How do people with chronic low back pain perceive specific and general exercise? A mixed methods survey.

PURPOSE: Exercise prescriptions for chronic low back pain (CLBP) often utilize reductionistic, trunk-focused exercise aimed at addressing proposed pain mechanisms. It is unknown if the use of these trunk-focused exercises imply beliefs to people with CLBP about the rationale for their use (e.g., etiology), even without concurrent biomedical narratives. This study aimed to explore people's perceptions of specific and general exercise without an accompanying narrative when experiencing CLBP. METHODS: An anonymous online survey was distributed. Mixed methods were utilized for analysis. Six-point Likert scales categorized people's beliefs about individual exercises. Open-ended questions were used to gather further beliefs which were then coded into themes. RESULTS: People with CLBP perceived specific exercise as more beneficial than general exercise. Eight themes and five subthemes were defined. A high volume of positive beliefs were centered around strengthening the low back and abdominal musculature, emphasizing the importance of correct technique. Negative beliefs were held against spinal flexion and external load. Both positive and negative beliefs were underpinned by spinal/pelvic stability being important as well as certain exercises being achievable or not. CONCLUSION: This study demonstrated that people with CLBP consider specific exercises to be more beneficial than general exercises for CLBP. Specific exercises irrespective of an accompanying narrative can imply meaning about the intent of an exercise. Understanding this requires practitioners to be mindful when prescribing and communicating exercise.

First Spectroscopy of the Near Drip-line Nucleus

One of the most exotic light neutron-rich nuclei currently accessible for experimental study is ^{40}Mg, which lies at the intersection of the nucleon magic number N=28 and the neutron drip line. Low-lying excited states of ^{40}Mg have been studied for the first time following a one-proton removal reaction from ^{41}Al, performed at the Radioactive Isotope Beam Factory of RIKEN Nishina Center with the DALI2 γ-ray array and the ZeroDegree spectrometer. Two γ-ray transitions were observed, suggesting an excitation spectrum that shows unexpected properties as compared to both the systematics along the Z=12, N≥20 Mg isotopes and available state-of-the-art theoretical model predictions. A possible explanation for the observed structure involves weak-binding effects in the low-lying excitation spectrum.

Species turnover (ß-diversity) in ectomycorrhizal fungi linked to NH4+ uptake capacity.

Ectomycorrhizal (EcM) fungal communities may be shaped by both deterministic and stochastic processes, potentially influencing ecosystem development and function. We evaluated community assembly processes for EcM fungi of Pseudotsuga menziesii among 12 sites up to 400 km apart in southwest British Columbia (Canada) by investigating species turnover (ß-diversity) in relation to soil nitrogen (N) availability and physical distance. We then examined functional traits for an N-related niche by quantifying net fluxes of NH4+, NO3- and protons on excised root tips from three contrasting sites using a microelectrode ion flux measurement system. EcM fungal communities were well aligned with soil N availability and pH, with no effect of site proximity (distance-decay curve) on species assemblages. Species turnover was significant (ß(1/2) = 1.48) along soil N gradients, with many more Tomentella species on high N than low N soils, in contrast to Cortinarius species. Ammonium uptake was greatest in the spring on the medium and rich sites and averaged over 190 nmol/m(2)/s for Tomentella species. The lowest uptake rates of NH4+ were by nonmycorrhizal roots of axenically grown seedlings (10 nmol/m(2)/s), followed by Cortinarius species (60 nmol/m(2)/s). EcM roots from all sites displayed only marginal uptake of nitrate (8.3 nmol/m(2)/s). These results suggest NH4+ uptake capacity is an important functional trait influencing the assembly of EcM fungal communities. The diversity of EcM fungal species across the region arguably provides critical belowground adaptations to organic and inorganic N supply that are integral to temperate rainforest ecology.

A prospective study of patient reported outcomes in pancreatic and peri-ampullary malignancy.

