A Profile of Immigrants in Arkansas

Discusses key demographic trends, economic factors, and public policy issues associated with immigrants in Arkansas, which has the fourth-fastest-growing immigrant population in the nation

Effects of degree and timing of social housing on reversal learning and response to novel objects in dairy calves

Rodents and primates deprived of early social contact exhibit deficits in learning and behavioural flexibility. They often also exhibit apparent signs of elevated anxiety, although the relationship between these effects has not been studied. To investigate whether dairy calves are similarly affected, we first compared calves housed in standard individual pens (n = 7) to those housed in a dynamic group with access to their mothers (n = 8). All calves learned to approach the correct stimulus in a visual discrimination task. Only one individually housed calf was able to re-learn the task when the stimuli were reversed, compared to all but one calf from the group. A second experiment investigated whether this effect might be explained by anxiety in individually housed animals interfering with their learning, and tested varying degrees of social contact in addition to the complex group: pair housing beginning early (approximately 6 days old) and late (6 weeks old). Again, fewer individually reared calves learned the reversal task (2 of 10 or 20%) compared to early paired and grouped calves (16 of 21 or 76% of calves). Late paired calves had intermediate success. Individually housed calves were slower to touch novel objects, but the magnitude of the fear response did not correlate with reversal performance. We conclude that individually housed calves have learning deficits, but these deficits were not likely associated with increased anxiety

Assessing learning and memory in pigs

In recent years, there has been a surge of interest in (mini) pigs (Sus scrofa) as species for cognitive research. A major reason for this is their physiological and anatomical similarity with humans. For example, pigs possess a well-developed, large brain. Assessment of the learning and memory functions of pigs is not only relevant to human research but also to animal welfare, given the nature of current farming practices and the demands they make on animal health and behavior. In this article, we review studies of pig cognition, focusing on the underlying processes and mechanisms, with a view to identifying. Our goal is to aid the selection of appropriate cognitive tasks for research into pig cognition. To this end, we formulated several basic criteria for pig cognition tests and then applied these criteria and knowledge about pig-specific sensorimotor abilities and behavior to evaluate the merits, drawbacks, and limitations of the different types of tests used to date. While behavioral studies using (mini) pigs have shown that this species can perform learning and memory tasks, and much has been learned about pig cognition, results have not been replicated or proven replicable because of the lack of validated, translational behavioral paradigms that are specially suited to tap specific aspects of pig cognition. We identified several promising types of tasks for use in studies of pig cognition, such as versatile spatial free-choice type tasks that allow the simultaneous measurement of several behavioral domains. The use of appropriate tasks will facilitate the collection of reliable and valid data on pig cognition

The Science of the Einstein Telescope

Einstein Telescope (ET) is the European project for a gravitational-wave (GW)observatory of third-generation. In this paper we present a comprehensivediscussion of its science objectives, providing state-of-the-art predictionsfor the capabilities of ET in both geometries currently under consideration, asingle-site triangular configuration or two L-shaped detectors. We discuss theimpact that ET will have on domains as broad and diverse as fundamentalphysics, cosmology, early Universe, astrophysics of compact objects, physics ofmatter in extreme conditions, and dynamics of stellar collapse. We discuss howthe study of extreme astrophysical events will be enhanced by multi-messengerobservations. We highlight the ET synergies with ground-based and space-borneGW observatories, including multi-band investigations of the same sources,improved parameter estimation, and complementary information on astrophysicalor cosmological mechanisms obtained combining observations from differentfrequency bands. We present advancements in waveform modeling dedicated tothird-generation observatories, along with open tools developed within the ETCollaboration for assessing the scientific potentials of different detectorconfigurations. We finally discuss the data analysis challenges posed bythird-generation observatories, which will enable access to large populationsof sources and provide unprecedented precision.<br

The Movement and Distribution of Water in Soils

Synopsis Moisture plays a particularly important role in the soil mechanics of shallow foundations, because of the comparatively large seasonal changes occurring in the moisture condition of the soil close to the earth's surface. In particular, methods of estimating the changes which occur in the moisture condition when soil is paved are required in the design of roads and airfields. This article discusses the fundamental factors which give rise to moisture movements in soil and, on the basis of this discussion, methods are outlined for estimating the moisture distribution with depth beneath impervious pavements under equilibrium conditions. Differences in the soil moisture suction (or reduced pressure at which water is retained in the soil structure) provide the “potential” causing water to move within a soil mass. The movements which occur can only be expressed in terms of moisture content if the relationship between soil moisture suction and moisture content for the soil is known. The nature of this relationship and the manner in which it can be used to estimate equilibrium moisture distributions are discussed in relation to incompressible, partially compressible, and fully compressible soils. Some experimental confirmation of the theories involved has been obtained from laboratory and field investigations at present in progress. L'humidité joue un rôle particulièrement important dans la mécanique des sols des fondations peu profondes, à cause des changements saisonniers d'une ampleur relativement grande, qui se produisent dans l'humidité du sol juste au-dessous de la surface du terrain. En particulier, pour l'étude des routes et des aérodromes, on a besoin d'un moyen d'évaluer l'ampleur des changements d'humidité lorsque le sol est pourvu d'un revêtement. Cet article traite des facteurs fondamentaux qui donnent lieu aux mouvements de l'humidité dans le sol; sur la base de cette discussion, l'auteur donne une indication des méthodes pour évaluer la répartition de l'humidité à une profondeur donnée audessous des revêtements imperméables dans des conditions d'équilibre. Les différences dans la succion d'humidité du sol (c'est-à-dire la basse pression à laquelle la structure du sol peut retenir l'eau) donnent lieu au “potentiel” qui provoque des mouvements de l'eau dans le sol. Ces mouvements ne pourront être exprimés en termes de teneur en eau que si le rapport entre la succion et la teneur en eau du sol est connu. L'auteur discute le caractère de ce rapport et la manière dans laquelle on peut s'en servir pour évaluer ces répartitions équilibres d'humidité par rapport aux sols incompressibles. partiellement compressibles, et entièrement compressibles. Les théories en cause ont reçu certaines confirmations expérimentales par suite des recherches en laboratoire et en chantier qui sont en tours. </jats:p

Factors controlling the seasonal variation in soil water content and pore water pressures within a lightly vegetated clay slope

Seasonal cycles of soil water content cause shrinking and swelling in clay soils that can in turn contribute to strain-softening and progressive failure. This paper presents and analyses six years of field measurements of soil water content and pore water pressures in the upper layers of a lightly vegetated London Clay slope near Newbury, UK. The field observations are set in the context of a 40 year run of rainfall data for the site. Moderately extreme rainfall and drought events were experienced over the period 2003-2008, allowing almost the full variation in likely pore water pressures to be characterised. Pore water pressures were found to return to near hydrostatic during most winters. Variations in summer rainfall, particularly during June-August, are shown to have a large influence on the magnitude of the cycles of pore water pressure and effective stress. The 40 year rainfall dataset is used to calculate approximate return periods for the observed soil conditions and provides a benchmark for calculating the impacts of expected climate change on similar sites