bluuebunny/crossref_metadata_2025 huggingface dataset:
Do all epistaxis patients with a nasal pack need admission? A retrospective study of 116 patients managed in accident and emergency according to a peer reviewed protocol
Authors: Van Wyk F C , Massey S , Worley G , Brady S
Published: October 2006

Introduction: Epistaxis is the most common nasal emergency and if nasal packing is required this commonly results in admission.

Methods: A literature search could find no published (UK) protocols for the management of this common condition in accident and emergency (A&E) departments. This paper presents a retrospective review of 116 patients with epistaxis, following implementation of the new peer reviewed protocol in June 2004.

Results: Apart from cautery, 62 had nasal packing inserted. Only 17 required admission. Forty-six patients were discharged with nasal packing in situ and only seven (16 per cent) returned due to bleeding. The overall return rate was 11 per cent.

Discussion: We feel this is a safe and logical protocol. Compared to mandatory admission after nasal pack insertion, we saved 39 admissions in five months. There were also the added benefits to patients of being able to recuperate at home rather than in hospital and avoidance of the risk of hospital acquired infection.
The NcGRA7gene encodes the immunodominant 17 kDa antigen ofNeospora caninum
Authors: ÁLVAREZ-GARCÍA G. , PITARCH A. , ZABALLOS A. , FERNÁNDEZ-GARCÍA A. , GIL C. , GÓMEZ-BAUTISTA M. , AGUADO-MARTÍNEZ A. , ORTEGA-MORA L. M.
Published: October 2006

ANeospora caninum17–19 kDa antigenic protein fraction (p17) in one-dimensional polyacrylamide gel electrophoresis (SDS-PAGE) is the immunodominant antigen recognized by sera from bovines naturally infected byN. caninum. To identify the proteins making up the p17 fraction, we screened a newN. caninumtachyzoite cDNA library with an affinity-purified antibody against p17 (APA17). We isolated several cDNA clones with 100% sequence identity to the NcGRA7gene. This previously described gene encodes a dense granule protein with an apparent molecular mass of 33 kDa. A second line of evidence emerged through a combined proteomic approach associating two-dimensional PAGE (2D-PAGE) to Western blotting and to mass spectrometry to characterize the p17 fraction. Two acidic immunodominant but minority protein spots were recognized by APA17 and by bovine sera. These antigens of 17 and 33 kDa are respectively composed of 4 and 2 isoforms. Furthermore, p17 isolation by 2D-PAGE and peptide sequencing by tandem mass spectrometry yielded a partial sequence of 17 amino acids, which allowed the putative amino terminal region of the NcGRA7 protein to be identified unambiguously.The NcGRA7 protein, without the putative signal peptide at the NH2-terminus, was cloned and expressed inEscherichia coliand when the purified recombinant protein (rNcGRA7) was analysed by SDS-PAGE and mass spectrometry, 2 bands of 24 and 33 kDa were resolved and identified as NcGRA7. These results demonstrate that the immunodominant 17 kDa antigen ofN. caninumis encoded by the NcGRA7gene.
Evaluation of an indirect fluorescence immunoassay for the detection of serum antibodies againstBabesia divergensin humans
Authors: DUH D. , JELOVšEK M. , AVšIČ-ŽUPANC T.
Published: October 2006

Since an indirect fluorescence immunoassay (IFA) for the detection of specific antibodies againstBabesia divergensin human sera is not commercially available, an in-house preparedB. divergensIFA for the examination of bovine sera was established for serological studies in humans. To determine whether the described IFA is appropriate for such studies, 2B. divergensantigens (of human or bovine origin) were tested using serum samples obtained from febrile human patients with a history of ‘tick bite’. Sera from other species of animals infected withB. divergens,BabesiaEU1,B. microtiorB. caniswere also included for comparative purposes. All serum samples were also tested using a commercially available IFA for the detection of antibodies againstB. microti, and the results compared with those obtained using blood smear and molecular techniques. This study showed that the evaluation and standardization of aB. divergensIFA for testing human sera is critical and that differentB. divergensantigens provide different end-point titres of antibodies, leading to false negative or positive results. Serological cross-reactivity betweenB. divergensandBabesiaEU1 needs to be taken into account when interpreting IFA results.
Vector seasonality, host infection dynamics and fitness of pathogens transmitted by the tickIxodes scapularis
Authors: OGDEN N. H. , BIGRAS-POULIN M. , O'CALLAGHAN C. J. , BARKER I. K. , KURTENBACH K. , LINDSAY L. R. , CHARRON D. F.
Published: October 2006

Fitness of tick-borne pathogens may be determined by the degree to which their infection dynamics in vertebrate hosts permits transmission cycles if infective and uninfected tick stages are active at different times of the year. To investigate this hypothesis we developed a simulation model that integrates the transmission pattern imposed by seasonally asynchronous nymphal and larvalIxodes scapularisticks in northeastern North America, with a model of infection in white-footed mice (Peromyscus leucopus) reservoir hosts, using the bacteriaBorrelia burgdorferiandAnaplasma phagocytophilumas examples. In simulations, survival of microparasites, their sensitivity to reduced rodent and tick abundance, and to ‘dilution’ by a reservoir-incompetent host depended on traits that allowed (i) highly efficient transmission from acutely-infected hosts, (ii) long-lived acute or ‘carrier’ host infections, and/or (iii) transmission amongst co-feeding ticks. Minimum values for transmission efficiency to ticks, and duration of host infectivity, necessary for microparasite persistence, were always higher when nymphal and larval ticks were seasonally asynchronous than when these instars were synchronous. Thus, traits influencing duration of host infectivity, transmission efficiency to ticks and co-feeding transmission are likely to be dominant determinants of fitness inI. scapularis-borne microparasites in northeastern North America due to abiotic forcings influencingI. scapularisseasonality.
Marvels of the system. Art, perception and engagement with the environment in Minoan Crete
Authors: Herva Vesa-Pekka
Published: October 2006

