Maternal relationship instability and the school behavior of children from disadvantaged families.

This longitudinal study examined the relation between the instability of maternal intimate relationships and the school behavior of 3rd-grade children from economically disadvantaged families. After ecological correlates were controlled, chronic relationship instability predicted externalizing behavior for boys and girls and internalizing behavior for girls, but not academic competence. In addition, past and recent instability had independent effects: Recent instability moderated the relation for past instability, and child adjustment in highly unstable families varied with verbal ability and aspects of the family ecology. The theoretical implications concern conceptualizations of the diverse and dynamic nature of family arrangements experienced by disadvantaged children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Augmenting a window system with speech input

Some necessary background in speech recognition and window systems is given, with an analysis of how they might be combined. Xspeak, a navigation application, and its operation and a field study of its use are described. With Xspeak, window navigation tasks usually performed with a mouse can be controlled by voice. An improved version, Xspeak II, which incorporates a language for translating spoken commands, is introduced     

Static and dynamic characteristics of DFB lasers with longitudinalnonuniformity

Static and dynamic characteristics of 1.55-μm distributed-feedback (DFB) lasers with longitudinal nonuniformity in optical intensity and carrier density are discussed. The nonuniformity is manifested in soft light-current threshold and varying differential quantum efficiency, blue-shifted static tuning, and free-carrier induced FM response     

High-speed fiber-optic links for distribution of satellite traffic

Low-loss fiber-optic links are designed for distribution of data and the frequency reference in large-aperture phased-array antennas based on the transmit/receive-level data mixing architecture. In particular, design aspects of a fiber-optic link satisfying the distribution requirements of satellite data traffic are presented. The design is addressed in terms of reactively matched optical transmitter and receiver modules. Analog and digital characterization of a 50-m fiber-optic link realized using these modules indicates the applicability of this architecture as the only viable alternative for distribution of data signals inside a satellite at present. It is demonstrated that the design of a reactive matching modules enhances the link performance. A dynamic range of 88 dB/MHz was measured for analog data over 500-1000-MHz bandwidth     

High gain, wide dynamic range L-band externally modulated fibre optic link

An L-band externally modulated fibre-optic datalink consisting of a semiconductor laser source, a LiNbO/sub 3/ E-O modulator, and an InGaAs detector with lossless impedance matching networks is operated at 900 MHz with 6.4 dB gain and a dynamic range of 70 dB MHz/sup 2/3/ over a 3 dB bandwidth of 50 MHz.<>     

Preparation and luminescence of Pb2OFX; X=Cl,Br, I

The title compounds were prepared and crystallized with the ideal Perite structure. Low temperature luminescence spectra are presented.     

Trade-off studies of a hyperspectral infrared sounder on a geostationary satellite

Trade-off studies on spectral coverage, signal-to-noise ratio (SNR), and spectral resolution for a hyperspectral infrared (IR) sounder on a geostationary satellite are summarized. The data density method is applied for the vertical resolution analysis, and the rms error between true and retrieved profiles is used to represent the retrieval accuracy. The effects of spectral coverage, SNR, and spectral resolution on vertical resolution and retrieval accuracy are investigated. The advantages of IR and microwave sounder synergy are also demonstrated. When focusing on instrument performance and data processing, the results from this study show that the preferred spectral coverage combines long-wave infrared (LWIR) with the shorter middle-wave IR (SMidW). Using the appropriate spectral coverage, a hyperspectral IR sounder with appropriate SNR can achieve the required science performance (1 km vertical resolution, 1 K temperature, and 10% relative humidity retrieval accuracy). The synergy of microwave and IR sounders can improve the vertical resolution and retrieval accuracy compared to either instrument alone.     

Exploiting bias in a non-immune human antibody library to predict antigenicity

Non-immune human antibody fragment libraries have generated antigen-binding proteins useful as prospective research, imaging, diagnostic and therapeutic agents. However, because the generation of such libraries relies on cloning antibody sequences from the circulating immune repertoire rather than truly na?ve, germline sequences, their composition may reflect the deletion of autoreactive sequences, making them less suited for isolating binding clones to human antigens, but perhaps useful in applications where an in vitro handle on representative circulating antibody diversity is desired. Here we demonstrate that a large non-immune human scFv library is relatively depleted of sequences capable of recognizing human antigens as compared with orthologs antigens. Additionally, because this non-na?ve, non-immune library may capture a representative section of antibody diversity, we explore its possible utility in conducting early pre-screens to predict the antigenicity of prospective therapeutics and find a correlation between the clinical immunogenicity of a small panel of protein therapeutics with their propensity for interacting with the library.     

Mercury exposure may suppress baseline corticosterone levels in juvenile birds

Mercury exposure has been associated with a wide variety of negative reproductive responses in birds, however few studies have examined the potential for chick impairment via the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis regulates corticosterone levels during periods of stress. We examined the relationship between baseline fecal corticosterone metabolite concentrations and mercury concentrations in down feathers of recently hatched (<3 days) and blood of older (15-37 days) Forster's tern (Sterna forsteri) chicks in San Francisco Bay, California. Baseline fecal corticosterone metabolite concentrations were negatively correlated with mercury concentrations in blood of older chicks (decreasing by 81% across the range of observed mercury concentrations) while accounting for positive correlations between corticosterone concentrations and number of fledgling chicks within the colony and chick age. In recently hatched chicks, baseline fecal corticosterone metabolite concentrations were weakly negatively correlated with mercury concentrations in down feathers (decreasing by 45% across the range of observed mercury concentrations) while accounting for stronger positive correlations between corticosterone concentrations and colony nest abundance and date. These results indicate that chronic mercury exposure may suppress baseline corticosterone concentrations in tern chicks and suggests that a juvenile bird's ability to respond to stress may be reduced via the downregulation of the HPA axis.     

When recognition memory fails: The use of an elimination strategy by young children.

Two experiments explored the response strategies of young children in the case of the evident failure of recognition memory. 20 4-yr-olds and 20 7-yr-olds were shown a series of pictorial paired associates. At test, Ss had to choose from a set of 4 items the response that had been paired with a particular stimulus during study. The response set consisted of 3 response items paired with a stimulus during study, and 1 new item. In addition to testing the pairs seen during study, 4 new stimulus–response pairs were tested in the same manner. Response choices for these new stimuli, as well as for the stimuli seen during study, allowed an assessment of the strategies used by Ss in the situation where recognition memory has apparently failed. Results show that Ss of both ages employed a reasoning-by-exclusion elimination strategy in responding to the stimuli. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)