The epidemiology workforce : are we planning for the future?

Epidemiology has a central role in public health practice, education and research, and is arguably the only discipline unique to public health. A strong perception exists among epidemiologists in Australia that there is a substantial shortage in epidemiological capacity within the health workforce and health research, and that there are few graduates with sufficient high-level epidemiological training to fill the educational and leadership roles that will be essential to building this capacity. It was this concern that led the Australasian Epidemiological Association (AEA)--the peak professional body for epidemiologists in Australia and New Zealand--to convene a working group in 2007 to assess and address these concerns. This article summarises the key training challenges and opportunities discussed within this group, and the larger organisation, with the intention of stimulating greater public debate of these issues.

Strategies for the implementation of continuing professional development for SMEs in construction

The Victorian government (in Australia) intends to mandate that all registered building practitioners (RBP) undertake a minimum level of Continuing Professional Development (CPD) as part of the registration process. The introduction of CPD increases the travel costs for construction practitioners; due to the necessity to undertake a minimum level of training. This places an increased burden on construction companies' especially small regional-based firms that are not in a position of financial strength. This research is based on study of training needs of 73 construction companies in Victoria, Australia. The results show that training costs are being unequally weighted towards small regional-based firms; suggesting that the location of the company is a major contributing factor to their ability to meet registration requirements. Regional companies have comparatively high costs for training compared to metropolitan-based firms. Company location is a limiting factor that impacts on the ability of regional firms to implement training programs. This research investigates the notion that increasing registration requirements will improve outcomes for all participants.

Polyterthiophene/CNT composite as a cathode material for lithium batteries employing an ionic liquid electrolyte

A polyterthiophene (PTTh)/multi-walled carbon nanotube (CNT) composite was synthesised by in situ chemical polymerisation and used as an active cathode material in lithium cells assembled with an ionic liquid (IL) or conventional liquid electrolyte, LiBF₄/EC–DMC–DEC. The IL electrolyte consisted of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF₄) containing LiBF₄ and a small amount of vinylene carbonate (VC). The lithium cells were characterised by cyclic voltammetry (CV) and galvanostatic charge/discharge cycling. The specific capacity of the cells with IL and conventional liquid electrolytes after the 1st cycle was 50 and 47 mAh g⁻¹ (based on PTTh weight), respectively at the C/5 rate. The capacity retention after the 100th cycle was 78% and 53%, respectively. The lithium cell assembled with a PTTh/CNT composite cathode and a non-flammable IL electrolyte exhibited a mean discharge voltage of 3.8 V vs Li⁺/Li and is a promising candidate for high-voltage power sources with enhanced safety.

Needleless electrospinning : developments and performances

Electrospinning technique has attracted a lot of interests recently, although it was invented in as early as 1934 by Anton (Anton, 1934). A basic electrospinning setup normally comprises a high voltage power supply, a syringe needle connected to power supply, and a counter-electrode collector as shown in Fig. 1. During electrospinning, a high electric voltage is applied to the polymer solution, which highly electrifies the solution droplet at the needle tip (Li & Xia, 2004). As a result, the solution droplet at the needle tip receives electric forces, drawing itself toward the opposite electrode, thus deforming into a conical shape (also known as “Taylor cone” (Taylor, 1969)). When the electric force overcomes the surface tension of the polymer solution, the polymer solution ejects off the tip of the “Taylor cone” to form a polymer jet. The charged jet is stretched by the strong electric force into a fine filament. Randomly deposited dry fibers can be obtained on the collector due to the evaporation of solvent in the filament. There are many factors affecting the electrospinning process and fiber properties, including polymer materials (e.g. polymer structure, molecular weight, solubility), solvent (e.g. boiling point, dielectric properties), solution properties (e.g. viscosity, concentration, conductivity, surface tension), operating conditions (e.g. applied voltage, collecting distance, flow rate), and ambient environment (e.g. temperature, gas environment, humidity).

