A Chemical Glycoproteomics Platform Reveals O-GlcNAcylation of Mitochondrial Voltage-Dependent Anion Channel 2

SummaryProtein modification by O-linked β-N-acetylglucosamine (O-GlcNAc) is a critical cell signaling modality, but identifying signal-specific O-GlcNAcylation events remains a significant experimental challenge. Here, we describe a method for visualizing and analyzing organelle- and stimulus-specific O-GlcNAcylated proteins and use it to identify the mitochondrial voltage-dependent anion channel 2 (VDAC2) as an O-GlcNAc substrate. VDAC2−/− cells resist the mitochondrial dysfunction and apoptosis caused by global O-GlcNAc perturbation, demonstrating a functional connection between O-GlcNAc signaling and mitochondrial physiology through VDAC2. More broadly, our method will enable the discovery of signal-specific O-GlcNAcylation events in a wide array of experimental contexts

Synthesis and multiplexed activity profiling of synthetic acylphloroglucinol scaffolds

Reported here are novel formic-acid-mediated rearrangements of dearomatized acylphloroglucinols to access a structurally diverse group of synthetic acylphloroglucinol scaffolds (SASs). Density-functional theory (DFT) optimized orbital and stereochemical analyses shed light on the mechanism of these rearrangements. Products were evaluated by multiplexed activity profiling (MAP), an unbiased platform which assays multiple biological readouts simultaneously at single-cell resolution for markers of cell signaling, and can aid in distinguishing genuine activity from assay interference. MAP identified a number of SASs that suppressed pS6 (Ser235/236), a marker for activation of the mTOR and ERK signaling pathways. These results illustrate how biomimetic synthesis and multiplexed activity profiling can reveal the pharmacological potential of novel chemotypes by diversity-oriented synthesis.R35 GM118173 - NIGMS NIH HHS; R01 CA226833 - NCI NIH HHS; U01 TR002625 - NCATS NIH HHS; R24 GM111625 - NIGMS NIH HHS; R01 GM092218 - NIGMS NIH HHS; P30 DK058404 - NIDDK NIH HHS; P41 GM076263 - NIGMS NIH HHS; T32 GM007347 - NIGMS NIH HHS; F30 CA236131 - NCI NIH HHS; P30 CA068485 - NCI NIH HHS; T32 GM065086 - NIGMS NIH HHSAccepted manuscrip

Mantle sources and magma evolution in Europe's largest rare earth element belt (Gardar Province, SW Greenland) : new insights from sulfur isotopes

This work is a contribution to the HiTech AlkCarb project and was funded by the European Union's Horizon 2020 research and innovation programme under grant agreement No. 689909. W.H. also acknowledges support from a UKRI Future Leaders Fellowship (MR/S033505/1). A.J.B. is funded by the NERC National Environment Isotope Facility award (NE/S011587/1) and the Scottish Universities Environmental Research Centre.Alkaline igneous complexes are often rich in rare earth elements (REE) and other metals essential for modern technologies. Although a variety of magmatic and hydrothermal processes explain the occurrence of individual deposits, one common feature identified in almost all studies, is a REE-enriched parental melt sourced from the lithospheric mantle. Fundamental questions remain about the origin and importance of the mantle source in the genesis of REE-rich magmas. In particular, it is often unclear whether localized enrichments within an alkaline province reflect heterogeneity in the mantle source lithology (caused by prior subduction or plume activity) or variations in the degree of partial melting and differentiation of a largely homogeneous source. Sulfur isotopes offer a means of testing these hypotheses because they are unaffected by high temperature partial melting processes and can fingerprint different mantle sources. Although one must be careful to rule out subsequent isotope fractionation during magma ascent, degassing and crustal interactions. Here, we present new S concentration and isotope (δ34S) measurements, as well as a compilation of major and trace element data, for a suite of alkaline magmatic units and crustal lithologies from the Mesoproterozoic Gardar Province. Samples span all phases of Gardar magmatism (1330–1140 Ma) and include regional dykes, rift lavas and the alkaline complexes Motzfeldt and Ilímaussaq, which represent two of Europe's largest REE deposits. We show that the vast majority of our 115 samples have S contents >100 ppm and δ34S of −1 to 5‰. Only 8 samples (with low S contents, <100 ppm) show evidence for crustal interactions, implying that the vast majority of Gardar melts preserve the S isotopic signature of their magma source. Importantly, samples from across the Gardar Province δ34S have above the canonical mantle range (≤−1.4‰) and therefore require recycled surface S in their mantle source. Elevated values are explained by a period of Andean-style subduction and mantle metasomatism which took place ∼500 Ma before rift onset and are also supported by trace elements signatures (e.g. Ba/La) which match modern subduction zones. Comparing the various generations of Gardar magmas, we find that δ34S  values, large ion lithophile elements (K, Ba, P) and selective incompatible elements (Nb and light REE) are particularly enriched in the Late Gardar dykes, alkaline complexes and clusters of silica-undersaturated dykes spatially associated with the alkaline complexes. These data indicate that subduction-related metasomatism of the Gardar mantle was spatially heterogeneous, and that alkaline complexes are sourced from localized mantle domains highly enriched in 34S, REE, alkalis and volatiles (particularly, F). Since alkalis and volatiles play an essential role in driving extreme differentiation of alkaline melts and fluids, we suggest the co-location of these species plus incompatible metals at high concentrations in the lithospheric mantle is a critical first-step in the genesis of a world-class alkaline REE deposit. S isotopes are powerful tools for identifying enriched mantle domains and the sources of mineralized alkaline igneous bodies.Publisher PDFPeer reviewe

