Factors that influence parental and caregiver acceptance of routine childhood vaccination: Summary of a qualitative evidence synthesis.

We summarise a Cochrane review of qualitative evidence that explored parents' views and practices around routine childhood vaccination, and provide implications for research and practice that are relevant to the South African (SA) context. Many public health interventions to encourage vaccination are informed by an assumption that vaccine hesitancy is due to a lack of knowledge or irrational forms of thinking. The findings from this review suggest that childhood vaccination views and practices are complex social processes that are shaped by multiple factors and carry a variety of meanings. As such, we suggest that biomedical approaches must be supplemented by more nuanced and sociopolitically informed strategies for enhancing and sustaining childhood vaccination practices in SA.

Impact of heatwaves and environmental ammonia on energy metabolism, nitrogen excretion, and mRNA expression of related genes in the indicator model system Daphnia magna.

Due to increasing anthropogenic impacts, heatwaves and prolonged exposure to elevated concentrations of ammonia (HEA) may occur in aquatic environments as a single stressor or a combination thereof, potentially impacting the physiology of exposed animals. In the current study, common water fleas Daphnia magna were exposed for one week to either a 5°C increase in temperature, an increase of 300 µmol l-1 total environmental ammonia, or to both of these stressors simultaneously. Exposure to elevated temperature caused a decrease in MO2, ammonia excretion rates, a downregulation of mRNA coding for key Krebs cycle enzymes and the energy consuming Na+/K+-ATPase and V-type H+-ATPase, as well as the energy distributing crustacean hyperglycemic hormone Rh-protein. High environmental ammonia inflicted a lesser inhibitory effect on the energy metabolism of Daphnia, but initiated ammonia detoxification processes via urea synthesis evident by elevated urea excretion rates and a mRNA upregulation of arginase. Effects observed under the combined stressors resembled largely the effects seen after acclimation to elevated temperature alone, potentially due to the animals' capability to efficiently detoxify critical ammonia loads. The observed physiological effects and potential threats of the environmental stressor are discussed in detail.

Closing the reporting gap for childhood tuberculosis in South Africa: improving hospital referrals and linkages.

SETTING: A referral hospital in Cape Town, Western Cape Province, Republic of South Africa. OBJECTIVE: To measure the impact of a hospital-based referral service (intervention) to reduce initial loss to follow-up among children with tuberculosis (TB) and ensure the completeness of routine TB surveillance data. DESIGN: A dedicated TB referral service was established in the paediatric wards at Tygerberg Hospital, Cape Town, in 2012. Allocated personnel provided TB education and counselling, TB referral support and weekly telephonic follow-up after hospital discharge. All children identified with TB were matched to electronic TB treatment registers (ETR.Net/EDRWeb). Multivariable logistic regression was used to compare reporting of culture-confirmed and drug-susceptible TB cases before (2007-2009) and during (2012) the intervention. RESULTS: Successful referral with linkage to care was confirmed in 267/272 (98%) and successful reporting in 227/272 (84%) children. Children with drug-susceptible, culture-confirmed TB were significantly more likely to be reported during the intervention period than in the pre-intervention period (OR 2.52, 95%CI 1.33-4.77). The intervention effect remained consistent in multivariable analysis (adjusted OR 2.62; 95%CI 1.31-5.25) after adjusting for age, sex, human immunodeficiency virus status and the presence of TB meningitis. CONCLUSIONS: A simple hospital-based TB referral service can reduce initial loss to follow-up and improve recording and reporting of childhood TB in settings with decentralised TB services.

Ferromagnetic Resonance Spin Pumping and Electrical Spin Injection in Silicon-Based Metal-Oxide-Semiconductor Heterostructures.

We present the measurement of ferromagnetic resonance (FMR-)driven spin pumping and three-terminal electrical spin injection within the same silicon-based device. Both effects manifest in a dc spin accumulation voltage V_{s} that is suppressed as an applied field is rotated to the out-of-plane direction, i.e., the oblique Hanle geometry. Comparison of V_{s} between these two spin injection mechanisms reveals an anomalously strong suppression of FMR-driven spin pumping with increasing out-of-plane field H_{app}^{z}. We propose that the presence of the large ac component to the spin current generated by the spin pumping approach, expected to exceed the dc value by 2 orders of magnitude, is the origin of this discrepancy through its influence on the spin dynamics at the oxide-silicon interface. This convolution, wherein the dynamics of both the injector and the interface play a significant role in the spin accumulation, represents a new regime for spin injection that is not well described by existing models of either FMR-driven spin pumping or electrical spin injection.

