Levels of prostaglandins in the small intestine of rats during primary and secondary infection with Nippostrongylus brasiliensis

The level of PGE is increased 10-fold in intestinal tissues during primary infection of the rat with Nippostrongylus brasiliensis. Peak levels (ca. 7,000 pg/cm) were assayed in the jejunal site of infection on day 7 of infection and similar levels were recorded in 'post-infection' (ileal) segments at this time. The level of PGE in 'post-infection' segments showed further increase to 12,000 pg/cm on day 10. The level of PGE also increased in 'pre-infection' (duodenal) but this was delayed by 4-5 days. The level of PGF also increased during primary infection (from about 100 to 950 pg/cm) but this occurred after expulsion. Increase in the level of PGE occurred earlier (at 3-4 days) during secondary challenge given 19 days after primary infection, but the PGE levels followed the primary response when challenge was given 10 weeks after primary infection. It is suggested that PGE plays a dual role in parasite immunity. (1) PGE may directly affect metabolism of the parasite. In this event it is also suggested that protective antibodies cause the release of PG. (2) Elevated levels of PGE act indirectly by affecting gastrointestinal function which alters the microenvironment at the site of infection. The duodenal migration of parasites may be due to this effect of PGE.     

Milk production per cow and per hectare of spring-calving dairy cows grazing swards differing in Lolium perenne L. ploidy and Trifolium repens L. composition

Grazed grass is the cheapest feed available for dairy cows in temperate regions; thus, to maximize profits, dairy farmers must optimize the use of this high-quality feed. Previous research has defined the benefits of including white clover (Trifolium repens L.) in grass swards for milk production, usually at reduced nitrogen usage and stocking rate. The aim of this study was to quantify the responses in milk production of dairy cows grazing tetraploid or diploid perennial ryegrass (Lolium perenne L.; PRG) sown with and without white clover but without reducing stocking rate or nitrogen usage. We compared 4 grazing treatments in this study: tetraploid PRG-only swards, diploid PRG-only swards, tetraploid with white clover swards, and diploid with white clover swards. Thirty cows were assigned to each treatment, and swards were rotationally grazed at a farm-level stocking rate of 2.75 cows/ha and a nitrogen fertilizer rate of 250 kg/ha annually. Sward white clover content was 23.6 and 22.6% for tetraploid with white clover swards and diploid with white clover swards, respectively. Milk production did not differ between the 2 ploidies during this 4-yr study, but cows grazing the PRG-white clover treatments had significantly greater milk yields (+596 kg/cow per year) and milk solid yields (+48 kg/cow per year) compared with cows grazing the PRG-only treatments. The PRG-white clover swards also produced 1,205 kg of DM/ha per year more herbage, which was available for conserving and buffer feeding in spring when these swards were less productive than PRG-only swards. Although white clover is generally combined with reduced nitrogen fertilizer use, this study provides evidence that including white clover in either tetraploid or diploid PRG swards, combined with high levels of nitrogen fertilizer, can effectively increase milk production per cow and per hectare.     

Expansion of a physical function item bank and development of an abbreviated form for clinical research

We expanded an existing 33-item physical function (PF) item bank with a sufficient number of items to enable computerized adaptive testing (CAT). Ten items were written to expand the bank and the new item pool was administered to 295 people with cancer. For this analysis of the new pool, seven poorly performing items were identified for further examination. This resulted in a bank with items that define an essentially unidimensional PF construct, cover a wide range of that construct, reliably measure the PF of persons with cancer, and distinguish differences in self-reported functional performance levels. We also developed a 5-item (static) assessment form ("BriefPF") that can be used in clinical research to express scores on the same metric as the overall bank. The BriefPF was compared to the PF-10 from the Medical Outcomes Study SF-36. Both short forms significantly differentiated persons across functional performance levels. While the entire bank was more precise across the PF continuum than either short form, there were differences in the area of the continuum in which each short form was more precise: the BriefPF was more precise than the PF-10 at the lower functional levels and the PF-10 was more precise than the BriefPF at the higher levels. Future research on this bank will include the development of a CAT version, the PF-CAT.     

