bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and properties of phenyleneethynylene-based dendritic structures
Authors: Nierengarten Jean-François
Published: March 2006

In this paper, we report on our ongoing progress on the synthesis and study of branched molecular architectures with a conjugated scaffold. Specifically, new conjugated dendrons incorporating 1,2,4-triethynyl-phenyl units have been developed and used as building blocks for the synthesis of isomeric branched conjugated systems and light-harvesting dendrimers.
Surface Texture Analysis of Artificial Disks Wear-Tested under Different Conditions and Comparison to a Retrieved Implant
Authors: Pare PE , Chan FW , Buchholz P , Kurtz S , McCombe P
Published: March 2006

Total disk arthroplasty is growing in popularity and becoming an alternative to fusion for the treatment of some degenerative disk diseases. To date, there is little consensus regarding the appropriate in vitro techniques with which to evaluate the biotribological properties of these devices. The current study evaluated the surface texture and topography of lumbar metal-on-metal artificial disks tested in a spine wear simulator compared to an explanted device after twelve months in situ. Six implants were tested under a constant load and unidirectional flexion-extension motion as defined by the ASTM standard guide. One implant was tested under a variable load using a combination of flexion-extension, lateral bending, and axial rotation as specified by the ISO standard. While the retrieved disk retained its initial mirror-like surface finish, implants tested under unidirectional motion were severely damaged by abrasive wear resulting in a significant increase in roughness. The implant tested under combined motions exhibited a multi-directional wear scar with limited surface damage. Although only a single retrieved implant was characterized, the current study suggests that wear testing under unidirectional motion may not produce clinically-relevant surface morphology of metal-on-metal artificial disks.
Observational Study on Fall Trends in Snowboarders
Authors: Cooper N , Greenwald RM
Published: March 2006

Snowboarding has distinctly different injury patterns compared with traditional alpine skiing. Injuries occur more frequently in the upper extremity and less frequently in the knees compared to alpine skiing. Snowboarding continues to evolve as a sport, with active participation at all age and experience levels, and on different terrain including slopes, pipes, and terrain parks. An observational study of snowboarders at one U.S. and one Austrian ski resort was conducted during the 2004–05 season to investigate fall trends in a snowboarding population. The purpose of the study was to quantify the incidence of falling, what anatomical structure impacted during a fall, fall direction, and helmet usage as a function of age, gender, ability level, and terrain. Two categories of terrain were identified; standard slopes and terrain parks including half-pipes. Children and adults fall twice as often as youths and young adults. Beginners fall approximately six times more often than advanced snowboarders, and average more than one fall per beginner per run. Runs in the pipe and in a terrain park resulted in a fall 34 and 20 % of the time, respectively. Terrain and experience dictated which body part impacted the snow surface. For beginners, 72 % of all falls were onto the hands. For more experienced participants in the half-pipe or in a terrain park, 50 % of falls were onto the boarder's back or bottom. Helmet use for snowboarders was slightly greater than 50 %. Children were most likely to use a helmet (>90 %), while less than 40 % of young adults used helmets. These observational data will be expanded and combined with injury data to quantify injury risk in the sport of snowboarding as a function of key demographics and environmental variables.
Evaluating Redband Trout Habitat in Sagebrush Desert Basins in Southwestern Idaho
Authors: Zoellick Bruce W. , Cade Brian S.
Published: March 2006

We estimated abundance quantiles of redband trout Oncorhynchus mykiss gairdneri relative to five site-specific habitat variables (stream shading, bank cover, bank stability, fine sediment in the stream substrate, and cover for adults) and one landscape variable (distance from stream headwaters) on 30 streams in southwestern Idaho during 1993–1998. In addition, the five site-specific habitat variables were used to calculate a habitat suitability rating (HSR) used by the U.S. Bureau of Land Management to determine habitat quality of sagebrush desert streams for redband trout. Variation in abundance increased significantly with increasing HSR; the highest abundances were only found with high HSRs, indicating that the HSR model correctly predicted habitat quality for redband trout. However, a model that consisted of stream shade, distance from stream headwaters, and their interaction best predicted redband trout density, explaining 36% of the variation in adult density in sagebrush desert basin streams; stream shade explained most of the variation in redband trout density. When habitat quality was modeled on shade alone, the precision in predicting adult redband trout density was similar to that of the HSR model, as evaluated with tolerance intervals that contained 80% of future observations of redband trout density with 95% confidence. Increasing stream shade in the uppermost 50 km of a stream would result in the greatest increase in redband trout density. We recommend that land managers primarily evaluate the habitat quality of sagebrush desert streams by quantifying the amount of stream shade provided by riparian shrubs and trees. Use of a multivariable habitat model should be retained for desert streams where shade from riparian plant communities is limited.
Scale Pattern Analysis Discriminates Atlantic Salmon by River Reach Rearing Origin
Authors: Haas-Castro Ruth E. , Sheehan Timothy F. , Cadrin Steven X. , Trial Joan G.
Published: March 2006

