bluuebunny/crossref_metadata_2025 huggingface dataset:
On utilizing uncertainty information in template‐based EEG‐fMRI ballistocardiogram artifact removal
Authors: Schulz Marc‐Andre , Regenbogen Christina , Moessnang Carolin , Neuner Irene , Finkelmeyer Andreas , Habel Ute , Kellermann Thilo
Published: February 2015

The correction of ballistocardiogram artifacts in simultaneous EEG‐fMRI often yields unsatisfactory results. To improve the signal‐to‐noise ratio (SNR) of results, we inferred EEG signal uncertainty from postcorrection artifact residuals and computed the uncertainty‐weighted mean of ERPs. Using an uncertainty‐weighted mean significantly and consistently reduced both inter‐ and intrasubject SEM in the analysis of auditory evoked responses (AER, indicated by the N1‐P2 complex) and in the effects of an auditory oddball paradigm (N1‐P3 complex, standard‐deviant difference). SNR increased by 3% on average for the AER amplitude (intrasubject) and 17% on average for the auditory oddball ERP (intersubject). This demonstrates that weighting by uncertainty complements existing artifact correction algorithms to increase SNR in ERPs. More specifically, it is an efficient method to utilize seemingly corrupt (difficult‐to‐correct) EEG data that might otherwise be discarded.
Striving for a life worth living: stroke survivors' experiences of home rehabilitation
Authors: Taule Tina , Strand Liv Inger , Skouen Jan Sture , Råheim Målfrid
Published: February 2015

Background

For mild‐to‐moderate stroke survivors, early supported discharge from hospital, followed by home rehabilitation is preferred over conventional care. How this mode of service contributes to recovery from stroke survivors' perspective needs further investigation.

Aim

The aim of this study was to explore mild‐to‐moderate stroke survivors' experiences with home rehabilitation after early supported discharge from hospital.

Methods

A qualitative interpretive interview design was used in the context of a randomised controlled trial. A purposive sample of eight participants (45–80 years) was followed by an ambulant team, and a specific healthcare team provided home rehabilitation. Data were analysed using interpretive description, systematic text condensation and coping theory.

Findings

A crucial determinant for the participants' hopes for a life worth living was the mutual confidence expressed in encounters with healthcare professionals and the participants' ability to make sense of their now‐altered body. The professional caretakers' communication qualities and their ability to attend to individual needs were important. Help in processing the emotional reactions caused by a changed body and in socialising was requested by participants. Professional caretakers providing home rehabilitation should strive for a more flexible‐ and individually tailored service and should seek increased cooperation among stakeholders.

Conclusion

The focus on therapeutic communicative qualities, bodily changes, emotional processes, social concerns and long‐term follow‐up should be increased in order to achieve a more beneficial experience for stroke survivors.
Caring behaviour perceptions from nurses of their first‐line nurse managers
Authors: Peng Xiao , Liu Yilan , Zeng Qingsong
Published: February 2015

Background

Nursing is acknowledged as being the art and science of caring. According to the theory of nursing as caring, all persons are caring but not every behaviour of a person is caring. Caring behaviours in the relationship between first‐line nurse managers and Registered Nurses have been studied to a lesser extent than those that exist between patients and nurses. Caring behaviour of first‐line nurse managers from the perspective of Registered Nurses is as of yet unknown. Identifying caring behaviours may be useful as a reference for first‐line nurse managers caring for nurses in a way that nurses prefer.

Aims

To explore first‐line nurse managers' caring behaviours from the perspective of Registered Nurses in mainland China.

Design

Qualitative study, using descriptive phenomenological approach.

Methods

Fifteen Registered Nurses recruited by purposive sampling method took part in in‐depth interviews. Data were analysed according to Colaizzi's technique.

Results

Three themes of first‐line nurse managers' caring behaviours emerged: promoting professional growth, exhibiting democratic leadership and supporting work‐life balance.

Conclusions

A better understanding of the first‐line nurse managers' caring behaviours is recognised. The three kinds of behaviours have significant meaning to nurse managers. Future research is needed to describe what first‐line nurse managers can do to promote nurses' professional growth, increase the influence of democratic leadership, as well as support their work‐life balance.
Family caregiving during 1‐year follow‐up in individuals with advanced chronic organ failure
Authors: Nakken Nienke , Spruit Martijn A. , Wouters Emiel F.M. , Schols Jos M.G.A. , Janssen Daisy J.A.
Published: February 2015

Background

Family caregivers already have a paramount role in daily care for patients with chronic obstructive pulmonary disease (COPD), chronic heart failure (CHF), or chronic renal failure (CRF). To date, it remains unknown whether and to what extent the experience of caregiving changes over time.

Objectives

To examine changes in caregiver burden and positive aspects of caregiving during 1‐year follow‐up in patients with advanced COPD, CHF or CRF and to study determinants of changes in caregiver burden and positive aspects of caregiving.

Methods

In this longitudinal observational study, patients and their family caregivers who had complete data at baseline and 12 months (n = 104) and family caregivers of patients who died during 1‐year follow‐up (n = 15) were included. Caregiver burden and positive aspects of caregiving were assessed using the Family Appraisal of Caregiving Questionnaire for Palliative Care (FACQ‐PC). Domain scores were classified into three categories, and baseline characteristics were compared between these categories.

