Individual effects and dynamics in count data models

In this paper we examine the panel data estimation of dynamic models for count data that include correlated fixed effects and predetermined variables.dtnamic count panel data, individual effects, predetermined regressors, Generalised Method of Moments, pre-smaple information

The benefits to the Australian Pig meat industry from an increase in demand for a hypothetical low cholesterol pork product

This is the third of a series of papers examining the potential economic effects from the introduction of a hypothetical low cholesterol pork product into the Australian market. Here, a newly updated pig meat model reported by Griffith et al. (2010) is used to model the industry wide impacts of the Bellhouse et al. (2010) survey results on consumer willingness to pay for this new pork product. Six different scenarios are examined that are combinations of a 10, 20 or 30 per cent increase in consumer demand, with and without a 10 per cent increase in the costs of producing the more valuable pork. The simulation results for the various scenarios indicate total annual industry benefits of some $450m for an increase in aggregate willingness to pay of 30 per cent and no cost increase, down to$88m for an increase in aggregate willingness to pay of 10 per cent and a 10 per cent cost increase. Australian consumers receive about 80 per cent of total benefits, pork producers receive about 7-8 per cent and all other market participants together receive about 12-13 per cent. These values provide a guide to the size of the annual investment that could be justified by pork producers to produce a pig that is low in cholesterol.cholesterol, pork, Australia, consumer willingness to pay, demand, Agribusiness, Demand and Price Analysis, Environmental Economics and Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries, Production Economics,

Australian consumers' willingness to pay and willingness to purchase a hypothetical lower cholesterol pork product

This study investigated whether there would be an increase in consumer willingness to pay and purchase if reduced cholesterol pork was introduced to the Australian market. A stated choice analysis was used, with the following questions addressed. How are current purchases of fresh pork affected by concerns about cholesterol content? What financial premium, if any, would consumers place on reduced cholesterol pork? Would consumers buy more pork if a low cholesterol option were available? Is there a group of consumers, such as those with high cholesterol, who have an increased willingness to pay for or purchase reduced cholesterol pork when compared to consumers without this health problem? Results from this study indicated that at present the majority of consumers are relatively unconcerned about the cholesterol content of fresh pork and that there is a minimal effect of such concerns on fresh pork purchases. The results also predicted a significant financial premium for the reduced cholesterol product at the retail level, with increased willingness to pay for and consume reduced cholesterol pork by the average pork consuming family. However, as these results are the product of a stated choice analysis and not a revealed preference study, and therefore simply reasonable expectations, it is likely that the reported increase in demand in both quantity and price by potential consumers is overstated to some extent.pork, cholesterol, choice analysis, Australian pork, Agribusiness, Agricultural and Food Policy, Consumer/Household Economics, Farm Management, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries, Risk and Uncertainty,

If At First You Do Not Succeed: The Student Benefits of Multiple Trials on Summative Assessments

Learning management systems offer flexibility in assessments. In Canvas, questions can be pulled from pools, customizing each quiz. Canvas also allows unique feedback options. Unique feedback can be programmed for students whether they got the question correct or incorrect. Feedback can even be customized based on which wrong answer was selected. Canvas also allows multiple attempts on assessments, with various options for awarding credit (final attempt, best score, average score, etc.). Combining immediate feedback with multiple attempts is a power - yet underexplored - tool

If at First You Do Not Succeed: Student Behavior When Provided Feedforward With Multiple Trials for Online Summative Assessments

Best practices suggest that timely, actionable feedback is provided with the option to apply the feedback. We used a learning management system to deliver assessments with automatic feedback provided at the conclusion of the assessment, allowing for multiple attempts in order to apply the knowledge gained. Questions were pooled so each attempt was unique, the highest score earned was awarded, with no penalty for failure to use multiple attempts. We found that students who did not earn an A on their first attempt were more likely to try again. Those that did tended to score better on their second attempt. This leads us to conclude that assessment design with multiple attempts that incorporates feedforward influences student behavior. Future work will include additional STEM general education courses in a broader study and a survey of student opinions regarding the utility of the feedback and the option for multiple attempts

