Spinal pain: Current understanding, trends, and the future of care

© 2015 Trainor et al. This commissioned review paper offers a summary of our current understanding of nonmalignant spinal pain, particularly persistent pain. Spinal pain can be a complex problem, requiring management that addresses both the physical and psychosocial components of the pain experience. We propose a model of care that includes the necessary components of care services that would address the multidimensional nature of spinal pain. Emerging care services that tailor care to the individual person with pain seems to achieve better outcomes and greater consumer satisfaction with care, while most likely containing costs. However, we recommend that any model of care and care framework should be developed on the basis of a multidisciplinary approach to care, with the scaffold being the principles of evidence-based practice. Importantly, we propose that any care services recommended in new models or frameworks be matched with available resources and services-this matching we promote as the fourth principle of evidence-based practice. Ongoing research will be necessary to offer insight into clinical outcomes of complex interventions, while practice-based research would uncover consumer needs and workforce capacity. This kind of research data is essential to inform health care policy and practice

Variabilidade espacial de características químicas de um Cambissolo cultivado com mamão no semi-árido do Rio Grande do Norte.

Este trabalho teve como objetivo avaliar a variabilidade espacial de atributos químicos de um Cambissolo Háplico léptico (CX), sob cultivo de mamão, por meio da geoestatística. A área amostrada apresentou 43 pontos amostrais, onde foram coletadas amostras de solo, na camada de 0 - 0,2 m, e amostras do tecido foliar. Nas amostras de solo determinou-se pH, CE, Ca, Mg, Na, K, P, C. A partir dessas análises calculou-se a CTC, S, V e PST. Os dados foram avaliados por estatística descritiva e por meio de técnicas geoestatísticas. O coeficiente de variação indicou variabilidade baixa para pH e V (%), e alta para P e CE, enquanto as demais variáveis apresentaram variação alta. A maioria das variáveis apresentaram dependência espacial, sendo o esférico o modelo ajustado a todos os semivariogramas. O efeito pepita teve pequena contribuição na variância total dos dados, indicando forte dependência espacial para todas as variáveis estudadas. Houve pequena variação na distância até onde as características químicas do solo apresentaram dependência espacial

First Results from the KMOS Lens-Amplified Spectroscopic Survey (KLASS): Kinematics of Lensed Galaxies at Cosmic Noon

We present the first results of the KMOS Lens-Amplified Spectroscopic Survey (KLASS), a new ESO Very Large Telescope (VLT) large program, doing multi-object integral field spectroscopy of galaxies gravitationally lensed behind seven galaxy clusters selected from the HST Grism Lens-Amplified Survey from Space (GLASS). Using the power of the cluster magnification we are able to reveal the kinematic structure of 25 galaxies at $0.7 \lesssim z \lesssim 2.3$, in four cluster fields, with stellar masses $8 \lesssim \log{(M_\star/M_\odot)} \lesssim 11$. This sample includes 5 sources at $z>1$ with lower stellar masses than in any previous kinematic IFU surveys. Our sample displays a diversity in kinematic structure over this mass and redshift range. The majority of our kinematically resolved sample is rotationally supported, but with a lower ratio of rotational velocity to velocity dispersion than in the local universe, indicating the fraction of dynamically hot disks changes with cosmic time. We find no galaxies with stellar mass $<3 \times 10^9 M_\odot$ in our sample display regular ordered rotation. Using the enhanced spatial resolution from lensing, we resolve a lower number of dispersion dominated systems compared to field surveys, competitive with findings from surveys using adaptive optics. We find that the KMOS IFUs recover emission line flux from HST grism-selected objects more faithfully than slit spectrographs. With artificial slits we estimate slit spectrographs miss on average 60% of the total flux of emission lines, which decreases rapidly if the emission line is spatially offset from the continuum.Comment: Accepted for publication in Ap

Localized starbursts in dwarf galaxies produced by impact of low metallicity cosmic gas clouds