BACKGROUND: The purpose of the present study was to describe the impact of treatment of pancreatic and peri-ampullary malignancy on patient reported outcomes (PRO). However, limited data are available describing the impact of curative or palliative therapy on pancreatic/peri-ampullary malignancy and quality of life. METHODS: Patients selected for pancreaticoduodenectomy (PD) completed the European Organisation for Research and Treatment of Cancer QLQ-C30 questionnaire pre-surgery and 6 weeks, 3, 6, 12, 18, and 24 months postoperatively. Patients selected for palliative treatments completed the same questionnaire before treatment and monthly thereafter. Mean scores and 95 % confidence intervals (CI) were calculated for functional scales. Symptom scales and single items were categorized as either minimal or severe, and they were reported as proportions of patients experiencing severe symptoms with 95 % CI. RESULTS: A total of 100 patients (53 planned PD, 47 palliative) were enrolled. Of the 53 patients planned for surgery, 12 had tumors that were unresectable and 41 underwent pancreatoduodenectomy (PD). Seven patients were excluded because of benign histology or concurrent malignancy. Baseline questionnaire compliance was 70 %. For those undergoing PD, there were 53 complications, 7 deaths at 1 year, and 14 deaths at 2 years. Post-surgery most functions and symptoms deteriorated. Recovery in global health and most symptoms occurred by 3 months, and functional scales recovered by 6 months. Recovery of PRO was maintained in the survivors at 2 years. Palliative patients had poorer function and more symptoms at baseline; however, poor follow-up questionnaire compliance prevented further analysis of this group. CONCLUSIONS: Pancreaticoduodenectomy has a short-term negative impact on PRO that recovers within 6 months and is maintained at 2 years in survivors. Further work evaluating palliative and curative treatment in larger patient groups with disease-specific questionnaires is necessary.

The prognostic and predictive value of serum CA19.9 in pancreatic cancer.

BACKGROUND: Current staging methods for pancreatic cancer (PC) are inadequate, and biomarkers to aid clinical decision making are lacking. Despite the availability of the serum marker carbohydrate antigen 19.9 (CA19.9) for over two decades, its precise role in the management of PC is yet to be defined, and as a consequence, it is not widely used. METHODS: We assessed the relationship between perioperative serum CA19.9 levels, survival and adjuvant chemotherapeutic responsiveness in a cohort of 260 patients who underwent operative resection for PC. RESULTS: By specifically assessing the subgroup of patients with detectable CA19.9, we identified potential utility at key clinical decision points. Low postoperative CA19.9 at 3 months (median survival 25.6 vs 14.8 months, P=0.0052) and before adjuvant chemotherapy were independent prognostic factors. Patients with postoperative CA 19.9 levels>90 U/ml did not benefit from adjuvant chemotherapy (P=0.7194) compared with those with a CA19.9 of ≤90 U/ml (median 26.0 vs 16.7 months, P=0.0108). Normalization of CA19.9 within 6 months of resection was also an independent favorable prognostic factor (median 29.9 vs 14.8 months, P=0.0004) and normal perioperative CA19.9 levels identified a good prognostic group, which was associated with a 5-year survival of 42%. CONCLUSIONS: Perioperative serum CA19.9 measurements are informative in patients with detectable CA19.9 (defined by serum levels of >5 U/ml) and have potential clinical utility in predicting outcome and response to adjuvant chemotherapy. Future clinical trials should prioritize incorporation of CA19.9 measurement at key decision points to prospectively validate these findings and facilitate implementation.

The bio-tribological characteristics of synthetic tissue grafts.

The use of synthetic connective tissue grafts became popular in the mid-1980s, particularly for anterior cruciate ligament reconstruction; however, this trend was soon changed given the high failure rate due to abrasive wear. More than 20 years later, a vast range of grafts are available to the orthopaedic surgeon for augmenting connective tissue following rupture or tissue loss. While the biomechanical properties of these synthetic grafts become ever closer to the natural tissue, there have been no reports of their bio-tribological (i.e. bio-friction) characteristics. In this study, the bio-tribological performance of three clinically available synthetic tissue grafts, and natural tendon, was investigated. It was established that the natural tissue exhibits fluid-film lubrication characteristics and hence is highly efficient when sliding against opposing tissues. Conversely, all the synthetic tissues demonstrated boundary or mixed lubrication regimes, resulting in surface-surface contact, which will subsequently cause third body wear. The tribological performance of the synthetic tissue, however, appeared to be dependent on the macroscopic structure. This study indicates that there is a need for synthetic tissue designs to have improved frictional characteristics or to use a scaffold structure that encourages tissue in-growth. Such a development would optimize the bio-tribological properties of the synthetic tissue and thereby maximize longevity.

