bluuebunny/crossref_metadata_2025 huggingface dataset:
Atomic force microscopy investigation of cold‐plasma‐treated poly(ethyleneterephthalate) textiles
Authors: Poletti G. , Orsini F. , Riccardi C. , Raffaele‐Addamo A. , Barni R.
Published: March 2003

Atomic force microscopy (AFM) has been applied to investigate the morphological and topographical surface modifications induced by radiofrequency cold plasma processing of poly(ethyleneterephthalate) textiles. Surface effects are analysed in low‐pressure air plasma for different plasma exposure times. The results show a progressive degradation of the surface with increasing roughness. The analysis suggests that modification of the surface during textile treatment may be ascribed to a plasma‐induced physical process. Copyright © 2003 John Wiley & Sons, Ltd.
Comparison of energy‐loss functions from REELS spectra with surface and bulk energy loss functions for Ag
Authors: Zengming Zhang , Koshikawa Takanori , Iyasu Takeshi , Shimizu Ryuichi , Goto Keisuke
Published: March 2003

Effective energy‐loss functions were derived from the reflection electron energy‐loss spectroscopy (REELS) spectra of Ag by an extended Landau approach. The effective energy‐loss functions obtained are close to the surface energy‐loss function in the low‐energy‐loss region, but tend to be closer to the bulk energy‐loss function in the higher energy‐loss region for higher primary energy. The REELS spectra incorporating the effective energy‐loss function are also reproduced in a Monte‐Carlo simulation model and confirm that the simulation reproduces the experimental REELS spectra with considerable success. Copyright © 2003 John Wiley & Sons, Ltd.
Arthropod trackways from the Early Devonian of South Wales: a functional analysis of producers and their behaviour
Authors: SMITH A. , BRADDY S. J. , MARRIOTT S. B. , BRIGGS D. E. G.
Published: March 2003

Abundant arthropod trackways, assigned to Diplichnites gouldi, are described from the Lower Old Red Sandstone (Early Devonian; Lochkovian) of Pant-y-Maes quarry, Brecon Beacons, South Wales. The trackways are preserved on bedding planes of finely laminated planar and rippled siltstones. The sedimentology of the succession indicates that these units represent bar top and marginal deposits in a braided fluvial setting. Two trackway types are recognized (Type A and B); comparisons with contemporaneous myriapodous producers favour kampecarid and eoarthropleurid myriapods, respectively. Functional analysis of the trackways indicates that the producers were not using the most efficient, stable, walking techniques, but instead utilized in-phase ‘swimming stroke’-like gaits. Together with their occurrence on rippled surfaces, and lateral displacement of some trackways (attributed to currents), this indicates that they were produced sub-aqueously.
Joint spacing and distribution in deformation band shear zones
Authors: TINDALL S. E. , DAVIS G. H.
Published: March 2003

Tectonic joints localized within deformation band shear zones on the Kaibab uplift in Utah, USA, show the same spacing and distribution characteristics as joints controlled by primary lithological mechanical stratigraphy, despite the fact that deformation band shear zones are secondary structural features oblique to primary sedimentary layers. The spacing and distribution of joints that traverse deformation band shear zones are important factors in the permeability and connectivity of sandstone reservoirs compartmentalized by deformation band shear zones.
TRACES IN THE LANDSCAPE: HUNTERS, HERDERS AND FARMERS ON THE CEDARBERG FRONTIER, SOUTH AFRICA, 1725–95
Authors: MITCHELL LAURA J.
Published: March 2003

Land tenure was at the center of the struggle between settlers and Khoisan on the colonial frontier during the eighteenth century. Different perceptions of land claims and differing patterns of land use prevented the possibility of mutual accommodation. Although pre-colonial hunters and herders co-existed in the Cedarberg region, the introduction of competition from settler pastoralism challenged the survival of both San and Khoikhoi patterns of subsistence. The fight for territory was rooted in competition over specific locations – sites endowed with resources such as permanent water, defensible shelter and ritual significance for the San. Colonial social structure supported settler land claims, eventually enabling successful occupation of a rugged region relatively isolated from the rest of the colony. In the last quarter of the century some Khoisan individuals worked within this system to make land claims of their own. Superior technology and a tightly woven social structure did not alter the basic features of the landscape, so colonists continued to subsist from transhumant pastoralism throughout the century.
ARROWS AND EARTH SHRINES: TOWARDS A HISTORY OF DAGARA EXPANSION IN SOUTHERN BURKINA FASO
Authors: KUBA RICHARD , LENTZ CAROLA
Published: March 2003

The history of the Black Volta region in what is currently south-west Burkina Faso and north-west Ghana has been marked by the agricultural expansion of Dagara-speaking groups. This article explores how and why these groups were able to expand at the expense of neighbouring segmentary societies such as the Phuo and the Sisala. Violence certainly played a role in their territorial expansion, but so did specific strategies of ritual appropriation of new territories. The Dagara system, with its characteristic fission of existing earth shrines and networks of interlinked shrines, allowed mobility and helped the migrants bring new territories under their ritual control. In addition, patriclans and matriclans as well as joking relationships, clan alliances and institutionalized friendship enabled the Dagara pioneers to recruit many new settlers within a short time. This was a crucial asset for the security of the newly founded settlements and the territorial encroachment on Phuo and Sisala lands. In addition, mobility was, and continues to be, supported by an explicit ethos of independence and autonomy. Focusing on the late pre-colonial periods, the article looks at different stages of Dagara expansion and the changing interethnic relations.
The viscous catenary
Authors: TEICHMAN J. , MAHADEVAN L.
Published: March 2003

