Testis size, sperm characteristics and testosterone concentrations in four species of shrews (Mammalia, Soricidae).

The aim of this study was to establish and compare the sperm characteristics in four shrew species in the context of the sperm competition hypothesis. As expected, the large relative testis size in promiscuous species was associated with a high number of cauda epididymal spermatozoa and a high concentration of circulating testosterone. In addition, in Sorex and Neomys, species with high intensity of sperm competition, the spermatozoa stored in cauda epididymis were characterized by high percentage of progressive motility whereas in Crocidura and Suncus, the cauda epididymal spermatozoa were motile but with very low percentage of progressive motility. This capability is achieved only following the passage through the vas gland, a specialized region for sperm storage located along the vas deferens in these shrew species. The hypothesis that sperm competition is positively correlated with spermatozoa length could not be confirmed. In Crocidura and Suncus, the total sperm length is increased by the large sperm head due to a big acrosome. This trait, specific to the subfamily Crocidurinae, may results from a selective pressure independent of the context of sperm competition, related to a specific, but as yet unclear role, for the acrosome during the fertilization.

Statin treatment is associated with improved prognosis in patients with AF-related stroke.

BACKGROUND/OBJECTIVES: The most recent ACC/AHA guidelines recommend high-intensity statin therapy in ischemic stroke patients of presumably atherosclerotic origin. On the contrary, there is no specific recommendation for the use of statin in patients with non-atherosclerotic stroke, e.g. strokes related to atrial fibrillation (AF). We investigated whether statin treatment in patients with AF-related stroke is associated with improved survival and reduced risk for stroke recurrence and future cardiovascular events. METHODS: All consecutive patients registered in the Athens Stroke Registry with AF-related stroke and no history of coronary artery disease nor clinically manifest peripheral artery disease were included in the analysis and categorized in two groups depending on whether statin was prescribed at discharge. The primary outcome was overall mortality; the secondary outcomes were stroke recurrence and a composite cardiovascular endpoint comprising of recurrent stroke, myocardial infarction, aortic aneurysm rupture or sudden cardiac death during the 5-year follow-up. RESULTS: Among 1602 stroke patients, 404 (25.2%) with AF-related stroke were included in the analysis, of whom 102 (25.2%) were discharged on statin. On multivariate Cox-proportional-hazards model, statin treatment was independently associated with a lower mortality (hazard-ratio (HR): 0.49, 95%CI:0.26-0.92) and lower risk for the composite cardiovascular endpoint during the median 22months follow-up (HR: 0.44, 95%CI:0.22-0.88), but not with stroke recurrence (HR: 0.47, 95%CI:0.22-1.01, p: 0.053). CONCLUSIONS: In this long-term registry of patients with AF-related stroke, statin treatment was associated with improved survival and reduced risk for future cardiovascular events.

