bluuebunny/crossref_metadata_2025 huggingface dataset:
Suture versus staple for fixation of mesh in incisional hernia repair
Authors: Dhillon Raminder S. , Van Dalen Ralph
Published: October 2008

The incidence of incisional hernia has been reported to be between 11 and 20% in patients post laparotomy and carries the risk of pain, incarceration and strangulation. Prosthetic mesh for incisional hernia repair has been shown to be superior to suture repair. The recurrence rate of primary mesh repair of incisional hernias has been reported to be as high as 38%. This experimental study in euthanised rats aims to compare the fixation strength of mesh using sutures and surgical staples. Forty euthanised adult male Sprague–Dawley rats were used for midline laparotomy incisions and repair of the abdominal wall carried out using polypropylene mesh anchored using either skin staples or Prolene sutures. An intra‐abdominal expander device was inserted into the abdomen and inflated to measure ‘burst pressure’. Pressure changes and surgical time were recorded. There was no statistically significant difference (P = 0.83) in the pressure required to disrupt the mesh fixation between the two groups, 101 ± 12 mmHg in the suture group versus 102 ± 14 mmHg in the staple group. Staple fixation was 9.7 times faster compared with suture fixation, 291 ± 42 s for suture versus 30 ± 8 s for staples (P < 0.001) (power = 94%). The immediate strength of fixation is equal using both sutures and staples, however staple fixation is faster. Mesh migration due to inadequate fixation using either method is unlikely to cause early failure, however suture and staple ‘cut out’ during early movement may explain this.
THE PREVALENCE OF E. COLI O157/O157:H7, L. MONOCYTOGENES AND SALMONELLA SPP. ON BOVINE CARCASSES IN TURKEY
Authors: AKKAYA L. , CETINKAYA Z. , ALISARLI M. , TELLI R. , GÖK V.
Published: October 2008

Escherichia coli, O157, E. coli O157:H7, Listeria monocytogenes and Salmonella spp. are important foodborne pathogens, that some studies have demonstrated that cattle are a major reservoir of these pathogens. The main purpose of this study was to evaluate the prevalence of E. coli O157/O157:H7, L. monocytogenes and Salmonella spp. on slaughtered bovine carcasses. In this study, five abattoirs in Afyonkarahisar were visited between March and August in 2005 in the center of Afyonkarahisar Province, Turkey. A total of 250 bovine carcasses were sampled by surface swabbing the carcasses at four points. The presence of E. coli O157/O157:H7, L. monocytogenes and Salmonella spp. in the samples collected from 250 cattle was determined with the application of the immunomagnetic separation method. Overall, the prevalence of E. coli O157/O157:H7, L. monocytogenes and Salmonella spp. was 3.2, 0.8, 6.8 and 10%, respectively. Our results demonstrated that bovine carcasses can also be a source for E. coli O157/O157:H7, L. monocytogenes and Salmonella spp. infections for humans. The widespread occurrence of these pathogens in slaughterhouses reinforces the need for the implementation of effective control measures.

PRACTICAL APPLICATIONS

This study indicates that relatively high values, particularly Salmonella spp., and widespread occurrence of these pathogens in bovine carcasses require the need for the implementation of effective public health measures.
An Imminent Human Resource Crisis in Ground Water Hydrology?
Authors: Stephens Daniel B.
Published: October 2008

Anecdotal evidence, mostly from the United States, suggests that it has become increasingly difficult to find well‐trained, entry‐level ground water hydrologists to fill open positions in consulting firms and regulatory agencies. The future prospects for filling positions that require training in ground water hydrology are assessed by considering three factors: the market, the numbers of qualified students entering colleges and universities, and the aging of the existing workforce. The environmental and water resources consulting industry has seen continuous albeit variable growth, and demand for environmental scientists and hydrologists is expected to increase significantly. Conversely, students’ interest and their enrollment in hydrology and water resources programs have waned in recent years, and the interests of students within these departments have shifted away from ground water hydrology in some schools. This decrease in the numbers of U.S. students graduating in hydrology or emphasizing ground water hydrology is coinciding with the aging of and pending retirement of ground water scientists and engineers in the baby boomer generation. We need to both trigger the imagination of students at the elementary school level so that they later want to apply science and math and communicate the career opportunities in ground water hydrology to those high school and college graduates who have acquired the appropriate technical background. Because the success of a consulting firm, research organization, or regulatory agency is derived from the skills and judgment of the employees, human resources will be an increasingly more critical strategic issue for many years.
Does limb angular motion raise limb arterial pressure?
Authors: Sheriff D. D. , Mullin T. M. , Wong B. J. , Ladouceur M.
Published: October 2008

Aim:  Mechanical factors such as the muscle pump have been proposed to augment flow by several mechanisms. The potential for limb angular motion to augment local perfusion pressure (pressure = ½ρr2ω2, where ρ is the fluid density, r the radius and ω the angular velocity) has been overlooked. We sought to test the hypothesis that limb angular motion augments limb arterial pressure.

Methods:  Nine human subjects performed horizontal shoulder flexion (∼±90° at 0.75 Hz for 30 s). We measured finger arterial pressure (photoplethysmography) in the moving (Trial 1) and non‐moving arm (Trial 2) in separate trials along with the pressure (strain gauge) generated at the fingers within a length of water‐filled tubing mounted on the moving arm in both trials.

