Space shuttle orbiter auxiliary power unit development challenges

When the flying spacecraft was approved for development, a power unit for the hydraulic system had to be developed. Unlike other systems on the orbiter, there was no precedent in earlier spacecraft for a hydraulic system nor for the power unit to drive the hydraulic pumps. The only prototypes available were airplane auxiliary power units (APU), which were not required to operate in the severe environments of a spacecraft nor to have the longevity of an orbiter hydraulic power unit. The challenge was to build a hydraulic power unit which could operate in 0g or 3g, in a vacuum or at sea level pressure, and at -65 F or 225 F, which would be capable of restarting while hot, and which would be capable of sustaining the hydraulic loads for the life of the orbiter. The basic approach to providing hydraulic power for the orbiter was to use a small, high speed, monopropellant fueled turbine power unit to drive a conventional aircraft type hydraulic pump. The stringent requirements imposed on the orbiter APU quickly made this machine different from existing aircraft APUs

Communication

Section on "Communication" from Encyclopedia of Applied Animal Behaviour and Welfar

The role of contextual constraints and chronic expectancies on behavior categorizations and dispositional inferences

The authors examined the roles of chronic expectancies and other contextual information in the dispositional inference process within the domain of ability judgments. Prior to viewing a videotaped performance under either cognitive load or no load, participants in Studies 1 and 2 were given additional information designed to constrain their categorizations of the performance. In Study 2, chronic future-event expectancies also were assessed. Analyses revealed that when under cognitive load, participants' ability inferences were assimilated to the constraint information (Studies 1 and 2) and to chronic expectancies (Study 2). Furthermore, Study 2 analyses revealed that these effects were mediated by participants' behavior categorizations. Evidence suggestive of a proceduralized form of correction for task difficulty (Studies 1 and 2) and an effortful, awareness-based correction for the constraint information and for chronic expectancies also was found. Results are examined in light of recent models of the dispositional inference process

A Scientific Conception of Animal Welfare that Reflects Ethical Concerns

Scientific research on \u27animal welfare\u27 began because of ethical concerns over the quality of life of animals, and the public looks to animal welfare research for guidance regarding these concerns. The conception of animal welfare used by scientists must relate closely to these ethical concerns if the orientation of the research and the interpretation of the findings is to address them successfully. At least three overlapping ethical concerns are commonly expressed regarding the quality of life of animals: (1) that animals should lead natural lives through the development and use of their natural adaptations and capabilities, (2) that animals should feel well by being free from prolonged and intense fear, pain, and other negative states, and by experiencing normal pleasures, and (3) that animals should function well, in the sense of satisfactory health, growth and normal functioning of physiological and behavioural systems. Various scientists have proposed restricted conceptions of animal welfare that relate to only one or other of these three concerns. Some such conceptions are based on value positions about what is truly important for the quality of life of animals or about the nature of human responsibility for animals in their care. Others are operational claims: (1) that animal welfare research must focus on the functioning of animals because subjective experiences fall outside the realm of scientific enquiry, or (2) that studying the functioning of animals is sufficient because subjective experiences and functioning are closely correlated. We argue that none of these positions provides fully satisfactory guidance for animal welfare research. We suggest instead that ethical concerns about the quality of life of animals can be better captured by recognizing three classes of problems that may arise when the adaptations possessed by an animal do not fully correspond to the challenges posed by its current environment. (1) If animals possess adaptations that no longer serve a significant function in the new environment, then unpleasant subjective experiences may arise, yet these may not be accompanied by significant disruption to biological functioning. Thus, a bucket-fed calf may experience a strong, frustrated desire to suck, even though it obtains adequate milk. (2) If the environment poses challenges for which the animal has no corresponding adaptation, then functional problems may arise, yet these may not be accompanied by significant effects on subjective feelings. Thus, a pig breathing polluted air may develop lung damage without appearing to notice or mind the problem. (3) Where animals have adaptations corresponding to the kinds of environmental challenges they face, problems may still arise if the adaptations prove inadequate. For example, an animal\u27s thermoregulatory adaptations may be insufficient in a very cold environment such that the animal both feels poorly and functions poorly. We propose that all three types of problems are causes of ethical concern over the quality of life of animals and that they together define the subject matter of animal welfare science