Meta-analysis of the effect of white clover inclusion in perennial ryegrass swards on milk production

There is increased demand for dairy products worldwide, which is coupled with the realization that consumers want dairy products that are produced in a sustainable and environmentally benign manner. Forage legumes, and white clover (Trifolium repens L.; WC) in particular, have the potential to positively influence the sustainability of pasture-based ruminant production systems. Therefore, there is increased interest in the use of forage legumes because they offer opportunities for sustainable pasture-based production systems. A meta-analysis was undertaken to quantify the milk production response associated with the introduction of WC into perennial ryegrass swards and to investigate the optimal WC content of dairy pastures to increase milk production. Two separate databases were created. In the grass-WC database, papers were selected if they compared milk production of lactating dairy cows grazing perennial ryegrass-WC (GC) swards with that of cows grazing perennial ryegrass-only swards (GO). In the WC-only database, papers were selected if they contained milk production from lactating dairy cows grazing on GC swards with varying levels of WC content. Data from both databases were analyzed using mixed models (PROC MIXED) in SAS (SAS Institute, Cary, NC). Within the grass-WC database, where mean sward WC content was 31.6%, mean daily milk and milk solids yield per cow were increased by 1.4 and 0.12 kg, respectively, whereas milk and milk solids yield per hectare were unaffected when cows grazed GC compared with GO swards. Stocking rate and nitrogen fertilizer application were reduced by 0.25 cows/ha and 81 kg/ha, respectively, on GC swards compared with GO swards. These results highlight the potential of GC production systems to achieve similar levels of production to GO systems but with reduced fertilizer nitrogen inputs, which is beneficial from both an economic and environmental point of view. In the context of increased demand for dairy products, there may be potential to increase the productivity of GC systems by increasing fertilizer nitrogen use to increase stocking rate and carrying capacity while also retaining the benefit of WC inclusion on milk production per cow.     

The effect of Lolium perenne L. ploidy and Trifolium repens L. inclusion on dry matter intake and production efficiencies of spring-calving grazing dairy cows

The objective of this study was to investigate the effect of perennial ryegrass (Lolium perenne L.; PRG) ploidy and white clover (Trifolium repens L.) inclusion on milk production, dry matter intake (DMI), and milk production efficiencies. Four separate grazing treatments were evaluated: tetraploid PRG only, diploid PRG only, tetraploid PRG with white clover, and diploid PRG with white clover. Individual DMI was estimated 8 times during the study (3 times in 2015, 2 times in 2016, and 3 times in 2017) using the n-alkane technique. Cows were, on average, 64, 110, and 189 d in milk during the DMI measurement period, corresponding to spring, summer, and autumn, respectively. Measures of milk production efficiency were total DMI/100 kg of body weight (BW), milk solids (kg of fat + protein; MSo)/100 kg of BW, solids-corrected milk/100 kg of BW, and MSo/kg of total DMI. Perennial ryegrass ploidy had no effect on DMI; however, a significant increase in DMI (+0.5 kg/cow per day) was observed from cows grazing PRG-white clover swards compared with PRG-only swards. Sward white clover content influenced DMI as there was no increase in DMI in spring (9% sward white cover content), whereas DMI was greater in summer and autumn for cows grazing PRG-white clover swards (+0.8 kg/cow per day) compared with PRG-only swards (14 and 23% sward white clover content, respectively). The greater DMI of cows grazing PRG-white clover swards led to increased milk (+1.3 kg/cow per day) and MSo (+0.10 kg/cow per day) yields. Cows grazing PRG-white clover swards were also more efficient for total DMI/100 kg of BW, solids-corrected milk/100 kg of BW, and MSo/100 kg of BW compared with cows grazing PRG-only swards due to their similar BW but higher milk and MSo yields. The results highlight the potential of PRG-white clover swards to increase DMI at grazing and to improve milk production efficiency in pasture-based systems.     

