bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for Global Motion Interactions between First-Order and Second-Order Stimuli
Authors: Mather George , Murdoch Linda
Published: January 2007

Recent research indicates that the early stages of visual-motion analysis involve two parallel neural pathways, one conveying information from luminance-defined (first-order) image features, the other conveying information from texture-defined (second-order) features. It is still not clear whether these two pathways converge during later stages of global motion integration. According to one account they remain segregated, and feed separate global analyses. In the alternative account, all responses feed a common stage of global analysis. Two perceptual phenomena are universally held to result from interactions between detector responses during global motion integration—direction repulsion and motion capture. We conducted two psychophysical experiments on these phenomena to test for segregation of first-order and second-order responses during integration. Stimuli contained two components, either two random-block patterns transparently drifting in different directions (repulsion measurements), or a drifting square-wave grating superimposed on an incoherent random-block pattern (capture measurements). Repulsion and capture effects were measured when both stimulus components were the same order, and when one component was first order and the other was second order. Both effects were obtained for all combinations of first-order and second-order patterns. Repulsion effects were stronger with first-order inducing patterns, and capture effects were stronger with second-order inducers. The presence of perceptual interactions regardless of stimulus order strongly suggests that responses in first-order and second-order pathways interact during global motion analysis.
Surface Discontinuity is Critical in a Moving Observer's Perception of Objects’ Depth Order and Relative Motion from Retinal Image Motion
Authors: Kitazaki Michiteru , Shimojo Shinsuke
Published: January 2007

The visual system perceptually decomposes retinal image motion into three basic components that are ecologically significant for the human observer: object depth, object motion, and self motion. Using this conceptual framework, we explored the relationship between them by examining perception of objects’ depth order and relative motion during self motion. We found that the visual system obeyed what we call the parallax-sign constraint, but in different ways depending on whether the retinal image motion contained velocity discontinuity or not. When velocity discontinuity existed (eg in dynamic occlusion, transparent motion), the subject perceptually interpreted image motion as relative motion between surfaces with stable depth order. When velocity discontinuity did not exist, he/she perceived depth-order reversal but no relative motion. The results suggest that the existence of surface discontinuity or of multiple surfaces indexed by velocity discontinuity inhibits the reversal of global depth order.
The Interaction of Binocular Disparity and Motion Parallax in Determining Perceived Depth and Perceived Size
Authors: Bradshaw Mark F , Parton Andrew D , Eagle Richard A
Published: January 2007

Although binocular disparity and motion parallax are powerful cues for depth, neither, in isolation, can specify information about both object size and depth. It has been shown that information from both cues can be combined to specify the size, depth, and distance of an object in a scene (Richards, 1985 Journal of the Optical Society of America A2 343 – 349). Experiments are reported in which natural viewing and physical stimuli have been used to investigate the nature of size and depth perception on the basis of disparity and parallax presented separately and together at a range of viewing distances. Observers adjusted the relative position of three bright LEDs, which were constrained to form a triangle in plan view with the apex pointing toward the observer, so its dimensions matched that of a standard held by the subject. With static monocular viewing, depth settings were inaccurate and erratic. When both cues were present together accuracy increased and the perceptual outcome was consistent with an averaging of the information provided by both cues. When an apparent bias evident in the observers’ responses (the tendency to under-estimate the size of the standard) was taken into account, accuracy was high and size and depth constancy were close to 100%. In addition, given this assumption, the same estimate of viewing distance was used to scale size and depth estimates.
The Minimum Contrast Requirements for Stereopsis
Authors: Simmons David R
Published: January 2007

A number of researchers have compared the contrast requirements for stereopsis with those for detection of the stereoscopic stimulus, but they have generally failed to allow for the fact that stereopsis requires a detectable stimulus in both eyes at the same time. It is argued that the most appropriate detection threshold for this comparison is that for simultaneous monocular detection (SMD) of the stereoscopic half images. Experiments in which this comparison threshold has been used are summarised and the hypothesis generated that, on using stimuli that are localised in both space and spatial frequency (eg Gabor patches or differences of Gaussians), a range of disparities can always be found over which contrast thresholds for depth identification are less than or equal to this SMD threshold (the SMD hypothesis). It is argued that the success of this hypothesis in describing data obtained with these stimuli is consistent with the notions of labelled lines for disparity sign and the size - disparity correlation. Last, experiments are reported in which contrast thresholds for stereoscopic depth identification (front/back) were measured with interocular differences in contrast. The data obtained are consistent with the presence of both inhibitory and excitatory interactions between the eyes when unequal monocular contrasts are presented. The implications of these results and the SMD hypothesis for theories of stereopsis and binocular function are discussed.
The Time it Takes to Stratify Two Phenomenal Surfaces
Authors: Masin Sergio Cesare
Published: January 2007

The time the perceptual system takes to generate two overlapping phenomenal surfaces is estimated to be about 60 ms by a recognition task and 200 – 250 ms by a primed matching task. Here, a reaction-time task was used to test these estimates. It is plausible that when two overlapping phenomenal surfaces appear abruptly in the visual field the perceptual system sends a signal to the response system when the localisation of the parts of these surfaces begins. The perceptual system should send a subsequent signal when the phenomenal overlapping of the surfaces is achieved. The reaction times to these signals were estimated in two experiments. The difference between these estimates confirms the time estimate provided by the primed matching task.
Manipulation of Colour and Shape Information and its Consequence upon Recognition and Best-Likeness Judgments
Authors: Lee Kieran J , Perrett David I
Published: January 2007