Results

A majority of the individuals showed 1‐year changes in FACQ‐PC domain scores. These individual changes were not explained by demographic or clinical patient characteristics at baseline or changes in patient characteristics during 1‐year follow‐up. Furthermore, caregiver burden was higher for caregivers of patients who died during 1‐year follow‐up compared to caregivers whose relative completed 1‐year follow‐up.

Conclusion

This study showed that caregiver burden and positive aspects of caregiving can change over time, and these changes are highly individual. Therefore, healthcare providers should regularly pay attention to family caregivers, regardless the patients' characteristics.
Dietary Restrictions in Dialysis Patients: Is There Anything Left to Eat?
Authors: Kalantar‐Zadeh Kamyar , Tortorici Amanda R. , Chen Joline L. T. , Kamgar Mohammad , Lau Wei‐Ling , Moradi Hamid , Rhee Connie M. , Streja Elani , Kovesdy Csaba P.
Published: February 2015

A significant number of dietary restrictions are imposed traditionally and uniformly on maintenance dialysis patients, whereas there is very little data to support their benefits. Recent studies indicate that dietary restrictions of phosphorus may lead to worse survival and poorer nutritional status. Restricting dietary potassium may deprive dialysis patients of heart‐healthy diets and lead to intake of more atherogenic diets. There is little data about the survival benefits of dietary sodium restriction, and limiting fluid intake may inherently lead to lower protein and calorie consumption, when in fact dialysis patients often need higher protein intake to prevent and correct protein‐energy wasting. Restricting dietary carbohydrates in diabetic dialysis patients may not be beneficial in those with burnt‐out diabetes. Dietary fat including omega‐3 fatty acids may be important caloric sources and should not be restricted. Data to justify other dietary restrictions related to calcium, vitamins, and trace elements are scarce and often contradictory. The restriction of eating during hemodialysis treatment is likely another incorrect practice that may worsen hemodialysis induced hypoglycemia and nutritional derangements. We suggest careful relaxation of most dietary restrictions and adoption of a more balanced and individualized approach, thereby easing some of these overzealous restrictions that have not been proven to offer major advantages to patients and their outcomes and which may in fact worsen patients' quality of life and satisfaction. This manuscript critically reviews the current paradigms and practices of recommended dietary regimens in dialysis patients including those related to dietary protein, carbohydrate, fat, phosphorus, potassium, sodium, and calcium, and discusses the feasibility and implications of adherence to ardent dietary restrictions and future research.
Sex differences in elite swimming with advanced age are less than marathon running
Authors: Senefeld J. , Joyner M. J. , Stevens A. , Hunter S. K.
Published: February 2015

The sex difference in marathon performance increases with finishing place and age of the runner but whether this occurs among swimmers is unknown. The purpose was to compare sex differences in swimming velocity across world record place (1st–10th), age group (25–89 years), and event distance. We also compared sex differences between freestyle swimming and marathon running. The world's top 10 swimming times of both sexes for World Championship freestyle stroke, backstroke, breaststroke, and butterfly events and the world's top 10 marathon times in 5‐year age groups were obtained. Men were faster than women for freestyle (12.4 ± 4.2%), backstroke (12.8 ± 3.0%), and breaststroke (14.5 ± 3.2%), with the greatest sex differences for butterfly (16.7 ± 5.5%). The sex difference in swimming velocity increased across world record place for freestyle (P < 0.001), breaststroke, and butterfly for all age groups and distances (P < 0.001) because of a greater relative drop‐off between first and 10th place for women. The sex difference in marathon running increased with the world record place and the sex difference for marathon running was greater than for swimming (P < 0.001). The sex difference in swimming increased with world record place and age, but was less than for marathon running. Collectively, these results suggest more depth in women's swimming than marathon running.
Barriers associated with frequency of leisure‐time physical activity among Brazilian adults of different income strata
Authors: Silva K. S. , Del Duca G. F. , Garcia L. M. T. , da Silva J. A. , Bertuol C. , de Oliveira E. S. A. , de Barros M. V. G. , Nahas M. V.
Published: February 2015

This study aimed to estimate the prevalence of the main perceived barriers to leisure‐time physical activity (LTPA) and their associations with the frequency of LTPA in a representative sample of industrial workers from Brazil (n = 47 477), according to their income strata (low income: ≤$US280, middle income: $US281–$US1400, and high income: ≥$US1401). Data were collected between 2006 and 2008 via questionnaires about the main perceived barrier to LTPA and the frequency of LTPA. Multinomial logistic regression was performed to evaluate differences among groups. There was a lower prevalence of regular practice of LTPA in the low‐ (15.8%) and middle‐income strata (18.2%) than among the individuals of the high‐income stratum (27.6%). A large proportion of workers who regularly participated in LTPA reported no barriers (low: 43.1%; middle: 46.8%; high: 51.6%). Additional obligations and fatigue were the two most common perceived barriers in all family income strata among participants who engaged in different frequencies of LTPA. The odds for all perceived barriers showed a positive trend related to frequency of LTPA (from regular to no LTPA), with higher values according to income. In summary, the ordering of the main perceived barriers to LTPA differed according to workers' income stratum and frequency of engaging in LTPA.
The diagnostic accuracy of exercise electrocardiography in asymptomatic recreational and competitive athletes
Authors: van de Sande D. A. J. P. , Hoogeveen A. , Hoogsteen J. , Kemps H. M. C.
Published: February 2015

