Organochlorine compounds (Polychlorinated biphenyls and Pesticides) and Polycyclic aromatic hydrocarbons in populations of Hexaplex trunculus affected by imposex in the lagoon of Venice, Italy

Concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides, and polycyclic aromatic hydrocarbons (PAHs) were measured in gastropods from the Lagoon of Venice, Italy. The visceral coil and the rest of the soft body of organisms (Hexaplex trunculus) sampled at two stations inside the lagoon and three stations on the seaward side were analyzed to evaluate their contamination levels. Preferential accumulation of PCBs and pesticides in the visceral coil (>80%) compared with the rest of the soft body was observed, whereas on average, PAHs showed no preferential partitioning. Differences between levels of organochlorine contaminants in the gastropods highlighted a gradient of pollution from the stations inside the lagoon (PCBs, 45-363 ng/g; pesticides, 4-51 ng/g) to the sea (PCBs, 13-131 ng/g; pesticides, 2-29 ng/g). The possible role of the three classes of contaminants, in addition to that of organotin compounds (OTCs), previously analyzed in the same samples, in causing one of the anatomic modifications because of imposex in this gastropod also was studied. A modeling approach by partial least squares (PLS) in latent variables was applied to explain the penis length of imposex-affected females with concentrations of organic pollutants. The synergistic role of PCBs, pesticides, and OTCs was evidenced, whereas the contribution of PAHs appeared to be very low

Survival analysis in plantations of Araucaria angustifolia (Paraná pine) derived from seedlings and seeds.

Edição dos abstracts do 24º IUFRO World Congress, 2014, Salt Lake City. Sustaining forests, sustaining people: the role of research

Acute hypoglycemia impairs executive cognitive function in adults with and without type 1 diabetes

OBJECTIVE: Acute hypoglycemia impairs cognitive function in several domains. Executive cognitive function governs organization of thoughts, prioritization of tasks, and time management. This study examined the effect of acute hypoglycemia on executive function in adults with and without diabetes. RESEARCH DESIGN AND METHODS: Thirty-two adults with and without type 1 diabetes with no vascular complications or impaired awareness of hypoglycemia were studied. Two hyperinsulinemic glucose clamps were performed at least 2 weeks apart in a single-blind, counterbalanced order, maintaining blood glucose at 4.5 mmol/L (euglycemia) or 2.5 mmol/L (hypoglycemia). Executive functions were assessed with a validated test suite (Delis-Kaplan Executive Function). A general linear model (repeated-measures ANOVA) was used. Glycemic condition (euglycemia or hypoglycemia) was the within-participant factor. Between-participant factors were order of session (euglycemia-hypoglycemia or hypoglycemia-euglycemia), test battery used, and diabetes status (with or without diabetes). RESULTS: Compared with euglycemia, executive functions (with one exception) were significantly impaired during hypoglycemia; lower test scores were recorded with more time required for completion. Large Cohen d values (>0.8) suggest that hypoglycemia induces decrements in aspects of executive function with large effect sizes. In some tests, the performance of participants with diabetes was more impaired than those without diabetes. CONCLUSIONS: Executive cognitive function, which is necessary to carry out many everyday activities, is impaired during hypoglycemia in adults with and without type 1 diabetes. This important aspect of cognition has not received previous systematic study with respect to hypoglycemia. The effect size is large in terms of both accuracy and speed

Moderate-Resolution Spectroscopy of the Lensed Quasar 2237+0305: A search for Ca ii Absorption Due to the Interstellar Medium in the Foreground Lensing Galaxy

The gravitational lens system 2237 + 0305 consists of a low-redshift barred spiral galaxy (z = 0.0394) centered on a more distant quasar (z = 1.695). Because the lensing galaxy is nearly face on, spectroscopy of the background quasar affords a unique opportunity to study the interstellar medium in the galaxy\u27s center and buW:. We report moderate-resolution spectroscopy of QS02237 + 0305 yielding a 3u upper limit of 72 rnA forthe rest equivalent width of Ca II K absorption d);le to gas in the intervening galaxy. Since gas in the Milky Way thick disk typically produces 220 mA Ca II lines along lines of sight at high galactic latitude, while our line of sight to QSO 2237 + 0305 is effectively the weighted mean of four lines of sight, each of which transects an entire halo diameter in the lensing galaxy rather than just a radius, our Ca II upper limit argues against the presence. of such a thick disk near the center of the lensing galaxy. Also, published studies indicate that at 8200 A, QSO 2237 + 0305 suffers roughly 0.5 mag of extinction due to the lensing galaxy. Assuming a normal gas-to-dust ratio and allowing for various sources of uncertainty, this absorption estimate combined with our Ca II Kupper limit implies that calcium is depleted with respect to hydrogen by at least 2.7-3.7 dex, compared to solar abundances. This depletion is similar to the more extreme cases seen in our own galaxy, and higher-dispersion observations may further decrease the upper limit on Ca II absorption