Models of galaxy formation predict that gas accretion from the cosmic web is a primary driver of star formation over cosmic history. Except in very dense environments where galaxy mergers are also important, model galaxies feed from cold streams of gas from the web that penetrate their dark matter haloes. Although these predictions are unambiguous, the observational support has been indirect so far. Here we report spectroscopic evidence for this process in extremely metal-poor galaxies (XMPs) of the local Universe, taking the form of localized starbursts associated with gas having low metallicity. Detailed abundance analyses based on Gran Telescopio Canarias (GTC) optical spectra of ten XMPs show that the galaxy hosts have metallicities around 60 % solar on average, while the large star-forming regions that dominate their integrated light have low metallicities of some 6 % solar. Because gas mixes azimuthally in a rotation timescale (a few hundred Myr), the observed metallicity inhomogeneities are only possible if the metal-poor gas fell onto the disk recently. We analyze several possibilities for the origin of the metal-poor gas, favoring the metal-poor gas infall predicted by numerical models. If this interpretation is correct, XMPs trace the cosmic web gas in their surroundings, making them probes to examine its properties.Comment: Accepted for publication in ApJ

Inferences on the Timeline of Reionization at z~8 From the KMOS Lens-Amplified Spectroscopic Survey

Detections and non-detections of Lyman alpha (Ly$\alpha$) emission from $z>6$ galaxies ($<1$ Gyr after the Big Bang) can be used to measure the timeline of cosmic reionization. Of key interest to measuring reionization's mid-stages, but also increasing observational challenge, are observations at z > 7, where Ly$\alpha$ redshifts to near infra-red wavelengths. Here we present a search for z > 7.2 Ly$\alpha$ emission in 53 intrinsically faint Lyman Break Galaxy candidates, gravitationally lensed by massive galaxy clusters, in the KMOS Lens-Amplified Spectroscopic Survey (KLASS). With integration times of ~7-10 hours, we detect no Ly$\alpha$ emission with S/N>5 in our sample. We determine our observations to be 80% complete for 5$\sigma$ spatially and spectrally unresolved emission lines with integrated line flux $>5.7\times10^{-18}$ erg s$^{-1}$ cm$^{-2}$. We define a photometrically selected sub-sample of 29 targets at $z=7.9\pm0.6$, with a median 5$\sigma$ Ly$\alpha$ EW limit of 58A. We perform a Bayesian inference of the average intergalactic medium (IGM) neutral hydrogen fraction using their spectra. Our inference accounts for the wavelength sensitivity and incomplete redshift coverage of our observations, and the photometric redshift probability distribution of each target. These observations, combined with samples from the literature, enable us to place a lower limit on the average IGM neutral hydrogen fraction of $> 0.76 \; (68\%), \; > 0.46 \; (95\%)$ at z ~ 8, providing further evidence of rapid reionization at z~6-8. We show that this is consistent with reionization history models extending the galaxy luminosity function to $M_\textrm{UV} \lesssim -12$, with low ionizing photon escape fractions, $f_\textrm{esc} \lesssim 15\%$.Comment: Accepted for publication in MNRA

Hubble imaging of the ionizing radiation from a star-forming galaxy at z=3.2 with fesc>50%

Star-forming galaxies are considered to be the leading candidate sources that dominate the cosmic reionization at z>7, and the search for analogs at moderate redshift showing Lyman continuum (LyC) leakage is currently a active line of research. We have observed a star-forming galaxy at z=3.2 with Hubble/WFC3 in the F336W filter, corresponding to the 730-890A rest-frame, and detect LyC emission. This galaxy is very compact and also has large Oxygen ratio [OIII]5007/[OII]3727 (>=10). No nuclear activity is revealed from optical/near-infrared spectroscopy and deep multi-band photometry (including the 6Ms X-ray, Chandra). The measured escape fraction of ionizing radiation spans the range 50-100\%, depending on the IGM attenuation. The LyC emission is detected at S/N=10 with m(F336W)=27.57+/-0.11 and it is spatially unresolved, with effective radius R_e<200pc. Predictions from photoionization and radiative transfer models are in line with the properties reported here, indicating that stellar winds and supernova explosions in a nucleated star-forming region can blow cavities generating density-bounded conditions compatible with optically thin media. Irrespective to the nature of the ionizing radiation, spectral signatures of these sources over the entire electromagnetic spectrum are of central importance for their identification during the epoch of reionization, when the LyC is unobservable. Intriguingly, the Spitzer/IRAC photometric signature of intense rest-frame optical emissions ([OIII]+Hbeta) observed recently at z~7.5-8.5 is similar to what is observed in this galaxy. Only the James Webb Space Telescope will measure optical line ratios at z>7 allowing a direct comparison with lower redshift LyC emitters, as reported here.Comment: 6 pages, 5 figures, ApJ submitted (comments welcome

