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Sharp
Kinds of Sharp Terms modified by Sharp Selected AbstractsThe RNA coregulator SRA, its binding proteins and nuclear receptor signaling activityIUBMB LIFE, Issue 3 2008Shane M. Colley Abstract Nuclear receptor (NR) coregulators are key modulators of hormone signaling. Discovery of steroid receptor RNA activator (SRA), a coregulator that is active as a RNA, transformed thinking in the field of hormone action. The subsequent identification of SRA-binding coregulator proteins, including p68, SHARP and more recently SLIRP, has provided important insight into SRA's mechanism of action and potentially offers new opportunities to target NR signaling pathways for therapeutic gain. Here we outline advances in the field of NR coregulator biology, with a bias on recent progress in understanding SRA-protein interactions. © 2008 IUBMB IUBMB Life, 60(3): 159,164, 2008 [source] Instrument-independent specification of the diffraction geometry and polarization state of the incident X-ray beamJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 1 2009Marc Schiltz This work augments the proposal of Schwarzenbach & Flack [J. Appl. Cryst. (1989), 22, 601,605], who have advocated the use of a diffractometer-independent definition of the azimuthal angle , to specify the diffraction geometry of a Bragg reflection. It is here proposed that one additional angle ,, which is also based on a diffractometer-independent definition, is needed to encode the direction of linear polarization for those experiments where this quantity is of importance. This definition is then extended to the cases of partially and/or elliptically polarized X-ray beams, and the use of three normalized Stokes parameters, P1, P2 and P3, together with ,, is advocated in order to characterize exhaustively the polarization state of the incident beam. The conventions proposed here present a general, unambiguous and economical means of encoding the information about the diffraction geometry, without the need to record any further information about the instrument, crystal orientation matrix and goniometer angles. Data-processing software using these definitions to analyse polarization-dependent phenomena becomes instrument-independent and completely general. These methods have been implemented in the macromolecular phasing program SHARP for exploiting the polarization anisotropy of anomalous scattering in protein crystals. [source] De novo sulfur SAD phasing of the lysosomal 66.3,kDa protein from mouseACTA CRYSTALLOGRAPHICA SECTION D, Issue 3 2009Kristina Lakomek The 66.3,kDa protein from mouse is a soluble protein of the lysosomal matrix. It is synthesized as a glycosylated 75,kDa preproprotein which is further processed into 28 and 40,kDa fragments. Despite bioinformatics approaches and molecular characterization of the 66.3,kDa protein, the mode of its maturation as well as its physiological function remained unknown. Therefore, it was decided to tackle this question by means of X-ray crystallography. After expression in a human fibrosarcoma cell line, the C-terminally His-tagged single-chain 66.3,kDa variant and the double-chain form consisting of a 28,kDa fragment and a 40,kDa fragment were purified to homogeneity but could not be separated during the purification procedure. This mixture was therefore used for crystallization. Single crystals were obtained and the structure of the 66.3,kDa protein was solved by means of sulfur SAD phasing using data collected at a wavelength of 1.9,Å on the BESSY beamline BL14.2 of Freie Universität Berlin. Based on the anomalous signal, a 22-atom substructure comprising 21 intrinsic S atoms and one Xe atom with very low occupancy was found and refined at a resolution of 2.4,Å using the programs SHELXC/D and SHARP. Density modification using SOLOMON and DM resulted in a high-quality electron-density map, enabling automatic model building with ARP/wARP. The initial model contained 85% of the amino-acid residues expected to be present in the asymmetric unit of the crystal. Subsequently, the model was completed and refined to an Rfree factor of 19.8%. The contribution of the single Xe atom to the anomalous signal was analyzed in comparison to that of the S atoms and was found to be negligible. This work should encourage the use of the weak anomalous scattering of intrinsic S atoms in SAD phasing, especially for proteins, which require both expensive and time-consuming expression and purification procedures, preventing extensive screening of heavy-atom crystal soaks. [source] Exploiting the anisotropy of anomalous scattering boosts the phasing power of SAD and MAD experimentsACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2008Marc Schiltz The X-ray polarization anisotropy of anomalous scattering in crystals of brominated nucleic acids and selenated proteins is shown to have significant effects on the diffraction data collected at an absorption edge. For conventionally collected single- or multi-wavelength anomalous diffraction data, the main manifestation of the anisotropy of anomalous scattering is the breakage of the equivalence between symmetry-related reflections, inducing intensity differences between them that can be exploited to yield extra phase information in the structure-solution process. A new formalism for describing the anisotropy of anomalous scattering which allows these effects to be incorporated into the general scheme of experimental phasing methods using an extended Harker construction is introduced. This requires a paradigm shift in the data-processing strategy, since the usual separation of the data-merging and phasing steps is abandoned. The data are kept unmerged down to the Harker construction, where the symmetry-breaking is explicitly modelled and refined and becomes a source of supplementary phase information. These ideas have been implemented in the phasing program SHARP. Refinements using actual data show that exploitation of the anisotropy of anomalous scattering can deliver substantial extra phasing power compared with conventional approaches using the same raw data. Examples are given that show improvements in the phases which are typically of the same order of magnitude as those obtained in a conventional approach by adding a second-wavelength data set to a SAD experiment. It is argued that such gains, which come essentially for free, i.e. without the collection of new data, are highly significant, since radiation damage can frequently preclude the collection of a second-wavelength data set. Finally, further developments in synchrotron instrumentation and in the design of data-collection strategies that could help to maximize these gains are outlined. [source] Phasing power at the K absorption edge of organic arsenicACTA CRYSTALLOGRAPHICA SECTION D, Issue 5 2003Pascal Retailleau Single/multiple-wavelength anomalous dispersion (SAD/MAD) experiments were performed on a crystal of an organic arsenic derivative of hen egg-white lysozyme. A para -arsanilate compound used as a crystallizing reagent was incorporated into the ordered solvent region of the lysozyme molecule. Diffraction data were collected to high resolution (,2.0,Å) at three wavelengths around the K edge (1.04,Å) of arsenic at beamline BM30A, ESRF synchrotron. Anomalous Patterson maps clearly showed the main arsanilate site to be