Bunch frequency multiplication by RF injection into an isochronous ring

La collaboration CLIC (Compact LInear Collider, collisionneur linéaire compact) étudie la possibilité de réaliser un collisionneur électron-positon linéaire à haute énergie (3 TeV dans le centre de masse) et haute luminosité (1034 cm-2s-1), pour la recherche en physique des particules. Le projet CLIC se fonde sur l'utilisation de cavités accélératrices à haute fréquence (30 GHz). La puissance nécessaire à ces cavités est fournie par un faisceau d'électrons de basse énergie et de haute intensité, appelé faisceau de puissance, circulant parallèlement à l'accélérateur linéaire principal (procédé appelé « Accélération à Double Faisceau »). Dans ce schéma, un des principaux défis est la réalisation du faisceau de puissance, qui est d'abord généré dans un complexe accélérateur à basse fréquence, puis transformé pour obtenir une structure temporelle à haute fréquence nécessaire à l'alimentation des cavités accélératrices de l'accélérateur linéaire principal. La structure temporelle à haute fréquence des paquets d'électrons est obtenue par le procédé de multiplication de fréquence, dont la manipulation principale consiste à faire circuler le faisceau d'électrons dans un anneau isochrone en utilisant des déflecteurs radio-fréquence (déflecteurs RF) pour injecter et combiner les paquets d'électrons. Cependant, ce type de manipulation n'a jamais été réalisé auparavant et la première phase de la troisième installation de test pour CLIC (CLIC Test Facility 3 ou CTF3) a pour but la démonstration à faible charge du procédé de multiplication de fréquence par injection RF dans un anneau isochrone. Cette expérience, qui a été réalisée avec succès au CERN au cours de l'année 2002 en utilisant une version modifiée du pré-injecteur du grand collisionneur électron-positon LEP (Large Electron Positron), est le sujet central de ce rapport. L'expérience de combinaison des paquets d'électrons consiste à accélérer cinq impulsions dont les paquets d'électrons sont espacés de 10 cm, puis à les combiner dans un anneau isochrone pour obtenir une seule impulsion dont les paquets d'électrons sont espacés de 2 cm, multipliant ainsi la fréquence des paquets d'électrons, ainsi que la charge par impulsion, par cinq. Cette combinaison est réalisée au moyen de structures RF résonnantes sur un mode déflecteur, qui créent dans l'anneau une déformation locale et dépendante du temps de l'orbite du faisceau. Ce mécanisme impose plusieurs contraintes de dynamique de faisceau comme l'isochronicité, ainsi que des tolérances spécifiques sur les paquets d'électrons, qui sont définies dans ce rapport. Les études pour la conception de la Phase Préliminaire du CTF3 sont détaillées, en particulier le nouveau procédé d'injection avec les déflecteurs RF. Les tests de haute puissance réalisés sur ces cavités déflectrices avant leur installation dans l'anneau sont également décrits. L'activité de mise en fonctionnement de l'expérience est présentée en comparant les mesures faites avec le faisceau aux simulations et calculs théoriques. Finalement, les expériences de multiplication de fréquence des paquets d'électrons sont décrites et analysées. On montre qu'une très bonne efficacité de combinaison est possible après optimisation des paramètres de l'injection et des déflecteurs RF. En plus de l'expérience acquise sur l'utilisation de ces déflecteurs, des conclusions importantes pour les futures activités CTF3 et CLIC sont tirées de cette première démonstration de la multiplication de fréquence des paquets d'électrons par injection RF dans un anneau isochrone.<br/><br/>The Compact LInear Collider (CLIC) collaboration studies the possibility of building a multi-TeV (3 TeV centre-of-mass), high-luminosity (1034 cm-2s-1) electron-positron collider for particle physics. The CLIC scheme is based on high-frequency (30 GHz) linear accelerators powered by a low-energy, high-intensity drive beam running parallel to the main linear accelerators (Two-Beam Acceleration concept). One of the main challenges to realize this scheme is to generate the drive beam in a low-frequency accelerator and to achieve the required high-frequency bunch structure needed for the final acceleration. In order to provide bunch frequency multiplication, the main manipulation consists in sending the beam through an isochronous combiner ring using radio-frequency (RF) deflectors to inject and combine electron bunches. However, such a scheme has never been used before, and the first stage of the CLIC Test Facility 3 (CTF3) project aims at a low-charge demonstration of the bunch frequency multiplication by RF injection into an isochronous ring. This proof-of-principle experiment, which was successfully performed at CERN in 2002 using a modified version of the LEP (Large Electron Positron) pre-injector complex, is the central subject of this report. The bunch combination experiment consists in accelerating in a linear accelerator five pulses in which the electron bunches are spaced by 10 cm, and combining them in an isochronous ring to obtain one pulse in which the electron bunches are spaced by 2 cm, thus achieving a bunch frequency multiplication of a factor five, and increasing the charge per pulse by a factor five. The combination is done by means of RF deflecting cavities that create a time-dependent bump inside the ring, thus allowing the interleaving of the bunches of the five pulses. This process imposes several beam dynamics constraints, such as isochronicity, and specific tolerances on the electron bunches that are defined in this report. The design studies of the CTF3 Preliminary Phase are detailed, with emphasis on the novel injection process using RF deflectors. The high power tests performed on the RF deflectors prior to their installation in the ring are also reported. The commissioning activity is presented by comparing beam measurements to model simulations and theoretical expectations. Eventually, the bunch frequency multiplication experiments are described and analysed. It is shown that the process of bunch frequency multiplication is feasible with a very good efficiency after a careful optimisation of the injection and RF deflector parameters. In addition to the experience acquired in the operation of these RF deflectors, important conclusions for future CTF3 and CLIC activities are drawn from this first demonstration of the bunch frequency multiplication by RF injection into an isochronous ring.<br/><br/>La collaboration CLIC (Compact LInear Collider, collisionneur linéaire compact) étudie la possibilité de réaliser un collisionneur électron-positon linéaire à haute énergie (3 TeV) pour la recherche en physique des particules. Le projet CLIC se fonde sur l'utilisation de cavités accélératrices à haute fréquence (30 GHz). La puissance nécessaire à ces cavités est fournie par un faisceau d'électrons de basse énergie et de haut courant, appelé faisceau de puissance, circulant parallèlement à l'accélérateur linéaire principal (procédé appelé « Accélération à Double Faisceau »). Dans ce schéma, un des principaux défis est la réalisation du faisceau de puissance, qui est d'abord généré dans un complexe accélérateur à basse fréquence, puis transformé pour obtenir une structure temporelle à haute fréquence nécessaire à l'alimentation des cavités accélératrices de l'accélérateur linéaire principal. La structure temporelle à haute fréquence des paquets d'électrons est obtenue par le procédé de multiplication de fréquence, dont la manipulation principale consiste à faire circuler le faisceau d'électrons dans un anneau isochrone en utilisant des déflecteurs radio-fréquence (déflecteurs RF) pour injecter et combiner les paquets d'électrons. Cependant, ce type de manipulation n'a jamais été réalisé auparavant et la première phase de la troisième installation de test pour CLIC (CLIC Test Facility 3 ou CTF3) a pour but la démonstration à faible charge du procédé de multiplication de fréquence par injection RF dans un anneau isochrone. L'expérience consiste à accélérer cinq impulsions, puis à les combiner dans un anneau isochrone pour obtenir une seule impulsion dans laquelle la fréquence des paquets d'électrons et le courant sont multipliés par cinq. Cette combinaison est réalisée au moyen de structures déflectrices RF qui créent dans l'anneau une déformation locale et dépendante du temps de la trajectoire du faisceau. Les résultats de cette expérience, qui a été réalisée avec succès au CERN au cours de l?année 2002 en utilisant une version modifiée du pré-injecteur du grand collisionneur électron-positon LEP (Large Electron Positon), sont présentés en détail.

