bluuebunny/crossref_metadata_2025 huggingface dataset:
Bird species richness patterns of northern Taiwan: primary productivity, human population density, and habitat heterogeneity
Authors: Koh Chao‐Nien , Lee Pei‐Fen , Lin Ruey‐Shing
Published: May 2006

Energy, climate, habitat heterogeneity, and human activity are important correlates of spatial variation in species richness. We examined the correlation between species richness and these variables using the birds that breed in northern Taiwan. We conducted general linear models (GLMs) and spatial correlation models to examine the relationship between bird species richness (BSR) and environmental variables. We found that normalized difference vegetation index (NDVI) was the most important predictor of BSR. We suggest productivity is the primary process of BSR. Additionally, we hypothesized that scale dependency might exist in the relationship between BSR and NDVI in Taiwan. Human population density, the second most important factor, was inversely correlated with BSR. The factor and BSR did not have similar response to NDVI, which contradicted observations in most of the previous studies on human population vs. species richness. We proposed that the human population density had an effect on NDVI, which in turn had an effect on BSR. Moreover, we hypothesized that the contradiction between our study and the previous studies might arise from a higher level of human disturbance in Taiwan than in other areas. The necessity of conserving native species in intensively developed lowlands of Taiwan cannot be overemphasized. Number of land cover type was another significant predictor of BSR. Habitat heterogeneity may have an effect on BSR in Taiwan.
Neurological toxicity of acyclovir: Report of a case in a six‐month‐old liver transplant recipient
Authors: Chevret L. , Debray D. , Poulain C. , Durand Ph. , Devictor D.
Published: May 2006

Abstract:  Acyclovir‐induced neurotoxicity is a rare adverse effect, found especially in adults with pre‐existing renal failure. We report a case of neurotoxicity of acyclovir in a six‐month‐old liver transplant recipient. Case report and review of literature are discussed.
Morphology of the male reproductive system and sperm ultrastructure of Leucoptera coffeella (Lepidoptera: Lyonetiidae)
Authors: Alves L. , Mancini K. , Lino‐Neto J. , Dolder H.
Published: May 2006

The male reproductive tract of Leucoptera coffeella was processed for light and transmission electron microscopy. In the testis, the eupyrene cells are arranged in individual cysts, while the apyrene cysts form aggregates, never observed in other Lepidoptera. Both cysts contain 128 spermatozoa, which differ from the typical pattern. In the seminal vesicle, both types of spermatozoa are dispersed in the lumen, also different from other Lepidoptera. The apyrene spermatozoa are similar to those observed for other Lepidoptera. They present an anterior region covered by a dense cap and the flagellum is composed of a 9 + 9 + 2 axoneme and two mitochondrial derivatives. The eupyrene spermatozoa, however, differ from the typical pattern for Lepidoptera. Their anterior region contains a nucleus, an acrosome and a peculiar arc of eight accessory microtubules connected to the plasma membrane by dense bridges. In the nucleus–flagellum region, the ninth accessory microtubule is assembled between both mitochondrial derivatives, to participate in the axoneme. The flagellum comprises a 9 + 9 + 2 axoneme and two mitochondrial derivatives with paracrystalline cores. External to the plasma membrane and close to the accessory microtubules, there are tufts of an amorphous material, suggesting reduced lacinate appendages, while the reticular ones are absent. The reduction of lacinate appendages and the absence of sperm bundles in the seminal vesicle support the concept that the appendages of other Lepidoptera could be associated with the eupyrene aggregations. The characters ‘number of spermatozoa per cyst’ and ‘absence of bundles’ should be considered plesiomorphic, supporting the position of this taxon in the base of the Ditrysia.
Tumour volume is an independent predictor of prostate‐specific antigen recurrence in patients undergoing radical prostatectomy for clinically localized prostate cancer
Authors: NELSON BRADFORD A. , SHAPPELL SCOTT B. , CHANG SAM S. , WELLS NANCY , FARNHAM SCOTT B. , SMITH JOSEPH A. , COOKSON MICHAEL S.
Published: May 2006

Authors from the USA sought to establish the relationship between tumour volume, pathological stage and outcomes after radical prostatectomy. In a large series of patients they found that tumour volume was correlated directly with pathological stage, and that it was independently correlated with PSA recurrence. The authors suggested that tumour volume had a potential use for prognostication in patients undergoing radical prostatectomy.

Two papers, one from the USA and one from Germany, advise a re‐staging TUR in patients with superficial bladder cancer who are at high risk of early tumour progression. In a large series of patients they found that residual tumour after initial resection was commoner than might be expected, and that the second resection indicated the way to earlier radical treatment and a better prognosis.

OBJECTIVE

To establish the relationship between tumour volume (TV), pathological stage and outcome after radical prostatectomy (RP), as TV is theoretically an important variable in prostate cancer pathology, but to date it has not been routinely reported and its independent prognostic significance is not well defined.

PATIENTS AND METHODS

The study included 431 consecutive patients undergoing RP for clinically localized cancer, from January 2000 to January 2002, who had a pathological examination of totally submitted whole‐mount processed RP specimens. In addition to Gleason grade, tumour stage and margin assessment by standard techniques, TV was determined by digital planimetry. The total TV or index TV, for cases with obvious discrete separate tumours, were correlated with pathological stage and prostate‐specific antigen (PSA) recurrence.

