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In Vivo Phosphorylation Site Mapping and Functional Characterization of Arabidopsis Phototropin 1

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Molecular Plant 2008年第1期1卷 178-194页

作者： Stuart Sullivan Catriona e. Thomson Douglas J. Lamont matthew A. Jones John M. Christie Plant Science Group Division of Biochemistry and Molecular Biology. Institute of Biomedical and Life Sciences University of Glasgow. University Avenue. Glasgow Scotland UK FingerPrints Proteomics Facility Post-Genomics and Molecular Interactions Centre. School of Life Sciences MSI/WTB/CIR Complex University of Dundee. Dundee Scotland UK

Phototropins （phot1 and phot2） are blue-light receptor kinases controlling a range of responses that optimize the photosynthetic efficiency of plants. Light sensing is mediated by two flavin-binding motifs, known as LOVl and LOV2, located within the N-terminal region of the protein. Photoexcitation via LOV2 leads to activation of the C-terminal kinase domain and consequently receptor autophosphorylation. However, knowledge of the in-vivo phosphorylation sites for Arabidopsis phototropins is lacking and has impeded progress in elucidating the functional significance of receptor phos- phorylation. We have purified photl from Arabidopsis and identified the in-vivo sites of receptor phosphorylation by liquid chromatography tandem mass spectrometry. Arabidopsis-derived photl binds flavin mononucleotide as chromophore and is phosphorylated at four major sites located upstream of LOV2 （Ser^58, Ser^85, Ser^350, and Ser^410）, three of which are induced by blue light. Nevertheless, structure-function analysis indicates that the biological activity of photl can be attributed to a modular unit comprising the LOV2-kinase region of the protein. Thus, peptide regions upstream of LOV2, including the sites of receptor phosphorylation identified here, do not appear to be important for receptor signaling. By contrast, these regions may be necessary for maximizing stomatal performance and possibly light-induced relocalization of photl.

关键词： Phototropins (phot1 and phot2) lavin-binding motifs

Balanced and Unbalanced Components of Moist Atmospheric Flows with Phase Changes

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Chinese Annals of Mathematics,Series B 2019年第6期40卷 1005-1038页

作者： Alfredo N.WeTZeL Leslie M.smith Samuel N.STeCHMANN Jonathan e.MARTIN Department of Mathematics University of Wisconsin-MadisonMadisonWI 53706USA Department of Mathematics and Department of engineering Physics University of Wisconsin-MadisonMadisonWI 53706USA Department of Mathematics and Department of Atmospheric and Oceanic Sciences University of Wisconsin-MadisonMadisonWI 53706USA Department of Atmospheric and Oceanic Sciences University of Wisconsin-MadisonMadisonWI 53706USA

Atmospheric variables(temperature, velocity, etc.) are often decomposed into balanced and unbalanced components that represent low-frequency and high-frequency waves, respectively. Such decompositions can be defined, for instance, in terms of eigenmodes of a linear operator. Traditionally these decompositions ignore phase changes of water since phase changes create a piecewise-linear operator that differs in different phases(cloudy versus non-cloudy). Here we investigate the following question: How can a balanced–unbalanced decomposition be performed in the presence of phase changes? A method is described here motivated by the case of small Froude and Rossby numbers,in which case the asymptotic limit yields precipitating quasi-geostrophic equations with phase changes. Facilitated by its zero-frequency eigenvalue, the balanced component can be found by potential vorticity(PV) inversion, by solving an elliptic partial differential equation(PDe), which includes Heaviside discontinuities due to phase changes. The method is also compared with two simpler methods: one which neglects phase changes, and one which simply treats the raw pressure data as a streamfunction. Tests are shown for both synthetic, idealized data and data from Weather Research and Forecasting(WRF) model simulations. In comparisons, the phase-change method and no-phase-change method produce substantial differences within cloudy regions, of approximately 5K in potential temperature, due to the presence of clouds and phase changes in the data. A theoretical justification is also derived in the form of a elliptic PDe for the differences in the two streamfunctions.

