First Day Of Testing Research Articles

Effects of 30Years of Disuse on Exceptional Memory Performance.

In the mid-1980s, Dario Donatelli (DD) participated in a laboratory study of the effects of around 800h of practice on digit-span and increased his digit-span from 8 to 104 digits. This study assessed changes in the structure of his memory skill after around 30years of essentially no practice on the digit-span task. On the first day of testing, his estimated span was only 10 digits, but over the following 3 days of testing it increased to 19 digits. Further analyses of his recall performance and verbal reports identified which mechanisms of the original memory skill he could retrieve or reacquire over the 3days of practice. We discuss theoretical implications for the retention of skilled memory performance, the effects of age-related changes in memory on it, and for the future study of the effects of disuse on exceptional performance and complex skill.

Overheating phenomena induced by fully-glazed facades: Investigation of a sick building in Italy and assessment of the benefits achieved via model predictive control of the AC system

This paper addresses the potential benefit achievable via model-based, predictive control of the AC system in overheated buildings with large glazed façades.A sick building in Italy (and more specifically a protractedly and intensely sunlit office on the south-exposed, fully-glazed façade) was selected as case study.It was monitored over a week in December. The sensor network mapped the indoor climatic conditions, the surface temperature distribution on the glazed façade and the thermodynamic parameters of the air inlet from the 3-speed fan coil unit serving the room (originally in manual mode).The MPC relied on a grey-box model of the room’s thermal dynamics, built on a short-term monitoring dataset (4-day-lasting collection in November) and tuned during the first day of testing. Its ergonomic and energetic performance was assessed on the two days of maximum and minimum solar radiation.Considerably high operative temperature persisted all over the period of observation. However, while in free running the room reached peak values of almost 28°C, during the operation of the MPC the setpoint value of 24°C was never exceeded by more than 2°C. Indeed, the offset stayed within ±0.5°C for the 95.8% of the time on the sunnier day and for the 60.8% on the cloudier day, while the PMV remained within the ±0.5 range for the 85% and the 80% respectively. No local discomfort from vertical gradients or drafts occurred.Furthermore, the energy consumptions were remarkably contained since the fan operated at minimum speed for nearly the 80% of time.

A novel test for evaluating horses' spontaneous visual attention is predictive of attention in operant learning tasks.

Attention is described as the ability to process selectively one aspect of the environment over others. In this study, we characterized horses' spontaneous attention by designing a novel visual attention test (VAT) that is easy to apply in the animal's home environment. The test was repeated over three consecutive days and repeated again 6months later in order to assess inter-individual variations and intra-individual stability. Different patterns of attention have been revealed: 'overall' attention when the horse merely gazed at the stimulus and 'fixed' attention characterized by fixity and orientation of at least the visual and auditory organs towards the stimulus. The individual attention characteristics remained consistent over time (after 6months, Spearman correlation test, P<0.05). The validity of this novel test as a predictor of individual attentional skills was assessed by comparing the results, for the same horses, with those obtained in both a 'classical' experimental attention test the 'five-choice serial reaction time task' (5-CSRTT) and a work situation (lunge working context). Our results revealed that (i) individual variations remained consistent across tests and (ii) the VAT attention measures were not only predictive of attentional skills but also of learning abilities. Differences appeared however between the first day of testing and the following test days: attention structure on the second day was predictive of learning abilities, attention performances in the 5-CSRRT and at work. The VAT appears as a promising easy-to-use tool to assess animals' attention characteristics and the impact of different factors of variation on attention.

Increased complement activation during platelet storage.

It has been shown that platelet transfusion carries a higher incidence of transfusion-related adverse events than any other blood components, and prolonged platelet storage is associated with more transfusion reactions, most of which are considered to be inflammatory responses. However, the role of complement, which has very important proinflammatory activities, in the pathogenesis of platelet-related adverse events has not been fully understood. Three units of platelets collected by apheresis were stored on a platelet rotator with the temperature controlled between 22 and 24°C. Plasma samples were obtained using a sterile technique on Days 2 through 7. Complement components were assayed to evaluate the activation of complement activation and included C4d (classical pathway), Factor Bb (alternative pathway), C3a (common pathway), C5a (terminal pathway), and C5b-9 (terminal pathway). Both C4d and C3a were elevated on the first day of testing (Day 2) compared with the established normal ranges and continued to increase over time in storage. In contrast, Factor Bb levels remained stable and were within the normal range over time. Over a span of 7 days in storage, the terminal complement factors C5a and C5b-9 were also significantly increased, although the magnitude of increases was not as striking as those in C4d and C3a levels. Our results demonstrate that substantial complement activation occurs in platelets under standard storage conditions, and this activation increases with the duration of storage. After transfusion, these activated complement components might result in accelerated complement activation in recipients, leading to transfusion-related adverse events.

