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2021 ◽  
Vol 15 (8) ◽  
pp. 4135-4143
Author(s):  
Daniela Festi ◽  
Margit Schwikowski ◽  
Valter Maggi ◽  
Klaus Oeggl ◽  
Theo Manuel Jenk

Abstract. Dating glaciers is an arduous yet essential task in ice core studies, which becomes even more challenging when the glacier is experiencing mass loss in the accumulation zone as result of climate warming, leading to an older ice surface of unknown age. In this context, we dated a 46 m deep ice core from the Central Italian Alps retrieved in 2016 from the Adamello glacier in the locality Pian di Neve (3100 m a.s.l.). Here we present a timescale for the core obtained by integrating results from the analyses of the radionuclides 210Pb and 137Cs with annual layer counting derived from pollen and refractory black carbon concentrations. Our results clearly indicate that the surface of the glacier is older than the drilling date of 2016 by about 20 years and that the 46 m ice core reaches back to around 1944. For the period of 1995–2016 the mass balance at the drilling site (former accumulation zone) decreased on average of about 1 m w.e. a−1 compared to the period 1963–1986. Despite the severe mass loss affecting this glacier even in the former accumulation zone, we show that it is possible to obtain a reliable timescale for such a temperate glacier using black carbon and pollen seasonality in combination with radionuclides 210Pb and 137Cs. Our results are therefore very encouraging and open new perspectives on the potential of such glaciers as informative palaeoarchives.


2021 ◽  
Vol 12 ◽  
pp. 420
Author(s):  
Jaims Lim ◽  
Steven B. Housley ◽  
Douglas Drumsta ◽  
Richard M. Spiro

Background: Epidural hematomas are common intracranial pathologies secondary to traumatic brain injuries and are associated with overlying skull fractures up to 85% of the time. Although many require immediate surgical evacuation, some are observed for stability and followed up conservatively with serial imaging or enlarge slowly overtime, similar to chronic subdural hematomas. Those in the latter category may present with vague symptoms such as diplopia or headache and are often found on routine outpatient evaluation. When concerning findings such as significant mass effect are present, surgical evacuation is necessary. Case Description: Here, we present the case of a 32-year-old man who presented with diplopia 6 weeks after experiencing head trauma and was found to have a chronic epidural hematoma. On resection, thick, inflammatory tissue was observed and carefully resected, revealing normal dura underneath. Six weeks after evacuation of the hematoma, the patient had near-complete resolution of his diplopia and complete resolution of his epidural hematoma. Conclusion: Given the consistency and nature of the fibrous material observed intraoperatively in this case, near-complete resection of the tissue was likely necessary to help facilitate adequate reexpansion of brain parenchyma and improve clinical outcomes.


2021 ◽  
Author(s):  
Héctor Carreon ◽  
Mayra Carrillo

Abstract Aging in wood is the inevitable modification of physical and mechanical properties due to deterioration caused by different factors such as organisms that destroy wood, photodegradation, weathering or long-term loading. During the wood degradation process, significant mass, stiffness and strength are lost. Therefore, it is relevant to monitor the wood decomposition process to guarantee the structural requirements in buildings. This research work aims to report the influence of degradation in wood due to deterioration through the use of ultrasonic measurements. Longitudinal and transverse ultrasonic velocities were calculated using the ultrasonic emission-transmission technique for aged and unaged Mexican pine (Pinus Strobus) wood. The experimental measurements were carried out using longitudinal and shear wave ultrasonic transducers with a center frequency of 1.0 MHz and 0.5MHz respectively. Scanning electron microscopy (SEM) was performed to establish a direct correlation with the behavior of the ultrasonic wave developed in naturally aged and unaged wood. Measurements revealed higher ultrasonic velocity values for unaged wood samples in longitudinal, tangential and radial directions compared to aged wood samples, but no significant differences were found in all other wood directions.


