Diffusive majority-vote model.

We define a stochastic reaction-diffusion process that describes a consensus formation in a nonsedentary population. The process is a diffusive version of the majority-vote model, where the state update follows two stages: In the first stage, spins are allowed to jump to a random neighbor node with probabilities D_{+} and D_{-} for the respective spin orientations, and in the second stage, the spins in the same node can change its values according to the majority-vote update rule. The model presents a consensus formation phase when the concentration is greater than a threshold value and a paramagnetic phase on the converse for equal diffusion probabilities, i.e., maintaining the inversion symmetry. Setting unequal diffusion probabilities for the respective spin orientations is the same as applying an external magnetic field. The system undergoes a discontinuous phase transition for concentrations higher than the critical threshold on the external field. The individuals that diffuse more dominate the stationary collective opinion.

Are experienced and high-level race walking athletes able to match pre-programmed with executed pacing?

The objective of this study was to verify the agreement between pre-programmed and executed pacing during race walking and whether level of the athletes experience and performance influenced this relationship. Twenty-nine national and international race walkers participated in this study (14 males, 24.0±7.1 years old, and 15 females, 23.3±7.3 years old). Pre-programmed pacing for 10- and 20-km official walking races was self-selected via demonstrative pacing charts prior to races, while executed pacing was analyzed by a specialist investigator via an individual plot of current velocity versus distance. There was no agreement between pre-programmed and executed pacing (P=0.674). There was no association between the ability to match the pre-programmed pace with the executed pace and race walking experience or level of performance. Low- and high-performance athletes pre-programmed a similar pacing profile (P=0.635); however, high-performance athletes generally executed an even pacing strategy, while low-performance athletes generally adopted a positive pacing strategy (P=0.013). Race walkers did not faithfully match their pre-programmed with their executed pacing, and this seemed to be independent of previous experience and level of performance. High-performance athletes, however, tended to execute an even pacing strategy, even though this had not been pre-programmed.

Are experienced and high-level race walking athletes able to match pre-programmed with executed pacing?

The objective of this study was to verify the agreement between pre-programmed and executed pacing during race walking and whether level of the athletes experience and performance influenced this relationship. Twenty-nine national and international race walkers participated in this study (14 males, 24.0±7.1 years old, and 15 females, 23.3±7.3 years old). Pre-programmed pacing for 10- and 20-km official walking races was self-selected via demonstrative pacing charts prior to races, while executed pacing was analyzed by a specialist investigator via an individual plot of current velocity versus distance. There was no agreement between pre-programmed and executed pacing (P=0.674). There was no association between the ability to match the pre-programmed pace with the executed pace and race walking experience or level of performance. Low- and high-performance athletes pre-programmed a similar pacing profile (P=0.635); however, high-performance athletes generally executed an even pacing strategy, while low-performance athletes generally adopted a positive pacing strategy (P=0.013). Race walkers did not faithfully match their pre-programmed with their executed pacing, and this seemed to be independent of previous experience and level of performance. High-performance athletes, however, tended to execute an even pacing strategy, even though this had not been pre-programmed.

Cardiac autonomic responses at onset of exercise: effects of aerobic fitness.

Analyzes of cardiac autonomic responses at the initial transient of exercise have been used for the investigation of the cardiovascular health. We evaluated the influence of aerobic fitness on HR and HRV responses at the onset of exercise. 25 male subjects (22.3±2.4 years) were divided into 2 groups: 'low aerobic fitness' (36.2±2.6ml.kg(-1).min(-1); n=10) and 'high aerobic fitness' (46.4±5.0ml.kg(-1).min(-1); n=15). The experimental session consisted of assessing the beat-to-beat HR at rest and during submaximal exercise. The autonomic responses at the onset of exercise were calculated by fitting the HR and HRV (rMSSD-index) curves during the initial 300s of exercise into a first-order exponential equation. The time constant of HR and of the rMSSD index (τonHR and τonrMSSD) were calculated for analysis. We observed lower values of τonrMSSD in the high aerobic fitness group compared to the low aerobic fitness group (26.8±5s vs. 38.0±18s, respectively; p=0.02). The τonHR (42.0±15 vs. 49.3±26s, p=0.38) for the groups showed no difference. Aerobic fitness partially influenced the autonomic responses during exercise, since individuals with higher fitness showed faster decreases in beat-to-beat HRV at the onset of exercise.