This paper discusses the relationship between art, perception and human engagement with the environment in Minoan Crete through the depiction of landscapes and the ‘natural world’ in art. It is argued that the conventional approaches to Minoan ‘nature scenes’, based on the representation and expression theories of art, are overshadowed by modernist assumptions about art and human–environment relations. The paper then proceeds to discuss the workings of visual perception and the dynamics of human–environment systems. On that basis, the nature of human–environment relations in Minoan Crete is reconsidered and an ‘ecological’ approach to ancient art explored. A tentative suggestion is made that Minoan nature scenes might be understood as instruments for perceiving and knowing the environment, and some broader implications of the ecological perspective for the interpretation of the archaeological record of Minoan Crete are indicated.
On the nature of theoretical archaeology and archaeological theory
Authors: Johnson Matthew H.
Published: October 2006

In this paper I want to make some general comments on the state of archaeological theory today. I argue that a full answer to the question ‘does archaeological theory exist?’ must be simultaneously ‘yes’ and ‘no’. Yes, there is, demonstrably, a discourse called archaeological theory, with concrete structures such as individuals and schools of thought more or less substantively engaged with it; no, in that the claims for a distinctive way of thinking about the world in theoretical terms specific to archaeology, to which most or even the largest group of archaeologists would willingly or knowingly subscribe, are over-stated. In particular there is a lack of correspondence between theoretical backgrounds and affiliations that are overtly cited by archaeologists, on the one hand, and, on the other, the deeper underlying assumptions and traditions that structure their work and condition its acceptance. These underlying traditions stretch from field habits to underlying paradigms or discourses. I will explore this latter point with reference to the manner in which agency theory and phenomenology have been developed in archaeology. My conclusion suggests some elements of a way forward for archaeological theory; it is striking that many of these elements have been addressed in recent issues of Archaeological dialogues.
Archaeology, conflict and contemporary identity in the north of Ireland. Implications for theory and practice in comparative archaeologies of colonialism
Authors: Horning Audrey J.
Published: October 2006

Current trends in historical archaeology emphasize the centrality of capitalism and colonial discourse in examining commonalities in the archaeologies of fictive worlds such as the British Atlantic. Yet far from informing archaeological practice, overly simplistic incorporation of postcolonial and neo-Marxian approaches in comparative archaeologies can actually impede our ability to disentangle the complexities of the early modern colonial experience in a socially relevant fashion. While the disparate colonial settlements of the Atlantic share a recognizable material culture as physical testament to the overarching impact of European expansion, contemporary implications and memories of colonial entanglements vary wildly. A critical consideration of the role of overtly theoretical approaches in developing a nuanced archaeology of the early modern period in the north of Ireland, where the construction of present-day identities is firmly rooted in dichotomous understandings of the impact of British expansion in the 16th and 17th centuries, raises broader questions about our responsibilities in addressing conflict and in redressing the disjuncture between espousing and practising theoretically informed archaeology.
Enhancement of Cellulose Pellicle Production by Constitutively Expressing Vitreoscilla Hemoglobin in Acetobacter xylinum
Authors: Chien Liang‐Jung , Chen Hsiao‐Ting , Yang Pei‐Fen , Lee Cheng‐Kang
Published: October 2006

Vitreoscilla hemoglobin (VHb) gene driven by the constitutive bla promoter was expressed in the cellulose‐producing Acetobacter xylinum. The expressed VHb was biochemically active and could enhance cell growth in a shaken culture containing cellulase. VHb‐expressing A. xylinum (VHb+) exhibited a specific growth rate 50% higher than that of the host strain (VHb−). Probably because of its faster growth rate, the size of tentacled cellulose beads produced by VHb+ was about 20% of that produced by VHb− after 2 days cultivation in a shake‐flask. When cultured statically, the amount of cellulose pellicle produced by VHb+ could be 2‐fold that produced by VHb−. Cellulose pellicle concentration of 11 g/L was obtained for VHb+, whereas 6 g/L was obtained for VHb− after 6 days of microaerobic incubation.
Cloud‐to‐ground lightning and surface rainfall in warm‐season Florida thunderstorms
Authors: Gungle Bruce , Krider E. Philip
Published: October 2006

