bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution, Amplification, and Summation of Cyclic Nucleotide Sensitivities within Single Olfactory Sensory Cilia
Authors: Takeuchi Hiroko , Kurahashi Takashi
Published: January 2008

Submicron local cAMP elevation was used to map the distribution of transduction channels in single olfactory cilia. After the fine fluorescent visualization of the cilium with the laser-scanning confocal microscope, the intraciliary cAMP was jumped locally with the laser beam that photolyzes cytoplasmic caged compounds. Simultaneously, cells' responses were obtained with the whole-cell patch clamp. Responses were observed anywhere within the cilia, showing the broad distribution of transduction channels. For odor detection, such distribution would be useful for expanding the available responding area to increase the quantum efficiency. Also, the stimulus onto only 1 μm region induced >100 pA response operated by >700 ∼2300 channels, although only 1 pA is sufficient for olfactory cells to generate action potentials. The large local response indicates a presence of strong amplification achieved with a high-density distribution of the transduction channels for the local ciliary excitation.
Visualizing Cold Spots: TRPM8-Expressing Sensory Neurons and Their Projections
Authors: Dhaka Ajay , Earley Taryn J. , Watson James , Patapoutian Ardem
Published: January 2008

Environmental stimuli such as temperature and pressure are sensed by dorsal root ganglion (DRG) neurons. DRG neurons are heterogeneous, but molecular markers that identify unique functional subpopulations are mainly lacking. ThermoTRPs are members of the transient receptor potential family of ion channels and are gated by shifts in temperature. TRPM8 is activated by cooling, and TRPM8-deficient mice have severe deficits in cool thermosensation. The anatomical and functional properties of TRPM8-expressing fibers have not been not comprehensively investigated. We use mice engineered to express the farnesylated enhanced green fluorescent protein (EGFPf) from the TRPM8 locus (TRPM8EGFPf) to explore this issue. Virtually all EGFPf-positive cultured DRG neurons from hemizygous mice (TRPM8EGFPf/+) responded to cold and menthol. In contrast, EGFPf-positive DRGs from homozygous mice (TRPM8EGFPf/EGFPf) had drastically reduced cold responses and no menthol responses.In vivo, EGFPf-positive neurons marked a unique population of DRG neurons, a majority of which do not coexpress nociceptive markers. The fraction of DRG neurons expressing EGFPf was not altered under an inflammatory condition, although an increase in TRPV1-coexpressing neurons was observed.TRPM8EGFPfneurons project to the superficial layer I of the spinal cord, making distinct contacts when compared with peptidergic projections. At the periphery,TRPM8EGFPfprojections mark unique endings in the most superficial layers of epidermis, including bush/cluster endings of the mystacial pads. We show that TRPM8 expression functionally associates with cold sensitivity in cultured DRGs, and provide the first glimpses of the unique anatomical architecture of cold fibersin vivo.
Regulation of Respiratory and Vocal Motor Pools in the Isolated Brain ofXenopus laevis
Authors: Zornik Erik , Kelley Darcy B.
Published: January 2008

The aquatic frogXenopus laevisuses a complex vocal repertoire during mating and male–male interactions. Calls are produced without breathing, allowing the frogs to vocalize for long periods underwater. TheXenopusvocal organ, the larynx, is innervated by neurons in cranial motor nucleus (n.) IX–X, which contains both vocal (laryngeal) and respiratory (glottal) motor neurons. The primary descending input to n.IX–X comes from the pretrigeminal nucleus of the dorsal tegmental area of the medulla (DTAM), located in the rostral hindbrain. We wanted to characterize premotor inputs to respiratory and vocal motor neurons and to determine what mechanisms might be involved in regulating two temporally distinct rhythmic behaviors: breathing and calling. Using isolated brain and larynx preparations, we recorded extracellular activity from the laryngeal nerve and muscles and intracellular activity in laryngeal and glottal motor neurons. Spontaneous nerve activities mimicking respiratory and vocal patterns were observed. DTAM projection neurons (DTAMIX–Xneurons) provide direct input to glottal and laryngeal motor neurons. Electrical stimulation produced short-latency coordinated activity in the laryngeal nerve. DTAMIX–Xneurons provide excitatory monosynaptic inputs to laryngeal motor neurons and mixed excitatory and inhibitory inputs to glottal motor neurons. DTAM stimulation also produced a delayed burst of glottal motor neuron activity. Together, our data suggest that neurons in DTAM produce vocal motor output by directly activating laryngeal motor neurons and that DTAM may coordinate vocal and respiratory motor activity.
Appropriating Law in Harriet Beecher Stowe's Dred
Authors: Korobkin Laura H.
Published: January 2008

