Alternative Tasks for the Teaching and the Learning of functions: analysis of an intervention in the High School

In this paper we focus on the application of two mathematical alternative tasks to the teaching and learning of functions with high school students. The tasks were elaborated according to the following methodological approach: (i) Problem Solving and/or mathematics investigation and (ii) a pedagogical proposal, which defends that mathematical knowledge is developed by means of a balance between logic and intuition. We employed a qualitative research approach (characterized as a case study) aimed at analyzing the didactic pedagogical potential of this type of methodology in high school. We found that tasks such as those presented and discussed in this paper provide a more significant learning for the students, allowing a better conceptual understanding, becoming still more powerful when one considers the social-cultural context of the students.

Teaching and aligning upper level mathematics classes to Michigan high school content expectations in an alternative education setting : approaches and issues

After teaching regular education secondary mathematics for seven years, I accepted a position in an alternative education high school. Over the next four years, the State of Michigan adopted new graduation requirements phasing in a mandate for all students to complete Geometry and Algebra 2 courses. Since many of my students were already struggling in Algebra 1, getting them through Geometry and Algebra 2 seemed like a daunting task. To better instruct my students, I wanted to know how other teachers in similar situations were addressing the new High School Content Expectations (HSCEs) in upper level mathematics. This study examines how thoroughly alternative education teachers in Michigan are addressing the HSCEs in their courses, what approaches they have found most effective, and what issues are preventing teachers and schools from successfully implementing the HSCEs. Twenty-six alternative high school educators completed an online survey that included a variety of questions regarding school characteristics, curriculum alignment, implementation approaches and issues. Follow-up phone interviews were conducted with four of these participants. The survey responses were used to categorize schools as successful, unsuccessful, and neutral schools in terms of meeting the HSCEs. Responses from schools in each category were compared to identify common approaches and issues among them and to identify significant differences between school groups. Data analysis showed that successful schools taught more of the HSCEs through a variety of instructional approaches, with an emphasis on varying the ways students learned the material. Individualized instruction was frequently mentioned by successful schools and was strikingly absent from unsuccessful school responses. The main obstacle to successful implementation of the HSCEs identified in the study was gaps in student knowledge. This caused pace of instruction to also be a significant issue. School representatives were fairly united against the belief that the Algebra 2 graduation requirement was appropriate for all alternative education students. Possible implications of these findings are discussed.

The effect of acute exercise and psychosocial stress on fine motor skills and testosterone concentration in the saliva of high school students

Little is known about the influence of different stressors on fine motor skills, the concentration of testosterone (T), and their interaction in adolescents. Therefore, 62 high school students aged 14–15 years were randomly assigned to two experimental groups (exercise, psychosocial stress) and a control group. Exercise stress was induced at 65–75% of the maximum heart rate by running for 15 minutes (n = 24). Psychosocial stress was generated by an intelligence test (HAWIK- IV), which was uncontrollable and characterized by social-evaluative-threat to the students (n=21). The control group followed was part of a regular school lesson with the same duration (n = 28). Saliva was collected after a normal school lesson (pre-test) as well as after the intervention/control period (post-test) and was analyzed for testosterone. Fine motor skills were assessed pre- and post-intervention using a manual dexterity test (Flower Trail) from the Movement Assessment Battery for Children-2. A repeated measure ANCOVA including gender as a covariate revealed a significant group by test interaction, indicating an increase in manual dexterity only for the psychosocial stress group. Correlation analysis of all students shows that the change of testosterone from pre- to post-test was directly linked (r = 2.31, p = .01) to the changes in manual dexterity performance. Participants showing high increases in testosterone from pre- to post-test made fewer mistakes in the fine motor skills task. Findings suggest that manual dexterity increases when psychosocial stress is induced and that improvement of manual dexterity performance corresponds with the increase of testosterone.

