bluuebunny/crossref_metadata_2025 huggingface dataset:
The Acute Effect of Bipolar Radiofrequency Energy Thermal Chondroplasty on Intrinsic Biomechanical Properties and Thickness of Chondromalacic Human Articular Cartilage
Authors: Dutcheshen Nicholas , Maerz Tristan , Rabban Patrick , Haut Roger C. , Button Keith D. , Baker Kevin C. , Guettler Joseph
Published: July 2012

Radio frequency energy (RFE) thermal chondroplasty has been a widely-utilized method of cartilage debridement in the past. Little is known regarding its effect on tissue mechanics. This study investigated the acute biomechanical effects of bipolar RFE treatment on human chondromalacic cartilage. Articular cartilage specimens were extracted (n = 50) from femoral condyle samples of patients undergoing total knee arthroplasty. Chondromalacia was graded with the Outerbridge classification system. Tissue thicknesses were measured using a needle punch test. Specimens underwent pretreatment load-relaxation testing using a spherical indenter. Bipolar RFE treatment was applied for 45 s and the indentation protocol was repeated. Structural properties were derived from the force-time data. Mechanical properties were derived using a fibril-reinforced biphasic cartilage model. Statistics were performed using repeated measures ANOVA. Cartilage thickness decreased after RFE treatment from a mean of 2.61 mm to 2.20 mm in Grade II, II-III, and III specimens (P < 0.001 each). Peak force increased after RFE treatment from a mean of 3.91 N to 4.91 N in Grade II and III specimens (P = 0.002 and P = 0.003, respectively). Equilibrium force increased after RFE treatment from a mean of 0.236 N to 0.457 N (P < 0.001 each grade). Time constant decreased after RFE treatment from a mean of 0.392 to 0.234 (P < 0.001 for each grade). Matrix modulus increased in all specimens following RFE treatment from a mean 259.12 kPa to 523.36 kPa (P < 0.001 each grade). Collagen fibril modulus decreased in Grade II and II-III specimens from 60.50 MPa to 42.04 MPa (P < 0.001 and P = 0.005, respectively). Tissue permeability decreased in Grade II and III specimens from 2.04 *10−15 m4/Ns to 0.91 *10−15 m4/Ns (P < 0.001 and P = 0.009, respectively). RFE treatment decreased thickness, time constant, fibril modulus, permeability, but increased peak force, equilibrium force, and matrix modulus. While resistance to shear and tension could be compromised due to removal of the superficial layer and decreased fibril modulus, RFE treatment increases matrix modulus and decreases tissue permeability which may restore the load- bearing capacity of the cartilage.
Pelvi-ureteric junction obstruction in autosomal-dominant polycystic kidney disease: an association yet to be reported
Authors: Goyal Neeraj Kumar , Goel Apul , Yadav Rahul , Sankhwar Satyanarayan
Published: July 2012

Autosomal-dominant polycystic kidney disease (ADPKD) is the most common inherited renal cystic disease. It is characterised by the development of renal parenchymal cysts and a variety of other extrarenal manifestations. Pelvi-ureteric junction (PUJ) obstruction has not been described in association with ADPKD in the literature. We present a case of a 23-year-old man presenting with bilateral flank pain. On evaluation he was diagnosed to have ADPKD with bilateral renal calculi and left-sided PUJ obstruction. He underwent successful right percutaneous nephrolithotomy and left laparoscopic dismembered pyeloplasty with simultaneous stone removal.
MRI for the detection of prostate cancer origin vertebral metastases in the preosteoblastic phase
Authors: Revannasiddaiah Swaroop , Rastogi Madhup , Thakur Pragyat , Gupta Manoj Kumar , Sood Ashwani , Sharma Chittranjan
Published: July 2012

This report describes the case of a gentleman aged 59 years presenting with low-back pain, who had underwent radical prostatectomy for prostate cancer 8 years ago. On evaluation, a slightly elevated serum alkaline-phosphatase level prompted a search for bone metastases. Although x-ray radiography and a bone scan were apparently normal, an MRI scan revealed the presence of metastatic marrow infiltration in the lumbar vertebrae. The patient subsequently was initiated on therapy with androgen-deprivation therapy and bisphosphonates, and currently enjoys symptom-free and progression-free survival. The images in this paper intend to impress upon the limitations of bone scan and x-ray radiography with regard to the detection of vertebral marrow infiltration in the absence of cortical bone invasion. In addition, a brief review of the pathophysiology of vertebral metastases arising from prostate cancer is included.
TOWARDS GHOST-FREE GRAVITY AND STANDARD MODEL
Authors: TKACH V. I.
Published: July 2012

This paper presents a new higher derivative gravity which in spontaneous breaking electroweak symmetry state does not have ghost in gravity sector. We show that Newton constant of the gravity and dark energy density depend on the fundamental TeV scale and the coupling constant at the quadratic curvature term. We consider the supersymmetric extension of this model.
Constructions of Vector‐Valued Filters and Vector‐Valued Wavelets
Authors: He Jianxun , Huang Shouyou
Published: July 2012

Let a   = (a1, a2, …, am)∈ℂm be an m‐dimensional vector. Then, it can be identified with an m × m circulant matrix. By using the theory of matrix‐valued wavelet analysis (Walden and Serroukh, 2002), we discuss the vector‐valued multiresolution analysis. Also, we derive several different designs of finite length of vector‐valued filters. The corresponding scaling functions and wavelet functions are given. Specially, we deal with the construction of filters on symmetric matrix‐valued functions space.
Plasmonic Bandgaps in 1D Arrays of Slits on Metal Layers Excited by Out-of-Plane Sources
Authors: Marani Roberto , Grande Marco , Petruzzelli Vincenzo , D'Orazio Antonella
Published: July 2012

