Force variability and movement accuracy in space-time.

In four experiments we examined the relative contribution of different impulse parameters to response outcome variability in a unidimensional timing task. The findings indicate that (a) there is not a linear and proportional relation between force and force variability; (b) low rates of force production are proportionally more variable than high rates of force production; (c) adding a preload to the limb induces effects on movement error different from those induced by the addition of mass to the manipulandum; and (d) the space-time error function for movement control is strongly linked to the average rate of force production. Collectively, these findings indicate limitations to the extant impulse-variability models and suggest that rate of force production is an important parameter determining response outcome variability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The maturing of the U.S. nuclear industry

In a technoeconomic context, maturity is a state characterized by full development and consequently by a lack of opportunity for further growth and development. The objective of this paper is to develop a perspective on where the nuclear industry in the United States appears to stand in the economic and technological maturation process. The paper outlines certain government and industry objectives, as well as certain joint efforts, which, if successfully developed, could result in a turnabout in the U.S. outlook for renewed growth.     

Review of The challenge of the borderline patient: Competency in diagnosis and treatment.

Reviews the book, The challenge of the borderline patient: Competency in diagnosis and treatment by Jerome Kroll (see record 1988-97021-000). In this new volume on borderline psychopathology, Jerome Kroll has some axes to grind-of the kind found in DSM-III, that is. He offers a refreshing perspective on this popularized topic and casts a healthy skepticism on the current trends and trendiness reflected in the literature. Unique in its back-to-basics, common-sensical approach to diagnosis and treatment, the book, in its essence, aims at demystifying and debunking the aura that surrounds this field. Kroll's volume spans the three predominant areas of inquiry that constitute most of the published works on borderline personality disorders, namely: 1) empirically rooted efforts to establish its construct validity as a diagnostic entity, 2) psychotherapeutic strategies that are primarily enmeshed in larger, unresolved theoretical controversies between the object relations versus self psychology factions within contemporary psychoanalytic thinking, and 3) the search for the magical psychopharmacological bullet that will eradicate borderline symptomotology. For both novice and experienced clinician, this book serves as a useful counterpoint to the current directions in empirical and theoretical work on borderline pathology, a reminder of the potential dangers of getting caught up in methodological precision or overelaborated theory or high-technology psychopharmacology and, as a consequence, of losing sight of the individual, whole patient. It is supportive therapy of the best kind for those of us who face the challenge of treating the borderline patient. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Endovascular surgery--an overview

Endovascular surgery is the vascular equivalent of minimally invasive surgery. It offers the benefits of minimal morbidity and mortality rates as well as short hospital stay, with its associated cost curtailment. In spite of many technological innovations, only balloon dilatation and intravascular stenting have established their places in vascular surgery with the newer field of stent grafting for both occlusive and aneurysmal disease still being evaluated.     

Necropsy survey of metacarpal fusion in the horse

Paired metacarpi obtained at necropsy from 100 horses ranging in age from term fetus to 35 years were examined to estimate the prevalence and sites of metacarpal fusion. Metacarpal fusion was seen in 192 of 200 metacarpi, and 78% of all horses 2 years or older had 2 or more fusions. Fusion of the second metacarpal bone to the third metacarpal bone was significantly (P < 0.001) more common than was fusion of the fourth to the third metacarpal bone. Fusions appeared for the most part in pairs and were bilaterally symmetric. Rooney-Prickett type-A carpometacarpal joint configurations (in which there is no measurable articulation between the third carpal and second metacarpal bones) were rare in this population, and Rooney-Prickett type-B configurations (in which there is a measurable articulation between the third carpal and second metacarpal bones) were observed in 98.5% of metacarpi. Medial metacarpal fusion was positively correlated with age, occupation, and proportion of the proximal projection of the carpometacarpal distal joint surface that was taken by the second metacarpal bone. Lateral metacarpal fusion was positively correlated with age and the proportion of the proximal projection of the carpometacarpal distal joint surface taken by the fourth metacarpal bone. Horses in performance careers (racing, race training, or show ring occupations) had an earlier development of the first 2 fusions than did horses in other or unknown occupations; development of the third and fourth fusions were not significantly different between occupation groups. The rate of metacarpal fusion per horse-year appeared to be at least 10 times higher than a clinically evident rate. A variety of gross morphologic features was observed in the fusions from this sample, some of which were small, subtle, and possibly difficult to detect in vivo. It is hypothesized that many instances of metacarpal fusion may be a result of functional adaptation of the metacarpus to increased or changed loading conditions, rather than a response to isolated traumatic events.     

