On the generation of internal waves by river plumes in subcritical initial conditions.

Internal waves (IWs) in the ocean span across a wide range of time and spatial scales and are now acknowledged as important sources of turbulence and mixing, with the largest observations having 200 m in amplitude and vertical velocities close to 0.5 m s-1. Their origin is mostly tidal, but an increasing number of non-tidal generation mechanisms have also been observed. For instance, river plumes provide horizontally propagating density fronts, which were observed to generate IWs when transitioning from supercritical to subcritical flow. In this study, satellite imagery and autonomous underwater measurements are combined with numerical modeling to investigate IW generation from an initial subcritical density front originating at the Douro River plume (western Iberian coast). These unprecedented results may have important implications in near-shore dynamics since that suggest that rivers of moderate flow may play an important role in IW generation between fresh riverine and coastal waters.

Long lived second mode internal solitary waves in the Andaman Sea.

Internal waves are density oscillations propagating along the ocean's inner stratification, which are now acknowledged as a key constituent of the ocean's dynamics. They usually result from barotropic tides, which flow over bottom topography, causing density oscillations to propagate along the pycnocline with a tidal frequency (i.e. internal tides). These large-scale waves propagate away from their forcing bathymetry and frequently disintegrate into nonlinear short-scale (higher-frequency) internal wave packets. Typically, short-scale internal wave observations in the ocean are associated with vertical structures (in the water column) of the lowest fundamental mode. Higher vertical modes have recently been documented as well, but these are commonly short-lived (up to a few hours). However, unprecedented satellite images showing long-lived short-scale mode-2 internal waves have now been documented in the Andaman Sea, and we report here the companion results of a non-hydrostatic and fully nonlinear numerical model. The simulations reproduce the waves' main characteristics as observed in satellite imagery, and the results suggest a resonant coupling with a larger-scale mode-4 internal tide as an explanation for their long-lived character.

Timed artificial insemination plus heat I: effect of estrus expression scores on pregnancy of cows subjected to progesterone-estradiol-based protocols.

Expression of estrus near timed artificial insemination (TAI) is associated with greater fertility, and estrus detection could improve TAI fertility or direct TAI management, although accurate estrus detection can be difficult and time-consuming using traditional methods. The aim of this study is to evaluate influence of estrus on pregnancy (artificial insemination pregnancy rates (P/AI)) and to validate an alternative method to classify estrus/heat expression using tail chalking (HEATSC) in postpartum Bos indicus cows subjected to TAI in progesterone-estrogen-based protocols. In experiment 1 (Exp. 1), cows (5491) were subjected to visual observation of estrus after progesterone device removal, before TAI, and P/AI was evaluated according to estrus and body condition score (BCS). Cows received a progesterone device and 2 mg estradiol benzoate (EB). After 8 days, the device was removed and 150 µg of d-cloprostenol and 300 IU equine chorionic gonadotrophin was given. Later, animals in Exp. 1 received 1 mg EB and TAI 44 to 48 h. In the Exp. 2 - 3830 cows using similar protocol, received different ovulation inducers: 1 mg EB (n=1624) or 1 mg estradiol cypionate (EC; n=2206) on day 8 (D8). Cows were then marked with chalk, and HEATSC evaluated at TAI on D10 (HEATSC1 - no chalk removal=no estrus expression; HEATSC2 - partial chalk removal=low estrus expression; HEATSC3 - near complete/complete chalk removal=high estrus expression). In Exp. 1, cows showing estrus presented greater P/AI (48.4% v. 40.2%, P<0.05). In Exp. 2, P/AI (HEATSC1 - 40.0%; HEATSC2 - 49.7%; HEATSC3 - 60.9%; P<0.001), and larger follicle timed artificial insemination (LFTAI) (<0.001) varied according to HEATSC. There was no difference in P/AI (P=0.41) or LFTAI (P=0.33) according to ovulation inducer. Cows with greater BCS showed greater P/AI in both experiments (P<0.05). Estrus presence and greater HEATSC improved P/AI, and EC v. EB used promoted differential estrus manifestation (cows showing HEATSC2 and HEATSC3: 79.5% with EB v. 69.98% with EC use, P<0.001), however, with similar P/AI. The use of HEATSC in B. indicus cows subjected to TAI is useful to identify cows with greater estrus expression and consequently improved pregnancy rates in TAI, allowing the cows with low HEATSC to be targeted for additional treatments aimed at improving P/AI.