Oncologic Outcomes After Clinically Node-Negative Salvage Laryngectomy

IMPORTANCE: Controversy exists regarding management of the clinically node-negative neck in patients with recurrent larynx or hypopharynx cancers who received total laryngectomy after definitive radiation with or without chemotherapy. OBJECTIVE: To explore clinical and oncologic outcomes after elective neck dissection vs observation in patients who received clinically node-negative salvage total laryngectomy. DESIGN, SETTING, AND PARTICIPANTS: This cohort study was performed from January 2009 to June 2021 at a single, high-volume tertiary care center. Follow-up was conducted through June 2021 for all patients. Survival outcomes were based on at least 2 years of follow-up. Patients aged 18 years or older with recurrent, clinically node-negative larynx or hypopharynx tumors after definitive nonsurgical treatment who were treated with a salvage total laryngectomy were included. Data were analyzed from October 2021 through September 2022. EXPOSURES: Elective neck dissection. MAIN OUTCOMES AND MEASURES: Presence and location of occult nodal metastasis in electively dissected necks, along with differences in fistula rates and overall and disease-free survival between patients receiving elective neck dissection vs observation. RESULTS: Among 107 patients receiving clinically node-negative salvage total laryngectomy (median [IQR] age, 65.0 [57.8-71.3] years; 91 [85.0%] men), 81 patients underwent elective neck dissection (75.7%) and 26 patients underwent observation (24.3%). Among patients with elective neck dissection, 13 patients had occult nodal positivity (16.0%). Recurrent supraglottic (4 of 20 patients [20.0%]) or advanced T classification (ie, T3-T4; 12 of 61 patients [19.7%]) had an occult nodal positivity rate of 20% or more, and positive nodes were most likely to occur in levels II and III (II: 6 of 67 patients [9.0%]; III: 6 of 65 patients [9.2%]; VI: 3 of 44 patients [6.8%]; IV: 3 of 62 patients [4.8%]; V: 0 of 4 patients; I: 0 of 18 patients). There was a large difference in fistula rate between elective neck dissection (12 patients [14.8%]) and observed (8 patients [30.8%]) groups (difference, 16.0 percentage points; 95% CI, -3.4 to 35.3 percentage points), while the difference in fistula rate was negligible between 50 patients undergoing regional or free flap reconstruction (10 patients [20.0%]) vs 57 patients undergoing primary closure (10 patients [17.5%]) (difference, 2.5 percentage points; 95% CI, -12.4 to 17.3 percentage points). Undergoing elective neck dissection was not associated with a clinically meaningful improvement in overall or disease-free survival compared with observation. Recurrent hypopharynx subsite was associated with an increased risk of death (hazard ratio, 4.28; 95% CI, 1.81 to 10.09) and distant recurrence (hazard ratio, 7.94; 95% CI, 2.07 to 30.48) compared with glottic subsite. CONCLUSIONS AND RELEVANCE: In this cohort study, patients with recurrent supraglottic or advanced T classification tumors had an increased occult nodal positivity rate, elective neck dissection was not associated with survival, and patients with recurrent hypopharynx subsite were more likely to have a distant recurrence and die of their disease. These findings suggest that underlying disease pathology rather than surgical management may be associated with survival outcomes in this population

Submental Island Flaps for Lateral Reconstruction: Technical Refinements for Optimal Outcomes and Resource Efficiency

