Toposequential effects on water balance and productivity in rainfed lowland rice ecosystem in Southern Laos

In the Mekong region, most paddies in rainfed lowland rice (Oryza sativa L.) lie in a sequence on gentle sloping land, and grain yield (GY) often depends on the toposequence position. There is, however, lack of information on toposequential effects on field water supply in rainfed lowland rice and how that influences GY. A total of eight field experiments were carried out on sandy, coarse-textured soils in Southern Laos (Champassak Province and Savannakhet Province) over three wet seasons (2000-2002). Components of the water balance, including downward and lateral water movement (D and L, respectively), were quantified at three different positions along toposequences (top, middle and bottom). GY, days-to-flower (DTF) and rainfall were measured, and the water productivity (WP) was determined. In most experiments, standing water disappeared first in the top position and gradually in lower positions. This was associated with the observation that when there was standing water in the field, the higher position had larger D in both the provinces and also larger L in Champassak Province. However, in one experiment, water loss appeared later in the higher position, as the result of lower L, apparently due to some water inputs other than rainfall occurring at this position. Despite larger D plus L at the top position, seasonal sum of D and L were not much affected by the toposequence position, as the daily rate of D plus L became minimal when the standing water was lost earlier in the top position. Lower GY was associated with earlier disappearance of standing water from the field. Relatively low GY was expected in the top toposequence position. This was clearly shown in the toposequence of Phonthong, Champassak Province, as the timing of standing water disappearance relative to flowering was earlier in the top position. Variation in GY across the toposequence positions was coupled with the WP variation, and both GY and WP tended to decline with increased DTF. Therefore, variation in productivity of rainfed lowland rice across toposequence positions depends mainly on the field water status around flowering time. (c) 2005 Elsevier B.V. All rights reserved.

The impact of computer display height and desk design on 3D posture during information technology work by young adults

Computer display height and desk design to allow forearm support are two critical design features of workstations for information technology tasks. However there is currently no 3D description of head and neck posture with different computer display heights and no direct comparison to paper based information technology tasks. There is also inconsistent evidence on the effect of forearm support on posture and no evidence on whether these features interact. This study compared the 3D head, neck and upper limb postures of 18 male and 18 female young adults whilst working with different display and desk design conditions. There was no substantial interaction between display height and desk design. Lower display heights increased head and neck flexion with more spinal asymmetry when working with paper. The curved desk, designed to provide forearm support, increased scapula elevation/protraction and shoulder flexion/abduction.

AVALIAÇÃO DAS TÁBUAS ÓSSEAS VESTIBULARES E LINGUAIS DOS DENTES ANTERIORES INFERIORES E MOLARES SUPERIORES APÓS O TRATAMENTO COM OS APARELHOS FUNCIONAIS FIXOS FORSUS E TWIN FORCE BITE CORRECTOR

