We make publicly available a catalog of calibrated environmental measures for galaxies in the five 3D-Hubble Space Telescope (HST)/CANDELS deep fields. Leveraging the spectroscopic and grism ...redshifts from the 3D-HST survey, multiwavelength photometry from CANDELS, and wider field public data for edge corrections, we derive densities in fixed apertures to characterize the environment of galaxies brighter than mag in the redshift range . By linking observed galaxies to a mock sample, selected to reproduce the 3D-HST sample selection and redshift accuracy, each 3D-HST galaxy is assigned a probability density function of the host halo mass, and a probability that it is a central or a satellite galaxy. The same procedure is applied to a z = 0 sample selected from Sloan Digital Sky Survey. We compute the fraction of passive central and satellite galaxies as a function of stellar and halo mass, and redshift, and then derive the fraction of galaxies that were quenched by environment specific processes. Using the mock sample, we estimate that the timescale for satellite quenching is it is longer at lower stellar mass or lower redshift, but remarkably independent of halo mass. This indicates that, in the range of environments commonly found within the 3D-HST sample ( ), satellites are quenched by exhaustion of their gas reservoir in the absence of cosmological accretion. We find that the quenching times can be separated into a delay phase, during which satellite galaxies behave similarly to centrals at fixed stellar mass, and a phase where the star formation rate drops rapidly ( Gyr), as shown previously at z = 0. We conclude that this scenario requires satellite galaxies to retain a large reservoir of multi-phase gas upon accretion, even at high redshift, and that this gas sustains star formation for the long quenching times observed.
We present a census of ionized gas outflows in 599 normal galaxies at redshift 0.6 < z < 2.7, mostly based on integral field spectroscopy of Hα, N ii, and S ii line emission. The sample fairly ...homogeneously covers the main sequence of star-forming galaxies with masses 9.0 < log(M */M ⊙) < 11.7, and probes into the regimes of quiescent galaxies and starburst outliers. About one-third exhibits the high-velocity component indicative of outflows, roughly equally split into winds driven by star formation (SF) and active galactic nuclei (AGNs). The incidence of SF-driven winds correlates mainly with SF properties. These outflows have typical velocities of ∼450 km s−1, local electron densities of n e ∼ 380 cm−3, modest mass loading factors of ∼0.1–0.2 at all galaxy masses, and energetics compatible with momentum driving by young stellar populations. The SF-driven winds may escape from log(M */M ⊙) ≲ 10.3 galaxies, but substantial mass, momentum, and energy in hotter and colder outflow phases seem required to account for low galaxy formation efficiencies in the low-mass regime. Faster AGN-driven outflows (∼1000–2000 km s−1) are commonly detected above log(M */M ⊙) ∼ 10.7, in up to ∼75% of log(M */M ⊙) ≳ 11.2 galaxies. The incidence, strength, and velocity of AGN-driven winds strongly correlates with stellar mass and central concentration. Their outflowing ionized gas appears denser (n e ∼ 1000 cm−3), and possibly compressed and shock-excited. These winds have comparable mass loading factors as the SF-driven winds but carry ∼10 (∼50) times more momentum (energy). The results confirm our previous findings of high-duty-cycle, energy-driven outflows powered by AGN above the Schechter mass, which may contribute to SF quenching.