Previous forays into the study of recognition have revealed an advantage for line-drawn and photographic shape caricatures of faces in reaction-time paradigms. When a presentation-time technique was used, photographs with enhanced colour intensity and saturation were also found to provide superior recognition accuracy to veridical images. This has provided strong evidence that distinctive information can produce a recognition advantage for famous faces in both colour and shape domains. Such a presentation-time paradigm allows the display of stimuli over a range of brief display periods. Using this paradigm, subjects recognised photorealistic target faces caricatured in shape with greater accuracy than veridical images, consistent with previous findings when reaction time was used as a measure. Subjects were also asked to identify the best likeness for individuals using photorealistic stimuli and an interactive paradigm with shape caricature, colour caricature, and contrast control varied by the user in real-time. The best likeness with shape manipulation was a slight anticaricature, while with colour-caricature and contrast-control images a mildly exaggerated image was selected as the best likeness. Thus, although images caricatured substantially in colour or shape (+40%) induce superior recognition compared to veridical images, such substantial exaggerations are not necessarily seen as best likenesses under prolonged exposure.
Tangible Pictures: Viewpoint Effects and Linear Perspective in Visually Impaired People
Authors: Heller Morton A , Brackett Deneen D , Scroggs Eric , Steffen Heather , Heatherly Kim , Salik Shana
Published: January 2007

Perception of raised-line pictures in blindfolded-sighted, congenitally blind, late-blind, and low-vision subjects was studied in a series of experiments. The major aim of the study was to examine the value of perspective drawings for haptic pictures and visually impaired individuals. In experiment 1, subjects felt two wooden boards joined at 45°, 90°, or 135°, and were instructed to pick the correct perspective drawing from among four choices. The first experiment on perspective found a significant effect of visual status, with much higher performance by the low-vision subjects. Mean performance for the congenitally blind subjects was not significantly different from that of the late-blind and blindfolded-sighted subjects. In a further experiment, blindfolded subjects drew tangible pictures of three-dimensional (3-D) geometric solids, and then engaged in a matching task. Counter to expectations, performance was not impaired for the 3-D drawings as compared with the frontal viewpoints. Subjects were also especially fast and more accurate when matching top views. Experiment 5 showed that top views were easiest for all of the visually impaired subjects, including those who were congenitally blind. Experiment 5 yielded higher performance for 3-D than frontal viewpoints. The results of all of the experiments were consistent with the idea that visual experience is not necessary for understanding perspective drawings of geometrical objects.
Chiral imine copper chloride-catalyzed enantioselective desymmetrization of 2-substituted 1,2,3-propanetriols
Authors: Jung Byunghyuck , Kang Sung Ho
Published: January 2007

Catalytic enantioselective desymmetrization of meso-2-substituted glycerols has been developed to secure a novel synthetic route to chiral tertiary alcohols. The transformation has been realized by monobenzoylation using benzoyl chloride and triethylamine in the presence of the imine ligand (
25
)-CuCl
2
complex in THF at ambient temperature. The desymmetrization turned out to be greatly dependent on acylating reagent, base, solvent, and needless to say, catalyst. Extensive screening of chiral ligands led us to combine bromopyridinecarboxaldehyde 1 and phenyloxazoline amine 12 derived from
tert
-leucine, the bromo and phenyl substituents of which proved to be indispensable. All of the substrates have been desymmetrized to the corresponding monobenzoates with high enantioselectivity up to 96% enantiomeric excess. The catalytic system allows broad structural diversity of substrates and its synthetic versatility has been demonstrated by an efficient synthetic route to a known key precursor 68 of triazole antifungals.
Topological locking restrains replication fork reversal
Authors: Fierro-Fernández Marta , Hernández Pablo , Krimer Dora B. , Stasiak Andrzej , Schvartzman Jorge B.
Published: January 2007

Two-dimensional agarose gel electrophoresis, psoralen cross-linking, and electron microscopy were used to study the effects of positive supercoiling on fork reversal in isolated replication intermediates of bacterial DNA plasmids. The results obtained demonstrate that the formation of Holliday-like junctions at both forks of a replication bubble creates a topological constraint that prevents further regression of the forks. We propose that this topological locking of replication intermediates provides a biological safety mechanism that protects DNA molecules against extensive fork reversals.
RNaseE and the other constituents of the RNA degradosome are components of the bacterial cytoskeleton
Authors: Taghbalout Aziz , Rothfield Lawrence
Published: January 2007