Results:  Arm swinging raised (P < 0.05) the mean pressure measured in the tubing by 11 ± 2 and 14 ± 2 mmHg (Trials 1 and 2 respectively). In response to exercise, the rise in mean finger arterial pressure in the swinging limb (18 ± 3 mmHg, Trial 1) exceeded (P < 0.05) the rise in the resting limb (8 ± 2 mmHg, Trial 2) by an amount similar to the 11 mmHg rise in pressure generated in the tubing in Trial 1.

Conclusions:  We conclude that the swinging of a limb creates centrifugal force (a biomechanical centrifuge) which imparts additional pressure to the arteries, but not the veins owing to the venous valves, which further widens the arterial–venous pressure difference.
Blue and fin whale acoustic presence around Antarctica during 2003 and 2004
Authors: Širović Ana , Hildebrand John A. , Wiggins Sean M. , Thiele Deborah
Published: October 2008

Abstract

Seasonal and spatial variations of blue (Balaenoptera musculus) and fin whale (B. physalus) calls were analyzed from recordings collected with Acoustic Recording Packages (ARPs) deployed between January 2003 and July 2004 at four circumpolar locations: the Western Antarctic Peninsula (WAP), the Scotia Sea (SS), Eastern Antarctica (EA), and the Ross Sea (RS). Call characteristics were compared among sites using the average pressure spectrum levels from 1 month of data at each location. Presence of calls was analyzed using automatic call detection and acoustic power analysis methods. Blue whale calls were recorded year‐round, with the highest detections in February–May and November. This suggests that the blue whale population may not migrate synchronously, and may indicate long duration calls are more common during migrations. Fin whale calls were detected only during February–July. Two distinct fin whale call types were recorded, suggesting a possible separation into two populations. The calls at the EA site had a secondary frequency peak in the pressure spectrum at 99 Hz and the calls at the WAP and the SS sites had a peak at 89 Hz. No fin whale calls were detected at the RS site. Acoustics are a good tool to monitor large whales in the Southern Ocean.
Health reform in Alberta: The introduction of health regions
Authors: Church John , Smith Neale
Published: October 2008

Abstract: In 1994, the Government of Alberta passed the Regional Health Authorities Act to abolish nearly 200 existing local hospital and public health boards and replace them with seventeen regional health authorities. Consistent with the larger fiscal agenda, the government's intention was to address health‐care system efficiency through larger integrated management and governance structures. In this article, the authors examine why Alberta decided to create regional health authorities for the management and delivery of a significant range of health services. In examining the interaction of ideas, interests and institutions, the authors conclude that the government was partially successful in aligning existing institutional and interest relationships with an emerging political consensus about cost and sustainability of the health‐care system.

Sommaire: En 1994, le gouvernement de l'Alberta a adopté la loi intitulée Regional Health Authorities Act (Loi sur les offices régionaux de santé) en vue d'abolir près de 200 commissions hospitalières et commissions de santé publique locales et de les remplacer par dix‐sept offices régionaux de la santé. Conformément au programme fiscal plus large, l'intention du gouvernement était d'examiner l'efficience du système des soins de santé grâce à des structures intégrées de gestion et de gouvernance plus vastes. Dans le présent article, les auteurs examinent les raisons pour lesquelles l'Alberta a décidé de créer des offices régionaux de la santé pour la gestion et la prestation d'une gamme importante de services de santé. Après avoir étudié les interactions d'idées, d'intérêts et d'institutions, les auteurs ont conclu que le gouvernement avait partiellement réussi à aligner les relations institutionnelles et les relations d'intérêts existantes sur un consensus politique émergent au sujet des coûts et de la viabilité du système de soins de santé.
The politics of governance: Government—voluntary sector relationships
Authors: Tsasis Peter
Published: October 2008

Abstract: This article examines the dynamics at play as national non‐government AIDS organizations engage in shared governance with Health Canada, where the allocation of power between them is disproportionate and periodically, where their perspectives are at odds. This study takes a qualitative approach in identifying some of the relations, discourses and institutional processes that shape the informants' experiences. Findings reveal how power disparities are managed in order to affect the distribution of resources and ultimately the governance process.

Sommaire : Cet article examine les dynamiques en jeu lorsque les organisations non gouvernementales (ONG) nationales de lutte contre le SIDA participent à une gouvernance partagée avec Santé Canada, alors que la distribution de pouvoir entre ces parties est disproportionnée et que périodiquement leurs points de vue sont opposés. Cette étude adopte une approche qualitative pour identifier un certain nombre de relations, de discours et de processus institutionnels qui influencent les expériences des sujets interrogés. Les conclusions révèlent comment les disparités de pouvoir sont gérées afin d'avoir une incidence sur la distribution des ressources et, en bout de ligne, sur le processus de gouvernance.
Aboriginal policy reform and the subsidiarity principle: A case study of the division of matrimonial real property on Canadian Indian reserves
Authors: Alcantara Christopher
Published: October 2008

