bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrogen Use Efficiency in Maize as Affected by Nitrogen Availability and Row Spacing
Authors: Barbieri Pablo A. , Echeverría Hernán E. , Saínz Rozas Hernán R. , Andrade Fernando H.
Published: June 2008

Efficient use of N in plant production is an essential goal in crop management. An experiment was performed at INTA Balcarce, Argentina during 3‐yr to evaluate the effect of row spacing and N level on nitrogen use efficiency (NUE) in no‐till (NT) irrigated maize (Zea mays L.). Treatments consisted of a factorial combination of row width (70, 52 and 35 cm) and N rates (0 to 180 kg N ha−1). Nitrogen rate and narrow rows increased total dry matter (DM), grain yield, and N accumulation. Relative responses to narrow rows decreased as N availability increased. The NUE decreased with N rate and increased with narrow row spacing. Narrow rows increased NUE by 12 and 15% expressed as DM or grain yield per unit of available N, respectively. Physiological efficiency decreased with N rate and was not affected by row spacing. Recovery efficiency (RE) decreased with increasing N rate, and increased for the narrow row spacings. The effect of narrow rows on RE decreased as N availability increased. Narrow rows increased NUE largely as a result of increased RE. These increments in RE could contribute to increase the profitability of maize production and to diminish the risk of environmental pollution.
Presidedress Soil Nitrogen Test for No‐Tillage Maize at Different Row Spacing
Authors: Barbieri Pablo A. , Echeverría Hernán E. , Saínz Rozas Hernán R.
Published: June 2008

A presidedress soil nitrate test (PSNT) can be used to evaluate preplant N applications as a complementary method to N budget in maize (Zea mays L.) under different management practices. Narrow rows have shown increased N accumulation and recovery efficiency by maize, and therefore soil NO3−–N critical concentration (CC) for maximum yield could be lower than in conventional row spacing. An experiment was performed at Balcarce (Argentina) in 1996–1997, 1999–2000, and 2000–2001 to evaluate the PSNT for irrigated no‐till (NT) maize with different row spacings (70, 52, and 35 cm) and N rates (0, 90, 140, and 180 kg N ha−1). Soil samples were collected to a 30‐cm and 30‐ to 60‐cm depth when maize was at the six‐leaf stage (V6). Grain yield was significantly increased by narrow rows mainly at low N availability. Relative yield was highly associated (r2 = 0.73 and 0.68) with soil NO3−–N concentration (0–30 cm) at V6 for conventional and narrow rows, respectively. Soil NO3−–N concentration for maximum yield (95%) was greater for conventional row spacing (22 mg kg−1) compared with narrow rows (17 mg kg−1). The reliability of the PSNT (r2) did not improve when sampling was done up to a 60‐cm depth. These results confirm the hypothesis that the NO3−–N CC determined for the PSNT is lower for maize crops growing in narrow rows than conventional row spacing. Narrow rows maize is a simple management practice that could contribute to enhancing system sustainability.
Indicators of Last Effective Boll Population and Harvest Aid Timing in Cotton
Authors: Bynum Josh B. , Cothren J. Tom
Published: June 2008

Maintaining profitable and sustainable production of cotton (Gossypium hirsutum L.) relies on improvements in management. The objective of this study was to determine the proper defoliation timing to optimize lint yield and fiber quality through calculating heat unit (HU; DD15.5) accumulation beyond cutout, defined as five nodes above white flower (NAWF = 5). Experiments were conducted in Burleson County, Texas, in 2003 and 2004, on a Weswood silt loam soil (fine‐silty, mixed, superactive, thermic, Udifluventic Halplustepts). Treatments were applied in a split‐plot arrangement using a randomized complete block design with four replications. The main plots consisted of three nodal positions (NAWF = 3, 4, and 5) and the five subplots were HUs (361, 417, 472, 528, and 583) accumulated beyond the corresponding nodal positions (NAWF), at which time a tank‐mix of harvest aids was applied. Immediately before defoliation, 10 plants plot−1 were evaluated for percent open boll (POB) and nodes above cracked boll (NACB). Lint yield was detrimentally impacted in south central Texas when defoliation was initiated at 472 HUs beyond NAWF = 5. Defoliation at 60 POB resulted in as much as 29% more lint yield than defoliation based on the current benchmark of NAWF = 5 plus 472 HUs. This finding suggests NAWF = 5 is neither an indicator of the last effective flower population in all production locations, nor a proper guide for timing cutout on which end‐of‐season management decisions should be based in south central Texas.
Site‐Specific Nitrogen and Plant Density Management in Irrigated Maize
Authors: Ping J. L. , Ferguson R. B. , Dobermann A.
Published: June 2008

