The jungle of methods for evaluating phenotypic and phylogenetic structure of communities

13 páginas, 4 figuras, 4 tablas.The way communities are assembled is an old ecological question currently experiencing renewed interest thanks to the recent advances in molecular biology and phylogenetics. The generality of these new methods has allowed us to understand the structure of communities of organisms from different kingdoms and at different scales. Concomitant with this growing interest, new methods, metrics, terms, and software have appeared that independently solve similar questions, but with different approaches. Here we provide a unifying framework on methods for community structure based on the relationships between four key concepts: phylogeny, phenotype, environment, and co-occurrence. The different approaches are based on different community representations of traits, the phylogenetic relationships of species in the community, or species occurrence along the environmental gradients. We finally provide insights on future directions of this emerging discipline.We thank María Clara Castellanos, Steve Kembel, Evan Weiher, and three anonymous referees for helpful comments and suggestions. This work has been developed under the framework of the Spanish projects VIRRA (CGL2009-12048/BOS) and VAMPIRO(CGL2008-05289-C02-01).Peer reviewe

Effects of ecstasy/polydrug use on memory for associative information

Rationale Associative learning underpins behaviours that are fundamental to the everyday functioning of the individual. Evidence pointing to learning deficits in recreational drug users merits further examination. Objectives A word pair learning task was administered to examine associative learning processes in ecstasy/polydrug users. Methods After assignment to either single or divided attention conditions, 44 ecstasy/polydrug users and 48 non-users were presented with 80 word pairs at encoding. Following this, four types of stimuli were presented at the recognition phase: the words as originally paired (old pairs), previously presented words in different pairings (conjunction pairs), old words paired with new words, and pairs of new words (not presented previously). The task was to identify which of the stimuli were intact old pairs. Results Ecstasy/ploydrug users produced significantly more false-positive responses overall compared to non-users. Increased long-term frequency of ecstasy use was positively associated with the propensity to produce false-positive responses. It was also associated with a more liberal signal detection theory decision criterion value. Measures of long term and recent cannabis use were also associated with these same word pair learning outcome measures. Conjunction word pairs, irrespective of drug use, generated the highest level of false-positive responses and significantly more false-positive responses were made in the divided attention condition compared to the single attention condition. Conclusions Overall, the results suggest that long-term ecstasy exposure may induce a deficit in associative learning and this may be in part a consequence of users adopting a more liberal decision criterion value

The differential effects of ecstasy/polydrug use on executive components: shifting, inhibition, updating and access to semantic memory

Rationale/Objectives Recent theoretical models suggest that the central executive may not be a unified structure. The present study explored the nature of central executive deficits in ecstasy users. Methods In study 1, 27 ecstasy users and 34 non-users were assessed using tasks to tap memory updating (computation span; letter updating) and access to long-term memory (a semantic fluency test and the Chicago Word Fluency Test). In study 2, 51 ecstasy users and 42 non-users completed tasks that assess mental set switching (number/letter and plus/minus) and inhibition (random letter generation). Results MANOVA revealed that ecstasy users performed worse on both tasks used to assess memory updating and on tasks to assess access to long-term memory (C- and S-letter fluency). However, notwithstanding the significant ecstasy group-related effects, indices of cocaine and cannabis use were also significantly correlated with most of the executive measures. Unexpectedly, in study 2, ecstasy users performed significantly better on the inhibition task, producing more letters than non-users. No group differences were observed on the switching tasks. Correlations between indices of ecstasy use and number of letters produced were significant. Conclusions The present study provides further support for ecstasy/polydrug-related deficits in memory updating and in access to long-term memory. The surplus evident on the inhibition task should be treated with some caution, as this was limited to a single measure and has not been supported by our previous work