The aim of this study were the retrospective evaluation of the compressive effect and complication rates of transsacral stabilization of osteoporosis-associated sacral fragility fractures in 106 ...patients using three different implants (6.0 mm sacral bar, n = 32; 7.3 mm screw, n = 26; 7.5 mm ISG-Rod System, n = 48) with regard to the image morphological and clinical-perioperative outcome.PURPOSEThe aim of this study were the retrospective evaluation of the compressive effect and complication rates of transsacral stabilization of osteoporosis-associated sacral fragility fractures in 106 patients using three different implants (6.0 mm sacral bar, n = 32; 7.3 mm screw, n = 26; 7.5 mm ISG-Rod System, n = 48) with regard to the image morphological and clinical-perioperative outcome.For this purpose, the sacral width was determined preoperatively and postoperatively using multiplanar CT reconstructions and correlated with the measured bone density (HU). The results were compared with each other on an implant-specific basis.METHODSFor this purpose, the sacral width was determined preoperatively and postoperatively using multiplanar CT reconstructions and correlated with the measured bone density (HU). The results were compared with each other on an implant-specific basis.A significant compressive effect was found for all implants (6.0 mm sacral bar 7.1 ± 3.4 mm, 7.3 mm screw 6.9 ± 1.8 mm, 7.5 mm ISG-Rod System 8 ± 2.4 mm). No implant-specific difference in compression could be detected. Overall, the washers broke into the iliac cortex in 9% of cases. The subgroups did not differ significantly in this respect (6.0 mm sacral bar: 4 13%, 7.3 mm screw 1 1%, 7.5 mm ISG-Rod System (5 10%, p = 0.581). A correlation between the degree of osteoporosis and the compressive effect could not be demonstrated. Significant implant-specific differences were found in the incision-suture time, with only ø0:39 ± 0:13 h required for implantation of the 7.5 mm ISG Rod System (6.0 mm sacral bar: ø1:09 ± 0:22 h, 7.3 mm screw: ø0:55 ± 0:20 h). The fluoroscopy time was significantly lower with the 7.3 mm screw (ø0:57 ± 0:23 min) and the 7.5 mm ISG Rod System (ø0:42 ± 00:17 min) than with the 6.0 mm sacral bar (ø1:36 ± 0:46 min).RESULTSA significant compressive effect was found for all implants (6.0 mm sacral bar 7.1 ± 3.4 mm, 7.3 mm screw 6.9 ± 1.8 mm, 7.5 mm ISG-Rod System 8 ± 2.4 mm). No implant-specific difference in compression could be detected. Overall, the washers broke into the iliac cortex in 9% of cases. The subgroups did not differ significantly in this respect (6.0 mm sacral bar: 4 13%, 7.3 mm screw 1 1%, 7.5 mm ISG-Rod System (5 10%, p = 0.581). A correlation between the degree of osteoporosis and the compressive effect could not be demonstrated. Significant implant-specific differences were found in the incision-suture time, with only ø0:39 ± 0:13 h required for implantation of the 7.5 mm ISG Rod System (6.0 mm sacral bar: ø1:09 ± 0:22 h, 7.3 mm screw: ø0:55 ± 0:20 h). The fluoroscopy time was significantly lower with the 7.3 mm screw (ø0:57 ± 0:23 min) and the 7.5 mm ISG Rod System (ø0:42 ± 00:17 min) than with the 6.0 mm sacral bar (ø1:36 ± 0:46 min).A significant compressive effect was demonstrated with all three implants. No implant-specific complications or surgical site complications were identified in either the overall cohort or the subgroups. The 7.5 mm ISG Rod System shows advantages with regard to the duration of surgery and fluoroscopy.CONCLUSIONA significant compressive effect was demonstrated with all three implants. No implant-specific complications or surgical site complications were identified in either the overall cohort or the subgroups. The 7.5 mm ISG Rod System shows advantages with regard to the duration of surgery and fluoroscopy.
Using integral field spectroscopy, we investigate the kinematic properties of 35 massive centrally dense and compact star-forming galaxies (SFGs; \(\mathrm{log}{\overline{M}}_{* }{M}_{\odot }=11.1\), ...\(\mathrm{log}({{\rm{\Sigma }}}_{1\mathrm{kpc}}{M}_{\odot }\,{\mathrm{kpc}}^{-2})\gt 9.5\), \(\mathrm{log}({M}_{* }/{r}_{e}^{1.5}{M}_{\odot }\,{\mathrm{kpc}}^{-1.5})\gt 10.3\)) at z ∼ 0.7–3.7 within the KMOS3D survey. We spatially resolve 23 compact SFGs and find that the majority are dominated by rotational motions with velocities ranging from 95 to 500 km s−1. The range of rotation velocities is reflected in a similar range of integrated Hα line widths, 75–400 km s−1, consistent with the kinematic properties of mass-matched extended galaxies from the full KMOS3D sample. The fraction of compact SFGs that are classified as “rotation-dominated” or “disklike” also mirrors the fractions of the full KMOS3D sample. We show that integrated line-of-sight gas velocity dispersions from KMOS3D are best approximated by a linear combination of their rotation and turbulent velocities with a lesser but still significant contribution from galactic-scale winds. The Hα exponential disk sizes of compact SFGs are, on average, 2.5 ± 0.2 kpc, 1–2נthe continuum sizes, in agreement with previous work. The compact SFGs have a 1.4נhigher active galactic nucleus (AGN) incidence than the full KMOS3D sample at fixed stellar mass with an average AGN fraction of 76%. Given their high and centrally concentrated stellar masses, as well as stellar-to-dynamical mass ratios close to unity, the compact SFGs are likely to have low molecular gas fractions and to quench on a short timescale unless replenished with inflowing gas. The rotation in these compact systems suggests that their direct descendants are rotating passive galaxies.