Congruent validity and reliability of two metabolic systems to measure resting metabolic rate.

Determine the congruent validity and intra- and inter-day reliability of RMR measures assessed by the ParvoMedics Trueone 2 400 hood dilution method (Parvo) and Cosmed K4b(2) (Cosmed) breath-by-breath metabolic systems. Participants underwent 6 RMR assessments over 2 consecutive mornings, 3 with the Parvo (Day 1: Parvo 1; Day 2: Parvo 2, 3), 3 with the Cosmed (Day 1: Cosmed 1; Day 2: Cosmed 2, 3). Measured VE, FEO(2), FECO(2), VO(2), VCO(2), kcal/day, and HR values were averaged over a minimum of 10 min. Intra- and inter-day reliability within each system was determined with RMANOVA, and congruent validity was assessed via paired sample t-tests.31 participants (13 females, 18 males; 27.3±7 years, 24.8±3.1 kg.m(2)) completed the study. There were no significant differences in any within or between day Parvo values or Cosmed values. When systems were compared, there was a significant difference between VE (Parvo2: 25.03 L/min, Cosmed2: 8.98 L/min) and FEO(2) (Parvo2: 19.68%, Cosmed2: 16.63%), however, there were no significant difference in device-calculated RMR (kcals/day).The Parvo and Cosmed are reliable metabolic system with no intra- or inter-day differences in RMR. Due to differences in measurement technology, FEO(2), V(E) were significantly different between systems, but the resultant RMR values were not significantly different.

Validation of a portable EMG device to assess muscle activity during free-living situations.

Portable amplifiers that record electromyograms (EMGs) for longer than four hours are commonly priced over $20,000 USD. This cost, and the technical challenges associated with recording EMGs during free-living situations, typically restrict EMG use to laboratory settings. A low-cost system (µEMG; OT Bioelecttronica, 100€), using specialized concentric bipolar electrodes, has been developed specifically for free-living situations. The purpose of this study was to validate the µEMG system by comparing EMGs from µEMG with a laboratory-based alternative (Telemyo 900; Noraxon USA, Inc.). Surface EMGs from biceps brachii (BB) and tibialis anterior (TA) of ten subjects were recorded simultaneously with both systems as subjects performed maximal voluntary contractions (MVCs), submaximal contractions at 25%, 50%, and 75% MVC, seven simulated activities of daily living (ADLs), and >60min of simulated free-living inside the laboratory. In general, EMG parameters (e.g., average full-wave rectified EMG amplitude) derived from both systems were not significantly different for all outcome variables, except there were small differences across systems in baseline noise and absolute EMG amplitudes during MVCs. These results suggest that µEMG is a valid approach to the long-term recording of EMG.

Incomplete registration and reporting of culture-confirmed childhood tuberculosis diagnosed in hospital.

SETTING: The South African National Tuberculosis Programme (NTP) recommends the registration of tuberculosis (TB) patients at community clinics. TB in children is often diagnosed at referral hospitals, and there are concerns as to whether these children are accurately reflected in routine NTP reporting. OBJECTIVE: To assess the completeness of registration of children with culture-confirmed TB diagnosed in a referral hospital, in the routine provincial electronic TB register (ETR.Net), and to describe TB treatment outcomes. DESIGN: A retrospective cohort study including children aged <13 years diagnosed with culture-confirmed TB at Tygerberg Children's Hospital from July 2007 to June 2009. Data on demographic, clinical and referral factors were collated from hospital data sources. Electronic matching was used to identify children in the provincial ETR.Net. RESULTS: Only 166 of 267 (62%) children were registered in ETR.Net. Children with TB meningitis and death prior to referral were significantly less likely to be registered. Treatment outcome data were available for only 70% of children; favourable outcomes were reported in 56%. CONCLUSIONS: A large proportion of children diagnosed with confirmed TB at a referral hospital were not registered, resulting in underreporting of the burden and severity of childhood TB. Routine surveillance of childhood TB should include linkage of hospital data.

