9,793 research outputs found
Recommended from our members
The area around the Orion Nebula observed in the CO (J = 1- 0) transition
An area 1 deg2 around the Orion Nebula has been surveyed with a 2.6 km s-1 wide single-channel receiver. The map shows considerable structure in the east including a bright spot 24' (2.8 pc) from the main CO peak
Infrared scanner Patent
Infrared scanning system for maintaining spacecraft orientation with earth referenc
Studies in costs of production town milk supply farms 1974-75
This Report is the second in the annual serilies of
cost of production surveys on New Zealand town milk supply
farms. The surveys are being undertaken by the Unit on a
contract basis for the New Zealand Milk Board and the Town
Milk Producers Federation of New Zealand (Inc.).
The first Report which related to the 1973/74 season
was published in March of this year as Research Report No. 74. As in the past the major objective of the surveys
is to determine the average labour return being received
by town milk producers in New Zealand.
Nevertheless the opportunity provjded by the surveys
has been used to collect additional data so that over a
period of time a more comprehensive profile of the industry
will be built up
Molecular Clock on a Neutral Network
The number of fixed mutations accumulated in an evolving population often
displays a variance that is significantly larger than the mean (the
overdispersed molecular clock). By examining a generic evolutionary process on
a neutral network of high-fitness genotypes, we establish a formalism for
computing all cumulants of the full probability distribution of accumulated
mutations in terms of graph properties of the neutral network, and use the
formalism to prove overdispersion of the molecular clock. We further show that
significant overdispersion arises naturally in evolution when the neutral
network is highly sparse, exhibits large global fluctuations in neutrality, and
small local fluctuations in neutrality. The results are also relevant for
elucidating the topological structure of a neutral network from empirical
measurements of the substitution process.Comment: 10 page
Books and materiality
This chapter considers medieval English books as objects embedded in European and global networks. From the pigments used to adorn pages to the people who made those pages, bookmaking connected England to the continent and the world. The chapter describes the movement of materials, methods, artisans, and books along international routes, and it examines the domestication of the foreign, as new elements and processes became familiar to English book producers and were incorporated into local traditions. The chapter pays particular attention to the influence on English books, bookmakers, and book collectors of their closest neighbours in Ireland, Scotland, Wales, and especially France. We offer a new approach to the study of medieval English manuscripts and early printed books, in which the tension between the local and the global recasts the material text as a transnational object
Spider webs, stable isotopes and molecular gut content analysis: Multiple lines of evidence support trophic niche differentiation in a community of Hawaiian spiders
1.Adaptive radiations are typically characterized by niche partitioning among their constituent species. Trophic niche partitioning is particularly important in predatory animals, which rely on limited food resources for survival.2.We test for trophic niche partitioning in an adaptive radiation of Hawaiian Tetragnatha spiders, which have diversified in situ on the Hawaiian Islands. We focus on a community of nine species belonging to two different clades, one web-building and the other actively hunting, which co-occur in wet forest on East Maui. We hypothesize that trophic niches differ significantly both: (a) among species within a clade, indicating food resource partitioning, and (b) between the two clades, corresponding to their differences in foraging strategy.3.To assess niches of the spider species, we measure: (a) web architecture, the structure of the hunting tool, and (b) site choice, the physical placement of the web in the habitat. We then test whether differences in these parameters translate into meaningful differences in trophic niche by measuring (c) stable isotope signatures of carbon and nitrogen in the spiders\u27 tissues, and (d) gut content of spiders based on metabarcoding data.4.We find significant interspecific differences in web architecture and site choice. Importantly, these differences are reflected in stable isotope signatures among the five web-building species, as well as significant isotopic differences between web-builders and active hunters. Gut content data also show interspecific and inter-clade differences. Pairwise overlaps of web architecture between species are positively correlated with overlaps of isotopic signature.5.Our results reveal trophic niche partitioning among species within each clade, as well as between the web-building and actively hunting clades. Based on the correlation between web architecture and stable isotopes, it appears that the isotopic signatures of spiders\u27 tissues are influenced by architectural differences among their webs. Our findings indicate an important link between web structure, microhabitat preference and diet in the Hawaiian Tetragnatha
- …