First Day Of Exposure Research Articles

Immune Responses to Plasma-Derived Versus Recombinant FVIII Products.

The most severe side effect of hemophilia treatment is the inhibitor development occurring in 30% of patients, during the earliest stages of treatment with factor (F)VIII concentrates. These catastrophic immune responses rapidly inactivate the infused FVIII, rendering the treatment ineffective. This complication is associated with a substantial morbidity and mortality. The risk factors involved in the onset of the inhibitors are both genetic and environmental. The source of FVIII products, i.e. plasma-derived or recombinant FVIII products, is considered one of the most relevant factors for inhibitor development. Numerous studies in the literature report conflicting data on the different immunogenicity of the products. The SIPPET randomized trial showed an increased in the inhibitor rate in patients using recombinant FVIII products than those receiving plasma-derived products in the first exposure days. The SIPPET randomized trial showed an increase in the inhibitor rate in patients using recombinant FVIII products compared to those treated with plasma-derived products in the first days of exposure. The potential increase in the immunogenicity of recombinant products can be attributed to several factors such as: the different post-translational modification in different cell lines, the presence of protein aggregates, and the role played by the chaperon protein of FVIII, the von Willebrand factor, which modulates the uptake of FVIII by antigen presenting cells (APCs). Furthermore, the presence of non-neutralizing antibodies against FVIII has shown to be in increased inhibitor development as demonstrated in a sub-analysis of the SIPPET study. In addition, the presence of the specific subclasses of the immunoglobulins may also be an important biomarker to indicate whether the inhibitor will evolve into a persistent neutralizing antibody or a transient one that would disappear without any specific treatment. Recently, the availability of novel non-replacement therapies as well as emicizumab, administered by weekly subcutaneous infusion, have significantly changed the quality of life of patients with inhibitors showing a considerable reduction of the annual bleeding rate and in most patients the absence of bleeding. Although, these novel drugs improve patients' quality of life, they do not abolish the need to infuse FVIII during acute bleeding or surgery. Therefore, the issue of immunogenicity against FVIII still remains an important side effect of hemophilia treatment.

Potential impact of marine heatwaves on selected phytoplankton adapted to the Gulf of Guinea during stable hydrographic periods

Reports suggest that the Gulf of Guinea (northeastern tropical Atlantic) frequently experiences marine heatwaves (MHW)—prolonged periods of anomalously warm seawater—of ≥1.5 °C above baseline. We assessed the likely impact of this anomaly on two microalgae, Thalassiosira weissflogii (diatom) and Gymnodinium sp. (dinoflagellate), adapted to the surface temperature (28 ± 1.5 °C) of the gulf during stable hydrographic periods. The algae were adapted over ∼400 generations. They were assessed for specific growth rate (μ), dry weight, and protein content after exposure to 5 or 6 days of warming (+2 °C or +4 °C above the temperature of the stock cultures), in line with the minimum duration of MHW. Under each of the investigated warming scenarios, the effect of warming on the diatom was immediate, occurring during the first day of exposure, and μ had decreased by ∼75% by the end of the warming period. In contrast, the warming effect on the dinoflagellate became significant during the second day, with μ reduced by ∼78–86%. Also, the protein content of the dinoflagellate had been reduced by ∼32% by the end of the warming period. The dry weight of T. weissflogii increased three-fold under +2 °C of warming. In contrast, the dry weight of Gymnodinium sp. decreased by ∼78% and did not recover when warming was removed. These results highlight vulnerability of these algae to MHW and their unique responses to the anomaly.

Molecular Mechanisms of Muscle Tone Impairment under Conditions of Real and Simulated Space Flight.

Kozlovskaya et al. [1] and Grigoriev et al. [2] showed that enormous loss of muscle stiffness (atonia) develops in humans under true (space flight) and simulated microgravity conditions as early as after the first days of exposure. This phenomenon is attributed to the inactivation of slow motor units and called reflectory atonia. However, a lot of evidence indicating that even isolated muscle or a single fiber possesses substantial stiffness was published at the end of the 20th century. This intrinsic stiffness is determined by the active component, i.e. the ability to form actin-myosin cross-bridges during muscle stretch and contraction, as well as by cytoskeletal and extracellular matrix proteins, capable of resisting muscle stretch. The main facts on intrinsic muscle stiffness under conditions of gravitational unloading are considered in this review. The data obtained in studies of humans under dry immersion and rodent hindlimb suspension is analyzed. The results and hypotheses regarding reduced probability of cross-bridge formation in an atrophying muscle due to increased interfilament spacing are described. The evidence of cytoskeletal protein (titin, nebulin, etc.) degradation during gravitational unloading is also discussed. The possible mechanisms underlying structural changes in skeletal muscle collagen and its role in reducing intrinsic muscle stiffness are presented. The molecular mechanisms of changes in intrinsic stiffness during space flight and simulated microgravity are reviewed.