The potential effects of floor impact surfaces on infant head injury outcome during a short fall.

When considering cases of infant head injury as a result of a short fall, investigators often have to base their opinions on the potential severity of a head injury on a scene description and/or photographic evidence of the potential impact surfaces. While variation in the attenuation properties of typical domestic surfaces and underlying support structures have been reported in the literature, this study investigates whether there is a need to consider the nature and composition of specific potential impact floor surfaces/sites, within a scene, prior to providing an opinion about the likely head impact injury outcome. An instrumented headform was impacted within a suspected crime scene to determine whether different potential impact sites posed different risks of producing head injury. The impact acceleration-time waveform, for the headform, was shown to vary considerably across the floor. By applying recognized head impact injury risk measures (peak g and head injury criterion), it was illustrated that the risk of an infant sustaining a significant head injury could vary considerably, depending upon the exact point of impact with the floor. This study highlights the potential for variation in impact force across a scene and illustrates the need to consider surface composition at specific sites across the entire potential impact area, since the risk of head injury can vary significantly. Caution should therefore be exercised when expressing opinions based solely on verbal, written or photographic evidence of head impact surfaces, without due consideration of the specific area onto which a head might have impacted.

A finite element-guided mathematical surrogate modeling approach for assessing occupant injury trends across variations in simplified vehicular impact conditions.

A finite element (FE)-guided mathematical surrogate modeling methodology is presented for evaluating relative injury trends across varied vehicular impact conditions. The prevalence of crash-induced injuries necessitates the quantification of the human body's response to impacts. FE modeling is often used for crash analyses but requires time and computational cost. However, surrogate modeling can predict injury trends between the FE data, requiring fewer FE simulations to evaluate the complete testing range. To determine the viability of this methodology for injury assessment, crash-induced occupant head injury criterion (HIC15) trends were predicted from Kriging models across varied impact velocities (10-45 mph; 16.1-72.4 km/h), locations (near side, far side, front, and rear), and angles (-45 to 45°) and compared to previously published data. These response trends were analyzed to locate high-risk target regions. Impact velocity and location were the most influential factors, with HIC15 increasing alongside the velocity and proximity to the driver. The impact angle was dependent on the location and was minimally influential, often producing greater HIC15 under oblique angles. These model-based head injury trends were consistent with previously published data, demonstrating great promise for the proposed methodology, which provides effective and efficient quantification of human response across a wide variety of car crash scenarios, simultaneously. This study presents a finite element-guided mathematical surrogate modeling methodology to evaluate occupant injury response trends for a wide range of impact velocities (10-45 mph), locations, and angles (-45 to 45°). Head injury response trends were predicted and compared to previously published data to assess the efficacy of the methodology for assessing occupant response to variations in impact conditions. Velocity and location were the most influential factors on the head injury response, with the risk increasing alongside greater impact velocity and locational proximity to the driver. Additionally, the angle of impact variable was dependent on the location and, thus, had minimal independent influence on the head injury risk.

Band narrowing and Mott localization in iron oxychalcogenides La2O2Fe2O(Se,S)2.

Bad metal properties have motivated a description of the parent iron pnictides as correlated metals on the verge of Mott localization. What has been unclear is whether interactions can push these and related compounds to the Mott-insulating side of the phase diagram. Here we consider the iron oxychalcogenides La2O2Fe2O(Se,S)2, which contain an Fe square lattice with an expanded unit cell. We show theoretically that they contain enhanced correlation effects through band narrowing compared to LaOFeAs, and we provide experimental evidence that they are Mott insulators with moderate charge gaps. We also discuss the magnetic properties in terms of a Heisenberg model with frustrating J1-J2-J2' exchange interactions on a "doubled" checkerboard lattice.

Clinical risk score can be used to select patients for staging laparoscopy and laparoscopic ultrasound for colorectal liver metastases.

