Simplified Method for Efficient Intravascular Inoculation of Chicken Embryos

The simple syringe-stabilizer unit described in this note provides a means for rapid intravascular inoculation of embryonated chicken eggs with minimal embryonic death from vascular trauma

Sanitation of Feedlot Soil

The topic is the sanitation of feedlot soil due to the presence of coliform bacteria from feces and naturally occurring in the soil. This bacteria can caused diarrhea in lambs, calves and piglets. This article reviews a study on this topic that was conducted in the Fall of 1979 at NDSU in the Departments of Veterinary Science and Bacteriology

Incidence of Ovine Progressive Pneumonia in the North Dakota State University Sheep Flocks, Determined by Agar-gel Immunodiffusion

In 1968, the causative agent of OPP, ovine progressive pneumonia virus (PPV) or Lunger's Disease was first isolated in the United States. A serological test, agar-gel imuno-diffusion (AGID) was applied for the detection of precipitating antibodies aginst PPV in sheep sera (colostrum-whey) against PPV is indicative of infection. But, antibodies are evidently play no part in fighting infection. By the time taht antibodies are produced, the virus is residing intracellularly and is unattainable to antibodies. The article gives a description of the symptoms and effects of the disease. The objective of this study was to characterize the extent of OPP in a naturally infected sheep flock by AGID, to determine whether differences in age or breed of the sheep influences the susceptibility to OPP and to attempt to establish an OPP-free from an infected source flock. The incidence of ovine progressive pneumonia by breed and age in a naturally infected flock was determined. An ovine progressive pneumonia free flock was established five years prior

More than 20 degrees posterior tilt of the femoral head in undisplaced femoral neck fractures results in a four times higher risk of treatment failure

Purpose In this study, we aimed to determine the correlation between the preoperative posterior tilt of the femoral head and treatment failure in patients with a Garden type I and II femoral neck fracture (FNF) treated with the dynamic locking blade plate (DLBP). Methods Preoperative posterior tilt was measured in a prospective documented cohort of 193 patients with a Garden type I and II FNF treated with the DLBP. The correlation between preoperative posterior tilt and failure, defined as revision surgery because of avascular necrosis, non-union, or cut-out, was analyzed. Results Patients with failed fracture treatment (5.5%) had a higher degree of posterior tilt on the initial radiograph than the patients with uneventful healed fractures: 21.4 degrees and 13.8 degrees, respectively (p = 0.03). The failure rate was 3.2% for Garden type I and II FNF with a posterior tilt = 20 degrees. A posterior tilt of >= 20 degrees was associated with an odds ratio of 4.24 (95% CI 1.09-16.83; p = 0.04). Conclusion Garden type I and II FNFs with a significant preoperative posterior tilt (>= 20 degrees) seem to behave like unstable fractures and have a four times higher risk of failure. Preoperative posterior tilt >= 20 degrees of the femoral head should be considered as a significant predictor for failure of treatment in Garden type I and II FNFs treated with the DLBP.Trauma Surger

Southern Hemisphere bog persists as a strong carbon sink during droughts

Peatland ecosystems have been important global carbon sinks throughout the Holocene. Most of the research on peatland carbon budgets and effects of variable weather conditions has been done in Northern Hemisphere Sphagnum-dominated systems. Given their importance in other geographic and climatic regions, a better understanding of peatland carbon dynamics is needed across the spectrum of global peatland types. In New Zealand, much of the historic peatland area has been drained for agriculture but little is known about rates of carbon exchange and storage in unaltered peatland remnants that are dominated by the jointed wire-rush, Empodisma robustum. We used eddy covariance to measure ecosystem-scale CO₂ and CH₄ fluxes and a water balance approach to estimate the sub-surface flux of dissolved organic carbon from the largest remaining raised peat bog in New Zealand, Kopuatai bog. The net ecosystem carbon balance (NECB) was estimated over four years, which included two drought summers, a relatively wet summer, and a meteorologically average summer. In all measurement years, the bog was a substantial sink for carbon, ranging from 134.7 gC m⁻² yr⁻¹ to 216.9 gC m⁻² yr⁻¹, owing to the large annual net ecosystem production (−161.8 to −244.9 gCO2-C m⁻² yr⁻¹). Annual methane fluxes were large relative to most Northern Hemisphere peatlands (14.2 to 21.9 gCH4-C  m⁻² yr⁻¹1), although summer and autumn emissions were highly sensitive to dry conditions leading to very predictable seasonality according to water table position. The annual flux of dissolved organic carbon was similar in magnitude to methane emissions but less variable, ranging from 11.7 to 12.8 gC m⁻² yr⁻¹. Dry conditions experienced during late summer droughts led to significant reductions in annual carbon storage, which resulted nearly equally from enhanced ecosystem respiration due to lowered water tables and increased temperatures, and from reduced gross primary production due to vapor pressure deficit-related stresses to the vegetation. However, the net C uptake of Kopuatai bog during drought years was large relative to even the maximum reported NECB from Northern Hemisphere bogs. Furthermore, GWP fluxes indicated the bog was a strong sink for greenhouse gases in all years despite the relatively large annual methane emissions. Our results suggest that adaptations of E. robustum to dry conditions lead to a resilient peatland drought response of the NECB

