Recently, research has picked up a fervent pace in the area of fault diagnosis of electrical machines. The manufacturers and users of these drives are now keen to include diagnostic features in the software to improve salability and reliability. Apart from locating specific harmonic components in the line current (popularly known as motor current signature analysis), other signals, such as speed, torque, noise, vibration etc., are also explored for their frequency contents. Sometimes, altogether different techniques, such as thermal measurements, chemical analysis, etc., are also employed to find out the nature and the degree of the fault. In addition, human involvement in the actual fault detection decision making is slowly being replaced by automated tools, such as expert systems, neural networks, fuzzy-logic-based systems; to name a few. It is indeed evident that this area is vast in scope. Hence, keeping in mind the need for future research, a review paper describing different types of faults and the signatures they generate and their diagnostics' schemes will not be entirely out of place. In particular, such a review helps to avoid repetition of past work and gives a bird's eye view to a new researcher in this area.

It was hypothesized that a high-concentrate diet fed during early calfhood alters the expression of genes within the arcuate nucleus that subserve reproductive competence. Beef heifers (n = 12) were weaned at approximately 3 mo of age, and after acclimation, were allocated randomly to 1 of 2 nutritional groups: 1) High Concentrate/High Gain (HC/HG), a high concentrate diet fed to promote a gain of 0.91 kg/d; or 2) High Forage/Low Gain (HF/LG), a forage-based diet fed to promote a gain of 0.45 kg/d. Experimental diets were fed under controlled intake for 91 d. At the end of 91 d, heifers were slaughtered by humane procedures, blood samples were collected, brains were removed, liver weights were determined, and rumen fluid was collected for VFA analyses. Tissue blocks containing the hypothalamus were dissected from the brains, frozen, and cut using a cryostat, and frozen sections were mounted on slides. Tissue from the arcuate nucleus (ARC) was dissected from sections for mRNA extraction. Microarray analysis was used to assess genome-wide transcription in the ARC using a 60-mer oligonucleotide 44K bovine expression array. The ADG was greater (P < 0.001) in heifers fed the HC/HG diet than in heifers fed the HF/LG diet. At slaughter, mean propionate to acetate ratios in the ruminal fluid and liver weight as a percentage of BW were increased (P < 0.005) in HC/HG compared with HF/LG heifers. Mean serum concentrations of insulin (P < 0.05) and IGF-1 (P < 0.005) were greater, and leptin tended to be greater (P = 0.1) in HC/HG heifers compared with HF/LG heifers. Approximately 345 genes were observed to be differentially expressed in the HC/HG group with approximately two-thirds of the genes exhibiting increased expression in the HC/HG group. Genes exhibiting decreased expression in the HC/HG group included agouti-related protein and neuropeptide Y, products of which are known to regulate feed intake and energy expenditure. Functional annotation of enriched Gene Ontology terms indicates that a number of biological processes within the hypothalamus are affected by consumption of high-concentrate diets, including those related to control of feed intake, regulation of cellular metabolic processes, receptor and intracellular signaling, and neuronal communication. In summary, dietary treatments shown previously to accelerate the timing of pubertal onset in heifers increased ruminal propionate, promoted enhanced metabolic hormone secretion, and altered gene expression in the ARC.

Campylobacter jejuni is one of the most common causes of acute enteritis worldwide. Chickens are believed to be the main reservoir of C. jejuni. The role that host genetics play in resistance/susceptibility to C. jejuni colonization in broilers is still not clear. Day-old broilers from 2 parental lines (A and B) and their F(1) reciprocal crosses (C and D) were challenged orally with 10(5) cfu of C. jejuni to address the role of genetics in determining resistance/susceptibility to C. jejuni colonization in broilers. Cloacal swabs were collected on 6, 10, and 13 d postinoculation (dpi), and cecal contents cultured for C. jejuni on 7 and 14 dpi. The number of C. jejuni colonies in the cloacal swabs and cecal contents of each bird were recorded at each time point. Significantly fewer bacteria were found in the cecal contents from line A than B (P < 0.05) and cross D (A male x B female) when compared with cross C (A female x B male) at both 7 and 14 dpi. There was a significant correlation between C. jejuni counts in cloacal swabs and those in cecal contents. The results indicated that a paternal effect might be one of the important genetic factors influencing resistance to C. jejuni colonization in broilers.

