Fetal magnetic resonance imaging (MRI) of ischemic brain injury

The aim of the present study was to demonstrate the usefulness of fetal magnetic resonance imaging (MRI) in ischemic brain injury. We report seven cases of fetal brain ischemia prenatally suspected on ultrasound (US) and confirmed by fetal MRI. Sonographic abnormalities included ventricular dilatation (n=3), microcephaly (n=1), twin pregnancy with in utero death of a twin and suspected cerebral lesion in the surviving co-twin (n=3). MRI was performed with a 1.0 T unit using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences between 28 and 35 weeks of gestation. US and MRI images were compared with pathologic findings or postnatal imaging. MRI diagnosed hydranencephaly (n=1), porencephaly (n=2), multicystic encephalomalacia (n=2), unilateral capsular ischemia (n=1), corpus callosum and cerebral atrophy (n=1). In comparison with US, visualization of fetal brain anomalies was superior with MRI. The present cases demonstrate that MRI is a valuable complementary means of investigation when a brain pathology is discovered or suspected during prenatal US. Copyright © 2001 John Wiley & Sons, Ltd.     

Norovirus and Other Human Enteric Viruses in Moroccan Shellfish

The aim of this study was to evaluate the presence of human enteric viruses in shellfish collected along the Mediterranean Sea and Atlantic Coast of Morocco. A total of 77 samples were collected from areas potentially contaminated by human sewage. Noroviruses were detected in 30 % of samples, with an equal representation of GI and GII strains, but were much more frequently found in cockles or clams than in oysters. The method used, including extraction efficiency controls, allowed the quantification of virus concentration. As in previous reports, results showed levels of contamination between 100 and 1,000 copies/g of digestive tissues. Sapoviruses were detected in 13 % of samples mainly in oyster and clam samples. Hepatitis A virus was detected in two samples, with concentrations around 100 RNA copies/g of digestive tissues. Only two samples were contaminated with enterovirus and none with norovirus GIV or Aichi virus. This study highlights the interest of studying shellfish samples from different countries and different production areas. A better knowledge of shellfish contamination helps us to understand virus levels in shellfish and to improve shellfish safety, thus protecting consumers.     

Oxygen isotope fractionation between bird bone phosphate and drinking water

Oxygen isotope compositions of bone phosphate (δ¹⁸O_p) were measured in broiler chickens reared in 21 farms worldwide characterized by contrasted latitudes and local climates. These sedentary birds were raised during an approximately 3 to 4-month period, and local precipitation was the ultimate source of their drinking water. This sampling strategy allowed the relationship to be determined between the bone phosphate δ¹⁸O_p values (from 9.8 to 22.5‰ V-SMOW) and the local rainfall δ¹⁸O_w values estimated from nearby IAEA/WMO stations (from ?16.0 to ?1.0‰ V-SMOW). Linear least square fitting of data provided the following isotopic fractionation equation: δ¹⁸O_w = 1.119 (±0.040) δ¹⁸O_p ? 24.222 (±0.644); R ² = 0.98. The δ¹⁸O_p–δ¹⁸O_w couples of five extant mallard ducks, a common buzzard, a European herring gull, a common ostrich, and a greater rhea fall within the predicted range of the equation, indicating that the relationship established for extant chickens can also be applied to birds of various ecologies and body masses. Applied to published oxygen isotope compositions of Miocene and Pliocene penguins from Peru, this new equation computes estimates of local seawater similar to those previously calculated. Applied to the basal bird Confuciusornis from the Early Cretaceous of Northeastern China, our equation gives a slightly higher δ¹⁸O_w value compared to the previously estimated one, possibly as a result of lower body temperature. These data indicate that caution should be exercised when the relationship estimated for modern birds is applied to their basal counterparts that likely had a metabolism intermediate between that of their theropod dinosaur ancestors and that of advanced ornithurines.     

