405 research outputs found
Keeper-animal interactions: differences between the behaviour of zoo animals affect stockmanship
Stockmanship is a term used to describe the management of animals with a good stockperson someone who does this in a in a safe, effective, and low-stress manner for both the stock-keeper and animals involved. Although impacts of unfamiliar zoo visitors on animal behaviour have been extensively studied, the impact of stockmanship i.e familiar zoo keepers is a new area of research; which could reveal significant ramifications for zoo animal behaviour and welfare. It is likely that different relationships are formed dependant on the unique keeper-animal dyad (human-animal interaction, HAI). The aims of this study were to (1) investigate if unique keeper-animal dyads were formed in zoos, (2) determine whether keepers differed in their interactions towards animals regarding their attitude, animal knowl- edge and experience and (3) explore what factors affect keeper-animal dyads and ultimately influence animal behaviour and welfare. Eight black rhinoceros (Diceros bicornis), eleven Chapman’s zebra (Equus burchellii), and twelve Sulawesi crested black macaques (Macaca nigra) were studied in 6 zoos across the UK and USA. Subtle cues and commands directed by keepers towards animals were identified. The animals latency to respond and the respective behavioural response (cue-response) was recorded per keeper-animal dyad (n=93). A questionnaire was constructed following a five-point Likert Scale design to record keeper demographic information and assess the job satisfaction of keepers, their attitude towards the animals and their perceived relationship with them. There was a significant difference in the animals’ latency to appropriately respond after cues and commands from different keepers, indicating unique keeper-animal dyads were formed. Stockmanship style was also different between keepers; two main components contributed equally towards this: “attitude towards the animals” and “knowledge and experience of the animals”. In this novel study, data demonstrated unique dyads were formed between keepers and zoo animals, which influenced animal behaviour
Craig Goch Report No. 14 The production of juvenile Atlantic salmon (Salmo salar L.) in the Upper Wye, Wales
Apart from the work of Egglishaw (1970) there are few data available on the production of Atlantic salmon (Salmo salar L.) in freshwaters. Stream studies on salmon are generally confined to the enumeration of smolts (Elson, 1957a; Meister, 1962; Jessop, 1975). In contrast, the production of brown trout (S. trutta L.), brook trout (Salvelinus fontinalis Mitchill) and coho salmon (Oncorhynchus kisutch Walbaum) is well documented (Allen, 1951; Hunt 1974; Chapman, 1965).
This paper reports estimates of salmon production (sensu Ivlev, 1966) in 16 study sites in 16 study sites in the upper catchment of the River Wye over a two year period and forms part of a broader study of fish populations in the Wye
Craig Goch Report No. 10 The effect of density on mortality in juvenile Atlantic salmon (Salmo salar L.)
Le Cren (1973) suggested that the most likely population-regulating process in salmonid populations is density-dependent territorial behaviour. Thus, in trout (Salmo trutta L.) populations aggressive territorial behaviour was manifested in density-dependent mortality and the size of the adult stock was largely dependent on the area of suitable rearing ground for the fry (Le Cren, 1973). Ricker (1954) also concluded that in most fish populations compensatory mortality in the juvenile stages, rather than in the mature stock, was of greatest importance as a regulator of population size. The nature of such regulating mechanisms in juvenile populations is, therefore, of fundamental importance in the understanding of the dynamics of fish populations and the implementation of management policies.
This paper considers mortality rates of young Atlantic salmon (Salmo salar L.) in the upper catchment of the R. Wye over a two year period. The work forms part of a broader study of fish populations in the R. Wye
Overview of the design of the ITER heating neutral beam injectors
The heating neutral beam injectors (HNBs) of ITER are designed to deliver 16.7MWof 1 MeVD0 or
0.87 MeVH0 to the ITER plasma for up to 3600 s. They will be the most powerful neutral beam\uf0a0(NB)
injectors ever, delivering higher energy NBs to the plasma in a tokamak for longer than any previous
systems have done. The design of the HNBs is based on the acceleration and neutralisation of negative
ions as the efficiency of conversion of accelerated positive ions is so low at the required energy that a
realistic design is not possible, whereas the neutralisation ofH 12 andD 12 remains acceptable ( 4856%).