Developmental exposure to an environmental PCB mixture delays the propagation of electrical kindling from the amygdala

Developmental PCB exposure impairs hearing and induces brainstem audiogenic seizures in adult offspring. The degree to which this enhanced susceptibility to seizure is manifest in other brain regions has not been examined. Thus, electrical kindling of the amygdala was used to evaluate the effect of developmental exposure to an environmentally relevant PCB mixture on seizure susceptibility in the rat. Female Long-Evans rats were dosed orally with 0 or 6mg/kg/day of the PCB mixture dissolved in corn oil vehicle 4 weeks prior to mating and continued through gestation and up until postnatal day (PND) 21. On PND 21, pups were weaned, and two males from each litter were randomly selected for the kindling study. As adults, the male rats were implanted bilaterally with electrodes in the basolateral amygdala. For each animal, afterdischarge (AD) thresholds in the amygdala were determined on the first day of testing followed by once daily stimulation at a standard 200μA stimulus intensity until three stage 5 generalized seizures (GS) ensued. Developmental PCB exposure did not affect the AD threshold or total cumulative AD duration, but PCB exposure did increase the latency to behavioral manifestations of seizure propagation. PCB exposed animals required significantly more stimulations to reach stage 2 seizures compared to control animals, indicating attenuated focal (amygdala) excitability. A delay in kindling progression in the amygdala stands in contrast to our previous finding of increased susceptibility to brainstem-mediated audiogenic seizures in PCB-exposed animals in response to a an intense auditory stimulus. These seemingly divergent results are not unexpected given the distinct source, type, and mechanistic underpinnings of these different seizure models. A delay in epileptogenesis following focal amygdala stimulation may reflect a decrease in neuroplasticity following developmental PCB exposure consistent with reductions in use-dependent synaptic plasticity that have been reported in the hippocampus of developmentally PCB exposed animals.

Bio-oil from a fast pyrolysis pilot plant as antifungal and hydrophobic agent for wood preservation

Residual wood fines were used as raw material to produce fast pyrolysis bio-oil in a pilot plant for further utilization as antifungal and hydrophobic agent for wood protection. Phenolic compounds derived from lignin mostly composed the obtained bio-oil. Pinewood was impregnated with natural and diluted bio-oil aiming three different final loads. Scanning electron microscopy images revealed that the internal surface of the tracheids was coated by the bio-oil. Fourier-transformed infrared analysis showed no chemical reactions between wood and bio-oil, while thermogravimetric studies stated changes in the thermal stability of the impregnated pinewood. The bio-oil impregnation proved to be effective to decrease the water absorption and wettability of the pinewood. In addition, the bio-oil impregnated pinewood with low load (7.95%) had decay resistance improved by 2.6 and 4.5 times against T. versicolor and G. trabeum fungi, respectively, meanwhile the highest bio-oil loading (81.3%) inside pinewood caused the mortality of the whole fungal colony in the first days of test.

Effects of exogenous testosterone and mating context on men's preferences for female facial femininity

Correlational research suggests that men show greater attraction to feminine female faces when their testosterone (T) levels are high. Men's preferences for feminine faces also seem to vary as a function of relationship context (short versus long-term). However, the relationship between T and preferences for female facial femininity has yet to be tested experimentally. In the current paper, we report the results of two experiments examining the causal role of T in modulating preferences for facial femininity across both short and long-term mating contexts. Results of Experiment 1 (within-subject design, n=24) showed that participants significantly preferred feminized versus masculinized versions of women's faces. Further, participants showed a stronger preference for feminine faces in the short versus the long-term context after they received T, but not after they received placebo. Post-hoc analyses suggested that this effect was driven by a lower preference for feminine faces in the long-term context when on T relative to placebo, and this effect was found exclusively for men who received placebo on the first day of testing, and T on the second day of testing (i.e., Order x Drug x Mating context interaction). In Experiment 2 (between-subject design, n=93), men demonstrated a significant preference for feminized female faces in the short versus the long-term context after T, but not after placebo administration. Collectively, these findings provide the first causal evidence that T modulates men's preferences for facial femininity as a function of mating context.

