1,721,081 research outputs found
Environmental noise and hearing loss
No full textWe are all living constantly surrounded by noise. It is present in the cities, in work environments and in every house, where we are subjected to sounds and music produced by radios, televisions, smartphones and headphones. The most annoying noise is the one produced by cars and public transportation, followed by music, sounds coming from TV and radio, conversations between groups of people and electrical appliances. Hearing loss is more pronounced in people living in urban context. Musicians, both modern and classical, frequently suffer from hearing loss although they do not often perceive symptoms. Also listening to music from portable audio players can expose people to peak levels of 120 dB HL, with regular listening equal to about 100 dB HL for prolonged periods. These kinds of sound exposure can produce at last hearing loss and could assume a relevant epidemiological effect. In conclusion, the noise existing in the environment where we live probably is one of the causes of a slight progressive increasing of hearing loss. This trend is more pronounced in those subjects professionally exposed to noise, although not only factory workers are nowadays at risk. It is necessary, therefore, to inform above all young people about the necessity to avoid exposure to loud noise
Breeding for improved calving performance in Piemontese cattle : genetic parameters for different parities
No full textGenetic relationships between calving performance and beef production traits in Piemontese cattle
No full textThe aim of the study was to obtain estimates of genetic correlations between direct and maternal calving performance of heifers and cows and beef production traits in Piemontese cattle. Beef production traits were daily gain, live fleshiness, and bone thinness measured on 1,602 young bulls tested at a central station. Live fleshiness (six traits) and bone thinness were subjectively scored by classifiers using a nine-point linear grid. Data on calving performance were calving difficulty scores (five classes from unassisted to embryotomy) routinely recorded in the farms. Calving performance of heifers and cows were considered different traits. A total of 30,763 and 80,474 calving scores in first and later parities, respectively, were used to estimate covariance components with beef traits. Data were analyzed using bivariate linear animal models, including direct genetic effects for calving performance and beef traits and maternal genetic effects only for calving performance. Due to the nature of the data structure, which involved traits measured in different environments and on different animals, covariances were estimated mostly through pedigree information. Genetic correlations of daily gain were positive with direct calving performance (0.43 in heifers and 0.50 in cows) and negative with maternal calving performance (-0.23 and -0.28 for heifers and cows, respectively). Live fleshiness traits were moderately correlated with maternal calving performance in both parities, ranging from 0.06 to 0.33. Correlations between live fleshiness traits and direct calving performance were low to moderate and positive in the first parity, but trivial in later parities. Bone thinness was negatively correlated with direct calving performance (-0.17 and -0.38 in heifers and cows, respectively), but it was positively correlated to maternal calving performance (0.31 and 0.40). Estimated residual correlations were close to zero. Results indicate that, due to the existence of antagonistic relationships between the investigated traits, specific selection strategies need to be studied
Definition of a breeding goal for the Piemontese breed: economic and biological values and their sensitivity to production circumstances.
No full textEconomic values have been derived for the Piemontese breed using a bio-economic deterministic model that simulates an integrated beef cattle enterprise. Investigated traits were post-weaning daily gain (DG), live fleshiness scores (FLESH) that are related to the market value of animals for slaughter, calving ease in the first (CEh) and later parities (CEc) and calving interval (Q. Economic values, calculated using a fixed number of cows per herd as a basis of evaluation and expressed in Euro per cow per year, were 0.20 per g/day for DG, 57.01 per point for FLESH (measured with a linear scoring system in nine classes), - 2.60 per day for Cl. For calving ease economic values per a 1% increase in the liability scale were 0.57Euro in the first and 1.99Euro in later parities, respectively. The economic value of the studied traits showed moderate dependence on trait levels. Production circumstances poorly affected the estimated economic values with the exception of energy input and live weight output limitations that markedly decreased the economic values of all traits but FLESH. Biological values, reflecting improvement in efficiency in energy utilization, corresponded well in relative size to economic values in most of the considered traits. (C) 2004 Elsevier B.V. All rights reserved
Genetic associations between daily gain and live fleshiness of station-tested young bulls and carcass and meat quality traits of commercial intact males in Piemontese cattle.
