α5β1-Integrin promotes tension-dependent mammary epithelial cell invasion by engaging the fibronectin synergy site.

Tumors are fibrotic and characterized by abundant, remodeled, and cross-linked collagen that stiffens the extracellular matrix stroma. The stiffened collagenous stroma fosters malignant transformation of the tissue by increasing tumor cell tension to promote focal adhesion formation and potentiate growth factor receptor signaling through kinase. Importantly, collagen cross-linking requires fibronectin (FN). Fibrotic tumors contain abundant FN, and tumor cells frequently up-regulate the FN receptor α5β1 integrin. Using transgenic and xenograft models and tunable two- and three-dimensional substrates, we show that FN-bound α5β1 integrin promotes tension-dependent malignant transformation through engagement of the synergy site that enhances integrin adhesion force. We determined that ligation of the synergy site of FN permits tumor cells to engage a zyxin-stabilized, vinculin-linked scaffold that facilitates nucleation of phosphatidylinositol (3,4,5)-triphosphate at the plasma membrane to enhance phosphoinositide 3-kinase (PI3K)-dependent tumor cell invasion. The data explain why rigid collagen fibrils potentiate PI3K activation to promote malignancy and offer a perspective regarding the consistent up-regulation of α5β1 integrin and FN in many tumors and their correlation with cancer aggression

HI Detection in two Dwarf S0 Galaxies in Nearby Groups: ESO384-016 and NGC 59

An \hi survey of 10 dE/dS0 galaxies in the nearby Sculptor and Centaurus A groups was made using the Australia Telescope Compact Array (ATCA). The observed galaxies have accurate distances derived by Jerjen et al (1998; 2000b) using the surface brightness fluctuation technique. Their absolute magnitudes are in the range $-9.5 > M_B > -15.3$. Only two of the ten galaxies were detected at our detection limit ($\sim 1.0 \times 10^6$ \msol for the Centaurus group and $\sim 5.3 \times 10^5$ \msol for the Sculptor group), the two dS0 galaxies ESO384-016 in the Centaurus A Group and NGC 59 in the Sculptor Group, with \hi masses of $6.0 \pm 0.5 \times 10^6$ \msol and $1.4 \pm 0.1 \times 10^7$ \msol respectively. Those two detections were confirmed using the Green Bank Telescope. These small \hi reservoirs could fuel future generations of low level star formation and could explain the bluer colors seen at the center of the detected galaxies. Similarly to what is seen with the Virgo dEs, the two objects with \hi appear to be on the outskirt of the groups.Comment: 25 pages (11 figures), accepted by A

Physical Properties of Complex C Halo Clouds

Observations from the Galactic Arecibo L-Band Feed Array HI (GALFA-HI) Survey of the tail of Complex C are presented and the halo clouds associated with this complex cataloged. The properties of the Complex C clouds are compared to clouds cataloged at the tail of the Magellanic Stream to provide insight into the origin and destruction mechanism of Complex C. Magellanic Stream and Complex C clouds show similarities in their mass distributions (slope = -0.7 and -0.6, respectively) and have a common linewidth of 20 - 30 km/s (indicative of a warm component), which may indicate a common origin and/or physical process breaking down the clouds. The clouds cataloged at the tail of Complex C extend over a mass range of 10^1.1 to 10^4.8 solar masses, sizes of 10^1.2 to 10^2.6 pc, and have a median volume density of 0.065 cm^(-3) and median pressure of (P/k) = 580 K cm^{-3}. We do not see a prominent two-phase structure in Complex C, possibly due to its low metallicity and inefficient cooling compared to other halo clouds. From assuming the Complex C clouds are in pressure equilibrium with a hot halo medium, we find a median halo density of 5.8 x 10^(-4) cm^(-3), which given a constant distance of 10 kpc, is at a z-height of ~3 kpc. Using the same argument for the Stream results in a median halo density of 8.4 x 10^(-5) x (60kpc/d) cm^(-3). These densities are consistent with previous observational constraints and cosmological simulations. We also assess the derived cloud and halo properties with three dimensional grid simulations of halo HI clouds and find the temperature is generally consistent within a factor of 1.5 and the volume densities, pressures and halo densities are consistent within a factor of 3.Comment: Accepted for publication in AJ. 54 pages, including 6 tables and 16 figure

A Proper Motion for the Pulsar Wind Nebula G359.23-0.82, "the Mouse," Associated with the Energetic Radio Pulsar J1747-2958

