Enhanced Room-Temperature Geometric Magnetoresistance in Inhomogeneous Narrow-Gap Semiconductors

A symmetric van der Pauw disk of homogeneous nonmagnetic indium antimonide with an embedded concentric gold inhomogeneity is found to exhibit room-temperature geometric magnetoresistance as high as 100, 9100, and 750,000 percent at magnetic fields of 0.05, 0.25, and 4.0 teslas, respectively. For inhomogeneities of sufficiently large diameter relative to that of the surrounding disk, the resistance is field-independent up to an onset field above which it increases rapidly. These results can be understood in terms of the field-dependent deflection of current around the inhomogeneity.     

Ameliorative Effects of Melatonin against Hydrogen Peroxide‐Induced Oxidative Stress on Boar Sperm Characteristics and Subsequent In Vitro Embryo Development

Melatonin, the major secretory product of the pineal gland, scavenges a variety of reactive oxygen and nitrogen species in vivo and in vitro, indicating that melatonin is a potent function as an antioxidant. The objective of this study was to investigate the effect of melatonin in the presence or absence of hydrogen peroxide (H₂O₂) on sperm characteristics (motility, viability, survival rate, membrane integrity, lipid peroxidation (LPO) and mitochondria activity) and also to examine the developmental rates to the blastocysts stage of porcine oocytes fertilized in vitro with semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ). The sperm were treated with melatonin in the presence or absence of H₂O₂ for 3, 6, 9 and 12 h at 37°C and then analysed for the sperm characteristics. The porcine embryos were produced by in vitro maturation and in vitro fertilization (IVM/IVF) using semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ) for 6 h. The semen characteristics, including motility, viability, survival rate, membrane integrity and mitochondria activity, were higher in the groups that were treated with melatonin in comparison to other groups, irrespective of incubation periods. Malondialdehyde levels in control, melatonin and melatonin + H₂O₂ groups were lower than H₂O₂ only group. A positive correlation was shown among motility, viability, survival rate and membrane integrity, but a negative correlation was observed between LPO and the other evaluation methods. The developmental rates to blastocysts of IVM/IVF porcine oocytes fertilized by semen treated with melatonin were significantly increased compared with any other groups, with the cell number of blastocysts shown to have a similar trend to the developmental rates. These results demonstrate that melatonin can improve the semen characteristics during in vitro storage and support the developmental ability of IVM/IVF embryos in pigs.     

Case report: tenesmus in a cow with a liver abscess and nephritis

A two-year-old Swiss Braunvieh cow was referred to our clinic because of tenesmus and weight loss. Clinical examination revealed a moderately abnormal general behaviour and condition, thin body condition and a rectal temperature of 40.1 degrees C. Tenesmus was evident, and rumen and intestinal motility were markedly reduced. All tests for a reticular foreign body were positive. On rectal examination, a round, smooth, firm, non-painful mass with a diameter of approximately 15 cm was palpated far cranially on the right side. Abnormal haematological and biochemical findings included marked anaemia, neutrophilic leucocytosis, markedly elevated concentration of fibrinogen and mildly elevated gamma-glutamyl-transferase activity. The clotting time of the glutaraldehyde test was one minute. Ultrasonographic examination revealed abscesses involving the liver and extending caudally into the right flank region. The liver parenchyma had diffuse changes. Because of a grave prognosis, the cow was euthanized. Postmortem findings substantiated ultrasonographic results; there were abscesses, caused by Fasciola hepatica infestation, originating in the liver and extending into the right flank. As well, there was severe, bilateral, multifocal, suppurative nephritis due to thromboembolism. Based on all the findings, a diagnosis of liver abscess caused by fascioliasis and bilateral suppurative nephritis was made.     

Assessment of Genetic Variability in the Coding Sequence of Melatonin Receptor Gene (MTNR1A) in Tropical Arid Sheep Breeds of India

Seasonal behaviour in sheep, which varies in tropical and temperate environmental conditions, is a matter of study, because it can provide a clue to address the problem of seasonality in sheep. Melatonin receptor is the membrane‐bound G‐coupled receptor, sensing the message of photoperiodic cues thorough melatonin. Restriction fragment length polymorphism (RFLP) studies were carried out to assess the variability of gene at G612A and C606T SNPs in MTNR1A gene, which have been studied to be markers for out‐of‐season breeding. Allelic frequency distribution corresponded to higher frequency of GG and CC genotype, in tropical arid sheep breed in comparison with temperate region sheep breed. PCR amplification of MTNR1A gene of 30 animals was performed and single nucleotide polymorphisms (SNPs) identification was carried out using Lasergene software. Seven SNPs/mutations were identified, but most of them were synonymous, except the one G706A, leading to substitution of valine by isoleucine. Polyphen‐2 analysis of G706A mutation revealed that it is a benign mutation. Two important SNPs C426T and G555A, which were identified in temperate sheep breeds, could not be traced in Magra and Marwari breeds of sheep. Thus, the Magra and Marwari breeds of tropical, arid region demonstrated the presence of both polymorphic SNPs markers G612A and C606T, associated with out‐of‐season breeding. GG and CC genotypes were having a higher prevalence in the studied population.     