Masticatory efficiency in complete denture wearers with reduced dental arches--a randomised cross-over study.

One obstacle to placing artificial posterior teeth in manufacturing complete dentures is a reduction of the space between the maxilla and the mandible. Occasionally, second molar placement is not performed, as it does not affect aesthetics, phonetics or comfort. The aim of this study was to compare the masticatory efficiency between patients wearing maxillary and mandibular complete dentures with reduced dental arches (without second molars) (WSM) and with full dental arches (FDA). Twenty subjects were divided into two groups and randomly received new complete dentures. Patients in Group 1 were given dentures WSM, and those in Group 2 were given dentures with FDA. After the post-placement visits, an initial masticatory efficiency test was performed with Optocal, an artificial test food. Fifteen days later, second molars were placed in Group 1 and removed from Group 2, and a new test was performed. Comminuted material was treated and sieved under vibration. The mean and standard deviation of masticatory efficiency with FDA were 10.4 and 8.1, respectively. In the tests WSM, the mean and standard deviation were 8.4 and 3.3, respectively. After removing the second molars in Group 2 and adding them in Group 1, the mean and standard deviation were 15.7 and 14.7 for Group 1 and 12.5 and 10.4 for Group 2, respectively. Within the limitations of this study, placing artificial teeth up to the first molars can be performed when needed without compromising masticatory efficiency.

24-h cardiac autonomic profile after exercise in sedentary subjects.

Most studies regarding the impact of exercise intensity on cardiac autonomic regulation were conducted with athletes and used exercise intensities exceeding those recommended by position stands. We evaluated the influence of exercise intensity in a typical ACSM-aerobic session on 24-h cardiac autonomic modulation in sedentary subjects. Ten healthy sedentary subjects participated in the 3-day study. On 2 days, subjects performed a moderate- or high-intensity aerobic exercise session (MI, HI). The post-exercise protocol consisted of a continuous electrocardiographic recording for 1 h at the laboratory plus 23 h under ambulatory conditions. On the third day 24-h electrocardiographic recording was done without prior exercise (NPE). Heart rate (HR) and frequency-domain parameters (LF, HF) of heart rate variability were evaluated during the entire recovery period. Higher values of HR and lower values of HF and LF were observed throughout the first hour after the HI compared with the MI session. This difference was not observed after in ambulatory awake condition, but reappeared during sleep, when HF values after HI were lower compared with the NPE and MI (p<0.05). Even within the submaximal intensity-range of a typical exercise session, the intensity of exercise influences the post-exercise cardiac autonomic modulation in sedentary subjects.

Short-term effects of silage volatile compounds on feed intake and digestion in beef cattle.

Two experiments were conducted to evaluate whether fermentation end products in silage affect intake and digestion in beef cattle. Six rumen-cannulated Nellore steers were randomly assigned to a replicated 3 × 3 Latin square design with 14-d periods. Each period consisted of 9 d for adaptation and 5 d for sample collection. Steers were housed in a tie-stall barn and individually fed once daily at 0800 h. The dietary treatments in Exp. 1 were as follows: 60% corn silage plus 40% concentrate (CON), 60% corn silage with added ethanol (2.8% on a DM basis) and 40% concentrate (ET), and 60% corn silage with added lactic acid (5.4% on a DM basis) and 40% concentrate (LA). The DMI was similar (P = 0.41) across treatments (average 11.7 kg/d); however, the LA treatment increased the ruminal pH (P = 0.01) and decreased the acetate:propionate ratio (P < 0.01). Diet digestibility decreased by 2.2 to 2.5 percentage units when the DM content was determined by oven drying (at 105°C) rather than by toluene distillation. The treatments in Exp. 2 were as follows: 75% sugarcane silage with no volatile fraction (oven dried at 60°C and rehydrated) and 25% concentrate (75D), 75% sugarcane silage (original moisture content) and 25% concentrate (75W), and 40% sugarcane silage and 60% concentrate (40W). Approximately 21% of the DM content of sugarcane silage consisted of volatile compounds. The presence of these compounds did not alter the DMI (P = 0.36) but did increase both the acetate:propionate ratio (P < 0.01) and the fractional absorption rates of valerate (P < 0.01) and ethanol (P = 0.02) in the empty reticulorumen. The 40W diet led to a greater DMI (40W = 9.79 vs. 75W = 6.19 kg/d; P < 0.01), which altered most of the measured variables traditionally associated with high-concentrate diets. As in Exp. 1, diet digestibility decreased by 1.5 to 5.4 units when the DM content was determined by oven drying at 105°C rather than by toluene distillation. In this short-term study, volatile compounds did not inhibit the DMI or the digestion process of the animals. On the contrary, volatile compounds contributed to the energy content of the silage, composing up to 10% of the energy value as determined by digestibility. Due to the short experimental periods, the results from this study should be interpreted with caution.