关键词： Potential vorticity inversion Moist atmospheric dynamics Slow-fast systems Balanced-unbalanced decomposition elliptic partial differential equations

Infection does not increase long-term mortality in patients with acute severe alcoholic hepatitis treated with corticosteroids

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World Journal of Gastroenterology 2017年第11期23卷 2052-2059页

作者： Ashwin D Dhanda Ashish Sinha Vicky Hunt Sarah Saleem matthew e Cramp Peter L Collins Institute of Translational and Stratified Medicine Plymouth University Peninsula Schools of Medicine and Dentistry South West Liver Unit Plymouth Hospitals NHS Trust Department of Liver Medicine University Hospitals Bristol NHS Foundation Trust

AIM To determine whether infection in patients with acute severe alcoholic hepatitis(AAH) treated with corticosteroids is associated with increased *** Consecutive patients with AAH were treated with steroids and recruited to the study. Clinically relevant infections(body temperature > 38 ℃ or e than 4 h, ascitic neutrophil count > 0.25 ×109/L, consolidation on chest radiograph or clinically relevant positive microbiological culture of bodily fluid) were recorded prospectively. Clinical and laboratory parameters were recorded and survival at 90 d and 6 mo was determined. Univariate analysis of factors associated with 90-d mortality was performed and significant variables included in a multivariate *** Seventy-two patients were included in the final analysis(mean age 47.9 years, 26% female, mean discriminant function 53.0). Overall mortality in the group occurred in 15(21%), 23(32%) and 31(43%) at day 28, day 90 and 1 year respectively. 36(50%) had a clinically relevant infection during their hospitalisation(23 after initiation of steroids). The median time to development of incident infection after commencement of steroids was 10 d. The commonest site of infection was ascites(31%) and bacteraemia(31%) followed by urinary tract(19%) and respiratory tract(8%). Forty-one separate organisms were isolated in 33 patients; the most frequent genus was escherichia(22%) and enterococcus(20%). Infection was not associated with 90-d or 1 year mortality but was associated with higher creatinine, model for end-stage liver disease and Lille score. Baseline urea was the only independent predictor of 90-d *** Clinically relevant infections are common in patients with AAH but are not associated with increased 90-d or 1 year mortality.

关键词： Alcoholic hepatitis escherichia Infection Lille score Corticosteroids

Process stability and microbial community composition in pig manure and food waste anaerobic co-digesters operated at low HRTs

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Frontiers of environmental Science & engineering 2017年第3期11卷 53-65页

作者： Conor Dennehy Peadar G. Lawlor Gillian e. Gardiner Yan Jiang Paul Cormican matthew S. McCabe Xinmin Zhan Department of Civil engineering College of Engineering and Informatics National University of Ireland Galway Ireland Teagasc Pig Development Department Animal and Grassland Research and Innovation Centre Fermoy Ireland Department of Science Waterford Institute of Technology Waterford Ireland Teagasc Animal and Bioscience Research Department Animal and Grassland Research and Innovation Centre Dunsany Meath Ireland

This study assessed the effects of reducing hydraulic retention times （HRTs） from 21 days to 10.5 days when anaerobically co-digesting pig manure and food waste. Continuously stirred tank reactors of 3.75 L working volume were operated in triplicate at 42℃. Digester HRT was progressively decreased from 21 to 15 days to 10.5 days, with an associated increase in organic loading rate （OLR） from 3.1 kg volatile solids （VS）·m^-***^-1 to 5.1 kg VS·m^***-1 to 7.25 kg VS.m^-3·day^-1. Reducing HRT from 21 days to 15 days caused a decrease in specific methane yields and VS removal rates. Operation at a HRT of 10.5 days initially resulted in the accumulation of isobutyric acid in each reactor. High throughput 16S rRNA gene sequencing revealed that this increase coincided with a shift in acidogenic bacterial populations, which most likely resulted in the increased isobutyric acid concentrations. This may in turn have caused the increase in relative abundance of Clocamonaceae bacteria, which syntrophically degrade non-acetate volatile fatty acids （VFAs） into H2 and CO2. This, along with the increase in abundance of other syntrophic VFA oxidizers, such as Spiorchatetes, suggests that VFA oxidation plays a role in digester operation at low HRTs. Reducing the HRT to below 21 days compromised the ability of the anaerobic digestion system to reduce enteric indicator organism counts below regulatory limits.

