Association between energy cost of walking, muscle activation, and biomechanical parameters in older female fallers and non-fallers

Objective: To determine the nervous activation, muscle strength, and biomechanical parameters that influence the cost of walking in older fallers and non-fallers. Methods: Maximal voluntary isokinetic torque was measured for the hip, knee and ankle of older women. Oxygen consumption was measured at rest and during 8 min of walking at self-selected speed. An additional minute of walking was performed to collect kinematic variables and the electromyographic signal of trunk, hip, knee, and ankle muscles, which was analyzed by the linear envelope. Cost of walking was calculated by subtracting resting body mass-normalized oxygen consumption from walking body mass-normalized oxygen consumption. Stride time and length, and ankle and hip range of motion were calculated from kinematic data. Findings: Older adult fallers had 28% lower knee extensor strength (p = 0.02), 47% lower internal oblique activation at heel contact (p = 0.03), and higher coactivation between tibialis anterior and gastrocnemius lateralis in each of the gait phases (p < 0.05). For fallers, a higher activation of gluteus maximus was associated with a higher cost of walking (r = 0.55, p < 0.05 and r = 0.71, p < 0.01, before and after heel contact, respectively). For non-fallers, an association between cost of walking and age (r = 0.60, p = 0.01) and cost of walking and thigh muscle coactivation (r = 0.53, p = 0.01) existed. Interpretation: This study demonstrated that there may be links between lower-extremity muscle weakness, muscle activation patterns, altered gait, and increased cost of walking in older fallers. © 2013 Elsevier Ltd. All rights reserved.

Female germ cell renewal during the annual reproductive cycle in Ostariophysians fish

The objective was to characterize female germ cell renewal during the annual reproductive cycle in two species of ostariophysian fish with distinct reproductive strategies: a siluriform, Pimelodus maculatus, in which oocyte development is group synchronous and the annual reproductive period is short; and a characiform, Serrasalmus maculatus, with asynchronous oocyte development and a prolonged reproductive period. These reproductive strategies result in fish determinate and indeterminate fecundity, respectively. Annual reproductive phases were determined by biometric and histologic analysis of gonads and interpreted according to new proposals for phase classification and stages of oocyte development (with special attention to germinal epithelium activity). Histologically, there were two types of oogonia in the germinal epithelium: single oogonia and those in mitotic proliferation. Oogonial proliferation and their entry into meiosis resulted in formation of cell nests (clusters of cells in the ovarian lamellae). Morphometric analysis was used to estimate germ cell renewal. Based on numbers of single oogonia in the lamellar epithelium, and nests with proliferating oogonia or early prophase oocytes throughout the annual reproductive cycle, oogonial proliferation and entrance into meiosis were more intense during the regenerating phase and developing phase, but decreased sharply (P < 0.05) during the spawning-capable phase. Oogonial proliferation gradually recovered during the regressing phase. We concluded that, independent of species or features of the reproductive cycle, germ cell renewal occurred during the regenerating phase, ensuring availability of eggs for the spawning event. © 2013 Elsevier Inc.

Effects of exposure to estradiol and estradiol plus testosterone on the mongolian gerbil (Meriones unguiculatus) female prostate

The female prostate is a differentiated organ found in several mammal species, including humans and rodents. This gland has been related to important functions on female reproductive biology. Although the factors, which regulate prostate's development and activity are not well known, its functionality has been related to steroid hormones. It is well established that cyclic changes of estradiol and progesterone levels promote histophysiological adaptations of the whole female body. In contrast, only a few is found about those adaptations in female prostate. Thus, this study aimed to evaluate the effect of estradiol and estradiol+testosterone association on gerbil female prostate in order to verify, which hormonal associations are necessary to its homeostasis. For this, adult females had the ovaries surgically removed. After recovering, they received estradiol and estradiol+testosterone doses through 30 days, each 48 h. The prostatic tissue underwent morphological and morphometric-estereological analysis. Hormonal restriction caused great gland involution and decreased secretory activity, aspects that were reverted by exposure to estradiol and estradiol+testosterone. However, these hormones were not able to re-establish the normal prostate histoarchitecture. The immunoreaction of steroid receptors (ER-α, ER-β, and AR) responded differently among the experimental and control groups, and PCNA assay showed a decrease in epithelial cell proliferation within groups that had hormone privation. Therefore, we conclude that estradiol and testosterone are able to influence prostate morphophysiology and the maintenance of gland homeostasis depends on a balance among these and other hormones. © 2013 Wiley Periodicals, Inc.

