892 research outputs found
Low-scale inflation in a model of dark energy and dark matter
We present a complete particle physics model that explains three major
problems of modern cosmology: inflation, dark matter and dark energy, and also
gives a mechanism for leptogenesis. The model has a new gauge group
that grows strong at a scale eV. We focus on the
inflationary aspects of the model. Inflation occurs with a Coleman-Weinberg
potential at a low scale, down to \sim 6\times 10^5\gev, being compatible
with observational data.Comment: 5 two-column pages, RevTex4; two reference added and minor changes
made in the text; published in JCA
Axions and their Relatives
A review of the status of axions and axion-like particles is given. Special
attention is devoted to the recent results of the PVLAS collaboration, which
are in conflict with the CAST data and with the astrophysical constraints.
Solutions to the puzzle and the implications for new physics are discussed. The
question of axion-like particles being dark matter is also addressed.Comment: Updated version of an invited talk at the Axion Training (CERN,
December 2005). To appear as a Lecture Notes in Physics (Springer-Verlag),
edited by B. Beltran, M. Kuster and G. Raffel
HEMATURIA POR ROTURA DE ANEURISMA ILĂACO-URETERAL.
Arch Esp Urol. 2006 Apr;59(3):287-9.
[Hematuria after ureteral-iliac aneurysm rupture]
[Article in Spanish]
Palacios A, MassĂł P, Osorio L, Oliveira A, Soares J, Marcelo F.
Servicio de UrologĂa, Hospital General de Santo Antonio, Porto, Portugal. [email protected]
Abstract
OBJECTIVE: Ureteral-iliac artery fistula is a rare condition. We perform a bibliographic review and report a case of ureter-iliac artery fistula reviewing its major differential diagnosis.
METHODS: This case-study describes a patient with massive hematuria that presented a ureter-iliac artery fistula secondary to spontaneous rupture of an internal iliac artery aneurysm.
RESULTS: 86 -year-old male patient with history of previous surgery for aneurysm and ureteral catheterization.
CONCLUSIONS: This difficult diagnosis should be thought of in a patient with massive macroscopic hematuria and previous vascular surgery. The treatment is always surgery.
PMID: 16724715 [PubMed - indexed for MEDLIN
ADENOCARCINOMA TĂBULOVELLOSO DE LA PELVIS RENAL. A PROPĂSITO DE UN CASO.
Arch Esp Urol. 2006 Nov;59(9):916-9.
[Tubulovillous adenocarcinoma of the renal pelvis. Case report]
[Article in Spanish]
Palacios A, Lima O, MassĂł P, OsĂłrio L, Versos R, Soares J, Marcelo F.
Servicio de UrologĂa, Hospital Geral de Santo Antonio, Porto, Portugal. [email protected]
Abstract
OBJECTIVE: To present a case of tubulovillous renal pelvis adenocarcinoma.
METHODS/RESULTS: An 81 year-old patient presented at Emergency Department with sepsis. CT scan showed a staghorn calculus with signs suggestive of pyonefrosis. A nephrectomy was performed and pathological exam revealed tubulovillous renal pelvis adenocarcinoma.
CONCLUSIONS: Renal pelvis adenocarcinoma is a rare disease. It is usually accompanied by chronic urinary infections, on inflammatory state and staghorn calculi. The best therapeutic option is nephrectomy and the prognosis is poor.
PMID: 17190219 [PubMed - indexed for MEDLIN
Accurate and efficient gp120 V3 loop structure based models for the determination of HIV-1 co-receptor usage
<p>Abstract</p> <p>Background</p> <p>HIV-1 targets human cells expressing both the CD4 receptor, which binds the viral envelope glycoprotein gp120, as well as either the CCR5 (R5) or CXCR4 (X4) co-receptors, which interact primarily with the third hypervariable loop (V3 loop) of gp120. Determination of HIV-1 affinity for either the R5 or X4 co-receptor on host cells facilitates the inclusion of co-receptor antagonists as a part of patient treatment strategies. A dataset of 1193 distinct gp120 V3 loop peptide sequences (989 R5-utilizing, 204 X4-capable) is utilized to train predictive classifiers based on implementations of random forest, support vector machine, boosted decision tree, and neural network machine learning algorithms. An <it>in silico </it>mutagenesis procedure employing multibody statistical potentials, computational geometry, and threading of variant V3 sequences onto an experimental structure, is used to generate a feature vector representation for each variant whose components measure environmental perturbations at corresponding structural positions.</p> <p>Results</p> <p>Classifier performance is evaluated based on stratified 10-fold cross-validation, stratified dataset splits (2/3 training, 1/3 validation), and leave-one-out cross-validation. Best reported values of sensitivity (85%), specificity (100%), and precision (98%) for predicting X4-capable HIV-1 virus, overall accuracy (97%), Matthew's correlation coefficient (89%), balanced error rate (0.08), and ROC area (0.97) all reach critical thresholds, suggesting that the models outperform six other state-of-the-art methods and come closer to competing with phenotype assays.</p> <p>Conclusions</p> <p>The trained classifiers provide instantaneous and reliable predictions regarding HIV-1 co-receptor usage, requiring only translated V3 loop genotypes as input. Furthermore, the novelty of these computational mutagenesis based predictor attributes distinguishes the models as orthogonal and complementary to previous methods that utilize sequence, structure, and/or evolutionary information. The classifiers are available online at <url>http://proteins.gmu.edu/automute</url>.</p
ABSCESO DEL PENE. A PROPĂSITO DE UN CASO.
