94 research outputs found
An assessment of pulse transit time for detecting heavy blood loss during surgical operation
Copyright @ Wang et al.; Licensee Bentham Open.
This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License
(http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the
work is properly cited.The main contribution of this paper is the use of non-invasive measurements such as electrocardiogram (ECG) and photoplethysmographic (PPG) pulse oximetry waveforms to develop a new physiological signal analysis technique for detecting blood loss during surgical operation. Urological surgery cases were considered as the control group due to its generality, and cardiac surgery as experimental group since it involves blood loss and water supply. Results show that the control group has the tendency of a reduction of the pulse transient time (PTT), and this indicates an increment in the blood flow velocity changes from slow to fast. While for the experimental group, the PTT indicates high values during blood loss, and low values during water supply. Statistical analysis shows considerable differences (i.e., P <0.05) between both groups leading to the conclusion that PTT could be a good indicator for monitoring patients' blood loss during a surgical operation.The National Science Council (NSC) of Taiwan and the Centre for Dynamical Biomarkers and Translational Medicine, National Central University, Taiwan
Enhanced photoluminescence extraction efficiency from a diamond photonic crystal via leaky modes
Temperature effect on the temporal dynamic of terrestrial invertebrates in technosols formed after reclamation at a post-mining site in Ukrainian steppe drylands
The research was carried out at the Research Centre of the Dnipro State Agrarian and Economic University in Pokrov city. Sampling was carried out in 2013–2015 on a variant of artificial soil (technosols) formed on loess-like loam, red-brown clay, green-grey clay, technological mixture of rocks, and also formed on loess-like loam with a humus-rich 70 cm top soil layer. To investigate the spatiotemporal variation in the abundance, species richness and species composition of invertebrate assemblages within the experimental polygon, the animals were sampled using pitfall traps. In total, 60 pitfall traps were operated simultaneously during each sampling period. Each year the pitfalls were emptied 26 times every 7–9 days. Invertebrates (Arthropoda and Mollusca) of 6 classes, 13 orders, 50 families and 202 species or parataxonomic units were recorded. Diplopoda was most abundant taxonomic group, though it was represented by only one species Rossiulus kessleri (Lohmander, 1927). Coleoptera and Araneae were the most numerous taxonomic groups. Readily available water for plants, precipitation, wind speed, atmospheric temperature (daily minimum, daily maximum, daily mean), atmospheric humidity and atmospheric pressure were used as environmental predictors. Two dimension geographic coordinates of the sampling locations were used to generate a set of orthogonal eigenvector-based spatial variables. Time series of sampling dates were used to generate a set of orthogonal eigenvector-based temporal variables. The moisture content in the technosols was revealed to be the most important factor determining the temporal dynamics of the terrestrial invertebrate community in conditions of semi-arid climate and the ecosystem which formed as a result of the reclamation process. Following soil moisture, the factor most strongly affecting invertebrates in the technosols was temperature. From the total set of the invertebrates, two relatively homogeneous species groups in terms of thermal preferences were extracted: the microtemperature and mesotemperature groups. The microtemperature species are more tolerant to the thermal factor, and the mesotemperature species are more sensitive. The Huisman-Olff-Fresco approach expanded by Jansen-Oksanen provides a wide set of ecologically relevant models which are able to explain species response. The species response to temperature is affected by a complex of other environmental, temporal and spatial factors. The effect of other factors on the species response must be previously extracted to find real estimations of the species temperature optima and tolerance. The approaches to solving this problem may be the object of future investigation
The response of invertebrate communities to a moisture gradient in artificial soils of Ukrainian steppe arid zone
Animals were sampled within the experimental area using traps to investigate the spatial and temporal variation in abundance, species richness, and species composition of invertebrate communities. A total of 60 traps were operated simultaneously during each sampling period. Traps were emptied 26 times every 7-9 days each year. Plant water availability, precipitation, wind speed, air temperature (minimum, maximum, daily mean), air humidity, and atmospheric pressure were used as ecological
predictors of invertebrate community status and structure. Two-dimensional geographic coordinates of sampling locations were used to create a set of orthogonal spatial variables based on eigenvectors. We used time series of sampling dates to produce a set of orthogonal eigenvector time variables. The moisture content in technosols was the most important factor
determining the terrestrial invertebrate community's temporal dynamics under semi-arid climate and reclaimed ecosystem
conditions. Each ecological group of terrestrial invertebrates is homogeneous in terms of moisture gradient (xerophilic, xerozoophilic, mesophilic) and has a specific set of patterns best explain the species response to water content in technosols.
