Preliminary observations on the presence of sustained tendon strain and eccentric contractions of the wrist extensors during a common manual task: implications for lateral epicondylitis

Lateral epicondylitis (LE) is hypothesized to occur as a result of repetitive, strenuous and abnormal postural activities of the elbow and wrist. There is still a lack of understanding of how wrist and forearm positions contribute to this condition during common manual tasks. In this study the wrist kinematics and the wrist extensors’ musculotendon patterns were investigated during a manual task believed to elicit LE symptoms in susceptible subjects. A 42-year-old right-handed male, with no history of LE, performed a repetitive movement involving pushing and turning a spring-loaded mechanism. Motion capture data were acquired for the upper limb and an inverse kinematic and dynamic analysis was subsequently carried out. Results illustrated the presence of eccentric contractions sustained by the extensor carpi radialis longus (ECRL), together with an almost constant level of tendon strain of both extensor carpi radialis brevis (ECRB) and extensor digitorum communis lateral (EDCL) branch. It is believed that these factors may partly contribute to the onset of LE as they are both responsible for the creation of microtears at the tendons’ origins. The methodology of this study can be used to explore muscle actions during movements that might cause or exacerbate LE.

Variation in the sensitivity of Callosobruchus (Coleoptera: Bruchidae) acetylcholinesterase to the organophosphate insecticide malaoxon: effect of species, geographical strain and food type

BACKGROUND: Bruchid beetles, Callosobruchus species, are serious pests of economically important grain legumes; their activity in stores is often controlled by use of synthetic insecticides. Esterases are known to be involved in insecticide resistance in insects. However, there is dearth of information on esterase activity in the genus Callosobruchus. In this study we investigated the effect of species, geographical strain and food type on the variation of acetylcholinesterase (AChE) activity and its inhibition by malaoxon (malathion metabolite) using an in vitro spectrophotometric method. RESULT: AChE activity varied significantly among species and strains and also among legume type used for rearing them. Generally irrespective of species, strain or food type, the higher the AChE activity of a population, the higher its inhibition by malaoxon. C. chinensis had the highest AChE activity of the species studied and in the presence of malaoxon it had the lowest remaining AChE activity, while C. rhodesianus retained the highest activity. CONCLUSION: A firsthand knowledge of AChE activity in regional Callosobruchus in line with the prevailing food types should be of utmost importance to grain legume breeders, researchers on plant materials for bruchid control and pesticide manufacturer/applicators for a robust integrated management of these bruchids.

Word position and stress effects in consonant cluster perception and production

The aim of the present study was to investigate whether the saliency effect for word beginnings reported in children with Dyslexia (Marshall & van der Lely, 2009) can be found also in TD children. Thirty-four TD Italian children aged 8-10 completed two specifically designed tasks: a production task and a perception task. Both tasks used nonwords containing clusters consisting of plosive plus liquid (eg. pl). Clusters could be either in a stressed or in an unstressed syllable, and could be either in initial position (first syllable) or in medial position (second syllable). In the production task children were asked to repeat the non-words. In the perception task, the children were asked to discriminate between two nonwords differing in one phoneme belonging to a cluster by reporting whether two repetitions were the same or different. Results from the production task showed that children are more accurate in repeating stressed than unstressed syllables, but there was no difference with respect to position of the cluster. Results from the perception task showed that children performed more accurately when discriminating word initial contrasts than when discriminating word medial contrasts, especially if the cluster was unstressed. Implications of this finding for clinical assessments are discussed.

Sex differences in the programming effects of prenatal stress on psychopathology and stress responses: an evolutionary perspective

There is strong evidence from animal studies that prenatal stress has different effects on male and female offspring. In general, although not always, prenatal stress increases anxiety, depression and stress responses, both hypothalamic–pituitary–adrenal and cardiovascular, in female offspring rather than in male. Males are more likely to show learning and memory deficits. There have been few studies so far in humans which differentiate effects of prenatal stress on male and female psychopathology. Some studies support the animal models, but the evidence is inconsistent. The mediating mechanisms for any sex specific effects are little understood, but there is evidence that placental function can differ depending on the sex of the fetus. We suggest that there may be an evolutionary reason for any sex differences in the long term effects of prenatal stress. In a stressful environment it may be adaptive for females, who are more likely to stay in one place and look after children, to be more vigilant, alert to danger and thus show more stress responsiveness. This can give rise to a more anxious or depressed phenotype. With males it may be more adaptive to go out and explore new environments, compete with other males, and be more aggressive. For this it may help to be less responsive to external stressors. More research is needed into sex differences in the effects of prenatal stress in humans, to test these ideas.