The goals of this study were to determine the prevalence and determinants of false‐positive exercise tests in athletes. Data from all athletes who visited the Department of Sport Medicine for assessment of sports eligibility during a 1.5‐year period were reviewed retrospectively. Potential determinants of (false) positive test results that were evaluated included demographics, cardiovascular risk factors, sports characteristics, resting electrocardiogram (ECG) abnormalities, and exercise capacity. Data from 1298 athletes were included. In 53 athletes (4.1%), the exercise ECG was classified as positive. Among 38 athletes who were referred to a sports cardiologist for further diagnostic evaluation, 36 (95%) were classified as having a false‐positive test result and 2 athletes (5%) required coronary revascularization. Athletes with a false‐positive test were older than athletes with a negative test (53 ± 8 vs 45 ± 13 years, P = 0.03). In conclusion, exercise electrocardiography has a low positive predictive value in asymptomatic recreational and competitive athletes, with a false‐positive test result being associated with higher age. Given the relatively high prevalence of false‐positive test results in this population, efforts should be made to develop strategies aimed at identifying false‐positive test results in a simple noninvasive manner.
Polymicrobial bacterial or fungal infections: incidence, spectrum of infection, risk factors, and clinical outcomes from a large hematopoietic stem cell transplant center
Authors: Trifilio S. , Zhou Z. , Fong J.L. , Zomas A. , Liu D. , Zhao C. , Zhang J. , Mehta J.
Published: February 2015

Background

Infections cause significant morbidity and mortality for patients who undergo hematopoietic stem cell transplantation (HSCT). Cancer patients who develop polymicrobial infection (PI) are at increased risk for poor clinical outcomes, yet very limited data have been published within the HSCT setting.

Methods

An observational study of 901 stem cell transplant recipients was conducted at Northwestern Memorial Hospital to identify the incidence, risk factors and outcomes for HSCT recipients who develop infection(s) with multiple bacterial or fungal organisms.

Results

Among 901 HSCT recipients reviewed (675 autografts and 226 allografts), 237 patients (27%) had microbiologically documented microorganisms isolated, including 179 patients (76%) with monomicrobial infection and 59 patients (24%) with multiple microorganisms, of which 34 (14%) were classified as PI, and 25 (10%) as multiple distinct episodes of infection.

Conclusion

The results show co‐infection with multiple organisms during HSCT is relatively rare; however, these patients are at an increased risk for the development of acute graft‐versus‐host disease, delayed engraftment, and overall mortality.
Impact of nucleic acid amplification test on screening of blood donors in Northern Pakistan
Authors: Niazi Saifullah Khan , Bhatti Farhat Abbas , Salamat Nuzhat , Ghani Eijaz , Tayyab Muhammad
Published: February 2015

BACKGROUND

The Armed Forces Institute of Transfusion located in Rawalpindi, Northern Pakistan, acts as a regional blood center with more than 50,000 donations collected annually. Nucleic acid amplification testing (NAT) was introduced in our institution in September 2012 for screening all seronegative blood donors.

STUDY DESIGN AND METHODS

The study was conducted from September 21, 2012, to September 20, 2013. Samples from the seronegative donors were run on cobas s 201 platform (Roche) in pools of six. Reactive donors were followed up for further confirmatory testing to rule out false‐positive results. Viral load estimation was done for all NAT‐reactive donors.

RESULTS

After serologic screening of 56,772 blood donors, 2334 were found to be reactive; 719 (1.27%) were reactive for hepatitis B surface antigen, 1046 (1.84%) for antibody to hepatitis C virus (anti‐HCV), 12 (0.02%) for antibody to human immunodeficiency virus, and 557 (0.98%) for syphilis antibodies. A total of 27 NAT‐reactive donors were confirmed after testing 54,438 seronegative donors, with an overall NAT yield of one in 2016 donors: 23 for hepatitis B virus (HBV) DNA (HBV NAT yield, 1:2367) and four for HCV RNA (HCV NAT yield, 1:13,609). The residual risk after NAT implementation, calculated for the first‐time blood donors, was 62.5 and 4.4 per million donors for HBV and HCV, respectively.

CONCLUSIONS

NAT has improved the safety of blood products at our transfusion institution. Confirmation of NAT results must always be done either on follow‐up samples or on samples from the retrieved frozen plasma bag.
Evaluation of different testing methods for identification of RhIG in red blood cell antibody detection
Authors: Mikesell Kael V. , George Melissa R. , Castellani William J. , Domen Ronald E. , Gould Joy M. , Davis Jerry W. , Herman Jay H.
Published: February 2015

BACKGROUND

RhIG has had great success in protecting fetuses from potential harm; however, little work has been done to demonstrate how long RhIG reactivity is detected in the mother after administration when using common red blood cell antibody detection methods.

