Influence of castration on growth performance and carcass and meat quality of heavy female pigs

The main objetive of this Doctoral Thesis was to study the influence of female castration and pig sex on growth performance and carcass and meat quality of white pigs slaughtered at different final weights. Three experiments (Exp.) were conducted. In Exp. 1, a total of 200 (Landrace * Large White dam x Pietrain * Large White sire) gilts of 50 ± 3 days of age (23.3 ± 1.47 kg BW) was used to investigate the effects of castration (intact females, IF vs. castrated feamles, CF) and slaughter weight (106 vs. 122 kg BW) on productive performance and carcass and meat quality. There were four experimental treatments arranged as a 2 x 2 factorial and 5 replicates of 10 pigs each per treatment. Half of the gilts were ovariectomized at 58 d of age (8 days after the beginning of the trial; 29.8 ± 1.64 kg BW) whereas the other half remained intact. Meat samples were taken at m. Longissimus thoracis at the level of the last rib and subcutaneous fat samples were taken at the tail insertion. For the entire experiment period, CF had higher BW gain (P<0.05) and backfat and m. Gluteus medius (GM) fat thickness (P<0.001) than IF. However, IF had higher loin and trimmed primal cut yields (P<0.05) than CF. Meat quality was similar for IF and CF but the proportion of linoleic acid in subcutaneous fat was higher (P<0.001) for IF. Pigs slaughtered at 122 kg BW had higher (P<0.001) feed intake and poorer feed efficiency than pigs slaughtered at 106 kg BW. An increase in slaughter weight (SW) improved (P<0.001) carcass yield but decreased (P<0.05) trimmed primal cut yield. Meat from females slaughtered at the heavier BW was redder (a*; P<0.001) and had more (P<0.01) intramuscular fat and less thawing (P<0.05) and cooking (P<0.10) loss than meat from females slaughtered at the lighter BW. Also, females slaughtered at 122 kg BW had less (P<0.01) linoleic acid content in the subcutaneous fat than pigs slaughtered at 106 kg BW. Castration of gilts and slaughtering at heavier BW might be useful practices for the production of heavy pigs destined to the dry cured industry in which a certain amount of fat in the carcass is required. In contrast, when the carcasses are destined to fresh meat production, IF slaughtered at 106 kg BW are a more efficient alternative. In Exp. 2, crossbred pigs (n=240) from Pietrain*Large White sires mated to Landrace*Large White dams with an average of 100 d of age (60.5 ± 2.3 kg) were used to investigate the effects of gender and slaughter weight (SW) on growth performance and carcass and meat quality characteristics. There were 6 treatments arranged factorially with 3 genders (IF vs. CF vs.castrated males, CM) and 2 SW (114 vs. 122 kg BW). Each of the 6 combinations of treatments was replicated 4 times and the experimental unit was a pen with 10 pigs. Castrated males and CF ate more feed, grew faster and had more carcass backfat depth and fat thickness at the GM muscle, but lower loin yield than IF (P<0.05). In addition, CF and CM had more intramuscular fat (P<0.05) and less linoleic acid content in the subcutaneous fat (P<0.01) than IF. Pigs slaughtered at 122 kg BW had lower ADG (P<0.05), poor gain-to-feed ratio (P<0.05), and more GM fat than pigs slaughtered at 114 kg BW (P < 0.05). It is concluded that CF and CM had similar productive performance and meat quality characteristics when slaughtered at the same age, and that the castration of females improved daily gains and increased weight and fat content of primal cuts with respect to IF. Therefore, castration of females is recommended in pigs destined to the dry-cured industry because of the beneficial effects on the quality of the primal cuts. In Exp. 3, the effects of gender and castration of females (IF vs. CF vs. CM) on performance and carcass and meat quality were studied in crossbred pigs (Landrace x Large White dams x Duroc sires) slaughtered at 119.2 (trial 1) or 131.6 (trial 2) kg BW. Intact females had better feed conversion and less carcass fat than CF and CM. Trimmed shoulder yield was higher for CM than for CF with IF being intermediate. Primal cut yield and meat quality, however were similar for all treatments. Proportion of linoleic acid in backfat was lower for CF than for IF or CM, and the differences were significant in pigs slaughtered witn 131.6 kg BW. The higher fat content and the fatty acid profile favour the use of CF and CM over IF for the production of heavy pigs destined to the dry-cured industry.