Performance, survivability and carcass traits of crossbred lambs from five paternal breeds with local hair breed Santa Inês ewes

The present study aimed to evaluate the performance, survivability and carcass traits of crossbred lambs. Data from 299 lambs born to 209 ewes were used. The dams were from a local hair breed (Santa Inês) and five breeds of sires were used: Dorper (DR), Ile de France (IF), Hampshire Down (HD), Texel (TX) and Santa Inês (SI). The lambs were weighed at birth, weaning and slaughter. Fasting body weight, skin thickness, hot and cold carcass weight, carcass yield and carcass length were measured at slaughter. Carcasses were separated into commercial cuts: neck, shoulder, rib, belly, loin and leg. Leg length and circumference were measured. Analyses of variances using MIXED procedure in SAS® were carried out for weights and carcass traits. Factor, discriminant and canonical analysis were carried out. Mortality data of animals from birth until slaughter was analyzed using logistic regression. The HD animals had the highest mortality rate. TX lambs had similar growth rate and survivability compared to DR and IF and had better carcass traits than these genetic groups. Therefore, this breed can be used as paternal breed to crossbreeding with Santa Inês dams. Santa Inês animals did not differ in growth from birth until slaughter compared to crossbred animals, which highlights the potential of this naturalized breed for meat production. Moreover, there is a great variability inside this breed for carcass and growth traits which may undergo great improvement through selection programs. © 2013 Elsevier B.V.

Progesterone restores the female prostate activity in ovariectomized gerbil and may act as competitor of testosterone in intraprostatic environment

Aims Little is known about the effect of progesterone on gerbil female prostate. It is known that normal oscillation in the progesterone and estradiol levels during the estrous cycle phases influence the morphophysiology of this gland. The present study aims to evaluate the isolated effect of prolonged administration of progesterone combined or not with testosterone on the prostate of ovariectomized female gerbil. Main methods To observe the morphological changes caused by castration in the prostate of different groups stereologic analyses of all prostate compartments, analysis of nuclear area and perimeter, and morphometric measurements of epithelial and smooth muscle cells layers were used. In addition, immunocytochemistry was performed to investigate the distribution of the androgen, estrogen alfa and beta and progesterone receptors in different prostatic compartments. Key findings This study demonstrated that both treatments partially recovered the structure of the gland. In the group treated with progesterone plus testosterone a higher incidence of epithelial and stromal disorders occurred, besides the absence of secretory activity. Thus, treatment only with progesterone showed better results in the restoration of glandular homeostasis mainly seen by the regulation of the secretory activity. Significance Collectively, the findings of this study indicate that progesterone may have a significant role on the maintenance of prostate morphophysiology, and showed an interesting evidence of hormonal competition between progesterone and testosterone. © 2013 Elsevier Inc.

Lower limb strength is associated with gait biomechanical abnormalities in older female fallers and non-fallers

BACKGROUND: Age-related loss in lower limb strength is related with impaired mobility. However, the association between decreased lower limb strength and gait biomechanical abnormalities is unclear. %In line with this, With respect to these statements, our study aimed to compare the maximum isokinetic voluntary strength (MIVS) of hip, knee and ankle of older women with and without history of falls. Also, we correlate the strength of each group with gait biomechanics. METHODS: The MIVS were assessed during concentric/concentric movements performed for hip, knee and ankle joints. Gait biomechanics (kinematic and electromyography) were assessed during 1-minute recorded during the volunteers walking on the treadmill at self-selected speed. Electromyographic signal was analyzed by the linear envelop after heel strike and before toe-off. The kinematic data were analyzed using the variables: step time, length and step width and ankle angle at heel strike, and hip angle at toe-off. RESULTS: In faller group, we found that a decreased hip abduction and adduction MIVS is associated with a higher tibialis anterior activation at initial stance (p =0.04 and r =-0.53 and p=0.04 and r=-0.52). CONCLUSION: Therefore, an impaired strength of hip could causes compensation in ankle stabilizer muscles activation at initial stance in older female fallers. © 2013 - IOS Press and the authors. All rights reserved.