Timed artificial insemination plus heat II: gonadorelin injection in cows with low estrus expression scores increased pregnancy in progesterone/estradiol-based protocol.

The use of tail chalk and estrus/heat expression scores (HEATSC) evaluation is instrumental in identifying cows with greater estrus expression and greater artificial insemination pregnancy rates (P/AI) in cows submitted to timed artificial insemination (TAI), and cows with low or no estrus expression present lower P/AI. It was intended in this study to improve the pregnancy rates in TAI for Bos indicus beef cows, and gonadotrophin-releasing hormone (GnRH) injection was hypothesized to increase pregnancy rates in a TAI program for cows submitted to progesterone-estradiol-based protocols with low or no estrus expression, evaluated by HEATSC. Cows (n= 2284) received a progesterone device and 2 mg estradiol benzoate, after 8 days the device was removed and 1 mg estradiol cypionate, 150 µg of d-cloprostenol and 300 IU equine chorionic gonadotropin was administered. All cows were marked with chalk and HEATSC evaluated (scales 1 to 3) at TAI performed on day 10. Animals with HEATSC1 and HEATSC2 (n= 937) received 100 µg de gonadorelin (GNRH group; n= 470), or 1 ml saline (Control group; n= 467), and cows with HEATSC3 (named HEAT group; n= 1347) received no additional treatment. The larger dominant follicle, evaluated on day 8and at TAI (day 10), was greater in HEAT group (P= 0.0145 and P <0.001, respectively). Corpus luteum (CL) area and progesterone concentration was evaluated on day 17, and CL area was larger in HEAT group, intermediary in Control and lower in GnRH group (Control= 2.68 cm2, GnRH= 2.37 cm2, HEAT group= 3.07 cm2, P <0.001). Greater progesterone concentrations were found in HEAT group than in Control and GnRH groups (Control= 4.74 ng/ml, GnRH= 4.29 ng/ml, HEAT group= 6.08 ng/ml, P<0.001). There was a difference in ovulation rate, greater in HEAT group than GnRH and Control groups (Control= 72.5%; GnRH= 81.25%; HEAT group= 90.71%; P= 0.0024). Artificial insemination pregnancy rates was greater in HEAT group (57.09% (769/1347) than in Control and GNRH groups, with positive effect of GnRH injection at the time of TAI in P/AI (Control= 36.18% (169/467), GnRH= 45.95% (216/470); P<0.0001). In conclusion, GnRH application in cows with low HEATSC (1 and 2) is a simple strategy, requiring no changes in TAI management to increase pregnancy rates in postpartum beef cows submitted to progesterone-estradiol-based TAI protocols, without reaching, however, the pregnancy rates of cows that demonstrate high estrus expression at the TAI.

Plasma anti-Müllerian hormone as a predictive endocrine marker to select Bos taurus (Holstein) and Bos indicus (Nelore) calves for in vitro embryo production.

