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1.
J Dairy Sci ; 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38908711

ABSTRACT

Milking speed is an important trait influencing udder health of dairy cows as well as labor efficiency. Yet, it has received little attention in genomic association studies. The main objective of this study was to determine regions and genes on the genome with a potential effect on milking speed in Fleckvieh (dual purpose Simmental) cattle. Genome-wide association studies were conducted using de-regressed breeding values of bulls as phenotypes. Six SNP on 4 autosomes were significantly associated with milking speed for additive effects. Significant regions on BTA4 and BTA19 correspond with findings for other dairy cattle breeds. Based on the observation of Fleckvieh breed managers, variation of milking speed in batches of daughters of some bulls is much higher than in daughter groups of other bulls. This difference in within family variation may be caused by transmission of alternative alleles of bulls being heterozygous for a gene affecting milking speed. To check on this, we considered standard deviation of yield deviations in milking speed of half-sib daughters as a new trait and performed GWAS for dominance effects. One signal on BTA5 passed the genome wide Bonferroni threshold that corresponded to the significant signal from standard GWAS on de-regressed breeding values. The key conclusion of this study is that several strong genomic signals were found for milking speed in Fleckvieh cattle and that the strongest of them are supported by similar findings in Brown Swiss and Holstein Friesian cattle. Milking speed is a complex trait whose sub-processes have not yet been elucidated in detail. Hence, it remains a challenge to link the associated regions on the genome with causal genes and their functions.

2.
Schweiz Arch Tierheilkd ; 163(9): 565-576, 2021 Sep.
Article in German | MEDLINE | ID: mdl-34465560

ABSTRACT

INTRODUCTION: Due to the widespread resistance of small ruminant gastrointestinal nematodes (GIN) against anthelmintic drugs the established control strategies need to get adapted, aiming to reduce their high dependence from chemical drugs. Host-specific development of GIN can be used as a tool when grazing different species on the same pastures. The aim of this study was to estimate the effect of mixed grazing with cattle on the development of GIN infections in goats. Goat flocks with 3 heifers (Group Mix; Visp: n = 12, Chur: n = 15) and without heifers (Group Solo; Visp: n = 7, Chur: n = 15) were grazed separately on pastures at altitudes of 910 m (location Chur) and 1240 m (location Visp) above sea level resp. during one grazing season each. The composition of the mixed groups aimed to achieve a similar intake of roughage of both species. The stocking rate and the availability of roughage in the solo groups was balanced proportionately according to the situation in the mixed groups. The individual GIN egg excretion, the composition of the GIN larvae in the faeces, the FAMACHA©-Score and the pasture contamination with infective GIN larvae was determined in monthly intervals. At both sites the goats in the mixed groups showed a significantly lower mean GIN egg excretion compared with those of the Solo groups (p .


INTRODUCTION: En raison de la résistance généralisée des nématodes gastro-intestinaux (NGI) des petits ruminants aux médicaments anthelminthiques, les stratégies de contrôle établies doivent être adaptées, visant à réduire leur forte dépendance aux substances chimiques. Le développement des NGI spécifiques à leur hôte peut être exploité, en introduisant la présence de différentes espèces d'hôtes sur les mêmes pâturages. Le but de cette étude était d'estimer l'effet du pâturage mixte avec des bovins sur le développement d'infections à NGI chez les chèvres. Des troupeaux de chèvres avec 3 génisses (Groupe Mix : Viège : n = 12, Coire : n = 15) et sans génisses (Groupe Solo : Viège : n = 7, Coire : n = 15) ont été placés sur des pâturages à des altitudes de 910 m (Coire) et 1240 m (Viège) au-dessus du niveau de la mer pendant une saison de pâturage. La composition des groupes mixtes visait à obtenir une consommation similaire de fourrage des deux espèces. La densité animale et la disponibilité du fourrage dans les groupes solos étaient en proportion comparables aux groupes mixtes. L'excrétion individuelle d'oeufs de NGI, les variétés de genres de NGI dans les fèces, le taux d'anémie (score FAMACHA©) et la contamination des pâturages par des larves infectieuses de NGI ont été déterminés à intervalles mensuels. Sur les deux sites, les chèvres des groupes Mix ont montré une excrétion d'oeufs de NGI significativement inférieure par rapport à celle des groupes Solo (p .