关键词： Biogas Sequencing Clocamonaeeae Spiorchatetes Isobutyrate Biosafety

A post-classical theory of enamel biomineralization… and why we need one

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International Journal of Oral Science 2012年第3期4卷 129-134页

作者： James P Simmer Amelia S Richardson Yuan-Yuan Hu Charles e.smith Jan Ching-Chun Hu Department of Biologic and Materials Sciences School of Dentistry University of Michigan Ann Arbor USA Facility for electron Microscopy Research Department of Anatomy and CellBiology and Faculty ofDentstry McGlIUniversity. Montreal Canada

enamel crystals are unique in shape, orientation and organization. They are hundreds of thousands times longer than they are wide, run parallel to each other, are oriented with respect to the ameloblast membrane at the mineralization front and are organized into rod or interrod enamel. The classical theory of amelogenesis postulates that extracellular matrix proteins shape crystallites by specifically inhibiting ion deposition on the crystal sides, orient them by binding multiple crystallites and establish higher levels of crystal organization. elements of the classical theory are supported in principle by in vitro studies; however, the classical theory does not explain how enamel forms in vivo. In this review, we describe how amelogenesis is highly integrated with ameloblast cell activities and how the shape, orientation and organization of enamel mineral ribbons are established by a mineralization front apparatus along the secretory surface of the ameloblast cell membrane.

关键词： ameloblastin amelogenin enamelin mineralization front tooth

An unusual presentation of primary sclerosing cholangitis

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World Journal of Gastroenterology 2008年第43期14卷 6748-6749页

作者： Franklin Whitney Goldwire William e Norris Jonathan M Koff Zachary D Goodman Milton T smith Internal Medicine Walter Reed Army Medical Center Washington DC 20307United States Gastroenterology Walter Reed Army Medical Center Washington DC 20307United States Armed Forces Institute of Pathology Washington DC 20307United States

This case report describes the unusual presentation of a patient who had findings which were initially suggestive of a type Ⅳ choledochal cyst. Her liver biopsy demonstrated biliary cirrhosis. She was treated with endoscopic retrograde cholangiopancreatography and biliary stent exchanges over one year. Her cholangiogram one year later demonstrated resolution of the biliary cystic dilation which led to her initial diagnosis, with beading and stricturing of the hepatic ducts consistent with primary sclerosing cholangitis. Liver-associated enzymes and physical findings also improved. A liver biopsy one year later demonstrated a marked improvement in hepatic fibrosis with no evidence of cirrhosis.

关键词： Biliary cysts Cholangiogram endoscopic retrograde cholangiopancreatography Liver fibrosis Primary sclerosing cholangitis

Can bacterial virulence factors predict antibiotic resistant Helicobacter pylori infection?

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World Journal of Gastroenterology 2018年第9期24卷 971-981页

作者： Denise e Brennan Colin Dowd Colm O'Morain Deirdre McNamara Sinéad M smith Department of Clinical Medicine School of Medicine Trinity College Dublin

AIM To evaluate the association between virulence factor status and antibiotic resistance in Helicobacter pylori(H. pylori)-infected patients in Ireland. MeTHODS DNA was extracted from antral and corpus biopsies obtained from 165 H. pylori-infected patients. Genotyping for clarithromycin and fluoroquinolone-mediating mutations was performed using the Genotype Helico DR assay. cag A and vac A genotypes were investigated using PCR. ReSULTS Primary, secondary and overall resistance rates for clarithromycin were 50.5%(n = 53/105), 78.3%(n = 47/60) and 60.6%(n = 100/165), respectively. Primary, secondary and overall resistance rates for fluoroquinolones were 15.2%(n = 16/105) and 28.3%(n = 17/60) and 20%(n = 33/165), respectively. Resistance to both antibiotics was 12.4%(n = 13/105) in treatment-na?ve patients, 25%(n = 15/60) in those previously treated and 17%(n = 28/165) overall. A cag A-positive genotype was detected in 22.4%(n = 37/165) of patient samples. The dominant vac A genotype was S1/M2 at 44.8%(n = 74/165), followed by S2/M2 at 26.7%(n = 44/165), S1/M1 at 23.6%(n = 39/165) and S2/M1 at 4.8%(n = 8/165). Primary clarithromycin resistance was significantly lower in cag A-positive strains than in cag A-negative strains [32%(n = 8/25) vs 56.3%(n = 45/80); P = 0.03]. Similarly, in patients infected with more virulent H. pylori strains bearing the vac A s1 genotype, primary clarithromycin resistance was significantly lower than in those infected with less virulent strains bearing the vac A s2 genotype, [41%(n = 32/78) vs 77.8%(n = 21/27); P = 0.0001]. No statistically significant association was found between primary fluoroquinolone resistance and virulence factor *** Genotypic H. pylori clarithromycin resistance is high and cag A-negative strains are dominant in our population. Less virulent(cag A-negative and vac A S2-containing) strains of H. pylori are associated with primary clarithromycin resistance.

