Search results for "Aggregation"

Potamogeton pusillus agg. in Tajikistan (Middle Asia)

2011

The locality of <em>Potamogeton berchtoldii</em> Fieber, the new species to the flora of Tajikistan (Middle Asia), together with its ecological conditions are presented. Additionally, the list of herbarium specimens of <em>P. pusillus</em> L. s. stricto gathered in Tajikistan and few specimens of <em>P. berchtoldii</em> collected from the area of adjacent countries are also provided. Taxonomical position of the species within the <em>Potamogeton pusillus</em> aggregation, the main morphological features of both taxa and possibility of finding other localities are discussed.

Small Molecules Targeting and Modulating Toxic Tau Oligomeric Strains

Alzheimer’s disease (AD) is one of over 18 different disorders known as tauopathies, characterized by the pathological aggregation and accumulation of tau, a microtubule-associated protein. Tau aggregates are heterogeneous and can be divided into two major groups: large metastable neurofibrillary tangles (NFTs) and oligomers. Recently, it has been shown that tau oligomers are highly toxic in vitro and efficient seeds for the propagation of pathology as compared to NFTs. While the toxicity of recombinant tau oligomers has been studied extensively, within the same aggregation state, tau exhibits conformational differences, termed tau oligomeric strains. Due to the dynamic nature of these stra…

Monitoring 10-m LST from the Combination MODIS/Sentinel-2, Validation in a High Contrast Semi-Arid Agroecosystem

2020

Downscaling techniques offer a solution to the lack of high-resolution satellite Thermal InfraRed (TIR) data and can bridge the gap until operational TIR missions accomplishing spatio-temporal requirements are available. These techniques are generally based on the Visible Near InfraRed (VNIR)-TIR variable relations at a coarse spatial resolution, and the assumption that the relationship between spectral bands is independent of the spatial resolution. In this work, we adopted a previous downscaling method and introduced some adjustments to the original formulation to improve the model performance. Maps of Land Surface Temperature (LST) with 10-m spatial resolution were obtained as output fro…

Demand Response for Integrating Photovoltaic Plants in Lampedusa Island

2021

This paper presents the results of a simulation study concerning different Demand Response logics applied to Electric Storage Water Heaters on the island of Lampedusa. Electric Storage Water Heaters are the devices that are primarily used on the island to produce domestic hot water. Starting from measured load profiles collected in Lampedusa, a domestic hot water consumption profile was derived, to simulate the energy usage of the Storage Water Electric Heaters during the day. This work was carried out as a preliminary feasibility study for the BloRin project, financed by cohesion funds in the Sicilian region. According to the project, which also includes the installation of domestic photov…

Appropriazione e (ri)semantizzazione dello spazio urbano: lo sport in una piazza palermitana

2019

Il contributo, attraverso uno studio di campo, con un approccio geografico culturale esplora le modalità attraverso cui uno spazio urbano, piazza Vittorio Emanuele Orlando a Palermo, può essere oggetto di complessi processi di (ri)semantizzazione. La piazza diviene infatti luogo per sport giovanili improvvisati, al centro di dialettiche opposte (ufficialità/improvisazione) e di forme multistratificate di socialità e aggregazione.

Thermal Denaturation of Pea Globulins (Pisum sativum L.)—Molecular Interactions Leading to Heat-Induced Protein Aggregation

2013

The heat-induced denaturation and aggregation of mixed pea globulins (8%, w/w) were investigated using differential scanning calorimetry (DSC), SDS-PAGE, and size-exclusion chromatography (SEC-HPLC). DSC data showed that the pea proteins denaturation temperature (T(d)) was heating-rate dependent. The T(d) value decreased by about 4 °C by lowering the heating rate from 10 to 5 °C/min. The SDS-PAGE analysis revealed that protein denaturation upon heating at 90 °C was mainly governed by noncovalent interaction. The SEC-HPLC measurements indicated that low-denatured legumin (≈350-410 kDa) and vicilin/convicilin (≈170 kDa) globulins were heat-denatured and most of their subunits reassociated int…

Dimerization of visinin-like protein 1 is regulated by oxidative stress and calcium and is a pathological hallmark of amyotrophic lateral sclerosis

2014

AbstractRedox control of proteins that form disulfide bonds upon oxidative challenge is an emerging topic in the physiological and pathophysiological regulation of protein function. We have investigated the role of the neuronal calcium sensor protein visinin-like protein 1 (VILIP-1) as a novel redox sensor in a cellular system. We have found oxidative stress to trigger dimerization of VILIP-1 within a cellular environment and identified thioredoxin reductase as responsible for facilitating the remonomerization of the dimeric protein. Dimerization is modulated by calcium and not dependent on the myristoylation of VILIP-1. Furthermore, we show by site-directed mutagenesis that dimerization is…

Fluctuation Methods To Study Protein Aggregation in Live Cells: Concanavalin A Oligomers Formation

2011

Prefibrillar oligomers of proteins are suspected to be the primary pathogenic agents in several neurodegenerative diseases. A key approach for elucidating the pathogenic mechanisms is to probe the existence of oligomers directly in living cells. In this work, we were able to monitor the process of aggregation of Concanavalin A in live cells. We used number and brightness analysis, two-color cross number and brightness analysis, and Raster image correlation spectroscopy to obtain the number of molecules, aggregation state, and diffusion coefficient as a function of time and cell location. We observed that binding of Concanavalin A to the membrane and the formation of small aggregates paralle…

Species-specific aggregation factor in sponges V. Influence on programmed syntheses

1976

Isolated cells from the siliceous sponge Geodia cydonium as well as small primary aggregates (diameter: 70 mum) consisting of them show no increase in rates of programmed syntheses and mitotic activity with time. After addition of a highly purified aggregation factor to a culture with primary aggregates which subsequently form secondary aggregates (diameter: larger than 1000 mum), a dramatic increase of DNA, RNA and protein synthesis occurs. Together with this increase, the cells show a high mitotic activity. The values for the mitotic coefficient reach a first maximum 8 h after the beginning of the secondary aggregation process. The stimulation of the mitotic activity of cells during the a…

Heterogeneity of aggregates in the fibrillation mechanisms of proteins probed by time resolved fluorescence

2010

Under appropriate conditions almost all proteins are able to aggregate to form long, well-ordered and beta-sheet rich arrays known as amyloid fibrils. The formation of such structures involves complex intra and intermolecular interactions modulated by the structure and dynamics of the native protein, and by the physico-chemical properties of the solvent. Multiple interactions and cross-feedback during the aggregation pathway cause different ultimate aggregates’ morphologies and the possible simultaneous occurrence of multiple species. The structural definition of such assemblies is complicated by the polymorphism of the amyloid fibrils. Aim of this study is to inquire on the different natur…