Comparison of Portable to Laboratory-based Near Infrared Spectroscopy Sensors for Assessing Muscle Health During Exercise

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Permafrost distribution offshore of West Yamal : extended abstract

The results of seismic studies in the near-shore, shallow waters of the south-western Kara Sea - at the Shpindler, Kharsavey and Mare-Sale sites - showed the presence of a seismic interface which can be interpreted as a submarine permafrost table. The proposed permafiost exhibits a continuous distribution and a strongly dissected top surface overlain by unfrozen sediments. The permafrost table is located at a depth of 4-6 m and 5-10 m below the sea floor at the Shpindler and Mare-Sale sites, respectively. Three dimensional modeling of the permafrost table suggests the presence of relict buried thermodenudational depressions (up to 2 km across) at a minimum sea depth of 40-45 m at the Shpindler and Mare-Sale sites. The depressions may be considered as paragenetic to thermocirques found in cliffs at the Shpindler site. At the Kharasavey site, the permafrost table has an elongated depression parallel to the modern shoreline. The maximum depression depth is 20 m below the seafloor. At present, the relict therrnocirques (Shpindler and Mare-Sale) and the elongated depression (Kharasavey) are completely filled in with sediment and are not evident in modern bottom topography

Submarine permafrost in the nearshore zone of the southwestern Kara Sea

The results of seismic studies in the shallow waters of the southwestern Kara Sea show the presence of a seismic unit that can be interpreted as relict submarine permafrost. The permafrost table has a strongly dissected upper surface and is located at a water depth of 5–10 m. A 3D modeling of the permafrost table suggests the presence of relict buried thermodenudational depressions (up to 2 km across) at a water depth of 5–10 m. The depressions may be considered to be paragenetic to thermocirques found at the Shpindler site. Relict thermocirques are completely filled with sediment and not exposed at the sediment surface

SOME PROPERTIES OF OPERATOR EXPONENT

We study operators given by series, in particular, operators of the form $e^B=\sum\limits_{n=0}^{\infty}{B^n}/{n!},$ where $B$ is an operator acting in a Banach space $X$. A corresponding example is provided. In our future research, we will use these operators for introducing and studying functions of operators constructed (with the use of the Cauchy integral formula) on the basis of scalar functions and admitting a faster than power growth at infinity

Role of subsea permafrost and gas hydrate in postglacial Arctic methane releases

The papers of this thesis are not available in Munin.<br>Paper I: 'Offshore permafrost decay and massive seabed methane escape in water depths > 20 m at the South Kara Sea shelf.' Alexey Portnov, Andrew J. Smith, Jürgen Mienert, Georgy Cherkashov, Pavel Rekant, Peter Semenov, Pavel Serov, Boris Vanshtein. Available in <a href=http://dx.doi.org/10.1002/grl.50735> Geophysical Research Letters, vol. 40, 1–6</a><br>Paper II: 'Modeling the evolution of climate-sensitive Arctic subsea permafrost in regions of extensive gas expulsion at the West Yamal shelf.' Alexey Portnov, Jurgen Mienert, Pavel Serov. Available in <a href=http://dx.doi.org/10.1002/2014JG002685> Journal of Geophysical Research: Biogeosciences, vol. 119, issue 11, 2014</a> <br>Paper III: 'Methane release from pingo-like features across the South Kara Sea shelf, an area of thawing offshore permafrost'. Pavel Serov, Alexey Portnov, Jurgen Mienert, Peter Semenov, Polina Ilatovskaya. (Manuscript). Published version available in <a href=http://dx.doi.org/10.1002/2015JF003467> Journal of Geophysical Research: Earth Surface, vol. 120, issue 8, 2015</a> <br>Paper IV: 'Ice-sheet driven methane storage and release in the Arctic.' Alexey Portnov, Sunil Vadakkepulyambatta, Jurgen Mienert, Alun Hubbard. (Manuscript)Greenhouse gas methane is contained as gas hydrate, an icy structure, under the seabed in enormous amounts of Arctic regions. West Svalbard continental margin, which we investigated here, is one of these regions. Also, in the Russian Kara Sea the subsea permafrost is acting as a cap for the gas to be released in the future. But continuous expulsions of methane have been already observed in both places. This study shows how the subsea permafrost in the Kara Sea, and gas hydrate systems offshore West Svalbard, have evolved from the last ice age to the present day. The conclusions are based on integrated field geophysical and gas-geochemical studies as well as modeling of permafrost, gas hydrate reservoirs and Barents Sea ice sheet dynamics. It shows that continuous permafrost of the Kara Sea is more fragile than previously thought. It is likely to be limited to the shallow water depths of 20 meters on this Arctic shelf region, allowing expulsions of methane from an area of 7500 sq km. Offshore Svalbard almost 2000 active and inactive gas expulsion sites are associated with melting of gas hydrate and thawing of shallow permafrost from past to present. Our research approach shows that natural climate drivers such as methane release can change and that they are connected to the ice sheet retreat since the last ice age. These processes triggered widespread seafloor gas discharge, observed in Arctic shelf and upper continental margins to this day

