Obvious Source Research Articles

Tectonic Inversion of Intracontinental Basins and the Conundrum of Plate‐Scale Stress Propagation: The Case of the Jatobá Basin, NE Brazil

AbstractWe chose the Jatobá Basin (JB) in the Borborema Province in northeastern Brazil to address two outstanding problems, basin tectonic inversion and stress propagation, because (a) evidence of tectonic inversion is conspicuous in the JB, and (b) the basin sits on intracontinental northeastern Brazil, far from plate boundaries and the most obvious stress sources. We found robust evidence of oblique reverse faulting inside the basin, putting sediments of the JB's depocenter hundreds of meters above the hard granitic host basement. We also found sound evidence of hydrographic flow reversal, that is, earlier basement‐to‐basin runoff, followed by basin‐to‐basement runoff. This change means that formerly the basement stood higher than the basin, and later the basin was uplifted (inverted) to currently stand hundreds of meters higher than the basement, especially where the gravity anomaly map shows the deepest depocenter. Coarse conglomerates, sourced in the uplifted basin and blanketing the adjacent basement for kilometers, are only cut by the current hydrographic network. From these main lines of evidence, we infer recent basin tectonic inversion (Quaternary, i.e., <2.6 Ma?). The WSW‐ENE orientation of the maximum compressive stress needed to invert the basin likely results from Mid‐Atlantic and Andean pushes. We conclude that lithospheric plates can deform in their cores because of stresses propagating from plate boundaries to distant plate interiors, where the lithosphere has been locally weakened and strain has concentrated.

An adaptive method for real‐time photovoltaic power forecasting utilizing mathematics and statistics: Case studies in Australia and Vietnam

AbstractThe advancement of Photovoltaic technology has undergone rapid acceleration in recent years. Nonetheless, the most significant drawback of Photovoltaic is its intermittence, making it an obvious source of power fluctuation. This study proposes a novel scheme for real‐time or intraday PV power forecasting by adopting two predictive models, namely, White‐box and Combination. The White‐box model is implemented employing mathematical calculations and statistics called Exceedance Probability. Meanwhile, the Combination model is an aggregation of several predictive models' outputs including the White‐box model and benchmark ones by dynamically adjusting the weight coefficient of each model based on their forecasting accuracy. The experimental results, which are verified on two PV systems corresponding to two case studies located at Vietnam and Australia, indicate that the two proposed models outperform other referenced models as improves approximately 40% and 38% in terms of the first and second case study, respectively. In particular, the White‐box model shows superiority by updating the forecast every 10 min, which can adapt to the fluctuation of weather conditions whereas the Combination one yields acceptable precision, indicating its flexible application.

Microplastics in coral from three Mascarene Islands, Western Indian Ocean

Little is known about microplastics (MPs) in corals from the Indian Ocean. We compared MP concentrations, morphotypes, size, colours, and polymer compositions in six coral genera from three remote Mascarene islands (Rodrigues, St. Brandon's Atoll, and Agalega) of the Republic of Mauritius, on a 1200 km transect located in the South Equatorial Current (SEC). The mean MP concentration was 0.78 n/g (53 % fibres) with no significant differences between islands. Polymers were polypropylene (78 %) and polyethylene (18 %). We conclude that the SEC's MP concentrations and compositions have homogenized over thousands of kilometres across the Indian Ocean. We discuss the lack of hazardous polyurethane MPs in coral samples given obvious sources on St Brandon. To the best of our knowledge, this study is the first to report on MPs in coral from the Western Indian Ocean and the Mascarene Islands providing a baseline for further research, monitoring, mitigation, and policy development.

Material characteristic of Vetvisty creek placer gold and prospects for atypical-source deposits in the middle course of the Selennyakh river (Momsky and Abyisky district, Yakutia)

