The Variability of M Dwarfs

M dwarfs have been the subject of renewed interest as potential habitable planet hosts and have increasingly become the targets of planet detection surveys. Currently, however, the number of detections of transiting M dwarf planets remain low. The characterisation of M dwarf activity is an important consideration for such surveys, and provides constraints on the modelling of magnetically active low mass stars. Currently the spottedness of M dwarfs is not well understood owing to their intrinsic faintness and the lack of diagnostics for assessing starspot morphologies and distributions. The WFCAM Transit Survey (WTS) contains long term observations of M dwarfs in the near infra-red and presents an opportunity to study the long term variability of M dwarfs. The M dwarfs in the WTS are identified by use of colour-spectral type relations, and the periodically variable M dwarfs in the sample are detected using a Lomb-Scargle periodogram analysis. A total of 72 periodically variable M dwarfs are found with periods ranging from 0.16 to 90.33 days. The relations between the spectral subtypes, amplitudes and periods are studied and comparisons to earlier works studying M dwarf rotation are made. A number of examples of significant spot evolution are found, which exhibit complex light curve morphologies that vary in form and amplitude over periods of months to years. This provides an indication as to the nature of the spottedness of these stars. Simulations are performed to probe the connection between spot coverage, temperature and light curve amplitude. Using the results from these simulations, the spot coverage fractions of the WTS M dwarfs are estimated and they are found to be heavily spotted. Dynamic models with spots evolving at various average rates are used to explore how spot evolution can drive increased dispersion in the light curves, and to what extent this affects the detectability of periodicity by the method used. It is found that spot evolution can invoke significant noise in an M dwarf light curve, and in combination with photon noise, can in some instances inhibit the detection of a period. In reflection of the results, the relation between the light curve dispersion and spot coverage of the WTS M dwarfs is considered and it is found that more heavily spotted M dwarfs have intrinsically noisier light curves. The morphologies of the light curves produced by the simulations, and the manner in which they evolve, are qualitatively similar to the real M dwarfs in the WTS sample and indicate how models extrapolated from sunspot distributions can explain behaviour seen in active M dwarf light curves

Management Models of the Manila Clam (Ruditapes philippinarum) Fisheries in Invaded European Coastal Systems

The Manila clam (Ruditapes philippinarum, Adam & Reeve 1850) is a non-indigenous species that was introduced in Europe (France) in the 1970s for commercial purposes, and reached Portugal in the 1980s. Currently, it occurs in several European coastal systems, from the Bay of Biscay to the north Mediterranean. In Portugal, it is present in estuarine systems and coastal lagoons from the north to south, such as Ria de Aveiro, Óbidos Lagoon and Sado estuary, but a sharp rise in the prevalence of this species in the largest Portuguese estuary, the Tagus, resulted in the exponential growth of the number of harvesters and, consequently, an increase in the illegal exploitation of this resource. At least 1700 harvesters were estimated in this system and an annual catch volume of between around 4,000 and 17,000 t which corresponds to an annual value around €10,000,000 to €23,000,000 of sales. There is a general failure to comply with current legislation, both in relation to harvesting and marketing, as well as constraints arising from spatial planning instruments in force on the estuary. The failure to comply with sanitary standards for the exploitation and trade of bivalve mollusks presents a risk to public health and a social-economic issue resulting from this activity. The goal of this study is to propose management models for this activity with the aim of contributing to create a legal framework in which sustainable harvesting can be achieved, in the different systems where exploitation occurs. In order to accomplish this goal, the current state play, legal framework, regulation for harvesting and trade and relevant spatial planning instruments in Portugal are analyzed. In order to ascertain an adequate national management strategy, a variety of case studies in France, Spain and Italy were studied. The outcome is a management model which includes a co-management strategy of concessions as well as a mixed regime with concession areas and free areas. The creation of specific regulations; implementation of a co-management model with the active participation of harvesters; science-based regulation of a closed season and maximum daily quotas and an improved surveillance of the activity are recommended.info:eu-repo/semantics/publishedVersio