Economic or environmental benefits resulting from variable‐rate (VR) application of N and seed are uncertain in irrigated maize (Zea mays L.) systems with high yield potential. We evaluated different plant population and N management strategies in two irrigated maize fields in Nebraska. Inputs were varied according to yield zones derived from yield maps, detailed maps of soil organic matter (SOM), and sampled seasonal NO3 status. Uniform management following Best Management Practices (BMPs) resulted in high levels of grain yield (>15 t ha−1 at Site 1; >12 t ha−1 at Site 2), nitrogen use efficiency (NUE), and gross return above input cost. Management of high‐yielding irrigated systems on relatively flat terrain was not improved through the predictive site‐specific approaches tested in this study, which relied on available historical field information (yield maps, weather) and seasonal soil sampling. Among four site‐years, only one site‐year showed significant increases in yield and NUE and decrease in N input with the VR N. Yield interactions between VR N management strategies and plant population were not significant. More potential for increasing yields, resource efficiency, and profitability may exist through integrating such approaches with dynamic, in‐season management of water and N. Such approaches are emerging, but remain to be evaluated thoroughly, particularly under high‐yielding conditions and against conventional BMPs.
Economics of Irrigated Continuous Corn under Conventional‐Till and No‐Till in Northern Colorado
Authors: Archer David W. , Halvorson Ardell D. , Reule Curtis A.
Published: June 2008

Conversion of irrigated cropland from conventional tillage (CT) to no‐till (NT) could have several environmental benefits including reduced erosion potential, reduction of greenhouse gas emissions, and conservation of water. However NT must be economically viable if it is to be adopted. Costs of production and economic returns were evaluated for an irrigated, continuous corn (Zea mays L.) system under CT and NT over 6 yr on a clay loam soil in northern Colorado. Yield responses to N fertilization were included to determine economic optimum fertilization rates under each tillage system. Corn grain yields at economic optimum N fertilizer rates were 1.1 to 1.4 Mg ha−1 lower for NT than for CT. However, net returns were $46 to 74 ha−1 higher for NT than for CT due to reductions in operating costs of $57 to 114 ha−1 and reductions in machinery ownership costs of $87 to 90 ha−1. Operating cost savings were realized largely due to fuel and labor reductions of 75% and 71 to 72%, respectively, and in spite of higher N fertilizer requirements of 16 to 55 kg ha−1 for NT compared to CT. No‐till, irrigated, continuous corn appears to be an economically viable option for replacing CT production systems in the central Great Plains, especially when combined with the environmental benefits of the NT system.
Fall Growth Potential of Cereal Grain Forages in Northern Arkansas
Authors: Gunsaulis J. L. , Coblentz W. K. , Ogden R. K. , Bacon R. K. , Coffey K. P. , Hubbell D. S. , Skinner J. V. , Akins M. S. , Caldwell J. D. , Lusby K. S. , Gunter S. A.
Published: June 2008

In Arkansas, maximizing fall forage production from cereal grains is important for optimizing growth of fall‐weaned calves (Bos taurus). Our objectives were to evaluate eight cultivars of wheat (Triticum aestivum L.), oat (Avena sativa L.), rye (Secale cereale L.), and triticale (×Triticosecale Wittmack) for their potential to accumulate fall forage dry matter (DM). At Fayetteville during 2004, triticale and oat cultivars accumulated DM in a cubic (P ≤ 0.01) pattern over time, most likely because growing tillers exhibited stem elongation, and were then susceptible to freeze damage in late December. Wheat and rye cultivars accumulated DM in less complex patterns over harvest dates, but the maximum yield for any wheat cultivar was only 2554 kg ha−1 compared to 4661 kg ha−1 for oat. For Batesville 2004 and Fayetteville 2005, DM yields ranked similarly, but respective mean yields (491 and 988 kg ha−1) averaged over all harvest dates were only 25 and 50% of those for Fayetteville 2004 (1960 kg ha−1), largely due to drought. For Batesville 2005, growing conditions were somewhat unique relative to other site‐years, and wheat, rye, and triticale cultivars accumulated an overall mean of 4148 kg ha−1 of forage DM on the final (4 January) harvest date. In contrast, oat cultivars were sensitive to freezing temperatures in November, and ranked last among all cultivars for yield on the final harvest date. Producers can usually improve fall forage production with cultivars that exhibit some stem elongation when planted in early September; however, this trait may make winter survival problematic.
Sensitivity of Narrow‐Band and Broad‐Band Indices for Assessing Nitrogen Availability and Water Stress in an Annual Crop
Authors: Perry Eileen M. , Roberts Dar A.
Published: June 2008

We evaluated a suite of vegetation indices to detect treatment differences in nutrient and water availability in corn for areas larger and smaller than the ground sample diameter (GSD) from both a portable spectrometer and the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). The ANOVA results for a N trial showed that indices based on the chlorophyll red‐edge were more sensitive to differences in N treatment than those based on the visible and near infrared (NIR) regions only. Classifications of pixels for a spatial detection study using unfertilized strips with widths of 6 m, 12 m, 18 m, and 24 m were performed and scored as the percentage of correctly classified pixels. Generally, the indices using the red‐edge produced more accurate detections, although none of the indices could detect nutrient stress in the 6‐m strips based on 15‐m imagery. A water stress study was set up in another location of the same field by withholding irrigation water. While the indices based on the chlorophyll red‐edge outperformed others for N application detection, the visible and NIR indices differentiated water stress the best.
Radiation Use Efficiency of Arrowleaf, Crimson, Rose, and Subterranean Clovers
Authors: Kiniry James R. , Evers Gerald W.
Published: June 2008

