20,832 research outputs found
The Mannitol-Fermenting Group of Dysentery Bacilli
The term dysentery was originally used to describe any condition having as a symptom diarrhoea with stools containing blood and mucus. The discovery of Entamoeba histolytica by Losch (1875) and its incrimination as a cause of dysentery was the first step in the more accurate classification of this group of diseases. In 1898 Shiga described a non-lactose fermenting coliform bacillus and produced convincing evidence that infection with this organism gives rise to acute inflammatory and ulcerative colitis. Closely related bacilli, differing from Shiga's organism in their biochemical reactions and antigenic pattern, were isolated from cases of dysentery by Plexner (1900), Strong (1900) and others. In 1915 Sonne found yet another type, and In 1917 Schmitz added one more to the list. A critical review by Murray in 1918 gave convincing confirmation of the existence of four main types of dysentery bacilli. Three of these, Shiga's bacillus, Sonne's bacillus, and Schmitz's bacillus, were clearly defined in their biochemical reactions and antigenic structure. The fourth type - or more correctly, group - embracing the organisms named after Flexner, Strong, Hiss, Russell, and Lentz, had identical biochemical reactions, but,*though closely related, were not wholly alike in their antigenic pattern. This latter group was investigated by Andrewss and Inman (1919) and divided into five types, which they named V, W, X, Y and Z. According to their conception, these types shared four main antigens. Each of the strains, V, W, X and Z was believed to contain a dominant quantity of one of these antigens and minor quantities of the other three, while Y contained approximately equal amounts of all four. For purposes of identification, a polyvalent antiserum was prepared from all five strains, and it was hoped that this would enable all organisms of the Flexner "spectrum" to be recognised with certainty. This hope did not materialise. Experience in India revealed that about 30io of all strains having the general and biochemical characters of the group failed to react with this 'polyvalent' antiserum. For purposes of diagnosis these inagglutinable strains were regarded as atypical but none the less pathogenic Flexner-group bacilli, but this compromise had many disadvantages, and failed to carry conviction to many who at that time still believed in the widespread occurrence of amoebic dysentery. IDENTIFICATION OF NEW TYPES OF MANNITOL-FERMENTING DYSENTRY BACILLI. In view of this state of affairs, an investigation was started which had as its object the differentiation by serological methods of these inagglutinable strains, and the confirmation, or otherwise, of their pathogenic action. Annexures I and II cover the initial part of this work. In all, nine distinct strains were identified which had the biochemical characters of the Flexner group but could be recognised as separate entities by virtue of their antigenic structure. These nine strains could be divided into two groups. The first, consisting of three members, not only resembled Andrewss' types biochemically, but also exhibited a certain degree of cross-agglutination with them. There was no reasonable doubt that they were members of this series, and would have been recognised as such by Andrewes had they found their way into his collection, which contained only one strain emanating from India. The remaining six strains fell into a different category, as they had no demonstrable antigenic relationship with the Flexner group. Their claims to be considered pathogenic are discussed in detail, and at the date of publication of Annexure II, it was considered that three of them could be incriminated. (Abstract shortened by ProQuest.)
Relation between socioeconomic deprivation and death from a first myocardial infarction in Scotland: population based analysis
No abstract available
Analytical model of brittle destruction based on hypothesis of scale similarity
The size distribution of dust particles in nuclear fusion devices is close to
the power function. A function of this kind can be the result of brittle
destruction. From the similarity assumption it follows that the size
distribution obeys the power law with the exponent between -4 and -1. The model
of destruction has much in common with the fractal theory. The power exponent
can be expressed in terms of the fractal dimension. Reasonable assumptions on
the shape of fragments concretize the power exponent, and vice versa possible
destruction laws can be inferred on the basis of measured size distributions.Comment: 10 pages, 3 figure
Strong nonlinear optical response of graphene flakes measured by four-wave mixing
We present the first experimental investigation of nonlinear optical
properties of graphene flakes. We find that at near infrared frequencies a
graphene monolayer exhibits a remarkably high third-order optical nonlinearity
which is practically independent of the wavelengths of incident light. The
nonlinear optical response can be utilized for imaging purposes, with image
contrasts of graphene which are orders of magnitude higher than those obtained
using linear microscopy.Comment: 4 pages, 5 figure
Complex light: Dynamic phase transitions of a light beam in a nonlinear non-local disordered medium
The dynamics of several light filaments (spatial optical solitons)
propagating in an optically nonlinear and non-local random medium is
investigated using the paradigms of the physics of complexity. Cluster
formation is interpreted as a dynamic phase transition. A connection with the
random matrices approach for explaining the vibrational spectra of an ensemble
of solitons is pointed out. General arguments based on a Brownian dynamics
model are validated by the numerical simulation of a stochastic partial
differential equation system. The results are also relevant for Bose condensed
gases and plasma physics.Comment: 11 pages, 20 figures. Small revisions, added a referenc
Short-term and long-term outcomes in 133 429 emergency patients admitted with angina or myocardial infarction in Scotland, 1990-2000: population-based cohort study
Objective: To analyse short- and long-term outcomes and prognostic factors in a large population-based cohort of unselected patients with a first emergency admission for suspected acute coronary syndrome between 1990 and 2000 in Scotland.
Methods: All first emergency admissions for acute myocardial infarction (AMI) and all first emergency admissions for angina (the proxy for unstable angina) between 1990 and 2000 in Scotland (population 5.1 million) were identified. Survival to five years was examined by Cox multivariate modelling to examine the independent prognostic effects of diagnosis, age, sex, year of admission, socioeconomic deprivation and co-morbidity.