Scale pattern analysis was used to discriminate among juvenile Atlantic salmon Salmo salar reared in different reaches of the Narraguagus River basin. Measurements of parr scales collected during 1990–1999 were used in a principal components analysis and to create linear discriminant functions for seven geographic strata and three river basin strata groups reflecting natural habitat breaks and Atlantic salmon management regimens. Discriminant functions were calculated with both pooled and annual data. Sufficient differentiation existed among rearing habitats of different reaches (or between geographically grouped reaches) in the Narraguagus River basin, particularly for tributary habitats, to allow discrimination to various degrees of possible use in management.
Incorporation of input function into displays using LTPS TFT technology
Authors: Nakamura T. , Hayashi H. , Yoshida M. , Tada N. , Ishikawa M. , Motai T. , Nakamura H. , Nishibe T.
Published: March 2006

Abstract— A new display in which an input function is incorporated has been developed by using LTPS TFT technology. A new circuit configuration that includes a lateral p‐i‐n diode with an in‐pixel amplifier, an LTPS A/D converter on the periphery of the glass substrate and an external image‐processing LSI is presented. The experimental results of two major applications of the image‐capture function and touch‐panel function are discussed.
Interpreting Senility: Cross-Cultural Perspectives
Authors: Traphagan John W.
Published: March 2006

In general, senility in American society is seen through the lens of biomedicine and conceptualized in terms of physical changes in the person. Research on attitudes about senility in other cultures shows that this is not the only way to conceptualize cognitive change in later life. This article explores cultural aspects related to cognitive change in old age by focusing on ethnographic examples from Japan. I argue that in Japan the social concepts related to defining the person are emphasized when thinking about cognitive change in later life, rather than biomedical concepts associated with pathologies of the brain. In part because of this focus, for older Japanese senility is often viewed as being a moral category as much as a category of disease.
Child Abduction, Parents’ Distress, and Social Support
Authors: Spilman Sarah K.
Published: March 2006

This study examines how parents of family and nonfamily abducted children cope with stress due to the disappearance of their child. The results show that all parents experience distress, regardless of whether it was a family or nonfamily abduction. Associated with parental distress are factors such as prior family stress, age of the child, recovery status of the child, and measures of social support. More specifically, helpful support from friends has been found to decrease parents’ levels of distress, whereas unhelpful support from family and attorneys may increase distress. Mothers and fathers responded to event circumstances and social support in significantly different ways. The need for further research is discussed in the study’s conclusions.
Effects of Community Violence Exposure and Parental Mental Health on the Internalizing Problems of Urban Adolescents
Authors: Self-Brown Shannon R. , LeBlanc Monique , Kelley Mary Lou , Hanson Rochelle , Laslie Karen , Wingate Annie
Published: March 2006

Previous research has documented an association between adolescent community violence exposure (CVE) and poor psychological functioning. The purpose of this study is to delineate the relations of CVE, parental mental health, and adolescent PTSD and depression. Participants consisted of 121 pairs of junior high and high school students and their parents. Adolescents completed measures to assess their history of violence exposure and current psychological functioning. Parents completed a demographic questionnaire and measures assessing their psychological functioning. Hierarchical regression analyses were conducted, and results indicated that, after controlling for demographic variables and family violence exposure, parental mental health emerged as a moderating variable in the relation between CVE and adolescent-rated PTSD, but not in the association between adolescent CVE and depression. Clinical implications of this study and directions for future research are discussed.
Patient Preferences and Adherence to Colorectal Cancer Screening in an Urban Population
Authors: Wolf Randi L. , Basch Charles E. , Brouse Corey H. , Shmukler Celia , Shea Steven
Published: March 2006

We measured patient preferences for colorectal cancer (CRC) screening strategies and actual receipt of alternative CRC screening tests among an urban minority sample participating in an intervention study. The fecal occult blood test was the most preferred test, reportedly owing to its convenience and the noninvasive nature. For individuals who obtained a test that was other than their stated preference (41.1%), reasons for this discordance may be due to physician preferences that override patient preferences.
Bridging Disparity: A Multidisciplinary Approach for Influenza Vaccination in an American Indian Community
Authors: Traeger Marc , Thompson Alette , Dickson Elizabeth , Provencio Augustine
Published: March 2006

Objectives. The Whiteriver Service Unit (WRSU) used proven effective methods to conduct an influenza vaccination campaign during the 2002–2003 influenza season to bridge the vaccination gap between American Indians and Alaska Natives and the US population as a whole.

Methods. In our vaccination program, we used a multidisciplinary approach that included staff and community education, standing orders, vaccination of hospitalized patients, and employee, outpatient, community, and home vaccinations without financial barriers.

Results. WRSU influenza vaccination coverage rates among persons aged 65 years and older, those aged 50 to 64 years, and those with diabetes were 71.8%, 49.6%, and 70.2%, respectively, during the 2002–2003 influenza season. We administered most vaccinations to persons aged 65 years and older through the outpatient clinics (63.6%) and public health nurses (30.0%). The WRSU employee influenza vaccination rate was 72.8%.