This essay investigates Harriet Beecher Stowe's interpolation of State v. Mann, a harsh 1829 North Carolina proslavery decision, into her 1856 novel Dred: A Tale of the Great Dismal Swamp. The essay argues that Stowe's use of State v. Mann continues a conversation about slavery that had been carried on through its text for many years in abolitionist writings. Bringing State v. Mann's circulation history into view shows Stowe engaging the antislavery establishment as well as the legal system, borrowing and imitating its techniques for handling proslavery materials. If her novel is infiltrated and structured by the many legal writings that it assimilates, its fictive world in turn infiltrates, interprets, and alters the significance of the writings she employs, so that proslavery legal writings are made to testify strongly against the slave system that they originally worked to maintain and enforce. Stowe's hybrid text dominates the law while smoothly assimilating it into an interpretive fictive context. Simultaneously, Stowe's typographical cues remind readers of State v. Mann's ongoing, destructive extratextual legal existence. By linking fictive context to legal content, Stowe's novel suggests that slave law must be read and interpreted as a unit that includes the individual suffering it imposes. Misreading State v. Mann as revealing its author's belief in the immorality of slavery, Stowe constructs a fictional judge who upholds slave law despite his personal beliefs. By absorbing, imitating, and besting the strategies and the reach of both legal and abolitionist writings, Dred implicitly stakes a claim for the superior power of political fiction to act in the world.
Treatment of arrhythmias associated with surgery for congenital heart disease using transcatheter ablation
Authors: Szili-Török Tamás , Szeghy Szabolcs , Kardos Attila , Környei László , Paprika Dóra , Szatmári András , Temesvári András
Published: January 2008

A veleszületett szívbetegségek miatt végzett szívsebészeti beavatkozások után nem ritka a ritmuszavarok megjelenése. A ritmuszavarok egy része a szívbetegség előrehaladása miatt lép fel, de jelentős hányada éppen a szívsebészeti műtétek következményeként jön létre. A gyógyszeres próbálkozások gyakran csődöt mondanak ezekben az esetekben, az intervenciós kezelés pedig bonyolult lehet az aritmia kiindulásának összetett jellege miatt.
Célkitűzés és módszer:
A szerzők közleményükben a veleszületett szívbetegség miatt operált betegeiknél 2004 és 2006 között végzett katéteres ablatiós beavatkozások eredményeit foglalják össze retrospektív elemzéssel.
Eredmények:
A vizsgált időszakban 26 esetben végeztek katéteres ablatiós beavatkozást, 24 betegnél eredményesen (92%). Kiújulás miatt ismételt beavatkozásra 3 esetben került sor (11%). Jelentős szövődményt nem észleltek, kisebb szövődmény (vérömleny a szúrás helyén) 4 esetben fordult elő.
Következtetések:
Ebben a betegcsoportban a katéteres ablatiók hatásásos esélyt nyújtanak a gyógyszeres kezeléssel szemben, kis megterhelést rónak a betegekre, és gyógyító eljárásnak számítanak. Ugyanakkor az összetett ritmuszavarok kezelése megfelelő szakértelmet és technológiai hátteret kíván, a klasszikus aritmiákhoz képest a beavatkozás megismétlése gyakrabban válik szükségessé.
Assessing the biological relevance of exposing freshwater organisms to atrazine and molinate in environmentally realistic exposure test systems
Authors: Phyu Yin Latt , Warne Michael St. J , Lim Richard P
Published: January 2008

Assessing the toxicity of chemicals in treated laboratory water may not accurately represent the toxicity of chemicals in natural aquatic systems. In natural water, dissolved organic matter, suspended particulate matter, and sediment play key roles in the sorption of contaminants from the water. Our previously published series of papers illustrated that the presence of sediment in aquatic toxicity testing systems significantly (p < 0.05) reduced the bioavailability of the herbicides atrazine and molinate to five Australian freshwater organisms. It is not clear whether the reduced bioavailability means that the trigger values (TVs) in the current Australian and New Zealand water quality guidelines, which are calculated using toxicity data from water-only toxicity tests, provide appropriate environmental protection. Several new sets of TVs were derived in the present study and were compared to each other and to the current Australian and New Zealand TVs for atrazine and molinate. The current Australian and New Zealand TVs for atrazine and molinate provided appropriate protection to Australian freshwater species. Australian freshwater species have a sensitivity distribution similar to those of overseas species to atrazine and molinate.
Interaction of stilbene compounds with human and rainbow trout estrogen receptors
Authors: Simmons Denina Bobbie Dawn , Trudeau Vance Lionel , Marlatt Vicki Lee , Moon Thomas William , Sherry James P , Metcalfe Chris David
Published: January 2008

Compounds with stilbene structures are widely used as pharmaceuticals and personal care products (PPCPs) and are present in plants. A suite of stilbene-related compounds, including PPCPs and plant-derived compounds were tested in vitro for interactions with the human and rainbow trout estrogen receptors and in vivo with rainbow trout using vitellogenin levels as a biomarker. Among the compounds with antagonistic activity, the common structural similarity was (in addition to the stilbene backbone) the presence of 4-hydroxy substitution. Stilbene-related compounds found to act as inhibitors at the estrogen receptor included the plant-derived compound resveratrol and two formulations of fluorescent whitening agents used in detergents, 4,4′-bis(2-sulfostyryl)biphenyl and diaminostilbene-1. In the yeast estrogenicity screening assay, the concentrations which caused a 50% inhibition in estrogenic response (IC50s) with the human estrogen receptor ranged from 2.56 × 10−6 to 2.56 × 10−6 M. In the rainbow trout estrogen receptor assay, the IC50s ranged from 7.75 × 10−8 to 1.11 × 10−5 M. However, in the in vivo rainbow trout vitellogenin assay, tamoxifen was the only stilbene of the compounds tested to have a significant effect as an inhibitor of estrogenicity.
Fonofos poisons raptors and waterfowl several months after granular application
Authors: Elliott John E , Birmingham Anna L , Wilson Laurie K , McAdie Malcolm , Trudeau Suzanne , Mineau Pierre
Published: January 2008

