Current concepts of Down syndrome screening tests in assisted reproduction twin pregnancies: another double trouble

Assisted reproductive technologies (ART) have increased both the number of pregnancies in women beyond the age of 35 and the incidence of multiple pregnancies. Various methods of screening for Down syndrome (DS) were introduced in clinical practice during the last two decades, and specific problems were encountered when they were applied for twin pregnancies. The current review aims to explore the problematic issue of prenatal DS screening in ART twins. Overall, more women with twin pregnancies (mainly those who conceived via assisted reproduction) are found to be false positive for DS. This is because mid-trimester maternal serum screening is associated with a higher false-positive rate secondary to changes in the feto-placental endocrinologic metabolism, reflected mainly in high human chorionic gonadotrophin (hCG) levels in the ART pregnancies. First-trimester nuchal translucency (NT) measurement in twin pregnancies is not affected by the problems encountered in serum screening. This sonographic screening approach enables a fetus-specific identification of those fetuses at high risk of DS and is associated with a lower false-positive rate than mid-trimester serum screening. DS screening in ART twins presents several challenges in determining the most appropriate screening test modality. Whether there is any significant benefit of adding first-trimester biochemistry or nasal bone scanning in screening ART-conceived twins awaits further investigation. Copyright © 2005 John Wiley & Sons, Ltd.     

Conserved male-specific cuticular hydrocarbon patterns in the trap-jaw ant Odontomachus brunneus

Cuticular hydrocarbons have been identified as the source of sex-recognition signals for many insects, but for social insects, specifically ants, cuticular hydrocarbon profiles of males are often ignored. This study reports male-specific cuticular hydrocarbon patterns for the trap-jaw ant Odontomachus brunneus. Analysis of samples from four Florida populations demonstrated that male-specific overabundance of four hydrocarbons is conserved across populations despite population-level divergence of the remainder of the profile. In addition, hydrocarbon patterns unique to adult males were not present on the cuticle of final instar male larvae, indicating that male-specific profiles arise late in development. The pattern of an abundant subset of conserved cuticular hydrocarbons characteristic of males across divergent populations was compared to earlier findings of the conservation of fertility signals of females across these same populations.     

Large carnivore hunting and the social license to hunt

The social license to operate framework considers how society grants or withholds informal permission for resource extractors to exploit publicly owned resources. We developed a modified model, which we refer to as the social license to hunt (SLH). In it we similarly consider hunters as operators, given that wildlife are legally considered public resources in North America and Europe. We applied the SLH model to examine the controversial hunting of large carnivores, which are frequently killed for trophies. Killing for trophies is widespread, but undertaken by a minority of hunters, and can pose threats to the SLH for trophy-seeking carnivore hunters and potentially beyond. Societal opposition to large carnivore hunting relates not only to conservation concerns but also to misalignment between killing for trophies and dominant public values and attitudes concerning the treatment of animals. We summarized cases related to the killing of grizzly bears (Ursus arctos), wolves (Canis lupus), and other large carnivores in Canada, the United States, and Europe to illustrate how opposition to large carnivore hunting, now expressed primarily on social media, can exert rapid and significant pressure on policy makers and politicians. Evidence of the potential for transformative change to wildlife management and conservation includes proposed and realized changes to legislation, business practice, and wildlife policy, including the banning of some large carnivore hunts. Given that policy is ultimately shaped by societal values and attitudes, research gaps include developing increased insight into public support of various hunting policies beyond that derived from monitoring of social media and public polling. Informed by increased evidence, the SLH model can provide a conceptual foundation for predicting the likelihood of transient versus enduring changes to wildlife conservation policy and practice for a wide variety of taxa and contexts.     

Should apple snail Pomacea canaliculata (Caenogastropoda, Ampullariidae) be used as bioindicator for BDE-209?

Apple snail Pomacea canaliculata has been reported to accumulate polybrominated diphenyl ethers (PBDEs) and was recently proposed as PBDE bioindicator. This work investigates the ability of P. canaliculata to accumulate BDE-209 by dietary exposure under controlled experimental conditions. A 30-day long enrichment feeding assay was carried out using 30 adult apple snails, placed in individual aquaria. Food was enriched at three BDE-209 concentrations (400, 4,700, and 8,300 μg g^?1 lipid weight). Correlation between BDE-209 values in food and snail tissue were estimated according to Stockholm Convention suggested criteria for chemicals with K_OW >5. All animals survived with no evident physical alterations, and all of them accumulated BDE-209. BDE-209 levels in tissue samples increased exponentially with the exposure concentration. The bioaccumulation factor vs. food concentration plot showed a peculiar pattern, in which at intermediate concentrations the snails accumulated less BDE-209 than expected. Our results suggest that P. canaliculata would present a detoxification mechanism for BDE-209 different from the most commonly reported metabolic pathways.     