Limits on the LyC signal from z~3 sources with secure redshift and HST coverage in the E-CDFS field

Aim: We aim to measure the LyC signal from a sample of sources in the Chandra deep field south. We collect star-forming galaxies (SFGs) and active galactic nuclei (AGN) with accurate spectroscopic redshifts, for which Hubble Space Telescope (HST) coverage and multi-wavelength photometry are available. Method: We selected a sample of about 200 sources at z~3. Taking advantage of HST resolution, we applied a careful cleaning procedure and rejected sources showing nearby clumps with different colours, which could be lower-z interlopers. Our clean sample consisted of 86 SFGs (including 19 narrow-band selected Lya emitters) and 8 AGN (including 6 detected in X-rays). We measured the LyC flux from aperture photometry in four narrow-band filters covering wavelengths below a 912 A rest frame (3.11<z<3.53). We estimated the ratio between ionizing (LyC flux) and 1400 A non-ionizing emissions for AGN and galaxies. Results: By running population synthesis models, we assume an average intrinsic L(1400 A)/L(900 A) ratio of 5 as the representative value for our sample. With this value and an average treatment of the lines of sight of the inter-galactic medium, we estimate the LyC escape fraction relative to the intrinsic value (fesc_rel(LyC)). We do not directly detect ionizing radiation from any individual SFG, but we are able to set a 1(2)sigma upper limit of fesc_rel(LyC)<12(24)%. This result is consistent with other non-detections published in the literature. No meaningful limits can be calculated for the sub-sample of Lya emitters. We obtain one significant direct detection for an AGN at z=3.46, with fesc_rel(LyC) = (72+/-18)%. Conclusions: Our upper limit on fescrel(LyC) implies that the SFGs studied here do not present either the physical properties or the geometric conditions suitable for efficient LyC-photon escape.Comment: Accepted for publication in A&A on Jan 5th, 201

Nuclear Saturation with in-Medium Meson Exchange Interactions

We show that the assumption of dropping meson masses together with conventional many-body effects, implemented in the relativistic Dirac-Brueckner formalism, explains nuclear saturation. We use a microscopic model for correlated $2\pi$ exchange and include the standard many-body effects on the in-medium pion propagation, which initially increase the attractive nucleon-nucleon ($NN$) potential with density. For the vector meson exchanges in both the $\pi\pi$ and $NN$ sector, we assume Brown-Rho scaling which---in concert with `chiral' $\pi\pi$ contact interactions---reduces the attraction at higher densities.Comment: 5 pages REVTeX, 2 eps-figures included, submitted to Phys. Rev. Let

Scalar and vector decomposition of the nucleon self-energy in the relativistic Brueckner approach

We investigate the momentum dependence of the nucleon self-energy in nuclear matter. We apply the relativistic Brueckner-Hartree-Fock approach and adopt the Bonn A potential. A strong momentum dependence of the scalar and vector self-energy components can be observed when a commonly used pseudo-vector choice for the covariant representation of the T-matrix is applied. This momentum dependence is dominated by the pion exchange. We discuss the problems of this choice and its relations to on-shell ambiguities of the T-matrix representation. Starting from a complete pseudo-vector representation of the T-matrix, which reproduces correctly the pseudo-vector pion-exchange contributions at the Hartree-Fock level, we observe a much weaker momentum dependence of the self-energy. This fixes the range of the inherent uncertainty in the determination of the scalar and vector self-energy components. Comparing to other work, we find that extracting the self-energy components by a fit to the single particle potential leads to even more ambiguous results.Comment: 35 pages RevTex, 7 PS figures, replaced by a revised and extended versio