RESULTS

The mean (range) follow‐up was 25.4 (6–51) months, and the mean TV for all patients was 3.28 (0.4–38.8) mL. There was a direct correlation between TV and pathological stage (P < 0.001). The TV for organ‐confined and extraprostatic disease was 2.09 and 6.02 mL, respectively (P < 0.001). In a multivariate analysis, TV was an independent predictor of PSA recurrence (P = 0.04). The mean TV for patients with PSA recurrence vs no recurrence was 6.8 and 2.6 mL, respectively (P < 0.001).

CONCLUSION

TV correlates directly with pathological stage in RP specimens; furthermore, it is independently correlated with PSA recurrence. TV has potential use for prognostication in patients undergoing RP, and may be combined with other well established clinical variables to aid in predicting outcomes.
Calcium currents in interstitial cells from the guinea‐pig bladder
Authors: McCLOSKEY KAREN D.
Published: May 2006

OBJECTIVE

To determine whether there are inward currents in interstitial cells (IC) isolated from the guinea‐pig detrusor and if so, to characterise them using the patch‐clamp technique and pharmacological agents.

MATERIALS AND METHODS

Using the whole‐cell patch‐clamp technique, inward currents were studied in IC enzymatically isolated from the detrusor of the guinea‐pig bladder. Currents were evoked by stepping positively from a holding potential of − 80 mV.

RESULTS

Outward K+ currents were blocked by Cs+ internal solution to reveal inward currents, which activated at voltages more positive than − 50 mV, peaked at 0 mV, reversed near + 50 mV and were half‐maximally activated at − 27 mV. The inward currents showed voltage‐dependent inactivation and were half‐maximally inactivated at − 36 mV. Fitting the activation and inactivation data with a Boltzmann function revealed a window current between − 40 mV and + 20 mV. The decay of the current evoked at 0 mV could be fitted with a single exponential with a mean time‐constant of 88 ms. Replacing external Ca2+ with Ba2+ significantly increased this to 344 ms. The current amplitude was augmented by Ba2+, and by Bay K 8644. Inward currents were significantly reduced by 1 µm nifedipine, across the voltage range, but the blockade was more effective on the current evoked at 0 mV than that evoked by a step to − 20 mV, perhaps indicating voltage‐dependence of the action of nifedipine or another component of inward current. Increasing the concentration of the drug to 10 µm caused no further significant reduction either at 0 mV or at −20 mV. However, in the presence of 1 µm nifedipine the latter current was significantly reduced by 100 µm Ni2+. Both currents were significantly reduced in Ca2+‐free solution.

CONCLUSIONS

IC from the guinea‐pig detrusor possess inward currents with typical characteristics of L‐type Ca2+ current. They also have a component of inward Ca2+ current, which was resistant to nifedipine, but sensitive to Ni2+. Further work is needed to characterise the latter conductance.
Distribution of nodal metastases after chemotherapy in nonseminomatous testis cancer: a possible indication for limited dissection
Authors: EHRLICH YARON , YOSSEPOWITCH OFER , KEDAR DANIEL , BANIEL JACK
Published: May 2006

OBJECTIVE

To assess the clinical and pathological findings of patients treated by bilateral retroperitoneal lymph node dissection (RPLND) after chemotherapy, to identify a subset for whom modified template nodal resection might be contemplated, as bilateral RPLND is the treatment of choice in patients with residual retroperitoneal disease after chemotherapy for nonseminomatous germ‐cell tumour (GCT).

PATIENTS AND METHODS

The medical records were reviewed of 50 consecutive patients who had RPLND after chemotherapy between 1996 and 2005. Bilateral template RPLND was performed uniformly. Extracted lymph nodes were surgically stratified into three distinct anatomical zones by two sagittal planes running in front of the aorta and the inferior vena cava. The pathological findings were correlated with the side of the primary lesion and the extent of metastatic disease before chemotherapy.

RESULTS

Pathological assessment of the resected lymph nodes revealed teratoma in 28 patients (56%), viable carcinoma in three (6%), and necrosis or fibrosis in 19 (38%). All clinical stage Is, IIA and IIB left‐sided primary tumours followed a predictable pattern of spread constricted to a modified left‐sided template. Patients with clinical stage IIC and III, or right‐sided primary tumour, had a less predictable metastatic pattern, having crossover metastases to the contralateral template.

CONCLUSION

Bilateral RPLND should be considered as the reference standard in patients with metastatic GCT and residual retroperitoneal mass after completing chemotherapy. However, the present data suggest that a modified template dissection might be considered even after chemotherapy in patients with left‐sided primary tumours and limited nodal involvement at presentation.
Urinary incontinence after radical prostatectomy: incidence by definition, risk factors and temporal trend in a large series with a long‐term follow‐up
Authors: SACCO EMILIO , PRAYER‐GALETTI TOMMASO , PINTO FRANCESCO , FRACALANZA SIMONETTA , BETTO GIOVANNI , PAGANO FRANCESCO , ARTIBANI WALTER
Published: May 2006

OBJECTIVES

To investigate the incidence of urinary incontinence and its development over time, to compare the effects of alternative definitions on the incontinence rate and to explore risk factors for incontinence after radical retropubic prostatectomy (RRP) for clinically localized prostate cancer.

PATIENTS AND METHODS

Urinary continence was assessed using a questionnaire administered by a third party in 1144 consecutive patients after undergoing RRP at our department from January 1986 to December 2001. Overall, 985 men (86%) were suitable for evaluation (mean age 64.5 years, mean follow‐up 95.5 months). We compared the effects of three definitions on the actuarial rate of continence: (1) no or occasional pad use; (2) 0 or 1 pads used daily, but for occasional dribbling only; (3) 0–1 pads daily. The time to recovery of continence was defined as the date on which the patient met the continence definitions. The impact of incontinence on health‐related quality of life (HRQoL) was also evaluated. Univariate and multivariate analyses were used to identify predictors of incontinence, using data gathered prospectively.

