with FEP had significantly greater impairment in response inhibition but not in reflection impulsivity compared with healthy controls. By contrast, patients who reported current cannabis use demonstrated greater reflection impulsivity than those that had either given up or never used, whereas there were no differences in response inhibition.

Conclusions

These data suggest that abnormal reflection impulsivity is associated with substance use in psychosis but not psychosis itself; the opposite relationship may hold for response inhibition.
Let Many Civil Societies Bloom: The Rise of Consultative Authoritarianism in China
Authors: Teets Jessica C.
Published: January 2013

In this article, I analyse civil society development in China using examples from Beijing to demonstrate the causal role of local officials' ideas about these groups during the last 20 years. I argue that the decentralization of public welfare and the linkage of promotion to the delivery of these goods supported the idea of local government–civil society collaboration. This idea was undermined by international examples of civil society opposing authoritarianism and the strength of the state-led development model after the 2008 economic crisis. I find growing convergence on a new model of state–society relationship that I call “consultative authoritarianism,” which encourages the simultaneous expansion of a fairly autonomous civil societyandthe development of more indirect tools of state control. This model challenges the conventional wisdom that an operationally autonomous civil society cannot exist inside authoritarian regimes and that the presence of civil society is an indicator of democratization.
Physiological Responses of Medical Team Members to a Simulated Emergency in Tropical Field Conditions
Authors: Brearley Matt B. , Heaney Michael F. , Norton Ian N.
Published: January 2013

Introduction

Responses to physical activity while wearing personal protective equipment in hot laboratory conditions are well documented. However less is known of medical professionals responding to an emergency in hot field conditions in standard attire. Therefore, the purpose of this study was to assess the physiological responses of medical responders to a simulated field emergency in tropical conditions.

Methods

Ten subjects, all of whom were chronically heat-acclimatized health care workers, volunteered to participate in this investigation. Participants were the medical response team of a simulated field emergency conducted at the Northern Territory Emergency Services training grounds, Yarrawonga, NT, Australia. The exercise consisted of setting up a field hospital, transporting patients by stretcher to the hospital, triaging and treating the patients while dressed in standard medical response uniforms in field conditions (mean ambient temperature of 29.3°C and relative humidity of 50.3%, apparent temperature of 27.9°C) for a duration of 150 minutes. Gastrointestinal temperature was transmitted from an ingestible sensor and used as the index of core temperature. An integrated physiological monitoring device worn by each participant measured and logged heart rate, chest temperature and gastrointestinal temperature throughout the exercise. Hydration status was assessed by monitoring the change between pre- and post-exercise body mass and urine specific gravity (USG).

Results

Mean core body temperature rose from 37.5°C at the commencement of the exercise to peak at 37.8°C after 75 minutes. The individual peak core body temperature was 38.5°C, with three subjects exceeding 38.0°C. Subjects sweated 0.54 L per hour and consumed 0.36 L of fluid per hour, resulting in overall dehydration of 0.7% of body mass at the cessation of exercise. Physiological strain index was indicative of little to low strain.

Conclusions

The combination of the unseasonably mild environmental conditions and moderate work rates resulted in minimal heat storage during the simulated exercise. As a result, low sweat rates manifested in minimal dehydration. When provided with access to fluids in mild environmental conditions, chronically heat-acclimatized medical responders can meet their hydration requirements through ad libitum fluid consumption. Whether such an observation is replicated under a harsher thermal load remains to be investigated.

BrearleyMB, HeaneyMF, NortonIN. Physiological responses of medical team members to a simulated emergency in tropical field conditions. Prehosp Disaster Med. 2013;28(2):1-6.
Effects of glucocorticoid treatment given in early or late gestation on growth and development in sheep
Authors: Li S. , Sloboda D. M. , Moss T. J. M. , Nitsos I. , Polglase G. R. , Doherty D. A. , Newnham J. P. , Challis J. R. G. , Braun T.
Published: January 2013

