Arctic marine climate of the early nineteenth century

The climate of the early nineteenth century is likely to have been significantly cooler than that of today, as it was a period of low solar activity (the Dalton minimum) and followed a series of large volcanic eruptions. Proxy reconstructions of the temperature of the period do not agree well on the size of the temperature change, so other observational records from the period are particularly valuable. Weather observations have been extracted from the reports of the noted whaling captain William Scoresby Jr., and from the records of a series of Royal Navy expeditions to the Arctic, preserved in the UK National Archives. They demonstrate that marine climate in 1810 - 1825 was marked by consistently cold summers, with abundant sea-ice. But although the period was significantly colder than the modern average, there was considerable variability: in the Greenland Sea the summers following the Tambora eruption (1816 and 1817) were noticeably warmer, and had less sea-ice coverage, than the years immediately preceding them; and the sea-ice coverage in Lancaster Sound in 1819 and 1820 was low even by modern standards. © 2010 Author(s)

Mitochondrial Intergenic Spacer in Fairy Basslets (Serranidae: Anthiinae) and the Simultaneous Analysis of Nucleotide and Rearrangement Data

We present the results of a study that implements a recently developed phylogenetic algorithm that combines fixed-states nucleotide optimization with breakpoint analysis to identify and examine the evolution of a mitochondrial intergenic spacer between the tRNAVal and 16S rRNA loci in a clade of fairy basslets (Serranidae: Anthiinae). The results of the analysis indicate that this spacer evolved once and that it may be increasing in size through evolutionary time. The resulting molecular hypothesis corroborates much of the previous morphological phylogenetic work.We would like to thank J. Smith (Los Alamos National Laboratory) and J. Faivovich, T. Grant, K. Pickett, J. Sparks, M. Stiassny, and K. Tang (all at or formerly at the American Museum of Natural History [AMNH]) for discussing aspects of this project with us. We are grateful to H. Endo (Kochi University), the Gahan Family, J. Leis and M. McGrouther (Australian Museum), Reef and Fin (Stamford, CT), and H. Walker (Scripps Institution of Oceanography) for providing specimens used in this study. This project was supported by funding from the AMNH Lerner-Gray Program for Marine Research, the NASA–Ames Fundamental Space Biology Program, the Field Museum of Natural History, and the National Science Foundation (DEB-0405246 and DEB-0732642)

Short-term movements and behaviour govern the use of road mitigation measures by a protected amphibian

Road mitigation infrastructure for pond‐breeding amphibians aims to provide a safe and sustainable passage for individuals between critical habitat patches. However, relatively little is known about how amphibians interact with mitigation systems because of the challenges of documenting movements at sufficiently large sample sizes. The effect of real or perceived barriers to short‐term movement could ultimately determine the success or failure of road mitigation schemes. We quantified behavioural responses of the protected great crested newt Triturus cristatus in a complex road mitigation system in the UK. We used fluorescent paint to mark individuals in order to measure distance travelled and trajectory orientation over two seasons (spring when adults migrate to breeding ponds and autumn when newts disperse) and in three components of the mitigation system (fences, tunnel entrances and inside the tunnels). A total of 250 juveniles and 137 adult great crested newts were marked and tracked during 38 survey nights. Adults were individually identified using belly‐pattern recognition. There was substantially greater activity along the fences during autumn (82% of newt captures) compared to spring. Triturus cristatus typically moved short distances each night (3.21 m per night in spring and 6.72 m per night in autumn), with a maximum of 25.6 m travelled inside a tunnel. Adult recapture rates were low (9.7%) and only 3% of the newts found along the fences reached the tunnel entrances. Movements were straighter in spring and inside the tunnels and newts had higher crossing rates in autumn compared to spring. Overall, behaviour and seasonal movement patterns significantly influenced the use of the mitigation system, in a way that could impact landscape connectivity for T. cristatus over the long‐term. Adequate incorporation of fine‐scale movement dynamics could help develop new behavioural models, inform our understanding of amphibian ecology and substantially improve future road mitigation projects

Subdivision of arthropod cap-n-collar expression domains is restricted to Mandibulata