An examination of the rate of high school completion experienced by handicapped and nonhandicapped students in the state of Texas

This research examines the graduation rate experienced by students receiving public education services in the state of Texas. Special attention is paid to that subgroup of Texas students who meet Texas Education Agency criteria for handicapped status. The study is guided by two research questions: What are the high school completion rates experienced by handicapped and nonhandicapped students attending Texas public schools? and What are the predictors of graduation for handicapped and nonhandicapped students?^ In addition, the following hypotheses are explored. Hypothesis 1: Handicapped students attending a Texas public school will experience a lower rate of high school completion than their nonhandicapped counterparts. Hypothesis 2: Handicapped and nonhandicapped students attending school in a Texas public school with a budget above the median budget for Texas public schools will experience a higher rate of high school completion than similar students in Texas public schools with a budget below the median budget. Hypothesis 3: Handicapped and nonhandicapped students attending school in large Texas urban areas will experience a lower rate of high school completion than similar students in Texas public schools in rural areas. Hypothesis 4: Handicapped and nonhandicapped students attending a Texas public school in a county which rates above the state median for food stamps and AFDC recipients will experience a lower rate of high school completion than students living in counties below the median.^ The study will employ extant data from the records of the Texas Education Agency for the 1988-1989 and the 1989-1990 school years, from the Texas Department of Health for the years of 1989 and 1990, and from the 1980 Census.^ The study reveals that nonhandicapped students are graduating with a two year average rate of.906, while handicapped students following an Individualized Educational Program (IEP) achieve a two year average rate of.532, and handicapped students following the regular academic program present a two year average graduation rate of only.371. The presence of other handicapped students, and the school district's average expense per student are found to contribute significantly to the completion rates of handicapped students. Size groupings are used to elucidate the various impacts of these variables on different school districts and different student groups.^ Conclusions and implications are offered regarding the need to reach national consensus on the definition and computation of high school completion for both handicapped and nonhandicapped students, and the need for improved statewide tracking of handicapped completion rates. ^

High-school students' need for cognition, self-control capacity, and school achievement: testing a mediation hypothesis

In the present article, we examine the hypothesis that high-school students' motivation to engage in cognitive endeavors (i.e., their need for cognition; NFC) is positively related to their dispositional self-control capacity. Furthermore, we test the prediction that the relation between NFC and school achievement is mediated by self-control capacity. A questionnaire study with grade ten high-school students (N = 604) revealed the expected relations between NFC, self-control capacity, and school achievement. Sobel tests showed that self-control capacity mediated the relation between NFC and school grades as well as grade retention.

Back pain in migrant farmworker families and farmworker high school students from Starr County, Texas

Back symptoms are a major global public health problem with the lifetime prevalence ranging between 50-80%. Research suggests that work-related factors contribute to the occurrence of back pain in various industries. Despite the hazardous nature, strenuous tasks, and awkward postures associated with farm work, little is known about back injury and symptoms in farmworker adults and children. Research in the United States is particularly limited. This is a concern given the large proportion of migrant farmworkers in the United States without adequate access to healthcare as well as a substantial number of youth working in agriculture. The present study describes back symptoms and identifies work-related factors associated with back pain in migrant farmworker families and farmworker high school students from Starr County, TX. Two separate datasets were used from two cohort studies "Injury and Illness Surveillance in Migrant Farmworkers (MANOS)" (study A: n=267 families) and "South Texas Adolescent Rural Research Study (STARRS)" (study B: n=345). Descriptive and inferential statistics including multivariable logistic regression were used to identify work-related factors associated with back pain in each study. In migrant farmworker families, the prevalence of chronic back pain during the last migration season ranged from 9.5% among youngest children to 33.3% among mothers. Chronic back pain was significantly associated with increasing age; fairly bad/very bad quality of sleep while migrating; fewer than eight hours of sleep at home in Starr County, TX; depressive symptoms while migrating; self-provided water for washing hands/drinking; weeding at work; and exposure to pesticide drift/direct spray. Among farmworker adolescents, the prevalence of severe back symptoms was 15.7%. Severe back symptoms were significantly associated with being female; history of a prior accident/back injury; feeling tense, stressed, or anxious sometimes/often; lifting/carrying heavy objects not at work; current tobacco use; increasing lifetime number of migrant farmworker years; working with/around knives; and working on corn crops. Overall, results support that associations between work-related exposures and chronic back pain and severe back symptoms remain after controlling for the effect of non-work exposures in farmworker populations. ^

Prevalence of depressive symptoms in urban middle and high school Hispanic and African American students