Parameters describing the growth of cool‐season annual clovers are necessary for potential growth simulations, but have not yet been determined. Accordingly, the objective of this study was to quantify and compare the key parameter for biomass production, radiation use efficiency (RUE), for arrowleaf (Trifolium vesiculosum Savi.), crimson (T. incarnatum L.), rose (T. hirtum All.), and subterranean (T. subterraneum L.) clovers. Data on the fraction of light intercepted and biomass were collected biweekly over 2 yr at Overton, TX, and were used to calculate the RUE. Radiation use efficiency was calculated for biomass as a function of cumulative intercepted photosynthetically active radiation (IPAR) for aboveground biomass and for total biomass including roots. Similarly, RUE was calculated for regrowth following one or two cuttings. Over the 2 yr of this study, the mean RUEs for aboveground biomass original growth were 2.92, 2.52, 1.94, and 1.86 g MJ−1 for rose, arrowleaf, crimson, and subterranean, respectively. The mean RUEs for the total biomass including roots, during this time were 3.01, 2.59, 2.00, and 1.98 g MJ−1, respectively. Relative to the original growth aboveground RUE values, the RUE of aboveground regrowth following one cutting averaged 92% across the four species. Likewise, the mean RUE of aboveground regrowth of the four species following two cuttings was 119%. These values of RUE will aid modelers in simulating these important N2 fixing species.
Soil Carbon Levels in Irrigated Western Corn Belt Rotations
Authors: Varvel G. E. , Wilhelm W. W.
Published: June 2008

Proposals promoting the use of massive amounts of crop residues and other lignocellulosic biomass for biofuel production have increased the need for evaluation of the sustainability of cropping practices and their effect on environment quality. Our objective was to evaluate the effects of crop rotation and N fertilizer management and their stover production characteristics on soil organic carbon (SOC) levels in a long‐term high‐yielding irrigated study in the western Corn Belt. An irrigated monoculture corn (Zea mays L.), monoculture soybean [Glycine max (L.) Merr.], and soybean–corn cropping systems study was initiated in 1991 on a uniform site in the Platte Valley near Shelton, NE. Soil samples were collected in 1991 before initiation of the study and in the spring of 2005 and analyzed for SOC. Significant differences in total SOC values were obtained between rotations and N rates at the 0‐ to 7.5‐ and 0‐ to 15‐cm depths in 2005 and all total SOC values were equal to or greater than SOC values obtained in 1991. Residue production was greater than 6 Mg ha−1, a level that appears to be sufficient to maintain SOC levels, in all systems. Can residue amounts above this level be harvested sustainably for biofuel production in cropping systems similar to these? Though these results suggest that a portion of corn stover could be harvested without reducing SOC under the conditions of this investigation, the direct impact of stover removal remains to be evaluated.
Methane Production from the Soluble Fraction of Distillers' Dried Grains with Solubles in Anaerobic Sequencing Batch Reactors
Authors: Cassidy D. P. , Hirl P. J. , Belia E.
Published: June 2008

Methane production from the soluble fraction of distillers' dried grains with solubles, a co‐product of ethanol production, was studied in 2‐L anaerobic sequencing batch reactors (ASBRs) under 10 different operating conditions. Methane production and chemical oxygen demand (COD) removal were quantified for a wide range of operating parameters. Chemical oxygen demand removals of 64 to 95% were achieved at organic loading rates ranging from 1.5 to 22.2 g COD/L · d, solids retention times from 8 to 40 days, and food‐to‐microorganism ratios ranging from 0.4 to 1.9 g COD/g volatile suspended solids (VSS) · d. Biogas methane content varied from 61 to 74%, with 0.29 L CH 4 produced/g COD removed. Roughly 56% of the influent COD and 84% of the COD removed in the ASBRs was converted to methane. Microbial yield (Y) and decay (b) constants were determined to be Y = 0.126 g VSS/g COD removed and b = 0.032 day −1, respectively. Methane produced from co‐products can reduce the costs and fossil‐fuel consumption of ethanol manufacture.
Evaluation of Groundwater Dynamic Regime with Groundwater Depth Evaluation Indexes
Authors: Genxu Wang , Jian Zhou , Kubota Jumpei , Jianping Su
Published: June 2008

An accurate quantitative evaluation of anthropogenic effects on regional groundwater dynamics is critical to the rational planning, management, and use of such resources and in maintaining the sustainability of groundwater‐dependent ecosystems. Based on groundwater dynamics, a series of groundwater depth evaluation indexes were created to quantitatively evaluate the effects of anthropogenic activities on the groundwater system. These indexes were based on mathematical relationships relating groundwater depth to surface runoff (γ t), precipitation (ρ t), and extraction (δ t). The anthropogenic effects on these relationships were evaluated statistically, with respect to both temporal and spatial variation. The anthropogenic effects on groundwater dynamics within the arid Zhangye Basin, located in the middle reaches of northwest China's Heihe River, were investigated. River valley plains in the western portion of the basin excepted, anthropogenic activities have, since 1995, dramatically altered the basin's groundwater dynamics; in particular, in the mid‐upper and lower portions of alluvial–diluvial fans and in localized northerly fine‐soil plains regions, the relationship of groundwater to surface runoff and atmospheric precipitation has shifted. This and other changes indicate that anthropogenic effects on groundwater systems in this region show clear spatiotemporal variation.
Comparison of Bioluminescence and Nitrification Inhibition Methods for Assessing Toxicity to Municipal Activated Sludge
Authors: Mamais Daniel , Noutsopoulos Constantinos , Stasinakis Athanasios S. , Kouris Nikolaos , Andreadakis Andreas D.
Published: June 2008