STUDY DESIGN AND METHODS

A retrospective investigation was performed examining positive antibody identification panels due to RhIG. These panels were run on solid‐phase (SP) testing. The time to a positive result, length of detection, and positive strength of reactivity (PSR) were evaluated. Additionally, a comparative study was performed evaluating how sensitive SP, gel (GT), and tube testing (TT) were at detecting RhIG using serially diluted plasma samples spiked with different RhIG formulas.

RESULTS

Retrospectively, most antibody identification panels by SP were positive 3.5 months after RhIG administration and demonstrated a strong PSR. The longest recorded positive panel was present at 4.5 months. RhIG administered intramuscularly could not be detected until several hours after injection. The comparative study showed that SP was the most sensitive method while GT and TT were comparable to one another in detecting RhIG. SP also recorded strong PSR at very low concentrations of RhIG. GT and TT recorded weak PSR even with higher concentrations of RhIG.

CONCLUSION

SP is the most sensitive testing method and has the ability to detect RhIG 4 to 5 months after administration. TT and GT have the ability to detect RhIG up to 3 to 4 months after administration. Different RhIG formulas may show slightly different lengths of detection.
Computing Néron–Severi groups and cycle class groups
Authors: Poonen Bjorn , Testa Damiano , van Luijk Ronald
Published: February 2015

Assuming the Tate conjecture and the computability of étale cohomology with finite coefficients, we give an algorithm that computes the Néron–Severi group of any smooth projective geometrically integral variety, and also the rank of the group of numerical equivalence classes of codimension $p$cycles for any$p$.
Eye‐specific visual processing in the mouse suprachiasmatic nuclei
Authors: Walmsley Lauren , Brown Timothy M.
Published: February 2015

Key points

Daily changes in global levels of illumination synchronise daily physiological rhythms via bilateral retinal projections to the suprachiasmatic nuclei.

We aimed to determine how retinal signals are integrated within the suprachiasmatic nuclei.

By monitoring electrophysiological responses to visual stimuli we show that most suprachiasmatic neurons receive input from just one eye.

Our results establish that suprachiasmatic neurons measure local light intensity and that any assessment of global light levels occurs at the network level.

Internal circadian clocks are important regulators of mammalian biology, acting to coordinate physiology and behaviour in line with daily changes in the environment. At present, synchronisation of the circadian system to the solar cycle is believed to rely on a quantitative assessment of total ambient illumination, provided by a bilateral projection from the retina to the suprachiasmatic nuclei (SCN). It is currently unclear, however, whether this photic integration occurs at the level of individual cells or within the SCN network. Here we use extracellular multielectrode recordings from the SCN of anaesthetised mice to show that most SCN neurons receive visual input from just one eye. While we find that binocular inputs to a subset of cells are important for rapid responses to changes in illumination, we find no evidence indicating that individual SCN cells are capable of reporting the average light intensity across the whole visual field. As a result of these local irradiance coding properties, our data establish that photic integration is primarily mediated at the level of the SCN network and suggest that accurate assessments of global light levels would be impaired by non‐uniform illumination of either eye.
Transient Gas Turbine Performance Diagnostics Through Nonlinear Adaptation of Compressor and Turbine Maps
Authors: Tsoutsanis Elias , Meskin Nader , Benammar Mohieddine , Khorasani Khashayar
Published: February 2015

Gas turbines are faced with new challenges of increasing flexibility in their operation while reducing their life cycle costs, leading to new research priorities and challenges. One of these challenges involves the establishment of high fidelity, accurate, and computationally efficient engine performance simulation, diagnosis, and prognosis schemes, which will be able to handle and address the gas turbine's ever-growing flexible and dynamic operational characteristics. Predicting accurately the performance of gas turbines depends on detailed understanding of the engine components behavior that is captured by component performance maps. The limited availability of these maps due to their proprietary nature has been commonly managed by adapting default generic maps in order to match the targeted off-design or engine degraded measurements. Although these approaches might be suitable in small range of operating conditions, further investigation is required to assess the capabilities of such methods for use in gas turbine diagnosis under dynamic transient conditions. The diversification of energy portfolio and introduction of distributed generation in electrical energy production have created need for such studies. The reason is not only the fluctuation in energy demand but also more importantly the fact that renewable energy sources, which work with conventional fossil fuel based sources, supply the grid with varying power that depend, for example, on solar irradiation. In this paper, modeling methods for the compressor and turbine maps are presented for improving the accuracy and fidelity of the engine performance prediction and diagnosis. The proposed component map fitting methods simultaneously determine the best set of equations for matching the compressor and the turbine map data. The coefficients that determine the shape of the component map curves have been analyzed and tuned through a nonlinear multi-objective optimization scheme in order to meet the targeted set of engine measurements. The proposed component map modeling methods are developed in the object oriented matlab/simulink environment and integrated with a dynamic gas turbine engine model. The accuracy of the methods is evaluated for predicting multiple component degradations of an engine at transient operating conditions. The proposed adaptive diagnostics method has the capability to generalize current gas turbine performance prediction approaches and to improve performance-based diagnostic techniques.
Rotordynamic Behavior of 225 kW (300 HP) Class PMS Motor–Generator System Supported by Gas Foil Bearings
Authors: Choe Bok Seong , Kim Tae Ho , Kim Chang Ho , Lee Yong Bok
Published: February 2015