BACKGROUND: Despite advanced staging investigations, some patients with potentially resectable colorectal liver metastases (CLM) are unresectable at laparotomy. Staging laparoscopy and laparoscopic ultrasound (Lap + LUS) detects a subset of these unresectable patients before a major laparotomy. Clinical risk scoring may be helpful to identify this subgroup. The goal of our study was to evaluate the role of Lap + LUS and to assess the value of the Memorial Sloan Kettering clinical risk score (CRS) in identifying this subset. METHODS: Patients were identified from the regional multidisciplinary team (MDT) cancer database and operative records for a 5-year period. All patients whose tumors were deemed resectable proceeded to Lap + LUS. LUS findings were recorded and any change in MDT plan was noted. LUS findings were compared with resectability at open surgery. The CRS (Memorial Sloan-Kettering) based on five factors was calculated. RESULTS: A total of 79 patients were identified. In 15 of 74 patients, LUS prevented an unnecessary laparotomy by predicting the benign nature of lesions or demonstrating unresectability. The CRS ranged from 0 to 4. Lap + LUS prevented an operation in only 7% of patients with a CRS of < or =2. However in patients with a CRS > 2, Lap + LUS prevented an operation in 24% of patients. CONCLUSIONS: LUS prevented an unnecessary laparotomy in 20% of patients. This may reduce inpatient stay, morbidity, and mortality, allowing some patients to proceed to palliative treatments earlier. The benefit of Lap + LUS is limited in patients with a CRS of < or =2. It is worth considering selective use of Lap + LUS for the staging of CLM.

Simultaneous identification of bacterial virulence genes by negative selection.

An insertional mutagenesis system that uses transposons carrying unique DNA sequence tags was developed for the isolation of bacterial virulence genes. The tags from a mixed population of bacterial mutants representing the inoculum and bacteria recovered from infected hosts were detected by amplification, radiolabeling, and hybridization analysis. When applied to a murine model of typhoid fever caused by Salmonella typhimurium, mutants with attenuated virulence were revealed by use of tags that were present in the inoculum but not in bacteria recovered from infected mice. This approach resulted in the identification of new virulence genes, some of which are related to, but functionally distinct from, the inv/spa family of S. typhimurium.

Oxygen delivery to the brain before and after birth.

We studied the relationship between cerebral oxygen consumption and cerebral oxygen delivery (cerebral blood flow x arterial oxygen content) in fetal, newborn, and adult sheep, Relative to the amount of oxygen consumed, cerebral oxygen delivery in the fetus exceeds that in the lamb and adult by 70 percent. This may represent a protective advantage for the fetus or simply a necessary adaptation to the low arterial oxygen pressure in the intrauterine environment.

Medical engineering at Cardiff University. Part 1: Undergraduate programmes of study.

Cardiff University has offered a medical engineering undergraduate programme since 2001 and hence delivers one of the longest-running and most established medical engineering programmes within the UK. It currently offers BEng (Hons) and MEng (Hons) programmes that are both accredited by the Institution of Mechanical Engineers and include the option to undertake a year in industrial employment. The admissions policy ensures that the intake consists of a diverse range of students and is typically very successful in attracting female students. The programmes consist of six key academic threads which ensure that the content is both relevant and continuous, with all threads tailored to provide a patient-focused learning environment. Students initially learn core and fundamental principles in years 1 and 2, supported by a range of laboratories and practical experimentation. The latter years then encourage the students to corroborate and apply this knowledge, including involvement in a range of project-based learning exercises. The programme is delivered by a core of experienced academic medical engineers, with support from other engineering colleagues, as well as colleagues from the School of Biosciences, the School of Medicine, and the National Health Service. Thus, the programme delivers a wide range of modules which guarantee that graduating students have a thorough understanding of all possible career options. These two factors are significant in making it possible for students to follow their chosen career path upon graduation.

Medical engineering at Cardiff University. Part 2: Postgraduate programmes of study.

The Medical Engineering team within the School of Engineering, Cardiff University, delivers two postgraduate programmes of study. Established over 10 years ago, the part-time MSc programmes in Orthopaedic Engineering and Clinical Engineering offer the opportunity of further study while remaining within full-time employment. Both programmes deliver 120 taught credits over two academic years via a series of residential weekends, with successful completion enabling the student to undertake and then defend a 60-credit research dissertation. Fulfilling a specific role on the career pathway for both student cohorts, the strength of each programme is indicated by the consistent number of applicants.