We analyze the effective opening of finite bands of inhibited transmission in realistic systems excited by actual out-of-plane sources. We first observe how the excitation of surface plasmon polaritons in one-dimensional arrays of metal slits depends on the angle of incidence of the source field. Then, the well-known grating-coupling equation is revised in order to find an asymmetric structure with equivalent parameters which, under perfectly normal excitation, is able to exhibit surface plasmon polariton modes at the same wavelengths of the original structure which undergoes a nonorthogonal incidence of the light. In this way we demonstrate through finite-element simulations that a realistic system, probed by a source beam in a finite light-cone, can be effectively decomposed in several equivalent systems with different physical and geometrical parameters, with results in the enlargement of the theoretically expected punctual minimum of transmission.
Effect of Crude Plant Extracts on Mushroom Mite,Luciaphorussp. (Acari: Pygmephoridae)
Authors: Bussaman Prapassorn , Sa-uth Chirayu , Rattanasena Paweena , Chandrapatya Angsumarn
Published: July 2012

The use of plant extracts for controlling agricultural pests has become increasingly popular in the recent years. Mushroom mite,Luciaphorussp., is a destructive pest of several mushroom species and has been reported to cause severe loss of mushroom cultivation in many settings. The efficacies of 23 rhizome and leaf extracts were evaluated against female adults ofLuciaphorussp. At 3 days after treatment, the rhizome extracts derived fromCurcuma xanthorrhizaRoxb. andZingiber montanum(Koenig) Link ex Dietr. were found to have very strong acaricidal activities, resulting in 100% mite mortality, followed byCurcuma longaLinn. (98.89%),Zingiber zerumbet(L.) Smith. (97.78%),Kaempferia parvifloraWall. Ex Baker (88.89%), andZingiber officinaleRoscoe. (84.44%). The leaf extracts ofOcimum sanctumLinn. andMelissa officinalisL. also resulted in 100% mite mortality 3 days after treatment, while the other leaf extracts induced mite mortality only below 70%. The results suggested that rhizome extracts ofC. xanthorrhizaandZ. montanumand leaf extracts ofO. sanctumandM. officinalishave a great potential for future development as natural acaricides for controllingLuciaphorussp.
The Existence of Positive Solutions for Fractional Differential Equations with Sign Changing Nonlinearities
Authors: Jiang Weihua , Qiu Jiqing , Guo Weiwei
Published: July 2012

We investigate the existence of at least two positive solutions to eigenvalue
problems of fractional differential equations with sign changing nonlinearities in more generalized
boundary conditions. Our analysis relies on the Avery‐Peterson fixed point theorem
in a cone. Some examples are given for the illustration of main results.
DSD and Professionalism from a Multilateral View: Supplementing the Consensus Statement on the Basis of a Qualitative Survey
Authors: Streuli Jürg C. , Köhler Birgit , Werner-Rosen Knut , Mitchell Christine
Published: July 2012

Treatment and support of a child with DSD calls for experience and expertise in diagnosis, surgical techniques, understanding of psychosocial issues, and recognizing and accepting the significance of individual values of children, families, and support groups. The range of what is considered “appropriate” care and treatment is still very broad and critics point at major gaps between ethical guidelines and current clinical practice. Based on a qualitative study with 27 members of multidisciplinary teams and support groups, we supplement the professional consensus statements and current ethical guidelines with 14 requirements from four different perspectives, to characterize more fully the responsible treatment and support of children and families affected by DSD. Overall, our findings highlight the importance of close collaborations between different experts and a shift from the often simplified dispute about genital surgeries to a more holistic perspective with a long-term management strategy, which should serve as a cornerstone not only for clinical practice but also for future research and evaluation studies.
Chinese-Language Montreal Cognitive Assessment for Cantonese or Mandarin Speakers: Age, Education, and Gender Effects
Authors: Zheng Ling , Teng Evelyn L. , Varma Rohit , Mack Wendy J. , Mungas Dan , Lu Po H. , Chui Helena C.
Published: July 2012

The Montreal Cognitive Assessment Chinese-Language Los Angeles version (MoCA-ChLA) was developed and administered during an in-home interview to 1,192 participants (mean age 62.5 years, mean education 11.6 years) in a population-based Chinese American Eye Study (CHES) in Los Angeles. The MoCA-ChLA score (mean ± SD) was23.8±4.2with little ceiling and no floor effects. The score increased with higher education, decreased with advancing age, and was not related to gender. Compared to the education 1–6 years group, the mean MoCA-ChLA score was 2.6 and 4.6 higher in the education 7–11 and 12–20 years groups, respectively. The Mandarin- (n=612) and Cantonese- (n=612) speaking subgroups performed comparably; Cronbach's alpha of the MoCA-ChLA score was 0.78 and 0.79 for these two groups, respectively. Item response theory analysis showed good discriminating power for executive function and memory. These properties support the MoCA-ChLA as a useful screening tool for aging and dementia studies for Mandarin or Cantonese speakers.
Odontogenic Myxoma of the Mandible
Authors: Manne Rakesh Kumar , Kumar Venkata suneel , Venkata Sarath P. , Anumula Lavanya , Mundlapudi Sridhar , Tanikonda Rambabu
Published: July 2012