Relationships between cloud‐to‐ground (CG) lightning and surface rainfall have been examined in nine isolated, warm‐season thunderstorms on the east coast of central Florida. CG flashes and the associated rain volumes were measured as a function of time in storm‐centered reference frames that followed each storm over a network of rain gauges. Values of the storm‐average rain volume per CG flash ranged from 0.70 × 104 to 6.4 × 104 m3/CG flash, with a mean (and standard deviation) of 2.6 × 104 ± 2.1 × 104 m3/CG flash. Values of the rain volume concurrent with CG flashes ranged from 0.11 × 104 to 4.9 × 104 m3/CG flash with a mean of 2.1 × 104 ± 2.0 × 104 m3/CG flash. The lag‐time between the peak CG flash rate and the peak rainfall rate (using 5 min bins), and the results of a lag correlation analysis, show that surface rainfall tends to follow the lightning (positive lag) by up to 20 min in six storms. In one storm the rainfall preceded the lightning by 5 min, and two storms had nonsignificant lags. Values of the lagged rain volume concurrent with CG flashes ranged from 0.43 × 104 to 4.9 × 104 m3/CG flash, and the mean was 1.9 × 104 ± 1.7 × 104 m3/CG flash. For the five storms that produced 12 or more flashes and had significant lags, a plot of the optimum lag time versus the total number of CG flashes shows a linear trend (R2 = 0.56). The number of storms is limited, but the lag results do indicate that large storms tend to have longer lags. A linear fit to the lagged rain volume vs. the number of concurrent CG flashes has a slope of 1.9 × 104 m3/CG flash (R2 = 0.83). We conclude that warm‐season Florida thunderstorms produce a roughly constant rain volume per CG flash and that CG lightning can be used to estimate the location and intensity of convective rainfall in that weather regime.
Size sorting in marine muds: Processes, pitfalls, and prospects for paleoflow‐speed proxies
Authors: McCave I. N. , Hall I. R.
Published: October 2006

The basis for, and use of, fine grain size parameters for inference of paleoflow speeds is reviewed here. The basis resides in data on deposited sediment taken in conjunction with flow speed measurements in the field, experimental data on suspended sediment transport and deposition, and theoretical treatments of the generation of size distributions of deposits from suspension controlled by particle settling velocity and flow speed. In the deep sea, sorting events occur under resuspension/deposition events in benthic storms. At flow speeds below 10–15 cm s−1, size in the noncohesive “sortable silt” (10–63μm) range is controlled by selective deposition, whereas above that range, removal of finer material by winnowing also plays a role. The best particle size instruments to measure a flow speed–related grain size employ the settling velocity method, while laser diffraction sizers can yield misleading results because of particle shape effects. Potential problems, including source effects, downslope supply on continental margins, spatial variability of flow over bedforms, and influence of ice‐rafted detritus, are examined. A number of studies using the sortable silt flow speed proxy are reviewed, and inverse modeling of grain size distributions is examined. Outstanding problems are that corroboration is sparse because almost no studies have yet used the full range of proxies for flow rate and water mass identification and that the sortable silt mean size is not yet properly calibrated in terms of flow speed.
Remote sensing of a magnetotail reconnection X‐line using polar rain electrons
Authors: Alexeev I. V. , Sergeev V. , Owen C. J. , Fazakerley A. , Lucek E. , Réme H.
Published: October 2006

We report on electron phase space distributions (PSDs) observed near the plasma sheet (PS) boundary layer (PSBL) by the Cluster electron spectrometers when the northern lobe was occupied by significant fluxes of polar rain (PR) electrons. These observations reveal the spatial structure of the electron transition layer (TL) between the polar rain electrons and the PSBL electron population accelerated during reconnection. This TL comprises overlapping spatial dispersion signatures in both energy and pitch angle, which are caused by convection of flux tubes across the magnetic separatrix during the electron time‐of‐flight (TOF) from the X‐line combined with acceleration in the reconnection region. Analysis of this structure allows us to estimate the location of the X‐line. By assuming the PSBL population arises through acceleration of the PR electrons, comparison of their PSD indicates that the electrons gain energy proportional to their initial energy.
Coronal mass ejections and magnetic flux buildup in the heliosphere
Authors: Owens M. J. , Crooker N. U.
Published: October 2006

To test for magnetic flux buildup in the heliosphere from coronal mass ejections (CMEs), we simulate heliospheric flux as a constant background open flux with a time‐varying interplanetary CME (ICME) contribution. As flux carried by ejecta can only contribute to the heliospheric flux budget while it remains closed, the ICME flux opening rate is an important factor. Two separate forms for the ICME flux opening rate are considered: (1) constant and (2) exponentially decaying with time. Coronagraph observations are used to determine the CME occurrence rates, while in situ observations are used to estimate the magnetic flux content of a typical ICME. Both static equilibrium and dynamic simulations, using the constant and exponential ICME flux opening models, require flux opening timescales of ∼50 days in order to match the observed doubling in the magnetic field intensity at 1 AU over the solar cycle. Such timescales are equivalent to a change in the ICME closed flux of only ∼7–12% between 1 and 5 AU, consistent with CSE signatures; no flux buildup results. The dynamic simulation yields a solar cycle flux variation with high variability that matches the overall variability of the observed magnetic field intensity remarkably well, including the double peak forming the Gnevyshev gap.
Development of a ground level enhancement alarm system based upon neutron monitors
Authors: Kuwabara T. , Bieber J. W. , Clem J. , Evenson P. , Pyle R.
Published: October 2006