The aim of this study was to compare two alternative toxicity assessment methods to determine wastewater toxicity and predict treatment plant process upsets. The toxicity of two synthetic organic compounds (triclosan and 4‐n‐nonylphenol), which are commonly detected in municipal wastewater, and municipal and industrial wastewaters with different heavy metals content were evaluated by the nitrification inhibition assay and bioluminescence toxicity test. Comparison between both assays confirmed that Vibrio fischeri is generally more sensitive than autotrophic bacteria, and, if not calibrated, the bioluminescence method tends to overestimate toxic effects on activated sludge biomass. The nitrification inhibition assay appears to predict plant process upsets more accurately. Both methods showed a significant toxicity decrease through treatment that could be partially attributed to the significant heavy metals removal obtained by primary and secondary treatment. A good correlation for the two assays was obtained, as indicated by a high correlation coefficient (r 2 = 0.80).
Effectiveness and Kinetics of Ferrate as a Disinfectant for Ballast Water
Authors: Jessen Andrea , Randall Andrew , Reinhart Debra , Daly Luke
Published: June 2008

This study examined whether ferrate could meet the international standards for successful ballast water treatment, including final concentrations of less than 1 CFU/mL of Enterococci, less than 2.5 CFU/mL of Escherichia coli, and less than 1 CFU/100 mL of Vibrio cholerae. Pure cultures of E. coli, Klebsiella pneumoniae, and V. cholerae, and a mixed culture of Enterococcus faecium and E. faecilis were grown in saline solution to simulate ballast water and were treated with dosages of ferrate ranging from 0.25 to 5.0 mg/L. A ferrate dose of 5 mg/L resulted in complete disinfection of all organisms tested, and smaller dosages were also very effective. Tailing was consistently observed, and the Hom's model (1972) appeared to most accurately represent the action of ferrate on these organisms. Salinity and pH did not adversely affect results, and regrowth was not a problem. Ferrate shows good potential as an effective disinfectant in the treatment of ballast water.
ASSOCIATIONS OF ORGANIZATIONAL JUSTICE AND INGRATIATION WITH ORGANIZATIONAL CITIZENSHIP BEHAVIOR: THE BENEFICIARY PERSPECTIVE
Authors: Chen Yi-Jung , Lin Cheng-Chen , Tung Yu-Chuan , Ko Yuan-ta
Published: June 2008

In this study we investigated whether the two motivational forces – social exchange and impression management – behind Organizational Citizenship Behavior (OCB) proposed by Bolino (1999) would be associated differently with an individual's OCB toward a coworker, supervisor,
and organization. Organizational justice and ingratiation represented the social exchange and impression management motives, respectively. Based on the data collected from managers, colleagues, and employees, the results of a total sample size of 529 questionnaires showed that both ingratiation
and perception of organizational justice were positively associated with individuals' OCB toward their supervisors. However, for individuals performing OCB toward their jobs, only the perception of distributive justice showed a positive correlation, and neither motive was positively associated
with individuals' OCB toward their coworkers.
FACTORS AFFECTING PERSONNEL PERFORMANCE IN RETAIL MARKETING: AN APPLICATION OF STRUCTURAL EQUATION MODELING
Authors: Yener Hüseyin , Kurt Mustafa
Published: June 2008

Using the available literature a model of personnel factors affecting the performance of a retail marketing chain was developed. This was tested by using Structural Equation Modeling (SEM). The data were collected by means of a questionnaire completed by employees and their superiors
in a retail market chain in Ankara, Turkey. The results suggest that this model provides a framework for the future evaluation of retail sector performance factors and performance.
EXPLORING DIFFERENCES IN LEADERSHIP STYLES: A STUDY OF MANAGER TASKS, FOLLOWER CHARACTERISTICS, AND TASK ENVIRONMENTS IN KOREAN HUMAN SERVICE ORGANIZATIONS
Authors: Hur Mann Hyung
Published: June 2008

This study was designed to analyze the leadership style of managers in Korean Public Human Service Organizations (PHSOs) in terms of the leadership continuum developed by Tannenbaum and Schmidt (1973). Its purposes were to explore whether or not there is a difference in leadership styles
between human services and administrative work and, if there is, to examine whether or not their leadership styles are adaptive to the follower's characteristics and task environment. Results showed that the leadership style of administrative managers is significantly different from that
of human service managers. However, the leadership style was not changed in accordance with follower characteristics and task environment. This result indicates either one of the following interpretations; (1) that follower characteristics and task environments cannot be counted as an independent
variable of the leadership process, or (2) that the leaders in Korean PHSOs have not yet been transformed into situational leaders.
EXPLORING THE RELEVANCE OF GENDER AND AGE DIFFERENCES IN THE ASSESSMENT OF SOCIAL FEARS IN ADOLESCENCE
Authors: Lopez Luis-Joaquin Garcia , Ingles Candido J. , Garcia-Fernandez Jose M.
Published: June 2008