Effect of a Gonadotropin-releasing Hormone Vaccine (ImprovacTM) on Steroid Hormones, Boar Taint Compounds and Performance in Entire Male Pigs

The objective of this study, comprising two trials, was to evaluate the effect of a gonadotropin‐releasing hormone (GnRH‐vaccine Improvac^TM; Pfizer Ltd) in a sample of the Swedish pig population. The pigs (n = 120) were assigned to three groups: control (entire male pigs), surgical castration and immunization against GnRH. Surgically castrated pigs did not express detectable levels of either testosterone or estrone sulphate (E1S) in plasma, or androstenone in fat and had lower skatole and indole levels in fat than entire male pigs. Immunization significantly reduced testes weight and bulbourethral gland length, plasma levels of the testicular hormones testosterone and E1S, and fat levels of androstenone, skatole and indole. Skatole levels in plasma were significantly lower than in entire male pigs in the second trial, but not in the first due to overall low skatole levels. All immunized pigs and surgically castrated pigs expressed skatole concentrations in fat below the level of 0.2 μg/g, above which meat is regarded as tainted. In contrast, eight entire male pigs exceeded this level. Indole levels in plasma from immunized pigs were lower than those from entire male pigs. Surgical castration caused lower daily weight gain in the suckling period compared with piglets raised intact, whereas in the post‐weaning period no difference was observed. Immunization resulted in higher feed intake and daily weight gain after the second injection. The estimated lean meat content was improved in comparison with the castrated pigs, but was lower than for entire male pigs. Dressing percentage was lower in immunized pigs than in surgically castrated and entire male pigs. The frequency of skin damage did not differ between immunized and entire male pigs or between immunized and surgically castrated pigs.     

Near-field investigations of the landers earthquake sequence, april to july 1992

The Landers earthquake, which had a moment magnitude (M(w)) of 7.3, was the largest earthquake to strike the contiguous United States in 40 years. This earthquake resulted from the rupture of five major and many minor right-lateral faults near the southern end of the eastern California shear zone, just north of the San Andreas fault. Its M(w) 6.1 preshock and M(w) 6.2 aftershock had their own aftershocks and foreshocks. Surficial geological observations are consistent with local and far-field seismologic observations of the earthquake. Large surficial offsets (as great as 6 meters) and a relatively short rupture length (85 kilometers) are consistent with seismological calculations of a high stress drop (200 bars), which is in turn consistent with an apparently long recurrence interval for these faults.     

HLA and NK cell inhibitory receptor genes in resolving hepatitis C virus infection

Natural killer (NK) cells provide a central defense against viral infection by using inhibitory and activation receptors for major histocompatibility complex class I molecules as a means of controlling their activity. We show that genes encoding the inhibitory NK cell receptor KIR2DL3 and its human leukocyte antigen C group 1 (HLA-C1) ligand directly influence resolution of hepatitis C virus (HCV) infection. This effect was observed in Caucasians and African Americans with expected low infectious doses of HCV but not in those with high-dose exposure, in whom the innate immune response is likely overwhelmed. The data strongly suggest that inhibitory NK cell interactions are important in determining antiviral immunity and that diminished inhibitory responses confer protection against HCV.     

Rupture process of the 2004 Sumatra-Andaman earthquake

The 26 December 2004 Sumatra-Andaman earthquake initiated slowly, with small slip and a slow rupture speed for the first 40 to 60 seconds. Then the rupture expanded at a speed of about 2.5 kilometers per second toward the north northwest, extending 1200 to 1300 kilometers along the Andaman trough. Peak displacements reached approximately 15 meters along a 600-kilometer segment of the plate boundary offshore of northwestern Sumatra and the southern Nicobar islands. Slip was less in the northern 400 to 500 kilometers of the aftershock zone, and at least some slip in that region may have occurred on a time scale beyond the seismic band.     

Boar Taint is Related to Endocrine and Anatomical Changes at Puberty but not to Aggressive Behaviour in Entire Male Pigs

This study aimed to describe the association between incidence of boar taint and pubertal changes in gonadal hormones, size of reproductive organs and aggressive behaviour in entire male pigs. In total, 111 entire male pigs were included in the study. Sampling was performed first at 90 kg live weight (LW) and, then, at 115 kg LW. Variables measured were skatole and androstenone levels in plasma and fat, testosterone and oestrone sulphate in plasma, free oestrone in fat, weight of testes and length of bulbourethral glands. Aggressive interactions between pigs were registered when a limited amount of feed was provided to the pigs prior to routine feeding. The number of initiated interactions (attacks) and the difference between number of initiated and received interactions (relative attacks) were calculated for each pig. Multivariate analysis revealed that gonadal hormones and reproductive organ size influenced prevalence of boar taint, accounting for 30% of the variation in skatole levels in fat and for 37% of the variation in androstenone levels in fat. These relations were independent of aggression levels in entire male pigs. Skatole levels were influenced by the levels of oestrone sulphate in plasma and free oestrone in fat, but not levels of plasma testosterone. Pigs with testes weight below 565 g and a bulbourethral gland length <90 mm did not produce high amounts of skatole; therefore, these values can be used as a threshold level to detect pig carcasses with low skatole levels. High androstenone levels could not be predicted by measuring reproductive organ sizes. More research is required to develop a rapid and accurate method for the analysis of carcasses of entire male pigs.     

CIDR和PMSG诱导东北梅花鹿同期发情的初步研究

应用阴道内孕酮释放装置 (CIDR)结合不同来源和不同剂量的PMSG处理 ,观察东北梅花鹿同期发情效果。 2 6只试验鹿分成 5组 ,将CIDR放置母鹿阴道内 15d后取出 ,肌注不同剂量 (10 0～ 5 0 0IU)孕马血清促性腺激素 ,放入带试情布的公鹿试情 ,持续观察 72h。结果表明 ,取出CIDR后试验鹿在 (33.3± 7.0 )h发情。其中含 10 0IUPMSG的“Folligon”处理的试验鹿同期发情率达 10 0 % ;国产PMSG处理的梅花鹿随着PMSG剂量的增加 ,发情率有增加的趋势 ,但各组间差异不显著 (χ2 检验P >0 .0 5 )。同时 ,不同剂量的PMSG处理没有显著影响CIDR取出后至发情时的平均时间长度。