RESULTS

At the last follow‐up at 24 months after RRP, 83%, 92.3% and 93.4% of men achieved continence according to definitions 1, 2 and 3, respectively. The difference in time to recovering continence was significant for definition 1 compared to the others (P < 0.001). Most men using 1 pad/day complained of occasional dribbling only (89.3%), considered themselves continent (98%) and their HRQoL was not as seriously affected as those requiring ≥ 2 pads/day. Men continent (by definition 3) at 2 years had an actuarial probability of preserving continence of 72.2% at the last follow‐up. On multivariate analysis the age at surgery (P = 0.009), anastomotic stricture and follow‐up interval (both P < 0.001) were independent prognostic factors. Bilateral neurovascular bundle resection was another independent predictive factor (P = 0.03) in the subset of the last 560 men with available data on surgical technique. The reduction in the incidence of incontinence over time was as high as 86%.

CONCLUSIONS

Continence improves progressively until 2 years from RRP but some patients can become incontinent later. The criterion of pad use discriminates well between men with a limited reduction in their QoL (no or one pad used) and those with a markedly affected QoL (≥2 pads/day). It could be clinically valid to consider users of 1 pad/day as continent. Age, bilateral neurovascular bundle resection and anastomotic stricture are significant risk factors for incontinence. There was a marked trend for the incidence of incontinence and anastomotic stricture to decrease with time.
Aim, shoot, ready! Future teachers learn to ‘do’ video
Authors: Hernández‐Ramos Pedro
Published: May 2006

This paper describes an intensive 2‐hr workshop designed to introduce preservice teachers to digital video in the context of an instructional technology course or as a stand‐alone activity. Acknowledging time constraints in most real‐life instructional situations, this format takes novices with no or very limited knowledge of video making to the point where they have experienced most of the steps involved in crafting a finished (though almost certainly unpolished) digital video. Conversations introduce project‐based collaborative learning as the pedagogical context for digital video production, the value of supporting a sense of creativity in students to promote deeper engagement with subject matter through hands‐on activities, and how to involve a variety of learning modalities as opposed to predominantly passive reading and listening. Possible extensions like time‐lapsed video are discussed.
The Role of Language, Appearance, and Culture in Children's Social Category‐Based Induction
Authors: Diesendruck Gil , HaLevi Heidi
Published: May 2006

Four studies examined whether Israeli 5‐year‐olds (N=88) and adults (N=48) drew inferences about psychological properties based on a character's social category, personality trait, or physical appearance trait. Study 1 revealed that while children drew inferences mostly by social category, adults did it by personality trait. Study 2 showed that the children's pattern was not due to how the categorical information was conveyed. Studies 3 and 4 demonstrated that for kindergarteners, labels, not appearances, are determinant of the inductive potential of social categories. Studies indicated that “Jew” and “Arab” were the most inductively powerful social categories for both children and adults. The results carry implications for the roles of language, appearances, and culture in the conceptualization of “human kinds.”
Socialization of Coping With Community Violence: Influences of Caregiver Coaching, Modeling, and Family Context
Authors: Kliewer Wendy , Parrish Katie Adams , Taylor Kelli W. , Jackson Kate , Walker Jean M. , Shivy Victoria A.
Published: May 2006

A socialization model of coping with community violence was tested in 101 African American adolescents (55% male, ages 9–13) and their maternal caregivers living in high‐violence areas of a mid‐sized, southeastern city. Participants completed interviews assessing caregiver coping, family context, and child adjustment. Caregiver–child dyads also discussed a film clip depicting community violence. Parental coaching (caregivers' strategies suggesting how to cope) and child‐reported coping were coded from the discussion. Coaching, modeling (caregivers' own coping), and family context each contributed to children's coping with violence. Children's problem‐focused coping in response to violence had the strongest associations with changes in their adjustment 6 months later. Implications for interventions with youth and families are discussed.
Delayed Intermodal Contingency Affects Young Children's Recognition of Their Current Self
Authors: Miyazaki Michiko , Hiraki Kazuo
Published: May 2006

This study investigated whether 2‐, 3‐, and 4‐year‐olds use their video feedback as a reflection of their current state, even when their feedback was presented with a short temporal delay. In Experiment 1, the effects of 1‐ and 2‐s delayed feedback were examined on an analog of the mark test. In the case of live and 1‐s delayed feedback, 3‐year‐olds passed the test; however, they failed in the case of 2‐s delayed feedback. Experiment 2 examined the effect of prior experience of delayed contingency and explorative behavior. The results showed a significant effect of prior experience. These results suggest that detection of visual–proprioceptive contingency contributes to recognition of visual feedback as one's current self.
DAF‐12‐dependent rescue of dauer formation in Caenorhabditis elegans by (25S)‐cholestenoic acid
Authors: Held Jason M. , White Mark P. , Fisher Alfred L. , Gibson Bradford W. , Lithgow Gordon J. , Gill Matthew S.
Published: May 2006