Conclusions. We achieved influenza vaccination rates in targeted groups of an American Indian population that are comparable to or higher than rates in other US populations. Our system may be a useful model for other facilities attempting to bridge disparity for influenza vaccination.
Maternal Risk Profiles and the Primary Cesarean Rate in the United States, 1991–2002
Authors: Declercq Eugene , Menacker Fay , MacDorman Marian
Published: March 2006

Objectives. We examined factors contributing to shifts in primary cesarean rates in the United States between 1991 and 2002.

Methods. US national birth certificate data were used to assess changes in primary cesarean rates stratified according to maternal age, parity, and race/ethnicity. Trends in the occurrence of medical risk factors or complications of labor or delivery listed on birth certificates and the corresponding primary cesarean rates for such conditions were examined.

Results. More than half (53%) of the recent increase in overall cesarean rates resulted from rising primary cesarean rates. There was a steady decrease in the primary cesarean rate from 1991 to 1996, followed by a rapid increase from 1996 to 2002. In 2002, more than one fourth of first-time mothers delivered their infants via cesarean. Changing primary cesarean rates were not related to general shifts in mothers’ medical risk profiles. However, rates for virtually every condition listed on birth certificates shifted in the same pattern as with the overall rates.

Conclusions. Our results showed that shifts in primary cesarean rates during the study period were not related to shifts in maternal risk profiles.
Antismoking Advertisements for Youths: An Independent Evaluation of Health, Counter-Industry, and Industry Approaches
Authors: Pechmann Cornelia , Reibling Ellen T.
Published: March 2006

Objectives. We used a validated copy test method to examine the effectiveness of 8 types of antismoking advertisements representing health, counterindustry, and industry approaches. We tested the hypothesis that health ads about tobacco victims can lower most adolescents’ intent to smoke if the ads elicit disgust and anti-industry feelings rather than fear. We hypothesized null effects for adolescents with conduct disorder because of their abnormally low empathy.

Methods. Ninth-grade students from 8 California public schools (n=1725) were randomly assigned to view 1 of 9 videotapes containing a TV show with ads that included either a set of antismoking ads or a set of control ads. Participants completed baseline measures assessing personality traits and postexposure measures assessing smoking intent, feelings, beliefs, and ad evaluations.

Results. Ads focusing on young victims suffering from serious tobacco-related diseases elicited disgust, enhanced anti-industry motivation, and reduced intent to smoke among all but conduct-disordered adolescents. Counterindustry and industry ads did not significantly lower smoking intention.

Conclusions. Sponsors of tobacco use prevention ad campaigns should consider using ads showing tobacco-related disease and suffering, not just counterindustry ads. Ads should be copy tested before airing.
Exposure to the World Trade Center Attack and the Use of Cigarettes and Alcohol Among New York City Public High-School Students
Authors: Wu Ping , Duarte Cristiane S. , Mandell Donald J. , Fan Bin , Liu Xinhua , Fuller Cordelia J. , Musa George , Cohen Michael , Cohen Patricia , Hoven Christina W.
Published: March 2006

We examined exposure to the World Trade Center attack and changes in cigarette smoking and drinking among 2731 New York City public high-school students evaluated 6 months after the attack. Increased drinking was associated with direct exposure to the World Trade Center attack (P < .05). Increased smoking was not directly associated with exposure to the World Trade Center attack but was marginally significantly associated with posttraumatic stress disorder (P= .06). Our findings suggest that targeted substance-use interventions for youths may be warranted after large-scale disasters.
Perceived Neighborhood Problems and Quality of Life, Physical Functioning, and Depressive Symptoms Among Adults With Asthma
Authors: Yen Irene H. , Yelin Edward H. , Katz Patricia , Eisner Mark D. , Blanc Paul D.
Published: March 2006

Objectives. We investigated associations between perceived neighborhood problems and quality of life (QOL), physical functioning, and depressive symptoms among adults with asthma.

Methods. Using cross-sectional data from adults with asthma in northern California (n=435), we examined associations between 5 types of perceived neighborhood problems (traffic, noise, trash, smells, and fires) and asthma-specific QOL (Marks instrument), physical functioning (Short Form-12 physical component summary), and depressive symptoms (Center for Epidemiological Studies–Depression). We used multivariate regression analysis.

Results. When asthma severity and sociodemographics were taken into account, people reporting a score of 8 or higher on a scale of 0 to 25 for serious problems (the top quartile of seriousness) in their neighborhoods had significantly poorer QOL scores (mean difference=5.91; standard error [SE]=1.63), poorer physical functioning (mean difference=−3.04; SE=1.27), and almost a fivefold increase in depressive symptoms (odds ratio=4.79; 95% confidence interval=2.41, 9.52).

Conclusions. A high level of perceived neighborhood problems was associated with poorer QOL, poorer physical functioning, and increased depressive symptoms among people with asthma when disease severity and sociodemographic factors were taken into account.
The Mortality Divide in India: The Differential Contributions of Gender, Caste, and Standard of Living Across the Life Course
Authors: Subramanian S.V. , Nandy Shailen , Irving Michelle , Gordon Dave , Lambert Helen , Davey Smith George
Published: March 2006

Objectives. We investigated the contributions of gender, caste, and standard of living to inequalities in mortality across the life course in India.

