Behavioral depression during cocaine withdrawal is associated with decreased spontaneous activity of ventral tegmental area dopamine neurons.

Withdrawal from an escalating-dose, bingelike regimen of cocaine administration in rats produced significantly depressed levels of locomotor activity during the nocturnal portion of the day-night cycle. This effect was observed during the first 48 hrs of testing. Extracellular single-unit recordings of ventral tegmental area (VTA) dopamine (DA) neurons revealed no differences between saline- and cocaine-treated rats with respect to basal firing rates. However, significantly fewer spontaneously active VTA DA neurons were encountered in rats withdrawn from binge cocaine. As with the nocturnal hypoactivity, this effect was observed only during the first 48 hrs of withdrawal. These findings suggest that short-term DA neuron dysfunction during cocaine withdrawal temporally corresponds to behavioral disruptions that are similar to those described in human addicts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generating compact, guaranteed passive reduced-order models of 3-D RLC interconnects

As very large scale integration (VLSI) circuit speeds and density continue to increase, the need to accurately model the effects of three-dimensional (3-D) interconnects has become essential for reliable chip and system design and verification. Since such models are commonly used inside standard circuit simulators for time or frequency domain computations, it is imperative that they be kept compact without compromising accuracy, and also retain relevant physical properties of the original system, such as passivity. In this paper, we describe an approach to generate accurate, compact, and guaranteed passive models of RLC interconnects and packaging structures. The procedure is based on a partial element equivalent circuit (PEEC)-like approach to modeling the impedance of interconnect structures accounting for both the charge accumulation on the surface of conductors and the current traveling in their interior. The resulting formulation, based on nodal or mixed nodal and mesh analysis, enables the application of existing model order reduction techniques. Compactness and passivity of the model are then ensured with a two-step reduction procedure where Krylov-subspace moment-matching methods are followed by a recently proposed, nearly optimal, passive truncated balanced realization-like algorithm. The proposed approach was used for extracting passive models for several industrial examples, whose accuracy was validated both in the frequency domain as well as against measured time-domain data.     

Preparation and characterization of high molecular weight poly(hydroxy ethers) with unusually high glass transition temperatures

A series of novel poly(hydroxy ethers) have been prepared via polymerization of the diglycidyl ethers of bisphenol-A ( 4 ), 4,4 ′-tribromotetramethylbiphenol ( 6a ), and 4,4 ′-tetrabromotetramethylbiphenol ( 6b ) with a variety of rigid diols in an effort to systematically modify structural features of the phenoxy repeat unit in order to control the torsional mobility of polymer backbones and produce materials with softening temperatures higher than are typical for the class. The resulting poly(hydroxy ethers) displyed glass transition temperatures ranging from 109 to 242°C. There of the polymers were characterized with respect to tensile and impact properties and were compared to the polymer sythesized from bisphenol-A ( 1 ) and bisphenol-A diglycidyl ether ( 4 ).     

A case of intractable epistaxis

The surgical management of intractable epistaxis by external carotid artery ligation may become complicated if there is a high bifurcation of the common carotid artery. Occlusion of the bleeding vessels by catheter embolization is described in a patient in whom exploration of the neck had failed to locate the external carotid artery.     

Continuity and change: past experience as adaptive repertoire in occupational adaptation

Narratives are gaining recognition as important ways occupational therapists and other clinicians can think about the life stories of clients. The purpose of this article is to examine a conceptualization of how changes from one chapter to another occur in life stories, using the metaphor of an adaptive repertoire, and to consider how this notion can be useful in helping clients maintain continuity and a coherent life story in times of change. Three premises based on the concept of adaptation address (a) configurations of occupational forms embedded in particular local worlds, (b) cumulative development of an adaptive repertoire that allows one to perform both competently and appropriately, and (c) adaptive transitions and application of one's repertoire to new circumstances. Implications for research and clinical practice in occupational therapy also are examined.     

Designing a Senior Capstone Course to Satisfy Industrial Customers

It is sometimes forgotten that industry is an important customer of engineering education. Ignoring this relationship has produced graduates that often fail to meet the changing needs of industry in today's competitive environment. On the basis of feedback from our industrial customers, faculty from Mechanical Engineering and Manufacturing Engineering at Brigham Young University have jointly developed a new senior capstone design course entitled “Integrated Product and Process Design.” This new capstone course is centered on industrial design and manufacturing projects. These projects involve both product and process design activities. Multidisciplinary teams of students are taught a structured development approach to produce typical industrial deliverables. These deliverables include a functional specification, product and process design, prototype, and first production sample. This paper identifies changing industrial needs, describes how the course was designed to meet these needs, and presents results from the initial offerings of the course.     

Work-site smoking policies: their population impact in Washington State

This article presents data from a population-based, random-digit dialing telephone survey of 1228 employed adults in Washington State, conducted 1989 through 1990. Eighty-one percent of men and 91% of women reported work-site smoking restrictions. Employees in work sites with no-smoking policies were less likely to be current smokers; men in work sites with policies restricting smoking smoked fewer cigarettes on both workdays and nonworkdays. Forty-eight percent of male and 53% of female smokers reported reduced smoking as a result of work-site policy. Work-site smoking policies, intended to protect against smoke exposure, may also reduce employee smoking.     

Jitter reduction through feedback for picosecond pulsed InGaAsPlasers

Following a comparison of picosecond-pulse generation techniques, feedback schemes are reported for the generation of picosecond pulse trains with improved jitter for both multicontact and conventional single-contact InGaAsP-InP lasers. Subpicosecond jitter is achieved for Q-switched laser sources using a novel optoelectronic feedback scheme. The use of resonant electrical feedback is shown to improve the timing jitter of gain-switched pulses by up to six times. Pulse-to-pulse timing jitter as low as 250 fs is demonstrated for a hybrid of optical and electrical feedback schemes. Limits for timing jitter in diode lasers are established for optoelectronic, electrical, and optical feedback schemes, and the key picosecond pulse generation schemes are compared in terms of timing jitter for the first time     

Clinical and historical predictors of dental caries on radiographs

Jet injection can be used to introduce genes into the cells of differentiated tissues of living animals and organ cultures. When a solution of plasmid DNA is jet injected into a selected tissue or organ, cells lying in or near the path of the jet injection are transfected with the DNA and the introduced gene(s) are expressed. Since there is minimal morbidity from each jet injection, multiple injections can be performed at the same or nearby sites. Both mRNA and protein expression from transfected genes can be quantitated using standard methods. In addition, the technique is an efficient means of DNA immunization. Methodology for using jet injection to transfer plasmid DNA into the cells of skin, fat, mammary gland, and muscle are described.