Productive performance of brown-egg laying pullets from hatching to 5 weeks of age as affected by fiber inclusion, feed form, and energy concentration of the diet1

The effects of fiber inclusion, feed form, and energy concentration of the diet on the growth performance of pullets from hatching to 5 wk age were studied in 2 experiments. In Experiment 1, there was a control diet based on cereals and soybean meal, and 6 extra diets that included 2 or 4% of cereal straw, sugar beet pulp (SBP), or sunflower hulls (SFHs) at the expense (wt/wt) of the whole control diet. From hatching to 5 wk age fiber inclusion increased (P < 0.05) ADG and ADFI, and improved (P < 0.05) energy efficiency (EnE; kcal AMEn/g ADG), but body weight (BW) uniformity was not affected. Pullets fed SFH tended to have higher ADG than pullets fed SBP (P = 0.072) with pullets fed straw being intermediate. The feed conversion ratio (FCR) was better (P < 0.05) with 2% than with 4% fiber inclusion. In Experiment 2, 10 diets were arranged as a 2×5 factorial with 2 feed forms (mash vs. crumbles) and 5 levels of AMEn (2,850, 2,900, 2,950, 3,000, and 3,050 kcal/kg). Pullets fed crumbles were heavier and had better FCR than pullets fed mash (P < 0.001). An increase in the energy content of the crumble diets reduced ADFI and improved FCR linearly, but no effects were detected with the mash diets (P < 0.01 and P < 0.05 for the interactions). Feeding crumbles tended to improve BW uniformity at 5 wk age (P = 0.077) but no effects were detected with increases in energy concentration of the diet. In summary, the inclusion of moderate amounts of fiber in the diet improves pullet performance from hatching to 5 wk age. The response of pullets to increases in energy content of the diet depends on feed form with a decrease in feed intake when fed crumbles but no changes when fed mash. Feeding crumbles might be preferred to feeding mash in pullets from hatching to 5 wk age.

REFLEXOS INDIVIDUAIS DO USO PESSOAL E EXCESSIVO DE COMUNICADORES INSTANTÂNEOS NO AMBIENTE DE TRABALHO

A Internet está inserida no cotidiano do indivíduo, e torna-se cada vez mais acessível por meio de diferentes tipos de dispositivos. Com isto, diversos estudos foram realizados com o intuito de avaliar os reflexos do seu uso excessivo na vida pessoal, acadêmica e profissional. Esta dissertação buscou identificar se a perda de concentração e o isolamento social são alguns dos reflexos individuais que o uso pessoal e excessivo de aplicativos de comunicação instantânea podem resultar no ambiente de trabalho. Entre as variáveis selecionadas para avaliar os aspectos do uso excessivo de comunicadores instantâneos tem-se a distração digital, o controle reduzido de impulso, o conforto social e a solidão. Através de uma abordagem de investigação quantitativa, utilizaram-se escalas aplicadas a uma amostra de 283 pessoas. Os dados foram analisados por meio de técnicas estatísticas multivariadas como a Análise Fatorial Exploratória e para auferir a relação entre as variáveis, a Regressão Linear Múltipla. Os resultados deste estudo confirmam que o uso excessivo de comunicadores instantâneos está positivamente relacionado com a perda de concentração, e a variável distração digital exerce uma influência maior do que o controle reduzido de impulso. De acordo com os resultados, não se podem afirmar que a solidão e o conforto social exercem relações com aumento do isolamento social, devido à ausência do relacionamento entre os construtos.

Calcium block of Na+ channels and its effect on closing rate

Calcium ion transiently blocks Na+ channels, and it shortens the time course for closing of their activation gates. We examined the relation between block and closing kinetics by using the Na+ channels natively expressed in GH3 cells, a clonal line of rat pituitary cells. To simplify analysis, inactivation of the Na+ channels was destroyed by including papain in the internal medium. All divalent cations tested, and trivalent La3+, blocked a progressively larger fraction of the channels as their concentration increased, and they accelerated the closing of the Na+ channel activation gate. For calcium, the most extensively studied cation, there is an approximately linear relation between the fraction of the channels that are calcium-blocked and the closing rate. Extrapolation of the data to very low calcium suggests that closing rate is near zero when there is no block. Analysis shows that, almost with certainty, the channels can close when occupied by calcium. The analysis further suggests that the channels close preferentially or exclusively from the calcium-blocked state.