The effect of lumbosacral manipulation on corticospinal and spinal reflex excitability on asymptomatic participants

Objective The aim of the study was to examine the effects of a high-velocity, low-amplitude (HVLA) manipulation to the lumbosacral joint on corticospinal excitability, as measured by motor evoked potentials (MEPs) using transcranial magnetic stimulation, and spinal reflex excitability, as measured by the Hoffman reflex (H-reflex).

Methods In a randomized, controlled, crossover design, 14 asymptomatic volunteers (mean age, 23 ± 5.4 years; 10 men; 4 women) were measured for MEPs and H-reflexes immediately before and after a randomly allocated intervention. The interventions consisted of HVLA applied bilaterally to the lumbosacral joint and a control intervention. Participants returned a week later, and the same procedures were performed using the other intervention. Data for H-reflex and MEP amplitudes were normalized to the M-wave maximum amplitude and analyzed using 2-way analysis of variance with repeated measures.

Results A significant interaction of treatment by time was found for MEP (F1,13 = 4.87, P = .04), and post hoc analyses showed that the MEP/M-wave maximum ratio decreased significantly in the HVLA treatment (P = .02; effect size, 0.68). For H-reflex, there was a significant effect of time (F1,13 = 8.186, P = .01) and treatment and time interaction (F1,13 = 9.05, P = .01), with post hoc analyses showing that H-reflexes were significantly reduced after the HVLA manipulation (P = .004; effect size, 0.94). There were no significant changes in MEP latency or silent period duration.

Conclusion An HVLA manipulation applied to the lumbosacral joint produced a significant decrease in corticospinal and spinal reflex excitability, and no significant change occurred after the control intervention. The changes in H-reflexes were larger than those in MEPs, suggesting a greater degree of inhibition at the level of the spinal cord.

Corrosion properties of a RF-magnetron-sputtered TiN coating deposited on 316L stainless steel

The effect of rf-power in the range from 100 to 200 W on the electrochemical properties of TiN coatings deposited on 316L stainless steel was investigated by using various electrochemical techniques in a 3.5-wt\% NaCl solution. Surface analyses were also conducted to analyze the coating characteristics. X-ray diffraction (XRD) and atomic force microscopy (AFM) analyses confirmed that increasing the rf-power led to a preferred orientation of the TiN(200) microstructure and decreased the surface roughness. The potentiodynamic test results confirmed the passive behavior of all of the specimens with low passive current densities and demonstrated that the effective pitting resistance of the TiN coatings increased with increasing rf-power. The electrochemical impedance spectroscopy (EIS) tests showed that the TiN films deposited with high rf-power had excellent corrosion resistance during an immersion time of 720 h due to their high total resistance and low porosity.

Powerlessness following service failure and its implications for service recovery

This research examines whether service failure in hospitality settings reduces situational power and whether feelings of powerlessness have implications for service recovery efforts. Three studies demonstrated that service failure reduced consumers’ situational power, but only among those with high dispositional power motivation (studies 1 and 2). Moreover, those with high dispositional power motivation evinced greater satisfaction with service recovery efforts that involved status-enhancing compensation as opposed to utility-enhancing compensation (study 2), and when status-enhancing compensation was presented in public as opposed to in private (study 3). These findings suggest that consumers with high dispositional power motivation prefer service recovery attempts that counteract the feelings of powerlessness they experience from service failure. Service managers can benefit from these findings by understanding how feelings of power interact with service recovery efforts.

Modeling of shear ductile fracture considering a changeable cut-off value for stress triaxiality

 A macroscopic ductile fracture criterion is proposed based on micro-mechanism analysis of nucleation, growth and shear coalescence of voids from experimental observation of fracture surfaces. The proposed ductile fracture model endows a changeable cut-off value for the stress triaxiality to represent effect of micro-structures, the Lode parameter, temperature, and strain rate on ductility of metals. The proposed model is used to construct fracture loci of AA 2024- T351. The constructed fracture loci are compared with experimental data covering wide stress triaxiality ranging between –0.5 and 1.0. The comparison suggests that the proposed model can provide a satisfactory prediction of ductile fracture for metals from compressive upsetting tests to plane strain tension with slanted fracture surfaces. Moreover, it is expected that the proposed model reasonably describes ductile fracture behavior in high velocity perforation simulation since a reasonable cut-off value for the stress triaxiality is coupled with the proposed ductile fracture criterion.