Abstract: According to the Indian Act, aboriginal women in Canada do not have the same equality rights as aboriginal men living on‐reserve and non‐aboriginal women living off‐reserve. The Indian Act's provisions governing the division of matrimonial real property on Canadian Indian reserves have dispossessed many aboriginal women of their property entitlements during and after separation and divorce proceedings. Despite the existence of this problem for the last fifty‐five years, the Indian Act has proven highly resistant to reform. A number of First Nations, however, have recently been able to address this issue by developing local matrimonial property laws through the First Nations Land Management Act, a federal piece of legislation that is separate from the Indian Act. Not only have these local laws provided solutions to a policy problem left unaddressed by the federal government, they have also given aboriginal women greater equality rights during and after divorce proceedings while respecting local preferences. This article argues that government and aboriginal policy‐makers should consider making greater use of the subsidiarity principle when engaging in reforms to the Indian Act.

Sommaire: Aux termes de la Loi sur les Indiens, les femmes autochtones au Canada n'ont pas les mêmes droits à l'égalité que les hommes autochtones dans les réserves et que les femmes non autochtones hors des réserves. Les dispositions de la Loi sur les Indiens régissant la division des biens immobiliers matrimoniaux sur les réserves indiennes canadiennes ont dépossédé de nombreuses femmes autochtones de leurs droits de propriété pendant et après les procédures de séparation et de divorce. Alors que ce problème existe depuis 55 ans, il se trouve que la Loi sur les Indiens a fortement résistéà la réforme. Cependant, un certain nombre de Premières nations ont réussi récemment à aborder ce problème en élaborant des lois locales sur les biens matrimoniaux par l'intermédiaire de la Loi sur la gestion des terres des premières nations, texte de loi fédéral distinct de la Loi sur les Indiens. Non seulement ces lois locales ont‐elles apporté des solutions à un problème de politique que le gouvernement fédéral n'avait pas réglé, mais elles ont également donné aux femmes autochtones de plus grands droits en matière d'égalité pendant et après les procédures de divorce tout en respectant les préférences locales. Le présent article indique que le gouvernement et les décideurs de politiques autochtones devraient envisager faire un plus grand usage du principe de subsidiarité lorsqu'ils entreprennent des réformes de la Loi sur les Indiens.
Negotiating Tactics in Low Intensity Conflicts: The Cases of Northern Ireland, the Basque Country and Corsica
Authors: Filippidou Anastasia
Published: October 2008

The article examines via the cases of Northern Ireland, the Basque country and Corsica the theories and practice of negotiating methods in long‐standing violent intrastate conflicts. Despite the uniqueness of each case depending on contextual and circumstantial parameters this article reaches general answers that contribute to establishing commonalities vis‐à‐vis conflict resolution and the effectiveness of certain peace processes and the failure of others. In general, the three case studies show that policies designed to accommodate fuller recognition and rights to an ethnic community have been more successful in preventing or diminishing polarisation and violent conflict than rigid policies. For a long lasting solution the parties involved would have to redefine their relationship in a way that either they could realise their goals without violent conflict or in a way that their goals would no longer conflict.
Isolation and characterization of microsatellites in the woody shrub, Banksia sphaerocarpa var. caesia (Proteaceae)
Authors: NISTELBERGER H. M. , LLORENS T. M. , BYRNE M.
Published: October 2008

Microsatellite markers were developed for the Australian bird‐pollinated woody shrub Banksia sphaerocarpa var. caesia to study gene flow among populations in a highly fragmented landscape. Eight loci were developed, and in a sample of 40 individuals from one population, the number of alleles per locus ranged from five to 21 and observed heterozygosities ranged from 0.385 to 0.914. All eight loci showed independent inheritance. Analysis of open‐pollinated progeny arrays confirmed Mendelian inheritance at seven loci, while null alleles were suspected at the remaining locus.
Microsatellite markers for the Indian golden silkmoth, Antheraea assama (Saturniidae: Lepidoptera)
Authors: ARUNKUMAR K. P. , KIFAYATHULLAH L. , NAGARAJU J.
Published: October 2008

Antheraea assama, an economically important and scientifically unexplored Indian wild silkmoth, is unique among saturniid moths. For this species, a total of 87 microsatellite markers was derived from 35 000 expressed sequence tags and a microsatellite‐enriched sub‐genomic library. Forty individuals collected from Tura and West Garo Hills region of Northeast India were screened for each of these loci. Ten loci from expressed sequence tags and one from genomic library were found to be polymorphic. These microsatellite markers will be useful resources for population genetic studies of A. assama and other closely related species of saturniids. This is the first report on development of microsatellite markers for any saturniid species.
Characterization of 14 polymorphic microsatellite loci for the facultatively eusocial sweat bee Halictus rubicundus (Hymenoptera, Halictidae) and their variability in related species
Authors: SORO ANTONELLA , PAXTON ROBERT J.
Published: October 2008

Sweat bees display considerable variation in social organization and a few species, such as Halictus rubicundus, are even facultatively eusocial. Fourteen polymorphic, unlinked microsatellite loci were isolated from H. rubicundus and characterized in 45 females. The number of alleles per locus ranged from two to 18 (mean 10.1), observed heterozygosity ranged from 0.24 to 0.98 (mean 0.71) and expected heterozygosity ranged from 0.24 to 0.98 (mean 0.70). Six or more loci cross‐amplified in four other sweat bees. These loci will be useful for the study of social evolution and population genetic structure in H. rubicundus and many other sweat bees.
A Comparison of Real World and Virtual World Interior Environments
Authors: Lindsey Patricia F. , McLain–Kark Joan
Published: October 2008

Objective

The objective of the study was to investigate whether observation of virtual reality simulation (virtual world) of interior environments provides the same information about characteristics of that environment as observation of the existing (real world) interior environment.