RNaseE is the main component of the RNA degradosome of
Escherichia coli
, which plays an essential role in RNA processing and decay. Localization studies showed that RNaseE and the other known degradosome components (RNA helicase B, polynucleotide phosphorylase, and enolase) are organized as helical filamentous structures that coil around the length of the cell. These resemble the helical structures formed by the MreB and MinD cytoskeletal proteins. Formation of the RNaseE cytoskeletal-like structure requires an internal domain of the protein that does not include the domains required for any of its known interactions or the minimal domain required for endonuclease activity. We conclude that the constituents of the RNA degradosome are components of the
E. coli
cytoskeleton, either assembled as a primary cytoskeletal structure or secondarily associated with another underlying cytoskeletal element. This suggests a previously unrecognized role for the bacterial cytoskeleton, providing a mechanism to compartmentalize proteins that act on cytoplasmic components, as exemplified by the RNA processing and degradative activities of the degradosome, to regulate their access to important cellular substrates.
Viral induction of AID is independent of the interferon and the Toll-like receptor signaling pathways but requires NF-κB
Authors: Gourzi Polyxeni , Leonova Tatyana , Papavasiliou F. Nina
Published: January 2007

Activation-induced cytidine deaminase (AID) is expressed in germinal centers of lymphoid organs during immunoglobulin diversification, in bone marrow B cells after infection with Abelson murine leukemia retrovirus (Ab-MLV), and in human B cells after infection by hepatitis C virus. To understand how viruses signal AID induction in the host we asked whether the AID response was abrogated in cells deficient in the interferon pathway or in signaling via the Toll-like receptors. Here we show that AID is not an interferon responsive gene and abrogation of Toll-like receptor signaling does not diminish the AID response. However, we found that NF-κB was required for expression of virally induced AID. Since NF-κB binds and activates the AID promoter, these results mechanistically link viral infection with AID transcription. Thus, induction of AID by viruses could be the result of several signaling pathways that culminate in NF-κB activation, underscoring the versatility of this host defense program.
Diamond and biology
Authors: Nebel Christoph E , Shin Dongchan , Rezek Bohuslav , Tokuda Norio , Uetsuka Hiroshi , Watanabe Hideyuki
Published: January 2007

A summary of photo- and electrochemical surface modifications applied on single-crystalline chemical vapour deposition diamond films is given. The covalently bonded formation of amine and phenyl linker molecular layers is characterized using X-ray photoelectron spectroscopy, atomic force microscopy (AFM), cyclic voltammetry and field-effect transistor characterization experiments. Amine and phenyl layers are very different with respect to formation, growth, thickness and molecular arrangement. We deduce a sub-monolayer of amine linker molecules on diamond with approximately 10% coverage of 1.5×10
15
 cm
−2
carbon bonds. Amine is bonded only on initially H-terminated surface areas. In the case of electrochemical deposition of phenyl layers, multilayer properties are detected with three-dimensional nitrophenyl growth properties. This leads to the formation of typically 25 Å thick layers. The electrochemical bonding to boron-doped diamond works on H-terminated and oxidized surfaces.

After reacting such films with heterobifunctional cross-linker molecules, thiol-modified ss-DNA markers are bonded to the organic system. Application of fluorescence and AFM on hybridized DNA films shows dense arrangements with densities up to 10
13
 cm
−2
. The DNA is tilted by an angle of approximately 35° with respect to the diamond surface. Shortening the bonding time of thiol-modified ss-DNA to 10 min causes a decrease in DNA density to approximately 10
12
 cm
−2
. Application of AFM scratching experiments shows threshold removal forces of approximately 75 and 45 nN for the DNA bonded to the phenyl and the amine linker molecules, respectively. First, DNA sensor applications using Fe(CN
6
)
3−/4−
mediator redox molecules and DNA field-effect transistor devices are introduced and discussed.
The interaction between inner and outer regions of turbulent wall-bounded flow
Authors: Morrison Jonathan F
Published: January 2007

The nature of the interaction between the inner and outer regions of turbulent wall-bounded flow is examined. Townsend's theory of inactive motion is shown to be a first-order, linear approximation of the effect of the large eddies at the surface that acts as a quasi-inviscid, low-frequency modulation of the shear-stress-bearing motion. This is shown to be a ‘strong’ asymptotic condition that directly expresses the decoupling of the inner-scale active motion from the outer-scale inactive motion. It is further shown that such a decoupling of the inner and outer vorticity fields near the wall is inappropriate, even at high Reynolds numbers, and that a ‘weak’ asymptotic condition is required to represent the increasing effect of outer-scale influences as the Reynolds number increases. High Reynolds number data from a fully developed pipe flow and the atmospheric surface layer are used to show that the large-scale motion penetrates to the wall, the inner–outer interaction is not describable as a linear process and the interaction should more generally be accepted as an intrinsically nonlinear one.
Characterization of enterotoxigenic Escherichia coli from diarrhoeal patients in Bangladesh using phenotyping and genetic profiling
Authors: Ansaruzzaman M. , Bhuiyan N. A. , Begum Y. A. , Kühn I. , Nair G. B. , Sack D. A. , Svennerholm A.-M. , Qadri F.
Published: January 2007