Minimal progesterone concentration required for embryo survival after embryo transfer in lactating Holstein cows.

Objectives were to determine progesterone concentration (P4) from days 4 to 28 relative to presumptive estrus necessary for maintenance of pregnancy in lactating Holstein cows. Cows were assigned to the low P4 (LowP4, n=28) or control (n=153) treatments. All cows were presynchronized with two injections of PGF(2α) (14d apart) and an ovulation synchronization protocol (11d later; GnRH on day -10, PGF(2α) on day -3; and GnRH on day 0=presumptive estrus). Cows in the Low P4 treatment received 2 injections of prostaglandin F(2α) on days 4 and 5 (day 0=presumptive estrus) and a new CIDR insert on day 5 that was replaced every 7d until day 28. Blood was sampled on days -9, -2, 0, 4, 7,14, 21, and 28. Ovaries were examined with ultrasound on days -9, -3, and 7 and cows bearing a corpus luteum ≥20mm on day 7 received an embryo. On days 0, 4 and 7 P4 did not differ (P≥0.27) but control cows had greater (P<0.01) P4 on days 14, 21, and 28. Progesterone concentration fold change from day 0 to 7 was not (P=0.14) affected by treatment, but P4 concentration fold change from day 7 to 14 was (P<0.01) greater for control cows compared with LowP4 cows. No LowP4 cows became pregnant after embryo transfer, whereas 35.7, 25.5, and 21.4% of control cows were pregnant on day 28, 42, and 63, respectively. Progesterone concentration fold changes from day 0 to 7 (P=0.03) and from day 7 to 14 (P=0.05) were associated with pregnancy outcomes on day 63. Among cows that were pregnant on day 63, the minimum P4 concentration fold changes from day 0 to 7 and from day 7 to 14 were 2.71 and 1.48, respectively. Interestingly, cows with P4 concentration <5ng/mL on day 14 were (P=0.01) and tended to be (P=0.07) more likely to lose pregnancy from day 28 to 42 and from day 28 and 63, respectively. Faster rise in P4 concentration during the metestrus and early diestrus are associated with pregnancy establishment following embryo transfer, which suggests that early rise in P4 concentration has an indirect effect on embryo development through modulation of uterine environment and secretion of histotroph. Furthermore, the positive effects of early rise in P4 concentration appear to go beyond the phase of maternal recognition of pregnancy through adhesion and placentation stages.

Monitorización de las presiones de la vía aérea con la modalidad de flujo continuo en cirugía toracoscópica pediátrica. Estudio en modelo animal / Airway pressure monitoring by the continuous flow method in paediatric thoracoscopic surgery. A study in an animal model