This paper presents the dynamic behavior of a 225 kW class (300 HP), 60,000 rpm, permanent magnet synchronous (PMS) motor–generator system supported on gas foil bearings (GFBs). The rotor of a 225 kW PMS motor is supported by two identical gas foil journal bearings (GFJBs) and one pair of gas foil thrust bearings (GFTBs). The total weight and axial length of the coupled rotors are 272 N and 1042 mm, respectively. During the speed-up test to 60,000 rpm, unexpected large subsynchronous rotor motions appear at around 120–130 Hz above 35,040 rpm. After disassembling the motor, an inspection of the top foils of the GFJBs reveals significant rotor rubbing. Thus, the GFJBs are redesigned to have a smaller load capacity by reducing their axial length to 45 mm. In addition, three 50 μm thick shims are installed in the GFJBs at 120 deg intervals for reducing the swirl speed of air and producing bearing preloads. The modification delays the onset speed of subsynchronous motions to 43,200 rpm and decreases the amplitude of the subsynchronous motions from 20 to 15 μm. These results indicate that the modification improves the stability margin of the high-speed rotor system with increasing stiffness and damping. In addition, the logarithmic decrement trends are in good agreement with the test results.
Continuous Galerkin Petrov Time Discretization Scheme for the Solutions of the Chen System
Authors: Hussain S. , Salleh Z.
Published: February 2015

In this paper, the continuous Galerkin Petrov time discretization (cGP) scheme is applied to the Chen system, which is a three-dimensional system of ordinary differential equations (ODEs) with quadratic nonlinearities. In particular, we implement and analyze numerically the higher order cGP(2)-method which is found to be of fourth order at the discrete time points. A numerical comparison with classical fourth-order Runge–Kutta (RK4) is given for the presented problem. We look at the accuracy of the cGP(2) as the Chen system changes from a nonchaotic system to a chaotic one. It is shown that the cGP(2) method gains accurate results at larger time step sizes for both cases.
Development of seed layer for electrodeposition of copper on carbon nanotube bundles
Authors: Jordan Matthew B. , Feng Ying , Burkett Susan L.
Published: February 2015

The reliability of metal filled through silicon vias (TSVs) will determine their suitability in the semiconductor industry. The adoption of this technology will depend strongly on the materials used for filling vias that function as vertical interconnects. Conventional materials for filling TSVs include copper and tungsten. Carbon nanotubes (CNTs) are an excellent candidate to replace or be used in conjunction with these materials due to their superior electrical and mechanical properties. Metallic CNT bundles can allow nearly unhampered transport of electrons, resulting in a low resistance interconnect capable of withstanding high current densities. The growth of CNTs with ethylene and methane precursors by thermal chemical vapor deposition has been investigated using thin films of aluminum oxide and iron as catalysts. Nickel and cobalt were investigated as well with limited success. CNT growth is followed by electrochemical deposition (ECD) of copper. Traditionally, sputtered or evaporated Cu is used as a seed layer for ECD; however, the high temperatures necessary for CNT growth made Cu an unsuitable seed layer due to migration. The authors investigated combinations of ECD seed layers and CNT catalysts on the surface of a silicon wafer to qualify the best materials for the formation of a Cu/CNT matrix. ECD of Cu was studied on as-grown and densified CNTs with a tungsten seed layer. Once the process for covering CNT bundles with copper is optimized, future work will focus on placing the materials system inside cylindrical vias formed using an inductively coupled plasma etch process.
Sparse‐view proton computed tomography using modulated proton beams
Authors: Lee Jiseoc , Kim Changhwan , Min Byungjun , Kwak Jungwon , Park Seyjoon , Lee Se Byeong , Park Sungyong , Cho Seungryong
Published: February 2015

Purpose:

Proton imaging that uses a modulated proton beam and an intensity detector allows a relatively fast image acquisition compared to the imaging approach based on a trajectory tracking detector. In addition, it requires a relatively simple implementation in a conventional proton therapy equipment. The model of geometric straight ray assumed in conventional computed tomography (CT) image reconstruction is however challenged by multiple‐Coulomb scattering and energy straggling in the proton imaging. Radiation dose to the patient is another important issue that has to be taken care of for practical applications. In this work, the authors have investigated iterative image reconstructions after a deconvolution of the sparsely view‐sampled data to address these issues in proton CT.

Methods:

Proton projection images were acquired using the modulated proton beams and the EBT2 film as an intensity detector. Four electron‐density cylinders representing normal soft tissues and bone were used as imaged object and scanned at 40 views that are equally separated over 360°. Digitized film images were converted to water‐equivalent thickness by use of an empirically derived conversion curve. For improving the image quality, a deconvolution‐based image deblurring with an empirically acquired point spread function was employed. They have implemented iterative image reconstruction algorithms such as adaptive steepest descent‐projection onto convex sets (ASD‐POCS), superiorization method–projection onto convex sets (SM‐POCS), superiorization method–expectation maximization (SM‐EM), and expectation maximization‐total variation minimization (EM‐TV). Performance of the four image reconstruction algorithms was analyzed and compared quantitatively via contrast‐to‐noise ratio (CNR) and root‐mean‐square‐error (RMSE).