Population density, temperature and food availability all regulate the formation of the Caenorhabditis elegans dauer larva by modulating endocrine signaling pathways. The orphan nuclear receptor DAF‐12 is pivotal for the decision to form a dauer or to undergo normal reproductive development. The DAF‐12 ligand has been predicted to be a sterol that is metabolized by DAF‐9, a cytochrome P450. Here we chemically characterize purified lipophilic nematode extracts and show that the ligand for DAF‐12 contains a carboxyl moiety and is likely to be derived from a sterol. Using a candidate ligand approach we find that the C27 bile acid cholestenoic acid (5‐cholesten‐3β‐ol‐(25S)‐carboxylic acid) promotes reproductive growth in dauer‐constitutive mutants in a daf‐9‐ and daf‐12‐dependent manner. Furthermore, we find that cholestenoic acid can act as a DAF‐12 ligand by activating DAF‐12 in a cell‐based transcription assay. Analysis of dauer‐rescuing lipophilic extracts from nematodes by gas chromatography–mass spectrometry indicates the presence of several regioisomers of cholestenoic acid that are distinct from Δ5‐cholestenoic acid and are not present in extracts from daf‐9 mutants. These data suggest that carboxylated sterols may be key determinants of life history.
Aggregation and the Measurement of Health Care Costs
Authors: Getzen Thomas E.
Published: May 2006

Objective. This study evaluated the extent to which the causes of variation in health care costs differ by the level at which observations are made.

Methods. More than 40 U.S. and international studies providing empirical estimates of the sources of variation in health care costs were reviewed and arrayed by size of observational units. A simplified graphical analysis demonstrating how estimated correlation coefficients change with the level and type of aggregation is presented.

Results. As the unit of observation becomes larger, association between health care costs and health status/morbidity becomes weaker and smaller in magnitude, while correlation with income (per capita GDP) becomes stronger and larger. Individual expenditure variation within a particular health care system is largely due to differences in health status, but across systems, morbidity has almost no effect on costs. For nations, differences in per capita income explain over 90 percent of the variation in both time series and cross section.

Conclusions. Units of observation used for analysis of health care costs must be matched to the units at which decision making occurs. The observed pattern of empirical results is consistent with a multilevel allocative model incorporating aggregate capacity constraints. To the extent that macro constraints determine total budgets at the national level, policy interventions at the micro level (substitution of generic pharmaceuticals, use of CEA for allocation of treatments, controls on construction and technology, etc.) can act to improve efficiency, equity and average health status, but will not usually reduce aggregate average per capita costs of medical care.
Family approval as a constraint in dependency regulation: Evidence from Australia and Indonesia
Authors: MacDONALD GEOFF , JESSICA MARGARETA
Published: May 2006

Murray and colleagues’ dependency regulation model suggests that individuals in romantic relationships permit themselves to be emotionally dependent on a romantic partner only when they are certain they are valued by their partners. We argue that in cultures where family has a role in mate selection, family approval of the relationship provides an additional constraint on emotional dependence. Reports of relationship perceptions were collected from Australian and Indonesian individuals in dating relationships. The traditional dependency regulation model was affirmed for the Australian sample, but regulation of emotional dependence was best accounted for by both feelings of security in a partner’s affections and perceptions of approval from the partner’s family for the Indonesian sample.
The role of marital attributions in the relationship between life stressors and marital quality
Authors: GRAHAM JAMES M. , CONOLEY COLLIE W.
Published: May 2006

This study examines the role that marital attributions play in the relationship between the occurrence of stressful life events and marital quality. Using a stress adaptation theory framework, data from 58 couples were used to test for the presence of a moderating relationship. The results supported the moderational model, indicating that the marital quality of couples who make relationship‐enhancing attributions about their spouses’ negative behaviors is less related to stress than those who make distress‐maintaining attributions. Couples’ successful adaptation to stress may be dependent on their ability to use their marital attributions as a coping resource. While the types of marital attributions a couple makes have the potential to make their marriage more vulnerable to the effects of stress, they also have the potential to serve a protective role.
Fellow’ Forum Fellows’ Forum in Dialysis: Response to Cyclosporine A in a Patient with Pure Red Cell Aplasia Due to Antierythropoietin‐α Antibodies
Authors: Perazella Mark A. , Fraer Mony , Campbell Adam , Sawaya B. Peter
Published: May 2006

Reported cases of pure red cell aplasia (PRCA) from the administration of erythropoietin (EPO)‐α molecule in the United States are rare, and the optimal treatment is still unknown. We present a patient with end‐stage renal disease (ESRD) who became hyporesponsive and later unresponsive to EPO‐α treatment a few months after initiation of hemodialysis. A comprehensive anemia examination was negative while the patient became transfusion dependent. The diagnosis of EPO‐α‐induced PRCA was confirmed by bone marrow biopsy, by undetectable serum EPO levels following the administration of a large dose of EPO‐α, and by documenting the presence of EPO‐neutralizing antibodies. Administration of cyclosporine A in addition to prednisone enabled the patient to become transfusion and EPO independent. This case further documents the possible occurrence of PRCA with EPO‐α administration in the United States and reaffirms the potential beneficial effect of cyclosporine A.
Failing the Transition from Welfare to Work: Women Chronically Disconnected from Employment and Cash Welfare*
Authors: Turner Lesley J. , Danziger Sheldon , Seefeldt Kristin S.
Published: May 2006

Objectives. Although employment among welfare mothers increased substantially following the 1996 welfare reform, some former welfare recipients failed to find stable employment. We review the extent to which low‐income mothers are without work and cash welfare for long periods of time and seek to understand the correlates of becoming chronically disconnected.

Methods. We analyze data from a 1997–2003 panel study of single mothers who received cash welfare in an urban county in Michigan in February 1997. We develop a new measure of the extent to which former recipients are “chronically disconnected” from both employment and cash welfare and estimate regression models of the correlates of this economic outcome.