Objetivo. Comparar las presiones en la vía aérea obtenidas antes del tubo endotraqueal con las intratraqueales en la modalidad ventilatoria de flujo continuo, en cirugía toracoscópica para ventilación unipulmonar, en modelo pediátrico en animales. Material y métodos. Estudio prospectivo observacional simple. Se emplearon 10 cerdos Large White, con un peso de 4,6±0,8kg. Los animales se ventilaron en modo neonatal (flujo continuo) con un respirador Temel Supra. Mediante traqueotomía realizamos un sellado completo del sistema respiratorio para usar tubos sin neumotaponamiento especiales que permiten el registro traqueal de presiones sin interferir en la ventilación. Se realizó colapso del pulmón derecho por videotoracoscopia y se mantuvo durante 120min. Las variables se analizaron en 10 tiempos: inicio y 5min en bipulmonar, tras el colapso en los tiempos 5, 15, 30, 60, 90 y 120min, y 5 y 15min tras la reexpansión pulmonar. Registramos la presión basal, pico, meseta y teleespiratoria en la boca del animal e intratraqueal. Resultados. La media de la presión pico en la boca del animal en ventilación unipulmonar fue de 23,38mmHg y traqueal de 21,24mmHg, mientras que la media de la presión meseta en la boca de animal en ventilación unipulmonar fue de 21,88mmHg y traqueal de 21,39mmHg, respectivamente, con diferencias significativas en todas (p<0,05). Encontramos diferencias estadísticamente significativas (p<0,05) para la presión pico y meseta al comparar el registro en la boca del animal con el registro traqueal, siendo la diferencia en valor absoluto mayor para el registro de presión pico. Conclusiones. Los parámetros de presiones registrados en la boca del animal fueron asumibles para la cirugía, manteniéndose una adecuada estabilidad respiratoria y hemodinámica. Podemos afirmar que la modalidad de flujo continuo según el estudio de presiones puede ser idónea para este tipo de cirugía, y que el registro en la boca del animal (paciente) para la presión pico no refleja lo que realmente ocurre en el alvéolo, pero sí podemos tener una aproximación clínica adecuada para la presión meseta(AU)

Objective. To compare the airway pressures obtained before the endotracheal tube with the intratracheal ones in the continuous flow ventilation mode, in thoracoscopic surgery for one lung ventilation, in a paediatric model in animals. Material and methods. A simple prospective observational study was conducted. Ten Large White pigs weighing 4.6±0.8kg were used. The animals were ventilated in neonatal mode (continuous flow) with a Temel Supra ventilator. Using tracheotomy, we completely sealed the respiratory system in order to use tubes without special endotracheal cuffs, which would enable tracheal pressures to be registered without interfering with ventilation. Collapse of the right lung was performed by videothoracoscopy and was maintained for 120min. The variables were measured at 10 time periods: start and 5min with both lungs, after collapse at 5, 15, 30, 60, 90 and 120min, and 5 and 15min after lung re-expansion. We recorded the baseline, peak, plateau and positive end expiratory pressure in the mouth of the animal and intratracheal. Results. The mean peak pressure in the mouth of the animal in one lung ventilation was 23.38mmHg and tracheal ventilation was 21.24mmHg, while the mean plateau pressure in the mouth of the animal in one lung ventilation it was 21.88mmHg and tracheal was 21.39mmHg, respectively, with significant differences in all of them (P<.05). We found statistically significant differences (P<.05) for peak and plateau pressure on comparing the record in the animal mouth with the tracheal record. The difference in absolute value was higher for the peak pressure record. Conclusions. The pressure parameters recorded in the animal mouth were acceptable for surgery, with a suitable respiratory and haemodynamic stability being maintained. We can state that the continuous flow mode according to the pressures study may be suitable for this type of surgery, and that the mouth of the animal (patient) record for the peak pressure does not reflect what really happens in the alveoli, but we can give a suitable clinical estimate for the plateau pressure(AU)

[Airway pressure monitoring by the continuous flow method in paediatric thoracoscopic surgery. A study in an animal model]. / Monitorización de las presiones de la vía aérea con la modalidad de flujo continuo en cirugía toracoscópica pediátrica. Estudio en modelo animal.

