406 research outputs found
NOISE REMOVAL FOR PIECEWISE POLYNOMIAL SIGNALS BASED ON PARTICAL SWARM OPTIMİZATION
Parçalı sürekli yapıdaki sinyallerin üzerindeki gürültünün bastırımı amacıyla parçacık sürüsü optimizasyon tekniğinin kullanıldığı bir teknik geliştirilmiştir. Model sinyal olarak parçaların başlangıç noktaları ve her bir parçanın az sayıda parametreyle tanımlandığı bir sinyal kümesi kullanılmıştır. Önerilen yaklaşımda, parça sayısının bilindiği durumda yerel en iyi konumlandırmalardan kaçınmak amacıyla, parçalar arasındaki optimal geçiş sınırları Parçacık Sürüsü Optimizasyonu (PSO) ile bulunur. Her bir parça içerisindeki sinyal parametreleri ise optimal geçiş sınırlarına bağlı olarak En Büyük Olabilirlik (EBO) kestirimiyle elde edilir. Önerilen algoritma geçiş sınırlarının sayısı bilinmediği durumlarda kullanılabilecek şekilde genelleştirilmiştir. Sıklıkla kullanılan ve başarımı yüksek diğer tekniklerle yapılan kıyaslama sonunda önerilen tekniğin önemli başarım artışı sağladığı gösterilmiştir. Piecewise smooth signal denoising is cast as a non-linear optimization problem in terms of transition boundaries and a parametric signal family. To avoid locally optimal placement of boundaries, optimal positions of transition boundaries for a given number of transitions are obtained by using particle swarm optimization. The piecewise smooth section parameters are obtained as the maximum likelihood estimates conditioned on the optimal transition boundaries. The proposed algorithm is extended to the case where the number of transition boundaries are unknown by sequentially increasing number of sections until the residual error is at the level of noise standard deviation. Performance comparison with the state of the art techniques reveals the important advantages of the proposed technique
Changes in novel gastrointestinal and renal injury markers in the blood plasma of sheep following increasing intravenous doses of tolfenamic acid
The administration of high doses of non-steroidal anti-inflammatory drugs (NSAID), such as tolfenamic acid (TA), has undesirable effects on different organs. Some novel biomarkers have been reported that can determine the gastrointestinal and renal injury caused by a high dose of NSAIDs or other toxic substances. This study was aimed at determining the changes in gastrointestinal (TFF2 and HYP), renal (NGAL and KIM-1) and cardiac (cTn-I, CK-MB) injury markers after the use of increasing intravenous doses of TA in sheep. TA was administered intravenously to groups of six sheep each, at the dose levels of 0 (Group 0, i.e., G0), 2 (G2), 4 (G4), 8 (G8) and 16 (G16) mg/kg. The concentrations of the studied biomarkers were measured at 3, 9, 18 and 36 h after administration of TA. The TFF2 and NGAL concentrations in G16 were found to be significantly higher (P < 0.05) than in the other groups except for G8 at different sampling times. HYP concentration in G16 was observed to be significantly (P < 0.05) lower than that in all other groups at 36 h. KIM-1 level in G16 was significantly (P < 0.05) higher than in all other groups at different sampling times. An increase in the renal markers, KIM-1 and NGAL, in G8 was observed before any change in plasma creatinine and urea. The cardiac marker cTn-I in G16 was significantly (P < 0.05) higher than in other groups at different sampling times. The results showed that the novel biomarkers (HYP, TFF2, NGAL, and KIM-1) can be used to determine gastric and renal injury in sheep
Doxycycline plus streptomycin versus ciprofloxacin plus rifampicin in spinal brucellosis [ISRCTN31053647]
Background: The optimal treatment regimen and duration of the therapy is still controversial in spinal brucellosis. The aim of this study is to compare the efficacy, adverse drug reactions, complications and cost of ciprofloxacin plus rifampicin versus doxycycline plus streptomycin in the treatment of spinal brucellosis
Gastroenterology Cases of Cutaneous Leukocytoclastic Vasculitis