No full textThe aim of this study was to investigate genetic relationships between beef traits of station-tested young bulls and carcass and meat quality traits (MQ) of commercial intact males in Piemontese cattle. Phenotypes for daily gain (DG) and live fleshiness traits (width at withers: WW; shoulder muscularity: SM; loin width: LW; loin thickness: LT; thigh muscularity: TM; thigh profile: TP) and thinness of the shin bone (BT) were available for 3,109 and 2,183 performance-tested young bulls, respectively. Carcass daily gain (CDG), carcass conformation (SEUS), pH at 24 h (pH24h) and 8 d after slaughter (pH8d), lightness (L*), redness (a*), yellowness (b*), hue angle (HA), saturation index (SI), drip loss (DL), cooking loss (CL), and shear force (SF) were assessed for 1,208 commercial intact males. (Co) variance components were estimated in a set of twelve 9-traits analyses using REML and linear animal models including all performance-test traits and 1 carcass or MQ trait at a time. Heritabilities ± SE of beef traits ranged from 0.26 ± 0.03 (LW) to 0.47 ± 0.01 (DG), whereas those of carcass traits and MQ from 0.06 ± 0.03 (CL) to 0.63 ± 0.04 (HA). The genetic correlation (rg) between DG and CDG was 0.75 ± 0.10, indicating that DG, as measured at the test station, is a good indicator of the carcass gain achieved by commercial animals under farms conditions. Daily BW gain of station-tested bulls correlated positively with color traits (from 0.11 ± 0.12 to 0.54 ± 0.09), ph8d (rg ± SE = 0.31 ± 0.11), DL (rg ± SE = 0.29 ± 0.17), and CL (rg ± SE = 0.27 ± 0.18). Live fleshiness of station-tested bulls exhibited genetic correlations with MQ of commercial animals that were positive for L* and b* (from 0.13 ± 0.08 to 0.65 ± 0.14) and negative for pH (from –0.27 ± 0.15 to –0.57 ± 0.11), CL (from –0.16 ± 0.23 to –0.43 ± 0.22), and SF (TM: rg ± SE = –0.31 ± 0.15; TP: rg ± SE = –0.41 ± 0.17). The thinness of the shin bone correlated unfavorably with CDG (rg ± SE = –0.74 ± 0.07) and favorably with SEUS (rg ± SE = 0.65 ± 0.17), CL (rg ± SE = –0.39 ± 0.13), and SF (rg ± SE = –0.32 ± 0.17). The estimated genetic correlations indicate that selection to increase DG, as measured at the test station, exerts moderate adverse effects on MQ. Because selection emphasis is greater for live fleshiness than for DG, the correlated response in MQ and carcass traits is expected to be influenced to a greater extent by selection for muscularity, even though these traits are less heritable than DG
Genetic parameters for daily live-weight gain, live fleshiness and bone thinness in station-tested Piemontese young bulls
No full textEstimates of genetic parameters for beef production traits were obtained for Piemontese cattle. Data were from 988 young bulls station-tested from 1989 till 1998. Bulls entered the station at 6 to 8 weeks of age and, after an adaptation period of 3 months, were tested for growth, live fleshiness and bone thinness. Length of test was 196 days. Growth traits considered were gain at farm, gain during the adaptation period, gain on test and total gain at the station. Six different fleshiness traits and bone thinness were scored on live animals at the end of the test using a linear system. Live evaluations of fleshiness were adjusted for the weight at scoring in order to provide an assessment of conformation independent of body size. Genetic parameters were estimated using animal models. Heritability of live-weight gain ranged from 0·20 in the adaptation period to 0·60 for total gain at the station. Genetic correlations between gains at station in different periods were high (from 0·63 to 0·97). Residual correlation between gain during the adaptation period and gain during test was negative, probably due to the occurrence of compensatory growth of the animals.
Live fleshiness traits and bone thinness were of moderate to high heritability (from 0·34 to 0·55) and highly correlated indicating that heavy muscled bulls also have thin bones. Accuracy of breeding values and therefore response to selection were improved by multiple trait analysis of the live fleshiness traits and bone thinness. Overall weight gain at the station had a moderate negative genetic correlation with all live fleshiness traits and bone thinness (from -0·11 to -0·39)
Menieres' disease symptomatology in relation to the AAO-HNS 1995 guidelines
No full textAim. Meniere's disease (MD) is a complex progressive disorders of the inner ear characterized by sensorineural hearing loss, episodic vertigo, tinnitus and aural fullness. MD diagnosis is essentially clinical and specialized test equipment should not be required. In 1995 the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology - Head and Neck Surgery published recommended guidelines for the diagnosis of the MD (3) classifying it in certain, definite, probable and possible. It was the aim of this paper to determine, in a large series of subjects affected by MD according to the AAO-HNS 1995 criteria, the distribution of the different forms, their relationship with clinical paramters and the aspects of the evolution of the disease over time. Methods. The study group consisted of 384 consecutive subjects affected by MD according to the AAO-HNS 1995 guidelines. In each case we have carried out an exhaustive anamnesis regarding all the aspects of the disease and audiometric threshold. Results. According to AAO-HNS classification 228 subjects (59%) at the moment of the first control in our department were affected by definite MD, 30 (8%) by probable MD and 126 (33%) by possible MD. In this sample, among the 129 subjects of this group 90 (73%) were affected only by hearing loss and 36 (27%) only by vertigo. Age at the beginning of the disease was not different among definite, probable and possible forms while subjects affected by the certain MD were older and presented a longer duration of the disease. Disability level was lesser in the possible forms, condition in which the lower degrees are more represented. Among the 228 definite forms, MD appeared with both vertigo and hearing loss together (temporal delay less than 24 hours) in 79 cases (35%), with hearing loss alone in 96 cases (42%) and with vertigo alone in 53 cases (23%). PTA mean threshold at 0.5-1-2-3 kHz at the first control in the 228 cases of definite MD is worse than in the 90 subjects subjects affected by possible MD in its cochlear form. Conclusion. In conclusion definite form represents the most common form of MD at diagnosis and comprises the most disabling cases. However in the larger part of cases it begin as possible and transforms in definite later, normally within 5 years
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