Subject(s)
Anthelmintics , Goat Diseases , Nematoda , Nematode Infections , Animals , Anthelmintics/therapeutic use , Cattle , Feces , Female , Goat Diseases/drug therapy , Goat Diseases/epidemiology , Goats , Nematode Infections/veterinary , Parasite Egg Count/veterinary
3.
Nat Plants ; 4(7): 473-484, 2018 07.
Article in English | MEDLINE | ID: mdl-29892093

ABSTRACT

Rose is the world's most important ornamental plant, with economic, cultural and symbolic value. Roses are cultivated worldwide and sold as garden roses, cut flowers and potted plants. Roses are outbred and can have various ploidy levels. Our objectives were to develop a high-quality reference genome sequence for the genus Rosa by sequencing a doubled haploid, combining long and short reads, and anchoring to a high-density genetic map, and to study the genome structure and genetic basis of major ornamental traits. We produced a doubled haploid rose line ('HapOB') from Rosa chinensis 'Old Blush' and generated a rose genome assembly anchored to seven pseudo-chromosomes (512 Mb with N50 of 3.4 Mb and 564 contigs). The length of 512 Mb represents 90.1-96.1% of the estimated haploid genome size of rose. Of the assembly, 95% is contained in only 196 contigs. The anchoring was validated using high-density diploid and tetraploid genetic maps. We delineated hallmark chromosomal features, including the pericentromeric regions, through annotation of transposable element families and positioned centromeric repeats using fluorescent in situ hybridization. The rose genome displays extensive synteny with the Fragaria vesca genome, and we delineated only two major rearrangements. Genetic diversity was analysed using resequencing data of seven diploid and one tetraploid Rosa species selected from various sections of the genus. Combining genetic and genomic approaches, we identified potential genetic regulators of key ornamental traits, including prickle density and the number of flower petals. A rose APETALA2/TOE homologue is proposed to be the major regulator of petal number in rose. This reference sequence is an important resource for studying polyploidization, meiosis and developmental processes, as we demonstrated for flower and prickle development. It will also accelerate breeding through the development of molecular markers linked to traits, the identification of the genes underlying them and the exploitation of synteny across Rosaceae.


Subject(s)
Genome, Plant/genetics , Rosa/genetics , Centromere/genetics , Chromosomes, Plant/genetics , Flowers/anatomy & histology , Flowers/genetics , Fragaria/genetics , Genetic Variation/genetics , Haploidy , In Situ Hybridization, Fluorescence , Phylogeny , Quantitative Trait Loci/genetics , Quantitative Trait, Heritable , Rosa/anatomy & histology , Sequence Analysis, DNA , Synteny/genetics
4.
Anaesthesist ; 65(4): 258-66, 2016 Apr.
Article in German | MEDLINE | ID: mdl-27033115