The "Mouse" (PWN G359.23-0.82) is a spectacular bow shock pulsar wind nebula, powered by the radio pulsar J1747-2958. The pulsar and its nebula are presumed to have a high space velocity, but their proper motions have not been directly measured. Here we present 8.5 GHz interferometric observations of the Mouse nebula with the Very Large Array, spanning a time baseline of 12 yr. We measure eastward proper motion for PWN G359.23-0.82 (and hence indirectly for PSR J1747-2958) of 12.9+/-1.8 mas/yr, which at an assumed distance of 5 kpc corresponds to a transverse space velocity of 306+/-43 km/s. Considering pressure balance at the apex of the bow shock, we calculate an in situ hydrogen number density of approximately 1.0(-0.2)(+0.4) cm^(-3) for the interstellar medium through which the system is traveling. A lower age limit for PSR J1747-2958 of 163(-20)(+28) kyr is calculated by considering its potential birth site. The large discrepancy with the pulsar's spin-down age of 25 kyr is possibly explained by surface dipole magnetic field growth on a timescale ~15 kyr, suggesting possible future evolution of PSR J1747-2958 to a different class of neutron star. We also argue that the adjacent supernova remnant G359.1-0.5 is not physically associated with the Mouse system but is rather an unrelated object along the line of sight.Comment: 8 pages, 4 figures, emulateapj format. Accepted for publication in The Astrophysical Journa

Trends and emissions of six perfluorocarbons in the Northern Hemisphere and Southern Hemisphere

Perfluorocarbons (PFCs) are potent greenhouse gases with global warming potentials up to several thousand times greater than CO2 on a 100-year time horizon. The lack of any significant sinks for PFCs means that they have long atmospheric lifetimes of the order of thousands of years. Anthropogenic production is thought to be the only source for most PFCs. Here we report an update on the global atmospheric abundances of the following PFCs, most of which have for the first time been analytically separated according to their isomers: c-octafluorobutane (c-C4F8), n-decafluorobutane (n-C4F10), n-dodecafluoropentane (n-C5F12), n-tetradecafluorohexane (n-C6F14), and n-hexadecafluoroheptane (n-C7F16). Additionally, we report the first data set on the atmospheric mixing ratios of perfluoro-2-methylpentane (i-C6F14). The existence and significance of PFC isomers have not been reported before, due to the analytical challenges of separating them. The time series spans a period from 1978 to the present. Several data sets are used to investigate temporal and spatial trends of these PFCs: time series of air samples collected at Cape Grim, Australia, from 1978 to the start of 2018; a time series of air samples collected between July 2015 and April 2017 at Tacolneston, UK; and intensive campaign-based sampling collections from Taiwan. Although the remote “background” Southern Hemispheric Cape Grim time series indicates that recent growth rates of most of these PFCs are lower than in the 1990s, we continue to see significantly increasing mixing ratios that are between 6 % and 27 % higher by the end of 2017 compared to abundances measured in 2010. Air samples from Tacolneston show a positive offset in PFC mixing ratios compared to the Southern Hemisphere baseline. The highest mixing ratios and variability are seen in air samples from Taiwan, which is therefore likely situated much closer to PFC sources, confirming predominantly Northern Hemispheric emissions for most PFCs. Even though these PFCs occur in the atmosphere at levels of parts per trillion molar or less, their total cumulative global emissions translate into 833 million metric tonnes of CO2 equivalent by the end of 2017, 23 % of which has been emitted since 2010. Almost two-thirds of the CO2 equivalent emissions within the last decade are attributable to c-C4F8, which currently also has the highest emission rates that continue to grow. Sources of all PFCs covered in this work remain poorly constrained and reported emissions in global databases do not account for the abundances found in the atmosphere

The Social and Economic Long Term Monitoring Program (SELTMP) 2014: Recreation in the Great Barrier Reef

[Extract] Introduction.\ud People love to spend their recreational time visiting the Great Barrier Reef World Heritage Area (GBRWHA), (GBRMPA, 2009), and many people are doing it! The recent SELTMP surveys revealed that 95% of residents of coastal town adjacent to the GBR had visited the GBRWHA for recreation at least once, and 87% had visited in the previous 12 months. Many of these visits appeared to be to a mainland beach to walk, swim, and relax. However, 68% of people who told us about their recent trips had been beyond the mainland beach to islands, reefs, shoals, etc., to take part in activities such as fishing, snorkelling and diving. Other activities include boating, sailing, jet skiing, camping, kayaking, sight-seeing, photography, and wildlife viewing, to name a few. Recreational visitors are currently very satisfied with their use of the Marine Park.\ud \ud While most trips beyond the beach were made by ferry, about a third of these trips were accessed by residents' own or someone else's boat. While not everyone is using their vessel very frequently, vessel registration by coastal residents has increased substantially in recent years (Old Department of Transport, unpublished data, 2011).\ud \ud Given all of this activity, it is not surprising that recreation in the GBRWHA provides significant social and cultural benefits as well as many health and wellbeing benefits associated with the psychological interaction with nature (Synergies Economic Consulting, 2012). In economic terms, recreation (defined by Deloitte Access Economics as GBR catchment residents visiting an island, sailing, boating and fishing), contributed $126m in direct value or$243.9m value added to the Australian economy in 2011/12 (Deloitte Access Economics, 2013). This estimate did not include beach visits.\ud Importantly, recreation differs from tourism. The Great Barrier Reef Marine Park Authority define recreation as an independent visit for enjoyment that is not part of a commercial operation (GBRMPA, 2012). For the purposes of the SELTMP Surveys (outline following), any resident of the GBR catchment who visits the GBRWHA is included within recreation; while tourists are defined as those residing outside of the GBR catchment