between three symmetry-related lysozyme molecules, at a location previously occupied by a para -toluenesulfonate anion. MAD phases at 2,Å derived using the program SHARP led to an electron-density map of sufficient quality to start manual building of the protein model. Amplitudes from a second crystal measured to a resolution of 1.8,Å at the peak wavelength revealed two additional heavy-atom sites, which reinforced the anomalous subset model and therefore dramatically improved the phasing power of the arsenic derivative. The subsequent solvent-flattened map was of such high accuracy that the program ARP/wARP was able to build a nearly complete model automatically. This work emphasizes the great potential of arsenic for de novo structure determination using anomalous dispersion methods. [source] High-resolution experimental phases for tryptophanyl-tRNA synthetase (TrpRS) complexed with tryptophanyl-5,AMPACTA CRYSTALLOGRAPHICA SECTION D, Issue 11 2001Pascal Retailleau Native data, anomalous data at three wavelengths and an independent peak-wavelength data set for SeMet-substituted protein have been collected from cryoprotected crystals of the TrpRS,adenylate product (TAM) complex to a resolution limit of 1.7,Å. Independent phase sets were developed using SHARP and improved by solvent flipping with SOLOMON using molecular envelopes derived from experimental densities for, respectively, peak-wavelength SAD data from four different crystals, MAD data and their M(S)IRAS combinations with native data. Hendrickson,Lattman phase-probability coefficients from each phase set were used in BUSTER to drive maximum-likelihood refinements of well defined parts of the previously refined room-temperature 2.9,Å structure. Maximum-entropy completion followed by manual rebuilding was then used to generate a model for the missing segments, bound ligand and solvent molecules. Surprisingly, peak-wavelength SAD experiments produced the smallest phase errors relative to the refined structures. Selenomethionylated models deviate from one another by 0.25,Å and from the native model by 0.38,Å, but all have r.m.s. deviations of ,1.0,Å from the 2.9,Å model. Difference Fourier calculations between amplitudes from the 300,K experiment and the new amplitudes at 100,K using 1.7,Å model phases show no significant structural changes arising from temperature variation or addition of cryoprotectant. The main differences between low- and high-resolution structures arise from correcting side-chain rotamers in the core of the protein as well as on the surface. These changes improve various structure-validation criteria. [source] Korean species of the genus Bisnius Stephens (Coleoptera: Staphylinidae)ENTOMOLOGICAL RESEARCH, Issue 1 2008Young Bok CHO Abstract Two Korean species of the genus Bisnius Stephens are studied. Bisnius macies (Sharp), found along the seashore of some islands, is introduced for the first time in Korea. [source] Taxonomic Notes on Myllocerus malignus Faust (Coleoptera: Curculionidae, Entiminae)ENTOMOLOGICAL RESEARCH, Issue 4 2003Kyungduk HAN ABSTRACT ABSTRACT Myllocerus malignus Faust was described new to science from Korea in 1887. Since then, the species collected from Korea and Far-east Russia has been misidentified as Eumyllocerus gratiosus Sharp, E. filicornis (Reitter), or E. longulus Egorov et Zherikhin. A taxonomic review of Myllocerus malignus Faust (1887) with its synonymy and the clarification of sexual dimorphism is presented. As a results, Myllocerus viridiaureus Suvorov (1915) and Eumyllocerus longulus Egorov et Zherikhin (1990) are synonymized with Myllocerus malignus. [source] What determines a species' geographical range?JOURNAL OF ANIMAL ECOLOGY, Issue 1 2010Thermal biology, latitudinal range size relationships in European diving beetles (Coleoptera: Dytiscidae) Summary 1.,The geographical range sizes of individual species vary considerably in extent, although the factors underlying this variation remain poorly understood, and could include a number of ecological and evolutionary processes. A favoured explanation for range size variation is that this result from differences in fundamental niche breadths, suggesting a key role for physiology in determining range size, although to date empirical tests of these ideas remain limited. 2.,Here we explore relationships between thermal physiology and biogeography, whilst controlling for possible differences in dispersal ability and phylogenetic relatedness, across 14 ecologically similar congeners which differ in geographical range extent; European diving beetles of the genus Deronectes Sharp (Coleoptera, Dytiscidae). Absolute upper and lower temperature tolerance and acclimatory abilities are determined for populations of each species, following acclimation in the laboratory. 3.,Absolute thermal tolerance range is the best predictor of both species' latitudinal range extent and position, differences in dispersal ability (based on wing size) apparently being less important in this group. In addition, species' northern and southern range limits are related to their tolerance of low and high temperatures respectively. In all cases, absolute temperature tolerances, rather than acclimatory abilities are the best predictors of range parameters, whilst the use of independent contrasts suggested that species' thermal acclimation abilities may also relate to biogeography, although increased acclimatory ability does not appear to be associated with increased range size. 4.,Our study is the first to provide empirical support for a relationship between thermal physiology and range size variation in widespread and restricted species, conducted using the same experimental design, within a phylogenetically and ecologically controlled framework. [source] Improved treatment of sudden hearing loss by specific fibrinogen aphaeresisJOURNAL OF CLINICAL APHERESIS, Issue 2 2004Heidrun Ullrich Abstract The etiology of sudden sensorineural hearing loss is still unclear and is thought to result from disturbances of microcirculation, infectious causes, or autoimmune disorders. So far standard therapy did not show clear improvement over spontaneous remission rate, which is assumed to be about 50% [Nakashima et al., Acta. Otolaryngol. Stockh. 514:14,16, 1994; Schuknecht and Donovan, Arch. Otorhinolaryngol. 243:1,15, 1986; Harris and Sharp, Laryngoscope 100:516,524, 1990; Mayot et al., Clin. Immunol. Immunopath. 68:41,45, 1993; Gussen, Ann. Otol. Rhinol. Laryngol. 85:94,100, 1976]. Elevated blood viscosity due to high fibrinogen levels is supposed to cause decreased cochlear blood flow and thus initiate sudden hearing loss. The specific lowering of fibrinogen immediately decreases plasma viscosity exactly to the desired extent and should lead to improved cochlear blood flow [Suckfüll et al., Acta. Otolaryngol 119:763,766, 1999; Suckfüll, Lancet 360:1811,1817, 2002; Walch et al., Laryngol. Rhino. Otol. 75:641,645, 1996; Suckfüll et al., Otol. Neurotol. 