However, one should consider the fact that the species response to soil water content is influenced not only by soil water content but also by a complex of other environmental, temporal and spatial factors. That is why the effect of other factors on the species response must be extracted previously to find real estimations of the species optima and tolerance. This task can be solved using the constrained correspondence analysis (CCA) or constrained redundancy analysis (RDA) depending on the
type of response to ecological factors prevailing in the community – monotone or unimodal. We found that in more dry conditions, the prevalent species responses are unimodal asymmetric, in moister – bimodal, and in moderate conditions, the distributions are symmetric unimodal. The asymmetric species response to soil moisture in different parts of the soil humidity
range may be assumed as predominantly due to the abiotic factors in the gradient's aridest margin and due predominantly to the biotic factors in the most humid margin of the gradient.
Keywords: species response, niche, optima, tolerance, reclamation, gradient, temporal dynami
Temporal aspect of the terrestrial invertebrate response to moisture dynamic in technosols formed after reclamation at a post-mining site in ukrainian steppe drylands
Different approaches were applied to assess soil moisture optima and tolerance of the ecological niche temporal projection of terrestrial invertebrates within an experimental polygon created to investigate the reclamation processes after deep underground hard-rock mining in the Ukrainian steppe drylands. Sampling was carried out in 2013–2015 on a variant of artificial soil (technosols). To investigate the spatiotemporal variation in the abundance,
species richness and species composition of invertebrate assemblages the animals were sampled using pitfall traps. The readily available water for plants, precipitation, wind speed, atmospheric temperature, atmospheric humidity, and atmospheric pressure were used as environmental predictors.
The two-dimension geographic coordinates of the sampling locations were used to generate a set of orthogonal eigenvector-based spatial variables. Time series of sampling dates were used to generate a set of orthogonal eigenvector-based temporal variables. Weighted averaging, generalized
linear mixed models, Huisman-Olff-Fresco models expanded by Jansen-Oksanen, correspondence analysis, and constrained correspondence analysis were used to estimate soil moisture species optima and tolerance. The moisture content in the technosols was revealed to be the most important factor
determining the temporal dynamics of terrestrial invertebrate community in conditions of semi-arid climate and the ecosystem which formed as a result of the reclamation process. The species response to the soil water content is affected not only by the soil water content but also by the complex of the other environmental, temporal, and spatial factors. The effect of other factors on the species response must be extracted previously to find real
estimations of the species optima and tolerance
The temporal dynamics of readily available soil moisture for plants in the technosols of the Nikopol Manganese Ore Basin
The restoration of a stable and productive ecosystem after drastic disturbances to the natural environment due to mining and open-cast mining may be achieved by means of reclamation. Investigation of the hydrological budget of technosols is important task in developing adequate approaches to reclamation. Sod lithogenic soils on red-brown clay, on grey-green clay were chosen as the objects of the investigation. The simulation of moisture content in Nikopol Manganese Ore Basin technosols was performed using the Penman-Monteith approach and evaluated the role of the dependence of soils’ surface albedo on the
humidity in the intensity of evapotranspiration. The research was conducted during 2013–2015 at the station for research on reclaimed land within the Nikopol Manganese Ore Basin (city Pokrov, Ukraine). The experimental area for the study of optimal modes of agricultural reclamation was created in 1968–1970. Precipitation in the investigated area was found to fall very unevenly in time. In 2013, the duration of the rainless period was 259 days, in 2014 – 264 days, in 2015 – 261 days. The maximum daily rainfall varies within 18–49 mm. There are significant interannual differences in the intensity of rainfall. The minimum total annual precipitation in 2014 was due to a decrease in atypical rainfall in late winter and early winter. The maximum
annual rainfall in 2015 was caused by intense rainfall both in the spring and in mid-summer and late autumn. The average annual temperature was 11.1 ºC and the annual totals did not statistically significantly vary within the study period. The average wind speed and average atmospheric humidity are statistically significantly different from year to year. The technosols’ colour
properties and surface albedo varied depending on the moisture content. There is a linear relationship between the moisture content in the soil and albedo of the soil surface. The evaluation of readily available water content was carried out based on the Penman-Monteith model taking into account meteorological data, the water-physical properties of the technosols and the dependence of soil surface albedo on soil humidity. The distribution of this index for different teсhnosols is characterized by a high level of similarity of shape due to the fact that the overall climate factors are crucial in shaping the dynamics of moisture.
