bluuebunny/crossref_metadata_2025 huggingface dataset:
Diminishing the Gap Between University and High School Research Programs: Computational Physics
Authors: Vondracek Mark
Published: September 2007

There are many schools (grades K-12) around the country that offer some sort of science research option for students to pursue. Often this option is a local science fair, where students do smaller projects that are then presented at poster sessions. Many times the top local projects can advance to some type of regional and, possibly, state science fair. However, the projects students tend to do for a fair are “lower-level” research; that is, a project where the answer is at least known by the teacher and is often a lab activity from a standard experiment booklet. If there is a smaller subset of students who are more interested and motivated in science and who would like to take on more of a challenge with their research project, to the point where there is some element of originality and a truly unknown result being investigated (particularly in high school), most teachers do not have the means, or at least do not believe they have the means, of allowing them to do so unless there is a possibility of working in a university or professional laboratory outside of school. This more advanced level of research could be defined as the type that yields papers for major national science competitions.1 While the widespread belief among many high school teachers is that high-end research requires professional facilities, it is not always necessary to work outside of school in order to have a strong physics research program,2 especially when the research is computer based. This article offers suggestions for and examples of computational research projects for high school students, as well as students in introductory college physics classes.
A Simplified Adiabatic Compression Apparatus
Authors: Moloney Michael J. , McGarvey Albert P.
Published: September 2007

Mottmann1 described an excellent way to measure the ratio of specific heats for air (γ = Cp/Cv) by suddenly compressing a plastic 2-liter bottle. His arrangement can be simplified so that no valves are involved and only a single connection needs to be made. This is done by adapting the plastic cap of a 2-liter plastic bottle so it connects directly to a Vernier Software Gas Pressure Sensor2 and the LabPro3 interface.
Teachers as Actors: The Implications of Acting on Physics Teaching
Authors: Milner-Bolotin Marina
Published: September 2007

In the spring of 2006, a rather unusual advertisement by the Centre of Teaching and Academic Growth at UBC (http://www.tag.ubc.ca) came to my attention. Faculty members were invited to take part in a workshop entitled “All the World's a Stage: Teachers as Actors,” offered by a zoology instructor and an amateur actor, Greg Bole:

Teaching can be seen as creating an interpersonal relationship and hence uses many of the same skills as acting. The investigation and use of acting skills in teacher preparation can allow a greater facility with diverse methods, increase skill at adapting to change in the classroom or lecture hall, and an increased ability to quickly form positive relationships with students. (Greg Bole: http://www.tag.ubc.ca/programs/series-detail.php?series_id=249 )
Role of Lon, an ATP-Dependent Protease Homolog, in Resistance of
Pseudomonas aeruginosa
to Ciprofloxacin
Authors: Brazas Michelle D. , Breidenstein Elena B. M. , Overhage Joerg , Hancock Robert E. W.
Published: September 2007

With few novel antimicrobials in the pharmaceutical pipeline, resistance to the current selection of antibiotics represents a significant therapeutic challenge. Microbial persistence in subinhibitory antibiotic environments has been proposed to contribute to the development of resistance.
Pseudomonas aeruginosa
cultures pretreated with subinhibitory concentrations of ciprofloxacin were found to exhibit an adaptive resistance phenotype when cultures were subsequently exposed to suprainhibitory ciprofloxacin concentrations. Microarray experiments revealed candidate genes involved in such adaptive resistance. Screening of 10,000 Tn
5
-
luxCDABE
mutants identified several mutants with increased or decreased ciprofloxacin susceptibilities, including mutants in PA1803, a close homolog of the ATP-dependent
lon
protease, which were found to exhibit ≥4-fold-increased susceptibilities to ciprofloxacin and other fluoroquinolones, but not to gentamicin or imipenem, as well as a characteristic elongated morphology. Complementation of the
lon
mutant restored wild-type antibiotic susceptibility and cell morphology. Expression of the
lon
mutant, as monitored through a luciferase reporter fusion, was found to increase over time in the presence of subinhibitory ciprofloxacin concentrations. The data are consistent with the hypothesis that the induction of Lon by ciprofloxacin is involved in adaptive resistance.
Activities of Several Classes of Acyclic Nucleoside Phosphonates against Camelpox Virus Replication in Different Cell Culture Models
Authors: Duraffour Sophie , Snoeck Robert , Krečmerová Marcela , van Den Oord Joost , De Vos Rita , Holý Antonín , Crance Jean-Marc , Garin Daniel , De Clercq Erik , Andrei Graciela
Published: September 2007