Microplastic Consumption and Its Effect on Respiration Rate and Motility of Calanus helgolandicus From the Marmara Sea

Consumption rates of polystyrene microplastics (beads of 6, 12, and 26 μm diameter) and their effects on energy metabolism and motor activity of the copepodCalanus helgolandicusliving in the Marmara Sea were investigated. All sizes of microplastic particles were actively consumed and excreted via fecal pellets, however, copepods displayed a significant preference for beads sized 6 μm. In a mixture of algae and microplastics beads of 6 μm, microplastics consumption rates linearly (r2= 0.78,n= 154) increased 800 times from 50.8 ± 17.3 to 8,612 ± 5,972 beads ind–1day–1with an increase in bead concentration from 10 to 44,000 beads ml–1. The total and basal metabolic rates as well as time spent swimming forC. helgolandicus, decreased 1.7, 1.8 and about 3-fold, respectively after 7–8 days exposure to microplastic treatments, which was similar to the metabolism and activity of starving animals in filtered water. In copepods consuming microplastics, all vital parameters decreased on the first day of exposure, indicating either accelerated starvation, probably due to increased losses of energy and biological matter in the formation of fecal pellets and/or traumatic/toxic effects of the polystyrene beads on the copepods. Our data from laboratory experiments indicate that the presence of large concentrations of microplastics in water, even when mixed with algae, lowered energy metabolism levels ofC. helgolandicus.

Behavior of horizontal sub-surface flow wetlands as an alternative for the wastewater treatment contaminated with florfenicol

In recent years, the increase in the use and production of antibiotics for the protection of animals has been associated not only with human health problems due to bacterial resistance, but also with environmental problems, which have led to the deterioration of the water resources, since a large part of these are discharged into the environment without any type of treatment. This situation has highlighted the fact that a large part of the antibiotics are not efficiently removed in conventional wastewater treatment plants, being necessary to implement efficient and low-cost treatment alternatives. The evaluation of the removal of the antibiotic florfenicol was carried out using pilot horizontal subsurface flow wetlands, with a hydraulic retention time of 4.2 d, planted with macrophytes (Phragmites australis) and using concentrations of 10, 15, 20 and 25 mg/L of florfenicol. It was concluded that the removal of the antibiotic and the COD was decreasing over time, with a maximum removal percentage of 77.9% of florfenicol and 85.2% of COD during the first days of exposure. The results found allowed to demonstrate that florfenicol was not retained in the granular material of the wetlands, even in the macrophytes and that the predominant removal mechanism was biological degradation.

Effects of fine particulate matter on acute health events during critics episodes: a case crossover study in Medellín-Colombia 2015

During March of 2015, two critics episodes of PM2.5 were observed in Medellín-Colombia (levels over 75 µg/m3: three times the recommended by the World Health Organization, for three days or more). A case- crossover study stratified over time was carried out to establish the effects of these episodes in the use of emergency services for respiratory and cardiovascular events. Conditional logistic regression models were used to estimate the relative risks with 95% confidence intervals. Data of atmospheric conditions, particulate matter and the diagnostics in emergencia services were collected from public environmental information system and the individual records of health service provision. The analysis was made in populations under 5 years old and and adults aged 65 years and over. In under 5 years old population every 10 μg/m³ increase in PM2.5 was associated with increases in the risk percentage of emergency room visits for asthma (2.8%), acute respiratory infection (2.0%) and pneumonia (2.2%) in the same day of exposure, and for acute respiratory infection (3.6%) in the first day of exposure. For adults 65 and older the increase of 10 μg/m³ in PM2.5 were associated to excess risks for emergencies room visits due to COPD complications in the first day of exposure (0.8%), cerebrovascular disease after two days of (7.2%) and acute respiratory infection in the same day of exposure and after seven days of cumulative exposure with increases in risk pecentages of 0.6% and 0.5% respectively.These results confirm clear associations between ambient PM2.5 and negative health effects in respiratory and cardiovascular systems during critc episodes in Colombia

