1,284 research outputs found
Honeaite, a new gold-thallium-telluride from the Eastern Goldfields, Yilgarn Craton, Western Australia
Honeaite, ideal formula Au3TlTe2, is a new mineral from the late Archaean Karonie gold deposit, Eastern Goldfields province, Western Australia. Honeaite is found with native gold, tellurobismuthite, petzite, hessite, calaverite, melonite, mattagamite, frohbergite, altaite, pyrrhotite and molybdenite. These minerals are concentrated in microvughs and microfractures mainly within areas of prehnite alteration of amphibolite. The mineralisation appears to have been deposited under greenschistfacies conditions at lower temperatures than most gold deposits in the Eastern Goldfields. Single-crystal X-ray studies identified the structure of honeaite as orthorhombic, space group Pbcm, and unit cell parameters a = 8.9671(4) Å, b = 8.8758(4) Å, c = 7.8419(5) Å, V = 624.14(6) Å3 (Z = 4). The strongest reflections of the calculated powder X-ray diffraction pattern are [d in Å (I rel)(hkl)]: 2.938(100)(022), 2.905 (39,8)(322, 411), 2.989 (31)(300), 2.833 (23)(310), 1.853 (17)(332). Electron-microprobe analysis (EDS mode) gave (wt%) Au 56.33, Tl 19.68, Te 24.30, total 100.31, leading to an empirical formula (based on 2 Te apfu) of Au3.00Tl1.01Te2.00. Honeaite is black with a metallic lustre and no observed cleavage. The calculated density is 11.18 g/cm3. In reflected plane-polarized light it is slightly bluish grey. Between crossed polars it is weakly anisotropic with dark brown to dark blue rotation tints. Reflectance values in air and in oil are given. Honeaite is named after the late Russell M. Honea (1929–2002).© 2016 E. Schweizerbart'sche Verlagsbuchhandlung, D-70176 Stuttgart. This document is the author's final accepted version of the journal article. You are advised to consult the publisher's version if you wish to cite from it
Mobile Communication Signatures of Unemployment
The mapping of populations socio-economic well-being is highly constrained by
the logistics of censuses and surveys. Consequently, spatially detailed changes
across scales of days, weeks, or months, or even year to year, are difficult to
assess; thus the speed of which policies can be designed and evaluated is
limited. However, recent studies have shown the value of mobile phone data as
an enabling methodology for demographic modeling and measurement. In this work,
we investigate whether indicators extracted from mobile phone usage can reveal
information about the socio-economical status of microregions such as districts
(i.e., average spatial resolution < 2.7km). For this we examine anonymized
mobile phone metadata combined with beneficiaries records from unemployment
benefit program. We find that aggregated activity, social, and mobility
patterns strongly correlate with unemployment. Furthermore, we construct a
simple model to produce accurate reconstruction of district level unemployment
from their mobile communication patterns alone. Our results suggest that
reliable and cost-effective economical indicators could be built based on
passively collected and anonymized mobile phone data. With similar data being
collected every day by telecommunication services across the world,
survey-based methods of measuring community socioeconomic status could
potentially be augmented or replaced by such passive sensing methods in the
future
Novel gallium(III) complexes transported by MDR1 P-glycoprotein: potential PET imaging agents for probing P-glycoprotein-mediated transport activity in vivo
AbstractBackground: Multidrug resistance (MDR) mediated by expression of MDR1 P-glycoprotein (Pgp) represents one of the best characterized barriers to chemotherapy in cancer patients. Positron emission tomography (PET) agents for analysis of Pgp-mediated drug transport activity in vivo would enable noninvasive assessment of chemotherapeutic regimens and MDR gene therapy.Results: Candidate Schiff-base phenolic gallium(III) complexes were synthesized from their heptadentate precursors and gallium(III)acetylacetonate. Crystal structures demonstrated a hexacoordinated central gallium with overall trans-pseudo-octahedral geometry. Radiolabeled 67Ga-complexes were obtained in high purity and screened in drug-sensitive (Pgp−) and MDR (Pgp+) tumor cells. Compared with control, lead compound 6 demonstrated antagonist-reversible 55-fold lower accumulation in Pgp-expressing MDR cells. Furthermore, compared with wild-type control, quantitative pharmacokinetic analysis showed markedly increased penetration and retention of 6 in brain and liver tissues of mdr1a/b(−/−) gene disrupted mice, correctly mapping Pgp-mediated transport activity at the capillary blood–brain barrier and hepatocellular biliary cannalicular surface in vivo.Conclusions: These results indicate that gallium(III) complex 6 is recognized by MDR1 Pgp as an avid transport substrate, thereby providing a useful scaffold to generate 68Ga radiopharmaceuticals for molecular imaging of Pgp transport activity in tumors and tissues in vivo using PET
