232 research outputs found

    Neonatal feed restriction modulates circulating levels of corticosterone and expression of glucocorticoid receptor and heat shock protein 70 in aged Japanese quail exposed to acute heat stress.

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    This study aimed to determine the effect of neonatal feed restriction on plasma corticosterone concentration (CORT), hippocampal glucocorticoid receptor (GR) expression, and heat shock protein (Hsp) 70 expression in aged male Japanese quail subjected to acute heat stress. Equal numbers of chicks were subjected to either ad libitum feeding (AL) or 60% feed restriction on d 4, 5, and 6 (FR). At 21 (young) and 270 (aged) d of age, birds were exposed to 43 ± 1°C for 1 h. Blood and hippocampus samples were collected to determine CORT and Hsp 70 and GR expressions before heat stress and following 1 h of heat stress, 1 h of post-heat stress recovery, and 2 h of post-heat stress recovery. With the use of real-time PCR and enzyme immunoassay, we examined the hippocampal expression of GR and Hsp 70 and CORT. The GR expression of the young birds increased following heat stress and remained consistent throughout the period of recovery. Conversely, no significant changes were noted on GR expression of aged birds. Although both young and aged birds had similar CORT before and during heat stress, the latter exhibited greater values following 1 and 2 h of recovery. Within the young group, feeding regimens had no significant effect on Hsp 70 expression. However, neonatal feed restriction improved Hsp 70 expression in aged birds. Neonatal feed restriction, compared with the AL group, resulted in higher CORT on d 21 but the converse was noted on d 270. Neonatal feed restriction appears to set a robust reactive hypothalamo-pituitary-adrenal response allowing the development of adaptive, healthy, and resilient phenotypes in aged quail as measured by a higher hippocampal Hsp 70 expression along with lower CORT

    Physiological responses of 3 chicken breeds to acute heat stress.

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    Domestic animals have been modified by selecting individuals exhibiting desirable traits and culling the others. To investigate the alterations introduced by domestication and selective breeding in heat stress response, 2 experiments were conducted using Red Jungle Fowl (RJF), village fowl (VF), and commercial broilers (CB). In experiment 1, RJF, VF, and CB of a common chronological age (30 d old) were exposed to 36 ± 1°C for 3 h. In experiment 2, RJF, VF, and CB of common BW (930 ± 15 g) were subjected to similar procedures as in experiment 1. Heat treatment significantly increased body temperature, heterophil:lymphocyte ratio, and plasma corticosterone concentration in CB but not in VF and RJF. In both experiments and irrespective of stage of heat treatment, RJF showed lower heterophil:lymphocyte ratio, higher plasma corticosterone concentration, and higher heat shock protein 70 expression than VF and CB. It can be concluded that selective breeding for phenotypic traits in the domestication process has resulted in alterations in the physiology of CB and concomitantly the ability to withstand high ambient temperature compared with RJF and VF. In other words, domestication and selective breeding are leading to individuals that are more susceptible to stress rather than resistant. It is also apparent that genetic differences in body size and age per se may not determine breed or strain variations in response to heat stress

    Propagation Path Loss Modeling and Outdoor Coverage Measurements Review in Millimeter Wave Bands for 5G Cellular Communications

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    The global bandwidth inadequacy facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks, and mmWave band is one of the promising candidates due to wide spectrum. This paper presents propagation path loss and outdoor coverage and link budget measurements for frequencies above 6 GHz (mm-wave bands) using directional horn antennas at the transmitter and omnidirectional antennas at the receiver. This work presents measurements showing the propagation time delay spread and path loss as a function of separation distance for different frequencies and antenna pointing angles for many types of real-world environments. The data presented here show that at 28 GHz, 38 GHz and 60 GHz, unobstructed Line of Site (LOS) channels obey free space propagation path loss while non-LOS (NLOS) channels have large multipath delay spreads and can utilize many different pointing angles to provide propagation links. At 60 GHz, there is more path loss and smaller delay spreads. Power delay profiles PDPs were measured at every individual pointing angle for each TX and RX location, and integrating each of the PDPs to obtain received power as a function of pointing angle. The result shows that the mean RMS delay spread varies between 7.2 ns and 74.4 ns for 60 GHz and 28 GHz respectively in NLOS scenario

    Experimental respiratory infection of goats with Mycoplasma arginini and Pasteurella haemolytica A2

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    Twenty-one healthy local goats of about eight months old were divided into four groups consisting of six animals in groups 1, 2 and 3 and three animals in group 4. Goats in groups 1 and 2 were inoculated intratracheally with Mycoplasma arginini. Goats in group 2 were inoculated again with Pasteurella haemolytica A2 six days later. Goats in group 3 were inoculated intratracheally with P. haemolytica A2 alone while goats in group 4 received intratracheal inoculation ofPBS. The goats were euthanised at day 1, 3 and 7 post inoculation with P. haemolytica. Four goats in group 1 and three goats in group 3 had small patches of mild pneumonic lesions. Goats in group 2 had severe lung lesions typical of pneumonic pasteurellosis at the anteroventral region of the lungs. None of the goats in group 4 had pulmonary lesions. P. haemolytica was reisolated from all goats in group 2 and from three goats in group 3 but M. arginini was not reisolated