OBJECTIVE: To compare the airway pressures obtained before the endotracheal tube with the intratracheal ones in the continuous flow ventilation mode, in thoracoscopic surgery for one lung ventilation, in a paediatric model in animals. MATERIAL AND METHODS: A simple prospective observational study was conducted. Ten Large White pigs weighing 4.6 ± 0.8 kg were used. The animals were ventilated in neonatal mode (continuous flow) with a Temel Supra ventilator. Using tracheotomy, we completely sealed the respiratory system in order to use tubes without special endotracheal cuffs, which would enable tracheal pressures to be registered without interfering with ventilation. Collapse of the right lung was performed by videothoracoscopy and was maintained for 120 min. The variables were measured at 10 time periods: start and 5 min with both lungs, after collapse at 5, 15, 30, 60, 90 and 120 min, and 5 and 15 min after lung re-expansion. We recorded the baseline, peak, plateau and positive end expiratory pressure in the mouth of the animal and intratracheal. RESULTS: The mean peak pressure in the mouth of the animal in one lung ventilation was 23.38 mmHg and tracheal ventilation was 21.24 mmHg, while the mean plateau pressure in the mouth of the animal in one lung ventilation it was 21.88 mmHg and tracheal was 21.39 mmHg, respectively, with significant differences in all of them (P<.05). We found statistically significant differences (P<.05) for peak and plateau pressure on comparing the record in the animal mouth with the tracheal record. The difference in absolute value was higher for the peak pressure record. CONCLUSIONS: The pressure parameters recorded in the animal mouth were acceptable for surgery, with a suitable respiratory and haemodynamic stability being maintained. We can state that the continuous flow mode according to the pressures study may be suitable for this type of surgery, and that the mouth of the animal (patient) record for the peak pressure does not reflect what really happens in the alveoli, but we can give a suitable clinical estimate for the plateau pressure.

Low progesterone concentration during the development of the first follicular wave reduces pregnancy per insemination of lactating dairy cows.

Objectives were to determine the effect of progesterone (P4) concentration on fertility of lactating dairy cows induced to ovulate follicles of the first follicular wave. Lactating dairy cows (n=989) at 38±3d postpartum were balanced by parity and body condition score and randomly assigned to 3 treatments: first follicular wave (FFW), first follicular wave with exogenous P4 (FFWP), or second follicular wave (SFW). All cows had their estrous cycle presynchronized with 2 injections of prostaglandin (PG) F(2α) given 14 d apart. Cows in the FFW and FFWP treatments started the ovulation synchronization protocol 3 d after the last PGF(2α) of the presynchronization protocol, whereas SFW cows received a GnRH injection (100 µg of gonadorelin diacetate; Cystorelin, Merial Ltd., Duluth, GA) 3 d after the last PGF(2α) of the presynchronization protocol and started the synchronization protocol 7 d later. The synchronization protocol consisted of GnRH on d -10, PGF(2α) on d -3, and GnRH concurrent with timed artificial insemination (AI) on d 0. Cows in the FFWP treatment received 2 controlled internal drug release inserts containing 1.38 g of P4 from d -8 to -3. Progesterone concentration was determined on d -10, -8, -6, -3, and 0 from all cows and at 7, 14, and 21 d after AI from a subsample of cows (n=170). Cows (n=715) had their ovaries scanned by ultrasound on d -10, -3, and 7 d. Pregnancy was diagnosed at 38 and 66 d after AI. Concentration of P4 from study d -8 to -3 was lowest for FFW cows (1.4±0.1 ng/mL) and similar between SFW (3.7±0.2 ng/mL) and FFWP (3.7±0.1 ng/mL) cows. Diameter of the dominant follicle on study d -3 was greater for FFW cows (16.5±0.3 mm) than for SFW cows (15.4±0.3 mm), but diameter of the dominant follicle of FFWP cows was not different (15.9±0.3 mm) compared with that of SFW and FFW cows. The incidence of multiple ovulation was largest for FFW cows (SFW=19.5, FFW=33.6, FFWP=19.0%), but pregnancy per AI (P/AI) at 66 d was smallest for FFW cows (SFW=38.9, FFW=22.3, FFWP=32.0%). Anovular cows in the SFW (19.4 vs. 42.8%) and FFWP (22.1 vs. 37.2%) treatments had reduced P/AI compared with cyclic cows, despite having similar or greater P4 concentration from study d -8 to -3, respectively. Estrus and ovulation synchronization protocols for lactating dairy cows must result in growth of ovulatory follicle under P4 concentration >2 ng/mL to ensure high P/AI.