Computerized dynamic posturography detects balance deficits in individuals with a history of chronic severe traumatic brain injury

Background: Mild balance deficits can be challenging to detect in individuals with long-standing traumatic brain injuries. This study compared Computerized Dynamic Posturography (CDP) scores from individuals with traumatic brain injuries (TBI) to controls to determine if CDP could differentiate between the two groups and determine if there was a learning effect associated with testing that could be used to guide evaluation of baseline balance.Methods: Ten ambulatory individuals with a history of severe TBI and 10 individuals without participated in three CDP sessions (24–72 hours apart). During each session, participants performed the Berg Balance Test, Dynamic Gait Index and three trials of a standardized balance assessment and Dynamic Movement Analysis (DMA) scores were recorded for each test.Results: Individuals with TBI scored 93% higher (i.e. reflecting poorer balance) than the control group. The group with TBI exhibited 6.6-times more variability compared to the control group, with estimated variances of 0.3407 and 0.0517, respectively. A learning effect was detected in the group with TBI on the first day of testing (βTBI F = –0.1241, p-value < 0.01).Discussion: The CDP system detected balance differences between individuals with TBI and controls. Given the documented learning effect, the best of three trials should be used to accurately assess baseline scores.

Effects of motherwort alkaloids on rat ear acne

The aim of this study was to explore the effects of motherwort alkaloids on rat ear acne. The rats that were administered high, medium, and low doses of motherwort alkaloids, tanshinone capsules, a model and a control group. Each group of rats was subjected to gavage once daily for 14 consecutive days. On the first day of testing, the control and model groups were administered an intradermal auricle injection of sterilized saline solution and the remaining groups were administered an intradermal auricle injection of Staphylococcus epidermidis in addition to the gavage. The thicknesses of the rats’ auricles were measured for five consecutive days following the injections. Anticoagulated blood was used for erythrocyte rheology index measurement. In addition, the entire ear of each rat was removed for morphological examination. Compared to the model group, the group administered motherwort alkaloids exhibited significantly reduced swelling, improved localized auricle proliferation, and reduced blood viscosity. This result suggests motherwort alkaloids are effective in rat ear acne.

Effects of motherwort alkaloids on rat ear acne

&lt;p class="Abstract"&gt;The aim of this study was to explore the effects of motherwort alkaloids on rat ear acne. The rats that were administered high, medium, and low doses of motherwort alkaloids, tanshinone capsules, a model and a control group. Each group of rats was subjected to gavage once daily for 14 consecutive days. On the first day of testing, the control and model groups were administered an intradermal auricle injection of sterilized saline solution and the remaining groups were administered an intradermal auricle injection of &lt;em&gt;Staphylococcus epidermidis&lt;/em&gt; in addition to the gavage. The thicknesses of the rats’ auricles were measured for five consecutive days following the injections. Anticoagulated blood was used for erythrocyte rheology index measurement. In addition, the entire ear of each rat was removed for morphological examination. Compared to the model group, the group administered motherwort alkaloids exhibited significantly reduced swelling, improved localized auricle proliferation, and reduced blood viscosity. This result suggests motherwort alkaloids are effective in rat ear acne.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;