Planktonic Phases of Symbiotic Copepods: a Review

In symbiotic copepods, most naupliar stages are typically planktonic, playing a primary role in dispersal, while the first copepodid usually represents the infective stage. Later copepodid stages, including adults, are associated with host organisms. Many symbiotic copepods have abbreviated life cycles, with a reduced number of naupliar stages and two different feeding habits. These patterns are presumably related to distinct life cycles strategies. Exceptional cases are exemplified by members of the Monstrillidae and Thaumatopsyllidae, both of which are protelean parasites, with infective nauplii and non-feeding planktonic adults. In the Caligidae, the life cycle follows a generalized pattern, but adults of many species like Caligus undulatus seem to exhibit a dual mode of life involving host switching. Adults leaving the first host become temporarily planktonic before attaching to the final host. This dual mode of life is also found in adults of the Ergasilidae. Abbreviation of the planktonic phase is characteristic for some symbiotic taxa, thus suggesting that they have evolved to become highly efficient in locating and infecting new hosts without needing long-distance larval dispersal. The life cycle of copepods associated with zooplankters is also briefly reviewed. Zooplankters are clearly less used as hosts by copepods than benthic invertebrates. It is likely that symbiotic copepods dynamically utilize planktonic phases in their life cycle, thus maintaining the balance between dispersal, host location, reproduction, and predator-avoidance strategies

Autistic traits foster effective curiosity-driven exploration

Curiosity-driven exploration involves actively engaging with the environment to learn from it. Here, we hypothesize that the cognitive mechanisms underlying exploratory behavior may differ across individuals depending on personal characteristics such as autistic traits. In turn, this variability might influence successful exploration. To investigate this, we collected self- and other-reports of autistic traits from university students, and tested them in an exploration task in which participants could learn the hiding patterns of multiple characters. Participants’ prediction errors and learning progress (i.e., the decrease in prediction error) on the task were tracked with a hierarchical delta-rule model. Crucially, participants could freely decide when to disengage from a character and what to explore next. We examined whether autistic traits modulated the relation of prediction errors and learning progress with exploration. We found that participants with lower scores on other-reports of insistence-on-sameness and general autistic traits were less persistent, primarily relying on learning progress during the initial stages of exploration. Conversely, participants with higher scores were more persistent and relied on learning progress in later phases of exploration, resulting in better performance in the task. This research advances our understanding of the interplay between autistic traits and exploration drives, emphasizing the importance of individual traits in learning processes and highlighting the need for personalized learning approaches

Intrinsic Absorption Lines in Seyfert 1 Galaxies. I. Ultraviolet Spectra from the Hubble Space Telescope

We present a study of the intrinsic absorption lines in the ultraviolet spectra of Seyfert 1 galaxies. We find that the fraction of Seyfert 1 galaxies that show absorption associated with their active nuclei is more than one-half (10/17), which is much higher than previous estimates (3 - 10%) . There is a one-to-one correspondence between Seyferts that show intrinsic UV absorption and X-ray ``warm absorbers''. The intrinsic UV absorption is generally characterized by high ionization: C IV and N V are seen in all 10 Seyferts with detected absorption (in addition to Ly-alpha), whereas Si IV is present in only four of these Seyferts, and Mg II absorption is only detected in NGC 4151. The absorption lines are blueshifted (or in a few cases at rest) with respect to the narrow emission lines, indicating that the absorbing gas is undergoing net radial outflow. At high resolution, the absorption often splits into distinct kinematic components that show a wide range in widths (20 - 400 km/s FWHM), indicating macroscopic motions (e.g., radial velocity subcomponents or turbulence) within a component. The strong absorption components have cores that are much deeper than the continuum flux levels, indicating that the regions responsible for these components lie completely outside of the broad emission-line regions. The covering factor of the absorbing gas in the line of sight, relative to the total underlying emission, is C > 0.86, on average. The global covering factor, which is the fraction of emission intercepted by the absorber averaged over all lines of sight, is C > 0.5.Comment: 56 pages, Latex, includes 4 figures (encapsulated postscript), Fig. 1 has 2 parts and Fig. 2 has 3 parts, to appear in the Astrophysical Journa