Camelpox virus (CMLV) is the closest known virus to variola virus. Here we report on the anti-CMLV activities of several acyclic nucleoside phosphonates (ANPs) related to cidofovir [(
S
)-1-(3-hydroxy-2-phosphonomethoxypropyl)cytosine (HPMPC; Vistide)] against two CMLV strains, CML1 and CML14. Cytopathic effect (CPE) reduction assays performed with human embryonic lung fibroblast monolayers revealed the selectivities of the first two classes of ANPs (cHPMPA, HPMPDAP, and HPMPO-DAPy) and of the hexadecyloxyethyl ester of 1-{[(5
S
)-2-hydroxy-2-oxido-1,4,2-dioxaphosphinan-5-yl]methyl}-5-azacytosine (HDE-cHPMP-5-azaC), belonging to the newly synthesized ANPs, which are HPMP derivatives containing a 5-azacytosine moiety. The inhibitory activities of ANPs against both strains were also confirmed with primary human keratinocyte (PHK) monolayers, despite the higher toxicity of those molecules on growing PHKs. Virus yield assays confirmed the anti-CML1 and anti-CML14 efficacies of the compounds selected for the highest potencies in CPE reduction experiments. Ex vivo studies were performed with a 3-dimensional model of human skin, i.e., organotypic epithelial raft cultures of PHKs. It was ascertained by histological evaluation, as well as by virus yield assays, that CMLV replicated in the human skin equivalent. HPMPC and the newly synthesized ANPs proved to be effective at protecting the epithelial cells against CMLV-induced CPE. Moreover, in contrast to the toxicity on PHK monolayers, signs of toxicity in the differentiated epithelium were seen only at high ANP concentrations. Our results demonstrate that compounds belonging to the newly synthesized ANPs, in addition to cidofovir, represent promising candidates for the treatment of poxvirus infections.
The
Streptococcus pyogenes
Serotype M49 Nra-Ralp3 Transcriptional Regulatory Network and Its Control of Virulence Factor Expression from the Novel
eno ralp3 epf sagA
Pathogenicity Region
Authors: Kreikemeyer Bernd , Nakata Masanobu , Köller Thomas , Hildisch Hendrikje , Kourakos Vassilios , Standar Kerstin , Kawabata Shigetada , Glocker Michael O. , Podbielski Andreas
Published: September 2007

Many
Streptococcus pyogenes
(group A streptococcus [GAS]) virulence factor- and transcriptional regulator-encoding genes cluster together in discrete genomic regions. Nra is a central regulator of the FCT region. Previous studies exclusively described Nra as a transcriptional repressor of adhesin and toxin genes. Here transcriptome and proteome analysis of a serotype M49 GAS strain and an isogenic Nra mutant of this strain revealed the complete Nra regulon profile. Nra is active in all growth phases tested, with the largest regulon in the transition phase. Almost exclusively, virulence factor-encoding genes are repressed by Nra; these genes include the GAS pilus operon, the capsule synthesis operon, the cytolysin-mediated translocation system genes, all Mga region core virulence genes, and genes encoding other regulators, like the Ihk/Irr system, Rgg, and two additional RofA-like protein family regulators. Surprisingly, our experiments revealed that Nra additionally acts as a positive regulator, mostly for genes encoding proteins and enzymes with metabolic functions. Epidemiological investigations revealed strong genetic linkage of one particular Nra-repressed regulator, Ralp3 (SPy0735), with a gene encoding Epf (extracellular protein factor from
Streptococcus suis
). In a serotype-specific fashion, this
ralp3 epf
gene block is integrated, most likely via transposition, into the
eno sagA
virulence gene block, which is present in all GAS serotypes. In GAS serotypes M1, M4, M12, M28, and M49 this novel discrete genetic region is therefore designated the
eno ralp3 epf sagA
(ERES) pathogenicity region. Functional experiments showed that Epf is a novel GAS plasminogen-binding protein and revealed that Ralp3 activity counteracts Nra and MsmR regulatory activity. In addition to the Mga and FCT regions, the ERES region is the third discrete chromosomal pathogenicity region. All of these regions are transcriptionally linked, adding another level of complexity to the known GAS growth phase-dependent regulatory network.
Coinfection with Antigenically and Genetically Distinct Virulent Strains of
Babesia bovis
Is Maintained through All Phases of the Parasite Life Cycle
Authors: Berens Shawn J. , Brayton Kelly A. , McElwain Terry F.
Published: September 2007

Antigenic polymorphism is a defining characteristic of the
Babesia bovis
variable merozoite surface antigen (VMSA) family. Sequence analysis strongly suggests that recombination between virulent strains contributes to VMSA diversity. While meiosis during the aneuploid stage of the parasite's life cycle in the tick vector
Rhipicephalus
(
Boophilus
)
microplus
is the most probable source of interstrain recombination, there is no definitive evidence that coinfection of the mammalian host or
R. microplus
ticks with more than one virulent strain occurs. Using allele-specific real-time quantitative PCR, we tested the hypotheses that cattle could support coinfection of two antigenically variant virulent tick-transmissible strains of
B. bovis
and that
R. microplus
ticks could acquire and transmit these two divergent strains. The results indicate that both calves and ticks can support virulent
B. bovis
coinfection through all phases of the hemoparasite's life cycle. Neither strain dominated in either the mammalian or invertebrate host, and larval tick progeny, which could be coinfected individually, were also able to transmit both strains, resulting in virulent babesiosis in recipients. While coinfection of the tick vector provides the context in which allelic antigenic diversity can be generated, recombination of VMSA genes could not be confirmed, suggesting that VMSA allelic changes are slow to accumulate.
Comparison of Tissue-Selective Proinflammatory Gene Induction in Mice Infected with Wild-Type, DNA Adenine Methylase-Deficient, and Flagellin-DeficientSalmonella enterica
Authors: Simon Raphael , Heithoff Douglas M. , Mahan Michael J. , Samuel Charles E.
Published: September 2007