ABSTRACT

BACKGROUND: Existential questions concerning the limitation of treatment must be answered when a major complication occurs after an elective operation. In these situations, the patient himself/herself cannot be asked about his/her will. Therefore, medical professionals must attempt to determine the patient's presumed will either through an existing advance directive (AD) or by consulting with the patient's relatives. Only one-fifth of all patients create an AD in advance, and the relatives cannot always reliably reproduce the patient's presumed will. Thus, it is important to talk about issues such as do-not-resuscitate before a patient undergoes elective major surgery. However, such discussions may unsettle and frighten the patient. This study aimed to determine if patients are willing to talk about difficult questions such as resuscitation before major surgery. How many patients create an AD? Who should decide when patients themselves are no longer capable? OBJECTIVES: Between March 1 and October 30, 2014, patients who attended the preoperative anaesthesia consultation service received a one-page questionnaire. In addition to a few personal questions (e.g. sex, age, surgery, health status), the questionnaire included four questions that could be answered according to a four-point Likert scale, with a yes or no response, or a with a selection of answers. RESULTS: 272 men (45.5%) and 321 women (53.7%) with a mean age of 52.9 years (standard deviation: 17.8 years) completed a questionnaire. 312 patients (52.2%) claimed to be healthy, while 116 patients (19.4%) observed a minimal health restriction. 125 patients (19.4%) suffered from a chronic illness that markedly (n = 108) or strongly (n = 17) limited daily life. More than three-fourths of the respondents were very ready (377/63.0%) or ready (79 patients/13.2%) to talk about the treatment of severe complications after an elective operation. 12.7% of the patients would rather not to talk about this topic (n = 47) or refused (n = 37). 58 patients (9.7%) checked the box "I do not know" or gave no answer. There was no significant difference between men and women (p = 0.58). The patient's state of health did not significantly affect the patient's willingness to talk (p = 0.61). 110 patients (18.4%) had already completed an AD. The probability of having an AD is highly dependent on the age and state of health. The likelihood of having one increases by 4% for each year of life, and in health-impaired patients it is 73% higher than in healthy ones. If the patient could no longer decide for himself/herself, the following options were selected from multiple possible answers: a relative decides (n = 272), discussing this with a physician prior to surgery (n = 212), previously created AD (n = 198), the treatment team decides (n = 28), I do not know/not (n = 48). CONCLUSIONS: Although the majority of the respondents were willing to talk about difficult issues before an operation, it remains unclear to what extent these results can be generalized. However, the results justify efforts to carefully inquire about and document the will of sick patients prior to major surgery. Both the treatment team and the relatives are relieved if the patient's will is known when difficult decisions have to be made.


Subject(s)
Anesthesia , Elective Surgical Procedures/methods , Preoperative Care/methods , Referral and Consultation , Adult , Advance Directives , Age Factors , Aged , Chronic Disease , Female , Health Status , Humans , Male , Middle Aged , Physician-Patient Relations , Postoperative Complications/epidemiology , Surveys and Questionnaires
5.
Microb Ecol ; 54(3): 417-23, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17468962

ABSTRACT

It is assumed in current literature that the fungus garden cultivated by leaf-cutting ants consists of a single fungus species, the putative mutualistic fungus. However, most studies report a very high rate of fungi contamination (fungi isolated from fungus gardens that are considered not to be the mutualistic fungus). In this article, we report a genetic similarity analysis of all fungi (regardless of their mutualistic condition) isolated from 16 fungus gardens of three Acromyrmex species in Córdoba, Argentina, using intersimple sequence repeat (ISSR) as genetic markers. We isolated 60 clones, of which the three primers employed yielded 53 loci. The patterns revealed a high interclone polymorphism, with a few bands shared by the clones. Of all possible pairwise comparisons, 99% showed a genetic similarity (S) lower than 0.5, the threshold level assumed for fungus Operational Taxonomy Unit (OTU). We found more than one fungus OTU in all studied nests (range 2-11). Cumulative number of OTUs increased linearly with the number of nests sampled. The number of fungus OTUs common to both ant species and sites was very small. We did not find a core group composed of few very common OTUs, as expected if a set of truly mutualistic OTU was present. A simple explanation for the high number of OTUs found is that they are regular components of the fungus garden, which may be used as food source by the ants.


Subject(s)
Ants/microbiology , Fungi/genetics , Genetic Variation , Animals , Ants/physiology , Argentina , DNA, Fungal/analysis , DNA, Fungal/genetics , Fungi/classification , Fungi/isolation & purification , Nesting Behavior , Phylogeny , Plant Leaves/parasitology , Species Specificity
6.
Anaesthesia ; 59(8): 743-9, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15270963

