Is Screening Cargo Containers for Smuggled Nuclear Threats Worthwhile?

In recent years, Customs and Border Protection (CBP) has installed radiation sensors to screen cargo containers entering theUnited States. They are concerned that terrorists could use containers to smuggle radiological material into the country and carry out attacks with dirty bombs or a nuclear device. Recent studies have questioned the value of improving this screening system with new sensor technology. The cost of delays caused by frequent false alarms outweighs any reduction in the probability of an attack in an expected cost analysis. We extend existing methodology in three ways to demonstrate how additional factors affect the value of screening investments. We examine the effect that screening has in discouraging terrorists. We model multiple levels of screening. Finally, we consider additional objectives beyond cost. We find that the conclusion about screening depends on key inputs to the probability model (reflecting uncertainties) and to the value function (reflecting the stakeholders’ fundamental objectives)

DVT Surveillance Program in the ICU: Analysis of Cost-Effectiveness

Background Venous Thrombo-embolism (VTE – Deep venous thrombosis (DVT) and/or pulmonary embolism (PE) – in traumatized patients causes significant morbidity and mortality. The current study evaluates the effectiveness of DVT surveillance in reducing PE, and performs a cost-effectiveness analysis. Methods All traumatized patients admitted to the adult ICU underwent twice weekly DVT surveillance by bilateral lower extremity venous Duplex examination (48-month surveillance period – SP). The rates of DVT and PE were recorded and compared to the rates observed in the 36-month pre-surveillance period (PSP). All patients in both periods received mechanical and pharmacologic prophylaxis unless contraindicated. Total costs – diagnostic, therapeutic and surveillance – for both periods were recorded and the incremental cost for each Quality Adjusted Life Year (QALY) gained was calculated. Results 4234 patients were eligible (PSP – 1422 and SP – 2812). Rate of DVT in SP (2.8%) was significantly higher than in PSP (1.3%) – p Conclusions Surveillance of traumatized ICU patients increases DVT detection and reduces PE incidence. Costs in terms of QALY gained compares favorably with other interventions accepted by society

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Designing Aviation Security Systems: Theory and Practice

122 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006.Next-generation aviation security systems need not merely be makeshift political solutions for mending complex problems; they can be the result of modeling, analysis, and planning. This dissertation provides a systematic approach for designing and analyzing aviation security systems, which provides insight into the operation of passenger screening systems and guidance for the design of next-generation aviation security systems.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Designing Aviation Security Systems: Theory and Practice

122 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006.Next-generation aviation security systems need not merely be makeshift political solutions for mending complex problems; they can be the result of modeling, analysis, and planning. This dissertation provides a systematic approach for designing and analyzing aviation security systems, which provides insight into the operation of passenger screening systems and guidance for the design of next-generation aviation security systems.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Acquisition, generalisation and retention of object names in 4 year old children : a comparison of child-led and adult-led learning interactions : a dissertation.

In recent times incidental teaching has become the preferred method for encouraging children's learning and language development within the early childhood setting. It is argued that this naturalistic, unstructured and predominantly child-led style of teaching is the best way of fostering children's language acquisition and generalisation across settings. Few studies however have compared this method with more traditional, structured, adult-led teaching strategies. The present experiment compared the effectiveness of child-led and adult-led teaching interactions in the acquisition, retention and generalisation of object names in seven, 4-year old children. A comparison of the effects of the two teaching conditions revealed that children learned more object names during the adult-led interactions. However this difference did not prove to be significant. No difference was found between the two groups in either retention or generalisation. These findings have significant implications for the way in which young children should be taught and raises questions about one of the fundamental assumptions underlying developmentally appropriate practice

A study of teaching strategies that facilitate stimulus generalisation in children with autism

Language development involves the learning of multiple sets of equivalence relations. Research has shown that if certain conditional relations are directly taught for one member of a class of stimuli, then additional conditional relations often emerge for other members of that class, without direct training. There are currently very few studies which have demonstrated this research finding in individuals with autism spectrum disorder (ASD). The research design used for the present experiment was a single-subject AB cross-over design replicated across five plus five children with ASD and five plus five typically developing children. The children with ASD and the typically developing children were matched on their level of vocabulary development. Participants were randomly assigned to either a teaching order Treatment A+B or a teaching order Treatment B+A. The first experimental treatment (Treatment A+B) involved teaching responses to S1 and S2 in the order Condition A followed by Condition B. The second experimental treatment (Treatment B+A) involved teaching responses to S1 and S2 in the order Condition B followed by Condition A. Condition A involved the teaching of AB and AC (hear-select) relations, and Condition B involved the teaching of BA and CA (see-say) relations. The participants in this study were taught stimulus-response relations that involved six names and numerical representations of quantities in the range 1 to 18. Tests for the emergence of symmetry and transitivity were then conducted. The relationships between the emergence of the untaught equivalence relations and teaching condition, the entering characteristics of the children, and trials to criterion were examined. The results of this study showed that five out of ten participants with ASD demonstrated the emergence of all of the untaught equivalence relations regardless of the treatment condition. The remaining five participants with ASD showed substantial variability. Of the children in the Typically Developing Group nine of the ten demonstrated emergence of all of the untaught equivalence relations. The variables that were most strongly correlated with the emergence of untaught equivalence relations were speed of acquisition of taught relations, functional academics scores, and the chronological age of the participants. The effect of communication ability, pre-academic numeracy skill level, and the experimental treatment (the teaching order conditions) were not strongly related to the emergence of untaught equivalence relations. These findings suggest that outcomes on tests for emergence may have been a function of children’s rate of development and prior learning history. The findings of the current study are best explained by Relational Frame Theory. The implications of these findings for teaching children with ASD and other developmental disabilities, and also teaching in general are discussed