Pelo fato das consequências do uso de aparelhos ortopédicos fixos sobre o periodonto ósseo vestibular e lingual ainda serem uma incógnita para o ortodontista clínico e pesquisador, este estudo teve como objetivo avaliar, por meio de tomografia computadorizada de feixe cônico (TCFC) as alterações em espessura das tábuas ósseas vestibulares e linguais em primeiros molares superiores e incisivos e caninos inferiores, após a utilização de aparelhagem fixa e dos aparelhos Twin Force (grupo A) e Forsus (grupo B) para o tratamento da maloclusão de Classe II, 1ª divisão. Para tanto, obteve-se uma amostra de 22 pacientes jovens adultos, divididos em dois grupos, de acordo com o aparelho propulsor da mandíbula. Grupo experimental A: 11 pacientes, 6 masculinos e 5 femininos, com idade média de 15,09 anos na instalação do Twin Force, e 11 pacientes, 7 masculinos e 4 femininos, com idade média de 15,45 anos na instalação do Forsus. O tempo médio de uso do aparelho Twin Force foi de 3,73 meses e do Forsus, 7,09 meses. O grupo A realizou TCFC antes do início do tratamento (T1), antes da instalação do Twin Force (T2), após a remoção do Twin Force (T3); e o grupo B somente antes da instalação do Forsus (T2) e após a remoção do Forsus (T3). Para comparação entre os tempos T2 e T3 foi utilizado o teste t pareado e entre os tempos T1, T2 e T3 foi utilizada a Análise de Variância (ANOVA) a um critério e o teste post-hoc de Tukey. Para comparação entre os grupos foi utilizado o teste t . Na comparação intergrupos os resultados evidenciaram que não houve diferença estatisticamente significante entre as alterações das espessuras das tábuas ósseas vestibular e lingual; por outro lado, na avaliação intra-grupo, de 48 medidas avaliadas, no grupo A houve reduções estatisticamente significantes nos terços cervical e médio por vestibular, nos dentes anteroinferiores e nos primeiros molares superiores e aumento nos terços cervical e médio, por lingual nos dentes anteriores inferiores, totalizando 25 medidas significantes. Já no grupo B, houve aumento significante da tábua óssea lingual nos dentes anteriores inferiores e redução em vestibular nos molares superiores, totalizando apenas sete medidas significantes, mas com mais medidas significantes de redução óssea vestibular em terços cervical e médio nos primeiros molares superiores, em comparação com o grupo A. Não houve diferença significante entre as medições obtidas com voxel 0,2 mm e 0,4 mm e nem dimorfismo entre os gêneros. As reduções em espessura óssea alveolar, principalmente em terços cervicais e médios vestibulares nos dentes avaliados neste estudo são um alerta ao clínico, para que realize essa abordagem diagnóstica periodontal antes de iniciar o tratamento ortodôntico.

Laminar distribution of ballooned neurons and tau positive neurons with inclusions in patients with corticobasal degeneration

The laminar distribution of ballooned neurons (BN) and tau positive neurons with inclusions (tau+ neurons) was studied in the frontal and temporal cortex in twelve patients with corticobasal degeneration (CBD). In the majority of brain areas, the density of BN and tau+ neurons was maximal in the lower and upper cortical laminae respectively. The densities of tau+ neurons in the upper and lower cortex were positively correlated. In the majority of brain areas, however, no correlations were observed between the densities of BN and tau+ neurons. The laminar distribution of the BN may reflect the degeneration of the feedback cortico-cortical and/or the efferent cortical pathways. By contrast, the distribution of the tau+ neurons may reflect the degeneration of the feed-forward cortico-cortical pathways. In addition, BN and tau+ neurons may arise as a result of distinct pathological processes.

Pryolytic and kinetic study of Chlorella Vulgaris under isothermal and non-isothermal conditions

Algae are a new potential biomass for energy production but there is limited information on their pyrolysis and kinetics. The main aim of this thesis is to investigate the pyrolytic behaviour and kinetics of Chlorella vulgaris, a green microalga. Under pyrolysis conditions, these microalgae show their comparable capabilities to terrestrial biomass for energy and chemicals production. Also, the evidence from a preliminary pyrolysis by the intermediate pilot-scale reactor supports the applicability of these microalgae in the existing pyrolysis reactor. Thermal decomposition of Chlorella vulgaris occurs in a wide range of temperature (200-550°C) with multi-step reactions. To evaluate the kinetic parameters of their pyrolysis process, two approaches which are isothermal and non-isothermal experiments are applied in this work. New developed Pyrolysis-Mass Spectrometry (Py-MS) technique has the potential for isothermal measurements with a short run time and small sample size requirement. The equipment and procedure are assessed by the kinetic evaluation of thermal decomposition of polyethylene and lignocellulosic derived materials (cellulose, hemicellulose, and lignin). In the case of non-isothermal experiment, Thermogravimetry- Mass Spectrometry (TG-MS) technique is used in this work. Evolved gas analysis provides the information on the evolution of volatiles and these data lead to a multi-component model. Triplet kinetic values (apparent activation energy, pre-exponential factor, and apparent reaction order) from isothermal experiment are 57 (kJ/mol), 5.32 (logA, min-1), 1.21-1.45; 9 (kJ/mol), 1.75 (logA, min-1), 1.45 and 40 (kJ/mol), 3.88 (logA, min-1), 1.45- 1.15 for low, middle and high temperature region, respectively. The kinetic parameters from non-isothermal experiment are varied depending on the different fractions in algal biomass when the range of apparent activation energies are 73-207 (kJ/mol); pre-exponential factor are 5-16 (logA, min-1); and apparent reaction orders are 1.32–2.00. The kinetic procedures reported in this thesis are able to be applied to other kinds of biomass and algae for future works.

