Management factors affecting the use of pasture by table chickens in extensive production systems

Whether chickens will make proper use of pasture is a problem experienced by producers of free-range and organic chickens. The aims of this project are to identify husbandry techniques and aspects of system design that encourage good pasture use. Two studies have been conducted comprising a winter and a summer flock. The aim of the winter flock was to examine the effect of outdoor artificial shelter on pasture usage. This was done for female Ross 308 birds grown to day 56, and ISA 657 birds grown to day 81. In summer, ISA 657 birds were grown to day 81. Treatments were either standard or enriched brooding, with pasture only or enriched pasture. Standard brooding was in a controlled environment house until day 42. Enriched brooding was in naturally ventilated houses in which birds had sight of pasture from an early age and access from day 21. Enriched pasture included artificial shelter, with straw bales and a conifer “wigwam” used to provide natural shelter. Chickens may be encouraged to go outdoors by brooding in a less “controlled” environment than that used for intensive broilers, and by allowing access to pasture when young. However, mortality was higher. Conifer wigwams may offer a means for more even use of pasture and better distribution of droppings

Hepatitis B immunisation : a survey of surgeons and theatre nurses

Acute viral hepatitis remains a serious condition. Its long-term sequelae include cirrhosis and hepatocellular carcinoma. Health workers constitute a high-risk group for contracting hepatitis B. A group of clinicians associated with invasive procedures and nurses working in operating theatres were invited to answer a confidential questionnaire concerning hepatitis B immunisation and the use of protective measures. A self-administered confidential questionnaire was sent to 152 clinicians and 97 theatre nurses, of whom 82 and 74 respectively responded, giving an overall response rate of 63 %. Whilst 91% of respondents considered their speciality as being of high risk for hepatitis B only 63% of them were fully immunised and of these only 51% had had their immunity tested. Out of those who checked their antibody status 19% did so following a needle stick injury. 60% of our respondents had had a needle stick injury over the past year. Even so barrier precaution techniques were used infrequently with only 17% always or at least frequently using double gloving and 10% wearing a visor during operations. Some respondents also commented on the poor availability of resources such as impermeable gowns or blunt needles which are established precautions against contamination from hepatitis B.peer-reviewe

An FeLoBAL Binary Quasar

In an ongoing infrared imaging survey of quasars at Keck Observatory, we have discovered that the z=1.285 quasar SDSS J233646.2-010732.6 comprises two point sources with a separation of 1.67". Resolved spectra show that one component is a standard quasar with a blue continuum and broad emission lines; the other is a broad absorption line (BAL) quasar, specifically, a BAL QSO with prominent absorption from MgII and metastable FeII, making it a member of the ``FeLoBAL'' class. The number of known FeLoBALs has recently grown dramatically from a single example to more than a dozen, including a gravitationally lensed example and the binary member presented here, suggesting that this formerly rare object may be fairly common. Additionally, the presence of this BAL quasar in a relatively small separation binary adds to the growing evidence that the BAL phenomenon is not due to viewing a normal quasar at a specific orientation, but rather that it is an evolutionary phase in the life of many, if not all, quasars, and is particularly associated with conditions found in interacting systems.Comment: AASTEX 13 pp., 4 figs; accepted by ApJ Letter

Effect of enzyme pre-treatments on bioactive compounds in extracted Tiger Nut oil and sugars in residual meals

Tiger nut oil is a novel oil that requires more research data on its characteristics. In this study, the oil was extracted using both enzyme-aided pressing (EAP) and aqueous enzymatic extraction (AEE) methods. Using enzymes as a pre-treatment prior to mechanical pressing increased the concentration of some phenolic acids and tocopherols present in extracted oils compared to controls. High pressure processing as a pre-treatment before aqueous enzymatic extraction also enhanced tocopherols and total polyphenolic content in oils. The percentage free fatty acid and peroxide values indicated that under the initial extraction parameters, the oils were stable and they all met the standards for virgin olive oil set by the International Olive Oil Council. Residual meals from both extraction processes contained low protein contents ranging from 2.4 to 4.6 %. Additionally, EAP and AEE meals contained low DP (degree of polymerisation) sugars that appeared as 1-kestose (DP3) and nystose (DP4). EAP had the highest total DP3 and DP4 sugar content of 82.5 mg/g. These sugars would need further assessment to verify their identity and determine their suitability as a potential food

A Configural-Cur Network Model of Animal and Human Associative Learning

test a configural-cue network model of human classification and recognition learning based on Rescorla & Wagner's (1972) model of classical conditioning. The model extends the stimulus representation assumptions from our earlier one-layer network model (Gluck & Bower, 1988b) to include pair-wise conjunctions of features as unique cues. Like the exemplar context model of Medin & Schaffer(1978), the representational assumptions of the configural-cue network model embody an implicit exponential decay relationship between stimulus similarity and and psychological (Hamming) distance, a relationship which has received substantial independent empirical and theoretical support (Shepard, 1957,1987). In addition to results from animal learning, the model accounts for several aspects of complex human category learning, including the relationship between category similarity and linear separability in determining classification difficulty (Medin &Schwanenflugel, 1981), the relationship between classification and recognition memory for instances (Hayes-Roth & Hayes-Roth, 1977), and the impact of correlated attributes on classification (Medin, Altom, Edelson, & Freko, 1982)

Effects of live-bait shrimp trawling on seagrass beds and fish bycatch in Tampa Bay, Florida

The use of live shrimp for bait in recreational fishing has resulted in a controversial fishery for shrimp in Florida. In this fishery, night collections are conducted over seagrass beds with roller beam trawls to capture live shrimp, primarily pink shrimp, Penaeus duorarum. These shrimp are culled from the catch on sorting tables and placed in onboard aerated “live” wells. Beds of turtlegrass, Thalassia testudinum, a species that has highest growth rates and biomass during summer and lowest during the winter (Fonseca et al., 1996) are predominant areas for live-bait shrimp trawling (Tabb and Kenny, 1969). Our study objectives were 1) to determine effects of a roller beam trawl on turtlegrass biomass and morphometrics during intensive (up to 18 trawls over a turtlegrass bed), short-term (3-hour duration) use and 2) to examine the mortality of bycatch finfish following capture by a trawl

Trace gas sensing using DFB laser and QCL with miniaturized 3D-printed photoacoustic gas cells

Miniaturized 3D-printed photoacoustic trace gas sensors are presented, targeting gas species with absorption features in the telecommunications band as well as the mid-infrared with recovered gas concentrations down to the parts-per-billion range