Repeatability of methane emission measurements in Australian beef cattle

Records on 175 young Angus heifer and bull progeny from 46 sires, measured for methane production in respiration chambers, were used to evaluate the repeatability of methane measurement over short- and long-term periods. The traits assessed were dry matter intake (DMI), methane production rate (MPR), methane yield (MPR per unit DMI), and four residual methane (RMP) traits. The RMP traits were computed as actual MPR minus expected MPR, where the expected MPR for the first three RMP traits were calculated from three different published and widely used equations. The expected MPR for the fourth was computed by regressing MPR on DMI, using the data from the study. Animals underwent an initial (first) methane measurement test for 48 h, and one repeat methane measurement test up to 450 days after the first test. Repeat tests were classified into four different time periods: tested across consecutive days; re-tested within 60 days of first test; re-tested 61–120 days after first test; and re-tested 121–450 days after first test. Repeatabilities were calculated for all traits across all time periods, and phenotypic correlations for the same trait measured over time were obtained from bivariate analyses. Methane traits from tests conducted over consecutive days were highly repeatable (0.75–0.94) and highly phenotypically correlated (0.85–0.95). Repeatabilities from tests conducted within 60 days of the first test were moderate to high (0.59–0.91), whereas phenotypic correlations were, in general, moderate (0.30–0.44), with the exception of MPR (0.78). Results for both longer-term time periods (61–120 days and 121–450 days after the first test) were very similar, with low estimates of repeatabilities (0.16–0.27) and phenotypic correlations (0.12–0.27). Correlations between sire progeny means from the first and repeat methane test were moderate (0.46–0.77) for all traits except RMPR (0.19). Results from this study indicate that methane traits from tests conducted either on consecutive days or within a short-term time frame afterward (~60 days) are highly repeatable and highly phenotypically correlated. However, methane tests conducted over longer-term time frames are substantially, but consistently, less repeatable and are lowly phenotypically correlated, which indicates that multiple measures may be required to accurately record methane traits over the life time of an animal.

Abstract 14720: Firefighters Have the Highest Risk for Heart Disease Among Emergency Personnel

Introduction: Prior studies have shown obesity, lower activity levels and increased stress among emergency personnel, yet it is unclear if the specific sub-type of emergency personnel impacts stress levels and physical activity (PA). The purpose of this study was to compare emergency personnel sub-types for risk of heart disease and compare on and off duty PA and stress levels. Hypothesis: We hypothesized that there would be differences in cardiac risk factors, exercise behaviors, and salivary cortisol by type of emergency responders and would be different when on/off duty. Methods: We recruited 37 male emergency personnel workers (12 paramedics, 12 police officers and 13 firefighters, ages 20-40) who then underwent three non-sequential days of testing. We measured body composition, lipids, blood pressure, and peak VO2 with a standard Bruce treadmill protocol and calculated Framingham Risk Scores (FRS) on the first day of testing. Participants then wore an accelerometer and measured AM and PM salivary cortisol on and off duty. Results: Contrary to our hypothesis, PA levels did not differ between on and off duty. Firefighters expended significantly more kcals per day and took more steps per day compared to paramedics (p &lt; 0.05). Cortisol concentration was significantly higher AM vs. PM on duty (p &lt; 0.05); although off duty cortisol remained elevated. No significance was found between off duty values. Firefighters’ FRS was significantly higher than paramedics (p &lt; 0.05). See Table. Conclusion: In conclusion, although firefighters were more active than police and paramedics, they had a higher FRS. Among all emergency personnel types, cortisol concentrations showed a prolonged stress response in the emergency personnel population suggesting a sustained off duty stress response for unclear reasons. These finding suggest that firefighters should focus on decreasing cardiac risk factors and interventions are needed to reduce emergency personnel off duty stress.