23:309,311, 2002]. In a prospective uncontrolled pilot study on 36 patients with unilateral sudden onset sensorineural hearing loss (SHL) we tried to establish that 1,3 specific fibrinogen aphaereses alone improve recovery of hearing and that it is possible to lower fibrinogen to the target of 80,100 mg/dl without important side effects. Pure tone audiometry was carried out immediately before and after each aphaeresis as well as at 2 and 4 weeks and 6 months after treatment. Sixteen patients recovered spontaneously before undergoing fibrinogen adsorption. All 20 aphaeresis patients improved during immunoadsorption; in 60% of patients auditory thresholds returned to normal after the first immunoadsorption and treatment could be discontinued, in another 20% of patients complete recovery was reached after 4 weeks. The mean plasma fibrinogen concentration of the 20 patients before the first aphaeresis session was 308.1 ± 51.5 mg/dl. Immediately after the first treatment session, the fibrinogen concentration was lowered to 100.7 ± 25.3 mg/dl (P < 0.001). The second and third sessions also showed highly significant reductions in plasma fibrinogen. No important side effects were seen. In conclusion, specific fibrinogen adsorption is a promising new treatment modality that should be tested in a prospective, randomized controlled trial in patients with sudden hearing loss. J. Clin. Apheresis 19:71,78, 2004. © 2004 Wiley-Liss, Inc. [source] The Picture of the Linguistic Brain: How Sharp Can It Be?LINGUISTICS & LANGUAGE COMPASS (ELECTRONIC), Issue 8 2010Reply to Fedorenko & Kanwisher What is the best way to learn how the brain analyzes linguistic input? Two popular methods have attempted to segregate and localize linguistic processes: analyses of language deficits subsequent to (mostly focal) brain disease and functional Magnetic Resonance Imaging (fMRI) in health. A recent Compass article by Fedorenko and Kanwisher (FK, 2009) observes that these methods group together data from many individuals through methods that rely on variable anatomical landmarks and that results in a murky picture of how language is represented in the brain. To get around the variability problem, FK propose to import into neurolinguistics a method that has been successfully used in vision research , one that locates functional Regions Of Interest (fROIs) in each individual brain. In this note, I propose an alternative perspective. I first take issue with FK's reading of the literature. I point out that, when the neurolinguistic landscape is examined with the right linguistic spectacles, the emerging picture , while intriguingly complex , is not murky, but rather, stable and clear, parsing the linguistic brain into functionally and anatomically coherent pieces. I then examine the potential value of the method that FK propose, in light of important micro-anatomical differences between language and high-level vision areas and conclude that as things stand the method they propose is not very likely to bear much fruit in neurolinguistic research. [source] Sharp by order estimates of solutions of a simplest singular boundary value problemMATHEMATISCHE NACHRICHTEN, Issue 2 2008N. A. Chernyavskaya Abstract We consider a boundary value problem ((0.1)) where f , Lp(,), p , [1, ,] (L, (,) , C (,)) and 0 , q , Lloc1 (,). For a given p , [1, ,], for a correctly solvable problem (0.1) in Lp(,), we obtain minimal requirements to a positive, continuous function ,(x) for x , , under which, regardless of f , Lp(,), the solution y , Lp(,) of problem (0.1) satisfies the equality . (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Taxonomic revision of Mecyclothorax Sharp (Coleoptera, Carabidae) of Hawaii Island: abundant genitalic variation in a nascent island radiationMITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE IN BERLIN-DEUTSCHE ENTOMOLOGISCHE ZEITSCHRIFT, Issue 1 2008James K. Liebherr Abstract The Hawaii Island fauna of Mecyclothorax Sharp, 1903 is taxonomically revised and found to comprise 30 species, 18 newly described: M. gagnei sp. n., M. nitidus sp. n., M. maunakukini sp. n., M. punakukini sp. n., M. kaukukini sp. n., M. perivariipes sp. n., M. aa sp. n., M. giffini sp. n., M. hephaestus sp. n., M. funebris sp. n., M. granulipennis sp. n., M. rufipennis sp. n., M. blackburnianus sp. n., M. swezeyi sp. n., M. sinuosus sp. n., M. williamsi sp. n., M. purpuripennis sp. n., and M. footei sp. n. New synonymies include: Mecyclothorax parvus Britton, 1948 = M. subunctus (Perkins), 1917; Thriscothorax munroi Perkins, 1937 = M. karschi (Blackburn), 1882; Thriscothorax gracilis Sharp, 1903 and Mecyclothorax proximus Britton, 1948 = M. konanus Sharp, 1903; Mecyclothorax terminalis Britton, 1948 = M. discedens (Sharp) 1903. Mecyclothorax vulcanus (Blackburn) was described from a mixed series, with the cryptic sibling species M. hephaestus newly described to correct the partial misidentification. Species delimitation for the highly variable M. konanus is achieved using a hierarchical analysis based on infraspecifically variable attributes. Extensive male genitalic variation is documented within M. konanus and M. deverilli (Blackburn), and also among the cryptic sibling species pair M. variipes (Blackburn) and M. perivariipes. The observed variation is consistent with various hypotheses of sexual selection, but not with the genitalic lock and key hypothesis. Areas of endemism are tentatively proposed based on the most restricted distributions of Hawaii Island Mecyclothorax, with various flanks of Mauna Kea and Mauna Loa volcanoes identified as distinctive areas. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Latest news and product developmentsPRESCRIBER, Issue 7 2007Article first published online: 11 JUL 200 Poor asthma control with off-licence prescribing Children who are prescribed off-licence medications are more likely to have poor asthma control, according to an analysis from Dundee (Br J Gen Practice 2007;57:220-2). The review of 17 163 consultations identified 1050 (6.1 per cent) who received a prescription for an unlicensed use (defined as not licensed for children or the particular age group, or dose not licensed). High doses (4.5 per cent) were more frequent than unlicensed indications (1.9 per cent). Children who received off-label prescriptions reported statistically significantly more symptoms in the day or night, symptoms during activity, and increased use of daily short-acting beta2-agonists. The authors note that off-label prescribing appears to be increasing. Atkins diet most effective over one year? The ultra low-carbohydrate, high-protein Atkins diet achieved greater weight loss than other popular diets in overweight women over one year, say US investigators (J Am Med Assoc 2007;297:969-77). The study compared the Atkins diet with three diets designed as low- or very high-carbohydrate, or based on USA nutritional guidance, in 311 women with body mass index 27-40. After one year, mean weight loss was 4.7kg with the Atkins diet , significantly greater than with the low- carbohydrate diet (1.6kg) but not compared with very high-carbohydrate (2.2kg) or the nutrition-based diet (2.6kg). Metabolic endpoints were comparable or more favourable in women using the Atkins diet. Androgen therapy linked to gum disease The majority of men treated with androgen deprivation therapy for prostate cancer are more likely to have periodontal disease (J Urol 2007;177:921-4). After controlling for risk factors, the prevalence of periodontal disease was 80.5 per cent among treated men compared with 3.7 per cent in matched controls not receiving treatment. There was no difference in bone mineral density between the groups but plaque scores were significantly higher among treated men. Food Commission