# Sampling PointsRecently Published Documents

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(FIVE YEARS 878)

## H-INDEX

34
(FIVE YEARS 11)

2021 ◽
pp. 175815592110528
Author(s):
Nitharsan Aloysius ◽
Chathuri Chandrika
Keyword(s):

The critically endangered Indian Courser ( Cursorius coromandelicus) is a rare resident bird species in Sri Lanka. This bird species is restricted to the northern avifaunal region of Sri Lanka, and even there it has been recorded from only a few locations. Thus, it is identified as one of the rarest birds in Sri Lanka. A 1-year study was conducted to investigate Indian Courser population and their distribution within the Delft Island from 5th of January to 20th of December 2020. Ten (10) randomly selected points were investigated in this study. Of the 10 sampling points, the Indian Courser was observed within three (03) sampling points year around while several sightings were recorded in points 8, and 9 during 3 months of the year. Their abundance significantly varied among sampling locations (one-way ANOVA, F = 15.04, p < .05). The maximum number of individuals recorded was 18 ± 4.64 in December and the minimum number was 4 ± 4.64 during the non-migrant season. Although most of the area in the island is covered with dry grasslands, their distribution in Delft is largely confined to a few grassland patches where human activities are minimum. Hunting, egg collection, and trampling of their nest by the Delft ponies (feral horses) can be identified as the main threats of this species. It is of utmost importance to immediately implement holistic conservation measures to save this critically endangered bird as Delft is the only known location where a viable resident population of Indian Courser is found.

2021 ◽
Vol 13 (21) ◽
pp. 2996
Author(s):
Hao Li ◽
Enze Zhang
Keyword(s):

As an important primary producer in aquatic ecosystems, the various parameters within the mathematical models are used to describe the growth of microalgae and need to be estimated by carefully designed experiments. Non-uniform sampling has proved to generate a deliberately optimized sampling temporal schedule that can benefit parameter estimation. However, the current non-uniform sampling method depends on prior knowledge of the nominal values of the model parameters. It also largely ignores the uncertainty associated with the nominal values, thus inducing unacceptable parameter estimates. This study focuses on the uncertainty problem and describes a new sampling design that couples the traditional uniform and non-uniform sampling schedules to benefit from the merits of both methods. Based on D-optimal design, we first derive the non-uniform optimal sampling points by maximizing the determinant of the Fisher information matrix. Then the confidence interval around the non-uniform sampling points is determined by Monte Carlo simulations based on the prior knowledge of parameter distribution. Finally, we wrap the non-uniform sampling points with the uniform sampling points within the confidence interval to obtain the ultimate optimal experimental design. Scenedesmus obliquus, whose growth curve follows a four-parameter model, was used as a case study. Compared with the traditional sampling design, the simulation results show that our proposed coupled sampling schedule can partly eliminate the uncertainty in parameter estimates caused by fixed systematic errors in observations. Our coupled sampling can also retain some advantages belonging to non-uniform sampling, in exploiting information maximization and managing the cost of sampling.

2021 ◽
Vol 7 (10) ◽
pp. 857
Author(s):
LingLing Liu ◽
WenXia Wu ◽
ShuaiFei Chen
Keyword(s):

The genus Calonectria includes pathogens of various agricultural, horticultural, and forestry crops. Species of Calonectria are commonly collected from soils, fruits, leaves, stems, and roots. Some species of Calonectria isolated from soils are considered as important plant pathogens. Understanding the species diversity and distribution characteristics of Calonectria species in different soil layers will help us to clarify their long-term potential harm to plants and their patterns of dissemination. To our knowledge, no systematic research has been conducted concerning the species diversity and distribution characteristics of Calonectria in different soil layers. In this study, 1000 soil samples were collected from five soil layers (0–20, 20–40, 40–60, 60–80, and 80–100 cm) at 100 sampling points in one 15-year-old Eucalyptus urophylla hybrid plantation in southern China. A total of 1037 isolates of Calonectria present in all five soil layers were obtained from 93 of 100 sampling points. The 1037 isolates were identified based on DNA sequence comparisons of the translation elongation factor 1-alpha (tef1), β-tubulin (tub2), calmodulin (cmdA), and histone H3 (his3) gene regions, as well as the combination of morphological characteristics. These isolates were identified as C. hongkongensis (665 isolates; 64.1%), C. aconidialis (250 isolates; 24.1%), C. kyotensis (58 isolates; 5.6%), C. ilicicola (47 isolates; 4.5%), C. chinensis (2 isolates; 0.2%), and C. orientalis (15 isolates; 1.5%). With the exception of C. orientalis, which resides in the C. brassicae species complex, the other five species belonged to the C. kyotensis species complex. The results showed that the number of sampling points that yielded Calonectria and the number (and percentage) of Calonectria isolates obtained decreased with increasing depth of the soil. More than 84% of the isolates were obtained from the 0–20 and 20–40 cm soil layers. The deeper soil layers had comparatively lower numbers but still harbored a considerable number of Calonectria. The diversity of five species in the C. kyotensis species complex decreased with increasing soil depth. The genotypes of isolates in each Calonectria species were determined by tef1 and tub2 gene sequences. For each species in the C. kyotensis species complex, in most cases, the number of genotypes decreased with increasing soil depth. The 0–20 cm soil layer contained all of the genotypes of each species. To our knowledge, this study presents the first report of C. orientalis isolated in China. This species was isolated from the 40–60 and 60–80 cm soil layers at only one sampling point, and only one genotype was present. This study has enhanced our understanding of the species diversity and distribution characteristics of Calonectria in different soil layers.