    Isolation and characterization of genotype VII Newcastle disease virus from NDV vaccinated farms in Malaysia

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    Molecular analysis, particularly sub-genotype classification, and study on the relationship of recent Malaysian NDVs with other isolates from around the world are lacking. Therefore, in the present study, a molecular epidemiological investigation was conducted to characterise six Newcastle disease viruses (NDV) isolated between 2014 and 2015 from vaccinated commercial poultry flocks. Partial Fusion (F) and Hemagglutinin-neuraminidase (HN) genes were amplified from IBS046/2014, IBS060/2014, IBS061/2014, IBS074/2014, IBS160/2015, and IBS162A/2015 isolates using one-step reverse transcription polymerase chain reaction (RT-PCR), sequenced and phylogenetically analysed. Sequence and phylogenetic analysis revealed that all the recently isolated strains of NDV belonged to sub-genotype VIIa and lineage 5a. Moreover, deduced amino acid sequence at the F protein cleavage site of the isolates revealed either 112RRQKRF117 or 112KRRKRF117 consistent with the motif found in velogenic pathotypes. The study concluded that the genotype VIIa was the causative agent of recent ND outbreaks in vaccinated broiler flocks from Malaysia. Interestingly, five out of the six isolates characterised in this study had a unique F0 protein cleavage site (112KRRKRF117). Further studies are required to determine the role of these motifs on the virulent potential of the isolates

    Pathogenicity of salmonella enteritidis phage types 3A and 35 after experimental infection of white leg horn chicks.

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    Out of 155 newly hatched SPF White Leghorn chicks, five chicks were randomly separated to confirm the SPF status of the chicks before inoculation. The remaining 150 chicks were divided into six groups. The three sacrificed groups (A, B and C) of 30 chicks each and their respective three mortality groups (MA, MB and MC) of 20 chicks each. The chicks in groups A and MA, and in groups B and MB were challenged orally with 0.1mL containing 107 cfu of SE phage type 3A(UPM-0541) and SE phage type 35 ( UPM-0525), respectively. The un-inoculated groups C and MC served as negative controls. Pathogenicity of Salmonella enteri caserovar enteritidis (S.Enteritidis) phage types (PTs) 3A and 35 infections was determined through inoculation orally with (0.1mL/chick) 107 colony forming units (cfu). Clinical signs and mortality were observed for 21 days post inoculation (pi). Body weights, bacterial isolation, gross lesions and histological lesions were recorded on days 1, 3,5,7,14 and 21pi. The inoculated chicks in A and B groups showed clinical signs of depression, anorexia, ruffled feathers, vent pasting and diarrhea starting from day 1pi. Lifting of wings from thorax was observed in group A only at day 5 and 7pi. The chicks in MA and MB groups that died during experiment showed all the clinical sings before death. There was no significant difference (p>0.05) in body weight gain among the inoculated and the control groups. The growth index value (0.035) for all the groups remained increased. The mortality caused by SE PT3A and PT35 was 10% and 5%, respectively. About 20-10% inoculated sacrificed and all the dead birds showed gross lesions of enlarged livers, fibrinous perihepatitis and pericarditis which was supported by histopathology. The Salmonella was isolated from the cultured samples of chicks inoculated with SE PT3A and SE PT35 throughout the experiment period with the individual variation of chicks and samples. It was concluded that newly hatched SPF chicks are susceptible to PT3A and PT35 infections. These phage types are mild to moderately pathogenic for SPF chicks

    Pathogenicity of Salmonella enteritidis phage types 6A and 7 in experimentally infected chicks