The influence of follower cultural orientation on attitudinal responses towards transformational leadership: evidence from the Chinese hospitality industry

In addition to extending the empirical investigation of the relationship between transformational leadership and follower affective commitment to the Chinese hospitality industry, this study makes a theoretical contribution by investigating the influence of individually held cultural values on this relationship. Building on previous research which has examined whether collectivism moderates the transformational leadership/affective commitment relationship, this study investigates the moderating effects of two additional cultural value orientations, namely power distance and uncertainty avoidance. Hierarchical regression analysis was utilized to analyse survey data from 398 employees of four Chinese hotels in Zhejiang Province. In addition to finding a positive relationship between transformational leadership and affective commitment, data analysis revealed that followers low in power distance exhibited higher levels of affective commitment when working under a transformational leader than those high in power distance. In addition, followers high in uncertainty avoidance and collectivism exhibited greater commitment when working under a transformational leader than those low in uncertainty avoidance and collectivism. These findings clearly indicate the importance of within-country cultural differences to the effectiveness of leaders in the workplace. © 2014 © 2013 Taylor & Francis.

Short duration heat acclimation in Australian football players

This study examined if five sessions of short duration (27 min), high intensity, interval training (HIIT) in the heat over a nine day period would induce heat acclimation in Australian football (AF) players. Fourteen professional AF players were matched for VO2peak (mL∙kg-1∙min-1) and randomly allocated into either a heat acclimation (Acc) (n = 7) or Control (Con) group (n = 7). The Acc completed five cycle ergometer HIIT sessions within a nine day period on a cycle ergometer in the heat (38.7 ± 0.5 °C; 34.4 ± 1.3 % RH), whereas Con trained in thermo-neutral conditions (22.3 ± 0.2 °C; 35.8 ± 0. % RH). Four days prior and two days post HIIT participants undertook a 30 min constant load cycling test at 60% V̇O2peak in the heat (37.9 ± 0.1 °C; 28.5 ± 0.7 % RH) during which VO2, blood lactate concentration ([Lac-]), heart rate (HR), rating of perceived exertion (RPE), thermal comfort, core and skin temperatures were measured. Heat acclimation resulted in reduced RPE, thermal comfort and [Lac-] (all p < 0.05) during the submaximal exercise test in the heat. Heart rate was lower (p = 0.007) after HIIT, in both groups. Heat acclimation did not influence any other measured variables. In conclusion, five short duration HIIT sessions in hot dry conditions induced limited heat acclimation responses in AF players during the in-season competition phase. In practice, the heat acclimation protocol can be implemented in a professional team environment; however the physiological adaptations result-ing from such a protocol were limited.

Analytical assessment of optimum magnet pole-arc for PMSM under influence of different magnetization patterns

Permanent magnet synchronous machines (PMSMs) are popular in both industrial and domestic applications because of its high efficiency, power density, and reliability as compared with the conventional types of electrical machines. Generally, the analytical models and their field solutions are preferable to provide an accurate insight of the PMSM performances, instead of using the finite element models, because the former takes a considerably shorter computational time. PMSM design could have different properties of either slotted or slotless, or varieties of magnet placement on the rotor. By focusing on semi-closed surface-mounted PMSMs, the 2D analytical subdomain model in [1] demonstrates an accurate prediction of the magnetic fields that can facilitate the evaluation of the global quantities of PMSMs, such as cogging torque (Tcog), back-EMF, and total harmonic distortion (THDv). Previously, researchers investigated the influences of the machine performance by a single factor, e.g., the variation of Tcog during changes of magnet pole-arc (αP) [2, 3], or slot-opening [2, 3]. These investigations normally considered two types of magnetization patterns, i.e., parallel (PaM) and radial magnetization (RM). Therefore, the motivation of our work hinges on predicting the optimum value of αP in designing a surface-mounted PMSM under influence of four different magnetization patterns, using the analytical subdomain model.

