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1.
J Small Anim Pract ; 62(10): 918-923, 2021 10.
Article in English | MEDLINE | ID: mdl-33599994

ABSTRACT

Historically, omentalisation and serosal patching have been used to augment gastrointestinal wall defects or incisions where gastrointestinal viability is of concern. This report describes the novel use of a transversus abdominis muscle on-lay flap to augment and provide support to compromised intestine in three cases. The muscle flap was used to support: the ileum following reduction of an intussusception in a dog (case 1), the gastric wall following gastric strangulation, dilation and volvulus in a diaphragmatic rupture in a cat (case 2) and the jejunum following enterotomy and full-thickness ulcer resection with primary repair in a dog (case 3). All animals were discharged within 4 days postoperatively with no short- or long-term complications reported by either the referring veterinary surgeons on routine postoperative examination or on telephone follow-up with the owners (case 1: 10 months, case 2: 30 months, case 3: 6 weeks). The creation of a flap of the transversus abdominis muscle may provide a useful alternative or adjunct to previously described techniques for supporting the gastrointestinal tract when gastrointestinal tissue viability is questionable or resection is not feasible. Further prospective clinical evaluation studies would be indicated to determine whether the muscle flap remains viable or compare whether this technique should be recommended over conventional methods.


Subject(s)
Abdominal Muscles , Plastic Surgery Procedures , Abdominal Muscles/surgery , Animals , Cats , Dogs , Intestines , Plastic Surgery Procedures/veterinary , Stomach , Surgical Flaps/veterinary
2.
J Small Anim Pract ; 62(1): 55-58, 2021 01.
Article in English | MEDLINE | ID: mdl-31045244

ABSTRACT

This report describes a novel technique for abdominal wall reconstruction using an internal abdominal oblique muscle flap in an Australian kelpie. En bloc resection of a chondrosarcoma and biopsy scar centred on the 13th rib was performed to include full thickness thoracic wall (12th rib, extending caudally) and lateral abdominal wall (including the vascular pedicle of the external abdominal oblique muscle). The diaphragm was advanced to close the thorax. A flap using the caudal internal abdominal oblique muscle with the base dorsally was elevated and rotated 90° to fill the dorsal defect. The ventral defect was closed using the composite ventral abdominal muscles. The skin was closed primarily. The dog developed a self-resolving seroma. Twelve months postoperatively, the dog was able to engage in agility competitions. A viable muscle flap using the internal abdominal oblique muscle provides a useful alternative to previously described techniques for autogenous closure of a large abdominal wall wound.


Subject(s)
Abdominal Wall , Plastic Surgery Procedures , Abdominal Muscles/surgery , Abdominal Oblique Muscles , Abdominal Wall/surgery , Animals , Australia , Dogs , Plastic Surgery Procedures/veterinary , Surgical Flaps/veterinary
3.
J Small Anim Pract ; 60(3): 191-197, 2019 Mar.
Article in English | MEDLINE | ID: mdl-29380371

ABSTRACT

Internal obturator and/or semitendinosus muscle flaps were used to reinforce primary appositional rectal wall repair in three dogs and one cat in this case series. All three dogs incurred rectal wall compromise during surgical excision of anal sac tumours. The cat sustained bite wounds to the perianal region resulting in abscessation and a rectal tear. Our results indicate that application of an internal obturator and/or semitendinosus muscle flap can reduce the risk of rectal wall dehiscence after primary repair, and consequently the risk of pararectal abscess or rectocutaneous fistula formation.


Subject(s)
Hamstring Muscles , Animals , Cats , Dogs , Muscle, Skeletal , Perineum , Surgical Flaps
4.
J Small Anim Pract ; 60(2): 86-95, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30387152