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    Pathogenicity of Salmonela enterica serovar enteritdis (S.E) phage types (PTs) 6A and 7 were determined in oraly inoculated newly hatched specific pathogen fre (SPF) chicks. Clinical signs and mortality were observed daily. Body weights, bacterial isolation, gros lesions and histological lesions were recorded on days 1, 3, 5, 7, 14 and 21 post inoculations (pi). Out of 15 newly hatched SPF White Leghorn chicks, five chicks were randomly separated to confirm the SPF status of the chicks before inoculation. The remaining chicks were divided into thre sacrificed groups (A, B and C) of 30 chicks each and their respective thre mortality groups (MA, MB and MC) of 20 chicks each. Groups A and MA, and groups B and MB were inoculated oraly with 0.1mL containing 107 cfu of SE PT6A (UPM-0527) and SE PT7 (UPM-0530), respectively. The un-inoculated groups C and MC served as negative controls. Chicks in groups A and B showed clinical signs of depresion, anorexia, rufled feathers, vent pasting and diarhea starting from day 1 pi. Lifting of wings from thorax was observed in group A and B from day 1 and 5 pi, respectively. There was significant diference (p<0.05) in body weight gain among the inoculated and the control groups on days 14 and 21 pi. Growth index values were 0.035, 0.036 and 0.037 for groups A, B and C, respectively. Mortality of 20% was recorded only in MA group. Gos lesions of unabsorbed yolk, airsaculits, fibrinous pericardits, fibrinous perihapatis, enlarged kidneys, splenomegaly and dehydration were observed in about 15% of sacrificed chicks in group A and 10% in group B. Mild to moderate lesions were observed under microscope. Salmonela was isolated from the cultured samples of group A and B throughout the experiment period with the individual variation of chicks and samples. It was concluded that newly hatched SPF chicks are susceptible to PT6A and PT7 infections. These SE PTs are mild to moderately pathogenic for SPF chicks. SE PT6A is more pathogenic than SE PT7

    Molecular characterization of fowl adenoviruses isolated from inclusion body hepatitis outbreaks in commercial broiler chickens in Malaysia

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    Fowl adenoviruses (FAdVs), belonging to the Aviadenovirus genus of the family Adenoviridae, have been classified into five species (A to E) and further divided into 12 serotypes. The objective of this study was to identify the serotype classification of five Malaysian FAdV isolates obtained from field outbreaks of IBH in commercial broiler chickens. Hexon-based polymerase chain reactions (PCR), combined with restriction enzyme analysis (REA), were applied. Viral DNA reacted positively with H1/H2 and H3/ H4 primer pairs which hybridised to highly conserved regions of the hexon genes. The restriction enzyme profiles of the H1/H2 fragment digested with HaeII and the H3/H4 fragment digested with HpaII revealed that all five isolates shared identical patterns and are characterised as being FAdV-8b, species E. Meanwhile, sequence analysis of the L1 loop region of the hexon gene revealed 98.1% identity with FAdV-8b strain 764. High bootstrap values in phylogenetic analysis supported the clustering of the Malaysian FAdV isolates into FAdV species E. The present study has provided a very useful reference for further studies of FAdVs in Malaysia. Vaccination strategies should be developed against FAdVs infection in commercial broiler chickens to prevent IBH outbreaks in the country

    The impact of board diversity on financial reporting quality in the GCC listed firms: the role of family and royal directors

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    The present study examines the impact of board diversity on financial reporting quality with special consideration of the extent to which family and royal directors influence financial reporting quality (FRQ). The study utilises a sample of 181 listed GCC firms over the period from 2010 to 2016. Board personal attributes, including board expertise, age, gender, and nationality are investigated along with some other board issues such as; board size, meetings, and independence. Panel data analysis with fixed and random effect models are conducted to estimate the results. The results reveal that companies with large board size and greater age have less FRQ. Further, the results report that institutional founders, higher board independence, and expertise associate with greater levels of FRQ. The results also find that board meetings and family founders negatively influence FRQ. However, female directors, foreign directors, and royal board members setting in the board did not contribute to the levels of FRQ in the sampled companies. Finally, the results indicate that companies with a CEO royal member have higher levels of FRQ however, companies with chair board royals have less levels of FRQ. This research has valuable implications for investors, board of directors, analysts, academicians, and policymakers

    Oil palm leaf fibre and its suitability for paper-based products

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    Due to the shortage of wood as origin materials for paper-based production, agro-residue materials have been explored in the quest of finding the best alternative fibre. Oil palm leaf (OPL) is one of agro-residue that has potential due to its comparable characteristics with wood fibre. Studies on chemical compositions, fibre morphology, and mechanical property of OPL have been carried out aiming to evaluate its potential as a substitute raw material for pulp and paper-based production. The chemical compositions were analysed according to the TAPPI standard, Kurscher-Hoffner and chlorite methods accordingly. The mechanical property (tensile, tearing and bursting strengths) were determined as described in TAPPI test methods. Fibre dimensions were determined using Franklin method and analysed under the optical microscope. The content of cellulose in the OPL is determined to be 43.8%. Although, this result is lower than wood fibre (53%), OPL has higher hemicellulose content (36.4%) than the wood fibre (27.5%). In addition, the lignin content (19.7%) of OPL is in the low range of those in wood resources (18 - 25%). These parameters are important components to produce good quality pulp and will provide high mechanical strength of the paper-based products. The measured fibre length of oil palm leaf (1.13 mm) is shorter than the wood fibre (1.90 mm). Meanwhile, the mechanical property of OPL showed lower indexes than wood resources, however, tear (1.80 mN.m2/g) and burst (0.95 kPa.m2/g) indexes of OPL are higher than other published and successful wood resources (Eucalyptus). Based on the analyses, the oil palm leaf is indeed a suitable alternative of raw material for pulp and paper-based industries
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