We analyze the angular momenta of massive star-forming galaxies (SFGs) at the peak of the cosmic star formation epoch (z~ 0.8-2.6). Our sample of ~360 log(M sub(*)/M sub(middot in circle)) ~ 9.3-11.8 ...SFGs is mainly based on the KMOS super(3D) and SINS/zC-SINF surveys of Halpha kinematics, and collectively provides a representative subset of the massive star-forming population. The inferred halo scale angular momentum distribution is broadly consistent with that theoretically predicted for their dark matter halos, in terms of mean spin parameter left angle bracketlambdaright angle bracket ~ 0.037 and its dispersion (sigma sub(loglambda)~ 0.2). Spin parameters correlate with the disk radial scale and with their stellar surface density, but do not depend significantly on halo mass, stellar mass, or redshift. Our data thus support the long-standing assumption that on average, even at high redshifts, the specific angular momentum of disk galaxies reflects that of their dark matter halos (j sub(d)= j sub(DM)). The lack of correlation between lambda x (j sub(d)/j sub(DM)) and the nuclear stellar density Sigma sub(*)(1 kpc) favors a scenario where disk-internal angular momentum redistribution leads to "compaction" inside massive high-redshift disks. For our sample, the inferred average stellar to dark matter mass ratio is ~2%, consistent with abundance matching results. Including the molecular gas, the total baryonic disk to dark matter mass ratio is ~5% for halos near 10 super(12)M sub(middot in circle), which corresponds to 31% of the cosmologically available baryons, implying that high-redshift disks are strongly baryon dominated.
Abstract Sacroiliac (SI) screw fixation represents an effective method to stabilise pelvic injuries. However, to date neither reliable radiological landmarks nor effective anatomical classifications ...of the sacrum exist. This study investigates the influence of variability in sacral shape on secure transverse SI-screw positioning. Furthermore, consistent correlations of these anatomical conditions are analysed with respect to standard planar pelvic views. For shape analysis, 80 human computed tomography data sets were segmented with the software Amira 4.2 to obtain 3D reconstructions. We identified anatomical conditions (ACs) according to the extent of the effect on the bony screw pathway. Subsequently, the pelvis was spatially aligned using representative bone protuberances in order to create standard Matta projections. In each view, the ACs were described in terms of distance from bone landmarks. Three-dimensional shape analysis revealed the height of the pedicular isthmus (PH) as the limiting variable for secure screw insertion. The lateral and outlet views allowed an orthogonal projection of PH. In the lateral view, the ratio of the lateral sacral triangle framed by the S1 body height and width showed a high correlation to PH ( p = 0.0001). A boundary ratio of 1.5 represented a reliable variable to determine whether or not a screw can be inserted (positive predictive value: 97%). In the outlet view, the distance between the S1 endplate and the SI joint top level (EJ) strongly correlated with PH ( p = 0.0001). With EJ ≤ 0 mm, screw insertion was possible in all cases (100%). SI-screw insertion requires a well-planned procedure. Orientation of the sacral pedicle is of extreme relevance. A narrow sacroiliac channel and high sacral shape variability limit secure screw placement. However, no determining parameters exist, allowing accurate prediction of secure screw insertion based on X-rays or fluoroscopy. The lateral sacral triangle in the lateral view represents a simple and accurate preoperative method of support for the surgeon's decision to undertake this procedure. No additional technical effort is necessary. A boundary ratio of 1.5 predicts a sufficient bone stock for at least one 7.3 mm screw. Furthermore, the evaluation of the outlet projection can be used to assess the safety of the operation. Basically, a preoperative lateral pelvic image should be mandatory.
Abstract Sacroiliac (SI) screw fixation for unstable pelvic fractures stands out as the only minimally invasive method among all other ORIF procedures. A strictly transverse screw trajectory is ...needed for central or bilateral fracture patterns up to a complete iliosacroiliac fixation. However, secure screw insertion is aggravated by a narrow sacroiliac bone stock. This study investigates the influence of a highly variable sacral morphology to the existence of S1 and S2 transverse corridors. The analysis contained in this study is based on 125 CT datasets of intact human pelvises. First, sacral dysplasia was identified using the “lateral sacral triangle” method in a lateral 3-D semi-transparent pelvic view. Second, 3-D corridors for a 7.3 mm screw in the upper two sacral levels were visualised using a proprietary IT workflow of custom-made programme scripts based on the Amira® -software. Shape-describing measurement variables were calculated as output variables. The results show a significant linear correlation between ratioT and the screw-limiting S1 isthmus height (Pearson coefficient of 0.84). A boundary ratio of 1.5 represented a positive predictive value of 96% for the existence of a transverse S1-corridor for at least one 7.3 mm screw. In 100 out of 125 pelvises (80%), a sufficient S1 corridor existed, whereas in 124 specimens (99%), an S2 corridor was found. Statistics revealed significantly larger S1 and S2 corridors in males compared to females ( p < 0.05). However, no gender-related differences were observed for clinically relevant numbers of up to 3 screws in S1 and 1 screw in S2. The expanse of the S1 corridor is highly influenced by the dimensions of the dysplastic elevated upper sacrum, whereas the S2 corridor is not affected. Hence, in dysplastic pelvises, sacroiliac screw insertion should be recommended into the 2nd sacral segment. Our IT workflow for the automatic computation of 3-D corridors may assist in surgical pre-operative planning. Furthermore, the workflow could be implemented in computer-assisted surgery applications involving pelvic trauma.
