Off-axis crustal thickness across and along the east pacific rise within the MELT area

Wide-angle seismic data along the Mantle Electromagnetic and Tomography (MELT) arrays show that the thickness of 0.5- to 1. 5-million-year-old crust of the Nazca Plate is not resolvably different from that of the Pacific Plate, despite an asymmetry in depth and gravity across this portion of the East Pacific Rise. Crustal thickness on similarly aged crust on the Nazca plate near a magmatically robust part of the East Pacific Rise at 17 degrees15'S is slightly thinner (5.1 to 5.7 kilometers) than at the 15 degrees55'S overlapping spreading center (5.8 to 6.3 kilometers). This small north-south off-axis crustal thickness difference may reflect along-axis temporal variations in magma supply, whereas the across-axis asymmetry in depth and gravity must be caused by density variations in the underlying mantle.     

Cutaneous innervation of the thorax and abdomen of the dog

The anatomy of the cutaneous nerves innervating the canine thorax and abdomen was investigated by gross dissection of 38 dogs. Additionally, the cutaneous areas innervated by the thoracic and abdominal cutaneous nerves were mapped in a 2nd group of 33 barbiturate-anesthetized male dogs, using electrophysiologic techniques. The skin of the thorax was innervated by dorsal cutaneous branches, lateral cutaneous branches, and ventral cutaneous branches of the spinal nerves. The dorsal cutaneous branches were branches of the dorsal primary branches of spinal nerves C6 and T2 through T11. The lateral cutaneous branches were branches of the ventral primary branches of spinal nerves T2 through T12. The ventral cutaneous branches were branches of the ventral primary branches of spinal nerves T2 through T10. The skin of the abdomen was innervated by dorsal and lateral cutaneous branches of spinal nerves T12 through L3 (and occasionally L4). The cutaneous areas of the dorsal cutaneous branches occupied the dorsal half of the scapular and thoracic regions and the dorsal 2/5 of the abdominal region. The cutaneous areas of the lateral cutaneous branches covered the major portion of the ventral half of the thorax and the ventral 3/5 of the abdomen. The cutaneous areas of the ventral cutaneous branches occupied the axilla and the ventral part of the thoracic wall.     

Cellular and cytokine responses associated with dinitrofluorobenzene-induced contact hypersensitivity in the chicken

The objective of the study was to determine the cellular and cytokine responses associated with dinitrofluorobenzene (DNFB)-induced skin contact hypersensitivity (SCH), as an indicator of cell-mediated immune response, in the chicken. The thickness of the DNFB-treated foot web was increased by 6h.p.i. (hours post-induction), peaked by 24h.p.i. and then declined gradually until the lowest measurements were observed at 72h.p.i. Infiltration of eosinophils was the highest at 6 and 12h.p.i. and gradually declined by 48h.p.i. The degree of infiltration of both CD8+ and CD4+ T cells varied with mild infiltration observed at 6h.p.i., moderate to heavy infiltration observed at 12h.p.i. that persisted through 24 and 48h.p.i. and declined by 72h.p.i. Infiltration of macrophages during the study period was prominent, yet less remarkable differences were recorded between observations. Expression of interleukin (IL)-4, IL-6, IL-10 and interferon (IFN)-gamma in skin tissue was at its highest at 6h.p.i. compared to other observed time points, yet only the expression of IFN-gamma and IL-10 genes turned out to be significantly higher at 6h.p.i. compared to all other time points. In conclusion, DNFB-induced SCH in chicken was associated with an early up-regulation of cytokine genes, and infiltration of eosinophils along with macrophages, CD8+, and CD4+ T cells at the site of induction.     

Cytokine gene expression in chicken cecal tonsils following treatment with probiotics and Salmonella infection