A hypothesis about the origin of sperm storage in the Eubrachyura, the effects of seminal receptacle structure on mating strategies and the evolution of crab diversity: How did a race to be first become a race to be last?

The origins and evolution of sperm storage in Brachyura are enigmatic: sperm is either stored in seminal receptacles, accessible via the vulvae on the sixth thoracic sternite, or in spermathecae at the border between the seventh and eighth sternites. Crabs with spermathecae are collectively referred to as "podotremes" while crabs with seminal receptacles belong to the Eubrachyura. The position of gonopores is the primary basis for subdividing the Eurachyura into the Heterotremata (female vulvae + males with coxal gonopores) and Thoracotremata (female vulvae + males with sternal gonopores). We present a hypothesis about the evolution of seminal receptacles in eubrachyuran female crabs and argue that the sternal gonopore has been internalized into chitin-lined seminal receptacles and the vulva is in fact a secondary aperture. The loss of some or all of the ancestral chitinous seminal receptacle lining was linked to ventral migration of the oviduct connection. Male and female strategies are to maximize gamete fertilization. The most important variable for females is sperm supply, enhanced by long-term storage made possible by the seminal receptacle. To maximize their fertilization rates males must adapt to the structure of the seminal receptacle to ensure that their sperm are close to the oviduct entrance. The major evolutionary impetus for female mating strategies was derived from the consequences of better sperm conservation and the structure of the seminal receptacle. The advantages were all to the females because their promiscuity and sperm storage allowed them to produce more genetically variable offspring, thereby enhancing variation upon which natural selection could act. We extend our arguments to Brachyura as a whole and offer a unifying explanation of the evolution of seminal receptacles, comparing them with the spermathecae found in "Podotremata": they were independent solutions to the same problem: maintaining sperm supply during evolutionary carcinization. Explanation of eubrachyuran mating strategies requires analysis of the mating-moulting link, indeterminate vs. determinate growth format and seminal receptacle structure. Two alternatives for each of these characters means that there are eight possible outcomes. Six of these outcomes have been realized, which we term Portunoid, Majoid, Eriphoid, Xanthoid, Cancroid, and Grapsoid-Ocypodoid strategies, respectively. Mapping these characters on to a workable phylogeny (wherein some changes to the seminal receptacle + moulting-mating links are assumed to have occurred more than once) produces the following relationships: Portunoids + Majoids are a sister group to the rest of the Eubrachyura, which fall into two sister groups, Eriphoids + Xanthoids and Cancroids + Grapsoid-Ocypodoids and the "Podotremata" is sister group to all the Eubrachyura. We conclude that what began as a race to be the first to mate was turned on its head to become a race to be last, by the evolutionary changes to the seminal receptacle. Eubrachyuran females were advantaged by greater reproductive autonomy, more opportunity to mate with other males, resulting in more genetically variable progeny and leading to the evolution of much greater taxonomic diversity compared to "podotremes".Fil: McLay, Colin L.. University Of Canterbury; Nueva ZelandaFil: Lopez, Laura Susana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Is Screening Cargo Containers for Smuggled Nuclear Threats Worthwhile

[email protected]} I n recent years, Customs and Border Protection has installed radiation sensors to screen cargo containers entering the United States. They are concerned that terrorists could use containers to smuggle radiological material into the country and carry out attacks with dirty bombs or a nuclear device. Recent studies have questioned the value of improving this screening system with new sensor technology. The cost of delays caused by frequent false alarms outweighs any reduction in the probability of an attack in an expected-cost analysis. We extend existing methodology in three ways to demonstrate how additional factors affect the value of screening investments. We examine the effect that screening has in discouraging terrorists. We model multiple levels of screening. Finally, we consider additional objectives beyond cost. We find that the conclusion about screening depends on key inputs to the probability model (reflecting uncertainties) and to the value function (reflecting the stakeholders' fundamental objectives)

Using simulation-optimization to construct screening strategies for cervical cancer

Simulation-optimization, Health care policy, Preventive medicine, Women’s health, Vaccination,