rebuts MHRA on additives An independent watchdog has not accepted the MHRA's justification for including certain additives in medicines for children. The Food Commission (www.foodcomm.org.uk) found that most medicines for children contained additives, some of which , including azo dyes and benzoates , are not permitted in food. The Commission called on the pharmaceutical industry to stop using ,questionable additives'. The MHRA stated that the licensing process takes into account the likely exposure to excipients that are considered essential to make medicines palatable to children. Colouring helps children to identify the correct medicine, and preservatives ensure a reasonable shelf-life. A list of additives is included in the product's summary of product characteristics and patient information leaflet. In response, the Commission states: , , it is quite possible to flavour medicines with natural oils or extracts, and natural colourings such as beetroot and beta-carotene can be used instead of azo dyes. If parents were advised to give these medicinal products at mealtimes the manufacturers could also add a little sugar to sweeten their products, rather than relying on artificial sweeteners.' All triptans the same? There is no economic case for choosing one triptan over another and no evidence for preferring a particular triptan for adults, a systematic review has concluded. The Canadian Agency for Drugs and Technologies in Health (www.cadth.ca) found that published trials had compared most triptans with sumatriptan but not with one another, and most economic evaluations were flawed. New drug for HIV Janssen-Cilag has introduced darunavir (Prezista), a new protease inhibitor for the treatment of HIV infection. Licensed for highly pre- treated patients in whom more than one other pro- tease inhibitor regimen has failed, darunavir must be co-administered with ritonavir (Norvir). A month's treatment at the recommended dose of 600mg twice daily costs £446.70. Variation in liquid captopril for children The NHS uses a wide range of liquid formulations of captopril to treat children with heart failure , with no assurance of their bioequivalence (Arch Dis Child 2007; published online 15 March. doi: 10.1136/adc.2006.109389). Specialists in Leicester surveyed 13 tertiary paediatric cardiac centres and 13 hospitals that referred patients to them. Only three tertiary centres supplied the same liquid for-mulation of captopril as their referring hospitals. Four hospitals supplied tablets for crushing and dissolving in water; the other hospitals and centres used a total of nine different formulations. The authors say the formulations had widely varying shelf-lives, determined empirically in all but one case, and were used interchangeably despite a lack of quality control data to establish their bioequivalence. QOF CVD targets not good enough for GPs Two-thirds of GPs want Quality Outcome Framework (QOF) targets for cardiovascular disease brought into line with those of the Joint British Societies latest guidance (JBS2), according to a survey by doctor.net.uk. The survey of 1000 GPs showed that 88 per cent were aware of the JBS2 guidelines and most were already implementing the targets for lipids, blood pressure and blood glucose in some form; however, only 55 per cent were implementing the JBS2 obesity target and 14 per cent were implementing screening for the over-40s. The JBS2 target for lipids in at-risk patients is <4mmol per litre total cholesterol and <2 mmol per litre LDL-cholesterol, compared with <5 and <3mmol per litre respectively in QOF and the NSF. The survey was commissioned by Merck Sharp & Dohme and Schering- Plough. Fracture warning Following warnings in the US that rosiglitazone (Avandia) is associated with an increased risk of fractures in women, Takeda has advised prescribers that pioglitazone (Actos) carries a similar risk. An analysis of the company's clinical trials database has revealed an excess risk of fractures of bones below the elbow and knee. The incidence was similar to the excess risk associated with rosiglitazone and also confined to women. Scottish approvals The Scottish Medicines Consortium (www.scottish medicines.org.uk) has approved for use within NHS Scotland the sublingual tablet formulation buprenorphine/naloxone (Suboxone) for the treatment of opioid dependence. It has also approved the combined formulation of valsartan and amlodipine (Exforge) and the restricted use of the If inhibitor ivabradine (Procoralan). [source] Manufacturing technology for terrestrial PV systems: high efficiency crystalline Si through amorphous SiPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 2 2002Minoru Kaneiwa In order to meet the rapidly growing demands for solar power photovoltaic systems, grounded on public consciousness of global environmental issues, Sharp has increased the production of solar cells and modules 50-fold in last 7 years. Efforts to establish manufacturing technologies of solar cells for terrestial use and approaches toward high light-to-electricity conversion efficiency using silicon material (crystalline to amorphous ) are described. Copyright © 2002 John Wiley & Sons, Ltd. [source] Presenting Mark Twain: Keeping the Edge SharpTHE MARK TWAIN ANNUAL, Issue 1 2008REGINA FADEN First page of article [source] Front and Back Covers, Volume 24, Number 4.ANTHROPOLOGY TODAY, Issue 4 2008August 200 Front cover and back cover caption, volume 24 issue 4 Front cover Front cover: Front cover The front cover of this issue illustrates Vasiliki P. Neofotistos' article on the 2006 film Borat: Cultural learnings of America for make benefit glorious nation of Kazakhstan. In the film, British comedian Sacha Baron Cohen plays Borat Sagdiyev, a Kazakh journalist, who leaves his country on a project funded by the Ministry of Information to travel with his film producer to ,US and A, the greatest country in the world' and make a ,movie film' about American culture, with the putative aim of gaining insights into what makes America great and applying them to Kazakhstan. The film has generated contrasting reactions, ranging from CNN's praise of it as ,most excellent comedy' to lawsuits filed by, among others, residents of the Romanian village in which part of the film was shot. Borat has been condemned as deeply offensive to women, Kazakhs, fraternity brothers and Jews alike. In this issue Neofotistos focuses on some of the lessons that Western audiences could potentially take away from the film, using the notion of the grotesque as a tool to read Borat as an allegory of America that invites us to revisit aspects of our own culture and hence as a highly appropriate film for our times. Back cover Back cover: ,FORTRESS' SOUTH AFRICA? A South African and a foreigner find common ground in Islam. The two men are about to enter a mosque in downtown Pretoria for Friday prayers. Prayers at this mosque provide a meeting ground for Muslim men and women from all over Africa, and from Pakistan, India, Bangladesh and Afghanistan. Foreigners attending the mosque range from diplomats to illegal immigrants. Significant numbers of black South Africans from all walks of life have converted to Islam in recent years. In this issue John Sharp shows that there are many circumstances in which - as in this photograph - South Africans and foreigners from elsewhere in Africa pursue