Electrochemical study of carbon steel protection with a superhydrophobic coating under conditions of 100% humidity and the presence of corrosion stimulants in the air

100% humidity and the presence in the air of such corrosion stimulants as CO2, NH3 and H2S are characteristic of livestock buildings. Under these conditions, a surface phase film of moisture is formed on the surface of the metals in which the indicated micro-mixtures of air are dissolved and hydrated almost completely with the formation of NH4OH and acids H2CO3 and H2S. The potentiodynamic polarization method was used to study the corrosion and kinetics of electrode processes on steel with a superhydrophobic coating in a NaCl background solution (used to provide sufficient electrical conductivity) saturated in pairs with CO2 and NH3, NH3 and H2S. Similar studies were conducted with uncoated electrodes. Superhydrophobic coating was obtained on the basis of laser texturing of the surface with subsequent hydrophobization with fluoroxysilane (wetting angle 165±2°, rolling angle 3±1°). The influence of the duration of the exposure of the electrodes in solution (0,25…168 h) on the kinetics of electrode processes and the corrosion rate of steel is considered. In the presence of CO2 and NH3 dissolution products, the corrosion rate of an electrode with a superhydrophobic coating on the second and third days of exposure is about an order of magnitude, and on the fourth and seventh days it is more than an order of magnitude lower than without coating. During the entire time the electrodes are in solution, the anode process on the superhydrophobic electrode is inhibited compared to an unprotected electrode. The medium containing the dissolution products of NH3 and H2S is more aggressive than the previous solution. Therefore, the corrosion rate of the electrodes without coating and with a coating here is higher than in the latter one. The corrosion rate of electrodes with superhydrophobic coating in the study period is only 1,5…2,5 times lower than that of uncoated electrodes. During the first day of exposure, the anode process is inhibited, and in the next 144 hours, on the contrary, it is facilitated in comparison with an unprotected electrode. Taking into account the corrosivity of the chloride solution, the possible effect of the dissolution products of aggressive air micro-impurities in the absence of background salt was analyzed.

Multimarker approach to assess the exposure of the wild rodent Calomys laucha to a simulated crude oil spill.

A mysterious oil spill occurred in the ocean near Brazil in 2019, which affected coastal areas in northeastern Brazil. When oil pollution occurs in coastal zones, organisms such as small mammals can suffer deleterious effects to their health. This study aimed to evaluate the effects of exposure to contaminated sandy soil with different crude oil concentrations in males of the species Calomys laucha. The exposure to crude oil resulted in multiple health issues for the subjects in the very first days of exposure. Furthermore, the exposure resulted in mutagenic damage to bone marrow blood cells and behavioral and morphological alterations, which were almost always in a dose-dependent form. The present study demonstrates the sensibility of the biomarkers used and highlights that small wild mammals such as C. laucha are useful for predicting environmental damage caused by the exposure to crude oil.

The Combined Effect of Bacteriophages and Antibiotics on Pseudomonas aeruginosa Biofilm

Currently, the problem of nosocomial infections is of urgent concern. Pseudomonas aeruginosa is one of the key causative agents of this type of disease. The prospect of using bacteriophages in the prevention and control of infectious diseases is now being actively studied. The aim of the work is to study the effect of new bacteriophages on P.aeruginosa biofilm when used together with the antibiotic gentamicin. Cells of the laboratory reference strain P.aeruginosa PAO1 were grown in 96-well plates for a day, the resulting biofilms were treated with gentamicin in various concentrations, as well as bacteriophages AN14 and AN1. The degree of biofilm degradation was evaluated by staining the cells with crystal violet dye. The new lytic bacterio­phages AN14 (Siphoviridae family), AN1 (Myoviridae family) used in the study, showed pronounced antibiofilm activity on the first day of exposure to P.aeruginosa biofilm ( p <0.001). The destructive effect of gentamicin on biofilms increased when the concentration of the antibiotic was increased in the range of 2—16 mg/ml. Addition of lytic bacteriophages AN14 and AN1 enhanced the effect of the antibiotic ( p =0.05). Thus, the combined use of lytic bacteriophages and antibiotics led to a more effective eradication of biofilms than when used separately.