From 1994 to 1999 in the Lower Fraser Valley region of southwest Canada, fonofos (Dyfonate G) was recommended for control of introduced wireworm (Agriotes spp.) pests on potato and other root crops. As part of a wildlife-monitoring program, we collected 15 raptors, including 12 bald eagles (Haliaeetus leucocephalus), found dead or debilitated on or near agricultural lands with severely inhibited brain and/or plasma cholinesterase activity and fonofos residues in ingesta. Bird remains, in nine cases waterfowl, were identified in the ingesta samples. Another seven bald eagles had severe cholinesterase inhibition, but without evidence of fonofos residues. During two winters from 1996 to 1998, 420 ha of potato fields, half of which had been treated the previous spring with fonofos and the remainder untreated, were searched weekly for evidence of wildlife mortality. Search efficiency was assessed with placed duck carcasses. Waterfowl outnumbered other species in field-use counts and comprised the greatest proportion of birds found dead. We found 211 wildlife remains, most scavenged; 35 intact carcasses were suitable for postmortem examination and/or toxicology analyses. Cholinesterase activity was assayed in brains of 18 waterfowl, five of which had severely depressed activity (average inhibition 74%; range, 69–78%). The gastrointestinal tract of a mallard found in a field treated with granular product contained 49 μg/g fonofos residues, linking waterfowl mortality with labelled use of the product. These findings demonstrate the risk of both primary and secondary poisoning by anticholinesterase insecticides where wildlife make intensive use of farmed fields.
Effect of prolonged exposition to pulp mill effluents on the invasive aquatic plantEgeria densaand other primary producers: A mesocosm approach
Authors: Palma Alvaro T , Silva Marcelo G , Muñoz Carlos A , Cartes Carolina , Jaksic Fabián M
Published: January 2008

The recent disappearance of the aquatic plant Egeria densa, a Brazilian native invasive species, from a wetland in southern Chile prompted several efforts to unveil the origin of this phenomenon. Because these changes occurred by the time a newly built pulp mill started its operations in the area, a reasonable doubt for a cause–effect relationship is plausible. We implemented a mesocosm approach to directly evaluate the effect of treated pulp mill effluents (PMEs) on several growth-related parameters of E. densa as well as other primary producers. We hypothesize that effluent, at a dilution similar to that detected in the zone of the wetland where the negative environmental impacts were evident, has a significant negative effect on this aquatic plant as well as on other primary producers inside a mesocosm system. After a prolonged (months) exposure to both 0% PME with pure river water and a 4 to 5% (v/v) dilution of treated PME, no effect on E. densa was measured. Furthermore, plants exposed to effluent exhibited a significantly greater general growth rate. Coincidently, chlorophyll a concentration in the water column and periphyton biomass also changed over time, but without any pattern attributable to the effluent. Values of the autotrophic index obtained from the periphyton growth pattern did not suggest enrichment of the system with organic matter. Our results only refer to the direct effect of mill effluents on several biotic responses, but they represent an important advance toward generation of the scientific knowledge necessary to understand how the ecosystem functions while receiving this and other unquantified sources of water.
Arsenate-induced toxicity: Effects on antioxidative enzymes and DNA damage in Vicia faba
Authors: Lin Aijun , Zhang Xuhong , Zhu Yong-Guan , Zhao Fang-Jie
Published: January 2008

A glasshouse hydroponic experiment was conducted to investigate the toxicity of arsenate to broad bean (Vicia faba) plants when grown with external arsenate concentrations at 10 μmol/L. The treated plants showed no obvious symptoms of phytotoxicity, but shoot/root growth was inhibited. Lipid peroxidation in leaves and roots increased with the addition of arsenate, indicating oxidative stress. We investigated the responses to arsenate exposure in the activities of several representative antioxidant enzymes, including peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD), in plant tissues, and the DNA damage in plant leaves and root tips induced by arsenate in this plant was detected for the first time. Arsenate addition increased POD activity in the leaves significantly but decreased its activity in the roots in the 10 μmol/L treatment. Arsenate addition caused an induction of SOD and CAT activities in both leaves and roots, but not in roots at the arsenate concentration of 10 μmol/L. The DNA damage in V. faba was detected using Comet assay; in both leaves and roots, DNA damage increased with increasing arsenate concentrations, indicating genotoxicity of arsenate. These results indicate that arsenate toxicity causes oxidative stress in V. faba, which might be one of the mechanisms through which arsenic induces DNA damage.
Photodegradation of decabromodiphenyl ether in house dust by natural sunlight
Authors: Stapleton Heather M , Dodder Nathan G
Published: January 2008