Odontogenic myxomas are benign but locally aggressive neoplasms found almost exclusively in the jaws and arise only occasionally in other bones. We present a rare case of odontogenic myxoma occurring in the mandible of a 19-year-old male patient with a brief review of clinical and radiological features, and diagnostic and operative dilemmas in managing the same.
Random Attractors for Stochastic Three‐Component Reversible Gray‐Scott System on Infinite Lattices
Authors: Gu Anhui , Wang Zhaojuan , Zhou Shengfan
Published: July 2012

We prove the existence of a compact random attractor for the random dynamical system generated by stochastic three‐component reversible Gray‐Scott system with a multiplicative white noise on infinite lattices.
Heavy Rainfall Episodes in the Eastern Northeast Brazil Linked to Large-Scale Ocean-Atmosphere Conditions in the Tropical Atlantic
Authors: Kouadio Yves K. , Servain Jacques , Machado Luiz A. T. , Lentini Carlos A. D.
Published: July 2012

Relationships between simultaneous occurrences of distinctive atmospheric easterly wave (EW) signatures that cross the south-equatorial Atlantic, intense mesoscale convective systems (lifespan > 2 hour) that propagate westward over the western south-equatorial Atlantic, and subsequent strong rainfall episodes (anomaly > 10 mm·day−1) that occur in eastern Northeast Brazil (ENEB) are investigated. Using a simple diagnostic analysis, twelve cases with EW lifespan ranging between 3 and 8 days and a mean velocity of 8 m·s−1were selected and documented during each rainy season of 2004, 2005, and 2006. These cases, which represent 50% of the total number of strong rainfall episodes and 60% of the rainfall amount over the ENEB, were concomitant with an acceleration of the trade winds over the south-equatorial Atlantic, an excess of moisture transported westward from Africa to America, and a strengthening of the convective activity in the oceanic region close to Brazil. Most of these episodes occurred during positive sea surface temperature anomaly patterns over the entire south-equatorial Atlantic and low-frequency warm conditions within the oceanic mixing layer. A real-time monitoring and the simulation of this ocean-atmosphere relationship could help in forecasting such dramatic rainfall events.
Francisella tularensisBacteremia: A Case Report from Sudan
Authors: Mohamed Salma E. R. , Mubarak Aymun I. , Alfarooq Lamia O.
Published: July 2012

Francisella tularensisis a highly virulent intracellular gram-negative bacterium. The organism is usually isolated from wild and domestic animals and invertebrate. Man gets infection by direct contact with those animals or their products but the most common mode of transmission is via arthropod vectors. The disease is endemic in North America, parts of Europe, and Asia but has never been reported in Africa. A 29-year old male living in a rural area of Southern Sudan has been maintained on continuous ambulatory peritoneal dialysis for two years. He presented to our center in May 2010 complaining of fever, dry cough, shortness of breath, and abdominal discomfort for four days. He was very ill, pale, and dehydrated. There were enlarged tender submandibular lymph nodes, but no mouth ulcers or other palpable lymph nodes. Peritonitis was excluded by effluent white blood cell count and culture. Empiric antibiotic treatment with ceftriaxon, and ciprofloxacin was started. Gram-negative coccobacilli were isolated by blood culture. The organism was identified asFrancisella tularensis. We started him on a ten-day course of gentamicin after which he improved. This is, to the best of our knowledge, the first reported case of bacteremia caused byFrancisella tularensisin Sudan.
On a Functional Equation Associated with (a, k)‐Regularized Resolvent Families
Authors: Lizama Carlos , Poblete Felipe
Published: July 2012

Let and k ∈ C(ℝ+) be given. In this paper, we study the functional equation R(s)(a*R)(t)−(a*R)(s)R(t) = k(s)(a*R)(t) − k(t)(a*R)(s), for bounded operator valued functions R(t) defined on the positive real line ℝ+. We show that, under some natural assumptions on a(·) and k(·), every solution of the above mentioned functional equation gives rise to a commutative (a, k)‐resolvent family R(t) generated by defined on the domain exists in X} and, conversely, that each (a, k)‐resolvent family R(t) satisfy the above mentioned functional equation. In particular, our study produces new functional equations that characterize semigroups, cosine operator families, and a class of operator families in between them that, in turn, are in one to one correspondence with the well‐posedness of abstract fractional Cauchy problems.
Titanium as a Potential Addition for High-Capacity Hydrogen Storage Medium
Authors: Zuliani Filippo , Bernasconi Leonardo , Baerends Evert Jan
Published: July 2012

We study the adsorption of hydrogen molecules on a titanium atom supported by a benzene molecule using generalized gradient corrected Density Functional Theory (DFT). This simple system is found to bear important analogies with titanium adsorption sites in (8, 0) titanium-coated single-walled carbon nanotubes (SWNTs) (T. Yildirim and S. Ciraci, 2005) In particular, we show that up to fourH2molecules can coordinate to the metal ion center, with adsorption patterns similar to those observed in Ti-SWNTs and no more than one molecule dissociating in the process. We analyze in detail the orbital interactions responsible for Ti-benzene binding and for the electron transfer responsible for theH2dissociation. We find the latter to involve a transition from a triplet to a singlet ground state as the hydrogen molecule approaches the adsorption site, similar to what has been observed in Ti-SWNTs. The total Ti-H2-binding energy for the first dissociative addition is somewhat inferior (~0.4 eV) to the value estimated for adsorption on Ti-SWNTs. We analyze in detail the orbital interactions responsible for theH2binding.
Determining the Incidence of Adult Fractures: How Accurate Are Emergency Department Data?
Authors: Aitken Stuart A. , Rodrigues Mark A. , Duckworth Andrew D. , Clement Nicholas D. , McQueen Margaret M. , Court-Brown Charles M.
Published: July 2012

