How to motivate laying hens to use the hen run?

In organic agriculture, hens are kept in free range systems. A free range is an enrichment for the hens and brings several advantages for them. Laying hens may show behavioural elements that are not possible in a poultry house. For instance, sunbathing behaviour is only shown in direct sunlight and not in artificial light (Huber, 1987). Hens spend 35.3-47.5% of their time with food searching (Fölsch and Vestergaard, 1981) and, in natural habitats, invertebrate food appears to be an importnat addition to the diet (Savory et al. 1978). Free range systems may also have an influence on animal health and product quality. Lopez-Bote et al. (1998) suggested that some constituents of grass might be of interest for the production of eggs rich in (n-3) fatty acids. In flocks of free range hens, generally only a small proportion of the flock is outside at any one time, and most hens stay near the poultry house. In an account of the uneven distribution of the hens in the free range area, Menzi et al. (1997) found a nutrient and heavy metal overload on the frequently used parts of the run. For a better distribution, they, as well as several label programmes, recommend to structure the outdoor area with trees and installations providing shade and protection for the hens. We attempted to determine management and structural factors that would result in more hens in the run and a more even distribution of the animals in several experiments, with a special emphasis on the idea that the hen run should be easily manageable for the farmer

Optimising the use of hen runs by structures and management

One of the main problems in free range husbandry of laying hens is the uneven use of the hen run. This leads to an overuse of pasture near the hen house. In a series of behavioural experiments we tried to determine management and structuring factors which may result in more hens in the run and a more even distribution of the animals

Interview with Robert and Esther Fortenbaugh, February 22, 2004

Robert & Esther Fortenbaugh were interviewed on February 22, 2004 by Michael J. Birkner. Esther discussed her early years and Robert discussed his career at American Cyanimid and then as a United Methodist Minister. They both discussed their time at Gettysburg College (including meeting each other), their life after college, and returning to Gettysburg after retirement. Length of Interview: 88 minutes Collection Note: This oral history was selected from the Oral History Collection maintained by Special Collections & College Archives. Transcripts are available for browsing in the Special Collections Reading Room, 4th floor, Musselman Library. GettDigital contains the complete listing of oral histories done from 1978 to the present. To view this list and to access selected digital versions please visit -- http://gettysburg.cdmhost.com/cdm/landingpage/collection/p16274coll

Economic integration and corruption: The corrupt soul of the European Union

We study the link between corruption and economic integration. We show that if an economic union establishes a common regulation for public procurement, the country more prone to corruption benefits more from integration. However, if the propensities to corruption are too distinct, the less corrupt country will not be willing to join the union. This difference in corruption propensities can be offset by a difference in efficiency. We also show that corruption is lower if integration occurs. A panel data analysis for the European Union confirms that more corrupt countries are more favorable towards integration but less acceptable as potential new members.Corruption, procurement, economic integration

Allocating ideas: Horizontal competition in tournaments

We develop a stylized model of horizontal and vertical competition in tournaments with two competing firms. The sponsor cares about the quality of the design but also about the design location. A priori not even the sponsor knows his preferred design location, which is only discovered once he has seen the actual proposals. We show that the more efficient firm is more likely to be conservative when choosing the design location. Also, to get some differentiation in design locations, the cost difference between contestants can neither be too small nor too big. Therefore, if the sponsor mainly cares about the design location, participation in the tournaments by the two lowest cost contestants cannot be optimal for the sponsor.Horizontal and vertical competition, tournaments

Crystal Structure of the P Pilus Rod Subunit PapA

P pili are important adhesive fibres involved in kidney infection by uropathogenic Escherichia coli strains. P pili are assembled by the conserved chaperone-usher pathway, which involves the PapD chaperone and the PapC usher. During pilus assembly, subunits are incorporated into the growing fiber via the donor-strand exchange (DSE) mechanism, whereby the chaperone's G1 β-strand that complements the incomplete immunoglobulin-fold of each subunit is displaced by the N-terminal extension (Nte) of an incoming subunit. P pili comprise a helical rod, a tip fibrillum, and an adhesin at the distal end. PapA is the rod subunit and is assembled into a superhelical right-handed structure. Here, we have solved the structure of a ternary complex of PapD bound to PapA through donor-strand complementation, itself bound to another PapA subunit through DSE. This structure provides insight into the structural basis of the DSE reaction involving this important pilus subunit. Using gel filtration chromatography and electron microscopy on a number of PapA Nte mutants, we establish that PapA differs in its mode of assembly compared with other Pap subunits, involving a much larger Nte that encompasses not only the DSE region of the Nte but also the region N-terminal to it. Author Summary. Bacterial adhesion to a host is a crucial step that determines the onset of bacterial infection. It is mediated through recognition of a receptor on the host cell surface by a protein called an adhesin displayed on the surface of the bacterium. Many adhesins are displayed at the tip of specialized organelles called pili, some of which are assembled by the ubiquitous chaperone-usher pathway. In this pathway, each pilus subunit is assisted in folding by a chaperone. The resulting chaperone-subunit complex is targeted to a pore located in the outer membrane, called the usher, that serves as assembly platform. There, pilus subunits dissociate from the chaperone and polymerize, resulting in a surface organelle, the pilus, that protrudes out of the usher. Here, we have determined the structure of the major subunit of the P pilus, PapA. The P pilus, produced in uropathogenic Escherichia coli, displays the adhesin PapG responsible for targeting the bacterium to the kidney epithelium. We have determined the structure of PapA either bound to its cognate chaperone, PapD, or bound to another PapA subunit. These structures provide a view of PapA before and after its assembly in the pilus and shed light on the mechanism of PapA assembly.National Institutes of Health (DE 09761, GM040388, DE 09161); Committee of Scientific Research (3 PO4A 003 24, 2 P05A 137 24); Foundation for Polish Science (SUBSYDIUM PROFESORSKIE award); Swedish Rheumatism Association; Nanna Svartz Foundation; King Gustaf V Foundatio

Qubit authentication

Secure communication requires message authentication. In this paper we address the problem of how to authenticate quantum information sent through a quantum channel between two communicating parties with the minimum amount of resources. Specifically, our objective is to determine whether one elementary quantum message (a qubit) can be authenticated with a key of minimum length. We show that, unlike the case of classical-message quantum authentication, this is not possible.Comment: LaTeX, 8 page