Search results for "ABO"

Data from: Grazing decreases N partitioning among coexisting plant species

2018

1. Herbivores play a key role in shaping ecosystem structure and functions by influencing plant and microbial community composition and nutrient cycling. 2. This study investigated the long-term effects of herbivores on plant resource acquisition. We explored differences in the natural δ15N signatures in plant, microbial and soil N pools, and examined mycorrhizal colonization in two tundra sites that have been either lightly or heavily grazed by reindeer for more than 50 years. The study examined changes in nutrient acquisition in five common tundra plants with contrasting traits and mycorrhiza status; the mycorrhizal dwarf shrubs, Betula nana, Vaccinium myrtillus and Empetrum hermaphroditu…

Data from: Fitness costs of worker specialisation for ant societies

2015

Division of labour is of fundamental importance for the success of societies, yet little is known about how individual specialization affects the fitness of the group as a whole. While specialized workers may be more efficient in the tasks they perform than generalists, they may also lack the flexibility to respond to rapid shifts in task needs. Such rigidity could impose fitness costs when societies face dynamic and unpredictable events, such as an attack by socially parasitic slavemakers. Here, we experimentally assess the colony-level fitness consequences of behavioural specialization in Temnothorax longispinosus ants that are attacked by the slavemaker ant T. americanus. We manipulated …

Data from: Gene expression is more strongly associated with behavioural specialisation than with age or fertility in ant workers

2018

The ecological success of social insects is based on division of labour, not only between queens and workers, but also among workers. Whether a worker tends the brood or forages is influenced by age, fertility and nutritional status, with brood carers being younger, more fecund and more corpulent. Here, we experimentally disentangle behavioural specialisation from age and fertility in Temnothorax longispinosus ant workers and analyse how these parameters are linked to whole-body gene expression. A total of 3644 genes were associated with behavioural specialisation which is ten times more than associated with age and 50 times more than associated with fertility. Brood carers were characteriz…

Interrelationship Among Morphology, Metabolism, and Proliferation of Tumor Cells in Monolayer and Spheroid Culture

1989

Previous investigations have indicated a positive correlation between the proliferative and metabolic activities of tumor cells in monolayer culture (Freyer et al., 1984; Freyer and Sutherland, 1985; Walenta and Mueller-Klieser, 1987). On the other hand, no difference in the local oxygen consumption has been found between highly proliferating outer cell areas and non-proliferating inner cellular regions in multicellular tumor spheroids (Mueller-Klieser, 1984, 1987). Therefore, the interrelationship among metabolism, proliferation, and cellular morphology was investigated systematically in tumor cells both in monolayer and spheroid culture.

Myofibroblast Cell Transition Induced By TGF-b1 Implies An Altered Arachidonic Acid Metabolism In Human Lung

2010

Proton magnetic resonance imaging with para-hydrogen induced polarization.

2012

A major challenge in imaging is the detection of small amounts of molecules of interest. In the case of magnetic resonance imaging (MRI) their signals are typically concealed by the large background signal of e.g. the body. This problem can be tackled by hyperpolarization which increases the NMR signals up to several orders of magnitude. However, this strategy is limited for (1)H, the most widely used nucleus in NMR and MRI, because the enormous number of protons in the body screens the small amount of hyperpolarized ones. Here, we describe a method giving rise to high (1)H MRI contrast for hyperpolarized molecules against a large background signal. The contrast is based on the J-coupling i…

Epilepsy stages diagnosis by Gabor atom density according to their aspect ratio

2008

During epilepsy seizure Electrocorticogram (ECoG) may change dramatically from a nearly chaotic signal (basal state) into a highly synchronized signal during a seizure, characterized by high amplitude and low frequency, and suddenly go back to the basal sate, making hard to identify them from time series. The epileptic seizure shows some stages as it is evolving, the here studied are: basal, preictal, ictal and posictal. As most of the bioelectrical signal, ECoG is a highly non periodical signal, so the most suitable techniques to analyze them are the Time-Frequency algorithms (T-F), allowing to follow up its frequency evolution through the seizure. Each seizure stage has a set of frequency…

Body composition with dual energy X-ray absorptiometry: from basics to new tools

2020

Dual-energy X-ray absorptiometry (DXA) in nowadays considered one of the most versatile imaging techniques for the evaluation of metabolic bone disorders such as osteoporosis, sarcopenia and obesity. The advantages of DXA over other imaging techniques are the very low radiation dose, its accuracy and simplicity of use. In addition, fat mass (FM) and lean mass (LM) values by DXA shows very good accuracy compared to that of computed tomography and magnetic resonance imaging. In this review we will explain the technical working principles of body composition with DXA, together with the possible limitations and pitfalls that should be avoided in daily routine to produce high-quality DXA examina…

Obstructive sleep apnea is an independent predictor for dyslipidemia: Data from the European Sleep Apnea Database (ESADA)

2017

Background and aim: Obstructive sleep apnea (OSA) and dyslipidemia are both independently well-recognized risk factors for cardiovascular disease. Previous data are inconclusive regarding the relationship between OSA and dyslipidemia. The aim of the present study was to investigate the association between OSA and dyslipidemia in ESADA (European Sleep Apnea Database). Methods: The cross-sectional analysis included 8592 patients (age 50.1±12.7 years, 69.1% male, BMI 30.8±6.6 kg/m2, mean AHI 25.7±25.9 n/h) from the ESADA. The independent relationship between measures of OSA (AHI, ODI, mean and lowest saturation) and lipid profile (total cholesterol [TC], HDL-cholesterol [HDL-C] (n=3289) and fa…

A Knowledge-Based System for the Diagnosis of Alzheimer’s Disease

2003

Therapies to slow down the progression of Alzheimer’s disease are most effective when applied in its initial stages. Therefore it is important to develop methods to diagnose the disease as early as possible. It is also desirable to establish standards which can be used generally by physicians who may not be experts in diagnosis of the disease. One possible method to obtain an early diagnosis is the evaluation of the glucose metabolism of the brain. In this paper we present a prototype of an expert system that automatically diagnoses Alzheimer’s disease on the basis of positron emission tomography images displaying the metabolic activity in the brain.