shared interests peacefully. Anthropological field research points to the range of these contexts, which have largely been ignored by commentators attempting to explain the episode of mass ,xenophobic' violence that wracked South African cities and towns in May 2008. Explanations focus on the xenophobic attitudes of ordinary South Africans, and link these attitudes to competition for resources between locals who are poor and their equally poor counterparts from further north. Recent research indicates, however, not only that relationships between poor South Africans and poor foreigners are more complex than most commentators allow, but also that South African xenophobia begins at the top, among the leaders of the ANC government and the black and white elites whose interests it serves. Sharp argues that a newly-issued report on the xenophobic violence by a government-orientated think tank reproduces the dominant xenophobic discourse in its recommendation that the state should construct a ,Fortress SA' with impenetrable borders, while seeking to mask its adherence to official discourse by representing its proposals as a response to the xenophobic attitudes of poor South Africans. As Sharp suggests, anthropological research might offer a more nuanced response to the issues. [source] Bone edema scored on magnetic resonance imaging scans of the dominant carpus at presentation predicts radiographic joint damage of the hands and feet six years later in patients with rheumatoid arthritisARTHRITIS & RHEUMATISM, Issue 7 2003Fiona M. McQueen Objective Magnetic resonance imaging (MRI) is capable of revealing synovitis and tendinitis in early rheumatoid arthritis (RA), as well as bone edema and erosion. These features are visible before radiographic joint damage occurs. We sought to examine whether MRI of one body region (the wrist) can be used to predict whole-body radiography scores reflecting joint damage at 6 years. Methods We conducted a 6-year prospective study of a cohort of patients who fulfilled the criteria for RA at presentation, using clinical parameters, radiographs, and MRI scans of the dominant wrist. Of the 42 patients enrolled at baseline, full MRI, radiographic, and clinical data were available for 31 at 6-year followup. MRI scans were scored by 2 radiologists, using a validated scoring system. Radiographs of the hands and feet were graded using the modified Sharp scoring method. MRI and radiography scores obtained at baseline and 6 years were compared, and baseline MRI scores were examined for their ability to predict radiographic outcome at 6 years. Results At 6 years, the total Sharp score correlated significantly with the total MRI score and the MRI erosion score (r = 0.81, P < 0.0001 and r = 0.79, P < 0.0001, respectively). The 6-year Sharp score also correlated with the baseline total MRI and MRI erosion scores (r = 0.56, P < 0.0001 and r = 0.33, P = 0.03, respectively). MRI synovitis and bone edema scores remained constant for the group as a whole over 6 years, but bone erosion scores progressed (P = 0.0001), consistent with radiographic deterioration. Erosions on 6-year MRI scans were frequently preceded by MRI bone edema at baseline (odds ratio 6.5, 95% confidence interval 2.78,18.1). Regression models indicated that the baseline MRI bone edema score was predictive of the 6-year total Sharp score (P = 0.01), as was the C-reactive protein (CRP) level (P = 0.0002). Neither shared epitope status nor swollen or tender joint counts predicted radiographic outcome in this cohort. A model incorporating baseline MRI scores for erosion, bone edema, synovitis, and tendinitis plus the CRP level and the erythrocyte sedimentation rate explained 59% of the variance in the 6-year total Sharp score (R2 = 0.59, adjusted R2 = 0.44). Conclusion MRI scans performed at the first presentation of RA can be used to help predict future radiographic damage, allowing disease-modifying therapy to be targeted to patients with aggressive disease. [source] COBRA combination therapy in patients with early rheumatoid arthritis: Long-term structural benefits of a brief interventionARTHRITIS & RHEUMATISM, Issue 2 2002Robert B. M. Landewé Objective The Combinatietherapie Bij Reumatoide Artritis (COBRA) trial demonstrated that step-down combination therapy with prednisolone, methotrexate, and sulfasalazine (SSZ) was superior to SSZ monotherapy for suppressing disease activity and radiologic progression of rheumatoid arthritis (RA). The current study was conducted to investigate whether the benefits of COBRA therapy were sustained over time, and to determine which baseline factors could predict outcome. Methods All patients had participated in the 56-week COBRA trial. During followup, they were seen by their own rheumatologists and were also assessed regularly by study nurses; no treatment protocol was specified. Disease activity, radiologic damage, and functional ability were the primary outcome domains. Two independent assessors scored radiographs in sequence according to the Sharp/van der Heijde method. Outcomes were analyzed by generalized estimating equations on the basis of intent-to-treat, starting with data obtained at the last visit of the COBRA trial (56 weeks after baseline). Results At the beginning of followup, patients in the COBRA group had a significantly lower mean time-averaged 28-joint disease activity score (DAS28) and a significantly lower median radiologic damage (Sharp) score compared with those in the SSZ monotherapy group. The functional ability score (Health Assessment Questionnaire [HAQ]) was similar in both groups. During the 4,5 year followup period, the time-averaged DAS28 decreased 0.17 points per year in the SSZ group and 0.07 in the COBRA group. The Sharp progression rate was 8.6 points per year in the SSZ group and 5.6 in the COBRA group. After adjustment for differences in treatment and disease activity during followup, the between-group difference in the rate of radiologic progression was 3.7 points per year. The HAQ score did not change significantly over time. Independent baseline predictors of radiologic progression over time (apart from treatment allocation) were rheumatoid factor positivity, Sharp score, and DAS28. Conclusion An initial 6-month cycle of intensive combination treatment that includes high-dose corticosteroids results in sustained suppression of the rate of radiologic progression in patients with early RA, independent of subsequent antirheumatic therapy. [source] Paroster extraordinarius sp. nov., a new groundwater diving beetle from the Flinders Ranges, with notes on other diving beetles from gravels in South Australia (Coleoptera: Dytiscidae)AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 1 2010Remko Leys Abstract The first groundwater (stygobitic) diving beetle is reported from South Australia. Paroster extraordinarius sp. nov. (Dytiscidae: Hydroporini) is described and figured. Its morphology and mitochondrial DNA sequences place it in the hydroporine genus Paroster Sharp. Phylogenetic analysis shows that the new species is imbedded in a clade of stygobitic species from the Yilgarn area of Western Australia. The evolution of this species is discussed and compared with observations on the behaviour and distribution of other dytiscid beetles found in subterranean habitats in South Australia. [source] Jumping across Wallace's