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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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The nuclei below lead but with more than 126 neutrons are crucial to an understanding of the astrophysical r process in producing nuclei heavier than Aâ¼190. Despite their importance, the structure and properties of these nuclei remain experimentally untested as they are difficult to produce in nuclear reactions with stable beams. In a first exploration of the shell structure of this region, neutron excitations in ^{207}Hg have been probed using the neutron-adding (d,p) reaction in inverse kinematics. The radioactive beam of ^{206}Hg was delivered to the new ISOLDE Solenoidal Spectrometer at an energy above the Coulomb barrier. The spectroscopy of ^{207}Hg marks a first step in improving our understanding of the relevant structural properties of nuclei involved in a key part of the path of the r process.
RESUMEN
There is sparse direct experimental evidence that atomic nuclei can exhibit stable "pear" shapes arising from strong octupole correlations. In order to investigate the nature of octupole collectivity in radium isotopes, electric octupole (E3) matrix elements have been determined for transitions in ^{222,228}Ra nuclei using the method of sub-barrier, multistep Coulomb excitation. Beams of the radioactive radium isotopes were provided by the HIE-ISOLDE facility at CERN. The observed pattern of E3 matrix elements for different nuclear transitions is explained by describing ^{222}Ra as pear shaped with stable octupole deformation, while ^{228}Ra behaves like an octupole vibrator.
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Superheavy elements are formed in fusion reactions which are hindered by fast nonequilibrium processes. To quantify these, mass-angle distributions and cross sections have been measured, at beam energies from below-barrier to 25% above, for the reactions of ^{48}Ca, ^{50}Ti, and ^{54}Cr with ^{208}Pb. Moving from ^{48}Ca to ^{54}Cr leads to a drastic fall in the symmetric fission yield, which is reflected in the measured mass-angle distribution by the presence of competing fast nonequilibrium deep inelastic and quasifission processes. These are responsible for reduction of the compound nucleus formation probablity P_{CN} (as measured by the symmetric-peaked fission cross section), by a factor of 2.5 for ^{50}Ti and 15 for ^{54}Cr in comparison to ^{48}Ca. The energy dependence of P_{CN} indicates that cold fusion reactions (involving ^{208}Pb) are not driven by a diffusion process.
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There is a large body of evidence that atomic nuclei can undergo octupole distortion and assume the shape of a pear. This phenomenon is important for measurements of electric-dipole moments of atoms, which would indicate CP violation and hence probe physics beyond the Standard Model of particle physics. Isotopes of both radon and radium have been identified as candidates for such measurements. Here, we observed the low-lying quantum states in 224Rn and 226Rn by accelerating beams of these radioactive nuclei. We show that radon isotopes undergo octupole vibrations but do not possess static pear-shapes in their ground states. We conclude that radon atoms provide less favourable conditions for the enhancement of a measurable atomic electric-dipole moment.
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The successful treatment of boys with cancer has led to increasing attention to preserving their quality of life after completing cancer therapy. One of the top priorities for living a full life is keeping open the opportunity to have children. While sperm banking for males facing sterilizing cancer treatment can be effective, this approach requires subsequent use of reproductive procedures such as in vitro fertilization (IVF) or intrauterine insemination (IUI) to achieve a pregnancy. Advances in fertility preservation techniques may allow pre-pubertal boys to conceive using advanced stem cell technologies and stem cell transplantation in the future. This review summarizes the ethical positions of leading medical societies and explores the religious and moral stances of major religious institutions regarding these options.
