The Effect on Meat Quality of Integrating Pasturing Systems into Cattle Finishing Programs

The effect on meat quality of integrating pasturing systems into cattle finishing programs was observed over a two-year period. Year one consisted of 84 fall born calves and 28 spring born calves and year two consisted of 116 fall born calves. The effect of using Rumensinâ for cattle on bromegrass pasture was incorporated into year one. In year two cattle on pasture received bromegrass pasture, and one treatment group received switchgrass during the warm season. In both years there was a control group of calves that went directly to the feedlot with the remaining calves going to pasture for varying periods of time before being finished in drylot. At the conclusion of the feeding trial, cattle were processed into beef, and a ribeye steak was removed from each carcass for sensory evaluation. In year one cattle that were on pasture the longest had the lowest (P<0.05) average quality grades. In year two this trend was reversed, and cattle placed directly into drylot had the lowest (P<0.05) average quality grades. In both years cattle carcasses in all treatments averaged yield grade 2. Warner Bratzler shear force values were not affected by treatments. Sensory panel evaluations indicated tenderness was unaffected by treatments, and in year two flavor and flavor intensity were unaffected by treatments. In year one flavor intensity was lowest (P<0.05) for steaks derived from cattle that were on pasture the longest and received Rumensinâ. Inclusion of Rumensinâ for cattle on pasture did not influence yield and quality grades or affect tenderness, juiciness, and flavor. Results of this study indicate that steer calves placed on cool and warm season pastures prior to being finished in drylot, can produce carcasses with acceptable yield and quality grades and that the meat eating qualities will be largely unaffected by the inclusion of pasture.

Impacto do pH final na maciez do músculo Longissimus lumborum de animais zebuínos: mudanças estruturais de proteínas da carne crua e cozida durante a maturação

O objetivo do presente trabalho foi determinar a força de cisalhamento Warner-Bratzler do músculo Longissimus lumborum de animais zebuínos machos inteiros (Bos indicus) durante o período de maturação, nas faixas de pH final (pHf 48 horas post mortem) normal (pH entre 5,5 e 5,8) e anormal (pH entre 5,81 e 6,19) e temperaturas internas de cozimento. Concomitante com a avaliação de força de cisalhamento, foram avaliadas também a degradação da desmina e troponina T, o comprimento do sarcômero, o teor de colágeno total e solúvel, as temperaturas máximas de desnaturação das proteínas e a morfologia geral de agregação das fibras do músculo no cozimento. A degradação da desmina e troponina T foi maior no pHf normal, aparecendo produtos de degradação a partir do dia 7 nessa faixa de pHf. Não houve diferenças nos valores de comprimento do sarcômero, descartando-se assim, a contribuição desse parâmetro sobre a temperatura máxima de desnaturação (Tmáx) das proteínas, determinada utilizando calorímetro exploratório diferencial (DSC). Similarmente, não foram encontradas diferenças para os teores de colágeno total e solúvel, e os valores de colágeno total foram baixos, sugerindo que sua contribuição na segunda transição térmica e nos valores de força de cisalhamento foi mínima. As Tmáx1 e Tmáx2, correspondentes à desnaturação da meromiosina leve e pesada, respectivamente, foram menores no pHf normal, mas o efeito foi maior para a Tmáx2. A Tmáx3 da actina e titina aumentou até 14 dias post mortem na faixa de pHf normal, e posteriormente diminuiu significativamente após 21 dias, sugerindo possível degradação dessas proteínas nesse período de dias. Não foram encontradas diferenças nos valores de Tmáx no pHf anormal, em todos os dias post mortem, o que sugere a contribuição de um possível mecanismo de proteção que estabiliza as miofibrilas no aquecimento. Houve maior agregação das fibras do músculo no pHf normal nas temperaturas internas de cozimento de 65 e 80°C, provavelmente devido à maior desnaturação térmica das miofibrilas. Os valores de força de cisalhamento foram maiores com o aumento da temperatura interna de cozimento, devido ao aumento da desnaturação térmica das miofibrilas do músculo. Independente da temperatura interna de cozimento, os valores de força de cisalhamento foram altos em quase todos os dias post mortem para ambas as faixas de pHf, o que sugere a necessidade de utilizar métodos físicos ou químicos para aumentar a maciez do músculo Longissimus lumborum de animais zebuínos.

