The spatial ecology of free-ranging domestic pigs (Sus scrofa) in western Kenya

Background In many parts of the developing world, pigs are kept under low-input systems where they roam freely to scavenge food. These systems allow poor farmers the opportunity to enter into livestock keeping without large capital investments. This, combined with a growing demand for pork, especially in urban areas, has led to an increase in the number of small-holder farmers keeping free range pigs as a commercial enterprise. Despite the benefits which pig production can bring to a household, keeping pigs under a free range system increases the risk of the pig acquiring diseases, either production-limiting or zoonotic in nature. This study used Global Positioning System (GPS) technology to track free range domestic pigs in rural western Kenya, in order to understand their movement patterns and interactions with elements of the peri-domestic environment. Results We found that these pigs travel an average of 4,340 m in a 12 hr period and had a mean home range of 10,343 m2 (range 2,937–32,759 m2) within which the core utilisation distribution was found to be 964 m2 (range 246–3,289 m2) with pigs spending on average 47% of their time outside their homestead of origin. Conclusion These are the first data available on the home range of domestic pigs kept under a free range system: the data show that pigs in these systems spend much of their time scavenging outside their homesteads, suggesting that these pigs may be exposed to infectious agents over a wide area. Control policies for diseases such as Taenia solium, Trypanosomiasis, Trichinellosis, Toxoplasmosis or African Swine Fever therefore require a community-wide focus and pig farmers require education on the inherent risks of keeping pigs under a free range system. The work presented here will enable future research to incorporate movement data into studies of disease transmission, for example for the understanding of transmission of African Swine Fever between individuals, or in relation to the life-cycle of parasites including Taenia solium

Power Law Distribution of the Frequency of Demises of U.S Firms

Both theoretical and applied economics have a great deal to say about many aspects of the firm, but the literature on the extinctions, or demises, of firms is very sparse. We use a publicly available data base covering some 6 million firms in the US and show that the underlying statistical distribution which characterises the frequency of firm demises - the disappearances of firms as autonomous entities - is closely approximated by a power law. The exponent of the power law is, intriguingly, close to that reported in the literature on the extinction of biological species.Comment: 8 pages, 2 figure

Swimming ability in three Costa Rican dry forest rodents

We investigated the swimming abilities of three Costa Rican dry forest rodents (Coues' rice rat. Oryzomys couesi, hispid cotton rat, Sigmodon hispidus, and spiny pocket mouse, Liomys salvini) associated with a large marsh, Laguna Palo Verde, using 90 s swim trials in a plastic container. Swimming ability was evaluated by observing the use of limbs and tail in the water, inclination to the surface, and diving and floating behavior. Rice rats could float, swim and dive, suggesting that they can exploit surface and underwater resources. Cotton rats swam at the water's surface, but were less skilled swimmers than rice rats. Spiny pocket mice tired quickly and had difficulty staying at the water's surface. Results suggest that differential swimming ability is related to the distribution of the three sympatric species within the marsh and adjacent forest habitats. We investigated the swimming abilities of three Costa Rican dry forest rodents (Coues' rice rat. Oryzomys couesi, hispid cotton rat, Sigmodon hispidus, and spiny pocket mouse, Liomys salvini) associated with a large marsh, Laguna Palo Verde, using 90 s swim trials in a plastic container. Swimming ability was evaluated by observing the use of limbs and tail in the water, inclination to the surface, and diving and floating behavior. Rice rats could float, swim and dive, suggesting that they can exploit surface and underwater resources. Cotton rats swam at the water's surface, but were less skilled swimmers than rice rats. Spiny pocket mice tired quickly and had difficulty staying at the water's surface. Results suggest that differential swimming ability is related to the distribution of the three sympatric species within the marsh and adjacent forest habitats

Absolute Frequency Measurement of the lLevel of Neutral Using Two-Photon Spectroscopy

We report absolute frequency measurements on the level of neutral using sub-Doppler two-photon spectroscopy. The absolute center-of-gravity energy for the level is determined to be , a factor of 170 times improvement over the previous measurement from 1964 of . This measurement also corrects a discrepancy with the previously measured value. The hyperfine coefficients were found to be and , which are consistent with previous results

