Going beyond defining: Preschool educators\u27 use of knowledge in their pedagogical reasoning about vocabulary instruction

Previous research investigating both the knowledge of early childhood educators and the support for vocabulary development present in early childhood settings has indicated that both educator knowledge and enacted practice are less than optimal, which has grave implications for children\u27s early vocabulary learning and later reading achievement. Further, the nature of the relationship between educators\u27 knowledge and practice is unclear, making it difficult to discern the best path towards improved knowledge, practice, and children\u27s vocabulary outcomes. The purpose of the present study was to add to the existing literature by using stimulated recall interviews and a grounded approach to examine how 10 preschool educators used their knowledge to made decisions about their moment-to-moment instruction in support of children\u27s vocabulary development. Results indicate that educators were thinking in highly context-specific ways about their goals and strategies for supporting vocabulary learning, taking into account important knowledge of their instructional history with children and of the children themselves to inform their decision making in the moment. In addition, they reported thinking about research-based goals and strategies for supporting vocabulary learning that went beyond simply defining words for children. Implications for research and professional development are discussed

Implications of "peak oil" for atmospheric CO2 and climate

Unconstrained CO2 emission from fossil fuel burning has been the dominant cause of observed anthropogenic global warming. The amounts of "proven" and potential fossil fuel reserves are uncertain and debated. Regardless of the true values, society has flexibility in the degree to which it chooses to exploit these reserves, especially unconventional fossil fuels and those located in extreme or pristine environments. If conventional oil production peaks within the next few decades, it may have a large effect on future atmospheric CO2 and climate change, depending upon subsequent energy choices. Assuming that proven oil and gas reserves do not greatly exceed estimates of the Energy Information Administration, and recent trends are toward lower estimates, we show that it is feasible to keep atmospheric CO2 from exceeding about 450 ppm by 2100, provided that emissions from coal, unconventional fossil fuels, and land use are constrained. Coal-fired power plants without sequestration must be phased out before mid-century to achieve this CO2 limit. It is also important to "stretch" conventional oil reserves via energy conservation and efficiency, thus averting strong pressures to extract liquid fuels from coal or unconventional fossil fuels while clean technologies are being developed for the era "beyond fossil fuels". We argue that a rising price on carbon emissions is needed to discourage conversion of the vast fossil resources into usable reserves, and to keep CO2 beneath the 450 ppm ceiling.Comment: (22 pages, 7 figures; final version accepted by Global Biogeochemical Cycles

Distribution and diversity of local strains of rice yellow motile virus in Tanzania

Rice (Oryza sativa) is a key staple in Tanzania but its productivity is affected by disease infestation, primary among which is the rice yellow mottle virus (RYMV). Tanzania possesses high RYMV densities and several locations including the Eastern Arc Mountains provide suitable habitat fragmentation that facilitates the diversification process of the virus. However, the distribution pattern and diversity of the local strains of RYMV remain largely unknown and this hinders progress in designing interventions. Efforts were, therefore, made to study the pattern and distribution of RYMV. Collection of isolates was made in May; recovery of virus on a susceptible elite line viz. TXD 220-1-3-3-1 was in June-July and molecular analysis was done in September-December 2005. The sequences of the coat protein (CP) gene of 23 isolates, representative of the three strains of RYMV found in Tanzania, were selected from 52 isolates collected from three regions. The phylogenetic analyses of the CP sequences revealed high (14.8%) nucleotide divergence between strains. Strain S6 was the most divergent with an intra- strain nucleotide divergence of 8.8%; this was consistent with its wide distribution in the region and particularly the eastern part of the Tanzania. Isolates of strains S4 were recorded for the first time in the eastern Arc Mountain region. These formed a monophyletic group with the Lake Malawi strain S4 sub-lineage (percentage identity of 95.4 to 96.8%) and differed from the Lake Victoria strain S4 sub-lineage by 4.5%. Coexistence within the same field of S4, S5 and S6 isolates was observed in the eastern Arc Mountains region. Strong competition between strains of RYMV was suspected from the limited distribution and rarity of strain S5. This study confirm speculations that the Eastern Arc Mountain region is the centre of origin of RYMV. Thus, the high viral load in the Eastern Arc Mountain imply that it is a suitable location for strategic studies aimed at designing control interventions against RYMV

Predicting the distributions of under-recorded Odonata using species distribution models

1. Absences in distributional data may result either from the true absence of a species or from a false absence due to lack of recording effort. I use general linear models (GLMs) and species distribution models (SDMs) to investigate this problem in North American Odonata and present a potential solution. 2. I use multi-model selection methods based on Akaike's information criterion to evaluate the ability of water-energy variables, human population density, and recording effort to explain patterns of odonate diversity in the USA and Canada using GLMs. Water-energy variables explain a large proportion of the variance in odonate diversity, but the residuals of these models are significantly related to recorder effort. 3. I then create SDMs for 176species that are found solely in the USA and Canada using model averaging of eight different methods. These give predictions of hypothetical true distributions of each of the 176species based on climate variables, which I compare with observed distributions to identify areas where potential under-recording may occur. 4. Under-recording appears to be highest in northern Canada, Alaska, and Quebec, as well as the interior of the USA. The proportion of predicted species that have been observed is related to recorder effort and population density. Maps for individual species have been made available online () to facilitate recording in the future. 5. This analysis has illustrated a problem with current odonate recording in the form of unbalanced recorder effort. However, the SDM approach also provides the solution, targeting recorder effort in such a way as to maximise returns from limited resources