ABSTRACT

OBJECTIVE: To estimate prevalence and identify demographic risk factors for urinary incontinence in male dogs. METHODS AND METHODS: The study population included all dogs within the VetCompass database from September 1, 2009 to July 7, 2013. Electronic patient records were searched for urinary incontinence cases; demographic and clinical information were extracted and analysed. RESULTS: Of 109,428 male dogs attending 119 clinics in England, there were an estimated 1027 dogs diagnosed with urinary incontinence, giving a prevalence of 0.94% (95% confidence interval: 0.88 to 1.00). Breeds with highest odds of incontinence in male dogs (compared with mixed breed dogs) included the bull mastiff (odds ratio: 17.21, 95% confidence interval: 6.65 to 44.56, case=5, non-case=314, P<0.001), Irish red setter (odds ratio: 12.79, 95% confidence interval: 4.83 to 33.84, case=5, non-case=142, P<0.001), fox terrier (odds ratio: 9.60, 95% confidence interval: 3.68 to 25.05, case=5, non-case=176, P < 0.001), bulldog (odds ratio: 5.72, 95% confidence interval: 2.24 to 14.59, case=5, non-case=929, P<0.001) and boxer (odds ratio: 3.65, 95% confidence interval: 1.84 to 7.25, case=10, non-case=1470, P<0.001). Increased odds of urinary incontinence were associated with greater age (age 9 to 12 years, odds ratio: 10.46, 95% confidence interval: 6.59 to 16.62, n=12,348, P<0.001) and being insured (odds ratio: 1.96, 95% confidence interval: 1.53 to 2.51, n=26,202, P<0.001). There was no association with castration or bodyweight using multi-variable analysis. CLINICAL SIGNIFICANCE: The overall prevalence of urinary incontinence in male dogs is approximately 1%, which may be higher than expected given the sparsity of reports describing this problem. In contrast to bitches, neutering and bodyweight were not associated with greater odds of urinary incontinence, which is important when giving neutering advice.


Subject(s)
Dog Diseases , Urinary Incontinence/veterinary , Animals , Cattle , Dogs , England , Male , Prevalence , Risk Factors
5.
Phys Rev Lett ; 119(24): 243601, 2017 Dec 15.
Article in English | MEDLINE | ID: mdl-29286721

ABSTRACT

We report on a laser locked to a silicon cavity operating continuously at 4 K with 1×10^{-16} instability and a median linewidth of 17 mHz at 1542 nm. This is a tenfold improvement in short-term instability, and a 10^{4} improvement in linewidth, over previous sub-10-K systems. Operating at low temperatures reduces the thermal noise floor and, thus, is advantageous toward reaching an instability of 10^{-18}, a long-sought goal of the optical clock community. The performance of this system demonstrates the technical readiness for the development of the next generation of ultrastable lasers that operate with an ultranarrow linewidth and long-term stability without user intervention.

6.
J Small Anim Pract ; 58(12): 685-693, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28881018

ABSTRACT

OBJECTIVES: To estimate prevalence and demographic risk factors for urinary incontinence in bitches under primary veterinary care in England. METHODS: The study population included all bitches within the VetCompass database from September 1, 2009 to July 7, 2013. Electronic patient records were searched for urinary incontinence cases and additional demographic and clinical information was extracted. RESULTS: Of 100,397 bitches attending 119 clinics in England, an estimated 3108 were diagnosed with urinary incontinence. The prevalence of urinary incontinence was 3·14% (95% confidence intervals: 2·97 to 3·33). Medical therapy was prescribed to 45·6% cases. Predisposed breeds included the Irish setter (odds ratio: 8·09; 95% confidence intervals: 3·15 to 20·80; P< 0·001) and Dobermann (odds ratio: 7·98; 95% confidence intervals: 4·38 to 14·54; P< 0·001). Increased odds of a diagnosis of urinary incontinence were associated with: (1) weight at or above the mean adult bodyweight for the breed (odds ratio: 1·31; 95% confidence intervals: 1·12 to 1·54; P< 0·001), (2) age 9 to 12 years (odds ratio: 3·86; 95% confidence intervals: 2·86 to 5·20, P< 0·001), (3) neuter status (odds ratio: 2·23; 95% confidence intervals: 1·52 to 3·25, P< 0·001) and (4) being insured (odds ratio: 1·59; 95% confidence intervals: 1·34 to 1·88, P< 0·001). CLINICAL IMPACT: Clinical Impact: Urinary incontinence affects just over 3% of bitches overall but affects more than 15% of bitches in high-risk breeds including the Irish setter, Dobermann, bearded collie, rough collie and Dalmatian. These results provide an evidence base for clinicians to enhance clinical recommendations on neutering and weight control, especially in high-risk breeds.