Various research methods have been used to obtain skeletal fracture data and report the incidence of fractures. A large number of British studies have used data collected in emergency departments, and not data derived from orthopaedic units. We hypothesised that fracture data will differ depending upon the methodology employed to capture it. Two commonly used sources of fracture data at our institution were compared, (the Emergency Department (ED) database and the Orthopaedic Trauma Unit (OTU) database), using a cohort of adult patients from our defined population as the study sample. We performed univariate analyses to identify differences between groups with accurate and inaccurate ED fracture diagnoses. We then performed a binary logistic regression analysis to determine the best predictors of diagnostic accuracy. In one year, 7,449 patients were referred to the OTU. Three-quarters were referred with fractures. The overall false positive fracture referral rate was 25%. Several fracture subtypes were commonly overdiagnosed in the ED. Regression analysis showed that patient age, patient gender, and the seniority of the referring clinician were independently predictive of an accurate fracture diagnosis. We suggest that studies making use of ED fracture data may potentially overestimate the incidence of adult fractures.
Orbital Apex Syndrome in Herpes Zoster Ophthalmicus
Authors: Arda Hatice , Mirza Ertugrul , Gumus Koray , Oner Ayse , Karakucuk Sarper , Sırakaya Ender
Published: July 2012

Orbital apex syndrome is a rare manifestation of Herpes Zoster Ophthalmicus. Herein we report on a case of orbital apex syndrome secondary to Herpes Zoster Ophthalmicus. A 75 year-old male complained of vision loss, conjunctival hyperemia and proptosis on the left eye, was referred to our clinic. Visual acuity was 5/10 Snellen lines and he had conjunctival hyperemia, chemosis, minimal nuclear cataract and proptosis on the left eye. A diagnosis of orbital pseudotumor was demonstrated firstly. The patient received oral and topical corticosteroids, antiinflammatory and antibiotic agents. On day 2, vesiculopustular lesions were observed, Herpes Zoster Ophthalmicus was diagnosed and corticosteroid treatment stopped, oral acyclovir treatment initiated. Two days later, total ophthalmoplegia, ptosis and significant visual loss were observed on the left. The diagnosis of orbital apex syndrome was considered and the patient commenced on an intravenous acyclovir treatment. After the improvement of acute symptoms, a tapering dose of oral cortisone treatment initiated to accelarate the recovery of ophthalmoplegia. At 5-month follow-up, ptosis and ocular motility showed improvement. VA did not significantly improve because of cataract and choroidal detachment on the left. We conclude that ophthalmoplegia secondary to Herpes Zoster Ophthalmicus responds favourably to intravenous acyclovir and steroids.
Adult BMI Change and Risk of Colon Cancer in Postmenopausal Women
Authors: Blake-Gumbs Lyla , Chen Zhengyi , Thompson Cheryl L. , Berger Nathan A. , Tucker Thomas C. , Li Li
Published: July 2012

Purpose. We recently reported an association of adult BMI change with colon cancer risk. Here, we sought to further explore this association with respect to postmenopausal HRT use in a larger study population.Methods. We included 1,457 postmenopausal women participating in an ongoing population-based case-control study of colon cancer.Results. We confirmed a previously reported association of adulthood weight gain and increased risk of colon cancer: compared to those with <5 kg/m2change of BMI, women who reported moderate (5–10 kg/m2) and large (>10 kg/m2) BMI changes since their 20s had OR estimates of 1.54 (95% CI = 1.09–2.19) and 1.45 (95% CI = 0.90–2.33), respectively (Pfor trend = 0.05). Stratified analyses showed that this association was limited to HRT nonusers: ORs were 1.77 (95% CI = 1.02–3.05) and 2.21 (95% CI = 1.09–4.45), respectively (Pfor trend = 0.03), for BMI changes occurring between the 20s decade and time of recruitment among non-users. Similar associations were observed for BMI changes since the 30s decade. There was no association among HRT users.Conclusion. Our results suggest early adulthood weight gain increases colon cancer risk in postmenopausal women who do not use HRT.
Markers of Treatment Response to Methotrexate in Rheumatoid Arthritis: Where Do We Stand?
Authors: Halilova Karina I. , Brown Elizabeth E. , Morgan Sarah L. , Bridges S. Louis , Hwang Min-Ho , Arnett Donna K. , Danila Maria I.
Published: July 2012

Methotrexate (MTX) is the most commonly used disease-modifying antirheumatic drug (DMARD) for the treatment of rheumatoid arthritis (RA). However, despite its efficacy and affordability, additional DMARDs or biologic agents are often required in order to achieve the recommended goals of low disease activity or remission. Although well tolerated by most, some patients develop important side effects such as cytopenias, gastrointestinal adverse events (stomatitis, nausea), or abnormal liver function tests, which may limit its use and may result in additional health care costs. Given the clinical implications of widespread use of MTX in RA, various studies have evaluated the role of potential biomarkers in predicting treatment effectiveness of MTX. These biomarkers include RBC MTX polyglutamate (PG) levels; genetic variation in genes from relevant biological and metabolic pathways; gene expression profiles; serum proteins. This paper provides an update on the current data regarding biomarkers of treatment response to MTX.
Stroke in the Very Elderly: Characteristics and Outcome in Patients Aged ≥85 Years with a First-Ever Ischemic Stroke
Authors: Gur A.Y. , Tanne D. , Bornstein N.M. , Milo R. , Auriel E. , Shopin L. , Koton S. ,   on behalf of the NASIS Investigators
Published: July 2012

