Search

It has been known for a long time that marine mammals, such as whales and dolphins, host a very specific epizoic community on their skin. Whether or not a similar community exists on the carapaces of sea turtles is less studied. The present paper describes two new epizoic diatoms from the genus Achnanthes sensu stricto found on the carapace of nesting olive ridley sea turtles (Lepidochelys olivacea) in Ostional Beach on the Pacific coast of Costa Rica, based upon detailed scanning electron microscopy and comparison with the type material of A. groenlandica var. phinneyi and A. pseudogroenlandica. The two taxa, A. elongata and A. squaliformis, appear to be closely related on the basis of their morphological features including long, slender valves, absence of terminal orbiculi, large cribrate areolae and absence of typical costae on the internal virgae of both valves. They can, however, be differentiated from each other by the number of areolae per stria, the position of the rapheless sternum, and differences in their length/width ratio. A new Labellicula species, L. lecohuiana Majewska & Van de Vijver sp. nov., was observed living epizoically on the carapaces of green sea turtles in Costa Rican coastal waters. The new species, showing a narrowly lanceolate valve outline, is characterized by uniseriate striae composed of one large macroareola, a rather simple raphe structure with hooked terminal raphe fissures, the presence of two globular structures in the valve interior covering the isolated pore and a cingulum composed of several open, doubly perforated copulae. The new taxon can be distinguished from the only other Labellicula species known to date, the sub-Antarctic L. subantarctica, by differences in raphe structure and valve outline. Labellicula lecohuiana lacks both the distinct bucinoportula and the marginal canal typical of the genus Olifantiella and thus, the latter is excluded as the host genus for the new taxon.

Objective: To assess the separate and combined associations of maternal pre-pregnancy body mass index (BMI) and gestational weight gain with the risks of pregnancy complications and their population impact. Design: Individual participant data meta-analysis of 39 cohorts. Setting: Europe, North America, and Oceania. Population: 265 270 births. Methods: Information on maternal pre-pregnancy BMI, gestational weight gain, and pregnancy complications was obtained. Multilevel binary logistic regression models were used. Main outcome measures: Gestational hypertension, pre-eclampsia, gestational diabetes, preterm birth, small and large for gestational age at birth. Results: Higher maternal pre-pregnancy BMI and gestational weight gain were, across their full ranges, associated with higher risks of gestational hypertensive disorders, gestational diabetes, and large for gestational age at birth. Preterm birth risk was higher at lower and higher BMI and weight gain. Compared with normal weight mothers with medium gestational weight gain, obese mothers with high gestational weight gain had the highest risk of any pregnancy complication (odds ratio 2.51, 95% CI 2.31– 2.74). We estimated that 23.9% of any pregnancy complication was attributable to maternal overweight/obesity and 31.6% of large for gestational age infants was attributable to excessive gestational weight gain. Conclusions: Maternal pre-pregnancy BMI and gestational weight gain are, across their full ranges, associated with risks of pregnancy complications. Obese mothers with high gestational weight gain are at the highest risk of pregnancy complications. Promoting a healthy pre-pregnancy BMI and gestational weight gain may reduce the burden of pregnancy complications and ultimately the risk of maternal and neonatal morbidity. Tweetable abstract: Promoting a healthy body mass index and gestational weight gain might reduce the population burden of pregnancy complications. © 2019 Royal College of Obstetricians and Gynaecologists

Importance: Both low and high gestational weight gain have been associated with adverse maternal and infant outcomes, but optimal gestational weight gain remains uncertain and not well defined for all prepregnancy weight ranges. Objectives: To examine the association of ranges of gestational weight gain with risk of adverse maternal and infant outcomes and estimate optimal gestational weight gain ranges across prepregnancy body mass index categories. Design, Setting, and Participants: Individual participant-level meta-analysis using data from 196 670 participants within 25 cohort studies from Europe and North America (main study sample). Optimal gestational weight gain ranges were estimated for each prepregnancy body mass index (BMI) category by selecting the range of gestational weight gain that was associated with lower risk for any adverse outcome. Individual participant-level data from 3505 participants within 4 separate hospital-based cohorts were used as a validation sample. Data were collected between 1989 and 2015. The final date of follow-up was December 2015. Exposures: Gestational weight gain. Main Outcomes and Measures: The main outcome termed any adverse outcome was defined as the presence of 1 or more of the following outcomes: preeclampsia, gestational hypertension, gestational diabetes, cesarean delivery, preterm birth, and small or large size for gestational age at birth. Results: Of the 196 670 women (median age, 30.0 years [quartile 1 and 3, 27.0 and 33.0 years] and 40 937 were white) included in the main sample, 7809 (4.0%) were categorized at baseline as underweight (BMI

