Amino Acids in Sea Water

Free amino acids in the waters of the English Channel have been measured over a twelve month period using a newly developed field technique. Samples have been taken over a wide area both from the surface and at depth. The results show that the levels of amino acids found in these studies are greater than those previously generally accepted. These findings are of considerable importance in productivity studies since amino nitrogen as a source of nutrient for phytoplankton has been largely neglected. This paper shows that the levels of amino acids in the upper layers of the sea are not insignificant and should not be disregarded as an alternative nitrogen source for phytoplankton.     

FEASIBILITY OF SEASONAL WATER PRICING CONSIDERING METERING COSTS1

ABSTRACT: Efficiency implications of seasonal pricing, uniform pricing, and optimal seasonal pricing with metering costs are analyzed qualitatively using classical optimization technique. The first two schemes are special cases of the last pricing scheme. A nonlinear-integer programming model is formulated for a case study application to Salt Lake City to examine the feasibility of seasonal pricing. The analysis indicates that uniform pricing is preferable unless metering costs are substantially lower than present levels.     

Effect of mixed liquor suspended solids concentration on the biodegradation of nitrilotriacetic acid in the activated sludge process

The biodegradation of nitrilotriacetic acid in laboratory simulations of the activated sludge process has been studied at two different concentrations of mixed liquor suspended solids. Responses to changes in the influent nitrilotriacetic acid concentration such as those which might be associated with a “wash day” have been examined.     

The last “pelycosaur”: a varanopid synapsid from the <Emphasis Type="Italic">Pristerognathus</Emphasis> Assemblage Zone,Middle Permian of South Africa

We report on a partial varanopid skull and mandible from the Pristerognathus Assemblage Zone of the Beaufort Group, in the South African Karoo Basin, which is probably latest Middle Permian (Capitanian) in age. This mycterosaurine is not only the youngest known varanopid from the Southern Hemisphere, but it is also the youngest known “pelycosaur” (i.e., non-therapsid synapsid). Like all other members of this clade of hypercarnivores, the teeth are strongly flattened, recurved, and have finely serrated cutting edges. The anterior dentary teeth form a caniniform region, and the splenial features a foramen intermandibularis oralis, the first ever to be described in a “pelycosaur.” The last varanopids were the smallest carnivores of latest Middle Permian continental faunas. Occupation of the small carnivore guild appears to have allowed varanopids to achieve a nearly cosmopolitan distribution throughout the Middle Permian, between the great Early Permian radiation of basal synapsids and the spectacular diversification of therapsid synapsids in the Late Permian and Early Triassic.     

Managing dependencies in forest offset projects: toward a more complete evaluation of reversal risk

Although forest carbon offsets can play an important role in the implementation of comprehensive climate policy, they also face an inherent risk of reversal. If such risks are positively correlated across projects, it can affect the integrity of larger project portfolios and potentially the entire offsets program. Here, we discuss three types of risks that could affect forest offsets—fat tails, micro-correlation, and tail dependence—and provide examples of how they could present themselves in a forest offset context. Given these potential dependencies, we suggest several new risk management approaches that take into account dependencies in reversal risk across projects and which could help guard the climate integrity of an offsets program. We also argue that data collection be included as an integral part of any offsets program so that disturbance-related dependencies may be identified and managed as early and to the greatest extent possible.     

Morphological relationships of the Wheatears (genus Oenanthe)

The genus Oenanthe comprises approximately 22 species, of which 16 species are restricted to the desert belt of the Palaearctic and Afrotropic regions, where they are often the most conspicuous passerines. Although they have been the subjects of some morphological and ecological studies, no complete morphometrical data has been used to verify their taxonomic relationships, and, the species relationships are still debated. Overall morphometrical similarities between Wheatears and their relationships in size and shape were assessed using measurements of 27 biometrical variables on 417 museum specimens. The 22 Wheatear species comprise some morphological groups: long migratory vegetation-tolerant species (O. pleschanka, O. hispanica, O. cypriaca and O. deserti), ground-dwelling migratory (O. isabellina and O. oenanthe), and sedentary (O. bottae, O. heuglini and O. pileata) of steppe-like habitants, relatively heavy and rock-dwelling species (O. leucura and O. monticola), inhabiting the most arid areas (O. monacha, O. leucopyga and O. alboniger), and finally a central core of medium-sized partial migrants, largely overlapping in morphometric space, that do not present any evident specialization (O. lugens, O. chrysopygia, O. xanthoprymna and O. finschii). It seems Wheatear species are well distributed in a morpho-space of size and shape with moderate overlaps and few hiatuses corresponding to a morphological continuum of species. Furthermore, our results largely hiatuses corresponding to a morphological continuum of species. Furthermore, our results largely differ from previous phylogenetic hypotheses (based on ecological, behavioural, and chromatic characters), but, are in congruence with molecular data.     

Primary and secondary organic winter aerosols in Mediterranean cities under different mixing layer conditions (Barcelona and Granada)

Environmental Science and Pollution Research - PM10 was collected during an EMEP winter campaign of 2017–2018 in two urban background sites in Barcelona (BCN) and Granada (GRA), two...     

Achievements,challenges and global implications of China’s carbon neutral pledge

China has been committed to achieving carbon neutrality by 2060. China’s pledge of carbon neutrality will play an essential role in galvanising global climate action, which has been largely deferred by the Covid-19 pandemic. China’s carbon neutrality could reduce global warming by approximately 0.2–0.3 °C and save around 1.8 million people from premature death due to air pollution. Along with domestic benefits, China’s pledge of carbon neutrality is a “game-changer” for global climate action and can inspire other large carbon emitters to contribute actively to mitigate carbon emissions, particularly countries along the Belt and Road Initiative (BRI) routes. In order to achieve carbon neutrality by 2060, it is necessary to decarbonise all sectors in China, including energy, industry, transportation, construction, and agriculture. However, this transition will be very challenging, because major technological breakthroughs and large-scale investments are required. Strong policies and implementation plans are essential, including sustainable demand, decarbonizing electricity, electrification, fuel switching, and negative emissions. In particular, if China can peak carbon emissions earlier, it can lower the costs of the carbon neutral transition and make it easier to do so over a longer time horizon. China’s pledge of carbon neutrality by 2060 and recent pledges at the 26^th UN Climate Change Conference of the Parties (COP26) are significant contributions and critical steps for global climate action. However, countries worldwide need to achieve carbon neutrality to keep the global temperature from growing beyond the level that will cause catastrophic damages globally.