First discovers of Pleistocene authigenous carbonate crusts (ACC) at the Mendeleev Rise, Arctic Ocean

The Mendeleev Rise (or Mendeleev Ridge) is a part of Central Arctic Uplifts domain that extends from the Eastern Siberian Shelfto the central areas of the ocean, where it is adjacent to the Alpha Ridge bisecting the Amerasian Basin. The crust of Mendeleev Rise belongs to the continental type (Poselov et al. 2007). New geological, geophysical and tectonic data were obtained within Alpha-Mendeleev Rise after few expeditions to Arctic Ocean in year 2000, 2005 and 2012. Thousands of rock fragments were dredged: 50–65% – carbonate rocks (mainly dolomite and limestone); 20–25% – sandstones, siltstones, mudstones; 5–20% – igneous rocks (mainly granites, gabbro-dolerite and few types of basalt); ~ 10% – metamorphic rocks (mainly greenschist facies). Light dolomites with little flora and fauna represent about two-thirds of the total amount of carbonate rocks, the rest are limestones, often containing well-preserved faunal remains. Paleontological study of limestones show abundance of D-P 1 fauna remnants that give us an evidence of structural connection of Mendeleev Rise and Wrangel Island (Morozov et al. 2013). Carbonate crusts were dredged from steep slopes (25–29°) with neotectonic faults on two sites at water depth more than 2 km during expedition “Arktika-2012”. Primary study showed that crusts compose of strong matrix with rounded and angular debris of local (edaphogenic) material: dolomites, dolerites, granites, metasomatic and terrigenous rocks of different size (0.5 mm to 5 cm) (Morozov et al. 2013, Kremenetskii et al. 2015). Three samples of matrix and two of soft clay-carbonate crust’s cover were selected for detailed analysis. Petrographic features were studied using optical microscope, microprobe and X-ray analysis. Chemical elements analysis was performed with XRF and ICP-MS. All analyses were carried out in A.P. Karpinsky Russian Geological Research Institute (VSEGEI) in Saint-Petersburg. AAC’s Matrix studied with microprobe in details and consists offine-grained calcite with angular quartz grains from 1 μm to 300 μm. X-ray analysis shows calcite predominance in the matrix (>70%), rest content is presented with clasts of quartz, illite and albite – about 10%, dolomite, chlorite, montmorillonite, chamosite – 1–2%. Clasts of local debris are presented by two association: 1) large, mainly angular clasts with size from 0.5 mm to 5 cm; 2) small, mainly rounded clasts with size from 200 μm to 0.5 mm. Surface of matrix and debris is covered with soft rose clay-carbonate mass. Mineral content of clay-carbonate mass is: quartz and illite – 25–30%, calcite and albite 15–20%, chlorite, orthoclase, halite, dolomite, montmorillonite – 1–5%. Chemical composition (in percents) of matrix is close to clay-carbonate terrigenous rocks: SiO 2 – 18, Al 2 O 3 – 3.62, TiO 2 – 0.2, Fe 2 O 3 t – 1.4, MnO – 0.05 MgO – 2.35, CaO – 39.2, Na 2 O – 0.18, K 2 O – 0.47, P 2 O 5 – 0.12, L.O.I. – 34.3. Rose mass differs from matrix with silica – 46, CaO – 19, higher alkalis (Na and K) – 1.15 and 1.3. Difference in content of silica (18% vs 46%), CaO (39.2% vs 19%) says that AAC matrix and rose mass have various sources. In contrast to Paleozoic remnants in carbonates, the AAC contain planktonic and benthic foraminifera of Pleistocene age. In Arctic seas, these species are distributed in modern conditions mainly in places where the Gulf Stream arrives (Herman 1974). These data indicates local origin of ACC, main evidences includes distribution, good preservation of samples, local debris in matrix, paleontological age. However, carbonates are very limited in the Arctic Ocean (Emelyanov 2005, Chierici & Fransson 2009). In view of these parameters, AAC can’t form by itself so it may be due only to external factors. Bottom water doesn’t provide such factors. Neither necessary conditions nor material occur in these waters. So in our opinion AAC were formed with help of neotectonic fault which are supposed to be a possible path for hot fluids, which created the conditions for crusts forming and Paleozoic carbonate rocks was a source of CaCO 3

Palaeozoic carbonates and fossils of the Mendeleev Rise (eastern Arctic): A study of dredged seafloor material