Background. The lower-middle course of the Selennyakh River in the Momsky and Abyisky districts of the Republic of Sakha, Yakutia, is characterized by a wide distribution of alluvial gold placers. The absence of obvious potential primary sources of these placers raises the question of their identification. Aim. To identify sources of gold placers found in interfluve area of the Selennyakh and Indigirka rivers, as well as to assess the gold-bearing potential of this area.Materials and methods. The data on the studied area obtained in previous works was analyzed. Microprobe analysis (CSRF IGEM RAS) was used to study the composition of alluvial gold grains sampled during field works in the Vetvisty Creek, the right tributary of the Selennyakh River, conducted in 2020–2021. The mineral composition of heavy concentrate was also studied.Results. The source of the gold placer under study was established to be an intermediate reservoir, i.e., Neogene coarse sand and gravel. Possible paths of gold transit within the placer were revealed. Theoretically, this allows enriched layers in the sediments feeding the placer to be localized.Conclusion. In order to replenish the gold mineral base of the country, including in such hard-toreach regions as the Arctic zone of the Russian Federation, regional research projects should be resumed. In addition, new models should be developed for forecasting and prospecting of atypical placer deposits, with gold sources from Tertiary sediments filling large Cenozoic depressions in the western rim of the Yano-Indigirskaya lowland).

Systematic errors in searches for nanohertz gravitational waves

ABSTRACT A number of pulsar timing arrays have recently reported preliminary evidence for the existence of a nanohertz frequency gravitational wave background. These analyses rely on noise analyses, which are inherently complex due to the many astrophysical and instrumental factors. We investigate whether realistic systematic errors, stemming from misspecified noise models that fail to capture salient features of the pulsar timing noise, could bias the evidence for gravitational waves. We consider two plausible forms of misspecification: small instrumental pulse arrival time offsets and radio-frequency-dependent time-correlated noise. Using simulated data, we calculate the distribution of the commonly used optimal statistic with no signal present and using plausibly misspecified noise models. By comparing the optimal statistic distribution with the distribution created using “quasi-resampling” techniques (such as sky scrambles and phase shifts), we endeavour to determine the extent to which plausible misspecification might lead to a false positive. The results are reassuring: we find that quasi-resampling techniques tend to underestimate the significance of pure-noise data sets. We conclude that recent reported evidence for a nanohertz gravitational wave background is likely robust to the most obvious sources of systematic errors; if anything, the significance of the signal is potentially underestimated.

H i Lyα Emission from a Metal-poor Cool Stream Fueling an Early Dusty Starburst

The GAMA J0913−0107 system is a rare conjunction of a submillimeter galaxy (SMG) at z ≈ 2.7 and two background QSOs with projected separations <200 kpc. Previous high-resolution QSO absorption-line spectroscopy has revealed high H i column density, extremely metal-poor (∼1% solar) gas streams in the circumgalactic medium of the SMG. Here we present deep optical integral-field spectroscopy of the system with the Keck Cosmic Web Imager (KCWI). Reaching a 2σ surface brightness limit ≈10−19 erg s−1 cm−2 arcsec−2 with ∼2 hr of integration time, we detect a filamentary Lyα nebula stretching ∼180 kpc from the SMG intercepting both QSO sightlines. This Lyα filament may correspond to the same cool gas stream penetrating through the hot halo seen in the absorption. In contrast to Lyα nebulae around QSOs, there is no obvious local source for photoionization due to the massive dust content. While uncertain, we consider the possibility that the nebula is ionized by shocks induced by the infall, obscured star formation, and/or a boosted UV background. The SMG–QSOs conjunction multiplied the efficiency of the KCWI observations, allowing a direct comparison of Lyα nebulae in two distinct environments. We find that the nebulae around the QSOs are much brighter and show steeper surface brightness profiles than the SMG nebula. This is consistent with the additional photoionization and Lyα scattering provided by the QSOs. While illustrating the challenges of detecting Lyα nebulae around SMGs, our work also demonstrates that important insights can be gained from comparative studies of high-z Lyα nebulae.

Nanofluidic Platform for Studying the First-Order Phase Transitions in Superfluid Helium-3

The symmetry-breaking first-order phase transition between superfluid phases 3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}He-A and 3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}He-B can be triggered extrinsically by ionising radiation or heterogeneous nucleation arising from the details of the sample cell construction. However, the role of potential homogeneous intrinsic nucleation mechanisms remains elusive. Discovering and resolving the intrinsic processes may have cosmological consequences, since an analogous first-order phase transition, and the production of gravitational waves, has been predicted for the very early stages of the expanding Universe in many extensions of the Standard Model of particle physics. Here we introduce a new approach for probing the phase transition in superfluid 3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}He. The setup consists of a novel stepped-height nanofluidic sample container with close to atomically smooth walls. The 3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}He is confined in five tiny nanofabricated volumes and assayed non-invasively by NMR. Tuning of the state of 3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}He by confinement is used to isolate each of these five volumes so that the phase transitions in them can occur independently and free from any obvious sources of heterogeneous nucleation. The small volumes also ensure that the transitions triggered by ionising radiation are strongly suppressed. Here we present the preliminary measurements using this setup, showing both strong supercooling of 3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}He-A and superheating of 3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}He-B, with stochastic processes dominating the phase transitions between the two. The objective is to study the nucleation as a function of temperature and pressure over the full phase diagram, to both better test the proposed extrinsic mechanisms and seek potential parallel intrinsic mechanisms.