Probiotics are currently employed for control of pathogens and enhancement of immune response in chickens. In this study, we investigated the underlying immunological mechanisms of the action of probiotics against colonization of the chicken intestine by Salmonella enterica subsp. enterica serovar Typhimurium (Salmonella serovar Typhimurium). Birds received probiotics by oral gavage on day 1 of age and, subsequently, received Salmonella serovar Typhimurium on day 2 of age. Cecal tonsils were removed on days 1, 3 and 5 post-infection (p.i.), RNA was extracted and subjected to real-time quantitative RT-PCR for measurement of interleukin (IL)-6, IL-10, IL-12 and interferon (IFN)-gamma gene expression. There was no significant difference in IL-6 and IL-10 gene expression in cecal tonsils of chickens belonging to various treatment groups. Salmonella serovar Typhimurium infection resulted in a significant increase in IL-12 expression in cecal tonsils on days 1 and 5p.i. However, when chickens were treated with probiotics prior to experimental infection with Salmonella, the level of IL-12 expression was similar to that observed in uninfected control chickens. Treatment of birds with probiotics resulted in a significant decrease in IFN-gamma gene expression in cecal tonsils of chickens infected with Salmonella compared to the Salmonella-infected birds not treated with probiotics. These findings reveal that repression of IL-12 and IFN-gamma expression is associated with probiotic-mediated reduction in intestinal colonization with Salmonella serovar Typhimurium.     

Corpus Luteum–Endometrium–Embryo Interactions in the Dairy Cow: Underlying Mechanisms and Clinical Relevance

Conception rates of dairy cows are currently declining at an estimated 1% every year. Approximately, 35% of embryos fail to prevent luteolysis during the first three weeks of gestation. Interactions between the corpus luteum, endometrium and embryo are critical to the successful establishment of pregnancy and inadequacies will result in the mortality of the embryo. For example, as little as a one day delay in the post-ovulatory rise of progesterone has serious consequences for embryo development and survival. Recently, we found that LH support, degree of vascularization and luteal cell steroidogenic capacity were not the major factors responsible for this luteal inadequacy, but are nevertheless essential for luteal development and function. Progesterone acting on its receptor in the endometrium stimulates the production of endometrial secretions on which the free-living embryo is dependent. However, their exact composition and effects of inadequate progesterone remains to be determined. The embryo is recognized through its secretion of interferon tau (IFNT), which suppresses luteolytic pulses of prostaglandin F_2α. In the cow, it is most likely that IFNT inhibits oxytocin receptor up-regulation directly and does not require the prior inhibition of oestrogen receptor α (ESR1). Unravelling the precise luteal-endometrium and embryo interactions is essential for us to understand pregnancy establishment and development of strategies to reverse the declining fertility of dairy cows.     

Simulation of the economic impact of proliferative enteritis on pig production in Australia

The economic impact of proliferative enteritis (PE) on an ‘average’ pig farm was calculated using the AUSPIG decision support system. Inputs were modelled on actual cases of PE, in which affected herds suffered from depressed growth rate, decreased feed efficiency and stock losses. The costs associated with non-haemorrhagic PE and proliferative haemorrhagic enteropathy ranged from $15/sow/yr to $141/sow/yr, respectively, depending on the clinical severity of the disease, incidence of infection and the type of medication strategy used to treat and control the disease.     

Activation of Zona‐Free Buffalo (Bubalus bubalis) Oocytes by Chemical or Electrical stimulation,and Subsequent Parthenogenetic Embryo Development

Parthenogenetic activation using zona‐free oocytes offers an alternative model that could be applied to develop protocols for the activation of reconstructed embryos for cloning. The aim of this study was to compare the efficacy of different methods for the activation of zona‐free buffalo oocytes in terms of their effects on the developmental competence of parthenogenetic embryos. The effects of zona removal on parthenogenetic activation and in vitro developmental competence of metaphase II oocytes were also examined. All activation methods were followed by incubation of 2 mm 6‐dimethylaminopurine (6‐DMAP) for 4 h. Out of three different pulse strengths (1.2, 2.1 or 3.3 kV/cm) used, 2.1 kV/cm resulted in the highest blastocyst rate (25.3%). On comparing different chemical agents and electric pulse, highest blastocyst rate was observed for calcium ionophore (CaI) (28.6%) followed by ethanol (25.0%), electric pulse (22.5%) and combined CaI and ethanol treatment (16.7%) although differences among them were not significant. Furthermore, a significantly reduced developmental potential was observed in zona‐free oocytes when compared to zona‐intact ones up to the blastocyst stage (44.3% vs 27.1%). In conclusion, zona‐free buffalo oocytes can be successfully activated for parthenogenetic development using chemical or electrical stimulation. Out of different agents examined, CaI followed by 6‐DMAP resulted in the highest blastocyst rate.