Mutants ofSalmonella entericaserovar Typhimurium deficient in DNA adenine methylase (Dam) are attenuated for virulence in mice and confer heightened immunity in vaccinated animals. In contrast, infection of mice with wild-type (WT) strains or flagellin-deficient mutants ofSalmonellacauses typhoid fever. Here we examined the bacterial load and spatiotemporal kinetics of expression of several classes of host genes in Peyer's patches, the liver, and the spleen following oral infection of mice with WT,dammutant, or flagellin-deficient (flhC)Salmonella. The genes evaluated included inflammatory (interleukin-1β [IL-1β], tumor necrosis factor alpha), chemokine (macrophage inflammatory protein 2), Th1/Th2 indicator (IL-12p40, IL-4), and interferon system (beta interferon [IFN-β], IFN-γ, protein Mx1 GTPase, RNA-dependent protein kinase, inducible nitric oxide synthase, suppressor of cytokine signaling 1) beacons. We showed that maximal interferon system and proinflammatory gene induction occurred by 5 days after infection and that the levels were comparable for the WT andflhCstrains but were significantly lower for thedammutant. Additionally, host gene expression in systemic tissues of individual animals was dependent on the bacterial load in the Peyer's patches for mice infected with WT,dammutant, orflhCmutantSalmonellaas early as 8 h after infection. Moreover, a bacterial load threshold in the Peyer's patches was necessary to stimulate the host gene induction in the liver and spleen. Taken together, these results suggest that bacterial load and the accompanying strain-specific cytokine signature are important determinants of the host innate immune response and associated disease manifestations observed indammutantSalmonella-infected animals compared to the immune response and disease manifestations observed in WT andflhCmutantSalmonella-infected animals.
Multilocus structure in thePinus contorta – Pinus banksianacomplex
Authors: Yang Rong-Cai , Yeh Francis C. , Ye Terrance Z.
Published: September 2007

Natural hybridization between lodgepole pine ( Pinus contorta Dougl. ex Loud.) and jack pine ( Pinus banksiana Lamb.) in western Canada provides a distinct opportunity to infer evolutionary and demographic determinants of nonrandom associations of the alleles at different loci occurring in this Pinus contorta – Pinus banksiana complex (PCBC). Here, we investigated multilocus associations among and within 40 PCBC populations sampled from central and northwestern Alberta, using 39 random amplified polymorphic DNA (RAPD) markers. For each of the 40 PCBC populations, we examined distributions of 741 pairs of linkage (gametic) disequilibria (LD) between the 39 RAPDs and measured the “average” multilocus associations using the summary statistics that allow for packaging of individual LD in each population. We then partitioned the variance of LD in the total population to assess the causes of multilocus population structure. The results showed that (i) LD were more prominent in hybrid populations than in parental populations; (ii) multilocus Wahlund effect was a much more important determinant of population structure than its single-locus counterpart, particularly in hybrid populations; and (iii) considerable mutlilocus associations across the populations within each taxa group was due to the presence of different multilocus haplotypes in different populations. Such results are best explained by the fact that PCBC populations are geographically and ecologically marginal and are produced at the balance between mixing of two distinct gene pools creating new recombinants and selection in favor of parental gametes, but against the recombinants.
Aggregated predators and vulnerability-independent mortality of prey
Authors: Torgersen Thomas
Published: September 2007

I present a mechanistic predation model with explicit representation of predator aggregation for analysing the relationship between mortality rate of prey and their vulnerability (e.g., conspicuousness, escape ability). The model is developed for an aquatic setting with plankton as prey and planktivores as predators, but the principle is general. When predators are aggregated, encounters between prey and predators are not independent events. This means that a prey that runs into one predator is more likely to run into more predators, and any prey that runs into a high number of predators will eventually be perceived and captured, almost irrespective of how cryptic it is or how well it escapes attacks. A prey that has not run into a predator yet is more likely to continue to not run into predators and may therefore avoid predation even if it displays no crypsis or anti predation behaviour. Therefore, the predation risk from aggregated predators is less dependent on prey vulnerability than the intuitive proportionality relationship that applies to predation risk from solitary predators. This has important implications for patterns of mortality within prey communities (e.g., size dependency of plankton mortality).
Modeling fish numbers dynamically by age and length: partitioning cohorts into "slices"
Authors: McGarvey Richard , Feenstra John E , Ye Qifeng
Published: September 2007

Fishery processes of selectivity and recruitment to legal size vary with fish length and are mediated by fish growth. Yet most fishery models are age-based. To model length-dependent change within each cohort, fish numbers must vary dynamically with length as well as with age in the model population array. The fishery model formalism described here achieves this by a partition of the continuous length-at-age distribution. This method is computationally efficient and cleanly differentiates legal from sublegal fish. Fish numbers within each cohort are partitioned into length bins, called slices. A slice is defined and calculated as the fish in each cohort length-at-age distribution that have grown into legal size since the start of the previous time step. When growth is estimated from catch length and age samples separately from the stock assessment, biases result from the implicit assumption that catch samples are representative of the population and from ignoring length-dependent change within cohorts. These biases are avoided by integrating recruitment, growth, and selectivity estimation into a stock assessment likelihood that represents changing population numbers by both age and length. Size dependence also permits a natural extension of fishery models to trophic interactions with the surrounding ecosystem.
Integrating multiple sources of data on migratory timing and catchability to estimate escapement for steelhead trout (Oncorhynchus mykiss)
Authors: Korman Josh , Melville Caroline C , Higgins Paul S
Published: September 2007