A filament of an incompressible highly viscous fluid that is supported at its ends sags
under the influence of gravity. Its instantaneous shape resembles that of a catenary,
but evolves with time. At short times, the shape is dominated by bending deformations.
At intermediate times, the effects of stretching become dominant everywhere except
near the clamping boundaries where bending boundary layers persist. Finally, the
filament breaks off in finite time via strain localization and pinch-off.
Characteristics of vortex packets in turbulent boundary layers
Authors: GANAPATHISUBRAMANI BHARATHRAM , LONGMIRE ELLEN K. , MARUSIC IVAN
Published: March 2003

Stereoscopic particle image velocimetry (PIV) was used to measure all three instantaneous components of the velocity field in streamwise–spanwise planes of a turbulent boundary layer at Reτ=1060 (Reθ=2500). Datasets were obtained in the logarithmic layer and beyond. The vector fields in the log layer (z+=92 and 150) revealed signatures of vortex packets similar to those proposed by Adrian and co-workers in their PIV experiments. Groups of legs of hairpin vortices appeared to be coherently arranged in the streamwise direction. These regions also generated substantial Reynolds shear stress, sometimes as high as 40 times −uw. A feature extraction algorithm was developed to automate the identification and characterization of these packets of hairpin vortices. Identified patches contributed 28% to −uw while occupying only 4% of the total area at z+=92. At z+=150, these patches occupied 4.5% of the total area while contributing 25% to −uw. Beyond the log layer (z+=198 and 530), the spatial organization into packets is seen to break down.
Analytical solutions for forced long waves on a sloping beach
Authors: LIU PHILIP L.-F. , LYNETT PATRICK , SYNOLAKIS COSTAS E.
Published: March 2003

We derive analytic solutions for the forced linear shallow water equation of the following form:

<?TeX \partial^2 Y \over \partial t^2}-b{\partial \over \partial
x}\left(x {\partial Y \over \partial x}\right)={\partial^2 f\over \partial t^2 ?>

for x>0,
in which Y(x,t) denotes an unknown variable, f(x,t) a
prescribed forcing function and b a positive constant. This equation has been used to
describe landslide-generated tsunamis and also long waves induced by moving atmospheric
pressure distributions. We discuss particular and general solutions. We then compare our
results with numerical solutions of the same equation and with the corresponding solutions
of the nonlinear depth-integrated equations and discuss them in terms of landslide-generated
tsunamis.
Size at first sexual maturity in Zidona dufresnei (CAENOGASTROPODA: VOLUTIDAE) of the south-western Atlantic Ocean (Mar del Plata, Argentina)
Authors: Giménez Juliana , Penchaszadeh Pablo E.
Published: March 2003

Size at sexual maturity was studied in Zidona dufresnei through analysis of gonadal tissue samples and secondary sexual characters. Individuals were sampled during two reproductive seasons (austral spring–summer) in the Mar del Plata area, Argentina. Gonadosomatic index was estimated for males and oocyte size frequency was used to estimate the stage of gonadal development in females. Gonadal maturity occurred prior to the development of secondary sexual characters. Size at first gonadal maturity in females was 12·8 cm shell length and in males 12·0 cm shell length, but size at which 50% of the population was mature was 15·7 cm in females and 15·0 cm in males. The results of this study could help to establish a minimal catching size.
Re-evaluation of Graneledone setebos (Cephalopoda: Octopodidae) and allocation to the genus Megaleledone
Authors: Allcock A.L. , Hochberg F.G. , Stranks T.N.
Published: March 2003

The holotype of the Antarctic octopodid Graneledone setebos was re-examined and found to lack the epidermal warts characteristic of the genus Graneledone. It is similar in its large size to another Southern Ocean species, Megaleledonesenoi. A comparative study of G. setebos and specimens attributed to M. senoi led us to conclude that M. senoi is a junior synonym of G. setebos. Although M. senoi is not valid, the genus Megaleledone can be separated from other genera by the structure of the radula (which lacks marginal plates) and we therefore consider the genus to be valid. We propose the new combination of Megaleledone setebos and have refigured the beaks and radula of the holotype herein and expanded the description. A search of museum specimens and the literature shows that Megaleledone setebos is more common in Antarctic waters than previously supposed.
Final Syllable Lengthening (FSL) in infant vocalizations
Authors: NATHANI SUNEETI , KIMBROUGH OLLER D. , COBO-LEWIS ALAN B.
Published: March 2003