Calcium isotope fractionation between soft and mineralized tissues as a monitor of calcium use in vertebrates

Calcium from bone and shell is isotopically lighter than calcium of soft tissue from the same organism and isotopically lighter than source (dietary) calcium. When measured as the 44Ca/40Ca isotopic ratio, the total range of variation observed is 5.5‰, and as much as 4‰ variation is found in a single organism. The observed intraorganismal calcium isotopic variations and the isotopic differences between tissues and diet indicate that isotopic fractionation occurs mainly as a result of mineralization. Soft tissue calcium becomes heavier or lighter than source calcium during periods when there is net gain or loss of mineral mass, respectively. These results suggest that variations of natural calcium isotope ratios in tissues may be useful for assessing the calcium and mineral balance of organisms without introducing isotopic tracers.

Detection of a Yb3+ binding site in regenerated bacteriorhodopsin that is coordinated with the protein and phospholipid head groups

Near infrared Yb3+ vibronic sideband spectroscopy was used to characterize specific lanthanide binding sites in bacteriorhodopsin (bR) and retinal free bacteriorhodopsin (bO). The VSB spectra for deionized bO regenerated with a ratio of 1:1 and 2:1 ion to bO are identical. Application of a two-dimensional anti-correlation technique suggests that only a single Yb3+ site is observed. The Yb3+ binding site in bO is observed to consist of PO2− groups and carboxylic acid groups, both of which are bound in a bidentate manner. An additional contribution most likely arising from a phenolic group is also observed. This implies that the ligands for the observed single binding site are the lipid head groups and amino acid residues. The vibronic sidebands of Yb3+ in deionized bR regenerated at a ratio of 2:1 ion to bR are essentially identical to those in bO. The other high-affinity binding site is thus either not evident or its fluorescence is quenched. A discussion is given on the difference in binding of Ca2+ (or Mg2+) and lanthanides in phospholipid membrane proteins.

A Calcium-Selective Channel from Root-Tip Endomembranes of Garden Cress1

A Ca2+ channel from root-tip endomembranes of garden cress (Lepidium sativum L.) (LCC1) was characterized using the planar lipid-bilayer technique. Investigation of single-channel recordings revealed that LCC1 is voltage gated and strongly rectifying. In symmetrical 50 mm CaCl2 solutions, the single-channel conductance was 24 picosiemens. LCC1 showed a moderate selectivity for Ca2+ over K+ (9.4:1) and was permeable for a range of divalent cations (Ca2+, Ba2+, and Sr2+). In contrast to Bryonia dioica Ca2+ channel 1, a Ca2+-selective channel from the endoplasmic reticulum of touch-sensitive tendrils, LCC1 showed no bursting channel activity and had a low open probability and mean open time (2.83 ms at 50 mV). Inhibitor studies demonstrated that LCC1 is blocked by micromolar concentrations of erythrosin B (inhibitor concentration for 50% inhibition [IC50] = 1.8 μm) and the trivalent cations La3+ (IC50 = 5 μm) and Gd3+ (IC50 = 10 μm), whereas verapamil showed no blocking effect. LCC1 may play an important role in the regulation of the cytoplasmic free Ca2+ concentration in root-tip and/or root-cap cells. The question of whether this ion channel is part of the gravitropic signal transduction pathway deserves further investigation.

Translation initiation of ornithine decarboxylase and nucleocytoplasmic transport of cyclin D1 mRNA are increased in cells overexpressing eukaryotic initiation factor 4E.

The structure of m7GpppN (where N is any nucleotide), termed cap, is present at the 5' end of all eukaryotic cellular mRNAs (except organellar). The eukaryotic initiation factor 4E (eIF-4E) binds to the cap and facilitates the formation of translation initiation complexes. eIF-4E is implicated in control of cell growth, as its overexpression causes malignant transformation of rodent cells and deregulates HeLa cell growth. It was suggested that overexpression of eIF-4E results in the enhanced translation of poorly translated mRNAs that encode growth-promoting proteins. Indeed, enhanced expression of several proteins, including cyclin D1 and ornithine decarboxylase (ODC), was documented in eIF-4E-overexpressing NTH 3T3 cells. However, the mechanism underlying this increase has not been elucidated. Here, we studied the mode by which eIF-4E increases the expression of cyclin D1 and ODC. We show that the increase in the amount of cyclin D1 and ODC is directly proportional to the degree of eIF-4E overexpression. Two mechanisms, which are not mutually exclusive, are responsible for the increase. In eIF-4E-overexpressing cells the rate of translation initiation of ODC mRNA was increased inasmuch as the mRNA sedimented with heavier polysomes. For cyclin D1 mRNA, translation initiation was not increased, but rather its amount in the cytoplasm increased, without a significant increase in total mRNA. Whereas, in the parental NIH 3T3 cell line, a large proportion of the cyclin D1 mRNA was confined to the nucleus, in eIF-4E-overexpressing cells the vast majority of the mRNA was present in the cytoplasm. These results indicate that eIF-4E affects directly or indirectly mRNA nucleocytoplasmic transport, in addition to its role in translation initiation.