We evaluated the influence of biological, physical, and year effects on catchability, survey life, and departure timing for a winter-run steelhead (Oncorhynchus mykiss) population and compared the performance of alternate escapement models. Date of entry and gender explained 65% of the variability in survey life, and there was no evidence for differences in survey life among years. The median date of departure for male spawners occurred 2 weeks later relative to females, and a gender-based departure model was strongly supported. Departure timing was significantly different among years (p < 0.05), but the maximum difference in median departure dates was only 11 days. The ratio of horizontal visibility to discharge explained 50% of the variation in catchability, and there was weak support for a model that accounted for effects associated with courtship and spawning behaviour. There was strong support for an escapement model that assumed survey life and catchability relationships were common among years. Joint use of departure timing and survey life data reduced uncertainty in escapement estimates by an average of 40%. The major advantage of our escapement model is that it increases the precision of estimates while avoiding the use of overly simplistic assumptions about run timing and catchability.
Effects of marine conditions, fishing, and smolt traits on the survival of tagged, hatchery-reared sea trout (Salmo trutta trutta) in the Baltic Sea
Authors: Kallio-Nyberg Irma , Saloniemi Irma , Jutila Eero , Saura Ari
Published: September 2007

The marine survival of tagged sea trout (Salmo trutta trutta) smolt groups (n  =  236) stocked from 1970 to 2001 in the Baltic Sea was analysed using a linear mixed model. The response variable, survival rate, was associated with smolt size, release date, sea surface temperature in May, and prey fish abundance, and interactions among these factors. The effect of smolt size was in interaction with Baltic herring (Clupea harengus membras) abundance; smolt size had an optimum of about 22 cm in years when herring were abundant, but when herring were less abundant, the survival of larger smolts was higher. Early stocking in warm springs or late stocking in cold springs gave the best survival rates for trout. Changes in return activity or fishing methods have made tag returns a less reliable way of estimating survival during the last 30 years. The actual return rate of undersized fish (<40 cm) compared with their estimated proportion among captured fish decreased over time, which suggests that the survival rate for the later years was probably underestimated. It is likely that we were unable to include all the relevant explanatory variables in the model, as year effects remained significant, suggesting unknown annual variation affecting survival.
Movements of adult coho salmon (Oncorhynchus kisutch) during colonization of newly accessible habitat
Authors: Anderson Joseph H , Quinn Thomas P
Published: September 2007

Pacific salmon (Oncorhynchus spp.) have repeatedly exploited new habitat following glacial recession and some artificial introductions, yet the initial process of colonization is poorly understood. Landsburg Diversion Dam on the Cedar River, Washington, excluded salmon from 33 km of habitat for over a century until it was modified to allow passage in 2003. Adult coho salmon (Oncorhynchus kisutch) were sampled as they entered the newly accessible habitat in the first 3 years and a subset received radio transmitters to assess spawning site selection and movement. Annual counts of coho colonists increased over time, and in 2 of 3 years, daily dam passage was positively correlated with river discharge. Contrary to our prediction that coho would spawn in tributaries, all identified spawning sites were in the mainstem Cedar River, though 38% of radio-tagged salmon entered a tributary at least temporarily. Females moved little within the new habitat (average = 5.8 km), whereas males moved extensively (average = 34.8 km), especially when females were scarce. The immediate use of the new habitat by colonists and their widespread movements suggest that exploration is an innate component of salmon breeding behavior, and restoring access to lost habitat merits prioritization as a conservation strategy.
Revisiting evolutionary dead ends in sockeye salmon (Oncorhynchus nerka) life history
Authors: Pavey Scott A , Hamon Troy R , Nielsen Jennifer L
Published: September 2007

This study challenges recent hypotheses about sockeye salmon (Oncorhynchus nerka) colonization based on life history and broadens the pathways that investigators should consider when studying sockeye colonization of novel habitats. Most sockeye populations exhibit lake-type life histories. Riverine populations are thought to be more likely to stray from their natal stream to spawn and therefore colonize new habitat. We examined genetic relationships among five geographically proximate sockeye populations from the Aniakchak region of the Alaska Peninsula, Alaska. Specifically, we sought to determine if the genetic population structure was consistent with the hypothesis that a riverine population colonized a recently available upriver volcanic caldera lake, and whether recent volcanism led to genetic bottlenecks in these sockeye populations. Heterozygosity and allelic richness were not higher in the riverine population. Patterns of genetic divergence suggested that the geographically proximate riverine sockeye population did not colonize the lake; the caldera populations were more genetically divergent from the downstream riverine population (FST =  0.047) than a lake-type population in a different drainage (FST =  0.018). Our results did not suggest the presence of genetic bottlenecks in the caldera populations.
Stream ecosystems respond to riparian invasion by Japanese knotweed (Fallopia japonica)
Authors: Lecerf Antoine , Patfield Denise , Boiché Anatole , Riipinen Miira P , Chauvet Eric , Dobson Michael
Published: September 2007