An in-vitro animal bone model study to predict spiral fracture strength of long bones in the young infant.

INTRODUCTION: The risk of fracture from a non-accidental injury is highest in the infant age group. A spiral fracture of the long bone can occur equally from accidental and non-accidental causes, meaning the clinical judgement of non-accidental injury in an infant is particularly challenging. This study aimed to assist in differentiating accidental, from non-accidental, injury in infants, by establishing whether correlation exists between geometry and torsional strength in the immature long bone. METHODS: Immature porcine third and fourth metacarpals (n = 21) were imaged with a dual energy x-ray absorptiometry (DEXA) scanner to measure their linear bone mineral content (BMCL), bone mineral density (BMD) and section modulus (Z). The specimens were then subjected to a torque of one degree per second until failure. The failure strength and the three DEXA measures were analyzed for a correlation. RESULTS: The mean failure strength of 11 successful tests was 13.71Nm (+/-SD 2.42Nm), with correlation to BMCL, BMD and Z described by r2 = 0.81, 0.283 and 0.75 respectively. CONCLUSION: This study is a novel attempt at estimating torsional strength of long bones in a specific paediatric age group using a size-matched animal bone model. It found a strong correlation between bone and fracture strength parameters over the BMCL range of 0.59-0.77 g/cm.

Intensity-dependent effects of aerobic training on pressure pain threshold in overweight men: A randomized trial.

PURPOSE: To investigate the chronic and acute effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on pressure pain thresholds (PPT) in overweight men. METHODS: Twenty-eight participants performed stationary cycling exercise three times per week for 6 weeks. Participants were randomly allocated to HIIT (10 × 1-min intervals at 90% peak heart rate) or MICT (30 min at 65-75% peak heart rate). PPTs were assessed over the rectus femoris, tibialis anterior and upper trapezius before and after the 6-week training programme (chronic effect) as well as before and after the first, middle and final exercise sessions (acute effect). RESULTS: For chronic exercise, PPTs increased more after MICT compared to HIIT over the rectus femoris (p = 0.009, effect size r = 0.54) and tibialis anterior (p = 0.012, r = 0.54), but not the trapezius (p = 0.399, r = 0.29). The effect of acute exercise on PPT was more varied and ranged from moderate hypoalgesia to moderate hyperalgesia. Overall, however, there was no consistent change in PPT after acute exercise for HIIT or MICT (p ≥ 0.231, r ≥ -0.31 and ≤0.31). CONCLUSION: Six weeks of MICT cycling (chronic exercise) increased PPT for the lower body, but not upper body, in overweight men, whereas HIIT did not provide any hypoalgesic effect for chronic exercise. The acute effect of exercise on PPT was highly variable and negligible overall. SIGNIFICANCE: This study shows that aerobic training increases pressure pain threshold in pain-free adults. This effect was observed only for MICT over-exercised muscles, implying intensity- and site-specific effects of exercise training on pain threshold.

Umbilical uptake of amino acids in the unstressed fetal lamb.

The whole blood concentrations of 22 amino acids were measured in a chronic, unstressed fetal lamb preparations. Samples were taken daily from the umbilical artery, umbilical vein, and maternal artery over the latter quarter of gestation. 73 sets of samples (from the umbilical artery and vein and the maternal artery) from 13 animals were analyzed for amino acid levels. Oxygen contents were determined simultaneously in 48 sets (umbilical artery and vein) to relate fetal oxygen consumption to amino acid uptake via the umbilical circulation. The results indicate that there is no umbilical uptake of the acidic amino acids, glutamate and aspartate; there is, in fact, a net flux of glutamate out of the fetus into the placenta. As both of these amino acids are major constituents of body proteins, the data indicate that they are formed within the fetus. The umbilical uptake of some neutral and basic amino acids (e.g., valine, leucine, isoleucine, arginine, phenylalanine, and tyrosine) is in considerable excess of estimated growth requirements, suggesting that some amino acids undergo extensive transamination and oxidative degradation in the fetus. Finally, the net uptake of nitrogen, carbon, and calories by the growing ovine fetus in the form of amino acids, glucose, and lactate is compared to estimated requirements as determined in previous studies.