Results. About 9 percent of respondents became chronically disconnected, defined as being without employment and cash welfare during at least one‐quarter of the months during the 79‐month study period. Important correlates of becoming chronically disconnected include having a physical limitation, having a learning disability, using illegal drugs or meeting the diagnostic screening criteria for alcohol dependence, and having no car or driver license. The chronically disconnected are more likely to have lost a job than to have lost welfare benefits and are more economically disadvantaged than those with regular sources of economic support.

Conclusions. To reduce the number of women who fail to make a successful transition from welfare to work, more attention should be given to programs and policies that attempt to reconnect disconnected women to regular sources of economic support.
The Effects of Marital Conflict and Marital Disruption on Depressive Affect: A Comparison Between Women In and Out of Poverty*
Authors: Liu Ruth X. , Chen Zeng‐yin
Published: May 2006

Objectives.We examine the independent and interactive effects of marital conflict and marital disruption on women's depressive affect and how these effects vary by family's poverty status.

Methods.We use the OLS regression and data from the National Longitudinal Survey of Youth to test the hypothesized relationships.

Results.The results showed that marital conflict and marital disruption each predicts subsequent depression after controlling for the initial level of depression and other antecedent variables. The effect of marital conflict on depression is stronger among women in poverty than those out of poverty. Furthermore, among women in poverty, marital conflict followed by marital breakup is related to a heightened level of depression, whereas among women financially better off, there is a reduction in the level of depressive affect.

Conclusions.These findings point to the importance of a family's economic condition and its impact on the interrelationships among marital processes and women's psychological health.
Gender Differences in Criminal Sentencing: Do Effects Vary Across Violent, Property, and Drug Offenses?*
Authors: Fernando Rodriguez S. , Curry Theodore R. , Lee Gang
Published: May 2006

Objective. Many studies find that females benefit from their gender in sentencing decisions. Few researchers, however, address whether the gender‐sentencing association might be stronger for some crimes, such as minor nonviolent offending, and weaker for other offenses, such as serious violent crime.

Method. Using a large random sample of convicted offenders in Texas drawn from a statewide project on sentencing practices mandated by the 73rd Texas Legislature, logistic regression and OLS regression analyses of likelihood of imprisonment and prison length illustrate the importance of looking at sentencing outcomes not only in terms of gender but also in terms of crime type.

Results. Specifically, we find that the effect of gender on sentencing does vary by crime type, but not in a consistent or predicted fashion. For both property and drug offending, females are less likely to be sentenced to prison and also receive shorter sentences if they are sentenced to prison. For violent offending, however, females are no less likely than males to receive prison time, but for those who do, females receive substantially shorter sentences than males.

Conclusions. We conclude that such variation in the gender‐sentencing association across crime type is largely due to features of Texas' legal code that channel the level of discretion available to judges depending on crime type and whether incarceration likelihood or sentence length is examined.
Overcoming City Limits: Vertical and Horizontal Models of Local Redistributive Policy Making*
Authors: Craw Michael
Published: May 2006

Objectives.Contrary to conventional wisdom, Census data show a substantial local role in providing health, housing, and public welfare services. I evaluate two models to explain local social welfare: an intergovernmental model, based on federal and state funds, and an interjurisdictional model, based on measures of local monopoly power.

Methods.I estimate a panel data model of local redistributive expenditures from 1992–2002 to test between these alternative explanations for local redistribution.

Results.I find that vertical arrangements tend to drive local redistributive spending.

Conclusions.Intergovernmental factors drive local social welfare policy and suppress the local welfare race to the bottom.
The Partisan Impact of Congressional Redistricting: The Case of Texas, 2001–2003*
Authors: McKee Seth C. , Teigen Jeremy M. , Turgeon Mathieu
Published: May 2006

Objective. In this article we assess the partisan effects of five plans proposed by Republican state legislators during Texas' 2003 congressional redistricting.

Methods. Using the JudgeIt statistical program developed by Gelman and King (2001), and data provided by the Texas Legislative Council, we assess the bias, responsiveness, and the probability that the Democratic Party wins each district for each plan.

Results. All five Republican plans, including the one enacted, are strongly biased in favor of the Republican Party.

Conclusions. Texas' Democratic legislators were wise to use every parliamentary maneuver available to block the enactment of a new congressional map. Beyond affecting the partisan makeup of the Texas delegation, Texas' redistricting has national implications because it adds to the GOP's narrow majority in the U.S. House of Representatives.
THERMAL CONDUCTIVITY OF PEACH, RASPBERRY, CHERRY AND PLUM JUICES AS A FUNCTION OF TEMPERATURE AND CONCENTRATION
Authors: MAGERRAMOV MIKAIL A. , ABDULAGATOV AZIZ I. , ABDULAGATOV ILMUTDIN M. , AZIZOV NAZIM D.
Published: May 2006

The thermal conductivity (k) of four fruit juices (peach, raspberry, cherry and plum) was measured using a coaxial‐cylinder (steady‐state) technique. Measurements were made in the temperature range from 20 to 120C and a range of concentration between 9.8 and 60.0°Brix. The total uncertainties of the k and temperature measurements were less than 2% and 0.03C, respectively. The reliability and accuracy of the experimental methodology for fruit juices was confirmed with measurements on pure water. The experimental and calculated values of k of pure water showed excellent agreement within their experimental uncertainty. The effect of temperature and concentration on the k of peach, raspberry, cherry and plum juices was evaluated. The predictive capability of various polynomial models was established.
A New Self-Piercing Riveting Process and Strength Evaluation
Authors: Wang Bin , Hao Chuanyong , Zhang Jinsong , Zhang Hongyan
Published: May 2006