Electrical investigation of p-type 4H-SiC heavily doped by ion implantation

In the last decades, an increasing interest in the research field of wide bandgap semiconductors was observed, mostly due to the progressive approaching of silicon-based devices to their theoretical limits. 4H-SiC is an example among these, and is a mature compound for applications. The main advantages offered 4H-SiC in comparison with silicon are an higher breakdown field, an higher thermal conductivity, a higher operating temperature, very high hardness and melting point, biocompatibility, but also low switching losses in high frequencies applications and lower on-resistances in unipolar devices. Then, 4H-SiC power devices offer great performance improvement; moreover, they can work in hostile environments where silicon power devices cannot function. Ion implantation technology is a key process in the fabrication of almost all kinds of SiC devices, owing to the advantage of a spatially selective doping. This work is dedicated to the electrical investigation of several differently-processed 4H-SiC ion- implanted samples, mainly through Hall effect and space charge spectroscopy experiments. It was also developed the automatic control (Labview) of several experiments. In the work, the effectiveness of high temperature post-implant thermal treatments (up to 2000°C) were studied and compared considering: (i) different methods, (ii) different temperatures and (iii) different duration of the annealing process. Preliminary p + /n and Schottky junctions were also investigated as simple test devices. 1) Heavy doping by ion implantation of single off-axis 4H-SiC layers The electrical investigation is one of the most important characterization of ion-implanted samples, which must be submitted to mandatory post-implant thermal treatment in order to both (i) recover the lattice after ion bombardment, and (ii) address the implanted impurities into lattice sites so that they can effectively act as dopants. Electrical investigation can give fundamental information on the efficiency of the electrical impurity activation. To understand the results of the research it should be noted that: (a) To realize good ohmic contacts it is necessary to obtain spatially defined highly doped regions, which must have conductivity as low as possible. (b) It has been shown that the electrical activation efficiency and the electrical conductivity increase with the annealing temperature increasing. (c) To maximize the layer conductivity, temperatures around 1700°C are generally used and implantation density high till to 10 21 cm -3 . In this work, an original approach, different from (c), is explored by the using very high annealing temperature, around 2000°C, on samples of Al + -implant concentration of the order of 10 20 cm -3 . Several Al + -implanted 4H-SiC samples, resulting of p-type conductivity, were investigated, with a nominal density varying in the range of about 1-5∙10 20 cm -3 and subjected to two different high temperature thermal treatments. One annealing method uses a radiofrequency heated furnace till to 1950°C (Conventional Annealing, CA), the other exploits a microwave field, providing a fast heating rate up to 2000°C (Micro-Wave Annealing, MWA). In this contest, mainly ion implanted p-type samples were investigated, both off-axis and on-axis <0001> semi-insulating 4H-SiC. Concerning p-type off-axis samples, a high electrical activation of implanted Al (50-70%) and a compensation ratio below 10% were estimated. In the work, the main sample processing parameters have been varied, as the implant temperature, CA annealing duration, and heating/cooling rates, and the best values assessed. MWA method leads to higher hole density and lower mobility than CA in equivalent ion implanted layers, resulting in lower resistivity, probably related to the 50°C higher annealing temperature. An optimal duration of the CA treatment was estimated in about 12-13 minutes. A RT resistivity on the lowest reported in literature for this kind of samples, has been obtained. 2) Low resistivity data: variable range hopping Notwithstanding the heavy p-type doping levels, the carrier density remained less than the critical one required for a semiconductor to metal transition. However, the high carrier densities obtained was enough to trigger a low temperature impurity band (IB) conduction. In the heaviest doped samples, such a conduction mechanism persists till to RT, without significantly prejudice the mobility values. This feature can have an interesting technological fall, because it guarantee a nearly temperature- independent carrier density, it being not affected by freeze-out effects. The usual transport mechanism occurring in the IB conduction is the nearest neighbor hopping: such a regime is effectively consistent with the resistivity temperature behavior of the lowest doped samples. In the heavier doped samples, however, a trend of the resistivity data compatible with a variable range hopping (VRH) conduction has been pointed out, here highlighted for the first time in p-type 4H-SiC. Even more: in the heaviest doped samples, and in particular, in those annealed by MWA, the temperature dependence of the resistivity data is consistent with a reduced dimensionality (2D) of the VRH conduction. In these samples, TEM investigation pointed out faulted dislocation loops in the basal plane, whose average spacing along the c-axis is comparable with the optimal length of the hops in the VRH transport. This result suggested the assignment of such a peculiar behavior to a kind of spatial confinement into a plane of the carrier hops. 3) Test device the p + -n junction In the last part of the work, the electrical properties of 4H-SiC diodes were also studied. In this case, a heavy Al + ion implantation was realized on n-type epilayers, according to the technological process applied for final devices. Good rectification properties was shown from these preliminary devices in their current-voltage characteristics. Admittance spectroscopy and deep level transient spectroscopy measurements showed the presence of electrically active defects other than the dopants ones, induced in the active region of the diodes by ion implantation. A critical comparison with the literature of these defects was performed. Preliminary to such an investigation, it was assessed the experimental set up for the admittance spectroscopy and current-voltage investigation and the automatic control of these measurements.

