Assessment of applying VLF geophysical method to determine the peat deposit thickness

Peat deposits accumulate large reserves of carbon and play an important role in formation of global climate, biosphere, and hydrological conditions. High degree of knowledge of peat reserves is one of the prerequisites for scientifically based and economically viable wetland management. For economically efficient commercial activity, an enterprise developing a peat deposit must be confident in the availability of sufficient and high quality commercial peat reserves. Therefore, the topic of studying the thickness of peat deposits is quite relevant. The paper analyzes the experience of using the geophysical method called VLF ("very low frequency") to study the thickness of peat deposits. The method consisted of using a VLF receiver to measure the properties of VLF emitted by the peat deposit and the underlying mineral ground. The study was carried out at the Beloe Lake peat deposit in the Tukayevsky district of Tatarstan, at three peat areas of different depths: deep-lying (over 3 m), intermediate (1.5 – 3 m), and shallow (up to 1.5 m). The depth was confirmed by direct measurements in the wells. Low-frequency (VLF) measurements were carried out along the geophysical paths at each area of the peat deposit. The data were processed using the NAMEMD (Noise Empirical Decomposition) method and converted to resistivity and depth values using the specialized software. The study showed that the resistivity differs significantly between the areas of deep-lying and shallow peat. The resistivity varies depending on the peat thickness and the thickness of the buried wood horizons. In the horizons of deep-lying peat, the resistivity is strongly influenced by the degree of peat decomposition, its natural density and moisture. The presence of peaks and their height on the data interpretation plots characterizes the number and thickness of the horizons of buried wood in the peat deposit. With increasing depth of peat occurrence, the resistivity increases significantly. However, in the shallow areas, it does not show differences, being characteristic for the deep-lying peat area. This proves that the VLF method works correctly in peat layers and is capable to indicate the peat thickness, the number and thickness of the buried wood horizons.

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Characterization of peat deposit using ground penetrating radar: Survey experiments and data interpretation

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/928/1/012011 ◽

2021 ◽

Vol 928 (1) ◽

pp. 012011

Author(s):

A A Sinyutkina

Keyword(s):

Accumulation Rate ◽

Spatial Differentiation ◽

Data Interpretation ◽

Peat Deposit ◽

Swamp Forest ◽

Peat Accumulation ◽

Raised Bogs ◽

Peat Deposits ◽

Zone Of Influence ◽

Ground Penetrating

Abstract The paper deals with the possibilities of different wave frequency antennae applications for estimation of the depth of peat deposits and detection of peat layers with different physical characteristics. We employed a GPR system “OKO-2” (“Logical systems”, Russia) with 250 MHz, 700 MHz, and 1700 MHz shielded antennae. The surveys were conducted in 2017–2019 within the pristine and drained raised bogs and swamp forest in the south taiga subzone of Western Siberia to assess the spatial differentiation of the peat deposit and the modern peat accumulation rate within drained bogs. The peculiarities of field surveying, GPR data processing and interpretation are shown. Based on GPR data analysis the influence zone of Bakchar bog and modern peat accumulation within drained bogs were assessed. We noted that the Bakchar bog has a vast zone of influence reaching 700 m from the bog border where peat accumulation is observed. The modern peat accumulation is observed within Bakchar the bog. Drained sites of Ust-Bakchar bog are characterised by the absent peat accumulation or degradation of the peat deposits.

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Myeloid Sarcoma of the Head and Neck Region

Archives of Pathology & Laboratory Medicine ◽

10.5858/arpa.2012-0537-oa ◽

2013 ◽

Vol 137 (11) ◽

pp. 1560-1568 ◽

Cited By ~ 25

Author(s):

Jane Zhou ◽

Diana Bell ◽

L. Jeffrey Medeiros

Keyword(s):