Megacrystals track magma convection between reservoir and surface

Active volcanoes are typically fed by magmatic reservoirs situated within the upper crust. The development of thermal and/or compositional gradients in such magma chambers may lead to vigorous convection as inferred from theoretical models and evidence for magma mixing recorded in volcanic rocks. Bi-directional flow is also inferred to prevail in the conduits of numerous persistently-active volcanoes based on observed gas and thermal emissions at the surface, as well as experiments with analogue models. However, more direct evidence for such exchange flows has hitherto been lacking. Here, we analyse the remarkable oscillatory zoning of anorthoclase feldspar megacrystals erupted from the lava lake of Erebus volcano, Antarctica. A comprehensive approach, combining phase equilibria, solubility experiments and melt inclusion and textural analyses shows that the chemical profiles are best explained as a result of multiple episodes of magma transport between a deeper reservoir and the lava lake at the surface. Individual crystals have repeatedly travelled up-and-down the plumbing system, over distances of up to several kilometers, presumably as a consequence of entrainment in the bulk magma flow. Our findings thus corroborate the model of bi-directional flow in magmatic conduits. They also imply contrasting flow regimes in reservoir and conduit, with vigorous convection in the former (regular convective cycles of ∼150 days at a speed of ∼0.5 mm s−1) and more complex cycles of exchange flow and re-entrainment in the latter. We estimate that typical, 1-cm-wide crystals should be at least 14 years old, and can record several (from 1 to 3) complete cycles between the reservoir and the lava lake via the conduit. This persistent recycling of phonolitic magma is likely sustained by CO2 fluxing, suggesting that accumulation of mafic magma in the lower crust is volumetrically more significant than that of evolved magma within the edifice.The work reported here has been partially supported by the National Science Foundation (Division of Polar Programs) under grant ANT1142083. The authors thank the Natural Environment Research Council (NERC) for access to the NERC Ion Microprobe Facility (Grant IMF453/1011) and Richard Hinton for invaluable help with SIMS analyses. Y.M. acknowledges support from the Cambridge Philosophical Society, the University of Cambridge Home and EU Scholarship Scheme, and the Philip Lake and William Vaughan Lewis funds from the Department of Geography, University of Cambridge. Y.M. also acknowledges support from ERC grant #279790.This is the final published version. It first appeared at http://www.sciencedirect.com/science/article/pii/S0012821X14007833#

Changes in soil carbon stocks of New Zealand’s grazed pasture in response to variations in management and environmental factors.

Dairy farming is New Zealand‟s pre-eminent primary industry. It achieves large export earnings but is also responsible for a large proportion of the country‟s greenhouse gas emissions. One of those greenhouse gases is CO₂, and in order to lower New Zealand‟s net greenhouse gas emissions, it is important to identify any management options that can lead to carbon sequestration in pasture soils and thereby minimise net CO₂ emissions to the atmosphere. It is equally important to understand what factors could lead to losses of soil carbon from pasture soils and thereby add further to New Zealand‟s CO₂ emissions. We addressed these questions by using two years of observations from an eddy-covariance system on a dairy farm in the Waikato that provided estimates of the exchanges of water and CO₂ with the atmosphere. We used CenW 4.1, a process-based ecosystem model, to describe these observations in terms of their biophysical drivers and the interactions between them. Agreement between the model and observations was excellent, especially for evapotranspiration and net photosynthesis, for which 91% and 79% of observed daily variations could be explained. The validated model was then used to run different scenarios to assess the effects on soil organic carbon of changes in the application of fertiliser and irrigation water, grazing scheduling, differences in plant-internal resource allocation, and changes in temperature and CO₂ concentration. We found that it was important to consider the combined effect of changes in net primary production, the amount of carbon taken off-site through grazing, the proportion of carbon allocated to pools, especially pools in the soil, that facilitates the stabilisation of carbon in organic matter, and any changes in the rate of organic matter decomposition. Soil organic carbon stocks were positively correlated with rates of fertiliser application and with the rate of water application (rain or irrigation) up to some moderate water application rates. For other changes in key properties, changes in soil organic carbon were often negatively correlated with changes in milk production. That was clearly evident for changes in the grazing regime and in plant root:shoot ratios. Anticipated environmental changes, such as increases in temperature and CO₂ concentration, and both increases and decreases in precipitation from moderate values had either neutral or detrimental effects on soil organic carbon stocks. Milk production was generally more positively affected under most environmental changes