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The present work evaluates the electrochemical behavior of the construction steel of an oil pipeline in the presence of two waters of different origins. The electrochemical techniques of linear polarization resistance and polarization curves were used to estimate the resistance of the steel to corrosion when the steel was in contact with the corrosive media. By the physicochemical and microbiological composition of the media, the difference between their corrosive aggressiveness was appreciated, in correspondence with the corrosion speed measurements determined by the Linear Polarization Resistance (LPR) method. The corrosion resistance of the evaluated material was noted to decrease with increasing temperature, in both aqueous media. The polarization curves of the steel showed processes of load transfer and oxygen diffusion in the tests carried out.

Este trabajo analiza la estrategia de seguridad del presidente George W. Bush y su posible vinculación con el comportamiento internacional de Donald Trump, ahondando en las similitudes de ambos casos, tanto en sus objetivos como contexto internacional. Sobre la base del accionar de Trump durante los primeros meses de su mandato, este trabajo sugiere que el actual mandatario estadounidense está desarrollando, y consolidará, una estrategia de seguridad sustentada en principios, valores y objetivos comparables a aquellos defendidos por George W. Bush a inicios del presente siglo.

Las exploraciones internacionales llevadas a cabo durante la denominada era heroica de la historia antártica, fueron determinantes en la configuración del futuro político del continente helado. Pese a ello, y mientras el Reino Unido, Francia, Bélgica, Noruega y otras naciones realizaban importantes y continuos esfuerzos para asegurar su presencia en dicha región, Estados Unidos -por entonces, una potencia en ascenso- permanecía al margen del proceso. De acuerdo a lo anterior, el presente trabajo intenta dilucidar algunas de las razones del comportamiento del país del norte, y -particularmente- examina las perspectivas que algunas influyentes sociedades científicas norteamericanas desarrollaron respecto de la inacción norteamericana en materia antártica durante la primera década del siglo XX. El trabajo -de carácter exploratorio- se basa, principalmente, en material de prensa, documentación institucional, y en artículos publicados en las revistas y boletines de las sociedades científicas analizadas.

The success of chemical engineering graduates depends on their aptitude and the skills received during the academic formation. Employers not only require that graduates have the knowledge of basic chemical engineering principles but knowing how to apply this knowledge in solving practical problems. In this paper, one form to obtain important skills is presented. The working practice is one of the most important subjects in the curriculum. HYSYS simulator which can realize the energetic evaluation was introduced. A simulation model of the preheat train of Fluid Catalytic Cracking Unit was obtained. The model was built using prebuilt models in HYSYS, however a fired heater to steady state doesn’t exist. In this case, a spreadsheet was utilized in programming the energetic evaluation. Sometimes it is useful because it is necessary to use our models for specific equipment. Finally, the model was utilized to predict the system efficiency when changes on the operation variables occur. The use of simulation inside of core subjects helps to improve the level and quality of students’ formation.

The ABC transporter gene family encodes proteins that form transmembrane channels and hydrolyze ATP to pump various substrates into and out of cells. Adult stem cell populations in numerous mammalian tissues express members of this gene family in order to efflux toxins or vital dyes, thereby conferring the "side population" trait, and cancer stem cells exhibit multidrug resistance upon expression of members of this gene family. In this study we investigated the expression of ABC transporters in a leading model organism stem cell niche, the Drosophila testis. We screened enhancer and gene trap lines with insertions near ABC transporter genes and identified six transporters with tissue-specific expression in the testis (ABCB7, MRP, rdog, CG3164, CG31121, and CG9663). Contrary to our expectation, we did not observe mostly stem cell-restricted expression patterns for these genes. We also report the expression patterns of ABC transporter genes in the testis from the published Fly Cell Atlas consortium single-cell sequencing of the testis (Li et al., 2022). Comparison of the expression levels and patterns of the six positive genes from the enhancer/gene trap screen with the FCA data showed only weak correlation between the two gene expression approaches. While there are reasons that the techniques might show different results, our work highlights the need for caution in over-reliance on single techniques to investigate gene expression., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Understanding causal relationships between evolution and ocean oxygenation hinges on reliable reconstructions of marine oxygen levels, typically from redox-sensitive geochemical proxies. Here, we develop a proxy, using dolomite U-Pb geochronology, to reconstruct seawater U/Pb ratios. Dolomite samples consistently give U-Pb dates and initial 207 Pb/ 206 Pb ratios lower than expected from their stratigraphic ages. These observations are explained by resetting of the U-Pb system long after deposition; the magnitude of deviations from expected initial 207 Pb/ 206 Pb are a function of the redox-sensitive U/Pb ratios during deposition. Reconstructed initial U/Pb ratios increased notably in the late-Paleozoic, reflecting an increase in oxygenation of marine environments at that time. This timeline is consistent with documented shifts in some other redox proxies and supports evolution-driven mechanisms for the oxygenation of late-Paleozoic marine environments, as well as suggestions that early animals thrived in oceans that on long time scales were oxygen-limited compared to today., (© 2024. The Author(s).)