Although social phobia is one of the most common mental disorders in adolescents, information on the need for normative data is missing. For this reason, this cross-sectional study was aimed at determining if there is a need to have normative data according to age and gender in socially
anxious adolescents. Furthermore, we analyzed whether or not boys and girls differ in the nature of their social fears. The study population comprised 2,543 Spanish-speaking adolescents randomly recruited from 10 schools. The results indicate that there is no need for different normative data
based on age and gender. Moreover, our data also indicate that even though there are quantitative differences between boys and girls, i.e., girls report a higher percentage, a qualitative analysis revealed that boys and girls experience the same social fears and, therefore, the nature of the
social-anxiety provoking situations is the same across gender. Implications for developmental theories and assessment are discussed as well.
DETERMINANTS OF SELF-HANDICAPPING STRATEGIES IN SPORT AND THEIR EFFECTS ON ATHLETIC PERFORMANCE
Authors: Coudevylle Guillaume R. , Ginis Kathleen A. Martin , Famose Jean-Pierre
Published: June 2008

The purpose of this study was to examine self-efficacy and self-esteem as predictors of claimed and behavioral self-handicapping, and to compare the relationship between behavioral and claimed self-handicaps and athletic performance. A total of 31 basketball players participated in
the study. Claimed self-handicaps were significantly negatively correlated with selfesteem whereas behavioral self-handicapping was significantly negatively correlated with self-efficacy. Performance was negatively correlated with behavioral self-handicapping, but was not correlated with claimed
self-handicapping. These findings reinforce the conceptual distinction between claimed and behavioral self-handicaps by demonstrating that the two strategies are indeed related to different factors and that they have different consequences for performance.
A CONFIRMATORY FACTOR ANALYSIS OF THE KUWAIT UNIVERSITY ANXIETY SCALE
Authors: Eid Ghada K. , Abdel-Khalek Ahmed M.
Published: June 2008

A sample of 2,754 male and female undergraduate students from 9 different Arab countries responded to the Kuwait University Anxiety Scale (KUAS: Abdel-Khalek, 2000). This study extends the exploratory factor analyses performed in previous studies, using confirmatory factor analysis
to test four models derived from Kuwaiti, Saudi, German and American samples. Four measures were used to assess the goodness of fit as follows: the Comparative Fit Index (Hu & Bentler, 1999), the Root Mean Square Errors of Approximation (Gao et al., 2004), the Normed Fit Index, and the
Goodness of Fit (Sanders et al., 2005). In applying these measures, it was found that the Saudi three-factor model is an optimal model. It is particularly noteworthy that the Saudi factorial pattern was based on a large sample size (N = 9,031). By and large, the present results confirmed
that the best fitted model on the KUAS was the threefactor model, namely, Cognitive/affective, Tension/nervousness, and Somatic anxiety.
QUALITY OF LIFE IN TURKISH UNIVERSITY STUDENTS AND ITS RELATIONSHIP TO LEVELS OF STATE-TRAIT ANXIETY
Authors: Unalan Demet , Celikten Mustafa , Soyuer Ferhan , Ozturk Ahmet
Published: June 2008

The purpose of this study was to determine the quality of life (QOL) of students and to determine the relationship between state-trait anxiety levels and QOL. This research was done with ½ sampling method of 276 students at Erciyes University. The data were gathered via the WHOQOL-100
Quality of Life Scale (WHOQOL Group, 1998) and State-Trait Anxiety Inventory (Spielberger, Gorsuch, & Lushelle, 1970). The lowest scoring area in our study was the social impression facet. The area scoring highest was the personal belief area. Negative correlations were found between level
of state anxiety and physical health, psychological well-being, and level of independence. Positive correlations were found between level of trait anxiety and physical health, psychological well-being, social relationships, environment, overall QOL and general health perceptions.
CHANGES IN EMOTION OF THE CHINESE PUBLIC IN REGARD TO THE SARS PERIOD
Authors: Zhu Xia , Wu Shengjun , Miao Danmin , Li Yunbo
Published: June 2008

The aim in this study was to investigate the characteristics and regularity of changes in mental state of the Chinese public during the period of the SARS outbreak in China (2003). The self-administered SARS Mentality Questionnaire was sent to 8775 people who came from 20 different
professions in the cities of Guangzhou (23.5%), Beijing (37.8%) and Xi'an (38.7%). Of the participants 59.4% were male. Ages ranged from 17 to 76 years. After the pilot study, 33 items were included in the questionnaire. Of the people surveyed, 96.4%
presented marked emotional change and 23.3% showed blind behavior; 76.7% took “access to relevant information” as effective measures against emergencies; 45.5% believed that SARS would cause more harm to human beings than cancer, AIDS and suicide resulting
from depression. The change of emotion during the SARS epidemic was significantly different, as compared to normal circumstances. The uncertainty people have about the epidemic development was a key cause of panic during this time.
THE RELATIONSHIP OF PSYCHOLOGICAL BIRTH ORDER TO IRATIONAL RELATIONSHIP BELIEFS
Authors: Kalkan Melek
Published: June 2008

Psychological birth order is examined as a predictor of irrational relationship beliefs among Turkish people (N= 423) using a Turkish version (Kalkan, 2005) of the White- Campbell Psychological Birth Order Inventory (Campbell, White, & Stewart, 1991) and the Relationship Belief Inventory (Kalkan, 2006). Results of Pearson correlation analysis indicate that positions of psychologically first, middle, and youngest child were significantly related to irrational relationship beliefs. The correlation between psychologically only child scores and irrational relationship beliefs was nonsignificant.
CORRELATES OF SUICIDE RISK AMONG SECONDARY SCHOOL STUDENTS IN CAPE TOWN
Authors: Peltzer Karl , Kleintjes Sharon , Wyk Brian Van , Thompson Elaine A. , Mashego Teresa-Ann B.
Published: June 2008