Kuumahierteen laadun ja energiankulutuksen optimointi

Kuumahierteen menestyksekäs kehitys on vähentänyt kemiallisten massojen käyttöä painopapereiden raaka-aineena. Hiertäminen kuluttaa kuitenkin huomattavasti enemmän energiaa muihin massanvalmistusmenetelmiin verrattuna. Tämän työn tavoitteena oli optimoida Stora Enson Varkauden tehtaiden uuden TMP-linjan massan laatua ja energiankäyttöä. Työ koostui jauhimien monimuuttujakoeajoista, Metso Paperin painekoeajosta sekä koko TMP-linjaa koskevista tarkistusajoista. Monimuuttujakoeajot suoritettiin 600 t vuorokausituotannolla 60 % kuorimohakesuhteella. Jauhatuksen kokonaisenergiankulutuksen rajaksi sovittiin vanhojen jauhinlinjojen perusteella 2,3 MWh/t. Massan laadun kriittisimmäksi tekijäksi osoittautui vetoindeksi, joten optimoinnin tavoitteeksi muodostui vetoindeksin kehittäminen annetun energiankulutuksen puitteissa. Kuumahierteen laadun kehittymisen kannalta merkittävin vaihe oli hakkeen kuituuntuminen. Kuituuntumisen tulee tapahtua riittävän korkeassa lämpötilassa ligniinin pehmenemisen ja kuitujen joustavuuden saavuttamiseksi sekä alhaisella intensiteetillä, jolloin kuituja ei katkota. Ensimmäisen vaiheen jauhatuksen EOK:n on oltava vähintään 1,00 MWh/t, jolloin toisen vaiheen jauhatus vaatii energiaa vähintään 0,70 MWh/t. Rejektijauhimen tuotantotason tulisi olla mahdollisimman suuri ja intensiiviseen jauhatukseen käytettävän ominaisenergian noin 1,00 MWh/t.