ABSTRACT

Spinal anaesthesia for Caesarean section has gained widespread acceptance. We assessed the impact of spinal anaesthesia and body mass index (BMI) on spirometric performance. In this prospective study, we consecutively assessed 71 consenting parturients receiving spinal anaesthesia with hyperbaric bupivacaine and fentanyl for elective Caesarean section. We performed spirometry during the antepartum visit (baseline), immediately after spinal anaesthesia, 10-20 min, 1 h, 2 h after the operation, and after mobilisation (3 h). Baseline values were within normal ranges. There was a significant decrease in all spirometric parameters after effective spinal anaesthesia that persisted throughout the study period. The decrease in respiratory function was significantly greater in obese (BMI > 30 kg x m(-2)) than in normal-weight parturients (BMI < 25 kg x m(-2)), e.g. median (IQR) vital capacity directly after spinal anaesthesia; -24 (-16 to -31)% vs. -11 (-6 to -16)%, p < 0.001 and recovery was significantly slower. We conclude that both spinal anaesthesia and obesity significantly impair respiratory function in parturients.


Subject(s)
Anesthesia, Obstetrical , Anesthesia, Spinal , Cesarean Section , Obesity/physiopathology , Pregnancy Complications/physiopathology , Respiration , Adult , Analgesics, Opioid , Body Mass Index , Female , Humans , Methadone , Pain Measurement , Pain, Postoperative/prevention & control , Pregnancy , Prospective Studies , Respiratory Function Tests/methods , Spirometry
7.
Anaesthesia ; 59(4): 350-3, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15023105

ABSTRACT

Lumbar epidural analgesia during labour has gained widespread acceptance. The impact of epidural analgesia based on mixtures of low-dose local anaesthetic solutions and lipophilic opioids on most clinically relevant obstetric outcomes is minimal. Since the pregnant state per se is associated with important alterations in respiration, we assessed whether a subtle degree of motor blockade brought about by epidural analgesia might compromise respiratory function as assessed by spirometry. Sixty consenting parturients receiving epidural analgesia were consecutively included in this prospective study. We performed spirometry during the antepartum visit and in labour after effective epidural analgesia was established; at both assessments the women were pain-free. Values were within normal ranges but increased significantly after effective epidural analgesia; median (IQR [range]) increase for vital capacity 7.4 (3.0-13 [-12-27])% (p < 0.001); forced vital capacity 4.4 (1.7-9.8 [-13-26])% (p < 0.001); forced expiratory volume in 1 s 5.5 (1.7-8.6 [-14-28])% (p < 0.001); and peak expiratory flow rate 2.3 (-1.6-5.8 [-18-16])% (p = 0.01)). We conclude that epidural analgesia for labour significantly improved respiratory function.


Subject(s)
Analgesia, Epidural , Analgesia, Obstetrical , Analgesics, Opioid/pharmacology , Anesthetics, Local/pharmacology , Respiratory Physiological Phenomena/drug effects , Adult , Body Mass Index , Bupivacaine/pharmacology , Female , Fentanyl/pharmacology , Humans , Pregnancy , Prospective Studies
8.
Nature ; 422(6927): 93, 2003 Mar 06.
Article in English | MEDLINE | ID: mdl-12621444
9.
Braz. j. biol ; 61(4)Nov. 2001.
Article in English | LILACS-Express | LILACS, VETINDEX | ID: biblio-1467570

ABSTRACT

Farmers in the Paranapanema Valley (São Paulo, Brazil) have reported problems with flocks of Eared Doves (Zenaida auriculata) eating sprouting soybeans. In this region these birds breed colonially in sugar-cane, and eat four crop seeds, using 70% of the dry weight, in the following order of importance: maize, wheat, rice, and soybeans. Three weeds (Euphorbia heterophylla, Brachiaria plantaginea, and Commelina benghalensis) were important. This information suggests that the doves adapted particularly well to the landscape created by the agricultural practices in the region, exploiting many available foods.


Agricultores no médio Vale do Paranapanema têm relatado problemas com bandos de pombas (Zenaida auriculata) que se alimentam de cotilédones de soja na época do plantio. Na região do município de Tarumã, SP, essas aves se reproduzem em uma colônia situada em um canavial, e sua dieta é composta de 70% do peso seco por 4 grãos cultivados (em ordem de importância: milho, trigo, arroz e soja). As sementes de três invasoras (Euphorbia heterophylla, Brachiaria plantaginea e Commelina benghalensis) são importantes. Essa informação sugere que as pombas se adaptaram particularmente bem à paisagem criada pelas práticas agrícolas da região, aproveitando vários alimentos oferecidos.