Kinetic and temporospatial parameters in male and female cats walking over a pressure sensing walkway

Background: Several factors may influence kinetic data measurements, including body conformation and body mass. In addition, gender differences in gait pattern have been observed in healthy humans. Therefore, the aim of this study was to compare the kinetic and temporospatial parameters in clinically healthy male and female cats using a pressure-sensitive walkway. Eighteen crossbreed adult cats were divided into two groups: G1 had ten male cats (nine neutered) aged from 1 to 4 years and body mass 3.1-6.8 kg; G2 had eight spayed female cats, aged from 1 to 6 years and body mass 3.3-4.75 kg. The data from the first five valid trials were collected for each cat. A trial was considered valid if the cat maintained a velocity between 0.54-0.74 m/s and acceleration from -0.20 to 0.20 m/s2. The peak vertical force (PVF), vertical impulse (VI), gait cycle time, stance time, swing time, stride length, and percentage body weight distribution among the four limbs were determined. In addition, the lengths of each forelimb and each hind limb were measured using a tape with the animal standing.Results: No significant differences were observed in each group in either the forelimbs or the hind limbs or between the left and right sides for any of the variables. For both groups, the PVF (%BW), the VI, and the percentage body weight distribution were higher at the forelimbs than the hind limbs. The stride length was larger for males; however, the other kinetic and temporospatial variables did not show any statistically significant differences between the groups. The lengths of the forelimbs and hind limbs were larger in the male cats. There was a significant moderate positive correlation between the stride length and the length of the limbs.Conclusions: In conclusion, the only difference observed between male and female cats was the stride length, and this was due to the greater body size of male cats. This difference did not affect other temporospatial or kinetics variables. © 2013 Verdugo et al.; licensee BioMed Central Ltd.

Morphological and cytochemical changes in synganglion of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) female ticks from exposure of andiroba oil (Carapa guianensis)

Actually, the most used method to control ticks is synthetic acaricides with neurotoxic action. However, the use of these methods presents inconveniences, such as the contamination of the environment and risks to the host's health due to the residual effects. Thus, several studies have been developed aiming to find alternative ways to control these ectoparasites, such as the use of natural compounds with active ingredients, which act controlling some species of plagues in addition to presenting medicinal properties that are beneficial to humans. The present study aimed to analyze the action of andiroba oil (Carapa guianensis) on the synganglion of Rhipicephalus sanguineus semiengorged females through morphological and cytochemical techniques aiming to verify if this natural product have neurotoxic action as the numerous synthetic acaricides. The results showed that andiroba oil interferes in the synganglion through structural and enzymatic changes, which lead the nervous tissue to apoptotic death involving autophagy. Among these changes was observed the emergence of large empty spaces between the perineurium and the cortical region, vacuolated cortex cells and with cell swelling, neural cells with picnotic nuclei or in initial stage of chromatin margination and neuropile with high structural disorganization. Considering these data, it can be concluded that andiroba seed oil can be used as an alternative method in the control of R. sanguineus ticks due to its neurotoxic action. © 2013 Wiley Periodicals, Inc.