Photolytic degradation of decabromodiphenyl ether (BDE 209) has been observed in several matrices such as solvent/water mixtures, sediments, and soil; however, no studies have investigated the degradation potential of BDE 209 in house dust. In the present study, both a natural and a BDE 209–spiked dust material were exposed to sunlight for 200 cumulative h. Degradation of BDE 209 was observed in both matrices but was 35% greater in the spiked dust relative to the natural dust material. The pseudo-first-order degradation rates were 2.3 × 10−3 and 1.7 × 10−3 per hour for the spiked and natural dust, respectively. During the 200-h exposure, as much as 38% of the original BDE 209 mass was degraded in the spiked dust, 25% of which could not be accounted for and was lost to unknown pathways and/or products. The remaining 13% was accounted for by the formation of lower brominated congeners. Debrominated products detected in the spiked dust included all three nonabrominated congeners (BDE 206, BDE 207, and BDE 208) and several octabrominated congeners (BDE 196, BDE 197, BDE 201, BDE 202, and BDE 203/200). In technical commercial octa-BDE mixtures, BDE 201 is a very small component (below detection limit to 0.8%), and BDE 202 is not detected. Therefore, the presence of these congeners in house dust may provide a marker of environmental debromination of BDE 209. The ratio of BDE 197 to BDE 201 may also be indicative of BDE 209 degradation. as the ratio of these two congeners appeared to reach a steady-state value (∼1) in both exposure scenarios in the present study.
Estimating metabolic biotransformation rates in fish from laboratory data
Authors: Arnot Jon A , Mackay Don , Bonnell Mark
Published: January 2008

A method is proposed for estimating metabolic biotransformation rate constants for nonionic organic chemicals from measured laboratory bioconcentration and dietary bioaccumulation data in fish. Data have been selected based on a quality review to reduce uncertainty in the measured values. A kinetic mass balance model is used to estimate rates of chemical uptake and elimination. Biotransformation rate constants are essentially calculated as the difference between two quantities, a measured bio-concentration factor or elimination rate constant, and a model-derived bioconcentration factor or elimination rate constant estimated assuming no biotransformation. Model parameterization exploits key empirical data when they are available and assumes default values when study specific data are unavailable. Uncertainty analyses provide screening level assessments for confidence in the biotransformation rate constant estimates. The uncertainty analyses include the range for 95% of the predicted values and 95% confidence intervals for the calculated biotransformation values. Case studies are provided to illustrate the calculation and uncertainty methods. Biotransformation rate constants calculated by the proposed method are compared with other published estimates for 31 chemicals that range in octanol–water partition coefficients from approximately 101 to 108 and represent over four orders of magnitude in biotransformation potential. The comparison of previously published values with those calculated by the proposed method shows general agreement with 82% of the estimated values falling within a factor of three.
Acute and delayed effects of the neonicotinoid insecticide thiacloprid on seven freshwater arthropods
Authors: Beketov Mikhail A , Liess Matthias
Published: January 2008

Ecotoxicological risk assessment of contaminants often is based on toxicity tests with continuous-exposure profiles. However, input of many contaminants (e.g., insecticides) to surface waters typically occurs in pulses rather than continuously. Neonicotinoids are a new group of insecticides, and little is known about their toxicity to nontarget freshwater organisms and potential effects on freshwater ecosystems. The aim of the present research was to assess effects of short-term (24-h) exposure to the neonicotinoid insecticide thiacloprid, including a postexposure observation period. A comparison of several freshwater insect and crustacean species showed an increase of sensitivity by three orders of magnitude in the following order: Daphnia magna < Asellus aquaticus = Gammarus pulex < Simpetrum striolatum < Culex pipiens = Notidobia ciliaris = Simulium latigonium, with median lethal concentrations (LC50s) of 4,400, 153, 190, 31.2, 6.78, 5.47, and 5.76 μg/L, respectively (postexposure observation 11–30 d). Thiacloprid caused delayed lethal and sublethal effects, which were observed after 4 to 12 d following exposure. Reduction in LC50s found when postexposure observation was extended from 1 d to a longer period (11–30 d) was up to >50-fold. Hence, delayed effects occurring after short-term exposure should be considered in risk assessment. The 5% hazardous concentration (HC5) of thiacloprid obtained in the present study (0.72 μg/L) is more than one order of magnitude below the currently predicted worst-case environmental concentrations in surface water. Concerning the selection of test organisms, we observed that the widely employed test organism D. magna is least sensitive among the arthropods tested and that, for neonicotinoid insecticides, an insect like the mosquito C. pipiens would be more suitable for predicting effects on sensitive species.
Variations of the Perforin Gene in Patients With Type 1 Diabetes
Authors: Orilieri Elisabetta , Cappellano Giuseppe , Clementi Rita , Cometa Angela , Ferretti Massimo , Cerutti Elisa , Cadario Francesco , Martinetti Miryam , Larizza Daniela , Calcaterra Valeria , D’Annunzio Giuseppe , Lorini Renata , Cerutti Franco , Bruno Graziella , Chiocchetti Annalisa , Dianzani Umberto
Published: January 2008

OBJECTIVE—Perforin plays a key role in cell-mediated cytotoxicity. Mutations of its gene, PRF1, cause familial hemophagocytic lymphohistiocytosis but have also been associated with lymphomas and the autoimmune/lymphoproliferative syndrome. The aim of this work was to investigate the role of PRF1 variations in type 1 diabetes.