Breakfast skipping is associated with cyberbullying and school bullying victimization:a school-based cross-sectional study

Breakfast skipping is a health concern that has well-known negative consequences physically and psychologically. It is therefore important to understand why children skip breakfast. The purpose of this study was to establish whether the experience of bullying and cyberbullying impacts upon breakfast skipping and to further evaluate whether the inability for youths to cope with bullying victimization affects their mental health (depression), and in turn predicts breakfast skipping. Data were obtained from the Eastern Ontario 2011 Youth Risk Behaviour Survey, a cross-sectional regional school-based survey of middle and high school students (11-20 years old) across the five counties of Eastern Ontario, Canada (N = 3035). Self-reported data about children's experiences of bullying victimization, breakfast eating habits, socio-economical status, depression, and other risk behaviours were analysed. Approximately half of the participants (50.4%) reported not eating breakfast on a regular basis: 26.3% and 24.1% reported often (usually eat breakfast three times or more per week) and frequent (usually eat breakfast twice a week or less) breakfast skipping behaviour, respectively. Victims of both cyberbullying and school bullying presented greater likelihood of often (adjusted relative risk ratio (RR) = 1.55; 95% confidence interval (CI) = 1.17-2.06) and frequent (RR = 1.97; 95% CI = 1.28-3.03) breakfast skipping. Mediation analysis further showed that depression fully mediated the relationship between school bullying victimization and frequent breakfast skipping. Moreover, depression partially mediated the associations between both cyberbullying and school bullying with frequent breakfast skipping. These findings highlight the potential interrelationships between cyberbullying, school bullying and depression in predicting unhealthy breakfast skipping behaviour in children. © 2014 Elsevier Ltd.

Dense Continuity and Selections of Set-Valued Mappings

∗ The first and third author were partially supported by National Fund for Scientific Research at the Bulgarian Ministry of Science and Education under grant MM-701/97.

Sequencing Jobs with Uncertain Processing Times and Minimizing the Weighted Total Flow Time

We consider an uncertain version of the scheduling problem to sequence set of jobs J on a single machine with minimizing the weighted total flow time, provided that processing time of a job can take on any real value from the given closed interval. It is assumed that job processing time is unknown random variable before the actual occurrence of this time, where probability distribution of such a variable between the given lower and upper bounds is unknown before scheduling. We develop the dominance relations on a set of jobs J. The necessary and sufficient conditions for a job domination may be tested in polynomial time of the number n = |J| of jobs. If there is no a domination within some subset of set J, heuristic procedure to minimize the weighted total flow time is used for sequencing the jobs from such a subset. The computational experiments for randomly generated single-machine scheduling problems with n ≤ 700 show that the developed dominance relations are quite helpful in minimizing the weighted total flow time of n jobs with uncertain processing times.