Methods. We conducted a multilevel cross-sectional analysis of individual mortality, using the 1998–1999 Indian National Family Health Survey data for 529321 individuals from 26 states.

Results. Substantial mortality differentials were observed between the lowest and highest standard-of-living quintiles across all age groups, ranging from an odds ratio (OR) of 4.61 (95% confidence interval [CI]=2.98, 7.13) in the age group 2 to 5 years to an OR of 1.97 (95% CI=1.68, 2.32) in the age group 45 to 64 years. Excess mortality for girls was evident only for the age group 2 to 5 years (OR=1.33, 95% CI=1.13, 1.58). Substantial caste differentials were observed at the beginning and end stages of life. Area variation in mortality is partially a result of the compositional effects of household standard of living and caste.

Conclusions. The mortality burden, across the life course in India, falls disproportionately on economically disadvantaged and lower-caste groups. Residual state-level variation in mortality suggests an underlying ecology to the mortality divide in India.
Research Recruitment Through US Central Cancer Registries: Balancing Privacy and Scientific Issues
Authors: Beskow Laura M. , Sandler Robert S. , Weinberger Morris
Published: March 2006

Cancer registries are a valuable resource for recruiting participants for public health–oriented research, although such recruitment raises potentially competing concerns about patient privacy and participant accrual.

We surveyed US central cancer registries about their policies for research contact with patients, and results showed substantial variation. The strategy used most frequently (37.5% of those that allowed patient contact), which was among the least restrictive, was for investigators to notify patients’ physicians and then contact patients with an opt-out approach. The most restrictive strategy was for registry staff to obtain physician permission and contact patients with an opt-in approach.

Population-based studies enhance cancer control efforts, and registry policies can affect researchers’ ability to conduct such studies. Further discussion about balanced recruitment approaches that protect patient privacy and encourage beneficial research is needed.
Paternal Age as a Risk Factor for Low Birthweight
Authors: Reichman Nancy E. , Teitler Julien O.
Published: March 2006

Objectives. We examined associations between paternal age and low birth-weight in the US urban population.

Methods. Using a population-based sample of 4621 births, we used multiple logistic regression analysis to estimate associations between paternal age and low birthweight, controlling for maternal age, other demographic factors, and the child’s gender.

Results. When the child’s gender and the mother’s race/ethnicity, birthplace, parity, marital status, and health insurance type were controlled, teenaged fathers were 20% less likely and fathers older than 34 years were 90% more likely than fathers aged 20 to 34 years to have low-birthweight babies. The associations were significant when maternal age was also controlled. No racial/ethnic differences in associations between paternal age and low birthweight were found.

Conclusions. We identified paternal age as an independent risk factor for low birthweight in the US urban population, suggesting that more attention needs to be paid to paternal influences on birth outcomes and to the interactive effects of urban environments and individual risk factors on health.
Barriers to Participation in the Food Stamp Program Among Food Pantry Clients in Los Angeles
Authors: Algert Susan J. , Reibel Michael , Renvall Marian J.
Published: March 2006

Substantial numbers of food pantry clients are eligible for food stamps but do not receive them. Background characteristics of 14317 food pantry users in Los Angeles were analyzed to provide information helpful in food stamp outreach programs. Ninety percent of food pantry users were living well below poverty level, 59% were Hispanic, and 44% were homeless. Only 15% of the food pantry clients received food stamps, with homelessness and limited English language skills acting as barriers to food stamp program participation.
Detection of Carbon Stock Change in Agricultural Soils Using Spectroscopic Techniques
Authors: Stevens Antoine , van Wesemael Bas , Vandenschrick Grégoire , Touré Souleymane , Tychon Bernard
Published: March 2006

Soil organic carbon (SOC) represents one of the major pools in the global C cycle. Therefore, even small changes in SOC stocks cause important CO2fluxes between terrestrial ecosystems and the atmosphere. However, SOC stocks are difficult to quantify accurately due to their high spatial variability. The aim of this paper is to evaluate the potential of Imaging Spectroscopy (IS) using the Compact Airborne Spectrographic Imager (CASI; 405–950 nm) and field spectroscopy with an Analytical Spectral Devices spectrometer (ASD; 350–2500 nm) to measure SOC content in heterogeneous agricultural soils. We used both stepwise and partial least square (PLS) regression analysis to relate spectral measurements to SOC contents. Standard Error of Prediction (SEP) for the ASD ranged from 2.4 to 3.3 g C kg−1depending on soil moisture content of the surface layer. Imaging spectroscopy performed poorly, mainly due to the narrow spectral range of the CASI. Tests using both the CASI and the Shortwave infrared Airborne Spectrographic Imager (SASI; 900–2500 nm) showed better results. The variation in soil texture and soil moisture content degrades the spectral response to SOC contents. Currently, SEP allows to detect a SOC stock change of 7.2–9.9 Mg C ha−1in the upper 30 cm of the soil, and is therefore still somewhat high in comparison with changes in SOC stocks as a result of management or land conversion (0.3–1.9 Mg C ha−1yr−1). A detailed SOC maps produced by IS reflected the patterns in SOC contents due to the recent conversion from grassland to cropland.
Sediment Inventory and Phosphorus Fractions for Water Conservation Area Canals in the Everglades
Authors: Diaz O. A. , Daroub S. H. , Stuck J. D. , Clark M. W. , Lang T. A. , Reddy K. R.
Published: March 2006