RESEARCH DESIGN AND METHODS—We typed for the N252S and A91V variations in an initial population of 352 type 1 diabetic patients and 816 control subjects and a second population of 365 patients and 964 control subjects. Moreover, we sequenced the coding sequence and intron-exons boundaries in 200 patients and 300 control subjects.

RESULTS—In both cohorts, allelic frequency of N252S was significantly higher in patients than in control subjects (combined cohorts: 1.5 vs. 0.4%; odds ratio 6.68 [95% CI 1.83–7.48]). Sequencing of the entire coding region detected one novel mutation in one patient, causing a P477A amino acid change not detected in 199 patients and 300 control subjects. Typing for HLA-DQA1 and DQB1 alleles showed that type 1 diabetes–predisposing DQα/DQβ heterodimers were less frequent in patients carrying N252S or P477A than in those carrying wild-type PRF1. We previously found that natural killer (NK) activity is not decreased in most N252S heterozygotes, but we detected one whose NK activity was normal at the age of 12 but strikingly low in early childhood. Here, we discovered that NK function was low in three heterozygotes in early childhood, one homozygous adult, and in the subject carrying P477A.

CONCLUSIONS—These data suggest that N252S and possibly other PRF1 variations are susceptibility factors for type 1 diabetes development.
A Novel Susceptibility Locus for Type 1 Diabetes on Chr12q13 Identified by a Genome-Wide Association Study
Authors: Hakonarson Hakon , Qu Hui-Qi , Bradfield Jonathan P. , Marchand Luc , Kim Cecilia E. , Glessner Joseph T. , Grabs Rosemarie , Casalunovo Tracy , Taback Shayne P. , Frackelton Edward C. , Eckert Andrew W. , Annaiah Kiran , Lawson Margaret L. , Otieno F. George , Santa Erin , Shaner Julie L. , Smith Ryan M. , Onyiah Chioma C. , Skraban Robert , Chiavacci Rosetta M. , Robinson Luke J. , Stanley Charles A. , Kirsch Susan E. , Devoto Marcella , Monos Dimitri S. , Grant Struan F.A. , Polychronakos Constantin
Published: January 2008

OBJECTIVE—In stage 1 of our genome-wide association (GWA) study for type 1 diabetes, one locus at 16p13 was detected (P = 1.03 × 10−10) and confirmed in two additional cohorts. Here we describe the results of testing, in these additional cohorts, 23 loci that were next in rank of statistical significance.

RESEARCH DESIGN AND METHODS—Two independent cohorts were studied. The Type 1 Diabetes Genetics Consortium replication cohort consisted of 549 families with at least one child diagnosed with diabetes (946 total affected) and DNA from both parents. The Canadian replication cohort consisted of 364 nuclear family trios with one type 1 diabetes–affected offspring and two parents (1,092 individuals).

RESULTS—One locus at 12q13, with the highest statistical significance among the 23, was confirmed. It involves type 1 diabetes association with the minor allele of rs1701704 (P = 9.13 × 10−10, OR 1.25 [95% CI 1.12–1.40]).

CONCLUSIONS—We have discovered a type 1 diabetes locus at 12q13 that is replicated in an independent cohort of type 1 diabetic patients and confers a type 1 diabetes risk comparable with that of the 16p13 locus we recently reported. These two loci are identical to two loci identified by the whole-genome association study of the Wellcome Trust Case-Control Consortium, a parallel independent discovery that adds further support to the validity of the GWA approach.
Evaluation of the Level of Difficulty of Patient Cases for Veterinary Problem-Solving Examination: A Preliminary Comparison of Three Taxonomies of Learning
Authors: Koskinen Heli
Published: January 2008

An important issue that has received insufficient attention in the use of problem-based learning in the medical curriculum is the mode of assessing the level of difficulty of patient cases. In the present study, the level of difficulty of case-based questions in a veterinary degree final examination in reproduction was evaluated. First, cognitive taxonomies were evaluated to clarify whether qualitative methods such as Bloom's taxonomy, the Structure of the Observed Learning Outcome (SOLO) taxonomy, and the Amsterdam Clinical Challenge Scale (ACCS) differed from each other as evaluation tools for problem-based cases. Using these taxonomies, 30 case-based questions from the final examination in reproduction in the Helsinki veterinary program were initially evaluated to determine which one was best suited to the evaluation of the difficulty of cases. In follow-up, the same cases were also evaluated by an experienced veterinary instructor in reproduction, with the aim of gaining insight into using these approaches to evaluating difficulty. It would appear, from this preliminary assessment, that the SOLO taxonomy may be the most suitable for evaluating the difficulty of patient cases, since the instructor's quality rating resembled more closely the SOLO than the Bloom taxonomy or the ACCS. It is to be emphasized that the purpose of this study was to provide a preliminary evaluation of possible approaches that might be used to assess patient-case difficulty. Resolving all issues will require a greater number of evaluations of all components.
Introducing DVM: DiVersity Matters (An Association of American Veterinary Medical Colleges Initiative)
Authors: Greenhill Lisa M.
Published: January 2008