We have developed a system that watches for count rate increases recorded in real time by eight neutron monitors, which triggers an alarm if a ground level enhancement (GLE) is detected. In this work, we determine optimal strategies for detecting the GLE event at a very early stage, while still keeping the false alarm rate at a very low level. We study past events to optimize appropriate intensity threshold values and a baseline to determine the intensity increase. The highest‐level alarm, which we term an “alert,” is generated when a 4% increase is recorded at three stations in 3 min averaged data. At this level, the false alarm rate obtained by backtesting over the past 4.4 years is zero. Ten GLEs occurred in this period, and our system produced GLE alarms for nine events. Alarm times for these nine events are compared with satellite proton data. The GLE alert precedes the earliest alert from GOES (100 MeV or 10 MeV protons) by ∼10–30 min. Real‐time GLE data may be viewed at http://neutronm.bartol.udel.edu/spaceweather. An automated e‐mail alert system is under development.
Sustained Neuronal Activation Raises Oxidative Metabolism to a New Steady-State Level: Evidence from 1H NMR Spectroscopy in the Human Visual Cortex
Authors: Mangia Silvia , Tkáč Ivan , Gruetter Rolf , Van de Moortele Pierre-Francois , Maraviglia Bruno , Uğurbil Kâmil
Published: October 2006

To date, functional 1H NMR spectroscopy has been utilized to report the time courses of few metabolites, primarily lactate. Benefiting from the sensitivity offered by ultra-high magnetic field (7 T), the concentrations of 17 metabolites were measured in the human visual cortex during two paradigms of visual stimulation lasting 5.3 and 10.6 mins. Significant concentration changes of approximately 0.2 μmol/g were observed for several metabolites: lactate increased by 23% ± 5% ( P < 0.0005), glutamate increased by 3% ± 1% ( P < 0.01), whereas aspartate decreased by 15% ± 6% ( P < 0.05). Glucose concentration also manifested a tendency to decrease during activation periods. The lactate concentration reached the new steady-state level within the first minute of activation and came back to baseline only after the stimulus ended. The changes of the concentration of metabolites implied a rise in oxidative metabolism to a new steady-state level during activation and indicated that amino-acid homeostasis is affected by physiological stimulation, likely because of an increased flux through the malate—aspartate shuttle.
Inflammation after Intracerebral Hemorrhage
Authors: Wang Jian , Doré Sylvain
Published: October 2006

Intracerebral hemorrhage (ICH) is a devastating clinical event without effective therapies. Increasing evidence suggests that inflammatory mechanisms are involved in the progression of ICH-induced brain injury. Inflammation is mediated by cellular components, such as leukocytes and microglia, and molecular components, including prostaglandins, chemokines, cytokines, extracellular proteases, and reactive oxygen species. Better understanding of the role of the ICH-induced inflammatory response and its potential for modulation might have profound implications for patient treatment. In this review, a summary of the available literature on the inflammatory responses after ICH is presented along with discussion of some of the emerging opportunities for potential therapeutic strategies. In the near future, additional strategies that target inflammation could offer exciting new promise in the therapeutic approach to ICH.
Magnetic Resonance Imaging Evidence of Cytotoxic Cerebral Edema in Acute Mountain Sickness
Authors: Kallenberg Kai , Bailey Damian M , Christ Stefan , Mohr Alexander , Roukens Robin , Menold Elmar , Steiner Thorsten , Bärtsch Peter , Knauth Michael
Published: October 2006

The present study applied T2- and diffusion-weighted magnetic resonance imaging to examine if mild cerebral edema and subsequent brain swelling are implicated in the pathophysiology of acute mountain sickness (AMS). Twenty-two subjects were examined in normoxia (21% O2), after 16 hours passive exposure to normobaric hypoxia (12% O2) corresponding to a simulated altitude of 4,500 m and after 6 hours recovery in normoxia. Clinical AMS was diagnosed in 50% of subjects during hypoxia and corresponding headache scores were markedly elevated ( P < 0.05 versus non-AMS). Hypoxia was associated with a mild increase in brain volume (+ 7.0 ± 4.8 ml, P < 0.05 versus preexposure baseline) that resolved during normoxic recovery. Hypoxia was also associated with an increased T2 relaxation time (T2rt) and a general trend toward an increased apparent diffusion coefficient (ADC). During the normoxic recovery, brain volume and T2rt recovered to pre-exposure baseline values, whereas a more marked reduction in ADC in the splenium of the corpus callosum (SCC) was observed ( P < 0.05). While changes in brain volume and T2rt were not selectively different in AMS, ADC values were consistently lower ( P < 0.05 versus non-AMS) and associated with the severity of neurologic symptoms. Acute mountain sickness was also characterized by an increased brain to intracranial volume ratio ( P < 0.05 versus non-AMS). These findings indicate that mild extracellular vasogenic edema contributes to the generalized brain swelling observed at high altitude, independent of AMS. In contrast, intracellular cytotoxic edema combined with an anatomic predisposition to a ‘tight-fit’ brain may prove of pathophysiologic significance, although the increase in brain volume in hypoxia was only about 0.5% of total brain volume.
Myelin—Associated Inhibitory Signaling and Strategies to Overcome Inhibition
Authors: Chaudhry Nagarathnamma , Filbin Marie T
Published: October 2006