Conflict and Cooperation: Sociobiological Principles and the Behaviour of Pigs

The pig provides many examples of how principles of behavioural ecology and sociobiology can lead to insights into farm animal behaviour. According to parent-offspring conflict theory, parents should tend to give a level of parental investment somewhat below that solicited by the young. When closely confined during lactation, sows can do little to limit the amount of contact with the piglets, and the young stimulate a prolonged, high level of lactation. Certain alternative housing systems allow the sow to limit the stimulation she receives, and the resulting reduction in lactation can actually be advantageous to both parties. Communal care of offspring has both advantages and disadvantages in various species; these may help to explain why communal care occurs to a limited extent in pigs, and why sows isolate their litters in early lactation. Neonatal competition and mortality among newborn piglets have strong parallels in the “facultative siblicide” which adjusts brood size in numerous species of birds. These species typically produce slightly more young than are normally raised, and the number of siblings that survive is determined by the ability of the smaller young to withstand intense competition. The hypothesis that pigs have evolved a similar system of brood reduction may explain why piglet mortality is such an enduring problem and requires solutions different from those that work for other domestic species. Resource defence theory provides a functional framework for studies of aggressive behaviour. Factors determining the defensibility of a resource include its degree of clumping in time and space, and these suggest ways to reduce competition for food and other resources. However, aggression involved in establishing social dominance is more likely to be influenced by manipulating traits of the competing animals (competitive ability, familiarity) rather than the defensibility of resources. We conclude that principles of behavioural ecology and sociobiology provide a useful functional and evolutionary perspective to complement other approaches to the study of farm animal behaviour

Conflict and Cooperation: Sociobiological Principles and the Behaviour of Pigs

The pig provides many examples of how principles of behavioural ecology and sociobiology can lead to insights into farm animal behaviour. According to parent-offspring conflict theory, parents should tend to give a level of parental investment somewhat below that solicited by the young. When closely confined during lactation, sows can do little to limit the amount of contact with the piglets, and the young stimulate a prolonged, high level of lactation. Certain alternative housing systems allow the sow to limit the stimulation she receives, and the resulting reduction in lactation can actually be advantageous to both parties. Communal care of offspring has both advantages and disadvantages in various species; these may help to explain why communal care occurs to a limited extent in pigs, and why sows isolate their litters in early lactation. Neonatal competition and mortality among newborn piglets have strong parallels in the “facultative siblicide” which adjusts brood size in numerous species of birds. These species typically produce slightly more young than are normally raised, and the number of siblings that survive is determined by the ability of the smaller young to withstand intense competition. The hypothesis that pigs have evolved a similar system of brood reduction may explain why piglet mortality is such an enduring problem and requires solutions different from those that work for other domestic species. Resource defence theory provides a functional framework for studies of aggressive behaviour. Factors determining the defensibility of a resource include its degree of clumping in time and space, and these suggest ways to reduce competition for food and other resources. However, aggression involved in establishing social dominance is more likely to be influenced by manipulating traits of the competing animals (competitive ability, familiarity) rather than the defensibility of resources. We conclude that principles of behavioural ecology and sociobiology provide a useful functional and evolutionary perspective to complement other approaches to the study of farm animal behaviour

Lying behavior: Assessing within- and betweenherd variation in free-stall-housed dairy cows

One of the most important design criteria for dairy cow housing is access to a comfortable lying area. Behaviors such as the time cows spend lying down and how often they lie down can be used to evaluate the quality of stalls; however, assessing lying behavior on farms can be challenging. Indices such as the cow comfort index (CCI) and stall use index (SUI) have been widely used in on-farm assessments. The aims were to establish reliable sampling and recording methods for measuring lying behavior, to evaluate the adequacy of the CCI and SUI as estimates of lying behavior, and to describe variation in the lying behaviors of free-stall-housed dairy cows. The time spent lying down and the number of lying bouts for 2,033 cows on 43 farms were recorded for 5 d using electronic data loggers sampling at 1-min intervals. The CCI and SUI were calculated based on a single observation taken 2 h before the afternoon milking on each farm. Subsets of data were created, including 4, 3, 2, or 1 d per cow and 40, 30, 20, 10, 5, or 1 cow(s) per farm. The estimates derived from each sample size were compared with the overall means (based on 5 d and 44 cows per farm) for lying time and number of lying bouts, and the CCI and SUI were compared with the farm means of lying time, number of lying bouts, and bout duration using linear regression. Recording 30 or more cows for 3 d or more represented the overall means with high accuracy (R2 \u3e 0.9), but using fewer cows or fewer days per cow resulted in poorer estimates of the farm mean. The CCI and SUI showed no association with the daily lying time (h/d; R2 \u3c 0.01), and CCI was only weakly associated with the number of lying bouts per day (R2 = 0.16) and bout duration (min/bout; R2 = 0.09). Cows lay down 11.0 ± 2.1 h/d in 9 ± 3 bouts/d, with a bout duration of 88 ± 30 min/bout. These values ranged from 9.5 to 12.9 h/d, 7 to 10 bouts/d, and 65 to 112 min/bout across farm means, and 4.2 to 19.5 h/d, 1 to 28 bouts/d, and 22 to 342 min/bout across individuals, showing that variation in lying behavior among individual cows within farm was greater than differences among farms

