Thermal Conditions Within Pens Fitted With Differing Zone-Heating Options and Resulting Performance of Newly Weaned Pigs in a Wean-to-Finish Facility

Research was conducted to assess the effects of the type of zone heater and floor mat used in a wean-to-finish building on the thermal environment created for newly weaned pigs and resulting pig performance. Gas-fired brooder heaters were compared to electric heat lamps and farm-cut wood sheathing was compared to commercial [unheated] rubber floor mats. No consistent differences in air temperature near the heating zone were found between either of the treatments. However, black-globe temperatures in pens having gas-fired heaters and/or wood mats were consistently warmer than in their comparison pens. Temperature deviations during the 26-day study period were similar statistically for both air and black-globe temperatures (about ±2.5°F) for all treatments, as were the temperature deviations from pen to pen for all treatment combinations (±1.7°F or less). Pig health was affected by an outbreak of porcine reproductive and respiratory syndrome (PRRSV). Performance of the disease-challenged pigs was similar for the two heating systems. However, pigs in pens having wood sheathing on the floor below the zone heater consumed more feed on a daily basis than those resting on rubber mats. This evidence supports statistically significant (P\u3c0.05) advantages for the wood mats in pig weight (+3%) and average daily gain (+6%) over the 26-day study period. Feed-to-gain ratios over this same time period were similar for all treatments. The fact that there was greater radiant heating (as indicated by warmer black-globe temperatures) with gas-fired heaters in this study suggests that extra adjustments in heater height and gas pressure may have been needed to obtain equivalent heating effects, and that additional information on placement and adjustment of zone heaters also would be useful to producers. The data collected in this study and associated experience of farm management imply that producers can develop an similarly stable thermal environment for nursery pigs using either electric heat lamps or gas-fired brooder heaters. The improved heating effect and pig performance observed in this study with floor mats made from wood sheathing have positive practical implications. Sheets of wood sheathing are readily available from many local lumber suppliers and hardware stores and can be purchased at a fraction of the price of commercial rubber mats. A small amount of labor is required to quarter the sheets, and we don’t recommend re-using the wood mats. But, the results of this study suggest that wood sheathing should be investigated further as a floor-mat option

Poisson's Ratios and Volume Changes for Plastically Orthotropic Material

Measurements of Poisson's ratios have been made in three orthogonal directions on aluminum alloy blocks in compression and on stainless-steel sheet in both tension and compression. These measurements, as well as those obtained by density determinations, show that there is no permanent plastic change in volume within the accuracy of observation. A method is suggested whereby a correlation may be effected between the measured individual values of the Poisson's ratios and the stress-strain curves for the material. Allowance must be made for the difference in the stress-strain in tension and compression; this difference, wherever it appears, is accompanied by significant changes in the Poisson's ratios

Down-regulation of human topoisomerase IIα expression correlates with relative amounts of specificity factors Sp1 and Sp3 bound at proximal and distal promoter regions