Self-piercing riveting (SPR) has become an important alternative joining technique for the automotive applications of aluminum sheets. Most existing SPR machines use electrical motors to drive a rivet into the sheets. A significant amount of research has been conducted to improve an SPR joint’s strength by increasing the mechanical interlock. In this paper, a new process is presented using gunpowder to drive the riveting process. A joint formed using the new process has different geometric characteristics from one created using a conventional system. The tensile-shear, cross-tension, fatigue, and impact performances of self-piercing riveted joints using the new device are compared to those of spot-welded joints on aluminum sheets. The experiment has proven that the new SPR joints have provided a similar or higher strength than resistance spot welds.
A Prediction Model of the Adhesive Coating Thickness on a Space Solar Cell
Authors: Fu Zhuang , Zhao Yanzheng , Yang Qinghua
Published: May 2006

This paper presents a prediction model of the adhesive coating thickness on a space solar cell. The model describes the non-Newtonian characteristics of the adhesive when it is bonded to the cover glass and the space solar cell in a non-vacuumed environment. The coating thickness is a function of the differential pressure inside the syringe and its relative speed. It can be indirectly controlled by the two feedbacks. Compared with other systems, the automatic one has better effect on the manufacture of the qualified space solar cell array.
Characterization of facing-target reactive sputtered polycrystalline Fe3O4 films
Authors: Shen J. J. , Mi W. B. , Li Z. Q. , Wu P. , Jiang E. Y. , Bai H. L.
Published: May 2006

Polycrystalline half-metallic Fe3O4 films fabricated by facing-target reactive sputtering were investigated systemically. Structural results reveal that typical Fe3O4 grains were well isolated by grain boundaries and grew with columnar structure. The room-temperature magnetization of Fe3O4 films at 50kOe field is much lower than that of bulk Fe3O4 (471emu∕cm3), due to the presence of strong antiferromagnetic coupling within grain boundary and the amorphous bottom and top layers. The insaturation magnetization and loop shift in high field region at low temperature also stem from the strong antiferromagnetic coupling. The resistivity increases with the decreasing temperature and is consistent with fluctuation-induced tunneling mechanism in a wide temperature ranging from 50to300K. The negative magnetoresistances up to −9.7% at 150K and −6.4% at 300K under 90kOe magnetic field perpendicular to the film plane were observed and discussed.
Selective etching of high-k HfO2 films over Si in hydrogen-added fluorocarbon (CF4∕Ar∕H2 and C4F8∕Ar∕H2) plasmas
Authors: Takahashi Kazuo , Ono Kouichi
Published: May 2006

Inductively coupled hydrogen-added fluorocarbon (CF4∕Ar∕H2 and C4F8∕Ar∕H2) plasmas were used to etch HfO2, which is a promising high-dielectric-constant material for the gate of complementary metal-oxide-semiconductor devices. The etch rates of HfO2 and Si were drastically changed depending on the additive-H2 flow rate in C4F8∕Ar∕H2 plasmas. The highly selective etching of HfO2 over Si was done in the condition with an additive-H2 flow rate, where the Si surface was covered with the fluorocarbon polymer. The results of x-ray photoelectron spectroscopy indicated that the carbon content of the selectively etched HfO2 surface was extremely low compared with the preetched surface contaminated by adventitious hydrocarbon in atmosphere. In the gas phase of the C4F8∕Ar∕H2 plasmas, Hf hydrocarbide molecules such as metal-organic compounds and Hf hydrofluoride were detected by a quadrupole mass analyzer. These findings indicate that the fluorine species, carbon, and hydrogen can work to etch HfO2 and that the carbon species also plays an important role in selective etching of HfO2 over Si.
Thin film reaction of transition metals with germanium
Authors: Gaudet S. , Detavernier C. , Kellock A. J. , Desjardins P. , Lavoie C.
Published: May 2006

A systematic study of the thermally induced reaction of 20 transition metals (Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, and Cu) with Ge substrates was carried out in order to identify appropriate contact materials in Ge-based microelectronic circuits. Thin metal films, nominally 30nm thick, were sputter deposited on both amorphous Ge and crystalline Ge(001). Metal-Ge reactions were monitored in situ during ramp anneals at 3°Cs−1 in an atmosphere of purified He using time-resolved x-ray diffraction, diffuse light scattering, and resistance measurements. These analyses allowed the determination of the phase formation sequence for each metal-Ge system and the identification of the most promising candidates—in terms of sheet resistance and surface roughness—for their use as first level interconnections in microelectronic circuits. A first group of metals (Ti, Zr, Hf, V, Nb, and Ta) reacted with Ge only at temperatures well above 450°C and was prone to oxidation. Another set (Cr, Mo, Mn, Re, Rh, Ru, and Ir) did not form low resistivity phases (<130μΩcm) whereas no reaction was observed in the case of W even after annealing at up to 1000°C. We found that Fe, Co, Ni, Pd, Pt, and Cu were the most interesting candidates for microelectronic applications as they reacted at relatively low temperatures (150–360°C) to form low resistivity phases (22–129μΩcm). Among those, two monogermanides, NiGe and PdGe, exhibited the lowest resistivity values (22–30μΩcm) and were stable over the widest temperature window during ramp anneals. In passing, we note that Cu, Ni, and Pd were the most effective in lowering the crystallization temperature of amorphous Ge, by up to 290°C for our typical ramp anneals at 3°Cs−1.
Detecting free radicals during the hot wire chemical vapor deposition of amorphous silicon carbide films using single-source precursors
Authors: Zaharias Gillian A. , Duan H. L. , Bent Stacey F.
Published: May 2006