An Investigation into the Poor Survival of an Endangered Coho Salmon Population
To investigate reasons for the decline of an endangered population of coho salmon (O. kisutch), 190 smolts were acoustically tagged during three consecutive years and their movements and survival were estimated using the Pacific Ocean Shelf Tracking project (POST) array. Median travel times of the Thompson River coho salmon smolts to the lower Fraser River sub-array were 16, 12 and 10 days during 2004, 2005 and 2006, respectively. Few smolts were recorded on marine arrays. Freshwater survival rates of the tagged smolts during their downstream migration were 0.0–5.6% (0.0–9.0% s.e.) in 2004, 7.0% (6.2% s.e.) in 2005, and 50.9% (18.6% s.e.) in 2006. Overall smolt-to-adult return rates exhibited a similar pattern, which suggests that low freshwater survival rates of out-migrating smolts may be a primary reason for the poor conservation status of this endangered coho salmon population
Visual Similarity Perception of Directed Acyclic Graphs: A Study on Influencing Factors
While visual comparison of directed acyclic graphs (DAGs) is commonly
encountered in various disciplines (e.g., finance, biology), knowledge about
humans' perception of graph similarity is currently quite limited. By graph
similarity perception we mean how humans perceive commonalities and differences
in graphs and herewith come to a similarity judgment. As a step toward filling
this gap the study reported in this paper strives to identify factors which
influence the similarity perception of DAGs. In particular, we conducted a
card-sorting study employing a qualitative and quantitative analysis approach
to identify 1) groups of DAGs that are perceived as similar by the participants
and 2) the reasons behind their choice of groups. Our results suggest that
similarity is mainly influenced by the number of levels, the number of nodes on
a level, and the overall shape of the graph.Comment: Graph Drawing 2017 - arXiv Version; Keywords: Graphs, Perception,
Similarity, Comparison, Visualizatio
Spatially Resolved Magnetic Field Structure in the Disk of a T Tauri Star
Magnetic fields in accretion disks play a dominant role during the star
formation process but have hitherto been observationally poorly constrained.
Field strengths have been inferred on T Tauri stars themselves and possibly in
the innermost part of the accretion disk, but the strength and morphology of
the field in the bulk of the disk have not been observed. Unresolved
measurements of polarized emission (arising from elongated dust grains aligned
perpendicular to the field) imply average fields aligned with the disks.
Theoretically, the fields are expected to be largely toroidal, poloidal, or a
mixture of the two, which imply different mechanisms for transporting angular
momentum in the disks of actively accreting young stars such as HL Tau. Here we
report resolved measurements of the polarized 1.25 mm continuum emission from
HL Tau's disk. The magnetic field on a scale of 80 AU is coincident with the
major axis (~210 AU diameter) of the disk. From this we conclude that the
magnetic field inside the disk at this scale cannot be dominated by a vertical
component, though a purely toroidal field does not fit the data well either.
The unexpected morphology suggests that the magnetic field's role for the
accretion of a T Tauri star is more complex than the current theoretical
understanding.Comment: Accepted for publication in Natur
[89Zr]Oxinate4 for long-term in vivo cell tracking by positron emission tomography
Purpose 111In (typically as [111In]oxinate3) is a gold standard
radiolabel for cell tracking in humans by scintigraphy. A long
half-life positron-emitting radiolabel to serve the same purpose
using positron emission tomography (PET) has long
been sought. We aimed to develop an 89Zr PET tracer for cell
labelling and compare it with [111In]oxinate3 single photon
emission computed tomography (SPECT).
Methods [89Zr]Oxinate4 was synthesised and its uptake and
efflux were measured in vitro in three cell lines and in human
leukocytes. The in vivo biodistribution of eGFP-5T33 murine
myeloma cells labelled using [89Zr]oxinate4 or [111In]oxinate3
was monitored for up to 14 days. 89Zr retention by living
radiolabelled eGFP-positive cells in vivo was monitored by
FACS sorting of liver, spleen and bone marrow cells followed
by gamma counting.
Results Zr labelling was effective in all cell types with yields
comparable with 111In labelling. Retention of 89Zr in cells
in vitro after 24 h was significantly better (range 71 to
>90 %) than 111In (43–52 %). eGFP-5T33 cells in vivo
showed the same early biodistribution whether labelled with
111In or 89Zr (initial pulmonary accumulation followed by
migration to liver, spleen and bone marrow), but later translocation
of radioactivity to kidneys was much greater for 111In.
In liver, spleen and bone marrow at least 92 % of 89Zr
remained associated with eGFP-positive cells after 7 days
in vivo.
