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The Antarctic ice sheet has been losing mass over past decades through the accelerated flow of its glaciers, conditioned by ocean temperature and bed topography. Glaciers retreating along retrograde slopes (that is, the bed elevation drops in the inland direction) are potentially unstable, while subglacial ridges slow down the glacial retreat. Despite major advances in the mapping of subglacial bed topography, significant sectors of Antarctica remain poorly resolved and critical spatial details are missing. Here we present a novel, high-resolution and physically based description of Antarctic bed topography using mass conservation. Our results reveal previously unknown basal features with major implications for glacier response to climate change. For example, glaciers flowing across the Transantarctic Mountains are protected by broad, stabilizing ridges. Conversely, in the marine basin of Wilkes Land, East Antarctica, we find retrograde slopes along Ninnis and Denman glaciers, with stabilizing slopes beneath Moscow University, Totten and Lambert glacier system, despite corrections in bed elevation of up to 1 km for the latter. This transformative description of bed topography redefines the high- and lower-risk sectors for rapid sea level rise from Antarctica; it will also significantly impact model projections of sea level rise from Antarctica in the coming centuries.A high-resolution update of Antarctic bed topography using mass conservation reveals broad stabilizing ridges for glaciers flowing across the Transantarctic Mountains, and stabilizing slopes beneath Moscow University, Totten and Lambert glacier system.

During the recent decades of satellite era, more tropical cyclogenesis locations (TCLs) were observed over the northwestern part of the western North Pacific (WNP), relative to the southeastern part, during the boreal autumn. This increase in TCLs over the northwestern WNP is largely attributed to the synergy of shifting El Niño-Southern Oscillation (ENSO) and the 1998 Pacific climate regime shift. Both central Pacific (CP) La Niña and CP El Niño have occurred more frequently since 1998, with only one eastern Pacific El Niño observed in autumn 2015. The change in the mean longitude of TCLs is closely linked to the ENSO diversity, whereas the change in the mean latitude is dominated by the warming of the WNP induced by an interdecadal tendency of CP La Niña-like events. The physical mechanisms responsible for this shifting ENSO-TCL linkage can be potentially explained by the tacit-and-mutual configurations between tropical upper-tropospheric trough and monsoon trough, on both interannual and interdecadal timescales, which is mainly due to the ENSO-related large-scale environment changes in ocean and atmosphere that modulate the WNP TCL.

Low-luminosity active galactic nuclei (AGNs) with low-mass black holes (BHs) in the early universe are fundamental to understanding the BH growth and their coevolution with the host galaxies. Utilizing JWST NIRCam Wide Field Slitless Spectroscopy, we perform a systematic search for broad-line Hα emitters (BHAEs) at z ≈ 4–5 in 25 fields of the A SPectroscopic survey of biased halos In the Reionization Era (ASPIRE) project, covering a total area of 275 arcmin2. We identify 16 BHAEs with FWHM of the broad components spanning from ∼1000 to 3000 km s−1. Assuming that the broad line widths arise as a result of Doppler broadening around BHs, the implied BH masses range from 107 to 108 M ⊙, with broad Hα-converted bolometric luminosities of 1044.5–1045.5 erg s−1 and Eddington ratios of 0.07–0.47. The spatially extended structure of the F200W stacked image may trace the stellar light from the host galaxies. The Hα luminosity function indicates an increasing AGN fraction toward the higher Hα luminosities. We find possible evidence for clustering of BHAEs: two sources are at the same redshift with a projected separation of 519 kpc; one BHAE appears as a composite system residing in an overdense region with three close companion Hα emitters. Three BHAEs exhibit blueshifted absorption troughs indicative of the presence of high column density gas. We find that the broad-line-selected and photometrically selected BHAE samples exhibit different distributions in the optical continuum slopes, which can be attributed to their different selection methods. The ASPIRE broad-line Hα sample provides a good database for future studies of faint AGN populations at high redshift.

Bright quasars, powered by accretion onto billion-solar-mass black holes, already existed at the epoch of reionization, when the Universe was 0.5–1 billion years old 1 . How these black holes formed in such a short time is the subject of debate, particularly as they lie above the correlation between black-hole mass and galaxy dynamical mass 2 , 3 in the local Universe. What slowed down black-hole growth, leading towards the symbiotic growth observed in the local Universe, and when this process started, has hitherto not been known, although black-hole feedback is a likely driver 4 . Here we report optical and near-infrared observations of a sample of quasars at redshifts 5.8 ≲  z  ≲ 6.6. About half of the quasar spectra reveal broad, blueshifted absorption line troughs, tracing black-hole-driven winds with extreme outflow velocities, up to 17% of the speed of light. The fraction of quasars with such outflow winds at z  ≳ 5.8 is ≈2.4 times higher than at z  ≈ 2–4. We infer that outflows at z  ≳ 5.8 inject large amounts of energy into the interstellar medium and suppress nuclear gas accretion, slowing down black-hole growth. The outflow phase may then mark the beginning of substantial black-hole feedback. The red optical colours of outflow quasars at z  ≳ 5.8 indeed suggest that these systems are dusty and may be caught during an initial quenching phase of obscured accretion 5 . A study reporting optical and near-infrared observations of quasars at redshifts 5.8–6.6 shows that about half have strong winds, up to 17% the speed of light, suppressing black-hole growth.

