Authentic student inquiry: the mismatch between the intended curriculum and the student-experienced curriculum

As a means of achieving scientific literacy goals in society, the last two decades have witnessed international science curriculum redevelopment that increasingly advocates a 'new look' inquiry-based approach to learning. This paper reports on the nature of the student-experienced curriculum where secondary school students are learning under a national curriculum that is intent on promoting students' knowledge and capabilities in authentic scientific inquiry, that is, inquiry that properly reflects that practiced by members of scientific communities. Using a multiple case study approach, this study found that layers of curriculum interpretation from several 'sites of influence' both outside and inside of the schools have a strong bearing on the curriculum enacted by teachers and actually experienced by the students, and runs counter to the aims of the national curriculum policy. Over-emphasis on fair testing limits students' exposure to the full range of methods that scientists use in practice, and standards-based assessment using planning templates, exemplar assessment schedules and restricted opportunities for full investigations in different contexts tends to reduce student learning about experimental design to an exercise in 'following the rules'. These classroom realities have implications for students' understanding of the nature of authentic scientific inquiry and support claims that school science is still far removed from real science

In Vitro Studies of the Prp9·Prp11·Prp21 Complex Indicate a Pathway for U2 Small Nuclear Ribonucleoprotein Activation

Pre-mRNA splicing takes place on a large ribonucleoprotein particle, the spliceosome which contains the five small nuclear ribonucleoproteins (snRNPs), U1, U2, U4, U5, and U6. In Saccharomyces cerevisiae the mRNA splicing factors, Prp9, Prp11, and Prp21, are necessary for addition of the U2 snRNP to the pre-mRNA in an early step of spliceosome assembly. This paper describes a study of interactions between these proteins and their role in spliceosome assembly. The proteins were expressed in Escherichia coli. Prp9 and Prp11 were purified by metal affinity chromatography. Prp21 was purified using a solubilization/renaturation protocol. We have combined these separately purified proteins and present direct evidence of a Prp9·Prp11·Prp21 protein complex that is functional in in vitro splicing assays. Characteristics of this Prp9·Prp11·Prp21 complex were further investigated using proteins synthesized in vitro. In addition, we found that Prp9, Prp11, and Prp21 influence the structure of the U2 snRNP in a manner that alters the accessibility of the branch point pairing region of the U2 snRNA to oligonucleotide-directed RNaseH cleavage. We present a model, based on the data presented here and in the accompanying paper, for a combined role of Prp9, Prp11, Prp21, and Prp5 in activating the U2 snRNP for assembly into the pre-spliceosome

ACCOUNTING FOR THE IMPORTANCE OF NONFARM INCOME ON FARM FAMILY INCOME INEQUALITY IN NEW YORK

As the proportion of farm family income due to nonfarm sources continues to grow nationally, it is important to understand how farm families in various regions or states are affected. This paper develops a better understanding of the contribution of income from nonfarm sources to the level and distribution of income among farm families in New York. In analyzing income distribution, the Gini ratio is decomposed to determine the effects of marginal changes in income by source to overall inequality. The results are compared with the simulated changes in income inequality due to changes in income by source as measured by an "adjusted" Gini ratio which accounts specifically for negative farm incomes. Differences in the policy implications from both procedures are compared. The relationships among sources of income and policy implications can be brought into sharper focus by examining both measures.Agricultural Finance,

THE DISTINCT IMPACT OF FOOD STAMPS ON FOOD SPENDING

The Southworth hypothesis predicts that inframarginal food stamp recipients should choose the same bundle of goods, whether they receive coupons or cash. Empirical research has contradicted this prediction. Here, we present a model that retains some attractive features of the Southworth hypothesis, while relaxing the key assumption that appears to be incorrect. In particular, we allow different forms of benefits to have distinct effects on desired, or unrestricted food spending. Two categories of previously commonly used empirical models are evaluated as special cases of our more general model. We estimate this model using data from two cash-out experiments.Consumer/Household Economics, Food Security and Poverty,

EFFECTS OF FOOD AND HEALTH SPENDING PATTERNS ON THE HEALTH OF THE ELDERLY

Examines linkages between food and health spending patterns, income, and health status of the elderly. Links these relationships to food insecurity and expenditures on nutraceuticals. Methodology includes simultaneous estimation of expenditure systems and health production functions. Preliminary results indicate simultaneity between health production function and spending patterns throughout the life cycle.Food Consumption/Nutrition/Food Safety, Health Economics and Policy,

DO HEALTHIER DIETS COST MORE?

