Effects of transportation on the tonic immobility fear reactions of broilers

1. The fear levels of broilers arriving from slaughter at 4 commercial processing plants were assessed using tonic immobility (TI) tests. The relative effects of selected variables were also examined.

2. Neither the position of the birds on the lorry, nor their sex, nor the ambient temperature nor the identity of the experimeter exerted any significant effects on tonic immobility reactions.

3. Although the longest and shortest immobility responses followed transportation in the fixed crates and metal modules respectively, system comparisons may be confounded by variations in the birds’ genetic and/or experiential backgrounds.

4. Both journey duration and waiting time before transport bore an unambiguous and positive linear relationship with mean TI duration. The duration of transit was the major factor determining fear levels following both commercial and simulated journeys.     

"Coulomb Staircase" at Room Temperature in a Self-Assembled Molecular Nanostructure

Double-ended aryl dithiols [alpha,alpha'-xylyldithiol (XYL) and 4,4'-biphenyldithiol] formed self-assembled monolayers (SAMs) on gold(111) substrates and were used to tether nanometer-sized gold clusters deposited from a cluster beam. An ultrahigh-vacuum scanning tunneling microscope was used to image these nanostructures and to measure their current-voltage characteristics as a function of the separation between the probe tip and the metal cluster. At room temperature, when the tip was positioned over a cluster bonded to the XYL SAM, the current-voltage data showed "Coulomb staircase" behavior. These data are in good agreement with semiclassical predictions for correlated single-electron tunneling and permit estimation of the electrical resistance of a single XYL molecule (approximately18 ± 12 megohms).     

Probing the Local Effects of Magnetic Impurities on Superconductivity

The local effects of isolated magnetic adatoms on the electronic properties of the surface of a superconductor were studied with a low-temperature scanning tunneling microscope. Tunneling spectra obtained near magnetic adsorbates reveal the presence of excitations within the superconductor's energy gap that can be detected over a few atomic diameters around the impurity at the surface. These excitations are locally asymmetric with respect to tunneling of electrons and holes. A model calculation based on the Bogoliubov-de Gennes equations can be used to understand the details of the local tunneling spectra.     

Systems of knowledge as systems of domination: The limitations of established meaning

The hegemony of Western science, inherent in international development projects, often increases the poverty and oppression of Third World women by pre-empting alternative realities. In African and Asian agrarian societies women grow from 60 to 90% of the food (World Bank, 1989); they hold incredible potential to increase food production. Their ability to operate under more marginal conditions than their male counterparts would seem to indicate that they have developed valuable knowledge— knowledge often generated in response to limited access to the more tangible resources offered by development assistance to male farmers. Recognizing the marginalization of women in the Third World, the Women in Development (WID) network was established during the 1970's to produce knowledge about women, fill in the gaps, and set the record straight. But knowledge creation for these purposes leaves underlying paradigms of Western science-based development unquestioned. Research from a feminist standpoint is used to challenge the objectivity and reliability of EuroAmerican development science. To date, WID has documented and analyzed the causes and consequences of Third World women's oppression with no substantial results to end them. Alternatively, feminist research validates women's perceptions of their reality, helping ordinary people to understand the connections between their experiences and broader social, economic, and political struggles. The paper emphasizes research pursued in order to act, closely linking knowing to doing to promote the emancipation of oppressed groups. A feminist standpoint is used to privilege the perspective of rural women in developing countries and ask: “What are the implications of the standard EuroAmerican approach to science for maximizing the potential contributions of rural women to agricultural development?” Some of these implications are illustrated with examples from on-farm research in Nigeria. To some extent, implications can be addressed by constructing meanings to structure a symbolic framework that includes female farmers and other disadvantaged groups.     

Fallout of pyroclastic debris from submarine volcanic eruptions

Volcanic fallout deposits on land, being widespread and accessible for study, have received much attention and have revealed a great deal about subaerial eruption mechanisms. In contrast, virtually nothing is known about equivalent deposits produced by submarine volcanoes, despite the probable abundance of such material in today's oceans and in accreted volcanic arc terrains. Many submarine deposits may form by the fallout of debris to the sea floor downcurrent from the umbrella region of submarine eruption columns. Experiments on water-saturated pumice and pieces of rock (lithics) show that particles settling to the sea floor at terminal velocities of 10 to 50 centimeters per second will display conspicuous bimodality of particle diameters: pieces of pumice may be five to ten times as large as codeposited lithic fragments. Similar material, erupted into the air and deposited on land, displays less well-developed bimodality; pumice diameters are generally two to three times as large as associated lithics. Submarine fallout deposits are therefore distinctive and may be used to indicate a subaqueous origin for some of the great thicknesses of nonfossiliferous volcanic debris contained in ancient volcanic terrains worldwide whose environment of deposition has been uncertain.     

Oestrogen,Progesterone and Oxytocin Receptors and COX‐2 Expression in Endometrial Biopsy Samples from the Induction of Ovulation to Luteolysis in Llamas (Lama glama)

Endometrial expression of oestrogen (ERα), progesterone (PR) and oxytocin receptor (OR) and cyclooxygenase‐2 (COX‐2) was evaluated from the induction of ovulation to luteolysis in llamas. Ovarian activity was daily assessed by ultrasonography in five females. Ovulation was induced immediately after the detection of an ovulatory follicle by a GnRH injection (Day 0). Endometrial samples were obtained by transcervical biopsies from the left and right horns on day 0 and days 4, 8, 10 and 12 post‐GnRH. Blood samples were collected daily for progesterone and estradiol‐17β determinations by RIA. An immunohistochemical technique was used to study receptors population and COX‐2 expression which were then evaluated by two independent observers. The expression of ERα and PR was highest on day 0 in the luminal epithelium and stroma in association with high plasma estradiol‐17β concentrations. Thereafter, a decrease in ERα population was registered on day 4 and a new increase of its expression was observed between days 8 and 12 in those cell types. Conversely, PR population was gradually down‐regulated until its lowest expression was reached on day 10 post‐GnRH in the luminal epithelium. Content of OR was similar throughout the study in all cell types. The expression of COX‐2 was highest from day 8 to 12 post‐GnRH in the luminal epithelium, in relation to the time of maximal PGF_2α release. Both steroid receptors populations and COX‐2 expression were similar between horns. Meanwhile, OR expression was higher in the right than in the left uterine horn. In summary, this study showed that the loss of endometrium sensitivity to progesterone by days 8–10 post‐induction of ovulation and the concomitant increase of COX‐2 expression could play a key role in the mechanism of luteolysis and somehow be related to the short corpus luteum lifespan of llamas.