Western blotting as a tool for the serodiagnosis of farmer's lung disease: validation with Lichtheimia corymbifera protein extracts.

Electrosyneresis and double diffusion are immunoprecipitation techniques commonly used in the serological diagnosis of Farmer's lung disease (FLD). These techniques are reliable but lack standardization. The aim of this study was to evaluate Western blotting for the serodiagnosis of FLD. We carried out Western blotting with an antigenic extract of Lichtheimia corymbifera, an important aetiological agent of the disease. The membranes were probed with sera from 21 patients with FLD and 21 healthy exposed controls to examine the IgG antibody responses against purified somatic antigens. Given the low prevalence of the disease, 21 patients could be considered as a relevant series. Four bands were significantly more frequently represented in membranes probed with FLD sera (bands at 27.7, 40.5, 44.0 and 50.5 kDa) than those probed with control sera. We assessed the diagnostic value of different criteria alone or in combination. The diagnostic accuracy of the test was highest with the inclusion of at least two of the following criteria: at least five bands on the strip and the presence of one band at 40.5 or 44.0 kDa. Sensitivity, specificity and positive and negative predictive values were all 81%, and the odds ratio was 18.06. Inclusion of bands of high intensity diminished rather than improved the diagnostic value of the test. We concluded that Western blotting is a valuable technique for the serodiagnosis of FLD. The industrial production of ready-to-use membranes would enable the routine use of this technique in laboratories, and provide reliable and standardized diagnostic results within a few hours.

The Effect of Two Speed Endurance Training Regimes on Performance of Soccer Players.

In order to better understand the specificity of training adaptations, we compared the effects of two different anaerobic training regimes on various types of soccer-related exercise performances. During the last 3 weeks of the competitive season, thirteen young male professional soccer players (age 18.5±1 yr, height 179.5±6.5 cm, body mass 74.3±6.5 kg) reduced the training volume by ~20% and replaced their habitual fitness conditioning work with either speed endurance production (SEP; n = 6) or speed endurance maintenance (SEM; n = 7) training, three times per wk. SEP training consisted of 6-8 reps of 20-s all-out running bouts followed by 2 min of passive recovery, whereas SEM training was characterized by 6-8 x 20-s all-out efforts interspersed with 40 s of passive recovery. SEP training reduced (p<0.01) the total time in a repeated sprint ability test (RSAt) by 2.5%. SEM training improved the 200-m sprint performance (from 26.59±0.70 to 26.02±0.62 s, p<0.01) and had a likely beneficial impact on the percentage decrement score of the RSA test (from 4.07±1.28 to 3.55±1.01%) but induced a very likely impairment in RSAt (from 83.81±2.37 to 84.65±2.27 s). The distance covered in the Yo-Yo Intermittent Recovery test level 2 was 10.1% (p<0.001) and 3.8% (p<0.05) higher after SEP and SEM training, respectively, with possibly greater improvements following SEP compared to SEM. No differences were observed in the 20- and 40-m sprint performances. In conclusion, these two training strategies target different determinants of soccer-related physical performance. SEP improved repeated sprint and high-intensity intermittent exercise performance, whereas SEM increased muscles' ability to maximize fatigue tolerance and maintain speed development during both repeated all-out and continuous short-duration maximal exercises. These results provide new insight into the precise nature of a stimulus necessary to improve specific types of athletic performance in trained young soccer players.

Short-term HIIT and Fatmax training increase aerobic and metabolic fitness in men with class II and III obesity.