Nutrient loading from the Everglades Agricultural Area and nearby urban communities plus water flow rate and canal size have significantly influenced the amount of sediment and phosphorus (P) pools stored in the Water Conservation Area (WCA) canals in the Everglades. A study was conducted to characterize the potential impact that sediments might have on the overlying water column by conducting an inventory of total P (TP) and major P forms in sediments of all major canals in the WCAs. Sediment samples and sediment depth measurements were taken at transects every 1.6‐km along all canals reaches. A total sediment volume of about 6.8 million m3, with a P mass of approximately 1808 Mg was estimated to be stored within all WCA canals, with the eastern canal accounting for 71% of the total sediment volume and about half of TP mass. Phosphorus fractions associated with Ca‐ and Mg‐compounds and residual organic P (Po) were the dominant forms stored in these canals, with the greatest P mass observed in the western side of the WCAs. These results indicates that >80% of the TP mass stored in surface sediments in the WCAs is fairly stable, and represent an important long‐term sink for P. Canal sediments from the eastern side of the WCAs were low in bulk density, highly organic and more susceptible to resuspension and transport during strong drainage events. These sediments showed higher Fe‐ and Al‐bound P and organic‐bound P fractions, making them more susceptible to changes in the redox potential of the sediments that could result in the long‐term release of Fe‐bound P to the overlying water column.
Modeling Phosphorus Transfer between Labile and Nonlabile Soil Pools
Authors: Vadas P. A. , Krogstad T. , Sharpley A. N.
Published: March 2006

Phosphorus transfer from agricultural soils to surface waters is an important environmental issue. Commonly used computer models like EPIC have not always been appropriately updated to reflect our improved understanding of soil P transformations and transfer to runoff. Our objectives were to determine if replacing EPIC's constant sorption and desorption rate factor (0.1) with more dynamic rate factors can more accurately predict changes in soil labile P on addition to and depletion of P from soils. From published data, methods were developed to easily determine dynamic sorption and desorption rate constants from soil properties. These methods were tested with data from new soil P incubation experiments where changes in soil labile P after P addition to and depletion from nine U.S. soils were measured. Replacing constant 0.1 P sorption rate factors with dynamic factors improved prediction of soil labile P with time after P additions but more so for high‐clay than low‐clay soils. EPIC's constant 0.1 P desorption rate factor greatly underpredicted soil P desorption. Increasing the constant to 0.6 improved predictions, whereas dynamic P desorption rate factors most accurately predicted P desorption. Soil P simulations showed that replacing constant P sorption and desorption rate factors with dynamic ones may change dissolved P loads (kg ha−1) in runoff for common soil, cropping, and runoff scenarios by only 1 to 8% in the long term but by 8 to 30% in the short term. These improvements are recommended given the simplicity of making EPIC's sorption and desorption rate factors dynamic.
Carbon Dioxide Emissions from Exhumed Petrocalcic Horizons
Authors: Serna-Pérez Alfonso , Monger H. Curtis , Herrick Jeffrey E. , Murray Leigh
Published: March 2006

The second largest pool of terrestrial carbon is soil CaCO3In addition to being an important sink of atmospheric CO2, soil carbonate is potentially an important source of atmospheric CO2The cemented form of soil carbonate—the petrocalcic horizon—develops in geomorphically stable soil in arid, semiarid, and some subhumid climates. In many of these dryland areas, such as the Chihuahuan Desert of North America, erosion has stripped away overlying soil and exhumed the petrocalcic horizon, thereby exposing it to a weathering zone above the calcification zone where it normally forms. This research tested the hypothesis that soil type 1 (eroded Aridisols with exhumed petrocalcic horizons) will emit more CO2than soil type 2 (noneroded Aridisols with petrocalcic horizons) or soil type 3 (Entisols formed in sandy, noncalcareous sediments). We tested this hypothesis by comparing the amount of CO2and the δ13C of CO2released from the three soil types. Using a randomized complete block design, CO2emissions were measured using NaOH and soda lime traps from June 2002 to October 2003. Neither the NaOH traps nor soda lime traps detected any statistical difference in cumulative CO2emissions from the three soil types at the α = 0.05 level. Moreover, the isotopic analysis of CO2did not match the isotopic values of pedogenic carbonate, nor were there any statistical differences (α = 0.05) in δ13C of CO2among the three soil types. We conclude, therefore, that exhumed petrocalcic horizons are not actively emitting CO2at a rate significantly greater than adjacent soils, and thus carbon stored in petrocalcic horizons can be considered a recalcitrant reservoir within the decadal timeframe pertinent to carbon sequestration policies.
Hydrolysis of Pyrophosphate in a Highly Calcareous Soil
Authors: McBeath T. M. , Smernik R. J. , Lombi E. , McLaughlin M. J.
Published: March 2006