A total of 99 isolates out of 370 colonization factor (CF)-positive, well-characterized enterotoxigenicEscherichia coli(ETEC) strains belonging to 13 different CF types isolated from diarrhoeal patients admitted to the hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh, were tested. The isolates were selected at random based on expression of the major CFs prevailing in Dhaka, Bangladesh, from 1996 to 1998. These isolates were characterized by O-antigenic serotyping, randomly amplified polymorphic DNA (RAPD) analysis and biochemical fingerprinting using the PhenePlate (PhP) system. The 99 ETEC isolates belonged to 10 O serogroups, the predominant ones being O6 (n=28), O115 (n=20) and O128 (n=20). Most isolates of serogroup O6 (CS1+CS3, 11/14; CS2+CS3, 5/8) belonged to the same PhP/RAPD type (H/f), whereas other isolates of serogroup O6 (n=12) belonged to different PhP/RAPD types (Si/f and F/c). Eleven serogroup O128 (CFA/I) isolates belonged to the same PhP/RAPD type (E/b), whereas the other O128 isolates formed different PhP/RAPD types. Fifteen (75 %) serogroup O115 isolates (together with fourteen isolates from serogroups O25, O114, O142 and O159) demonstrated two closely related common groups by PhP typing (A and A1) and belonged to the same PhP/RAPD type (A/a). Three major clonal groups were identified among the ETEC strains in this study, largely based on O-antigenic type, CF expression pattern and toxin profile.
PCR-based identification and strain typing of Pichia anomala using the ribosomal intergenic spacer region IGS1
Authors: Bhardwaj Sonia , Sutar Rajeshwari , Bachhawat Anand K. , Singhi Sunit , Chakrabarti Arunaloke
Published: January 2007

Frequent outbreaks of Pichia anomala fungaemia in paediatric patients have warranted the development of a rapid identification system for this organism. This study describes a specific PCR-based method targeting the rRNA gene intergenic spacer region 1 (IGS1) for rapid identification of Pichia anomala isolates and characterization at the strain level. These methods of species identification and strain typing were used on 106 isolates of Pichia anomala (77 from a previously described outbreak and 29 isolated post-outbreak from the same hospital). Using conventional morphological and biochemical methods, 11 strains isolated during the outbreak were misidentified as P. anomala. blast analysis of sequences of internal transcribed spacer (ITS) regions of rRNA genes confirmed that they were Pichia guilliermondii (eight isolates) and Debaryomyces hansenii (three isolates). Strain typing of Pichia anomala isolates confirmed the previous finding of a point-source outbreak. The results suggest that IGS sequences and their polymorphisms could be exploited for similar typing methods in other organisms.
Occurrence and genetic variability of Candida parapsilosis sensu lato in Hungary
Authors: Kocsubé Sándor , Tóth Mónika , Vágvölgyi Csaba , Dóczi Ilona , Pesti Miklós , Pócsi István , Szabó Judit , Varga János
Published: January 2007

The occurrence and genetic variability of Candida parapsilosis isolates in two Hungarian hospitals, located in Debrecen and Pécs, were examined. Among the 209 Candida isolates examined, 20 were found to belong to C. parapsilosis sensu lato, based on morphological, physiological and molecular data. The frequency of occurrence of C. parapsilosis isolates (9.6 %) was lower than that observed in Europe but higher than that observed previously in Hungary. The genetic variability of C. parapsilosis sensu lato isolates was also examined using random amplified polymorphic DNA (RAPD) analysis and sequence analysis of the intergenic transcribed spacer (ITS) region of the rRNA gene cluster. The genetic variability of the isolates was relatively high, as revealed by RAPD analysis. Two isolates were found to belong to the recently described Candida metapsilosis species (C. parapsilosis group III), based on ITS sequence data, RAPD analysis and phenotypic data. These two isolates could also be distinguished from C. parapsilosis sensu stricto isolates using a primer pair developed for the detection of C. parapsilosis group I isolates. To the best of the authors' knowledge, this is the first report on the identification of C. metapsilosis from bloodstream infection.
Growth in catheter biofilms and antibiotic resistance of Mycobacterium avium
Authors: Falkinham Joseph O.
Published: January 2007

Cells of Mycobacterium avium strain A5 adhered to plasticized polyvinyl chloride catheter tubing and grew at low nutrient concentration, consistent with reports of catheter-associated M. avium infection. Starting with initial cell densities of 1–2×106 c.f.u. ml−1, biofilms of approximately 350 c.f.u. cm−2 formed within 24 h at room temperature. Growth rates of cells in biofilms were exponential and equal to 2.45 days doubling time. Rates were exponential for 1–2 weeks incubation and reached cell densities of 6.5×104 c.f.u. cm−2 by 4 weeks. Cells grown in catheter biofilms were significantly more resistant to clarithromycin and rifamycin than cells grown in suspension.
Interactions of apomyoglobin with membranes: Mechanisms and effects on heme uptake
Authors: Vernier Grégory , Chenal Alexandre , Vitrac Heidi , Barumandzadhe Roya , Montagner Caroline , Forge Vincent
Published: January 2007