Final Syllable Lengthening (FSL) has been extensively examined in infant vocalizations in order to determine whether its basis is biological or learned. Findings suggest there may be a U-shaped developmental trajectory for FSL. The present study sought to verify this pattern and to determine whether vocal maturity and deafness influence FSL. Eight normally hearing infants, aged 0;3 to 1;0, and eight deaf infants, aged 0;8 to 4;0, were examined at three levels of prelinguistic vocal development: precanonical, canonical, and postcanonical. FSL was found at all three levels suggesting a biological basis for this phenomenon. Individual variability was, however, considerable. Reduction in the magnitude of FSL across the three sessions provided some support for a downward trend for FSL in infancy. Findings further indicated that auditory deprivation can significantly affect temporal aspects of infant speech production.
The development of inversion in wh-questions: a reply to Van Valin
Authors: ROWLAND CAROLINE F. , PINE JULIAN M.
Published: March 2003

Van Valin (Journal of Child Language29, 2002, 161–75) presents a critique of Rowland & Pine (Journal of Child Language27, 2000, 157–81) and argues that the wh-question data from Adam (in Brown, A first language, Cambridge, MA, 1973) cannot be explained in terms of input frequencies as we suggest. Instead, he suggests that the data can be more successfully accounted for in terms of Role and Reference Grammar. In this note we re-examine the pattern of inversion and uninversion in Adam's wh-questions and argue that the RRG explanation cannot account for some of the developmental facts it was designed to explain.
The effect of ‘missing’ information on children's retention of fast-mapped labels
Authors: WILKINSON KRISTA M. , MAZZITELLI KIM
Published: March 2003

This paper explores ‘fast mapping’, one of several processes that have been proposed to be involved in the rapid vocabulary expansion observed in the preschool years. An adaptation of a receptive word matching task examined how well children retained a just-mapped relation between word and referent when some information was later missing. Thirty-nine children between the ages of 3;0 and 5;6 (mean age 4;3) were taught to select a black square if the correct match for a spoken label was not visible in an array of pictures presented on a computer screen. This procedure allowed children to respond even when they perceived that the correct referent was absent. In experimental sessions, children experienced a single exposure to a word-referent relation. Then, under one condition they heard the just-learned label but were not presented with the matching referent; instead, a completely novel referent was visible along with the black square. Under another condition, they were presented with a just-learned referent (and the black square) but heard a completely new label. The question of interest was whether the children appreciated that an earlier-learned map precluded re-assigning a label to a new referent or re-assigning a referent with a second new label. If so, they should select the black square under both conditions. The majority of children (69%) resisted re-assigning a just-mapped label to a completely novel referent and selected the black square, even when the original referent was not in sight. However, fewer of these children resisted accepting a second label for a just-named referent (46%). Older children were significantly more likely to adhere to original maps than were younger children.
The soft red patch of the Australian freshwater crayfish (Cherax quadricarinatus (von Martens)): a review and prospects for future research
Authors: Karplus Ilan , Sagi Amir , Khalaila Isam , Barki Assaf
Published: March 2003

The red patch located on the propodus of Cherax quadricarinatus males is a sexually dimorphic structure. This patch presents an enigma because it is soft and uncalcified, consisting of a thin red to whitish‐orange membrane. It presents an impairment of the fighting capability of the males, which, like many other clawed crustaceans, use these appendages in intra‐ and interspecific aggressive interactions. Present knowledge on patch structure and colour, development and their endocrine control by the androgenic gland is reviewed. The function of the red patch as a possible sensory organ or social signal is discussed. The red patch may transmit information concerning the gender, size and quality of its owner. Several hypotheses concerning the signal function of the patch are suggested and evaluated in the light of our present knowledge of the social behaviour of C. quadicarinatus.
Bifurcation and stability of periodic solutions of differential equations with state-dependent delays
Authors: SCHLEY D.
Published: March 2003

We consider periodic solutions which bifurcate from equilibria in simple population models which incorporate a state-dependent time delay of the discrete kind. The delay is a function of the current size of the population. Solutions near equilibria are constructed using perturbation methods to determine the sub/supercriticality of the bifurcation and hence their stability. The stability of the bifurcating solutions depends on the qualitative form of the delay function. This is in contrast to the stability of an equilibrium, which is determined purely by the actual value of this function at the equilibrium.
Identification of nonlinear B–H curves based on magnetic field computations and multigrid methods for ill-posed problems
Authors: KALTENBACHER BARBARA , KALTENBACHER MANFRED , REITZINGER STEFAN
Published: March 2003

Our task is the identification of the reluctivity $\nu\,{=}\,\nu(B)$ in $\vec{H}\,{=}\,\nu(B) \vec{B}$, ($B\,{=}\,|\vec{B}|$) from measurements of the magnetic flux for different excitation currents in a driving coil, in the context of a nonuniform magnetic field distribution. This is a nonlinear inverse problem and ill-posed in the sense of unstable data dependence, whose solution is done numerically by a Newton type iterative scheme, regularized by an appropriate stopping criterion. The computational complexity of this method is determined by the number of necessary forward evaluations, i.e. the number of numerical solutions to the three-dimensional magnetic field problem. We keep the effort minimal by applying a special discretization strategy to the inverse problem, based on multigrid methods for ill-posed problems. Numerical results demonstrate the efficiency of the proposed method.
Exploring the Architecture of Potassium Channels Using Chimæras to Reveal Signal Transduction
Authors: Chanda Baron , Tiwari J. K. , Varshney Anurag , Mathew M. K.
Published: March 2003