Assessing the clinical utility of abdominal computed tomography in sepsis patients with unknown origin: A retrospective cohort study.

Early identification of the sources of infection in emergency department (ED) patients of sepsis remains challenging. Computed tomography (CT) has the potential to identify sources of infection. This retrospective study aimed to investigate the role of CT in identifying sources of infection in patients with sepsis without obvious infection foci in the ED. A retrospective chart review was conducted on patients with fever and sepsis visiting the ED of Linkou Chang Gung Memorial Hospital between July 1, 2020 and June 30, 2021. Data on patient demographics, vital signs, clinical symptoms, underlying medical conditions, laboratory results, administered interventions, length of hospital stay, and mortality outcomes were collected and analyzed. Of 218 patients included in the study, 139 (63.8%) had positive CT findings. The most common sources of infection detected by CT included liver abscesses, acute pyelonephritis, and cholangitis. Laboratory results showed that patients with positive CT findings had higher white blood cell and absolute neutrophil counts and lower hemoglobin levels. Positive blood culture results were more common in patients with positive CT findings. Additionally, the length of hospital stay was longer in the group with positive CT findings. Multivariate logistic regression analysis revealed that hemoglobin levels and positive blood culture results independently predicted positive CT findings in patients with fever or sepsis without an obvious source of infection. In patients with sepsis with an undetermined infection focus, those presenting with leukocytosis, anemia, and elevated absolute neutrophil counts tended to have positive findings on abdominal CT scans. These patients had high rates of bacteremia and longer lengths of stay. Abdominal CT remains a valuable diagnostic tool for identifying infection sources in carefully selected patients with sepsis of undetermined infection origins.

Pertumbuhan dan Perkembangan Ilmu Komunikasi

The aim of this study is to learn how the ancient growth and development of the communication sciences made such a widespread development in the present era. The study employed a library study method by conducting a qualitative study method using a descriptive method. The study gathered data available from journals and books associated with the growth and development of communication sciences. The technique employed in this data collection involves recording and summarizing a number of obvious data sources. Analysis in this data collection suggests that the growth and development of communication sciences go through many processes in the stages of its development. The results of this study suggest that the growth and development of the communications science are constantly changing over the years and is thus growing rapidly and broadly in the present era.

Subcutaneous Emphysema Following Laser Assisted Dilation of Subglottic Stenosis: A Case Report

Introduction: Subcutaneous emphysema is characterized by the accumulation of air beneath the dermal layers of the skin. We present a case of extensive subcutaneous emphysema of the neck, face and arms in a patient who was two days post operative from laser assisted dilation of subglottic stenosis. Materials and Methods: We present a case of subcutaneous emphysema in a patient who presented to the emergency department. As this is a case report, no additional materials or specific methods were required. Case Presentation: A 71-year-old man with history of tracheal stenosis status post laser assisted subglottic dilation presented to the emergency department two days post-operatively for progressively worsening swelling of the face, neck and arms. Physical exam was notable for crepitus of the face, neck and arms. Oropharyngeal exam showed no edema to the posterior oropharynx or tongue. Breathing was non-labored without stridor. Imaging revealed extensive subcutaneous emphysema without any obvious source. The otolaryngology (ENT) service evaluated the patient and admitted him to their service. Initially he was managed conservatively via observation and supportive care however, on day two of hospitalization his respiratory status worsened. He required intubation and tracheal stent placement. The tracheal defect was never found on exploration in the operating room, suggesting the defect was sub-centimeter in size. He was extubated on hospital day four and discharged with a plan to have the tracheal stent in place for three months. Conclusion: Subcutaneous emphysema secondary to a tracheobronchial tree defect is a known complication of laser dilatation of subglottic stenosis. Most cases resolve spontaneously and can be managed conservatively. However, patients require close airway monitoring as some may require emergent airway management. Clinicians should be aware of this complication and subsequent management.