Rarely, leukocytoclastic vasculitis can result from ischemic colitis, inflammatory bowel disease, and cryoglobulinemia. There is no established standard for the treatment of leukocytoclastic vasculitis associated with gastroenterologic diseases. This paper presents three cases of leukoytoclastic vasculitis, each of which is associated with a different gastroenterologic condition: ischemic colitis, Crohn’s disease, and chronic hepatitis C. Each condition went into remission by treatment of leukocytoclastic vasculitis, regardless of the underlying disease
Relationship between carotid intima-media thickness and coronary angiographic findings: a prospective study
<p>Abstract</p> <p>Background</p> <p>Since cardiovascular diseases are associated with high mortality and generally undiagnosed before the onset of clinical findings, there is a need for a reliable tool for early diagnosis. Carotid intima-media thickness (CIMT) is a non-invasive marker of coronary artery disease (CAD) and is widely used in practice as an inexpensive, reliable, and reproducible method. In the current study, we aimed to investigate prospectively the relationship of CIMT with the presence and extent of significant coronary artery narrowing in patients evaluated by coronary angiography for stable angina pectoris.</p> <p>Methods</p> <p>One hundred consecutive patients with stable angina pectoris and documented ischemia on a stress test were included in the study. The patients were divided into two groups according to the result of the coronary angiography: group 1 (39 patients) without a noncritical coronary lesion, and group 2 (61 patients) having at least one lesion more than 50% within the main branches of the coronary arteries. All of the patients underwent carotid Doppler ultrasound examination for measurement of the CIMT by a radiologist blinded to the angiographic data.</p> <p>Results</p> <p>The mean CIMT was 0.78 ± 0.21 mm in Group 1, while it was 1.48 ± 0.28 mm in Group 2 (p = 0.001). The mean CIMT in patients with single vessel disease, multi-vessel disease, and left main coronary artery disease were significantly higher compared to Group 1 (1.2 ± 0.34 mm, p = 0.02; 1.6 ± 0.32 mm, p = 0.001; and 1.8 ± 0.31 mm, p = 0.0001, respectively). Logistic regression analysis identified CIMT (OR 4.3, p < 0.001) and hypertension (OR 2.4, p = 0.04) as the most important factors for predicting CAD.</p> <p>Conclusions</p> <p>The findings of this study show that increase in CIMT is associated with the presence and extent of CAD. In conclusion, we demonstrated the usefulness of carotid intima-media thickness in predicting coronary artery disease but large-scale studies are required to define its role in clinical practice.</p
Seismic Constraints on Helium Abundances from the TESS Southern CVZ
Poster for Cool Stars 21
Stellar helium abundances strongly determine their structure and evolution. However, since helium cannot be detected directly in the photospheres of cool stars, helium abundances are one of the most poorly-constrained inputs to stellar models. It is therefore typical to assume a relationship with the initial abundances of other heavy elements, typically of linear form described by a gradient ΔY/ΔZ. Attempts to determine from globular-cluster stellar populations and Galactic H-II regions have so far not yielded any consensus about empirically reasonable values of ΔY/ΔZ, or, for that matter, even whether such a linear relation is observationally justifiable. Separately, asteroseismology permits the inference of stellar helium abundances, either directly through acoustic-glitch measurements, or indirectly through the forward modelling of stellar oscillation mode frequencies. Using constraints on the initial helium abundance derived from ensemble asteroseismology and stellar forward modelling against individual mode frequencies of a collection of field stars in the TESS, Kepler, and K2 fields, we characterise the helium-metallicity relation of the brightest cool stars in the solar neighbourhood. We find a large spread of seismic initial helium abundances for any given metallicity, rather than a single well-defined linear enrichment law
Catheter-related bacteremia due to Kocuria rosea in a patient undergoing peripheral blood stem cell transplantation