Colonizing microbiota protect zebrafish larvae against silver nanoparticle toxicity

Metal-based nanoparticles exhibiting antimicrobial activity are of emerging concern to human and environmental health. In addition to their direct adverse effects to plants and animals, indirect effects resulting from disruption of beneficial host–microbiota interactions may contribute to the toxicity of these particles. To explore this hypothesis, we compared the acute toxicity of silver and zinc oxide nanoparticles (nAg and nZnO) to zebrafish larvae that were either germ-free or colonized by microbiota. Over two days of exposure, germ-free zebrafish larvae were more sensitive to nAg than microbially colonized larvae, whereas silver ion toxicity did not differ between germ-free and colonized larvae. Using response addition modeling, we confirmed that the protective effect of colonizing microbiota against nAg toxicity was particle-specific. Nearly all mortality among germ-free larvae occurred within the first day of exposure. In contrast, mortality among colonized larvae increased gradually over both exposure days. Concurrent with this gradual increase in mortality was a marked reduction in the numbers of live host-associated microbes, suggesting that bactericidal effects of nAg on protective microbes resulted in increased mortality among colonized larvae over time. No difference in sensitivity between germ-free and colonized larvae was observed for nZnO, which dissolved rapidly in the exposure medium. At sublethal concentrations, these particles moreover did not exert detectable bactericidal effects on larvae-associated microbes. Altogether, our study shows the importance of taking host–microbe interactions into account in assessing toxic effects of nanoparticles to microbially colonized hosts, and provides a method to screen for microbiota interference with nanomaterial toxicity.

Evolution of blood rheology and its relationship to pulmonary hemodynamic during the first days of exposure to moderate altitude.

Blood rheology and hemodynamic parameters have never been explored together during acclimatization to altitude. This study aimed to investigate changes in blood rheology parameters and pulmonary hemodynamics during the first days of real moderate altitude exposure.Seventeen athletes were tested at sea-level, 20 hours after their arrival at 2,400 meters of altitude (H1) and five days later (H2). Blood was sampled to analyze red blood cell (RBC) aggregation, blood viscosity and hematocrit. Pulmonary arterial pressure (PAP), pulmonary capillary pressure (Pcap) and pulmonary vascular resistance (PVR) were assessed by echocardiography.We observed a rise in hematocrit, blood viscosity, RBC aggregation, PAP, Pcap and PVR between sea-level and H1. In H2, RBC aggregation, hematocrit, PAP, Pcap and PVR remained different compared to sea-level and no difference was observed between H1 and H2. Blood viscosity decreased in H2 and returned to sea-level values.Our results suggest that hemoconcentration occurring within the first hours of altitude exposure increased blood viscosity, which contributed to the changes in pulmonary hemodynamic. When blood viscosity decreased in H2, no change occurred in pulmonary hemodynamic parameters suggesting that hypoxic pulmonary vasoconstriction was still present. The elevated RBC aggregation observed after in H2 could participate in the increase of Pcap.

Biological control of Monacha cartusiana “glassy clover land snails” by microbial biopesticides Biozed and Biogard, using bait technique

Abstract The effectiveness of microbial derived insecticides (Biozed and Biogard) were tested for controlling the subversive clover snails causing wastage of economic plants at Sharkia Governorate, Egypt, using poisonous baits technique. The toxicity index, LC50 and relative potency values reveals the potential activity of Biozed (fungal) than Biogard (bacterial) against M. cartusiana snails. Biogard caused no mortalities among treated clover snails at all at the first day of exposure. Mortality percentages appeared after one week and increased gradually with increasing concentrations and time of treatments. The highest concentrations of Biozed (0.75%) and Biogard (3.9%) caused 66.6% and 40% mortalities respectively after 28 days of exposure. From the biochemical parameters, an increment of total proteins, AST, ALT, α-esterase levels while a strong reduction on the total lipids, β-esterase and Phenoloxidase levels were observed after treatments with LC25 of biocides for three weeks. Histopathological investigations on the digestive and hermaphrodite glands revealed that sublethal concentration of Biozed produced tubular disruptions, vacuolation, excessive luminal secretions in digestive gland tissues. Malformed sperms and oocytes were spotted in ovotestis acini treated with Biozed. Biogard caused extensive luminal secretions, hemocytes infiltration and lysis of peripheral cells of digestive tubules while hermaphroditic acini showed disrupted sperms and oocytes.