The aim of this study was to assess correlates of suicide risk in a South African school-based population (N= 1,157) from three secondary schools in Cape Town. Results indicated that using the Suicide Risk Screen (SRS; Eggert, Herting, & Thompson, 1995) a high rate of learners screened in at possible suicide risk (31.6%). Anger control problems, low self-esteem, perceived stress and unmet school goals were identified as predictors for suicide risk, while gender, age, drug involvement (alcohol and drug use, drug control problems and adverse consequences from alcohol and drug abuse), parental alcohol and/or drug abuse problems, perceived school performance, serious conflicts and tension with parents and unmet family goals were not associated with suicide risk.
ASSESSING MOTIVATION AND LEARNING STRATEGIES USING THE MOTIVATED STRATEGIES FOR LEARNING QUESTIONNAIRE IN A FOREIGN LANGUAGE LEARNING CONTEXT
Authors: Huang Shu-Chen
Published: June 2008

This study pinpointed the lack of, and necessity for, using standardized questionnaires for the study of learner motivation in the foreign language (L2) learning context. To compare the similarities and differences in general education and L2 learning, the researcher chose the Motivated
Strategies for Learning Questionnaire (MSLQ; Pintrich, Smith, Garcia, & McKeachie, 1991) and investigated the scale's reliability and its correlation with L2 achievement. Results suggested that, in spite of some inherent uniqueness, L2 learning is similar to other subjects in the
school environment and the MSLQ has the potential to be applied to L2-related studies.
TRIGGERS OF MOST EMBARRASSING MOMENT RECOLLECTIONS IN A COLLEGE SAMPLE
Authors: Pettijohn Terry F. , McDermott Lauren A. , Naples Ginny M.
Published: June 2008

Sabini, Siepmann, Stein, and Meyerowitz (2000) identified three types of situations which trigger embarrassment and created a subscale of each subtype of trigger. The three subtypes include faux pas (making a social mistake), center of attention, and sticky situations (threatening another's
social identity). Faux pas scenarios were rated as more embarrassing than the other subtypes. Consistent with this finding, we predicted faux pas would be the most prevalent mostembarrassing moment recalled in our free response study.
RIGIDITY AS A PREDICTOR OF OLDER PERSONS' AGING STEREOTYPES AND AGING SELF-PERCEPTIONS
Authors: Levy Becca R.
Published: June 2008

Rigidity has been previously associated with the propensity of dominant group members to target stigmatized groups with negative stereotypes. It was considered in this study whether or not rigidity predicts that members of a stigmatized group, the elderly will target their own group
with negative aging stereotypes; and, if so, whether these stereotypes predict aging self-perceptions, or thinking about themselves growing old. As expected (1) older individuals with more rigidity held significantly more negative aging stereotypes over time, (2) older individuals with more
negative aging stereotypes had significantly more negative aging self-perceptions over time, and (3) negative aging stereotypes partially mediated the relationship between rigidity and negative aging self-perceptions. The sample of 405 community-living individuals, aged 50 or older, was studied
in 6 waves over 20 years. The findings suggest that flexibility can benefit older individuals' self-views.
PERCEIVED CAUSES OF POVERTY IN DEVELOPING NATIONS: CAUSES OF THIRD WORLD POVERTY QUESTIONNAIRE IN SPANISH-SPEAKING SAMPLES
Authors: Panadero Sonia , Vázquez José Juan
Published: June 2008

The aim of this paper was to analyze the factorial structure of the Causes of Third World Poverty Questionnaire (CTWPQ; Harper, 2002) in Spanish-speaking samples from two countries at different levels of development: Spain (developed nation) and Nicaragua (developing nation). In the
English-speaking samples, the instrument displayed a factorial structure composed of four factors: “Blame the poor,” “Blame Third World governments,” “Blame nature,” and “Blame exploitation” (Harper, Wagstaff, Newton, & Harrison, 1990). Bolitho,
Carr, and Fletcher (2007) have since added a fifth factor: “Blame conflict”. In the Spanish-speaking samples, a factorial structure composed of five factors can be observed. The factors are very similar to those obtained from the English-speaking samples.
How to Compensate a Spreading Disturbance for a Class of Nonlinear Systems
Authors: Qaraai Youssef , Bernoussi Abdes , Jai Abdelhaq
Published: June 2008

How to Compensate a Spreading Disturbance for a Class of Nonlinear Systems

We consider a system which is assumed to be affected by an expanding disturbance which occurs at the initial time. The compensation of the disturbance is accomplished by extending the concept of remediability to a class of nonlinear systems. The results are implemented and illustrated with a nonlinear distributed model.
Approximate Controllability of Infinite Dimensional Systems of the n-th Order
Authors: Respondek Jerzy
Published: June 2008