Double aortic arch and aortotracheal fistula as cause of fatal massive bleeding: a rare and dangerous association

To present a clinical case with an unusual association of DAA with ATF and to reinforce the importance of maintaining high diagnostic suspicion in patients with massive aerodigestive bleeding without an obvious source. A 32-week preterm newborn who required prolonged mechanical ventilation and presented intermittent episodes of massive oropharyngeal bleeding with hemodynamic compromise associated with lower airway obstruction without pulmonary hemorrhage. The patient underwent upper endoscopy and exploratory laparotomy without evidence of bleeding. Flexible nasopharyngolaryngoscopy and direct laryngoscopy also showed no abnormalities. A CT angiography showed complete DAA with indentation of the left dominant arch over the trachea, without severe stenosis or evidence of a fistula. AEF was suspected, so exploratory surgery was considered. However, the patient died before surgery due to a massive pulmonary hemorrhage. The autopsy revealed the presence of ATF. In patients with massive aerodigestive bleeding without an obvious source, the presence of DAA and possible AEF/ ATF should be considered. Imaging studies have a poor performance for this diagnosis, so surgery should be considered for diagnosis and treatment in these patients.

Usefulness of the hybrid technique of interventional radiology and endoscopic treatment for intestinal bleeding after pancreaticoduodenectomy: a case report

Introduction and importance: In endovascular treatment of ruptured pseudoaneurysm after pancreaticoduodenectomy (PD) with gastrointestinal bleeding, treatment for vasospasm of the culprit vessel from haemorrhagic shock and subsequent reperfusion has not been determined before. Case presentation: The authors hereby present you with a case of a 59-year-old man with unknown operative method upon arrival at the Emergecy room and who had hematemesis and collapse 6 months post-PD surgery. Clinical discussion: An initial contrast-enhanced computed tomography (CT) revealed no obvious source of bleeding, so an upper gastrointestinal endoscope was performed. Rebleeding occurred during the examination, and interventional radiology was performed because haemostasis was difficult. Coil embolization was performed for leakage of contrast material from the gastroduodenal artery stump into the gastrointestinal tract. However, because the embolization was uncertain due to vasospasm of the common hepatic artery, endoscopic clipping of the perforation site was also performed to prevent rebleeding due to reperfusion after improvement of vasospasm. A CT scan 5 days later showed reperfusion of the coil-implanted vessel. No rebleeding or hepatic infarction occurred postoperatively. Conclusion: In this case, the haemostasis by coil embolization was uncertain due to the presence of vasospasm, and clipping was used in combination with the procedure to prevent rebleeding.

Particle Size, Effects of Distance and Height from Source, Carbon Components, and Source of Dust in Nanchang, Central China

Regional air quality and major sources can be reflected by dust. 87 dust samples in Nanchang (four residential areas and three roadside points) were collected, with particle size and carbon components determined to discuss the distribution characteristics and the sources. The distribution of dust particle size in different sampling areas was similar, composed mainly of particles larger than 10 μm (over 69.8%). Dust particle size showed a decreasing trend with increasing horizontal distance from the main road and vertical height from the ground. EC in road dust was higher than that in residential dust. EC outdoors was higher than EC indoors in the same area. OC in indoor dust was higher than that in atmospheric dust when there were obvious indoor OC emission sources. The main carbon fractions in residential dust were OC3 and EC1, and in road dust were EC2 and OC3. The distribution of carbon fractions showed that OC3 and EC2 were mainly affected by human activities and motor vehicle emissions, respectively. The ratio of OC/EC and SOC in dust decreased from autumn to winter. SOC in the dust of Nanchang was at a medium level compared to other cities/regions around world. Clustering analysis and principal component analysis indicated that combustion sources (coal and biomass combustion, etc.), motor vehicle exhaust sources (gasoline and diesel vehicles), and human sources (cooking fumes, cigarette smoking, etc.) were the main contributors to the carbon components in dust.