Background Tear trough deformity is a hallmark of periorbital aging. It is not, however, an exclusive feature of old age. While protruding orbital fat results in lower lid bags that are traditionally corrected by excision, correction of TTD can constitute a real challenge requiring volume enhancement in addition to addressing prolapse of orbital fat and descent of cheek tissues. Described therapeutic options include minimally invasive soft tissue augmentation with fillers or structural autologous fat transfer as well as invasive surgical procedures concomitantly with lower lid blepharoplasty or other facial rejuvenation procedures. Material and Methods Six eponyms have been used in the literature to describe the condition: (1) naso-jugal fold, (2) naso-jugal groove, (3) naso-jugal ditch, (4) tear trough, (5) tear trough deformity, and (6) tear trough depression. A separate PubMed database search of each of the 6 terms was conducted in addition to an advanced literature and systematic PICO searches to identify all described clinical retrospective or prospective, comparative or simple cohort studies related to surgical correction of TTD. An additional screening of references of retrieved clinical studies was performed to identify any missed reports. Results A total of 435 publications were identified with the initial search. After excluding all none relevant studies, 44 papers were selected for review. 6 additional studies were identified by screening relevant references. Conclusion Almost all authors agree on the necessity to release the tear trough retaining ligament together with volume enhancement. Transconjunctival and transcutaneous incisions are reported. Most recommend repositioning of the protruding orbital fat for volume enhancement to mostly subperiosteal, or pre-periosteal pockets. Other reported options include pedicled buccal fat pad transposition, segmental fat grafting, and minced micrografts. Internal as well as external fixation of repositioned fat flaps have been described. Despite lack of solid objective evidence, several of these techniques when properly executed for the proper indication in selected patients are reported to result in a rewarding and long-lasting outcome. Unfortunately, it is difficult to determine the most appropriate technique that would universally yield the most pleasant and harmonious facial contour without creating an unnatural puffy appearance. It remains for the surgeon to identify the safe surgical approach that does not compromise lower eyelid function and achieves the most pleasing aesthetic outcome with the least complications and downtime. Level of Evidence III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The separation and classification of ionospheric troughs in the winter evening and morning ionospheres of the southern hemisphere were performed using CHAMP satellite data for high solar activity (2000–2002). In the high-latitude ionosphere, the main ionospheric trough (MIT) was separated from the high-latitude trough (HLT). The separation was carried out using a thorough analysis of all the characteristic structures of the ionosphere in the framework of the auroral diffuse particle precipitation model. Two types of high-latitude troughs were identified: (1) a wide trough associated with zone II of diffuse precipitation on the poleward edge of the auroral oval and (2) a narrow trough of ionization, which is presumably associated with an electric field action. The poleward wall of MIT is as ever formed by diffuse precipitation in zone I on the equatorward edge of the auroral oval. The HLT and MIT separation is most difficult at the longitudes of the eastern hemisphere, where all structures are located at the highest latitudes and partially overlap. In the mid-latitude ionosphere, all the characteristic structures of the ionosphere were also identified and considered. MIT was separated from the ring ionospheric trough (RIT), which is formed by the decay processes of the magnetospheric ring current. The separation of MIT and RIT was performed based on an analysis of the prehistory of all geomagnetic disturbances during the period under study. In addition to the RIT, a decrease in the electron density equatorward of the MIT was found to be often formed at the America–Atlantic longitudes, which masks the MIT minimum. For completeness, all cases of a clearly defined polar cavity are also presented.

Warm Deep Water intrusion over the Antarctic continental shelves threatens the Antarctic ice-sheet stability by enhancing the basal melting of ice shelves. In East Antarctica, the Antarctic Slope Current (ASC), along with the Antarctic Slope Front (ASF), acts as a potential vorticity barrier to prevent the warm modified Circumpolar Deep Water (mCDW) from ventilating the cold and fresh shelf. However, mCDW onshore transport is still observed within certain shelf regions, such as submarine troughs running perpendicular to the continental shelf. This study focuses on the dynamic mechanisms governing mCDW intrusion within a submarine trough over the fresh shelf regions, East Antarctica. Based on an idealized eddy-resolving coupled ocean-ice shelf model, two high resolution process-oriented numerical experiments are conducted to reveal the mechanisms responsible for the mCDW onshore transport. Three dynamic mechanisms governing cross-slope mCDW intrusion are identified: 1) the bottom pressure torque, 2) the topography beta spiral, and 3) the topography Rossby waves. These three mechanisms simultaneously govern the mCDW intrusion together. The bottom pressure torque plays a leading role in driving the time-mean onshore flow whose vertical structure is determined by the topography beta spiral, while the topography Rossby waves contribute to the high-frequency oscillations in the onshore volume and heat transport. The simulated spatial distribution and seasonality of mCDW intrusion qualitatively coincide with the observed mCDW intrusion over fresh shelf regions, East Antarctica. Both the topography beta spiral and the ASC play an important role in governing the seasonality of mCDW intrusion.

