Search results for "niche"

A/D Conversion Based Measurements: Identification of the Parameters for the Uncertainty Evaluation

2009

EFFETTI DELL'ALLOPURINOLO SUL DECLINO DEL FILTRATO GLOMERULARE IN PAZIENTI IPERTESI CON INSUFFICIENZA RENALE CRONICA

2013

Il ruolo dell’iperuricemia asintomatica quale fattore in grado di favorire in modo indipendente la progressione della malattia renale cronica rimane controverso. Inoltre, gli studi finalizzati a valutare l’influenza della terapia ipouricemizzante sulla evoluzione delle nefropatie croniche sono poco numerosi e hanno dato risultati contrastanti. Scopo del nostro studio osservazionale è stato quello di analizzare retrospettivamente l'effetto del trattamento con allopurinolo, sul declino del filtrato glomerulare, in pazienti ipertesi con insufficienza renale cronica di grado moderato-severo. Sono stati pertanto selezionati 22 pazienti trattati con allopurinolo (A) (100-300 mg/die) che sono stat…

Life-history traits, abiotic environment and coexistence: The case of two cryptic rotifer species

2015

Abstract Trade-offs are important in life-history evolution and coexistence of competitors. However, how alternative life-history optima might promote competitor coexistence has received little attention. The rotifers Brachionus plicatilis and Brachionus manjavacas are two cryptic species with a considerable ecological overlap in relation to biotic factors. These species often co-occur in temporal brackish ponds characterised by environmental fluctuations. In these rotifers, sexual reproduction results in diapausing stages, which are able to survive through adverse conditions but constrain current population growth. In the present work, the differential responses of both cryptic rotifer spe…

Acquatina Lagoon: a model ecosystem to study community patterns

2013

Acquatina is a small lagoon ecosystem (0.45 km2) located on the Adriatic coast only 5 km north of Lecce (Italy). The lagoon has a freshwater input in the northern part and a connection with the sea at the south edge, being characterised by a latitudinal gradient of salinity and an internal patchiness of habitats. Here, we have used the lagoons as a model to study the influence of these sources of variation on the spatial distribution of macrobenthis and fish fauna, using both taxonomic and on taxonomic descriptors. Results showed a non random distribution of both species and functional traits of macroinvertebrate and fish fauna within the lagoon, despite the relatively small surface area. S…

Evolution of lactase persistence: an example of human niche construction

2011

Niche construction is the process by which organisms construct important components of their local environment in ways that introduce novel selection pressures. Lactase persistence is one of the clearest examples of niche construction in humans. Lactase is the enzyme responsible for the digestion of the milk sugar lactose and its production decreases after the weaning phase in most mammals, including most humans. Some humans, however, continue to produce lactase throughout adulthood, a trait known as lactase persistence. In European populations, a single mutation (−13910*T) explains the distribution of the phenotype, whereas several mutations are associated with it in Africa and the Middle …

Physiological Interactions between Microglia and Neural Stem Cells in the Adult Subependymal Niche

2018

Microglia are the prototypical innate immune cells of the central nervous system. They constitute a unique type of tissue-resident mononuclear phagocytes which act as glial cells. Elegant experiments in the last few years have revealed the origin, extraordinary molecular diversity, and phenotypic plasticity of these cells and how their potential relates to both immune and non-immune actions in the normal and diseased brain. Microglial cells originate in the yolk sac and colonize the brain during embryogenesis, playing a role in neural development and later in adult brain function. Neurogenesis continues after birth in discrete areas of the mammalian brain sustained by the postnatal persiste…

Laparoscopic, three-port and SILS cholecystectomy: a retrospective study.

2014

Introduction. The aim of this study was to compare the results of classic laparoscopic, three-port and SILS cholecystectomy. Materials and methods. We conducted a retrospective study of da- ta collected between January 2010 and December 2012 pertaining to 159 selected patients with symptomatic gallstones. 57 underwent lapa- roscopic cholecystectomy, 51 three-port cholecystectomy and 48 SILS cholecystectomy. We then compared the groups with respect to mean ope- rating time, intraoperative complications, postoperative pain, duration of hospitalization and final aesthetic result. Introduction The first laparoscopic cholecystectomy was carried out in 1987 in France by Philippe Mouret (1). The p…

Effects of hypocaloric diets with different glycemic indexes on endothelial function and glycemic variability in overweight and in obese adult patien…

2013

Background & aims: The role of glycemic index of the diet in glucose control and cardiovascular prevention is still not clear. The aim of this study was to determine the effects of hypocaloric diets with different glycemic indexes and glycemic loads on endothelial function and glycemic variability in nondiabetic participants at increased cardiovascular risk. Methods: Forty nondiabetic obese participants were randomly assigned to a three-month treatment with either a low glycemic index (LGI; n ¼ 19) or high glycemic index (HGI; n ¼ 21) hypocaloric diet with similar macronutrient and fiber content. Endothelial function was measured as flow-mediated dilatation (FMD) of the brachial artery befo…

Resting Energy expenditure in type 2 diabetic patients and the effect of insulin bolus

2014

Aims: Resting energy expenditure (REE) plays a critical role in the regulation of body weight, with important implications in type 2 diabetes (T2D). However, the relationships between REE and T2D have not been extensively evaluated. We compared REE in persons with diabetes and in persons without diabetes. We also investigated the acute effect of insulin on REE and venous lactate, the latter an indirect measure of neoglucogenetic activity. Methods: REE was measured using indirect calorimetry in 14 newly diagnosed, untreated T2D adults and in 14 non-diabetic age-, gender- and body mass index-matched persons. The REE and lactate venous concentrations were also measured in a subgroup of 5 T2D p…

Habitual fish intake and clinically silent carotid atherosclerosis

2014

Background: Fish consumption is recommended as part of a healthy diet. However, there is a paucity of data concerning the relation between fish consumption and carotid atherosclerosis. We investigated the association between habitual fish consumption and asymptomatic carotid atherosclerosis, defined as the presence of plaques and/or increased intima-media thickness (≥ 0.90 mm), in non-diabetic participants. Methods: Nine hundred-sixty-one (range of age: 18–89 yrs; 37.1% males) adult participants without clinically known atherosclerotic disease were randomly recruited among the customers of a shopping mall in Palermo, Italy, and cross-sectionally investigated. Each participant answered a foo…