Peering over the shoulders of giants?

‘Open’ is a highly-visible cultural trend of the early twenty-first century. A brief scan of anewspaper or quick Internet search reveals it as a prefix to learning, source, standard, data,knowledge, democracy, access, repository, innovation, government, science and probablymore. The expectations of the broadband generation – young people born around the turn ofthe century – for openness and instant, on‑demand access to information affect research asmuch as any other social activity. As the world’s population of digital residents – those whosee the Web as the place where they express opinions, form relationships, develop an identityand belong to a community – grows, the expectation that the Web will be the place whereinformation is created and communicated will grow alongside them

Systematics and species concepts in the genera Lentinus Fr. and Panus Fr., with emphasis on the Lentinus tigrinus, L. crinitus and Panus lecomtei complexes

The monographic work of Pegler (1983) on Lentinus has established the taxonomic guidelines for most recent studies involving members of the genus (Moncalvo et al. 2002, Rolen 2001, Krüger 2002). Pegler’s taxonomic hierarchy combined both Lentinus Fr. and Panus Fr. into one large genus, Lentinus Fr. The combination of these genera and its validity was one of the reasons for beginning this study. For generic level comparisons, ribosomal DNA sequence data can be helpful for determining relationships among taxa (Binder and Hibbett 2002, Hibbett and Vilgalys 1991, 1993, Hibbett and Donoghue 2001, Moncalvo et al. 2002, Thorn et al. 2000). In this study, ribosomal large subunit (LSU) sequences were used to determine if Lentinus sensu Pegler should contain both Lentinus Fr. and Panus Fr. LSU data were also used to explore the relationships of Lentinus sensu Pegler (1983) to genera affiliated with it in other works (Krüger 2002, Hibbett and Donoghue 2001, Moncalvo et al. 2002). I sought to assess various taxonomic schemes and the delineation of taxa using techniques such as morphology, sexual intercompatibility, and DNA sequence data. In order to determine if ITS data could be useful in elucidating biogeographical patterns, this study concentrated on three morphological species complexes: Lentinus crinitus (Linn.: Fr.) Fr., L tigrinus (Bull.: fr.) Fr., and L. strigosus (Schwein.) Fr. [Panus lecomtei (Fr.) Corner in this study]. The ribosomal ITS1 – 5.8S – ITS2 (ITS) region evolves faster and mutates more frequently than LSU (Hibbett 1992). ITS sequence data was used to study species circumscriptions and delineations among Lentinus sensu Pegler (1983) and its segregates. In some cases ITS sequence patterns can also be used to determine biogeographical patterns (Hughes et al. 1999, Petersen and Bermudes 1992, Petersen 1995a, 1995b). Lentinus and Panus were found to be separable at the generic level based on LSU sequence data. Several morphological sections (Pegler 1983) of the genera were polyphyletic in maximum parsimony and neighbor-joining analyses (sects. Rigidi, Velutini, and Panus). Group Polyporellus (Nuñez and Ryvarden 1995) was closely related to Lentinus tigrinus and sect. Tigrini (Pegler 1983). Synonymization of L. lindquistii Lechner and Albertó (2000) and L. glabratus under L. tigrinus is suggested. Data also suggests that Panus fragilis O. K. Miller (1965) should be synonymized under P. lecomtei Fr. Lentius suavissimus Fr. is not part of either generic clade containing Lentinus or Panus spp. The transfer of Lentinus suavissimus Fr. to another genus is necessary. A bioegeographical pattern observed in sect. Tigrini showed a correlation between geography and clades based on ITS data. Synonymization of L. lindquistii Lechner and Albertó and L. glabratus Mont. Under L. tigrinus (Bull.: fr.) Fr. is suggested based on sexual intercompatibility studies and molecular data. Polyporus group Polyporellus sensu Nuñez and Ryvarden appears to be a monophyletic group related to Lentinus sect. Tigrini. This study concentrated on the circumglobal species complex Panus lecomtei Fr. to access biogeographical relationships in that group. Sexual intercompatibility studies indicated that seven collections of this complex formed a cohesive intersterility group. Ribosomal ITS sequence data for all collections of P. lecomtei fr. sampled were nearly 100% identical. Two collections of Panus fragilis O. K. Miller (1965) were also included and found to be conspecific with P. lecomtei Fr. based on ITS and LSU sequence data. Because of the macromorphological similarity of Panus conchatus and P. lecomtei, data from both species were collected. Eight collections of P. conchatus were shown to form an intersterility group. Other species of subg. Panus sensu Pegler (1983) were sequenced for ITS data, but not used for intercompatibility studies. These species include the following: Panus ciliatus Lév. (= Lentinus ciliatus Lév. sensu Pegler 1983), Panus strigellus Berk. (= Lentinus similis Berk. sensu Pegler 1983), Panus fulvus (Berk.) Pegler and Rayner (= Lentinus velutinus sensu Pegler 1983), and Panus similis Berk. and Br. (= Lentinus similis sensu Pegler 1983). Lentinus suavissimus Fr., group Polyporellus (Nuñez and Ryvarden 1995), Ganoderma and Neolentinus Redhead and Ginns (1985) were included to explore possible supra-generic relationships