Accumulation of Nickel by Excluder Thlaspi arvense and Hyperaccumulator Noccaea caerulescens upon Short-Term and Long-Term Exposure

Abstract: The ability to accumulate nickel (Ni) was compared in hyperaccumulator Noccaea сaerulescens F.K. Mey and excluder Thlaspi arvense L. after a short-term (1, 2, or 3 days) and long-term (8 weeks) exposure. T. arvense and four accessions of N. сaerulescens (La Calamine (LC), Saint Felix de Pallieres (SF), Monte Prinzera (MP), and Lellingen (LE)) were grown on a half-strength Hoagland`s solution in the presence of 25 µM Ni(NO3)2 (N. сaerulescens and T. arvense) and 250 µM Ni(NO3)2 (N. сaerulescens; T. arvense for only 1–3 days). Metal content in the roots and shoots was determined by atomic absorption spectroscopy. The Ni content per unit mass in the roots and shoots of N. сaerulescens in most cases did not differ significantly after the short-term incubation. At 25 µM Ni in the nutrient solution, its content in the roots of LC plants after 2–3 days of incubation was lower than in T. arvense, whereas Ni content in the shoots of these plants was similar. In the plants of other accessions of N. сaerulescens, Ni content in the roots and shoots in most cases was higher than in T. arvense. At 250 µM Ni, the differences in metal content in the roots were insignificant, and its content in the shoots in all the accessions of the hyperaccumulator was much higher than in the excluder. The Ni translocation factor was higher in N. сaerulescens than in T. arvense and exceeded unity only in the plants of MP accession. After the long-term exposure, the Ni translocation factor was higher than 1 in plants of all accessions of N. сaerulescens and decreased in the following order: MP ≈ LC > LE ≥ SF; in T. arvense, it did not exceed 0.3. Upon both long-term and short-term exposure, the ability to accumulate Ni by N. сaerulescens plants of different accessions generally increased in the following order: LC < SF < LE < MP. However, minor changes were observed depending on the duration of exposure and Ni concentration in the medium. Thus, considerable differences in the ability to accumulate Ni among the plants of different accessions of hyperaccumulator N. сaerulescens became apparent as early as during the first days of exposure to Ni and hardly depended on the duration of incubation or metal concentration in the medium. The obtained data confirm the assumption about a constitutive or genetically predetermined ability of plants of different N. сaerulescens accessions to accumulate Ni.

Coagulation of organo-mineral colloids and formation of low molecular weight organic and metal complexes in boreal humic river water under UV-irradiation

Photodegradation of dissolved organic matter (DOM) is highly important in humic waters of peatland regions, yet the coupling between organic and organo-mineral colloids, trace metals and bioavailability of photodegraded products is poorly known. Here we studied photo-destruction of organo-mineral colloids induced by UV-irradiation of sterile-filtered mire water. We revealed two simultaneously occurring processes of transformation of DOM and trace elements speciation: (i) disintegration of high molecular weight organo-mineral colloids into lower molecular weight (<1 kDa) DOM and metal complexes and (ii) formation of particulate (>0.22 μm) aggregates of metals and organic matter. Over 26 days of UV-irradiation, up to 20% of dissolved organic carbon from peat waters was transformed into CO2. In addition to transformation of organic compounds, sizeable change in speciation and size fractionation of many trace metals such as Fe, Pb, Cd, Co, Zn, Cu, V, La, Ni and Cr occurred. Although short-term (1 day) UV-irradiation of mire water stimulated growth of cultivable Pseudomonas sp. bacterium, the long-term exposure (26 days) of organic substrate had a negative effect on bacterial development. Therefore, while sizeable transformation of the organic and metal colloidal load of peat water may occur over first 10 days of UV-irradiation, the enhanced bioavailability of UV-treated substrate is achieved after first day of exposure. The present study demonstrates the importance of even short-term UV-irradiation on colloidal transformation and potential bioavailability of humic waters from temperate mires and highlights the need for more detailed study of coupled metal-organic matter transformation induced by sunlight exposure of mire waters.