Prophylactic Antibiotic Use Prior to Port Placement and Its Effect on Insertion-Related Infection Rates: A Five-Year Retrospective Review

Abstract Purpose The aim of this study was to compare insertion-related port infection rates between patients who received intraprocedural prophylactic antibiotics versus those who did not. Materials and Methods All patients who underwent port insertion by interventional radiology from 7/1/ 2015 through 7/1/2020 at a single U.S.-based Health System were identified using electronic medical records database. During this period, 2,099 patients underwent port placement at three hospitals within the same health system. One-thousand sixty-three patients who underwent port placement at one hospital received periprocedural antibiotics and 1,036 patients at the two other hospitals did not receive antibiotics. Retrospective data were reviewed on each patient including demographics, reason for port insertion, and evidence of port infection. All relevant data up to 30 days postinsertion were reviewed, including blood cultures, unplanned readmissions, emergency room visits, and clinic visits. Qualitative trends were evaluated for various subgroups including presence of bacteremia, time from insertion, and demographics. Patients with an obvious external source of infection were excluded. Results Insertion-related infection rate was 0.9% for the entire cohort, 1.23% for the antibiotic group, and 0.68% for the nonantibiotic group. The insertion-related infection for adult patients was 0.88% for the antibiotic group and 0.68% for the nonantibiotic group. The pediatric insertion-related infection rate was 7.69%, all of whom received intravenous antibiotics. No other clear qualitative differences were noted for analyzed subgroups. Conclusion This study demonstrates low insertion-related port infection rate with no clinically significant difference between the groups that did or did not receive antibiotics. Subgroup analysis showed an exceptionally high infection rate in the pediatric population despite receiving preprocedure antibiotics.

Solar Active Region Coronal Jets. III. Hidden-onset Jets

Solar quiet- and coronal-hole region coronal jets frequently clearly originate from erupting minifilaments, but active-region jets often lack an obvious erupting-minifilament source. We observe a coronal-jet-productive active region (AR), AR 12824, over 2021 May 22 0–8 UT, primarily using Solar Dynamics Observatory (SDO) Atmospheric Imaging Array (AIA) EUV images and SDO/Helioseismic and Magnetic Imager magnetograms. Jets were concentrated in two locations in the AR: on the south side and on the northwest side of the AR’s lone large sunspot. The south-location jets are oriented so that we have a clear view of the jets’ origin low in the atmosphere: their source is clearly minifilaments erupting from locations showing magnetic flux changes/cancelations. After erupting a projected distance ≲5″ away from their origin site, the minifilaments erupt outward onto far-reaching field as part of the jet’s spire, quickly losing their minifilament character. In contrast, the northwest-location jets show no clear erupting minifilament, but the source site of those jets are obscured along our line of sight by absorbing chromospheric material. EUV and magnetic data indicate that the likely source sites were ≳15″ from where the we first see the jet spire; thus, an erupting minifilament would likely lose its minifilament character before we first see the spire. We conclude that such AR jets could work like non-AR jets, but the erupting-minifilament jet source is often hidden by obscuring material. Another factor is that magnetic eruptions making some AR jets carry only a harder-to-detect comparatively thin (∼1″–2″) minifilament “strand.”

Mineral Weathering and Metal Leaching under Meteoric Conditions in F-(Ba-Pb-Zn) Mining Waste of Hammam Zriba (NE Tunisia)

Mining waste is an obvious source of environmental pollution due to the presence of heavy metals, which can contaminate soils, water resources, sediments, air, and people living nearby. The F-(Ba-Pb-Zn) deposit of Hammam Zriba located in northeast Tunisia, 8 km southeast of Zaghouan was intensively exploited from 1970 to 1992. More than 250,000 m3 of flotation tailings were produced and stored in the open air in three dumps without any measure of environmental protection. Thus, in this paper, mineralogical and chemical characterization, especially the sulfide and carbonate phases, were carried out to evaluate the potential for acid mining drainage (AMD) and metal leaching (ML). Conventional analytical methods (XRD, XRF, SEM) have revealed that this mining waste contains on average 34.8% barite–celestine series, 26.6% calcite, 23% quartz, 6.3% anglesite, 4.8% fluorite, 2.1% pyrite, and 0.4% sphalerite. The content of sulfides is less important. The tailing leaching tests (AFNOR NFX 31-210 standard) did not generate acidic leachate (pH: 8.3). The acidity produced by sulfide oxidation was neutralized by calcite present in abundance. Furthermore, the leaching tests yielded leachates with high concentrations of heavy metals, above the authorized thresholds. This high mobilization rate in potential toxic elements (PTE) represents a contamination risk for the environment.