Sexual transmission of Toxoplasma gondii in sheep

Male sheep of reproductive age were distributed into three groups: GI, a sheep inoculated (oral) with 2.0×105 oocysts of the P strain of Toxoplasma gondii; GII, a sheep infected (subcutaneous) with 1.0×106 tachyzoites of the RH strain of T. gondii; and GIII, a sheep kept as a control (not infected). After the inoculation of the males, 12 breeding ewes, which were not pregnant and which were serologically negative for reproductive diseases (particularly toxoplasmosis), were distributed into three groups, synchronized, and subsequently exposed to natural mating with previously inoculated males. The distribution was as follows: five ewes that underwent natural mating with the GI male, five ewes that were exposed to natural mating with the GII male, and two ewes that were mated with the non-infected male (control). Serum samples of all the ewes were collected on days -30, -14, -7, -1, and 0 (days before natural mating) and on days 1, 3, 5, 7, 11, 14, and weekly until birth; the presence of serum antibodies against T. gondii was assessed by IFAT. Using a bioassay and PCR, T. gondii was isolated from the semen of the infected reproducing sheep before mating. Following natural mating, 5 of the 12 females displayed antibodies specific for T. gondii; of these animals, two of the ewes underwent natural mating with the male inoculated with oocysts (GI) and three with the male infected with tachyzoites (GII). One of the females that displayed antibodies specific to this coccidian and that underwent natural mating with the GII sheep had a macerated fetus on the 70th day following coverage. Using a bioassay after the birth, it was possible to isolate T. gondii from samples of the pool of tissues from the five females that seroconverted after natural mating and from their respective lambs. Using PCR, the DNA of T. gondii was isolated from the pool of tissues from one and two females exposed to natural mating with the reproductive males infected with the oocysts and tachyzoites, respectively. Using this technique, it was also possible to diagnose the presence of the parasite in the pool of tissues from the lambs of one female that underwent natural mating with the male sheep infected with oocysts. These results demonstrated the sexual transmission of T. gondii in the sheep species with consequent vertical transmission to their lambs. © 2013 Elsevier B.V.

Morphology of the female genital ducts of the blue land crab Cardisoma guanhumi (Crustacea: Brachyura: Gecarcinidae)

This is a histological and histochemical analysis of the terminal portion of the female reproductive system and genital ducts of the blue land crab (Cardisoma guanhumi). Animals were collected in the Jaguaribe estuary (Ceará, Brazil) and dissected. Genital duct fragments were fixed and submitted to different staining techniques. The female reproductive system consists of a pair of ovaries and a pair of genital ducts. In the mid-posterior portion of each lobe, the ovaries communicate with the genital ducts, which are subdivided into oviduct, spermatheca, vagina, and gonopore. Histologically, the spermatheca of C. guanhumi is composed of columnar secretory epithelium and is divided into a dorsal zone and a ventral zone, the latter covered internally by a cuticle layer. Both zones are enveloped by a thin layer of loose connective tissue. Histological cross sections revealed the vagina to be concave, a pattern considered phylogenetically more advanced than the simple, tubular form. Our findings suggest fertilization is internal, favoring sperm from the most recent copulation. © 2012 The Authors. Acta Zoologica © 2012 The Royal Swedish Academy of Sciences.

Genetic parameter estimates and principal component analysis of breeding values of reproduction and growth traits in female Canchim cattle

Phenotypic data from female Canchim beef cattle were used to obtain estimates of genetic parameters for reproduction and growth traits using a linear animal mixed model. In addition, relationships among animal estimated breeding values (EBVs) for these traits were explored using principal component analysis. The traits studied in female Canchim cattle were age at first calving (AFC), age at second calving (ASC), calving interval (CI), and bodyweight at 420 days of age (BW420). The heritability estimates for AFC, ASC, CI and BW420 were 0.03±0.01, 0.07±0.01, 0.06±0.02, and 0.24±0.02, respectively. The genetic correlations for AFC with ASC, AFC with CI, AFC with BW420, ASC with CI, ASC with BW420, and CI with BW420 were 0.87±0.07, 0.23±0.02, -0.15±0.01, 0.67±0.13, -0.07±0.13, and 0.02±0.14, respectively. Standardised EBVs for AFC, ASC and CI exhibited a high association with the first principal component, whereas the standardised EBV for BW420 was closely associated with the second principal component. The heritability estimates for AFC, ASC and CI suggest that these traits would respond slowly to selection. However, selection response could be enhanced by constructing selection indices based on the principal components. © CSIRO 2013.

