20 research outputs found

    Colonization by benthic algae on submarine in the southeastern area of the Gulf of Trieste

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    Scopo dello studio è stato quello di analizzare i processi di colonizzazione macroalgale su differenti tipi di substrati artificiali, in due aree del Golfo di Trieste (area nord-occidentale, area sud-orientale). Le due aree sono ecologicamente differenti, in termini di idrodinamismo, batimetria, esposizione a moto ondoso, sedimentazione, torpidità e struttura geologica del fondale. Tali fattori influenzano in maniera differente il processo di colonizzazione algale. Le fasi delle colonizzazioni macroalgali sono state seguite mediante immersioni subacquee dopo 2,6,12 e 24 mesi e i campioni sono stati prelevati tramite grattaggi del substrato. Per l’analisi dei campionamenti è stata utilizzata una scala arbitraria, già utilizzata in precedenti studi (Munda, 1978, 1979, 1991a, 2005). Dall’analisi dei campioni sono state osservate variazioni nel popolamento di alcune specie appartenenti ai gruppi Cystoseira e Sargassum come anche nelle associazioni di Fucales, quasi scomparse dal Golfo. In altri casi invece variazioni spazio-temporali (stagionalità) nella colonizzazione, sono state relazionate con la profondità del fondale, la tipologia dei substrati utilizzati e le diverse strategie di colonizzazione in particolare per quanto riguarda diatomee e macroalghe

    Rapid Growth Reduces Cold Resistance: Evidence from Latitudinal Variation in Growth Rate, Cold Resistance and Stress Proteins

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    Background: Physiological costs of rapid growth may contribute to the observation that organisms typically grow at submaximal rates. Although, it has been hypothesized that faster growing individuals would do worse in dealing with suboptimal temperatures, this type of cost has never been explored empirically. Furthermore, the mechanistic basis of the physiological costs of rapid growth is largely unexplored. Methodology/Principal Finding: Larvae of the damselfly Ischnura elegans from two univoltine northern and two multivoltine southern populations were reared at three temperatures and after emergence given a cold shock. Cold resistance, measured by chill coma recovery times in the adult stage, was lower in the southern populations. The faster larval growth rates in the southern populations contributed to this latitudinal pattern in cold resistance. In accordance with their assumed role in cold resistance, Hsp70 levels were lower in the southern populations, and faster growing larvae had lower Hsp70 levels. Yet, individual variation in Hsp70 levels did not explain variation in cold resistance. Conclusions/Significance: We provide evidence for a novel cost of rapid growth: reduced cold resistance. Our results indicate that the reduced cold resistance in southern populations of animals that change voltinism along the latitudinal gradient may not entirely be explained by thermal selection per se but also by the costs of time constraint-induced higher growth rates. This also illustrates that stressors imposed in the larval stage may carry over and shape fitness in the adul

    New contributions to the marine coastal fish fauna of Slovenia

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    Seven new records of marine fish fauna have been reported for Slovenia: Pteroplatytrigon violacea, Gobius roulei, Pomatoschistus bathi, Millerigobius macrocephalus, Thorogobius ephippiatus, Apletodon incognitus and Parablennius zvonimiri. Additional information on the occurrence of certain of certain lessknown species, such Labrus virdis and Clinitrachus argentatus, are presented..

    Interruptions in Mental Health Care, Cannabis Use, Depression, and Anxiety during the COVID-19 Pandemic: Findings from a Cohort of HIV-Positive and HIV-Negative MSM in Los Angeles, California.

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    The objective was to examine the impact of the COVID-19 pandemic on mental health care, cannabis use, and behaviors that increase the risk of STIs among men living with or at high risk for HIV. Data were from mSTUDY - a cohort of men who have sex with men in Los Angeles, California. Participants who were 18 to 45 years and a half were HIV-positive. mSTUDY started in 2014, and at baseline and semiannual visits, information was collected on substance use, mental health, and sexual behaviors. We analyzed data from 737 study visits from March 2020 through August 2021. Compared to visits prior to the COVID-19 pandemic, there were significant increases in depressive symptomatology (CES-D ≥ 16) and anxiety (GAD-7 ≥ 10). These increases were highest immediately following the start of the pandemic and reverted to pre-pandemic levels within 17 months. Interruptions in mental health care were associated with higher substance use (especially cannabis) for managing anxiety/depression related to the pandemic (50% vs. 31%; p-value < .01). Cannabis use for managing pandemic-related anxiety/depression was higher among those reporting changes in sexual activity (53% vs. 36%; p-value = 0.01) and was independently associated with having more than one sex partner in the prior 2 weeks (adjusted OR = 1.5; 95% CI 1.0-2.4). Our findings indicate increases in substance use, in particular cannabis, linked directly to experiences resulting from the COVID-19 pandemic and the associated interruptions in mental health care. Strategies that deliver services without direct client contact are essential for populations at high risk for negative sexual and mental health outcomes

    Lubricants and rectal douching: associations with rectal gonorrhea, chlamydia, and/or syphilis infection among men who have sex with men.

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    Despite widespread prevalence of lubricant use and rectal douching for receptive anal intercourse (RAI) among men who have sex with men (MSM), research evaluating the association of these behaviors with sexually transmitted infections (STIs) is limited. This is an observational analysis of a longitudinal cohort of predominantly Black/Latino MSM in Los Angeles. Every six months from August 2014 to January 2018, participants received STI screening and surveys evaluating lubricant use, douching, substance use, and sexual risk behaviors. General estimating equations evaluated the association between consistent lubricant use and douching for RAI with positive rectal Neisseria gonorrhoeae, Chlamydia trachomatis, and/or syphilis (positive STI). Among 313 participants across 552 study visits, 16.5% (91/552) had positive STI. Consistent lubricant use was reported in 52.7% (243/552) and rectal douching in 57.6% (318/552) of study visits. Consistent lubricant use was associated with STI diagnosis (adjusted OR [AOR] 1.81; 95% CI 1.11-2.96; p = 0.018). Each episode of rectal douching before RAI was associated with 2% increased odds of positive STI (AOR 1.02; 95% CI 1.00-1.04; p = 0.041). Among this cohort of HIV-positive and high-risk HIV-negative MSM, lubricant use and douching was common and independently associated with an STI, suggesting the utility of prevention messaging around barrier methods/condoms for sexual encounters involving douching/lubricant use

    Widespread microbial utilization of ribosomal β-amino acid-containing peptides and proteins

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    β-Amino residues are regarded as extremely rare features among ribosomal products. They can be installed by a remarkable non-canonical enzymatic splicing process occurring in some Nif11-type ribosomally synthesized and posttranslationally modified peptide (RiPP) pathways from select cyanobacteria. The functions of the final pathway products remained unknown. Here, a global bioinformatic analysis suggested an unexpectedly broad distribution of ribosomal β-amino acid products in diverse bacterial lineages as well as archaea. Characterization of 27 bacterial splicease-substrate pairs confirmed the modification in all cases. The “spliceotide” products include many previously unrecognized RiPP types as well as proteins, contain 35 to >600 residues, and feature single to multiple α-keto-β-amino acid moieties, with 15 different naturally occurring β units characterized and 20 predicted. Of three tested spliceotides, all exhibited exceptionally potent protease inhibitory activity, providing a potential rationale for the widespread splicease chemistry in prokaryotes and highlighting substantial potential for drug discovery and gene-based biomolecule diversification.ISSN:2451-9294ISSN:2451-930
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