10.
Braz. j. biol ; 61(4): 651-660, Nov. 2001. mapas, tab, graf
Article in English | LILACS | ID: lil-308295

ABSTRACT

Farmers in the Paranapanema Valley (Sä¯áPaulo, Brazil) have reported problems with flocks of Eared Doves (Zenaida auriculata) eating sprouting soybeans. In this region these birds breed colonially in sugar-cane, and eat four crop seeds, using 70 percent of the dry weight, in the following order of importance: maize, wheat, rice, and soybeans. Three weeds (Euphorbia heterophylla, Brachiaria plantaginea, and Commelina benghalensis) were important. This information suggests that the doves adapted particularly well to the landscape created by the agricultural practices in the region, exploiting many available foods


Subject(s)
Animals , Columbidae , Diet , Brazil , Breeding , Cotyledon , Crops, Agricultural , Edible Grain , Seeds , Glycine max
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 57(10): 2071-6, 2001 Sep 01.
Article in English | MEDLINE | ID: mdl-11666086

ABSTRACT

Homogeneous samples of La0.4Sr0.6CoO3-delta were obtained by the glycine nitrate process. The oxygen nonstoichiometry was determined from oxygen exchange measurements as a function of oxygen partial pressure (10(-4) bar < PO2 < 10(-2) bar) and temperature (300 degrees C < T< 900 degrees C). The chemical diffusion coefficient D was obtained from oxygen exchange measurements applying a stepwise variation of the oxygen partial pressure of the ambient atmosphere of a disk-shaped sample. The amount of oxygen absorbed or desorbed by the perovskite was analyzed as a function of time. Chemical diffusion data were evaluated using simplified and exact fitting procedures taking into account the surface exchange coefficient. Alternatively, galvanostatic polarization measurements were performed in a PO2-range between 10(-4) and 10(-2) bar to yield D and the ionic conductivity sigma(i) from the long time solution of the diffusion equation. Values for D from polarization measurements at T= 775 degrees C and from oxygen exchange measurements at T= 725 degrees C are in good agreement with each other. D and sigma(1) increase with increasing PO2 (10(-4) to 10(-2) bar). The ionic conductivity shows a maximum at 3-delta approximately 2.82 and decreases with decreasing oxygen content indicating the possible formation of vacancy ordered structures.


Subject(s)
Lanthanum/chemistry , Oxygen/chemistry , Strontium/chemistry , Kinetics , Models, Chemical , Spectrophotometry/methods , Temperature
12.
J Cell Biol ; 154(2): 403-14, 2001 Jul 23.
Article in English | MEDLINE | ID: mdl-11470827

ABSTRACT

Tissue functions and mechanical coupling of cells must be integrated throughout development. A striking example of this coupling is the interactions of body wall muscle and hypodermal cells in Caenorhabditis elegans. These tissues are intimately associated in development and their interactions generate structures that provide a continuous mechanical link to transmit muscle forces across the hypodermis to the cuticle. Previously, we established that mup-4 is essential in embryonic epithelial (hypodermal) morphogenesis and maintenance of muscle position. Here, we report that mup-4 encodes a novel transmembrane protein that is required for attachments between the apical epithelial surface and the cuticular matrix. Its extracellular domain includes epidermal growth factor-like repeats, a von Willebrand factor A domain, and two sea urchin enterokinase modules. Its intracellular domain is homologous to filaggrin, an intermediate filament (IF)-associated protein that regulates IF compaction and that has not previously been reported as part of a junctional complex. MUP-4 colocalizes with epithelial hemidesmosomes overlying body wall muscles, beginning at the time of embryonic cuticle maturation, as well as with other sites of mechanical coupling. These findings support that MUP-4 is a junctional protein that functions in IF tethering, cell-matrix adherence, and mechanical coupling of tissues.