Development of gripping devices based on electroadhesive forces

In a context of technological innovation, the aim of this thesis is to develop a technology that has gained interest in both scientific and industrial realms. This technology serves as a viable alternative to outdated and energy-consuming industrial systems. Electro-adhesive devices (EADs) leverage electrostatic forces for grasping objects or adhering to surfaces. The advantage of employing electrostatics lies in its adaptability to various materials without compromising the structure or chemistry of the object or surface. These benefits have led the industry to explore this technology as a replacement for costly vacuum systems and suction cups currently used for handling most products. Furthermore, the broad applicability of this technology extends to extreme environments, such as space with ultra-high vacuum conditions. Unfortunately, research in this area has yet to yield practical results for industrially effective gripper prototyping. This is primarily due to the inherent complexity of electro-adhesive technology, which operates on basic capacitive principles that does not find satisfying physical descriptions. This thesis aims to address these challenges through a series of studies, starting with the manufacturing process and testing of an EAD that has become the standard in our laboratory. It then delves into material and electrode geometry studies to enhance system performance, ultimately presenting potential industrial applications of the technology. All the presented results are encouraging, as they have yielded shear force values three times higher than those previously reported in the literature. The various applications have demonstrated the significant effectiveness of EADs as brakes or, more broadly, in exerting shear forces. This opens up the possibility of utilizing cutting-edge technologies to push the boundaries of technology to the fullest.

Acoustic radiation force impulse elastography of the spleen in healthy dogs of different ages

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Acoustic radiation force impulse elastography of prostate and testes of healthy dogs: preliminary results

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Acoustic radiation force impulse (ARFI) elastography of the spleen in healthy adult cats - a preliminary study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Elastografia acoustic radiation force impulse (ARFI), doppler e ultrassonografia contrastada do baço canino

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

CARACTERÍSTICAS DE QUALIDADE DO CONTRAFILÉ (m. L. dorsi) DE TOUROS JOVENS DA RAÇA NELORE

Quality traits of boneless rib cut (L. dorsi muscle) from Nelore young bulls. To study the meat quality traits of Nelore breed young bulls, and the effect of age (690-780 days) on them, 113 animals were slaughtered after 109 days of intensive feeding with 20% concentrate and 80% roughage. All the carcasses were graded at the slaughter floor by the Federal Inspection and chilled for 24 hours (Tinitial=5°C, Tfinal=2°C). Fifty one half carcasses (right side), type B - B R A S I L `s grading system - from animals of 23 to 26 months were boned and separated into commercial cuts. Two steaks (2.5cm thick) were removed from each boneless rib cut (m. L. dorsi), vacuum packaged and aged for 7 days (0-2°C). The pH varied from 5.44 to 5.83 and only two samples had pH ³ 5.70. The L* (brightness) average value was 34.85. The water and fat content were 75.65% and 1.71%, respectively. The average WB shear force was 6.70kg, and it was not affected by age (690-734 days), but presented a trend (t test, p=0.22) for increasing values between 735 and 780 days. Animal age did not affect other quality traits (t test, p>0.20). It was concluded that the rib cut from Nelore young bulls may not have a good acceptability in exigent markets, and that carcasses graded B, presumed to be the best grade, do not necessarily present the best meat quality characteristics.

Retention force of T-bar clasps for titanium and cobalt-chromium removable partial dentures

The objective of this study was to evaluate the retention force of T-bar clasps made from commercially pure titanium (CP Ti) and cobalt-chromium (Co-Cr) alloy by the insertion/removal test simulating 5 years use. Thirty-six frameworks were cast from CP Ti (n=18) and Co-Cr alloy (n=18) with identical prefabricated patterns on refractory casts from a distal extension mandibular hemi-arch segment. The castings were made on a vacuum-pressure machine, under vacuum and argon atmosphere. Each group was subdivided in three, corresponding to 0.25 mm, 0.50 mm and 0.75 mm undercuts, respectively. No polishing procedures were performed to ensure uniformity. The specimens were subjected to an insertion/removal test and data was analyzed statistically to compare CP Ti and Co-Cr alloy in the same undercut (Student's t-test for independent samples) and each material in different undercuts (one-way ANOVA) (p=0.05). Comparisons between materials revealed significant differences (p=0.017) only for the 0.50-mm undercut. No significant differences (p>0.05) were found when comparing the same material for the undercuts. It may be concluded that for different undercuts, both Co-Cr alloy and CP Ti had no significant differences for T-bar clasps; CP Ti showed the lowest retention force values when compared to Co-Cr alloy in each undercut, but with significant difference only for the 0.50-mm undercut; and both materials maintained the retentive capacity during the simulation test.

