Evaluation of biogas production from seaweed in batch tests and in UASB reactors combined with the removal of heavy metals

Seaweed can be anaerobically digested for the production of energy-rich methane. However, the use of seaweed digestate as a fertilizer may be restricted because of the high heavy metal content especially cadmium. Reducing the concentration of heavy metals in the digestate will enable its use as a fertilizer. In this laboratory-scale study, the potential of seaweed and its leachate in the production of methane were evaluated in batch tests. The effect of removing the heavy metals from seaweed leachate was evaluated in both batch test and treatment in an upflow anaerobic sludge blanket (UASB) reactor. The heavy metals were removed from seaweed leachate using an imminodiacetic acid (IDA) polyacrylamide cryogel carrier. The methane yield obtained in the anaerobic digestion of seaweed was 0.12 N l CH₄/g VS_added. The same methane yield was obtained when the seaweed leachate was used for methane production. The IDA-cryogel carrier was efficient in removing Cd²⁺, Cu²⁺, Ni²⁺ and Zn²⁺ ions from seaweed leachate. The removal of heavy metals in the seaweed leachate led to a decrease in the methane yield. The maximum sustainable organic loading rate (OLR) attained in the UASB reactor was 20.6 g tCOD/l/day corresponding to a hydraulic retention time (HRT) of 12 h and with a total COD removal efficiency of about 81%. Hydrolysis and treatment with IDA cryogel reduced the heavy metals content in the seaweed leachate before methane production. This study also demonstrated the suitability of the treatment of seaweed leachate in a UASB reactor.     

Corporations,Consumerism and Culpability: Sustainability in the British Press

Sustainability and sustainable development are prominent themes in international policy-making, corporate PR, news-media and academic scholarship. Its definitions are contested, however sustainability is associated with a three-pillar focus on economic development, environmental conservation and social justice, most recently espoused in the adoption of the UN Sustainable Development Goals in 2015. In spite of its common usage, there is little research about how sustainability is represented and refracted in public discourse in different national contexts. We examine British national press coverage of sustainability and sustainable development in 2015 in a cross-market sample of national newspapers. Our findings show that key international policy events and environmental and social justice frames are peripheral, while neoliberalism and neoliberal environmentalism vis-à-vis the promotion of technocratic solutions, corporate social responsibility and “sustainable” consumerism are the predominant frames through which the British news-media reports sustainability. This holds regardless of newspaper quality and ideological orientation.     

Disarming the population bomb

This paper argues for a renewed international focus on managed population reduction as a key enabler of sustainable development. The paper presents development data that demonstrate why population reduction should be elevated to share top priority with poverty alleviation, as the two over-arching goals of international development strategy. The critical analysis put forth in this paper argues that the current ‘unsustainable’ approach to sustainable development stems from (1) ‘empty world’ economic growth theory applied to a ‘full world’, which is (2) supported and driven by socioeconomic incentives to expand population, (3) justified through flawed interpretation of demographic transition theory, (4) bolstered by the exaggerated efficacy of environmental economic theory applied in a resource-constrained world, (5) insulated from challenge by limitations of scientific knowledge and (6) perpetuated by herd behavior. This paper concludes that failure to reduce global population will inhibit attainment of poverty alleviation and worsen environmental degradation.     

Genetic variability in the cosmopolitan deep-water ophiuran Ophiomusium lymani

A population of the cosmopolitan deep-sea ophiuran Ophiomusium lymani was studied by gel electrophoresis, and proved to be highly variable genetically; about 53% of the 15 loci studied are polymorphic, and the average individual is heterozygous at about 17% of the loci. This is approximately the same genetic variability displayed by other species, belonging to other phyla or classes, from the same deep-sea trawl. A similarly high level of genetic variation occurs in deep-sea organisms in general, and in a shallow-water tropical species. Both the deep-sea and the tropics are trophically stable environments. On the other hand, low genetic variabilities have been found in marine species from trophically unstable environments. These data suggest that any phylogenetic effects on genetic variability are secondary, and that the trophic regime may be of major importance in determining genetic strategies of adaptation.This study is no. 5 of a series of reports on the results of Expedition Quagmire.     

