University of Crete

About: University of Crete is a education organization based out in Rethymno, Greece. It is known for research contribution in the topics: Population & Galaxy. The organization has 8681 authors who have published 21684 publications receiving 709078 citations. The organization is also known as: Panepistimio Kritis.

Slow Relaxation Phenomena Induced by Breathers in Nonlinear Lattices.

Abstract: We study relaxation properties of one dimensional nonlinear lattices which are initially thermalized and subsequently put intp contact with a cold bath simulated by absorbing boundary conditions. We observe a nonexponential lattice energy relaxation in contrast to the standard exponential relaxation law of the corresponding linear system. We connect the long-tail relaxation behavior with the presence of long-lived nonlinear localized modes. The mobility of the breathers is shown to play a substantial role in the lattice relaxation properties. [S0031-9007(96)01862-5]

Negative Association between Testosterone Concentration and Inflammatory Markers in Young Men: A Nested Cross-Sectional Study.

Abstract: Low grade systemic inflammation (LGSI) as well as androgen deficiency has in older men been associated with several pathologies, including cardiovascular disease (CVD) We wanted to investigate whether low testosterone levels are linked to biomarkers of LGSI already in young age, before any concurrent manifestations of CVD or other systemic diseases

Particle water and pH in the eastern Mediterranean: source variability and implications for nutrient availability

Abstract: . Particle water (liquid water content, LWC) and aerosol pH are important parameters of the aerosol phase, affecting heterogeneous chemistry and bioavailability of nutrients that profoundly impact cloud formation, atmospheric composition, and atmospheric fluxes of nutrients to ecosystems. Few measurements of in situ LWC and pH, however, exist in the published literature. Using concurrent measurements of aerosol chemical composition, cloud condensation nuclei activity, and tandem light scattering coefficients, the particle water mass concentrations associated with the aerosol inorganic (Winorg) and organic (Worg) components are determined for measurements conducted at the Finokalia atmospheric observation station in the eastern Mediterranean between June and November 2012. These data are interpreted using the ISORROPIA-II thermodynamic model to predict the pH of aerosols originating from the various sources that influence air quality in the region. On average, closure between predicted aerosol water and that determined by comparison of ambient with dry light scattering coefficients was achieved to within 8 % (slope = 0.92, R2 = 0.8, n = 5201 points). Based on the scattering measurements, a parameterization is also derived, capable of reproducing the hygroscopic growth factor (f(RH)) within 15 % of the measured values. The highest aerosol water concentrations are observed during nighttime, when relative humidity is highest and the collapse of the boundary layer increases the aerosol concentration. A significant diurnal variability is found for Worg with morning and afternoon average mass concentrations being 10–15 times lower than nighttime concentrations, thus rendering Winorg the main form of particle water during daytime. The average value of total aerosol water was 2.19 ± 1.75 µg m−3, contributing on average up to 33 % of the total submicron mass concentration. Average aerosol water associated with organics, Worg, was equal to 0.56 ± 0.37 µg m−3; thus, organics contributed about 27.5 % to the total aerosol water, mostly during early morning, late evening, and nighttime hours. The aerosol was found to be highly acidic with calculated aerosol pH varying from 0.5 to 2.8 throughout the study period. Biomass burning aerosol presented the highest values of pH in the submicron fraction and the lowest values in total water mass concentration. The low pH values observed in the submicron mode and independently of air mass origin could increase nutrient availability and especially P solubility, which is the nutrient limiting sea water productivity of the eastern Mediterranean.

Uterine cervical carcinoma: role of matrix metalloproteinases (review).

Abstract: Epidemiological and experimental studies have provided evidence that human papillomavirus (HPV) infection is a main player in the development of uterine cervical neoplasms. Migration of cancer cells from the origin tissue to surrounding or distant organs is essential for tumor progression. Many studies of tumor invasion and metastases have focused on the degradation of the extracellular matrix where matrix metalloproteinases (MMPs) play a central role. Two of these enzymes, MMP-2 and MMP-9, have been correlated with the processes of tumor cell invasion and metastasis in human cancers, including uterine neoplasms. It has been shown that the up-regulation of MMPs is associated with progression of cervical uterine neoplasms. This review describes the current understanding of MMP-2 and MMP-9 expression and activity in pre-cancer and cancer lesions of cervical uterine, which may open new strategies for diagnostic and therapeutic interventions.

A reevaluation of the magnitude and impacts of anthropogenic atmospheric nitrogen inputs on the ocean

Abstract: We report a new synthesis of best estimates of the inputs of fixed nitrogen to the world ocean via atmospheric deposition and compare this to fluvial inputs and dinitrogen fixation. We evaluate the scale of human perturbation of these fluxes. Fluvial inputs dominate inputs to the continental shelf, and we estimate that about 75% of this fluvial nitrogen escapes from the shelf to the open ocean. Biological dinitrogen fixation is the main external source of nitrogen to the open ocean, i.e., beyond the continental shelf. Atmospheric deposition is the primary mechanism by which land-based nitrogen inputs, and hence human perturbations of the nitrogen cycle, reach the open ocean. We estimate that anthropogenic inputs are currently leading to an increase in overall ocean carbon sequestration of ~0.4% (equivalent to an uptake of 0.15 Pg C yr−1 and less than the Duce et al. (2008) estimate). The resulting reduction in climate change forcing from this ocean CO2 uptake is offset to a small extent by an increase in ocean N2O emissions. We identify four important feedbacks in the ocean atmosphere nitrogen system that need to be better quantified to improve our understanding of the perturbation of ocean biogeochemistry by atmospheric nitrogen inputs. These feedbacks are recycling of (1) ammonia and (2) organic nitrogen from the ocean to the atmosphere and back, (3) the suppression of nitrogen fixation by increased nitrogen concentrations in surface waters from atmospheric deposition, and (4) increased loss of nitrogen from the ocean by denitrification due to increased productivity stimulated by atmospheric inputs.