The Influence of Bedroom CO2 Concentration on Sleep Quality

A person spends about a third of their life sleeping, and high sleep quality is very important for health. Environmental factors are one of the most important factors affecting sleep quality, and indoor carbon dioxide (CO2) concentration while sleeping has a significant effect on sleep quality. In an indoor bedroom with no open windows and no fresh air system, different numbers of people sleeping will lead to changes in indoor CO2 concentration. In order to study the changes in sleep quality caused by differences in CO2 concentration, experimental research was performed. Objective sleep quality data are collected with polysomnography (PSG) and a subjective questionnaire. The sleep quality of the subjects is tested under three different CO2 concentration levels; the average carbon dioxide concentration of three conditions is 680, 920, and 1350 ppm, which simulate a room with 1, 2, and 3 people sleeping, respectively. Other environment parameters are controlled as follows: test environment temperature is 26 ± 0.5 °C, relative humidity is 50 ± 5%, there is no obvious heat source in the test room, and the radiation temperature and air temperature difference is less than 1 °C. A total of 30 subjective tests were carried out with 10 subjects; the test lasted more than one month. The data subsequently underwent statistical analysis to determine the influence of CO2 concentration on sleep quality. The results show that as the CO2 concentration level increased, the sleep quietness and satisfaction of the subjects gradually decreased, the sleep duration gradually decreased, and symptoms such as throat discomfort, dyspnea, dry and itchy skin, difficulty falling asleep, difficulty waking up, congested nose and bad air smell become more obvious. The PSG test results showed that CO2 concentration has a significant impact on the proportion of the N3 period. According to the group of CO2 concentration conditions, the mean of the N3 period proportion under the conditions of one person, two persons, and three persons is 20.4%, 17.3%, and 14.4%, respectively. Finally, there was also an increase in turning over or awakening during sleep, indicating that sleep quality was reduced under higher CO2 concentrations.

The Role of Endoscopy in Investigating the Causes of Persistent Anaemia in Post-operative Fractured Neck of Femur Patients.

Introduction Post-operative anaemia in hip fracture patients has been associated with increased risk of blood transfusion, poorer functional outcomes, increased morbidity and mortality. Patients with persisting drop in haemoglobin after fractured neck of femur with no obvious source of blood loss are often referred for endoscopy to find the cause of anaemia. The reported incidence of perioperative acute upper gastrointestinal bleeding varies from 1 to 15%. Objective The aim of our study is to find out the usefulness of endoscopy in finding gastrointestinal causes leading to the occult loss of blood causing irreversible anaemia in post-operative neck of femur fractures. Material and methods The orthogeriatric unit conducted a study using retrospective dataon neck of femur fracture patients from January 2015 to December 2020. Out of 1863 cases, 918 (49.3%) developed post-operative anaemia. Forty-five patients (5%) with refractory anaemia underwent endoscopy referral. Patient demographics, fracture patterns, pre-existing anaemia, and co-morbidities (anaemia, heart disease, chronic kidney disease, oral anticoagulant usage) were recorded. The recorded information also included the type of procedure undergone by each patient. Intra-operative tranexamic acid injections were administered to all patients. Results Male patients accounted for 24% (11) and females for 76% (34). The average age was 82.3 years (range: 73-94). In terms of fracture type, 60% (27) were intracapsular and 40% (18) were extracapsular. Iron deficiency anaemia was present in 24% (11), oral anticoagulants in 20% (9), and systemic malignancy in 12% (6) of patients. The mean post-operative hemoglobin level during endoscopy referral was 7.3 g/dL. Endoscopy revealed normal findings in 60% (27), esophagitis/gastritis in 20% (8), and hiatus hernia in 16% (7) of patients. No patients were diagnosed with active gastrointestinal bleeding or malignancy as the cause of post-operative hemoglobin drop. Conclusion The study did not show evidence of any gastrointestinal bleeding in patients with resistant and refractory post-operative anaemia following fractured neck of femur surgery using endoscopy procedure.The value of such difficult, expensive and time-consuming procedure may be reviewed further.

Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures

Abstract. It has been demonstrated that decadal variations in the North Atlantic Oscillation (NAO) can be predicted by current forecast models. While Atlantic Multidecadal Variability (AMV) in sea surface temperatures (SSTs) has been hypothesised as the source of this skill, the validity of this hypothesis and the pathways involved remain unclear. We show, using reanalysis and data from two forecast models, that the decadal predictability of the NAO can be entirely accounted for by the predictability of decadal variations in the speed of the North Atlantic eddy-driven jet, with no predictability of decadal variations in the jet latitude. The sub-polar North Atlantic (SPNA) is identified as the only obvious common source of an SST-based signal across the models and reanalysis, and the predictability of the jet speed is shown to be consistent with a forcing from the SPNA visible already within a single season. The pathway is argued to be tropospheric in nature, with the SPNA-associated heating extending up to the mid-troposphere, which alters the meridional temperature gradient around the climatological jet core. The relative roles of anthropogenic aerosol emissions and the Atlantic Meridional Overturning Circulation (AMOC) at generating predictable SPNA variability are also discussed. The analysis is extensively supported by the novel use of a set of seasonal hindcasts spanning the 20th century and forced with prescribed SSTs.

SAT597 Pituitary Abscess Growing Serratia Marcescens With Associated Clivus Osteomyelitis

Abstract Disclosure: S. Brown: None. J. Milosavljevic: None. J. Chai: None. B.Y. Wong: None. Background: Pituitary abscesses are a rare etiology for pituitary lesions (0.2%-1.1%). Up to 60% of abscesses do not have an obvious source of infection. Pituitary abscesses can develop from the spread of local infection (usually the sphenoid sinus or cavernous sinus). Commonly isolated organisms of pituitary abscesses are gram positive cocci (Staphylococcus and Streptococcus) or gram negative bacilli (E. coli, Neisseria, and Corynebacterium). We present a case of a pituitary abscess growing Serratia marcescens with associated clivus osteomyelitis. Clinical Case: A 26-year-old woman with a history of recurrent left ear infections presented with right eye pain, sixth cranial nerve palsy and headaches. Brain MRI revealed 1.2 x 0.9 x 1.2 cm septated, cystic-appearing, rim-enhancing lesion originating from the sella, exerting mild pressure on the optic chiasm and infiltrating the right cavernous sinus. Contrast-enhanced CT scan revealed sclerotic and erosive changes concerning for clivus osteomyelitis and petrous apicitis. Hormonal evaluation demonstrated panhypopituitarism with undetectable cortisol (&amp;lt;1.0 µg/dL, n = 4-20 µg/dL), low ACTH (2.8 pg/mL, n = 7.2-63.3pg/mL), low-normal FT4 (0.6 ng/dL, n = 0.6-1.5ng/dL), low-normal TSH (0.32 µU/mL, n = 0.3-4.2µU/mL), undetectable estradiol (&amp;lt;25 pg/mL, n = 10-400pg/mL), low FSH (4.1 mIU/mL, n = &amp;lt;20 mIU/mL), low LH (0.5 mIU/mL, n = &amp;lt;10 mIU/mL), elevated prolactin (79 ng/mL, n&amp;lt;25ng/mL), and normal IGF-1 (192 ng/mL, n = 63-373ng/mL). Blood cultures, HIV testing, hepatitis serologies, Aspergillus galactomannan and cryptococcal antigen were negative. Replacement with hydrocortisone and levothyroxine was initiated, as well as empiric treatment with ceftriaxone, vancomycin, and metronidazole. Patient then underwent trans-sphenoidal evacuation of the sellar abscess. Specimen cultures grew Serratia marcescens. Post-operatively, she developed arginine vasopressin (AVP) deficiency and was started on desmopressin. Her symptoms and sixth nerve palsy resolved after surgery, and she was discharged with hormone replacements and a 6-week course of ceftriaxone. Conclusion: While other Enterobacteriaceae have previously been isolated from pituitary abscesses (including E. coli, Citrobacter, Salmonella, Proteus and Klebsiella), our case demonstrates, to the best of our knowledge, the first case of Serratia isolated from a pituitary abscess. Serratia is considered to be an opportunistic pathogen, although this patient had no identifiable risk factors for immunosuppression. Also, pituitary abscesses commonly spread from local infections. However, the source of infection in this case is likely the clivus osteomyelitis, which to the best of our knowledge, also has never been reported. In summary, this case differs from other reported cases due to the pituitary abscess growing Serratia with a potential source from the clivus osteomyelitis. Presentation: Saturday, June 17, 2023