Halogenated acetaldehydes: analysis, stability and fate in drinking water

In our previous studies, chloral hydrate has been the only chlorinated acetaldehyde determined in drinking water because authentic standards of other related haloacetaldehydes were not available. Recently, standards of dichloroacetaldehyde, bromochloroacetaldehyde, dibromoacetaldehyde, bromodichloroacetaldehyde, chlorodibromoacetaldehyde, and tribromoacetaldehyde have become available commercially. They were obtained and verified for purity and stability using a dual-column GC-ECD system. Each commercial standard was found to contain small amounts of the other target haloacetaldehydes (HAs). The stability of the HAs stock solutions was solvent dependent: in acetone, the brominated species partially degraded to bromoacetone, while all target HAs were stable in MTBE for up to 8 months. The analytical parameters, required for the quantification of HAs in water, were determined and used to evaluate the stability of the HAs in water. Under the conditions of the sampling protocol (field pH adjustment to pH 4.5 and storage at 4 degrees C), the target HAs were stable in water for up to 14 days. However, at typical drinking water pH and temperature conditions, the stability varied with the HA species, pH, temperature and storage period. The trihalogenated acetaldehydes degraded, in part, to their corresponding trihalomethanes (THMs) at increasing pH and temperature. Most target HAs were detected in drinking water samples collected from various Canadian drinking water systems, and the speciation was dependent on water parameters (e.g. bromide concentration) and treatment processes. From the water samples analysed, chloral hydrate ranged between 7% and 51% of the total HAs (w/w). The weigh ratio of total HAs to total THMs (10-46%) indicated that HAs contributed significantly to the pool of DBPs in drinking water.     

A schematic sampling protocol for contaminant monitoring in raptors

Birds of prey, owls and falcons are widely used as sentinel species in raptor biomonitoring programmes. A major current challenge is to facilitate large-scale biomonitoring by coordinating contaminant monitoring activities and by building capacity across countries. This requires sharing, dissemination and adoption of best practices addressed by the Networking Programme Research and Monitoring for and with Raptors in Europe (EURAPMON) and now being advanced by the ongoing international COST Action European Raptor Biomonitoring Facility. The present perspective introduces a schematic sampling protocol for contaminant monitoring in raptors. We provide guidance on sample collection with a view to increasing sampling capacity across countries, ensuring appropriate quality of samples and facilitating harmonization of procedures to maximize the reliability, comparability and interoperability of data. The here presented protocol can be used by professionals and volunteers as a standard guide to ensure harmonised sampling methods for contaminant monitoring in raptors.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01341-9) contains supplementary material, which is available to authorized users.     

Using a choice experiment and birder preferences to guide bird‐conservation funding

Conservation of biodiversity, including birds, continues to challenge natural‐area managers. Stated‐preference methods (e.g., choice experiment [CE]) are increasingly used to provide data for valuation of natural ecosystems. We used a CE to calculate birders’ willingness to pay for different levels of bioecological attributes (threatened species, endemic species, and diversity) of birding sites with hypothetical entry fees. The CE was delivered at popular birding and avitourism sites in Australia and the United Kingdom. Latent‐class modeling results revealed heterogeneous preferences among birders and correspondingly variable willingness to pay. Four clear groups were apparent: quantity‐driven birders, special‐birds seekers, confused respondents, and price‐is‐no‐object birders. Quantity‐driven birders were attracted to sites that deliver high levels of diversity and endemic species for which they were willing to pay $135 and $66 to visit, respectively, above what they were willing to pay to visit a site with low levels of diversity and few endemic and threatened species . Special‐bird seekers valued threatened species and high levels of endemic species most (willingness to pay $45 and $46, respectively). Confused respondents’ preferences were difficult to determine, but they were the most sensitive to the hypothetical entry fees, unlike the price‐is‐no‐object birders, who were not at all sensitive to cost. Our findings demonstrate that birders are amenable to paying for their preferred birding experience. These payments could provide an alternative source of funding in some avitourism sites on both public and private land. Such alternative revenue streams should be explored and given full consideration in increasingly competitive conservation‐financing environments.     

Political transition and emergent forest‐conservation issues in Myanmar

Political and economic transitions have had substantial impacts on forest conservation. Where transitions are underway or anticipated, historical precedent and methods for systematically assessing future trends should be used to anticipate likely threats to forest conservation and design appropriate and prescient policy measures to counteract them. Myanmar is transitioning from an authoritarian, centralized state with a highly regulated economy to a more decentralized and economically liberal democracy and is working to end a long‐running civil war. With these transitions in mind, we used a horizon‐scanning approach to assess the 40 emerging issues most affecting Myanmar's forests, including internal conflict, land‐tenure insecurity, large‐scale agricultural development, demise of state timber enterprises, shortfalls in government revenue and capacity, and opening of new deforestation frontiers with new roads, mines, and hydroelectric dams. Averting these threats will require, for example, overhauling governance models, building capacity, improving infrastructure‐ and energy‐project planning, and reforming land‐tenure and environmental‐protection laws. Although challenges to conservation in Myanmar are daunting, the political transition offers an opportunity for conservationists and researchers to help shape a future that enhances Myanmar's social, economic, and environmental potential while learning and applying lessons from other countries. Our approach and results are relevant to other countries undergoing similar transitions.     