Subject(s)
Dog Diseases/epidemiology , Urinary Incontinence/veterinary , Animals , Body Weight , Breeding , Dogs , Female , Ovariectomy/veterinary , Prevalence , Risk Factors , Urinary Incontinence/epidemiology
7.
J Helminthol ; 90(4): 476-82, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26278677

ABSTRACT

The presence of the cyclophyllidean cestode Rodentolepis straminea (Cestoda: Hymenolepididae), was confirmed by molecular DNA analysis from a wood mouse (Apodemus sylvaticus) population inhabiting urban woodland in Salford, Greater Manchester (UK) with a prevalence of 27.8%. It would appear that the only previously published record of this species in A. sylvaticus in the British Isles is that from south-west Ireland, where 24% of the wood mice examined were infected with R. straminea. This species has been recorded in studies on A. sylvaticus in continental Europe. The current report represents a new record for R. straminea on mainland Britain and a first study of helminth parasites in an urban wood mouse population.


Subject(s)
Cestoda/isolation & purification , Cestode Infections/veterinary , Murinae/parasitology , Rodent Diseases/epidemiology , Rodent Diseases/parasitology , Animals , Cestoda/anatomy & histology , Cestoda/classification , Cestoda/genetics , Cestode Infections/epidemiology , Cestode Infections/parasitology , Cities/epidemiology , DNA, Helminth/genetics , Mice , Microscopy , Prevalence , United Kingdom/epidemiology
8.
Opt Lett ; 39(7): 1980-3, 2014 Apr 01.
Article in English | MEDLINE | ID: mdl-24686654

ABSTRACT

Active control and cancellation of residual amplitude modulation (RAM) in phase modulation of an optical carrier is one of the key technologies for achieving the ultimate stability of a laser locked to an ultrastable optical cavity. Furthermore, such techniques are versatile tools in various frequency modulation-based spectroscopy applications. In this Letter we report a simple and robust approach to actively stabilize RAM in an optical phase modulation process. We employ a waveguide-based electro-optic modulator (EOM) to provide phase modulation and implement an active servo with both DC electric field and temperature feedback onto the EOM to cancel both the in-phase and quadrature components of the RAM. This technique allows RAM control on the parts-per-million level where RAM-induced frequency instability is comparable to or lower than the fundamental thermal noise limit of the best available optical cavities.

9.
Vet Rec ; 173(22): 549, 2013 Dec 07.
Article in English | MEDLINE | ID: mdl-24158327

ABSTRACT

This study aims to describe the incidence and risk factors for positive urinary tract culture, the prevalence of urinary tract pathogens in single organism and mixed cultures and changes in their antimicrobial resistance over 10 years. A retrospective review of computer records detailing canine urine samples submitted between August 1999 and September 2009 for culture and sensitivity in a UK tertiary referral hospital is described. 17.5 per cent of 5923 samples (670 of 4530 dogs) were positive cultures. 85.3 per cent of cultures yielded a single isolate. The prevalence of bacterial species differed between mixed and single isolate cultures. Entire and neutered female dogs were more likely to return positive cultures than male dogs (OR=2.5 and 1.5, respectively). Escherichia coli was most commonly isolated (53.9 per cent) and affected female dogs, older dogs and neutered dogs more. There was an increase in the antimicrobial resistance of Enterococcus faecalis and Pseudomonas Aeruginosa, and a decrease in the effectiveness of enrofloxacin, cephalexin and oxytetracycline. The prevalence of urinary bacterial isolates is described for a large group of dogs. Monitoring changes in antimicrobial efficacy and microbial resistance guides the empirical use of antimicrobials for the treatment of urinary tract infection and helps formulate strategic plans to limit drug resistance.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Dog Diseases/drug therapy , Dog Diseases/epidemiology , Drug Resistance, Multiple, Bacterial , Urinary Tract Infections/veterinary , Animals , Dog Diseases/microbiology , Dogs , Female , Male , Prevalence , Retrospective Studies , Risk Factors , United Kingdom/epidemiology , Urinary Tract Infections/drug therapy , Urinary Tract Infections/epidemiology , Urinary Tract Infections/microbiology
10.
Diabetologia ; 53(11): 2334-9, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20703447