Now more than ever, colleges of veterinary medicine (CVMs) are challenged to improve the educational experience, build environments that support long-term student and faculty success, and create a diverse and competitive workforce. Additionally, the nation's fast-evolving racial and ethnic demographics demand that the veterinary medical profession be responsive to the emerging needs of this changing population. In March 2005, during the 15th Iverson Bell Symposium, the Association of American Veterinary Medical Colleges (AAVMC) unveiled its DiVersity Matters (DVM) initiative, designed to bring the CVMs closer to achieving these goals. Several key objectives of the initiative and their possible long-term significance to success of the DiVersity Matters initiative are explored here, and CVMs are encouraged to expand efforts to increase racial and ethnic diversity in academic veterinary medicine.
Native American Tribal Cultures: Implications for Veterinary Medical Education
Authors: Gelberg Susan , Gelberg Howard
Published: January 2008

This article reviews the literature from veterinary medicine, tribal education, career development, and psychology to focus on the reasons that Native people are currently under-represented in the field of veterinary medicine. Educational implications and recruitment strategies are suggested. Local, state, and national resources are provided to help veterinary medical educators make their programs more culturally competent for Native veterinary students and faculty.
Institutional Commitment: What It Is and How to Get It
Authors: Offerman Michael J.
Published: January 2008

Institutional commitment is essential to developing and sustaining successful distance-education programs. This article begins by placing the discussion of institutional commitment within the context of today's distance-education or online environment and argues for the role of regional accrediting bodies in implementing best practices and quality assurance in distance education. It then explains why broad-based institutional commitment is necessary and recommends strategies for obtaining it. The author delineates different strategies for various institutional stakeholders such as students, faculty, administrators, and alumni. The author concludes by drawing on his personal observation and experience in developing a collaborative distance education degree program, noting the success of these different strategies with multiple stakeholders.
The Role of Faculty in Distance Education: The Same But Different
Authors: Ragan Lawrence C.
Published: January 2008

Distance education (DE) continues to grow as an effective means of education that complements more traditional education modes. Each, to be effective, requires of the instructor a detailed understanding of what creates optimal learning by participants. Because DE is a newer mode, the roles and functions that faculty must play to make it effective have been subject to more scrutiny. Many principles are common to both modes; however, there are some unique aspects of each that faculty of such courses must appreciate.
Distance Learning through Synchronous Interactive Television
Authors: Hall Janis L.
Published: January 2008

The advent and popularity of asynchronous online learning has somewhat obscured a standby technology developed over the last two decades. Interactive videoconferencing, sometimes called “interactive television,” though not as glamorous and popular a topic at distance-learning conferences, is still alive and well at many institutions. Three or four years ago, many of us were led to believe that interactive television would go the way of the dinosaurs—everything would soon be in an asynchronous format or on individual desktops. There would no longer be any need for elaborately designed classrooms, networks, and operations staff. To date, this prediction has not come true. In fact, synchronous interactive television has experienced significant growth as newer, easier, and cheaper technologies allow institutions to reach more students with less resource investment. Faculty and students, while appreciating the convenience of asynchronous delivery, still express a need for synchronous communication. This article explores the issues involved in synchronous distance education, the current technologies and proposed future developments, and best practices in terms of classroom design, faculty use, and operational issues. It is not a research article but an anecdotal case study based on Washington State University's experiences over the last 20 years in developing and adapting to new synchronous technologies and creating the support and technical infrastructure to best deliver academic courses through this medium.
Factors Associated with Practice Decisions of Nebraska Veterinarians Regarding Type of Practice and Community Size
Authors: Schmitz John A. , Vogt Rebecca J. , Rupp Gary P. , Brodersen Bruce W. , Abel Jeramie M. , Wohlers Arden R. , Marx David B.
Published: January 2008

Nebraska veterinary practitioners were surveyed to collect data about background characteristics and other factors related to veterinarians’ decision to include or not include food animals in their practices and to practice in rural versus urban communities. Background characteristics that were significantly (p ≤ 0.05) associated with choosing food-animal practice included growing up on a working farm or ranch; having parents who owned livestock; growing up in a town with a population of less than 10,000; majoring in animal science at university; being male; and having a primary interest, at the time of entering veterinary college, in food animal–exclusive or mixed-animal veterinary practice. The primary factor for choosing the community in which to practice was rural/urban lifestyle for rural veterinarians, while this factor was second for urban veterinarians. For all groups of veterinarians, the primary consideration in selecting their current practice was the species orientation of the practice. The primary reason for not choosing food-animal practice was better working conditions and lifestyle in companion-animal practice, followed by greater interest elsewhere.
Image-Processing Technology to Evaluate Static Segregation Resistance of Hardened Self-Consolidating Concrete
Authors: Fang Chuanxin , Labi Samuel
Published: January 2008