The chimæric channel, 4N/1, generated from two outwardly rectifying K+ channels by linking the N-terminal cytoplasmic domain of hKv1.4 with the transmembrane body of hKv1.1, functions as an inward rectifier. The operating range of the channel is shifted to hyperpolarizing potentials and it is inactivated at resting membrane potentials. Co-expression of a truncated form of hKv1.1 with the N-terminal domain of hKv1.4 results in the same physiology as the chimæra implying specific interactions between the two segments.
Ecological Factors Impacting Provider Attitudes Towards Human Service Delivery Reform
Authors: Foster-Fishman Pennie G. , Salem Deborah A. , Allen Nicole E. , Fahrbach Kyle
Published: March 2003

Although reform efforts are substantially altering the structural operations and guiding ideological framework of the human service delivery system, little empirical work has been done to systematically examine these transformations. This study examines providers' attitudes regarding two reform elements that are being widely implemented: an increased emphasis on inter‐agency collaboration and a shift from a medical model service delivery philosophy, that focuses on client deficits, to one that emphasizes consumer strengths. Through survey data collected from 186 providers from 32 human service agencies in one county, the relationship between providers' perceptions of contextual support for human service delivery reform and providers' attitudes towards these initiatives is explored. The findings from this study support the importance of attending to the ecology in which we initiate system reform efforts. For both reform elements, working within contexts that are perceived as providing ideological and functional support for change was associated with positive provider attitudes towards those changes. Staffs' perceptions of the external environment played the most critical role in shaping staff attitudes. Interestingly, unique aspects of providers' work environments were related to positive attitudes towards the two different reforms. The implications of these findings for the success of human service delivery reform are discussed.
Effect of Favorable Employment Change on Alcohol Abuse: One‐ and Five‐Year Follow‐Ups in the National Longitudinal Survey of Youth
Authors: Dooley David , Prause JoAnn
Published: March 2003

Job loss has been linked to adverse outcomes such as alcohol abuse, but improved employment, usually assumed to be beneficial, has seldom been evaluated and may not help with addictive disorders. Using the National Longitudinal Survey of Youth, young adults who were unemployed or underemployed (low income or involuntary part‐time) in 1984 were followed up in 1985 and 1989. Controlling for 1984 alcohol abuse, there were no effects of positive employment change on 1985 symptoms, but there were significant restorative effects on 1985 binge drinking among those who were heavy drinkers in 1984. There also appeared to be an indirect link of favorable 1984–1985 employment change to heavy drinking in 1989 via 1989 employment status. Because the effects of underemployment partially resembled those of unemployment, the discussion cautions against the conventional wisdom of promoting any work, including underemployment, as curative for the ills of unemployment.
Psychological Dysfunction in Southeast Asian Refugees as Mediated by Sense of Coherence
Authors: Ying Yu-Wen , Akutsu Phillip D. , Zhang Xiulan , Huang Larke N.
Published: March 2003

Investigated Antonovky's (1979, 1987) construct of sense of coherence (i.e., an individual's belief that the world was comprehensible, manageable, and meaningful) as the internal psychological mechanism mediating the effects of external stressors (generalized resistance deficits) and resources on psychological dysfunction (measured by depression, anxiety, and psychosocial dysfunction) in 2,234 Vietnamese, Cambodian, Laotian, Hmong, and Chinese‐Vietnamese refugees. Generalized resistance and deficits significantly predicted sense of coherence as well as psychological dysfunction. The amount of variance accounted for increased significantly when the mediating effect of sense of coherence was tested using a path analysis. Sense of coherence significantly reduced the predictive power of generalized resistance and deficits in the psychological dysfunction models. Results support the hypothesized mediating role of sense of coherence. Thus, interventions aiming to enhance Southeast Asian refugees' functioning may gain in effectiveness by targeting and promoting their sense of coherence.
Profiles of Self‐Esteem in Early Adolescence: Identification and Investigation of Adaptive Correlates
Authors: DuBois David L. , Felner Robert D. , Brand Stephen , George Gina R.
Published: March 2003

Investigated profiles of self‐esteem during early adolescence and their adaptive correlates in two separate longitudinal studies. Using multidimensional ratings of self‐esteem within a developmental‐ecological framework, cluster analysis revealed five distinct profiles for each sample. The profiles found were characterized by differing patterns of self‐evaluation across major contexts of development, including consistently positive or negative ratings for all domains as well as more variable patterns in which ratings for one or more domains (e.g., school) were elevated or diminished relative to those for other areas. Profiles, in turn, were found to be related to measures of youth adjustment both concurrently and longitudinally, independent of their associations with ratings of global self‐esteem. Prospective analyses in each study further revealed that profile type predicted differential change in measures of youth adjustment over time, whereas this type of relationship was not found for global ratings of self‐esteem. Implications for esteem‐enhancement interventions with youth are discussed.
Validity of Adolescents' Report of Maternal Age
Authors: Zimmerman Marc A. , Rowe Karen , Tuttle Lisa , Bryant Alison
Published: March 2003