ABSTRACT

AIMS/HYPOTHESIS: Genetic mapping has identified over 20 loci contributing to genetic risk of type 2 diabetes. The next step is to identify the genes and mechanisms regulating the contributions of genetic risk to disease. The goal of this study was to evaluate the effect of age, height, weight and risk alleles on expression of candidate genes in diabetes-associated regions in three relevant human tissues. METHODS: We measured transcript abundance for WFS1, KCNJ11, TCF2 (also known as HNF1B), PPARG, HHEX, IDE, CDKAL1, CDKN2A, CDKN2B, IGF2BP2, SLC30A8 and TCF7L2 by quantitative RT-PCR in human pancreas (n = 50), colon (n = 195) and liver (n = 50). Tissue samples were genotyped for single nucleotide polymorphisms (SNPs) associated with type 2 diabetes. The effects of age, height, weight, tissue and SNP on RNA expression were tested by linear modelling. RESULTS: Expression of all genes exhibited tissue bias. Immunohistochemistry confirmed the findings for HHEX, IDE and SLC30A8, which showed strongest tissue-specific mRNA expression bias. Neither age, height nor weight were associated with gene expression. We found no evidence that type 2 diabetes-associated SNPs affect neighbouring gene expression (cis-expression quantitative trait loci) in colon, pancreas and liver. CONCLUSIONS/INTERPRETATION: This study provides new evidence that tissue-type, but not age, height, weight or SNPs in or near candidate genes associated with increased risk of type 2 diabetes are strong contributors to differential gene expression in the genes and tissues examined.


Subject(s)
Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Adult , Aged , Body Height , Body Weight , Cation Transport Proteins/genetics , Cation Transport Proteins/metabolism , Cyclin-Dependent Kinase 5/genetics , Cyclin-Dependent Kinase 5/metabolism , Cyclin-Dependent Kinase Inhibitor p15/genetics , Cyclin-Dependent Kinase Inhibitor p15/metabolism , Cyclin-Dependent Kinase Inhibitor p16/genetics , Cyclin-Dependent Kinase Inhibitor p16/metabolism , Female , Genotype , Hepatocyte Nuclear Factor 1-beta/genetics , Hepatocyte Nuclear Factor 1-beta/metabolism , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Immunohistochemistry , In Vitro Techniques , Insulysin/genetics , Insulysin/metabolism , Male , Membrane Proteins/genetics , Membrane Proteins/metabolism , Middle Aged , PPAR gamma/genetics , PPAR gamma/metabolism , Polymorphism, Single Nucleotide/genetics , Potassium Channels, Inwardly Rectifying/genetics , Potassium Channels, Inwardly Rectifying/metabolism , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Transcription Factor 7-Like 2 Protein/genetics , Transcription Factor 7-Like 2 Protein/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Zinc Transporter 8 , tRNA Methyltransferases
11.
Diabetologia ; 53(4): 712-6, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20033802

ABSTRACT

AIMS/HYPOTHESIS: Variants in the TCF7L2 gene remain the strongest genetic associations with increased risk of type 2 diabetes. Recently, we identified a unique splicing form of TCF7L2 expressed in pancreatic islets, pancreas and colon and detected by assay 'ex13-13b'. The expression of ex13-13b strongly correlated with proinsulin in glucose-stimulated pancreatic islets, suggesting a potential role for this form in the development of type 2 diabetes. The goal of this study was to further characterise this unique TCF7L2 splicing form in human tissues. METHODS: We used a panel of 34 human tissues and 80 human cell lines to measure the expression of assay ex13-13b with use of quantitative RT-PCR. RESULTS: The highest expression of assay ex13-13b was detected in several areas of the brain (hypothalamus/thalamus, occipital lobe) and in neuronal cell line SHS5Y5. Low expression was confirmed in pancreatic islets, small intestine, pancreas and colon, while no expression was detected in other human tissues and cell lines. The expression of assay ex13-13b correlated with the gene for cocaine- and amphetamine-regulated transcript (CART, also known as CARTPT) in a panel of human tissues (n = 12, r = 0.85, p = 0.00046), pancreatic islets (n = 23, r = 0.62, p = 0.0016) and colon (n = 98, r = 0.54, p < 0.0001). CONCLUSIONS/INTERPRETATION: The significant correlation between expression of a unique splicing form of TCF7L2, named here TCF7L2-NE, and CART, the gene for an anorexigenic neurohormone expressed in the central and peripheral nervous system, suggests that these transcripts may share neuroendocrine functions important for brain, gut and pancreatic islets.


