2,516 research outputs found
A new catalog of photometric redshifts in the Hubble Deep Field
Using the newly available infrared images of the Hubble Deep Field in the J,
H, and K bands and an optimal photometric method, we have refined a technique
to estimate the redshifts of 1067 galaxies. A detailed comparison of our
results with the spectroscopic redshifts in those cases where the latter are
available shows that this technique gives very good results for bright enough
objects (AB(8140) < 26.0). From a study of the distribution of residuals
(Dz(rms)/(1+z) ~ 0.1 at all redshifts) we conclude that the observed errors are
mainly due to cosmic variance. This very important result allows for the
assessment of errors in quantities to be directly or indirectly measured from
the catalog. We present some of the statistical properties of the ensemble of
galaxies in the catalog, and finish by presenting a list of bright
high-redshift (z ~ 5) candidates extracted from our catalog, together with
recent spectroscopic redshift determinations confirming that two of them are at
z=5.34 and z=5.60.Comment: 28 pages, 12PS+4JPEG figures, aaspp style. Accepted for publication
in The Astrophysical Journal. The catalog, together with a clickable map of
the HDF, Tables 4 and 5 (HTML, LaTeX or ASCII format), and the figures, are
available at http://bat.phys.unsw.edu.au/~fsoto/hdfcat.htm
Tennis play intensity distribution and relation with aerobic fitness in competitive players
15 p.Los objetivos de este estudio fueron (1) describir la intensidad relativa del juego de tenis simulado en función del tiempo acumulado en tres zonas de intensidad metabólica y (2) determinar las relaciones entre esta distribución de intensidad de juego y la aptitud aeróbica de un grupo de jugadores competitivos. 20 jugadores masculinos de nivel avanzado a élite (ITN) realizaron una prueba de tenis de resistencia específica en el campo incremental hasta el agotamiento para determinar el consumo máximo de oxígeno (VO2max) y los umbrales de ventilación primero y segundo (VT1, VT2). Los parámetros de ventilación y de intercambio de gases se monitorizaron utilizando un analizador de gas portátil telemétrico (K4 b2, Cosmed, Roma, Italia). Dos semanas después, los participantes jugaron un juego de tenis simulado contra un oponente de nivel similar. Las zonas de intensidad (1: baja, 2: moderada y 3: alta) fueron delimitadas por los valores individuales de VO2 correspondientes a VT1 y VT2, y se expresaron como porcentaje del VO2 máximo y la frecuencia cardíaca. Cuando se expresó en relación con el VO 2 máx. El porcentaje de tiempo de juego en la zona 1 (77 ± 25%) fue significativamente mayor (p <0,001) que en la zona 2 (20 ± 21%) y la zona 3 (3 ± 5%). Se encontraron correlaciones positivas de moderadas a altas entre VT1, VT2 y VO2max, y el porcentaje del tiempo de juego transcurrido en la zona 1 (r = 0,68-0,75), así como las correlaciones inversas de bajas a altas entre las variables metabólicas y el porcentaje de tiempo empleado en las zonas 2 y 3 (r = -0.49–0.75). Los jugadores con mejor aptitud aeróbica juegan a intensidades relativamente más bajas. Concluimos que los jugadores pasaron más del 75% del tiempo en su zona de baja intensidad, con menos del 25% del tiempo dedicado a intensidades moderadas a altas. La aptitud aeróbica parece determinar la intensidad metabólica que los jugadores pueden mantener durante todo el juegoS
Ibuprofen-loaded calcium phosphate granules : combination of innovative characterization methods to relate mechanical strength to drug location
This paper studies the impact of the location of a drug substance on the physicochemical and mechanical properties of two types of calcium phosphate granules loaded with seven different contents of ibuprofen, ranging from 1.75% to 46%. These implantable agglomerates were produced by either low or high shear granulation. Unloaded Mi-Pro pellets presented higher sphericity and mechanical properties, but were slightly less porous than Kenwood granules (57.7% vs 61.2%). Nevertheless, the whole expected quantity of ibuprofen could be integrated into both types of granules. A combination of surface analysis, using near-infrared (NIR) spectroscopy coupling chemical imaging, and pellet porosity, by mercury intrusion measurements, allowed ibuprofen to be located. It was shown that, from 0% to 22% drug content, ibuprofen deposited simultaneously on the granule surface, as evidenced by the increase in surface NIR signal, and inside the pores, as highlighted by the decrease in pore volume. From 22%, porosity was almost filled, and additional drug substance coated the granule surfaces, leading to a large increase in the surface NIR signal. This coating was more regular for Mi-Pro pellets owing to their higher sphericity and greater surface deposition of drug substance. Unit crush tests using a microindenter revealed that ibuprofen loading enhanced the mechanical strength of granules, especially above 22% drug content, which was favorable to further application of the granules as a bone defect filler
Predictors Of Positivity Of [F-18]F-Choline PET-CT In Prostate Cancer Recurrence. Preliminary Results
EP-173
Aim/Introduction: To analyze the validity of [18F]F-Choline PET-CT results in prostate cancer recurrence in our daily practice, based on theoretical cut-off points of prostatespecific antigen (PSA), its kinetic, and PSA doubling time (PSADT), to identify predictors of positivity and modify the indication criteria. Materials and
Methods: Prior to the validity analysis, a descriptive, prospective analysis of consecutive patients with prostate cancer treated with curative intent by radical prostatectomy (RP) or radiotherapy (RT), who underwent PET-CT scan with recurrence criteria: PSA =1 or PSA 0.4-1 with PSADT Nadir + 2 after RT, was performed.