Research Design

The participants observed a real world test environment, a virtual simulation of the environment, and a virtual simulation with some altered components. A questionnaire was developed to compare observations. The questions consisted of comparative rating scales, closed–ended questions, open–ended questions, and a semantic differential scale. Real, virtual, and altered virtual worlds were compared for differences in visual accessibility, reach accessibility, and perception of ability to converse.

Analysis

Wilcoxon's Signed Ranks Test and tests were used to test the hypotheses. Additionally, frequencies, percentages, and mean scores were used to analyze the data.

Key Findings

Comparisons among a real world environment, a virtual world environment, and an altered virtual world environment suggest that visibility of objects and obstacles, the ability to reach objects and specified points, and the ability to share or communicate with other persons within the environments are consistent among the three worlds.

Conclusion

The findings of the study suggest that a virtual simulation can be a viable method for planning, creating, and testing environments before they are constructed or for creating recognizable simulations of existing environments, furnishings, and architectural components. Virtual simulation may be used to assess planned environments and changes to existing environments.
Computer Animation: A Tool for Teaching Design Fundamentals to Elementary School Students
Authors: Clemons Stephanie
Published: October 2008

Issue

Teaching design fundamentals to elementary school students can help create in them awareness about interior design. Elementary school teachers may not have the time, budget, or knowledge to add this subject to their curriculum, yet they are teaching basic computer skills. Therefore, this project explored using the computer to teach design fundamentals related to interior design.

Goal

Exploration of design fundamentals during the elementary grades may create an awareness of their importance in everyday life. This awareness of design could generate interest in the interior design profession.

Application

This project explored the use of computer technology, specifically animation, to teach design fundamentals to students in 3rd through 6th grades.

Description

A computer animation workshop was developed and offered to elementary students during the summer months at a higher education institution. Selected design elements and principles were taught through a series of 2–dimensional, 3–dimensional, and animation exercises.

Conclusion

Students are successful in learning both design fundamentals and computer animation. Computer animation techniques appeal to elementary students and encourage them to discover more about design.
Neurotransmitters and peptides: whispered secrets and public announcements
Authors: Leng Gareth , Ludwig Mike
Published: October 2008

The magnocellular oxytocin and vasopressin neurones of the hypothalamus are now understood in exceptional detail. Extensive quantitative details from many independent sources are available describing the electrical activity of the neurones in diverse circumstances, the subcellular localization of vesicles, and rates of hormone secretion from nerve endings into the blood and from dendrites into the brain. These data enable the relationship of electrical (spike) activity to vesicle exocytosis to be inferred with some precision. Such calculations lead to the conclusion that exocytosis of peptide‐containing vesicles is a relatively rare event even in this vesicle‐dense system. At any given release site in the neurohypophysis, it seems that several hundred spikes are needed on average to release a single vesicle. Release from compartments within the brain seems also to be very rare, making it implausible that peptides can act in a temporally precise, anatomically specific manner. However, very large amounts of peptide are released by these infrequent events, consistent with their likely role as neurohormonal messengers.
A common polymorphism in the brain‐derived neurotrophic factor gene (BDNF) modulates human cortical plasticity and the response to rTMS
Authors: Cheeran Binith , Talelli Penelope , Mori Francesco , Koch Giacomo , Suppa Antonio , Edwards Mark , Houlden Henry , Bhatia Kailash , Greenwood Richard , Rothwell John C.
Published: October 2008

The brain‐derived neurotrophic factor gene (BDNF) is one of many genes thought to influence synaptic plasticity in the adult brain and shows a common single nucleotide polymorphism (BDNF Val66Met) in the normal population that is associated with differences in hippocampal volume and episodic memory. It is also thought to influence possible synaptic changes in motor cortex following a simple motor learning task. Here we extend these studies by using new non‐invasive transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (TDCS) techniques that directly test the excitability and plasticity of neuronal circuits in human motor cortex in subjects at rest. We investigated whether the susceptibility to TMS probes of plasticity is significantly influenced by the BDNF polymorphism. Val66Met carriers were matched with Val66Val individuals and tested on the following protocols: continuous and intermittent theta burst TMS; median nerve paired associative stimulation; and homeostatic plasticity in the TDCS/1 Hz rTMS model. The response of Met allele carriers differed significantly in all protocols compared with the response of Val66Val individuals. We suggest that this is due to the effect of BNDF on the susceptibility of synapses to undergo LTP/LTD. The circuits tested here are implicated in the pathophysiology of movement disorders such as dystonia and are being assessed as potential new targets in the treatment of stroke. Thus the polymorphism may be one factor that influences the natural response of the brain to injury and disease.
Altered expression of triadin 95 causes parallel changes in localized Ca2+ release events and global Ca2+ signals in skeletal muscle cells in culture
Authors: Fodor János , Gönczi Monika , Sztretye Monika , Dienes Beatrix , Oláh Tamás , Szabó László , Csoma Eszter , Szentesi Péter , Szigeti Gyula P. , Marty Isabelle , Csernoch László
Published: October 2008