How the Neurotoxin β-N-Methylamino-l-Alanine Accumulates in Bivalves: Distribution of the Different Accumulation Fractions among Organs.

The environmental neurotoxin β-methylamino-l-alanine (BMAA) may represent a risk for human health. BMAA accumulates in freshwater and marine organisms consumed by humans. However, few data are available about the kinetics of BMAA accumulation and detoxification in exposed organisms, as well as the organ distribution and the fractions in which BMAA is present in tissues (free, soluble bound or precipitated bound cellular fractions). Here, we exposed the bivalve mussel Dreissena polymorpha to 7.5 µg of dissolved BMAA/mussel/3 days for 21 days, followed by 21 days of depuration in clear water. At 1, 3, 8, 14 and 21 days of exposure and depuration, the hemolymph and organs (digestive gland, the gills, the mantle, the gonad and muscles/foot) were sampled. Total BMAA as well as free BMAA, soluble bound and precipitated bound BMAA were quantified by tandem mass spectrometry. Free and soluble bound BMAA spread throughout all tissues from the first day of exposure to the last day of depuration, without a specific target organ. However, precipitated bound BMAA was detected only in muscles and foot from the last day of exposure to day 8 of depuration, at a lower concentration compared to free and soluble bound BMAA. In soft tissues (digestive gland, gonad, gills, mantle and muscles/foot), BMAA mostly accumulated as a free molecule and in the soluble bound fraction, with variations occurring between the two fractions among tissues and over time. The results suggest that the assessment of bivalve contamination by BMAA may require the quantification of total BMAA in whole individuals when possible.

Investigating the effects of a sub-lethal metal mixture of Cu, Zn and Cd on bioaccumulation and ionoregulation in common carp, Cyprinus carpio

The aquatic environment is continuously under threat because it is the final receptor and sink of waste streams. The development of industry, mining activities and agriculture gave rise to an increase in metal pollution in the aquatic system. Thus a wide occurrence of metal mixtures exists in the aquatic environment. The assessment of mixture stress remains a challenge considering that we can not predict the toxicity of a mixture on the basis of single compounds. Therefore the analysis of the effects of environmentally relevant waterborne mixtures is needed to improve our understanding of the impact of metal pollution in aquatic ecosystems. Our aim was to assess whether 10 % of the concentration of the 96 h LC50 (the concentration that is lethal to 50 % of the population in 96 h) of individual metal exposures can be considered as a “safe” concentration when applied in a trinomial mixture. Therefore, common carp were exposed to a sublethal mixture of Cu 0.07 ± 0.001 μM (4.3 ± 0.6 μg/L), Zn 2.71 ± 0.81 μM (176.9 ± 52.8 μg/L) and Cd 0.03 ± 0.0004 μM (3.0 ± 0.4 μg/L) at 20 °C for a period of one week. Parameters assessed included survival rate, bioaccumulation and physiological biomarkers related to ionoregulation and defensive mechanisms such as MT induction. Our results showed a sharp increase in Cu and Cd concentration in gills within the first day of exposure while Zn levels remained stable. The accumulation of these metals led to a Na drop in gills, liver and muscle as well as a decreased K content in the liver. Biomarkers related to Na uptake were also affected: on the first day gene expression for H+-ATPase was transiently increased while a concomitant decreased gene expression of the Na+/H+ exchanger occurred. A fivefold induction of metallothionein gene expression was reported during the entire duration of the experiment. Despite the adverse effects on ionoregulation all fish survived, indicating that common carp are able to cope with these low metal concentrations, at least during a one week exposure.

Ocean acidification impact on ascidian Ciona robusta spermatozoa: New evidence for stress resilience

Rising atmospheric CO2 is causing a progressive decrease of seawater pH, termed ocean acidification. Predicting its impact on marine invertebrate reproduction is essential to anticipate the consequences of future climate change on species fitness and survival. Ocean acidification may affect reproductive success either in terms of gamete or progeny quality threating species survival. Despite an increasing number of studies focusing on the effects of ocean acidification on the early life history of marine organisms, very few have investigated the effects on invertebrate gamete quality. In this study, we set up two experimental approaches simulating the ocean conditions predicted for the end of this century, in situ transplant experiments at a naturally acidified volcanic vent area along the Ischia island coast and microcosm experiments, to evaluate the short-term effects of the predicted near-future levels of ocean acidification on sperm quality of the ascidian Ciona robusta after parental exposure. In the first days of exposure to acidified conditions, we detected alteration of sperm motility, morphology and physiology, followed by a rapid recovery of physiological conditions that provide a new evidence of resilience of ascidian spermatozoa in response to ocean acidification. Overall, the short-term tolerance to adverse conditions opens a new scenario on the marine species capacity to continue to reproduce and persist in changing oceans.