Background: Epidemiological and clinical features of very elderly patients with stroke are still uncertain. Our aim was to study the patient characteristics and outcomes in the very elderly (aged ≥85 years) with a first-ever ischemic stroke in the National Acute Stroke Israeli Survey (NASIS) registry. Methods: The NASIS registry is a nationwide prospective hospital-based study performed triennially (2004, 2007, 2010). Patients with ischemic stroke aged ≥85 years were compared with those 65–84 years old regarding their baseline characteristics, stroke severity, etiology of stroke and stroke outcomes. Logistic regression analyses were used to adjust for potential confounders. Stroke severity was determined according to the National Institute of Health Stroke Scale (NIHSS) score. Results: The proportion of very elderly (≥85 years) patients among the NASIS population increased from 18.3% in 2004 to 19.9% in 2007 and 24.5% in 2010 (p for trend = 0.005). The percentage of women was higher in patients aged ≥85 years (p < 0.0001). Atrial fibrillation, congestive heart disease and prior disability were significantly more common, while diabetes, current smoking and dyslipidemia were less frequent in the very elderly. The very elderly presented with more severe strokes: 36.3% of the ≥85-year-old patients had an NIHSS score ≥11 compared with 22.0% in the younger age group (p < 0.05). Conclusions: There is an increasing proportion of very elderly subjects, mostly women, among first-ever ischemic stroke patients. Current information on age-specific aspects of stroke in the very elderly is crucial to set up successful prevention pathways and implementing well-organized stroke care for this population.
Scale Localization of Cloud Particle Clustering Statistics
Authors: Larsen Michael L.
Published: July 2012

Recent work has examined the spatial distribution of droplets within a cloud. Experimentally, most studies analyze interevent times from static probes flown linearly through a cloud, allowing the spatial information to be conveyed through a time series of particle detections. Analysis of these data has shown unequivocally that most clouds have nontrivial spatial structure. There is still debate as to which of many different possible statistical descriptions is most appropriate for characterizing this spatial structure and for identifying spatiotemporal scales of physical significance from the data record. This paper seeks to clarify some pervasive misunderstandings and to outline more carefully the range of validity for several of these statistical tools. Simulations are used to explore the relative scale-localizing capabilities of various commonly used statistical tools.
Potential Predictability of the North Atlantic Heat Transport Based on an Oceanic State Estimate
Authors: Tiedje Bente , Köhl Armin , Baehr Johanna
Published: July 2012

This paper investigates the potential predictability of the meridional heat transport (MHT) in the North Atlantic on interannual time scales using hindcast ensembles based on an oceanic data assimilation product. The work analyzes the prognostic potential predictability (PPP), using the ocean synthesis of the German partner of the consortium for Estimating the Circulation and Climate of the Ocean (GECCO) as initial conditions and as boundary conditions. The PPP of the MHT varies with latitude: local maxima are apparent within the subpolar and the subtropical gyres, and a minimum is apparent at the boundary between the gyres. This PPP minimum can also be seen in the PPP structure of the Atlantic meridional overturning circulation (AMOC), although it is considerably less pronounced. The decomposition of the MHT shows that within the subpolar gyre, the gyre component of the MHT influences the PPP structure of the MHT. Within the subtropical gyre, the overturning component of the MHT characterizes the PPP structure of the MHT. At the boundary between the subpolar and the subtropical gyres, the dynamics of the Ekman heat transport limit the predictable lead times of the MHT. At most latitudes, variations in the velocity field control the PPP structure of the MHT. The PPP structure of the AMOC can also be classified into gyre and gyre-boundary regimes, but the predictable lead times within the gyres are only similar to those of the overturning component of the MHT. Overall, the analysis provides a reference point for the latitude dependence of the MHT’s PPP structure and relates it to the latitude dependence of the AMOC’s PPP structure.
Making contribution analysis work: A practical framework for handling influencing factors and alternative explanations
Authors: Lemire Sebastian T. , Nielsen Steffen Bohni , Dybdal Line
Published: July 2012

This article examines the methodological strengths and weaknesses of contribution analysis. The authors contend that a salient characteristic of contribution analysis is its accounting for influencing factors and alternative explanations. We argue that contribution analysis in its current form needs further methodological and practical elaboration in this respect. Therefore, this article pays particular attention to how the methodology can identify and determine the extent of influencing factors and alternative explanations. The authors propose a corresponding framework – the Relevant Explanation Finder – which can help evaluators account for these elements and thereby create more credible contribution stories.
Towards an evidence base of theory-driven evaluations: Some questions for proponents of theory-driven evaluation
Authors: Sridharan Sanjeev , Nakaima April
Published: July 2012