Numerous studies in the last two decades have resulted in significant progress in our understanding of the role of inhibitors on axonal regeneration and conditions that influence mature neurons to regrow in an inhibitory environment. These studies have revealed putative therapeutic targets and strategies to interfere in the inhibitory signaling cascade and promote axonal regeneration. Some agents that were successful in animal models are now being tested in human patients. All of these advances have raised hope of a cure for an injury that was once thought to be ʻan ailment for which nothing is done' (Quote from Edwin Smith surgical papyrus, 1600BC).
Identification and Ablation of Three Types of Ventricular Tachycardia Involving the His‐Purkinje System in Patients with Heart Disease
Authors: LOPERA GUSTAVO , STEVENSON WILLIAM G. , SOEJIMA KYOKO , MAISEL WILLIAM H. , KOPLAN BRUCE , SAPP JOHN L. , SATTI S. DINAKAR , EPSTEIN LAURENCE M.
Published: October 2006

Introduction: Ventricular tachycardia (VT) with involvement of the His‐Purkinje system (HPS) can be difficult to recognize in patients with heart disease, but it may be particularly susceptible to ablation targeting the HPS. This study defines the incidence and types of HPS involvement in VT.

Methods and Results: Involvement of the HPS was sought during electrophysiologic study with catheter mapping in 234 consecutive patients referred for catheter ablation of recurrent VT associated with heart disease. HPS VT was observed in 20 (8.5%) patients (mean ejection fraction 29%± 17%); in 9 (11%) of 81 patients with nonischemic heart disease and 11 (7.1%) of 153 patients with coronary artery disease (P = NS). Three types of HPS VT were observed: 16 patients (group 1) had typical bundle branch reentry, 2 patients (group 2) had bundle branch reentry and interfascicular reentry, and 2 patients (group 3) had VT consistent with a focal origin in the distal HPS. In all three groups, the VT QRS had morphologic similarity to the sinus rhythm QRS. Ablation of HPS VT was successful in all patients in whom it was attempted but produced high‐degree AV block in 6 (30%). In 12 patients (60%), other VTs due to reentry through scar also were inducible.

Conclusion: Involvement of the HPS in VT associated with heart disease has three distinct clinical forms, all of which are susceptible to ablation. Ablation often is not sufficient as the sole therapy due to other induced VT's and conduction abnormalities, requiring pacemaker and/or defibrillator implantation. (J Cardiovasc Electrophysiol, Vol. 15, pp. 52‐58, January 2004)
Shock‐Induced Epicardial and Endocardial Virtual Electrodes Leading to Ventricular Fibrillation via Reentry, Graded Responses, and Transmural Activation
Authors: EVANS FREDERICK G. , GRAY RICHARD A.
Published: October 2006

Introduction: The mechanism of ventricular fibrillation (VF) induction by T wave shocks has been attributed to reentry, propagated graded responses (PGR), and triggered activity. The limitation of recording transmembrane potential (Vm) from only a single surface has hampered efforts to elucidate the relative role of these phenomena and their relationship to shock‐induced virtual electrodes.

Methods and Results:
Vm patterns from epicardial and endocardial surfaces of isolated sheep right ventricles were recorded with two CCD cameras for monophasic (M) and biphasic (B) shocks delivered at various coupling intervals (CI) from a unipolar mesh electrode on the epicardium. VF was induced via (1) the formation of reentry following make or break excitation; (2) propagated graded responses during apparent isoelectric window; and (3) breakthrough activation patterns coincident with endocardial‐to‐epicardial gradients in Vm. M shocks depolarized both surfaces at long CIs and polarized epicardial and endocardial surfaces oppositely at short CIs. At intermediate CIs, postshock Vm patterns could lead to reentry on one surface or endocardial‐to‐epicardial gradients resulting in breakthrough. B induced VF less than M for short and intermediate CIs due to more homogeneous end‐shock Vm patterns. However, at long CIs these homogeneous patterns resulted in more VF induction because B left the tissue closer to the Vm threshold for propagation.

Conclusion: Postshock activity occurred either immediately via epicardial or endocardial reentry, or after a delay caused by transmural propagation or propagated graded responses. These findings could explain the isoelectric window and focal activation patterns observed on the epicardium following VF induction shocks. (J Cardiovasc Electrophysiol, Vol. 15, pp. 79‐87, January 2004)
Phenotypic Characterization of a Large European Family with Brugada Syndrome Displaying a Sudden Unexpected Death Syndrome Mutation in SCN5A:
Authors: HONG KUI , BERRUEZO‐SANCHEZ ANTONIO , POUNGVARIN NARAVAT , OLIVA ANTONIO , VATTA MATTEO , BRUGADA JOSEP , BRUGADA PEDRO , TOWBIN JEFFREY A. , DUMAINE ROBERT , PIÑERO‐GALVEZ CARLOS , ANTZELEVITCH CHARLES , BRUGADA RAMON
Published: October 2006

Introduction: Brugada syndrome is characterized by sudden death secondary to malignant arrhythmias and the presence of ST segment elevation in leads V1 to V3 of patients with structurally normal hearts. This ECG pattern often is concealed but can be unmasked using potent sodium channel blockers. Like congenital long QT syndrome type 3 (LQT3) and sudden unexpected death syndrome, Brugada syndrome has been linked to mutations in SCN5A.

Methods and Results: We screened a large European family with Brugada syndrome. Three members (two female) had suffered malignant ventricular arrhythmias. Ten members showed an ECG pattern characteristic of Brugada syndrome at baseline, and eight showed the pattern only after administration of ajmaline (total 12 female). Haplotype analysis revealed that all individuals with positive ECG at baseline shared the SCN5A locus. Sequencing of SCN5A identified a missense mutation, R367H, previously associated with sudden unexpected death syndrome. Two of the eight individuals who displayed a positive ECG after the administration of ajmaline, but not before, did not have the R367H mutation, and sequencing analysis failed to identify any other mutation in SCN5A. The R367H mutation failed to generate any current when heterologously expressed in HEK cells.