Nanomateriais luminescentes de terras raras utilizando complexos de benzenotricarboxilatos como precursores

O material Y2O3:Eu3+ vem sendo usado comercialmente como luminóforo vermelho desde da década de 1960, em uma grande variedade de aplicações devido ao seu elevado rendimento quântico (próximo de 100 %), elevada pureza de cor e boa estabilidade. Portanto, este trabalho propõe um novo método de síntese baseado nos complexos benzenotricarboxilatos (BTC) de terras raras trivalentes (RE3+) dopados com íons Eu3+. O objetivo principal é produzir materiais luminescente RE2O3:Eu3+ a temperatura mais baixa (500 °C) e em escala nanométrica. Os complexos precursores [RE(BTC):Eu3+] e [RE(TLA)·n(H2O):Eu3+], onde RE3+: Y, Gd e Lu; BTC: ácido trimésico (TMA) e ácido trimelítico (TLA) foram calcinados em diferentes temperaturas de 500 a 1000 °C, a fim de obter os materiais luminescentes RE2O3:Eu3+. Os complexos foram caracterizados por análise elementar de carbono e hidrogênio, analise térmica (TG), espectroscopia de absorção no infravermelho (FTIR), difração de raios-X - método do pó (XPD) e microscopia eletrônica de varredura (SEM). Todos os complexos são cristalinos e termo estáveis até 460 °C. Dados de fosforescência dos complexos de Y, Gd e Lu mostram que o nível T1 do aníon BTC3- tem energia acima do nível emissor 5D0 do íon Eu3+, indicando que os ligantes podem atuar como sensibilizadores de energia intramolecular. O estudo das propriedades fotoluminescentes dos complexos dopados foi baseado nos espectros de excitação e emissão e curvas de decaimento de luminescência. Ademais, foram determinados os parâmetros de intensidades experimentais (Ωλ), tempos de vida (τ), taxas de decaimentos radiativo (Arad) e não-radiativo (Anrad). Os materiais luminescentes RE2O3:Eu3+ foram sintetizados de forma bem sucedida por meio do método benzenotricarboxilatos calcinados a 500, 600, 700, 800, 900 e 1000 °C, apresentando alta homogeneidade química e controle de tamanho de cristalito. Os nanomateriais foram caracterizados pelas técnicas de FTIR, XPD SEM e TEM revelando a obtenção dos materiais C-RE2O3:Eu3+ mesmo a 500 °C. Os dados de XPD dos materiais confirmaram um aumento do tamanho dos cristalitos de 5 até 52 nm (equação de Scherrer) de em função da temperatura de calcinação de 500 a 1000 °C, respectivamente, corroborados pelas técnicas de SEM e TEM. Os espectros de emissão de RE2O3:Eu3+ mostram uma banda larga atribuída a transição interconfiguracional de transferência de carga ligante-metal (LMCT) em 260 nm, i.e. O2-(2p)→Eu3+(4f6). Além disso, foram observadas linhas finas de absorção devido as transições intraconfiguracionais 4f do íon európio (7F0,1𔾹LJ; J: 0, 1, 2, 3 e 4), como esperado. As propriedades fotoluminescentes dos luminóforos foram baseadas nos espectros (excitação e emissão) e curvas de decaimento luminescente. Os parâmetros de intensidade experimental, tempos de vida, assim como as taxas de decaimentos radiativos e não radiativos foram calculados. As propriedades fotônicas dos nanomateriais são consistentes com o sítio de baixa simetria C2 ocupado pelo íon Eu3+ no C-RE2O3:Eu3+, produzindo emissão vermelha dominada pela transição hipersensível 5D0𔾻F2 do íon Eu3+ no sitio C2, ao invés do sítio centrossimétrico S6. Além disso, os nanomateriais Y2O3:Eu3+ exibem características espectroscópicas semelhantes e elevados valores de eficiência quântica (η~91 %), compatível com os luminóforos comerciais disponíveis no mercado. Este novo método pode ser utilizado para o desenvolvimento de novos nanomateriais contendo íons terras raras, assim como outros íons metálicos.