There are growing concerns about the rapid spread of exotic plants into riparian zones, yet little information is currently available on their influence on stream ecosystems. This study assessed the impact of riparian invasion by Japanese knotweed (Fallopia japonica), an aggressive invader, on leaf litter breakdown and its associated biota (aquatic hyphomycete fungi and benthic invertebrates) in heterotrophic, low-order streams in The Pennines (England) and the Pyrenees (France). Our results suggest that leaf consumers (aquatic hyphomycetes and invertebrate shredders) can readily use knotweed leaf litter even in stream sites where it was not previously present. However, aquatic hyphomycete and invertebrate assemblages differed between stream sites with and without knotweed. Leaf litter breakdown rate and relative abundance of large invertebrate shredders (mainly Trichoptera) were enhanced in the Pyrenean invaded site, whose channel contained a high proportion of knotweed leaf litter, whereas no such effects were observed in The Pennines, possibly because of the less extensive knotweed invasion. Alteration of riparian vegetation by plant invaders could therefore increasingly influence instream community and ecological functions as the severity of invasion rises.
Overwintering habitat use of shortnose sturgeon (Acipenser brevirostrum): defining critical habitat using a novel underwater video survey and modeling approach
Authors: Li Xinhai , Litvak Matthew K , Clarke John E. Hughes
Published: September 2007

The overwintering habitat use of shortnose sturgeon (Acipenser brevirostrum) was investigated from January to March 2005 in the upper Kennebecasis River, New Brunswick, Canada, using a novel underwater video camera system and modeling approach. Following a random sampling procedure, 187 holes were drilled into the ice, and 234 sturgeon were counted and video-recorded. We found that sturgeon concentrated in a 2 ha area at the confluence of the Kennebecasis and Hammond rivers on a flat sandy substrate at a depth of 3.1–6.9 m. Generalized linear models were developed to describe the relationship of shortnose sturgeon density and habitat variables. The model indicated that the shortnose sturgeon had significant preference to deeper areas within this region. The total abundance of shortnose sturgeon in the area was estimated to be 4836 ± 69 (mean ± standard error) using the ordinary kriging method to interpolate sturgeon density at unsampled sites. This overwintering habitat of shortnose sturgeon can be defined as critical habitat following the identification policies of the Canadian Species at Risk Act (SARA).
Genetic dissection of the Nrf2-dependent redox signaling-regulated transcriptional programs of cell proliferation and cytoprotection
Authors: Reddy Narsa M. , Kleeberger Steven R. , Yamamoto Masayuki , Kensler Thomas W. , Scollick Catherine , Biswal Shyam , Reddy Sekhar P.
Published: September 2007

The beta zipper (bZip) transcription factor, nuclear factor erythroid 2, like 2 (Nrf2), acting via an antioxidant/electrophile response element, regulates the expression of several antioxidant enzymes and maintains cellular redox homeostasis. Nrf2 deficiency diminishes pulmonary expression of several antioxidant enzymes, rendering them highly susceptible to various mouse models of prooxidant-induced lung injury. We recently demonstrated that Nrf2 deficiency impairs primary cultured pulmonary epithelial cell proliferation and greatly enhances sensitivity to prooxidant-induced cell death. Glutathione (GSH) supplementation rescued cells from these defects associated with Nrf2 deficiency. To further delineate the mechanisms by which Nrf2, via redox signaling, regulates cellular protection and proliferation, we compared the global expression profiling of Nrf2-deficient cells with and without GSH supplementation. We found that GSH regulates the expression of various networks of transcriptional programs including 1) several antioxidant enzymes involved in cellular detoxification of reactive oxygen species and recycling of thiol status and 2) several growth factors, growth factor receptors, and integrins that are critical for cell growth and proliferation. We also found that Nrf2 deficiency enhances the expression levels of several genes encoding proinflammatory cytokines; however, GSH supplementation markedly suppressed their expression. Collectively, these findings uncover an important insight into the nature of genes regulated by Nrf2-dependent redox signaling through GSH that are involved in cellular detoxification and proliferation.
Extracorporeal Membrane Oxygenation to Aid Cardiopulmonary Resuscitation in Infants and Children
Authors: Thiagarajan Ravi R. , Laussen Peter C. , Rycus Peter T. , Bartlett Robert H. , Bratton Susan L.
Published: September 2007

Background—

Extracorporeal membrane oxygenation (ECMO) has been used to support cardiorespiratory function during pediatric cardiopulmonary resuscitation (CPR). We report on outcomes and predictors of in-hospital mortality after ECMO used to support CPR (E-CPR).