2021 ◽  
Author(s):  
László Oláh ◽  
Hiroyuki K. M. Tanaka ◽  
Gergő Hamar

Abstract Post-eruptive destabilization of volcanic edifices by gravity driven debris flows or erosion can catastrophically impact the landscapes, economies and human societies surrounding active volcanoes. In this work, we propose muography as a tool for the remote monitoring of hydrogeomorphic responses to volcano landscape disturbances. We conducted the muographic monitoring of Sakurajima volcano, Kyushu, Japan and measured continuous post-eruptive activity with over 30 lahars per year. The sensitive surface area of the Multi-Wire-Proportional-Chamber-based Muography Observation System was upgraded to 7.67 m2 ; this made it possible for the density of tephra within the crater region to be measured in 40 days. We observed the muon flux decrease from 10 % to 40 % through the different regions of the crater from September 2019 to October 2020 due to the continuous deposition of tephra fallouts. In spite of the long-term mass increase, significant mass decreases were also observed after the onsets of rain-triggered lahars that induced the erosion of sedimented tephra. The first muographic observation of these post-eruptive phenomena demonstrate that this passive imaging technique has the potential to contribute to the assessment of indirect volcanic hazards.


Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 570
Author(s):  
Tae-Jin Kim

As we observe an increase in muscle mass by lifting weights or a significant mass loss in musculoskeletal tissues of astronauts returning after a stay in space, we note the manifestation of the mechanism of mechanotransduction that is central to mechanobiology [...]


Author(s):  
Linda Paegle ◽  
Žanna Martinsone ◽  
Ivars Vanadziņš ◽  
Ilona Pavlovska ◽  
Lāsma Akūlova

For many years the printers have been essential part of our offices and exposures from various printing technologies have been widely researched. The main objective of this study was to compare emitted number and mass of fine particles from laser printers and new Micro Piezo technology ink jet printers during the printing process and one hour afterwards as these emissions have potential for negative health effects.Air samples were taken with the particle size spectrometer for real-time ELPI+, Dekati (air flow rate 10 l/min). Measurements were taken ~0.5 m from the printers: one hour before the test, during printing and one hour afterwards. Similar class blackwhite (b/w) and colour printer of each technology were tested. Each printer performed a 10-page and a 100-page test  according to ECMA 328-1 Standard [1].During laser printer tests from 8324 to 19943 pt/cm3 fine particles were determined on printing phase from b/w and colour printers. Ink jet (Micro Piezo) printers produced less: from 3239 to 5247 pt/cm3. One hour after the printing phase for both types of laser printers’ there were 54722 to 152351 pt/cm3 particles in air and 4270 to 9579 pt/cm3 particles for ink jet printers. Detected particle mass differences was insignificant: in range of 0.002 to 0.012 mg/m³ for laser printers and 0.002 to 0.019 mg/m³ for ink jet printers. Micro Piezo technology printers emitted mass particles were with bigger median size μm.The highest number of particles was observed one hour after the printing for both tested printer technologies. Laser printers’ emitted 2.5 to 3.8 times more particles in printing phase and 12.8 to 15.9 times more after printing phase. Particle mass in mg/m³ was detected in the size range 6nm - 2.5 μm with no significant mass differences. 


2021 ◽  
Vol 19 (1) ◽  
pp. 79-99
Author(s):  
Pedro Acuña

The article contributes to the field of cultural studies and radio history by focusing on soccer (or fútbol), arguably the most significant mass spectacle in twentieth-century Latin America. By exploring the trajectories, iconic voices and styles of sportscasters, the article reconstructs the masculine soundscape of soccer in Argentina and Chile between the 1920s and 1960s. Play-by-play announcers, who ranged from second-rate actors and singers to professional journalists, crafted their own versions of masculinity and nationalism that were central to representing sports culture in an increasingly transnational context. The article pays special attention to the sporting press, audio records and sports films, since many commentators borrowed heavily from other forms of mass culture. Their oral representations of the game, loaded with moral evaluations and political statements, can be seen as cultural texts because they enabled new ways of imagining sports for much larger audiences than those sitting in the stadium.


2021 ◽  
Vol 12 ◽  
pp. 105
Author(s):  
Saad Moughal ◽  
Micaela Uberti ◽  
Alaa Al-Mousa ◽  
Salem Al-Dwairy ◽  
Anan Shtaya ◽  
...  