A complex mixture of normal distributions is the best model for representing the experimental data. The readily available water content distribution can best be represented as a mixture of two normal distributions. The relatively high moisture level is characterized for winter and spring periods. Water content in sodlithogenic soils on red-brown clay over the period of research
never reached the value of the permanent wilting point. In 2013, the period when the moisture content was less than the value of the permanent wilting point lasted 23 days, and in 2014 this period lasted 39 days. Thus, you can always expect the phenomenon of drought under typical climatic conditions for the technosols on grey-green clay. It was found that monitoring water supplies before the start of the growing season can provide valuable information necessary for the selection of crops for cultivation in the current year. The results indicate the urgency of measures to save the winter rainfall on the fields.
Keywords: reclamation; water regime; albedo; evapotranspiration; Penman-Monteith equation
The temporal dynamics of readily available soil moisture for plants in the technosols of the Nikopol Manganese Ore Basin
The restoration of a stable and productive ecosystem after drastic disturbances to the natural environment due to mining and open-cast mining may be achieved by means of reclamation. Investigation of the hydrological budget of technosols is important task in developing adequate approaches to reclamation. Sod lithogenic soils on red-brown clay, on grey-green clay were chosen as the objects of the investigation. The simulation of moisture content in Nikopol Manganese Ore Basin technosols was performed using the Penman-Monteith approach and evaluated the role of the dependence of soils’ surface albedo on the humidity in the intensity of evapotranspiration. The research was conducted during 2013–2015 at the station for research on reclaimed land within the Nikopol Manganese Ore Basin (city Pokrov, Ukraine). The experimental area for the study of optimal modes of agricultural reclamation was created in 1968–1970. Precipitation in the investigated area was found to fall very unevenly in time. In 2013, the duration of the rainless period was 259 days, in 2014 – 264 days, in 2015 – 261 days. The maximum daily rainfall varies within 18–49 mm. There are significant interannual differences in the intensity of rainfall. The minimum total annual precipitation in 2014 was due to a decrease in atypical rainfall in late winter and early winter. The maximum annual rainfall in 2015 was caused by intense rainfall both in the spring and in mid-summer and late autumn. The average annual temperature was 11.1 ºC and the annual totals did not statistically significantly vary within the study period. The average wind speed and average atmospheric humidity are statistically significantly different from year to year. The technosols’ colour properties and surface albedo varied depending on the moisture content. There is a linear relationship between the moisture content in the soil and albedo of the soil surface. The evaluation of readily available water content was carried out based on the Penman-Monteith model taking into account meteorological data, the water-physical properties of the technosols and the dependence of soil surface albedo on soil humidity. The distribution of this index for different teсhnosols is characterized by a high level of similarity of shape due to the fact that the overall climate factors are crucial in shaping the dynamics of moisture. A complex mixture of normal distributions is the best model for representing the experimental data. The readily available water content distribution can best be represented as a mixture of two normal distributions. The relatively high moisture level is characterized for winter and spring periods. Water content in sod-lithogenic soils on red-brown clay over the period of research never reached the value of the permanent wilting point. In 2013, the period when the moisture content was less than the value of the permanent wilting point lasted 23 days, and in 2014 this period lasted 39 days. Thus, you can always expect the phenomenon of drought under typical climatic conditions for the technosols on grey-green clay. It was found that monitoring water supplies before the start of the growing season can provide valuable information necessary for the selection of crops for cultivation in the current year. The results indicate the urgency of measures to save the winter rainfall on the fields
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