Methods and Results—

Outcomes for patients aged <18 years using E-CPR were analyzed with data from the Extracorporeal Life Support Organization, and predictors of in-hospital mortality were determined. Of 26 242 ECMO uses reported, 695 (2.6%) were for E-CPR (n=682 patients). Survival to hospital discharge was 38%. In a multivariable model, pre-ECMO factors such as cardiac disease (odds ratio [OR] 0.51, 95% confidence interval [CI] 0.31 to 0.82) and neonatal respiratory disease (OR 0.28, 95% CI 0.12 to 0.66), white race (OR 0.65, 95% CI 0.45 to 0.94), and pre-ECMO arterial blood pH >7.17 (OR 0.50, 95% CI 0.30 to 0.84) were associated with decreased odds of mortality. During ECMO, renal dysfunction (OR 1.89, 95% CI 1.17 to 3.03), pulmonary hemorrhage (OR 2.23, 95% CI 1.11 to 4.50), neurological injury (OR 2.79, 95% CI 1.55 to 5.02), CPR during ECMO (OR 3.06, 95% CI 1.42 to 6.58), and arterial blood pH <7.2 (OR 2.23, 95% CI 1.23 to 4.06) were associated with increased odds of mortality.

Conclusions—

ECMO used to support CPR rescued one third of patients in whom death was otherwise certain. Patient diagnosis, absence of severe metabolic acidosis before ECMO support, and uncomplicated ECMO course were associated with improved survival.
Transcatheter Closure of Patent Foramen Ovale Without an Implant
Authors: Sievert Horst , Fischer Evelyn , Heinisch Corinna , Majunke Nico , Roemer Albrecht , Wunderlich Nina
Published: September 2007

Background—

Currently available catheter techniques for closure of a patent foramen ovale (PFO) rely on the placement of an implantable closure device. The objective of the Paradigm I study was to evaluate the safety and feasibility of transcatheter closure of PFO using radiofrequency energy without an implanted device in patients with cryptogenic stroke or transient ischemic attack.

Methods and Results—

Thirty patients were enrolled (15 females; mean age 48 years). Mean PFO size was 8.5±2.7 mm. Technical success (ie, successful application of radiofrequency energy) was achieved in 27 patients. The remaining 3 patients received an implantable closure device. All 30 patients were free from serious procedure-related adverse events. No recurrent strokes, deaths, or perforations occurred as a result of the procedure. The mean follow-up was 6 months, and 13 (43%) of the 30 patients experienced PFO closure after the first procedure. Nine of the patients whose PFOs remained patent after the first procedure elected to receive a second procedure using radiofrequency. The PFO was closed for 6 of those patients after the second procedure, which resulted in a secondary closure rate of 63%.

Conclusions—

This study demonstrates that transcatheter closure of an intracardiac defect without a permanent implant is technically feasible. Achievement of improved primary closure rates through technique and device modifications will warrant randomized clinical comparison to permanently implanted devices.
Y-Box Binding Protein-1 Controls CC Chemokine Ligand-5 (CCL5) Expression in Smooth Muscle Cells and Contributes to Neointima Formation in Atherosclerosis-Prone Mice
Authors: Krohn Regina , Raffetseder Ute , Bot Ilze , Zernecke Alma , Shagdarsuren Erdenechimeg , Liehn Elisa A. , van Santbrink Peter J. , Nelson Peter J. , Biessen Erik A. , Mertens Peter R. , Weber Christian
Published: September 2007

Background—

The CC chemokine CCL5/Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES) is upregulated in mononuclear cells or deposited by activated platelets during inflammation and has been implicated in atherosclerosis and neointimal hyperplasia. We investigated the influence of the transcriptional regulator Y-box binding protein (YB)-1 on CCL5 expression and wire-induced neointimal hyperplasia.

Methods and Results—

Analysis of the CCL5 promoter revealed potential binding sites for YB-1, and interaction of YB-1 with a sequence at position −204/−173 was confirmed by DNA binding assays. Both YB-1 expression and CC chemokine ligand-5 (CCL5) mRNA expression were increased in neointimal versus medial smooth muscle cells, as analyzed by real-time polymerase chain reaction. Overexpression of YB-1 in smooth muscle cells (but not macrophages) enhanced CCL5 transcriptional activity in reporter assays, mRNA and protein expression, and CCL5-mediated monocyte arrest. Carotid arteries of hyperlipidemic apolipoprotein E–deficient mice were subjected to intraluminal transfection with a lentivirus encoding YB-1 short hairpin RNA or empty vector directly after wire injury. Double immunofluorescence revealed YB-1 expression in neointimal smooth muscle cells but not macrophages and colocalization with neointimal CCL5, which was downregulated by YB-1 short hairpin RNA. Neointima formation was decreased significantly after YB-1 knockdown compared with controls and was associated with a diminished content of lesional macrophages. A reduction of lesion formation by YB-1 knockdown was not observed in apolipoprotein E–deficient mice deficient in the CCL5 receptor CCR5 or after treatment with the CCL5 antagonist Met-RANTES, which indicates that YB-1 effects were dependent on CCL5.

