1,941 research outputs found
A new source detection algorithm using FDR
The False Discovery Rate (FDR) method has recently been described by Miller
et al (2001), along with several examples of astrophysical applications. FDR is
a new statistical procedure due to Benjamini and Hochberg (1995) for
controlling the fraction of false positives when performing multiple hypothesis
testing. The importance of this method to source detection algorithms is
immediately clear. To explore the possibilities offered we have developed a new
task for performing source detection in radio-telescope images, Sfind 2.0,
which implements FDR. We compare Sfind 2.0 with two other source detection and
measurement tasks, Imsad and SExtractor, and comment on several issues arising
from the nature of the correlation between nearby pixels and the necessary
assumption of the null hypothesis. The strong suggestion is made that
implementing FDR as a threshold defining method in other existing
source-detection tasks is easy and worthwhile. We show that the constraint on
the fraction of false detections as specified by FDR holds true even for highly
correlated and realistic images. For the detection of true sources, which are
complex combinations of source-pixels, this constraint appears to be somewhat
less strict. It is still reliable enough, however, for a priori estimates of
the fraction of false source detections to be robust and realistic.Comment: 17 pages, 7 figures, accepted for publication by A
An adolescent with recurrent ankle swelling
A 14-year-old girl was admitted to our institute with a history of intermittent bilateral ankle swelling, and moderate but progressively worsening pain which has lasted for 2 years. The patient's history was unremarkable. She did not take medications and was not involved in any sports activity. She reported no fever, gastrointestinal symptoms, fatigue, weight loss, travels abroad or previous infections. She reported moderate pain at night, associated with a sense of heaviness, tightness and general discomfort, and with no response to ibuprofen. Physical examination was remarkable only for bilateral ankle non-pitting oedema, more evident on the left leg, with a thickened skinfold at the base of the second toe, and without redness, swelling or skin warming. The patient had been previously examined, and her foot and ankle X-rays, ultrasound (US) and MRI were all negative. Blood tests (white cell count, C reactive protein, erythrocyte sedimentation rate, albumin, antinuclear antibodies, creatinine, transaminase, creatine kinase, lactate dehydrogenase, thyroid function and glucose) and urinalysis were in the normal range. Her ocular assessment and echocardiogram were also normal. Question 1: Based on the clinical picture and laboratory tests, what is the most likely diagnosis? Deep venous thrombosis. Osteochondritis. Lymphoedema. Juvenile idiopathic arthritis. Question 2: Based on what you see infigure 1, what is the underlying cause? Recurrent bacterial lymphangitis. Primary lymphoedema. Tumour. Filariasis. Figure 1 Lymphoscintigraphy of the lower extremities showing insufficient deep lymphatic circulation in the left leg (red arrow, A) replaced by superficial drainage (B). Question 3: Which is the best diagnostic test to confirm the diagnosis? US scan. MRI. Lymphoscintigraphy. Reassurance and clinical follow-up. Question 4: What is the mainstay of management of this condition? Wait and see. Antibiotic course. Supportive therapy (ie, physical activity, elevation of extremities, pneumatic compression). Surgical intervention. Answers can be found on page 2
Compositional and Morphological Characterization of ‘Sorrento’ and ‘Chandler’ Walnuts
In Italy, most of the cultivated walnuts belong to the Sorrento ecotype, and they are
considered commercially valuable due to their specific organoleptic characteristics. The aim of this
study is to evaluate and compare the morphological and compositional characteristics of walnuts
sampled from ‘Sorrento’ trees cultivated in different locations in Campania and trees of both the
‘Chandler’ and ‘Sorrento’ varieties derived from the same location. The results demonstrated that
‘Sorrento’ and ‘Chandler’ walnuts have different biometric characteristics and a different fat content,
with the highest fat content being found in the ‘Sorrento’ variety. Regarding the fatty acid (FA)
composition, the content of monounsaturated and saturated fatty acids (MUFAs and SFAs) was
highest in the ‘Sorrento’ variety (from 13 to 15% for MUFAs and from 11 to 13% for SFAs), while
the polyunsaturated fatty acids (PUFAs) content was highest in the ‘Chandler’ variety (77%). The
total phenolics content (TPC) was highest in the ‘Sorrento’ variety (from 910 to 1230 mg GAE/100 g),
while no difference in γ-tocopherol content was found. Furthermore, the influence of walnut area
cultivation was shown for fat content, FA composition and TPC. Therefore, both walnut varieties
demonstrated good nutritional properties considering the PUFAs and γ-tocopherol conten
Modeling the effects of climate and land use change on carbon and trace gas budgets over the Amazon Region using NASA satellite products.