Antenatal corticosteroids are used to augment fetal lung maturity in human pregnancy. Dexamethasone (DEX) is also used to treat congenital adrenal hyperplasia of the fetus in early pregnancy. We previously reported effects of synthetic corticosteroids given to sheep in early or late gestation on pregnancy length and fetal cortisol levels and glucocorticoids alter plasma insulin-like growth factor (IGF) and insulin-like growth factor binding protein (IGFBP) concentrations in late pregnancy and reduce fetal weight. The effects of administering DEX in early pregnancy on fetal organ weights and betamethasone (BET) given in late gestation on weights of fetal brain regions or organ development have not been reported. We hypothesized that BET or DEX administration at either stage of pregnancy would have deleterious effects on fetal development and associated hormones. In early pregnancy, DEX was administered as four injections at 12-hourly intervals over 48 h commencing at 40–42 days of gestation (dG). There was no consistent effect on fetal weight, or individual fetal organ weights, except in females at 7 months postnatal age. When BET was administered at 104, 111 and 118 dG, the previously reported reduction in total fetal weight was associated with significant reductions in weights of fetal brain, cerebellum, heart, kidney and liver. Fetal plasma insulin, leptin and triiodothyronine were also reduced at different times in fetal and postnatal life. We conclude that at the amounts given, the sheep fetus is sensitive to maternal administration of synthetic glucocorticoid in late gestation, with effects on growth and metabolic hormones that may persist into postnatal life.
Analysis of unequal error protection for LDPCA codes
Authors: Sun Y.‐C. , Tsai W.‐J.
Published: January 2013

Unequal error protection extensions of low density parity check accumulate (UEP‐LDPCA) codes are discussed and several potential applications are proposed. Two UEP‐LDPCA schemes are analysed and code parameters are optimised using a density evolution algorithm. Simulation results show that the extensions have the significant unequal error protection property. This activates new directions for existing applications.
Parallel array histogram architecture for embedded implementations
Authors: Gan Q. , Langlois J.M.P. , Savaria Y.
Published: January 2013

Proposed is a parallel array histogram architecture (PAHA) suitable for embedded implementations. The PAHA uses a register array instead of a memory block to store the histogram bins. In each step, M inputs can be processed in parallel to update the histogram bins without any additional latency. Also described is a second version of the PAHA with a flexible number of inputs, potentially avoiding the need for multiple PAHAs in a single application. Implementation results show that the architecture can achieve a super‐linear speed‐up of 43.75× for a 16‐way PAHA when compared to a software implementation in a general‐purpose processor.
Compact UWB BPF with triple‐notched bands based on stub loaded resonator
Authors: Wei Feng , Wang Zhu Dan , Yang Fan , Shi Xien Wei
Published: January 2013

A compact ultra‐wideband (UWB) bandpass filter (BPF) with triple‐notched bands and wide stopband is presented. The basic UWB BPF comprises four folded shunt quarter‐wavelength short‐circuited stubs separated by connecting lines with lengths of λg0/4 and λg0/2, respectively. The proposed coupled triple‐mode stub loaded resonator is found to have the advantage of introducing triple‐notched bands simultaneously. Five stepped‐impedance shunt stubs are chosen to suppress the harmonic passband. The predicted results are compared with measured data and good agreement is reported.
Thru‐reflect‐line calibration for substrate integrated waveguide devices with tapered microstrip transitions
Authors: Caballero E. Diaz , Belenguer A. , Esteban H. , Boria V.E.
Published: January 2013

One of the main problems when exciting or measuring substrate integrated waveguide (SIW) devices lies in the need of a good interconnection with planar structures. In this reported work, the negative effects produced by the connectors and the tapered microstrip‐to‐SIW transitions are de‐embedded from the measurements of the SIW structure by a thru‐reflect‐line calibration with an adequate and cheap SIW calibration kit.
Design of wide‐stopband microstrip bandpass filter with assistance of spur lines
Authors: Tang C.W. , Teng C.H. , Sun J.M.
Published: January 2013

A novel microstrip bandpass filter with compact size is proposed. With two short‐circuited stubs, one open‐circuited coupled line using symmetrical feeding, and two spur lines, a wide passband can be obtained. Detailed design and synthesis procedures are provided for filter development. Moreover, the electromagnetic simulator IE3D is used; the prototype of the bandpass filter is consequently fabricated and measured. Agreement between measured results and the theoretical prediction validates the proposed structure.
Efficient ADE‐WE‐PML formulations for scalar dispersive FDTD applications
Authors: Ramadan O.
Published: January 2013

Efficient wave equation perfectly matched layer (WE‐PML) formulations, based on the auxiliary differential equation (ADE) scheme, are presented for truncating scalar dispersive finite difference time domain (FDTD) grids. The formulations maintain the same accuracy as previous WE‐PML approaches but with fewer additional auxiliary variables. Moreover, the formulations can be coupled easily with the classical WE‐FDTD scheme.
Periodically poled lithium niobate ridge waveguides with high conversion efficiency for 2f‐to‐3f self‐referencing interferometer
Authors: Hitachi K. , Ishizawa A. , Nishikawa T. , Asobe M. , Sogawa T.
Published: January 2013