This cross-sectional study examined the prevalence of depressive symptoms in urban Hispanic and African American middle and high school students (N=1,292) using data collected from a multi-component, multi-wave violence and substance use intervention program targeted at a large urban school district in Texas. Chi-square analysis was used to examine differences in race/ethnicity, gender, grade level and whether or not a student had been held back/repeated a grade in school. Univariate and multivariate logistic regression were used to analyze the association between depressive symptoms and demographic variables. Being female and being held back/repeating a grade was significantly associated with depressive symptoms in both univariate and multivariate analyses. Overall 16% of the students reported depressive symptoms; Hispanic youth had a higher prevalence of depressive symptoms (16.8%) than the African American youth (14.8%). Minority females and those who had been held back/repeated a grade reported a prevalence of 19.4% and 21.2%, respectively. Further research is needed to understand why Hispanic youth continue to report a higher prevalence of depressive symptoms than other minorities. Additionally research is required to further explore the association between academic performance and depressive symptoms in urban minorities, specifically the effect of being held back/repeating a grade.^

Sexual initiation of U.S. Latino and Colombian high school students: Toward a new theory of adolescent sexuality and implications for sexual health prevention and promotion

The general research question for this dissertation was: do the data on adolescent sexual experiences and sexual initiation support the explicit or implicit adolescent sexuality theories informing the sexual health interventions currently designed for youth? To respond to this inquiry, three different studies were conducted. The first study included a conceptual and historical analysis of the notion of adolescence introduced by Stanley Hall, the development of an alternative model based on a positive view of adolescent sexuality, and the rationale for introducing to adolescent sexual health prevention programs the new definitions of sexual health and the social determinants of health approach. The second one was a quantitative study aimed at surveying not only adolescents' risky sexual behaviors but also sexual experiences associated with desire/pleasure which have been systematically neglected when investigating the sexual and reproductive health of the youth. This study was conducted with a representative sample of the adolescents attending public high schools in the State of Caldas in the Republic of Colombia. The third study was a qualitative analysis of 22 interviews conducted with male and female U.S. Latino adolescents on the reasons for having had or having not had vaginal sex. The more relevant results were: most current adolescent sexual health prevention programs are still framed in a negative approach to adolescent sexuality developed a century ago by Stanley Hall and Sigmund Freud which do not accept the adolescent sexual experience and propose its sublimation. In contrast, the Colombian study indicates that, although there are gender differences, adolescence is for males and females a normal period of sexual initiation not limited to coital activity, in which sexual desire/pleasure is strongly associated with sexual behavior. By the same token, the study about the reasons for having had or not had initiated heterosexual intercourse indicated that curiosity, sexual desire/pleasure, and love are basic motivations for deciding to have vaginal sexual intercourse for the first time and that during adolescence, young women and men reach the cognitive development necessary for taking conscious decisions about their sexual acts. The findings underline the importance of asking pertinent questions about desire/pleasure when studying adolescent sexuality and adopting an evidence-based approach to sexual health interventions.^

A study of factors influencing high school students' attitudes and opinions about violence

Tenth grade students in a lower income neighborhood Houston school were surveyed on violence related beliefs, attitudes, and coping ability. Self-administered questionnaires were used to collect information for scale scores for statistical analysis.^ One hundred twenty six students participated of which 60% were Hispanic, 18% Black, 18% White, 2 American Indians, and 3 Asian/Pacific persons. There were 60 males, mean age 16.03, and 66 females, mean age 15.49. One-half of the sample reported repeating a grade, 53.4% of males, and 47% of females. Females' self-reported grades were slightly higher than males.^ Measures of student acceptance of violence and ability to handle conflict peacefully were studied in relation to student responses to questions about five areas: parental monitoring of the student, parent type of punishment, optimism about future prospects, frustration tolerance, and perceived peer group attitudes and practices.^ Significant gender differences included males having higher violence acceptance scores and females higher on coping with conflict peacefully. No significant race differences or gender interactions were found.^ Females' scores on future orientation were inversely related to their scores on the measure of acceptance of violence. For males, parents' punishment and perceived peer attitudes were positively related to their acceptance of violence, p $<$.0083.^ Female handling of conflict was significantly related to frustration tolerance and optimism; not significant were perceived peer attitudes, parent monitoring or punishment method. For males significantly related to handling conflict were perceived peer attitudes, parental monitoring, and severity of punishment, with the last two terms having a significant interaction effect, and inversely correlated (less monitoring, harsher punishment explained lower ability to handle conflict). ^