The design of a long pulse negative ion based injector is inherently more complicated than that of
short pulse positive ion based injectors because:
\u2022 negative ions are harder to create so that they can be extracted and accelerated from the ion source;
\u2022 electrons can be co-extracted from the ion source along with the negative ions, and their
acceleration must be minimised to maintain an acceptable overall accelerator efficiency;
\u2022 negative ions are easily lost by collisions with the background gas in the accelerator;
\u2022 electrons created in the extractor and accelerator can impinge on the extraction and acceleration
grids, leading to high power loads on the grids;
\u2022 positive ions are created in the accelerator by ionisation of the background gas by the accelerated
negative ions and the positive ions are back-accelerated into the ion source creating a massive power
load to the ion source;
\u2022 electrons that are co-accelerated with the negative ions can exit the accelerator and deposit power on
various downstream beamline components.
The design of the ITER HNBs is further complicated because ITER is a nuclear installation which
will generate very large fluxes of neutrons and gamma rays. Consequently all the injector components
have to survive in that harsh environment. Additionally the beamline components and theNBcell,
where the beams are housed, will be activated and all maintenance will have to be performed remotely.
This paper describes the design of theHNBinjectors, but not the associated power supplies, cooling
system, cryogenic system etc, or the high voltage bushingwhich separates the vacuum of the beamline
fromthehighpressureSF6 of the high voltage (1MV) transmission line, through which the power, gas and
coolingwater are supplied to the beam source. Also themagnetic field reduction system is not described
Discovery, activity and characterisation of an AA10 lytic polysaccharide oxygenase from the shipworm symbiont Teredinibacter turnerae
Background: The quest for novel enzymes for cellulosic biomass-degradation has recently been focussed on lytic polysaccharide monooxygenases (LPMOs/PMOs), Cu-containing proteins that catalyse the oxidative degradation of otherwise recalcitrant polysaccharides using O2 or H2O2 as a co-substrate. Results: Although classical saprotrophic fungi and bacteria have been a rich source of lytic polysaccharide monooxy genases (LPMOs), we were interested to see if LPMOs from less evident bio-environments could be discovered and assessed for their cellulolytic activity in a biofuel context. In this regard, the marine shipworm Lyrodus pedicellatus represents an interesting source of new enzymes, since it must digest wood particles ingested during its natural tunnel boring behaviour and plays host to a symbiotic bacterium, Teredinibacter turnerae, the genome of which has revealed a multitude of enzymes dedicated to biomass deconstruction. Here, we show that T. turnerae encodes a cellulose-active AA10 LPMO. The 3D structure, at 1.4 Å resolution, along with its EPR spectrum is distinct from other AA10 polysaccharide monooxygenases insofar as it displays a “histidine-brace” catalytic apparatus with changes to the surrounding coordination sphere of the copper. Furthermore, TtAA10A possesses a second, surface accessible, Cu site 14 Å from the classical catalytic centre. Activity measurements show that the LPMO oxidises cellulose and thereby signifcantly augments the rate of degradation of cellulosic biomass by classical glycoside hydrolases. Conclusion: Shipworms are wood-boring marine molluscs that can live on a diet of lignocellulose. Bacterial sym bionts of shipworms provide many of the enzymes needed for wood digestion. The shipworm symbiont T. turnerae produces one of the few LPMOs yet described from the marine environment, notably adding to the capability of shipworms to digest recalcitrant polysaccharides
Large magnetoresistance by Pauli blockade in hydrogenated graphene
We report the observation of a giant positive magnetoresistance in millimetre
scale hydrogenated graphene with magnetic field oriented in the plane of the
graphene sheet. A positive magnetoresistance in excess of 200\% at a
temperature of 300 mK was observed in this configuration, reverting to negative
magnetoresistance with the magnetic field oriented normal to the graphene
plane. We attribute the observed positive, in-plane, magnetoresistance to
Pauli-blockade of hopping conduction induced by spin polarization. Our work
shows that spin polarization in concert with electron-electron interaction can
play a dominant role in magnetotransport within an atomic monolayer.Comment: 6 pages, 3 figures, and supplemental informatio
Discovery and characterization of a new family of lytic polysaccharide monooxygenases