This article discusses the further development of theory-driven evaluation approaches that are informed by contribution analysis. Using an illustrative example of an ongoing dance/physical activity programme for health promotion, a number of challenges are identified when applying a theory-driven evaluation approach. These challenges are reformulated as questions that need to be answered to make further progress with theory-driven evaluation including contribution analysis. Questions include: What is a ‘good enough’ programme theory? How does one arrive at expectations of programme impacts? How does the programme theory incorporate heterogeneous mechanisms that programme recipients might need? What does causality mean for complex interventions? What are structures that can facilitate learning from evaluations? How does the application of theory-driven evaluation approaches help generate an ‘ecology of evidence’? Discussion of these questions leads to a ‘roadmap’ for how contribution analysis might be further tested and refined.
Los Caminos
Authors: Irizarry Jason G.
Published: July 2012

This article draws from data collected as part of a 3-year ethnographic study that followed two groups of Latino/a students through their final years of high school, the college application process, and for some, the inception of their postsecondary studies. Using Latino/a critical theory as an analytical framework, this article provides insights into the distinct pathways—or caminos—taken by students in their pursuit of college, highlighting the support structures that Latino/a youth identify as necessary for increasing Latino/a participation in higher education.
Tissue-specific differential induction of duplicated fatty acid-binding protein genes by the peroxisome proliferator, clofibrate, in zebrafish (Danio rerio)
Authors: Venkatachalam Ananda B , Lall Santosh P , Denovan-Wright Eileen M , Wright Jonathan M
Published: July 2012

Background

Force, Lynch and Conery proposed the duplication-degeneration-complementation (DDC) model in which partitioning of ancestral functions (subfunctionalization) and acquisition of novel functions (neofunctionalization) were the two primary mechanisms for the retention of duplicated genes. The DDC model was tested by analyzing the transcriptional induction of the duplicated fatty acid-binding protein (fabp) genes by clofibrate in zebrafish. Clofibrate is a specific ligand of the peroxisome proliferator-activated receptor (PPAR); it activates PPAR which then binds to a peroxisome proliferator response element (PPRE) to induce the transcriptional initiation of genes primarily involved in lipid homeostasis. Zebrafish was chosen as our model organism as it has many duplicated genes owing to a whole genome duplication (WGD) event that occurred ~230-400 million years ago in the teleost fish lineage. We assayed the steady-state levels of fabp mRNA and heterogeneous nuclear RNA (hnRNA) transcripts in liver, intestine, muscle, brain and heart for four sets of duplicated fabp genes, fabp1a/fabp1b.1/fabp1b.2, fabp7a/fabp7b, fabp10a/fabp10b and fabp11a/fabp11b in zebrafish fed different concentrations of clofibrate.

Result

Electron microscopy showed an increase in the number of peroxisomes and mitochondria in liver and heart, respectively, in zebrafish fed clofibrate. Clofibrate also increased the steady-state level of acox1 mRNA and hnRNA transcripts in different tissues, a gene with a functional PPRE. These results demonstrate that zebrafish is responsive to clofibrate, unlike some other fishes. The levels of fabp mRNA and hnRNA transcripts for the four sets of duplicated fabp genes was determined by reverse transcription, quantitative polymerase chain reaction (RT-qPCR). The level of hnRNA coded by a gene is an indirect estimate of the rate of transcriptional initiation of that gene. Clofibrate increased the steady-state level of fabp mRNAs and hnRNAs for both the duplicated copies of fabp1a/fabp1b.1, and fabp7a/fabp7b, but in different tissues. Clofibrate also increased the steady-state level of fabp10a and fabp11a mRNAs and hnRNAs in liver, but not for fabp10b and fabp11b.

Conclusion

Some duplicated fabp genes have, most likely, retained PPREs, but induction by clofibrate is over-ridden by an, as yet, unknown tissue-specific mechanism(s). Regardless of the tissue-specific mechanism(s), transcriptional control of duplicated zebrafish fabp genes by clofibrate has markedly diverged since the WGD event.
Omega-3 fatty acids status in human subjects estimated using a food frequency questionnaire and plasma phospholipids levels
Authors: Garneau Véronique , Rudkowska Iwona , Paradis Ann-Marie , Godin Gaston , Julien Pierre , Pérusse Louis , Vohl Marie-Claude
Published: July 2012

Background

Intakes of omega-3 (n-3) fatty acids (FA) are associated with several health benefits. The aim of this study was to verify whether intakes of n-3 FA estimated from a food frequency questionnaire (FFQ) correlate with n-3 FA levels measured in plasma phospholipids (PL).

Methods

The study sample consisted of 200 French-Canadians men and women aged between 18 to 55 years. Dietary data were collected using a validated FFQ. Fasting blood samples were collected and the plasma PL FA profile was measured by gas chromatography.

Results

Low intakes of n-3 long-chain FA together with low percentages of n-3 long-chain FA in plasma PL were found in French-Canadian population. Daily intakes of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) were similar between men and women. Yet, alpha-linolenic acid (ALA) and total n-3 FA intakes were significantly higher in men compared to women (ALA: 2.28 g and 1.69 g, p < 0.0001, total n-3 FA: 2.57 g and 1.99 g, p < 0.0001; respectively). In plasma PL, DPA and DHA percentages were significantly different between men and women (DPA: 1.03% and 0.88%, p < 0.0001, DHA: 3.00% and 3.43%, p = 0.0005; respectively). Moreover, DHA (men: r = 0.52, p < 0.0001; women: r = 0.57, p < 0.0001) and total n-3 FA (men: r = 0.47, p < 0.0001; women: r = 0.52, p < 0.0001) intakes were positively correlated to their respective plasma PL FA levels. In women, EPA (r = 0.44, p < 0.0001) and DPA (r = 0.23, p = 0.02) intakes were also correlated respectively with EPA and DPA plasma PL FA percentages.

