To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Data from the mouth of the decelerating Whillans Ice Stream (WIS), West Antarctica, spanning 42 years are reviewed. Deceleration has continued, with local areas of both thinning and thickening occurring. The mean thinning rate is 0.48 ± 0.77 ma–1. No consistent overall pattern is observed. Ice thickens immediately upstream of Crary Ice Rise where deceleration and divergence are strongest, suggesting expanded upstream influence of the ice rise. Thinning is prevalent on the Ross Ice Shelf. Grounding-line advance at a rate of 0.3 km a–1 is detected in a few locations. Basal stresses vary across an ice-stream transect with a zone of enhanced flow at the margin. Marginal shear is felt at the ice-stream center. Mass-balance values are less negative, but larger errors of earlier measurements mask any possible temporal pattern. Comparisons of the recent flow field with flow stripes suggest WIS contributes less ice to the deep subglacial channel carved by Mercer Ice Stream and now flows straighter. The general lack of geometric changes suggests that the regional velocity decrease is due to changing basal conditions.
Low heart rate variability (HRV) predicts sudden cardiac death. Long-chain (LC) n-3 PUFA (C20–C22) status is positively associated with HRV. This cross-sectional study investigated whether vegans aged 40–70 years (n 23), whose diets are naturally free from EPA (20 : 5n-3) and DHA (22 : 6n-3), have lower HRV compared with omnivores (n 24). Proportions of LC n-3 PUFA in erythrocyte membranes, plasma fatty acids and concentrations of plasma LC n-3 PUFA-derived lipid mediators were significantly lower in vegans. Day-time interbeat intervals (IBI), adjusted for physical activity, age, BMI and sex, were significantly shorter in vegans compared with omnivores (mean difference −67 ms; 95 % CI −130, −3·4, P<0·05), but there were no significant differences over 24 h or during sleep. Vegans had higher overall HRV, measured as 24 h standard deviation of normal-to-normal intervals (SDNN) (mean adjusted difference 27 ms; 95 % CI 1, 52, P=0·039). Conversely, vegans presented with decreased 8 h day-time HRV: mean adjusted difference in SDNN −20 ms; 95 % CI −37, −3, P=0·021, with no differences during nocturnal sleep. Day-time parameters of beat-to-beat HRV (root of the mean of the sum of the squares of differences between adjacent normal-to-normal intervals, percentage of adjacent normal-to-normal intervals that differ by >50 % and high-frequency power) were similarly lower in vegans, with no differences during sleep. In conclusion, vegans have higher 24 h SDNN, but lower day-time HRV and shorter day-time IBI relative to comparable omnivores. Vegans may have reduced availability of precursor markers for pro-resolving lipid mediators; it remains to be determined whether there is a direct link with impaired cardiac function in populations with low-n-3 status.
How deep and how long-lasting Mikhail Gorbachev's reforms will be remains an open question. Obstacles to the realization of some of his goals may be built into Soviet life. Soviet resources may limit economic development; industrial managers (however willing they may be) may lack the knowledge and skills necessary to operate in a market environment and continuing state orders may absorb the productive capacity of the factories and may limit the extent to which they can respond to market forces.
We question whether the increasingly popular, radical idea of turning half the Earth into a network of protected areas is either feasible or just. We argue that this Half-Earth plan would have widespread negative consequences for human populations and would not meet its conservation objectives. It offers no agenda for managing biodiversity within a human half of Earth. We call instead for alternative radical action that is both more effective and more equitable, focused directly on the main drivers of biodiversity loss by shifting the global economy from its current foundation in growth while simultaneously redressing inequality.
The anticipated release of EnlistTM cotton, corn, and soybean cultivars likely will increase the use of 2,4-D, raising concerns over potential injury to susceptible cotton. An experiment was conducted at 12 locations over 2013 and 2014 to determine the impact of 2,4-D at rates simulating drift (2 g ae ha−1) and tank contamination (40 g ae ha−1) on cotton during six different growth stages. Growth stages at application included four leaf (4-lf), nine leaf (9-lf), first bloom (FB), FB + 2 wk, FB + 4 wk, and FB + 6 wk. Locations were grouped according to percent yield loss compared to the nontreated check (NTC), with group I having the least yield loss and group III having the most. Epinasty from 2,4-D was more pronounced with applications during vegetative growth stages. Importantly, yield loss did not correlate with visual symptomology, but more closely followed effects on boll number. The contamination rate at 9-lf, FB, or FB + 2 wk had the greatest effect across locations, reducing the number of bolls per plant when compared to the NTC, with no effect when applied at FB + 4 wk or later. A reduction of boll number was not detectable with the drift rate except in group III when applied at the FB stage. Yield was influenced by 2,4-D rate and stage of cotton growth. Over all locations, loss in yield of greater than 20% occurred at 5 of 12 locations when the drift rate was applied between 4-lf and FB + 2 wk (highest impact at FB). For the contamination rate, yield loss was observed at all 12 locations; averaged over these locations yield loss ranged from 7 to 66% across all growth stages. Results suggest the greatest yield impact from 2,4-D occurs between 9-lf and FB + 2 wk, and the level of impact is influenced by 2,4-D rate, crop growth stage, and environmental conditions.