Results: From April to December 2019, 69 patients were included, 40 were treated with RP (58%) and 29 with RT (42%). In 45 patients (65%) PET-CT was able to identify recurrence of the disease (positive PET) and in 24 it was not (negative PET). Of patients treated with RP, 82, 5% (33/40) had PSA>1, and of those, 61% were positive PET. 17, 5% (7/40) had PSA6months (28/69), in 71% if PSADT6 months, in 61% and 92% if PSADT<6 months and in 77% and 100% if PSADT<3 months.
Conclusion: Preliminarily and awaiting validation, it seems that PSA>1 after RP or Nadir +2 after RT is an indicator of PET-CT. There seems to be a tendency that shows that PSA<1 after RP is an indicator of PET-CT if PSADT<3 months. PSADT <3 or <6 months could be the best predictor of positivity of PET-CT with [18F]F-Choline in recurrent prostate cancer
Loop Quantum Gravity and the The Planck Regime of Cosmology
The very early universe provides the best arena we currently have to test
quantum gravity theories. The success of the inflationary paradigm in
accounting for the observed inhomogeneities in the cosmic microwave background
already illustrates this point to a certain extent because the paradigm is
based on quantum field theory on the curved cosmological space-times. However,
this analysis excludes the Planck era because the background space-time
satisfies Einstein's equations all the way back to the big bang singularity.
Using techniques from loop quantum gravity, the paradigm has now been extended
to a self-consistent theory from the Planck regime to the onset of inflation,
covering some 11 orders of magnitude in curvature. In addition, for a narrow
window of initial conditions, there are departures from the standard paradigm,
with novel effects, such as a modification of the consistency relation
involving the scalar and tensor power spectra and a new source for
non-Gaussianities. Thus, the genesis of the large scale structure of the
universe can be traced back to quantum gravity fluctuations \emph{in the Planck
regime}. This report provides a bird's eye view of these developments for the
general relativity community.Comment: 23 pages, 4 figures. Plenary talk at the Conference: Relativity and
Gravitation: 100 Years after Einstein in Prague. To appear in the Proceedings
to be published by Edition Open Access. Summarizes results that appeared in
journal articles [2-13
Inter-species differences in polychlorinated biphenyls patterns from five sympatric species of odontocetes : Can PCBs be used as tracers of feeding ecology?