line: Allodessus Guignot and Limbodessus Guignot revisited (Coleoptera: Dytiscidae, Bidessini) based on molecular-phylogenetic and morphological dataAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 2 2004Michael Balke Abstract The monotypic genus Allodessus (Coleoptera: Dytiscidae: Bidessini) has previously been considered to be strictly Australian, with A. bistrigatus (Clark) having a wide range on that continent and in Tonga. Based on data gathered from extensive museum collections and a molecular phylogeny of the group, this concept is revised. The following species of the Bidessini are now assigned to Allodessus: Bidessus megacephalus Gschwendtner (East Palearctic), Liodessus oliveri Ordish (New Zealand), Bidessus skottsbergi Zimmermann (Chile: Easter Island) and Bidessus thienemanni Csiki (Indonesia: Java). The latter, as well as L. oliveri, are morphologically extremely similar to A. bistrigatus and are, perhaps, the same species. As currently delimited, Allodessus has a wide range, spanning parts of the Australian, Oriental, Palearctic and Oceanian regions. Based on a cladistic analysis of mtDNA sequence data, we synonymize Boongurrus Larson and Tjirtudessus Watts & Humphreys with Limbodessus Guignot. Australian species of Liodessus Guignot are transferred to Limbodessus, which is the sister group of Allodessus. The following 33 species are transferred to Limbodessus: Oceania ,Liodessus cheesmanae (Balfour-Browne 1939) [Vanuatu], Bidessus curviplicatus Zimmermann 1927[Samoa]; Australian epigean,Bidessus dispar Sharp 1882, B. praelargus Lea 1899, Hydroporus amabilis Clark 1862, H. gemellus Clark 1862, B. inornatus Sharp 1882, B. Shuckardii Clark 1862; Australian hyporheic ,Boongurrus rivulus Larson 1994; Australian stygobiont ,Nirridessus bigbellensis Watts & Humphreys 2000, N. challaensis Watts & Humphreys 2001, N. cueensis Watts & Humphreys 2000, N. fridaywellensis Watts & Humphreys 2001, N. hinkleri Watts & Humphreys 2000, N. lapostaae Watts & Humphreys 1999, N. masonensis Watts & Humphreys 2001, N. morgani Watts & Humphreys 2000, N. pinnaclesensis Watts & Humphreys 2001, N. pulpa Watts & Humphreys 1999, N. windarraensis Watts & Humphreys 1999, Tjirtudessus bialveus Watts & Humphreys 2003, T. cunyuensis Watts & Humphreys 2003, T. eberhardi Watts & Humphreys 1999, T. hahni Watts & Humphreys 2 00, T. jundeeensis Watts & Humphreys 2003, T. karalundiensis Watts & Humphreys 2003, T. macrotarsus Watts & Humphreys 2003, T. magnificus Watts & Humphreys 2000, T. raesidensis Watts & Humphreys 2001, T. silus Watts & Humphreys 2003, T. sweetwatersensis Watts & Humphreys 2003, T. wilunaensis Watts & Humphreys 2003, T. yuinmeryensis Watts & Humphreys 2003. Limbodessus compactus (Clark) has a wide Asian/Australian range, while all other Limbodessus spp. are endemic to the Australian region and represent an adaptive radiation of epigean, hyporheic and subterranean species, as well as numerous undescribed New Guinea high-altitude specialists. Another species of Bidessini, Papuadessus pakdjoko Balke, is newly recorded from Papua New Guinea here. [source] Ablation of Posteroseptal and Left Posterior Accessory Pathways Guided by Left Atrium,Coronary Sinus Musculature Activation SequenceJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2008RÓBERT PAP M.D. Introduction: While some posteroseptal and left posterior accessory pathways (APs) can be ablated on the tricuspid annulus or within the coronary venous system, others require a left-sided approach. "Fragmented" or double potentials are frequently recorded in the coronary sinus (CS), with a smaller, blunt component from left atrial (LA) myocardium, and a larger, sharp signal from the CS musculature. Methods and Results: Forty patients with posteroseptal or left posterior AP were included. The LA,CS activation sequence was determined at the earliest site during retrograde AP conduction. Eleven APs (27.5%) were ablated on the tricuspid annulus (right endocardial), 9 (22.5%) inside the coronary venous system (epicardial), and 20 (50%) on the mitral annulus (left endocardial). A "fragmented" or double "atrial" potential was recorded in all patients inside the CS at the earliest site during retrograde AP conduction. Sharp potential from the CS preceded the LA blunt component (sharp/blunt sequence) in all patients with an epicardial AP, and in 10 of 11 (91%) patients with a right endocardial AP. Therefore, 18 of 19 (95%) APs ablated by a right-sided approach produced this pattern. The reverse sequence (blunt/sharp) was recorded in 19 of 20 (95%) patients with a left endocardial AP. Conclusion: During retrograde AP conduction, the sequence of LA,CS musculature activation,as deduced from analysis of electrograms recorded at the earliest site inside the CS,can differentiate posteroseptal and left posterior APs that require left heart catheterization from those that can be eliminated by a totally venous approach. [source] Villin: A marker for development of the epithelial pyloric borderDEVELOPMENTAL DYNAMICS, Issue 1 2002Evan M. Braunstein Abstract In the adult gastrointestinal tract, the morphologic borders between esophagus and stomach and between stomach and small intestine are literally one cell thick. The patterning mechanisms that underlie the development of these sharp regional divisions from a once continuous endodermal tube are still obscure. In the embryonic endoderm of the developing gut, region-specific expression of certain genes (e.g., intestine-specific expression of the actin bundling protein villin) can be detected as early as 9.0 days post coitum, although the morphologic differentiation of the gut epithelium proper does not begin until 4 to 5 days later. By using a mouse model in which a ,-galactosidase marker has been inserted into the endogenous villin locus, we examined the development of the stomach/intestinal (pyloric) border during gut organogenesis. The data indicate that the border is not sharp from the outset. Rather, the initial border region is characterized by a decreasing gradient of villin/,-galactosidase expression that extends into the distal stomach. A sharp epithelial border of villin/,-galactosidase expression appears abruptly at day 16 and is further refined over the next 3 weeks to form the distinct one-cell-thick border characteristic of the adult. These results indicate that an important previously unrecognized patterning event occurs in the gut epithelium at 16 days; this event may define an epithelial compartment boundary between the stomach and the intestine. The villin/,-galactosidase mouse model characterized here provides an excellent substrate with which to further dissect the mechanisms involved in this patterning process. © 2002 Wiley-Liss, Inc. [source] Parameters governing reproducibility of flow properties of porous monoliths photopatterned within microfluidic channelsELECTROPHORESIS, Issue 14 2010Mei He Abstract We report the patternability as well as the reproducibility and stability of flow resistance of polymer monolithic beds photopatterned within microfluidic channels as a function of initial reagent composition and preparation conditions. 