Vision-independent odometry in the ant Cataglyphis cursor

In contrast to flying insects, in which distance estimation is visually mediated, self-induced image motion and use of familiar landmarks are known to play a minor role in ants. Here we show that strictly diurnal Cataglyphis cursor ants can gauge with accuracy the distance they have travelled even in complete darkness in the absence of any other cues, i.e. chemical or protocounting information. Thus, an ants odometer is a vision-independent system based on proprioceptive cues, implicating some form of step counting, which remain to be elucidated.     

Nest excavation in ants: group size effects on the size and structure of tunneling networks

Collective digging activity was studied in the ant Messor sancta Forel in laboratory conditions and with a two dimensional set-up. We analyzed the digging dynamics and topology of tunneling networks excavated by groups of workers ranging from 50 to 200 individuals over 3 days. In all conditions, the dynamics of excavated sand volume were clearly non-linear. Excavation began with an exponential growth and after 3 days reached a saturation phase in which activity was almost totally stopped. The final volume of sand excavated was positively correlated with the number of workers. At the end of the experiments, the two-dimensional tunneling networks were mapped onto planar graphs where the vertices represent small chambers or intersections between tunnels and the edges represent tunnels. We found that all the networks belonged to a same topological family and exhibited several striking invariants such as the distribution of vertex degree that follows a power law. When increasing the number of ants, some changes occurred in the network structure, mainly an increase in the number of edges and vertices, and the progressive emergence of enlarged and highly connected vertices.     

Baboons adjust secondary sex ratio in response to predictors of sex-specific offspring survival

Summary Most theories of sex ratio adjustment assume that parents will adjust the sex ratio of births (secondary sex ratio) in a manner that maximizes offspring reproductive success (as long as this does not jeopardize parental reproductive success). Survival to maturity is typically the largest component of variance in offspring reproductive success. This should make environmental predictors of sex-specific offspring survival strong predictors of secondary sex ratio adjustment. We tested this survivorship maximization hypothesis for secondary sex ratio adjustment using data from a 17-year demographic study of 315 yellow baboon infants at Mikumi National Park, Tanzania. Sex differences were found in the degree to which several social and ecological conditions affected infant survival to 1 year. Female, but not male, infant survival was inversely correlated with birth order and the proportion of infant females in their birth cohort. Male, but not female, infant survival was inversely correlated with the amount of rainfall early in the year (January) and the proportion of infant males in their birth cohort; male survival also was positively correlated with maternal dominance rank. The consistency and timing of these effects across years suggested that such information was, in fact, available to females around the time of conception. Most importantly, social and ecological conditions that predicted improved survivorship of a given sex also were positively correlated with production of that sex. Early births were female-biased; and low January rainfall was correlated with a male-biased sex ratio, becoming increasingly female-biased as January rainfall increased. However, no sex ratio effects were correlated with maternal rank. Data supported the hypothesis that females adjusted secondary sex ratio in a manner that maximized sex-specific infant survival. This hypothesis also offered a plausible explanation for some of the contradictory data that have arisen from studies of maternal rank effects on sex ratio both within and between species.Correspondence to: S. K. Wasser     

Reproductive cycle of the subarctic brooding asteroid Leptasterias polaris

The reproductive cycle of the large brooding seastar Leptasterias polaris Müller and Troschel was examined over an 18-month period in the St. Lawrence Estuary, Québec, Canada. There is a distinct annual cycle with spawning over several months in the autumn. The female has an unusual cycle in that the ovary only slightly decreases in size during spawning, and the size structure of the oocyte population is remarkably stable throughout the year. The major annual change observed in the oocyte population is the development of a small number of 600-to 800- oocytes prior to spawning and their loss during spawning. This stability, combined with the lack of evidence of phagocytosis, suggests that oocyte development takes place over many years. By contrast, the developmental cycle of the testis is similar to that of most echinoderms. The large reservoir of oocytes probably guarantees a steady annual recruitment, and brooding during the winter probably minimizes metabolic costs for the female and ensures the release of the juveniles when conditions are favourable in the spring and summer.     

Amylo-1,6-glucosidase activity in cultured cells: A deficiency in type III glycogenosis with prenatal studies

Deficiency of amylo-1,6–glucosidase activity was expressed in parallel in liver and skin fibroblasts from a patient with type III glycogenosis. In crude extracts of control liver and muscle, amylo-1, 6–glucosidase (M.W. 164000) was identified by immunoprecipitation; no cross-reacting material was found in the patient's liver. Assay of amylo-1,6–glucosidase activity in cultured skin fibroblasts from the affected family revealed less than 10 per cent of control value in mutant homozygous cells whereas in cells from the parents, activity was reduced to 40–60 per cent of the control value. Activity in cultured amniotic fluid cells was similar to that of control fibroblasts. In cultured amniotic fluid cells obtained during the mother's subsequent pregnancy, the normal amylo–1,6–glucosidase activity measured, predicted correctly the outcome of this pregnancy prior to the 20th week of gestation.