Results:

Objects of higher electron density have been reconstructed more accurately than those of lower density objects. The bone, for example, has been reconstructed within 1% error. EM‐based algorithms produced an increased image noise and RMSE as the iteration reaches about 20, while the POCS‐based algorithms showed a monotonic convergence with iterations. The ASD‐POCS algorithm outperformed the others in terms of CNR, RMSE, and the accuracy of the reconstructed relative stopping power in the region of lung and soft tissues.

Conclusions:

The four iterative algorithms, i.e., ASD‐POCS, SM‐POCS, SM‐EM, and EM‐TV, have been developed and applied for proton CT image reconstruction. Although it still seems that the images need to be improved for practical applications to the treatment planning, proton CT imaging by use of the modulated beams in sparse‐view sampling has demonstrated its feasibility.
Human cortical sensitivity to interaural level differences in low- and high-frequency sounds
Authors: Salminen Nelli H.
Published: February 2015

Interaural level difference (ILD) is used as a cue in horizontal sound source localization. In free field, the magnitude of ILD depends on frequency: it is more prominent at high than low frequencies. Here, a magnetoencephalography experiment was conducted to test whether the sensitivity of the human auditory cortex to ILD is also frequency-dependent. Robust cortical sensitivity to ILD was found that could not be explained by monaural level effects, but this sensitivity did not differ between low- and high-frequency stimuli. This is consistent with previous psychoacoustical investigations showing that performance in ILD discrimination is not dependent on frequency.
Dependences of ultrasonic properties on frequency and trabecular spacing in trabecular-bone-mimicking phantoms
Authors: Lee Kang Il
Published: February 2015

The dependences of ultrasonic properties on the frequency and the trabecular spacing were investigated in 20 trabecular-bone-mimicking phantoms consisting of cellular copper foams. The strong slow waves were consistently observed in the signals transmitted through all of the phantoms. The frequency-dependent phase velocity and attenuation coefficient of the slow wave were measured at frequencies from 0.7 to 1.3 MHz. The phase velocity decreased approximately linearly with increasing frequency while the attenuation coefficients increased with increasing frequency. The phase velocity increased monotonically with increasing trabecular spacing from 1337 to 2931 μm while the attenuation coefficient decreased with increasing spacing.
Local iontophoretic administration of cytotoxic therapies to solid tumors
Authors: Byrne James D. , R. Jajja Mohammad N. , O’Neill Adrian T. , Bickford Lissett R. , Keeler Amanda W. , Hyder Nabeel , Wagner Kyle , Deal Allison , Little Ryan E. , Moffitt Richard A. , Stack Colleen , Nelson Meredith , Brooks Christopher R. , Lee William , Luft J. Chris , Napier Mary E. , Darr David , Anders Carey K. , Stack Richard , Tepper Joel E. , Wang Andrew Z. , Zamboni William C. , Yeh Jen Jen , DeSimone Joseph M.
Published: February 2015

Local administration of cytotoxic drugs using iontophoresis results in drug accumulation and therapeutic efficacy in mouse models of pancreatic and breast cancer and favorable PK in a large animal model.
A smartphone dongle for diagnosis of infectious diseases at the point of care
Authors: Laksanasopin Tassaneewan , Guo Tiffany W. , Nayak Samiksha , Sridhara Archana A. , Xie Shi , Olowookere Owolabi O. , Cadinu Paolo , Meng Fanxing , Chee Natalie H. , Kim Jiyoon , Chin Curtis D. , Munyazesa Elisaphane , Mugwaneza Placidie , Rai Alex J. , Mugisha Veronicah , Castro Arnold R. , Steinmiller David , Linder Vincent , Justman Jessica E. , Nsanzimana Sabin , Sia Samuel K.
Published: February 2015

A smartphone accessory can perform a point-of-care test that simultaneously detects three infectious disease markers from fingerprick whole blood in 15 min, as operated by health care workers trained on a software app.
Effect of selective LRRK2 kinase inhibition on nonhuman primate lung
Authors: Fuji Reina N. , Flagella Michael , Baca Miriam , S. Baptista Marco A. , Brodbeck Jens , Chan Bryan K. , Fiske Brian K. , Honigberg Lee , Jubb Adrian M. , Katavolos Paula , Lee Donna W. , Lewin-Koh Sock-Cheng , Lin Tori , Liu Xingrong , Liu Shannon , Lyssikatos Joseph P. , O’Mahony Jennifer , Reichelt Mike , Roose-Girma Merone , Sheng Zejuan , Sherer Todd , Smith Ashley , Solon Margaret , Sweeney Zachary K. , Tarrant Jacqueline , Urkowitz Alison , Warming Søren , Yaylaoglu Murat , Zhang Shuo , Zhu Haitao , Estrada Anthony A. , Watts Ryan J.
Published: February 2015

LRRK2 kinase inhibitors, under development for Parkinson’s disease, have an effect on type II pneumocytes in nonhuman primate lung, suggesting that pulmonary toxicity may be a critical safety liability.
Leaky blood-brain barriers and memory loss
Authors: Nishijima Daniel K.
Published: February 2015