Self-consolidating concrete (SCC) is a highly flowable, nonsegregating concrete that spreads into place, fills formwork, and encapsulates reinforcement without mechanical consolidation. SCC is increasingly being used worldwide because it has been found to offer a high-quality product with significant reductions in equipment use, construction time, labor, and construction noise. The stability, or static segregation resistance, of this new concrete type is typically assessed according to a hardened visual stability index (HVSI). Traditionally, HVSI assessment is based on visual judgment, and therefore its accuracy can be severely limited by human error, low efficiency, and work tedium. Thus, a study developed and implemented a methodology for automatically evaluating SCC stability. This was done in several steps: converting the image of a typical concrete sample (a cut surface with various shades of gray) into a binary image of light colors (aggregates) and dark colors (concrete cement), identifying aggregate sizes, detecting the mortar layer thickness, and using statistical analysis to derive the HVSI. Algorithms were developed for each phase and were implemented with standard coding languages. In effect, the methodology digitally processes a given concrete sample image and assesses its stability with respect to the HVSI. Accuracy of the new methodology was checked with control observations and was found to provide a reliable assessment of SCC stability in regard to static segregation resistance.
Alkali-Silica Reactivity Potential of Aggregate and Concrete Evaluated by Dilatometer Method
Authors: Shon Chang-Seon , Mukhopadhyay Anal K. , Zollinger Dan G.
Published: January 2008

Undesirable expansion of concrete due to a reaction between alkalis and certain type of reactive siliceous aggregates known as alkali-silica reactivity (ASR) continues as a major problem worldwide. Renewed interest in minimizing distress resulting from ASR emphasizes the need to develop predictable modeling of concrete ASR behavior under field conditions. Current test methods are either incapable of that or need long testing periods, which offer only limited predictive estimates of ASR behavior in a narrow band of field conditions. Therefore, an attempt was made to formulate a robust performance approach based on basic aggregate and concrete ASR material properties derived from dilatometry and a kinetic-based mathematical expression for ASR behavior. Since ASR is largely an alkali as well as a thermally activated process, the use of rate theory (Arrhenius relationship between temperature and alkali solution concentration) on the dilatometer time-expansion relationship provides a fundamental aggregate ASR material property known as activation energy. Activation energy is an indicator of aggregate reactivity, which is a function of alkalinity, particle size, crystallinity, calcium concentration, and so on. The studied concrete ASR material properties represent combined effects of mixture-related properties (e.g., water-cementitious material ratio, porosity, presence of supplementary cementitious materials) and maturity. A performance-based approach provides direct accountability for various factors affecting ASR, such as aggregate reactivity, temperature, moisture, calcium concentration, solution alkalinity, and water-cementitious material ratio. From test results, it was determined that the proposed model provides a means to predict ASR expansion development in concrete.
Thermal and Autogenous Shrinkages of Very Early Strength Latex-Modified Concrete
Authors: Yun Kyong-Ku , Choi Pan-Gil , Choi Sung-Yong , Kim Ki-Heun
Published: January 2008

A study evaluated the factors influencing thermal and autogenous shrinkages of very early strength latex-modified concrete (VES-LMC) with respect to latex content (latex solids-cement ratio, by weight); water-cement ratio; retarder content (retarder solids-cement ratio, by weight); and antifoamer content (antifoamer-latex solids ratio, by weight). Examined were three levels of latex content (0%, 5%, 15%) at a constant slump, three levels of water-cement ratio (0.34, 0.38, 0.42) at a constant latex content of 15%, three levels of retarder content (0.0%, 0.3%, 0.6%), and three levels of antifoamer content (0.0%, 0.5% and 1.0%) at a constant latex content and water-cement ratio. Results were that total shrinkage was governed by thermal deformation at very early age because of the high heat of hydration of VES cement. After 5 h, total shrinkage was governed by the autogenous shrinkage process. The absolute magnitude of thermal expansion was 130 micro strains while the autogenous shrinkage was 120 micro strains. The autogenous shrinkage increased as latex content increased. VES-LM concrete with a high latex content and low water-cement ratio caused autogenous shrinkage. The total and autogenous shrinkages of VES-LMC were not affected or only slightly affected by the water-cement ratio or the antifoamer content. Excessive retarder induced expansion at very early age, which increased the absolute shrinkage. Thus, attention should be paid whenever retarder is added in response to weather conditions. Furthermore, immediate and proper wet curing is necessary when adding more retarder because of greater susceptibility to plastic shrinkage.
Influence of Mixture Design and Environmental Factors on Continuously Reinforced Concrete Pavement Cracking
Authors: Johnston Daniel P. , Surdahl Roger W.
Published: January 2008

The influence of concrete mixture design and environmental factors on cracking in a continuously reinforced concrete (CRC) pavement was documented on Interstate 90 in Hanson County, South Dakota. A project evaluated three mix designs, which were placed in the eastbound direction in 2005. From the study, it was shown that crack frequency was directly related to the initial concrete temperature as specifically contributed by the aggregate in the mix–and a reduced cement content making a less workable concrete. The study recommends an application of curing compound within 30 min to reduce CRC cracking, and wetting the aggregate stockpiles in hot weather to cool them overnight to reduce concrete temperature. Construction of CRC test sections containing at least 510 lb/yd3 of cement with 112 lb/yd3 (15% cement replaced with 18.75%) Class F fly ash is under way to examine the effects of the rate of early strength gain on cracking.
Use of Context-Sensitive Methods to Influence Operating Speeds
Authors: Stamatiadis Nikiforos , Bailey Keiron , Grossardt Ted , Ripy John , Strombotne Anne
Published: January 2008