Subject(s)
Alternative Splicing , Brain/physiology , Colon/physiology , Intestine, Small/physiology , Islets of Langerhans/physiology , TCF Transcription Factors/genetics , Cell Line , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/genetics , Genetic Variation , Humans , Mutation , Pancreas/physiology , Reverse Transcriptase Polymerase Chain Reaction , Risk Factors , Transcription Factor 7-Like 2 Protein
12.
Br J Surg ; 93(11): 1342-6, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16989011

ABSTRACT

BACKGROUND: The aim of this randomized clinical trial was to determine whether a single intravenous dose of 2 g flucloxacillin could prevent wound infection after primary non-reconstructive breast surgery. METHODS: The study included 618 patients undergoing local excision (n = 490), mastectomy (n = 107) or microdochectomy (n = 21). Patients were randomized to receive either a single dose of flucloxacillin immediately after the induction of anaesthesia or no intervention. Wound morbidity was monitored by an independent research nurse for 42 days after surgery. RESULTS: The incidence of wound infection was similar in the two groups: 10 of 311 (3.2 percent) in the flucloxacillin group and 14 of 307 (4.6 percent) in the control group (chi(2) = 0.75, P = 0.387; relative risk 0.71, 95 percent confidence interval 0.32 to 1.53). The groups also had similar wound scores and rates of moderate or severe cellulitis. Wound infection presented a median of 16 days after surgery. CONCLUSION: The administration of a single dose of flucloxacillin failed to reduce the rate of wound infection after non-reconstructive breast surgery.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Antibiotic Prophylaxis/methods , Floxacillin/administration & dosage , Mammaplasty/methods , Surgical Wound Infection/prevention & control , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Patient Compliance , Preoperative Care/methods , Treatment Outcome
13.
Mycol Res ; 110(Pt 1): 28-37, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16431274

ABSTRACT

Little is known at the molecular level about the transporters involved in nutrient transfer in the plant/powdery mildew interaction. A PCR-based approach was used to identify and isolate a partial-length cDNA coding for an isoform of the plasma membrane H+ -ATPase (EcPMA1) in the biotrophic pathogenic fungus Erysiphe cichoracearum. Southern analysis suggests that EcPMA1 exists as a single-copy gene. Sequence analysis indicated a high similarity of EcPMA1 to other fungal H+ -ATPases. Expression of EcPMA1 increases in infected Arabidopsis leaves as the disease progresses, correlating with the growth of the pathogen.


Subject(s)
Ascomycota/enzymology , Proton-Translocating ATPases/genetics , Amino Acid Sequence , Ascomycota/classification , Ascomycota/genetics , Cell Membrane , Cloning, Molecular , Gene Expression , Membrane Proteins/genetics , Membrane Proteins/metabolism , Molecular Sequence Data , Phylogeny , Proton-Translocating ATPases/isolation & purification , Proton-Translocating ATPases/metabolism
14.
Opt Lett ; 29(23): 2806-8, 2004 Dec 01.
Article in English | MEDLINE | ID: mdl-15605512

ABSTRACT

We demonstrate optical clockwork without the need for carrier-envelope phase control by use of sum-frequency generation between a continuous-wave optical parametric oscillator at 3.39 microm and a femtosecond mode-locked Ti:sapphire laser with two strong spectral peaks at 834 and 670 nm, a spectral difference matched by the 3.39-microm radiation.

15.
J Exp Bot ; 54(393): 2601-13, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14585824

ABSTRACT

Transition metals such as Fe, Cu, Mn, and Zn are essential minerals for normal plant growth and development, although they can be toxic when present in excess. Thus, for healthy plant growth, a range of transition metals must be acquired from the soil, distributed around the plant, and their concentrations carefully regulated within different cells and organelles. Membrane transport systems are likely to play a central role in these processes. The application of powerful genetic and molecular techniques has now identified a range of gene families that are likely to be involved in transition metal transport. These include the heavy metal ATPases (HMAs), the Nramps, the cation diffusion facilitator (CDF) family, the ZIP family, and the cation antiporters. This review provides a broad overview of the range of potential transport systems now thought to be involved in the uptake, distribution and homeostasis of transition metals in plants.