The authors gratefully acknowledge the assistance of volunteers from the Galician (CEMMA) and Portuguese (SPVS) stranding networks. The authors would like to thank R. Gallois and C. Trichet for their participation on total lipid content analysis. P. Méndez-Fernandez was supported during the research period through a PhD grant from the Fundação do Ministério de Ciência e Tecnologia de Portugal and ANIMATE project (SFRH/BD/36766/2007) and through a Science Without Borders (CSF) young talent postdoctoral grant of the Brazilian government. G. J. Pierce acknowledges support from the EU ANIMATE project (MEXC-CT-2006-042337), University of Aveiro and Caixa Geral de Depósitos (Portugal).Peer reviewedPostprin
Rapid tests and urine sampling techniques for the diagnosis of urinary tract infection (UTI) in children under five years: a systematic review
Background: Urinary tract infection (UTI) is one of the most common sources of infection in children under five. Prompt diagnosis and treatment is important to reduce the risk of renal scarring. Rapid, cost-effective, methods of UTI diagnosis are required as an alternative to culture. Methods: We conducted a systematic review to determine the diagnostic accuracy of rapid tests for detecting UTI in children under five years of age. Results: The evidence supports the use of dipstick positive for both leukocyte esterase and nitrite (pooled LR+ = 28.2, 95% CI: 17.3, 46.0) or microscopy positive for both pyuria and bacteriuria (pooled LR+ = 37.0, 95% CI: 11.0, 125.9) to rule in UTI. Similarly dipstick negative for both LE and nitrite (Pooled LR- = 0.20, 95% CI: 0.16, 0.26) or microscopy negative for both pyuria and bacteriuria (Pooled LR- = 0.11, 95% CI: 0.05, 0.23) can be used to rule out UTI. A test for glucose showed promise in potty-trained children. However, all studies were over 30 years old. Further evaluation of this test may be useful. Conclusion: Dipstick negative for both LE and nitrite or microscopic analysis negative for both pyuria and bacteriuria of a clean voided urine, bag, or nappy/pad specimen may reasonably be used to rule out UTI. These patients can then reasonably be excluded from further investigation, without the need for confirmatory culture. Similarly, combinations of positive tests could be used to rule in UTI, and trigger further investigation
Observation of Pulsed Gamma-rays Above 25 GeV from the Crab Pulsar with MAGIC
One fundamental question about pulsars concerns the mechanism of their pulsed
electromagnetic emission. Measuring the high-end region of a pulsar's spectrum
would shed light on this question. By developing a new electronic trigger, we
lowered the threshold of the Major Atmospheric gamma-ray Imaging Cherenkov
(MAGIC) telescope to 25 GeV. In this configuration, we detected pulsed
gamma-rays from the Crab pulsar that were greater than 25 GeV, revealing a
relatively high cutoff energy in the phase-averaged spectrum. This indicates
that the emission occurs far out in the magnetosphere, hence excluding the
polar-cap scenario as a possible explanation of our measurement. The high
cutoff energy also challenges the slot-gap scenario.Comment: Slight modification of the analysis: Fitting a more general function
to the combined data set of COMPTEL, EGRET and MAGIC. Final result and
conclusion is unchange
Design and Synthesis of Potent in Vitro and in Vivo Anticancer Agents Based on 1-(3′,4′,5′-Trimethoxyphenyl)-2-Aryl-1H-Imidazole
A novel series of tubulin polymerization inhibitors, based on the 1-(3',4',5'-trimethoxyphenyl)-2-aryl-1H-imidazole scaffold and designed as cis-restricted combretastatin A-4 analogues, was synthesized with the goal of evaluating the effects of various patterns of substitution on the phenyl at the 2-position of the imidazole ring on biological activity. A chloro and ethoxy group at the meta- and para-positions, respectively, produced the most active compound in the series (4o), with IC50 values of 0.4-3.8 nM against a panel of seven cancer cell lines. Except in HL-60 cells, 4o had greater antiproliferative than CA-4, indicating that the 3'-chloro-4'-ethoxyphenyl moiety was a good surrogate for the CA-4 B-ring. Experiments carried out in a mouse syngenic model demonstrated high antitumor activity of 4o, which significantly reduced the tumor mass at a dose thirty times lower than that required for CA-4P, which was used as a reference compound. Altogether, our findings suggest that 4o is a promising anticancer drug candidate that warrants further preclinical evaluation
Multi-Wavelength Observations of the Blazar 1ES 1011+496 in Spring 2008
The BL Lac object 1ES 1011+496 was discovered at Very High Energy gamma-rays
by MAGIC in spring 2007. Before that the source was little studied in different
wavelengths. Therefore a multi-wavelength (MWL) campaign was organized in
spring 2008. Along MAGIC, the MWL campaign included the Metsahovi radio
observatory, Bell and KVA optical telescopes and the Swift and AGILE
satellites. MAGIC observations span from March to May, 2008 for a total of 27.9
hours, of which 19.4 hours remained after quality cuts. The light curve showed
no significant variability. The differential VHE spectrum could be described
with a power-law function. Both results were similar to those obtained during
the discovery. Swift XRT observations revealed an X-ray flare, characterized by
a harder when brighter trend, as is typical for high synchrotron peak BL Lac
objects (HBL). Strong optical variability was found during the campaign, but no
conclusion on the connection between the optical and VHE gamma-ray bands could
be drawn. The contemporaneous SED shows a synchrotron dominated source, unlike
concluded in previous work based on nonsimultaneous data, and is well described
by a standard one zone synchrotron self Compton model. We also performed a
study on the source classification. While the optical and X-ray data taken
during our campaign show typical characteristics of an HBL, we suggest, based
on archival data, that 1ES 1011+496 is actually a borderline case between
intermediate and high synchrotron peak frequency BL Lac objects.Comment: 13 pages, accepted for publication in MNRA
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