Theoretical study of quantum capacitance and associated delay in armchair-edge graphene nanoribbons

This work presents a comprehensive investigation of the quantum capacitance and the associated effects on the carrier transit delay in armchair-edge graphene nanoribbons (A-GNRs) based on semi-analytical method. We emphasize on the realistic analysis of bandgap with taking edge effects into account by means of modified tight binding (TB) model. The results show that the edge effects have significant influence in defining the bandgap which is a necessary input in the accurate analyses of capacitance. The quantum capacitance is discussed in both nondegenerate (low gate voltage) and degenerate (high gate voltage) regimes. We observe that the classical capacitance limits the total gate (external) capacitance in the degenerate regime, whereas, quantum capacitance limits the external gate capacitance in the nondegenerate regime. The influence of gate capacitances on the gate delay is studied extensively to demonstrate the optimization of switching time. Moreover, the high-field behavior of a GNR is studied in the degenerate and nondegenerate regimes. We find that a smaller intrinsic capacitance appears in the channel due to high velocity carrier, which limits the quantum capacitance and thus limit the gate delay. Such detail analysis of GNRs considering a realistic model would be useful for the optimized design of GNR-based nanoelectronic devices.

Stable deep doping of vapor-phase polymerized poly(3,4-ethylenedioxythiophene)/ionic liquid supercapacitors

Liquid-solution polymerization and vapor-phase polymerization (VPP) have been used to manufacture a series of chloride- and tosylate-doped poly(3,4-ethylenedioxythiophene) (PEDOT) carbon paper electrodes. The electrochemistry, specific capacitance, and specific charge were determined for single electrodes in 1-ethyl-3-methylimidazolium dicyanamide (emim dca) ionic liquid electrolyte. VPP-PEDOT exhibits outstanding properties with a specific capacitance higher than 300 F g(-1) , the highest value reported for a PEDOT-based conducting polymer, and doping levels as high as 0.7 charges per monomer were achieved. Furthermore, symmetric PEDOT supercapacitor cells with the emim dca electrolyte exhibited a high specific capacitance (76.4 F g(-1) ) and high specific energy (19.8 Wh kg(-1) ). A Ragone plot shows that the VPP-PEDOT cells combine the high specific power of conventional ("pure") capacitors with the high specific energy of batteries, a highly sought-after target for energy storage.

Intrinsic motivation in two exercise interventions: Associations with fitness and body composition

OBJECTIVE: To examine the motivational process through which increases in aerobic capacity and decreases in total body fat are achieved during high-intensity intermittent training (HIT) and moderate-intensity continuous training (MICT) interventions. METHOD: Eighty-seven physically inactive adults (65% women, age = 42 ± 12, BMI = 27.67 ± 4.99 kg/m²) took part in a 10-week randomized intervention testing group-based HIT, operationalized as repeated sprints of 15-60 s interspersed with periods of recovery cycling ≤ 25 min/session, 3 sessions/wk⁻¹, or MICT, operationalized as cycling at constant workload of ∼65% maximum aerobic capacity (VO₂max, 30-45 min/session⁻¹, 5 sessions/wk⁻¹. Assessments of VO₂max and total body fat were made pre- and postintervention. Motivation variables were assessed midintervention and class attendance was monitored throughout. Path analysis was employed, controlling for treatment arm and baseline values of VO₂max and total body fat. RESULTS: The 2 groups differed in adherence only, favoring HIT. Baseline VO₂max predicted intrinsic motivation midintervention. Intrinsic motivation predicted program adherence, which in turn predicted increases in VO2max and decreases in total body fat by the end of the study. CONCLUSION: Intrinsic motivation in HIT and MICT is positively linked to adherence to these programs, which can facilitate improvements in fitness and body composition.