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Phase Coexistence of Ferroelectric Vortices and Classical a1/a2 Domains in PbTiO3/SrTiO3 Superlattices.
Organizing the innovation process : complementarities in innovation networking
This paper contributes to the developing literature on complementarities in organizational design. We test for the existence of complementarities in the use of external networking between stages of the innovation process in a sample of UK and German manufacturing plants. Our evidence suggests some differences between the UK and Germany in terms of the optimal combination of innovation activities in which to implement external networking. Broadly, there is more evidence of complementarities in the case of Germany, with the exception of the product engineering stage. By contrast, the UK exhibits generally strong evidence of substitutability in external networking in different stages, except between the identification of new products and product design and development stages. These findings suggest that previous studies indicating strong complementarity between internal and external knowledge sources have provided only part of the picture of the strategic dilemmas facing firms
White Blood, Black Gold: The Commodification of Wild Rubber in the Bolivian Amazon, 1870-1920
The Bolivian rubber boom thrived during the 1880 and 1920 decades throughout the Amazonian fluvial network (Madre de Dios, Beni, PurĂșs, Madeira and Beni rivers). The economic potential of rubber quickly became a decisive phenomenon in the social history of Eastern Bolivia, linked with the definitive ocupation of marginal territories, new interethnic relations, national and international migration, taxation, property entitlement, the foundation of cities, the rise of nationalism, the struggle to settle republican frontiers and a novel regional opening to global economy. The boom also encouraged substantial developments in cartography, hidrography, botanics and ethnology. Our goal is to describe the singularities of the rubber-tapping industry in Bolivia and to analyse the representations of ânatureâ held by rubber tappers of the period: there was indeed a modernist discourse based on the usual ideas of "progress" and "civilization" of the industry opposed to the "wildness", "savagery" and "barbarism" massively attributed to Amazonia, and also a generalized notion of the jungle as a "desert land" open to opportunities for the self-made man. In retrospect, these discourses can certainly reveal a lack of âecological awarenessâ. However, a closer analysis of historical sources also shows the existence of voices that were more nuanced and reflexive, and in some cases even dared to point out the limits of extractivism ânot only in "ecological" terms but also in reference to the life of the indigenous and creole populations involved in the rubber boom
Guidelines on the use of Structure from Motion Photogrammetry in Geomorphic Research
As a topographic modelling technique, structure-from-motion (SfM) photogrammetry combines the utility of digital photogrammetry with a flexibility and ease of use derived from multi-view computer vision methods. In conjunction with the rapidly increasing availability of imagery, particularly from unmanned aerial vehicles, SfM photogrammetry represents a powerful tool for geomorphological research. However, to fully realize this potential, its application must be carefully underpinned by photogrammetric considerations, surveys should be reported in sufficient detail to be repeatable (if practical) and results appropriately assessed to understand fully the potential errors involved. To deliver these goals, robust survey and reporting must be supported through (i) using appropriate survey design, (ii) applying suitable statistics to identify systematic error (bias) and to estimate precision within results, and (iii) propagating uncertainty estimates into the final data products
Guidelines on the use of Structure from Motion Photogrammetry in Geomorphic Research
As a topographic modelling technique, structure-from-motion (SfM) photogrammetry combines the utility of digital photogrammetry with a flexibility and ease of use derived from multi-view computer vision methods. In conjunction with the rapidly increasing availability of imagery, particularly from unmanned aerial vehicles, SfM photogrammetry represents a powerful tool for geomorphological research. However, to fully realize this potential, its application must be carefully underpinned by photogrammetric considerations, surveys should be reported in sufficient detail to be repeatable (if practical) and results appropriately assessed to understand fully the potential errors involved. To deliver these goals, robust survey and reporting must be supported through (i) using appropriate survey design, (ii) applying suitable statistics to identify systematic error (bias) and to estimate precision within results, and (iii) propagating uncertainty estimates into the final data products