OBJECTIVE: To compare the effects of two different 2-week-long training modalities [continuous at the intensity eliciting the maximal fat oxidation (Fatmax ) versus high-intensity interval training (HIIT)] in men with class II and III obesity. METHODS: Nineteen men with obesity (BMI ≥ 35 kg(.) m(-2) ) were assigned to Fatmax group (GFatmax ) or to HIIT group (GHIIT ). Both groups performed eight cycling sessions matched for mechanical work. Aerobic fitness and fat oxidation rates (FORs) during exercise were assessed prior and following the training. Blood samples were drawn to determine hormones and plasma metabolites levels. Insulin resistance was assessed by the homeostasis model assessment of insulin resistance (HOMA2-IR). RESULTS: Aerobic fitness and FORs during exercise were significantly increased in both groups after training (P ≤ 0.001). HOMA2-IR was significantly reduced only for GFatmax (P ≤ 0.001). Resting non-esterified fatty acids (NEFA) and insulin decreased significantly only in GFatmax (P ≤ 0.002). CONCLUSIONS: Two weeks of HIIT and Fatmax training are effective for the improvement of aerobic fitness and FORs during exercise in these classes of obesity. The decreased levels of resting NEFA only in GFatmax may be involved in the decreased insulin resistance only in this group.

Overspeed HIIT in Lower-Body Positive Pressure Treadmill Improves Running Performance.

PURPOSE: Optimal high-intensity interval training (HIIT) regimens for running performance are unknown, although most protocols result in some benefit to key performance factors (running economy (RE), anaerobic threshold (AT), or maximal oxygen uptake (V˙O2max)). Lower-body positive pressure (LBPP) treadmills offer the unique possibility to partially unload runners and reach supramaximal speeds. We studied the use of LBPP to test an overspeed HIIT protocol in trained runners. METHODS: Eleven trained runners (35 ± 8 yr, V˙O2max, 55.7 ± 6.4 mL·kg·min) were randomized to an LBPP (n = 6) or a regular treadmill (CON, n = 5), eight sessions over 4 wk of HIIT program. Four to five intervals were run at 100% of velocity at V˙O2max (vV˙O2max) during 60% of time to exhaustion at vV˙O2max (Tlim) with a 1:1 work:recovery ratio. Performance outcomes were 2-mile track time trial, V˙O2max, vV˙O2max, vAT, Tlim, and RE. LBPP sessions were carried out at 90% body weight. RESULTS: Group-time effects were present for vV˙O2max (CON, 17.5 vs. 18.3, P = 0.03; LBPP, 19.7 vs. 22.3 km·h; P < 0.001) and Tlim (CON, 307.0 vs. 404.4 s, P = 0.28; LBPP, 444.5 vs. 855.5, P < 0.001). Simple main effects for time were present for field performance (CON, -18; LBPP, -25 s; P = 0.002), V˙O2max (CON, 57.6 vs. 59.6; LBPP, 54.1 vs. 55.1 mL·kg·min; P = 0.04) and submaximal HR (157.7 vs. 154.3 and 151.4 vs. 148.5 bpm; P = 0.002). RE was unchanged. CONCLUSIONS: A 4-wk HIIT protocol at 100% vV˙O2max improves field performance, vV˙O2max, V˙O2max and submaximal HR in trained runners. Improvements are similar if intervals are run on a regular treadmill or at higher speeds on a LPBB treadmill with 10% body weight reduction. LBPP could provide an alternative for taxing HIIT sessions.

Retinal damage induced by commercial light emitting diodes (LEDs).

Spectra of "white LEDs" are characterized by an intense emission in the blue region of the visible spectrum, absent in daylight spectra. This blue component and the high intensity of emission are the main sources of concern about the health risks of LEDs with respect to their toxicity to the eye and the retina. The aim of our study was to elucidate the role of blue light from LEDs in retinal damage. Commercially available white LEDs and four different blue LEDs (507, 473, 467, and 449nm) were used for exposure experiments on Wistar rats. Immunohistochemical stain, transmission electron microscopy, and Western blot were used to exam the retinas. We evaluated LED-induced retinal cell damage by studying oxidative stress, stress response pathways, and the identification of cell death pathways. LED light caused a state of suffering of the retina with oxidative damage and retinal injury. We observed a loss of photoreceptors and the activation of caspase-independent apoptosis, necroptosis, and necrosis. A wavelength dependence of the effects was observed. Phototoxicity of LEDs on the retina is characterized by a strong damage of photoreceptors and by the induction of necrosis.

Determination of Rod and Cone Influence to the Early and Late Dynamic of the Pupillary Light Response.