The 95 kDa triadin (Trisk 95), an integral protein of the sarcoplasmic reticular membrane in skeletal muscle, interacts with both the ryanodine receptor (RyR) and calsequestrin. While its role in the regulation of calcium homeostasis has been extensively studied, data are not available on whether the overexpression or the interference with the expression of Trisk 95 would affect calcium sparks the localized events of calcium release (LCRE). In the present study LCRE and calcium transients were studied using laser scanning confocal microscopy on C2C12 cells and on primary cultures of skeletal muscle. Liposome‐ or adenovirus‐mediated Trisk 95 overexpression and shRNA interference with triadin translation were used to modify the level of the protein. Stable overexpression in C2C12 cells significantly decreased the amplitude and frequency of calcium sparks, and the frequency of embers. In line with these observations, depolarization‐evoked calcium transients were also suppressed. Similarly, adenoviral transfection of Trisk 95 into cultured mouse skeletal muscle cells significantly decreased both the frequency and amplitude of spontaneous global calcium transients. Inhibition of endogenous triadin expression by RNA interference caused opposite effects. Primary cultures of rat skeletal muscle cells expressing endogenous Trisk 95 readily generated spontaneous calcium transients but rarely produced calcium sparks. Their transfection with specific shRNA sequence significantly reduced the triadin‐specific immunoreactivity. Functional experiments on these cells revealed that while caffeine‐evoked calcium transients were reduced, LCRE appeared with higher frequency. These results suggest that Trisk 95 negatively regulates RyR function by suppressing localized calcium release events and global calcium signals in cultured muscle cells.
Weighing the evidence for a ternary protein complex mediating A‐type K+ currents in neurons
Authors: Maffie Jonathon , Rudy Bernardo
Published: October 2008

The subthreshold‐operating A‐type K+ current in neurons (ISA) has important roles in the regulation of neuronal excitability, the timing of action potential firing and synaptic integration and plasticity. The channels mediating this current (Kv4 channels) have been implicated in epilepsy, the control of dopamine release, and the regulation of pain plasticity. It has been proposed that Kv4 channels in neurons are ternary complexes of three types of protein: pore forming subunits of the Kv4 subfamily and two types of auxiliary subunits, the Ca2+ binding proteins KChIPs and the dipeptidyl peptidase‐like proteins (DPPLs) DPP6 (also known as DPPX) and DPP10 (4 molecules of each per channel for a total of 12 proteins in the complex). Here we consider the evidence supporting this hypothesis. Kv4 channels in many neurons are likely to be ternary complexes of these three types of protein. KChIPs and DPPLs are required to efficiently traffic Kv4 channels to the plasma membrane and regulate the functional properties of the channels. These proteins may also be important in determining the localization of the channels to specific neuronal compartments, their dynamics, and their response to neuromodulators. A surprisingly large number of additional proteins have been shown to modify Kv4 channels in heterologous expression systems, but their association with native Kv4 channels in neurons has not been properly validated. A critical consideration of the evidence suggests that it is unlikely that association of Kv4 channels with these additional proteins is widespread in the CNS. However, we cannot exclude that some of these proteins may associate with the channels transiently or in specific neurons or neuronal compartments, or that they may associate with the channels in other tissues.
Easy Implementation of Internet-Based Whiteboard Physics Tutorials
Authors: Robinson Andrew
Published: October 2008

The requirement for a method of capturing problem solving on a whiteboard for later replay stems from my teaching load, which includes two classes of first-year university general physics, each with relatively large class sizes of approximately 80–100 students. Most university-level teachers value one-to-one interaction with the students and find working out problems on a board a useful teaching method. However, in most institutions of higher education, the staff-to-student ratio precludes giving every student this learning experience. The syllabus of the algebra-based physics course at the University of Saskatchewan (Physics 111) is relatively ambitious in terms of the content covered, given the physics and mathematics background knowledge of the average student. This means that the number of problems worked on in class is rather limited if a thorough discussion of the basic principles is required. Some form of tutorial that records the essence of working out a problem on a board, with both visual and audio elements and which can be replayed over the Internet, is desirable. Obviously, this loses the interactive question-and-answer element possible in a true tutorial where the student and teacher are both physically present, but it does have the significant advantage that the tutorial can be replayed as many times as the student deems it necessary, thus allowing the lesson to proceed at a pace dictated by the student. Moreover, these lessons only have to be prepared once, can be used many times over, and can be used in distance-learning courses. In this paper, I describe the necessary hardware and software required to do this, all of which is relatively affordable and requires little specialist IT knowledge to set up.
Physics Exam Problems Reconsidered: Using Logger Pro to Evaluate Student Understanding of Physics
Authors: Milner-Bolotin Marina , Moll Rachel
Published: October 2008