Arch Esp Urol. 2006 Oct;59(8):809-11.
[Penile abscess. Case report]
[Article in Spanish]
Palacios A, MassĂł P, Versos R, Osorio L, Carvalho LF, Soares J, Marcelo F.
Servicio de UrologĂa, Hospital Geral de Santo Antonio, Porto, Portugal. [email protected]
Abstract
OBJECTIVE: To report one case of penile abscess, with special reference to diagnostic and therapeutic aspects.
METHODS: One case of penile abscess is presented in a patient referred for penile swelling.
RESULTS: During surgical exploration it showed to be a corpora cavernosum rupture with drainage of a small volume of purulent fluid.
CONCLUSIONS: Penile abscess is uncommon. High frequency ultrasonography is a reliable diagnostic imaging method. We were able to incise the affected area of the corpus cavernosum and glans safely, and with appropriate antibiotics this patient was treated successfully.
PMID: 17153501 [PubMed - indexed for MEDLIN
Searching for energetic cosmic axions in a laboratory experiment: testing the PVLAS anomaly
Astrophysical sources of energetic gamma rays provide the right conditions
for maximal mixing between (pseudo)scalar (axion-like) particles and photons if
their coupling is as strong as suggested by the PVLAS claim. This is
independent of whether or not the axion interaction is standard at all energies
or becomes supressed in the extreme conditions of the stellar interior. The
flux of such particles through the Earth could be observed using a metre long,
Tesla strength superconducting solenoid thus testing the axion interpretation
of the PVLAS anomaly. The rate of events in CAST caused by axions from the Crab
pulsar is also estimated for the PVLAS-favoured parameters.Comment: 5 pages, 3 figur
Axion-like particles as ultra high energy cosmic rays?
If Ultra High Energy Cosmic Rays (UHECRs) with E>4 10^{19} eV originate from
BL Lacertae at cosmological distances as suggested by recent studies, the
absence of the GZK cutoff can not be reconciled with Standard-Model particle
properties. Axions would escape the GZK cutoff, but even the coherent
conversion and back-conversion between photons and axions in large-scale
magnetic fields is not enough to produce the required flux. However, one may
construct models of other novel (pseudo)scalar neutral particles with
properties that would allow for sufficient rates of particle production in the
source and shower production in the atmosphere to explain the observations. As
an explicit example for such particles we consider SUSY models with light
sgoldstinos.Comment: 5 pages, 2 postscript figures, ref. adde
Use of Non-Steroidal Anti-Inflammatory Drugs That Elevate Cardiovascular Risk: An Examination of Sales and Essential Medicines Lists in Low-, Middle-, and High-Income Countries
PMCID: PMC3570554This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Dilemma of nitrogen management for future food security in sub-Saharan Africa â a review
Article purchased; Published online: 13 July 2017Food security entails having sufficient, safe, and nutritious food to meet dietary needs. The need to optimise nitrogen (N) use for nutrition security while minimising environmental risks in sub-Saharan Africa (SSA) is overdue. Challenges related to managing N use in SSA can be associated with both insufficient use and excessive loss, and thus the continent must address the âtoo littleâ and âtoo muchâ paradox. Too little N is used in food production (80% of countries have N deficiencies), which has led to chronic food insecurity and malnutrition. Conversely, too much N load in water bodies due mainly to soil erosion, leaching, limited N recovery from wastewater, and atmospheric deposition contributes to eutrophication (152 Gg N yearâ1 in Lake Victoria, East Africa). Limited research has been conducted to improve N use for food production and adoption remains low, mainly because farming is generally practiced by resource-poor smallholder farmers. In addition, little has been done to effectively address the âtoo muchâ issues, as a consequence of limited research capacity. This research gap must be addressed, and supportive policies operationalised, to maximise N benefits, while also minimising pollution. Innovation platforms involving key stakeholders are required to address N use efficiency along the food supply chain in SSA, as well as other world regions with similar challenges
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