Physical State of Molecular Gas in High Galactic Latitude Translucent Clouds
The rotational transitions of carbon monoxide (CO) are the primary means of
investigating the density and velocity structure of the molecular interstellar
medium. Here we study the lowest four rotational transitions of CO towards
high-latitude translucent molecular clouds (HLCs). We report new observations
of the J = (4-3), (2-1), and (1-0) transitions of CO towards eight
high-latitude clouds. The new observations are combined with data from the
literature to show that the emission from all observed CO transitions is
linearly correlated. This implies that the excitation conditions which lead to
emission in these transitions are uniform throughout the clouds. Observed
13CO/12CO (1-0) integrated intensity ratios are generally much greater than the
expected abundance ratio of the two species, indicating that the regions which
emit 12CO (1-0) radiation are optically thick. We develop a statistical method
to compare the observed line ratios with models of CO excitation and radiative
transfer. This enables us to determine the most likely portion of the physical
parameter space which is compatible with the observations. The model enables us
to rule out CO gas temperatures greater than 30K since the most likely
high-temperature configurations are 1 pc-sized structures aligned along the
line of sight. The most probable solution is a high density and low temperature
(HDLT) solution. The CO cell size is approximately 0.01 pc (2000 AU). These
cells are thus tiny fragments within the 100 times larger CO-emitting extent of
a typical high-latitude cloud. We discuss the physical implications of HDLT
cells, and we suggest ways to test for their existence.Comment: 19 pages, 13 figures, 2 tables, emulateapj To be published in The
Astrophysical Journa
The Antarctic Submillimeter Telescope and Remote Observatory (AST/RO)
AST/RO, a 1.7 m diameter telescope for astronomy and aeronomy studies at
wavelengths between 200 and 2000 microns, was installed at the South Pole
during the 1994-1995 Austral summer. The telescope operates continuously
through the Austral winter, and is being used primarily for spectroscopic
studies of neutral atomic carbon and carbon monoxide in the interstellar medium
of the Milky Way and the Magellanic Clouds. The South Pole environment is
unique among observatory sites for unusually low wind speeds, low absolute
humidity, and the consistent clarity of the submillimeter sky. Four heterodyne
receivers, an array receiver, three acousto-optical spectrometers, and an array
spectrometer are installed. A Fabry-Perot spectrometer using a bolometric array
and a Terahertz receiver are in development. Telescope pointing, focus, and
calibration methods as well as the unique working environment and logistical
requirements of the South Pole are described.Comment: 57 pages, 15 figures. Submitted to PAS
High HIV Prevalence Among Men Who have Sex with Men in Soweto, South Africa: Results from the Soweto Menâs Study
The Soweto Menâs Study assessed HIV prevalence and associated risk factors among MSM in Soweto, South Africa. Using respondent driven sampling (RDS) recruitment methods, we recruited 378 MSM (including 15 seeds) over 30Â weeks in 2008. All results were adjusted for RDS sampling design. Overall HIV prevalence was estimated at 13.2% (95% confidence interval 12.4â13.9%), with 33.9% among gay-identified men, 6.4% among bisexual-identified men, and 10.1% among straight-identified MSM. In multivariable analysis, HIV infection was associated with being older than 25 (adjusted odds ratio (AOR) 3.8, 95% CI 3.2â4.6), gay self-identification (AOR 2.3, 95% CI 1.8â3.0), monthly income less than ZAR500 (AOR 1.4, 95% CI 1.2â1.7), purchasing alcohol or drugs in exchange for sex with another man (AOR 3.9, 95% CI 3.2â4.7), reporting any URAI (AOR 4.4, 95% CI 3.5â5.7), reporting between six and nine partners in the prior 6Â months (AOR 5.7, 95% CI 4.0â8.2), circumcision, (AOR 0.2, 95% CI 0.1â0.2), a regular female partner (AOR 0.2, 95% CI 0.2â0.3), smoking marijuana in the last 6Â months (AOR 0.6, 95% CI 0.5â0.8), unprotected vaginal intercourse in the last 6Â months (AOR 0.5, 95% CI 0.4â0.6), and STI symptoms in the last year (AOR 0.7, 95% CI 0.5â0.8). The results of the Soweto Menâs Study confirm that MSM are at high risk for HIV infection, with gay men at highest risk. HIV prevention and treatment for MSM are urgently needed
The association between serum biomarkers and disease outcome in influenza A(H1N1)pdm09 virus infection: results of two international observational cohort studies
BACKGROUND
Prospective studies establishing the temporal relationship between the degree of inflammation and human influenza disease progression are scarce. To assess predictors of disease progression among patients with influenza A(H1N1)pdm09 infection, 25 inflammatory biomarkers measured at enrollment were analyzed in two international observational cohort studies.