Tropospheric observations of CFC-114 and CFC-114a with a focus on long-term trends and emissions

Chlorofluorocarbons (CFCs) are ozone-depleting substances as well as strong greenhouse gases, and the control of their production and use under the Montreal Protocol has had demonstrable benefits to both mitigation of increasing surface UV radiation and climate forcing. A global ban on consumption came into force in 2010, but there is evidence of continuing emissions of certain CFCs from a range of sources. One compound has received little attention in the literature, namely CFC-114 (C2Cl2F4). Of particular interest here is the differentiation between CFC-114 (CClF2CClF2) and its asymmetric isomeric form CFC-114a (CF3CCl2F) as atmospheric long-term measurements in the peer-reviewed literature to date have been assumed to represent the sum of both isomers with a time-invariant isomeric speciation. Here we report the first long-term measurements of the two isomeric forms separately, and find that they have different origins and trends in the atmosphere. Air samples collected at Cape Grim (41° S), Australia, during atmospheric background conditions since 1978, combined with samples collected from deep polar snow (firn) enable us to obtain a near-complete record of both gases since their initial production and release in the 1940s. Both isomers were present in the unpolluted atmosphere in comparably small amounts before 1960. The mixing ratio of CFC-114 doubled from 7.9 to 14.8 parts per trillion (ppt) between the start of the Cape Grim record in 1978 and the end of our record in 2014, while over the same time CFC-114a trebled from 0.35 to 1.03 ppt. Mixing ratios of both isomers are slowly decreasing by the end of this period. This is consistent with measurements of recent aircraft-based samples showing no significant interhemispheric mixing ratio gradient

Interplay of Superconductivity and Fermi-Liquid Transport in Rh-Doped CaFe2As2 with Lattice-Collapse Transition

Ca(Fe$_{1-x}$Rh$_x$)$_2$As$_2$ undergoes successive phase transitions with increasing Rh doping in the $T$ $=$ 0 limit. The antiferromagnetic-metal phase with orthorhombic structure at 0.00 $\le$ $x$ $\le$ 0.020 is driven to a superconducting phase with uncollapsed-tetragonal (ucT) structure at 0.020 $\le$ $x$ $\le$ 0.024; a non-superconducting collapsed-tetragonal (cT) phase takes over at $x$ $\geq$ 0.024. The breakdown of Fermi-liquid transport is observed in the ucT phase above $T_{\rm c}$. In the adjacent cT phase, Fermi-liquid transport is restored along with a disappearance of superconductivity. This interplay of superconductivity and Fermi-liquid transport suggests the essential role of magnetic fluctuations in the emergence of superconductivity in doped CaFe$_2$As$_2$.Comment: 11 pages, 4 figure

Compact HI clouds from the GALFA-HI survey

The Galactic Arecibo L-band Feed Array HI (GALFA-HI) survey is mapping the entire Arecibo sky at 21-cm, over a velocity range of -700 to +700 km/s (LSR), at a velocity resolution of 0.18 km/s and a spatial resolution of 3.5 arcmin. The unprecedented resolution and sensitivity of the GALFA-HI survey have resulted in the detection of numerous isolated, very compact HI clouds at low Galactic velocities, which are distinctly separated from the HI disk emission. In the limited area of ~4600 deg$^2$ surveyed so far, we have detected 96 of such compact clouds. The detected clouds are cold with a median T$_{k,max}$ (the kinetic temperature in the case in which there is no non-thermal broadening) of 300 K. Moreover, these clouds are quite compact and faint, with median values of 5 arcmin in angular size, 0.75 K in peak brightness temperature, and $5 \times 10^{18}$ cm$^{-2}$ in HI column density. Most of the clouds deviate from Galactic rotation at the 20-30 km/s level, and a significant fraction show evidence for a multiphase medium and velocity gradients. No counterparts for these clouds were found in other wavebands. From the modeling of spatial and velocity distributions of the whole compact cloud population, we find that the bulk of the compact clouds are related to the Galactic disk, and their distances are likely to be in the range of 0.1 to a few kpc. We discuss various possible scenarios for the formation and maintenance of this cloud population and its significance for Galactic ISM studies.Comment: Accepted for publication in the Astrophysical Journa