Influence of peroxyacetic acid concentration, temperature, pH, and treatment time on antimicrobial efficacy against Salmonella on chicken wings.

Peroxyacetic acid (PAA) is commonly used during poultry processing to reduce the prevalence of Salmonella on carcasses and parts. Wash solutions containing PAA are used at varying concentrations during processing and processors use internally validated practices that best suit the needs of the individual establishment. This study was conducted to determine how temperature, pH, and contact time in combination with PAA concentration can affect the survival of Salmonella on poultry. The effectiveness of PAA in reducing the population of Salmonella on chicken wings was dependent on the concentration and temperature of the PAA solutions. The pH or contact time had no effects (P > 0.05) on total Salmonella or Salmonella Infantis reduction (log CFU/mL). Treatment with 0 ppm PAA at 27°C did not reduce (P > 0.05) total Salmonella or Salmonella Infantis compared to the inoculated, untreated control; in contrast, treatment at 4°C and 0 ppm PAA reduced (P < 0.05) total Salmonella and Salmonella Infantis. Treatments applied at 4°C significantly reduced (P < 0.05) total Salmonella at 50, 200, and 500 ppm PAA, compared to treatment at 27°C among the same PAA concentration. The population of Salmonella Infantis was significantly reduced (P < 0.05) at 4°C with 0, 50, 200, 500, and 1,000 ppm PAA among the same PAA concentration, compared to treatment at 27°C. Treatment conditions, such as temperature, can impact the effectiveness of PAA used as an antimicrobial treatment during poultry processing, and the results from this study can provide useful insights that could assist poultry processors to effectively incorporate PAA into antimicrobial intervention systems.

Work Engagement Among Physical Therapists and Physical Therapist Assistants.

AIMS: Work engagement is an important component of occupational wellness. The purpose of this study was to compare work engagement between physical therapists (PTs) and physical therapist assistants (PTAs) and to analyze relationships with participant demographics. METHODS: An online survey was emailed to all licensed PTs and PTAs in Texas, with 975 completed surveys returned. The survey consisted of demographic information and the Utrecht Work Engagement Scale-9. RESULTS: PTs and PTAs had similar levels of work engagement. Participants with a productivity requirement and those intending to leave their position had decreased work engagement, while American Physical Therapy Association (APTA) members had increased work engagement. CONCLUSION: The presence of a productivity requirement was associated with decreased work engagement and intent to leave one's position. To promote work engagement, organizations should assess productivity expectations and ensure job resources are adequate.

Job Satisfaction and Productivity Requirements Among Physical Therapists and Physical Therapist Assistants.

BACKGROUND: Job satisfaction is a concern within many professions and may lead to decreased employee recruitment and retention. The purpose of this study was to compare the level of job satisfaction in PTs and PTAs and to analyze relationships between job satisfaction, demographics, and productivity requirements. METHODS: 245 PTs and PTAs in Washington state completed a survey consisting of demographic information and the Job Satisfaction Survey (JSS), which measures job satisfaction within nine subscales. RESULTS: PTs and PTAs had similar levels of job satisfaction, and participants had higher total job satisfaction than established norms. 60% of subjects had a productivity standard, with an average standard of 82.1%. Participants with a productivity standard had lower job satisfaction, and lower satisfaction regarding rewards, operating conditions, nature of work, and communication. Significant negative correlations were found between productivity standards, total job satisfaction, and satisfaction regarding pay, supervision, benefits, rewards, and communication. CONCLUSIONS: PTs and PTAs with a productivity standard and those seeking employment should be aware that productivity standards may negatively impact job satisfaction. Organizations should evaluate policies regarding productivity requirements to ensure adequate levels of employee job satisfaction are maintained and to potentially improve employee recruitment and retention.

Hip-Muscle Activity in Men and Women During Resisted Side Stepping With Different Band Positions.