Tropical estuaries often have a low buffering capacity and may experience acidification, both naturally through microbial degradation and run-off from acid sulphate soils (ASS), or from various anthropogenic sources. Here, we describe phytoplankton communities from the turbid, acidified, and eutrophic Sungai Brunei and Brunei Bay estuarine system. Four sampling stations were selected, representing the full spectrum of the salinity (0.4-28.5 PSU) and pH (5.87-8.06) gradients associated with this system. A total of 25 microalgal families of phytoplankton (including 22 diatom and seven dinoflagellate genera) and one of ciliates were recorded in the survey, which was carried out between August 2011 and June 2012. Phytoplankton density ranged from 7 to 9107 cells ml-1. Diatoms were a dominant component of the communities, with Nitzschia spp., Rhizosolenia spp., and Leptocylindrus sp. reaching the highest abundances. Phytoplankton communities present at the four sampling stations differed significantly in terms of both algal abundance and composition and were strongly influenced by the effect of season (30% of the total variance). The interactive effects of pH and salinity, and of pH and temperature, explained 16.7% and 17.5% of the total observed variation, respectively. A positive correlation between pH and the number of taxa found was detected. The functional diversity observed in phytoplankton from the Brunei River estuary was generally low with few taxa adapted well to the chronically low pH conditions. This study provides baseline data about structural and compositional changes in a tropical estuarine phytoplankton community associated with various levels of acidification of both natural and anthropogenic origins.

Background: Gestational weight gain differs according to pre-pregnancy body mass index and is related to the risks of adverse maternal and child health outcomes. Gestational weight gain charts for women in different pre-pregnancy body mass index groups enable identification of women and offspring at risk for adverse health outcomes. We aimed to construct gestational weight gain reference charts for underweight, normal weight, overweight, and grades 1, 2 and 3 obese women and to compare these charts with those obtained in women with uncomplicated term pregnancies. Methods: We used individual participant data from 218,216 pregnant women participating in 33 cohorts from Europe, North America, and Oceania. Of these women, 9065 (4.2%), 148,697 (68.1%), 42,678 (19.6%), 13,084 (6.0%), 3597 (1.6%), and 1095 (0.5%) were underweight, normal weight, overweight, and grades 1, 2, and 3 obese women, respectively. A total of 138, 517 women from 26 cohorts had pregnancies with no hypertensive or diabetic disorders and with term deliveries of appropriate for gestational age at birth infants. Gestational weight gain charts for underweight, normal weight, overweight, and grade 1, 2, and 3 obese women were derived by the Box-Cox t method using the generalized additive model for location, scale, and shape. Results: We observed that gestational weight gain strongly differed per maternal pre-pregnancy body mass index group. The median (interquartile range) gestational weight gain at 40 weeks was 14.2 kg (11.4-17.4) for underweight women, 14.5 kg (11.5-17.7) for normal weight women, 13.9 kg (10.1-17.9) for overweight women, and 11.2 kg (7.0-15.7), 8.7 kg (4.3-13.4) and 6.3 kg (1.9-11.1) for grades 1, 2, and 3 obese women, respectively. The rate of weight gain was lower in the first half than in the second half of pregnancy. No differences in the patterns of weight gain were observed between cohorts or countries. Similar weight gain patterns were observed in mothers without pregnancy complications. Conclusions: Gestational weight gain patterns are strongly related to pre-pregnancy body mass index. The derived charts can be used to assess gestational weight gain in etiological research and as a monitoring tool for weight gain during pregnancy in clinical practice. © 2018 The Author(s).