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Antineoplásicos/efectos adversos , Supervivientes de Cáncer , Preservación de la Fertilidad/ética , Fertilidad , Infertilidad Masculina/terapia , Principios Morales , Neoplasias/terapia , Adolescente , Factores de Edad , Niño , Preescolar , Criopreservación/ética , Fertilidad/efectos de los fármacos , Fertilidad/efectos de la radiación , Fertilización In Vitro/ética , Humanos , Infertilidad Masculina/etiología , Infertilidad Masculina/fisiopatología , Masculino , Radioterapia/efectos adversos , Religión y Medicina , Bancos de Esperma/ética , Inyecciones de Esperma Intracitoplasmáticas/ética , Trasplante de Células Madre/éticaRESUMEN
Understanding the source of phenotypic variability is a challenge in the biological sciences. Variation in phenotypes is the result of variation in the genetics and environment the organism experiences, but elucidating the relative contribution of these two parameters can pose problems, especially in the field of systematics. Systematists are challenged to classify biological diversity into groups that share common ancestry. Phenotypic variation can be useful to demonstrate common ancestry, but only when the primary contributor to the variation is under strong genetic control, and thus heritable. Cusick's milkvetch (Astragalus cusickii) is a perennial forb endemic to the northwestern intermountain region of the United States. The species currently comprises four varieties based on subtle morphological dissimilarities, such as leaf size and density, and the size and shape of the seed pods. The taxonomic organization of the varieties of A. cusickii and related species of Astragalus were reexamined through phylogenetic analysis of low copy nuclear, nuclear-ribosomal, and chloroplast gene regions. Maximum parsimony, maximum likelihood, Bayesian inference, the genealogical sorting index, and an approximately unbiased test were used to determine appropriate species boundaries under the phylogenetic species concept. The results support reclassification of A. cusickii var. packardiae and A. cusickii var. sterilis as separate species. Additionally, evidence suggests a chloroplast capture event may have occurred in one population of A. cusickii var. packardiae.
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Fabaceae/clasificación , Teorema de Bayes , Cloroplastos/clasificación , Cloroplastos/genética , ADN de Plantas/química , ADN de Plantas/aislamiento & purificación , ADN de Plantas/metabolismo , Fabaceae/genética , Filogenia , Análisis de Secuencia de ADNRESUMEN
A trial was performed to assess the effect of evaporative pads on core body temperature (CBT) and lying behavior of lactating Holstein cows housed in cross-ventilated freestall facilities in a humid environment. This trial was undertaken in 2 barns equipped with (EP) or without (NP) evaporative pads. Each facility had 4 pens, 1 baffle/pen, and a nominal width of 122 m. Stocking density was higher (123.4 vs. 113.1%) and freestalls were slightly shorter (2.3 vs. 2.4 m) and narrower (1.16 vs. 1.21 m) in EP compared with NP barns. In each pen, lying behavior of 20 cows was monitored using electronic data loggers that recorded at 1-min intervals. A subset (n=14) of these cows within each pen were also fitted with temperature loggers attached to blank controlled intravaginal drug release devices to determine CBT every 5 min. Ambient conditions were collected every 15 min. Individual cow lying duration and lying bouts were assessed for each cow, as well as time spent standing and CBT within the following categories: CBT <38.6°C, and CBT >38.6, >38.9, >39.2, >39.4, and >39.7°C. These variables were analyzed using pen as the experimental unit, with cow and day as additional random effects. The average maximum ambient conditions over the 9 d were 25°C and 78.74% relative humidity. No differences were observed in lying duration and number of lying bouts over the 9-d period, with overall means of 696±31 min/d and 12.6±0.5 bouts/d. The EP cows spent 170 min/d longer with a CBT <38.6°C and 107 min/d less with CBT >39.2°C than did NP cows. Cooling with evaporative pads tended to increase time spent lying with a CBT >8.6°C and lying bouts/d for EP cows versus NP cows. Results from this trial show that even under mild heat stress, evaporative cooling in cross-ventilated facilities can decrease CBT and tended to increase lying time.