Light- and flotsam-dependent ‘float-and-wait’ foraging by pelagic sea snakes (<Emphasis Type="Italic">Pelamis platurus</Emphasis>)

Efficient detection of food patches in oceanic areas by pelagic predators is often linked to large-scale physical structures (e.g. fronts, upwellings) that are usually rich and predictable. At smaller scales, however, predictability of resource becomes less clear because of the lability of smaller physical structures such as slicks and drift lines. Here, we explore how light levels and quantity of flotsam affect the occurrence of foraging Yellow-bellied sea snakes (Pelamis platurus) on slicks. Although this pelagic species was formerly hypothesised to surface randomly and drift passively to reach slicks, our results show that foraging snakes are far more abundant on slicks if light levels are high and if slicks display flotsam. The combination of both light and flotsam should enhance the contrast between a potentially favourable slick and the adjacent waters as seen from an underwater viewpoint. Although our results do not unambiguously demonstrate the ability of Pelamis platurus to visually detect surface drift lines, they clearly suggest a role of both light levels and amount of flotsam on surfacing decision. Accordingly, this hypothesis is supported by several complementary traits that are specific to this species. ‘Float-and-wait’ foraging undoubtedly requires efficient detection of, and orientation to, oceanic slicks—processes that are likely less random and passive than formerly believed. Successful pelagic foraging is no doubt important to this species of sea snake that is the world’s most widely distributed snake species.     

Age-dependent attractivity of males�� sexual pheromones in Bombus terrestris (L.) [Hymenoptera, Apidae]

Males of Bombus terrestris (L.) adopt a patrolling behaviour during their nuptial parade using cephalic labial gland (CLG) secretions containing sexual pheromones to attract conspecific virgin queens. The changes in chemical composition of their CLG secretions with age are quite well known. In this study, we investigate the evolution of CLG secretions with age in greater detail and compare behavioural reactions of conspecific virgin queens to the secretions. We show that compounds of CLG secretions follow two profiles. Most of the compounds increase from the first day after emergence until the bees are 15-days-old and then decrease. Others are less abundant in 1 to 15-day-old males and then increase (e.g. tricosane, tricosene, henicosane, tetradecanoic acid, pentacosene, pentacosane, heptacosene, heptacosane, nonacosene and geranylcitronellyl tetradecanoate). Differences in secretion composition lead to preferences of virgin queens for males according to the male??s age. Virgin queens prefer the pheromonal gland secretions of bees of the following ages in decreasing order; 1?day?=?3?days?<?7?days?=?30?days?<?15?days?<?10?days. The virgin queens are strongly attracted by secretions containing high amounts of 2,3-dihydrofarnesol, 2,3-dihydrofarnesal, ethyl dodecanoate and hexadecanol. On the contrary, geranylcitronellol is more abundant in 30-day-old males.     

A large scale survey of trace metal levels in coastal waters of the Western Mediterranean basin using caged mussels (Mytilus galloprovincialis)

A large scale study of trace metal contamination (Hg, Cd, Pb and Ni) by means of caged mussels Mytilus galloprovincialis was undertaken along the coastal waters of the Western Mediterranean Sea within the context of the MYTILOS project. Individual mussels from an homogeneous population (shell size 50 ± 5 mm) obtained from an aquaculture farm were consecutively caged and deployed at 123 sites located in the Alborán, North-Western, South-Western and Tyrrhenian sub-basins for 12 weeks (April-July) in 2004, 2005 and 2006. After cage recoveries, both the metal content in the whole mussel tissue and the allometric parameters were measured. Statistical analysis of the datasets showed significant differences in concentrations between sub-basins for some metals and mussel condition index (CI). Linear regression models coupled to the CI were revisited for the data adjustment of certain trace metals (Hg, Cd and Ni), and four level categories were statistically derived to facilitate interregional comparison. Seawater masses surrounding coastal areas impacted by run-off from land mineralised coasts and industrial activities displayed the highest concentration ranges (Hg: 0.15-0.31 mg kg(-1) dw; Cd: 1.97-2.11; Ni: 2.18-3.20 and Pb: 3.1-3.8), although the levels obtained in most of the sites fitted within moderate or low categories, and they could be considered as baseline concentrations. However, few sites considered little-influenced by human activities, at present, showed high concentrations of Cd, Ni and Pb, which constitute new areas of concern. Overall, the use of active biomonitoring (ABM) approach allowed to investigate trace metal contamination in order to support policy makers in establishing regional strategies (particularly, with regard to the European Marine Strategy Directive).