Long-term birth cohort studies are essential to understanding the life course and childhood predictors of allergy and the complex interplay between genes and the environment (including lifestyle and socioeconomic determinants). Over 100 cohorts focusing on asthma and allergy have been initiated in the world over the past 30 years. Since 2004, several research initiatives funded under the EU Framework Program for Research and Technological Development FP6-FP7 have attempted to identify, compare, and evaluate pooling data from existing European birth cohorts (GA2LEN: Global Allergy and European Network, FP6; ENRIECO: Environmental Health Risks in European Birth Cohorts, FP7; CHICOS: Developing a Child Cohort Research Strategy for Europe, FP7; MeDALL: Mechanisms of the Development of ALLergy, FP7). However, there is a general lack of knowledge about these initiatives and their potentials. The aim of this paper is to review current and past EU-funded projects in order to make a summary of their goals and achievements and to suggest future research needs of these European birth cohort networks. © 2012 S. Karger AG, Basel.

This work was supported by Environmental Health Risks in European Birth Cohorts (ENRIECO), a project conducted within the European Union’s Seventh Framework Programme (Theme 6, Environment, including climate change), grant agreement 226285., Vrijheid, M., Casas, M., Bergström, A., Carmichael, A., Cordier, S., Eggesbø, M., Eller, E., Fantini, M.P., Fernández, M.F., Fernández-Somoano, A., Gehring, U., Grazuleviciene, R., Hohmann, C., Karvonen, A.M., Keil, T., Kogevinas, M., Koppen, G., Krämer, U., Kuehni, C.E., Magnus, P., Majewska, R., Andersen, A.-M.N., Patelarou, E., Petersen, M.S., Pierik, F.H., Polanska, K., Porta, D., Richiardi, L., Santos, A.C., Slama, R., Sram, R.J., Thijs, C., Tischer, C., Toft, G., Trnovec, T., Vandentorren, S., Vrijkotte, T.G.M., Wilhelm, M., Wright, J., Nieuwenhuijsen, M.

Seasonal studies of water bodies in separate branches of the Vistula River estuary in Northern Poland were conducted over 30 months from May 2005 to October 2007. Diatom samples were collected from different substrata from two sites located in the river mouth, which has physical characteristics as a result of a complex interplay of natural and human influences that have taken place over the last 100+ years. The diatom flora growing on hard surfaces near the river banks such as sand, muddy sand, rocks, macroscopic green algae and/or vascular aquatic plants was recorded. All diatom taxa collected were distinguished based on their morphological features using light (LM) and scanning electron microscopy (SEM). A total of 187 species belonging to 61 genera were identified. A canonical correspondence analysis indicated that the diatom assemblages were definitely associated with salinity as well as nutrient concentrations and substratum type. During the study, malformations of diatom valves were observed in 48% of the microphytobenthos samples. Abnormal outline morphology and ornamentation deformities in several individuals of nine different species were recorded, which were mainly in epilithic and epiphytic communities collected from spring to autumn. © 2012 Japanese Society of Phycology.