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Conducta Animal/fisiología , Temperatura Corporal , Bovinos/fisiología , Ventilación/métodos , Animales , Femenino , Calor , Vivienda para Animales , Lactancia , Postura , Estrés FisiológicoRESUMEN
Efficacy of 2 cooling systems (Korral Kool, KK, Korral Kool Inc., Mesa, AZ; FlipFan dairy system, FF, Schaefer Ventilation Equipment LLC, Sauk Rapids, MN) was estimated utilizing 400 multiparous Holstein dairy cows randomly assigned to 1 of 4 cooled California-style shade pens (2 shade pens per cooling system). Each shaded pen contained 100 cows (days in milk=58±39, milk production=56±18 kg/d, and lactation=3±1). Production data (milk yield and reproductive performance) were collected during 3mo (June-August, 2013) and physiological responses (core body temperature, respiration rates, surface temperatures, and resting time) were measured in June and July to estimate responses of cows to the 2 different cooling systems. Water and electricity consumption were recorded for each system. Cows in the KK system displayed slightly lower respiration rates in the month of June and lower surface temperatures in June and July. However, no differences were observed in the core body temperature of cows, resting time, feed intake, milk yield, services/cow, and conception rate between systems. The FF system used less water and electricity during this study. In conclusion, both cooling systems (KK and FF) were effective in mitigating the negative effects of heat stress on cows housed in arid environments, whereas the FF system consumed less water and electricity and did not require use of curtains on the shade structure.
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Aire Acondicionado/instrumentación , Bovinos/fisiología , Industria Lechera/instrumentación , Vivienda para Animales , Animales , Temperatura Corporal , Enfermedades de los Bovinos/prevención & control , Industria Lechera/métodos , Ambiente , Femenino , Trastornos de Estrés por Calor/prevención & control , Trastornos de Estrés por Calor/veterinaria , Lactancia/fisiología , Leche/química , Reproducción/fisiología , Frecuencia Respiratoria , Arabia Saudita , Estaciones del Año , TemperaturaRESUMEN
Cooling systems used to reduce heat stress in dairy operations require high energy, water usage, or both. Steady increases in electricity costs and reduction of water availability and an increase in water usage regulations require evaluation of passive cooling systems to cool cows and reduce use of water and electricity. A study was conducted to evaluate the use of heat exchangers buried 25 cm below the surface as components in a conductive system for cooling cows. Six cows were housed in environmentally controlled rooms with tie-stall beds, which were equipped with a heat exchanger and filled with 25 cm of either sand or dried manure. Beds were connected to supply and return lines and individually controlled. Two beds (one per each kind of bedding material) constituted a control group (water off), and the other 4 (2 sand and 2 dried manure) used water at 7°C passing through the heat exchangers (water on). The experiment was divided in 2 periods of 40 d, and each period involved 3 repetitions of 3 different climates (hot and dry, thermo neutral, and hot and humid). Each cow was randomly assigned to a different treatment after each repetition was over. Sand bedding remained cooler than dried manure bedding in all environments and at all levels of cooling (water on or off). Bed temperatures were lower and heat flux higher during the bed treatment with sand and water on. We also detected a reduction in core body temperatures, respiration rates, rectal temperatures, and skin temperatures of those cows during the sand and water on treatment. Feed intake and milk yield numerically increased during the bed treatment with sand and water on for all climates. No major changes were observed in the lying time of cows or the composition of the milk produced. We conclude that use of heat exchangers is a viable adjunct to systems that employ fans, misters, and evaporative cooling methods to mitigate effects of heat stress on dairy cows. Sand was superior to dried manure as a bedding material in combination with heat exchangers.
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Crianza de Animales Domésticos , Bovinos/fisiología , Industria Lechera/economía , Industria Lechera/métodos , Animales , Ropa de Cama y Ropa Blanca/veterinaria , Temperatura Corporal , Ambiente Controlado , Femenino , Calor , Lactancia , Leche/economía , Distribución Aleatoria , Frecuencia Respiratoria , AguaRESUMEN
Cattle show several responses to heat load, including spending more time standing. Little is known about what benefit this may provide for the animals. Data from 3 separate cooling management trials were analyzed to investigate the relationship between behavioral patterns in lactating dairy cows experiencing mild to moderate heat stress and their body temperature. Cows (n=157) were each fitted with a leg data logger that measured position and an intravaginal data logger that measures core body temperature (CBT). Ambient conditions were also collected. All data were standardized to 5-min intervals, and information was divided into several categories: when standing and lying bouts were initiated and the continuance of each bout (7,963 lying and 6,276 standing bouts). In one location, cows were continuously subjected to heat-stress levels according to temperature-humidity index (THI) range (THI≥72). The THI range for the other 2 locations was below and above a heat-stress threshold of 72 THI. Overall and regardless of period of day, cows stood up at greater CBT compared with continuing to stand or switching to a lying position. In contrast, cows lay down at lower CBT compared with continuing to lie or switching to a standing position, and lying bouts lasted longer when cows had lower CBT. Standing bouts also lasted longer when cattle had greater CBT, and they were less likely to lie down (less than 50% of lying bouts initiated) when their body temperature was over 38.8°C. Also, cow standing behavior was affected once THI reached 68. Increasing CBT decreased lying duration and increased standing duration. A CBT of 38.93°C marked a 50% likelihood a cow would be standing. This is the first physiological evidence that standing may help cool cows and provides insight into a communally observed behavioral response to heat.