Age-dependent blood-brain barrier permeability demonstrated an association with cognitive impairment.
Dynamics of Infant Gut Microbiota Are Influenced by Delivery Mode and Gestational Duration and Are Associated with Subsequent Adiposity
Authors: Dogra Shaillay , Sakwinska Olga , Soh Shu-E , Ngom-Bru Catherine , Brück Wolfram M. , Berger Bernard , Brüssow Harald , Lee Yung Seng , Yap Fabian , Chong Yap-Seng , Godfrey Keith M. , Holbrook Joanna D.
Published: February 2015

We found that the relatively simple microbiota of young infants shifts predictably to a more mature anaerobic microbiota during infancy and the dynamics of this shift are influenced by environmental factors. In this longitudinal study of 75 infants, we demonstrate high interindividual variability within the normal range of birth outcomes, especially in the rate of microbiota progression. Most had acquired a microbiota profile high in Bifidobacterium and Collinsella by 6 months of age, but the time point of this acquisition was later in infants delivered by caesarean section and those born after a shorter duration of gestation. Independently of the delivery mode and gestation duration, infants who acquired a profile high in Bifidobacterium and Collinsella at a later age had lower adiposity at 18 months of age.

IMPORTANCE  This study shows that the acquisition of the early microbiota is strongly influenced by environmental factors such as the delivery mode and duration of gestation, even in healthy neonates. The composition of the early microbiota has been linked with long-lasting effects on health and disease. Here we show that the rate of acquisition of certain microbiota predicts adiposity at 18 months of age and so potentially the risk of later obesity.
A Burkholderia pseudomallei Colony Variant Necessary for Gastric Colonization
Authors: Austin C. R. , Goodyear A. W. , Bartek I. L. , Stewart A. , Sutherland M. D. , Silva E. B. , Zweifel A. , Vitko N. P. , Tuanyok A. , Highnam G. , Mittelman D. , Keim P. , Schweizer H. P. , Vázquez-Torres A. , Dow S. W. C. , Voskuil M. I.
Published: February 2015

Diverse colony morphologies are a hallmark of
Burkholderia pseudomallei
recovered from infected patients. We observed that stresses that inhibit aerobic respiration shifted populations of B. pseudomallei from the canonical white colony morphotype toward two distinct, reversible, yet relatively stable yellow colony variants (YA and YB). As accumulating evidence supports the importance of B. pseudomallei enteric infection and gastric colonization, we tested the response of yellow variants to hypoxia, acidity, and stomach colonization. Yellow variants exhibited a competitive advantage under hypoxic and acidic conditions and alkalized culture media. The YB variant, although highly attenuated in acute virulence, was the only form capable of colonization and persistence in the murine stomach. The accumulation of extracellular DNA (eDNA) was a characteristic of YB as observed by 4′,6-diamidino-2-phenylindole (DAPI) staining of gastric tissues, as well as in an
in vitro
stomach model where large amounts of eDNA were produced without cell lysis. Transposon mutagenesis identified a transcriptional regulator (BPSL1887, designated YelR) that when overexpressed produced the yellow phenotype. Deletion of
yelR
blocked a shift from white to the yellow forms. These data demonstrate that YB is a unique B. pseudomallei pathovariant controlled by YelR that is specifically adapted to the harsh gastric environment and necessary for persistent stomach colonization.

IMPORTANCE
  Seemingly uniform populations of bacteria often contain subpopulations that are genetically identical but display unique characteristics which offer advantages when the population is faced with infrequent but predictable stresses. The pathogen
Burkholderia pseudomallei
is capable of forming several reversible colony types, and it interconverted between one white type and two yellow types under certain environmental stresses. The two yellow forms exhibited distinct advantages in low-oxygen and acidic environments. One yellow colony variant was the only form capable of chronic stomach colonization. Areas of gastric infection were marked by bacteria encased in a DNA matrix, and the yellow forms were able to produce large amounts of extracellular DNA
in vitro
. We also identified the regulator in control of yellow colony variant formation. These findings demonstrate a role in infection for colony variation and provide a mechanism for chronic stomach colonization—a frequently overlooked niche in melioidosis.
Older doctors and progression through specialty training in the UK: a cohort analysis of General Medical Council data
Authors: Pyne Yvette , Ben-Shlomo Yoav
Published: February 2015

Objective

To determine whether older age at graduation is associated with any difference in outcomes from the annual specialty training progression assessment.

Design

An open cohort of 38 308 doctors who graduated from a UK medical school with annual assessments of progression in their specialty training programme with data centrally collected by the General Medical Council between 5 August 2009 to 31 July 2012.

Results

Mature junior doctors (≥29 years at graduation) were more likely to have problems with progression on their annual review of competence progression record of in training assessment (ARCP/RITA) than their younger colleagues (OR 1.34, 95% CI 1.22 to 1.49, p<0.001). This association was, if anything, even stronger (OR 1.57, 95% CI 1.41 to 1.74, p<0.001) after adjustment for gender, ethnicity, type of University and specialty. The same was true when only looking at the most extreme ARCP outcome (4) which is being asked to leave their specialist programme (OR 1.81, 95% CI 1.34 to 2.44, p<0.001).