Conclusion [89Zr]Oxinate4 offers a potential solution to the
emerging need for a long half-life PET tracer for cell tracking
in vivo and deserves further evaluation of its effects on survival
and behaviour of different cell types
Influence of inspiratory resistive loading on expiratory muscle fatigue in healthy humans
Expiratory resistive loading elicits inspiratory as well as expiratory muscle fatigue, suggesting parallel co-activation of the inspiratory muscles during expiration. It is unknown whether the expiratorymuscles are similarly co-activated to the point of fatigue during inspiratory resistive loading (IRL).The purpose of this study was to determine whether IRL elicits expiratory as well as inspiratory muscle fatigue. Healthy male subjects (n=9) underwent isocapnic IRL (60% maximal inspiratory pressure, 15 breaths∙min-1, 0.7 inspiratory duty cycle) to task failure. Abdominal and diaphragm contractile function was assessed at baseline and at 3, 15 and 30 min post-IRL by measuring gastric twitch pressure (Pga,tw) and transdiaphragmatic twitch pressure (Pdi,tw) in response to potentiated magnetic stimulation of the thoracic and phrenic nerves, respectively. Fatigue was defined as a significant reduction from baseline in Pga,tw or Pdi,tw. Throughout IRL, there was a time-dependent increase in cardiac frequency and mean arterial blood pressure, suggesting activation of the respiratory muscle metaboreflex. Pdi,tw was significantly lower than baseline (34.3 9.6 cmH2O) at 3min (23.2 5.7 cmH2O, P<0.001), 15 min (24.2 5.1 cmH2O, P<0.001) and 30 min post-IRL (26.3 6.0 cmH2O, P<0.001). Pga,tw was not significantly different from baseline (37.6 17.1 cmH2O) at 3min (36.5 14.6 cmH2O), 15 min (33.7 12.4 cmH2O) and 30 min post-IRL (32.9 11.3 cmH2O). IRL elicits objective evidence of diaphragm, but not abdominal, muscle fatigue. Agonist-antagonist interactions for the respiratory muscles appear to be more important during expiratory versus inspiratory loading.The Natural Sciences and Engineering Research Council (NSERC) of Canada supported this study. C.M. Peters, P.B. Dominelli, and Y. Molgat-Seon were supported by NSERC postgraduate scholarships. J.F Welch was supported by a University of British Columbia graduate fellowship
Adipocyte-specific protein tyrosine phosphatase 1B deletion increases lipogenesis, adipocyte cell size and is a minor regulator of glucose homeostasis
Peer reviewedPublisher PD
A cluster randomized controlled trial of the effectiveness and cost-effectiveness of Intermediate Care Clinics for Diabetes (ICCD) : study protocol for a randomized controlled trial
Background
World-wide healthcare systems are faced with an epidemic of type 2 diabetes. In the United Kingdom, clinical care is primarily provided by general practitioners (GPs) rather than hospital specialists. Intermediate care clinics for diabetes (ICCD) potentially provide a model for supporting GPs in their care of people with poorly controlled type 2 diabetes and in their management of cardiovascular risk factors. This study aims to (1) compare patients with type 2 diabetes registered with practices that have access to an ICCD service with those that have access only to usual hospital care; (2) assess the cost-effectiveness of the intervention; and (3) explore the views and experiences of patients, health professionals and other stakeholders.
Methods/Design
This two-arm cluster randomized controlled trial (with integral economic evaluation and qualitative study) is set in general practices in three UK Primary Care Trusts. Practices are randomized to one of two groups with patients referred to either an ICCD (intervention) or to hospital care (control).
Intervention group: GP practices in the intervention arm have the opportunity to refer patients to an ICCD - a multidisciplinary team led by a specialist nurse and a diabetologist. Patients are reviewed and managed in the ICCD for a short period with a goal of improving diabetes and cardiovascular risk factor control and are then referred back to practice.
or
Control group: Standard GP care, with referral to secondary care as required, but no access to ICCD.
Participants are adults aged 18 years or older who have type 2 diabetes that is difficult for their GPs to control. The primary outcome is the proportion of participants reaching three risk factor targets: HbA1c (≤7.0%); blood pressure (<140/80); and cholesterol (<4 mmol/l), at the end of the 18-month intervention period. The main secondary outcomes are the proportion of participants reaching individual risk factor targets and the overall 10-year risks for coronary heart disease(CHD) and stroke assessed by the United Kingdom Prospective Diabetes Study (UKPDS) risk engine. Other secondary outcomes include body mass index and waist circumference, use of medication, reported smoking, emotional adjustment, patient satisfaction and views on continuity, costs and health related quality of life. We aimed to randomize 50 practices and recruit 2,555 patients
- …