A vacuum ultraviolet single photon ionization technique has been used to probe gas-phase species important in the hot wire chemical vapor deposition (HW-CVD) of amorphous silicon carbide(a-SiC:H) films using different single-source precursors. This study focuses on monomethylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, and 1,1-dimethyl-1-silacyclobutane, and the reactions of these precursors on tungsten and rhenium filaments between 1000 and 1950°C. Silane is also considered for comparison. Si radicals are found to be major products of hot wire decomposition for all the organosilicon precursors; CH3 is also observed. C and H radicals are expected to be produced as well but are not detected at the ionization energy used in these experiments. Within the series of methylsilanes, the reaction rate on the filament is found to decrease with increasing number of methyl groups on the precursor. We propose a model in which Si–H bonds are cleaved with lower activation barriers than Si–CH3 bonds as the molecule adsorbs onto the hot metal surface. 1,1-dimethyl-1-silacyclobutane produces Si with a lower apparent activation energy than the other molecules. Coverage-dependent reaction pathways are proposed to play a role in the temperature profile of CH3 generation. Infrared spectra of films deposited by HW-CVD show that the film composition and growth rate for the different precursors correlate with the hot wire chemistry studied by single photon ionization.
Arsenic doping for synthesis of nanocrystalline p-type ZnO thin films
Authors: Xu Ning , Xu Yingliang , Li Li , Shen Yiqun , Zhang Tinwei , Wu Jiada , Sun Jian , Ying Zhifeng
Published: May 2006

Nanocrystalline p-type arsenic-doped ZnO (ZnO:As) films have been synthesized on (0001) sapphire substrates by pulsed laser deposition using a ZnO target mixed with 6.6wt% As2O3. The process of synthesizing p-type ZnO:As films was performed in an ambient gas of ultrapure (<99.99%) oxygen. The ambient gas pressure was 5Pa with the substrate temperature in the range of 350–500°C. The ZnO:As films grown at 500°C are p type, and the acceptor concentration in ZnO:As films is about 1.9×1018at.∕cm3 as determined by Hall effect measurements. The concentration of As in ZnO:As films is estimated to be about 1.7% from the x-ray photoemission spectroscopy (XPS) spectrum. Guided by the XPS analysis and a model for large-sized-mismatched group-V dopant in ZnO, an AsZn–2VZn complex was thought to be the most possible acceptor.
Hydrothermal synthesis, crystal structure, and vibrational and Mössbauer spectra of a new tricationic orthophosphate  KCo3Fe(PO4)3
Authors: Assaaoudi Hassane , Fang Zhen , Ryan Dominic H , Butler Ian S , Kozinski Janusz A
Published: May 2006

Crystals of a new potassium cobalt(II) iron(II) triorthophosphate salt, KCo3Fe(PO4)3, as well as amorphous nanoparticles of the same material have been produced by hydrothermal reactions, under supercritical water (SCW) conditions, of equivalent quantities of aq. CoCl2·6H2O (2 mol/L) and K4P2O7(1 mol/L) in concd. HCl in a stainless steel batch reactor at 400450 °C and 2532 MPa. The dark-violet crystals of the new salt have been characterized by single-crystal X-ray diffraction and IR, Raman, and Mössbauer spectroscopy. The Fe(II) in the new orthophosphate salt must derive from leaching of iron from the stainless steel walls of the reactor by concd. HCl under the SCW conditions. The salt crystallizes in the orthorhombic space group Pnnm, Z = 4, with unit cell parameters as follows: a = 9.672(1) Å, b = 16.457(2) Å, c = 6.2004(8) Å, V = 986.97 Å3. Microporous KCo3Fe(PO4)3exhibits infinite chains of corner-sharing [PO43], [FeO6], and [CoO5] units, which form two large rhombus tunnels, occupied by K+ions, running parallel to [100] in the unit cell. The vibrational spectra have been interpreted partly on the basis of factor group effects and are in accord with the centrosymmetric structure of the material. The particle sizes of this new nanomaterial and their distribution have been determined by scanning electron micrography and laser scattering particle size distribution analysis, while the amorphous nanomaterial has also been characterized by X-ray powder diffraction and Raman spectroscopy. Key words: crystal structure, vibrational and Mössbauer spectra, orthophosphate, nanomaterial.
An acidity scale of phosphonium tetraphenylborate salts and ruthenium dihydrogen complexes in dichloromethane
Authors: Li Tianshu , Lough Alan J , Zuccaccia Cristiano , Macchioni Alceo , Morris Robert H
Published: May 2006

Equilibrium constants (KDM) for reactions between acids and bases of the title compounds in CD2Cl2 (DM) have been determined by 31P and 1H NMR spectroscopy at room temperature. [HPCy3]BPh4 and [HPCy3]BF4, with pKDM assigned by literature convention to 9.7, have been used as the anchor compounds for the pKDM determinations. A continuous scale of pKDM values covering the range 9.7 to 5.7 is created with the acidic compounds [HPR3]BPh4. Those acids with pKDM greater than 6 are stable, while those with more acidic cations HPR3+ protonate BPh4 to produce R3PBPh3 and benzene. The literature pKTHF values reported for [HPBu2Ph]BPh4, [HPMePh2]BPh4, and [HPEtPh2]BPh4 are questionable because of this protonation reaction. NOE and PGSE 1H NMR techniques are used to show that [HPCy2Ph]BPh4 in DM exists as ion pairs and higher aggregates up to quadrupoles at the concentrations used in the acidbase studies. The new dihydrogen complexes [Ru(H2)Cl(PPh3)2(dach)]BF4 (dach = (1R,2R)-()-diaminocyclohexane) and [Ru(H2)Cl{tmeP2(NH)2}]BF4 (tmeP2(NH)2 = PPh2C6H4CH2NHCMe2CMe2NHCH2C6H4PPh2) were prepared by reaction of RuHCl(PPh3)2(dach) and RuHCl{tmeP2(NH)2} with HBF4. Their crystal structures are reported, and the pKDM values of their BPh4 salts were determined to be 8.6 and 6.9, respectively.Key words: acidity, dihydrogen complex, hydride, phosphonium, dichloromethane.
Reactions of MAlH4 (M = Li, Na) with primary amines — Synthetic and structural studies of alkali metal tetrakis(amido)aluminates and related dinuclear complexes
Authors: Eisler Dana J , Chivers Tristram
Published: May 2006