Signaling pathways mediating cardiac myocyte gene expression in physiological and stress responses

The contractile cells in the heart (the cardiac myocytes) are terminally differentiated. In response to pathophysiological stresses, cardiac myocytes undergo hypertrophic growth or apoptosis, responses associated with the development of cardiac pathologies. There has been much effort expended in gaining an understanding of the stimuli which promote these responses, and in identifying the intracellular signaling pathways which are activated and potentially involved. These signaling pathways presumably modulate gene and protein expression to elicit the end-stage response. For the regulation of gene expression, the signal may traverse the cytoplasm to modulate nuclear-localized transcription factors as occurs with the mitogen-activated protein kinase or protein kinase B/Akt cascades. Alternatively, the signal may promote translocation of transcription factors from the cytoplasm to the nucleus as is seen with the calcineurin/NFAT and JAK/STAT systems. We present an overview of the principal signaling pathways implicated in the regulation of gene expression in cardiac myocyte pathophysiology, and summarize the current understanding of these pathways, the transcription factors they regulate and the changes in gene expression associated with the development of cardiac pathologies. Finally, we discuss how intracellular signaling and gene expression may be integrated to elicit the overall change in cellular phenotype.

Intake, water consumption, ruminal fermentation, and stress response of beef heifers fed after different lengths of delays in the daily feed delivery time

Four rumen-fistulated Holstein heifers (134 +/- 1 kg initial BW) were used in a 4 x 4 Latin square design to determine the effects of delaying daily feed delivery time on intake, ruminal fermentation, behavior, and stress response. Each 3-wk experimental period was preceded by 1 wk in which all animals were fed at 0800 h. Feed bunks were cleaned at 0745 h and feed offered at 0800 h (T0, no delay), 0900 (T1), 1000 (T2), and 1100 (T3) from d1 to 21 with measurements taken during wk 1 and 3. Heifers were able to see each other at all times. Concentrate and barley straw were offered in separate compartments of the feed bunks, once daily and for ad libitum intake. Ruminal pH and saliva cortisol concentrations were measured at 0, 4, 8, and 12 h postfeeding on d 3 and 17 of each experimental period. Fecal glucocorticoid metabolites were measured on d 17. Increasing length of delay in daily feed delivery time resulted in a quadratic response in concentrate DMI (low in T1 and T2; P = 0.002), whereas straw DMI was greatest in T1 and T3 (cubic P = 0.03). Treatments affected the distribution of DMI within the day with a linear decrease observed between 0800 and 1200 h but a linear increase during nighttimes (2000 to 0800 h), whereas T1 and T2 had reduced DMI between 1200 and 1600 h (quadratic P = 0.04). Water consumption (L/d) was not affected but decreased linearly when expressed as liters per kilogram of DMI (P = 0.01). Meal length was greatest and eating rate slowest in T1 and T2 (quadratic P <= 0.001). Size of the first meal after feed delivery was reduced in T1 on d 1 (cubic P = 0.05) and decreased linearly on d 2 (P = 0.01) after change. Concentrate eating and drinking time (shortest in T1) and straw eating time (longest in T1) followed a cubic trend (P = 0.02). Time spent lying down was shortest and ruminating in standing position longest in T1 and T2. Delay of feeding time resulted in greater daily maximum salivary cortisol concentration (quadratic P = 0.04), which was greatest at 0 h in T1 and at 12 h after feeding in T2 (P < 0.05). Daily mean fecal glucocorticoid metabolites were greatest in T1 and T3 (cubic P = 0.04). Ruminal pH showed a treatment effect at wk 1 because of increased values in T1 and T3 (cubic P = 0.01). Delaying feed delivery time was not detrimental for rumen function because a stress response was triggered, which led to reduced concentrate intake, eating rate, and size of first meal, and increased straw intake. Increased salivary cortisol suggests that animal welfare is compromised.

Short-Term Modulation of Extracellular Signal-Regulated Kinase 1/2 and Stress-Activated Protein Kinase/c-Jun NH2-Terminal Kinase in Pancreatic Islets by Glucose and Palmitate Possible Involvement of Ceramide

Objectives: The effect of glucose and palmitate on the phosphorylation of proteins associated with cell growth and survival (extracellular signal-regulated kinase 1/2 [ERK1/2] and stress-activated protein kinase/c-Jun NH2-terminal kinase [SAPK/JNK]) and on the expression of immediate early genes was investigated. Methods: Groups of freshly isolated rat pancreatic islets were incubated in 10-mmol/L glucose with palmitate, LY294002, or fumonisin B1 for the measurement of the phosphorylation and the content of ERK1/2, JNK/SAPK, and v-akt murine thymoma viral oncongene (AKT) (serine 473) by immunoblotting. The expressions of the immediate early genes, c-fos and c-jun, were evaluated by reverse transcription-polymerase chain reaction. Results: Glucose at 10 mmol/L induced ERK1/2 and AKT phosphorylations and decreased SAPK/JNK phosphorylation. Palmitate (0.1 mmol/L) abolished the glucose effect on ERK1/2, AKT, and SAPK/JNK phosphorylations. LY294002 caused a similar effect. The inhibitory effect of palmitate on glucose-induced ERK1/2 and AKT phosphorylation changes was not observed in the presence of fumonisin B1. Glucose increased c-fos and decreased c-jun expressions. Palmitate and LY294002 abolished these latter glucose effects. The presence of fumonisin B1 abolished the effect induced by palmitate on c-jun expression. Conclusions: Our results suggest that short-term changes of mitogen-activated protein kinase and AKT signaling pathways and c-fos and c-jun expressions caused by glucose are abolished by palmitate through phosphatidylinositol 3-kinase inhibition via ceramide synthesis.