METHODS
Among patients with RT-PCR-confirmed influenza A(H1N1)pdm09 virus infection, odds ratios (ORs) estimated by logistic regression were used to summarize the associations of biomarkers measured at enrollment with worsened disease outcome or death after 14 days of follow-up for those seeking outpatient care (FLU 002) or after 60 days for those hospitalized with influenza complications (FLU 003). Biomarkers that were significantly associated with progression in both studies (p<0.05) or only in one (p<0.002 after Bonferroni correction) were identified.
RESULTS
In FLU 002 28/528 (5.3%) outpatients had influenza A(H1N1)pdm09 virus infection that progressed to a study endpoint of complications, hospitalization or death, whereas in FLU 003 28/170 (16.5%) inpatients enrolled from the general ward and 21/39 (53.8%) inpatients enrolled directly from the ICU experienced disease progression. Higher levels of 12 of the 25 markers were significantly associated with subsequent disease progression. Of these, 7 markers (IL-6, CD163, IL-10, LBP, IL-2, MCP-1, and IP-10), all with ORs for the 3(rd) versus 1(st) tertile of 2.5 or greater, were significant (p<0.05) in both outpatients and inpatients. In contrast, five markers (sICAM-1, IL-8, TNF-α, D-dimer, and sVCAM-1), all with ORs for the 3(rd) versus 1(st) tertile greater than 3.2, were significantly (pâ€.002) associated with disease progression among hospitalized patients only.
CONCLUSIONS
In patients presenting with varying severities of influenza A(H1N1)pdm09 virus infection, a baseline elevation in several biomarkers associated with inflammation, coagulation, or immune function strongly predicted a higher risk of disease progression. It is conceivable that interventions designed to abrogate these baseline elevations might affect disease outcome
Dynamics of mild strombolian activity on Mt. Etna
Here we report the first measurements of gas masses released during a rare period of strombolian activity at
the Bocca Nuova crater, Mt. Etna, Sicily. UV camera data acquired for 195 events over an â27 minute period
(27th July 2012) indicate erupted SO2 masses ranging from â0.1 to â14 kg per event, with corresponding
total gas masses of â0.1 to 74 kg. Thus, the activity was characterised by more frequent and smaller events
than typically associated with strombolian activity on volcanoes such as Stromboli. Events releasing larger
measured gas masses were followed by relatively long repose periods before the following burst, a feature not
previously reported on from gas measurement data. If we assume that gas transport within the magma can be
represented by a train of rising gas pockets or slugs, then the high frequency of events indicates that these
slugs must have been in close proximity. In this case the longer repose durations associated with the larger
slugs would be consistent with interactions between adjacent slugs leading to coalescence, a process expedited
close to the surface by rapid slug expansion. We apply basic modelling considerations to the measured gas
masses in order to investigate potential slug characteristics governing the observed activity.We also cross correlated
the acquired gas fluxes with contemporaneously obtained seismic data but found no relationship between
the series in line with the mild form of manifest explosivity
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