Conclusion: Our results support the hypothesis that (1) sudden unexpected death syndrome and Brugada syndrome are the same disease; (2) male predominance of the phenotype observed in sudden unexpected death syndrome does not apply to this family, suggesting that factors other than the specific mutation determine the gender distinction; and (3) ajmaline may provide false‐positive results. These findings have broad implications relative to the diagnosis and risk stratification of family members of patients with the Brugada syndrome. (J Cardiovasc Electrophysiol, Vol. 15, pp. 64‐69, January 2004)
Phase Transitions and Topological Defects in the Early Universe
Authors: Kibble T. W. B.
Published: October 2006

Our present theories of particle physics and cosmology, taken together,
suggest that very early in its history, the universe underwent a series of
phase transitions, at which topological defects, similar to those formed in
some condensed matter transitions, may have been created. Such defects, in
particular cosmic strings, may survive long enough to have important
observable effects in the universe today. Predicting these effects requires us
to estimate the initial defect density and the way that defects subsequently
evolve. Very similar problems arise in condensed matter systems, and recently
it has been possible to test some of our ideas about the formation of defects
using experiments with liquid helium-3 (in collaboration with the Low
Temperature Laboratory in Helsinki). I shall review the present status of this
theory.
Construction of Real Space{Time from Complex Linear Metric Connections
Authors: Smrz P. K.
Published: October 2006

A construction of real space-time based on metric linear connections in a
complex manifold is described. The construction works only in two or four
dimensions. The four-dimensional case based on a connection reducible to group
U(2, 2) can generate Riemann-Cartan geometry on the real
submanifold of the original complex manifold. The possibility of connecting
the appearance of Dirac fields with anholonomic complex frames is discussed.
Physical Processes determining the Antarctic Sea Ice Environment
Authors: Allison Ian
Published: October 2006

The Antarctic sea ice zone undergoes one of the greatest seasonal surface
changes on Earth, with an annual change in extent of around 15 × 10
6 km 2 . This ice, and its
associated snow cover, plays a number of important roles in the
ocean-atmosphere climate system: the high albedo ice cover restricts surface
absorption of solar radiation and acts as a barrier to the exchange of mass
and energy between the ocean and atmosphere, and salt rejected by the growing
ice cover affects the ocean structure and circulation. Additionally, a number
of sea ice feedback processes have the potential to play an important role in
climate change.
The extent to which a sea ice cover modifies ocean-atmosphere interaction is
primarily determined by the thickness and concentration of the ice, but these
themselves are determined by ocean and atmospheric interaction. The thickness
distribution of the pack is determined by both thermodynamic and dynamic
processes: most important at the geophysical scale are the dynamic processes
of ice drift and deformation, and of lead formation. Compared to the ice cover
in the central Arctic Basin, the Antarctic sea ice is highly mobile. Drifting
buoy studies show that the Antarctic pack can move at speeds of up to 60 km
per day or greater, and that around most of the Antarctic coast, the drift of
the pack ice is generally divergent, with divergence rates of 10% or
more per day being observed under some circumstances. Consequently there is
generally some open water within the Antarctic pack and much of the total ice
mass forms by rapid growth within these areas. This influences the crystal
structure of the ice and results in a considerable portion of the Antarctic
pack (up to 25% in spring-time) having a thickness of less than 0
· 3 m. In general much of the Antarctic sea ice only grows
thermodynamically to about 0·5 m thick, with thickness increases beyond
that resulting from the deformational processes of rafting and ridge-building.
Running over rough terrain reveals limb control for intrinsic stability
Authors: Daley Monica A. , Biewener Andrew A.
Published: October 2006

Legged animals routinely negotiate rough, unpredictable terrain with agility and stability that outmatches any human-built machine. Yet, we know surprisingly little about how animals accomplish this. Current knowledge is largely limited to studies of steady movement. These studies have revealed fundamental mechanisms used by terrestrial animals for steady locomotion. However, it is unclear whether these models provide an appropriate framework for the neuromuscular and mechanical strategies used to achieve dynamic stability over rough terrain. Perturbation experiments shed light on this issue, revealing the interplay between mechanics and neuromuscular control. We measured limb mechanics of helmeted guinea fowl (
Numida meleagris
) running over an unexpected drop in terrain, comparing their response to predictions of the mass–spring running model. Adjustment of limb contact angle explains 80% of the variation in stance-phase limb loading following the perturbation. Surprisingly, although limb stiffness varies dramatically, it does not influence the response. This result agrees with a mass–spring model, although it differs from previous findings on humans running over surfaces of varying compliance. However, guinea fowl sometimes deviate from mass–spring dynamics through posture-dependent work performance of the limb, leading to substantial energy absorption following the perturbation. This posture-dependent actuation allows the animal to absorb energy and maintain desired velocity on a sudden substrate drop. Thus, posture-dependent work performance of the limb provides inherent velocity control over rough terrain. These findings highlight how simple mechanical models extend to unsteady conditions, providing fundamental insights into neuromuscular control of movement and the design of dynamically stable legged robots and prosthetic devices.
Neural correlates of epigenesis
Authors: Canli Turhan , Qiu Maolin , Omura Kazufumi , Congdon Eliza , Haas Brian W. , Amin Zenab , Herrmann Martin J. , Constable R. Todd , Lesch Klaus Peter
Published: October 2006