In the past few decades, the physics teaching community has witnessed a surge in creative and often effective ways of using technology to improve physics instruction.1–3 Most of these findings suggest how technology can help instructors create interactive learning environments and how interactivity influences the effectiveness of physics learning.4 However, every physics teacher knows that in order for any teaching method to be effective, the exams have to test the skills and concepts addressed by the teacher. Exam content and style sends the clearest message to students about what skills and content are valued by instructors. The mismatch between what we intend to teach and what we effectively test in exams is of great concern to many science teachers. These were our motives for creating data-rich questions to be used in the exams in a large undergraduate first-year physics course at the University of British Columbia. These data-rich questions were developed to support the use of an innovative teaching pedagogy called Interactive Lecture Experiments.3
Environmental Genomics Reveals a Single-Species Ecosystem Deep Within Earth
Authors: Chivian Dylan , Brodie Eoin L. , Alm Eric J. , Culley David E. , Dehal Paramvir S. , DeSantis Todd Z. , Gihring Thomas M. , Lapidus Alla , Lin Li-Hung , Lowry Stephen R. , Moser Duane P. , Richardson Paul M. , Southam Gordon , Wanger Greg , Pratt Lisa M. , Andersen Gary L. , Hazen Terry C. , Brockman Fred J. , Arkin Adam P. , Onstott Tullis C.
Published: October 2008

DNA from low-biodiversity fracture water collected at 2.8-kilometer depth in a South African gold mine was sequenced and assembled into a single, complete genome. This bacterium,
Candidatus Desulforudis audaxviator
, composes >99.9% of the microorganisms inhabiting the fluid phase of this particular fracture. Its genome indicates a motile, sporulating, sulfate-reducing, chemoautotrophic thermophile that can fix its own nitrogen and carbon by using machinery shared with archaea.
Candidatus Desulforudis audaxviator
is capable of an independent life-style well suited to long-term isolation from the photosphere deep within Earth's crust and offers an example of a natural ecosystem that appears to have its biological component entirely encoded within a single genome.
Carbon Nanotube Arrays with Strong Shear Binding-On and Easy Normal Lifting-Off
Authors: Qu Liangti , Dai Liming , Stone Morley , Xia Zhenhai , Wang Zhong Lin
Published: October 2008

The ability of gecko lizards to adhere to a vertical solid surface comes from their remarkable feet with aligned microscopic elastic hairs. By using carbon nanotube arrays that are dominated by a straight body segment but with curly entangled top, we have created gecko-foot–mimetic dry adhesives that show macroscopic adhesive forces of ∼100 newtons per square centimeter, almost 10 times that of a gecko foot, and a much stronger shear adhesion force than the normal adhesion force, to ensure strong binding along the shear direction and easy lifting in the normal direction. This anisotropic force distribution is due to the shear-induced alignments of the curly segments of the nanotubes. The mimetic adhesives can be alternatively binding-on and lifting-off over various substrates for simulating the walking of a living gecko.
Base Sequence and Higher-Order Structure Induce the Complex Excited-State Dynamics in DNA
Authors: Schwalb Nina K. , Temps Friedrich
Published: October 2008

The high photostability of DNA is commonly attributed to efficient radiationless electronic relaxation processes. We used femtosecond time-resolved fluorescence spectroscopy to reveal that the ensuing dynamics are strongly dependent on base sequence and are also affected by higher-order structure. Excited electronic state lifetimes in dG-doped d(A)
20
single-stranded DNA and dG·dC-doped d(A)
20
·d(T)
20
double-stranded DNA decrease sharply with the substitution of only a few bases. In duplexes containing d(AGA)·d(TCT) or d(AG)·d(TC) repeats, deactivation of the fluorescing states occurs on the subpicosecond time scale, but the excited-state lifetimes increase again in extended d(G) runs. The results point at more complex and molecule-specific photodynamics in native DNA than may be evident in simpler model systems.
Laboratory Simulation of Volcano Seismicity
Authors: Benson Philip M , Vinciguerra Sergio , Meredith Philip G , Young R Paul
Published: October 2008

The physical processes generating seismicity within volcanic edifices are highly complex and not fully understood. We report results from a laboratory experiment in which basalt from Mount Etna volcano (Italy) was deformed and fractured. The experiment was monitored with an array of transducers around the sample to permit full-waveform capture, location, and analysis of microseismic events. Rapid post-failure decompression of the water-filled pore volume and damage zone triggered many low-frequency events, analogous to volcanic long-period seismicity. The low frequencies were associated with pore fluid decompression and were located in the damage zone in the fractured sample; these events exhibited a weak component of shear (double-couple) slip, consistent with fluid-driven events occurring beneath active volcanoes.
Global Warming, Elevational Range Shifts, and Lowland Biotic Attrition in the Wet Tropics
Authors: Colwell Robert K. , Brehm Gunnar , Cardelús Catherine L. , Gilman Alex C. , Longino John T.
Published: October 2008