Electrical transport in disordered and ordered magnetic domains under pressures and magnetic fields

Magnetic M( T, H, P) and electrical transport.( T, H, P) measurements in a strong spin-lattice-charge coupled La(0.7)Ca(0.3)MnO(3) system have been conducted. The application of H and P leads to the formation of different magnetic domain structures in the vicinity and below the polaronic-to-ferromagnetic transition temperature. The charge mobility is more sensitive to the variation of the spatial wave function overlap between Mn(3+) eg and O(2-) 2p orbitals due to the applied compacting pressure rather than the relative spin orientation between neighbouring Mn ions when the magnetic field is applied. In spite of the presence of different magnetic domain structures due to the sample history, the effect of magnetic field and pressure is less pronounced at lower temperatures on electrical transport properties.

Divining Rods and Lightning Fields: Interactions and Interfaces: A Studio Exhibition in Communication With Save the Bay

"Design proposals for an outdoor 'exhibit' on the Shores of Narragansett Bay".

Occupational exposure of physical therapists to electric and magnetic fields and the efficacy of Faraday cages

Objective. Measure physical therapists' exposure to the electric and magnetic fields produced by 17 shortwave diathermy devices in physical therapy clinics in the city of Presidente Prudente, São Paulo State, Brazil. Compare the observed values with the exposure levels recommended by the International Commission on Non-ionizing Radiation Protection (ICNIRP). Observe the efficacy of Faraday cages as a means of protecting physical therapists from exposure to oscillating electric and magnetic fields.Methods. Electric and magnetic field measurements were taken at four points during actual physical therapy sessions: in proximity to the operator's pelvis and head, the devices' electrical cables, and the electrodes. The measuring equipment was a Wandel & Goltermann EMR-200.Results. The values obtained in proximity to the electrodes and cables were 10 to 30 times higher than ICNIRP's recommended occupational reference levels. In the shortwave diathermy treatment rooms with Faraday cages, the fields were even higher than in treatment rooms not so equipped-principally the magnetic field, where the values were more than 100 times higher than the ICNIRP exposure limit.Conclusions. The electric and magnetic field intensities obtained in this study are generally above the exposure levels recommend in ICNIRP standards. It was also observed that the Faraday cage offers physical therapists no protection, and instead, increases their level of exposure.

Development of a Validated Stability-Indicating LC Assay and Stress Degradation Studies of Linezolid in Tablets

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Model to localize gauge and tensor fields on thick branes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

An evaluation of shot peening, residual stress and stress relaxation on the fatigue life of AISI 4340 steel

Shot peening is a method widely used to improve the fatigue strength of materials. through the creation of a compressive residual stress field (CRSF) in their surface layers. In the present research the gain in fatigue life of AISI 4340 steel, Used in landing gear. is evaluated under four Shot peening conditions. Rotating bending fatigue tests were conducted and the CRSF was measured by an X-ray tensometry prior and during fatigue tests. It was observed that relaxation of the CRSF occurred due to the fatigue process. In addition, the fractured fatigue specimens were investigated using a scanning electron microscope in order to obtain information about the crack initiation points. The evaluation of fatigue life, relaxation of CRSF and crack sources are discussed. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Leaf trait variation on Erythroxylum tortuosum (Erythroxylaceae) and its relationship with oviposition preference and stress by a host-specific leaf miner

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Arabidopsis thaliana Uncoupling Proteins (AtUCPs): insights into gene expression during development and stress response and epigenetic regulation

Mitochondrial inner membrane uncoupling proteins (UCP) catalyze a proton conductance that dissipates the proton electrochemical gradient established by the respiratory chain, thus affecting the yield of ATP synthesis. UCPs are involved in mitochondrial energy flow regulation and have been implicated in oxidative stress tolerance. Based on the global gene expression profiling datasets available for Arabidopsis thaliana, in this review we discuss the regulation of UCP gene expression during development and in response to stress, and provide interesting insights on the possible existence of epigenetic regulation of UCP expression.