Subject(s)
Caenorhabditis elegans Proteins , Caenorhabditis elegans/metabolism , Cell Adhesion Molecules/metabolism , Epithelial Cells/metabolism , Animals , Animals, Genetically Modified , Caenorhabditis elegans/embryology , Caenorhabditis elegans/growth & development , Cell Adhesion/physiology , Cell Adhesion Molecules/genetics , Cloning, Molecular , Embryo, Nonmammalian/metabolism , Epithelial Cells/cytology , Gene Expression/drug effects , Green Fluorescent Proteins , Helminth Proteins/genetics , Helminth Proteins/metabolism , Hemidesmosomes/metabolism , Larva/metabolism , Larva/ultrastructure , Luminescent Proteins/genetics , Membrane Proteins/metabolism , Molecular Sequence Data , Muscles/metabolism , Muscles/ultrastructure , Mutation , Organ Specificity , Physical Chromosome Mapping , RNA, Double-Stranded/pharmacology , Sequence Analysis, DNA , Sequence Homology, Amino Acid
13.
Phys Rev Lett ; 86(19): 4350-3, 2001 May 07.
Article in English | MEDLINE | ID: mdl-11328172

ABSTRACT

Tl 9BiTe (6) exhibits a thermoelectric figure of merit of ZT approximately 1.2 around 500 K, which significantly exceeds the state-of-the-art materials in this temperature range. The extraordinary thermoelectric performance is mainly due to the extremely low thermal conductivity of Tl 9BiTe (6) [ 0.39 W/(m times K) at 300 K]. In fact, the minimum lifetime of the phonons has to be taken into account to describe the thermal conductivity data.

14.
J Biol Chem ; 276(24): 20817-20, 2001 Jun 15.
Article in English | MEDLINE | ID: mdl-11313333

ABSTRACT

Increasing emissions of heavy metals such as cadmium, mercury, and arsenic into the environment pose an acute problem for all organisms. Considerations of the biochemical basis of heavy metal detoxification in animals have focused exclusively on two classes of peptides, the thiol tripeptide, glutathione (GSH, gamma-Glu-Cys-Gly), and a diverse family of cysteine-rich low molecular weight proteins, the metallothioneins. Plants and some fungi, however, not only deploy GSH and metallothioneins for metal detoxification but also synthesize another class of heavy metal binding peptides termed phytochelatins (PCs) from GSH. Here we show that PC-mediated heavy metal detoxification is not restricted to plants and some fungi but extends to animals by demonstrating that the ce-pcs-1 gene of the nematode worm Caenorhabditis elegans encodes a functional PC synthase whose activity is critical for heavy metal tolerance in the intact organism.


Subject(s)
Aminoacyltransferases/genetics , Aminoacyltransferases/metabolism , Cadmium Chloride/pharmacokinetics , Caenorhabditis elegans/enzymology , Metals, Heavy/pharmacokinetics , Animals , Cadmium Chloride/toxicity , Caenorhabditis elegans/drug effects , Caenorhabditis elegans/genetics , Gene Deletion , Glutathione/metabolism , Inactivation, Metabolic , Metalloproteins/metabolism , Metallothionein/metabolism , Phytochelatins , Plant Proteins/metabolism , RNA, Double-Stranded/genetics , Saccharomyces cerevisiae/enzymology
15.
Braz J Biol ; 61(4): 651-60, 2001 Nov.
Article in English | MEDLINE | ID: mdl-12071322

ABSTRACT

Farmers in the Paranapanema Valley (São Paulo, Brazil) have reported problems with flocks of Eared Doves (Zenaida auriculata) eating sprouting soybeans. In this region these birds breed colonially in sugar-cane, and eat four crop seeds, using 70% of the dry weight, in the following order of importance: maize, wheat, rice, and soybeans. Three weeds (Euphorbia heterophylla, Brachiaria plantaginea, and Commelina benghalensis) were important. This information suggests that the doves adapted particularly well to the landscape created by the agricultural practices in the region, exploiting many available foods.