Lytic polysaccharide monooxygenases (LPMOs) are a recently discovered class of enzymes capable of oxidizing recalcitrant polysaccharides. They are attracting considerable attention owing to their potential use in biomass conversion, notably in the production of biofuels. Previous studies have identified two discrete sequence-based families of these enzymes termed AA9 (formerly GH61) and AA10 (formerly CBM33). Here, we report the discovery of a third family of LPMOs. Using a chitin-degrading exemplar from Aspergillus oryzae, we show that the three-dimensional structure of the enzyme shares some features of the previous two classes of LPMOs, including a copper active center featuring the 'histidine brace' active site, but is distinct in terms of its active site details and its EPR spectroscopy. The newly characterized AA11 family expands the LPMO clan, potentially broadening both the range of potential substrates and the types of reactive copper-oxygen species formed at the active site of LPMOs
Frequent range visits further from the shed relate positively to free-range broiler chicken welfare
Little is known about the implications of accessing an outdoor range for broiler chicken welfare, particularly in relation to the distance ranged from the shed. Therefore, we monitored individual ranging behaviour of commercial free-range broiler chickens and identified relationships with welfare indicators. The individual ranging behaviour of 305 mixed-sex Ross 308 broiler chickens was tracked on a commercial farm from the second day of range access to slaughter age (from 16 to 42 days of age) by radio frequency identification (RFID) technology. The radio frequency identification antennas were placed at pop-holes and on the range at 2.7 and 11.2 m from the home shed to determine the total number of range visits and the distance ranged from the shed. Chickens were categorised into close-ranging (CR) or distant-ranging (DR) categories based on the frequency of visits less than or greater than 2.7 m from the home shed, respectively. Half of the tracked chickens (n=153) were weighed at 7 days of age, and from 14 days of age their body weight, foot pad dermatitis (FPD), hock burn (HB) and gait scores were assessed weekly. The remaining tracked chickens (n=152) were assessed for fear and stress responses before (12 days of age) and after range access was provided (45 days of age) by quantifying their plasma corticosterone response to capture and 12 min confinement in a transport crate followed by behavioural fear responses to a tonic immobility (TI) test. Distant-ranging chickens could be predicted based on lighter BW at 7 and 14 days of age (P=0.05), that is before range access was first provided. After range access was provided, DR chickens weighed less every week (P=0.001), had better gait scores (P=0.01) and reduced corticosterone response to handling and confinement (P
A Cage Is a Cage, Unless You Educate. Rhetoric Negatively Impacts Support for a Novel Housing System for Laying Hens Unless the Public Are Educated
It has been proposed that terminology on commercially available eggs can impact the manner in which the eggs are discussed and ultimately consumer support. In this paper we tested if the label of 'furnished cage' eggs is a barrier for its support in Australia. Furthermore, we examined if educational interventions could change support and the way furnished cages were discussed. Survey participants (n = 1,157) were recruited by a stratified random sample of Australian adults. The participants were surveyed on their demographics, attitudes toward the poultry industry and animal welfare, and their egg buying behavior. Participants were randomly assigned to one of four treatment groups" two control groups and two educational groups. Participants were shown one of three videos, the control groups were shown a video with general information about chickens, the educated groups were shown one of two almost identical videos that educated them on aspects of the egg-laying industry in Australia, and the welfare implications of different housing systems including furnished systems. The only difference between the two educational videos was the name given to the furnished housing system" one group was introduced to furnished cages, the other was introduced to furnished coops. Educated participants were more likely to support furnished eggs and discuss them more positively than the control groups. When asked to discuss their support for furnished systems, control group participants exposed to the term cage were more likely to discuss the impacts of caged environments than the other treatment groups. The study suggests any negative impacts of housing system terminology can be mitigated through educational interventions
- …