Subject(s)
Cation Transport Proteins/metabolism , Metals/metabolism , Plants/metabolism , Cell Membrane/metabolism , Plant Proteins/metabolism
16.
Plant J ; 35(2): 164-76, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12848823

ABSTRACT

Mechanisms are required by all organisms to maintain the concentration of essential heavy metals (e.g. Zn and Cu) within physiological limits and to minimise the detrimental effects of non-essential heavy metals (e.g. Cd). Heavy-metal P-type ATPases (HMAs) are a subgroup of the P-type ATPase superfamily that may contribute to metal homeostasis in plants. We cloned and characterised a member of this family, AtHMA4, from Arabidopsis thaliana that clusters with the Zn/Co/Cd/Pb subclass of HMAs on phylogenetic analysis. Sequencing of the AtHMA4 cDNA showed that it contained the conserved motifs found in all P-type ATPases and also motifs that are characteristic of heavy-metal ATPases. Escherichia coli mutants defective in the HMAs, CopA and ZntA, were used in functional complementation studies. AtHMA4 was able to restore growth at high [Zn] in the zntA mutant but not at high [Cu] in the copA mutant, suggesting a role in zinc transport. Heterologous expression of AtHMA4 in Saccharomyces cerevisiae made the yeast more resistant to Cd but did not affect sensitivity to other metals compared with vector-transformed controls. The organ specificity of AtHMA4 was analysed in Arabidopsis and showed that AtHMA4 was expressed in a range of tissues with highest expression in roots. AtHMA4 was upregulated in roots exposed to elevated levels of Zn and Mn but downregulated by Cd. Possible physiological roles of this transporter in Arabidopsis are discussed.


Subject(s)
Adenosine Triphosphatases/genetics , Arabidopsis Proteins/genetics , Arabidopsis/enzymology , Metals, Heavy/metabolism , Adenosine Triphosphatases/metabolism , Amino Acid Sequence , Arabidopsis/chemistry , Arabidopsis/genetics , Arabidopsis Proteins/metabolism , Cadmium/metabolism , Cadmium/pharmacology , Cloning, Molecular , Copper/metabolism , Copper/pharmacology , DNA, Complementary/chemistry , DNA, Complementary/genetics , Escherichia coli/genetics , Escherichia coli/metabolism , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Plant/drug effects , Lead/metabolism , Lead/pharmacology , Metals, Heavy/pharmacology , Molecular Sequence Data , Phylogeny , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Substrate Specificity , Zinc/metabolism , Zinc/pharmacology
17.
Plant Physiol ; 132(2): 821-9, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12805612

ABSTRACT

Powdery mildew fungi are biotrophic pathogens that form a complex interface, the haustorium, between the host plant and the parasite. The pathogen acts as an additional sink, competing with host sinks, resulting in considerable modification of photoassimilate production and partitioning within the host tissue. Here, we examine the factors that may contribute to these changes. We show for the first time in one biotrophic interaction (Arabidopsis/Erysiphe cichoracearum) all of the following responses: Glc uptake in host tissues is enhanced after fungal infection; this coincides with the induction of expression of the monosaccharide transporter gene, Arabidopsis sugar transport protein 4 (AtSTP4), in infected leaves; invertase activity and transcript levels for a cell wall invertase, Atbetafruct1, increase substantially in Arabidopsis during attack by this pathogen. Before infection, Arabidopsis plants transformed with an AtSTP4 promoter-beta-glucuronidase construct show expression mainly in sink tissues such as roots; after infection, AtSTP4 expression is induced in the mature leaves and increases over the 6-d time period. Sections of infected leaves stained for beta-glucuronidase show that AtSTP4 expression is not confined to infected epidermal cells but is also evident in a wider range of cells, including those of the vascular tissue. The results are discussed in relation to the possible coordinated expression of hexose transporters and cell wall invertase in the host response to powdery mildew infection.