The last step of the folding reaction of myoglobin is the incorporation of a prosthetic group. In cells, myoglobin is soluble, while heme resides in the mitochondrial membrane. We report here an exhaustive study of the interactions of apomyoglobin with lipid vesicles. We show that apomyoglobin interacts with large unilamellar vesicles under acidic conditions, and that this requires the presence of negatively charged phospholipids. The pH dependence of apomyoglobin interactions with membranes is a two‐step process, and involves a partially folded state stabilized at acidic pH. An evident role for the interaction of apomyoglobin with lipid bilayers would be to facilitate the uptake of heme from the outer mitochondrial membrane. However, heme binding to apomyoglobin is observed at neutral pH when the protein remains in solution, and slows down as the pH becomes more favorable to membrane interactions. The effective incorporation of soluble heme into apomyoglobin at neutral pH suggests that the interaction of apomyoglobin with membranes is not necessary for the heme uptake from the lipid bilayer. In vivo, however, the ability of apomyoglobin to interact with membrane may facilitate its localization in the vicinity of the mitochondrial membranes, and so may increase the yield of heme uptake. Moreover, the behavior of apomyoglobin in the presence of membranes shows striking similarities with that of other proteins with a globin fold. This suggests that the globin fold is well adapted for soluble proteins whose functions require interactions with membranes.
Outcomes in occupational asthma caused by reactive dye after long‐term avoidance
Authors: Park H. ‐W. , Kim D. ‐I. , Sohn S. ‐W. , Park C. ‐H. , Kim S. ‐S. , Chang Y. ‐S. , Min K. ‐U. , Kim Y. ‐Y. , Cho S. ‐H.
Published: January 2007

Background
Reactive dye (RD) is known to be a causative agent of occupational asthma (OA). However, to date, no report has been issued concerning the long‐term outcomes of RD‐induced OA.

Objectives
We sought to evaluate the long‐term outcomes in cases of OA caused by RD.

Methods
A total of 11 OA patients confirmed by RD bronchial challenge were enrolled in this study. First and second follow‐up examinations were conducted at 4.3±2.3 and 13.7±2.3 years (means±SD) after the initial examinations, respectively. Skin prick test with RD and 11 common inhalant allergens, pulmonary function test, methacholine bronchial provocation testing, symptom and medication scores were determined at each visit. In addition, inflammatory cells in induced sputum were measured at the second follow‐up examinations.

Results
Reduced lung function at initial examinations did not recover at the first and second examinations despite cessation of exposure and proper pharmacological treatment. In addition, asthma severity (as determined by symptom and medication scores) and non‐specific airway hyper‐responsiveness to methacholine also did not improve. However, skin reactivity to RD almost disappeared at the second examinations. Interestingly, four of the six patients who showed negative skin responses to all 11 common inhalant allergens at initial examinations were found to be atopic at the second examinations. Moreover, in terms of airway inflammation, seven of the 11 patients showed eosinophilia in induced sputum (3%) at the second examinations despite having been on high‐dose inhaled corticosteroid medication.

Conclusion
The present study demonstrates that reduced lung function and asthmatic symptoms persist in RD‐induced OA even after long‐term exposure avoidance.
The functional heterogeneity of eosinophil cationic protein is determined by a gene polymorphism and post‐translational modifications
Authors: Trulson A. , Byström J. , Engström Å. , Larsson R. , Venge P.
Published: January 2007

Background
The eosinophil is a cytotoxic cell and takes part in parasite killing and tissue‐destructive processes by secretion of proteins such as eosinophil cationic protein (ECP). A polymorphism was demonstrated in the ECP gene, giving rise to a substitution of arginine at position 97 with threonine. This polymorphism is related to disease development.

Objective
To investigate the functional and molecular heterogeneity of native ECP and the functional consequences of the replacement of arginine with a threonine.

Methods
ECP was purified from healthy blood donors by gel filtration, ion‐exchange chromatography and reversed‐phase chromatography. Recombinant ECPs i.e. rECP 97arg and rECP 97thr were produced by the pFASTBAC baculovirus expression system. The cytotoxic activity was determined against an erythroleukaemia or a small cell lung cancer cell line.

Results
Native ECP was purified to apparent homogeneity and showed a considerable molecular heterogeneity and a corresponding functional heterogeneity with respect to cytotoxic activity. After reduction, the native cytotoxic ECP showed three bands on sodium dodecylsulphate polyacrylamide gel electrophoresis : one major band at 18–20 kDa and two minor bands at about 10 and 5 kDa, respectively. The 5 kDa contained two masses differing with 56.2 Da, which corresponds to the difference in molecular masses of arginine and threonine. rECP 97arg was cytotoxic in contrast to rECP97thr. Deglycosylation with N‐glycosidase F did not affect the cytotoxic activity of native ECP to any measurable extent nor the activity of rECP 97arg, whereas rECP 97thr achieved cytotoxic activity. The RNase activities of the recombinant and native ECPs were similar.

Conclusion
We conclude that ECP is present in several molecular forms with varying biological activities. Some of this functional heterogeneity is based on the genetic polymorphism of the ECP gene and some on post‐translational modifications. In subjects carrying the ECP 97thr variant, the cytotoxic activity may be disguised by N‐linked glycosylation of the active site.
Continued need of appropriate betalactam‐derived skin test reagents for the management of allergy to betalactams
Authors: Blanca M. , Romano A. , Torres M. J. , Demoly P. , DeWeck A.
Published: January 2007

Immediate allergic reactions to betalactams (BLs) are due to IgE antibodies that recognize the ring‐derived penicilloyl determinant or side‐chain structures of common BLs. The presence of specific IgE antibodies can be demonstrated by skin testing, the determination of specific IgE antibodies in sera or their binding to basophils with subsequent activation upon contact with penicillinsin vitro. Skin tests are still the most sensitive technique followed byin vitrotests, which may sometimes yield useful complementary information. The diversity of the response to BLs has meant that in some instances, in addition to benzylpenicillin‐derived determinants, testing for amoxycillin, cephalosporins or other BLs may also be required to establish the diagnosis. The recent withdrawal from the market of BL‐derived materials for skin testing will have a serious effect on public health, resulting in a return to the pre‐1960 era before these reagents became available. Because of their greater sensitivity, these skin tests cannot yet be replaced byin vitrotests. Furthermore, skin tests are the most readily available form of allergy testing for physicians. This paper reviews the results of skin tests in BL allergy and provides evidence for their continued need.
Collection fluid helps preservation in voided urine cytology
Authors: Raistrick J. , Shambayati B. , Dunsmuir W.
Published: January 2007