Manipulation of spin transport in graphene by surface chemical doping.

The effects of surface chemical doping on spin transport in graphene are investigated by performing nonlocal measurements in ultrahigh vacuum while depositing gold adsorbates. We demonstrate manipulation of the gate-dependent nonlocal spin signal as a function of gold coverage. We discover that charged impurity scattering is not the dominant mechanism for spin relaxation in graphene, despite its importance for momentum scattering. Finally, unexpected enhancements of the spin lifetime illustrate the complex nature of spin relaxation in graphene.

Tunneling spin injection into single layer graphene.

We achieve tunneling spin injection from Co into single layer graphene (SLG) using TiO2 seeded MgO barriers. A nonlocal magnetoresistance (ΔR(NL)) of 130 Ω is observed at room temperature, which is the largest value observed in any material. Investigating ΔR(NL) vs SLG conductivity from the transparent to the tunneling contact regimes demonstrates the contrasting behaviors predicted by the drift-diffusion theory of spin transport. Furthermore, tunnel barriers reduce the contact-induced spin relaxation and are therefore important for future investigations of spin relaxation in graphene.

Oscillatory spin polarization and magneto-optical Kerr effect in Fe3O4 thin films on GaAs(001).

The spin dependent properties of epitaxial Fe3O4 thin films on GaAs(001) are studied by the ferromagnetic proximity polarization (FPP) effect and magneto-optical Kerr effect (MOKE). Both FPP and MOKE show oscillations with respect to Fe3O4 film thickness, and the oscillations are large enough to induce repeated sign reversals. We attribute the oscillatory behavior to spin-polarized quantum well states forming in the Fe3O4 film. Quantum confinement of the t(2g) states near the Fermi level provides an explanation for the similar thickness dependences of the FPP and MOKE oscillations.

Anisotropic dependence of superconductivity on uniaxial pressure in CeIrIn5.

We measure the effect of uniaxial pressure on the superconducting transition temperature T_{c} in CeIrIn5. We find a linear change in T_{c} with both a-axis and c-axis pressure, with slopes of 56 and -66 mK/kbar, respectively. By comparing results from doping studies and different types of pressure measurements, we separate the influences of hybridization and dimensionality on T_{c}. We find the true geometric influence, for constant hybridization, is partial differentialT_{c}/ partial differential(c/a)=44 K.

Prenatal detection and evaluation of an extralobar pulmonary sequestration in the posterior mediastinum.

Extralobar pulmonary sequestration (EPS) is a rare developmental anomaly with aberrant nonfunctioning parenchymal tissue, associated with an increased risk of perinatal morbidity and, rarely, mortality owing to possible neonatal respiratory distress. In most cases supernumerary lobes are detected as isolated intra- or extrapleural lesions with independent systemic arterial blood supply. We report an atypical case of prenatal detection and perinatal outcome of a mediastinal EPS.

Effects of body mass index on the accuracy of an electronic pedometer.