The Effects of Dynamic Stretching on Hemodynamics and Metabolic Functions

INTRODUCTION: The application of warm-up prior to exercise is commonly used to prepare the body for exercise demands. Dynamic stretching remains a controversial topic regarding the impact on human performance and the applicability in competition and overall influence on physical activity. There appears to be little evidence on the variables responsible for metabolic improvements associated with dynamic stretching. PURPOSE: To determine if a specific, lower body dynamic stretching protocol will have any effect on metabolic functioning and how cardiac variables may influence that while performing a submaximal cycle protocol. METHODS: Twenty-four participants consisting of both healthy males (25.11.2 years, 179.8 30.1 pounds) and females (24.7 1.1 years, 147.5 13.9 pounds) were tested twice, with and without prior stretching exercises. The inclusion of 4 lower extremity dynamic stretches on the first day of testing was randomly assigned. All participants underwent a submaximal lower extremity cycle ergometer protocol for 10 minutes with workload increasing by 20 watts every minute. A 3 minute warm-up and cool-down were completed prior to and after the cycle protocol. Hemodynamic variables were monitored using thoracic bioimpedance device and metabolic variables were collected with a ParvoMedics metabolic cart. RESULTS: When stretching was compared to non-stretching condition, significant differences were found only in the VO2 (8.7 1.9 vs. 7.8 2.0 ml/kg/min, p < 0.05) and minute ventilation (VE) (19.1 3.0 vs 16.6 3.7 L/min, p < 0.05) prior to warm up. No significant difference was revealed among genders based on condition. Linear regression analyses indicated cardiac index as the single best predictor for VO2 (R2 = 0.16, p<0.05) and ejection fraction and heart rate the predictors for VE (R2 = 0.18, p<0.05). CONCLUSION: Dynamic stretching had minimal effect on metabolic variables during and after the performance of a submaximal exercise test, however, higher baseline VO2 and VE were seen. These elevations were likely due to an increased intramuscular temperature and improved efficiency of muscle contraction shortly after the dynamic stretching protocol. It is possible that the stretching was not intense or long enough to perpetuate the benefits into the exercise routine.

No trade-off between high and low temperature tolerance in a winter acclimatized Danish Drosophila subobscura population

Coping with cold winter conditions is a major challenge for many insects.In early spring we observed newly emerged Drosophila subobscura, which had overwintered as larvae and pupae. As temperatures increase during spring these flies are faced with higher minimum and maximum temperatures in their natural microhabitat. Thus, there is a potential costly mismatch between winter and early spring acclimatization and the increased ambient temperatures later in adult life.We obtained individuals from a natural Danish population of D. subobscura and acclimated them in the laboratory to 20°C for one generation, and compared critical thermal maximum (CTmax) and minimum (CTmin) to that of individuals collected directly from their natural microhabitat. The two populations (laboratory and field) were subsequently both held in the laboratory at 20°C and tested for their CTmax and CTmin every third day for 28days.At the first day of testing, field acclimatized D. subobscura had both higher heat and cold resistance compared to laboratory flies, and thereby a considerable larger thermal scope. Following transfer to the laboratory, cold and heat resistance of the field flies decreased over time relative to the laboratory flies. Despite the substantial decrease in thermal tolerances the thermal scope remained larger for field acclimatized individuals for the duration of the experiment.We conclude that flies acclimatized to their natural microhabitat had increased cold resistance, without a loss in heat tolerance. Thus while a negative correlation between cold and heat tolerance is typically observed in laboratory studies in Drosophila sp., this was not observed for field acclimatized D. subobscura in this study. We suggest that this is an adaptation to juvenile overwintering in temperate cold environments, where developmental (winter) temperatures can be much lower than temperatures experienced by reproducing adults after emergence (spring). The ability to gain cold tolerance through acclimatization without a parallel loss of heat tolerance affects thermal scope and suggests that high and low thermal tolerance act through mechanisms with different dynamics and reversibility.

Utilization of non-invasive measures to evaluate eccentric exercise damage in an untrained population

Background One of the most common modes of exercise among males is resistance training. The associated movements among the most common resistance training exercises completed include periods of both concentric and eccentric contraction. Previous research has demonstrated that repeated eccentric contractions of a muscle produce damaging results to the muscles involved. Invasive measures, such as blood draws and muscle biopsies have been utilized to assess skeletal muscle damage in individuals. However, the efficacy of the utilization of Creatine Kinase concentration as a marker of recovery has recently been called into question. Furthermore, biopsies and blood draws may not be applicable to identify muscle damage and recovery in an untrained population for the nutritional or strength and conditioning professional Methods Subjects (n= 19) volunteered to participate in this study and were untrained (resistance training) male college students between the ages of 18-30. Untrained criteria consisted of less than two years lower body resistance training. Prior to completion of the study participants completed a health history questionnaire. Participants were asked to refrain from physical activity for the duration of the study. The first day of testing included completion of a muscle soreness scale (DOMS), range of motion (ROM) of the dominant knee, swelling of the vastus lateralis (SWVL) via ultrasound (Terason T3200), Peak force measurement using an isokinetic dynamometer, a fatiguing exercise protocol on the dynamometer (a total of 50 eccentric contractions set at 120% of peak MVC force with an angular velocity of 60°/sec), followed immediately by post-test measurements of DOMS and peak force. The peak force measurement was determined using an isometric maximum voluntary contraction (MVC) of the quadriceps on the dynamometer with the knee joint held at 45°. The participants were then asked to return to the lab 24, 48 and 72 hours later. Each returning visit included a battery of tests comprising of measurements of DOMS, ROM, SWVL-Terascape, SWVL-Long, SWVL-Trans and peak force. Repeated measures ANOVAs (placebo vs. multi ingredient supplement) were used to analyze changes in peak power, intramuscular swelling, DOMS, and ROM. The alpha level was set at p≤ 0.05. Consent to publish the results was obtained from all participants. Results