Conclusion

Estimated n-3 long-chain FA intake among this young and well-educated French-Canadian population is lower than the recommendations. Further, FFQ data is comparable to plasma PL results to estimate DHA and total n-3 FA status in healthy individuals as well as to evaluate the EPA and DPA status in women. Overall, this FFQ could be used as a simple, low-cost tool in future studies to rank n-3 FA status of individuals.
Validity of activity monitors in health and chronic disease: a systematic review
Authors: Van Remoortel Hans , Giavedoni Santiago , Raste Yogini , Burtin Chris , Louvaris Zafeiris , Gimeno-Santos Elena , Langer Daniel , Glendenning Alastair , Hopkinson Nicholas S , Vogiatzis Ioannis , Peterson Barry T , Wilson Frederick , Mann Bridget , Rabinovich Roberto , Puhan Milo A , Troosters Thierry ,   PROactive consortium
Published: July 2012

The assessment of physical activity in healthy populations and in those with chronic diseases is challenging. The aim of this systematic review was to identify whether available activity monitors (AM) have been appropriately validated for use in assessing physical activity in these groups. Following a systematic literature search we found 134 papers meeting the inclusion criteria; 40 conducted in a field setting (validation against doubly labelled water), 86 in a laboratory setting (validation against a metabolic cart, metabolic chamber) and 8 in a field and laboratory setting. Correlation coefficients between AM outcomes and energy expenditure (EE) by the criterion method (doubly labelled water and metabolic cart/chamber) and percentage mean differences between EE estimation from the monitor and EE measurement by the criterion method were extracted. Random-effects meta-analyses were performed to pool the results across studies where possible. Types of devices were compared using meta-regression analyses. Most validation studies had been performed in healthy adults (n = 118), with few carried out in patients with chronic diseases (n = 16). For total EE, correlation coefficients were statistically significantly lower in uniaxial compared to multisensor devices. For active EE, correlations were slightly but not significantly lower in uniaxial compared to triaxial and multisensor devices. Uniaxial devices tended to underestimate TEE (−12.07 (95%CI; -18.28 to −5.85) %) compared to triaxial (−6.85 (95%CI; -18.20 to 4.49) %, p = 0.37) and were statistically significantly less accurate than multisensor devices (−3.64 (95%CI; -8.97 to 1.70) %, p<0.001). TEE was underestimated during slow walking speeds in 69% of the lab validation studies compared to 37%, 30% and 37% of the studies during intermediate, fast walking speed and running, respectively. The high level of heterogeneity in the validation studies is only partly explained by the type of activity monitor and the activity monitor outcome. Triaxial and multisensor devices tend to be more valid monitors. Since activity monitors are less accurate at slow walking speeds and information about validated activity monitors in chronic disease populations is lacking, proper validation studies in these populations are needed prior to their inclusion in clinical trials.
Central vein stenosis in a dialysis patient: a case report
Authors: Gottmann Uwe , Sadick Maliha , Kleinhuber Kathrin , Benck Urs , Huck Kurt , Krämer Bernhard K , Birck Rainer
Published: July 2012

Introduction

Central vein stenosis is not a rare problem in patients on dialysis. Placement of a central vein catheter for dialysis access substantially increases the risk of central vein stenosis. However, even in patients without a previous history of central vein catheter placement, a stenosis can be found in up to 40% of patients.

Case presentation

We report the case of a 60-year-old male Caucasian German dialysis patient who complained of dry cough, swelling of his right arm and facial edema. Computed tomography venography showed a near-total stenosis of his brachiocephalic vein. We discuss the incidence and risk of central vein stenosis in patients on dialysis and report on a successful minimally invasive interventional treatment.

Conclusion

Central vein stenosis is not a rare problem in patients on hemodialysis and can even occur without previous placement of central venous catheters. High shunt volumes seem to increase the risk associated with central vein catheters.
Predicting qualitative phenotypes from microarray data – the Eadgene pig data set
Authors: Robert-Granié Christèle , Lê Cao Kim-Anh , SanCristobal Magali
Published: July 2012

Background

The aim of this work was to study the performances of 2 predictive statistical tools on a data set that was given to all participants of the Eadgene-SABRE Post Analyses Working Group, namely the Pig data set of Hazard et al. (2008). The data consisted of 3686 gene expressions measured on 24 animals partitioned in 2 genotypes and 2 treatments. The objective was to find biomarkers that characterized the genotypes and the treatments in the whole set of genes.

Methods

We first considered the Random Forest approach that enables the selection of predictive variables. We then compared the classical Partial Least Squares regression (PLS) with a novel approach called sparse PLS, a variant of PLS that adapts lasso penalization and allows for the selection of a subset of variables.

Results

All methods performed well on this data set. The sparse PLS outperformed the PLS in terms of prediction performance and improved the interpretability of the results.