The effect of life stress on depression is moderated by a repeat length variation in the transcriptional control region of the serotonin transporter gene, which renders carriers of the short variant vulnerable for depression. We investigated the underlying neural mechanisms of these epigenetic processes in individuals with no history of psychopathology by using multimodal magnetic resonance-based imaging (functional, perfusion, and structural), genotyping, and self-reported life stress and rumination. Based on functional MRI and perfusion data, we found support for a model by which life stress interacts with the effect of serotonin transporter genotype on amygdala and hippocampal resting activation, two regions involved in depression and stress. Life stress also differentially affected, as a function of serotonin transporter genotype, functional connectivity of the amygdala and hippocampus with a wide network of other regions, as well as gray matter structural features, and affected individuals' level of rumination. These interactions may constitute a neural mechanism for epigenetic vulnerability toward, or protection against, depression.
Study of ligand substituent effects on the rate and stereoselectivity of lactide polymerization using aluminum salen-type initiators
Authors: Hormnirun Pimpa , Marshall Edward L. , Gibson Vernon C. , Pugh Robert I. , White Andrew J. P.
Published: October 2006

A series of aluminum salen-type complexes [where salen is
N
,
N
′-bis(salicylaldimine)-1,2-ethylenediamine] bearing ligands that differ in their steric and electronic properties have been synthesized and investigated for the polymerization of
rac
-lactide. X-ray crystal structures on key precatalysts reveal metal coordination geometries intermediate between trigonal bipyramidal and square-based pyramidal. Both the phenoxy substituents and the backbone linker have a significant influence over the polymerization. Electron-withdrawing groups attached to the phenoxy donor generally gave an increased polymerization rate, whereas large
ortho
substituents generally slowed down the polymerization. The vast majority of the initiators afforded polylactide with an isotactic bias; only one exhibited a bias toward heteroselectivity. Isoselectivity generally increases with increased flexibility of the backbone linker, which is presumed to be better able to accommodate any potential steric clashes between the propagating polymer chain, the inserting monomer unit, and the substituents on the phenoxy donor.
Early-phase transmission of
Yersinia pestis
by unblocked fleas as a mechanism explaining rapidly spreading plague epizootics
Authors: Eisen Rebecca J. , Bearden Scott W. , Wilder Aryn P. , Montenieri John A. , Antolin Michael F. , Gage Kenneth L.
Published: October 2006

Plague is a highly virulent disease believed to have killed millions during three historic human pandemics. Worldwide, it remains a threat to humans and is a potential agent of bioterrorism. Dissemination of
Yersinia pestis
, the etiological agent of plague, by blocked fleas has been the accepted paradigm for flea-borne transmission. However, this mechanism, which requires a lengthy extrinsic incubation period before a short infectious window often followed by death of the flea, cannot sufficiently explain the rapid rate of spread that typifies plague epidemics and epizootics. Inconsistencies between the expected rate of spread by blocked rat fleas and that observed during the Black Death has even caused speculation that plague was not the cause of this medieval pandemic. We used the primary vector to humans in North America,
Oropsylla montana
, which rarely becomes blocked, as a model for studying alternative flea-borne transmission mechanisms. Our data revealed that, in contrast to the classical blocked flea model,
O. montana
is immediately infectious, transmits efficiently for at least 4 d postinfection (early phase) and may remain infectious for a long time because the fleas do not suffer block-induced mortality. These factors match the criteria required to drive plague epizootics as defined by recently published mathematical models. The scenario of efficient early-phase transmission by unblocked fleas described in our study calls for a paradigm shift in concepts of how
Y. pestis
is transmitted during rapidly spreading epizootics and epidemics, including, perhaps, the Black Death.
Identifying cis-regulatory modules by combining comparative and compositional analysis of DNA
Authors: Pierstorff Nora , Bergman Casey M. , Wiehe Thomas
Published: October 2006

Motivation: Predicting cis-regulatory modules (CRMs) in higher eukaryotes is a challenging computational task. Commonly used methods to predict CRMs based on the signal of transcription factor binding sites (TFBS) are limited by prior information about transcription factor specificity. More general methods that bypass the reliance on TFBS models are needed for comprehensive CRM prediction.

Results: We have developed a method to predict CRMs called CisPlusFinder that identifies high density regions of perfect local ungapped sequences (PLUSs) based on multiple species conservation. By assuming that PLUSs contain core TFBS motifs that are locally overrepresented, the method attempts to capture the expected features of CRM structure and evolution. Applied to a benchmark dataset of CRMs involved in early Drosophila development, CisPlusFinder predicts more annotated CRMs than all other methods tested. Using the REDfly database, we find that some ‘false positive’ predictions in the benchmark dataset correspond to recently annotated CRMs. Our work demonstrates that CRM prediction methods that combine comparative genomic data with statistical properties of DNA may achieve reasonable performance when applied genome-wide in the absence of an a priori set of known TFBS motifs.

Availability: The program CisPlusFinder can be downloaded at . All software is licensed under the Lesser GNU Public License (LGPL).