Excessive speed is one of the primary safety hazards facing highway users. Too often, operating speeds exceed design speeds, and speed limit postings are generally ignored by drivers. There is renewed interest in designing roadways that encourage drivers to operate at or below design speeds. There is not, however, a reliable body of concomitant knowledge regarding what combinations of design properties should be used to accomplish this goal. To date, only limited interrelationships have been explored, but these explorations have not begun to approach evaluations of the complexity of the design environment, which encompasses combinations of design properties such as lane width, shoulder width, clear zone, horizontal and vertical curvatures, and even the type and intensity of vegetation along the corridor. This research integrates the use of virtual reality simulations of various highway sample designs. These sessions can simultaneously accommodate significant numbers of subjects and gather their feedback through electronic audience response systems. The response feedback is modeled through the use of a fuzzy set system that allows designers to inspect the interrelationships of many different design parameters. Such modeling systems are particularly well suited to nonlinear, data-sparse applications such as this. This research reports on a pilot data modeling effort, in which the discomfort responses of 15 participants to 22 different virtual roadway design combinations were gathered in less than 30 min. These data were sufficient for use for modeling the way in which more than 400 possible roadway design combinations would affect the participants' perceptions of speed and safety.
Principles of Heterogeneous Catalysis
Authors: Dumesic James A. , Huber George W. , Boudart Michel
Published: January 2008

The sections in this article are

Introduction

Definitions of Catalysis and Turnover

Steps in a Heterogeneous Catalytic Reaction

Desired Characteristics of a Catalyst

Reaction Schemes and Adsorbed Species

Conditions for Catalyst Optimality

Catalyst Design

Catalyst Development

Bridging Gaps in Heterogeneous Catalysis

A Philosophical Note
Ethical and policy issues in pediatric genetics
Authors: Ross Lainie Friedman
Published: January 2008

This article presents an overview to a special issue on ethical and policy issues in pediatric genetics. It discusses challenges to current practices and policies with regard to newborn screening, biobanking initiatives, and predictive genetic testing of minors. © 2008 Wiley‐Liss, Inc.
Attitudes regarding predictive genetic testing in minors: A survey of European clinical geneticists
Authors: Borry Pascal , Goffin Tom , Nys Herman , Dierickx Kris
Published: January 2008

The aim of this study is to gather information from European clinical geneticists about their practices and attitudes with regard to presymptomatic and predictive genetic testing in minors. European clinical institutes where genetic counseling is offered to patients were contacted. One hundred seventy‐seven of the 287 eligible respondents (63%) answered a questionnaire. There was strongest support for testing young children when it provides a clear medical benefit, such as in the case of FAP and MEN2A. However, there is disagreement about when to provide predictive genetic testing for childhood‐onset disorders for which therapeutic or preventive measures exist with some supporting the rule of earliest onset and others giving parents wider discretion. However, for childhood‐onset disorders that do not have therapeutic measures, the majority of the respondents is unwilling to provide a presymptomatic or predictive genetic test. With respect to adolescents, many held a cautious position regarding presymptomatic and predictive genetic testing. Most clinical geneticists were unwilling to provide a presymptomatic or predictive genetic test for adult‐onset diseases, except if it might provide a medical benefit. Although adolescents might be legally in the position to request a presymptomatic or predictive genetic test personally, the clinical geneticists are significantly more willing to provide a test if this request is made together with the minor's parents. This variability demonstrates the need for clinical geneticists to discuss their contradicting views and to develop harmonized practices throughout Europe. © 2008 Wiley‐Liss, Inc.
Cashew nut shell liquid based t‐BOC protected alternating “high ortho” copolymer as a possible e‐beam resist: Characterization using multi‐dimensional NMR spectroscopy
Authors: Sharma Maneesh , Raghunathan P. , Eswaran S. V.
Published: January 2008

A cardanol/m‐cresol‐based copolymer was esterified using di‐tert‐butyl dicarbonate (t‐BOC), which makes it a suitable candidate as a possible e‐beam resists. This work reports a full characterization of the product using the techniques of FTIR and UV–Visible spectroscopy, one dimensional 1H NMR, 13C NMR, DEPT‐135. Two dimensional NMR experiments such as, COSY, HSQC, and HMBC have been employed for exhaustive probing of the microstructural details of this derivatized copolymer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Paleogenomics in vertebrates, or the recovery of lost genomes from the mist of time
Authors: Muffato Matthieu , Crollius Hugues Roest
Published: January 2008

Knowledge of the structure of ancestral genomes provides the basis of a new framework to better represent and interpret results from genomic and evolutionary studies. Because these ancestors lived tens of hundreds of million years ago, this knowledge will inevitably take the form of abstract representations, reconstructed on the basis both of experimental evidence collected on extant genomes and of our understanding of evolutionary processes. This is the field of Paleogenomics, a young discipline that is providing an increasingly precise picture of our ancestral vertebrate genomes based on cytogenetic data, genome sequences and new algorithmic developments. Many recent studies have focused on the ancestral placental mammal and teleost fish genomes, although the outlines of even more distant pre‐vertebrate ancestors are being reported. BioEssays 30:122–134, 2008. © 2008 Wiley Periodicals, Inc.