Crop Genetic Improvement and Agricultural Development

Provisional synthesis by Robert Evenson of the results of an assessment of the impact of the crop improvement work of the CGIAR centers. This study was done Evenson in collaboration with eight IARCs under the auspices of IAEG. There is a forward written on behalf of SPIA, successor organization to IAEG, by Hans Gregersen. A previous version of the provisional synthesis was discussed at the CGIAR meeting in October 1999, and this one was the subject of a seminar at the CGIAR Mid Term Meeting 2000. Future publication plans for the study included a book to be published by CAB International, and academic articles. These are discussed in the SPIntellectual Assets Report to ICW 2000.The study traced germplasm improvements in ten crops through their introduction by national agricultural research systems and adoption by farmers, to their ultimate impacts on agricultural productivity, economic growth, income of producers, and affordability of food for poor consumers.The analysis considered the nature and magnitude of outputs and their costs; the CGIAR contribution to released varieties; related production gains; and impacts on producers and consumers. A related issue was the effect of IARC programs on NARS and private sector investments

Finite Element Analysis to model ischemia experienced in the development of device related pressure ulcers.

Pressure ulcers are a common occurrence of damage to skin. Severity ranges from slightly discoloured skin to full thickness tissue damage which can be fatal in some cases. Engineering effort, typically developing computational models had made significant progress in the understanding and demonstration of the formation mechanism of pressure ulcers with the aetiology of excessive stress however relatively limited attempts had been made to develop relevant models for pressure ulcers caused by ischemia. The aim of this paper is to present evidence of a computational model developed to simulate ischemic pressure ulcer formation and demonstrate the established relationship between the computational data and the acquired clinically relevant experimental data by utilising laser Doppler velocimetry. The application of the presented computational model and the established relationship allows the evaluation of the effect of a mechanical loading to the cutaneous blood flow velocity which is a step closing to understand and evaluate a mechanical load to the formation of pressure ulcers caused by ischemia

Aerodynamics of aero-engine installation

This paper describes current progress in the development of methods to assess aero-engine airframe installation effects. The aerodynamic characteristics of isolated intakes, a typical transonic transport aircraft as well as a combination of a through-flow nacelle and aircraft configuration have been evaluated. The validation task for an isolated engine nacelle is carried out with concern for the accuracy in the assessment of intake performance descriptors such as mass flow capture ratio and drag rise Mach number. The necessary mesh and modelling requirements to simulate the nacelle aerodynamics are determined. Furthermore, the validation of the numerical model for the aircraft is performed as an extension of work that has been carried out under previous drag prediction research programmes. The validation of the aircraft model has been extended to include the geometry with through flow nacelles. Finally, the assessment of the mutual impact of the through flow nacelle and aircraft aerodynamics was performed. The drag and lift coefficient breakdown has been presented in order to identify the component sources of the drag associated with the engine installation. The paper concludes with an assessment of installation drag for through-flow nacelles and the determination of aerodynamic interference between the nacelle and the aircraft

Kidney and uro-trauma : WSES-AAST guidelines

Renal and urogenital injuries occur in approximately 10-20% of abdominal trauma in adults and children. Optimal management should take into consideration the anatomic injury, the hemodynamic status, and the associated injuries. The management of urogenital trauma aims to restore homeostasis and normal physiology especially in pediatric patients where non-operative management is considered the gold standard. As with all traumatic conditions, the management of urogenital trauma should be multidisciplinary including urologists, interventional radiologists, and trauma surgeons, as well as emergency and ICU physicians. The aim of this paper is to present the World Society of Emergency Surgery (WSES) and the American Association for the Surgery of Trauma (AAST) kidney and urogenital trauma management guidelines.Peer reviewe

Theory and observations of ice particle evolution in cirrus using Doppler radar: evidence for aggregation

Vertically pointing Doppler radar has been used to study the evolution of ice particles as they sediment through a cirrus cloud. The measured Doppler fall speeds, together with radar-derived estimates for the altitude of cloud top, are used to estimate a characteristic fall time tc for the `average' ice particle. The change in radar reflectivity Z is studied as a function of tc, and is found to increase exponentially with fall time. We use the idea of dynamically scaling particle size distributions to show that this behaviour implies exponential growth of the average particle size, and argue that this exponential growth is a signature of ice crystal aggregation.Comment: accepted to Geophysical Research Letter