Objectives:  Degenerative change caused by delay in processing contributes to false‐negative and false‐positive diagnosis of urothelial carcinoma in cytology. The aim of the study was to see if the use of a collection fluid for urine samples made a significant difference to urine cytology diagnosis, and if one was better suited for routine use in the hospital laboratory. Three cell collection fluids were evaluated by analysing the preservation and degeneration of cells in urine samples, as was the routine preparation which did not use a collection fluid.

Methods:  In the design study 50 voided urine specimens were taken at random from the hospital haematuria clinic. Three commercially available collection fluids cytolytTM, cytospin® and cytoRich®Blue and the hospital's routine conventional preparation of urine were compared. The degree of degeneration, and so preservation, was assessed by a table of chosen criteria; then ranked and analysed by Friedman's nonparametric test, at P = 0.05. A second table showing the cell content of each slide was also made.

Results:  These showed no significant diagnostic difference between the collection fluids, but there was a significant difference between the collection fluids and the routine preparation. Minor differences that do not affect diagnosis, such as crystals and ghost red blood cells, were noted in cytospin® and cytoRich®Blue.

Conclusion:  It is recommended that a collection fluid is used. This choice should be made after health and safety issues and cost are considered.
Laminin‐5 immunocytochemistry: a new tool for identifying dysplastic cells in oral brush biopsies
Authors: Driemel O. , Dahse R. , Hakim S. G. , Tsioutsias T. , Pistner H. , Reichert T. E. , Kosmehl H.
Published: January 2007

Background:  The brush biopsy technique is not only a seminal technique but also a critically discussed method for detection of oral pre‐cancerous stages and manifest carcinomas. The γ2 chain of laminin‐5 and its proteolytic fragments comprise an invasion factor for many carcinomas.

Objectives:  The aim of this study was to determine whether the immunocytochemical presentation of the laminin γ2 chain identifies pre‐invasive or invasive squamous cells in brush biopsies.

Methods:  The value‐based identification of atypical epithelia was analysed in 93 consecutive brush biopsies with histopathological diagnoses: standardized haematoxylin and eosin staining; standardized immunocytochemistry: monoclonal antibodies against laminin γ2 chain: D4B5, 4G1, detection using ChemMate and Autostainer.

Results:  Conventional cytology did not result in any false‐positive cases, i.e. atypical cells in normal, inflamed or benignly hyperproliferative mucosa (specificity, 100%), whereas immunocytochemistry revealed one false‐positive case (specificity, 98%). In brush biopsies of oral squamous cell carcinomas, the following immunocytochemical patterns were possible: (1) staining of the cytoplasm, (2) banded markings between clumped carcinoma cells and (3) positive hazes surrounding atypical cells. Bacterial colonies appeared as false‐positive results. Four of 27 carcinomas and one of three recurrences were not cytologically identified (sensitivity of conventional cytology, 79%). Three of the five carcinomas not identified by cytology were immunocytochemically stained with laminin γ2 chain antibody (sensitivity of laminin γ2 chain immunocytochemistry, 93%). The positive predictive value was 100% for conventional cytology and 97% for laminin γ2 chain immunocytochemistry. The negative predictive value attained was 92% for conventional cytology and 97% for laminin γ2 chain immunocytochemistry.

Conclusions:  The high sensitivity level observed for method‐enhanced brush cytology suggests that this technique be used as an initial diagnostic step.
Social structure and facultative mating systems of hoary marmots (Marmota caligata)
Authors: KYLE C. J. , KARELS T. J. , DAVIS C. S. , MEBS S. , CLARK B. , STROBECK C. , HIK D. S.
Published: January 2007

Mate‐choice theory predicts different optimal mating systems depending on resource availability and habitat stability. Regions with limited resources are thought to promote monogamy. We tested predictions of monogamy in a social rodent, the hoary marmot (Marmota caligata), at the northern climatic extreme of its distribution. Mating systems, social structure and genetic relationships were investigated within and among neighbouring colonies of marmots within a 4 km2 valley near Kluane National Park, Yukon, Canada, using 21 microsatellite loci. While both monogamous and polygynous populations of hoary marmots have been observed in the southern reaches of this species’ range; northern populations of this species are thought to be predominantly monogamous. Contrary to previous studies, we did not find northern hoary marmot social groups to be predominantly monogamous; rather, the mating system seemed to be facultative, varying between monogamy and polygyny within, as well as among, social groups. These findings reveal that the mating systems within colonies of this species are more flexible than previously thought, potentially reflecting local variation in resource availability.
Clonal structure of Elytrigia atherica along different successional stages of a salt marsh
Authors: SCHEEPENS J. F. , VEENEKLAAS R. M. , VAN DE ZANDE L. , BAKKER J. P.
Published: January 2007