Examined the validity of adolescents' reports of their mother's age. Most research on the validity of self‐report focuses on personal behaviors such as alcohol and substance use, or response bias due to social desirability. Few studies investigate the validity of adolescents reporting of nonsensitive information. Data from 80 mother–adolescent pairs were collected. The sample included 9th graders from four high school English classes, equal numbers of males and females, and 15% African Americans. The correlation between mothers' reports and youths' reports of mother's age was .99, and 95% of the youth were within a year of their mother's correct age. No race or gender differences were found. These results allow researchers to examine adolescent outcomes for youth born to teen mothers without the expense of also collecting data from their mothers. Results also suggest that adolescents' self‐reports of other nonsensitive familial data may also be valid.
Gender, Race, and Class in Organizational Contexts
Authors: Bond Meg A.
Published: March 2003

Creating settings that support diversity has been a long‐standing concern of community psychology. In this paper, I propose two qualities as important aspects of organizational contexts that support the meaningful participation of diverse groups:(a) a culture of connection and (b) recognition of multiple “realities.” For each theme, I first examine countervailing values that can undermine meaningful participation of nondominant groups. I suggest that organizational values for independence and a press for sameness can contribute to settings where members of traditionally oppressed groups will be prevented from meaningful participation. I also suggest that fostering a culture of connectedness that actively legitimizes multiple realities is a constructive alternative. To illustrate these points, I share observations based on experiences in manufacturing, educational, and community‐based settings. Then, I explore two dynamics that are important when confronting the countervailing values and building more inclusive contexts: (a) accountability for impact and (b) privilege dynamics. Last, I turn to some possibilities for change through a stance of connected disruption.
Pathways to Risk Among Inner‐City African‐American Adolescent Females: The Influence of Gang Membership
Authors: Harper Gary W. , Robinson W. LaVome
Published: March 2003

Differential rates of participation in three categories of risk behaviors (i.e., sexual activity, substance use, violence) were explored, comparing gang members to nonmembers, within a sample of 1,143 inner‐city African American adolescent females. The relationship between gang membership and risk behavior also was examined, by exploring the association between a variety of microsystemic influences (e.g., gang, family, school) and participation in risk behaviors. MANOVA analyses indicated that gang members, relative to nonmembers, reported higher rates of participation in each of the three categories of risk behaviors. Stepwise linear regression analyses indicated that gang membership was the variable with the most consistent predictive ability, across all categories of risk, as it entered early in all equations and remained in all three final models after controlling for other statistically significant contextual variables. Findings suggest that intervention efforts aimed at reducing adolescent females' participation in sexual activity, substance use, and violence should consider the influence of gang membership on the participation in these behaviors.
A Survival Analysis of Communal‐Living, Self‐Help, Addiction Recovery Participants
Authors: Bishop Peter D. , Jason Leonard A. , Ferrari Joseph R. , Huang Cheng-Fang
Published: March 2003

We examined individual and group characteristics associated with the duration of community involvement (i.e., length of residence) in 11 Illinois Oxford Houses for 129 male recovering addicts. Survival analyses indicated that the best predictor of duration of community involvement from demographic items was age (i.e., older age and older age of fellow residents were associated with being more likely to continue residence). Among psychological measures, the best survival predictor was lack of pessimism of the future. Although the relationship between longer length of residence and treatment outcomes are complex, because it is often difficult to keep people involved in treatment programs, knowledge that we can gain about those factors that might lead to greater lengths of stay are of importance.
Ouabain Induces Apoptosis on PHA-Activated Lymphocytes
Authors: Olej Beni , dos Santos Neusa F. , Leal Ludmila , Rumjanek Vivian M.
Published: March 2003

Apoptotic cell death plays a critical role in immune system homeostasis, and c-myc protooncogene deregulated expression is a component of this programmed genomic response. Pharmacological intervention and modulation of peripheral lymphocytes apoptosis would have important implications. The present results indicate that ouabain, a specific inhibitor of Na+ K+-ATPase, promotes an increased expression of c-myc mRNA, and induces apoptosis in PHA-stimulated lymphocytes. Furthermore, this ouabain-induced apoptosis cannot be counteracted by the addition of exogenous IL-2.
The Public Schools: America's Achilles Heel
Authors: Sarason Seymour B.
Published: March 2003

In a 1973 paper in The American Psychologist, a case was made for why it would take many decades for Blacks to improve their performance on school achievement and other cognitive tests. The paper was in opposition to Jensen's conclusion which emphasized genetics. One important part of the argument was deliberately omitted in that paper. The present paper deals with that omission which concerns the fact that our schools violate what is known about context for productive learning, a fact by no means peculiar to city schools. The near total failure of the educational reform movement has had and will continue to have consequences beyond the educational arena, one of these being Black anti‐Semitism. Our cities are social time bombs. When they will ignite and explode is unpredictable. If classrooms become context for productive learning, the predicted positive outcomes require changes outside the schools, that is, the work arena.
A Longitudinal Assessment of Teacher Perceptions of Parent Involvement in Children's Education and School Performance
Authors: Izzo Charles V. , Weissberg Roger P. , Kasprow Wesley J. , Fendrich Michael
Published: March 2003