Work Analysis with Resource-Aware Session Types

While there exist several successful techniques for supporting programmers in deriving static resource bounds for sequential code, analyzing the resource usage of message-passing concurrent processes poses additional challenges. To meet these challenges, this article presents an analysis for statically deriving worst-case bounds on the total work performed by message-passing processes. To decompose interacting processes into components that can be analyzed in isolation, the analysis is based on novel resource-aware session types, which describe protocols and resource contracts for inter-process communication. A key innovation is that both messages and processes carry potential to share and amortize cost while communicating. To symbolically express resource usage in a setting without static data structures and intrinsic sizes, resource contracts describe bounds that are functions of interactions between processes. Resource-aware session types combine standard binary session types and type-based amortized resource analysis in a linear type system. This type system is formulated for a core session-type calculus of the language SILL and proved sound with respect to a multiset-based operational cost semantics that tracks the total number of messages that are exchanged in a system. The effectiveness of the analysis is demonstrated by analyzing standard examples from amortized analysis and the literature on session types and by a comparative performance analysis of different concurrent programs implementing the same interface.Comment: 25 pages, 2 pages of references, 11 pages of appendix, Accepted at LICS 201

Surveying the Safety Culture of Academic Laboratories

The university traditionally has been the foundation for young adults’ professional development, yet the proclivity toward safety culture has garnered less focus in higher education than in the workforce. A survey of faculty at a medium-sized, research-active, private institution revealed specific areas of policy noncompliance as well as specific safety attitudes that can be targeted for interventions. Albeit a snapshot view, the survey implies that safety needs better representation in the classroom, teaching laboratories, and research facilities at universities. Safety is not abandoned by any means, and there is a strong presence of safety-oriented individuals, but the data show barriers to safety do exist that need to be addressed. The implications of this small-scale study serve as a foundation for a more comprehensive multi-institutional study in the future

Electrical Cell-Substrate Impedance Spectroscopy Can Monitor Age-Grouped Human Adipose Stem Cell Variability During Osteogenic Differentiation

: Human adipose stem cells (hASCs) are an attractive cell source for bone tissue engineering applications. However, a critical issue to be addressed before widespread hASC clinical translation is the dramatic variability in proliferative capacity and osteogenic potential among hASCs isolated from different donors. The goal of this study was to test our hypothesis that electrical cell-substrate impedance spectroscopy (ECIS) could track complex bioimpedance patterns of hASCs throughout proliferation and osteogenic differentiation to better understand and predict variability among hASC populations. Superlots composed of hASCs from young (aged 24-36 years), middle-aged (aged 48-55 years), and elderly (aged 60-81 years) donors were seeded on gold electrode arrays. Complex impedance measurements were taken throughout proliferation and osteogenic differentiation. During osteogenic differentiation, four impedance phases were identified: increase, primary stabilization, drop phase, and secondary stabilization. Matrix deposition was first observed 48-96 hours after the impedance maximum, indicating, for the first time, that ECIS can identify morphological changes that correspond to late-stage osteogenic differentiation. The impedance maximum was observed at day 10.0 in young, day 6.1 in middle-aged, and day 1.3 in elderly hASCs, suggesting that hASCs from younger donors require a longer time to differentiate than do hASCs from older donors, but young hASCs proliferated more and accreted more calcium long-term. This is the first study to use ECIS to predict osteogenic potential of multiple hASC populations and to show that donor age may temporally control onset of osteogenesis. These findings could be critical for development of patient-specific bone tissue engineering and regenerative medicine therapies. SIGNIFICANCE: Human adipose stem cells (hASCs) are an appealing cell source for bone tissue engineering and regenerative medicine applications because they can be obtained in high quantities via liposuction procedures and can differentiate down musculoskeletal lineages. However, a major barrier to clinical translation of hASCs is that cells from different donors have varying capacities to proliferate and differentiate. This study used electrical impedance spectroscopy to noninvasively track osteogenic differentiation of age-grouped donors in real time, showing that age-grouped hASCs have distinct complex impedance patterns. This method could be used to improve understanding of the biology that causes variability among hASC populations and to provide quantitative quality control standards for hASC populations in stem cell manufacturing and bone tissue engineering applications