Elytrigia atherica is a tall clonal grass species typical of higher salt marshes, but is gradually invading to the lower marshes. At young successional stages of a salt marsh, E. atherica is found sparsely dispersed in small groups of ramets. These patches increase in size and ramet density over time, eventually forming extensive swards as succession proceeds. This study investigates the change in the clonal diversity of E. atherica stands during colonization as a result of its reproductive strategy. Clonal diversities of differently sized patches of E. atherica were investigated on two lower salt‐marsh sites of different age, 25 years and 35 years, respectively. Microsatellite fingerprint patterns were used to determine genet identities and to estimate relatedness and genetic differentiation between the sites, between patches within sites and within patches. The majority of the patches on both sites contained more than one genet. On the older site, the clonal diversity was higher than on the younger site. However, the clonal diversity tended to decrease with increasing patch size. Low genetic differentiation was found between the two sites, indicating habitat differentiation, whereas differentiation between patches within sites was high. It is reasoned that different environmental conditions could have resulted in different clonal structures: On an older marsh, the increase of successful seedling recruitment, due to more suitable environmental conditions, leads to an increase in clonal diversity. Over time, with increasing ramet density, intraspecific competition is likely to increase, resulting in a decrease of clonal diversity.
Population decline despite high genetic diversity in the new allopolyploid speciesSenecio cambrensis(Asteraceae)
Authors: ABBOTT RICHARD J. , IRELAND HELEN E. , ROGERS HILARY J.
Published: January 2007

Senecio cambrensis(Welsh groundsel) is a new allohexaploid species, which originated in Wales, UK, in the early part of the 20th century following hybridization between the native tetraploid groundsel (Senecio vulgaris) and the introduced diploid Oxford ragwort (Senecio squalidus). A survey of the number of populations and flowering individuals per population ofS. cambrensisin Wales was conducted at peak flowering time in June 2002, 2003 and 2004. The results show a dramatic decrease in both population number and population size of the species since the 1980s when the last population census was conducted. A survey of amplified fragment length polymorphism (AFLP) variation showed that this decline has occurred despite the fact thatS. cambrensiscontains a high level of genetic diversity with each individual screened possessing a unique multilocus phenotype. The level of variance within the species was similar to that found in one parent (S. vulgaris) and slightly greater than that among samples of the other parent (S. squalidus). Only a small proportion (5%) of AFLP diversity was partitioned among populations indicating a lack of population structure and possibly high levels of gene flow via seed dispersal in what is predominantly a selfing species.Senecio cambrensisshowed closer similarity in AFLP phenotype toS. vulgaristhan toS. squalidus. Possible causes of this and also the high level of AFLP diversity found inS. cambrensisare discussed. It is suggested that intergenomic recombination following occasional multivalent formation during meiosis inS. cambrensisis likely to be an important cause of both phenomena, although other causes are not ruled out.
Faulting on the western flank of Mt Etna and magma intrusions in the shallow crust
Authors: Mattia Mario , Patanè Domenico , Aloisi Marco , Amore Mauro
Published: January 2007

Surface deformations on the western flank of Mt Etna volcano, spanning 1980–2004, have been analysed as they pertain to stress interactions between magma intrusions within the shallow crust along the S–SE Rift and faulting sensitivity. During this period, an accurate analysis of strain parameters, computed by inversion of SW electro‐optical distance data, suggested that the observed strong displacements on this flank of the edifice can also be related to dextral shear movements along a roughly NE–SW buried fault crossing the area covered by this network, as supported by seismic observations of the 20–24 April 2001 swarm. Moreover, Coulomb stress change model analysis confirms that the displacement along this fault, heralding the July–August 2001 eruption 2 months earlier can be related to major stresses applied by a dike intrusion at depth along the S–SE Rift, as testified by the microseismicity occurring between November 2000 and 19 April 2001.
Subsidence due to crack closure and depressurization of hydrothermal systems: a case study from Mt Epomeo (Ischia Island, Italy)
Authors: Sepe Vincenzo , Atzori Simone , Ventura Guido
Published: January 2007

Levelling surveys carried out between 1990 and 2003 on the Mt Epomeo resurgent block (Ischia Island) record negative dislocations on its northern and southern flanks with a maximum subsidence rate of 1.27 cm yr−1. This deformation is not associated with the cooling, crystallization or lateral drainage of magma and cannot be explained by a pressure point or prolate ellipsoid source. Results from dislocation models and the available structural and geochemical information indicate that the subsidence is due to crack closure processes along two main ENE–WSW and E–W preexisting faults, which represent the preferred pathway of CO2 degassing from the hydrothermal system located beneath Mt Epomeo. The monitoring of the dislocations and CO2 flux along these faults could give useful information on the dynamics of the hydrothermal system.
Asthma and allergies in schoolchildren of Maputo
Authors: Mavale‐Manuel S. , Joaquim O. , Macome C. , Almeida L. , Nunes E. , Daniel A. , Malichocho J. , Pedro A. , Bandeira S. , Eduardo E. , Maciel L. , Constance E. , Marques S. , Tembe A. , De Blic J. , Annesi‐Maesano I.
Published: January 2007

Aim:  The study aimed to determine prevalence and severity of asthma, rhinitis and eczema in Maputo, Mozambique.