This study examines the ways in which parental involvement in children's education changes over time and how it relates to children's social and academic functioning in school. Teachers provided information on parent involvement and school performance for 1,205 urban, kindergarten through third‐grade children for 3 consecutive years. They rated the following four dimensions of parent involvement: frequency of parent‐teacher contact, quality of the parent‐teacher interactions, participation in educational activities at home, and participation in school activites. As predicted, the frequency of parent‐teacher contacts, quality of parent‐teacher interactions, and parent participation at school declined from Years 1 to 3. Every parent involvement variable correlated moderately with school performance and parent involvement in Years 1 and 2, and accounted for a small, but significant amount of variance in Year 3 performance after controlling for initial performance level. Participation in educational activities at home predicted the widest range of performance variables. Results suggest that enhancing parental involvement in children's schooling relates to improvements in school functioning.
Effects of Different Telephone Intervention Styles with Suicidal Callers at Two Suicide Prevention Centers: An Empirical Investigation
Authors: Mishara Brian L. , Daigle Marc S.
Published: March 2003

To determine the relative effectiveness of telephone intervention styles with suicidal callers, researchers listened unobtrusively to 617 calls by suicidal persons at two suicide prevention centers and categorized all 66,953 responses by the 110 volunteer helpers according to a reliable 20‐category checklist. Outcome measures showed observer evaluations of decreased depressive mood from the beginning to the end in 14% of calls, decreased suicidal urgency ratings from the beginning to the end in 27% of calls, and reaching a contract in 68% of calls, of which 54% of contracts were upheld according to follow‐up data. Within the context of relatively directive interventions, a greater proportion of “Rogerian” nondirective responses was related to significantly more decreases in depression. Reduction in urgency and reaching a contract were related to greater use of Rogerian response categories only with nonchronic callers.
Computational Observation of an Ion Permeation Through a Channel Protein
Authors: Suenaga Atushi , Komeiji Yuto , Uebayasi Masami , Meguro Toshiyuki , Saito Minoru , Yamato Ichiro
Published: March 2003

The ion permeation process, driven by a membrane potential through an outer membrane protein, OmpF porin of Escherichia coli, was simulated by molecular dynamics. A Na+ ion, initially placed in the solvent region at the outer side of the porin channel, moved along the electric field passing through the porin channel in a 1.3 nsec simulation; the permeation rate was consistent with the experimentally estimated channel activity (108∼109/sec). In this simulation, it was indicated that the ion permeation through the porin channel proceeds by a “push-out” mechanism, and that Asp113 is an important residue for the channel activity.
Comparison of Peritoneal Fluid and Peripheral Blood pH, Bicarbonate, Glucose, and Lactate Concentration as a Diagnostic Tool for Septic Peritonitis in Dogs and Cats
Authors: Bonczynski Jennifer J. , Ludwig Lori L. , Barton Linda J. , Loar Andrew , Peterson Mark E.
Published: March 2003

Objective—To establish a reliable diagnostic tool for septic peritonitis in dogs and cats using pH, bicarbonate, lactate, and glucose concentrations in peritoneal fluid and venous blood.

Study Design—Prospective clinical study.

Animals—Eighteen dogs and 12 cats with peritoneal effusion.

Methods—pH, bicarbonate, electrolyte, lactate, and glucose concentrations were measured on 1‐ to 2‐mL samples of venous blood and peritoneal fluid collected at admission. The concentration difference between blood and peritoneal fluid for pH, bicarbonate, glucose, and lactate concentrations were calculated by subtracting the peritoneal fluid concentration from the blood concentration. Peritoneal fluid was submitted for cytologic examination and bacterial culture. Peritonitis was classified as septic or nonseptic based on cytology and bacterial culture results.

Results—In dogs, with septic effusion, peritoneal fluid glucose concentration was always lower than the blood glucose concentration. A blood‐to‐fluid glucose (BFG) difference > 20 mg/dL was 100% sensitive and 100% specific for the diagnosis of septic peritoneal effusion in dogs. In 7 dogs in which it was evaluated, a blood‐to‐fluid lactate (BFL) difference < −2.0 mmol/L was also 100% sensitive and specific for a diagnosis of septic peritoneal effusion. In cats, the BFG difference was 86% sensitive and 100% specific for a diagnosis of septic peritonitis. In dogs and cats, the BFG difference was more accurate for a diagnosis of septic peritonitis than peritoneal fluid glucose concentration alone.

Conclusions—A concentration difference > 20 mg/dL between blood and peritoneal fluid glucose concentration provides a rapid and reliable means to differentiate a septic peritoneal effusion from a nonseptic peritoneal effusion in dogs and cats.

Clinical Relevance—The difference between blood and peritoneal fluid glucose concentrations should be used as a more reliable diagnostic indicator of septic peritoneal effusion than peritoneal fluid glucose concentration alone.
Nonlinear Increasing Axial Gap Stiffness in Type II External Skeletal Fixation: A Mechanical Study
Authors: Kowaleski Michael P. , Marston Mathew T. , Kraus Karl H.
Published: March 2003

Objective—To quantify the effect on gap stiffness and cranial to caudal bending stiffness of conversion of the 6 distal clamps of planar bilateral fixator models to sliding clamps and the effect of attachment of composite beams to the sliding clamp models.

Study Design—Mechanical testing performed on models.

Sample Population—Five models using birch dowels and a commercially available external skeletal fixator system.