Stellar Motion around Spiral Arms: Gaia Mock Data

We compare the stellar motion around a spiral arm created in two different scenarios, transient/co-rotating spiral arms and density-wave-like spiral arms. We generate Gaia mock data from snapshots of the simulations following these two scenarios using our stellar population code, SNAPDRAGONS, which takes into account dust extinction and the expected Gaia errors. We compare the observed rotation velocity around a spiral arm similar in position to the Perseus arm, and find that there is a clear difference in the velocity features around the spiral arm between the co-rotating spiral arm and the density-wave-like spiral arm. Our result demonstrates that the volume and accuracy of the Gaia data are sufficient to clearly distinguish these two scenarios of the spiral arms.Comment: 5 pages, 1 figure, to appear in the proceedings of "The Milky Way Unravelled by Gaia: GREAT Science from the Gaia Data Releases", Barcelona, 1-5 December 2014, eds. N. Walton, F. Figueras, C. Soubira

The Application of Macro- and Microfossils to Identify Paleoearthquakes in Sumatra, Indonesia and to Characterize Geomorphic and Ecological Succession on a Marsh Platform After Hurricane Isabel in North Carolina, USA

@font-face { font-family: Verdana ; }@font-face { font-family: Cambria ; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 0.0001pt; text-align: justify; line-height: 200%; font-size: 10pt; font-family: Times New Roman ; }div.Section1 { page: Section1; } In this research I revealed evidence for two buried soils in the Aceh Province, Sumatra. I focused on the litho- and biostratigraphy of the lower buried soil, which is indicative of coseismic subsidence from a paleoearthquake estimated to have occurred ca. 6500-7000 years BP. Approximately 1-3 m above the lower buried soil sequence is an upper buried soil with an age of ca. 5500-6000 years BP. I used a multi-proxy method that included pollen, foraminifera, and the gastropod Cerithidea cingulata (Gmelin, 1791) to identify the lower buried soil, establish the preseismic and postseismic paleoenvironments, and estimate the amount of coseismic subsidence to be 0.4 ± 0.3 m. Using our own distribution study and previous work, I determined the indicative meaning of C. cingulata in the modern environment. I then used this species as a sea-level indicator in the lower buried soil sequence to determine the elevation of the postseismic land surface and constrain the age of the paleoearthquake. I calibrated the 14C age of a C. cingulata shell in the postseismic unit of the lower soil by incorporating a species-specific regional correction (ΔR) to the marine reservoir effect. I developed the correction from 11 shells of known age collected prior to 1950 from sites across southeast Asia. Hurricane Isabel deposited overwash sand on a back-barrier salt marsh of Ocracoke Island, North Carolina on September 18th 2003. Data collected annually between May 2004 and October 2010 showed changes in the elevation, geomorphology, and the ecological evolution of the overwash deposit. The results indicated that marsh foraminifera and plants did not recolonize until the surface of the overwash deposit was eroded to an elevation within the intertidal zone. Once this elevation was crossed, recolonization occurred in less than one year. The erosion of the overwash deposit suggests that the stratigraphic record of storm-driven overwash is likely not representative of the actual number of landfalling hurricanes in environments such as the Outer Banks of North Carolina