2-Hydroxyethyl methacrylate and ethylene dimethacrylate-based polymer monoliths were selectively photopatterned within microchannels and their flow resistance was evaluated using a photobleaching, TOF linear flow rate measurement method developed in our lab. This measurement technique was found to be significantly more informative for columns formed in microfluidic channels compared with bulk monolith characterization by mercury intrusion porosimetry. 1-Octanol was determined to provide sharp bed edge formation and relatively low flow resistance by photopatterning relative to other porogenic solvents. Compared with literature formulations which did not achieve good flow stability and reproducibility from batch to batch, using 2-hydroxyethyl methacrylate, ethylene dimethacrylate and 1-octanol as porogenic solvents, less than 4% RSD was achieved in flow stability over 7 days for monoliths prepared with 60,80% crosslinker(monomer+crosslinker) ratio. Column-to-column variation of 5% RSD was obtained in this composition range. These results demonstrate that photopatterning of uniform polymer monolithic beds, which is critical for applications in multiplexed microfluidic systems, requires careful attention to the parameters that affect reproducibility, specifically the porogenic solvent choice and the crosslinker to monomer ratio. [source] Autosomal Dominant Inheritance of Centrotemporal Sharp Waves in Rolandic Epilepsy FamiliesEPILEPSIA, Issue 12 2007Bhavna Bali Summary Purpose: Centrotemporal sharp (CTS) waves, the electroencephalogram (EEG) hallmark of rolandic epilepsy, are found in approximately 4% of the childhood population. The inheritance of CTS is presumed autosomal dominant but this is controversial. Previous studies have varied considerably in methodology, especially in the control of bias and confounding. We aimed to test the hypothesis of autosomal dominant inheritance of CTS in a well-designed family segregation analysis study. Methods: Probands with rolandic epilepsy were collected through unambiguous single ascertainment. Siblings in the age range 4,16 years underwent sleep-deprived EEG; observations from those who remained awake were omitted. CTS were rated as present or absent by two independent observers blinded to the study hypothesis and subject identities. We computed the segregation ratio of CTS, corrected for ascertainment. We tested the segregation ratio estimate for consistency with dominant and recessive modes of inheritance, and compared the observed sex ratio of those affected with CTS for consistency with sex linkage. Results: Thirty siblings from 23 families underwent EEG examination. Twenty-three showed evidence of sleep in their EEG recordings. Eleven of 23 recordings demonstrated CTS, yielding a corrected segregation ratio of 0.48 (95% CI: 0.27,0.69). The male to female ratio of CTS affectedness was approximately equal. Conclusions: The segregation ratio of CTS in rolandic epilepsy families is consistent with a highly penetrant autosomal dominant inheritance, with equal sex ratio. Autosomal recessive and X-linked inheritance are rejected. The CTS locus might act in combination with one or more loci to produce the phenotype of rolandic epilepsy. [source] Movement-Induced Focal Motor Seizures and Choreoathetosis As- sociated with Nonketotic Hyperglycemia: A Case ReportEPILEPSIA, Issue 2000Hisashi Tanaka Case Report: We report the case of a diabetic woman who developed right-sided reflex seizures and bilateral choreoathetosis during an episode of nonketotic hyperglycemia. The patient was a 67-year-old woman with a 14-year history of HCV-related liver cirrhosis who experienced polydipsia and polyuria in January 1998. She began to have episodes of abnormal hyperkinetic movements of the right upper extremity and tonic-clonic seizures in the right arm triggered by voluntary movements of right or bilateral arms in the beginning of March 1998. The seizures increased in frequency and consequently left her disabled. She was admitted to our hospital with complaints of these abnormal motor phenomena on March 9, 1998. Neurological examinations revealed that she was alert, well-oriented, and that cranial nerve functions were normal. Slight motor weakness of the right upper limb and deep tendon hyporeflexes were observed in all extremities. Sensations and cerebellar functions were intact. Choreic or athetotic involuntary movements were seen in the bilateral upper limbs and neck. These involuntary movements were increased by voluntary movement or posturing of the upper limbs. The focal tonic-clonic seizures were easily triggered by voluntary movements such as knotting a cord. This seizure suddenly began by tonic movements in the right upper limb and gradually progressed to the right hemi-face and neck without loss of consciousness. The average duration of seizures was about one minute. The laboratory data demonstrated mild leukocytopenia, thrombocytopenia, hepatic dysfunction, and hyperglycemia without ketosis. Fasting blood glucose was 41 I mg/dl, and HbAlc was 14.5%. Blood ammonia was within normal levels. Cranial CT revealed no abnormalities. Brain MRI on T I-weighted images demonstrated bilateral high signal intensity in the putamen. An interictal EEG revealed a symmetrical slow background activity of 7,8 Hz. An ictal EEG recording showed a 2.5 4 Hz irregular sharp and slow wave discharge in the bilateral frontal-central regions. Treatment with carbamazepine was ineffective for the seizures. However, the seizures completely disappeared after the administration of insulin on March 17. Under good control of the hyperglycemia, the abnormal involuntary movements decreased gradually and then completely disappeared; the patient became neurologically asymptomatic by March 30. The follow-tip EEG demonstrated 9-Hz alpha background activity without any epileptic discharges. Conclusions: Nonketotic hyperglycemia has been rarely reported to cause stimulus-induced seizures or hyperkinetic involuntary movements such as hemichorea-ballism. To our knowledge, this is the first reported case of both induced seizures and involuntary movements simultaneously caused by hyperglycemia. Movement-induced seizures and choreoathetoid movements in this patient can be considered to result from transiently-increased activity in the basal ganglia and/or cerebral cortex associated with metaholic disorders. [source] Impact of S100B on local field potential patterns in anesthetized and kainic acid-induced seizure conditions in vivoEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2007Seiichi Sakatani Abstract S100B is a calcium-binding protein predominantly expressed in astrocytes. Previous studies using gene-manipulated animals have suggested that the protein has a role in synaptic plasticity and learning. In order to assess the physiological roles of the protein in active neural circuitry, we recorded spontaneous neural activities from various layers of the neocortex and hippocampus in urethane-anesthetized S100B knockout (KO) and wildtype (WT) control mice. Typical local field oscillation patterns including the slow (0.5,2 Hz) oscillations in the neocortex, theta (3,8 Hz) and sharp wave-associated ripple (120,180 Hz) oscillations in the hippocampus were observed in both genotypes. Comparisons of the frequency, power and peak amplitude have shown that these oscillatory patterns were virtually indistinguishable between WT and KO. When seizure was induced by intraperitoneal injection of kainic acid, a difference between WT and KO appeared in the CA1 radiatum local field potential pattern, where