Search results for "VARY"

Price convergence of peripheral European countries on the way to the EMU: A time series approach

2000

This paper examines price and inflation convergence between three European countries (Italy, Spain and the U.K.) and a European average and, alternatively, between them and Germany from the beginning of the 80's.

Comment on ‘Generating survival times to simulate Cox proportional hazards models with time-varying covariates’

2013

The coalescent in population models with time-inhomogeneous environment

2002

AbstractThe coalescent theory, well developed for the class of exchangeable population models with time-homogeneous reproduction law, is extended to a class of population models with time-inhomogeneous environment, where the population size is allowed to vary deterministically with time and where the distribution of the family sizes is allowed to change from generation to generation. A new class of time-inhomogeneous coalescent limit processes with simultaneous multiple mergers arises. Its distribution can be characterized in terms of product integrals.

Lifelong exposure to low dose xeno-hormones in rats : multi-generational effects of xeno-hormone mixtures on taste preferences, maternal behavior, an…

2012

During the last decade, the issue of health-related endocrine disruptors (ED) has been extended to the toxicity of mixtures. The objective of this study was to define the effects of lifelong exposure to ED mixtures, at low doses defined as "non-harmful" by the authorities. In this aim, the effects of mixtures combining genistein, vinclozolin and bisphenol A, have been investigated in the rat by using an integrative and multi-generational experimental approach which takes into account maternal behavior, feeding behavior and development. Our results show that these mixtures could: a) reduce maternal behavior, b) change taste preferences (sweet, salty), c) affect the development from the in ut…

Adaptation to fluctuations in temperature by nine species of bacteria

2018

Rapid environmental fluctuations are ubiquitous in the wild, yet majority of experimental studies mostly consider effects of slow fluctuations on organism. To test the evolutionary consequences of fast fluctuations, we conducted nine independent experimental evolution experiments with bacteria. Experimental conditions were same for all species, and we allowed them to evolve either in fluctuating temperature alternating rapidly between 20°C and 40°C or at constant 30°C temperature. After experimental evolution, we tested the performance of the clones in both rapid fluctuation and in constant environments (20°C, 30°C and 40°C). Results from experiments on these nine species were combined meta…

Influence of respiratory rate and end-expiratory pressure variation on cyclic alveolar recruitment in an experimental lung injury model

2012

Introduction Cyclic alveolar recruitment/derecruitment (R/D) is an important mechanism of ventilator-associated lung injury. In experimental models this process can be measured with high temporal resolution by detection of respiratory-dependent oscillations of the paO2 (ΔpaO2). A previous study showed that end-expiratory collapse can be prevented by an increased respiratory rate in saline-lavaged rabbits. The current study compares the effects of increased positive end-expiratory pressure (PEEP) versus an individually titrated respiratory rate (RRind) on intra-tidal amplitude of Δ paO2 and on average paO2 in saline-lavaged pigs. Methods Acute lung injury was induced by bronchoalveolar lavag…

Time-varying conditional correlation : effect on international portfolio diversification in Southeast Asia

2017

Tämä tutkimus tarkastelee USA:n ja valittujen Kaakkois-Aasian kehittyvien maiden markkinoita; Philippiinejä, Indonesiaa, Malesiaa ja Thaimaata. Tutkimus antaa tuloksia sekä USA:n että indonesialaisen sijoittajan näkökulmasta. Merkittävä rooli tutkimuksessa on ajassa muuttuvan korrelaation havainnollistamisessa osakeindeksien välillä käyttäen apuna Englen vuonna 2002 esittelemää DCC-GARCH mallia. Tutkimuksessa käytetty data on vuodesta 1988 vuoteen 2015 saakka. Tulokset paljastavat kuinka valittujen osakemarkkinoiden välinen korrelaatio on muuttunut kolmen kriisin - Aasian kriisin, teknologiakuplan ja globaali talouskriisin - myötä ja onko muutos ollut pysyvää vai ei. Lisäksi tutkimuksessa t…

Lipid and fatty acid variations inCiona intestinalis ovary after tri-n-butyltin(IV)chloride exposure

2005

Reduction of total lipids (TL) content and significant variations of triglyceride (TG) and phospholipid (PL) fractions were observed as a consequence of exposure of Ciona intestinalis ovaries to tributyltin chloride (TBTCL) solutions. In particular, an evident TG decrease and a PL increase were observed, which probably provoked an increment in membrane fluidity, because of the high concentration of long chain fatty acids and, as a consequence, PL. This could be a cell adaptive standing mechanism towards the pollutants, as observed in Saccharomyces cerevisiae. Also the increase in the content of the polyunsaturated fatty acids (PUFA), important in the synthesis of compounds such as prostagla…

The adenoid cystic carcinoma

1988

Summary In spite of its rare incidence the adenoid cystic carcinoma must be treated with respect because of its hidden malignant character. In 5 out of 21 patients recurrences occurred much longer than5 years after he first operation. The extension of this tumour along branches of the trigeminal nerve could be well demonstrated in 7 of our patients where we were able to produce histological proof or radiographic evidence. The theory of tumour growth along the “tissue of least resistance” is illustrated by a special case report. As for the therapy, ultra-radical surgery has proved to be the most effective so far, whereas radio- or chemotherapy were only useful as palliative measures.

Minor salivary gland tumors: a clinicopathological study of 18 cases

2008

Introduction: Minor salivary gland tumors (MSGTs) are infrequent, representing 10-15% of all salivary neoplasms. Despite this low frequency, MSGTs conform a heterogeneous group of neoplasms characterized by a broad range of histological types. Patients and method: We identified cases of MSGT in a retrospective study of the biopsies made in the period 1997-2007 in the Service of Oral Surgery (Dental Clinic of the University of Barcelona, Spain). The data collected comprised patient age and sex, the clinical characteristics and location of the tumor, the duration of the lesion, its size, the treatment provided, and the histopathological findings. Results: Of the 18 cases of MSGT studied, 12 c…