Subject(s)
Columbidae , Diet , Animals , Brazil , Breeding , Cotyledon , Crops, Agricultural , Edible Grain , Seeds , Glycine max
16.
Nature ; 407(6802): 351-5, 2000 Sep 21.
Article in English | MEDLINE | ID: mdl-11014185

ABSTRACT

There are two main theoretical descriptions of antiferromagnets. The first arises from atomic physics, which predicts that atoms with unpaired electrons develop magnetic moments. In a solid, the coupling between moments on nearby ions then yields antiferromagnetic order at low temperatures. The second description, based on the physics of electron fluids or 'Fermi liquids' states that Coulomb interactions can drive the fluid to adopt a more stable configuration by developing a spin density wave. It is at present unknown which view is appropriate at a 'quantum critical point' where the antiferromagnetic transition temperature vanishes. Here we report neutron scattering and bulk magnetometry measurements of the metal CeCu(6-x)Au(x), which allow us to discriminate between the two models. We find evidence for an atomically local contribution to the magnetic correlations which develops at the critical gold concentration (x(c) = 0.1), corresponding to a magnetic ordering temperature of zero. This contribution implies that a Fermi-liquid-destroying spin-localizing transition, unanticipated from the spin density wave description, coincides with the antiferromagnetic quantum critical point.

17.
Phys Rev Lett ; 85(18): 3930-3, 2000 Oct 30.
Article in English | MEDLINE | ID: mdl-11041963

ABSTRACT

We present high-resolution photoelectron spectra on the A15-type conventional superconductor V 3Si, where-for the first time-both singularities of the BCS density of states can be resolved by photoemission spectroscopy (PES). With a transition temperature of about T(c) approximately 17 K the gap Delta(gap) of this compound has a magnitude of approximately 5 meV. A measurement by PES on this small energy scale requires a very high energy resolution (DeltaE less, similar5 meV) and sample temperatures significantly below T(c).

19.
Eur J Clin Microbiol Infect Dis ; 19(2): 118-20, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10746498

ABSTRACT

Three cases are reported of spondylodiscitis caused by coagulase-negative staphylococci in patients without osteosynthetic material. All three patients had bacteraemia associated with an infected intravascular device left in place. On the basis of this observation, it is concluded that such devices should be removed promptly in cases of prolonged or relapsing bacteraemia. Furthermore, spondylodiscitis should be suspected in patients with back pain after bacteraemia caused by coagulase-negative staphylococci.


Subject(s)
Bacteremia/microbiology , Discitis/microbiology , Lumbar Vertebrae , Staphylococcal Infections/microbiology , Staphylococcus/isolation & purification , Aged , Catheters, Indwelling/adverse effects , Catheters, Indwelling/microbiology , Coagulase/metabolism , Equipment Contamination , Female , Humans , Male , Pacemaker, Artificial/adverse effects , Pacemaker, Artificial/microbiology , Staphylococcus/enzymology
20.
Nature ; 403(6768): 408-10, 2000 Jan 27.
Article in English | MEDLINE | ID: mdl-10667788

ABSTRACT

Recent work on solar cells based on interpenetrating polymer networks and solid-state dye-sensitized devices shows that efficient solar-energy conversion is possible using organic materials. Further, it has been demonstrated that the performance of photovoltaic devices based on small molecules can be effectively enhanced by doping the organic material with electron-accepting molecules. But as inorganic solar cells show much higher efficiencies, well above 15 per cent, the practical utility of organic-based cells will require their fabrication by lower-cost techniques, ideally on flexible substrates. Here we demonstrate efficiency enhancement by molecular doping in Schottky-type photovoltaic diodes based on pentacene--an organic semiconductor that has received much attention as a promising material for organic thin-film transistors, but relatively little attention for use in photovoltaic devices. The incorporation of the dopant improves the internal quantum efficiency by more than five orders of magnitude and yields an external energy conversion efficiency as high as 2.4 per cent for a standard solar spectrum. Thin-film devices based on doped pentacene therefore appear promising for the production of efficient 'plastic' solar cells.

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