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Conducta Animal/fisiología , Temperatura Corporal , Bovinos/fisiología , Trastornos de Estrés por Calor/veterinaria , Lactancia/fisiología , Animales , Enfermedades de los Bovinos/fisiopatología , Clima , Industria Lechera , Femenino , Trastornos de Estrés por Calor/fisiopatología , Calor , Humedad , Distribución Aleatoria , TemperaturaRESUMEN
Twelve field experiments and one laboratory experiment were conducted to determine the effects of furrow applied aldicarb and seed treatments of thiamethoxam, imidacloprid, Avicta (thiamethoxam + abamectin), Aeris (imidacloprid + thiodicarb), and acephate on twospotted spider mite, Tetranychus urticae Koch, on cotton, Cossypium hirsutum L. For the field experiments, data were pooled across all experiments for analysis. Aeris, thiamethoxam, and imidacloprid treatments resulted in twospotted spider mite densities greater than those in the untreated check, aldicarb, and acephate treatments. However, cotton treated with Avicta (thiamethoxam + abamectin) had 34% fewer mites than other neonicotinoid seed treatments when infestations occurred near cotyledon stage. Untreated check and aldicarb treatments had the lowest mite densities. Only aldicarb reduced mite densities below that in the untreated check. In a laboratory trial, the fecundity of twospotted spider mite was measured. While neonicotinoid seed treatments increased mite densities in the field, they did not increase fecundity in the laboratory experiment. Foliar applied thiamethoxam slightly elevated average fecundity in the laboratory experiment. Increased use of neonicotinoid seed treatments instead of furrow applied aldicarb is likely at least partly responsible for recent increased twospotted spider mite infestations in seedling cotton across the mid-south.
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Acaricidas , Gossypium , Tetranychidae , Animales , Mississippi , SemillasRESUMEN
Primiparous (n=33) and multiparous (n=63) lactating Holstein cows (186±51 d in milk) were used to evaluate the effects of supplementing metabolizable amino acids using lysine in a matrix of Ca salts of fatty acids (Megamine-L, Arm & Hammer Animal Nutrition, Princeton, NJ) and the isopropyl ester of 2-hydroxy-4-(methylthio) butanoic acid (MetaSmart, Adisseo Inc., Antony, France) in diets containing >26% wet corn gluten feed (dry matter basis). Cows were blocked by production level, parity, and pregnancy status, then randomly assigned to 1 of 8 pens and allowed a 7-d adaption period before receiving dietary treatments for 28 d. Pens were assigned randomly to either of 2 diets formulated to differ by metabolizable amino acid supply. Dry matter intake and production were monitored daily and milk components analyzed 3d/wk. Data were analyzed using mixed models with repeated measures. The original design of the study consisted of a control diet predicted to be deficient in lysine and methionine; however, after ingredient nutrients were analyzed and modeled with animal requirements at dry matter intake [26.6±0.35 kg/d (mean ± SEM)] and milk production levels achieved during the study (40.1±0.46 kg/d), only marginal deficiencies were predicted for the control (-8.1g/d for lysine; -1g/d for methionine) according to the National Research Council method, whereas the Cornell Net Carbohydrate and Protein System 5.0 and 6.1 models indicated positive balances for these amino acids (25.9 and 21.8 g/d for lysine, 14.7 and 18.9 g/d for methionine, respectively). Supplementing 30 g/d of metabolizable lysine in a Ca soap matrix and 2.4 g/d of metabolizable methionine as 2-hydroxy-4-(methylthio) butanoic acid led to positive predicted lysine and methionine balances by all 3 models, and predicted metabolizable lysine-to-methionine ratios ranging from 2.9 to 3.1. No treatment effects were observed for dry matter intake, milk yield, milk component concentrations or yields, or energy-corrected milk yield. Despite the negative lysine balance and low lysine-to-methionine ratio predicted by the National Research Council model, results provided no evidence of a lysine deficiency in the control diet.
