139 research outputs found
40Arâ39Ar dating of volcanogenic products from the AND-2A core (ANDRILL Southern McMurdo Sound Project, Antarctica): correlations with the Erebus Volcanic Province and implications for the age model of the core
The AND-2A drillcore (Antarctic Drilling ProgramâANDRILL) was successfully completed in late 2007 on the Antarctic continental margin (Southern McMurdo Sound, Ross Sea) with the aim of tracking ice proximal to shallow marine environmental fluctuations and to document the 20-Ma evolution of the Erebus Volcanic Province. Lava clasts and tephra layers from the AND-2A drillcore were investigated from a petrographic and stratigraphic point of view and analyzed by the 40Arâ39Ar laser technique in order to constrain the age model of the core and to gain information on the style and nature of sediment deposition in the Victoria Land Basin since Early Miocene. Ten out of 17 samples yielded statistically robust 40Arâ39Ar ages, indicating that the AND-2A drillcore recovered â€230 m of Middle Miocene (âŒ128â358 m below sea floor, âŒ11.5â16.0 Ma) and >780 m of Early Miocene (âŒ358â1093 m below sea floor, âŒ16.0â20.1 Ma). Results also highlight a nearly continuous stratigraphic record from at least 358 m below sea floor down hole, characterized by a mean sedimentation rate of âŒ19 cm/ka, possible oscillations of no more than a few hundreds of ka and a break within âŒ17.5â18.1 Ma. Comparison with available data from volcanic deposits on land, suggests that volcanic rocks within the AND-2A core were supplied from the south, possibly with source areas closer to the drill site for the upper core levels, and from 358 m below sea floor down hole, with the âproto-Mount Morningâ as the main source
Early Miocene volcanic activity and paleoenvironment conditions recorded in tephra layers of the AND-2A core (southern McMurdo Sound, Antarctica)
The ANtarctic geological DRILLing program (ANDRILL) successfully recovered 1138.54 m of core from drillhole, AND-2A, in the Ross Sea sediments (Antarctica). The core is composed of terrigenous claystones, siltstones, sandstones, conglomerates, breccias, and diamictites with abundant volcanic material. In this work we present sedimentological, morphoscopic, petrographic, and geochemical data on pyroclasts recovered from core AND-2A, which provide insights on eruption styles, volcanic sources, and environments of deposition. One pyroclastic fall deposit, 12 resedimented volcaniclastic deposits and 14 volcanogenic sedimentary deposits record a history of intense explosive volcanic activity in southern Victoria Land during the Early Miocene. Tephra were ejected during Subplinian and Plinian eruptions fed by trachytic to rhyolitic magmas and during Strombolian to Hawaiian eruptions fed by basaltic to mugearitic magmas in submarine/subglacial to subaerial environments. The long-lived Mt. Morning eruptive centre, located c. 80 km south of the drillsite, was recognized as the probable volcanic source for these products on the basis of volcanological, geochemical, and age constraints. The study of tephra in the AND-2A core provides important paleoenvironment information by revealing that the deposition of primary and moderately reworked tephra occurred in a proglacial setting under generally open water marine conditions
An Empirical Study of Offshore Software Development: the Case of a Ticketing Application
This is an industry report about a software development project that included a local team and an offshore team. Both teams contained highly qualified experts who had been selected before the project start up. After a year, which could be deemed as a break-in period, the project leaders observed that the quality and quantity of the software modules produced by the two teams were not up to expectation while costs had gone up. The management monitored the performance of the two groups by analysing the tests undertaken to ensure correctness of the modules. They reached the conclusion that the project failurewas influenced by cultural differences between the onshore and offshore teams. The management became convinced that the current work-organization prevented knowledge delivery and knowledge acquisition, so they established a new organization as the solution to this problem. Arapid validation of the newwork arrangement convinced all the involved experts that the diagnosis was right
40Ar--39Ar dating of volcanogenic products from the AND-2A core (ANDRILL Southern McMurdo Sound Project, Antarctica): correlations with the Erebus Volcanic Province and implications for the age model of the core
The AND-2A drillcore (Antarctic Drilling Program â ANDRILL) was successfully completed in late 2007 on the Antarctic continental margin (southern McMurdo Sound, Ross Sea) with the aim of tracking ice-proximal to shallow marine environmental fluctuations and to document the 20-Ma evolution of the Erebus Volcanic Province. Lava clasts and tephra layers from the AND-2A drillcore were investigated from a petrographic and stratigraphic point of view and analyzed by the 40Arâ39Ar laser technique in order to constrain the age model of the core and to gain information on the style and nature of sediment deposition in the Victoria Land Basin since Early Miocene. Ten out of 17 samples yielded statistically robust 40Arâ39Ar ages, indicating that the AND-2A drillcore recovered !230 m of Middle Miocene (~128â358 meters below sea floor, ~11.5â16.0 Ma) and >780 m of Early Miocene (~358â1093 48 meters below sea floor, ~16.0â20.1 Ma). Results also highlight a nearly continuous stratigraphic record from at least 358 meters below sea floor down hole, characterized by a mean sedimentation rate of ~19 cm/ka, possible oscillations of no more than a few hundreds of ka and a break within ~17.5â18.1 Ma. Comparison with available data from volcanic deposits on land, suggests that volcanic rocks within the AND-2A core were supplied from the south, possibly with source areas closer to the drill site for the upper core levels, and from 358 meters below sea floor down hole, with the âproto-Mount Morningâ as the main source
