Because of their small size, great abundance and easy dispersal, it is often assumed that marine planktonic microorganisms have a ubiquitous distribution that prevents any structured assembly into local communities. To challenge this view, marine bacterioplankton communities from coastal waters at nine locations distributed world-wide were examined through the use of comprehensive clone libraries

BACKGROUND: The IFCC Reference Measurement System for hemoglobin (Hb)A(1)c (IFCC-RM) has been developed within the framework of metrologic traceability and is embedded in a network of 14 reference laboratories. This paper describes the outcome of 12 intercomparison studies (periodic evaluations to control essential elements of the IFCC-RM). METHODS: Each study included: unknown samples (to test in

Smad5 is known to transduce intracellular signals from bone morphogenetic proteins (BMPs), which belong to the transforming growth factor-beta (TGF-beta) superfamily and are involved in the regulation of hematopoiesis. Recent findings suggest that BMP4 stimulates proliferation of human primitive hematopoietic progenitors in vitro, while early progenitors from mice deficient in Smad5 display increa

Our aim in this study was to explore women's responses to reported ad-hoc demands for unauthorized user fees during pregnancy and childbirth in Luanda, Angola. Ten focus group discussions were conducted and data were analysed using grounded theory. Women were found to apply six strategies as they "endeavored to cope with demands for unauthorized user fees" (core category): (i) blowing the whistle,

This dissertation contains a variety of contributions to econometric theory. Broadly speaking, econometrics may be categorized depending on what type of data is being analyzed, the two main categories being time series data and cross sectional data. A third category is panel data, combining cross sectional data observed over time. This is the area at which this dissertation is aimed. Panel data mo

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Objective: To compare the performance of the American College of Rheumatology (ACR), European League Against Rheumatism (EULAR), and simple disease activity index (SDAI) response criteria for rheumatoid arthritis at the individual level in an observational cohort. Methods: 184 outpatients were followed using a structured protocol. For each patient, the responses according to ACR 20% and 50%, EULAR

Recent studies have suggested that sensory nerves may influence insulin secretion and action. The present study investigated the effects of resiniferatoxin (RTX) inactivation of sensory nerves ( desensitization) on oral glucose tolerance, insulin secretion and whole body insulin sensitivity in the glucose intolerant, hyperinsulinemic, and insulin-resistant obese Zucker rat. After RTX treatment (0.

In asexual eukaryotes, the two allelic gene copies at a locus are expected to become highly divergent as a result of the independent accumulation of mutations in the absence of segregation. If sexual reproduction was abandoned millions of generations ago, intra-individual allelic divergences can be significantly larger than in species that reproduce sexually. Owing to the disputed existence of tru

We observe a correspondence between the zero modes of superconformal algebras S'(2,1) and W(4) ([8]) and the Lie superalgebras formed by classical operators appearing in the Kahler and hyper-Kahler geometry.

Several migratory bird species show active cycles of hypertrophy and atrophy of nutritional organs and selected muscle groups. We develop a model for nutritional organs to identify the conditions under which such a pattern of structural change is optimal. Migrants may choose the size of two components of lean mass: a constant component that they carry throughout the entire migration period and a c

1. Roots of emergent macrophytes depend on oxygen transported from aerial parts by diffusion and, in some species, by pressurised ventilation. The aim of this study was to determine if species with pressurised ventilation grow in deeper water in situ than species lacking this ability. 2. Species with pressurised ventilation grew significantly deeper than species lacking pressurised ventilation, an

Lacunar infarcts, small deep infarcts resulting from occlusion of a penetrating artery, account for about a quarter of all ischemic strokes. The view of lacunar infarcts as a benign and rather innocent vascular lesion has been modified during the last years. Although the prognosis is more favourable than other subtypes during the first years, probably due to the small lesion size, in a longer pers

Under de senaste tio åren har en känslig analysmetod för grundämnen utvecklats vid institutionen för kärnfysik vid LTH. Metoden kallas PIXE (Particle Induced X-ray Emisson) och medger att mycket små förekomster (109 – 1012 g) av grundämnen kanbestämmas i små prov. Metoden är snabb. Ett par minuters analys ger en samtidig bestämning av ett stort antal grundämnen. Analysmetoden används nu i ett stor

In the 1980s it became increasingly clear that the European Community market was still segmented by national borders because of non-tariff barriers to trade. A major objective of the Single Market Program in 1992 was to remove these barriers, thereby enforcing intra-union competition. In this paper, a panel of Swedish firm-level data is used to evaluate whether domestic market power has been curta

5-Aminolevulinic acid (ALA) is a common biosynthetic intermediate of both chlorophyll and heme. Glutamyl-tRNAGlu reductase, encoded by the hemA gene, is the initial enzyme of ALA biosynthesis. The presence of several hemA genes provides a possible explanation to the ability of plants to meet the different requirement of chlorophyll and heme using a common biosynthetic pathway. In this work, two ba