CONTEXT: Weakness or decreased activation of the hip abductors and external rotators has been associated with lower extremity injury, especially in females. Resisted side stepping is commonly used to address hip weakness. Whereas multiple variations of this exercise are used clinically, few data exist regarding which variations to select. OBJECTIVE: To investigate differences in muscle-activation and movement patterns and determine kinematic and limb-specific differences between men and women during resisted side stepping with 3 resistive-band positions. DESIGN: Controlled laboratory study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 22 healthy adults (11 men, 11 women; age = 22.8 ± 3.0 years, height = 171.6 ± 10.7 cm, mass = 68.5 ± 11.8 kg). INTERVENTION(S): Participants side stepped with the resistive band at 3 locations (knees, ankles, feet). MAIN OUTCOME MEASURE(S): We collected surface electromyography of the gluteus maximus, gluteus medius, and tensor fascia lata (TFL) for the moving and stance limbs during the concentric and eccentric phases. We also measured trunk inclination, hip and knee flexion, and hip-abduction excursion. RESULTS: Hip-abductor activity was higher in women than in men ( P ≤ .04). The pattern of TFL activity in the stance limb differed by sex. Women performed the exercise in greater forward trunk inclination ( P = .009) and had greater hip excursion ( P = .003). Gluteus maximus and medius activity increased when the band was moved from the knees to the ankles and from the ankles to the feet, whereas TFL activity increased only when the band was moved from the knees to the ankles. Findings were similar for both the stance and moving limbs, but the magnitudes of the changes differed. CONCLUSIONS: Compared with placing the band around the ankles, placing the band around the feet for resisted side stepping elicited more activity in the gluteal muscles without increasing TFL activity. This band placement is most appropriate when the therapeutic goal is to activate the muscles that resist hip adduction and internal rotation.

Effect of Rhodopsin Phosphorylation on Dark Adaptation in Mouse Rods.

UNLABELLED: Rhodopsin is a prototypical G-protein-coupled receptor (GPCR) that is activated when its 11-cis-retinal moiety is photoisomerized to all-trans retinal. This step initiates a cascade of reactions by which rods signal changes in light intensity. Like other GPCRs, rhodopsin is deactivated through receptor phosphorylation and arrestin binding. Full recovery of receptor sensitivity is then achieved when rhodopsin is regenerated through a series of steps that return the receptor to its ground state. Here, we show that dephosphorylation of the opsin moiety of rhodopsin is an extremely slow but requisite step in the restoration of the visual pigment to its ground state. We make use of a novel observation: isolated mouse retinae kept in standard media for routine physiologic recordings display blunted dephosphorylation of rhodopsin. Isoelectric focusing followed by Western blot analysis of bleached isolated retinae showed little dephosphorylation of rhodopsin for up to 4 h in darkness, even under conditions when rhodopsin was completely regenerated. Microspectrophotometeric determinations of rhodopsin spectra show that regenerated phospho-rhodopsin has the same molecular photosensitivity as unphosphorylated rhodopsin and that flash responses measured by trans-retinal electroretinogram or single-cell suction electrode recording displayed dark-adapted kinetics. Single quantal responses displayed normal dark-adapted kinetics, but rods were only half as sensitive as those containing exclusively unphosphorylated rhodopsin. We propose a model in which light-exposed retinae contain a mixed population of phosphorylated and unphosphorylated rhodopsin. Moreover, complete dark adaptation can only occur when all rhodopsin has been dephosphorylated, a process that requires >3 h in complete darkness. SIGNIFICANCE STATEMENT: G-protein-coupled receptors (GPCRs) constitute the largest superfamily of proteins that compose ∼4% of the mammalian genome whose members share a common membrane topology. Signaling by GPCRs regulate a wide variety of physiological processes, including taste, smell, hearing, vision, and cardiovascular, endocrine, and reproductive homeostasis. An important feature of GPCR signaling is its timely termination. This normally occurs when, after their activation, GPCRs are rapidly phosphorylated by specific receptor kinases and subsequently bound by cognate arrestins. Recovery of receptor sensitivity to the ground state then requires dephosphorylation of the receptor and unbinding of arrestin, processes that are poorly understood. Here we investigate in mouse rod photoreceptors the relationship between rhodopsin dephosphorylation and recovery of visual sensitivity.

Rhodopsin kinase and arrestin binding control the decay of photoactivated rhodopsin and dark adaptation of mouse rods.

Photoactivation of vertebrate rhodopsin converts it to the physiologically active Meta II (R*) state, which triggers the rod light response. Meta II is rapidly inactivated by the phosphorylation of C-terminal serine and threonine residues by G-protein receptor kinase (Grk1) and subsequent binding of arrestin 1 (Arr1). Meta II exists in equilibrium with the more stable inactive form of rhodopsin, Meta III. Dark adaptation of rods requires the complete thermal decay of Meta II/Meta III into opsin and all-trans retinal and the subsequent regeneration of rhodopsin with 11-cis retinal chromophore. In this study, we examine the regulation of Meta III decay by Grk1 and Arr1 in intact mouse rods and their effect on rod dark adaptation. We measure the rates of Meta III decay in isolated retinas of wild-type (WT), Grk1-deficient (Grk1(-/-)), Arr1-deficient (Arr1(-/-)), and Arr1-overexpressing (Arr1(ox)) mice. We find that in WT mouse rods, Meta III peaks ∼6 min after rhodopsin activation and decays with a time constant (τ) of 17 min. Meta III decay slows in Arr1(-/-) rods (τ of ∼27 min), whereas it accelerates in Arr1(ox) rods (τ of ∼8 min) and Grk1(-/-) rods (τ of ∼13 min). In all cases, regeneration of rhodopsin with exogenous 11-cis retinal is rate limited by the decay of Meta III. Notably, the kinetics of rod dark adaptation in vivo is also modulated by the levels of Arr1 and Grk1. We conclude that, in addition to their well-established roles in Meta II inactivation, Grk1 and Arr1 can modulate the kinetics of Meta III decay and rod dark adaptation in vivo.