Methods:  The International Study of Asthma and Allergies (ISAAC) protocol was applied in 27 schools in urban, suburban and semi‐rural areas.

Results:  A total of 2630 completed questionnaires were obtained from students aged 13–14 years, and 2383 from schoolchildren aged 6–7 years. The prevalence of current asthma was 13.3% in the two groups, the prevalence of rhinoconjuctivitis and eczema was 23% and 10% in teenagers and 8.8% and 8.5% respectively in children 6–7 years old. Overall, 35% of the adolescents and 23.8% of children were found to have at least one atopic condition or asthma in the last year. In symptomatic adolescents, the conditions were: rhinoconjuctivitis (41.3%), asthma (20%) and eczema (12.4%). In symptomatic children, asthma was the principal condition (36.2%), followed by eczema (20.3%) and rhinoconjunctivitis (19.1%). In adolescents, asthma was more frequently associated with rhinoconjuctivitis (28%). About 4% of all surveyed children had three atopic conditions associated. In adolescents, past year rhinitis was more frequent and severe in the urban area. Hay fever was commoner in the semi‐urban area. Eczema was significantly more recurrent in suburban and semi‐rural area. Exercise‐induced wheeze, nocturnal cough and ever asthma were more reported in children of suburban area.

Conclusion:  Asthma and allergic diseases are important public health problems in Maputo and improvement in prevention and management plans are required.
Young people’s experiences of growing up in a family affected by Huntington’s disease
Authors: Forrest Keenan K , Miedzybrodzka Z , Van Teijlingen E , McKee L , Simpson SA
Published: January 2007

Previous research and clinical experience suggest that Huntington’s disease (HD) can considerably affect family life, particularly for young people (YP) at risk. The goal of this study was to describe the experiences of YP from families affected by HD. YP were identified through the regional genetics clinic and the Scottish Huntington’s Association. In‐depth interviews were used to explore YP’s experiences of finding out about HD in the family; perceptions of their own risk; caring activities; protective or risk factors; and the impact of HD on relationships with siblings, parents, extended family members, and the wider community. Thirty‐three YP between the ages of 9 and 28 years were interviewed. A qualitative thematic analysis was undertaken. The analysis revealed four main themes: YP as carers, the worried well, those who cope, and those at risk/in need. These themes highlight the varied experience of growing up in a family affected by HD. Whilst some YP successfully coped, others experienced considerable problems and were at risk of physical and/or emotional harm. In understanding why some cope better than others, our findings suggest protective and risk factors within these themes. In particular, participants who grew up knowing about HD from an early age seemed to cope better.
The effects of fresh gas flow on the amount of sevoflurane vaporized during 1 minimum alveolar concentration anaesthesia for day surgery: a clinical study
Authors: Ekbom K. , Assareh H. , Anderson R. E. , Jakobsson J. G.
Published: January 2007

Background:  Even small costs per case can become economically significant in high volume day surgical units. While general anaesthesia with higher fresh gas flow rates has technical advantages, they result in higher costs. The aim of the present study was to evaluate drug consumption and direct costs related to variations in the fresh gas flow and use of nitrous oxide at a 1 minimum alveolar concentration (MAC) sevoflurane end‐tidal anaesthesia for day surgery.

Methods:  Thirty‐two ASA I–II patients undergoing elective day surgery under general anaesthesia [14 (10–21) min] were studied. Induction was with propofol and fentanyl 100 μg. After laryngeal mask airway placement, patients were randomized to one of four different fresh gas flows: 1 or 2 l/min oxygen in air (50% oxygen), 3 l/min (33% oxygen), or 3 l/min oxygen in nitrous oxide (33% oxygen). Anaesthesia was maintained at 1 MAC. The vaporizer was weighed before and after each procedure. The primary study variable was the sevoflurane utilization per minute.

Results:  Sevoflurane utilization increased with increasing fresh gas flow for oxygen in air (r2= 0.89). The nitrous oxide in oxygen group had the lowest sevoflurane utilization, even compared with the lowest oxygen in air group (0.36 vs. 0.48 g/min).

Conclusion:  Sevoflurane utilization during 1 MAC anaesthesia increases linearly with fresh gas flow and is still higher than when nitrous oxide is used even with very low fresh gas flow rates. Direct inhaled anaesthesia‐related costs are consequently 20% higher than when nitrous oxide is used, even for the lowest oxygen in air fresh gas flows.
Compact genes are highly expressed in the moss Physcomitrella patens
Authors: STENØIEN H. K.
Published: January 2007

Compact genes contain short and few introns, and they are highly expressed in different animal genomes. Recently, it has been shown that in Oryza sativa and Arabidopsis thaliana, highly expressed genes tend to be least compact, containing long and many introns. It has been suggested that selection on genome organization may have acted differently in plants compared with animals. Gene expression can be estimated as the number of hits when comparing a gene sequence with publicly available expressed sequence tags. Here it is shown that in the haploid moss Physcomitrella pates, highly expressed genes contain shorter introns than genes with low expression levels. This study therefore supports the hypothesis that selection may strongly favour transcriptional efficiency at least in the haploid phase of plant life cycles. It is concluded that plants do not necessarily respond to other selection pressures than animals regarding genome structuring.