The geologically rapid appearance of fossils of modern animal phyla within Cambrian strata is a defining characteristic of the history of life on Earth. However, temporal calibration of the base of the Cambrian Period remains uncertain within millions of years, which has resulted in mounting challenges to the concept of a discrete Cambrian explosion. We present precise zircon U-Pb dates for the lower Wood Canyon Formation, Nevada. These data demonstrate the base of the Cambrian Period, as defined by both ichnofossil biostratigraphy and carbon isotope chemostratigraphy, was younger than 533 Mya, at least 6 My later than currently recognized. This new geochronology condenses previous age models for the Nemakit-Daldynian (early Cambrian) and, integrated with global records, demonstrates an explosive tempo to the early radiation of modern animal phyla.

Objective: To analyze how the COVID-19 pandemic has influenced trends in head and neck squamous cell carcinoma (HNSCC) presentation and diagnosis-including referral patterns, stage at presentation, and time to diagnosis-over a longitudinal time course., Setting: Multicenter tertiary care academic institution., Methods: A retrospective review of patients with HNSCC presenting between January 1, 2019 and December 31, 2020 was performed. Patients were stratified into pre-COVID and COVID cohorts based upon presentation date either before or after the COVID pandemic was declared a national emergency. Data was collected on demographics, referral site, symptoms, tumor characteristics, and time to diagnosis., Results: Of 203 patients with HNSCC identified, 77.3% (157/203) were in the pre-COVID cohort and 22.7% (46/203) were in the COVID cohort. Patients in the COVID cohort were more likely to present through inpatient or ER consultation (26% vs. 11%) than outpatient setting. There was a greater than 50% decrease in new tumor board case presentations per month in the COVID cohort (4.8) relative to the pre-COVID (10.9) cohort. Cancer stage at presentation was similar between cohorts. Time from presentation to diagnosis was similar between the cohorts at approximately 30 days., Conclusions: These results suggest that patients presenting during the COVID pandemic may have unique referral patterns. A significant decrease in tumor board presentations was noted, which may contribute to more delayed presentations that have yet to be observed. Further investigation with a larger sample size is warranted., Lay Summary: The COVID-19 pandemic may have changed where and how patients with head and neck cancer initially seek care. We found that patients with newly diagnosed head and neck cancer more often were initially seen in urgent settings than before the pandemic., Level of Evidence: 3., Competing Interests: The author declares there is no potential conflicts of interest., (© 2022 The Authors. Laryngoscope Investigative Otolaryngology published by Wiley Periodicals LLC on behalf of The Triological Society.)

Scores and scales used in pediatric motor development for neuromuscular disorders have evolved greatly since the beginning of their development. In this review we provide a brief history of scales used in pediatric patients with neuromuscular disorders and an update regarding the advancement of the scales commonly used in patients with spinal muscular atrophy and Duchenne muscular dystrophy. We focus on the collaborative effort that has led to the development of outcomes and speak to the possible future of Clinical Outcome Assessments., Competing Interests: Declaration of Competing Interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The fossil record of the terminal Ediacaran Period is typified by the iconic index fossil Cloudina and its relatives. These tube-dwellers are presumed to be primitive metazoans, but resolving their phylogenetic identity has remained a point of contention. The root of the problem is a lack of diagnostic features; that is, phylogenetic interpretations have largely centered on the only available source of information-their external tubes. Here, using tomographic analyses of fossils from the Wood Canyon Formation (Nevada, USA), we report evidence of recognizable soft tissues within their external tubes. Although alternative interpretations are plausible, these internal cylindrical structures may be most appropriately interpreted as digestive tracts, which would be, to date, the earliest-known occurrence of such features in the fossil record. If this interpretation is correct, their nature as one-way through-guts not only provides evidence for establishing these fossils as definitive bilaterians but also has implications for the long-debated phylogenetic position of the broader cloudinomorphs.

Owing to the lack of temporally well-constrained Ediacaran fossil localities containing overlapping biotic assemblages, it has remained uncertain if the latest Ediacaran ( ca 550-541 Ma) assemblages reflect systematic biological turnover or environmental, taphonomic or biogeographic biases. Here, we report new latest Ediacaran fossil discoveries from the lower member of the Wood Canyon Formation in Nye County, Nevada, including the first figured reports of erniettomorphs, Gaojiashania , Conotubus and other problematic fossils. The fossils are spectacularly preserved in three taphonomic windows and occur in greater than 11 stratigraphic horizons, all of which are below the first appearance of Treptichnus pedum and the nadir of a large negative δ 13 C excursion that is a chemostratigraphic marker of the Ediacaran-Cambrian boundary. The co-occurrence of morphologically diverse tubular fossils and erniettomorphs in Nevada provides a biostratigraphic link among latest Ediacaran fossil localities globally. Integrated with a new report of Gaojiashania from Namibia, previous fossil reports and existing age constraints, these finds demonstrate a distinctive late Ediacaran fossil assemblage comprising at least two groups of macroscopic organisms with dissimilar body plans that ecologically and temporally overlapped for at least 6 Myr at the close of the Ediacaran Period. This cosmopolitan biotic assemblage disappeared from the fossil record at the end of the Ediacaran Period, prior to the Cambrian radiation., (© 2017 The Author(s).)