The Muscle Stretch Reflex throughout the Menstrual Cycle

The significant sex disparity in sports-related knee injuries may be due to underlying differences in motor control. Although the development of sex-specific movement patterns is likely multifactorial, this study specifically focuses on the potential modulatory role of sex hormones. This study aimed to investigate the muscle stretch reflex (MSR) across the menstrual cycle. We hypothesized that the MSR would fluctuate throughout the menstrual cycle and that the lowest response would correspond with peak concentrations of estrogen. Nineteen healthy women age 18-35 yr participated in this study: 8 eumenorrheic women and 11 women taking oral contraceptives. Serum estradiol and progesterone concentrations, anterior knee laxity (AKL), and the MSR response of the quadriceps muscles were measured three times during the menstrual cycle. The MSR response of the rectus femoris (RF) varied significantly across the menstrual cycle in both groups. Specifically, the RF MSR response was 2.4 times lower during the periovulatory phase when compared with the luteal phase (P = 0.007). The same trend was seen in the vastus medialis, but this did not reach statistical significance (P = 0.070). The MSR response of the vastus lateralis did not change significantly across the menstrual cycle (P = 0.494). A mixed model comparison did not show an association between endogenous concentrations of estradiol and progesterone, exposure to hormonal contraceptives or AKL, and the MSR response for any muscle. Our results demonstrate that the RF MSR response varies throughout the menstrual cycle with the lowest response around the time of ovulation. Additional research is needed to clarify the exact relationship between sex hormones, AKL, and MSR response and to determine the specific origin of the change along the monosynaptic reflex arc.

Mice with Deficient BK Channel Function Show Impaired Prepulse Inhibition and Spatial Learning, but Normal Working and Spatial Reference Memory

Genetic variations in the large-conductance, voltage- and calcium activated potassium channels (BK channels) have been recently implicated in mental retardation, autism and schizophrenia which all come along with severe cognitive impairments. In the present study we investigate the effects of functional BK channel deletion on cognition using a genetic mouse model with a knock-out of the gene for the pore forming α-subunit of the channel. We tested the F1 generation of a hybrid SV129/C57BL6 mouse line in which the slo1 gene was deleted in both parent strains.We first evaluated hearing and motor function to establish the suitability of this model for cognitive testing. Auditory brain stem responses to click stimuli showed no threshold differences between knockout mice and their wild-type littermates. Despite of muscular tremor, reduced grip force, and impaired gait, knockout mice exhibited normal locomotion. These findings allowed for testing of sensorimotor gating using the acoustic startle reflex, as well as of working memory, spatial learning and memory in the Y-maze and the Morris water maze, respectively.Prepulse inhibition on the first day of testing was normal, but the knockout mice did not improve over the days of testing as their wild-type littermates did. Spontaneous alternation in the y-maze was normal as well, suggesting that the BK channel knock-out does not impair working memory. In the Morris water maze knock-out mice showed significantly slower acquisition of the task, but normal memory once the task was learned. Thus, we propose a crucial role of the BK channels in learning, but not in memory storage or recollection.