Conclusions—

The transcriptional regulator YB-1 mediates CCL5 expression in smooth muscle cells and thereby contributes to neointimal hyperplasia, thus representing a novel target with which to limit vascular remodeling.
The consequences of assistant roles in the public services: Degradation or empowerment?
Authors: Bach Stephen , Kessler Ian , Heron Paul
Published: September 2007

This article considers whether and how shifts in the division of labour in the context of organizational change lead to the empowerment or degradation of workplace roles. It focuses on the emergence of assistants in the British public services and, in particular, whether this leads to the degradation or empowerment of those who fill the role and the professionals they work with. Concentrating upon assistant roles in education and social care, case study findings suggest that as these roles develop, the assistants themselves and their co-professionals are empowered to some degree both in terms of their work and employment conditions. However, it notes that these consequences are not unambiguously positive for the stakeholders and vary by sub-sector. The article lends support to those who have argued that changes in the division of labour result in blended and potentially contradictory outcomes for the workers involved. It also contributes to a literature which suggests that outcomes are contingent upon context, proposing that sub-sector conditions can be influential.
Motion Planning for Nonlinear Symmetric Distributed Robotic Formations
Authors: McMickell M. Brett , Goodwine Bill
Published: September 2007

This paper develops a motion planning algorithm which exploits symmetries in distributed systems to reduce motion planning computation complexity. Symmetries allow for algebraic manipulations that are computationally costly, which normally must be carried out for each component in a distributed system, to be related among various symmetric components in a distributed system by a simple algebraic relationship. This leads to a large reduction in the complexity of the overall motion planning problem for a group of distributed mobile robotic agents. In particular, due to the manner in which a symmetric system is defined, the structure of the Chen—Fliess—Sussmann differential equations has a simple relationship among various symmetric components of a distributed system. Essentially, symmetries are defined in a manner which preserves the Lie algebraic structure of each component. In a system with distributed computational capability, the motion planning computations may be distributed throughout formation in such a way that the objectives of the formation are satisfied and collision avoidance is guaranteed. The algorithm maintains a rigid body formation at the beginning and end of the trajectory, as well as possibly specified intermediate points. Due to the generally nonholonomic nature of mobile robots, guaranteeing a rigid body formation during the intermediate motion is impossible. However, it is possible to bound the magnitude of the deviation from the rigid body formation at any point along the trajectory. Simulation and experimental results are provided to demonstrate the utility of the algorithm.
Geometric Motion Planning Analysis for Two Classes of Underactuated Mechanical Systems
Authors: Shammas Elie A. , Choset Howie , Rizzi Alfred A.
Published: September 2007

In this paper we generate gaits for two types of underactuated mechanical systems: principally kinematic and purely mechanical systems. Our goal is to specify inputs in the form of gaits, that is, a sequence of controlled shape changes of a multi-bodied mechanical system that when executed would produce a desired change in the unactuated position or orientation variables of the entire mechanical system. In other words, we want to indirectly control the unactuated degrees of freedom of the mechanical system utilizing a controlled “internal” shape change. More precisely, in this paper we develop a gait evaluation tool which easily measures the change of position, computed in a body-attached coordinate frame, due to any closed curve in the shape space. This evaluation tool is simple enough that we can use it to generate gaits or to design curves that move the mechanical system along a desired direction. Finally, we verify that this gait analysis technique applies to two seemingly different classes of mechanical systems, purely mechanical and principally kinematic systems, and unify the gait generation problem for both classes.
Extending the Path-Planning Horizon
Authors: Nabbe Bart , Hebert Martial
Published: September 2007

The mobility sensors on a typical mobile robot vehicle have limited range. Therefore a navigation system has no knowledge about the world beyond this sensing horizon. As a result, path planners that rely only on this knowledge to compute paths are unable to anticipate obstacles sufficiently early and have no choice but to resort to an inefficient local obstacle avoidance behavior.

To alleviate this problem, we present an opportunistic navigation and view planning strategy that incorporates look-ahead sensing of possible obstacle configurations. This planning strategy is based on a “what-if” analysis of hypothetical future configurations of the environment. Candidate sensing positions are evaluated based on their ability to observe anticipated obstacles. These sensing positions identified by this forward-simulation framework are used by the planner as intermediate waypoints. The validity of the strategy is supported by results from simulations as well as field experiments with a real robotic platform. These results show that significant reduction in path length can be achieved by using this framework.
Differentiating COPD From Asthma in Clinical Practice
Authors: Chang Jesse , Mosenifar Zab
Published: September 2007

It has been recognized that features of chronic obstructive pulmonary disease (COPD) and asthma overlap, often rendering a firm diagnosis difficult to achieve for the clinical practitioner. There are hypotheses suggesting that both asthma and COPD may indeed share common origins with differences in phenotypic presentation being related to disease evolution or interaction between endogenous and exogenous factors. Others suggest that the two conditions are clinically and pathophysiologically distinct. Studies of the underlying inflammation demonstrate a difference in the preponderance of inflammatory cells and mediators in each disease, yet many shared characteristics in the inflammatory process can be found when examining the two conditions. Generally, later age of presentation favors a diagnosis of COPD; fully reversible airflow limitation on pulmonary function testing suggests a diagnosis of asthma; hyperinflation at rest makes a diagnosis of COPD likely; impaired diffusing capacity is associated with COPD whereas these measurements in patients suffering from asthma are usually normal or even elevated; reduced elastic recoil is the hallmark of COPD, particularly those who pathophysiologically demonstrate abnormal enlargement of air spaces with wall destruction seen in emphysema; and finally history of atopy favors a diagnosis of asthma, particularly if presenting at a younger age. This review reflects discussion of the differences and similarities in diagnosis and treatment.
Talking Shops or Talking Turkey?
Authors: Rothstein Henry
Published: September 2007