Financial Education Through Mathematics and IT Curricula: Pocket Money Management

Report published in the Proceedings of the National Conference on "Education in the Information Society", Plovdiv, May, 2013

Developing Financial Expertise Through Mathematics and IT School Curricula

Report published in the Proceedings of the National Conference on "Education and Research in the Information Society", Plovdiv, May, 2014

Tobacco use prevention education (TUPE) programs in the state of Florida: Teachers' perceptions of program structure and effectiveness

This study described teacher perceptions of TUPE program effectiveness in Florida in an attempt to improve programs by identifying factors that might influence teacher motivation and performance. Very little work has been done to examine how teachers' perceptions are related to the effectiveness of TUPE programs. A statewide survey provided information about how teachers' perceptions of program effectiveness are affected by variables such as: program structure, barriers, tobacco use norms, and training variables. Data were obtained from a telephone survey conducted in Florida as part of the Tobacco Pilot Project (TPP). The sample included 296 middle school teachers and 282 high school teachers as well as 193 middle school principals and 190 high school principals. Correlational and hierarchical regression analyses identified correlates and predictors of teachers' ratings of effectiveness. Results suggest that use of peer leaders, more frequent evaluations, a higher degree of parent involvement, fewer barriers, greater student interest, and lower tolerance for tobacco use were correlated with higher ratings of program effectiveness. Furthermore, student interest, peer, staff, and community tolerance norms, peer leaders, program evaluation, and parent involvement predicted middle school teachers' perceptions. Parent tolerance, student interest, number of barriers, and more frequent program evaluation predicted high school teachers' perceptions. In addition, middle school teachers who reported a lower number of factors negatively associated with teacher receptivity were more likely to view TUPE programs more favorably than teachers who reported a greater number of these risk factors. This relationship was not as robust among the high school teacher sample. Differences between the middle and high school sample were found in the magnitude and number of significant correlations, the proportion of variance accounted for by predictor variables, and the strength of the relationship between the number of factors negatively associated with teacher receptivity and teachers' perceptions of TUPE effectiveness. These findings highlighted the importance of the timing, program features, and the external environment for enhancing or minimizing teachers' ratings of TUPE program effectiveness. In conclusion, significant increases in TUPE teachers' self-efficacy will occur through the participation of peers, parents, staff, and community leaders in different aspects of TUPE programs. ^

Selected psychosocial and demographic factors affecting levels of pre-retirement planning

In September 2002, the State of Florida implemented a new retirement structure for those employed in the Florida Public School System. Teachers were given the option to maintain their existing defined benefit plan or choose the newly offered defined contribution plan. The variables that affect planning for retirement are innumerable. Identifying the most significant variables is essential to understanding how one plans for retirement. ^ This study examined the relationship between hypothesized psychosocial and demographic factors and an individual's level of pre-retirement planning. The criterion variable, the level of pre-retirement planning, comprised two concepts. First, the time spent thinking about retirement was determined by the score an individual received on a pre-retirement planning scale. This scale included the concepts of information gathering, goals, anticipated resources, and long-range planning. Second, implementation of retirement plan procedures was determined by the percentage an individual annually deferred to retirement. ^ The survey used for data collection contained 50 close-ended items. It was distributed to all full-time teachers in nine randomly selected elementary, middle, and senior high schools throughout Miami-Dade County Public Schools. Multiple regression and crosstabulation indicated that math anxiety, general risk, years of service, and total family income were significant predictors of the level of pre-retirement planning, as measured by the pre-retirement planning scale. In addition, the statistical analysis indicated that math anxiety, internal locus of control, years of service, and total family income were significant predictors of the level pre-retirement planning, as measured by the amount deferred to retirement. An individual's level of math anxiety and family income were the two factors that were the most significant predictors for both concepts on the level of pre-retirement planning. ^ Based on the findings of the study, recommendations focused on assessing an individual's level of math anxiety and educating teachers, particularly pre-service candidates, about the factors that affect pre-retirement planning. Further research should investigate the benefit of such educational programs. ^