Acute Esophageal Necrosis as a Rare Complication of Metabolic Acidosis in a Diabetic Patient: A Case Report
Objective: Challenging differential diagnosisBackground: Acute esophageal necrosis, or Gurvits syndrome, is a rare clinical process often secondary to a systemic low -flow state. It can be caused by several medical conditions, and it is thought to arise from a combination of impaired mucosal barrier and chemical and ischemic insults to the esophagus. Acute esophageal necrosis usually presents with severe complications due to delayed diagnosis and only rarely has surgical indications. We present a case of Gurvits syndrome, presumably triggered by metabolic acidosis in a diabetic patient.Case Report: A 61-year-old man with history of hypertension and type 2 diabetes mellitus treated with metformin, canagliflozin, glimepiride, and pioglitazone came to our attention with persistent vomiting, odynophagia, chest pain after each meal, and progressive weight loss. Arterial blood analysis showed mild metabolic acidosis, while the first esophagogastroduodenoscopy performed revealed a circumferential black appearance of the esophageal mucosa, as in concentric necrosis of the distal esophagus with possible fungal superinfection. Brushing cytology confirmed the infection by Candida spp. and the patient was treated with intravenous fluconazole. The second esophagogastroduodenoscopy, performed after 2 weeks, showed almost complete healing of the esophageal mucosa; in this case, biopsy confirmed mucosal ischemia and necrosis, without showing deep impairment of the mucosa by fungal agents.Conclusions: Due to its high lethality, often caused by the underlying medical diseases, acute esophageal disease should be considered in the differential diagnosis of digestive symptoms, even without upper gastrointestinal bleeding. Prompt diagnosis and treatment of contextual collateral conditions can help clinicians to avoid the worst out-comes of the disease. Among the causative factors of metabolic acidosis leading to esophageal necrosis we recognized metformin and dapagliflozin
Factors influencing weight loss practices in Italian boxers: A cluster analysis
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. It is common practice in combat sports that athletes rapidly lose body weight before a match, by applying different practicesâsome safer and others possibly dangerous. The factors behind the choice of practices utilised have not been fully studied. This study aimed to investigate the weight loss strategies used by Italian boxers and to look at the difference between higher and lower risk practice adaptors. A modified version of a validated questionnaire has been sent to 164 amateur (88%) and professional (12%) boxers by email. A heatmap with hierarchical clustering was used to explore the presence of subgroups. Weight loss strategies were used by 88% of the athletes. Two clusters were found, defined by the severity of weight loss behaviours. Professional fighters, high-level athletes and females were more represented in Cluster 2, the one with more severe weight-loss practices. These athletes were characterised by a higher weight loss magnitude and frequency throughout the season and reported being more influenced by physicians and nutritionists, compared with the boxers in Cluster 1. Not all the weight loss practices are used with the same frequency by all boxers. The level of the athlete and the boxing style have an influence on the weight-cutting practices
Safety at high altitude: the importance of emotional dysregulation on pilotsâ risk attitudes during flight
IntroductionAviation psychology is very interested in understanding how personological and psychological variables influence flight performances. Indeed, risk attitudes have been considered as a risk factor for aviation accidents. In this context, emotions and coping style are key variables which could influence concentration by affecting cognition and attention. In addition, the specific training backgrounds seemed to be associated with differences in in-flight accident rates. The aim of the present study was to investigate the association between age, sex, flight experience, emotional dysregulation, coping styles, flight licenses, and pilotsâ risk attitudes.MethodsEighty pilots completed an online survey composed of ad hoc questionnaire for sociodemographic and work-related informationâs and self-report questionnaires that assessed emotional dysregulation, coping styles, and risk attitudes.ResultsResults showed that older age and emotional dysregulation were associated with higher risk attitudes in pilots. Moreover, emotional dysregulation seemed to promote worse self-confidence. Ultralight pilots appeared to be more risk-oriented and less self-confident than civil pilots, while more flight experience appeared to favorite greater self-confidence.DiscussionIn conclusion, the study suggests the importance of promoting interventions based on sharing pilotsâ difficulties and emotions and promoting safe attitudes with special attention to ultralight pilots, age, and sex differences
Are there sex differences in physiological parameters and reaction time responses to overload in firefighters?
