Ozone stress and antioxidant substances in Trifolium repens and Centaurea jacea leaves

Ozone-sensitive (NC-S clone) and resistant plants (NC-R clone) of Trifolium repens and Centaurea jacea were exposed to moderate ozone concentrations in ambient air. The aim of this study was the investigation of the relation between ozone-sensitivity and leaf concentrations of antioxidants (ascorbic acid, total phenolics and total antioxidant capacity). NC-R clone showed the highest concentrations of antioxidants with 50-70% more ascorbic acid than NC-S. NC-R had about 5 times more ascorbic acid in the young leaves and 9 times more in the old leaves than Centaurea. In a fumigation experiment with acute ozone stress (100 nl L(-1)) the antioxidant levels changed profoundly. The ozone-injured leaves of NC-S had 6-8 times more total phenolics than uninjured leaves. Generally older leaves had lower antioxidant concentrations and were more prone to ozone injury than younger leaves. Ascorbic acid concentrations were closer related to the appearance of visible ozone injury than the other antioxidative parameters.     

Parvovirus B19 infection in pregnancy: new insights and management

In this article, we review the virology, pathology, epidemiology and clinical spectrum of intrauterine human parvovirus B19 (B19V) infection, including intrauterine fetal death, non-immune hydrops fetalis, thrombocytopenia and neurological manifestations such as pediatric stroke and perivascular calcifications. In addition, we discuss the new insights into the neurodevelopmental outcome of intrauterine B19V infection. Current diagnosis and management of B19V infection is summarized, including a diagnostic and follow-up flowchart for practical clinical use. Copyright © 2011 John Wiley & Sons, Ltd.     

Estuarine dependency in a marine fish evaluated with otolith chemistry

Life-long strontium patterns in otoliths of the sciaenid Micropogonias furnieri caught in the southwestern Atlantic Ocean were examined to evaluate estuarine dependency and habitat use. Otolith Sr concentrations were on average 820?±?55?μg?g^?1 for freshwater, 1,751?±?101?μg?g^?1 for estuarine, and ranged from 2,000 to over 4,000?μg?g^?1 for marine waters. The examination of life-long otolith Sr revealed that 71?% of the marine-sampled fish moved toward brackish waters from age 0 to age 1, and that estuarine egress ranged from ages 2.1 to 4.1?years depending on the sampling area. Three different long-term patterns of Sr accumulation were observed and inferred to be the result of ontogeny and habitat shifts. Given that an estuarine Sr signature was consistently present in all sampled fish, M. furnieri is suggested to be a true estuarine-dependent species during its early life history.     

Impacts of temperature and acidification on larval calcium incorporation of the spider crab <Emphasis Type="Italic">Hyas araneus</Emphasis> from different latitudes (54° vs. 79°N)

The combined effects of ocean warming and acidification were compared in larvae from two populations of the cold-eurythermal spider crab Hyas araneus, from one of its southernmost populations (around Helgoland, southern North Sea, 54°N, habitat temperature 3–18°C; collection: January 2008, hatch: January–February 2008) and from one of its northernmost populations (Svalbard, North Atlantic, 79°N, habitat temperature 0–6°C; collection: July 2008, hatch: February–April 2009). Larvae were exposed to temperatures of 3, 9 and 15°C combined with present-day normocapnic (380 ppm CO₂) and projected future CO₂ concentrations (710 and 3,000 ppm CO₂). Calcium content of whole larvae was measured in freshly hatched Zoea I and after 3, 7 and 14 days during the Megalopa stage. Significant differences between Helgoland and Svalbard Megalopae were observed at all investigated temperatures and CO₂ conditions. Under 380 ppm CO₂, the calcium content increased with rising temperature and age of the larvae. At 3 and 9°C, Helgoland Megalopae accumulated more calcium than Svalbard Megalopae. Elevated CO₂ levels, especially 3,000 ppm, caused a reduction in larval calcium contents at 3 and 9°C in both populations. This effect set in early, at 710 ppm CO₂ only in Svalbard Megalopae at 9°C. Furthermore, at 3 and 9°C Megalopae from Helgoland replenished their calcium content to normocapnic levels and more rapidly than Svalbard Megalopae. However, Svalbard Megalopae displayed higher calcium contents under 3,000 ppm CO₂ at 15°C. The findings of a lower capacity for calcium incorporation in crab larvae living at the cold end of their distribution range suggests that they might be more sensitive to ocean acidification than those in temperate regions.     

Thermal tolerance of larvae of Pollicipes elegans, a marine species with an antitropical distribution

For the antitropical gooseneck barnacle Pollicipes elegans, population-specific physiological temperature tolerance of larvae may serve as a barrier to larval dispersal across the warmest regions of the tropical Pacific Ocean. Thermal tolerance ranges of larvae of three different populations of P. elegans sampled in 2011 and 2012 (Mexico [MX], El Salvador [ES], and Peru [PE]) were investigated by measuring three indicators of physiological performance: swimming activity, oxygen consumption, and lethality or LT₅₀. The thermal tolerance profiles, which include measurable optimum (maximum aerobic performance), pejus (“getting worse”) and pessimum (worst aerobic performance) ranges, of larvae from the three populations were consistent with their characteristic environmental temperatures. In MX, larvae live close to the upper border of their optimum during warm months and so have a limited capacity to tolerate higher-than-normal temperatures. Larvae from the ES population likewise appear to live within their optimum temperature range, but these larvae lack a detectable pessimum range, suggesting they would be unable to cope with temperatures above their pejus range. Larvae from PE have a broad optimum but no pejus range. Different thermal tolerance ranges provide strong evidence for population-dependent physiological adaptations in P. elegans. For the southern (PE) and northern (MX) P. elegans populations, high tropical temperatures are likely to be a strong direct physiological barrier to larval survival and dispersal, which is in contrast to the more thermally tolerant ES population.     

Environmental parameters affecting induction of hatching in halibut (Hippoglossus hippoglossus) embryos

The influence of some environmental parameters in the regulation of hatching of halibut (Hippoglossus hippoglossus) embryos is reported. The progress of hatching was observed when light, oxygen and turbulence were varied. Environmental parameters influenced the induction of hatching, while the exit mechanism of halibut embryos was unaltered. Light arrests hatching of halibut eggs, and transfer of such eggs to darkness resulted in rapid and synchronous hatching. Hatching under different oxic conditions shows that better oxygen availability does not postpone the time of hatching in halibut. Oxygen seems therefore to have a minor role in the regulation of hatching in halibut. Induction of hatching was delayed under hypoxic conditions (15 mm Hg) compared to higher oxygen levels, but this probably reflects a minimal oxygen level needed for metabolism during hatching. Non-stationary water conditions delayed hatching for 1.5 d both in eggs incubated in turbulence, and in eggs subjected to turbulence at the time of hatching. Turbulence had an immediate inhibitory effect on hatching, but this inhibition was reversible under stationary conditions, under which hatching resumed after 150 to 250 min. We conclude that hatching in halibut occurs after sensory input from environmental factors which are integrated by the embryo before proceeding to hatch.