OBJECTIVE: To describe our modifications to the submental island flap (SMIF) in a case series that demonstrates improved reproducibility, shortened length of stay (LOS), and reduced utilization of hospital resources. STUDY DESIGN: This retrospective case series with chart review included adult patients who underwent resection of malignant or benign tumors resulting in lateral facial, parotid, or temporal bone defects, which were reconstructed with SMIF. SETTING: A tertiary-care academic referral center. METHODS: Retrospective case series included all adult patients who underwent SMIF reconstruction between March 2020 and August 2021. Patient demographic and clinical data were collected. Primary outcomes were measures of hospital utilization including duration of surgery, LOS, and postoperative outcomes. RESULTS: Twenty-eight patients were included with a mean age of 71.7 years. Eighty percent were male. All patients underwent parotidectomy, and the mean operative time was 347 minutes. The median LOS was 2.5 days (range 0-16 days). Seventy-five percent of the flaps drained into the internal jugular vein, and 25% drained into the external jugular vein. No patients required reoperation or readmission. All flaps survived. CONCLUSION: SMIFs are a safe and effective option for reconstruction of lateral facial, parotid, and temporal bone defects. Compared to free flap reconstruction, SMIFs offer reduced length of surgery, decreased use of health care resources, and lower rate of reoperation. As health care resource allocation is increasingly important, the SMIF offers an excellent alternative to free flap reconstruction of lateral defects

The varved succession of Crawford Lake, Milton, Ontario, Canada as a candidate Global boundary Stratotype Section and Point for the Anthropocene series

An annually laminated succession in Crawford Lake, Ontario, Canada is proposed as the Global boundary Stratotype Section and Point (GSSP) for the Anthropocene as a series/epoch with a base dated at 1950 CE. Varve couplets of organic matter capped by calcite precipitated each summer in alkaline surface waters reflect environmental change at global to local scales. Spheroidal carbonaceous particles and nitrogen isotopes record an increase in fossil fuel combustion in the early 1950s, coinciding with fallout from nuclear and thermonuclear testing—239+240Pu and 14C:12C, the latter more than compensating for the effects of old carbon in this dolomitic basin. Rapid industrial expansion in the North American Great Lakes region led to enhanced leaching of terrigenous elements by acid precipitation during the Great Acceleration, and calcite precipitation was reduced, producing thin calcite laminae around the GSSP that is marked by a sharp decline in elm pollen (Dutch Elm disease). The lack of bioturbation in well-oxygenated bottom waters, supported by the absence of fossil pigments from obligately anaerobic purple sulfur bacteria, is attributed to elevated salinities and high alkalinity below the chemocline. This aerobic depositional environment, unusual in a meromictic lake, inhibits the mobilization of 239Pu, the proposed primary stratigraphic guide for the Anthropocene

Parathyroid Hormone Treatment Increases Fixation of Orthopedic Implants with Gap Healing: A Biomechanical and Histomorphometric Canine Study of Porous Coated Titanium Alloy Implants in Cancellous Bone

Parathyroid hormone (PTH) administered intermittently is a bone-building peptide. In joint replacements, implants are unavoidably surrounded by gaps despite meticulous surgical technique and osseointegration is challenging. We examined the effect of human PTH(1–34) on implant fixation in an experimental gap model. We inserted cylindrical (10 × 6 mm) porous coated titanium alloy implants in a concentric 1-mm gap in normal cancellous bone of proximal tibia in 20 canines. Animals were randomized to treatment with PTH(1–34) 5 μg/kg daily. After 4 weeks, fixation was evaluated by histomorphometry and push-out test. Bone volume was increased significantly in the gap. In the outer gap (500 μm), the bone volume fraction median (interquartile range) was 27% (20–37%) for PTH and 10% (6–14%) for control. In the inner gap, the bone volume fraction was 33% (26–36%) for PTH and 13% (11–18%) for control. At the implant interface, the bone fraction improved with 16% (11–20%) for PTH and 10% (7–12%) (P = 0.07) for control. Mechanical implant fixation was improved for implants exposed to PTH. For PTH, median (interquartile range) shear stiffness was significantly higher (PTH 17.4 [12.7–39.7] MPa/mm and control 8.8 [3.3–12.4] MPa/mm) (P < 0.05). Energy absorption was significantly enhanced for PTH (PTH 781 [595–1,198.5] J/m2 and control 470 [189–596] J/m2). Increased shear strength was observed but was not significant (PTH 3.0 [2.6–4.9] and control 2.0 [0.9–3.0] MPa) (P = 0.08). Results show that PTH has a positive effect on implant fixation in regions where gaps exist in the surrounding bone. With further studies, PTH may potentially be used clinically to enhance tissue integration in these challenging environments