Pyrophosphate is the main form of condensed P in the fluid fertilizer ammonium polyphosphate (APP). When APP is applied to soil, pyrophosphate is hydrolyzed to orthophosphate. Hydrolysis of pyrophosphate was investigated in a highly calcareous soil over 3 wk. Changes in P speciation were measured using solid‐state31P nuclear magnetic resonance (NMR) spectroscopy for dried soil samples and ion chromatography for NaOH extracts. Both techniques showed a decrease in pyrophosphate and concomitant increase in orthophosphate concentration with time, but the rate of pyrophosphate hydrolysis calculated from the NaOH extract measured by ion chromatography was two times faster than the rate calculated from the NMR data indicating differences in P speciation between methods. The NMR technique employed spin counting to determine the proportion of P nuclei observable by NMR. Since this proportion (71–88%) was greater than the proportion of P extracted by NaOH and detected by ion chromatography (38–71%), we concluded that the NMR technique was able to quantify more of the pyrophosphate added than the extraction method. The results of the study suggest that solid‐state31P NMR is a powerful noninvasive technique for the investigation of pyrophosphate reactions in soil and that pyrophosphate has the ability to persist for several weeks in highly calcareous Australian soils in the presence of microbial activity. This has important implications for P availability processes where pyrophosphate is supplied as a fertilizer and is currently under investigation in Australian soil types.
Probability Distribution and Spatial Dependence of Nitrous Oxide Emission
Authors: Yates T. T. , Si B. C. , Farrell R. E. , Pennock D. J.
Published: March 2006

Climate controls soil N2O emissions via its effects on soil properties such as water‐filled pore space. Changes in climate should produce changes in the probability distribution and spatial dependency of soil N2O data. Knowing the extent of the changes in the distribution of this data is important for validating model predictions. The objectives of this study were to describe the probability distributions and estimate the spatial dependency of soil N2O emission data. On a hummocky, agricultural landscape in Saskatchewan, N2O emission data and related soil variables were taken from a 128‐point transect 15 times over 2 yr. Probability distributions were compared using a Chi‐square test. The range in spatial correlation was determined using the indicator semivariogram with a nested model fit approach. The mean N2O flux ranged from 25.3 to −0.2 ng N2O–N m−2s−1Probability distributions ranged in shape from reverse J‐shape through log normal to symmetrical. The majority of distributions were statistically different from each other, showing a lack of temporal stability. Mean N2O flux and distribution shape followed an event‐based/background emission pattern. High flux events had statistically similar, reverse J‐shaped distributions. As mean N2O flux decreased to a background level distribution, shape changed to log normal and symmetrical forms. A high nugget/sill ratio characterized the majority of sampling dates, although spatial dependency was generally moderate. Flux values in the fourth quartile tended to have a spatial dependency of 15 m, probably reflecting a topographic control at a landform element scale.
Tillage Effects on Nitrogen Dynamics and Grass Seed Crop Production in Western Oregon, USA
Authors: Nelson M. A. , Griffith S. M. , Steiner J. J.
Published: March 2006

Understanding N soil fertility in grass seed crops will lead to improved fertilizer practices and preserve water quality in Willamette Valley, Oregon. This study determined the effects of conventional tillage (CT) and no tillage (NT) on N dynamics and grass seed crop growth and seed yield on moderately well‐drained (MWD) and a well‐drained (WD) soils either in tall fescue (Festuca arundinacea Schreb.) or fine fescue (F. rubra L.) production. Temporal changes in soil N, N mineralization and immobilization, crop N uptake and biomass accumulation, and microbial biomass C (MBC) were determined. Net N mineralization was determined using the in situ buried bag method and MBC by fumigation extraction. Tillage treatment had no effect on fine fescue and tall fescue seed yield during the 3 yr of production. Soil MBC, under NT, was 20 to 30% higher (P = 0.05), regardless of soil drainage class or time of year, compared to the CT soil. Soils at the WD site had twice the amount of MBC compared to MWD. Crop N uptake was lowest in the fall and highest when soil N was elevated in the spring. Tillage enhanced annual total net N mineralization at the better‐drained site (WD) resulting in more potential soil NO3 to be leached the following winter high precipitation months when the crop's demand for N is low. This was especially true for fallow years when an actively growing crop was lacking. Net N mineralization was little affected by tillage in the more poorly drained soil.
Sources of Life Strengths as Predictors of Late-Life Mortality and Survivorship
Authors: Fry Prem S. , Debats Dominique L.
Published: March 2006