The reactions of MAlH4 (M = Li, Na) with primary amines NH2R (R = t-Bu, i-Pr, p-tolyl) in a 1:4 molar ratio in THF produce the tetrakis(amido)aluminates, [M(THF)n][Al(NHR)4], in yields of 46%–82% together with secondary products. The extent of solvation of the alkali-metal cation varies from none (n = 0) for M[Al(NH-i-Pr)4] (2b, M = Li; 3b, M = Na) to n = 4 in the complex [Li(THF)4][Al(NH-p-tolyl)4] (2c), which exists as a solvent-separated ion pair. The complexes 2b, 3b, and [Na(THF)][Al(NH-p-tolyl)4]∞ (3c) all exhibit one-dimensional polymeric structures in which the bis-N,N′-chelating tetrakis(amido)aluminate anions are bridged by four- (2b, 3b) and five-coordinate (3c) metal ions, respectively. The structures of two of the secondary products, {[Na(THF)2][(NH-t-Bu)Al(H)(µ-N-t-Bu)]}2 (4) and {[Na(THF)3][(NH-p-tolyl)2Al(µ-N-p-tolyl)]}2 (5), were established by X-ray crystallography. Complex 4 is a dimer of the [HAl(NH-t-Bu)(N-t-Bu)]– anion, which forms a central Al2N2 ring with each monoanion N,N′-chelated to a [Na(THF)2]+ cation. Complex 5 is a dimer of the [Al(NR)(NHR)2]– (R = p-tolyl) anion in which the bridging p-tolyl groups are coordinated in an N-monodentate fashion to the trisolvated [Na(THF)3]+ cations. Key words: aluminohydrides, alkali metals, primary amines, tetrakis(amido)aluminates, structures.
Face-selective Diels–Alder reactions of (1R,5R)-3-formyl-6,6-dimethylbicyclo[3.1.1]hept-3-en-2-one
Authors: Liu Hsing-Jang , Li Yanhong , Browne Eric N.C.
Published: May 2006

The stereofacially differentiated enone aldehyde 11 was chosen to study the effects of steric and electronic influence on the Diels–Alder reaction. Under Lewis acid catalysis, 11 adds to dienes at low temperatures at a reasonable rate. Yields of desired chiral adducts are good to high with zinc chloride and boron trifluoride etherate catalysis. In all cases only products of addition to the Re face of general type 27 were observed. The regiochemistry of the adducts is exclusively that predicted by the ortho and para rules. The stereochemistry shows a very high selectivity in favour of aldehyde-endo transition state products. Unusual byproducts were also obtained in some examples and mechanisms of these unexpected reactions are discussed.
Densities and viscosities of binary aqueous mixtures of nonelectrolytes: tert-Butyl alcohol and tert-butylamine
Authors: Kipkemboi Pius K. , Easteal Allan J.
Published: May 2006

The density and shear viscosity of mixtures of tert-butyl alcohol (BuOH) and tert-butylamine (TBA) with water have been determined for various temperatures (288 to 318 K for H2O + BuOH and 288 to 308 K for H2O + TBA) over the whole composition range. Excess molar volumes and apparent molar volumes of the components of each system were calculated from the density data. In both systems the apparent molar volume of the organic component passes through a minimum in the water-rich region. Both systems exhibit large negative excess molar volumes which are essentially independent of temperature at all compositions. The two systems show pronounced maxima in their shear viscosity isotherms.
Structural studies of organoboron compounds LXII. Synthesis and structure of various N-alkylated 1,3-dioxa-4-aza-2-boracyclohexanes
Authors: Kliegel Wolfgang , Amt Henning , Becker Harald , Lauterbach Ute , Lubkowitz Gottfried , Rettig Steven J. , Trotter James
Published: May 2006

The synthesis of a number of variously substituted N-alkyl 2-hydroxyaminoalkanols 3 and their reactions with phenylboronic acid are detailed. The crystalline products proved to be 1:2 condensates 4 in a few cases and 1:1 condensates 5 in all the other cases studied. Crystals of 2-mesityl-6,6-pentamethylene-1,3-dioxa-4-aza-2-boracyclohexane, 5l, are triclinic, a = 11.540(2), b = 10.402(3), c = 8.440(2) Å, α = 108.86(2)°, β = 97.62(2)°, γ = 89.36(2)°, Z = 2, space group [Formula: see text] and those of 4,4′-methylenebis(6,6-pentamethylene-2-phenyl-1,3-dioxa-4-aza-2-boracyclohexane) benzene solvate, 15a•C6H6, are monoclinic, a = 22.690(1), b = 16.867(1), c = 8.4783(9) Å, β = 104.912(8)°, Z = 4, space group C2/c. The structures were solved by direct methods and refined by full-matrix least-squares procedures to R = 0.037 and 0.035 (Rw = 0.035 and 0.044) for 3190 and 2084 reflections with I ≥ 3σ(F2)• respectively.