Composite spectra of 85 proximate absorbers log N(H i) ≥ 20 cm−2 and velocity difference between the absorption and emission redshifts, ΔV < 10 000 km s−1 in the Sloan Digital Sky Survey are used to ...investigate the trends of metal-line strengths with velocity separation from the quasi-stellar object (QSO). We construct composites in three velocity bins: ΔV < 3000 km s−1, 3000 < ΔV < 6000 km s−1 and ΔV > 6000 km s−1, with further sub-samples to investigate the metal-line dependence on N(H i) and QSO luminosity. Low (e.g. Si ii and Fe ii) and high ionization (e.g. Si iv and C iv) species alike have equivalent widths (EWs) that are larger by factors of 1.5-3 in the ΔV < 3000 km s−1 composite, compared to the ΔV > 6000 km s−1 spectrum. The EWs show an even stronger dependence on ΔV if only the highest neutral hydrogen column density log N(H i) ≥ 20.7 absorbers are considered. We conclude that proximate damped Lyman α systems (PDLAs) generally have higher metallicities than intervening absorbers, with the enhancement being a function of both ΔV and N(H i). It is also found that absorbers near QSOs with lower rest-frame UV luminosities have significantly stronger metal lines. We speculate that absorbers near to high luminosity QSOs may have had their star formation prematurely quenched. There is no evidence for Lyα emission in the trough of the composite spectrum. Finally, we search for the signature of dust reddening by the PDLAs, based on an analysis of the QSO continuum slopes relative to a control sample, and determine a limit of E(B−V) < 0.014 for a Small Magellanic Cloud extinction curve. This work provides an empirical motivation for distinguishing between proximate and intervening DLAs and establishes a connection between the QSO environment and galaxy properties at high redshifts.
Purpose
Posterior multilevel fixation of traumatic instability in ankylosing spinal disease (ASD) can be performed by open surgery (OS) or minimally invasive surgery (MIS). We investigated whether ...both methods differ based on the reduction results and perioperative parameters.
Methods
In this retrospective cohort study, OS and MIS groups were investigated. The bisegmental Cobb angles and dislocation angles were measured using pre- and postoperative CT images, and the initial malalignment and achieved reduction were calculated. Cut-seam time, calculated blood loss, transfusion number, fluoroscopy time, pedicle screw placement accuracy, duration of ICU stay, in-patient stay, and complications (bleeding, postoperative thrombosis and embolism, and postoperative mortality) were recorded.
Results
Seventy-five ASD patients with spine fractures (Ø 75 ± 11 years, male: 52, female: 23) (MIS: 48; OS: 27) were included in this study. The extent of reduction did not differ in the OS and MIS groups (
p
= 0.465; MIS:− 1 ± 3°, OS:−2 ± 6°). The residual postoperative malalignment angle was not significantly different (
p
= 0.283). Seventy-eight of the implanted screws (11%) showed malpositioning. No difference was found between OS and MIS (MIS, 37 7%; OS, 41 16%;
p
= 0.095). MIS was associated with less blood loss (OS: 1.28 ± 0.78 l, MIS: 0.71 ± 0.57 l,
p
= 0.001), cut-seam time (MIS: 98 ± 44 min, OS: 166 ± 69 min,
p
< 0.001), and hospital stay (MIS: Ø14 ± 16 d, OS: Ø38 ± 49 d,
p
= 0.02) than OS.
Conclusion
OS and MIS show equally limited performance in terms of the fracture reduction achieved. The MIS technique was superior to OS based on the perioperative outcome. Therefore, MIS should be preferred over OS for unstable spinal injuries, excluding C-type fractures, in ASD patients without neurological impairment.
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