Results: In Scotland between 1990 and 2000, 133 429 individual patients had a first emergency admission for suspected acute coronary syndrome: 96 026 with AMI and 37 403 with angina. After exclusion of deaths within 30 days, crude five-year case fatality was similarly poor for patients with angina and those with AMI (23.9% v 21.6% in men and 23.5% v 26.0% in women). The longer-term risk of a subsequent fatal or non-fatal event in the five years after first hospital admission was high: 54% in men after AMI (53% in women) and 56% after angina (49% in women). Event rates increased threefold with increasing age and 20–60% with different co-morbidities, but were 11–34% lower in women.
Conclusions: Longer-term case fatality was similarly high in patients with angina and in survivors of AMI, about 5% a year. Furthermore, half the patients experienced a fatal or non-fatal event within five years. These data may strengthen the case for aggressive secondary prevention in all patients presenting with acute coronary syndrome
Ultraslow light propagation in an inhomogeneously broadened rare-earth ion-doped crystal
We show that Coherent Population Oscillations effect allows to burn a narrow
spectral hole (26Hz) within the homogeneous absorption line of the optical
transition of an Erbium ion-doped crystal. The large dispersion of the index of
refraction associated with this hole permits to achieve a group velocity as low
as 2.7m/s with a ransmission of 40%. We especially benefit from the
inhomogeneous absorption broadening of the ions to tune both the transmission
coefficient, from 40% to 90%, and the light group velocity from 2.7m/s to
100m/s
A typical reconstruction limit of compressed sensing based on Lp-norm minimization
We consider the problem of reconstructing an -dimensional continuous
vector \bx from constraints which are generated by its linear
transformation under the assumption that the number of non-zero elements of
\bx is typically limited to (). Problems of this
type can be solved by minimizing a cost function with respect to the -norm
||\bx||_p=\lim_{\epsilon \to +0}\sum_{i=1}^N |x_i|^{p+\epsilon}, subject to
the constraints under an appropriate condition. For several , we assess a
typical case limit , which represents a critical relation
between and for successfully reconstructing the original
vector by minimization for typical situations in the limit
with keeping finite, utilizing the replica method. For ,
is considerably smaller than its worst case counterpart, which
has been rigorously derived by existing literature of information theory.Comment: 12 pages, 2 figure
Time trends in survival and readmission following coronary artery bypass grafting in Scotland, 1981-96: retrospective observational study
Improvements in coronary revascularisation techniques and an increase in the use of percutaneous interventions1 have led to a rise in the number of coronary artery bypass grafting operations in older patients with more severe cardiac disease and worse comorbidity and who have previously undergone revascularisation procedures. 2 3 Advances in surgical and anaesthetic techniques have prevented a worsening risk profile from being translated into an increase in perioperative deaths. 2 3 The aim of our study was to examine time trends in major outcomes up to two years after coronary artery bypass grafting
Especies nuevas de Elateridae (Coleoptera) de Madre de Dios, Perú, con nuevos cambios taxonómicos y registros de distribución
The Elateridae fauna of Peru is updated with species new to science, new country records and new taxonomic combinations from the Madre de Dios region. Ten species representing eight genera are described as new: Conoderus wachiperi new species (Agrypninae, Oophorini) Cosmesus aca new species (Elaterinae, Pomachilini), Dipropus amarakaeri new species and Dipropus losamigos new species (Elaterinae, Ampedini, Dicrepidiina), Esthesopus machiguenga new species (Cardiophorinae), Glyphonyx peruanus new species (Elaterinae, Adrastini), Lissomus carmen new species (Lissominae), Paradonus kosnipata new species (Negastriinae), and Pomachilius qusqu new species and Pomachilius wayqecha new species (Elaterinae, Pomachilini). Aeolus platynotus Candèze is changed to Conoderus platynotus (Candèze) new combination and Aeolus ticuna Johnson is changed to Conoderus ticuna (Johnson) new combination (Agrypninae, Oophorini); and Crigmus brunnipilis (Candèze) is changed to Probothrium brunnipilis (Candèze) new combination (Elaterinae, Elaterini). Twenty-seven (27) species, the genera Glyphonyx Candèze and Paradonus Stibick, the tribe Adrastini, and the subfamily Negastriinae are added to the Peru faunal list. There are now 201 species representing 48 genera and 9 subfamilies recorded from Peru.La fauna Elateridae del Perú se actualiza con especies nuevas para la ciencia, nuevos registros de países y nuevas combinaciones taxonómicas de la región de Madre de Dios. Diez especies que representan ocho géneros se describen como nuevas: Conoderus wachiperi nueva especie, Cosmesus aca nueva especie, Dipropus amarakaeri nueva especies, Dipropus losamigos, nueva especie, Esthesopus machiguenga nueva especie, Glyphonyx peruanus nueva especie, Lissomus carmen nueva especie, Paradonus kosnipata nueva especie, Pomachilius qusqu nueva especie, Pomachilius wayqecha nueva especie. Aeolus ticuna Johnson se cambia a Conoderus ticuna (Johnson) nueva combinación, Aeolus platynotus Candèze se cambia a Conoderus platynotus (Candèze) nueva combinación, y Crigmus brunnipilis (Candèze) se cambia a Probothrium brunnipilis (Candèze). Veintisiete (27) especies, los géneros Glyphonyx Candèze y Paradonus Stibick, la tribu Adrastini y la subfamilia Negastriinae se agregan a la lista de fauna de Perú. Ahora hay 201 especies que representan 48 géneros y 9 subfamilias se registran en el Perú
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