Sugar sweetened beverage consumption and behavioral correlates in a pilot study of high school students in Austin, Texas

Habitual consumption of sugar-sweetened beverages (SSB) has been reliably linked to obesity in adolescents. A wide variety of beverages sweetened with sugar are available to this population. The objective of this secondary data analysis was to assess the consumption of SSB by category and to identify behaviors that occur concurrently with the consumption of soda, sport drinks and fruit-flavored drinks in high school students. The analysis used self-reported survey data from 97 adolescents ages 14 to 18. SSB categories considered in the consumption analysis included regular soda, sports drinks, fruit-flavored drinks (FFD), iced tea, coffee drinks and energy drinks. The mean weekly sweetened beverage load in this population, calculated from the frequency and amount of consumption, was 145 ounces when all categories were considered. When SSB categories were considered independently, sports drinks (45 oz.) had the highest contribution to the mean sweetened beverage load followed by FFD (41 oz.), iced tea (27 oz.), soda (26 oz.) coffee drinks (15 oz.) and energy drinks (2 oz.). Sweetened beverage load was higher in boys (151 oz.) than girls (138 oz.) and was highest in Hispanics (159 oz.) followed by whites (152 oz.), blacks (137 oz.) and others (104 oz.). Behaviors that occurred on a usual basis during SSB consumption included watching TV, eating a family meal, eating salty and fried foods, being on the computer and hanging out with friends. Activities concurrent with sports drink consumption included physical activity behaviors whereas soda and FFD did not. Sports drink and FFD consumption commonly co-occurred with fruit consumption. Multiple SSB categories contribute to the total SSB consumption and the common dietary and activity behaviors are distinct between categories. Several of the concurrent behaviors point to the importance of home beverage availability, and to the influence that parents and peers have on SSB consumption. Identifying and assessing intervention strategies targeted to specific beverage categories could be an important step in behavioral intervention research aimed at reducing added sugar consumption, and ultimately, promote a healthy weight in adolescents. ^

Geochemistry of ODP Site 202-1233 and river sediments

Bulk sediment chemistry from three Chilean continental margin Ocean Drilling Program sites constrains regional continental erosion over the past 30,000 years. Sediments from thirteen rivers that drain the (mostly igneous) Andes and the (mostly metamorphic) Coast Range, along with existing rock chemistry datasets, define terrestrial provenance for the continental margin sediments. Andean river sediments have high Mg/Al relative to Coast-Range river sediments. Near 36°S, marine sediments have high-Mg/Al (i.e. more Andean) sources during the last glacial period, and lower-Mg/Al (less Andean) sources during the Holocene. Near 41°S a Ti-rich source, likely from coast-range igneous intrusions, is prevalent during Holocene time, whereas high-Mg/Al Andean sources are more prevalent during the last glacial period. We infer that there is a dominant ice-sheet control of sediment sources. At 36°S, Andean-sourced sediment decreased as Andean mountain glaciers retreated after ~17.6 ka, coincident with local oceanic warming and southward retreat of the Patagonian Forest and, by inference, westerly winds. At 41°S Andean sediment dominance peaks and then rapidly declines at ~19 ka, coincident with local oceanic warming and the earliest deglacial sea-level rise. We hypothesize that this decreased flux of Andean material in the south is related to rapid retreat of the marine-based portion of the Patagonian Ice Sheet in response to global sea-level rise, as the resulting flooding of the southern portion of the Central Valley created a sink for Andean sediments in this region. Reversal of the decreasing deglacial Mg/Al trend at 41°S from 14.5 to 13.0 ka is consistent with a brief re-advance of the Patagonian ice sheet coincident with the Antarctic Cold Reversal.