© 2018 Elsevier Ltd Fossiliferous carbonate rocks dredged during the “Arctic-2012” cruise on the Mendeleev Rise (eastern Arctic) provide proof of the presence of Upper Silurian(?)–Middle Devonian, Famennian–Tournaisian, Bashkirian–Kasimovian, Gshelian–lower Asselian(?) and Kungurian–Kazanian carbonate deposits. The wide spectrum of facies includes deposits of both photic zone (with fusulinids, algae, relicts of microbial and coral reefs) and deeper dysphotic areas (with trilobites, deep-water tentaculitids and ostracods). The results obtained suggest that there were at least three periods of carbonate platform sedimentation during the latest Silurian(?) to Permian. The Late Silurian?–Devonian biota do not show biogeographical differentiation, but rather are distributed globally. Shallow-water foraminifera and some algae of early Pennsylvanian–basal Cisuralian age belong to the warm-water province. These forms are unknown in the Moscovian–Permian of the Boreal Realm (Taimyr, New Siberian Islands, Verkhoyanie, Omolon Massif) but are typical for Alaska and Arctic Canada, Wrangel Island, Chukotka, Polar Urals and Svalbard. The disappearance of warm-water biota during late Artinskian-Kungurian times led to a subsequent predominance of smaller foraminifera: this assemblage with Protonodosaria is widely distributed in Permian deposits of Novaya Zemlya, Urals, Barents Sea and the eastern Arctic. The warm-water Bashkirian-Asselian biota suggests that the Mendeleev-Chukotka-Wrangel block was a low-latitude shallow basin with predominant carbonate sedimentation, being part of the Arctida supercontinent, connected temporarily with the eastern margin of Laurasia (Chukcha-Alaska block)

The Relationship Between Physical Activity Level and Movement Quality in Aging Adults with Obesity

Adults with obesity are at increased risk of injuries and disability as they age. Physical inactivity and poor functional mobility contribute to injury and disability development. Subtle changes in mobility are difficult to identify with standard outcome measures, however detecting these early changes can direct interventions to decrease injury and disability. The goals of this dissertation were to evaluate inertial measurement unit (IMU)-based motion capture for describing gait in normal weight adults and adults with obesity, and to determine the association of physical activity level (PAL) with measures of movement quality and musculoskeletal disability development risk in middle-aged and older adults with high body mass indexes (BMIs). To evaluate IMU-based motion capture, 10 normal weight adults and 10 adults with obesity walked while equipped with IMUs and optokinetic motion capture (OMC). In normal weight adults, IMUs showed greater agreement with OMC in the sagittal plane compared to frontal and transverse planes. Differences of greater than 5° between IMUs and OMC existed during gait in all planes. Angles measured at clinically meaningful timepoints were poorly associated between IMUs and OMC. Similar findings were observed in adults with obesity, with additional issues observed for hip angles. Amount of physical activity was associated with movement quality in middle-aged and older adults with high BMIs. A cross-sectional analysis of 42 middle-aged adults with obesity found PAL was associated with better balance and gait when instrumented tests were used to detect subtle changes in performance. Middle-aged adults with obesity with higher PALs demonstrated decreased kinetic markers of musculoskeletal impairment during walking. Different patterns in muscle oxygenation were observed during fatigability tests requiring further exploration. Future longitudinal studies are warranted to establish the temporal direction of associations observed between PAL and movement measures. This dissertation takes the first step towards leveraging wearable sensors to identify changes in mobility patterns predictive of disability development in aging adults with obesity. Future work should establish standards of use for implementing wearable sensor technologies into clinical practice to improve patient care, and direct interventions to disrupt the disability development process and compress years of disability in aging adults with obesity

Obesity-Specific Considerations for Assessing Gait with Inertial Measurement Unit-Based vs. Optokinetic Motion Capture

Adults with obesity experience high rates of disability and rapid functional decline. Identifying movement dysfunction early can direct intervention and disrupt disability development; however, subtle changes in movement are difficult to detect with the naked eye. This study evaluated how a portable, inertial measurement unit (IMU)-based motion capture system compares to a laboratory-based optokinetic motion capture (OMC) system for evaluating gait kinematics in adults with obesity. Ten adults with obesity performed overground walking while equipped with the OMC and IMU systems. Fifteen gait cycles for each participant were extracted for the 150 total cycles analyzed. Kinematics were compared between OMC and IMU across the gait cycles (coefficient of multiple correlations), at clinically significant time points (interclass correlations), and over clinically relevant ranges (Bland–Altman plots). Sagittal plane kinematics were most similar between systems, especially at the knee. Sagittal plane joint angles at clinically meaningful timepoints were poorly associated except for ankle dorsiflexion at heel strike (ρ = 0.38) and minimum angle (ρ = 0.83). All motions except for ankle dorsiflexion and hip abduction had >5° difference between systems across the range of angles measured. While IMU-based motion capture shows promise for detecting subtle gait changes in adults with obesity, more work is needed before this method can replace traditional OMC. Future work should explore standardization procedures to improve consistency of IMU motion capture performance