Arctic amplification has been proposed to promote temperature extremes by slowing the midlatitude jet and increasing the amplitude of its meanders. Observational and modeling studies have used a variety of metrics to quantify jet waviness. These studies show conflicting changes in jet waviness depending on the metric used and period examined. Here, we evaluate common metrics for dry idealized model simulations in which we apply polar warming of varying depth and meridional extent. In all simulations, polar warming increases the spatial extent of jet meanders, but reduces the magnitudes of ridges and troughs within the wave. As a result, geometric and anomaly‐amplitude measures of jet waviness can yield opposing responses. This contrast between metrics is particularly evident when warming extends into the midlatitudes. In all simulations, midlatitude temperature anomalies weaken as the poles warm, suggesting that a wavier jet need not imply stronger temperature extremes. Plain Language Summary The Arctic is warming faster than anywhere else on Earth, and this has been suggested to affect weather over midlatitude regions in Eurasia and North America. It has been proposed that, as the pole warms, the equator‐to‐pole temperature gradient is reduced and the atmospheric jet stream slows down and undergoes larger, slower‐moving meanders, which bring long‐lasting extreme temperatures. However, theories for understanding waves in the jet stream actually suggest that these waves could weaken when the equator‐to‐pole temperature gradient decreases. This study uses simple model simulations to test how different metrics for describing jet waviness respond when the pole is warmed. We find that the overall scale of meanders does seem to increase, but the associated temperature anomalies decrease, suggesting a wavier jet stream need not imply stronger temperature extremes. Key Points Spatial extent of midlatitude waves is increased by polar amplification Magnitudes of ridges and troughs within waves are decreased by polar amplification Accordingly, geometric, and anomaly‐amplitude measures of jet waviness can yield opposing responses

We present the first systematic study of 50 low-redshift (0.66 < z < 1.63) iron low-ionization broad absorption-line quasars (FeLoBALQs) using SimBAL, which represents a more than five-fold increase in the number of FeLoBALQs with detailed absorption line spectral analyses. We found the outflows have a wide range of ionization parameters, −4≲logU≲1.2 and densities, 2.8≲logn≲8[cm−3] . The objects in our sample showed FeLoBAL gas located at a wide range of distances 0≲logR≲4.4 [pc], although we do not find any evidence for disk winds (with R ≪ 0.01 pc) in our sample. The outflow strength primarily depends on the outflow velocity with faster outflows found in quasars that are luminous or that have flat or redder spectral energy distributions. We found that ∼18% of the FeLoBALQs in the sample have the significantly powerful outflows needed for quasar feedback. Eight objects showed overlapping troughs in the spectra, and we identified eleven loitering outflow objects, a new class of FeLoBALQs that are characterized by low outflow velocities and high column density winds located logR≲1 [pc] from the central engine. The FeLoBALs in loitering outflows objects do not show properties expected for radiatively driven winds, and these objects may represent a distinct population among FeLoBALQs. We discuss how the potential acceleration mechanisms and the origins of the FeLoBAL winds may differ for outflows at different locations in quasars.

Background and aims: Immunosuppressive therapy with intravenous ciclosporin is an alternative treatment option to total colectomy for patients with ulcerative colitis (UC), while the benefits of oral administration of tacrolimus are not well defined and are based on reports of several uncontrolled studies. Methods: Patients with refractory active UC were randomly assigned to a high trough concentration (10–15 ng/ml) group (HT group) (n = 21), low trough concentration (5–10 ng/ml) group (LT group) (n = 22), or placebo group (n = 20). Patients received an initial oral dose of 0.05 mg/kg tacrolimus or placebo twice daily. Efficacy was evaluated in 60 patients based on a disease activity index (DAI) score. Fifty eight patients had additional treatment with tacrolimus and were evaluated for efficacy in a 10 week open label extension. Results: An improvement in DAI score (⩾4 points, all categories improved) was observed for 68.4% of cases in the HT group compared with 10.0% in the placebo group (p<0.001). In the HT group, 20.0% of patients had clinical remission and 78.9% had mucosal healing. In the open label extension, 55.2% of all patients had an improved DAI score at week 10. Mean dose of prednisolone was reduced from 19.7 mg/day at study entry to 7.8 mg/day at week 10. The incidence of side effects in the HT group was significantly higher than that of the placebo group (p = 0.043). The most common event was mild finger tremor. Conclusions: Our findings demonstrate dose dependent efficacy and safety of oral tacrolimus for remission-induction therapy of refractory UC. The optimal target range appears to be 10–15 ng/ml in terms of efficacy with two week therapy.