Controle estatístico de processo univariado: monitoramento da produção de comprimidos de dipirona / Univariate Statistical Process Control: monitoring the production of dipyrone tablets

Investigou-se, através de histogramas e cartas de controle X e S, a ferramenta do Controle Estatístico de Processo (CEP) univariado e os parâmetros físicos dureza, peso médio e friabilidade da produção de dez lotes de dipirona sódica comprimidos. Por sua complexidade e influência no processo, a etapa de granulação de cada lote foi concomitantemente caracterizada através de determinações de densidade bruta, densidade compactada, índice de compressibilidade e fator de Hausner, além dos ângulos de repouso, tempos de escoamento e repartições granulométricas. As caracterizações dos granulados serviram como base na investigação da possível influência da etapa de granulação como uma das prováveis causas que poderiam levar o processo a se apresentar fora de controle estatístico. Os resultados da caracterização indicaram certa uniformidade entre os granulados, o que pode significar que não há ligação aparente entre a etapa de granulação e a falta de controle estatístico do processo, demonstrada na avaliação das cartas de controle. Na medida em que permitiu uma maior compreensão do processo, o CEP univariado mostrou sua importância no monitoramento da produção de comprimidos.

In this study, by means of histograms and and s control charts, the production control tool, univariate Statistical Process Control (SPC), was assessed for monitoring the physical variables hardness, weight and friability during the production of ten batches of sodium dipyrone tablets. In view of its complexity and influence on the process, the granulation step was concurrently characterized by determining the gross density, compacted density, compressibility index and Hausner factor, plus the angle of repose, flow time and particle size distributions of each batch. The properties of the granules were used as a basis for testing the hypothesis that the granulation step is probably the cause when the process runs out of statistical control. The results of the characterization indicated a degree of uniformity among the granules, which may mean that the lack of statistical process control demonstrated in the control charts does not arise from the granulation step. To the extent that it enabled a greater understanding of the process, univariate SCP proved its importance in the monitoring of tablet production.

Sex-sorted semen for dairy heifers: effects on reproductive and lactational performances.

The objectives of this study were to evaluate the effects of using sex-sorted semen for first AI of heifers on health and productivity during first lactation. Holstein heifers (herd A=227 and herd B=1,144) received first artificial insemination (AI) with sex-sorted semen (SX; n=343) or conventional semen (CS; n=1,028), and all heifers that displayed estrus after first AI were reinseminated with conventional semen up to 11 times before being culled. Age at first AI was 13.1+/-0.1 and 13.8+/-0.1 mo for SX and CS heifers, respectively, in herd A and 12.9+/-0.1 mo for both SX and CS heifers in herd B. Pregnancy per AI after first AI was greater for CS heifers than for SX heifers (51.8 vs. 40.2%). From heifers initially enrolled, 70.2% calved in herds A (n=188) or B (n=774) and first-lactation data were collected. Interval from first AI to calving was greater for SX heifers than for CS heifers (10.2+/-0.1 vs. 9.9+/-0.1 mo). Among heifers conceiving to first AI, SX heifers were more likely than CS heifers to deliver a female calf (85.7 vs. 47.7%), but because SX heifers were more likely to deliver a dead calf (8.8 vs. 3.4%), the difference in proportion of SX and CS heifers delivering a live female calf was smaller than expected (SX=79.1%; CS=47.2%). Rearing cost from first AI to calving was greater for SX heifers than for CS heifers ($775.3+/-6.7 vs. $750.0+/-5.9), but calf revenue tended to be greater for SX heifers ($142.0+/-7.2 vs. $126.7+/-6.4) and cost per female calf produced was smaller for SX heifers than for CS heifers ($-809.4+/-10.8 vs. $-1,249.7+/-10.9). Treatment did not affect calving difficulty, proportion of heifers needing assistance, and incidence of retained fetal membranes or metritis. Among heifers that conceived to first AI, however, SX heifers were more likely to be culled within 30 DIM (3.3 vs. 1.6%) and tended to be more likely to be culled within 60 DIM (5.5 vs. 3.4%) than CS heifers, but overall replacement cost was not different ($136.8+/-13.4). Total milk yield (9,245.5+/-84.7 kg) and income over feed cost ($554.7+/-5.1) were not different. Overall economic return was greater for SX heifers than CS heifers ($-83.7+/-36.7 vs. -175.3+/-33.4). Use of sex-sorted semen for first insemination of virgin heifers reduced the cost per female calf produced and increased the economic return during the first lactation.