Анализ методов ограничения водопритоков на месторождениях Западной Сибири

Объектом исследования являются добывающие скважины, на которых применяются технологии по ограничению водопритоков. Цель работы - оценить эффективность методов ограничения водопритоков на нефтяных месторождениях Западной Сибири.The object of the study are producing wells, which use technologies to limit water inflows. The aim of the work is to evaluate the effectiveness of methods for limiting water inflows in oil fields in Western Siberia

Modern Clinical Research on LSD

All modern clinical studies using the classic hallucinogen lysergic acid diethylamide (LSD) in healthy subjects or patients in the last 25 years are reviewed herein. There were five recent studies in healthy participants and one in patients. In a controlled setting, LSD acutely induced bliss, audiovisual synesthesia, altered meaning of perceptions, derealization, depersonalization, and mystical experiences. These subjective effects of LSD were mediated by the 5-HT2A receptor. LSD increased feelings of closeness to others, openness, trust, and suggestibility. LSD impaired the recognition of sad and fearful faces, reduced left amygdala reactivity to fearful faces, and enhanced emotional empathy. LSD increased the emotional response to music and the meaning of music. LSD acutely produced deficits in sensorimotor gating, similar to observations in schizophrenia. LSD had weak autonomic stimulant effects and elevated plasma cortisol, prolactin, and oxytocin levels. Resting-state functional magnetic resonance studies showed that LSD acutely reduced the integrity of functional brain networks and increased connectivity between networks that normally are more dissociated. LSD increased functional thalamocortical connectivity and functional connectivity of the primary visual cortex with other brain areas. The latter effect was correlated with subjective hallucinations. LSD acutely induced global increases in brain entropy that were associated with greater trait openness 14 days later. In patients with anxiety associated with life-threatening disease, anxiety was reduced for 2 months after two doses of LSD. In medical settings, no complications of LSD administration were observed. These data should contribute to further investigations of the therapeutic potential of LSD in psychiatry

The five-boson dynamics

The Alt-Grassberger-Sandhas equations for the five-body problem are solved for the case of the driving two-body potentials limited to s-waves. The separable pole expansion method is employed to convert the equations into the effective quasi-two-body form. Numerical results are presented for five identical bosons. Accuracy of the separable expansion is investigated. It is shown that both in (1+4) and (2+3) fragmentation, the corresponding eigenvalues decrease rather rapidly, what, combined with the alternation of their signs, leads to rather good convergence of the results

Проектирование теплообменного аппарата подогрева гидроксида натрия

Объектом исследования является кожухотрубчатый теплообменник. Цель работы – Разработка теплообменного аппарата подогрева гидроксида натрия. В ходе выполнения работы были произведены все необходимые расчеты для конструирования аппарата, определены его размеры и основные механические характеристики. Основные конструктивные, технологические и технико-эксплуатационные характеристики: Аппарат диаметром 600 мм, толщина стенки 8 мм, длина труб 3000 мм. Степень внедрения: подогрев гидроксида натрия. Область применения: химическая промышленность.The object of the study is a shell-and-tube heat exchanger. The purpose of the work is to develop a heat exchanger for heating sodium hydroxide. In the course of the work, all the necessary calculations were made for the design of the device, its dimensions and basic mechanical characteristics were determined. The main design, technological and technical-operational characteristics: The device with a diameter of 600 mm, wall thickness of 8 mm, pipe length of 3000 mm. Degree of introduction: heating of sodium hydroxide. Scope of application: chemical industry

Emotional cues enhance the attentional effects on spatial and temporal resolution

In the present study, we demonstrated that the emotional significance of a spatial cue enhances the effect of covert attention on spatial and temporal resolution (i.e., our ability to discriminate small spatial details and fast temporal flicker). Our results indicated that fearful face cues, as compared with neutral face cues, enhanced the attentional benefits in spatial resolution but also enhanced the attentional deficits in temporal resolution. Furthermore, we observed that the overall magnitudes of individuals’ attentional effects correlated strongly with the magnitude of the emotion × attention interaction effect. Combined, these findings provide strong support for the idea that emotion enhances the strength of a cue’s attentional response