Conclusions

Mature doctors are a growing part of the medical workforce and they are likely to broaden the spectrum of doctors by bring different life experience to the profession. These results suggest that they are more likely to have problems with progressing through their specialist training programme. More research is required to determine the reasons behind these associations and how mature doctors can be supported both in choosing the best training programme and in coping with the complex demands of higher training at a later stage in their lives.
Intravascular device administration sets: replacement after standard versus prolonged use in hospitalised patients—a study protocol for a randomised controlled trial (The RSVP Trial)
Authors: Rickard Claire M , Marsh Nicole M , Webster Joan , Gavin Nicole C , McGrail Matthew R , Larsen Emily , Corley Amanda , Long Debbie , Gowardman John R , Murgo Marghie , Fraser John F , Chan Raymond J , Wallis Marianne C , Young Jeanine , McMillan David , Zhang Li , Choudhury Md Abu , Graves Nicholas , Playford E Geoffrey
Published: February 2015

Introduction

Vascular access devices (VADs), such as peripheral or central venous catheters, are vital across all medical and surgical specialties. To allow therapy or haemodynamic monitoring, VADs frequently require administration sets (AS) composed of infusion tubing, fluid containers, pressure-monitoring transducers and/or burettes. While VADs are replaced only when necessary, AS are routinely replaced every 3–4 days in the belief that this reduces infectious complications. Strong evidence supports AS use up to 4 days, but there is less evidence for AS use beyond 4 days. AS replacement twice weekly increases hospital costs and workload.

Methods and analysis

This is a pragmatic, multicentre, randomised controlled trial (RCT) of equivalence design comparing AS replacement at 4 (control) versus 7 (experimental) days. Randomisation is stratified by site and device, centrally allocated and concealed until enrolment. 6554 adult/paediatric patients with a central venous catheter, peripherally inserted central catheter or peripheral arterial catheter will be enrolled over 4 years. The primary outcome is VAD-related bloodstream infection (BSI) and secondary outcomes are VAD colonisation, AS colonisation, all-cause BSI, all-cause mortality, number of AS per patient, VAD time in situ and costs. Relative incidence rates of VAD-BSI per 100 devices and hazard rates per 1000 device days (95% CIs) will summarise the impact of 7-day relative to 4-day AS use and test equivalence. Kaplan-Meier survival curves (with log rank Mantel-Cox test) will compare VAD-BSI over time. Appropriate parametric or non-parametric techniques will be used to compare secondary end points. p Values of <0.05 will be considered significant.

Ethics and dissemination

Relevant ethical approvals have been received. CONSORT Statement recommendations will be used to guide preparation of any publication. Results will be presented at relevant conferences and sent to the major organisations with clinical practice guidelines for VAD care.

Trial registration number

Australian New Zealand Clinical Trial Registry (ACTRN 12610000505000).
Occupational position, work stress and depressive symptoms: a pathway analysis of longitudinal SHARE data
Authors: Hoven H , Wahrendorf M , Siegrist J
Published: February 2015

Background

Several studies tested whether stressful work mediates the association between socioeconomic position (SEP) and health. Although providing moderate support, evidence is still inconclusive, partly due to a lack of theory-based measures of SEP and work stress, and because of methodological limitations. This contribution aims at overcoming these limitations.

Methods

We conduct pathway analysis and investigate indirect effects of SEP on mental health via stressful work. Data are derived from the first two waves of the ‘Survey of Health, Ageing and Retirement in Europe’ (SHARE) with information from employed men and women aged 50–64 across 11 European countries (N=2798). SEP is measured according to two alternative measures of occupational position: occupational class (focus on employment relations) and occupational status (focus on prestige). We assess work stress according to the effort-reward imbalance and the demand-control model (wave 1), and we use newly occurring depressive symptoms as health outcome (wave 2).

Results

Effort-reward imbalance and, less consistently, low control mediate the effect of occupational class and occupational status on depressive symptoms.

Conclusions

Our findings point to two important aspects of work stress (effort-reward imbalance and low control) in explaining socioeconomic differences in health. Further, we illustrate the significance of two alternative dimensions of occupational position, occupational class and occupational status.
Foundation doctors and dyslexia: a qualitative study of their experiences and coping strategies
Authors: Newlands Freda , Shrewsbury Duncan , Robson Jean
Published: February 2015

Background

Dyslexia is the most common form of specific learning difficulty affecting approximately 6% of the general UK population and believed to affect approximately 2% of UK medical students. The impact of dyslexia on early practice has not been studied.

Objectives

To develop an understanding of the challenges faced by doctors with dyslexia in the first year of practice and their support requirements.

Methods

Semistructured telephone interviews were conducted with seven foundation year 1 doctors with dyslexia from Scottish hospitals between March 2013 and August 2013.

Results

Foundation doctors indicated that due to their dyslexia, they experience difficulty with all forms of communication, time management and anxiety. There were concerns about disclosure of their dyslexia to colleagues and supervisors. Coping strategies used frequently were safety-netting and planning; technology solutions did offer some assistance.

Conclusions

Although technological interventions have the potential to offer benefits to foundation doctors with dyslexia, increased openness about a diagnosis of dyslexia with discussion between doctor and supervisors about the challenges and anxieties is likely to provide the most benefit.