UAV mapping of rhizoctonia bare patch for targeted treatment

Rhizoctonia patches can be easily identified on both normal (RGB) and NDVI images captured by UAV. Mapping shows the pattern of patch distribution across a paddock, highlighting areas of crop with high and low levels of rhizoctonia patches

Variable Hard X-ray Emission from the Candidate Accreting Black Hole in Dwarf Galaxy Henize 2-10

We present an analysis of the X-ray spectrum and long-term variability of the nearby dwarf starburst galaxy Henize 2-10. Recent observations suggest that this galaxy hosts an actively accreting black hole with mass ~10^6 M_sun. The presence of an AGN in a low-mass starburst galaxy marks a new environment for active galactic nuclei (AGNs), with implications for the processes by which "seed" black holes may form in the early Universe. In this paper, we analyze four epochs of X-ray observations of Henize 2-10, to characterize the long-term behavior of its hard nuclear emission. We analyze observations with Chandra from 2001 and XMM-Newton from 2004 and 2011, as well as an earlier, less sensitive observation with ASCA from 1997. Based on detailed analysis of the source and background, we find that the hard (2-10 keV) flux of the putative AGN has decreased by approximately an order of magnitude between the 2001 Chandra observation and exposures with XMM-Newton in 2004 and 2011. The observed variability confirms that the emission is due to a single source. It is unlikely that the variable flux is due to a supernova or ultraluminous X-ray source, based on the observed long-term behavior of the X-ray and radio emission, while the observed X-ray variability is consistent with the behavior of well-studied AGNs.Comment: 7 pages, 4 figures, 2 tables; accepted for publication in Ap

The MASSIVE Survey - X. Misalignment between Kinematic and Photometric Axes and Intrinsic Shapes of Massive Early-Type Galaxies

We use spatially resolved two-dimensional stellar velocity maps over a $107"\times 107"$ field of view to investigate the kinematic features of 90 early-type galaxies above stellar mass $10^{11.5}M_\odot$ in the MASSIVE survey. We measure the misalignment angle $\Psi$ between the kinematic and photometric axes and identify local features such as velocity twists and kinematically distinct components. We find 46% of the sample to be well aligned ($\Psi < 15^{\circ}$), 33% misaligned, and 21% without detectable rotation (non-rotators). Only 24% of the sample are fast rotators, the majority of which (91%) are aligned, whereas 57% of the slow rotators are misaligned with a nearly flat distribution of $\Psi$ from $15^{\circ}$ to $90^{\circ}$. 11 galaxies have $\Psi \gtrsim 60^{\circ}$ and thus exhibit minor-axis ("prolate") rotation in which the rotation is preferentially around the photometric major axis. Kinematic misalignments occur more frequently for lower galaxy spin or denser galaxy environments. Using the observed misalignment and ellipticity distributions, we infer the intrinsic shape distribution of our sample and find that MASSIVE slow rotators are consistent with being mildly triaxial, with mean axis ratios of $b/a=0.88$ and $c/a=0.65$. In terms of local kinematic features, 51% of the sample exhibit kinematic twists of larger than $20^{\circ}$, and 2 galaxies have kinematically distinct components. The frequency of misalignment and the broad distribution of $\Psi$ reported here suggest that the most massive early-type galaxies are mildly triaxial, and that formation processes resulting in kinematically misaligned slow rotators such as gas-poor mergers occur frequently in this mass range.Comment: Accepted to MNRA

Heterotrimeric G protein signaling functions with dynein to promote spindle positioning in C. elegans

Proper orientation and positioning of the mitotic spindle is essential for the correct segregation of fate determinants during asymmetric cell division. Although heterotrimeric G proteins and their regulators are essential for spindle positioning in many cell types, their mechanism of action remains unclear. In this study, we show that dyrb-1, which encodes a dynein light chain, provides a functional link between heterotrimeric G protein signaling and dynein activity during spindle positioning in Caenorhabditis elegans. Embryos depleted of dyrb-1 display phenotypes similar to a weak loss of function of dynein activity, indicating that DYRB-1 is a positive regulator of dynein. We find that the depletion of dyrb-1 enhances the spindle positioning defect of weak loss of function alleles of two regulators of G protein signaling, LIN-5 and GPR-1/2, and that DYRB-1 physically associates with these two proteins. These results indicate that dynein activity functions with regulators of G protein signaling to regulate common downstream effectors during spindle positioning in the early C. elegans embryo

