Foot-pad dermatitis in broilers and turkeys

Foot-pad dermatitis is a condition characterised by lesions on the ventral foot-pads of poultry. It is a type of contact dermatitis, which in an early stage results in hyperkeratosis, erosions and discoloration of the skin. The erosions can develop into ulcers. In severe cases, the foot-pad lesions may cause pain which together with a deteriorated state of health constitutes a welfare issue. It has also been indicated that broilers with severe foot-pad dermatitis show slower weight gain. The aim of the present work was to improve the knowledge concerning the epidemiology of foot-pad dermatitis in meat-type poultry in Sweden. The studies were focused on surveying the occurrence of foot-pad dermatitis on Swedish commercial broiler and turkey farms, identifying endogenous and exogenous risk factors for foot-pad dermatitis in meat-type poultry and to evaluate the function of foot health as an indicator of management, hygiene and housing standards. The prevalence of foot-pad dermatitis in Swedish broilers at time of slaughter was estimated at 5-10 % for severe lesions and 10-35 % for mild lesions. The corresponding prevalence of foot-pad dermatitis in turkeys was estimated at approximately 20 % for severe lesions and 78 % for mild lesions. A significantly higher prevalence of foot-pad dermatitis was found in flocks reared on wet litter than on dry litter. In broilers, a significantly higher prevalence of lesions was found in flocks reared on thick layers of litter material than on thinner layers. There was an association between litter material and turkey foot-pad dermatitis. Type of drinker system, which is related to both water spillage and water consumption, was significantly associated with the prevalence of foot-pad dermatitis in both broilers and turkeys. There was a significant seasonal effect on the prevalence of broiler foot-pad dermatitis, with the highest prevalence found during October to January. The prevalence and severity of foot-pad dermatitis in broilers decreased over time when a surveillance programme was initiated and executed. In summary, foot-pad dermatitis in both broilers and turkeys was shown to be linked to a number of management, hygiene and housing factors, and can thus be used as an indicator of the standard of these factors. Surveillance and advisory programmes can be used successfully to decrease the incidence of foot-pad lesions in broiler and turkey populations and thus improve the health and welfare of the birds

Enhanced diffusion by reciprocal swimming

Purcell's scallop theorem states that swimmers deforming their shapes in a time-reversible manner ("reciprocal" motion) cannot swim. Using numerical simulations and theoretical calculations we show here that in a fluctuating environment, reciprocal swimmers undergo, on time scales larger than that of their rotational diffusion, diffusive dynamics with enhanced diffusivities, possibly by orders of magnitude, above normal translational diffusion. Reciprocal actuation does therefore lead to a significant advantage over non-motile behavior for small organisms such as marine bacteria

Hereditary categories with Serre duality which are generated by preprojectives

AbstractWe show that every k-linear abelian Ext-finite hereditary category with Serre duality which is generated by preprojective objects is derived equivalent to the category of representations of a strongly locally finite thread quiver

The Moment Problem for Continuous Positive Semidefinite Linear functionals

Let $\tau$ be a locally convex topology on the countable dimensional polynomial $\reals$-algebra \rx:=\reals[X_1,...,X_n]. Let $K$ be a closed subset of $\reals^n$, and let $M:=M_{\{g_1, ... g_s\}}$ be a finitely generated quadratic module in \rx. We investigate the following question: When is the cone \Pos(K) (of polynomials nonnegative on $K$) included in the closure of $M$? We give an interpretation of this inclusion with respect to representing continuous linear functionals by measures. We discuss several examples; we compute the closure of M=\sos with respect to weighted norm-$p$ topologies. We show that this closure coincides with the cone \Pos(K) where $K$ is a certain convex compact polyhedron.Comment: 14 page

Methods and standards development for three-dimensional mapping of the Antioch Quadrangle, Lake County, Illinois a pilot study

The Pilot Study for the Central Great Lakes Geologic Mapping Coalition (CGLGMC) focused on the Antioch Quadrangle, Lake County, Illinois developing a series of maps and digital products, several protocols for database development and maintenance and field procedures to acquire and integrate drilling and geophysical data from a quadangle area featuring complex glacial geology over a 25,000 year period.U.S. Geological Survey, Central Great Lakes Geologic Mapping CoalitionOpe

On a P\'olya functional for rhombi, isosceles triangles, and thinning convex sets

Let $\Omega$ be an open convex set in ${\mathbb R}^m$ with finite width, and let $v_{\Omega}$ be the torsion function for $\Omega$, i.e. the solution of $-\Delta v=1, v\in H_0^1(\Omega)$. An upper bound is obtained for the product of $\Vert v_{\Omega}\Vert_{L^{\infty}(\Omega)}\lambda(\Omega)$, where $\lambda(\Omega)$ is the bottom of the spectrum of the Dirichlet Laplacian acting in $L^2(\Omega)$. The upper bound is sharp in the limit of a thinning sequence of convex sets. For planar rhombi and isosceles triangles with area $1$, it is shown that $\Vert v_{\Omega}\Vert_{L^{1}(\Omega)}\lambda(\Omega)\ge \frac{\pi^2}{24}$, and that this bound is sharp.Comment: 12 pages, 4 figure