seizure events were characterized by prominent appearance of hyper-synchronous gamma band (30,80 Hz) activity. Although both genotypes developed seizures within 40 min, the gamma amplitude was significantly smaller during the development of seizures in KO mice. Our results suggest that deficiency of S100B does not have a profound impact on spontaneous neural activity in normal conditions. However, when neural activity was sufficiently raised, activation of S100B-related pathways may take effect, resulting in modulation of neural activities. [source] Mapping responses to frequency sweeps and tones in the inferior colliculus of house miceEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2003Steffen R. Hage Abstract In auditory maps of the primary auditory cortex, neural response properties are arranged in a systematic way over the cortical surface. As in the visual system, such maps may play a critical role in the representation of sounds for perception and cognition. By recording from single neurons in the central nucleus of the inferior colliculus (ICC) of the mouse, we present the first evidence for spatial organizations of parameters of frequency sweeps (sweep speed, upward/downward sweep direction) and of whole-field tone response patterns together with a map of frequency tuning curve shape. The maps of sweep speed, tone response patterns and tuning curve shape are concentrically arranged on frequency band laminae of the ICC with the representation of slow speeds, build up response types and sharp tuning mainly in the centre of a lamina, and all (including high) speeds, phasic response types and broad tuning mainly in the periphery. Representation of sweep direction shows preferences for upward sweeps medially and laterally and downward sweeps mainly centrally in the ICC (either striped or concentric map). These maps are compatible with the idea of a gradient of decreasing inhibition from the centre to the periphery of the ICC and by gradients of intrinsic neuronal properties (onset or sustained responding). The maps in the inferior colliculus compare favourably with corresponding maps in the primary auditory cortex, and we show how the maps of sweep speed and direction selectivity of the primary auditory cortex could be derived from the here-found maps of the inferior colliculus. [source] The mechanism of fluid infiltration in peridotites at Almklovdalen, western NorwayGEOFLUIDS (ELECTRONIC), Issue 3 2002O. Kostenko Abstract A major Alpine-type peridotite located at Almklovdalen in the Western Gneiss Region of Norway was infiltrated by aqueous fluids at several stages during late Caledonian uplift and retrogressive metamorphism. Following peak metamorphic conditions in the garnet,peridotite stability field, the peridotite experienced pervasive fluid infiltration and retrogression in the chlorite,peridotite stability field. Subsequently, the peridotite was infiltrated locally by nonreactive fluids along fracture networks forming pipe-like structures, typically on the order of 10 m wide. Fluid migration away from the fractures into the initially impermeable peridotite matrix was facilitated by pervasive dilation of grain boundaries and the formation of intragranular hydrofractures. Microstructural observations of serpentine occupying the originally fluid-filled inclusion space indicate that the pervasively infiltrating fluid was characterized by a high dihedral angle (, > 60°) and ,curled up' into discontinuous channels and fluid inclusion arrays following the infiltration event. Re-equilibration of the fluid phase topology took place by growth and dissolution processes driven by the excess surface energy represented by the ,forcefully' introduced external fluid. Pervasive fluid introduction into the peridotite reduced local effective stresses, increased the effective grain boundary diffusion rates and caused extensive recrystallization and some grain coarsening of the infiltrated volumes. Grain boundary migration associated with this recrystallization swept off abundant intragranular fluid inclusions in the original chlorite peridotite, leading to a significant colour change of the rock. This colour change defines a relatively sharp front typically located 1,20 cm away from the fractures where the nonreactive fluids originally entered the peridotite. Our observations demonstrate how crustal rocks may be pervasively infiltrated by fluids with high dihedral angles (, > 60°) and emphasize the coupling between hydrofracturing and textural equilibration of the grain boundary networks and the fluid phase topology. [source] The Ridgeway Conglomerate Formation of SW Wales, and its implications.GEOLOGICAL JOURNAL, Issue 1 2007The end of the Lower Old Red Sandstone? Abstract The Devonian Old Red Sandstone Ridgeway Conglomerate Formation crops out in Pembrokeshire, SW Wales. It was deposited as part of a dryland alluvial fan, axial fluvial valley deposystem. It conformably overlies the mid Lochkovian Freshwater West Formation and probably predates deposition of the Lower Cosheston Group Mill Bay Formation indicating an Early Devonian (latest Lochkovian to earliest Pragian) age, rather than a Middle Devonian age as suggested by previous workers. It therefore represents the youngest preserved formation of the Milford Haven Group south of the Ritec Fault. The Formation thickens drastically into the Ritec Fault, indicating its control on sedimentation. The half-graben topography initiated deposition of a hangingwall alluvial fan that was sourced from a southerly Lower Palaeozoic/Precambrian provenance within the present-day Bristol Channel. The Formation is heterolithic in nature, with deposits on the fan reflecting a mixture of processes. Conglomerates were deposited primarily by laterally extensive sheetfloods, and as bars in low-relief, laterally accreted channels. Sandstones were also predominantly deposited by sheetfloods. Gritty mudrocks in comparison demonstrate deposition by cohesive debris flows. The fan prograded northward and interfingered with a low-gradient, high-sinuosity fluvial channel system dominated by inclined and non-inclined heterolithic stratification. Thinly laminated mudstone and sandstone interbeds were deposited in ephemeral fan-toe and axial valley lakes that may have developed during sub-humid climatic episodes. The lacustrine heterolithic association has associated matgrounds and possible ,algal roll-up' structures. Calcretized peetee structures and root traces comprise a lake margin calcrete association. Fan gravels prograded into the axial fluvial valley during periods of increased sediment flux that may represent semi-arid conditions and/or episodes of tectonic activity. Calcretes of varying development were established in both the fan and axial valley zones. Calcretes with lower stages of development are more proximal to the Ritec Fault reflecting decreased soil residence times and high deposition rates within the axial valley. More strongly developed soil profiles on the fan may indicate sequence boundaries associated with low sediment flux, or increased soil residence time due to active fan-channel migration (the pedofacies concept). Groundwater calcretes have sharp-based and layer-bound calcrete profiles. Gully-bed cements are locally developed within the fan gravels. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||||||||||||||