Head And Neck ◽

Low Frequency ◽

Neck Region ◽

Immunohistochemical Analysis ◽

Myeloid Sarcoma ◽

Head And Neck Region ◽

Bone Marrow Disease ◽

Highly Sensitive ◽

History Of ◽

High Degree

Context.—Myeloid sarcoma of the head and neck region can pose diagnostic challenges because of the low frequency of myeloid sarcoma and the potential for tumors of almost any lineage to occur in the head and neck. Objective.—To study the clinicopathologic and immunohistochemical characteristics of myeloid sarcoma in the head and neck region and to review the differential diagnosis. Design.—We searched for cases of myeloid sarcoma involving the head and neck region for a 24-year period at our institution. The medical records and pathology slides were reviewed. Additional immunohistochemical stains were performed. Results.—We identified 17 patients, age 17 to 85 years. Most tumors involved the oral cavity. Myeloid sarcoma was the initial diagnosis in 9 patients (53%); the remaining 8 patients (47%) had a history of bone marrow disease. Immunohistochemical analysis using antibodies specific for lysozyme, CD43, and CD68 were highly sensitive for diagnosis but were not specific. By contrast, assessment for myeloperoxidase in this study was less sensitive but more specific. We also used antibodies specific for CD11c and CD33 in a subset of cases, and these reagents seem helpful as well. Conclusions.—The clinical presentation of myeloid sarcoma involving the head and neck, particularly the mouth, is often nonspecific, and a high degree of suspicion for the possibility of myeloid sarcoma is needed. Immunohistochemistry is very helpful for establishing the diagnosis.

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Low-frequency unsteadiness in the wake of a normal flat plate

Journal of Fluid Mechanics ◽

10.1017/s0022112098002110 ◽

1998 ◽

Vol 370 ◽

pp. 101-147 ◽

Cited By ~ 88

Author(s):

F. M. NAJJAR ◽

S. BALACHANDAR

Keyword(s):

Shear Layer ◽

Flat Plate ◽

Free Stream ◽

Low Frequency ◽

Separated Flow ◽

Phase Mismatch ◽

Streamwise Vortices ◽

Long Time ◽

Drag And Lift ◽

High Degree

The separated flow past a zero-thickness flat plate held normal to a free stream at Re=250 has been investigated through numerical experiments. The long-time signatures of the drag and lift coefficients clearly capture a low-frequency unsteadiness with a period of approximately 10 times the primary shedding period. The amplitude and frequency of drag and lift variations during the shedding process are strongly modulated by the low frequency. A physical interpretation of the low-frequency behaviour is that the flow gradually varies between two different regimes: a regime H of high mean drag and a regime L of low mean drag. It is observed that in regime H the shear layer rolls up closer to the plate to form coherent spanwise vortices, while in regime L the shear layer extends farther downstream and the rolled-up Kármán vortices are less coherent. In the high-drag regime three-dimensionality is characterized by coherent Kármán vortices and reasonably well-organized streamwise vortices connecting the Kármán vortices. With a non-dimensional spanwise wavelength of about 1.2, the three-dimensionality in this regime is reminiscent of mode-B three-dimensionality. It is observed that the high degree of spanwise coherence that exists in regime H breaks down in regime L. Based on detailed numerical flow visualization we conjecture that the formation of streamwise and spanwise vortices is not in perfect synchronization and that the low-frequency unsteadiness is the result of this imbalance (or phase mismatch).

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Cytology of triploid and pentaploid hybrids of Elymus trachycaulus × Pseudoroegneria spicata and P. spicata ssp. inermis

Genome ◽

10.1139/g87-082 ◽

1987 ◽

Vol 29 (3) ◽

pp. 470-480 ◽

Cited By ~ 2

Author(s):

Taing Aung ◽

P. D. Walton

Keyword(s):