Tolerance of Fucus vesiculosus exposed to diesel water-accommodated fraction (WAF) and degradation of hydrocarbons by the associated bacteria

The viability and physiological state of brown macroalgae Fucus vesiculosus and its associated epiphytic bacteria exposed to diesel water-accommodated fraction (WAF), as well as the capacity of this association to deplete petroleum hydrocarbons (HCs) were experimentally tested. After a 6-day exposure treatment, the algal-surface associated bacteria were identified as primarily hydrocarbon-oxidising bacteria (HOB), and the algal-HOB association was able to deplete petroleum hydrocarbons from the diesel WAF by 80%. The HOB density on the algal surface exposed to diesel WAF was 350% higher compared to the control (i.e. HOB density on the algal surface exposed to ambient seawater), which suggest that they actively proliferated in the presence of hydrocarbons and most likely consumed hydrocarbons as their primary organic substrate. Exposure to diesel WAF did not affect the metabolic activity of F. vesiculosus. Higher lipid peroxidation was observed in F. vesiculosus exposed to diesel WAF while catalase concentration decreased only during the first day of exposure. Results suggest F. vesiculosus is tolerant to oil pollution and the algal-HOB association can efficiently deplete petroleum hydrocarbons in oil-contaminated seas.

Alterations of acoustic features of 50 kHz vocalizations by nicotine and phencyclidine in rats.

Ultrasonic vocalizations are widely used to examine affective states in rats, yet relatively few studies explore the acoustic features of vocalizations, especially in relation to drug exposure, and no studies have explored alterations in acoustic features over time. The goal of this study was to examine nicotine- and phencyclidine-induced alterations of bandwidth, duration, and frequency of 50 kHz vocalizations. The minimum and maximum frequency, bandwidth, and duration of calls were examined after 7 days of daily subcutaneous administration of phencyclidine (2.0 mg/kg) and nicotine (0.2 and 0.4 mg/kg) in male Sprague-Dawley rats. Bandwidth was significantly decreased in rats treated with both nicotine (0.2 and 0.4 mg/kg) and phencyclidine. Maximum frequency was lowest on the first day of exposure compared with all other days and was not altered by drug exposure. Call duration was not affected by time or drug exposure. These findings suggest the importance of studying alterations in acoustic features in time, especially those induced by drug exposure.

Microhardness Investigation of Dental Composite Resins Exposed to Corrosive Environment

The aim of this study was to evaluate the microhardness Rockwell and Young s modulus of a new nano-hybrid and nano-fill composite resins exposed to corrosive media. The study was performed on two composite resins, one nano-hybrid and one nano-fill, enamel, dentine, translucent, respectively body shade, of which were made 20 samples (25.0 � 0.1 mm lengths, 10.0 � 0.1 mm widths and 3.0 � 0.1 mm thicknesses), which were immersed in mouthwash for 1 minute per day for 10 days, the rest of the time being stored in artificial saliva. Measurements of Rockwell microhardness and Young�s modulus on samples were made between on the first day, after 6 days and 10 days of immersion in mouthwash comparative with 0 day. The results showed that after immersion in the corrosive environment, both materials had the hardness values changed, but medium values of Rockwell microhardness to nano-fill composite resin were higher than nano-hybride. At the nano-hybride composite resin, it was observed that the enamel and clear translucent groups had the mean values increased after the first day of exposure to mouthwash, compared to the dentine group, which showed a higher mean value after 6 days. At the nano-fill composite resin, for the enamel and body groups were obtained the higher values of HRC after 10 days. For the dentine group, after 6 days, Filtek Ultimate showed the same variation as Harmonize dentine shade. Harmonize composite resin showed higher values of Rockwell microhardness and Young�s modulus for all study groups compared to Filtek Ultimate.