On emotions and salsa : some thoughts on dancing to rethink consumers

Dance forms are a big business, highly marketable commoditized cultural universes, with a plethora of markets constructed around their spirit, vitality and possibilities. In this paper, we explore one particular dance form, that of Salsa, arguing that as consumer researchers we look for a more vibrant vocabulary and mindset with which to capture the experiential and transcendental nature of such social associations. We demonstrate that the metaphor of dancing is useful to revitalize our notions of consumer actions; taking them out of the grey mundane of calculative and rational action into the possibilities of emotional economies constructed around the effervescence and vitality of the social (cf. Maffesoli, [1996])

Studies on the behavior of the horn fly, Haematobia irritans (Linn.)

Published May 1962. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo

Scenario Thinking Approach for Leveraging ICT to Support SMEs in the Indian Construction Industry

Information and Communication Technology (ICT) plays a number of significant strategic and operational roles in the construction sector. However, studies have highlighted a series of challenges within this sector, from value-proposition aversion (regarding ICT expenditure), through to lack of aptitude (capability), and inability to ‘measure’ tangible outcomes (benefits) associated with ICT deployment. Given these issues, and also acknowledging the levels of nested fragmentation that exists in sectoral disciplines – especially within small to medium enterprises (SMEs); this paper presents a chronology of interrelated factors peculiar to the sector which has directly/indirectly engendered this slow (low) technology adopter positioning of these organisations. This paper argues that there is a need to break the status quo use of ICT by SMEs in the Indian construction industry, and a need to realise the benefits garnered in other sectors as a means of not only enhancing the existing business, but also creating new innovation opportunities (especially in the early adopter S curve). Using a scenario thinking approach, this research presents a framework which highlights the causal “deficits” associated with low ICT penetration in the sector. This framework also identifies the key forces that influence and impact upon ICT usage in the construction sector, especially the interplay of key pivotal forces (through the competing push-pull continuum). A series of different scenarios for ICT uptake, adoption and diffusion are envisioned. These were developed with the help of industry experts in order to embed relevance and establish priorities against tangible indicators. This framework presents a future state ICT vision for SME's, one which places direct emphasis on SMEs’ perspectives (operational and strategic) and their future business aspirations

The MASSIVE Survey - XII Connecting Stellar Populations of Early-Type Galaxies to Kinematics and Environment

We measure the stellar populations as a function of radius for 90 early-type galaxies (ETGs) in the MASSIVE survey, a volume-limited integral-field spectroscopic (IFS) galaxy survey targeting all northern-sky ETGs with absolute K-band magnitude M_K < -25.3 mag, or stellar mass M* 4x10^11 M_sun, within 108 Mpc. We are able to measure reliable stellar population parameters for individual galaxies out to 10-20 kpc (1-3 R_e) depending on the galaxy. Focusing on ~R_e (~10 kpc), we find significant correlations between the abundance ratios, sigma, and M* at large radius, but we also find that the abundance ratios saturate in the highest-mass bin. We see a strong correlation between the kurtosis of the line of sight velocity distribution (h4) and the stellar population parameters beyond R_e. Galaxies with higher radial anisotropy appear to be older, with metal-poorer stars and enhanced [alpha/Fe]. We suggest that the higher radial anisotropy may derive from more accretion of small satellites. Finally, we see some evidence for correlations between environmental metrics (measured locally and on >5 Mpc scales) and the stellar populations, as expected if satellites are quenched earlier in denser environments.Comment: 17 pages, 7 figures, Appendix not included here due to size constraints. Posted after responding to referee's comment