Characterization of a high-voltage-activated IA current with a role in spike timing and locomotor pattern generation

Transient A-type K+ channels (IA) in neurons have been implicated in the delay of the spike onset and the decrease in the firing frequency. Here we have characterized biophysically and pharmacologically an IA current in lamprey locomotor network neurons that is activated by suprathreshold depolarization and is specifically blocked by catechol at 100 μM. The biophysical properties of this current are similar to the mammalian Kv3.4 channel. The role of the IA current both in single neuron firing and in locomotor pattern generation was analyzed. The IA current facilitates Na+ channel recovery from inactivation and thus sustains repetitive firing. The role of the IA current in motor pattern generation was examined by applying catechol during fictive locomotion induced by N-methyl-d-aspartate. Blockade of this current increased the locomotor burst frequency and decreased the firing of motoneurons. Although an alternating motor pattern could still be generated, the cycle duration was less regular, with ventral roots bursts failing on some cycles. Our results thus provide insights into the contribution of a high-voltage-activated IA current to the regulation of firing properties and motor coordination in the lamprey spinal cord.

Low doses of ivermectin cause sensory and locomotor disorders in dung beetles

Ivermectin is a veterinary pharmaceutical generally used to control the ecto- and endoparasites of livestock, but its use has resulted in adverse effects on coprophilous insects, causing population decline and biodiversity loss. There is currently no information regarding the direct effects of ivermectin on dung beetle physiology and behaviour. Here, based on electroantennography and spontaneous muscle force tests, we show sub-lethal disorders caused by ivermectin in sensory and locomotor systems of Scarabaeus cicatricosus, a key dung beetle species in Mediterranean ecosystems. Our findings show that ivermectin decreases the olfactory and locomotor capacity of dung beetles, preventing them from performing basic biological activities. These effects are observed at concentrations lower than those usually measured in the dung of treated livestock. Taking into account that ivermectin acts on both glutamate-gated and GABA-gated chloride ion channels of nerve and muscle cells, we predict that ivermectin’s effects at the physiological level could influence many members of the dung pat community. The results indicate that the decline of dung beetle populations could be related to the harmful effects of chemical contamination in the dung.

The white gene and locomotor recovery from anoxia in Drosophila melanogaster

Locomotor recovery from anoxia is complicated and little is known about the molecular and cellular mechanisms regulating anoxic recovery in Drosophila. For this thesis I established a protocol for large-scale analysis of locomotor activity in adult flies with exposure to a transient anoxia. Using this protocol I observed that wild-type Canton-S flies recovered faster and more consistently from anoxia than the white-eyed mutant w1118, which carries a null allele of w1118 in an isogenic genetic background. Both Canton-S and w1118 are commonly used controls in the Drosophila community. Genetic analysis including serial backcrossing, RNAi knockdown, w+ duplication to Y chromosome as well as gene mutation revealed a strong association between the white gene and the timing of locomotor recovery. I also found that the locomotor recovery phenotype is independent of white-associated eye pigmentation, that heterozygous w+ allele was haplo-insufficient to induce fast and consistent locomotor recovery from anoxia in female flies, and that mini-white is insufficient to promote fast and consistent locomotor recovery. Moreover, locomotor recovery was delayed in flies with RNAi knockdown of white in subsets of serotonin neurons in the central nervous system. I further demonstrated that mutations of phosphodiesterase genes (PDE) displayed wild-type-like fast and consistent locomotor recovery, and that locomotor recovery was light-sensitive in the night in w1118. The delayed locomotor recovery and the light sensitivity were eliminated in PDE mutants that were dual-specific or cyclic guanosine monophosphate (cGMP)-specific. Up-regulation of cGMP using multiple approaches including PDE mutation, sildenafil feeding or specific expression of an atypical soluble guanylyl cyclase (Gyc88E) was sufficient to suppress w-RNAi induced delay of locomotor recovery. Taken together, these data strongly support the hypothesis that White transports cGMP and promotes fast and consistent locomotor recovery from anoxia.

Comparison of PRC and Vietnam's Responses to the Elimination of U.S. Textile and Apparel Quotas: Economic and Cultural Perspectives. ACES Working Paper No. 1, 2007

International trade in textiles and apparel has, as of January 1, 2005, been set free from the very intricate Multi-Fiber textile and apparel quota Arrangement (MFA). This event has raised many uncertainties about the new international trade climate and has placed enormous pressure on China as the expected clear cut beneficiary of this liberalization.' Other countries considered to be major contenders include Vietnam which also has a large population employed in the textile and apparel (T&A) sector. Since the old quota system had provided a certain degree of market certainty to competing T&A producers, will the new free trade environment lead to a shake out where mass producers with large economies of scale dominate the new reality? The removal of T&A quotas will create opportunities for Vietnam and China along with other developing countries, but it will also expose them to additional competition from each other. The outcome of this competition will depend on the demand in the US, the ability of the exporting countries to differentiate their exports and on their ability to transfer additional resources to expand domestic output in the direction of the new 'free market signals' and away from rent seeking objectives. Obviously, exporting countries that adjust to this new environment quickly will improve their competitiveness, and will be the new beneficiaries of a quota free international trade in textiles and apparel. This paper attempts to shed some light on the differences and similarities in the responses of Chinese and Vietnamese T&A sectors to this new environment. It first focuses on the demand side attempting to determine whether or not Chinese and Vietnamese T&A items, formally under quota control, are substitutes or compliments. On the supply side, the paper focuses on institutional differences between each country's T&A sectors, the different domestic government policies that have contributed to their growth and the unique cultural differences which will determine the future progress in each country's T&A sectors.

Sources of statistical data: textiles & apparel

"Original guide published in 1964."

Apparel manufacturing analysis.

Includes bibliography and index.

A work manual for the study of nontextile apparel accessories; leather, shoes, gloves, handbags, luggage, furs, jewelry metals, jewelry stones, cosmetics, soaps.

Mode of access: Internet.

Designing apparel through the flat pattern,

Mode of access: Internet.

Principles and problems of pattern making as applied to women's apparel,

Mode of access: Internet.

Sources of statistical data textiles and apparel /

Mode of access: Internet.

Pre-importation review program : documentary and procedural requirements for wearing apparel.

Mode of access: Internet.

Invoice description requirements for imported wearing apparel : guidelines and general information.

Mode of access: Internet.

Sources of statistical data : textiles and apparel, 1980.

Includes indexes.

Expenditures and apparel buying habits of Ohio state university students,

"Publications of the Bureau of business research" on inside back cover.

The worth of a penny : or, a caution to keep money. With the causes of the scarcity and misery of the want thereof as also how to save it in our diet, apparel, recreation, etc. And also what honest course men in want may take to live /

Mode of access: Internet.