The generation of second‐ and third‐harmonic light with single‐ and dual‐pitch periodically poled lithium niobate ridge waveguides for achieving a carrier‐envelope‐offset‐locked frequency comb with low pulse energy is investigated. The wavelengths of both the second‐ and third‐harmonic light converted by short‐ and long‐wavelength components of supercontinuum spectra are precisely adjusted by selecting appropriate pitch size and controlling the temperature of the devices. The output powers of the second‐ and third‐harmonic light are 9.1 and 4.8 µW, respectively, when using a 2/3‐octave‐wide supercontinuum light generated by a 1.2 nJ laser pulse at a repetition rate of 250 MHz.
Compact dual‐wideband bandpass filter using asymmetrical resonator
Authors: Hsu K.‐W. , Chien C.‐H. , Tu W.‐H.
Published: January 2013

A compact dual‐wideband bandpass filter using an asymmetrical resonator is presented. The proposed resonator consists of three uniform microstrip lines of different lengths, and provides not only three transmission poles but also two transmission zeros for each passband. Thus, the bandpass filter has wide bandwidths and sharp cutoff responses. Theory as well as experimential results are given to validate this design concept.
Highly conducting carbon nanotube composite for electric heating unit applications
Authors: Park S.H. , Chu K.‐M.
Published: January 2013

The fabrication of highly conducting carbon nanotubes (CNTs)/polydimethylsiloxane (PDMS) composite is presented with the aim of electric heating unit applications. High shear processing techniques were used to separate highly entangled multi‐walled carbon nanotubes with high aspect ratio (∼5000). No notable agglomerates or phase separation between the CNTs and PDMS matrix are observed, and the CNTs are well dispersed. It is observed that the approximate percolation threshold is found to be below 0.1 vol.%, which is a lower value than previously reported. The resulting conductivity of the CNT/PDMS composite is about 2.23 S/cm at 5.7 vol.% CNT loading. The fabricated CNT/PDMS composites can be quickly heated from room temperature to 130 °C within 90 s by applying a DC voltage of 5 V. The proposed CNT‐polymer composite system with obtained results could be used as a basis for light‐weight and high effective heating unit applications.
Micro‐motion modelling and analysis of extended ballistic targets based on inertial parameters
Authors: He F.Y. , Xiao Z.Y.
Published: January 2013

Mirco‐motion analysis of ballistic targets is a useful tool for discriminating different targets in the aerospace. A micro‐motion model combining inertial parameters with a target radar coss‐section is presented. The relation between target micro‐motion states and inertial parameters is deduced. By using the time‐frequency transform method, the micro Doppler spectrogram is obtained. Simulation results show that the proposed method can be used for evaluation of ballistic targets recognition and discrimination.
Suppression of multiple power line harmonic interference for low frequency signals
Authors: Trudeau L.C. , Gagnon F.
Published: January 2013

A novel and simple algorithm capable of extracting and cancelling harmonic disturbance from signals subject to severe power line interference is presented. The key element consists of the adaptation of a filter to a deterministic harmonic reference closely correlated to the interference. The resulting signal is optimal in the mean squared error sense. Simulation results show that this carefully crafted adaptive scheme can improve by up to 30 dB the signal to interference ratio. Minimal remaining interference and fast convergence are obtained by optimisation of the algorithm's parameters.
Switched‐capacitor power sensing in low‐power energy harvesting systems
Authors: Proynov P. , Szarka G. D. , McNeill N. , Stark B. H.
Published: January 2013

A method for power sensing in low‐power energy harvesting systems is presented. The technique utilises a small sense capacitor between the converter output and the main storage capacitor. The storage capacitor is disconnected from the converter for a short period of time and the change of sense capacitor voltage is measured. This change is proportional to the average output current of the converter for the period of the measurement, thus the relative output power can be determined using only voltage measurements. The method has been experimentally validated in a low‐power energy harvesting system that employs a microcontroller‐based control implementation.
Efficient phase regeneration of DPSK signal by sideband‐assisted dual‐pump phase‐sensitive amplifier
Authors: Gao M. , Kurosu T. , Inoue T. , Namiki S.
Published: January 2013

A high phase sensitivity of 25 dB at the nonlinear phase shift of 0.8 rad in a sideband‐assisted dual‐pump phase‐sensitive amplifier is achieved. Here the sidebands play an important role to evoke larger phase‐sensitive attenuations for achieving higher phase sensitivity at such a lower nonlinear phase shift. This feature is utilised to improve the efficiency in the phase regeneration of 21.5 Gbit/s DPSK signals. The phase error of 22.6° was squeezed to 2.5° by operating such a sideband‐assisted dual‐pump phase‐sensitive amplifier at 0.8 rad nonlinear phase shift. The operations at low nonlinear phase shift enable utilisation of the state‐of‐the‐art silica‐based highly nonlinear fibre with low noise and low dispersion slope by avoiding stimulated Brillouin scattering induced by higher pump power.