Quantified scenarios analysis of drivers and impacts of changing flood risk in England and Wales: 2030–2100

Flood risk to the economy, society and the environment reflects the cumulative effects of environmental and socio-economic change over decades. Long-term scenarios are therefore required in order to develop robust and sustainable flood risk management policies. Quantified national-scale flood risk analysis and expert appraisal of the mechanisms causing change in flood risk have been used to assess flood risk in England and Wales over the period 2030–2100. The assessment involved the use of socio-economic and climate change scenarios. The analysis predicts increasing flood risk unless current flood management policies, practices and investment levels are changed—up to 20-fold increase in economic risk by the 2080s in the scenario with highest economic growth. The increase is attributable to a combination of climate change (in particular increasing precipitation and relative sea level rise in parts of the UK) and increasing socio-economic vulnerability, particularly in terms of household/industrial contents and infrastructure vulnerability. The policy implications of these findings are discussed.     

Diving characteristics of southern rockhopper penguins (Eudyptes c. chrysocome) in the southwest Atlantic

The diving behaviour of southern rockhopper penguins (Eudyptes c. chrysocome) was studied at two breeding sites in the Southwest Atlantic: the Falkland Islands and Staten Island, Argentina. Incubating and brooding birds were equipped with time-depth recorders to monitor their foraging activities. Rockhopper penguins from Staten Island started their breeding season about 3 weeks earlier than their conspecifics from the Falkland Islands. The foraging area used by incubating males from the Falkland Islands comprised about 150,000 km² to the northeast of the breeding site and was characterised by shelf and slope waters, whereas the foraging area of incubating males from Staten Island comprised 350,000 km² of oceanic waters to the southeast of the breeding site. A number of dive parameters were measured and compared between the four study groups: Incubating males and brooding females from the Falkland Islands, and incubating males and females from Staten Island. In all study groups, dive depth correlated positively to light intensity, dive duration and vertical velocity. However, significant differences between various diving parameters of the study groups were noted, not only in terms of diving performance, but also as regards diving efficiency (DE). A principal component analysis (PCA) on 16 variables revealed that 75% of the variance could be explained by only two principal components: diving pattern (PC1) and diving effort (PC2). PC1 indicated that the birds from Staten Island, both males and females, dived deeper, covered a greater vertical distance per hour and had higher ascent rates, but spent less time underwater and at the bottom of a dive, and had a lower DE than conspecifics from the Falkland Islands. PC2, which included the percentage of foraging dives, the number of dives per hour, dive duration, bottom time and descent rate, differed significantly between incubating males from the Falkland Islands and the other three groups, which were all very similar. Overall, the diving behaviour was notably similar to that of conspecifics from the Indian and Pacific Oceans. The implications of the results in terms of intra-specific adaptations as well as potential threats from human activities are discussed.     

Why telecoupling research needs to account for environmental justice

ABSTRACT

Engaging with normative questions in land system science is a key challenge. This debate paper highlights the potential of incorporating elements of environmental justice scholarship into the evolving telecoupling framework that focuses on distant interactions in land systems. We first expose the reasons why environmental justice matters in understanding telecoupled systems, and the relevant approaches suited to mainstream environmental justice into telecoupled contexts. We then explore which specific elements of environmental justice need to be incorporated into telecoupling research. We focus on 1) the distribution of social-ecological burdens and benefits across distances, 2) power and justice issues in governing distantly tied systems, and 3) recognition issues in information flows, framings and discourses across distances. We conclude our paper highlighting key mechanisms to address injustices in telecoupled land systems.     

Novel brominated flame retardants: a review of their analysis, environmental fate and behaviour

This review summarises current knowledge about production volumes, physico-chemical properties, analysis, environmental occurrence, fate and behaviour and human exposure to the "novel" brominated flame retardants (NBFRs). We define the term NBFRs as relating to BFRs which are new to the market or newly/recently observed in the environment. Restrictions and bans on the use of some polybrominated diphenyl ether (PBDE) formulations, in many jurisdictions, have created a market for the use of NBFRs. To date, most data on NBFRs have arisen as additional information generated by research designed principally to study more "traditional" BFRs, such as PBDEs. This has led to a wide variety of analytical approaches for sample extraction, extract purification and instrumental analysis of NBFRs. An overview of environmental occurrence in abiotic matrices, aquatic biota, terrestrial biota and birds is presented. Evidence concerning the metabolism and absorption of different NBFRs is reviewed. Human exposure to NBFRs via different exposure pathways is discussed, and research gaps related to analysis, environmental sources, fate, and behaviour and human exposure are identified.