Electronic pedometers are accurate for assessing steps taken while walking in normal weight adults but the accuracy of these devices has not been tested in overweight and obese men and women. The primary purpose of this study was to assess the accuracy of an electronic pedometer for measuring steps taken at various walking speeds in groups of adults with variations in body mass index (BMI). The secondary purpose was to determine if the manufacturer recommended position is the best placement position for overweight and obese adults. Participants were categorized into one of three BMI categories identified by the World Health Organization: normal (N = 25; < 25 kg x m(-2)), overweight (N = 24; 25 - 29.9 kg x m(-2)), or obese (N = 17; > or = 30 kg x m(-2)). Participants walked on a treadmill for 3 min at 54, 67, 80, 94, and 107 m x min(-1) for a total of 15 min. During the treadmill walking, three electronic pedometers tallied steps taken. The pedometers were placed at the waist level, one on the anterior mid-line of the thigh (front; manufacturer recommended placement), one on the mid-axillary line (side), and one on the posterior mid-line of the thigh (back). Concurrently, a researcher counted steps using a hand-tally counter. Category of BMI did not affect the accuracy of the pedometer at any walking speed (54 m x min(-1), p = 0.991; 67 m x min(-1), p = 0.556; 80 m x min(-1), p = 0.591; 94 m x min(-1), p = 0.426; 107 m x min(-1), p = 0.869). At 54 m x min(-1), the front, side, and back pedometers significantly underestimated hand-tally counted steps by 20 % (p < 0.001), 33 % (p < 0.001), and 26 % (p < 0.001), respectively. At 67 m x min(-1) the front, side, and back pedometers significantly underestimated hand-tally counted steps by 7 % (p = 0.027), 13 % (p < 0.001), 11 % (p = 0.002), respectively. The steps recorded by the electronic pedometers placed at the front, side and back of the waist were not significantly different than steps counted by the hand-tally counter at speeds of 80 m x min(-1) and higher for all subjects combined. An electronic pedometer accurately quantified steps walked at speeds of 80 m x min(-1) or faster in persons with a normal BMI and those classified as overweight or obese. The placement of the pedometer on the front, side or back of the waistband did not affect accuracy of the pedometer for counting steps.

Comparison of MTI accelerometer cut-points for predicting time spent in physical activity.

The purpose of this study was to establish the accuracy of five published accelerometer regression equations that predict time spent in different intensity classifications during free-living activities. Ten participants completed physical tasks in a field setting for a near-continuous 5 - 6 h-period while oxygen uptake and accelerometer data were collected. The amount of time spent in resting/light, moderate and hard activity was computed from 3 and 6 MET cut-points associated with five existing regression formulas relating accelerometer counts x min -1 to energy expenditure. The Freedson cut-points over-estimated resting/light activity by 34 min (13 %) and under-estimated moderate activity by 38 min (60 %). The Hendelman cut-points for all activities underestimated resting/light activity by 77 min (29 %), and overestimated moderate activity by 77 min (120 %). The Hendelman cut-points developed from walking activities over-estimated resting/light activity by 37 min (14 %) and under-estimated moderate activity by 38 min (60 %). Estimates from the Swartz cut-points for estimating time spent in resting/light, moderate and hard intensity activity were not different from the criterion measure. The Nichols cut-points over-estimated resting/light activity by 31 min (12 %) and under-estimated moderate activity by 35 min (55 %). Even though the Swartz method did not differ from measured time spent in moderate activity on a group basis, on an individual basis, large errors were seen. This was true for all regression formulas. These errors highlight some of the limitations to using hip-mounted accelerometers to reflect physical activity patterns. The finding that different accelerometer cut-points gave substantially different estimates of time spent data has important implications for researchers using accelerometers to predict time spent in different intensity categories.

Simultaneous heart rate-motion sensor technique to estimate energy expenditure.

PURPOSE: Heart rate (HR) and motion sensors represent promising tools for physical activity (PA) assessment, as each provides an estimate of energy expenditure (EE). Although each has inherent limitations, the simultaneous use of HR and motion sensors may increase the accuracy of EE estimates. The primary purpose of this study was to establish the accuracy of predicting EE from the simultaneous HR-motion sensor technique. In addition, the accuracy of EE estimated by the simultaneous HR-motion sensor technique was compared to that of HR and motion sensors used independently. METHODS: Thirty participants (16 men: age, 33.1 +/- 12.2 yr; BMI, 26.1 +/- 0.7 kg.m(-2); and 14 women: age, 31.9 +/- 13.1 yr; BMI, 27.2 +/- 1.1 kg.m(-2) (mean +/- SD)) performed arm and leg work in the laboratory for the purpose of developing individualized HR-VO2 regression equations. Participants then performed physical tasks in a field setting for 15 min each. CSA accelerometers placed on the arm and leg were to discriminate between upper and lower body movement, and HR was then used to predict EE (METs) from the corresponding arm or leg laboratory regression equation. A hip-mounted CSA accelerometer and Yamax pedometer were also used to predict EE. Predicted values (METs) were compared to measured values (METs), obtained via a portable metabolic measurement system (Cosmed K4b(2)). RESULTS: The Yamax pedometer and the CSA accelerometer on the hip significantly underestimated the energy cost of selected physical activities, whereas HR alone significantly overestimated the energy cost of selected physical activities. The simultaneous HR-motion sensor technique showed the strongest relationship with VO(2) (R(2) = 0.81) and did not significantly over- or underpredict the energy cost (P = 0.341). CONCLUSION: The simultaneous HR-motion sensor technique is a good predictor of EE during selected lifestyle activities, and allows researchers to more accurately quantify free-living PA.