Low Frequency ◽

Plant Size ◽

Double Dose ◽

Homoeologous Pairing ◽

Pseudoroegneria Spicata ◽

Elymus Trachycaulus ◽

Chromosome Associations ◽

Size Variability ◽

High Degree ◽

Very High

Emasculated clones of tetraploid and octaploid Elymus trachycaulus crossed with Pseudoroegneria spicata yielded 69 triploids and 13 pentaploid hybrids. The triploid hybrids were morphologically intermediate between the parental species but the pentaploid hybrids resembled E. trachycaulus more closely than P. spicata. A very high degree of plant size variability (very weak to very vigorous) was observed among the 50 triploids that survived to maturity. The variability among the pentaploids, though apparent, was not high. Mean chromosome associations among the selected eight triploids varied from low multivalent formation at meiosis (7.60 I + 6.18 II + 0.24 III + 0.08 IV) to high multivalent-forming meiosis (7.28 I + 5.66 II + 0.32 III + 0.36 IV). The bivalent configurations in these triploids were attributed to homoeologous pairing between the S1 genome of P. spicata and S genomes of E. trachycaulus and the multivalents indicated intergenomal and intragenomal pairings. Mean chromosome associations of 5.22 I + 11.94 II + 1.97 III in 78.7% and 7 I + 14 II in 21.3% of the 150 cells were distributed among the three pentaploid hybrids. The low frequency of trivalents and the absence of multivalents higher than trivalent configurations suggest that homoeologous pairing was substantially reduced and there was no intergenomal and intragenomal pairing in these 2n = 35 x hybrids. Fourteen triploids and three pentaploid hybrids were produced from 4x and 8x forms of E. trachycaulus and P. spicata spp. inermis crosses. The triploids were intermediate between the parents but the pentaploids were more similar to E. trachycaulus. Mean chromosome associations in the triploids (6.020 I + 5.315 II + 0.554 III + 0.235 IV + 0.250 V + 0.048 VI + 0.03 VII) and in the pentaploids (3.50 I + 10.18 II + 3.54 III + 0.13 IV) indicated a very high degree of intergenomal and intragenomal pairing in the triploids; nevertheless, it was greatly reduced in the pentaploids. The Pseudoroegneria spicata ssp. inermis genome may have gene(s) that affect a high degree of intergenomal and intragenomal pairing in triploid hybrids with E. trachycaulus. However, in pentaploid hybrids (SS HH S2) the S and H genomes of E. trachycaulus in double dose seem to have restored its regular meiotic bahaviour, at least partially, and reduced homoeologous pairing as well as intergenomal and intragenomal pairing. Key words: Elymus trachycaulus, Pseudoroegneria spicata, regular meiotic behaviour, double dose, intergenomal pairing, intragenomal pairing.

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Concordance Among Indices of Intrinsic Brain Function: Insights from Inter-Individual Variation and Temporal Dynamics

10.1101/048405 ◽

2016 ◽

Author(s):

Chao-Gan Yan ◽

Zhen Yang ◽

Stanley J. Colcombe ◽

Xi-Nian Zuo ◽

Michael P. Milham

Keyword(s):

Individual Variation ◽

Brain Function ◽

Temporal Dynamics ◽

Brain Activity ◽

Low Frequency ◽

Resting State Fmri ◽

Surrogate Data ◽

Linear Increase ◽

Intrinsic Brain Activity ◽

High Degree

ABSTRACTVarious resting-state fMRI (R-fMRI) measures have been developed to characterize intrinsic brain activity. While each of these measures has gained a growing presence in the literature, questions remain regarding the common and unique aspects these indices capture. The present work provided a comprehensive examination of inter-individual variation and intra-individual temporal variation for commonly used measures, including fractional amplitude of low frequency fluctuations, regional homogeneity, voxel-mirrored homotopic connectivity, network centrality and global signal correlation. Regardless of whether examining intra-individual or inter-individual variation, we found that these definitionally distinct R-fMRI indices tend to exhibit a relatively high degree of covariation, which doesn’t exist in phase randomized surrogate data. As a measure of intrinsic brain function, concordance for R-fMRI indices was negatively correlated with age across individuals (i.e., concordance among functional indices decreased with age). To understand the functional significance of concordance, we noted that higher concordance was generally associated with higher strengths of R-fMRI indices, regardless of whether looking through the lens of inter-individual (i.e., high vs. low concordance participants) or intra-individual (i.e., high vs. low concordance states identified via temporal dynamic analyses) differences. We also noted a linear increase in functional concordance together with the R-fMRI indices through the scan, which may suggest a decrease in arousal. The current study demonstrated an enriched picture regarding the relationship among the R-fMRI indices, as well as provided new insights in examining dynamic states within and between individuals.

