From the Lab to the Classroom: Research at the Interface Between Cognitive Science and Education

Presented at the 29th Association for Psychological Science (APS) Annual Convention in Boston, MA

Financial Vulnerability of Midwest Grain Farms: Implications of Price, Yield, and Cost Shocks

Recent years have witnessed increasing volatility in crop prices and yields, fertilizer prices, and farm asset values. In this study, the financial performance of illustrative Midwest grain farms with different scales, tenure status, and capital structures was examined under the shocks of volatile crop prices, yields, fertilizer prices, farmland value, and cash rent. Illustrative farms of 550, 1,200, and 2,500 acres were constructed reflecting the production activity for these farms with three different farmland ownership structures (15%, 50%, and 85% of land owned) and two capital structures measured by debt-to- asset ratio (25% and 50%). Absolute measures and financial ratios were used to evaluate the income, cash flow, debt servicing, and equity position of these illustrative farms. The “stress test” results suggest that farms with modest size (i.e., 550 acres) and a large proportion of their land rented are very vulnerable irrespective of their leverage positions. Large-size farms with modest leverage (25% debt-to- asset ratio) that combine rental and ownership of the land they operated have strong financial performance and limited vulnerability to price, cost, yield, and asset value shocks. And these farms can increase their leverage positions significantly (from 25% to 50% in this study) with only modest deterioration in their financial performance and a slight increase in their vulnerability. These results suggest that the perspective that farmers are resilient to price, cost, yield, and asset value shocks because of the current low use of debt in the industry (an average of about 13% debt-to- asset ratio for the farming sector) does not adequately recognize the financial vulnerable of many typical family farms to those shocks

RGB: a scalable and reliable group membership protocol in mobile Internet

We propose a membership protocol for group commu-nications in mobile Internet. The protocol is called RGB, which is the acronym of “a Ring-based hierarchy of ac-cess proxies, access Gateways, and Border routers”. RGB runs in a parallel and distributed way in the sense that each network entity in the ring-based hierarchy maintains local information about its possible leader, previous, next, par-ent and child neighbors, and that each network entity inde-pendently collects/generates membership change informa-tion, which is propagated by the one-round membership al-gorithm concurrently running in all the logical rings. We prove that the proposed protocol is scalable in the sense that the scalability of a ring-based hierarchy is as good as that of a tree-based hierarchy. We also prove that the proposed protocol is reliable, in the sense that, with high probability of 99.500%, a ring-based hierarchy with up to 1000 access proxies attached by a large number of mobile hosts will not partition when node faulty probability is bounded by 0.1%; if at most 3 partitions are allowed, then the Function-Well probability of the hierarchy is 99.999 % accordingly. 1

A disk based stream oriented approach for storing big data

Abstract—This paper proposes an extension to the generally accepted definition of Big Data and from this extended definition proposes a specialized database design for storing high through-put data from low-latency sources. It discusses the challenges a financial company faces with regards to processing and storing data and how existing database technologies are unsuitable for this niche task. A prototype database called CakeDB is built using a stream oriented, disk based storage design and insert throughput tests are conducted to demonstrate how effectively such a design would handle high throughput data as per the use case. I

Field testing of World Health Organization (WHO) 2003 recommendations for initiating anti-retroviral therapy (ART) where CD4 is not available revealed low sensitivity among stage I and II patients; a combination of Automated Total Lymphocyte Count (TLC) and Haemoglobin (Hgb) can ration the referral for CD4 testing.

2006 AIDS Conference, Toront

Association Mapping of Insecticide Resistance in Wild Anopheles gambiae Populations: Major Variants Identified in a Low-Linkage Disequilbrium Genome

Background: Association studies are a promising way to uncover the genetic basis of complex traits in wild populations. Data on population stratification, linkage disequilibrium and distribution of variant effect-sizes for different trait-types are required to predict study success but are lacking for most taxa. We quantified and investigated the impacts of these key variables in a large-scale association study of a strongly selected trait of medical importance: pyrethroid resistance in the African malaria vector Anopheles gambiae. Methodology/Principal Findings: We genotyped <1500 resistance-phenotyped wild mosquitoes from Ghana and Cameroon using a 1536-SNP array enriched for candidate insecticide resistance gene SNPs. Three factors greatly impacted study power. (1) Population stratification, which was attributable to co-occurrence of molecular forms (M and S), and cryptic within-form stratification necessitating both a partitioned analysis and genomic control. (2) All SNPs of substantial effect (odds ratio, OR.2) were rare (minor allele frequency, MAF,0.05). (3) Linkage disequilibrium (LD) was very low throughout most of the genome. Nevertheless, locally high LD, consistent with a recent selective sweep, and uniformly high ORs in each subsample facilitated significant direct and indirect detection of the known insecticide target site mutation kdr L1014F (OR<6; P,1026), but with resistance level modified by local haplotypic background. Conclusion: Primarily as a result of very low LD in wild A. Gambiae, LD-based association mapping is challenging, but is feasible at least for major effect variants, especially where LD is enhanced by selective sweeps. Such variants will be of greatest importance for predictive diagnostic screening

Genetic Vaccination-Induced Immune Responses to the Human Immunodeficiency Virus Protein Rev: Emergence of the Interleukin 2-Producing Helper T Lymphocyte

Overview summary The immune system poses a major obstacle to the long-term success of in vivo gene therapies. Immune responses to foreign transgene products and/or the vectors that facilitate gene transfer may neutralize the transgene product, eliminate transfected cells, and culminate in inflammation within transfected tissues. The majority of studies that address these issues have focused on cytotoxic T lymphocyte (CTL) and antibody responses induced by gene transfer. However, the IL-2-producing helper T lymphocyte (HTL) represents a critical regulatory cell that likely influences the inductive phase of the immune response following gene transfer. The current study employed limiting dilution analysis (LDA) techniques to characterize the development of IL-2-producing HTLs induced by genetic vaccination with a plasmid encoding the mutated HIV protein Rev M10. Further, we assessed the ability to inhibit the transgene-induced HTL response by cotransfer of a plasmid encoding the immunosuppressive cytokine TGFβ1.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63282/1/hum.1998.9.15-2187.pd

iCartiGD: the Integrated Cartilage Gene Database

BACKGROUND: Diseases of cartilage, such as arthritis and degenerative disc disease, affect the majority of the general population, particularly with ageing. Discovery and understanding of the genes and pathways involved in cartilage biology will greatly assist research on the development, degeneration and disorders of cartilage. DESCRIPTION: We have established the Integrated Cartilage Gene Database (iCartiGD) of genes that are known, based on results from high throughput experiments, to be expressed in cartilage. Information about these genes is extracted automatically from public databases and presented as a single page report via a web-browser. A variety of flexible search options are provided and the chromosomal distribution of cartilage associated genes can be presented. CONCLUSION: iCartiGD provides a comprehensive source of information on genes known to be expressed in cartilage. It will remain current due to its automatic update capability and provide researchers with an easily accessible resource for studies involving cartilage. Genetic studies of the development and disorders of cartilage will benefit from this database