The aim of the research was to determine within a single study the extent to which demographic factors, self-rated-health and psychosocial factors present the strongest risks or benefits to older adults' mortality in the course of a 5.9-year longitudinal follow-up. The initial sample of 732 individuals was drawn randomly from the registry listings of four municipal branch offices of the Social Services and Community Associations for seniors in Southern Alberta. The final recruitment of 380 participants was based on a representative sample of elders who volunteered participation. A three-part Cox regression analyses model of predictor variables, controlling for age and subsequently controlling for self-rated health and self-rated physical functioning, was implemented to study gender differences in a number of sociodemographic and psychosocial factors, including individuals' sources of internal strengths. As hypothesized, individuals' sources of internal strengths (i.e., Perceptions of Self -Efficacy, Internal Control, Personal Maturity, Personal Commitments, and Social Engagement) are central to the prediction of mortality of both men and women. For men lower education and low levels of perceived internal control, personal commitment, and physical functioning are associated with the greatest threat to mortality but these factors are largely inconsequential for women's survival. By contrast, low levels of perceived social support and social engagement present the greatest risk to women's mortality. Implications of the findings are discussed with respect to factors that contribute to late-life longevity.
Conceptualizing the Everyday Life of Native Americans in the Distant Past
Authors: Tull Stephen W.
Published: March 2006

The daily lives of prehistoric Native Americans are often inappreciable to the contemporary researcher and sometimes overlooked by the professional archaeologist. The archaeological record is one source of information that helps us to conceptualize specific tribal events in the distant past. Written historic ethnographic accounts are a second source; a third, and perhaps most continuous, source of information for interpreting the past is traditional tribal knowledge passed down through generations by Native American oral communication. However, much more information is needed. Debates over such archaeological theories—old and new—are ongoing and contribute greatly to our notions of the past. Yet, more important than considering the profession's interpretive community is the definition of each theory's object of study or inquiry. This article discusses many complex cultural theories as composites of scientific and social-scientific approaches and how archaeologists use them to interpret the past.
Effective Computer Text Design to Enhance Readers' Recall: Text Formats, Individual Working Memory Capacity and Content Type
Authors: Lee Moon J. , Tedder Matthew C. , Xie Gangxin
Published: March 2006

This study investigated the effects of two different computer texts on readers' recall with three different content types (Blocked Constructs, Ordered Constructs, and Detail Layered Constructs) based on individuals' different working memory capacities. The findings indicated that the format and content types influenced how well information was remembered among readers. Participants with low working memory who read traditional scrolling text produced better recall scores than those who read the paged hypertext in two of the three content types. However, for those with high working memory capacity, all results came out differently depending on the content types.
Surprising Lack of Sex Differences in Normal Cognitive Aging in Twins
Authors: Finkel Deborah , Reynolds Chandra A. , Berg Stig , Pedersen Nancy L.
Published: March 2006

Sex differences in the etiology of normal cognitive functioning in aging remain largely unexplored. We conducted an investigation of genetic and environmental contributions to sex differences in level of cognitive performance and rate of decline in the Swedish Adoption/Twin Study of Aging (SATSA) (Finkel & Pedersen, 2004) data set. Behavioral genetic parameterizations of a latent growth curve model were fit to longitudinal data on 11 cognitive measures. Seven hundred and ninety-eight non-demented individuals had cognitive data across four waves of measurement covering 13 years. Participants ranged in age from 44 to 88 at first testing wave; 60% were female. Results indicated sex differences in mean performance for five cognitive measures and in rates of decline for Information and Card Rotations. Only Synonyms demonstrated sex differences in genetic and environmental contributions to mean performance: heritability was higher in men than women. Despite differential longevity and susceptibility to disease, there are no consistent indications that men and women show different patterns of cognitive aging.
Teaching the Complexity of Purpose: Promoting Complete and Creative Communications
Authors: Plung Daniel L.
Published: March 2006

The successful communicator is expected to provide communications that are not only complete but also representative of effective thinking (i.e., original). Creating complete and creative communications begins with a disciplined process of discovery—identifying, assessing, prioritizing, and integrating the articulated and embedded purposes. Expanding on the work of Linda Flower and John Hayes, this article first explores a means to promote a thorough examination of purpose. It then provides tools for capturing and integrating these insights into communications that are complete, capable of satisfying the rhetorical challenges, and compelling reflections of the student's creative problem solving abilities.
The Relationship between Internet-Specific Epistemological Beliefs and Learning within Internet Technologies
Authors: BrÅten Ivar , StrØmsØ Helge I. , Samuelstuen Marit S.
Published: March 2006

In a sample of 157 Norwegian political science undergraduates, two dimensions of epistemological beliefs concerning Internet-based knowledge and knowing were identified through factor analysis. The first dimension, general Internet epistemology, ranged from the integrated view that the Internet is an essential source of true, specific facts to doubt about the Internet as a good source of true, factual knowledge. The other dimension, justification for knowing, ranged from the view that Internet-based knowledge claims can be accepted without critical evaluation to the view that knowledge claims encountered on the Internet should be checked against other sources, reason, and prior knowledge. Further, it was found that students' personal epistemology concerning Internet-based knowledge and knowing predicted their self-reports of Internet-search and -communication activities in better and more consistent ways than did Internet self-efficacy beliefs.
Physical Recovery after Acute Myocardial Infarction: Positive Age Self-Stereotypes as a Resource
Authors: Levy Becca R. , Slade Martin D. , May Jeanine , Caracciolo Eugene A.
Published: March 2006