Abstract ID: 14. Publicado também on-line
Biphoton compression in standard optical fiber: exact numerical calculation
Generation of two-photon wavepackets, produced by spontaneous parametric down
conversion in crystals with linearly chirped quasi-phase matching grating, is
analyzed. Although being spectrally broad, two-photon wavepackets produced this
way are not Fourier transform limited. In the paper we discuss the temporal
compression of the wavepackets, exploiting the insertion of a standard optical
fiber in the path of one of the two photons. The effect is analyzed by means of
full numerical calculation and the exact dispersion dependencies in both the
crystal and the fiber are considered. The study opens the way to the practical
realization of this idea.Comment: 10 pages, 16 figure
An Expert Opinion on the Role of the Rosuvastatin/Amlodipine Single Pill Fixed Dose Combination in Cardiovascular Prevention
Current cardiovascular disease prevention strategies are based on the management of cardiovascular risk as a continuum, redefining the therapeutic goals for each individual based on the estimated global risk profile. Given the frequent clustering of the principal cardiovascular risk factors, such as hypertension, diabetes and dyslipidaemia, in the same individual, patients are required to take multiple drugs to achieve therapeutic targets. The adoption of single pill fixed dose combinations may contribute to achieve better control of blood pressure and cholesterol compared to the separate administration of the individual drugs, mostly due to better adherence related to therapeutic simplicities. This paper reports the outcomes of an Expert multidisciplinary Roundtable. In particular, the rational and potential clinical use of the single pill fixed dose combination "Rosuvastatin-Amlodipine" for the management of concomitant hypertension/hypercholesterolemia in different clinical fields are discussed. This Expert Opinion also illustrates the importance of an early and effective management of total cardiovascular risk, highlights the substantial benefits of combining blood pressure and lipid-lowering treatments in a single-pill fixed dose combination and attempts to identify and overcome the barriers to the implementation in clinical practice of the fixed dose combinations with dual targets. This Expert Panel identifies and proposes the categories of patients who may benefit the most from this fixed dose combination
Mesoscopic description of the annealed Ising model and Multiplicative noise
A new type of Langevin equation exhibiting a non trivial phase transition
associated with the presence of multiplicative noise is introduced. The
equation is derived as a mesoscopic representation of the microscopic annealed
Ising model (AIM) proposed by Thorpe and Beeman, and reproduces perfectly its
basic phenomenology. The AIM exhibits a non-trivial behavior as the temperature
is increased, in particular it presents a disorder-to-order phase transition at
low temperatures, and a order-to-disorder transition at higher temperatures.
This behavior resembles that of some Langevin equations with multiplicative
noise, which exhibit also two analogous phase transitions as the
noise-amplitude is increased. By comparing the standard models for
noise-induced transitions with our new Langevin equation we elucidate that the
mechanisms controlling the disorder-to-order transitions in both of them are
essentially different, even though for both of them the presence of
multiplicative noise is a key ingredient.Comment: Submitted to Phys. Rev.
Workplace violence in Queensland, Australia: the results of a comparative study
[Abstract]: This paper presents the results on workplace violence from a larger study undertaken in 2004. Comparison is made with the results of a similar study undertaken in 2001. The study involved the random sampling of 3000 nurses from the Queensland Nurses’ Union’s membership in the public (acute hospital and community nursing), private (acute hospital and domiciliary nursing) and aged care sectors (both public and private aged care facilities). The self-reported results suggest an increase in workplace violence in all three sectors. Whilst there are differences in the sources of workplace violence across the sectors, the major causes of workplace violence are: clients/patients, visitors/relatives, other nurses, nursing management and medical practitioners. Associations were also found between workplace violence and gender, the designation of the nurse, hours of employment, the age of the nurse, morale and perceptions of workplace safety. Whilst the majority of nurses reported that policies were in place for the management of workplace violence, these policies were not always adequate
Terrestrial Carbon Sinks in the Brazilian Amazon and Cerrado Region Predicted from MODIS Satellite Data and Ecosystem Modeling
A simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000-2004. Net ecosystem production (NEP) flux for atmospheric CO2 in the region for these years was estimated. Consistently high carbon sink fluxes in terrestrial ecosystems on a yearly basis were found in the western portions of the states of Acre and Rondonia and the northern portions of the state of Par a. These areas were not significantly impacted by the 2002-2003 El Nino event in terms of net annual carbon gains. Areas of the region that show periodically high carbon source fluxes from terrestrial ecosystems to the atmosphere on yearly basis were found throughout the state of Maranhao and the southern portions of the state of Amazonas. As demonstrated though tower site comparisons, NEP modeled with monthly MODIS Enhanced Vegetation Index (EVI) inputs closely resembles the measured seasonal carbon fluxes at the LBA Tapajos tower site. Modeling results suggest that the capacity for use of MODIS Enhanced Vegetation Index (EVI) data to predict seasonal uptake rates of CO2 in Amazon forests and Cerrado woodlands is strong
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