The effects of nonlocal impact ionization on the speed of avalanche photodiodes

The nonlocal enhancement in the velocities of charge carriers to ionization is shown to outweigh the opposing effects of dead space, increasing the avalanche speed of short avalanche photodiodes (APDs) over the predictions of a conventional local model which ignores both of these effects. The trends in the measured gain-bandwidth product of two short InAlAs APDs reported in the literature support this result. Relatively large speed benefits are predicted to result from further small reductions in the lengths of short multiplication regions.     

Generating systems from multiple sketched models

Diagrams are often used to model complex systems: in many cases several different types of diagrams are used to model different aspects of the system. These diagrams, perhaps from multiple stakeholders of different specialties, must be combined to achieve a full abstract representation of the system. Many CAD tools offer multi-diagram integration; however, sketch-based diagramming tools are yet to tackle this difficult integration problem. We extend the diagram sketching tool InkKit to combine software engineering sketches of different types. Our extensions support software design processes by providing a sketch-based approach that allows the iterative creation of multiple outputs interacting with one another from the inter-linked models. We demonstrate that InkKit can generate a functional system consisting of a user interface with processes to submit and retrieve data from a database from sketched user interfaces designs and sketched entity relationship diagrams.     

Using the community health assessment to screen for continued driving

This project used the interRAI based, community health assessment (CHA) to develop a model for identifying current elder drivers whose driving behavior should be reviewed. The assessments were completed by independent housing sites in COLLAGE, a non-profit, national senior housing consortium. Secondary analysis of data drawn from older adults in COLLAGE sites in the United States was conducted using a baseline assessment with 8042 subjects and an annual follow-up assessment with 3840 subjects. Logistic regression was used to develop a Driving Review Index (DRI) based on the most useful items from among the many measures available in the CHA assessment. Thirteen items were identified by the logistic regression to predict drivers whose driving behavior was questioned by others. In particular, three variables reference compromised decision-making abilities: general daily decisions, a recent decline in ability to make daily decisions, and ability to manage medications. Two additional measures assess cognitive status: short-term memory problem and a diagnosis of non-Alzheimers dementia. Functional measures reflect restrictions and general frailty, including receiving help in transportation, use of a locomotion appliance, having an unsteady gait, fatigue, and not going out on most days. The final three clinical measures reflect compromised vision, little interest or pleasure in things normally enjoyed, and diarrhea. The DRI focuses the review process on drivers with multiple cognitive and functional problems, including a significant segment of potentially troubled drivers who had not yet been publicly identified by others. There is a need for simple and quickly identified screening tools to identify those older adults whose driving should be reviewed. The DRI, based on the interRAI CHA, fills this void. Assessment at the individual level needs to be part of the backdrop of science as society seeks to target policy to identify high risk drivers instead of simply age-based testing.     

Chronic growth faltering amongst a birth cohort of Indian children begins prior to weaning and is highly prevalent at three years of age

Background  

Poor growth of children in developing countries is a major public health problem associated with mortality, morbidity and developmental delay. We describe growth up to three years of age and investigate factors related to stunting (low height-for-age) at three years of age in a birth cohort from an urban slum.     

Effects of stimulation on embryonic activity in the chick.

Studied the effects of stimulation on the stereotyped and coordinated movements in the chick (Rhode Island Red/Light Sussex hybrids) embryo using the type of stimulation (regular loud clicks) known to accelerate development and the time of hatching. The number of coordinated movements, the amount and approximate size of all activity, heart rates and, in 20-day embryos, respiration rates were assessed during 15-min control, stimulation, and no stimulation periods. Results show an increase in the number of coordinated movements, but not their size, and some changes in the heart and respiration rates after the onset of stimulation. Effects occurred mostly after several minutes' delay. It is suggested that this delay may be connected with the reciprocal relationship between the coordinated movements and random motility in that the former may be triggered more readily at times when the latter are suppressed. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The professional psychologist as evaluator in a community agency setting.

Describes a process evaluation of an industrial work unit for persons with disabilities and comments on the role of the psychologist as evaluator in an agency of this type. The relationship of process evaluation to other aspects of evaluation is discussed, and reasons are offered for establishing aims before embarking on an outcome evaluation. Suggestions are offered for ways of using ranked aims in every phase of the evaluation, and steps to facilitate the implementation of evaluation results are outlined. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Avalanche multiplication characteristics ofAl0.8Ga0.2As diodes

The avalanche multiplication characteristics of Al_0.8Ga _0.2As have been investigated in a series of p-i-n and n-i-p diodes with i-region widths, w, varying from 1 μm to 0.025 μm. The electron ionization coefficient, α, is found to be consistently higher than the hole ionization coefficient, β, over the entire range of electric fields investigated. By contrast with Al_xGa _1-xAs (x⩽0.6) a significant difference between the electron and hole initiated multiplication characteristics of very thin Al_0.8Ga_0.2As diodes (w=0.025 μm) was observed. Dead space effects in the diodes with w⩽0.1 μm were found to reduce the multiplication at low bias below the values predicted from bulk ionization coefficients. Effective α and β that are independent of w have been deduced from measurements and are able to reproduce accurately the multiplication characteristics of diodes with w⩾0.1 μm and breakdown voltages of all diodes with good accuracy. By performing a simple correction for the dead space, the multiplication characteristics of even thinner diodes were also predicted with reasonable accuracy     

Air permeation tests with orfralure for reduction in trap catch of oriental fruit moths

Orfralure [93% (Z), 7% (E)-8-dodecen-1-ol acetate], the synthetic pheromone of the oriental fruit moth,Grapholitha molesta (Busck), was released into the air of orchard test plots either by hanging plastic laminated dispensers on trees or by aerial dispersal of microcapsules containing a solution of the lure. Trap catch was reduced 95% or more with the most effective formulations, but consistently higher reductions were produced by the dispensers. In tests as long as 28 weeks with dispensers, a single retreatment at midseason maintained an effective concentration.Lepidoptera: Olethreutinae.Mention of a commercial or proprietory product does not constitute an endorsement of this product by the USDA.A preliminary report of some experiments included in this paper appeared elsewhere (Gentry et al., 1976).     

An improved preparation of some insect sex attractants: Synthesis and separation of geometrical isomers by formation of urea complexes

Wittig condensations of aldehydes or ketones with phosphonium salts are frequently used methods for the syntheses of straight-chain or branched alkenes. Suitable choice of reaction conditions may provide the desired geometrical isomer as reaction product. However, we have found that mixtures of geometrical isomers can be conveniently separated on a large scale by the relatively inexpensive method of urea inclusion complex formation. The recovery of both isomers from the separation procedure is almost quantitative. Urea inclusion complexes are formed preferentially withE isomers. Formation of the inclusion complex is affected by the skeletal structure and by the nature of the terminal functional group. By applying this method of separation at a convenient stage, several insect pheromones were prepared without the necessity of a stereoselective step. The technique was used for syntheses of (Z)-11-hexadecenal and (Z)-9-tetradecenal (components of theHeliothis virescens pheromone) and for the synthesis of candidate attractants possessing a trisubstituted double bond.This work was conducted under a Cooperative Agreement between the University of Maryland and the Agricultural Research Service.Mention of a commercial product in this paper does not constitute an endorsement of this product by the USDA.