We considered whether positive and stable self-stereotypes of stigmatized group members can influence functioning (in contrast, stereotype threat theory suggests these influential self-stereotypes are limited to ones that are negative and situational). Specifically, we examined older individuals' positive age stereotypes after a life-threatening event, an acute myocardial infarction (AMI). Sixty-two persons, aged 50 to 96, participated. As expected, positive age stereotypes were found, even immediately after an AMI, and they did not significantly change over the next seven months. Also as expected, these self-stereotypes predicted physical recovery, after adjusting for potentially relevant covariates. Recovery expectations acted as a mediator. These findings suggest the importance of understanding the role that positive stereotypes may play in the health of stigmatized group members.
Synthesis of New 3‐(Substituted Phenacyl)‐5‐[3′‐(4H‐4‐oxo‐1‐benzopyran‐2‐yl)‐benzylidene]‐2,4‐thiazolidinediones and their Antimicrobial Activity
Authors: Tuncbilek Meral , Altanlar Nurten
Published: March 2006

Synthesis of 3‐(3‐nitrophenacyl)thiazolidine‐2,4‐dione 2g and 3‐(substituted phenacyl)‐5‐[3′‐(4H‐4‐oxo‐1‐benzopyran‐2‐yl)‐benzylidene]‐2,4‐thiazolidinediones 4a–g are reported in this paper. These compounds 4a–g were prepared from 3′‐flavone carboxaldehyde and 3‐substituted phenacyl‐2,4‐thiazolidinediones using Knoevenagel reaction. The structures of all compounds were confirmed by IR, 1H‐NMR, mass spectral data, and elemental analyses. The molecules 4a–g were evaluated for in‐vitro antimicrobial activity against Staphylococcus aureus, Candida albicans, Candida krusei, Candida glabrata, and Candida parapsilosis. Compounds 4c and 4f showed better inhibitory activity when compared to fluconazole against Candida krusei and Candida glabrata.
Synthesis and Biological Evaluation of Heteroaryldiamides and Heteroaryldiamines as Cytotoxic Agents, Apoptosis Inducers and Caspase‐3 Activators
Authors: Echeverría Mikel , Mendívil Beatriz , Cordeu Lucía , Cubedo Elena , García‐Foncillas Jesús , Font María , Sanmartín Carmen , Palop Juan Antonio
Published: March 2006

The work described here involved the synthesis and biological evaluation of new heteroaryldiamides and heteroaryldiamines. A new general model in which the structures can be adjusted has been applied in this study. Three different structural units can be distinguished: a central nucleus and two symmetric terminal units. The central element is either an aliphatic chain of varying length and flexibility, piperazine, or a polyamine nucleus. However, the terminal units are pyridine, quinoline, indole, benzene or pyrido[2,3‐d]pyrimidine with different substituents. The antitumoural activities of the compounds were evaluated in vitro by examining their cytotoxic effects against human breast, colon, and bladder cancer cell lines. Compounds that showed cytotoxic activity were subjected to both apoptosis and caspase‐3 assays. With regard to selectivity, the cytotoxicity was also determined in cell cultures of two nontumoural lines. The most promising compounds are 4c, 5c and 7, which are amino‐pyridinium, quinolyl‐N‐oxide, and pyridyl derivatives, respectively, and these reveal a significant in vitro cytotoxicity in at least two of the three cell lines tested. These compounds induced apoptosis and also produced a rapid dose‐dependent increase in the caspase‐3 level in HT‐29 cells. Other encouraging profiles were found, such as those presented by 1k and 8d, which are cytotoxic and apoptotic but do not provoke an increase in the level of caspase‐3, or those presented by 2f, 3c and 4a, which are slightly cytotoxic but do not show any other significant activity. The different types of behaviour of each compound are not necessarily parallel in the three cell lines tested.
Muscarinic Allosteric Modulators: Atypical Structure‐Activity‐Relationships in Bispyridinium‐type Compounds
Authors: Sürig Ulf , Gaal Klaudia , Kostenis Evi , Tränkle Christian , Mohr Klaus , Holzgrabe Ulrike
Published: March 2006

Allosteric modulators of receptor binding are known for a variety of membrane receptors. In case of muscarinic receptors, a considerable number of structurally divergent modulators have been described. For the M2 receptor subtype which has a high sensitivity to allosteric modulation most of the allosteric agents bind to the common allosteric binding site of the receptor protein. In this study, a series of DUO compounds characterized by a bispyridinium middle chain and lateral benzyloximeether moieties of a systematically varied substitution pattern has been evaluated with regard to their allosteric potency to affect M2 receptors, whose orthosteric site was blocked by [3H]N‐methylscopolamine. The variations in potency were found to be surprisingly small and the structure‐activity relationships of the DUO compounds diverged from those of correspondingly substituted hexamethonio‐type allosteric modulators. One has to conclude that DUO compounds bind in an “atypical” manner which is in agreement with recently reported side‐directed mutagenesis and molecular modeling studies.