Search results for "ratifica"

Population dynamics of oxiclinal species in lake Arcas-2 (Spain)

1995

‘Oxiclinal’ rotifer species show high concentrations just above the oxic-anoxic interface in the hypolimnion of some lakes. The stratification of their populations is best shown by sampling at close depth intervals and quantifying their densities by the Utermohl technique. With this technique we were able to count males which otherwise pass through filters and more accurately count egg production. We evaluated female, male and egg numbers of the two main oxiclinal species of lake Arcas-2: Filinia hofmanni and Anuraeopsis fissa, during two annual cycles (1990–91). F. hofmanni was an exclusive oxiclinal species. It had an exponential growth phase at the onset of stratification giving a distin…

Segregation in Drying Binary Colloidal Droplets

2019

When a colloidal suspension droplet evaporates from a solid surface, it leaves a characteristic deposit in the contact region. These deposits are common and important for many applications in printing, coating, or washing. By the use of superamphiphobic surfaces as a substrate, the contact area can be reduced so that evaporation is almost radially symmetric. While drying, the droplets maintain a nearly perfect spherical shape. Here, we exploit this phenomenon to fabricate supraparticles from bidisperse colloidal aqueous suspensions. The supraparticles have a core-shell morphology. The outer region is predominantly occupied by small colloids, forming a close-packed crystalline structure. Tow…

A formula for the Euler characteristic of $\overline{{\cal M}}_{2,n}$

2001

In this paper we compute the generating function for the Euler characteristic of the Deligne-Mumford compactification of the moduli space of smooth n-pointed genus 2 curves. The proof relies on quite elementary methods, such as the enumeration of the graphs involved in a suitable stratification of \(\overline{{\cal M}}_{2,n}\).

Vertical distribution of planktonic rotifers in a karstic meromictic lake

1993

Vertical distribution of planktonic rotifers is described in relation to temperature and oxygen in Lake La Cruz, a single-doline, closed karstic lake (121 m diameter and 25 m maximum depth) which shows iron meromixis. Samples were taken by peristaltic pumping at 10 cm depth intervals in the oxycline zone from June 1987 to September 1988. A model of rotifer vertical structure in stratified lakes is proposed. Rotifers concentrate their populations at the depths with intense gradients. As stratification develops some rotifer populations show a downward migration following the thermocline and some others show an upward migration following the oxycline. The production-respiration balance in the …

Zooplankton communities in doline lakes and pools, in relation to some bathymetric parameters and physical and chemical variables

1999

The zooplankton communities from several lakes and pools in three zones of a karstic area in central Spain were studied in spring and early autumn, in relation to morphometric, physical and chemical characteristics of the lakes. Zooplankton diversity was higher in autumn than in spring and it was positively correlated with lake size (area and depth) in spring, but not in early autumn. This effect is partially explained by the sharp zooplankton stratification in deep lakes, in early autumn. Some morphometric characteristics of lake basins were also correlated with the structure of zooplank- ton communities. Principal component analyses (PCA) and Two-Way Indicator Species Analysis (TWINSPAN) …

2001

The main limnological characteristics of the biogenic meromictic Lake La Cruz, a small karstic lake located on a dolomitic substrate, are outlined below. The lake owes its chemical stratification mainly to high concentrations of bicarbonate and calcium in the permanent monimolimnion, located below a depth of 19 m. A massive precipitation of CaCO3 crystals ("whiting"), occurring in the euphotic zone every summer, leads to further sedimentation and redissolution in deep waters with enhanced CO2 concentrations. Other ions, like magnesium, ammonium, reduced iron, silicate, etc. also contribute to the chemically-induced stability of the monimolimnion. The patterns of stratification during two co…

Right Ventricular Dysfunction Staging System for Mortality Risk Stratification in Heart Failure with Preserved Ejection Fraction

2020

Right ventricular dysfunction (RVD) parameters are increasingly important features in heart failure with preserved ejection fraction (HFpEF). We sought to evaluate the prognostic impact of a progressive RVD staging system by combining the tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (TAPSE/PASP) ratio with functional tricuspid regurgitation (TR) severity. We prospectively included 1355 consecutive HFpEF patients discharged for acute heart failure (HF). Of them, in 471 (34.7%) patients, PASP could not be accurately measured, leaving the final sample size to be 884 patients. Patients were categorized as Stage 1: TAPSE/PASP &ge

Expenses for Dwelling – Comparisons by Regions and Territories in Latvia

2021

The research was supported by the NATIONAL RESEARCH PROGRAMME “LATVIAN HERITAGE AND FUTURE CHALLENGES FOR THE SUSTAINABILITY OF THE STATE” project “CHALLENGES FOR THE LATVIAN STATE AND SOCIETY AND THE SOLUTIONS IN INTERNATIONAL CONTEXT" (INTERFRAME-LV, Project No.VPP-IZM-2018/1-0005).

Access to Higher Education: An Instrument for Fair Societies?

2019

Access to higher education (HE) has a long history. To offer a view on the current debates and worldwide issues regarding access to HE, this editorial depicts how the control of educational access has historically been used as an instrument of governance at the interface of two processes: social stratification and the territorialisation of politics. Access to HE has remained embedded in these large structural processes even though HE has expanded from a highly elitist institution into mass education systems with equity of educational opportunities having become a desirable goal across societies. Analysing these processes helps understand the complex mechanisms producing inequalities in HE t…

Mazā Baltezera ķīmiskās un fizikālās stratifikācijas raksturojums

2019

Maģistra darba mērķis ir analizēt Mazā Baltezera stratifikācijas raksturu un to ietekmējošos faktorus. Zināšanas par stratifikācijas procesiem ir noderīgas, lai pilnveidotu ezera apsaimniekošanu. Literatūras apskatā aprakstīta stratifikācijas loma ezeros, to ietekmējošie faktori, kā arī ezeru klasifikācija pēc to termiskā režīma. Izvirzīto uzdevumi izpildes vajadzībām veikti lauka un laboratorijas pētījumi, pielietotas grafiskās, t. sk. kartogrāfiskās, un matemātiskās datu apstrādes metodes. Stratifikācijas analīze veikta, atsevišķi apskatot ezera termisko, ķīmisko un izšķīdušā skābekļa stratifikāciju. Secinājums: Mazajā Baltezerā pastāv termiskā stratifikācija, kuras ietekmē pastāv arī ķīm…