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Dieta/veterinaria , Lactancia/efectos de los fármacos , Lisina/farmacología , Metionina/farmacología , Animales , Bovinos , Suplementos Dietéticos , Femenino , Glútenes , Leche/química , Proteínas de la Leche/análisis , Proteínas de la Leche/biosíntesis , Zea maysRESUMEN
Cows readily seek shade to reduce solar heat load during periods of high ambient temperature. Typically, auxiliary cooling systems are oriented to maximize cooling for shaded cows. However, when a shade structure is oriented north-south, stationary fan and mister cooling systems are unable to track shade as the sun's angle shifts throughout the day, and thus can become ineffective. The FlipFan Dairy Cooling System (Schaefer Ventilation Equipment, Sauk Rapids, MN) employs fans and misters that follow shade and compensate for wind speed by rotating on a horizontal axis. Multiparous, lactating Holstein cows (n=144) on a commercial dairy in Arizona were cooled by a fixed system comprised of stationary fans and misters acting as control or the adjustable FlipFan operated for 16.5 h/d (0830 to 0100 h). Core body temperatures (CBT) of 64 cows (4 pens/treatment; 8 cows/pen; 6d) and lying behavior of 144 cows (4 pens/treatment; 18 cows/pen; 5d) were collected by intravaginal and leg data loggers, respectively. Cows were balanced by milk production, blocked by days in milk, and randomly assigned to pen within block. Pen was the experimental unit. In a second experiment, isothermal maps were developed using a fixed system of thermal data loggers arranged in the shaded areas of the pens at different times of day and were analyzed for differences in the temperature-humidity index (THI) achieved by each cooling treatment. Ambient conditions consisted of a mean temperature of 33.0°C, mean relative humidity of 40.3%, and mean THI of 80.2. Mean 24-h CBT for FlipFan was lower than control (38.9 vs. 39.1±0.04°C). A treatment × time interaction was observed in which CBT of FlipFan was 0.4°C lower than control from 0600 to 0800h and 1500 to 1600h. Cows cooled by FlipFan spent more time lying down compared with those cooled by control (9.5 vs. 8.6 h/d). Cows under FlipFan had more frequent lying bouts than did those under control (12.8 vs. 10.7 bouts/d). Lower CBT and decreased standing time are consistent with the findings of other studies when ambient heat load was reduced. In the second experiment, the FlipFan system achieved a lower THI in the morning and evening (5.9 and 1.7%, respectively), and the THI also tended to be 0.8% lower in the afternoon compared with that of control. Results indicate that FlipFan is more effective than a stationary fan and mister system at decreasing CBT, increasing lying time and bouts, and providing a more desirable microenvironment for cows throughout the day in a semiarid environment.