Síntese, caracterização e atividade catalítica de compostos organolantanídeos contendo os ânions metanossulfonato e pentametilciclopentadienil e o ligante pirazinamida

O estudo de compostos organolantanídeos consiste em um dos campos de maior interesse dentro da química organometálica, principalmente devido ao uso potencial como precursores ou catalisadores em reações de hidrogenação, hidroformilação, carbonilação, oxidação e principalmente polimerização de olefinas. Este interesse tem levado diversos grupos de pesquisa a sintetizarem compostos utilizando o ânion ciclopentadienil e seus derivados ligados a íons lantanídeos (III). O presente trabalho tem como objetivo contribuir para a aplicação desses compostos organolantanídeos como catalisadores em reações de polimerização de olefinas. O trabalho envolveu uma etapa de síntese e caracterização de duas classes de compostos organolantanídeos Ln(MS)2Cp*(Ln = Tb e Yb), e Ln(MS)2Cp*PzA (Ln = Sm, Tb e Yb) e uma etapa de estudo da atividade catalítica desses compostos frente a reações de polimerização de etileno, propileno e estireno, utilizando metilaluminoxano como co-catalisador e a caracterização dos polímeros formados. Os compostos sintetizados apresentaram atividade catalítica apenas para polimerização de estireno. O polímero formado, independente do composto organolantanídeo utilizado, foi caracterizado como poliestireno principalmente atático, indicando que a polimerização não é estereoespecífica e apresentou massa molar da ordem de 104 g/mol.

IRAS 18357-0604 – an analogue of the galactic yellow hypergiant IRC +10420?

Context. Yellow hypergiants represent a short-lived evolutionary episode experienced by massive stars as they transit to and from a red supergiant phase. As such, their properties provide a critical test of stellar evolutionary theory, while recent observations unexpectedly suggest that a subset may explode as Type II supernovae. Aims. The galactic yellow hypergiant IRC +10420 is a cornerstone system for understanding this phase since it is the strongest post-RSG candidate known, has demonstrated real-time evolution across the Hertzsprung-Russell diagram and been subject to extensive mass loss. In this paper we report on the discovery of a twin of IRC +10420 - IRAS 18357-0604. Methods. Optical and near-IR spectroscopy are used to investigate the physical properties of IRAS 18357-0604 and also provide an estimate of its systemic velocity, while near- to mid-IR photometry probes the nature of its circumstellar environment. Results. These observations reveal pronounced spectral similarities between IRAS 18357-0604 and IRC +10420, suggesting comparable temperatures and wind geometries. IR photometric data reveals a similarly dusty circumstellar environment, although historical mass loss appears to have been heavier in IRC +10420. The systemic velocity implies a distance compatible with the red supergiant-dominated complex at the base of the Scutum Crux arm; the resultant luminosity determination is consistent with a physical association but suggests a lower initial mass than inferred for IRC +10420 (≲20 M⊙ versus ~40 M⊙). Evolutionary predictions for the physical properties of supernova progenitors derived from ~18–20 M⊙ stars – or ~12–15 M⊙ stars that have experienced enhanced mass loss as red supergiants – compare favourably with those of IRAS 18357-0604, which in turn appears to be similar to the the progenitor of SN2011dh; it may therefore provide an important insight into the nature of the apparently H-depleted yellow hypergiant progenitors of some Type IIb SNe.

