5,477 research outputs found
Regulating the Timing of Development: Takings Clause and Substantive Due Process Challenges to Growth Control Regulations
Large amounts of optically-obscured star formation in the host galaxies of some type-2 quasars
We present Hubble Space Telescope images, and spectral energy distributions
from optical to infrared wavelengths for a sample of six 0.3<z<0.8 type-2
quasars selected in the mid-infrared using data from the Spitzer Space
Telescope. All the host galaxies show some signs of disturbance. Most seem to
possess dusty, star-forming disks. The disk inclination, estimated from the
axial ratio of the hosts, correlates with the depth of the silicate feature in
the mid-infrared spectra, implying that at least some of the reddening towards
the AGN arises in the host galaxy. The star formation rates in these objects,
as inferred from the strengths of the PAH features and far-infrared continuum,
range from 3-90 Msun/yr, but are mostly much larger than those inferred from
the [OII]3727 emission line luminosity, due to obscuration. Taken together with
studies of type-2 quasar hosts from samples selected in the optical and X-ray,
this is consistent with previous suggestions that two types of extinction
processes operate within the type-2 quasar population, namely a component due
to the dusty torus in the immediate environment of the AGN, and a more extended
component due to a dusty, star forming disk.Comment: 5 pages, 3 figures. Accepted by ApJ Letter
Spatio-temporal Patterns of Pre-harvest Brown Rot Epidemics within Individual Peach Tree Canopies
Tree canopies are architecturally complex and pose several challenges for measuring and character-izing spatial patterns of disease. Recently developed methods for fine-scale canopy mapping and three-dimensional spatial pattern analysis were applied in a 3-year study to characterize spatio-temporal development of pre-harvest brown rot of peach, caused by Monilinia fructicola, in 13 trees of different maturity classes. We observed a negative correlation between an index of disease aggregation and disease incidence in the same tree (r = −0.653, P \u3c 0.0001), showing that trees with higher brown rot incidence had lower aggregation of affected fruit in their canopies. Significant (P ≤ 0.05) within-canopy aggregation among symptomatic fruit was most pronounced for early-maturing cultivars and/or early in the epidemic. This is consistent with the notion of a greater importance of localized, within-tree sources of inoculum at the beginning of the epidemic. Four of five trees having \u3e10 blossom blight symptoms per tree showed a significant positive spatial association of pre-harvest fruit rot to blossom blight within the same canopy. Spatial association analyses further revealed one of two out-comes for the association of new fruit rot symptoms with previous fruit rot symptoms in the same tree, whereby the relationship was either not significant or exhibited a significant negative associa-tion. In the latter scenario, the newly diseased fruit were farther apart from previously symptomatic fruit than expected by random chance. This unexpected result could have been due to uneven fruit ripening in different sectors of the canopy, which could have affected the timing of symptom devel-opment and thus led to negative spatial associations among symptoms developing over time in a tree
Spatio-temporal Patterns of Pre-harvest Brown Rot Epidemics within Individual Peach Tree Canopies
Tree canopies are architecturally complex and pose several challenges for measuring and character-izing spatial patterns of disease. Recently developed methods for fine-scale canopy mapping and three-dimensional spatial pattern analysis were applied in a 3-year study to characterize spatio-temporal development of pre-harvest brown rot of peach, caused by Monilinia fructicola, in 13 trees of different maturity classes. We observed a negative correlation between an index of disease aggregation and disease incidence in the same tree (r = −0.653, P \u3c 0.0001), showing that trees with higher brown rot incidence had lower aggregation of affected fruit in their canopies. Significant (P ≤ 0.05) within-canopy aggregation among symptomatic fruit was most pronounced for early-maturing cultivars and/or early in the epidemic. This is consistent with the notion of a greater importance of localized, within-tree sources of inoculum at the beginning of the epidemic. Four of five trees having \u3e10 blossom blight symptoms per tree showed a significant positive spatial association of pre-harvest fruit rot to blossom blight within the same canopy. Spatial association analyses further revealed one of two out-comes for the association of new fruit rot symptoms with previous fruit rot symptoms in the same tree, whereby the relationship was either not significant or exhibited a significant negative associa-tion. In the latter scenario, the newly diseased fruit were farther apart from previously symptomatic fruit than expected by random chance. This unexpected result could have been due to uneven fruit ripening in different sectors of the canopy, which could have affected the timing of symptom devel-opment and thus led to negative spatial associations among symptoms developing over time in a tree
IMAGE PRE-PROCESSING STRATEGIES FOR ENHANCING PHOTOGRAMMETRIC 3D RECONSTRUCTION OF UNDERWATER SHIPWRECK DATASETS