Adaptive variability to low-pH river discharges in Acartia tonsa and stress responses to high PCO2 conditions

Environmental transitions leading to spatial physical-chemical gradients are of ecological and evolutionary interest because they are able to induce variations in phenotypic plasticity. Thus, the adaptive variability to low-pH river discharges may drive divergent stress responses [ingestion rates (IR) and expression of stress-related genes such as Heat shock protein 70 (Hsp70) and Ferritin] in the neritic copepod Acartia tonsa facing changes in the marine chemistry associated to ocean acidification (OA). These responses were tested in copepod populations inhabiting two environments with contrasting carbonate system parameters (an estuarine versus coastal area) in the Southern Pacific Ocean, and assessing an in situ and 96-h experimental incubation under conditions of high pressure of CO2 (PCO2 1200 ppm). Adaptive variability was a determining factor in driving variability of copepods' responses. Thus, the food-rich but colder and corrosive estuary induced a traits trade-off expressed as depressed IR under in situ conditions. However, this experience allowed these copepods to tolerate further exposure to high PCO2 levels better, as their IRs were on average 43% higher than those of the coastal individuals. Indeed, expression of both the Hsp70 and Ferritin genes in coastal copepods was significantly higher after acclimation to high PCO2 conditions. Along with other recent evidence, our findings confirm that adaptation to local fluctuations in seawater pH seems to play a significant role in the response of planktonic populations to OA-associated conditions. Facing the environmental threat represented by the inter-play between multiple drivers of climate change, this biological feature should be examined in detail as a potential tool for risk mitigation policies in coastal management arrangements.

Drought risk assessment as changes in the potential stand yield classes and potential forest production for Sitka spruce, Scots pine, and pedunculate oak over the next 80 years in the Great Britain

Probabilistic climate data have become available for the first time through the UK Climate Projections 2009, so that the risk of tree growth change can be quantified. We assess the drought risk spatially and temporally using drought probabilities and tree species vulnerabilities across Britain. We assessed the drought impact on the potential yield class of three major tree species (Picea sitchensis, Pinus sylvestris, and Quercus robur) which presently cover around 59% (400,700 ha) of state-managed forests, across lowland and upland sites. Here we show that drought impacts result mostly in reduced tree growth over the next 80 years when using b1, a1b and a1fi IPCC emissions scenarios. We found a maximum reduction of 94% but also a maximum increase of 56% in potential stand yield class in the 2080s from the baseline climate (1961-1990). Furthermore, potential production over the national forest estate for all three species in the 2080s may decrease due to drought by 42% in the lowlands and 32% in the uplands in comparison to the baseline climate. Our results reveal that potential tree growth and forest production on the national forest estate in Britain is likely to reduce, and indicate where and when adaptation measures are required. Moreover, this paper demonstrates the value of probabilistic climate projections for an important economic and environmental sector.

Tools in Spanish Universities to facilitate the transmission from High School to University and their assessment.

Incoming students in the University have education deficiencies, so universities studies require a sound basis of scientific knowledge. In this project are analysed instruments to reinforcing knowledge in those areas related to the studies that students are about to embark on public Spanish universities. There are important differences among universities and, in each university there are great differences among titles. Initial courses (cursos cero) are widespread (in 50% of universities) that selfevaluation instruments (14 % of universities). It is necessary to improve diffusion of those instruments because it is not possible to evaluate them. So are proposed the next actuations: to make regular standard surveys for professors and students; to publish results of surveys; public universities should institutionalize their basic training offer and improve the dissemination of this offer especially through the web. This paper presents a questionnaire to assess student opinion about these tools. To analyze the effectiveness, and make an initial estimate of the evaluation of these tools, we conducted a pilot test of the questionnaire with 68 students at the University of Extremadura. The results of preliminary statistical analysis conducted on the pilot test indicate that the survey results are reliable. A global evaluation of both tools, with a scale of 1 to 5, gave an average score of 3.29 for initial courses and 3.41 for selfevaluation. The 72.9% of the students consider the "self assessment" more effective than the "initial course"

Resources to introduce Inquire Based Scientic Education in Secondary and High School

The global Hands-on Universe association is producing and distributing free resources world- wide to implement Inquire Based Scienti?c Education (IBSE) at secondary and high school levels. The materials are inspired in astronomical research and space exploration. The association is implementing the Galileo Teacher Training Program world-wide. In this contribution, a summary on the most recent resources being implemented by HOU-Espa~na and developed with Spanish participation is presented.