Jacobs (United States)

We report on progress in fabrication of cladded rare earth doped single crystal fiber. Crystalline core fabrication, cladding compositions and cladding fabrication are discussed with the end goal of facilitating of splicing and integration into laser systems. Progress in splicing single crystal fiber to silica fiber with low loss will be reported.

Regulatory drivers and environmental concern continue to exert downward pressure on engine emissions from pipeline compressor stations. Collaboration among government, industry, and academic entities resulted in substantial reductions in most engine emissions, but several opportunities likely remain for continued improvement. The technologies needed to achieve improvements remain unknown. This document summarizes a collaborative effort among PRCI, key stakeholders in industry, and members of academia to create a research roadmap that intends to guide discovery of the opportunities and technologies for reduced engine emissions. The document summarizes a brief literature review conducted before an in-person workshop took place to identify the most likely research topics that target future technology development for improved engine emissions. Further, the document describes the jointly-developed roadmap and provides context to the various topics appearing on the roadmap. The document intends to serve members of PRCI Compressor and Pump Station Committee, along with members of industry and academia, in identifying potential research projects that could lead to new and innovated technology that primarily seeks to improve engine emissions and efficiency, but also considers engine reliability and maintainability. The document could serve prospective research contractors seeking to contribute to PRCI's mission. Finally, the document could serve other PRCI committees should this document serve as an exemplar for roadmap development and reporting.

Hypertension remains the leading modifiable risk factor attributable to 10.8 million premature deaths. Hence the study of hypertension and gut microbiome as a therapeutic target is very important. Yet the links between the gut microbiome and long-term incidence of hypertension are unknown. This study assessed the association between gut microbiome and incident hypertension. The study sample consisted of 3311 nonhypertensive individuals (60.7% women) aged 25-74 years who were drawn from the general population in Finland. In the baseline examination performed in the year 2002, the participants underwent a health examination and provided a stool sample. The gut microbiome was assessed using shallow shotgun metagenomic sequencing. Microbiome analyses were performed with Cox proportional hazards model. In total, 675 participants developed hypertension over a follow-up period of nearly 20 years. In multivariable-adjusted models, overall gut microbiome composition was not related to risk of future hypertension. Eight genera, including Agathobaculum, Blautia_A_141780, Blautia_A_141781, Mediterraneibacter_A_155590, Enterocloster , Bariatricus , CAG-317-146760 , and CAG-628 were significantly associated with incident hypertension in the age-adjusted and sex-adjusted models, but none remained significant in the multivariable-adjusted models. No functional pathways were associated with hypertension risk. Our results do not provide strong evidence for an association between the gut microbiome and risk of future hypertension, especially after adjusting for covariates that are known to influence the gut microbiome.

Posterior fossa decompression, with or without duraplasty, is effective for the treatment of pediatric patients with symptomatic Chiari malformation type I (CM-I). The aim of this study was to compare effectiveness and clinical outcomes of Y-shaped vs linear techniques during posterior fossa decompression with duraplasty (PFDD) for CM-I patients. Retrospective review of data for pediatric patients (≤21 years old) with CM-I and surgically managed with PFDD with or without C1 laminectomy was performed. Clinical characteristics, including presence of a syrinx and presentation, were recorded. Patients were dichotomized into 2 propensity score-matched (PSM) groups based on whether a Y-shaped or linear dural incision was used. All statistical tests were 2-tailed, and a P-value <.05 was significant. A total of 228 patients met the inclusion criteria, with 124 undergoing linear and 104 undergoing Y-shaped dural incision. After PSM, each group had 66 patients who were well-matched for age, sex, presentation, and extent of tonsillar herniation. Patients in the linear incision group had significantly lower estimated blood loss (Y-shaped: 66.5 ± 75.8 mL vs linear: 33.9 ± 18.9 mL, P < .01). Although the rate of complete symptom resolution was higher in the linear group before PSM (Y-shaped: 28.8% vs linear: 57.3%, P < .001), this difference was not significant after PSM (Y-shaped: 31.8% vs linear: 47%, P = .205). Similarly, fewer repeat decompression procedures were needed in the linear group before PSM (Y-shaped: 13.5% vs linear: 0.8%, P < .001) but not after (Y-shaped: 10.6% vs linear: 1.5%, P = .062). Linear and Y-shaped dural incisions are safe and effective for PFDD in pediatric CM-I patients. Linear incisions were associated with reduced blood loss, although neither group had a clinically significant blood loss and overall clinical outcomes were comparable after PSM. These findings can help guide surgical decision-making for CM-I. Further studies are warranted to validate these results and explore the influence of surgeon experience and preference on the associated outcomes.