Cloning and sequence of ADP-ribosylation factor 1 (ARF1) from Schizosaccharomyces pombe

A gene encoding a homologue of the ADP-ribosylation factor (ARF) family of small GTP binding proteins was cloned from a Schizosaccharomyces pombe cDNA library by a functional screen of suppressors of sensitivity to 3-aminotriazole in a gcn3 null strain of Saccharomyces cerevisiae. Two independent isolates each contained the full coding region of the ARF1 gene. The encoded SpARF1 protein has a predicted molecular weight of 20 618 and is 88% and 79% identical to human and S. cerevisiae ARF1 proteins, respectively. As independent isolates were obtained, this effect of the SpARF1 appears to be a real phenomenon, but cannot currently be easily understood within the context of the evidence for a role(s) for ARF proteins in the protein secretory pathway.     

Moisture diffusion in poltimide films in integrated circuits

This paper reports the use of planar aluminum-PI-aluminum capacitors, in which the variation of low frequency dielectric permittivity is shown to be proportional to absorbed moisture, to carry out in-situ studies of moisture uptake and diffusion in PMDA-ODA device-grade polyimide films. It is found that the equilibrium amount of moisture uptake depends on ambient relative humidity in the temperature range 20-80‡C, and that the diffusion kinetics obey a Fickian model with a diffusion coefficient in the range 3-5 x 10^-9 cm² /sec at room temperature. The diffusion coefficient is temperature dependent, with an activation energy of 0.32-0.34 eV, and is weakly dependent on absorbed moisture at fixed temperature. An asymmetry is observed between absorption and desorption kinetics which correlates with the moisture-dependent diffusion coefficient.     

X-ray lathe: An X-ray lithographic exposure tool for nonplanarobjects

An X-ray lithography lathe has been developed that can pattern cylindrical, ellipsoidal, and other nonplanar objects. This lathe is capable of patterning on a micron scale a wide variety of shapes including shapes impossible to achieve with a conventional lathe. A cylindrical core covered with a suitable resist is rotated while being exposed with a collimated X-ray source through a mask. The mask absorbs X rays up to a particular radius from the center of the core and the resist beyond that radius is removed in a developer. Several cylindrical cores were coated with poly(methylmethacrylate) (PMMA) 5 to 125 μm thick and patterned with X-rays down to a 250-μm horizontal scale (along the lathe axis). The exposure time for a cylindrical PMMA layer is ~three-four times longer than a planar layer with the same thickness. The capabilities of this technology, lathe apparatus, dose calculations, and initial exposure results are described     

Sex Attractant Pheromones of Virgin Queens of Sympatric Slave-Making Ant Species in the Genus <Emphasis Type="Italic">Polyergus,</Emphasis> and their Possible Roles in Reproductive Isolation

Species of the ant genus Polyergus are social parasites that steal brood from colonies of their hosts in the closely related genus Formica. Upon emergence as adults in a mixed population, host Formica workers carry out all the normal worker functions within the Polyergus colony, including foraging, feeding, grooming, and rearing brood of the parasitic Polyergus ants. Some unmated Polyergus gynes (queens) run in the raiding columns of their colonies and attract males by releasing a pheromone from their mandibular glands. There are two Polyergus species groups in North America: an eastern P. lucidus group and a western P. breviceps group. One species of each of these groups, P. lucidus Mayr and P. mexicanus Emery, are sympatric in Missouri. In this study, we characterized the sex pheromones of virgin queens of two species of the P. lucidus group (P. lucidus sensu stricto and P. sanwaldi) and one species of the P. breviceps group (P. mexicanus), and compared these with the previously identified sex pheromone of P. topoffi of the P. breviceps group. We then used sex pheromone blends reconstructed from synthesized components of the two groups to test their efficacy at reproductively isolating these species. We found that methyl 6-methylsalicylate is conserved as the major component of the pheromone blends for both Polyergus species groups; however, methyl (R)-3-ethyl-4-methylpentanoate is the species-specific minor component produced by P. lucidus group queens, and (R)-3-ethyl-4-methylpentan-1-ol is the crucial minor component for P. breviceps group queens. The optimal ratio of the major and minor components for P. lucidus group queens was about 100:1 salicylate to ester. In concurrent field trials in Missouri, males of P. lucidus sensu stricto and P. mexicanus (a member of the P. breviceps group) were attracted almost exclusively to their particular blends of sex pheromone components. To our knowledge, this is the first example of a possible sex-pheromone-based reproductive isolating mechanism in ants.