Stress in medical students

The object of this study was to examine the main stressors experienced by students in an Irish medical school and their effects on the attitude of the students towards their training. It also determined the students' knowledge of how they could receive help and their attitudes towards seeking such help. Data was collected by an anonymous self-report questionnaire distributed to a fifth year medical school class in the Hilary Term of the academic year. These 63 students had chosen medicine as a career mainly because of vocational and academic factors and almost two thirds of them had always wanted to do medicine. However four were no longer happy with that choice. Fifty-four percent of them had felt like making a complaint on at least one occasion, but did not do so. The perceived problems were mainly verbal in nature. 41% said that this had affected their attendance. The main source of perceived mistreatment was consultant staff. Rates of perceived racial and sexual discrimination were low. Other stressors included examinations, financial issues and family issues. 52% of students did not know the process by which they could make a complaint and 30% felt that seeking help or advice from staff would be damaging to their future career. This study analyses these issues and suggests ways of addressing them.     

X-ray topography of large single crystals

A requirement exists in the fabrication of certain electronic devices for non-destructive examinations of the structural perfection of large single crystals. Two X-ray topographical techniques which fulfill this requirement are described. A curved crystal transmission topography technique provides images of equivalent definition to those obtained by Lang topography, but with a very large gain in speed. This technique is restricted to the examination of flexible plates of uniform thickness and is particularly suited to silicon slices. A topographical method, incorporating an unorthodox scanning mode, has been applied to the assessment of the surface perfection of long crystals. Using this technique, crystals up to 205 mm in length have been examined on a suitably modified Lang camera of limited traverse capability.     

The Structure of Gold and Gold Alloys Produced Using High Speed Selective Jet Electrodeposition

Modern reel-to-reel plating facilities apply selective deposits of gold and gold alloys during the production of pressed copper and copper alloy or nickel-iron alloy strip components. These components are fabricated into electrical connectors or semi-conductor lead frames. Selectivity is usually achieved by the use of some form of dielectric masking. Recent developments have shown that such components may be plated with gold or gold alloys at deposition rates of up to 3.5 microns per second, selectively and without the need for masking. This paper discusses the microstructure of such deposits from studies using X-Ray diffraction and other physical testing methods and compares them with those produced under conventional deposition conditions.     

Modelling the impacts of building regulations and a property bubble on residential space and water heating

This paper develops a bottom-up model of space and water heating energy demand for new build dwellings in the Irish residential sector. This is used to assess the impacts of measures proposed in Ireland's National Energy Efficiency Action Plan (NEEAP). The impact of the housing construction boom, which resulted in 23% of occupied dwellings in 2008 having been built since 2002, and the subsequent bust, are also assessed. The model structure treats separately new dwellings added to the stock after 2007 and pre-existing occupied dwellings. The former is modelled as a set of archetype dwellings with energy end use affected by the relevant set of building regulations that apply during construction. Energy demand of existing dwellings is predicted by a simpler top down method based on historical energy use trends. The baseline scenario suggests residential energy demand will grow by 19% from 3206 ktoe in 2007 to 3810 ktoe in 2020. The results indicate that 2008 and 2010 building regulations will lead to energy savings of 305 ktoe (8.0%) in 2020. Had the 2008 building regulations been introduced in 2002, at the start of the boom, there would be additional savings of 238 ktoe (6.7%) in 2020.     

Supervisory guidance and behavioral integrity: Relationships with employee citizenship and deviant behavior.

The authors examined the effects of supervisory guidance (providing instruction to employees) and behavioral integrity (a pattern of word-deed alignment) on employee organizational citizenship behavior (OCB) and deviant behavior. Results revealed a pattern of Supervisory Guidance x Behavioral Integrity interaction effects, such that relationships between guidance and outcome variables were dependent on the level of behavioral integrity exhibited by supervisors. The interactions suggest a positive relationship between supervisory guidance and OCBs when behavioral integrity is high but also a positive relationship between guidance and deviant behavior when behavioral integrity is low. These results were consistent across 2 independent field samples: 1 assessing individual employee perceptions of supervisory behavior and the other assessing aggregate perceptions of supervisory behavior among employees in bank branches. (PsycINFO Database Record (c) 2010 APA, all rights reserved)