<p>Abstract</p> <p>Background</p> <p>Topoisomerase IIα has been shown to be down-regulated in doxorubicin-resistant cell lines. The specificity proteins Sp1 and Sp3 have been implicated in regulation of topoisomerase IIα transcription, although the mechanism by which they regulate expression is not fully understood. Sp1 has been shown to bind specifically to both proximal and distal GC elements of the human topoisomerase IIα promoter <it>in vitro</it>, while Sp3 binds only to the distal GC element unless additional flanking sequences are included. While Sp1 is thought to be an activator of human topoisomerase IIα, the functional significance of Sp3 binding is not known. Therefore, we sought to determine the functional relationship between Sp1 and Sp3 binding to the topoisomerase IIα promoter <it>in vivo</it>. We investigated endogenous levels of Sp1, Sp3 and topoisomerase IIα as well as binding of both Sp1 and Sp3 to the GC boxes of the topoisomerase IIα promoter in breast cancer cell lines <it>in vivo </it>after short term doxorubicin exposure.</p> <p>Results</p> <p>Functional effects of Sp1 and Sp3 were studied using transient cotransfection assays using a topoisomerase IIα promoter reporter construct. The <it>in vivo </it>interactions of Sp1 and Sp3 with the GC elements of the topoisomerase IIα promoter were studied in doxorubicin-treated breast cancer cell lines using chromatin immunoprecipitation assays. Relative amounts of endogenous proteins were measured using immunoblotting. <it>In vivo </it>DNA looping mediated by proteins bound at the GC1 and GC2 elements was studied using the chromatin conformation capture assay. Both Sp1 and Sp3 bound to the GC1 and GC2 regions. Sp1 and Sp3 were transcriptional activators and repressors respectively, with Sp3 repression being dominant over Sp1-mediated activation. The GC1 and GC2 elements are linked <it>in vivo </it>to form a loop, thus bringing distal regulatory elements and their cognate transcription factors into close proximity with the transcription start site.</p> <p>Conclusion</p> <p>These observations provide a mechanistic explanation for the modulation of topoisomerase IIα and concomitant down-regulation that can be mediated by topoisomerase II poisons. Competition between Sp1 and Sp3 for the same cognate DNA would result in activation or repression depending on absolute amounts of each transcription factor in cells treated with doxorubicin.</p

The effect of air injection at the exhaust ports of a gasoline engine on the oxides of nitrogen emissions

The importance of automobile exhaust as a source of atmospheric pollutants has been recognized for several years. With the control of stationary sources in geographic areas such as Los Angeles County, the automobile has become the major uncontrolled source of air pollution. The three major pollutants emitted by automobiles are unburned hydrocarbons, carbon monoxide, and oxides of nitrogen. Seventy percent of the emissions are from the exhaust. Maximum emission standards of 275 ppm hydrocarbons as n-hexane and 1.5 mole percent carbon monoxide in automotive exhaust have been enacted in California. Control measures for the oxides of nitrogen may possibly be effective for 1970 model vehicles. Exhaust control devices for hydrocarbon and carbon monoxide emissions submitted to the California Motor Vehicle Pollution Control Board for approval have included catalytic converters, direct-flame afterburners, engine modification systems, and secondary air injection at the exhaust port systems. Three of the automobile manufactures may use the fourth system which involves introduction of secondary air into the engine exhaust ports to promote flameless oxidation of hydrocarbons and carbon monoxide to carbon dioxide and water. Since this control system introduces air to the high temperature exhaust gases at the exhaust port, the question arises whether oxides of nitrogen might be formed. This would be detrimental from the outlook that oxides of nitrogen must be controlled. The purpose of this work was to determine the effects on the emissions of oxides of nitrogen from a gasoline engine by the installation and operation of an exhaust port secondary air injection system. The engine under test, given to Oregon State University by the Ford Motor Company, was installed in a vehicle and operated on a chassis dynamometer. Measurements of oxides of nitrogen emissions with and without the air injection system in operation were made both during steady state and transient conditions. For transient measurements, the vehicle was operated on the California seven-mode test cycle. Oxides of nitrogen samples were taken by a progressive grab sampling technique and analyzed with an absorption spectrophotom eter built at Oregon State University. Further measurements included unburned hydrocarbon, carbon monoxide, and carbon dioxide analyses with commercial non-dispersive infrared analyzers and total carbon measurement with a commercial hydrogen flame ionization analyzer. These analyses were made for the purpose of determining air dilution factors and correlating data with other work being done in the field. The results of the investigation are summarized as follows: 1) The addition of secondary air at the exhaust ports in creased the oxides of nitrogen emissions during acceleration for both rich and lean mixture operation. As high as 40 percent in crease occurred during operation with the rich carburetor. Appreciable increase also occurred during high speed steady state cruise conditions with the rich carburetor. Weighted average concentrations of NO[subscript x] for operation on the California cycle were not determined. 2) The grab sampling and spectrophotometric analysis methods for the oxides of nitrogen worked well during the testing. However, the time required to take a grab sample, three seconds, was too long to obtain instantaneous analysis. Sampling probes should be located closer to the engine to avoid mixing of exhaust from separate modes in the exhaust pipe prior to analysis. 3) Temperatures in the exhaust manifold were not markedly changed by the injection of secondary air into the exhaust ports. However, temperatures were 50 to 100° F higher at the end of the tailpipe due to increased exhaust mass flow rate. 4) The vehicle with the air system installed met California standards for operation with the rich carburetor, but emitted a higher concentration of unburned hydrocarbons than the standard during operation with the lean carburetor