Gas and Stellar Motions and Observational Signatures of Co-Rotating Spiral Arms

We have observed a snapshot of our N-body/Smoothed Particle Hydrodynamics simulation of a Milky Way-sized barred spiral galaxy in a similar way to how we can observe the Milky Way. The simulated galaxy shows a co-rotating spiral arm, i.e. the spiral arm rotates with the same speed as the circular speed. We observed the rotation and radial velocities of the gas and stars as a function of the distance from our assumed location of the observer at the three lines of sight on the disc plane, (l, b) = (90, 0), (120, 0) and (150,0) deg. We find that the stars tend to rotate slower (faster) behind (at the front of) the spiral arm and move outward (inward), because of the radial migration. However, because of their epicycle motion, we see a variation of rotation and radial velocities around the spiral arm. On the other hand, the cold gas component shows a clearer trend of rotating slower (faster) and moving outward (inward) behind (at the front of) the spiral arm, because of the radial migration. We have compared the results with the velocity of the maser sources from Reid et al. (2014), and find that the observational data show a similar trend in the rotation velocity around the expected position of the spiral arm at l = 120 deg. We also compared the distribution of the radial velocity from the local standard of the rest, V_LSR, with the APOGEE data at l = 90 deg as an example.Comment: 10 pages, 7 figures, accepted for publication in MNRA

Studying Gender in Conference Talks -- data from the 223rd meeting of the American Astronomical Society

We present a study on the gender balance, in speakers and attendees, at the recent major astronomical conference, the American Astronomical Society meeting 223, in Washington, DC. We conducted an informal survey, yielding over 300 responses by volunteers at the meeting. Each response included gender data about a single talk given at the meeting, recording the gender of the speaker and all question-askers. In total, 225 individual AAS talks were sampled. We analyze basic statistical properties of this sample. We find that the gender ratio of the speakers closely matched the gender ratio of the conference attendees. The audience asked an average of 2.8 questions per talk. Talks given by women had a slightly higher number of questions asked (3.2$\pm$0.2) than talks given by men (2.6$\pm$0.1). The most significant result from this study is that while the gender ratio of speakers very closely mirrors that of conference attendees, women are under-represented in the question-asker category. We interpret this to be an age-effect, as senior scientists may be more likely to ask questions, and are more commonly men. A strong dependence on the gender of session chairs is found, whereby women ask disproportionately fewer questions in sessions chaired by men. While our results point to laudable progress in gender-balanced speaker selection, we believe future surveys of this kind would help ensure that collaboration at such meetings is as inclusive as possible.Comment: 4 pages, 5 figures. Comments welcome

Unexpected Effect of Internal Degrees of Freedom on Transverse Phonons in Supercooled Liquids

We show experimentally that in a supercooled liquid composed of molecules with internal degrees of freedom the internal modes contribute to the frequency dependent shear viscosity and damping of transverse phonons, which results in an additional broadening of the transverse Brillouin lines. Earlier, only the effect of internal modes on the frequency dependent bulk viscosity and damping of longitudinal phonons was observed and explained theoretically in the limit of weak coupling of internal degrees of freedom to translational motion. A new theory is needed to describe this new effect. We also demonstrate, that the contributions of structural relaxation and internal processes to the width of the Brillouin lines can be separated by measurements under high pressure

The stellar kinematics of co-rotating spiral arms in Gaia mock observations

We have observed an N-body/Smoothed Particle Hydrodynamics simulation of a Milky Way like barred spiral galaxy. We present a simple method that samples N-body model particles into mock Gaia stellar observations and takes into account stellar populations, dust extinction and Gaia's science performance estimates. We examine the kinematics around a nearby spiral arm at a similar position to the Perseus arm at three lines of sight in the disc plane; (l,b)=(90,0), (120,0) and (150,0) degrees. We find that the structure of the peculiar kinematics around the co-rotating spiral arm, which is found in Kawata et al. (2014b), is still visible in the observational data expected to be produced by Gaia despite the dust extinction and expected observational errors of Gaia. These observable kinematic signatures will enable testing whether the Perseus arm of the Milky Way is similar to the co-rotating spiral arms commonly seen in N-body simulations.Comment: 9 pages 4 Figures, submitted to MNRAS 22nd Dec 201