Methods—A segmentally comminuted, middiaphyseal fracture was simulated with the use of wooden dowels, and a bilateral 6‐pin fixator was applied to create each of 5 models. The models were mechanically tested with all fixed clamps, with the 6 distal clamps converted to sliding clamps and with composite beams attached to the sliding clamp models. Testing was carried out in axial loading with physiologically relevant loads for a canine model, and in bending in the cranial to caudal plane.

Results—Sliding clamp fixators with composite beams attached exhibited a nonlinear increase in axial loading gap stiffness as load increased. The composite beam group also exhibited an increase in cranial to caudal bending stiffness as compared with fixed clamp and sliding clamp models.

Conclusions—Using composite beam elements, planar bilateral external fixators can be constructed such that the fracture site would undergo controlled amounts of displacement at low loads and lessening displacement at higher loads.

Clinical Relevance—The nonlinear stiffness profile attained by the addition of composite beam elements to a planar external fixator allows controlled axial micromotion at the fracture site. Because controlled axial micromotion appears to stimulate fracture healing, a nonlinear stiffness profile of this type should enhance fracture healing.
In vitro Elution of Gentamicin From Plaster of Paris Beads
Authors: Santschi Elizabeth M. , McGarvey Lisa
Published: March 2003

Objective—To determine the in vitro elution characteristics of gentamicin from Plaster of Paris–gentamicin (POP‐gent) beads.

Study design—In vitro, controlled, experimental study.

Methods—The POP‐gent beads were made using a bead mold from 20 g calcium sulfate hemihydrate, 5 mL (500 mg) gentamicin solution, and 3 mL of phosphate buffered saline (PBS). Control beads were made similarly, using 30 g of dried powder and 8 mL of PBS. Beads were left in the mold overnight, gas‐sterilized with ethylene oxide, and stored at room temperature for 5 months before testing. Bead chains were placed in sterile tubes containing porcine serum, and tubes were placed in a 37°C incubator on a rocker. Serum was removed at intervals over 14 days and the concentration of gentamicin determined by fluorescent polarization immunoassay. Serum antibacterial activity was determined against an equine originEscherichia coli.

Results—POP‐gent beads released gentamicin for the 14‐day sampling period. Eighty percent of the gentamicin incorporated in the beads was released over the first 48 hours. Eluent from POP‐gent beads inhibited the growth ofE coliat all time periods. No gentamicin was eluted from control beads and control eluent did not inhibit growth ofE coli.

Conclusions—In this experimental model, POP‐gent beads released bactericidal drug for 14 days. Eighty percent of the gentamicin incorporated into the beads was released during the first 48 hours. The drug retains its bactericidal activity after ethylene oxide sterilization and storage at room temperature for up to 5 months.

Clinical Relevance—Pop‐gent beads may be a useful repository device to deliver gentamicin locally in tissues.
Unilateral Thyroidectomy in 6 Horses
Authors: Elce Yvonne A. , Ross Michael W. , Davidson Elizabeth J. , Tulleners Eric P.
Published: March 2003

Objective,—To describe the surgical technique, complications, and outcome of thyroidectomy in 6 horses.

Study Design—Retrospective study.

Animals—Six horses, 10 to 22 years of age, with unilateral, rapidly enlarging thyroid masses.

Methods—Medical records between 1985 and 2000 were reviewed for horses that had unilateral thyroidectomy. Retrieved data included signalment, physical, clinical, and ultrasonographic examination findings, surgical technique, complications, and outcome. A minimum of 6 months follow‐up was obtained.

Results—Six horses were identified. Three horses had tracheal compression and 2 of these also had exercise intolerance. On ultrasonography (5 horses), the enlarged thyroid ranged from 125 to 990 cm3, and had either a heterogeneous (1 horse), cystic (2), or homogeneous (2) appearance. En bloc, unilateral thyroidectomy under general anesthesia was performed in all horses. After surgery, 3 horses had ipsilateral laryngeal hemiplegia, but tracheal compression was resolved. Thyroid masses were adenoma (3), C‐cell compact carcinoma (1), and adenocarcinoma (1). No tumor recurrence or metastatic disease was reported 6 to 14 months after surgery.

Conclusions—Unilateral thyroidectomy can be successfully performed in horses with large thyroid tumors, but laryngeal hemiplegia can be an important surgical complication. Ultrasonographic examination is useful to define thyroid enlargement and location but is seemingly not useful to characterize tumor type.

Clinical Relevance—Thyroidectomy is an uncommon surgical procedure and has an attendant risk for recurrent laryngeal nerve damage. Laryngoscopic examination before and after surgery and careful isolation of the recurrent laryngeal nerve during surgery is recommended.
Angularis Oris Axial Pattern Buccal Flap for Reconstruction of Recurrent Fistulae of the Palate
Authors: Bryant Karen J. , Moore Kenneth , McAnulty Jonathan F.
Published: March 2003

Objective—To describe the use of an axial pattern flap based on the angularis oris artery and vein for reconstruction of palate defects.

Study Design—Clinical case report

Animals—Two dogs with recurrent oronasal fistulae.