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Copy number variation refers to regions along chromosomes that harbor a type of structural variation, such as duplications or deletions. Copy number variants (CNVs) play a role in many important traits as well as in genetic diversity. Previous analyses of chickens using array comparative genomic hybridizations or single-nucleotide polymorphism chip assays have been performed on various breeds and genetic lines to discover CNVs. In this study, we assessed individuals from two highly inbred (inbreeding coefficiency > 99.99%) lines, Leghorn G-B2 and Fayoumi M15.2, to discover novel CNVs in chickens. These lines have been previously studied for disease resistance, and to our knowledge, this represents the first global assessment of CNVs in the Fayoumi breed. Genomic DNA from individuals was examined using the Agilent chicken 244 K comparative genomic hybridization array and quantitative PCR. We identified a total of 273 CNVs overall, with 112 CNVs being novel and not previously reported. Quantitative PCR using the standard curve method validated a subset of our array data. Through enrichment analysis of genes within CNV regions, we observed multiple chromosomes, terms and pathways that were significantly enriched, largely dealing with the major histocompatibility complex and immune responsiveness. Using an additional round of computational and statistical analysis with a different bioinformatic pipeline, we identified 43 CNVs among these as high-confidence regions, 14 of which were found to be novel. We further compared and contrasted individuals of the two inbred lines to discover regions that have a significant difference in copy number between lines. A total of 40 regions had significant deletions or duplications between the lines. Gene Ontology analysis of genomic regions containing CNVs between lines also was performed. This between-line candidate CNV list will be useful in studies with these two unique genetic lines, which may harbor variations that underlie quantitative trait loci for disease resistance and other important traits. Through the global discovery of novel CNVs in chicken, these data also provide resources for further genetic and functional genomics studies.

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Avian influenza virus (AIV) is a major respiratory disease of poultry that causes catastrophic losses to the poultry industry. The Mx protein has been shown to confer antiviral responses to influenza viruses in mice. One nonsynonymous substitution (S631N) in the chicken Mx protein is reported to be associated with resistance to AIV infection in vitro. The previous studies suggested controversy over whether this substitution in the Mx protein plays an important antiviral role in AIV infection in the chicken. It would be intriguing to investigate if the substitution is associated with resistance to AIV infection both in ovo and in vivo in chickens. In this study, the embryos and young chicks were generated from the cross of Mx1 heterozygous (S631N) parents with an expected segregating ratio of 1:2:1 in the progeny. A PCR length polymorphism was developed to genotype the Mx1 gene from 119 embryos and 48 chickens. The embryonated chicken eggs were inoculated with 10(6) 50% embryo infectious dose (EID(50)) H5N9 AIV on d 13. Hemagglutinating units in allantoic fluid were determined at 48 h postinoculation. For the in vivo study, twenty-four 1-wk-old broilers were inoculated with 10(6) EID(50) H5N3, and virus titers in lungs were evaluated at d 4 postinoculation. This is the first report revealing no significant association between Mx1 genotypes and low pathogenesis AIV infection both in ovo and in vivo in the chicken. Total RNA samples were isolated from chicken lung tissues in the in vivo study, and the Mx1 mRNA expression assay among 3 genotypes also suggested that only heterozygote birds had significantly greater expression with AIV infection than noninfected birds. A recombination breakpoint within Mx1 gene was also first identified, which has laid a solid foundation for further understanding biological function of the Mx1 gene in chickens. The current study provides valuable information on the effect of the Mx1 gene on the genetic resistance to AIV in chickens, and Mx1 will not be applicable for enhancing genetic resistance to AIV infection in chickens.

Microbiological assays involving Escherichia coli lysine auxotrophs must be optimized to facilitate routine use. Our objectives in this study were to characterize growth of an auxotrophic E. coli lysine mutant (American Type Culture Collection strain #23812) and examine the effect of agitation on E. coli mutant growth. A defined minimal salts basal medium was used and supplemented with various lysine concentrations. The E. coli lysine auxotroph responded to increasing lysine concentration with increasing optical density. When maximum optical density (MOD) was determined for the auxotroph, a linear increase was obtained as lysine concentrations were increased (R2± 0.96) for both agitation and static cultures. Growth rates were not significantly (p > 0.05) affected by lysine concentrations, cultural conditions or their combined effect. However, growth with agitation significantly (p < 0.05) reduced the assay time by shortening the lag phase and causing stationary phase to occur earlier. The values of R2 (± 0.96) relatively remained constant over the range while the bacterial population were in the stationary phase. In conclusion, the lysine growth assay using the E. coli lysine auxotroph can be made more rapid by agitating the culture during incubation.