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Aire Acondicionado/instrumentación , Conducta Animal/fisiología , Temperatura Corporal , Bovinos/fisiología , Clima Desértico , Humedad , Animales , Arizona , Femenino , Vivienda para Animales , Lactancia/fisiología , Postura/fisiologíaRESUMEN
We evaluated a product containing methionine mixed with soy lecithins and added to a mechanically extracted soybean meal (meSBM-Met). Lactational responses of cows, plasma methionine concentrations, and in vitro degradation of methionine were measured. Twenty-five Holstein cows were used in a replicated 5 × 5 Latin square design and fed a diet designed to be deficient in methionine or the same diet supplemented either with 4.2 or 8.3g/d of supplemental methionine from a ruminally protected source or with 2.7 or 5.3g/d of supplemental methionine from meSBM-Met. All diets were formulated to provide adequate amounts of metabolizable lysine. Concentration of milk true protein was greater when methionine was provided by the ruminally protected methionine than by meSBM-Met, but milk protein yield was not affected by treatment. Milk yields and concentrations and yields of fat, lactose, solids-not-fat, and milk urea nitrogen were not affected by supplemental methionine. Body condition scores increased linearly when methionine from meSBM-Met was supplemented, but responses were quadratic when methionine was provided from a ruminally protected source. Nitrogen retention was not affected by supplemental methionine. Plasma methionine increased linearly when methionine was supplemented from a ruminally protected source, but plasma methionine concentrations did not differ from the control when supplemental methionine from meSBM-Met was provided. In vitro degradation of supplemental methionine from meSBM-Met was complete within 3h. Data suggest that meSBM-Met provides negligible amounts of metabolizable methionine to dairy cows, and this is likely related to extensive ruminal destruction of methionine; however, cow body condition may be improved by ruminally available methionine provided by meSBM-Met.
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Glycine max/metabolismo , Lactancia/efectos de los fármacos , Lecitinas/metabolismo , Metionina/farmacocinética , Animales , Disponibilidad Biológica , Bovinos , Suplementos Dietéticos , Femenino , Lactancia/fisiología , Metionina/administración & dosificación , Metionina/sangre , Leche/química , Proteínas de la Leche/análisis , Rumen/metabolismoRESUMEN
Peyronie's disease (PD) is caused by progressive fibrotic scarring of the tunica albuginea resulting in curvature or other deformities of the erect penis. The severity of penile curvature or other deformity may contribute to a man's inability to have intercourse (sexual disability), due to difficulty with penetration, partner pain or emotional stress. To determine whether the degree of curvature or type of penile deformity predicts sexual disability among men with PD. This cross-sectional analysis of consecutive men evaluated for PD at a single tertiary referral center used a PD-specific questionnaire to evaluate risk factors for sexual disability in men with PD, who did not have erectile dysfunction (ED). Multivariate logistic regression was used to determine the clinical predictors of sexual disability. Sexual disability as defined by the inability to have penetrative intercourse. A total of 202 men were evaluated and 88 men with ED were excluded. Sexual disability was associated with relationship problems, penile curvature and penile length loss in bivariate, but not multivariate analysis. We found that although many of the demographic, medical and sexual function domains were significant predictors of inability to have sex, the only significant predictor of sexual disability in multivariate analysis was curvature>60° (odds ratio 3.23 95%CI 1.08-9.67). PD can be sexually disabling in many men without ED. Severe penile curvature is a robust independent predictor of the ability to have intercourse. Other penile deformities fail to predict sexual disability. This is important for counseling patients with newly diagnosed PD and those who are considering medical or surgical intervention.
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Induración Peniana/patología , Pene/patología , Adulto , Anciano , Coito/fisiología , Coito/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor , Induración Peniana/complicaciones , Pene/fisiopatología , Disfunciones Sexuales Fisiológicas/etiología , Disfunciones Sexuales Fisiológicas/patología , Disfunciones Sexuales Fisiológicas/terapia , Parejas Sexuales , Estrés PsicológicoRESUMEN
We analyzed associations of dissatisfaction with sexual life and desire for change in female medical students. Students enrolled in medical schools in North America between February and July 2008 were invited to participate in an internet-based survey of sexual function. The principle outcome measure was a single item question on sexual life satisfaction and desire for change. Women who reported dissatisfaction and desire for change were classified as 'sexually bothered'. The survey also assessed ethnodemographic factors, student status, sexual history and depressive symptoms. Respondents completed the Female Sexual Function Index (FSFI) and the Index of Sexual Life. Descriptive statistics, analysis of variance and multivariable logistic regression were utilized to analyze responses. There were 661 non-virgin female subjects with data adequate for analysis. Whereas 281 (43%) of these met criteria for high risk of female sexual dysfunction (HRFSD) based on FSFI scoring, just 173 (26%) reported sexual bother. Among women with HRFSD, 126 (45%) reported sexual bother; in women without HRFSD, 362 (95%) were not sexually bothered. Interference in sexual life from tiredness and stress were associated with sexual bother. Progressively better scores on the FSFI desire, orgasm and satisfaction domains were significantly associated with lower odds of sexual bother. Few women in this cohort with FSFI score >26.55 reported sexual bother. Women with FSFI <26.55 had greater odds of sexual bother but this criterion alone was not pathognomonic for sexual concerns. Issues of sexual desire and orgasm appear to have a more important role than lubrication, arousal and sexual pain issues in this population.