Approximate Controllability of Infinite Dimensional Systems of then-th Order

The objective of the article is to obtain general conditions for several types of controllability at once for an abstract differential equation of arbitrary order, instead of conditions for a fixed order equation. This innovative approach was possible owing to analyzing then-th order linear system in the Frobenius form which generates a Jordan transition matrix of the Vandermonde form. We extensively used the fact that the knowledge of the inverse of a Jordan transition matrix enables us to directly verify the controllability by Chen's theorem. We used the explicit analytical form of the inverse Vandermonde matrix. This enabled us to obtain more general conditions for different types of controllability for infinite dimensional systems than the conditions existing in the literature so far. The methods introduced can be easily adapted to the analysis of other dynamic properties of the systems considered.
Controllability and Observability of Linear Discrete-Time Fractional-Order Systems
Authors: Guermah Said , Djennoune Said , Bettayeb Maamar
Published: June 2008

Controllability and Observability of Linear Discrete-Time Fractional-Order Systems

In this paper we extend some basic results on the controllability and observability of linear discrete-time fractional-order systems. For both of these fundamental structural properties we establish some new concepts inherent to fractional-order systems and we develop new analytical methods for checking these properties. Numerical examples are presented to illustrate the theoretical results.
Extension of First Order Predictive Functional Controllers to Handle Higher Order Internal Models
Authors: Khadir Mohamed , Ringwood John
Published: June 2008

Extension of First Order Predictive Functional Controllers to Handle Higher Order Internal Models

Predictive Functional Control (PFC), belonging to the family of predictive control techniques, has been demonstrated as a powerful algorithm for controlling process plants. The input/output PFC formulation has been a particularly attractive paradigm for industrial processes, with a combination of simplicity and effectiveness. Though its use of a lag plus delay ARX/ARMAX model is justified in many applications, there exists a range of process types which may present difficulties, leading to chattering and/or instability. In this paper, instability of first order PFC is addressed, and solutions to handle higher order and difficult systems are proposed. The input/output PFC formulation is extended to cover the cases of internal models with zero and/or higher order pole dynamics in an ARX/ARMAX form, via a parallel and cascaded model decomposition. Finally, a generic form of PFC, based on elementary outputs, is proposed to handle a wider range of higher order oscillatory and non-minimum phase systems. The range of solutions presented are supported by appropriate examples.
Inferring Graph Grammars by Detecting Overlap in Frequent Subgraphs
Authors: Kukluk Jacek , Holder Lawrence , Cook Diane
Published: June 2008

Inferring Graph Grammars by Detecting Overlap in Frequent Subgraphs

In this paper we study the inference of node and edge replacement graph grammars. We search for frequent subgraphs and then check for an overlap among the instances of the subgraphs in the input graph. If the subgraphs overlap by one node, we propose a node replacement graph grammar production. If the subgraphs overlap by two nodes or two nodes and an edge, we propose an edge replacement graph grammar production. We can also infer a hierarchy of productions by compressing portions of a graph described by a production and then inferring new productions on the compressed graph. We validate the approach in experiments where we generate graphs from known grammars and measure how well the approach infers the original grammar from the generated graph. We show graph grammars found in biological molecules, biological networks, and analyze learning curves of the algorithm.
Not Wanted in the Boundary: The Expulsion of the Keeseekoowenin Ojibway Band from Riding Mountain National Park
Authors: Sandlos John
Published: June 2008

The expulsion of Aboriginal people from Canadian and US national parks has often been characterized as an attempt to create the illusion of an Edenic wilderness within the settled landscapes of the post-frontier West. In Manitoba's Riding Mountain National Park, however, the National Parks Branch evicted the Keeseekowenin Ojibway Band from a small reserve within the park boundary in 1936 in response to more specific local economic development concerns and federal administrative priorities. Parks Branch officials were alarmed initially over the status of elk in the region, but the expulsion was also carried out in response to pressure from both local and departmental tourism boosters who hoped to create an attraction for automobile travellers from within the province and from the United States. In addition, senior officials and local agents in the Department of Indian Affairs supported the removal of the Keeseekoowenin Ojibway from a rich hunting and fishing ground because they thought such a move would bolster the department's program of assimilating Native people through immersion in the supposedly more civilized occupation of agriculture. The expulsion of the Keeseekoowenin Ojibway from Riding Mountain National Park proceeded, in fact, with almost no reference to the protection of wilderness values, but was tied instead to state-driven and popular conceptions of race hierarchy, social progress, and economic development within the Riding Mountain region.
Revolutions without a Revolutionary Moment: Joint Stock Democracy & the Transition to Capitalism in Upper Canada
Authors: Schrauwers Albert
Published: June 2008

The transitions to capitalism and responsible government are two revolutions without a revolutionary moment in Ontario's history. This article examines the contribution of the corporation to both in the years before the Rebellion of 1837. It contrasts the ‘gentlemanly capitalism’ of chartered corporations under the oligarchic control of the Family Compact with a series of unincorporated joint stock companies managed by reformers, and by a small religious group, the Children of Peace, in particular. Tracing the overlapping boards of management of these joint stock companies with reform political organizations reveals the economic impetus for the emergence of a culture of deliberative democracy. These joint stock companies were developed to help preserve the freehold property of farmers, and hence their political voice. The irony of the capitalist and democratic revolutions in Ontario was their co-operative joint stock nature.
American Sign Language and Early Intervention
Authors: Snoddon Kristin
Published: June 2008

Abstract:

Since the beginning of the twenty-first century, the introduction in several countries of universal neonatal hearing screening programs has changed the landscape of education for deaf children. Due to the increasing provision of early intervention services for children identified with hearing loss, public education for deaf children often starts in infancy. While infant hearing screening and intervention programs hold promise for enhancing deaf children's language development, concerns have been raised that these programs may not provide a well-informed or adequate range of options for families with deaf children. In particular, Ontario children who receive cochlear implants have frequently not been provided with support for learning American Sign Language (ASL), despite evidence for the benefits that learning ASL confers on spoken and written English language development in deaf children. This paper presents an applied linguistics perspective on early intervention policies and programs for deaf children.
Peer–Peer Interaction between L2 Learners of Different Proficiency Levels: Their Interactions and Reflections
Authors: Watanabe Yuko
Published: June 2008

Abstract:

This study draws on sociocultural theory to explore how adult ESL learners interact with either a higher- or a lower-proficiency peer during pair problem solving, and how they each perceive the interactions with their partners. Three ESL learners engaged in a three-stage task: pair writing; pair noticing; and individual writing with two learners, one with a higher and one with a lower L2 proficiency level than their own. These three learners engaged in stimulated recall sessions and were interviewed after all the tasks were completed. Each pair's pattern of interaction and attitude towards the interactions were analyzed. Data showed that the higher- and the lower-proficiency peers could both provide opportunities for learning when they worked collaboratively. Moreover, all three learners preferred to work with a partner who ‘shared many ideas,’ regardless of their proficiency level. These findings suggest that proficiency differences are not the decisive factor affecting the nature of peer assistance. Rather, the pattern of interaction co-constructed by learners may have greater impact.
Évaluation du traitement des correspondances phonèmes/phonogrammes chez des lecteurs/scripteurs adultes en début d’apprentissage du français langue seconde
Authors: Daigle Daniel , Mathieu Isabelle , Montésinos-Gelet Isabelle
Published: June 2008

Abstract:

Learning to read and write in an alphabetic language, whether it is the learner's first or second language, requires the development of some sensitivity to correspondences between phonemes and phonograms. The study reported here investigated those correspondences in beginning learners of French as a second language. Three groups of learners participated in the study: anglophones, hispanophones and sinophones. In reading, a similarity judgement task was used at the graphemic level; in writing, participants were asked to write words presented orally. The results reveal that, in both reading and in writing, anglophones obtained the highest scores and sinophones the lowest scores. The results are discussed within the context of the hypothesis related to the effects of L1–L2 distance on L2 acquisition.
Structure Property Relationships in PA 6 and PP Copolymers Blended by Single and Twin Screw Extrusion
Authors: Correa C. A. , Carvalho C. L. , Bezzan A. L. , Razzino C. A. , Hage E.
Published: June 2008

Polyamides such as polycaprolactam (PA 6) and poly(hexamethylene adipamide) (PA 6.6), are generally classified as pseudo-ductile materials. Fracture behaviour of PA can be changed by melt compounding with modified olefinic elastomers such as Ethylene-propylene copolymers (EPM and EPDMs) and nitrile rubbers (NBRs). Often, small amounts of a compatibilizer are added to the polymer blend in order to assure good dispersion, morphology stability and consistent end-use properties. Maleated polypropylene (PP-MAH) has been used as compatibilizer in blends of polyamides with polyolefins as they tend to react with amine end groups in the polyamide molecules and also interact by molecular entanglement with non-funcionalized polypropylene chains. This work was intended to optimise stiffness-toughness balance in polyamide/ polypropylene blends by reactive processing of PA 6 with polypropylene heterophase copolymers using the PP-MAH as a compatibilizer. Effects of processing conditions on the blend morphology and mechanical properties were investigated by comparing compatibilized and non-compatibilized blends prepared by single and twin screw extrusion. Such approach was intended to investigate whether blend morphology and its response to processing steps can be controlled by blend composition, changes in rheology and interfacial tension during reactive processing. Viscosity measurements by torque rheometry and particle coalescence in-situ observations were performed in order to provide additional evidence of mechanisms relating to phase morphology definition in such systems.
Polymer Plastication during Injection Molding
Authors: Steller R. , Iwko J.
Published: June 2008

The mathematical model of polymer plastication in a reciprocating screw injection molding machine is presented. It takes into account all characteristic features of working of a real injector, such as periodical action of the three zones screw, to-and-from screw motion with controlled stroke, static and dynamic melting, etc. Methods for description of time changes of the solid bed profile in the screw channel during injection cycle as a function of operating parameters were developed. Ways of determination of pressure and temperature profiles in the screw channel were also discussed. Methods of caculation of the most important flow characteristics such as plasticizing capacity, power requirements, screw torque, energy consumption were analyzed. Results were presented in a form, which is most convenient for numerical applications in computer simulation programs.
Polymer Plastication during Injection Molding
Authors: Iwko J. , Steller R.
Published: June 2008

A computer program for the simulation of polymer plastication in screw injection molding machine created on basis of the theoretical model presented in part 1 of this paper is discussed. As simulation examples various process characteristics, e. g. solid bed, pressure and temperature profiles, are computed using the material parameters for high density polyethylene and three-zones-screw of diameter 20 mm. Effects of different geometric and operating parameters on plastication course are also demonstrated. Simulation results with respect to the screw rotation time are compared with experimental data measured for low density polyethylene, polypropylene, polystyrene, polyoxymethylene and polyamide 6. It was found that the computer program reflects correctly all features of a true plasticating system in injection molding machine. It provides also good agreement of model predictions with experimental data.