Genetic diversity: frameshift mechanisms alter coding of a gene (Epstein-Barr virus LF3 gene) that contains multiple 102-base-pair direct sequence repeats.

Frameshift mutations provide recognized mechanisms for changing the coding potential of an organism. Here, multiple frameshifts are identified in repetitive sequences within an Epstein-Barr virus unspliced early gene, LF3, which is associated with the viral replicative cycle and also transcriptionally expressed in many virally associated tumors. On the DNA strand encoding LF3, there are three open reading frames, only one of which contains an initiation codon. Most (>95%) of the gene consists of numerous (>20, varying with cell source) GC-rich copies of a 102-bp direct repeat (called IR 4) flanked by small unique sequences. LF3 may express a protein if its initiation and termination codons reside in the same reading frame, but this is not always the case. Frameshifting events, occurring in short runs of pyrimidines (mainly C residues) in the repeats, give rise to mutations which may provide a mechanism for escape of an LF3 function from host surveillance. Sequence studies link these frameshifts to DNA replication errors. Notably, the number of sites in LF3 at which such mutations can occur permits a very large amount of diversity in this gene. Our data also suggest a second degeneracy mechanism within the protein itself, which influences its stability and may reflect a host defense mechanism. LF3 thus provides a potentially important model for studying the quest for supremacy between a virus and its host.

Rib fractures in infancy: establishing the mechanisms of cause from the injuries--a literature review.

In the absence of a history of a significant accidental event, the most likely diagnosis in an infant with rib fractures is non-accidental injury. Medical opinion is essential when deciding if child abuse has taken place or not and this requires a consideration of whether a proposed causal explanation fits with the observed injuries. To assist in the interpretation of injuries and inform medical practitioners, it is essential to develop a clear understanding of their biomechanical mechanism of causation. The types and 'likely' mechanisms of rib fracture are well-documented, however, what forces, deflections and loading rates are required to produce particular fractures are relatively unknown. This paper presents a review of the literature, from a biomechanical engineering perspective, to assess information regarding the various types of rib fracture and their likely mechanisms, paying particular attention to the likely forces, deflections and loading rates involved. The biomechanical parameters, applied during 'two finger' infant cardiopulmonary resuscitation (CPR), are identified and discussed, and are currently believed to be below the limit at which rib fracture may occur. However, a new 'two thumb' CPR technique is identified which involves a holding/gripping mechanism of the infant thorax, similar to that which is believed to occur in inflicted injury scenarios, such as shaking. The two thumb method may provide a greater magnitude of force and deflection, a greater rate of loading and may perhaps pose a greater risk of fracture, compared with the 'two finger' supine, anterior-posterior chest compression approach. It is proposed to introduce a force/deflection boundary condition into mechanical and computer/numeric infant models. Subject to the future inclusion of loading rate/response data, a three-dimensional (force/deflection/loading rate) boundary condition will be used to provide a minimum injury threshold for potentially injurious scenarios. A number of further studies are suggested, since this paper is intended to provide a first step to developing a more sophisticated understanding of the causes of infant rib fracture. Areas of further study include specific rib fracture mechanisms, as well as the effects of age dependent characteristics, positioning and area of force application. Such additional information would allow the proposed initial boundary condition to be further refined to provide an indication of the likelihood, type and number of fractures that might be expected.

Choosing entrustable professional activities for neonatology: a Delphi study.

OBJECTIVE: To assess candidate neonatology EPAs taken from separate but overlapping sets from two organizations. STUDY DESIGN: Using a Delphi process, we asked that neonatology fellowship directors (1) assess importance and scope of 19 candidate EPAs, and (2) propose additional EPAs if necessary. In round 2, we sought clarification of first round responses and evaluated proposed additional EPAs. RESULTS: Twenty program directors participated. In round 1, all EPAs were scored as important, but four were overly broad. In round 2, respondents rejected proposed subdivisions of one overly broad EPA, retaining it as originally proposed. Specification of entrustment criteria improved the scope of the three other broad EPAs. However, after specification, they were re-rated as insufficiently important and therefore rejected. Neither newly proposed EPA from round 1 was rated as sufficiently important. CONCLUSION: The Delphi process yielded 13 EPAs with which to assess capability to practice clinical neonatology.