This study evaluated the association between plasma anti-Müllerian hormone (AMH) concentrations and in vitro embryo production in Bos indicus (Nelore; experiment 1) and Bos taurus (Holstein; experiment 2) calves superstimulated or not with 140 mg of porcine follicle-stimulating hormone (pFSH; 4 decreasing doses twice daily). Oocytes were recovered from calves aged 2 to 4 mo after receiving gonadotropin stimulation (Nelore, n = 15; Holstein, n = 12) or not (Nelore, n = 15; Holstein, n = 12). Cycling heifers formed a positive control group (n = 15 for Nelore [aged 18-24 mo], n = 10 for Holstein [aged 14-16 mo]). All the calves underwent laparoscopic ovum pickup, and cycling heifers underwent a regular transvaginal ultrasound-guided ovum pickup for oocyte recovery. Immediately before oocyte retrieval, blood samples were taken for subsequent AMH determination (ng/mL). Regardless of the genetic group, calves that received pFSH (3.6 ± 1.1 in Nelore and 4.6 ± 1.2 in Holstein) or did not receive pFSH (3.2 ± 1.0 in Nelore and 2.5 ± 0.8 in Holstein) had greater plasma AMH concentrations (P = 0.01 in Nelore and P = 0.003 in Holstein) than cycling heifers (1.1 ± 0.2 in Nelore and 0.6 ± 0.07 in Holstein). AMH concentrations in calves with or without pFSH were similar in both genetic groups (3.6 ± 1.1 vs 3.2 ± 1.0 in Nelore; 4.6 ± 1.2 vs 2.5 ± 0.8 in Holstein). In calves, positive correlations were observed between plasma AMH concentrations and the numbers of follicles >2 mm (r = 0.86, P < 0.0001 in Nelore; r = 0.78, P < 0.0001 in Holstein), cumulus-oocyte complexes (COCs) retrieved (r = 0.91, P < 0.0001 in Nelore; r = 0.82, P < 0.0001 in Holstein), COCs cultured (r = 0.71, P < 0.0001 in Nelore; r = 0.79, P < 0.0001 in Holstein), and blastocysts produced (r = 0.62, P = 0.0003 in Nelore; r = 0.58, P = 0.009 in Holstein), and these results were independent of pFSH treatment. In conclusion, calves had greater plasma AMH concentrations than cycling heifers. In addition, treatment with pFSH did not influence AMH concentrations in calves, regardless of the genetic group. More importantly, plasma AMH concentrations were positively correlated with the antral follicle population and the number of COCs retrieved, COCs cultured, and blastocysts produced in B indicus and B taurus calves. Therefore, AMH is a promising tool for selecting oocyte donor calves to maximize results during in vitro embryo production.

Cardiovascular responses to different stages of restorative dental treatment unaffected by local anaesthetic type.

BACKGROUND: The aim of this study was to evaluate the cardiovascular effects of maxillary infiltration using 2% lidocaine with 1:100,000 adrenaline, 4% articaine with 1:200,000 adrenaline, and 4% articaine with 1:100,000 adrenaline in different stages during restorative dental procedures. METHODS: Twenty healthy patients randomly received 1.8 mL of the three local anaesthetics. Systolic blood pressure, average blood pressure, diastolic blood pressure, and heart rate were evaluated by the oscillometric and photoplethysmograph methods in seven stages during the appointment. RESULTS: Statistical analysis by ANOVA and Tukey tests of cardiovascular parameters did not show significant differences between the anaesthetic associations. There were significant differences for the parameters among different clinical stages. CONCLUSIONS: The variation of cardiovascular parameters was similar for lidocaine and articaine with both adrenaline concentrations and showed no advantage of one drug over the other. Cardiovascular parameters were influenced by the stages of the dental procedures, which showed the effect of anxiety during restorative dental treatment.

Testicular traits as selection criteria for young Nellore bulls.

The objective of this study was to evaluate the possible use of biometric testicular traits as selection criteria for young Nellore bulls using Bayesian inference to estimate heritability coefficients and genetic correlations. Multitrait analysis was performed including 17,211 records of scrotal circumference obtained during andrological assessment (SCAND) and 15,313 records of testicular volume and shape. In addition, 50,809 records of scrotal circumference at 18 mo (SC18), used as an anchor trait, were analyzed. The (co)variance components and breeding values were estimated by Gibbs sampling using the Gibbs2F90 program under an animal model that included contemporary groups as fixed effects, age of the animal as a linear covariate, and direct additive genetic effects as random effects. Heritabilities of 0.42, 0.43, 0.31, 0.20, 0.04, 0.16, 0.15, and 0.10 were obtained for SC18, SCAND, testicular volume, testicular shape, minor defects, major defects, total defects, and satisfactory andrological evaluation, respectively. The genetic correlations between SC18 and the other traits were 0.84 (SCAND), 0.75 (testicular shape), 0.44 (testicular volume), -0.23 (minor defects), -0.16 (major defects), -0.24 (total defects), and 0.56 (satisfactory andrological evaluation). Genetic correlations of 0.94 and 0.52 were obtained between SCAND and testicular volume and shape, respectively, and of 0.52 between testicular volume and testicular shape. In addition to favorable genetic parameter estimates, SC18 was found to be the most advantageous testicular trait due to its easy measurement before andrological assessment of the animals, even though the utilization of biometric testicular traits as selection criteria was also found to be possible. In conclusion, SC18 and biometric testicular traits can be adopted as a selection criterion to improve the fertility of young Nellore bulls.