关键词： Helicobacter pylori Antibiotic resistance Fluoroquinolone Clarithromycin Virulence factor VacA CagA

Investigation of a cyanine dye assay for the evaluation of the biocompatibility of magnesium alloys by direct and indirect methods

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Bioactive Materials 2020年第1期5卷 26-33页

作者： Afrah Al Hegy Ryan smith eric R.Gauthier Joy e.Gray-Munro Dept.of Chemistry and Biochemistry Laurentian UniversitySudburyOntarioP3E 2C6Canada

Magnesium and its alloys are promising candidates for a new generation of biodegradable metals in orthopaedic applications due to their excellent biocompatibility,biodegradability,and mechanical properties that are similar to natural ***,direct in vitro assessment of these materials in the presence of cells is complicated by degradation products from the alloy that lead to a false positive for the most commonly used cell adhesion and cell proliferation *** this paper,a cyanine dye was used to quantitatively evaluate the in vitro biocompatibility of a Mg AZ31 alloy by both direct and indirect *** cytotoxicity of the corrosion products was evaluated via an indirect method;a 25%decrease in cell viability compared to control samples was ***,direct assessment of cell adhesion and proliferation showed a statistically significant increase in cell number at the surface after 72 *** addition,the degradation rate and surface characteristics of the Mg AZ31 alloy were evaluated for both direct and indirect *** degradation rate was unaffected by the presence of cells while evidence of an increase in calcium phosphate deposition on the magnesium alloy surface in the presence of cells was *** study demonstrates that a cyanine dye based assay provides a more accurate assessment of the overall in vitro biocompatibility of biodegradable metals than the more commonly used assays reported in the literature to date.

关键词： Magnesium alloys Biocompatibility Direct method Indirect method Cyanine dye Cell adhesion Cell proliferation Cytotoxicity

Water balloon-induced orbital fracture in an aviator

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Military Medical Research 2020年第2期7卷 245-248页

作者： Timothy e.Holland David M.smith Guy N.Gibson Jared G.Brinkerhoff Flight and Operational Medical Clinic 78th Medical Group655 Seventh StreetRobins Air Force BaseRobinsGA 31098USA Department of Radiology Ehrling Bergquist Clinic2501 Capehart RdOffutt AFBNEOffutt 68113-2160USA Flight and Operational Medical Clinic 5th Medical Group194 Missilie AveMinot AFBNDMinot 58705USA

Background:Orbital fractures are common injuries found in facial *** etiologies of orbital fractures include motor vehicle collisions and *** report the case of a 32-year-old male who suffered an orbital fracture from a water ***,we describe the aeromedical complications that may result from this ***,we attempt to answer the question of when a patient may return to flying after sustaining such an injury through review of the *** presentation:A 32-year-old male pilot with the United States Air Force was at an outdoor event with his unit when he was struck with a water balloon launched from a sling shot into his left *** afterwards,he had an onset of subcutaneous emphysema and was escorted to a nearby emergency *** tomography identified an orbital fracture with associated orbital and subcutaneous *** patient was evaluated by a plastic surgeon and was determined not to be a surgical *** weeks later,he returned to flying ***:Water balloons are thought to be safe and harmless ***,when coupled with sling shots,water balloons can become formidable projectiles capable of significant orbital injury including orbital *** injuries are concerning to aviators,as the most common sites for fractures of the orbit are the thin ethmoid and maxillary bones adjacent to the *** altitude,gases in the sinuses may expand and enter the orbit through these fractures,which may suddenly incapacitate the *** is important for flight surgeons to identify and assess these individuals to determine suitability for flying.

关键词： Boyle’s law Orbital emphysema Facial fracture