In the present study we aim to describe the diatom communities associated to some Gelidiacean species (Rodophyta) from Gran Canaria (Canary Islands) considering their seasonal and spatial variability, in terms of abundance, biomass and community structure. Five Gelidiacean species (Gelidium arbuscula, Gelidium canariense, Gelidium pusillum, Pterocladiella capillacea e Pterocladiella melanoidea) has been collected in different coastal localities of Gran Canaria Island (Boccabarranco (Galdar), Agaete e Quintanilla (Ba?aderos) during winter and summer season 2007-2008. Gelidium arbuscula, G. canariense e P. capillacea appeared distributed in clumps consisting of several ramets; thalli of G. pusillum e P. melaoidea looks liked to small carpet adhering to rocks. Sampled ramets were cut in a apical, central and basal fragment except in the case of G. pusillum e P. melanoidea for their reduced size (about 1cm). In order to preserve the integrity of the epiphytic diatom communities and to analyze them at Scanning Electron Microscope, ramets were fixed with glutaraldehyde 2.5% in filtered seawater and placed on a polycarbonate filter in a "Swinnex" filtration apparatus (Millipore). A second filter was placed over the first to form a sandwich in which the sample was trapped. A dehydration and Critical Point Dryer treatment were respectively carried out by directly immersing the Swinnex into specific containers in alcohol at increasing alcoholic strength and finally in a Critical Point Dryer. At the end of this treatments, each fragment was placed on a stub and covered with gold-palladium to be observed using SEM Total abundances of epiphytic diatoms in all Gelidiacean species studied were low in both the sampling seasons ranging from 200-480 cell/mm2 in winter to 150-300 cell/mm2 in Summer. Spatial distribution of epiphytic diatoms communities showed a marked increasing gradient form the basal to the apical part of the ramets. Considering the growth forms of diatom species, adnate forms (Amphora and Cocconeis spp.) were distributed mainly in the basal and central part of ramets whereas erect forms (mainly Grammatophora, Licmophora, and Achnantes spp.) were mainly distributed in the apical part of the colonies. Motile species were rarely found without showing a clear distribution pattern in the three portion of the ramets. Adnate diatoms were more abundant on those Gelidiaceae having harder, microstructurally complex and ramified thalli respect than with soft and smooth ones. This is due to the presence, in the former, of an higher number of microenvironments to which the adnate diatoms can adhere using their entire valve faces. Erected diatom species were less affected by these constrains since their adhesion to the substrate was mediated by mucilage pads or peduncles.

In polar waters, microalgal communities associated with macroalgae exhibit rates of primary production comparable or even higher than those of phytoplanktonic ones. These benthic communities are mainly represented by diatoms. Despite to their crucial ecological role, the biodiversity of Antarctic epiphytic diatoms is poorly studied and greatly underestimated. In the present study, the diversity of epiphytic diatom communities from coastal waters of Terra Nova Bay was investigated and described for the first time. Samplings were made during the 8 Italian Antarctic expeditions in the space of 15 years. Thalli of Iridaea cordata, Phyllophora antarctica and Plocamium cartilagineum were collected during the austral summer. Collections were made from different depths at 5 sampling sites. Taxonomical identification and counting of diatom cells has been carried out by scanning electron microscope. According to our results biomass appears to be inversely related to the diversity. The diatom community composition varied depending on the sampling site as well as on the morphology of the macroalgal host. Some differences could be observed along a depth gradient. In terms of growth form in most cases adnate (e.g. Cocconeis, Amphora) and mobile forms (e.g. Navicula, Nitzschia) dominated. Erect diatom taxa tended to be associated with animal macrofouling species.

Epiphytic diatoms are one of the key biotic element of the Antarctic marine ecosystem. Their unusually high metabolic flexibility gives them a crucial role in the Antarctic trophic chain. Despite being fundamental to the ecosystem functioning, diatom communities associated with marine macroalgae are frequently ignored in the floristic studies of the area. Few attempts to investigate substrate preferences have been reported. The present study provides the first examination and description of the epiphytic diatom flora from Terra Nova Bay (Ross Sea, Antarctica). Material was collected during Italian Antarctic campaigns in the years 1989-2005. Samples of thalli of Iridaea cordata, Phyllophora Antarctica, and Plocamium cartilagineum were taken from different depths at five sampling sites localized along the shore. All observations have been carried out under the scanning electron microscope. The genus Cocconeis was the most common. Two identified, previously described and well known from the Antarctic waters species - Cocconeis antiqua and C. fasciolata, as well as small naviculoid species (most likely Navicula perminuta), appeared in abundance. The Cocconeis component of the assemblage was estimated to approach 105 cells per cm2 on foliose hosts such as Iridaea. Melosira adelie was the only non-pennate diatom to achieve any degree of dominance, although Paralia sol and Trigonium arcticum were common on some of the filamentous parts of host macroalgae. Our results indicate a strong relation between the diatom assemblages and the sampling site. There is no clear evidence of diatoms host specificity. However, the filamentous forms as well as topographic anomalies (e.g. colonies of hydroids or bryozoans) can provide a point of attachment for a wider range of taxa.