Bite force in temporomandibular dysfunction (TMD) and healthy complete denture wearers

The signs and symptoms of temporomandibular dysfunction (TMD) may contribute to reduce bite force and muscular activity. The aims of this study were to compare bite force in complete denture wearers with TMD (TMD group) and without TMD (healthy group).The TMD group consisted of 9 individuals, who had worn a maxillary and a mandibular complete removable denture for more than 10 years. The healthy group consisted of 9 participants who wore dentures and had satisfactory interocclusal and maxillomandibular relationship. Helkimo Index was used to analyze the dysfunction level. Maximum bite force was measured using a digital dynamometer with capacity of 100 kgf and adapted to oral conditions.The TMD group presented smaller mean bite force values than the healthy group, though without statistical significance (p>0.05). This outcome suggests that the TMD signs and symptoms and the structural conditions of the dentures did not affect the maximal bite force of complete denture wearers.

Genetic trend estimates of meat quality traits in a male broiler line

The present research was conducted to estimate the genetic trends for meat quality traits in a male broiler line. The traits analyzed were initial pH, pH at 6 h after slaughter, final pH, initial range of falling pH, final range of falling pH, lightness, redness, yellowness, weep loss, drip loss, shrink loss, and shear force. The number of observations varied between 618 and 2125 for each trait. Genetic values were obtained by restricted maximum likelihood, and the numerator relationship matrix had 107,154 animals. The genetic trends were estimated by regression of the broiler average genetic values with respect to unit of time (generations), and the average genetic trend was estimated by regression coefficients. Generally, for the traits analyzed, small genetic trends were obtained, except for drip loss and shear force, which were higher. The small magnitude of the trends found could be a consequence of the absence of selection for meat quality traits in the line analyzed. The estimates of genetic trends obtained were an indication of an improvement in the meat quality traits in the line analyzed, except for drip loss.

Association of SNPs on CAPN1 and CAST genes with tenderness in Nellore cattle

We examined whether single-nucleotide polymorphisms (SNPs) in the calpain (CAPN) and calpastatin (CAST) genes, described from Bos primigenius taurus, are polymorphic in Nellore cattle. We also looked for a possible association of linkage disequilibrium of this polymorphism with tenderness of the longissimus dorsi muscle after 7, 14 and 21 days of postmortem aging in 638 purebred Nellore bulls. Meat tenderness was measured as Warner-Bratzler shear force. Additive and dominance effects were tested for SNPs of the three genotypic classes; the substitution effect was tested for SNPs with missing genotypic classes. Genotypic and gene frequencies were also calculated for the different SNPs. An increase in tenderness was observed from 7 to 21 days; the average values for shear force at 7, 14 and 21 days of aging were 5.92 +/- 0.06, 4.92 +/- 0.05, and 4.38 +/- 0.04 kg, respectively. All markers showed polymorphism, but there was no CC genotype for CAPN316, and few animals showed the AA genotype for CAPN530. The alleles CAPN4751, UOGCAST1, and WSUCAST were found to have additive and dominance effects for shear force at 7, 14 and 21 days, while CAPN316 showed a substitution effect for shear force at 7 and 21 days. An additive-by-additive epistatic interaction was observed between CAPN4751 and markers on the CAST gene. In conclusion, these markers should be considered for use in breeding programs.

Friction coefficient and abrasive wear modes in ball-cratering tests conducted at constant normal force and constant pressure-Preliminary results