PURPOSE: This study aims to identify which aspects of the pupil light reflex are most influenced by rods and cones independently by analyzing pupil recordings from different mouse models of photoreceptor deficiency. METHODS: One-month-old wild type (WT), rodless (Rho-/-), coneless (Cnga3-/-), or photoreceptor less (Cnga3-/-; Rho-/- or Gnat1-/-) mice were subjected to brief red and blue light stimuli of increasing intensity. To describe the initial dynamic response to light, the maximal pupillary constriction amplitudes and the derivative curve of the first 3 seconds were determined. To estimate the postillumination phase, the constriction amplitude at 9.5 seconds after light termination was related to the maximal constriction amplitude. RESULTS: Rho-/- mice showed decreased constriction amplitude but more prolonged pupilloconstriction to all blue and red light stimuli compared to wild type mice. Cnga3-/- mice had constriction amplitudes similar to WT however following maximal constriction, the early and rapid dilation to low intensity blue light was decreased. To high intensity blue light, the Cnga3-/- mice demonstrated marked prolongation of the pupillary constriction. Cnga3-/-; Rho-/- mice had no pupil response to red light of low and medium intensity. CONCLUSIONS: From specific gene defective mouse models which selectively voided the rod or cone function, we determined that mouse rod photoreceptors are highly contributing to the pupil response to blue light stimuli but also to low and medium red stimuli. We also observed that cone cells mainly drive the partial rapid dilation of the initial response to low blue light stimuli. Thus photoreceptor dysfunction can be derived from chromatic pupillometry in mouse models.

Metodología del entrenamiento de la resistencia específica en el tenis de competición. Revisión y propuesta

El principal objetivo del entrenamiento de la resistencia en el jugador de tenis de competición es mejorar la habilidad para realizar ejercicios de alta intensidad de manera repetida, recuperarse rápidamente de los esfuerzos y mantener dicha intensidad durante el juego, evitando o retardando de esta manera la aparición de la fatiga. Para el desarrollo de los sistemas energéticos específicos, el jugador debe dirigir los entrenamientos al desarrollo de las vías energéticas y patrones de movimiento que predominan en la competición, respetando en la medida de lo posible la naturaleza intermitente del deporte y la participación muscular específica. El entrenamiento intermitente (EI) es un método adecuado y mejora el nivel de especificidad en relación a los métodos continuos o interválicos largos utilizados tradicionalmente y puede realizarse en la pista de tenis mediante ejercicios específicos. Es importante controlar adecuadamente los parámetros de carga del EI para dirigir adecuadamente las adaptaciones fisiológicas y efectos del entrenamiento a las necesidades del deporte. El objetivo de este trabajo es realizar una revisión sobre los principales aspectos fisiológicos y parámetros específicos de carga necesarios para una orientación específica del EI para el tenis y proponer un modelo de variabilidad de dichos parámetros de carga en un entorno específico de entrenamiento.

Ledivalaisimet rautatiealueiden valaistuksessa

Leditekniikan kehitys viime vuosina on mahdollistanut niiden käytön yleisvalaistuksessa. Tässä työssä tehdään katsaus leditekniikan nykytilaan ja tulevaisuuteen, sekä osoitetaan, että ledivalaisimien energiankulutuksessa ja huoltokustannuksissa tehdyillä säästöillä voidaan kattaa suuremmat hankintakustannukset ja päästä yhtä suuriin tai pienempiin elinkaarikustannuksiin verrattuna perinteisiin kaasupurkausvalaisimiin. Valaisimien määrät on laskettu Dialux-valaistuslaskentaohjelmalla siten että rautatieasemien avolaitureiden ja katettujen laitureiden valaistusvaatimukset täyttyvät. Tuloksia voi soveltaa muihin vastaaviin tiloihin kuten asematunneleihin tai kevyen liikenteen väylille.