Background: The monophyly of Mandibulata - the division of arthropods uniting pancrustaceans and myriapods - is consistent with several morphological characters, such as the presence of sensory appendages called antennae and the eponymous biting appendage, the mandible. Functional studies have demonstrated that the patterning of the mandible requires the activity of the Hox gene Deformed and the transcription factor cap-n-collar (cnc) in at least two holometabolous insects: the fruit fly Drosophila melanogaster and the beetle Tribolium castaneum. Expression patterns of cnc from two non-holometabolous insects and a millipede have suggested conservation of the labral and mandibular domains within Mandibulata. However, the activity of cnc is unknown in crustaceans and chelicerates, precluding understanding of a complete scenario for the evolution of patterning of this appendage within arthropods. To redress these lacunae, here we investigate the gene expression of the ortholog of cnc in Parhyale hawaiensis, a malacostracan crustacean, and two chelicerates: the harvestman Phalangium opilio, and the scorpion Centruroides sculpturatus. Results: In the crustacean P. hawaiensis, the segmental expression of Ph-cnc is the same as that reported previously in hexapods and myriapods, with two distinct head domains in the labrum and the mandibular segment. In contrast, Po-cnc and Cs-cnc expression is not enriched in the labrum of either chelicerate, but instead is expressed at comparable levels in all appendages. In further contrast to mandibulate orthologs, the expression domain of Po-cnc posterior to the labrum is not confined within the expression domain of Po-Dfd. Conclusions: Expression data from two chelicerate outgroup taxa suggest that the signature two-domain head expression pattern of cnc evolved at the base of Mandibulata. The observation of the archetypal labral and mandibular segment domains in a crustacean exemplar supports the synapomorphic nature of mandibulate cnc expression. The broader expression of Po-cnc with respect to Po-Dfd in chelicerates further suggests that the regulation of cnc by Dfd was also acquired at the base of Mandibulata. To test this hypothesis, future studies examining panarthropod cnc evolution should investigate expression of the cnc ortholog in arthropod outgroups, such as Onychophora and Tardigrada

Membrane amplitude and triaxial stress in twisted bilayer graphene deciphered using first-principles directed elasticity theory and scanning tunneling microscopy

Twisted graphene layers produce a moir\'e pattern (MP) structure with a predetermined wavelength for given twist angle. However, predicting the membrane corrugation amplitude for any angle other than pure AB-stacked or AA-stacked graphene is impossible using first-principles density functional theory (DFT) due to the large supercell. Here, within elasticity theory we define the MP structure as the minimum energy configuration, thereby leaving the height amplitude as the only unknown parameter. The latter is determined from DFT calculations for AB and AA stacked bilayer graphene in order to eliminate all fitting parameters. Excellent agreement with scanning tunneling microscopy (STM) results across multiple substrates is reported as function of twist angle.Comment: to appear in Phys. Rev.

Preliminary phylogenetic analysis of the Andean clade and the placement of new Colombian blueberries (Ericaceae, Vaccinieae)

The blueberry tribe Vaccinieae (Ericaceae) is particularly diverse in South America and underwent extensive radiation in Colombia where many endemics occur. Recent fi eldwork in Colombia has resulted in valuable additions to the phylogeny and as well in the discovery of morphologically noteworthy new species that need to be phylogenetically placed before being named. Th is is particularly important, as the monophyly of many of the studied genera have not been confi rmed. In order to advance our understanding of the relationships within neotropical Vaccinieae and advice the taxonomy of the new blueberry relatives, here we present the most comprehensive phylogenetic analysis for the Andean clade. Anthopterus, Demosthenesia, and Pellegrinia are among the putative Andean genera recovered as monophyletic, while other eight Andean genera were not. Th e analyses also showed that genera that have been traditionally widely defi ned are non-monophyletic and could be further split into more discrete groups. Four newly discovered Colombian Vaccinieae are placed in the monophyletic Satyria s.s. and the Psammisia I clade. Although these new species are endemic to the Colombian Western Cordillera and Chocó biogeographic region and three are not known outside of Las Orquídeas National Park, they do not form sister pairs

Preliminary phylogenetic analysis of the Andean clade and the placement of new Colombian blueberries (Ericaceae, Vaccinieae)

The blueberry tribe Vaccinieae (Ericaceae) is particularly diverse in South America and underwent extensive radiation in Colombia where many endemics occur. Recent fi eldwork in Colombia has resulted in valuable additions to the phylogeny and as well in the discovery of morphologically noteworthy new species that need to be phylogenetically placed before being named. Th is is particularly important, as the monophyly of many of the studied genera have not been confi rmed. In order to advance our understanding of the relationships within neotropical Vaccinieae and advice the taxonomy of the new blueberry relatives, here we present the most comprehensive phylogenetic analysis for the Andean clade. Anthopterus, Demosthenesia, and Pellegrinia are among the putative Andean genera recovered as monophyletic, while other eight Andean genera were not. Th e analyses also showed that genera that have been traditionally widely defi ned are non-monophyletic and could be further split into more discrete groups. Four newly discovered Colombian Vaccinieae are placed in the monophyletic Satyria s.s. and the Psammisia I clade. Although these new species are endemic to the Colombian Western Cordillera and Chocó biogeographic region and three are not known outside of Las Orquídeas National Park, they do not form sister pairs