Conclusion

We recommend the use of machine learning methods such as Random Forest and multivariate methods such as sparse PLS for prediction purposes. Both approaches are well adapted to transcriptomic data where the number of features is much greater than the number of individuals.
Mild therapeutic hypothermia alters neuron specific enolase as an outcome predictor after resuscitation: 97 prospective hypothermia patients compared to 133 historical non-hypothermia patients
Authors: Steffen Ingo G , Hasper Dietrich , Ploner Christoph J , Schefold Joerg C , Dietz Ekkehart , Martens Frank , Nee Jens , Krueger Anne , Jörres Achim , Storm Christian
Published: July 2012

Introduction

Neuron specific enolase (NSE) has been proven effective in predicting neurological outcome after cardiac arrest with a current cut off recommendation of 33 μg/l. However, most of the corresponding studies were conducted before the introduction of mild therapeutic hypothermia (MTH). Therefore we conducted a study investigating the association between NSE and neurological outcome in patients treated with MTH

Methods

In this prospective observational cohort study the data of patients after cardiac arrest receiving MTH (n = 97) were consecutively collected and compared with a retrospective non-hypothermia (NH) group (n = 133). Serum NSE was measured 72 hours after admission to ICU. Neurological outcome was classified according to the Pittsburgh cerebral performance category (CPC 1 to 5) at ICU discharge.

Results

NSE serum levels were significantly lower under MTH compared to NH in univariate analysis. However, in a linear regression model NSE was affected significantly by time to return of spontaneous circulation (ROSC) and ventricular fibrillation rhythm but not by MTH. The model for neurological outcome identified NSE, NSE*MTH (interaction) as well as time to ROSC as significant predictors. Receiver Operating Characteristic (ROC) analysis revealed a higher cutoff value for unfavourable outcome (CPC 3 to 5) with a specificity of 100% in the hypothermia group (78.9 μg/l) compared to the NH group (26.9 μg/l).

Conclusions

Recommended cutoff levels for NSE 72 hours after ROSC do not reliably predict poor neurological outcome in cardiac arrest patients treated with MTH. Prospective multicentre trials are required to re-evaluate NSE cutoff values for the prediction of neurological outcome in patients treated with MTH.
3D modeling and inversion of VLF and VLF-R electromagnetic data
Authors: Kaikkonen P. , Sharma S. P. , Mittal S.
Published: July 2012

Three-dimensional linearized nonlinear electromagnetic inversion is developed for revealing the subsurface conductivity structure using isolated very low frequency (VLF) and VLF-resistivity anomalies due to conductors that may be arbitrarily directed towards the measuring profiles and the VLF transmitter. We described the 3D model using a set of variables in terms of geometric and physical parameters. These model parameters were then optimized (parametric inversion) to obtain their best estimates to fit the observations. Two VLF transmitters, i.e., the [Formula: see text], [Formula: see text] (“E”) and the [Formula: see text], [Formula: see text] (“H”) polarizations, respectively, can be considered jointly in inversion. After inverting several noise-free and noisy synthetic data, the results revealed that the estimated model parameters and the functionality of the approach were very good and reliable. The inversion procedure also worked well for the field data. The reliability and validity of the results after the field data inversion have been checked using data from a shear zone associated with uranium mineralization.
Time-lapse joint inversion of crosswell DC resistivity and seismic data: A numerical investigation
Authors: Karaoulis M. , Revil A. , Zhang J. , Werkema D. D.
Published: July 2012

Time-lapse joint inversion of geophysical data is required to image the evolution of oil reservoirs during production and enhanced oil recovery, [Formula: see text] sequestration, geothermal fields during production, and to monitor the evolution of contaminant plumes. Joint inversion schemes reduce space-related artifacts in filtering out noise that is spatially uncorrelated, and time-lapse inversion algorithms reduce time-related artifacts in filtering out noise that is uncorrelated over time. There are several approaches that are possible to perform the joint inverse problem. In this work, we investigate the structural crossgradient (SCG) joint inversion approach and the crosspetrophysical (CP) approach, which are appropriate for time-lapse problems. In the first case, the inversion scheme looks for models with structural similarities. In the second case, we use a direct relationship between the geophysical parameters. Time-lapse inversion is performed with an actively time-constrained (ATC) approach. In this approach, the subsurface is defined as a space-time model. All the snapshots are inverted together assuming a regularization of the sequence of snapshots over time. First, we showed the advantage of combining the SCG or CP inversion approaches and the ATC inversion by using a synthetic problem corresponding to crosshole seismic and DC-resistivity data and piecewise constant resistivity and seismic velocity distributions. We also showed that the combined SCG/ATC approach reduces the presence of artifacts with respect to individual inversion of the resistivity and seismic data sets, as well as with respect to the joint inversion of both data sets at each time step. We also performed a synthetic study using a secondary oil recovery problem. The combined CP/ATC approach was successful in retrieving the position of the oil/water encroachment front.
IUPAC/CITAC Guide: Investigating out-of-specification test results of
chemical composition based on metrological concepts (IUPAC Technical
Report)
Authors: Kuselman Ilya , Pennecchi Francesca , Burns Cathy , Fajgelj Aleš , de Zorzi Paolo
Published: July 2012

A metrological background for investigating out-of-specification (OOS) test
results of chemical composition is discussed. When an OOS test result is
identified, it is important to determine its root causes and to avoid
reoccurrence of such results. An investigation of the causes based on
metrological concepts is proposed. It includes assessment of validation data of
the measurement process and its metrological traceability chains, evaluation of
measurement uncertainty, and related producer’s and consumer’s risks. This
approach allows distinguishing between OOS test results that indicate an actual
change in chemical composition of an analyzed object, and OOS test results that
are metrologically related with a certain confidence probability, i.e., caused
by measurement problems, while the analyzed object still meets the specification
requirements at the time of testing. Practical examples illustrating
applications of the described approach in environ-mental and food analysis, as
well in drug analysis and stability study of drug products, are described.
Acceptance limits, warning and action lines for the test results, and
corresponding producer’s and consumer’s risks are discussed.