Discriminating age-associated memory impairment from Alzheimer's disease.

The authors attempt to provide a better understanding of the differences between the normal memory decline characteristic of age-associated memory impairment (AAMI) and the pathological decline typical of mild Alzheimer's disease (AD). Batteries of traditional memory tests and computer-simulated everyday-memory tests discriminated between the 2 groups, which were matched on age, gender, and education, with reasonable degrees of accuracy (87.5% and 88.4%, respectively). False positives were the most frequent classification errors when using either battery. These results indicate that it is possible to use ecologically valid memory assessment paradigms without sacrificing discriminant validity. The clinical significance of discriminating mild AD from AAMI is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and everyday memory: A cross-cultural study.

Performance on computer-simulated, everyday memory tasks was found to deteriorate with age in 434 Belgian (aged 14–88 yrs) and 434 American Ss matched on gender and age. This age-related memory decline was reasonably consistent across samples. Difficulties in cross-cultural research and the advantages of ecologically valid measurement instruments are discussed. Instruments included a grocery list selective reminding test, the Wechsler Memory Scale, the Benton Visual Retention Test, and the Wechsler Adult Intelligence Scale (WAIS). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interband Cascade Lasers with Wavelengths Spanning 2.9 μm to 5.2 μm

We report an experimental investigation of four interband cascade lasers with wavelengths spanning the mid-infrared spectral range, i.e., 2.9 μm to 5.2 μm, near room temperature in pulsed mode. One broad-area device had a pulsed threshold current density of only 3.8 A/cm² at 78 K (λ = 3.6 μm) and 590  A/cm² at 300 K (λ = 4.1 μm). The room-temperature threshold for the shortest-wavelength device (λ = 2.6 μm to 2.9 μm) was even lower, 450 A/cm². A␣cavity-length study of the lasers emitting at 3.6 μm to 4.1 μm yielded an internal loss varying from 7.8 cm⁻¹ at 78 K to 24 cm⁻¹ at 300 K, accompanied by a decrease of the internal efficiency from 77% to 45%.     

Mandibular reconstruction with transforming growth factor-beta1

This is a case report of a 43-year-old woman who received a transplant for end-stage liver disease due to hereditary hemorrhagic telangiectasia and fibropolycystic liver disease. This is an uncommon association of two autosomal-dominant conditions with defined genetic and molecular defects. The liver showed extensive vascular malformations of arteries and veins as well as telangiectasia and fibrosis. In addition, there were cystically dilated ducts containing inspissated bile and extensive von Meyenburg complexes. This case raises interesting questions about the possible relationship of these genes and their gene products, both of which are related to cell-matrix interactions and are strongly associated with blood vessels, one of them being expressed on endothelial cells and the other being developmentally important in blood vessels.     

An examination of verbal supraspan in normal adults and patients with head trauma or unilateral cerebrovascular accident.

Provided a normative data base for a measure of verbal supraspan based on 301 neurologically intact adults (aged 18–91 yrs) and examined the test's clinical sensitivity in 3 patient groups. Data from 55 patients with severe head trauma, 38 with right hemisphere and cerebrovascular accident (CVA), and 15 with left hemisphere CVA reveal significant age-related differences, with older Ss performing below levels obtained by younger ones. Group data reveal that Ss in all 3 groups performed significantly below levels obtained by age-matched controls. Supraspan scores did not correlate appreciably with years of education. However, scores on the supraspan test correlated modestly with Wechsler Adult Intelligence Scale—Revised (WAIS—R) Information and Block Design scores, suggesting that task performance may be dependent in part on the S's general level of cognitive functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Specimen biasing to enhance or suppress secondary electron emission from charging specimens at low accelerating voltages,

Biasing of the specimen is shown to produce improved images in the scanning electron microscope at low beam energies (0.8–2.5 keV) when charging effects (induced by the primary electron beam), topographic effects, or detector shadowing effects would otherwise be present. Examples of such improvement are given for gallium arsenide field-effect transistors (positive charging), patterned photoresist layers on silicon wafers (negative charging and shadowing in contact holes), fractured polymethylmethacrylate (negative charging), polyethylene wrapper material (positive charging), and polished diamond tools (positive charging). It is concluded that specimen biasing may be a simpler and more convenient way to achieve some of the advantages of the converted backscattered secondary electron (CBSE) technique for imaging, but without some of the fundamental disadvantages of that technique. Characterization of this backscattered electron-derived image bears further investigation for possible metrological applications.     

Automated Erection of Structures Utilizing ATLSS Connections and a Robotic Crane

Abstract: The need to automate the process of erecting structural frames has long been recognized by the engineering profession, especially in construction of multistory structures in which members of similar sizes and floor panels of similar dimensions are to be erected repeatedly. Modern automated construction processes, when properly applied, have the potential of producing cost-effective and higher-quality structures as well as providing a safer environment for workers during construction. Since 1986, the Center for Advanced Technology for Large Structural Systems at Lehigh University has been working on the development of an integrated building system that has features particularly suited for construction automation. One of these features is the new types of structural connections that are easy to fabricate and lend themselves to multiple automated construction techniques. The second is a computer-controlled, cable-driven platform that can be attached to a crane. The combination of these technologies leads to a process that can effectively increase productivity, quality, and safety at the job site. This paper discusses these technologies as well as a preliminary economic assessment of the new system.     

High-efficiency series operation of Gunn devices

Successful series operation of two Gunn devices, differing by about 10% in threshold current, has been achieved at X band (8.5?12GHz). The devices were mounted in a resonant cavity and biased to approximately six times the threshold voltage of a single device before both became active. At that point, the output power of the series combination was nearly equal to the sum of the powers observed previously for each device operating alone at its measured bias voltage. For one particular set of diodes, the observed efficiency (for series operation with N/f = 1.3 × 105 s/cm3) was 28.2% at 8.3GHz with 3.4W of peak pulsed power output. This is the highest efficiency ever reported for Gunn devices at such frequencies.     

Reexamination of a plea for multivariate analyses.

Re-examines 2 issues raised in an article by M. R. Leary and E. M. Altmaier (see record 1981-02539-001) proposing MANOVA as a solution to the problem of inflated Type I error. Guidelines are discussed for choosing an overall MANOVA test statistic and post hoc tests that determine the dependent variable or variables responsible for any significant effects. It is concluded that guidelines based on recent comparisons of the various test statistics be used by researchers rather than advice found in basic textbooks. A discussion of the power of MANOVA concludes that although MANOVA may under some conditions reduce the chances of detecting significance, it is powerful for detecting legitimate experimental effects that are spread across more than one dependent variable. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)