Parental absence and academic achievement in immigrant students

Academic achievement and educational expectations as a function of parental absence were examined among 268 newly immigrant elementary, middle, and high-school students from Spanish-speaking countries. Data collected as part of a longitudinal study of adaptation and achievement in newly immigrant students were analyzed. Participants had varying experiences with parental absence, in terms of length of absence, gender of absent parent, and reason for absence. Reasons for parental absence included parental divorce, parental death, and serial migration, a cause unique to immigrant children. Students who experienced parental absence reported lower educational expectations. Students who experienced the death of a parent had lower achievement scores and lower expectations than students who did not experience parental death. Prolonged absence was also important, with students who experienced parental absence for more than one year performing worse than students who had minimal parental separation. In addition, boys who experienced parental absence because of serial migration performed worse academically than boys who did not have this occurrence. Educational expectations were reduced among students who experienced parental absence as a result of the migratory process, especially for younger students. The extent to which parental absence related to achievement and expectations through potential mediating factors, such as economic hardship, perceived school support, and parental school involvement was assessed with structural equation modeling. Overall, the model was able to explain some of the relationship between parental absence and the academic achievement and educational expectations of immigrant students from Spanish-speaking countries.^

Nutrient impacts on epifaunal density and species composition in a subtropical seagrass bed

The capacity of epifauna to control algal proliferation following nutrient input depends on responses of both grazers and upper trophic level consumers to enrichment. We examined the responses of Thalassia testudinum (turtle grass) epifaunal assemblages to nutrient enrichment at two sites in Florida Bay with varying levels of phosphorus limitation. We compared epifaunal density, biomass, and species diversity in 2 m2 plots that had either ambient nutrient concentrations or had been enriched with nitrogen and phosphorus for 6 months. At the severely P-limited site, total epifaunal density and biomass were two times higher in enriched than in unenriched plots. Caridean shrimp, grazing isopods, and gammarid amphipods accounted for much of the increase in density; brachyuran crabs, primary predatory fish, and detritivorous sea cucumbers accounted for most of the increase in biomass. At the less P-limited site, total epifaunal density and biomass were not affected by nutrient addition, although there were more caridean shrimp and higher brachyuran crab and pink shrimp biomass in enriched plots. At both sites, some variation in epifaunal density and biomass was explained by features of the macrophyte canopy, such as T. testudinum and Halodule wrightii percent cover, suggesting that enrichment may change the refuge value of the macrophyte canopy for epifauna. Additional variation in epifaunal density and biomass was explained by epiphyte pigment concentrations, suggesting that enrichment may change the microalgal food resources that support grazing epifauna. Increased epifaunal density in enriched plots suggests that grazers may be able to control epiphytic algal proliferation following moderate nutrient input to Florida Bay.

Hurricane Wilma’s impact on overall soil elevation and zones within the soil profile in a mangrove forest

Soil elevation affects tidal inundation period, inundation frequency, and overall hydroperiod, all of which are important ecological factors affecting species recruitment, composition, and survival in wetlands. Hurricanes can dramatically affect a site’s soil elevation. We assessed the impact of Hurricane Wilma (2005) on soil elevation at a mangrove forest location along the Shark River in Everglades National Park, Florida, USA. Using multiple depth surface elevation tables (SETs) and marker horizons we measured soil accretion, erosion, and soil elevation. We partitioned the effect of Hurricane Wilma’s storm deposit into four constituent soil zones: surface (accretion) zone, shallow zone (0–0.35 m), middle zone (0.35–4 m), and deep zone (4–6 m). We report expansion and contraction of each soil zone. Hurricane Wilma deposited 37.0 (±3.0 SE) mm of material; however, the absolute soil elevation change was + 42.8 mm due to expansion in the shallow soil zone. One year post-hurricane, the soil profile had lost 10.0 mm in soil elevation, with 8.5 mm of the loss due to erosion. The remaining soil elevation loss was due to compaction from shallow subsidence. We found prolific growth of new fine rootlets (209 ± 34 SE g m−2) in the storm deposited material suggesting that deposits may become more stable in the near future (i.e., erosion rate will decrease). Surficial erosion and belowground processes both played an important role in determining the overall soil elevation. Expansion and contraction in the shallow soil zone may be due to hydrology, and in the middle and bottom soil zones due to shallow subsidence. Findings thus far indicate that soil elevation has made substantial gains compared to site specific relative sea-level rise, but data trends suggest that belowground processes, which differ by soil zone, may come to dominate the long term ecological impact of storm deposit.