Relationship of leisure-time physical activity and occupational activity to the prevalence of obesity.

OBJECTIVE: To assess the interaction between leisure-time physical activity (LTPA) and occupational activity (OA) on the prevalence of obesity. DESIGN: Secondary data analysis of a population based cross-sectional US national sample (NHANES III). SUBJECTS: A total of 4889 disease-free, currently employed adults over age 20 y. MEASUREMENTS: Subjects body mass index (BMI) was categorized as (1) obese (BMI> or =30 kg/m(2)), or (2) non-obese (BMI<30 kg/m(2)). LTPA was divided into four categories: (1) no LTPA; (2) irregular LTPA; (3) regular moderate intensity LTPA; and (4) regular vigorous intensity LTPA. OA was grouped as (1) high OA and (2) low OA. Age, gender, race-ethnicity, smoking status, urbanization classification, alcohol consumption and income were statistically controlled. RESULTS: In all, 16.8% (s.e. 0.7) of the total subject population were obese (15.1% (s.e. 1.1) of men and 19.1% (s.e. 1.1) of women). Logistic regression revealed that compared to those who engage in no LTPA and have low levels of OA, the likelihood of being obese is 42% (95% CI 0.35, 0.96) lower for those who engage in no LTPA and have high OA, 48% (95% CI 0.32, 0.83) lower for those who have irregular LTPA and have high levels of OA, and about 50% lower for all those who have regular LTPA through moderate or vigorous activity levels regardless of OA level. CONCLUSION: When considering disease free adults above 20 y of age employed in high and low activity occupations, a high level of occupational activity is associated with a decreased likelihood of being obese.

Estimation of energy expenditure using CSA accelerometers at hip and wrist sites.

PURPOSE: This study was designed to establish prediction models that relate hip and wrist accelerometer data to energy expenditure (EE) in field and laboratory settings. We also sought to determine whether the addition of a wrist accelerometer would significantly improve the prediction of EE (METs), compared with a model that used a hip accelerometer alone. METHODS: Seventy participants completed one to six activities within the categories of yardwork, housework, family care, occupation, recreation, and conditioning, for a total of 5 to 12 participants tested per activity. EE was measured using the Cosmed K4b2 portable metabolic system. Simultaneously, two Computer Science and Applications, Inc. (CSA) accelerometers (model 7164), one worn on the wrist and one worn on the hip, recorded body movement. Correlations between EE measured by the Cosmed and the counts recorded by the CSA accelerometers were calculated, and regression equations were developed to predict EE from the CSA data. RESULTS: The wrist, hip, and combined hip and wrist regression equations accounted for 3.3%, 31.7%, and 34.3% of the variation in EE, respectively. The addition of the wrist accelerometer data to the hip accelerometer data to form a bivariate regression equation, although statistically significant (P = 0.002), resulted in only a minor improvement in prediction of EE. Cut points for 3 METs (574 hip counts), 6 METs (4945 hip counts), and 9 METs (9317 hip counts) were also established. CONCLUSION: The small amount of additional accuracy gained from the wrist accelerometer is offset by the extra time required to analyze the data and the cost of the accelerometer.

Comparison of three methods for measuring the time spent in physical activity.