The social relations model for count data : an exploration of intergenerational co-activity within families

The social relations model (SRM) is typically used to identify sources of variance in interpersonal dispositions in families. Traditionally, it uses dyadic measurements that are obtained from a round-robin design, where each family member rates each other family member. Those dyadic measurements are mostly considered to be continuous, but we, however, wilt discuss how the SRM can be adapted to count dyadic measurements. Such SRM for count data can be formulated in the SEM-framework by viewing it as a confirmatory factor analysis (CFA), but it can also be defined in the multilevel framework. These two frameworks result in equivalent models of which the parameters can be estimated using maximum likelihood estimation or a Bayesian approach. We perform a simulation study to compare the performance of those two estimators. As an illustration, we consider intergenerational co-activity data from a block design and contrast family dynamics between non-divorced families and stepfamilies

Helminth Parasites of Two Species of Lepomis (Osteichthyes: Centrarchidae) from an Urban Watershed and their Potential Use in Environmental Monitoring

We provide a checklist of the common parasites of bluegill (Lepomis macrochirus) and redbreast sunfish (Lepomis auritus) collected from eight creeks within an urban watershed located in Columbus, Georgia. A total of 12 parasite species were observed from 427 fish dissected. Bluegill (n = 222) were infected with 11 species, which included five species of larval helminths (Proteocephalus sp., Bothriocephalus sp., Posthodiplostomum minimum, Diplostomulum sp. and Clinostomum complanatum), one adult trematode (Pisciamphistoma stunkardi), four adult nematodes (Philometra sp., Philometra intraoculus, Spinetectus carolini and Camallanus oxycephalus) and one adult acanthocephalan (Neochinorhynchus cylindratus). Redbreast sunfish (n = 205) were infected with the same parasite species, except for the absence of larval Bothriocephalus sp. and the presence of an adult trematode (Crepidostomum cooperi). Metacercariae of the trematode P. minimum were the most common parasite in both fish species. Similar parasite communities in these sunfishes suggest that these species share similar microhabitats within the watershed, food resources and foraging sites. Seasonal comparison between the number of summer and winter parasites indicate a greater mean number of parasites per host in summer. We discuss the utility of such baseline parasite data in the potential environmental monitoring of the Bull and Upatoi Creeks watershed

"Any lady can do this without much trouble ...": class and gender in The dining room (1878)

Macmillan's "Art at Home" series (1876–83) was a collection of domestic advice manuals. Mentioned in every study of the late-nineteenth-century domestic interior, they have often been interpreted, alongside contemporary publications such as Charles Eastlake's Hints on Household Taste (1868), as indicators of late 1870s home furnishing styles. Mrs Loftie's The Dining Room (1878) was the series' fifth book and it considers one of the home's principal (and traditionally masculine) domestic spaces. Recent research on middle-class cultural practices surrounding food has placed The Dining Room within the tradition of Mrs Beeton's Household Management (1861); however, it is not a cookery book and hardly mentions dinners. Drawing upon unpublished archival sources, this paper charts the production and reception of The Dining Room, aiming to unravel its relationships with other contemporary texts and to highlight the difficulties of using it as historical evidence. While it offers fascinating insights into contemporary taste, class and gender, this paper suggests that, as an example of domestic design advice literature, it reveals far more about the often expedient world of nineteenth-century publishing practices

Quadrupole moments of rotating neutron stars

Numerical models of rotating neutron stars are constructed for four equations of state using the computer code RNS written by Stergioulas. For five selected values of the star's gravitational mass (in the interval between 1.0 and 1.8 solar masses) and for each equation of state, the star's angular momentum is varied from J=0 to the Keplerian limit J=J_{max}. For each neutron-star configuration we compute Q, the quadrupole moment of the mass distribution. We show that for given values of M and J, |Q| increases with the stiffness of the equation of state. For fixed mass and equation of state, the dependence on J is well reproduced with a simple quadratic fit, Q \simeq - aJ^2/M c^2, where c is the speed of light, and a is a parameter of order unity depending on the mass and the equation of state.Comment: ReVTeX, 7 pages, 5 figures, additional material, and references adde