Design unbiased estimation in line intersect sampling using segmented transects

In many applications of line intersect sampling, transects consist of multiple, connected segments in a prescribed configuration. The relationship between the transect configuration and the selection probability of a population element is illustrated and a consistent sampling protocol, applicable to populations composed of arbitrarily shaped elements, is proposed. It is shown that this protocol obviates the arbitrary practice of treating multiple intersections of a single particle as independent probabilistic events and preserves the design-unbiasedness of Kaisers (1983, Biometrics 39, 965–976) conditional and unconditional estimators, suitably generalized to segmented transect designs. The relative efficiency and utility of segmented transect designs are also discussed from a fixed population perspective.     

SARS-CoV-2 in the context of past coronaviruses epidemics: Consideration for prenatal care

Since December 2019, the novel SARS-CoV-2 outbreak has resulted in millions of cases and more than 200 000 deaths worldwide. The clinical course among nonpregnant women has been described, but data about potential risks for women and their fetus remain scarce. The SARS and MERS epidemics were responsible for miscarriages, adverse fetal and neonatal outcomes, and maternal deaths. For COVID-19 infection, only nine cases of maternal death have been reported as of 22 April 2020, and pregnant women seem to develop the same clinical presentation as the general population. However, severe maternal cases, as well as prematurity, fetal distress, and stillbirth among newborns have been reported. The SARS-CoV-2 pandemic greatly impacts prenatal management and surveillance and raise the need for clear unanimous guidelines. In this narrative review, we describe the current knowledge about coronaviruses (SARS, MERS, and SARS-CoV-2) risks and consequences on pregnancies, and we summarize available current candidate therapeutic options for pregnant women. Finally, we compare current guidance proposed by The Royal College of Obstetricians and Gynaecologists, The American College of Obstetricians and Gynecologists, and the World Health Organization to give an overview of prenatal management which should be utilized until future data appear.     

Exploited species impacts on trophic linkages along reef-seagrass interfaces in the Florida Keys

The removal of fish biomass by extensive commercial and recreational fishing has been hypothesized to drastically alter the strength of trophic linkages among adjacent habitats. We evaluated the effects of removing predatory fishes on trophic transfers between coral reefs and adjacent seagrass meadows by comparing fish community structure, grazing intensity, and invertebrate predation potential in predator-rich no-take sites and nearby predator-poor fished sites in the Florida Keys (USA). Exploited fishes were more abundant at the no-take sites than at the fished sites. Most of the exploited fishes were either omnivores or invertivores. More piscivores were recorded at no-take sites, but most (approximately 95%) were moderately fished and unexploited species (barracuda and bar jacks, respectively). Impacts of these consumers on lower trophic levels were modest. Herbivorous and smaller prey fish (< 10 cm total length) densities and seagrass grazing diminished with distance from reefs and were not negatively impacted by the elevated densities of exploited fishes at no-take sites. Predation by reef fishes on most tethered invertebrates was high, but exploited species impacts varied with prey type. The results of the study show that, even though abundances of reef-associated fishes have been reduced at fished sites, there is little evidence that this has produced cascading trophic effects or interrupted cross-habitat energy exchanges between coral reefs and seagrasses.     

Line intersect sampling: Ell-shaped transects and multiple intersections

The probability of selecting a population element under line intersect sampling depends on the width of the particle in the direction perpendicular to the transect, as is well known. The consequence of this when using ell-shaped transects rather than straight-line transects are explicated, and modifications that preserve design-unbiasedness of Kaiser's (1983) conditional and unconditional estimators are presented. A case against treating multiple intersections as multiple probabilistic events is argued on the basis, also, of preserving design-unbiased estimation.