Relation between the level of self-mutilation and theconcentration of fecal metabolites of glucocorticoids incaptive chimpanzees (Pan troglodytes)

The influence of stress in an environment, according with the behavioral and endocrine variables of primates, are increasingly being studied by a diversity of authors, and have shown that abnormal behaviors associated with increased glucocorticoids may be directly related with the impairment of their well-being. In this work were used 22 adult chimpanzees (Pan troglodytes), 11 males and 11 females, kept in captivity in three different institutions. All animals had their behavior registered by focal session using a 30 seconds sample interval, during six months, totaling 4,800 registries per each animal. During this period, fecal samples were collected 3 times a week for the extraction and measurement of the concentration of fecal metabolites of glucocorticoid by radioimmunoassay. Of the total observed, stereotypical behaviors represented 13,45±2.76%, and among them, self-mutilation represented 38.28±3.98 %. The animals were classified into three different scores, according with the percentage of body surface with alopecia due to self-mutilation. It was found a positive correlation of high intensity between the scores of alopecia due to the observed mutilation and the average concentrations of fecal metabolites of glucocorticoids. This result strongly suggests that this measurement of self-mutilation in a chimpanzee can be used as an important auxiliary tool to evaluate de conditions of adaptation of an animal in captivity, functioning as a direct indicator of the presence of chronic stress.

Effect of strenuous maternal exercise before and during pregnancy on rat progeny renal function

The effects of strenuous exercise before and during pregnancy on the renal function and morphological alterations of the progeny were determined in a study on female Wistar rats. This research was done based on a previous study carried out in our laboratory, which showed morphological alterations in rats submitted to this kind of exercise. As the form is related to the function, the physiological relevance of submitting a pregnant female to a high-intensity exercise training regimen could be explained by the fact that morphological alterations can influence kidney function. The animals were assigned to one of two groups: control animals that did not exercise during pregnancy and trained animals that swam for 120 min 5 days a week for 8 weeks before pregnancy and daily for 60 min over a period of 8 weeks starting on the second day of pregnancy. Seven rats of each group were analyzed for morphological alterations and for renal function. The progeny of the rats used for morphological evaluation were born by cesarean section and the progeny of the animals used to evaluate renal function were born normally. The progeny were two months old when renal function was evaluated. Fertility and morbidity were the same for both groups. Strenuous maternal exercise had no significant influence on glomerular filtration rate (GFR) but renal plasma flow was lower in the progeny of the trained group (mean ± SD, 16.65 ± 3.77 ml min-1 kg-1) compared to the progeny of the control group (33.42 ± 2.56 ml min-1 kg-1). Antidiuretic and antinatriuretic effects on the progeny of the trained group were observed, since urine flow as percentage of GFR and the fraction of urinary sodium excretion were lower in this group (1.38 ± 0.10 and 0.60 ± 0.04%, respectively) compared to the progeny of the control group (2.36 ± 0.11 and 1.55 ± 0.20%, respectively). Moreover, in this exercise program, fetuses from trained animals were small-sized (2.45 ± 0.19 vs 4.66 ± 2.45 g for control animals) and showed lower differentiation compared to fetuses from the control group. These effects were probably caused by caloric restriction, hypoxia and reduction of umbilical cord length.

Effect of carbohydrate availability on time to exhaustion in exercise performed at two different intensities

This study examined the effects of pre-exercise carbohydrate availability on the time to exhaustion for moderate and heavy exercise. Seven men participated in a randomized order in two diet and exercise regimens each lasting 3 days with a 1-week interval for washout. The tests were performed at 50% of the difference between the first (LT1) and second (LT2) lactate breakpoint for moderate exercise (below LT2) and at 25% of the difference between the maximal load and LT2 for heavy exercise (above LT2) until exhaustion. Forty-eight hours before each experimental session, subjects performed a 90-min cycling exercise followed by 5-min rest periods and a subsequent 1-min cycling bout at 125% VO2max/1-min rest periods until exhaustion to deplete muscle glycogen. A diet providing 10% (CHOlow) or 65% (CHOmod) energy as carbohydrates was consumed for 2 days until the day of the experimental test. In the exercise below LT2, time to exhaustion did not differ between the CHOmod and the CHOlow diets (57.22 ± 24.24 vs 57.16 ± 25.24 min). In the exercise above LT2, time to exhaustion decreased significantly from 23.16 ± 8.76 min on the CHOmod diet to 18.30 ± 5.86 min on the CHOlow diet (P < 0.05). The rate of carbohydrate oxidation, respiratory exchange ratio and blood lactate concentration were reduced for CHOlow only during exercise above LT2. These results suggest that muscle glycogen depletion followed by a period of a low carbohydrate diet impairs high-intensity exercise performance.