Chronotype delay and sleep disturbances shaped by the Antarctic polar night.

Chronotype is a reliable biomarker for studying the influence of external zeitgebers on circadian entrainment. Assessment of chronotype variation in participants exposed to extreme photoperiods may be useful to investigate how changes in light-dark cycle modulate the circadian system. This study aimed to examine chronotype and sleep changes during a winter campaign at the Argentine Antarctic station Belgrano II.

Photodynamic Therapy with Nebulized Nanocurcumin on A549 Cells, Model Vessels, Macrophages and Beyond.

This study aimed to determine the damage mechanisms caused by naturally targeted nanoarchaeosomes made of diether lipids from loaded with curcumin (CUR, nATC), which mediated photodynamic therapy (PDT) on A549 cells and on THP-1-macrophages, two cell types found in airway cancers. The effect of nATC- PDT on vessels modeled with a chicken embryo chorioallantoic membrane (CAM), after dropping the formulations on its surface covered with mucins, was also determined. nATCs are known to efficiently trap CUR for at least six months, constituting easy-to-prepare, stable formulations suitable for nebulization.

Laccaria bicolor pectin methylesterases are involved in ectomycorrhiza development with Populus tremula × Populus tremuloides.

The development of ectomycorrhizal (ECM) symbioses between soil fungi and tree roots requires modification of root cell walls. The pectin-mediated adhesion between adjacent root cells loosens to accommodate fungal hyphae in the Hartig net, facilitating nutrient exchange between partners. We investigated the role of fungal pectin modifying enzymes in Laccaria bicolor for ECM formation with Populus tremula × Populus tremuloides.

Coping with Antarctic demands: Psychological implications of isolation and confinement.

Working in extreme environments requires a wide range of cognitive, psychological and social competences. Antarctica represents one of the most challenging habitats to work in due to its aridity, extremely cold weather, and isolated conditions. This study aimed to assess mood variations and coping strategies, as well as their possible modulation by group dynamics in a crew at the Belgrano II Argentine Antarctic Station throughout 1 year of confinement.

Subjective time estimation in Antarctica: The impact of extreme environments and isolation on a time production task.

Interval timing measures time estimation in the seconds-to-minutes range. Antarctica provides a real-world context to study the effect of extreme photoperiods and isolation on time perception. The aim of this study was to explore interval timing as a cognitive measure in the crew of Belgrano II Argentine Antarctic Station.

Sleep misalignment and circadian rhythm impairment in long-haul bus drivers under a two-up operations system.

Objectives: The objective of the study was to describe working and sleep conditions and to assess how sleep opportunities are associated with obtained sleep and alertness, in a sample of long-haul bus drivers working with a two-up operations system.

Methods: Measures of subjective sleep and sleepiness, actigraphy, circadian temperature rhythm, and psychomotor vigilance tasks were obtained from a sample of 122 drivers from Argentina. Variables were compared between high and low fatigue risk groups, which were formed using a median split of a fatigue risk score.

Hours of service regulations for professional drivers in continental Latin America.

Objectives: To describe the hours of service provisions in continental Latin America.

Design: Information on regulations of service hours was extracted from either the national transportation authorities or ministries of transportation (or the equivalent institution) from each country.

Setting: Seventeen sovereign countries in continental Latin America (Argentina, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Uruguay, Venezuela).

Correction to: Theoricity, observation and homology: a response to Pearson.

Due to an unfortunate turn of events, the family name of the first author was erroneously published as 'RoffÕ' in the original publication (PDF). The correct representation of the first author's family name is listed above and below.

Theoricity, observation and homology: a response to Pearson.

An interesting metatheoretical controversy took place during the 1980's and 1990's between pattern and phylogenetic cladists. What was always at stake in the discussion was not how work in systematics should be carried out, but rather how this practice should be metatheoretically interpreted. In this article, we criticize Pearson's account of the metatheoretical factors at play in this discussion.

Missing concepts in natural selection theory reconstructions.

The concept of fitness has generated a lot of discussion in philosophy of biology. There is, however, relative agreement about the need to distinguish at least two uses of the term: ecological fitness on the one hand, and population genetics fitness on the other. The goal of this paper is to give an explication of the concept of ecological fitness by providing a reconstruction of the theory of natural selection in which this concept was framed, that is, based on the way the theory was put to use in Darwin's main texts.