OBJECTIVE To evaluate effects of laparoscopic-assisted incisional gastropexy (LAIG) on gastric motility in dogs by use of a wireless motility device (WMD). ANIMALS 10 healthy client-owned large or giant-breed dogs. PROCEDURES 10 dogs owned by clients interested in prophylactic LAIG were enrolled. To determine effects of LAIG on gastrointestinal motility in dogs during the nonfed state, each dog was evaluated by use of a noninvasive WMD before and > 4 weeks after LAIG. All dogs underwent LAIG, with or without concurrent elective gonadectomy. Data obtained before and after LAIG were analyzed by use of proprietary software to determine the gastric emptying time, small bowel transit time, large bowel transit time, whole bowel transit time, and motility index. RESULTS No changes in variables were detected between measurements obtained before and after prophylactic LAIG. CONCLUSIONS AND CLINICAL RELEVANCE In this study, prophylactic LAIG did not have an effect on gastrointestinal motility. The WMD was tolerated well by all dogs and appeared to be a safe and effective method for evaluating gastrointestinal motility in this population of dogs.

Objective: To investigate differences in clinical variables among dogs with extrahepatic portosystemic shunts (EHPSSs) of various morphologies., Design: Retrospective case series., Animals: 53 dogs with EHPSSs., Procedures: Medical records of dogs undergoing preoperative CT angiography of an EHPSS over a 3-year period were reviewed. Analysis was performed to investigate relationships of clinical variables with shunt morphology. Morphologies were analyzed individually as well as in several groups., Results: Shunt morphologies included 10 splenocaval, 9 splenophrenic, 11 splenoazygos, 10 right gastric-caval, 12 right gastric-caval with a caudal loop, and 1 right gastric-azygos with a caudal loop. Several biochemical variables associated with EHPSS were lowest in dogs with splenocaval shunts. Preoperative clinical signs were more common in dogs that had shunts with vena caval than right azygos vein insertion (36/41 [88%] vs 7/12 [58%]) and insertion caudal to the liver than diaphragmatic insertion (29/32 [91%] vs 14/21 [67%]). Neurologic signs were more common when shunts inserted into the vena cava caudal to the liver than in other locations (21/32 [66%] vs 6/21 [29%]) and were most frequent with splenocaval shunts. Urinary tract signs were more common when shunts had right gastric vein origin than gastrosplenic vein origin (14/23 [61%] vs 10/30 [33%])., Conclusions and Clinical Relevance: Splenocaval shunts caused more clinical abnormalities than did other shunt morphologies. Results suggested that dogs with shunt insertion in the caudal vena cava, especially caudal to the liver, were most likely to have clinical signs.

Case Description: An 8-year-old 38-kg (84-lb) castrated male German Shepherd Dog cross was evaluated because of respiratory distress secondary to pneumothorax (detected radio-graphically prior to referral)., Clinical Findings: CT of the thorax confirmed the presence of pneumothorax and revealed pulmonary blebs without evidence of infiltrative pulmonary changes. A tentative diagnosis of primary spontaneous pneumothorax was made., Treatment and Outcome: Exploratory median sternotomy revealed emphysematous changes along the margins of all lung lobes, with the ventral margins of the left cranial, right cranial, and right middle lung lobes most affected. Partial lobectomies of the ventral aspects of these lobes were performed. Histologic examination of tissue samples from the lung lobes revealed diffuse smooth muscle hypertrophy of the terminal and respiratory bronchioles with moderate numbers of peribronchiolar eosinophils. Mucus plugs and mucous cell metaplasia within the airway epithelium were also evident. After surgery, clinical signs resolved and the dog was discharged from the hospital 2 days later. Eight months after surgery, the dog developed a mild cough, and treatment with prednisolone (tapering dosage starting at 0.5 mg/kg [0.023 mg/lb], PO, q 12 h) was initiated. Dosage reduction resulted in recurrence of coughing; however, with continued prednisolone treatment at a dosage of 0.5 mg/kg, PO, once daily, the dog was not coughing at 10 months after surgery., Clinical Relevance: Reactive bronchopneumopathy should be included as a differential diagnosis for spontaneous pneumothorax in dogs.

This study compared features and determined which of four end-user systems (PaperChase, GRATEFUL MED, Med-Base, or Compact Cambridge: MEDLINE) would best serve the Medical Sciences and Optometry Libraries of Indiana University in providing biomedical information to faculty and graduate students through MEDLINE. Cost, ease of use, retrieval, training needs, equipment requirements, and adequacy of documentation were examined. The study consisted of a comparison of the features of each system based on available documentation; a controlled search performed by the investigators on each system and on regular NLM MEDLINE; and a user study based on observations, questionnaires, and interviews with eleven library patrons who performed the same search of their choice on each of the four systems.