Abstract. Water scarcity and recurrent droughts threaten agricultural productivity and water security in the semi-arid Krishna River Basin of southern India. This study integrates satellite observations and machine learning techniques to assess long-term terrestrial water storage (TWS) and drought dynamics from 1992 to 2022. The Extreme Gradient Boosting (XGBoost) algorithm was employed to reconstruct GRACE-based Terrestrial Water Storage Anomalies (TWSA) using precipitation, temperature, evapotranspiration, and soil moisture as predictors. The reconstructed TWSA showed strong consistency with GRACE/GRACE-FO data (R2 = 0.92, RMSE = 43.18 mm), extending the GRACE record to earlier decades. The GRACE Drought Severity Index (GRACE-DSI), applied at a 3-month scale, identified 15 major drought events during 1992–2022, with the most severe occurring in 2015–2017 (minimum DSI = −2.0) and 2018–2019 (minimum DSI = −2.63). Droughts typically recurred every 5–7 years, showing increased intensity after 2010. Land use and land cover (LULC) analysis from ESA-CCI data revealed declining agricultural areas and shrublands, alongside expansion of forests and urban land. Correlation between LULC changes and TWSA was weak, indicating stronger climatic control on basin water storage. The study underscores the value of fusing remote sensing, statistical tools, and hydrological indices to support better monitoring and governance of land and water systems in drought-prone basins.

Simultaneous measurements of HDO, H218O, and H216O in water evolved during pyrolysis of powdered rock samples acquired by the Curiosity rover within Gale crater's clay-bearing units indicate extreme and variable heavy-isotope enrichments averaging ~4.5 times the D/H ratio and ~1.03 times the 18O/16O ratio of terrestrial seawater. These enrichments are recorded in water desorbed from mineral surfaces and evolved from poorly crystalline phases, hydrated salts, jarosite, and clays. All evolved waters are deuterium-enriched relative to common terrestrial waters, reflecting hydrogen loss to space. Because oxygen in structurally bound hydroxyl groups is least likely to exchange with other sources over geologic timescales, we focus on oxygen in water evolved during dehydroxylation of smectite clays. Several samples have 18O/16O ratios commensurate with precipitation from, or near-complete equilibration with, water moderately 18O-enriched relative to terrestrial meteoric waters-consistent with other evidence that Mars's hydrosphere is basically like Earth's in terms of oxygen isotopes. Unlike hydrogen, oxygen atmospheric escape did not lead to extreme 18O enrichments on Mars. Locally, however, most Gale smectites' 18O/16O values require a pronounced 18O-enrichment of their parental waters. On Earth, the most extreme 18O enrichments in surface waters are found in closed basins having undergone significant evaporative loss into a low-humidity atmosphere, and the 18O/16O of authigenic clay minerals formed in these environs reflect those enrichments. A similar process acting on the hydrologic reservoir local to Gale at the time of clay formation and early diagenesis is a plausible explanation for the distinctive oxygen isotopic compositions of these clays.

Academic Library Workers in Conversation is a C&amp;RL News series focused on elevating the everyday conversations of library professionals. The wisdom of the watercooler has long been heralded, but this series hopes to go further by minimizing barriers to traditional publishing with an accessible format. Each of the topics in the series was proposed by the authors, and the authors were given space to explore. This issue’s conversation connects with the article in the September 2025 issue1 and continues the exploration of contingent labor practices in libraries and precarity. This article explores how managers and leaders can better support workers. - Dustin Fife, series editor

Decreasing radiation exposure in renal colic management involves revisiting diagnostic, intraoperative, and postoperative practices. One approach is a shift in procedural standards from intraoperative fluoroscopy to ultrasonography. Despite the increased implementation of ultrasound in urology, the ultrasound visibility or echogenicity of various stents is not well-studied. Silicone stents, traditionally considered less radiopaque, pose challenges during placement under fluoroscopy due to their reduced visibility. However, a shift to ultrasound-based guidance can levels the playing field, as silicone stents demonstrate comparable echogenicity to stents made from other materials. This study aims to evaluate and quantify the echogenicity of different ureteral stents on the market, with a focus on silicone stents, which traditionally have been considered less radiopaque yet potentially advantageous for less patient discomfort. We conducted a simulation study using five different brands of ureteral stents in an ex-vivo porcine bladder model. We measured the mean grey intensity to quantify echogenicity of each stent. After comparing the echogenicity of individual stents, we grouped stents based on materials and diameters and performed T-tests. We established that ureteral stents can demonstrate good visibility inside porcine bladder under ultrasound. Upon further investigation, we found that diameter is the most important variable in determining the measured echogenicity of ureteral stents. 8 Fr ureteral stents have higher measured echogenicity than the Sensor wire and 6 Fr stents. Stent materials also play a role in the measured echogenicity of ureteral stents. With the same diameter, silicone is measurably more echogenic than polyurethane. This study describes a novel quantitative assessment of ureteral stent echogenicity, which can guide the development of novel echogenic stents and provide a benchmark for existing stents. In addition, it suggests that ultrasonography may facilitate the placement of silicone stents, which historically have been more difficult to visualize with fluoroscopy.