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The Appraisal of Commitment in Organizational Environments- Differentiating Organizational Commitment from Employee Satisfaction

European Journal of Interdisciplinary Studies ◽

10.26417/ejis.v4i2.p178-182 ◽

2016 ◽

Vol 4 (2) ◽

pp. 178

Author(s):

Radu Florea

Keyword(s):

Organizational Commitment ◽

Change Management ◽

Business Strategy ◽

Critical Incident ◽

Resistance To Change ◽

Data Interpretation ◽

General Level ◽

Organizational Environments ◽

Wide Range ◽

High Degree

In order to acquire (and maintain) a high degree of commitment of a company’s staff certain conditions must be met both general – that are valid for most organizations focused on profit - and specific - depending on the particularities of each company. Commitment is very relevant in calibrating the business strategy of companies in order to develop employees but also as a central objective for change management. At a general level, building commitment is conditioned on communication with employees on effective leadership, a high degree of satisfaction and a low degree of resistance to change. Change management theorists suggest that any kind of change - both planned and critical incident related- will have negative implications on organizational commitment. Becker considers communication as one of the main factors that affect commitment, important in the growth and continuation. Communication also has implications for organizational culture calibration, transmission of messages via multiple channels and is affected by several factors including commitment (Keyton, 2010). The main difference between commitment and satisfaction is strongly related to the emotional and affective study dimensions of Meyer and Allen’s model on commitment (Keyton, 2010); although satisfaction can generate certain reactions from employees, it has a wide range of meanings from which results can be reported. Commitment may have different affective values because of the implications that it generates and because of their complexity. Accuracy is the most important feature as it helps in measuring commitment and maintaining a high degree of objectivity in data interpretation. Measuring attitudes in social sciences is a subject often problematic because the instruments used do not meet the criteria of validity - do not measure what needs to be measured. Therefore, the measurements may be inaccurate without the use of an appropriate methodology for identifying the exact coefficients of the survey indicators.

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The Implications of Intergenic Polymorphism for Major Histocompatibility Complex Evolution

Genetics ◽

10.1093/genetics/156.2.867 ◽

2000 ◽

Vol 156 (2) ◽

pp. 867-877 ◽

Cited By ~ 1

Author(s):

Colm O'hUigin ◽

Yoko Satta ◽

Anja Hausmann ◽

Roger L Dawkins ◽

Jan Klein

Keyword(s):

Major Histocompatibility Complex ◽

Least Squares ◽

Balancing Selection ◽

Low Frequency ◽

Least Squares Estimate ◽

B Locus ◽

Histocompatibility Complex ◽

Intergenic Regions ◽

Major Histocompatibility Complex Evolution ◽

High Degree

Abstract A systematic survey of six intergenic regions flanking the human HLA-B locus in eight haplotypes reveals the regions to be up to 20 times more polymorphic than the reported average degree of human neutral polymorphism. Furthermore, the extent of polymorphism is directly related to the proximity to the HLA-B locus. Apparently linkage to HLA-B locus alleles, which are under balancing selection, maintains the neutral polymorphism of adjacent regions. For these linked polymorphisms to persist, recombination in the 200-kb interval from HLA-B to TNF must occur at a low frequency. The high degree of polymorphism found distal to HLA-B suggests that recombination is uncommon on both sides of the HLA-B locus. The least-squares estimate is 0.15% per megabase with an estimated range from 0.02 to 0.54%. These findings place strong restrictions on possible recombinational mechanisms for the generation of diversity at the HLA-B.

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Seasonal prediction in northern Atlantic Ocean and Norwegian Seas

10.5194/egusphere-egu21-13462 ◽

2021 ◽

Author(s):

Noel Keenlyside ◽

Sunil Pariyar ◽

Ingo Bethke ◽

Yiguo Wang ◽

Francois Counillon

Keyword(s):

Heat Budget ◽

Vertical Mixing ◽

Low Frequency ◽

Seasonal Prediction ◽

Boreal Summer ◽

Budget Analysis ◽

Low Frequency Variability ◽

Operational Systems ◽

High Degree ◽

High Skill

Recent operational systems are able to predict sea surface temperature (SST) on seasonal timescales in the extra-tropical North Atlantic and Nordic Seas to a high-degree and as high as in the tropical Pacific. While prediction on multi-year timescales is well documented, the source of the high skill on seasonal timescales is unclear and somewhat unexpected. Here, using the Norwegian Climate Prediction model, we show that the skill on seasonal timescales is associated primarily with low-frequency variability (timescales longer than five years). Consistently, there is high skill in predicting SST anomalies six seasons in advance, although there is a skill drop across boreal summer that seems associated with reduced vertical mixing. External forcing and initialized ocean variability contribute similarly to skill on seasonal timescales, as assessed through a heat budget analysis. Skill on these timescales can benefit fisheries and aqua culture.