Participative reforms to risk regulation are often argued to enhance the evidence base, improve the representation of the public interest, and build support for policy processes and outcomes. While rationales and mechanisms for participation have received most scholarly attention, less attention has been paid to the actual impact of participation on policy processes and outcomes. This article, therefore, considers the impacts of participation by examining the UK Food Standards Agency's (FSA) Consumer Committee, which was created in 2002 to institutionalize consumer representation within policy making, but which was disbanded as a failure in 2005. Using three case studies, the article identifies two broad institutional dimensions of regulation that shaped and constrained the committee's impact on the evidence base, policy outcomes and building support for policy, and contributed to its eventual failure. Those dimensions relate to the design and organization of regulatory regimes, and to the understandings and influence of regulatory actors.
Translocation of the novel cytokine HMGB1 to the cytoplasm and extracellular space coincides with the peak of clinical activity in experimentally UV-induced lesions of cutaneous lupus erythematosus
Authors: Barkauskaite V. , Ek M. , Popovic K. , Harris H.E. , Wahren-Herlenius M. , Nyberg F.
Published: September 2007

HMGB1 is a pro-inflammatory cytokine that together with TNF-α and IL-1β is involved in the pathogenesis of spontaneously occurring skin lesions in lupus erythematosus. The purpose of the present study was to explore the sequence of events in HMGB1, TNF-α and IL-1β expression under development and resolution of experimentally induced CLE lesions. The study involved investigation of 38 serial skin biopsies acquired from photoprovoked skin lesions of nine CLE patients, using immunohistochemical staining of tissue sections. In biopsies from the clinically most active phase of skin involvement extracellular, secreted HMGB1 and increased cytoplasmic HMGB1 were found, as compared with the late and fading lesions or non-lesional skin. Besides HMGB1, increased expression of TNF-α and IL-1β was observed in dermal infiltrates of the induced CLE lesions. These cytokines were however not upregulated in all lesions, and increased expression of IL-1β was seen predominantly in late biopsies.

In conclusion, extracellular and cytoplasmic HMGB1 coincides with the clinically most active phase of photoinduced lesions of cutaneous lupus, and suggests that HMGB1 is an important factor in the inflammatory autoimmune process of CLE. HMGB1 can induce expression of TNF-α and IL-1β, and formation of a pro-inflammatory loop between HMGB1, TNF-α, and IL-1β may be responsible for the prolonged and sustained inflammation in CLE. Lupus (2007) 16, 794—802.
Experiences From Cross-Institutional Exchanges of Undergraduate Business Student Written Cases
Authors: Ross Douglas N. , Zufan Pavel , Rosenbloom Al
Published: September 2007

This article describes an undergraduate course assignment that required 134 students in 52 student teams from three universities, two in the United States and one in the Czech Republic, to write, exchange, and give constructive feedback on a student-written strategic management or international business case and its accompanying teaching note. The article describes not only the overall process of the cross-institutional exchange but also the challenges that students and faculty experienced during the exchange itself. In addition, the article presents both faculty and student perspectives on the learning benefits derived from the complete assignment. Although various aspects of the assignment may have been tried before, the authors consider the case writing assignment's undergraduate focus and its cross-institution peer feedback plan to be the innovative aspects of this learning experiment.
Corporations, Democracy, and the Public Good
Authors: Barley Stephen R.
Published: September 2007

Organizational theorists have had much to say about how environments affect organizations but have said relatively little about how organizations shape their environment. This silence is particularly troubling, given that organizations, in general, and corporations, in particular, now wield inordinate political power. This article illustrates three ways in which corporations can undermine representative democracy and the public good: promoting legislation that benefits corporations at the expense of individual citizens, the capturing of regulatory agencies by those whom the agencies were designed to regulate, and the privatization of functions that have historically been the mandate of local, state, and federal governments.
Sitting in Your Reader's Chair
Authors: Johanson Linda M.
Published: September 2007

This article describes to authors what journal reviewers expect of the scholarly publications they review and how authors can anticipate reviewers' sensemaking processes to increase their chances of being understood and making their contribution clear. Authors are urged to (a) clarify their research question and intended contribution early in the paper; (b) guide readers' understanding of literature relevant to the paper; (c) understand readers' perspective and anticipate their questions; (d) be aware of and explain how terms and figures are used; (e) obtain collegial feedback on a paper before submitting it; (f) use editors' and reviewers' feedback to understand how they made sense of the paper; (g) use feedback to improve the paper in revising; and (h) manage the flow of papers from a project to incorporate sensemaking feedback.
Gender, Race, and Intersectionality on the Federal Appellate Bench
Authors: Collins Todd , Moyer Laura
Published: September 2007

While theoretical justifications predict that a judge's gender and race may influence judicial decisions, empirical support for these arguments has been mixed. However, recent increases in judicial diversity necessitate a reexamination of these earlier studies. Rather than examining individual judges on a single characteristic, such as gender or race alone, this research note argues that the intersection of individual characteristics may provide an alternative approach for evaluating the effects of diversity on the federal appellate bench. The results of cohort models examining the joint effects of race and gender suggest that minority female judges are more likely to support criminal defendants' claims when compared to their colleagues on the bench, even after controlling for other important factors. This suggests that our understanding of judicial behaviors may be assisted by the inclusion of how individual characteristics overlap rather than examining those characteristics alone.