Spatial Limits of the TCM revisited: Island Effects

The purpose of this paper is to address a problem that may arise with the assumption of a continuous spatial market in the TCM model. We find that this assumption can be challenged by geographical limitations that an area of study might have. Particularly for islands (or isolated island-like areas) that have a valuable non-market resource or good, the spatial market characteristic of the TCM model might be limited or truncated. The geographical truncation limits the observed maximum travel cost of the demand curve falsely implying a lower WTP than otherwise. The study uses a dichotomous choice CVM to confirm that the resulting demand schedules from the TCM underestimates WTP for day trips to the Caribbean National Forest in Puerto Rico. This results in a considerably smaller TCM WTP for the value of recreation sites at $17 to$29 versus $109 per day trip from the dichotomous choice CVM.Marketing,

Temperature Stressed \u3cem\u3eCaenorhabditis elegans\u3c/em\u3e Males Fail to Mate Successfully and Successful Males Produce Very Few Viable Cross Progeny

Exposure to moderate temperature stress can have profoundly negative effects on an organism’s reproductive capacity at temperatures where there are minimal or indiscernible effects on the organism as a whole. These negative effects are often more pronounced in males of the species that produce sperm. Previously we showed that few males of Caenorhabditis elegans wild type strains are able to successfully produce any cross progeny after experiencing temperature stress. However, these experiments did not assess the number of progeny from temperature stressed males. To understand if temperature stress can reduce the number of progeny a male sires, we crossed temperature stressed males of three wild type strains of C. elegans: JU1171, LKC34, and N2, to strain matched hermaphrodites of their own genetic background or to uncoordinated hermaphrodites in the N2 background. We found that significantly fewer males exposed to moderate temperature stress can successfully mate and that the small number of males in the population that do successfully mate produce significantly fewer viable cross progeny than unstressed controls. Our results suggest that exposure to moderate temperature stress significantly reduces male C. elegans chances at reproducing similar to what is seen in other organisms

Preferencias hacia carne de cordero en supermercados de Temuco, región de la Araucanía, Chile

Lobos, G (Lobos, German). Univ Talca, Escuela Ingn Comercial, Talca, ChileThe low levels of consumption of lamb meat in Chile suggest the need for studies on consumer preferences in order to orient production. A study with this object was carried out to evaluate preferences for various cuts, breeds, state (fresh or frozen) and price of lamb's meat among supermarket buyers in Temuco, Chile, and the existence of different market segments, through a survey of 400 persons. Using a fractional factorial design for conjoint analysis, it was determined that the state of the meat was more important than the cut, the price and the breed, with a preference for meat in half carcasses and quarters, Araucano lamb, fresh, at a medium price level. Four consumer segments were distinguished by analysis of hierarchic conglomerates. The majority group (47.7%) was sensitive to the state and the cut, with preference for meat in quarters, fresh, Texel breed. The second group (25.3%) was sensitive to the breed, presenting the strongest preferences for meat in whole carcass, fresh, Araucano lamb. The third group (14.3%) was sensitive to the price, preferred meat in quarters, fresh, Araucano lamb. The minority group (12.7%) was sensitive to the state and price, preferring meat in quarters, Texel breed, and was the only group which preferred frozen meat and would pay a higher price. The segments were distinguished by age, ethnic origin and satisfaction with food-related life. Thus the commercialisation strategy for lamb in supermarkets in Temuco should concentrate principally on the sale of fresh meat cut in quarter

Defects in Mating Behavior and Tail Morphology Are the Primary Cause of Sterility in \u3cem\u3eCaenorhabditis elegans\u3c/em\u3e Males at High Temperature

Reproduction is a fundamental imperative of all forms of life. For all the advantages sexual reproduction confers, it has a deeply conserved flaw: it is temperature sensitive. As temperatures rise, fertility decreases. Across species, male fertility is particularly sensitive to elevated temperature. Previously, we have shown in the model nematode Caenorhabditis elegans that all males are fertile at 20°C, but almost all males have lost fertility at 27°C. Male fertility is dependent on the production of functional sperm, successful mating and transfer of sperm, and successful fertilization post-mating. To determine how male fertility is impacted by elevated temperature, we analyzed these aspects of male reproduction at 27°C in three wild-type strains of C. elegans: JU1171, LKC34 and N2. We found no effect of elevated temperature on the number of immature non-motile spermatids formed. There was only a weak effect of elevated temperature on sperm activation. In stark contrast, there was a strong effect of elevated temperature on male mating behavior, male tail morphology and sperm transfer such that males very rarely completed mating successfully when exposed to 27°C. Therefore, we propose a model where elevated temperature reduces male fertility as a result of the negative impacts of temperature on the somatic tissues necessary for mating. Loss of successful mating at elevated temperature overrides any effects that temperature may have on the germline or sperm cells

Antibody and inflammatory responses in laying hens with experimental primary infections of Ascaridia galli

Ascaridia galli, an intestinal nematode that effects hens and other domestic and wild birds, causes economic losses in avian exploitations. The present work shows that A. galli stimulates a strongly antibody response as well as an intense inflammatory reaction, in the intestinal mucous of experimentally infected Lohmann Brown laying hens. IgG antibodies against soluble extracts of A. galli embrionated eggs and adult worms, were detected in both blood and yolks egges from infected hens during a period of 105 days after the infection. This indicates that hens transger to their offspring a part of the IgG antibodies produced when they become infected. The entigens responsible for the stimulation of specific IgG were molecules of 30-34, 44-54 and 58-90 KDa, while in the yolk eggs of infected hens a reactivity directed against antigens of molecular weight lower than 50 KDa was detected. Histology revealed traumatic lesions with leukocyte infiltration, and inflammation of the intestinal wall of the infected hens after 105 days of initial infection. The possible influence of the immune and inflammatory response onthe population dynamics of the parasite is discussed