Chronic voluntary alcohol consumption results in tolerance to sedative/hypnotic and hypothermic effects of alcohol in hybrid mice

The continuous two-bottle choice test is the most common measure of alcohol consumption but there is remarkably little information about the development of tolerance or dependence with this procedure. We showed that C57BL/6J×FVB/NJ and FVB/NJ×C57BL/6JF1 hybrid mice demonstrate greater preference for and consumption of alcohol than either parental strain. In order to test the ability of this genetic model of high alcohol consumption to produce neuroadaptation, we examined development of alcohol tolerance and dependence after chronic self-administration using a continuous access two-bottle choice paradigm. Ethanol-experienced mice stably consumed about 16–18g/kg/day of ethanol. Ethanol-induced withdrawal severity was assessed (after 59days of drinking) by scoring handling-induced convulsions; withdrawal severity was minimal and did not differ between ethanol-experienced and -naïve mice. After 71days of drinking, the rate of ethanol clearance was similar for ethanol-experienced and -naïve mice. After 77days of drinking, ethanol-induced loss of righting reflex (LORR) was tested daily for 5days. Ethanol-experienced mice had a shorter duration of LORR. For both ethanol-experienced and -naïve mice, blood ethanol concentrations taken at gain of righting reflex were greater on day 5 than on day 1, indicative of tolerance. After 98days of drinking, ethanol-induced hypothermia was assessed daily for 3days. Both ethanol-experienced and -naïve mice developed rapid and chronic tolerance to ethanol-induced hypothermia, with significant group differences on the first day of testing. In summary, chronic, high levels of alcohol consumption in F1 hybrid mice produced rapid and chronic tolerance to both the sedative/hypnotic and hypothermic effects of ethanol; additionally, a small degree of metabolic tolerance developed. The development of tolerance supports the validity of using this model of high alcohol consumption in genetic studies of alcoholism.

Determination of a stray voltage threshold in Holstein heifers, influence of predictability and past experience on behavioural and physiological responses

AbstractStray voltage (&lt; 10 V) may impair animal welfare. Our objectives were to: i) determine the threshold at which heifers react to voltage and ii) investigate effects of past experience and random applications of voltage. Firstly, forty heifers were trained to eat from two metallic feeders at the end of a test corridor. For 20 heifers, voltage was applied for 2 min (every day in steps of 0.33 V, 0 to 5 V) to the feeder (F1) in which the heifer started to eat (VOLT). Heifers could change to the non-electrified feeder (F2) if they wished. Twenty heifers (CONT) followed the same procedure without voltage exposure. For voltages≥ 2.3 V, percentage of feed eaten from F1 (%FeedF1) was lower, time spent eating in F1 and latency to change to F2 were shorter compared to 0 V. At 2 V and above, more VOLT than CONT heifers performed muzzle-licking and abrupt head movements. Secondly, after four weeks, the same heifers were exposed to 3.3 V for either 11 consecutive days (DAILY, n = 20) or randomly on 4/11 days (RAND, n = 20). CONT heifers had higher cortisol concentrations than VOLT heifers on the first day of test. %FeedF1 was higher for RAND than DAILY heifers. The threshold at which avoidance behaviour started appeared to be 2.3 V in our experimental conditions. Adaptation was more difficult with unpredictable rather than predictable voltage and past experience seemed to reduce the effects of subsequent exposure.

Test-Retest reliability of Biodex Balance SD on physically active old people

The purpose of this study was to determine the reliability of the Biodex Balance System in elderly. Forty-five subjects aged 66±5.5 years old and weight 71.6±9.8 kg were tested on the Biodex Balance System. In order to calculate the reliability, the Fall Risk Test (FRt) and the Postural Stability Test (PSt) were measured on two separate occasions 7 days apart. Every subject completed the Falls Efficacy Scale-International (FES-I) questionnaire the first day of testing. The Fall Risk Index (FRi) showed a good ICC (.80) and a low percentage of variation of method error. The Overall Stability Index (OSi) showed a good and acceptable reliability measured by the ICC (.69) but a percentage of variation of method error near to 25%. FES-I Score was 23.1 (±7.2). The reliability of the BBS using Bland-Altman method showed that systematic errors (mean difference between test-retest) for the balance test developed were nearly zero and the 95% limits of agreement narrow, indicating a good reliability of the measurement. Biodex balance measures were showed reliable and may be useful for measuring the risk of falls and monitoring programs for prevent falls in elderly. This study revealed that fall risk assessment in older people must be incorporated into the evaluation process of the physical functioning.