Supplementation of progesterone via controlled internal drug release inserts during ovulation synchronization protocols in lactating dairy cows.

Our objective was to determine the effect of exogenous progesterone (P4) during a timed artificial insemination (TAI) protocol on pregnancies per AI (P/AI) in dairy cows not previously detected in estrus. Lactating cows (n=3,248) from 7 commercial dairy herds were submitted to a presynchronization protocol (2 injections of PGF(2alpha) 14 d apart; Presynch), and cows in estrus after the second PGF(2alpha) received AI (EDAI; n=1,583). Cows not inseminated by 12 to 14 d after the second PGF(2alpha) injection were submitted to a TAI protocol (GnRH on d 0, PGF(2alpha) on d 7, and GnRH+TAI 72h after PGF(2alpha)). At onset of the TAI protocol, cows were balanced by parity and days in milk and assigned randomly to receive no exogenous P4 (control, n=803) or a controlled internal drug release (CIDR) insert containing 1.38g of P4 from d 0 to 7 (CIDR, n=862). Blood samples were collected at the second PGF(2alpha) injection of the Presynch and on the day of the first GnRH injection of the TAI protocol for P4 determination. When P4 in both samples was <1 ng/mL, cows were classified as anovular, whereas cows having at least 1 sample >or=1 ng/mL were classified as cyclic. Concentration of P4 at 11 to 14 d after AI was determined in a subgroup of cows (n=453) from 2 herds. Pregnancy was diagnosed at 40+/-5 and 65+/-5 d after AI. Proportion of cows inseminated on estrus after the second PGF(2alpha) injection of the Presynch protocol differed among herds (range=26.7 to 59.8%). Overall P/AI for EDAI cows at 40+/-5 and 65+/-5 d were 36.2 and 33.7%, respectively, and pregnancy loss was 8.8%. Proportion of cyclic cows at the onset of the TAI protocol differed among herds (range from 66.5 to 86.3%), but did not differ between treatments (control=72.4%, CIDR=74.1%). Treatment affected P/AI at 40+/-5 (control=33.3%, CIDR=38.1%) and 65+/-5 (control=30.0%, CIDR=35.1%) d after AI but did not affect pregnancy loss (8.6%). Cyclic cows had greater P/AI at 40+/-5 (38.2 vs. 29.3%) and 65+/-5 d (35.1 vs. 26.1%) after AI, but cyclic status had no effect on pregnancy loss. Treatment affected P4 concentration after AI, with more CIDR cows having P4 >or=1 ng/mL (94.4 vs. 86.9%) and P4 >or=3.2 ng/mL (81.8 vs. 68.0%) at 11 to 14 d after AI compared with control cows. Treatment of cows not previously detected in estrus with a CIDR insert during a TAI protocol increased proportion of cows with functional CL after AI and P/AI.

Effect of increasing amounts of supplemental progesterone in a timed artificial insemination protocol on fertility of lactating dairy cows.

The objectives were to evaluate the effect of supplemental progesterone during a timed artificial insemination (TAI) protocol on pregnancy per insemination and pregnancy loss. Lactating dairy cows from 2 dairy herds were presynchronized with 2 injections of PGF(2alpha) 14 d apart, and cows observed in estrus following the second PGF(2alpha) injection were inseminated (n = 1,301). Cows not inseminated by 11 d after the end of the presynchronization were submitted to the TAI protocol (d 0 GnRH, d 7 PGF(2alpha), d 8 estradiol cypionate, and d 10 TAI). On the day of the GnRH of the TAI protocol (study d 0), cows were assigned randomly to receive no exogenous progesterone (control = 432), one controlled internal drug-release (CIDR) insert (CIDR1 = 440), or 2 CIDR inserts (CIDR2 = 440) containing 1.38 g of progesterone each from study d 0 to 7. Blood was sampled on study d 0 before insertion of CIDR for determination of progesterone concentration in plasma, and cows with concentration <1.0 ng/mL were classified as low progesterone (LP) and those with concentration > or =1.0 ng/mL were classified as high progesterone (HP). From a subgroup of 240 cows, blood was sampled on study d 3, 7, 17 and 24 and ovaries were examined by ultrasonography on study d 0 and 7. Pregnancy was diagnosed at 38 +/- 3 and 66 +/- 3 d after AI. Data were analyzed including only cows randomly assigned to treatments and excluding cows that were inseminated after the second PGF(2alpha) injection. The proportion of cows classified as HP at the beginning of the TAI protocol was similar among treatments, but differed between herds. Concentrations of progesterone in plasma during the TAI protocol increased linearly with number of CIDR used, and the increment was 0.9 ng/mL per CIDR. The proportion of cows with plasma progesterone > or =1.0 ng/mL on study d 17 was not affected by treatment, but a greater proportion of control than CIDR-treated cows had asynchronous estrous cycles following the TAI protocol. Treatment with CIDR inserts, however, did not affect pregnancy at 38 +/- 3 and 66 +/- 3 d after AI or pregnancy loss.