Streets, Railroads, and the Great Strike of 1877

International audienc

Regulation of protein O-glycosylation by the endoplasmic reticulum–localized molecular chaperone Cosmc

Regulatory pathways for protein glycosylation are poorly understood, but expression of branchpoint enzymes is critical. A key branchpoint enzyme is the T-synthase, which directs synthesis of the common core 1 O-glycan structure (T-antigen), the precursor structure for most mucin-type O-glycans in a wide variety of glycoproteins. Formation of active T-synthase, which resides in the Golgi apparatus, requires a unique molecular chaperone, Cosmc, encoded on Xq24. Cosmc is the only molecular chaperone known to be lost through somatic acquired mutations in cells. We show that Cosmc is an endoplasmic reticulum (ER)–localized adenosine triphosphate binding chaperone that binds directly to human T-synthase. Cosmc prevents the aggregation and ubiquitin-mediated degradation of the T-synthase. These results demonstrate that Cosmc is a molecular chaperone in the ER required for this branchpoint glycosyltransferase function and show that expression of the disease-related Tn antigen can result from deregulation or loss of Cosmc function

Assessment of Ventilation Management Training Workshops

To achieve optimum swine performance, producer understanding of environmental control systems in mechanically or naturally ventilated facilities is extremely important. A ventilation workshop: “Managing Your Unseen Employee: The Ventilation System” was established. The primary objective of the training was to give swine producers and managers enough quality information so they could go back to their operations and properly assess their own ventilation systems and make appropriate adjustments as needed. The training workshops were established to be a multi-state and multi-disciplinary effort between South Dakota, Nebraska, Iowa and Minnesota universities. Ag engineers and animal scientists from each state participated in developing the workshop materials and delivery of the program. Four basic needs emerged that would enhance program delivery. These needs included basic environmental factors and their effects on pigs, ventilation system design principles, trouble-shooting ventilation problems, and hands-on demonstrations of instrumentation and ventilation equipment. A 1.8 m by 2.4 m by 2.4 m mobile ventilation room was used for the hands-on training. The mobile ventilation room was equipped with two variable-speed, 30-centimeter fans and one 30-cm, single-speed fan; a four-stage controller; and three types of air inlets. From 2002 to 2007, over 1000 people producing over 20 million pigs participated in more than 60 workshops. The backgrounds of participants included managers, feed consultants, extension educators, and veterinarians. Key points gained by producers included proper ventilation settings, trouble-shooting techniques, temperature control, and the effects of static pressure on airflow

The Real World of Ventilation Troubleshooting: A Swine Case Study

Swine finishing facility ventilation has become relatively complex and is often mismanaged as a system. One of the few ways to truly understand these systems is to spend time systematically going through the many components of the building. To learn to help producers better, a team of university Extension specialists that included agricultural engineers and animal scientists spent an extended period carefully documenting conditions in a deep-pit swine finishing building with two 1,000-head rooms. Exhaust fans in the pit and walls operated at various stages throughout the year as a negative-pressure ventilation system. A computerized controller activated exhaust fans, a ventilation curtain actuator, and heaters. Gravity baffled ceiling inlets were evenly spaced in the building to provide good air distribution during cold and mild weather conditions. Following the review of current conditions and operating parameters, performance deficiencies were identified and recommendations were given regarding controller settings, inlet settings, and curtain management. The overall operating characteristics of the ventilation system and air quality in the animal space were documented ventilation and related management changes were discussed with the owner/operator