Many studies suggest that global warming is driving species ranges poleward and toward higher elevations at temperate latitudes, but evidence for range shifts is scarce for the tropics, where the shallow latitudinal temperature gradient makes upslope shifts more likely than poleward shifts. Based on new data for plants and insects on an elevational transect in Costa Rica, we assess the potential for lowland biotic attrition, range-shift gaps, and mountaintop extinctions under projected warming. We conclude that tropical lowland biotas may face a level of net lowland biotic attrition without parallel at higher latitudes (where range shifts may be compensated for by species from lower latitudes) and that a high proportion of tropical species soon faces gaps between current and projected elevational ranges.
Collective Behavior in an Early Cambrian Arthropod
Authors: Hou Xian-Guang , Siveter Derek J. , Aldridge Richard J. , Siveter David J.
Published: October 2008

Examples that indicate collective behavior in the fossil record are rare. A group association of specimens that belong to a previously unknown arthropod from the Chengjiang Lagerst�tte, China, provides evidence that such behavior was present in the early Cambrian (about 525 million years ago), coincident with the earliest extensive diversification of the Metazoa, the so-called Cambrian explosion event. The chainlike form of these specimens is unique for any arthropod, fossil or living, and most likely represents behavior associated with migration.
Noncytotoxic Lytic Granule–Mediated CD8
+
T Cell Inhibition of HSV-1 Reactivation from Neuronal Latency
Authors: Knickelbein Jared E. , Khanna Kamal M. , Yee Michael B. , Baty Catherine J. , Kinchington Paul R. , Hendricks Robert L.
Published: October 2008

Reactivation of herpes simplex virus type 1 (HSV-1) from neuronal latency is a common and potentially devastating cause of disease worldwide. CD8
+
T cells can completely inhibit HSV reactivation in mice, with interferon-γ affording a portion of this protection. We found that CD8
+
T cell lytic granules are also required for the maintenance of neuronal latency both in vivo and in ex vivo ganglia cultures and that their directed release to the junction with neurons in latently infected ganglia did not induce neuronal apoptosis. Here, we describe a nonlethal mechanism of viral inactivation in which the lytic granule component, granzyme B, degrades the HSV-1 immediate early protein, ICP4, which is essential for further viral gene expression.
Reaction-Driven Restructuring of Rh-Pd and Pt-Pd Core-Shell Nanoparticles
Authors: Tao Feng , Grass Michael E. , Zhang Yawen , Butcher Derek R. , Renzas James R. , Liu Zhi , Chung Jen Y. , Mun Bongjin S. , Salmeron Miquel , Somorjai Gabor A.
Published: October 2008

Heterogeneous catalysts that contain bimetallic nanoparticles may undergo segregation of the metals, driven by oxidizing and reducing environments. The structure and composition of core-shell Rh
0.5
Pd
0.5
and Pt
0.5
Pd
0.5
nanoparticle catalysts were studied in situ, during oxidizing, reducing, and catalytic reactions involving NO, O
2
, CO, and H
2
by x-ray photoelectron spectroscopy at near-ambient pressure. The Rh
0.5
Pd
0.5
nanoparticles underwent dramatic and reversible changes in composition and chemical state in response to oxidizing or reducing conditions. In contrast, no substantial segregation of Pd or Pt atoms was found in Pt
0.5
Pd
0.5
nanoparticles. The different behaviors in restructuring and chemical response of Rh
0.5
Pd
0.5
and Pt
0.5
Pd
0.5
nanoparticle catalysts under the same reaction conditions illustrates the flexibility and tunability of the structure of bimetallic nanoparticle catalysts during catalytic reactions.
Immunogenicity of Proteome-DeterminedMycobacterium aviumsubsp.paratuberculosis-Specific Proteins in Sheep with Paratuberculosis
Authors: Hughes Valerie , Bannantine John P. , Denham Susan , Smith Stuart , Garcia-Sanchez Alfredo , Sales Jill , Paustian Michael L. , Mclean Kevin , Stevenson Karen
Published: October 2008

Mycobacterium aviumsubsp.paratuberculosiscauses paratuberculosis, a chronic granulomatous enteritis. Detecting animals with paratuberculosis infections is difficult because the currently available tools have low sensitivity and lack specificity; these tools are prone to generating spurious positive test results caused by exposure to environmentalM. aviumcomplex organisms. To generate candidate antigens for incorporation into a specific test for paratuberculosis, subspecies-specific proteins were determined by proteomic comparison ofM. aviumsubsp.paratuberculosisandM. aviumsubsp.avium. Analysis was aimed at revealing proteins only expressed (or predominant) in the protein profile ofM. aviumsubspeciesparatuberculosis. Two-dimensional gel electrophoresis resolved approximately 1,000 protein spots from each subspecies. Proteome analysis identified protein spots whose expression profile appeared markedly increased inM. aviumsubsp.paratuberculosis, and 32 were identified by analysis of their tryptic peptide profile by matrix-assisted laser desorption ionization-time of flight analysis. Thirty of these proteins were cloned, and their recombinant proteins were expressed. Ovine paratuberculosis sera were used to assess their immunoreactivity by enzyme-linked immunosorbent assay (ELISA), Western blotting, and dot blot analysis. Seventeen proteins were detected in at least one of the immunoassays, and eleven proteins were detected by ELISA with an optical density in excess of the cutoff of 0.1 in four of six sera tested. The immunoreactivity of these proteins indicates their potential as unique diagnostic antigens for the development of a specific serological detection of paratuberculosis.
Performance Characteristics of the Platelia
Aspergillus
Enzyme Immunoassay for Detection of
Aspergillus
Galactomannan Antigen in Bronchoalveolar Lavage Fluid
Authors: Husain S. , Clancy C. J. , Nguyen M. H. , Swartzentruber S. , Leather H. , LeMonte A. M. , Durkin M. M. , Knox K. S. , Hage C. A. , Bentsen C. , Singh N. , Wingard J. R. , Wheat L. J.
Published: October 2008