Tigers Need Cover: Multi-Scale Occupancy Study of the Big Cat in Sumatran Forest and Plantation Landscapes

The critically endangered Sumatran tiger (Panthera tigris sumatrae Pocock, 1929) is generally known as a forest-dependent animal. With large-scale conversion of forests into plantations, however, it is crucial for restoration efforts to understand to what extent tigers use modified habitats. We investigated tiger-habitat relationships at 2 spatial scales: occupancy across the landscape and habitat use within the home range. Across major landcover types in central Sumatra, we conducted systematic detection, non-detection sign surveys in 47, 17×17 km grid cells. Within each cell, we surveyed 40, 1-km transects and recorded tiger detections and habitat variables in 100 m segments totaling 1,857 km surveyed. We found that tigers strongly preferred forest and used plantations of acacia and oilpalm, far less than their availability. Tiger probability of occupancy covaried positively and strongly with altitude, positively with forest area, and negatively with distance-to-forest centroids. At the fine scale, probability of habitat use by tigers across landcover types covaried positively and strongly with understory cover and altitude, and negatively and strongly with human settlement. Within forest areas, tigers strongly preferred sites that are farther from water bodies, higher in altitude, farther from edge, and closer to centroid of large forest block; and strongly preferred sites with thicker understory cover, lower level of disturbance, higher altitude, and steeper slope. These results indicate that to thrive, tigers depend on the existence of large contiguous forest blocks, and that with adjustments in plantation management, tigers could use mosaics of plantations (as additional roaming zones), riparian forests (as corridors) and smaller forest patches (as stepping stones), potentially maintaining a metapopulation structure in fragmented landscapes. This study highlights the importance of a multi-spatial scale analysis and provides crucial information relevant to restoring tigers and other wildlife in forest and plantation landscapes through improvement in habitat extent, quality, and connectivity

Mammal responses to global changes in human activity vary by trophic group and landscape

Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amount and timing of animal activity varied widely. Under higher human activity, mammals were less active in undeveloped areas but unexpectedly more active in developed areas while exhibiting greater nocturnality. Carnivores were most sensitive, showing the strongest decreases in activity and greatest increases in nocturnality. Wildlife managers must consider how habituation and uneven sensitivity across species may cause fundamental differences in human–wildlife interactions along gradients of human influence.Peer reviewe

The Athena X-ray Integral Field Unit (X-IFU)

The X-ray Integral Field Unit (X-IFU) is the high resolution X-ray spectrometer of the ESA Athena X-ray observatory. Over a field of view of 5' equivalent diameter, it will deliver X-ray spectra from 0.2 to 12 keV with a spectral resolution of 2.5 eV up to 7 keV on similar to 5 '' pixels. The X-IFU is based on a large format array of super-conducting molybdenum-gold Transition Edge Sensors cooled at similar to 90 mK, each coupled with an absorber made of gold and bismuth with a pitch of 249 mu m. A cryogenic anti-coincidence detector located underneath the prime TES array enables the non X-ray background to be reduced. A bath temperature of similar to 50 mK is obtained by a series of mechanical coolers combining 15K Pulse Tubes, 4K and 2K Joule-Thomson coolers which pre-cool a sub Kelvin cooler made of a He-3 sorption cooler coupled with an Adiabatic Demagnetization Refrigerator. Frequency domain multiplexing enables to read out 40 pixels in one single channel. A photon interacting with an absorber leads to a current pulse, amplified by the readout electronics and whose shape is reconstructed on board to recover its energy with high accuracy. The defocusing capability offered by the Athena movable mirror assembly enables the X-IFU to observe the brightest X-ray sources of the sky (up to Crab-like intensities) by spreading the telescope point spread function over hundreds of pixels. Thus the X-IFU delivers low pile-up, high throughput (> 50%), and typically 10 eV spectral resolution at 1 Crab intensities, i.e. a factor of 10 or more better than Silicon based X-ray detectors. In this paper, the current X-IFU baseline is presented, together with an assessment of its anticipated performance in terms of spectral resolution, background, and count rate capability. The X-IFU baseline configuration will be subject to a preliminary requirement review that is scheduled at the end of 2018. The X-IFU will be provided by an international consortium led by France, the Netherlands and Italy, with further ESA member state contributions from Belgium, Czech Republic, Finland, Germany, Ireland, Poland, Spain, Switzerland and contributions from Japan and the United States.Peer reviewe