Although underwater photogrammetry has become widely adopted, there are still significant unresolved issues that are worthy of attention. This article focuses on the 3D model generation of underwater shipwrecks and intends explicitly to address the problem of dealing with sub-optimal datasets. Even if the definition of best practices and standards to be adopted during the acquisition phase appears to be crucial, there is a massive amount of data gathered so far by professionals and the scientific community all over the world that cannot be ignored. The compelling idea is to attempt to achieve the best reconstruction results possible, even from sub-optimal or less-than-ideal image datasets. This work focuses on the investigation of different strategies and approaches for balancing the quality of the photogrammetric products, without neglecting their reliability concerning the surveyed object. The case study of this research is the Mandalay MHT, a 34 m long steel-hulled auxiliary schooner that sank in 1966 and now lies in the Biscayne National Park (Florida - USA). The dataset has been provided by the Submerged Resources Center (SRC) of the US National Park Service, in order to develop an experimental image enhancement method functional to the virtualization and visualization of the generated products, as a part of a sustainable, affordable, and reliable method of studying submerged artefacts and sites. The original images have been processed using different image enhancement approaches, and the outputs have been compared and analysed
On the breaking of collinear factorization in QCD
We investigate the breakdown of collinear factorization for non-inclusive
observables in hadron-hadron collisions. For pure QCD processes, factorization
is violated at the three-loop level and it has a structure identical to that
encountered previously in the case of super-leading logarithms. In particular,
it is driven by the non-commutation of Coulomb/Glauber gluon exchanges with
other soft exchanges. Beyond QCD, factorization may be violated at the two-loop
level provided that the hard subprocess contains matrix element contributions
with phase differences between different colour topologies.Comment: Version 2: minor improvements for journal publicatio
The Claims Culture: A Taxonomy of Industry Attitudes
This paper presents an analysis of a familiar aspect of construction industry culture that we have dubbed 'the claims culture'. This is a culture of contract administration that lays a strong emphasis on the planning and management of claims. The principal elements of the analysis are two sets of distinctions. The first comprises economic and occupational orders, referring to two kinds of control that are exercised over the construction process; predicated respectively on economic ownership and occupational competence. The second refers to contrasting attitudes towards relationships and problem solving within these orders: respectively 'distributive' and 'integrative'. The concepts of economic and occupational order entail further sub-categories. The various attitudes associated with these categories and sub-categories are described. They are assessed as to their consequences for change initiatives in the industry
High dose, dose-intensive chemotherapy with doxorubicin and cyclophosphamide for the treatment of advanced breast cancer.
Eighteen patients with advanced breast cancer were commenced on treatment with high dose doxorubicin (100 mg m-2) or doxorubicin (100 mg m-2) and cyclophosphamide (500 mg m-2) at 2 weekly intervals. Three cycles of treatment were planned. rG-CSF was given subcutaneously for 10 days, starting 24 h after each cycle of chemotherapy. Sixteen out of 18 patients responded (89%) of whom six (33%) achieved a complete remission. Twelve (67%) completed the three planned cycles, four (22%) received two cycles and two (11%) received one cycle only. The median time to progression was 5 1/2 months and the median survival was 18 1/2 months. Neutropenia occurred after 89% of courses and 65% of courses were accompanied by a significant (WHO grade III or IV) infection. The duration of neutropenia was short (mean 5.4 days) and mean time to absolute neutrophil count recovery (ANC > 1,000 x 10(6) litre) from the start of treatment was 11 days. Moderate to severe epithelial toxicity (WHO grade 3 or 4) accompanied 43% of courses and was dose limiting. Conclusion: High dose, dose intensive chemotherapy has an excellent initial therapeutic effect in advanced breast cancer but does not prolong duration of remission or overall survival beyond that of standard treatment. Although subcutaneous rG-CSF curtailed the expected duration of neutropenia substantially, the overall incidence of neutropenia and of infections requiring intravenous antibiotics was high. Furthermore, almost half of the courses were complicated by moderate to severe oral mucositis and/or mild to moderate palmar and plantar inflammation. The lack of survival benefit and excess toxicity seriously limits the wider application of this regime. It should not be used in place of standard dose palliative chemotherapy for metastatic breast cancer
Gender differences in the Force Concept Inventory for different educational levels in the United Kingdom
The Force Concept Inventory (FCI) is widely used to investigate the effect of education level on conceptual understanding of Newtonian mechanics but has only recently been scrutinized for gender effects and retention. This study examines both the gender gap in first year physics undergraduates compared to the gap for nonphysicists and the FCI retention after three months. All participants were either studying or working at the University of Sheffield in the UK and had completed a similar compulsory level of secondary education. As expected the results show that a greater level of education in physics is associated with a larger average FCI score. However, further analysis shows that there exists a gender gap at all levels of education. The size of the effect of gender is quantified using Cohen’s
d
and ranges from 0.84 to 1.17 which indicates a large effect due to gender for all levels of education. Despite the FCI having been used as a tool to measure learning gains immediately following instruction in Newtonian mechanics there has been little work to investigate whether this increase in FCI score remains after some time has elapsed. Here the increase in FCI scores is found to remain increased after a three month absence of mechanics-related teaching, and that this retention of FCI scores is independent of gender. Despite this, the gender gap still remains large and statistically significant after the three month delay
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