Lying behavior: Assessing within- and betweenherd variation in free-stall-housed dairy cows

One of the most important design criteria for dairy cow housing is access to a comfortable lying area. Behaviors such as the time cows spend lying down and how often they lie down can be used to evaluate the quality of stalls; however, assessing lying behavior on farms can be challenging. Indices such as the cow comfort index (CCI) and stall use index (SUI) have been widely used in on-farm assessments. The aims were to establish reliable sampling and recording methods for measuring lying behavior, to evaluate the adequacy of the CCI and SUI as estimates of lying behavior, and to describe variation in the lying behaviors of free-stall-housed dairy cows. The time spent lying down and the number of lying bouts for 2,033 cows on 43 farms were recorded for 5 d using electronic data loggers sampling at 1-min intervals. The CCI and SUI were calculated based on a single observation taken 2 h before the afternoon milking on each farm. Subsets of data were created, including 4, 3, 2, or 1 d per cow and 40, 30, 20, 10, 5, or 1 cow(s) per farm. The estimates derived from each sample size were compared with the overall means (based on 5 d and 44 cows per farm) for lying time and number of lying bouts, and the CCI and SUI were compared with the farm means of lying time, number of lying bouts, and bout duration using linear regression. Recording 30 or more cows for 3 d or more represented the overall means with high accuracy (R2 \u3e 0.9), but using fewer cows or fewer days per cow resulted in poorer estimates of the farm mean. The CCI and SUI showed no association with the daily lying time (h/d; R2 \u3c 0.01), and CCI was only weakly associated with the number of lying bouts per day (R2 = 0.16) and bout duration (min/bout; R2 = 0.09). Cows lay down 11.0 ± 2.1 h/d in 9 ± 3 bouts/d, with a bout duration of 88 ± 30 min/bout. These values ranged from 9.5 to 12.9 h/d, 7 to 10 bouts/d, and 65 to 112 min/bout across farm means, and 4.2 to 19.5 h/d, 1 to 28 bouts/d, and 22 to 342 min/bout across individuals, showing that variation in lying behavior among individual cows within farm was greater than differences among farms

Mixing at Young Ages Reduces Fighting in Unacquainted Domestic Pigs

Under normal farming practices, piglets from different litters are often mixed around the time of weaning, and a high incidence of fighting and minor injuries often occur. The aim of this experiment was to determine the effect of age on the incidence of fighting in piglets mixed before weaning, at different ages between 5 and 26 days. We found no significant relationship between age and the likelihood that a pair of piglets would fight during the first 75 min after mixing. However, the duration of the first fight observed increased from 101±38 s at 5 days to 621±278 s at 26 days, mainly because of higher levels of unretaliated harassment and resting during the bouts. Younger pigs also showed 80% fewer injuries from the fighting. The results suggest some potential welfare advantage to allowing litters to mix at younger ages

Preference and usage of pasture versus free-stall housing by lactating dairy cattle

The aim of the current study was to assess if cows preferred pasture or indoor housing, and how diurnal and environmental factors affected this preference. Lactating dairy cows (n = 5 groups, each containing 5 cows) were sequentially housed either in a free-stall barn on pasture, or given the choice between the 2 environments. Each group was tested 3 times under each condition, for a total of 21 d, to assess the effects of varying climatic conditions (outdoor temperature ranged from 9.9 to 28.2°C and daily rainfall from 0 to 65 mm/d over the course of the experiment). When provided the choice, cows spent on average (± SD) 13.0 ± 0.6 h/d on pasture, mainly at night. The time cows spent on pasture during the day decreased with the temperature-humidity index (R2 = 0.55); time on pasture at night decreased with rainfall (R2 = 0.12). When provided a choice, cows spent more of their lying time on pasture (69.4 ± 0.02% of the total lying time/d) than indoors in the free-stalls. Cows also spent more time in total lying down when provided a choice than when confined to pasture [0.6 h/d more lying time; standard error of the difference (SED) = 0.21 h/d] and spent even more time lying down when confined indoors (1.1 h/d more time; SED = 0.21 h/d). Cows used the indoor housing especially for feeding; feeder use peaked when cows returned from morning and afternoon milkings. However, cows with free access to pasture spent 1.0 h/d (SED = 0.09 h/d) less time eating the TMR available indoors, resulting in a decline in intake of 2.9 kg of dry matter/d (SED = 0.36 kg of dry matter/d). How cows used the indoor housing differed when cows were provided a choice; for example, cows spent a greater percentage of their time indoors at the feed alley both during the day (47% of the total time spent indoors, versus 41% for cows confined indoors, SED = 0.02%) and at night (22 vs. 5%, SED = 0.04%). In conclusion, under the housing and environmental conditions tested, cows showed a strong preference for access to pasture at night and for access to indoor housing during the day when temperature and humidity increased