Male and female firefighters work side-by-side in the same in strenuous and risky conditions. Anthropometrics, physiological, and reaction time (mean of reaction time -MRT-, and errors made -E) parameters of 12 Female and 13 Male firefighters were compared. Effect of overload (step test with and without equipment) on the MRT and E were analyzed on 3 trials (T1 = 1-1s, T2 = 0.5-1s, T3 = 0.5-0.5s), compared with a pre-test condition (basal). T-test between males and females was applied to assess differences (p<0.05) in all parameters. ANOVA with repeated measures and Bonferroni on 3 conditions of step test between males and females was applied in reaction time variables. Between MRT and E, in T1, T2 and T3 trials and the 3 test conditions, ANCOVA models with interactions were used. Differences (p<0.05) in anthropometric, physiological and reaction time data emerged across groups, and on the 3rd trials (T3 vs T1 and T2) in reaction time parameters of each group. ANCOVA showed differences (p<0.001) in E among trials. Post hoc showed significant differences in T1vsT3 and T1vsT2. MRT x trial interaction was extremely significant (P<0.001). Implementing fitness and reaction time exercise programs is important to decrease the injury risk and increase work capacity in firefighters with reference to female workers
Petrologic and Geochemical Composition of the AND-2A Core, ANDRILL Southern McMurdo Sound Project, Antartica
The compositional record of the AND-2A drillcore is examined using petrological, sedimentological, volcanological and geochemical analysis of clasts, sediments and pore waters. Preliminary investigations of basement clasts (granitoids and metasediments) indicate both local and distal sources corresponding to variable ice-volume and ice-flow directions. Low abundance of sedimentary clasts (e.g., arkose, litharenite) suggests reduced contributions from sedimentary covers while intraclasts (e.g., diamictite, conglomerate) attest to intrabasinal reworking. Volcanic material includes pyroclasts (e.g., pumice, scoria), sediments and lava. Primary and reworked tephra layers occur within the Early Miocene interval (1093 to 640 metres below sea floor). The compositions of volcanic clasts reveal a diversity of alkaline types derived from the McMurdo Volcanic Group. Finer-grained sediments (e.g., sandstone, siltstone) show increases in biogenic silica and volcanic glass from 230 to 780 mbsf and higher proportions of terrigenous material ca. 350 to 750 mbsf and below 970 mbsf. Basement clast assemblages suggest a dominant provenance from the Skelton Glacier - Darwin Glacier area and from the Ferrar Glacier - Koettlitz Glacier area. Provenance of sand grains is consistent with clast sources. Thirteen Geochemical Units are established based on compositional trends derived from continuous XRF scanning. High values of Fe and Ti indicate terrigenous and volcanic sources, whereas high Ca values signify either biogenic or diagenic sources. Highly alkaline and saline pore waters were produced by chemical exchange with glass at moderately elevated temperatures
Effects of a Home-Based Lifestyle Intervention Program on Cardiometabolic Health in Breast Cancer Survivors during the COVID-19 Lockdown
This study aimed to evaluate the cardiometabolic effects of a home-based lifestyle intervention (LI) in breast cancer survivors (BCSs) during the COVID-19 lockdown. In total, 30 BCSs (women; stages 0-II; non-metastatic; aged 53.5 ± 7.6 years; non-physically active; normal left ventricular systolic function) with a risk factor for recurrence underwent a 3-month LI based on nutrition and exercise. Anthropometrics, Mediterranean diet adherence, physical activity level (PAL), cardiorespiratory fitness (VO2max), echocardiographic parameters, heart rate variability (average standard deviation of NN intervals (ASDNN/5 min) and 24 h very- (24 hVLF) and low-frequency (24 hLF)), and metabolic, endocrine, and inflammatory serum biomarkers (glycemia, insulin resistance, progesterone, testosterone, and high-sensitivity C-reactive protein (hs-CRP)) were evaluated before (T0) and after (T1) the LI. After the LI, there were improvements in: body mass index (kg/m2: T0 = 26.0 ± 5.0, T1 = 25.5 ± 4.7; p = 0.035); diet (Mediet score: T0 = 6.9 ± 2.3, T1 = 8.8 ± 2.2; p < 0.001); PAL (MET-min/week: T0 = 647 ± 547, T1 = 1043 ± 564; p < 0.001); VO2max (mL·min-1·kg-1: T0 = 30.5 ± 5.8, T1 = 33.4 ± 6.8; p < 0.001); signs of diastolic dysfunction (participants: T0 = 15, T1 = 10; p = 0.007); AS-DNN/5 min (ms: T0 = 50.6 ± 14.4, T1 = 55.3 ± 16.7; p = 0.032); 24 hLF (ms2: T0 = 589 ± 391, T1 = 732 ± 542; p = 0.014); glycemia (mg/dL: T0 = 100.8 ± 11.4, T1 = 91.7 ± 11.0; p < 0.001); insulin resistance (HOMA-IR score: T0 = 2.07 ± 1.54, T1 = 1.53 ± 1.11; p = 0.005); testosterone (ng/mL: T0 = 0.34 ± 0.27, T1 = 0.24 ± 0.20; p = 0.003); hs-CRP (mg/L: T0 = 2.18 ± 2.14, T1 = 1.75 ± 1.74; p = 0.027). The other parameters did not change. Despite the home-confinement, LI based on exercise and nutrition improved cardiometabolic health in BCSs
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