Methods—Oronasal fistulae previously treated by buccal mucosal random pattern flaps that subsequently dehisced were repaired using an angularis oris‐based buccal tissue axial pattern flap. This flap was developed by full thickness incision of the cheek tissue, excluding the skin, about the angularis oris vascular pedicle resulting in a vascularized flap covered by oral mucosa on one side.

Results—In one dog, the repair was intact and healed 6 months after surgery. In the second dog with a fistula that resulted because of radiation necrosis, approximately 95% of the defect healed with a small (<1.0 cm2) area of dehiscence. Repair of this persistent fistula with a random pattern buccal flap failed and this small fistula remained with minimal clinical signs.

Conclusion—An axial pattern flap based on the angularis oris artery and vein can be used to repair difficult or recurrent palate defects.

Clinical Relevance—Angularis oris axial pattern flaps provide an additional effective option for repair of defects in the hard and soft palate to the distal gingival margin of the canine tooth or beyond, depending on skull conformation. Advantages of this flap include its highly vascular and robust character, high degree of mobility and a surface of tough buccal mucosa.
Orthogonal View Analysis for Evaluating the Femoral Component Position of Total Hip Implants in Dogs Using Postoperative Radiographs
Authors: Jehn Carl T. , Bergh Mary Sarah , Manley Paul A.
Published: March 2003

Objective—To show the ability to obtain repeatable, accurate, quantitative data to assess the position of the femoral component of canine total hip implants using postoperative radiographs.

Study Design—Cadaveric study and clinical trial.

Animals—Five cadaveric canine femurs and 4 patients.

Methods—Femoral implants were placed into 5 cadaveric canine femurs in predetermined locations. Orthogonal radiographs were taken of each femur at 10° intervals as they were moved through a natural range of hip motion. An assessment of implant position was made with each set of radiographs and analyzed to observe significant inconsistencies in the values obtained when the femur was repositioned. Three investigators positioned and radiographed the hips of 4 client‐owned dogs that had total hip arthroplasty (THA). Each investigator obtained a set of orthogonal radiographic views from which implant position was measured. The measurements obtained from each investigator's set of radiographs were statistically analyzed to evaluate for interobserver differences.

Results—The methods described indicate that consistent data regarding femoral implant placement can be obtained from postoperative radiographs of THA patients. Under most circumstances, change in position of the femur did not significantly affect femoral implant measurements. There were no significant differences noted among values obtained by different investigators.

Conclusions—Measurements based on the femoral and implant axes obtained from orthogonal radiographic views of the femur provide a means for obtaining accurate and consistent quantitative data regarding femoral implant position using postoperative radiographs of canine THA patients.

Clinical Relevance—Acquisition of quantitative information about femoral implant position using postoperative radiographs will facilitate development of a readily available data source. This information, attainable in a clinical setting, may help identify elements of implant position that are important in determining the clinical outcome of THA in dogs.
Magnetic diagnostics for ITER/BPX plasmas (invited)
Authors: Vayakis G. , Walker C. ,   ITER International Team and Participant Teams
Published: March 2003

The measurement requirements and expected performance of the International Thermonuclear Experimental Reactor (ITER) magnetics system are summarized. The constraints of a burning plasma experiment (BPX) on tokamak magnetic diagnostic system designs are listed and illustrated using the parameters and design of sensors being developed for the ITER device. Design principles to meet the constraints are discussed, with an emphasis on radiation effects, reliability, and redundancy for sensors and subsystems. The remaining research and development for the ITER system is outlined.
Phase-locked-loop-based delay-line-free picosecond electro-optic sampling system
Authors: Lin Gong-Ru , Chang Yung-Cheng
Published: March 2003

A delay-line-free, high-speed electro-optic sampling (EOS) system is proposed by employing a delay-time-controlled ultrafast laser diode as the optical probe. Versatile optoelectronic delay-time controllers (ODTCs) based on modified voltage-controlled phase-locked-loop phase-shifting technologies are designed for the laser. The integration of the ODTC circuit and the pulsed laser diode has replaced the traditional optomechanical delay-line module used in the conventional EOS system. This design essentially prevents sampling distortion from misalignment of the probe beam, and overcomes the difficulty in sampling free-running high-speed transients. The maximum tuning range, error, scanning speed, tuning responsivity, and resolution of the ODTC are 3.9π (700°), <5% deviation, 25–2405 ns/s, 0.557 ps/mV, and ∼1 ps, respectively. Free-running wave forms from the analog, digital, and pulsed microwave signals are sampled and compared with those measured by the commercial apparatus.
Reconnection scaling experiment: A new device for three-dimensional magnetic reconnection studies
Authors: Furno I. , Intrator T. , Torbert E. , Carey C. , Cash M. D. , Campbell J. K. , Fienup W. J. , Werley C. A. , Wurden G. A. , Fiksel G.
Published: March 2003

The reconnection scaling experiment (RSX), a linear device for studying three-dimensional magnetic reconnection in both collisional and collisionless laboratory plasmas, has been constructed at Los Alamos National Laboratory. Advanced experimental features of the RSX that lead to scientific advantages include the use of simple technology (commercial plasma guns) to create plasma and current channels. Physics motivations, design and construction features of the RSX, are presented. Basic plasma parameters that characterize the RSX are shown together with preliminary measurements of visible light emission during the merging of two parallel current channels.