The micro-scale abrasive wear test by rotative ball has gained large acceptance in universities and research centers, being widely used in studies on the abrasive wear of materials. Two wear modes are usually observed in this type of test: ""rolling abrasion"" results when the abrasive particles roll on the surface of the tested specimen, while ""grooving abrasion"" is observed when the abrasive particles slide; the type of wear mode has a significant effect on the overall behaviour of a tribological system. Several works on the friction coefficient during abrasive wear tests are available in the literature, but only a few were dedicated to the friction coefficient in micro-abrasive wear tests conducted with rotating ball. Additionally, recent works have identified that results may also be affected by the change in contact pressure that occurs when tests are conducted with constant applied force. Thus, the purpose of this work is to study the relationship between friction coefficient and abrasive wear modes in ball-cratering wear tests conducted at ""constant normal force"" and ""constant pressure"". Micro-scale abrasive wear tests were conducted with a ball of AISI52100 steel and a specimen of AISIH10 tool steel. The abrasive slurry was prepared with black silicon carbide (SiC) particles (average particle size of 3 mu m) and distilled water. Two constant normal force values and two constant pressure values were selected for the tests. The tangential and normal loads were monitored throughout the tests and their ratio was calculated to provide an indication of the friction coefficient. In all cases, optical microscopy analysis of the worn craters revelated only the presence of grooving abrasion. However, a more detailed analysis conducted by SEM has indicated that different degrees of rolling abrasion have also occurred along the grooves. The results have also shown that: (i) for the selected values of constant normal force and constant pressure, the friction coefficient presents, approximately, the same range of values and (ii) loading conditions play an important role on the occurrence of rolling abrasion or grooving abrasion and, consequently, on the average value and scatter of the friction coefficient in micro-abrasive wear tests. (C) 2009 Elsevier B.V. All rights reserved.

Evaluation of molar and incisor bite force in indigenous compared with white population in Brazil

The purpose of this study was to deter-mine maximum bite force in molar and incisor regions in young Brazilian indigenous individuals, who have had a natural diet since birth, and compare the sample with white Brazilian individuals. To do this, individuals were paired one-to-one (same weight, height, and Class I facial pattern). A secondary purpose was to elucidate the relation between bite force and gender in both populations. Eighty-two Brazilians took part in this study. Participants were aged between 18 and 28 years and were divided into two groups: 41 Xingu indigenous individuals and 41 white Brazilian individuals, with 28 men and 13 women in each group. The inclusion criteria were: having complete dentition; normal occlusion; no neurological, psychiatric or movement disorders.; no reports of toothaches; having satisfactory periodontal health; absence of large facial skeletal alterations (typical Class II and Class III individuals); and no previous treatments using occlusal splints. To measure maximum bite force, a digital dynamometer model IDDK (Kratos-Equipamentos Industriais Ltda, Cotia, Sao Paulo, Brazil) was used, with a capacity of 1000 N, adapted for oral conditions. Assessments were made in the first molar (right and left) and central incisive regions. Results reveal that mean maximum bite forces in indigenous individuals of the right molar is 421 N, left molar 429 N and incisor region is 194 14 and for white individuals of the right molar is 410 N, left molar 422 N and incisor region is 117 N. Comparing indigenous with white individuals, maximal bite force showed a tendency of being greater in the indigenous group. It was observed that the incisor region showed statistical significance (p < 0.0005) but no significance was observed in the molar region. Moreover, indigenous men showed the highest bite force values. (C) 2007 Elsevier Ltd. All rights reserved.

Análise comparativa das ações do tráfego rodoviário definidas em diversos regulamentos internacionais de pontes

O presente trabalho pretende avaliar as diferenças de efeitos que os modelos de sobrecarga rodoviária de dez regulamentos (RSA, EC1-2, NBR, AASHTO, SATCC, CSA, IRC:6, SNiP, Manual de Hong Kong, NCP) provocam em pontes rodoviárias de pequeno a médio vão. Numa primeira parte são cobertas questões relacionadas com os efeitos dinâmicos em pontes referenciando-se diversos estudos. Em seguida são apresentados os principais fatores que influenciam os efeitos das sobrecargas rodoviárias. Os modelos de sobrecarga rodoviária, definidos nos diversos regulamentos, são descritos pormenorizadamente com o objetivo de clarificar e facilitar a sua aplicação. No que se refere à componente numérica do trabalho, a quantificação dos efeitos que cada modelo origina foi realizada através da modelação em elementos finitos de tabuleiros de comprimento variável entre 10 e 40 metros. Longitudinalmente analisaram-se os valores máximos do momento fletor e do esforço transverso, e numa análise transversal estudaram-se os valores máximos de momentos fletores positivos e negativos originados em cada tabuleiro. No capítulo 7 é realizada uma análise comparativa dos efeitos causados pelos modelos de sobrecarga rodoviária definidos em cada regulamento tomando como referência os valores obtidos pelo RSA.