Resisted Side Stepping: The Effect of Posture on Hip Abductor Muscle Activation.

STUDY DESIGN: Controlled laboratory study, repeated-measures design. OBJECTIVES: To compare hip abductor muscle activity and hip and knee joint kinematics in the moving limb to the stance limb during resisted side stepping, and to determine whether muscle activity was affected by the posture (upright standing versus squat) used to perform the exercise. BACKGROUND: Hip abductor weakness has been associated with a variety of lower extremity injuries. Resisted side stepping is often used as an exercise to increase strength and endurance of the hip abductors. Exercise prescription would benefit from knowing the relative muscle activity level generated in each limb and for different postures during the side-stepping exercise. METHODS: Twenty-four healthy adults participated in this study. Kinematics and surface electromyographic data from the gluteus maximus, gluteus medius, and tensor fascia lata were collected as participants performed side stepping with a resistive band around the ankle, while maintaining each of 2 postures: (1) upright standing and (2) squat. RESULTS: Mean normalized electromyographic signal amplitude of the gluteus maximus, gluteus medius, and tensor fascia lata was higher in the stance limb than in the moving limb (P≤.001). Gluteal muscle activity was higher, whereas tensor fascia lata muscle activity was lower, in the squat posture compared to the upright standing posture (P<.001). Hip abduction excursion was greater in the stance limb than in the moving limb (P<.001). CONCLUSION: The 3 hip abductor muscles respond differently to the posture variations of the side-stepping exercise in healthy individuals. When prescribing resisted side-stepping exercises, therapists should consider the differences in hip abductor activation across limbs and variations in trunk posture.

Burnout among physical therapist assistant program directors: a nationwide survey and analysis.

PURPOSE: The purpose of this study was to assess burnout in directors of physical therapist assistant (PTA) programs and to analyze the relationship between individual and institutional variables and burnout. METHODS: Surveys were completed by 120 directors from accredited PTA programs. The surveys consisted of demographic information and the Maslach Burnout Inventory-Educators Survey (MBI-ES). The MBI-ES assesses burnout in the areas of emotional exhaustion, depersonalization, and personal accomplishment. RESULTS: PTA program directors showed moderate levels of emotional exhaustion, low levels of depersonalization, and high levels of personal accomplishment. Gender, the number of faculty in a department, and length of academic contract had no correlation with participant burnout levels. Significantly lower levels of emotional exhaustion were found in participants who were in their current position for more than 11 years and those who planned to remain in their current position or within higher education for at least 5 additional years. A significant negative correlation was found between participant age and depersonalization. DISCUSSION: PTA program directors and their institutions should develop strategies to minimize the effects of burnout in younger program directors and those in the early years of their position.

Injury type and incidence among elite level curlers during world championship competition.

Our objective was to investigate the incidence of musculoskeletal injuries sustained by elite level curling athletes during international competition. This study was conducted during the 2008 World Men's Curling Championships. All registered athletes and the tournament medical team were given report forms for documenting injuries that occurred during the tournament. Report form information included demographics, area injured, types of injuries sustained, and curling-specific aggravating conditions. During the competition five injuries were reported, resulting in an injury rate of .07 injuries per game. Only one reported injury resulted in missed competition (.014 injuries per game). All reported injuries involved increased pain during curling-specific activities. At the elite international competitive level, injury incidence in curling was found to be low. Future exploration over the course of a season may be beneficial to identify risk factors and to assist with formulating training strategies to decrease injury risk.

Substrate suppression of thermal roughness in stacked supported bilayers.

We have fabricated a stack of five 1,2-dipalmitoyl-sn-3-phosphatidylethanolamine (DPPE) bilayers supported on a polished silicon substrate in excess water. The density profile of these stacks normal to the substrate was obtained through analysis of x-ray reflectivity. Near the substrate, we find the layer roughness and repeat spacing are both significantly smaller than values found in bulk multilayer systems. The reduced spacing and roughness result from suppression of lateral fluctuations due to the flat substrate boundary. The layer spacing decrease then occurs due to reduced Helfrich repulsion.