Contact:  nora.pierstorff@uni-koeln.de.

Supplementary information: Supplementary data are available at Bioinformatics online.
The diversity of microbes: resurgence of the phenotype
Authors: Fenchel Tom , Finlay Bland J
Published: October 2006

The introduction of molecular genetic methods has caused confusion about the nature of microbial species. Environmental DNA extraction has indicated the existence of a vast diversity of genotypes, but how this relates to functional and phenotypic diversity has not been sufficiently explored. It has been implied that genetic distanceper secorrelates with phenotypic differentiation and thus reflects subtle (but undiscovered) adaptive fine-tuning to the environment, and that microbes may show biogeographic patterns at the genetic level. Here, we argue that no theoretically based species concept exists; species represent only the basic unit in the taxonomic hierarchy. The significance of naming species is that it organizes biological information. The reason why microbial species collectively represent large genetic differences is owing to huge absolute population sizes, absence of allopatric speciation and low extinction rates. Microbial phenotypes are, therefore, ancient in terms of the geological time-scale and have been maintained through stabilizing selection. These problems are discussed with special reference to eukaryotic micro-organisms.
Malingering, Perceptions of Illness, and Compensation Seeking in Whiplash Injury: A Comparison of Illness Beliefs Between Individuals in Simulated Compensation Scenarios and Litigation Claimants1
Authors: Linnell Maggie , Easton Simon
Published: October 2006

This paper compares beliefs about whiplash injury between individuals in simulated compensation/no compensation scenarios and actual litigant claimants. Comparisons between simulators and the clinical sample revealed that chronic patients reported significantly more symptoms than all simulator groups. The beliefs of the real compensation claimants in the acute phase of the condition were similar to those in the ‘injury only’ simulator group. The analyses identified a trend towards beliefs in the expected timeline of the illness becoming more negative with time, whilst feelings of control over the symptoms improve. The paper discusses indicators of malingering behavior and the possible involvement of litigation and treatment processes in the transition to a chronic state of ill health.
Majority Support for Minority Out‐Groups: The Roles of Compassion and Guilt
Authors: Karaçanta Aydin , Fitness Julie
Published: October 2006

The purpose of this study was to examine the effects of compassion and guilt on support for and avoidance of an out‐group program. Participants were 98 heterosexuals who were given 3 different sets of perspective‐taking instructions: other‐focused, self‐focused, and detachment. Next, they watched a video of a bogus interview with a gay university student who described being physically assaulted because of his sexuality. It was hypothesized that other‐focused instructions would elicit stronger support for a gay and lesbian anti‐violence program than the other 2 conditions. This hypothesis was supported for willingness to volunteer for the program, but not for funds allocated to the program. Self‐focused instructions were associated with program avoidance. Implications of the results are discussed.
Rape Rumors: The Effects of Reporting or Denying Rumors of Sexual Assaults on Campus1
Authors: Fried Carrie B. , Maxwell Amiee
Published: October 2006

Two studies examine the effects of reporting rumors of sexual assaults on a college campus. Participants read headlines and short articles about an unfamiliar college. Key headlines and articles reported an increase in sexual assaults as a fact, a rumor, a denied rumor, or a proven falsehood. Participants then rated perceptions of the college, including opinions on the level of crime and safety on campus. Results showed that both reporting the crimes as rumors and reporting denials of the rumors increased concerns compared to control conditions, but these concerns were lower than the concerns raised by reporting the assaults as fact. Findings are in line with predictions and match previous research on rumors and the impact of reported innuendo.
Postnatal changes in the expression of genes located in the callipyge region in sheep skeletal muscle
Authors: Perkins A. C. , Kramer L. N. , Spurlock D. M. , Hadfield T. S. , Cockett N. E. , Bidwell C. A.
Published: October 2006

The expression of five genes surrounding the callipyge (CLPG) mutation was analysed in skeletal muscles from lambs at one prenatal and two postnatal ages that coincide with the onset and establishment of muscle hypertrophy. Genotype‐specific changes in transcript abundance were detected for paternal allele‐specific DLK1 and PEG11 (the official symbol of the latter is RTL1) and the maternal allele‐specific MEG3, PEG11AS and MEG8 when the mutation was inherited in cis. There were differences in the temporal and muscle‐specific effects on expression between the maternal allele‐specific genes and paternal allele‐specific genes. Maternal inheritance of the CLPG allele had a significant effect on the expression of MEG3 and MEG8 at prenatal and postnatal ages, whereas paternal inheritance of DLK1 and PEG11 only affected postnatal expression. Genotype‐specific changes in PEG11AS expression were detected only in prenatal muscle. Maternal inheritance of the mutation caused similar changes in MEG3 and MEG8 expression in the semimembranosus, which undergoes hypertrophy, and the supraspinatus, which does not hypertrophy. Paternal inheritance of the mutation caused changes in PEG11 expression in both muscles, although the magnitude of expression in semimembranosus was more than 100‐fold greater than in supraspinatus. DLK1 expression was upregulated in callipyge animals at both postnatal ages in the semimembranosus, but there was no effect of genotype on DLK1 expression in the supraspinatus at any age. Increased DLK1 expression was likely the primary cause of muscle hypertrophy, but a contribution of PEG11 to the phenotype cannot be ruled out based on gene expression.