Background: Subacute subdural hematomas (ASDH) are only treated surgically when they cause mass effect significant enough to give symptoms. Rarely, sub-ASDH may cause enough pressure to result in a malignant middle cerebral artery (MCA) territory infarction. Decompressive craniectomy (DC) is the last resort to reduce intracranial pressure following malignant MCA infarction. Herein, we review the literature and describe a case of MCA/posterior cerebral artery (PCA) territories infarction following drainage of a sub-ASDH that was treated with DC with good outcome. Case Description: We report a case of malignant right-sided MCA/PCA infarction in a 62-year-old man who presented with progressive headache following a cycling incident leading to a head injury. Initial CT head demonstrated a small right ASDH. He had no neurological deficit, headache settled on analgesia, and there was no expansion of the SDH on the repeat CT; therefore, he was managed conservatively. He was admitted 6-days later with worsening headaches and hyponatremia. Repeat CT revealed an increase in size of the hematoma and mass effect leading to a mini-craniotomy and evacuation of hematoma. He developed left-sided hemiplegia, slurred speech and hyponatremia, and CT head demonstrated a right-sided MCA/PCA infarction with significant mass effect. He underwent emergent DC and subsequent cranioplasty and ultimately recovered to mRS of 2. Conclusion: SDH are frequent neurosurgical entities. Malignant MCA/PCA strokes following mini-craniotomies are rare but need to be considered especially during the consent process.


2021 ◽  
Vol 503 (4) ◽  
pp. 4767-4786
Author(s):  
Tim D Pearce ◽  
Hervé Beust ◽  
Virginie Faramaz ◽  
Mark Booth ◽  
Alexander V Krivov ◽  
...  

ABSTRACT The star Fomalhaut hosts a narrow, eccentric debris disc, plus a highly eccentric companion Fomalhaut b. It is often argued that Fomalhaut b cannot have significant mass, otherwise it would quickly perturb the disc. We show that material in internal mean-motion resonances with a massive, coplanar Fomalhaut b would actually be long-term stable, and occupy orbits similar to the observed debris. Furthermore, millimetre dust released in collisions between resonant bodies could reproduce the width, shape, and orientation of the observed disc. We first re-examine the possible orbits of Fomalhaut b, assuming that it moves under gravity alone. If Fomalhaut b orbits close to the disc mid-plane then its orbit crosses the disc, and the two are apsidally aligned. This alignment may hint at an ongoing dynamical interaction. Using the observationally allowed orbits, we then model the interaction between a massive Fomalhaut b and debris. While most debris is unstable in such an extreme configuration, we identify several resonant populations that remain stable for the stellar lifetime, despite crossing the orbit of Fomalhaut b. This debris occupies low-eccentricity orbits similar to the observed debris ring. These resonant bodies would have a clumpy distribution, but dust released in collisions between them would form a narrow, relatively smooth ring similar to observations. We show that if Fomalhaut b has a mass between those of Earth and Jupiter then, far from removing the observed debris, it could actually be sculpting it through resonant interactions.


2021 ◽  
Author(s):  
Theo Jenk ◽  
Daniela Festi ◽  
Margit Schwikowski ◽  
Valter Maggi ◽  
Klaus Oeggl

<p>Dating glaciers is an arduous yet essential task in ice core studies, which becomes even more challenging for the dating of glaciers suffering from mass loss in the accumulation zone as result of climate warming. In this context, we present the dating of a 46 m deep ice core from the Central Italian Alps retrieved in 2016 from the Adamello glacier (Pian di Neve, 3100 m a.s.l.). We will show how the timescale for the core could be obtained by integrating results from the analyses of the radionuclides <sup>210</sup>Pb and <sup>137</sup>Cs with annual layer counting derived from pollen and refractory black carbon concentrations. Our results clearly indicate that the surface of the glacier is older than the drilling date of 2016 by about 20 years and that the 46 m ice core reaches back to around 1944. Despite the severe mass loss affecting this glacier even in the accumulation zone, we show that it is possible to obtain a reliable timescale for such a temperate glacier. These results are very encouraging and open new perspectives on the potential of such glaciers as informative palaeoarchives. We thus consider it important to present our dating approach to a broader audience.</p>


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