BACKGROUND: Micrococcus species may cause intracranial abscesses, meningitis, pneumonia, and septic arthritis in immunosuppressed or immunocompetent hosts. In addition, strains identified as Micrococcus spp. have been reported recently in infections associated with indwelling intravenous lines, continuous ambulatory peritoneal dialysis fluids, ventricular shunts and prosthetic valves. CASE PRESENTATION: We report on the first case of a catheter-related bacteremia caused by Kocuria rosea, a gram-positive microorganism belonging to the family Micrococcaceae, in a 39-year-old man undergoing peripheral blood stem cell transplantation due to relapsed Hodgkin disease. This uncommon pathogen may cause opportunistic infections in immunocompromised patients. CONCLUSIONS: This report presents a case of Kocuria rosea catheter related bacteremia after stem cell transplantation successfully treated with vancomycin and by catheter removal
Sepsis and Meningitis due to Listeria Monocytogenes
Purpose: This study focused on the effect of immuno-compromising conditions on the clinical presentation of severe listerial infection. Patients and Methods: Nine human listeriosis cases seen from 1991-2002 were reviewed. All adult patients, from whose blood, peritoneal fluid or cerebrospinal fluid (CSF) the L. monocytogenes was isolated, were included in this retrospective study. Results: Listeriosis presented as primary sepsis with positive blood cultures in 5 cases and meningitis with positive CSF cultures in 4 cases. All of these patients had at least one underlying disease, most commonly, hematologic malignancy, diabetes mellitus, amyloidosis and hepatic cirrhosis; 55.6% had received immunosuppressive or corticosteroid therapy within a week before the onset of listeriosis. The patients were adults with a mean age of 60 years. Fever, night sweats, chills and lethargy were the most common symptoms; high temperature (> 38 degrees C), tachycardia, meningeal signs and poor conditions in general were the most common findings on admission. The mortality rate was 33.3% and was strictly associated with the severity of the underlying disease. Mortality differences were significant between sepsis (20%) and meningitis (50%) patients. Conclusion: Listeriosis as an uncommon infection in our region and that immunesuppressive therapy is an important pre-disposing factor of listeriosis. Sepsis and meningitis were more common in this group of patients and had the highest case-fatality rate for food-bome illnesses
TESS Asteroseismology of Mensae: Benchmark Ages for a G7 Dwarf and its M-dwarf Companion
Asteroseismology of bright stars has become increasingly important as a
method to determine fundamental properties (in particular ages) of stars. The
Kepler Space Telescope initiated a revolution by detecting oscillations in more
than 500 main-sequence and subgiant stars. However, most Kepler stars are
faint, and therefore have limited constraints from independent methods such as
long-baseline interferometry. Here, we present the discovery of solar-like
oscillations in Men A, a naked-eye (V=5.1) G7 dwarf in TESS's Southern
Continuous Viewing Zone. Using a combination of astrometry, spectroscopy, and
asteroseismology, we precisely characterize the solar analog alpha Men A (Teff
= 5569 +/- 62 K, R = 0.960 +/- 0.016 Rsun, M = 0.964 +/- 0.045 Msun). To
characterize the fully convective M dwarf companion, we derive empirical
relations to estimate mass, radius, and temperature given the absolute Gaia
magnitude and metallicity, yielding M = 0.169 +/- 0.006, R = 0.19 +/- 0.01 and
Teff = 3054 +/- 44 K. Our asteroseismic age of 6.2 +/- 1.4 (stat) +/- 0.6 (sys)
Gyr for the primary places Men B within a small population of M dwarfs
with precisely measured ages. We combined multiple ground-based spectroscopy
surveys to reveal an activity cycle of 13.1 +/- 1.1 years, a period similar to
that observed in the Sun. We used different gyrochronology models with the
asteroseismic age to estimate a rotation period of ~30 days for the primary.
Alpha Men A is now the closest (d=10pc) solar analog with a precise
asteroseismic age from space-based photometry, making it a prime target for
next-generation direct imaging missions searching for true Earth analogs.Comment: Accepted to The Astrophysical Journal; 15 pages, 10 figure
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