Sökresultat

Filtyp

Din sökning på "*" gav 530856 sökträffar

A Monte Carlo Study of a Factor Analytical Method for Fixed-Effects Dynamic Panel Models

In a recent article Bai (2013a) proposes a new factor analytical method (FAM) for the estimation of fixed-effects dynamic panel data models, which has the unique and very useful property that it is asymptotically bias free. In this paper we provide Monte Carlo evidence of the good small-sample performance of FAM, that complement Bai's theoretical study.

Geographic and phylogenetic patterns in Silene section Melandrium (Caryophyllaceae) as inferred from chloroplast and nuclear DNA sequences

The phylogenetic relationships between the five dioecious species in Silene section Melandrium (Caryophyllaceae) and their putative hermaphrodite relatives are investigated based on an extensive geographic and taxonomic sample, using DNA sequence data from the chloroplast genome and the nuclear ribosomal ITS region. The hermaphrodite S. noctiflora (the type species of section Elisanthe) is distant

Pasture degradation modifies the water and carbon cycles of the Tibetan highlands

The Tibetan Plateau has a significant role with regard to atmospheric circulation and the monsoon in particular. Changes between a closed plant cover and open bare soil are one of the striking effects of land use degradation observed with unsustainable range management or climate change, but experiments investigating changes of surface properties and processes together with atmospheric feedbacks a

Capacity of capsazepinoids to relax human small airways and inhibit TLR3-induced TSLP and IFNβ production in diseased bronchial epithelial cells.

Thymic stromal lymphopoietin (TSLP), an immunomodulating potentially disease-inducing cytokine, is overproduced in TLR3-stimulated bronchial epithelial cells from asthmatic donors whereas production of antiviral IFNβ is deficient. It is of therapeutic interest that capsazepine inhibits epithelial TSLP and relaxes human small airways with similar potencies. However, it is not known if other capsaze

Reciprocal prospective associations between disordered eating and other psychological problems in a community sample of Swedish adolescent girls

Disordered eating and its associations with psychological difficulties and body satisfaction were prospectively studied in a community sample of 13-15 year old adolescent girls (N = 428). General psychological difficulties (including hyperactivity-inattention) and lower levels of body satisfaction at T1 were found to predict disordered eating at follow-up one year later (T2). Furthermore, reciproc

Towards more efficient infection and fire fighting

The firefighter problem models the situation where an infection, a computer virus, an idea or fire etc. is spreading through a network and the goal is to save as many as possible nodes of the network through targeted vaccinations. The number of nodes that can be vaccinated at a single time-step is typically one, or more generally O(1). In a nonstandard model, the so called spreading model, the vac

Determination of carbonate-C in biochars

Although carbonate-carbon (C), an integral part of biochar-C, contributes to the liming properties of that material, it also interferes with the estimation of the stable organic C fraction in biochars. In this study, four methods were compared in order to quantify the carbonate-C in biochars: two direct (a titrimetric procedure and thermogravimetric analysis, TGA), and two indirect (acid treatment

Neurobiology: Jumping Spiders Getting On Board

A new technique has overcome decades of failure to allow, for the first time, electrophysiological access to the brains of jumping spiders, a group of animals renowned for generating highly complex, seemingly vertebrate-like behavior from their tiny arthropod brains.

The composite of hydroxyapatite and calcium sulphate: a review of preclinical evaluation and clinical applications.

Recent publications have shown that the combination of α-calcium sulfate hemihydrate, the densest form of hydrates and hydroxyapatite (HA) particles gives good clinical outcome in various applications. It has large potential as bone substitute since the material transforms to bone throughout the entire volume and not only by creeping substitution, from the surface toward the inside. Release of imp

Assessment of volume segmentation in radiotherapy of adolescents : a treatment planning study by the Swedish Workgroup for Paediatric Radiotherapy.

Background and purpose. The variability in target delineation for similar cases between centres treating paediatric and adolescent patients, and the apparent differences in interpretation of radiotherapy guidelines in the treatment protocols encouraged us to perform a dummy-run study as a part of our quality assurance work. The aim was to identify and quantify differences in the segmentation of ta

Aerococcus: an increasingly acknowledged human pathogen.

Aerococci have often been misidentified as streptococci in microbiology laboratories, leading to an underestimation of these bacteria as causes of human infections. An increased awareness of aerococci and the introduction of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), has lead to an increased isolation of Aerococcus urinae and Aerococcus sanguinicol

In Vitro Neo-Cartilage Formation on a Three-Dimensional Composite Polymeric Cryogel Matrix

Limited blood supply and the avascular nature of articular cartilage restricts its self repair capacity, frequently leading to osteoarthritis. This work focuses on scaffolds for tissue repair from natural polymers, for example gelatin, chitosan, and agarose in the form of composite. A novel way of fabrication, known as cryogelation, is presented, in which matrices are synthesized at sub-zero tempe

The moment before touchdown: landing manoeuvres of the honeybee Apis mellifera

Although landing is a crucial part of insect flight, it has attracted relatively little study. Here, we investigate, for the first time, the final moments of a honeybee's (Apis mellifera) landing manoeuvre. Using high-speed video recordings, we analyse the behaviour of bees as they approach and land on surfaces of various orientations. The bees enter a stable hover phase, immediately prior to touc

Human immunoglobulin constant heavy G chain (IGHG) (Fcγ) (GM) genes, defining innate variants of IgG molecules and B cells, have impact on disease and therapy.

The distinguished alternative GM allotypes localized in immunoglobulin constant heavy G chain IGHG (Fcγ) (GM) genes on chromosome 14q32.3 define two unique variants of respectively IgG3, IgG1 and IgG2 subclasses, with different structures and functions. The IGHG allele (allotypes), expressed in homozygous or heterozygous forms, are assessed by new serological methods. Fixed combinations of γ3, γ1

Evolution of a morphological novelty occurred before genome compaction in a lineage of extreme parasites.

Intracellular parasitism results in extreme adaptations, whose evolutionary history is difficult to understand, because the parasites and their known free-living relatives are so divergent from one another. Microsporidia are intracellular parasites of humans and other animals, which evolved highly specialized morphological structures, but also extreme physiologic and genomic simplification. They a

Enhanced levels of immunoreactive beta-casomorphin-8 in milk of breastfeeding women with mastitis

An incorrect, superficial suckling technique in breastfeeding frequently leads to milk congestion and sometimes mastitis. In the present study we have examined whether milk congestion may affect levels of the atypical opioid beta-casomorphin-8 in milk and in plasma. We also investigated whether the rate of acute psychosis during the first half year after parturition has declined in Sweden over the