Subject(s)
Arabidopsis Proteins/genetics , Arabidopsis/genetics , Ascomycota/pathogenicity , Glycoside Hydrolases/genetics , Monosaccharide Transport Proteins/genetics , 4-Chloromercuribenzenesulfonate/pharmacology , Arabidopsis/drug effects , Arabidopsis/microbiology , Carbonyl Cyanide m-Chlorophenyl Hydrazone/pharmacology , Cell Wall/drug effects , Cell Wall/enzymology , Ethylmaleimide/pharmacology , Glucose/metabolism , Phlorhizin/pharmacology , Plant Diseases , Plant Leaves/drug effects , Plant Leaves/metabolism , beta-Fructofuranosidase
18.
J Exp Bot ; 53(366): 1-11, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11741035

ABSTRACT

Heavy metals such as Cu and Zn are essential for normal plant growth, although elevated concentrations of both essential and non-essential metals can result in growth inhibition and toxicity symptoms. Plants possess a range of potential cellular mechanisms that may be involved in the detoxification of heavy metals and thus tolerance to metal stress. These include roles for the following: for mycorrhiza and for binding to cell wall and extracellular exudates; for reduced uptake or efflux pumping of metals at the plasma membrane; for chelation of metals in the cytosol by peptides such as phytochelatins; for the repair of stress-damaged proteins; and for the compartmentation of metals in the vacuole by tonoplast-located transporters. This review provides a broad overview of the evidence for an involvement of each mechanism in heavy metal detoxification and tolerance.


Subject(s)
Adaptation, Physiological , Chelating Agents/metabolism , Metalloproteins/metabolism , Metals, Heavy/metabolism , Cell Wall/metabolism , Glutathione , Heat-Shock Proteins/metabolism , Inactivation, Metabolic , Metallothionein/metabolism , Metals, Heavy/pharmacokinetics , Phytochelatins , Plant Roots/metabolism , Vacuoles/metabolism
19.
J Acoust Soc Am ; 110(4): 2167-82, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11681393

ABSTRACT

We present results from a pilot study directed at developing an anchorable subjective speech quality test. The test uses multidimensional scaling techniques to obtain quantitative information about the perceptual attributes of speech. In the first phase of the study, subjects ranked perceptual distances between samples of speech produced by two different talkers, one male and one female, processed by a variety of codecs. The resulting distance matrices were processed to obtain, for each talker, a stimulus space for the various speech samples. This stimulus space has the properties that distances between stimuli in this space correspond to perceptual distances between stimuli and that the dimensions of this space correspond to attributes used by the subjects in determining perceptual distances. Mean opinion scores (MOS) scores obtained in an earlier study were found to be highly correlated with position in the stimulus space, and the three dimensions of the stimulus space were found to have identifiable physical and perceptual correlates. In the second phase of the study, we developed techniques for fitting speech generated by a new codec under investigation into a previously established stimulus space. The user is provided with a collection of speech samples and with the stimulus space for these speech samples as determined by a large-scale listening test. The user then carries out a much smaller listening test to determine the position of the new stimulus in the previously established stimulus space. This system is anchorable, so that different versions of a codec under development can be compared directly, and it provides more detailed information than the single number provided by MOS testing. We suggest that this information could be used to advantage in algorithm development and in development of objective measures of speech quality.


Subject(s)
Speech Acoustics , Speech Perception , Voice Quality , Adult , Aged , Female , Humans , Individuality , Judgment , Male , Middle Aged , Sound Spectrography
20.
Science ; 293(5533): 1286-9, 2001 Aug 17.
Article in English | MEDLINE | ID: mdl-11509721

ABSTRACT

We generated a coherently synthesized optical pulse from two independent mode-locked femtosecond lasers, providing a route to extend the coherent bandwidth available for ultrafast science. The two separate lasers (one centered at 760 nanometers wavelength, the other at 810 nanometers) are tightly synchronized and phase-locked. Coherence between the two lasers is demonstrated via spectral interferometry and second-order field cross-correlation. Measurements reveal a coherently synthesized pulse that has a temporally narrower second-order autocorrelation width and that exhibits a larger amplitude than the individual laser outputs. This work represents a new and flexible approach to the synthesis of coherent light.

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