We establish links between countable algebraically closed graphs and the endomorphisms of the countable universal graph R. As a consequence we show that, for any countable graph Γ, there are uncountably many maximal subgroups of the endomorphism monoid of R isomorphic to the automorphism group of Γ. Further structural information about End R is established including that Aut Γ arises in uncountably many ways as a Schützenberger group. Similar results are proved for the countable universal directed graph and the countable universal bipartite graph.
Background: “Mapping” onto generic preference-based outcome measures is increasingly being used as a means of generating health utilities for use within health economic evaluations. Despite publication of technical guides for the conduct of mapping research, guidance for the reporting of mapping studies is currently lacking. The MAPS (MApping onto Preference-based measures reporting Standards) statement is a new checklist, which aims to promote complete and transparent reporting of mapping studies.
Methods: In the absence of previously published reporting checklists or reporting guidance documents, a de novo list of reporting items was created by a working group comprised of six health economists and one Delphi methodologist. A two-round, modified Delphi survey with representatives from academia, consultancy, health technology assessment agencies, and the biomedical journal editorial community was used to identify a list of essential reporting items from this larger list.
Results: From the initial de novo list of twenty-nine candidate items, a set of twenty-three essential reporting items was developed. The items are presented numerically and categorized within six sections, namely: (i) title and abstract, (ii) introduction, (iii) methods, (iv) results, (v) discussion, and (vi) other. The MAPS statement is best applied in conjunction with the accompanying MAPS explanation and elaboration document.
Conclusions: It is anticipated that the MAPS statement will improve the clarity, transparency. and completeness of reporting of mapping studies. To facilitate dissemination and uptake, the MAPS statement is being co-published by seven health economics and quality of life journals, and broader endorsement is encouraged. The MAPS working group plans to assess the need for an update of the reporting checklist in five years’ time.
This article draws on La Via Campesina's definition of food sovereignty and its potential for reconceptualising food as a basic human right within the dominant Australian food discourse. We argue that the educative value that emerges from urban food production in Australia stems from the action of growing food and its capacity to transform individuals’ social and environmental concerns over food systems. Community participation in urban food production can promote a learning process that generates political understanding and concerns over food systems. We use the education theories of transformative learning and critical consciousness to discuss how Australian urban food production systems can create this social and environmental support for alternative food systems. By having control over food production practices and building collective understandings of how food choices impact global food systems, elements of food sovereignty can develop in an Australian urban context.
In North America, terrestrial records of biodiversity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean–atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010–2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between ~140 and 55 ka, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones of late Pleistocene megafauna, including mastodons, mammoths, ground sloths, horses, camels, deer, bison, black bear, coyotes, and bighorn sheep. In addition, the site contained more than 26,000 bones from at least 30 species of small animals including salamanders, otters, muskrats, minks, rabbits, beavers, frogs, lizards, snakes, fish, and birds. The combination of macro- and micro-vertebrates, invertebrates, terrestrial and aquatic plant macrofossils, a detailed pollen record, and a robust, directly dated stratigraphic framework shows that high-elevation ecosystems in the Rocky Mountains of Colorado are climatically sensitive and varied dramatically throughout MIS 5.
The two eggs of the Great Auk which I now exhibit were bought in Dowell's Auction Rooms rather more than a month ago, and formed part of a collection of “birds' eggs, shells, and other natural history specimens” which was disposed of among a lot of miscellaneous property belonging to a legal gentleman of this city. This small collection of eggs had been in the possession of the owner for about thirty years, and the two eggs in question had been purchased by his father from another collector in Edinburgh— a Mr Little—in whose possession it is thought, from collected and trustworthy evidence, the specimens had been at least other thirty years. These eggs, therefore, have probably not changed hands more than once during a period of fifty or sixty years. The present owner of the specimens, Mr Small, animal preserver, George Street, purchased the lot at the sale for £1, 12s., and has since taken great pains to establish the few facts I have stated regarding their history.
Ewing's theory of the construction of a magnetic atom separates the atom into two portions: (a) the Weber element, possessing constant magnetic moment and capable of turning in response to an applied magnetic field; and (b) an outer (or inner) group of fixed “magnets” (i.e. electrons moving in orbits), which have like poles all directed towards the centre of the atom. Owing to the want of symmetry of the elements composing the group or shell, there are several magnetic fields, each of different direction, acting in the neighbourhood of the Weber element, and the direction of each of these represents a position of stability of the Weber element.
Although numerous most admirable descriptions of the stomach of various species of Delphinidae (the family of toothed Whales to which the Narwhal belongs) have from time to time appeared from the pens of most able observers (of whom a list will be found in the references appended), we have found it impossible to find anything more than a mere indication of the histological structure of the various portions of the walls of the peculiar digestive apparatus of these animals. As one of us had an opportunity of obtaining material in a comparatively fresh condition, we decided to make arrangements for preserving it properly, so that it might be subjected to microscopic examination on being brought to this country, With all the care that was taken some portions of the mucous membrane have suffered slightly, but in all cases the changes are so slight that we are enabled to speak positively on the points to which reference is made.