Early determination of the reproductive number for vector-borne diseases: the case of dengue in Brazil.

OBJECTIVE: To evaluate a new method of deriving the reproductive number for vector-borne diseases from the early epidemic curves for vector-borne diseases with incubations in the vectors and in the hosts. METHOD: We applied the model to several dengue epidemics in different climatic regions of Brazil: Brasilia, Belém, Fortaleza, Boa Vista. RESULTS: The new method leads to higher estimates of the reproductive number than previous models. CONCLUSION: At present, Aedes aegypti densities, the meeting of more compatible strains of viruses and mosquitoes, may lead to re-emergence of urban yellow fever epidemics.

Relationship of bispectral index values, haemodynamic changes and recovery times during sevoflurane or propofol anaesthesia in rabbits.

The aim of this study was to determine and compare the degree of hypnosis achieved during propofol or sevoflurane anaesthesia in rabbits using bispectral index (BIS), and to evaluate its usefulness as a predictor of both haemodynamic changes during anaesthesia and recovery times. Twenty adult male New Zealand White rabbits, average weight 4.4 +/- 0.4 kg, were used for this study. Animals were randomly allocated to one of two groups with 10 rabbits/group. An electroencephalographic recording was obtained from each conscious rabbit prior to drug administration. All animals received buprenorphine as a preanaesthetic medication (0.05 mg/kg, intravenous [i.v.]). Anaesthesia was induced with propofol (8 mg/kg, i.v.) in all animals; 10 rabbits were maintained with sevoflurane via inhalation (1 minimum alveolar concentration--end-tidal sevoflurane concentration of 3.7%--at a fresh gas flow rate of 3 L/min; group I), and 10 were maintained with i.v. propofol (0.6 mg/kg/min; group II). The rabbits were orotracheally intubated and spontaneous ventilation was maintained throughout the study (100% oxygen). After abdominal surgery through a ventral midline laparotomy, rabbits were allowed to recover from anaesthesia. Cardiovascular variables and BIS values were recorded at intervals throughout the procedure, as was the duration of recovery from anaesthesia. In both groups, mean BIS values were significantly decreased immediately after induction, compared with baseline values obtained during consciousness. Anaesthetic depth (evaluated by clinical observation) was similar in both groups; however, group II rabbits had significantly higher (P<0.001) BIS values from 30 s before incision until anaesthesia was discontinued. There was no significant difference in BIS recorded 1 and 5 min after incision as compared with values obtained 30 s before incision in either group. During sevoflurane or propofol administration, correlations were found between BIS values and mean arterial blood pressure (MABP), and between BIS values and heart rate (HR). Mean BIS values at discontinuation of administration of the anaesthetic agent were greater in group II (69.1 +/- 6.0) than in group I (49.3 +/- 2.2). However, recovery from anaesthesia was significantly longer in group II (38.4 +/- 7.2 min) than in group I (11.5 +/- 2.5 min). In conclusion, BIS can be used to differentiate between conscious and unconscious states during anaesthesia in rabbits. BIS values derived from an electroencephalogram at the end of anaesthesia were not useful for predicting the speed of anaesthetic recovery in sevoflurane or propofol-anaesthetized rabbits undergoing abdominal surgery. Despite the correlation found between BIS and haemodynamic parameters, its usefulness as a predictor of clinically important changes in arterial blood pressure and HR in anaesthetized rabbits was limited.