Sökresultat

Filtyp

Din sökning på "*" gav 534700 sökträffar

Nitrate-regulated glutaredoxins control Arabidopsis thaliana primary root growth.

Nitrogen is an essential soil nutrient for plants, and lack of nitrogen commonly limits plant growth. Soil nitrogen is typically available to plants in two inorganic forms: nitrate and ammonium. To better understand how nitrate and ammonium differentially affect plant metabolism and development, we performed transcriptional profiling of the shoots of ammonium-supplied and nitrate-supplied Arabidop

Stratigraphic expressions of the Holocene-Anthropocene transition revealed in sediments from remote lakes

Stratigraphic boundaries are ideally defined by distinct lithological, geochemical, and palaeobiological signatures, to which a chronological framework can be applied. We present a range of observations that illustrate how the Holocene-Anthropocene transition meets these criteria in its expression in sediments from remote arctic and alpine lakes, removed from direct, catchment-scale, anthropogenic

An optimization model for renewable energy generation and its application in China: A perspective of maximum utilization

In response to climate change, China's power industry is undertaking the task of reducing carbon emissions. Renewable energy generation has become an important option. For the government and state grid companies, it is important to know the maximum possible capacities of renewable energy generation from its different sources in order to plan the construction of the power grid in the future. In thi

What is a domain? Dimensional structures versus meronomic relations

Within cognitive linguistics, the notion of domain is central. In the literature, the notion of domain has been interpreted in an all-encompassing way, which has led to conceptual confusion. The article proposes to distinguish between a more psychologically oriented description of domains based on dimensional structures, on the one hand; and meronomic relations, on the other. It is shown how Langa

Acinar ventilation heterogeneity in COPD relates to diffusion capacity, resistance and reactance.

The aim of this study was to investigate heterogenic ventilation in the acinar (Sacin) and conductive (Scond) airways of patients with varying chronic obstructive pulmonary disease (COPD) severity and how these relates to advanced lung function parameters, primarily measured by impulse oscillometry (IOS). A secondary aim was to investigate the effects of a short acting beta2-agonist and a muscarin

Adaptive Internal Model Control for Mid-Ranging of Closed-Loop Systems with Internal Saturation

This paper considers the problem of performing mid-ranging control of two closed-loop controlled systems that have internal saturations. The problem originates from previous work in machining with industrial robots, where an external compensation mechanism is used to compensate for position errors. Because of the limited workspace and the considerably higher bandwidth of the compensator, a mid-ran

Composition and evolution of volcanic aerosol from eruptions of Kasatochi, Sarychev and Eyjafjallajokull in 2008-2010 based on CARIBIC observations

Large volcanic eruptions impact significantly on climate and lead to ozone depletion due to injection of particles and gases into the stratosphere where their residence times are long. In this the composition of volcanic aerosol is an important but inadequately studied factor. Samples of volcanically influenced aerosol were collected following the Kasatochi (Alaska), Sarychev (Russia) and also dur

The application of palaeolimnology to evidence-based lake management and conservation : examples from UK lakes

1. To help meet the requirements of water legislation, palaeolimnology has been widely used to establish ‘reference conditions’ and restoration targets for lakes. However, its potential for assessing the necessity and appropriateness of different lake management activities has been less publicized. 2. With reference to selected case studies covering consultancy projects commissioned by UK conserv

An Exploration of Play Behaviors in Raven Nestlings

Play is widespread among vertebrates. Some animal groups stand out in their play behaviors in levels of complexity, innovativeness, sociality, and volume. Despite the vast phylogenetic distance between corvids, parrots, great apes, and dolphins, all are usually identified as among the most playful. These groups also have several complex cognitive skills in common. There is growing agreement that p

MR System Operator: Recommended Minimum Requirements for Performing MRI in Human Subjects in a Research Setting

This article is intended to provide guidelines for the minimum level of safety and operational knowledge that an MR system operator should exhibit in order to safely perform an MR procedure in a human subject in a research setting. This article represents the position of the International Society for Magnetic Resonance in Medicine (ISMRM) regarding this important topic and was developed by members

Ectomycorrhizal fungi decompose soil organic matter using oxidative mechanisms adapted from saprotrophic ancestors.

Ectomycorrhizal fungi are thought to have a key role in mobilizing organic nitrogen that is trapped in soil organic matter (SOM). However, the extent to which ectomycorrhizal fungi decompose SOM and the mechanism by which they do so remain unclear, considering that they have lost many genes encoding lignocellulose-degrading enzymes that are present in their saprotrophic ancestors. Spectroscopic an

Representations of religion in secular states: The Muslim communities in Sweden

The presence of Muslim populations in Western European societies is a relatively new phenomenon which begs the question how these societies treat religious minorities. This article on the Swedish case begins with a brief history of the historical development of Sweden from a religious state based on the Lutheran faith to today’s secular state in which state and religion are officially separated. T

High-level energy estimation in the sub-VT domain: simulation and measurement of a cardiac event detector

This paper presents a flow that is suitable to estimate energy dissipation of digital standard-cell based designs which are determined to be operated in the sub-threshold regime. The flow is applicable on gate-level netlists, where back-annotated toggle information is used to find the minimum energy operation point, corresponding maximum clock frequency, as well as the dissipated energy per clock

Dural lesions in lumbar disc herniation surgery: incidence, risk factors, and outcome.

In lumbar disc herniation surgery, dural lesions seem to be the most common complication today. Studies on incidence of and outcome after a dural lesion are mainly based on retrospective studies. In a prospective study within the framework of the Swedish Spine Register, 4,173 patients operated on for lumbar disc herniation were evaluated using pre- and 1-year postoperative protocols and complicati

Differing pattern of ambulatory blood pressure in very elderly men expresses dynamics in atherosclerotic load in the senescence.

To assess an impact of vascular risk factors on ambulatory blood pressure measurement (ABPM) in the elderly, we followed up a population-based cohort of men from 68 until 82 years, when 104 survivors underwent ABPM. Results. At age 68, hypertension and high clinic blood pressure (CBP) did not predict ABPM level. Smoking and low ankle-brachial index (ABI) predicted higher ABPM variability and pulse

Pre-treatment with antibiotics and Escherichia coli to equalize the gut microbiota in conventional mice.

The composition of the gut microbiota can vary widely between individual mice of the same batch and thereby affect the resulting outcome in experimental studies. Therefore, an efficient method is needed to equalize the gut microbiota prior to the start of critical experiments. In order to minimize variations in gut microbiota between animals and provide the animals with a Gram-negative flora expos