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Low-Frequency Variability and Blocking as Diagnostic Tools for Global Climate Models

Prediction of Interannual Climate Variations ◽

10.1007/978-3-642-76960-3_9 ◽

1993 ◽

pp. 173-182 ◽

Cited By ~ 1

Author(s):

Stefano Tibaldi

Keyword(s):

Climate Models ◽

Global Climate ◽

Low Frequency ◽

Global Climate Models ◽

Diagnostic Tools ◽

Low Frequency Variability

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Retrieving signs of buried historical roads by GPR: preliminary results from Villa dei Sette Bassi in Rome

10.5194/egusphere-egu21-16316 ◽

2021 ◽

Author(s):

Luca Bianchini Ciampoli ◽

Andrea Benedetto ◽

Alessandra Ten ◽

Carla Maria Amici ◽

Roberta Santarelli

Keyword(s):

Middle Ages ◽

Ground Penetrating Radar ◽

Road Network ◽

Quantitative Methods ◽

Low Frequency ◽

Archaeological Site ◽

Data Interpretation ◽

Computer Application ◽

Entire Area ◽

Ground Penetrating

Ground Penetrating Radar has widely proven to be an effective tool for archaeological purposes [1, 2]. Our contribution concerns a geophysical experimental activity carried out in the Complex of Villa dei Sette Bassi, an archaeological site located in Rome, Italy.In particular, the area was hypothesized to be interested by the track of the ancient via Latina [3, 4], which was the main internal route that connected Rome with the ancient Region of Campania; it ran parallel to the Via Appia, but it was built way before it.The historical evolution of this landscape has seen great changes since the Middle Ages with a new economy that designed new parcels, new land uses and the stripping of building material from ancient remains: activities that have profoundly altered the territory in its appearance and functioning but also its road network. The uncontrolled building development, has over time hidden the ancient road network, today witnessed only by decontextualized monuments immersed in modern urbanization. Accordingly, great portion of the ancient via Latina remains still buried.This works reports on the outcomes of the geophysical tests conducted within the area of Villa dei Sette Bassi, with the specific goal of locating the buried track of the via Latina. The survey has been carried out by using multi-frequency ground penetrating radar (GPR) systems with different central frequencies. In detail, a preliminary low frequency analysis was conducted over the entire area that was indicated to be interested by the hidden remains by literary sources, to the intent of detecting the position of the buried road with higher accuracy. Based on the this, a second survey with higher resolution was conducted over a regularly spaced grid.As a result, GPR tests have returned a coherent reflection pattern that is reasonably representative of a road subgrade/embankment. According to the preliminary archaeological interpretations, these results are most likely related to the historical track of via Latina, even though inspection pits are required in order to verify these assumptions.In conclusion, GPR demonstrated a great applicability to archaeological purposes, i.e. to detect buried remains and to interpret the function of buried structures, despite the reliability and productivity of the data interpretation are strongly influenced by the expertise of both the geophysicists and the archaeologists involved.&#160;References[1] Bianchini Ciampoli, L., Santarelli, R., Loreti, E.M., Ten, A., Benedetto, A. {2020} &#8220;Structural detailing of buried Roman baths through GPR inspection&#8221;, Archaeological Prospections, In Press.[2] Milligan, R., & M., Atkin, {1993}. The use of ground-probing radar within a digital environment on archaeological sites, in Andresen, J., Madsen, T. and Scollar, I., eds., Computing the Past: Computer Application and Quantitative methods in Archaeology: Aarhus, Denmark, Aarhus University Press, pp. 285&#8211;291.[3] Monti, P.G. {1995} &#8220;Via Latina&#8221;, Istituto Poligrafico e Zecca dello Stato. Libreria dello Stato Roma.[4] Rea, R., Montella, F., Egidi, R.. Alteri, R., Diamanti, F., Mongetta, M., {2005} &#8220;Via Latina&#8221;, in Lexicon Topographicum Urbis Romae, III, pp. 133-202, Quasar ed., Roma.

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