Do healthier diets cost more? We estimate a hedonic regression model of the U.S. diet. Given food expenditures and information on dietary intake we infer the marginal cost of improved quality. Meeting the Pyramid recommendations implies decreased expenditures from two of the seven food groups.Food Consumption/Nutrition/Food Safety,

Student attitudes to entrepreneurship

This study on Student Attitudes to Entrepreneurship investigates the image which university students have of entrepreneurs and entrepreneurship. It is an initial exploratory/empirical study, which looks at the situation in Germany, Romania, Latvia, Italy and Austria. The study, based on questionnaires, shows that there are significant differences but also common features to the image of entrepreneurship and attitudes to it in the five countries. It is interesting to note that the students polled in connection with the study tended to have a neutral to positive/very positive image of entrepreneurs.attitude, attributes, entrepreneurs, entrepreneurship, opinion.

Task Persistence: A Potential Mediator of the Income-Achievement Gap

Background: The pervasive gap in achievement among impoverished children has been investigated primarily in terms of parental investments, specifically parent to child speech and other forms of cognitive stimulation (e.g., toys, print materials). This research extends that literature by considering the role of a non-cognitive factor, namely task persistence, in the income-achievement gap. Using task persistence as the hypothesized mediator, duration of childhood in poverty is used to predict two educational variables - perceived academic competence and educational attainment. Although bivariate relationships between each of the variables have been demonstrated in past research, a full model linking task persistence with the income-achievement gap has not been investigated thus far. Methods: Using multiple waves of longitudinal data, duration of childhood poverty (ages 0-9) is used to predict both perceived academic competence (age 17) and educational attainment (age 23) with task persistence (average of ages 9, 13, 17) as a mediator. Results: With task persistence included in each model, the relationships between duration of childhood in poverty and both perceived academic competence and educational attainment are significantly reduced, confirming a mediational influence of task persistence. Conclusions: As hypothesized, task persistence statistically mediates the relationship between duration of childhood in poverty and educational outcomes. The implications of these findings on school success and intergenerational poverty are addressed, as well as suggestions for future research

First season maize performance in a long-term farming systems comparison trial at KARI-Thika, Kenya

Kenya’s smallholder farmers contribute 65% to total agricultural output in a predominantly mixed farming system where application of inorganic fertilizers and pesticides is minimal. By contrast, agriculture in developed temperate countries is dominated by large-scale farming and heavy reliance on fertilizers and pesticides to sustain high yields. Research conducted in temperate developed countries has shown that organic farming is superior to conventional farming in resource use efficiency, ecosystem functioning, soil fertility conservation and economic performance but results cannot be transferred directly to the tropics because of disparities in climate, soils and socio-economic environments. A long-term farming systems comparisons experiment was initiated at KARI-Thika in 2006 to assess the contribution of organic agriculture to food security, poverty alleviation and environmental conservation. Four treatments (Conventional High, Conventional Low, Organic High and Organic Low) were imposed in 8m x 8m plots using a randomized complete block design and replicated five times. The ‘High’ treatments received 118 kgN/ha and 66+5kgP/ha while the ‘Low’ treatments received 65 kgN/ha and 27 kgP/ha. Conventional treatments received the nutrients from farmyard manure, diammonium phosphate and calcium ammonium phosphate while compost, Tithonia diversifolia, and phosphate rock were applied in the organic treatments. Maize variety Pannar was planted at the onset of rains in April 2007 and harvested in August from a net plot area of 6m x 6m. The plots were hand weeded while stock borer was controlled using a Neem extract and ash/soil mixture in organic treatments and Bulldock® in conventional treatments. Stover dry weights were significantly higher in Conventional High than Organic Low (P=0.034) and indistinguishable from those observed in Conventional Low and Organic High. It was reasoned that availability of applied nutrients and the low poorly distributed rainfall received during the flowering and grain filling stages impacted negatively on grain yield