We have evaluated the Platelia
Aspergillus
enzyme immunoassay for detection of galactomannan in bronchoalveolar lavage (BAL) specimens in solid organ transplant patients with aspergillosis. The precision and reproducibility in serum or BAL to which galactomannan was added were similar. Sensitivity was 81.8% in patients with aspergillosis, and specificity was 95.8% in lung transplant patients who underwent BAL for surveillance for infection or rejection. Among transplant controls, positive results were more common in patients (i) who underwent diagnostic BAL performed for evaluation of symptoms or chest computed tomographic abnormalities, (ii) who had undergone lung transplantation, or (iii) who were colonized with
Aspergillus
. Galactomannan testing in BAL is useful for diagnosis of aspergillosis in transplant patients. The significance of positive results in patients without confirmed aspergillosis requires further evaluation.
Evaluation of a Recombinant Hc of
Clostridium botulinum
Neurotoxin Serotype F as an Effective Subunit Vaccine
Authors: Yu Yun-Zhou , Li Na , Wang Rui-Lin , Zhu Heng-Qi , Wang Shuang , Yu Wei-Yuan , Sun Zhi-Wei
Published: October 2008

A new gene encoding the Hc domain of
Clostridium botulinum
neurotoxin serotype F (FHc) was designed and completely synthesized with oligonucleotides. A soluble recombinant Hc of
C. botulinum
neurotoxin serotype F was highly expressed in
Escherichia coli
with this synthetic FHc gene. Subsequently, the purified FHc was used to vaccinate mice and evaluate their survival against challenge with active botulinum neurotoxin serotype F (BoNT/F). After the administration of FHc protein mixed with Freund adjuvant via the subcutaneous route, a strong protective immune response was elicited in the vaccinated mice. Mice that were given two or three vaccinations with a dosage of 1 or 10 μg of FHc were completely protected against an intraperitoneal administration of 20,000 50% lethal doses (LD
50
) of BoNT/F. The BoNT/F neutralization assay showed that the sera from these vaccinated mice contained high titers of protective antibodies. Furthermore, mice were vaccinated once, twice, or three times at four different dosages of FHc using Alhydrogel (Sigma) adjuvant via the intramuscular route and subsequently challenged with 20,000 LD
50
of neurotoxin serotype F. A dose response was observed in both the antibody titer and the protective efficacy with increasing dosage of FHc and number of vaccinations. Mice that received one injection of 5 μg or two injections of ≥0.04 μg of FHc were completely protected. These findings suggest that the recombinant FHc expressed in
E. coli
is efficacious in protecting mice against challenge with BoNT/F and that the recombinant FHc subunit vaccine may be useful in humans.
Comparison of Three Enzyme-Linked Immunosorbent Assays for Detection of Immunoglobulin G Antibodies to Tetanus Toxoid with Reference Standards and the Impact on Clinical Practice
Authors: van Hoeven Karen H. , Dale Connie , Foster Phil , Body Barbara
Published: October 2008

Accurate determination of the concentrations of immunoglobulin G (IgG) antibody to tetanus toxoid is important in order to evaluate the immunogenicity of tetanus toxoid vaccines, determine immune competence in individual patients, and measure the prevalence of immunity in populations. The performance of three commercially available enzyme-linked immunosorbent assays (ELISAs) for IgG antibodies to tetanus toxoid were evaluated. Serially diluted NIBSC 76/589 and TE-3 human tetanus IgG immunoglobulin international reference standards were analyzed in quadruplicate using ELISAs manufactured by The Binding Site, Inc. (VaccZyme); Scimedx; and Euroimmun. In addition, IgG antibodies to tetanus toxoid were measured in 83 deidentified serum specimens using each manufacturer's ELISA. Each ELISA provided linear results when evaluated with the reference preparations. The Binding Site ELISA provided results that closely corresponded to the reference preparations (
y
= 1.09
x
− 0.08), whereas the Scimedx ELISA gave results that were consistently lower (
y
= 0.21
x
− 0.07) and the Euroimmun ELISA gave results that were consistently higher (
y
= 1.5
x
+ 0.30) than the reference preparation concentrations. Using the recommended cutoff for each ELISA (<0.10 IU/ml), the overall agreement of all of the ELISA methods was 78%. Three of eighty-three (3.6%) human serum samples demonstrated inadequate immunity with all three assays. The Binding Site ELISA yielded nonprotective antibody concentrations in only these 3 samples, whereas 19 samples (22.9%) according to the Scimedx ELISA and 6 samples (7.2%) according to the Euroimmun ELISA demonstrated nonprotective concentrations. The performance characteristics of ELISAs for tetanus immunoglobulin titers were manufacturer dependent, and the differences translated into important disparities in reported results.