Nursing regimens: Effects on body condition, return to postpartum ovarian cyclicity in Santa Ines ewes, and performance of lambs

The effects of nursing regimens on the body condition, onset of ovarian cyclicity postpartum and weaning weight of lambs were assessed in Santa Ines ewes. Thirty-two ewes were blocked according to parity, number of lambs, and body weight at lambing and within each block randomly allocated to treatments: continuous nursing (CN), controlled nursing (CN2) with two daily feedings for an hour after the 10th day postpartum, or early weaning (EW) with total separation from the lambs after the 10th day. The animals were evaluated from the 12th day postpartum until the first estrus or until 60th day. The dry matter and nutrients intake did not differ among treatments ( P>. 0.05) but did differ over time ( P<. 0.01). The weight, body condition score, serum concentrations of non-esterified fatty acids and prolactin, the percentages of ewes in estrus, of ewes that ovulated within 60th day and had ovulation silent, the period from lambing to estrus, ovulation and follicle with a diameter ≥5. mm and the maximum follicular diameter did not differ ( P>. 0.05) among the treatments. The percentage of ovulation until 30th day was greater ( P<. 0.05) in the EW group. The percentage of short luteal phases was higher in the CN2 and EW groups ( P=0.07) and normal luteal phases were higher in the CN group ( P=0.01). Lamb weight weaning was lower in the EW group ( P<. 0.05). It is possible to use CN to obtain lambing periods less than eight months in Santa Ines ewes, with the advantages of simpler management and higher lamb weaning weights. © 2013 Elsevier B.V.

Vocal Economy in Vocally Trained and Untrained Female Subjects

Objectives: Vocally trained actresses are expected to have more vocal economy than nonactresses. Therefore, we hypothesize that there will be differences in the electroglottogram-based voice economy parameter quasi-output cost ratio (QOCR) between actresses and nonactresses. This difference should remain across different levels of intensity. Methods: A total of 30 actresses and 30 nonactresses were recruited for this study. Participants from both groups were required to sustain the vowels /a/, /i/, and /u/, in habitual, moderate, and high intensity levels. Acoustic variables such as sound pressure level (SPL), fundamental frequency (F0), and glottal contact quotient (CQ) were obtained. The QOCR was then calculated. Results: There were no significant differences among the groups for QOCR. Positive correlations were observed for QOCR versus SPL and QOCR versus F0 in all intensity levels. Negative correlation was found between QOCR and CQ in all intensity levels. Considering the differences among intensity levels, from habitual to moderate and from moderate to loud, only the CQ did not differ significantly. The QOCR, SPL, and F0 presented significant differences throughout the different intensity levels. Conclusion: The QOCR did not reflect the level of vocal training when comparing trained and nontrained female subjects in the present study. Both groups demonstrated more vocal economy in moderate and high intensity levels owing to more voice output without an increase in glottal adduction. © 2013 The Voice Foundation.

Influence of stocking density on weight gain and behavior of feedlot lambs

The aim of this study was to verify the influence of the animal density on the weight gain and behavior of confined lambs. 86 animals were confined after weaning in 23 pens of two lambs each (double pens) and four pens of ten animals each (collective pens). During the 80 days of confinement all lambs received the same diet and the animals were weighed at the beginning of the trial and every 14 days for the control of the weight gain. The behavioral patterns were recorded by focal sampling method using a time sampling of 30 minutes, from 6:00 am to 6:00 pm, for 4 days. The behavioral variables were: posture (standing; lying), activity (eating; ruminating; leisure; drinking water; grooming) and events (nid-nodding; pushing; picking up; bellowing; mounting; defecating; urinating). For the evaluation of the weight gain and behavior of the animals an analysis of variance and multiple comparison procedure by Student t test was used. The average weight gain was higher for pen animals (0.228 kg/day) compared to the animals housed in the collective pens (0.208 kg/day; P = 0.07). A higher percentage of animals housed in double pens remained standing compared to the animals housed in collective pens at 8:30 am (P < 0.05), 11:30 am (P < 0.01), 2:30 pm (P < 0.01), 4:30 pm (P < 0.01), and 5:30 pm (P < 0.01). For the eating activity, it was observed that 6.9% more animals kept in the double pens remained in this activity at 8:30 am (P < 0.05) and 4:30 pm (P < 0.05), than in collective pen. No statistical difference was found for the other activities and events between treatments. The number of animals per group influenced the behavior of confined lambs, changing the pattern of food intake which could improve the weight gain. © 2013 Elsevier B.V. All rights reserved.

The effects of parturition season and suckling mode on the puerperium of santa ines ewes and on the weight gain of lambs

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)