PURPOSE: Three methods for measuring time spent in daily physical activity (PA) were compared during a 21-d period among 83 adults (38 men and 45 women). METHODS: Each day, participants wore a Computer Science and Applications, Inc. (CSA) monitor and completed a 1-page, 48-item PA log that reflected time spent in household, occupational, transportation, sport, conditioning, and leisure activities. Once a week, participants also completed a telephone survey to identify the number of minutes spent each week in nonoccupational walking and in moderate intensity and hard/very hard-intensity PA. Data were analyzed using descriptive statistics and Spearman rank-order correlations. Three equations developed to compute CSA cut points for moderate and hard/very hard PA were also compared with the PA logs and PA survey. RESULTS: There was modest to good agreement for the time spent in different PA intensity categories between the three CSA cut point methods (r = 0.43-0.94, P < 0.001). Correlations between the CSA and PA logs ranged from r = 0.22 to r = 0.36, depending on the comparisons. Correlations between the survey items and PA logs were r = 0.26-0.54 (P < 0.01) for moderate and walking activities and r < 0.09 (P > 0.05) for hard/very hard activities. Correlations between the survey items and the CSA min per day varied according to the method used to compute the CSA intensity cut points. CONCLUSIONS: The results were consistent with findings from other PA validation studies that show motion sensors, PA logs, and surveys reflect PA; however, these methods do not always provide similar estimates of the time spent in resting/light, moderate, or hard/very hard PA.

Evaluation of heart rate as a method for assessing moderate intensity physical activity.

UNLABELLED: To further develop our understanding of the relationship between habitual physical activity and health, research studies require a method of assessment that is objective, accurate, and noninvasive. Heart rate (HR) monitoring represents a promising tool for measurement because it is a physiological parameter that correlates well with energy expenditure (EE). However, one of the limitations of HR monitoring is that training state and individual HR characteristics can affect the HR-VO2 relationship. PURPOSE: The primary purpose of this study was to examine the relationship between HR (beats x min(-1)) and VO2 (mL x kg(-1 x -1) min(-1)) during field- and laboratory-based moderate-intensity activities. In addition, we examined the validity of estimating EE from HR after adjusting for age and fitness. This was done by expressing the data as a percent of heart rate reserve (%HRR) and percent of VO2 reserve (%VO2R). METHODS: Sixty-one adults (18-74 yr) performed physical tasks in both a laboratory and field setting. HR and VO2 were measured continuously during the 15-min tasks. Mean values over min 5-15 were used to perform linear regression analysis on HR versus VO2. HR data were then used to predict EE (METs), using age-predicted HRmax and estimated VO2max. RESULTS: The correlation between HR and VO2 was r = 0.68, with HR accounting for 47% of the variability in VO2. After adjusting for age and fitness level, HR was an accurate predictor of EE (r = 0.87, SEE = 0.76 METs). CONCLUSION: This method of analyzing HR data could allow researchers to more accurately quantify physical activity in free-living individuals.

Validity of four motion sensors in measuring moderate intensity physical activity.

PURPOSE: This study tested the validity of four motion sensors for measuring energy expenditure (EE) during moderate intensity physical activities in field and laboratory settings. We also evaluated the accuracy of the EE values for selected moderate activities listed in the 1993 Compendium of Physical Activities. METHODS: A total of 81 participants (age 19-74 yr) completed selected tasks from six general categories: yardwork, housework, occupation, family care, conditioning, and recreation. Twelve individuals performed each of the 28 activities examined. During each activity, EE was measured using a portable metabolic measurement system. Participants also wore three accelerometers (Computer Science and Applications [CSA], Inc. model 7164; Caltrac; and Kenz Select 2) and the Yamax SW-701 electronic pedometer. For the CSA device, three previously developed regression equations were used to convert accelerometer scores to EE. RESULTS: The mean error scores (indirect calorimetry minus device) across all activities were: CSA1, 0.97 MET; CSA2, 0.47 MET, CSA3, 0.05 MET; Caltrac, 0.83 MET; Kenz, 0.96 MET; and Yamax, 1.12 MET. The correlation coefficients between indirect calorimetry and motion sensors ranged from r = 0.33 to r = 0.62. The energy cost for power mowing and sweeping/mopping was higher than that listed in the 1993 Compendium (P < 0.05), and the cost for several household and recreational activities was lower (P < 0.05). CONCLUSION: Motion sensors tended to overpredict EE during walking. However, they underpredicted the energy cost of many other activities because of an inability to detect arm movements and external work. These findings illustrate some of the limitations of using motion sensors to predict EE in field settings.