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Conducta Sexual/psicología , Estudiantes de Medicina/psicología , Adulto , Depresión , Fatiga , Femenino , Humanos , Internet , Modelos Logísticos , América del Norte , Orgasmo , Satisfacción Personal , Factores de Riesgo , Factores Sexuales , Disfunciones Sexuales Psicológicas , Estrés Psicológico , Encuestas y CuestionariosRESUMEN
The collection of calf birth weight on US dairies is not a common practice. Calf birth weight was collected on 3 dairies (2 Holstein herds and 1 Jersey herd) over a 6-wk period. All calf birth weights were collected less than 2h after birth. A total of 872 calves were weighed by a spring scale and their weight was also estimated using a hoof circumference tape, with both weights and sex recorded. The general linear models procedure (PROC GLM; SAS Institute Inc., Cary, NC) was used to estimate least squares means for spring scale birth weight along with sex of the calf and dairy. Calf spring scale versus hoof circumference-estimated birth weight was compared using the regression procedure (PROC REG; SAS Institute Inc.). Calf birth weight was also broken down into increments, and spring scale versus hoof circumference-estimated birth weight was compared by t-test. Bull calves had a heavier birth weight compared with heifer calves [36.7±0.4 kg (n=450) vs. 34.6±0.4 kg (n=422), respectively]. The dairy on which calves were born had a significant effect on calf birth weight [dairy 1: 36.8±0.4 kg (n=204); dairy 2: 39.5±0.2 kg (n=463); dairy 3: 25.9±0.4 kg (n=205)]. When the spring scale calf birth weight was linearly regressed by hoof circumference-estimated birth weight, a significant relationship was observed, with an R(2) value of 0.91. For calves weighing less than 31.3 kg, the hoof circumference tape overestimated calf birth weight compared with the spring scale. However, for calves that weighed between 31.3 and 44.9 kg, no significant difference was observed between spring scale and hoof circumference tape-estimated birth weight. For calves weighing greater than 44.9 kg, the hoof circumference tape underestimated birth weight compared with the spring scale. Collection of calf BW by spring scale or estimated by hoof circumference tape appeared to be comparable for most calves because most calves weighed between 31 and 45 kg, but caution should be used for calves with a light or heavy birth weight.
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Animales Recién Nacidos/anatomía & histología , Peso al Nacer , Bovinos/anatomía & histología , Animales , Industria Lechera/métodos , Femenino , Pezuñas y Garras/anatomía & histología , MasculinoRESUMEN
The Greenshell™ mussel (Perna canaliculus) is the main shellfish species farmed in New Zealand. The aim of this study was to evaluate the effects of cryoprotectant concentration, loading and unloading strategy as well as freezing and thawing method in order to develop a protocol for cryopreservation of trochophore larvae (16-20 h old). Toxicity tests showed that levels of 10-15% ethylene glycol (EG) were not toxic to larvae and could be loaded and unloaded in a single step. Through cryopreservation experiments, we designed a cryopreservation protocol that enabled 40-60% of trochophores to develop to D-larvae when normalized to controls. The protocol involved: holding at 0 °C for 5 min, then cooling at 1 °C min⻹ to -10 °C, holding for a further 5 min, then cooling at 0.5 °C min⻹ to -35 °C followed by a 5 min hold and then plunging into liquid nitrogen. A final larval rearing experiment of 18 days was conducted to assess the ability of these frozen larvae to develop further. Results showed that only 2.8% of the frozen trochophores were able to develop to competent pediveligers.