Species diversity of microorganisms inhabiting Antarctic waters seems to be relatively low. However, they metabolic flexibility is unusually high, making them fundamental to the Antarctic ecosystem functioning. In polar waters, microalgal communities associated to macroalgae and invertebrates exhibit rates of primary production comparable or even higher than those of phytoplanktonic ones. These benthic microalgal communities are for the most part represented by diatoms. Despite to their crucial ecological role in the trophic chain, the biodiversity of antarctic epiphytic diatoms is poorly studied and greatly underestimated. In the present study, the diversity of epiphytic diatom communities from coastal waters of Terra Nova Bay (Ross Sea, Antarctic continent) has been investigated and described for the first time. Samplings were made during the Italian Antarctic expeditions in the years: 1989/90, 1990/91, 1993/94, 1994/95, 1998/1999, 2000/01, 2001/02 and 2004/05. Thalli of Iridaea cordata, Phyllophora antarctica and Plocamium cartilagineum were collected by scuba diver during the austral summer. Collections were made from different depths at five sampling sites localized along the shore and fixed with formaldehyde. To observe diatom communities originally settled on the macroalgal host preserved thalli were cut, dehydrated, placed on a stub and sputter coated with thin layer of gold. Taxonomical identification and counting of diatom cells has been carried out by scanning electron microscope. According to our results biomass appears to be inversely related to the diversity. The diatom community composition varied depending on the sampling site as well as on the morphology of the macroalgal host. Some differences could be observed also along a depth gradient. In terms of growth form in most cases adnate (e.g. Cocconeis, Amphora) and mobile forms (e.g. Navicula, Nitzschia) dominated. Erect diatom taxa tended to be associated with animal macrofouling species.

In the present study we aim to describe the diatom communities associated to some Gelidiacean species (Rodophyta) from Gran Canaria (Canary Islands) considering their seasonal and spatial variability, in terms of abundance, biomass and community structure. Five Gelidiacean species (Gelidium arbuscula, Gelidium canariense, Gelidium pusillum, Pterocladiella capillacea e Pterocladiella melanoidea) has been collected in different coastal localities of Gran Canaria Island (Boccabarranco (Galdar), Agaete e Quintanilla (Bañaderos) during winter and summer season 2007-2008. Gelidium arbuscula, G. canariense e P. capillacea appeared distributed in clumps consisting of several ramets; thalli of G. pusillum e P. melaoidea looks liked to small carpet adhering to rocks. Sampled ramets were cut in a apical, central and basal fragment except in the case of G. pusillum e P. melanoidea for their reduced size (about 1cm). In order to preserve the integrity of the epiphytic diatom communities and to analyze them at Scanning Electron Microscope, ramets were fixed with glutaraldehyde 2.5% in filtered seawater and placed on a polycarbonate filter in a ―Swinnex‖ filtration apparatus (Millipore). A second filter was placed over the first to form a sandwich in which the sample was trapped. A dehydration and Critical Point Dryer treatment were respectively carried out by directly immersing the Swinnex into specific containers in alcohol at increasing alcoholic strength and finally in a Critical Point Dryer. At the end of this treatments, each fragment was placed on a stub and covered with gold-palladium to be observed using SEM. Total abundances of epiphytic diatoms in all Gelidiacean species studied were low in both the sampling seasons ranging from 200-480 cell/mm2 in winter to 150-300 cell/mm2 in Summer. Spatial distribution of epiphytic diatoms communities showed a marked increasing gradient form the basal to the apical part of the ramets. Considering the growth forms of diatom species, adnate forms (Amphora and Cocconeis spp.) were distributed mainly in the basal and central part of ramets whereas erect forms (mainly Grammatophora, Licmophora, and Achnantes spp.) were mainly distributed in the apical part of the colonies. Motile species were rarely found without showing a clear distribution pattern in the three portion of the ramets. Adnate diatoms were more abundant on those Gelidiaceae having harder, microstructurally complex and ramified thalli respect than with soft and smooth ones. This is due to the presence, in the former, of an higher number of microenvironments to which the adnate diatoms can adhere using their entire valve faces. Erected diatom species were less affected by these constrains since their adhesion to the substrate was mediated by mucilage pads or peduncles.