Plastisol foaming process. Decomposition of the foaming agent, polymer behavior in the corresponding temperature range and resulting foam properties

The decomposition of azodicarbonamide, used as foaming agent in PVC—plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min−1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g−1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 ± 50 g mol−1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse.

Donación voluntaria de sangre de cordón umbilical en el Hospital Universitario Virgen de la Arrixaca (2010-2011). Situación actual e influencia de las variables obstétrico-fetales

Objetivos: A principios de 2010 el Hospital Universitario Virgen de la Arrixaca puso en marcha, en el servicio de partos, el protocolo de donación voluntaria de sangre de cordón umbilical (SCU). Desde la reflexión y la autoevaluación, planteamos un análisis de nuestra situación actual a través del estudio de la influencia de las variables obstétrico-fetales en la calidad de las muestras. Métodos: Con este fin hemos planteado un trabajo de tipo observacional, descriptivo, retrospectivo y de corte transversal desde mayo de 2010 a noviembre de 2011, con el objetivo de aumentar la calidad de las unidades de SCU y optar por una gestión eficiente que haga sostenible el proyecto. Resultados: Se obtuvieron 123 donaciones potenciales de sangre de cordón y del análisis multivariable de las mismas obtuvimos una correlación positiva significativa entre el número de leucocitos, las semanas de gestación y el parto vaginal. El peso inicial de la unidad se incrementó significativamente a mayor peso del recién nacido y paridad de la donante. Conclusiones: Como conclusiones del estudio nos planteamos esbozar posibles factores predictivos que permitan seleccionar las muestras de mayor calidad y sean complemento de los actuales estándares elaborados por el Banco Público de Málaga. En este sentido nuestros resultados sugieren que en los partos con más semanas de gestación, paridad de la gestante y peso del recién nacido, así como en los partos vaginales, encontramos mayores posibilidades de obtener muestras de alta calidad.

Prevalência de lesões musculo-esqueléticas em profissionais de artes musicais

Enquadramento: As lesões músculo-esqueléticas relacionadas com o trabalho apresentam-se atualmente como um crescente flagelo e a profissão de músico é uma atividade predisponente para a ocorrência dessas lesões, exigindo uma atenção especial dos profissionais de saúde para identificar e controlar os fatores de risco. Objetivos: O presente estudo pretende identificar a prevalência das perturbações músculo-esqueléticas nos músicos profissionais praticantes de Cordofones beliscados e analisar a sua relação com as variáveis sociodemográficas, estado de saúde e características da prática instrumental. Métodos: Trata-se de um estudo não experimental, transversal, descritivo-correlacional e de caráter quantitativo, que envolveu 70 músicos portugueses praticantes de cordofones beliscados, residentes em Viseu, Porto e Lisboa, com idades compreendidas entre 18 e 55 anos. Foi realizado com recurso ao uso de um questionário que avalia as variáveis sociodemográficas, as clínicas e as relacionadas com a prática musical e para avaliação das perturbações musculoesqueléticas utilizámos o “Questionário Nórdico Músculo-Esquelético”. Resultados: Dos músicos estudados 70,0% referem sentir perturbações músculo-esqueléticas como dor/formigueiro/dormência nos últimos 12 meses, tendo estes ocorrido sobretudo nos punhos/mãos (68.6%), ombros (54.3%), pescoço e região lombar (44.3%). Observámos que são vários os fatores risco das perturbações musculoesqueléticas como a idade avançada, um Índice de Massa Corporal mais elevado, o consumo de bebidas alcoólicas, não praticar atividade física, o excesso de espetáculos, a postura adotada, instrumentos mais pesados e tocar sem pausas. Conclusões: O nosso estudo reforça a ideia de que as perturbações músculo-esqueléticas estão presentes nos músicos portugueses e que a sua origem está relacionada com características individuais, estado de saúde e exigências da prática instrumental. Cabe então ao Enfermeiro de Reabilitação criar estratégias preventivas, para evitar que os fatores de risco acrescidos causem ou aumentem as já instaladas lesões músculo-esqueléticas nos músicos, promovendo uma carreira longa e saudável. Palavras-chave: Músicos; Lesões musculoesqueléticas; Fatores de risco; Enfermagem de Reabilitação.