2021 ◽
Vol 3 (11) ◽
Author(s):
Thomas Oberleiter ◽
Kai Willner
Keyword(s):

AbstractThe paper presents an investigation of the accuracy of surrogate models for systems with uncertainties, where the uncertain parameters are represented by fuzzy numbers. Since the underlying fuzzy arithmetic using $$\alpha$$ α -level optimisation requires a large number of system evaluations, the use of numerically expensive systems becomes prohibitive with a higher number of fuzzy parameters. However, this problem can be overcome by employing less expensive surrogate models, where the accuracy of the surrogate depends strongly on the choice of the sampling points. In order to find a sufficiently accurate surrogate model with as few as possible sampling points, the influence of various sampling strategies on the accuracy of the fuzzy evaluation is investigated. As well suited for fuzzy systems, the newly developed Fuzzy Oriented Sampling Shift method is presented and compared with established sampling strategies. For the surrogate models radial basis functions and a Kriging model are employed. As test cases, the Branin and the Camelback function with fuzzy parameters are used, which demonstrate the varying accuracy for different sampling strategies. A more application oriented example of a finite element simulation of a deep drawing process is given in the end.

2021 ◽
Vol 20 (2) ◽
Author(s):
Ummu Sholochah
Keyword(s):

Polluted air especially indoors can cause serious problems compared to outdoors. One of the most common pollutants found indoors is carbon monoxide (CO). CO that binds to blood will form carboxyhemoglobin (COHb) bonds, the main source of CO in a closed room comes from cigarette smoke. CO levels that will enter the body are greater in smokers than non-smokers, paris lilies can reduce CO levels. The purpose of this study was to determine the relationship between age, smoking intensity, nutritional status, CO in indoor cigarette smoke and COHb. This research method is quantitative, room CO is measured at 3 sampling points 2 times and blood collection is carried out 2 times as much as 0.05 ml. Respondents in this study were 7 men aged 33-50 years. Yield of CO 4 ppm. COHb has a decreasing value of 0.717%. The value of simple linear regression analysis of the relationship between smoking intensity and COHb with the addition of 5 paris lilies R2 = 0.6379 means that it has a moderate relationship.Keywords: COHb, age, smoking intensity, nutritional status, indoor cigarette smoke CO

2021 ◽
Vol 22 (83) ◽
pp. 66-85
Author(s):
Miriam Fernanda Rodrigues ◽
Fabrício de Araújo Pedron ◽
Gabriel Antônio Deobald ◽
Bruno Giacomini Sari ◽
Ricardo Simão Diniz Dalmolin ◽
...
Keyword(s):

Plateau areas have been considered with high land-use capacity in the Brazilian Meridional Plateau Edge of South Brazil. These areas belong Atlantic Forest biome, the second most extinction threatened ecoregion in the world, and weak knowledge about the environment leads to intensive use and degradation. We aimed to identify soil fragility and land-use capacity and limitation of the Brazilian Meridional Plateau Edge, in South Brazil, by the soil properties. Soil morphology, steady-state water infiltration, and physical and chemical properties at 0.00-0.10 and 0.10-0.20 m layers were evaluated at 57 sampling points in a grid of 20 x 20 m. Although under a small elevation slope, these areas have high soils and their properties variability, which implies high natural fragility. Unlike the soils and properties expected by farmers and scientists, naturally fragile soils (Leptosols, Regosols) with only patches of developed soils (Cambisols, Alisols, Planosols/Gleysols) predominate in these areas. The proper land-use and management of the soil and its landscapes depend on a detailed knowledge of the soil. Because, considering only the expected soil and environment capacity without the evaluation obtained with this study, the soils were intensively used and degraded.

2021 ◽
Vol 11 (19) ◽
pp. 9172
Author(s):
Liliana Teodorof ◽
Antoaneta Ene ◽
Cristina Despina ◽
Daniela Seceleanu-Odor ◽
...
Keyword(s):

The Chilia branch is the north branch of the Danube River at the Romania-Ukraine border in the Danube Delta; it is a complex system with economic and ecological values. The surface water quality is a major concern and monitoring programs have been developed at the national and international level. The objective of this study was to evaluate the water quality of the Chilia branch in different sampling points from the mouth to the discharge in the Black Sea. The assessment of water quality was done at the individual level taking into account the nutrient concentrations and the standard limits for good ecological status and at integrative levels, using CCME WQI. The longitudinal distribution of Chilia branch water quality was done using GIS method. A total of 106 water samples were collected between 2013 and 2019 from five sampling points. At the individual level, the Chilia branch has a good ecological status except for its levels of total nitrogen, due to the organic nitrogen contribution in 2015. In 90% of nutrient concentrations, low values predominate and high values are considered extreme; only in 10% do high values predominate and low values are considered extreme concentrations. In equal percentages, 50% of the nutrient concentrations have a high degree of heterogeneity and the other 50% of concentration values are very close to the average values, with a high degree of homogeneity. CCME WQI method indicated that 39.93% of surface waters from the Chilia branch had an excellent quality, 45.45% a good quality, and only 14.62% a fair quality.

2021 ◽
Vol 42 (Supplement_1) ◽
Author(s):
I Tollefsen ◽
C Shetelig ◽
P Hoffmann ◽
J Eritsland ◽
I Seljeflot ◽
...
Keyword(s):

Abstract Background Inflammation has emerged as a new treatment target in patients with coronary artery disease, and inflammation seems to play an important role in the ischemia/reperfusion injury in ST-elevation myocardial infarction (STEMI). The pro-inflammatory cytokine interleukin-6 (IL-6) has been shown to be associated with myocardial injury and poor prognosis in patients with STEMI. Purpose The aim of the study was to further elucidate possible associations between the IL-6 trans-signalling system and final infarct size, myocardial function, adverse remodelling, and future cardiovascular events in patients with STEMI. Methods A total of 272 patients with first-time STEMI included in the POSTEMI study on ischaemic postconditioning, with symptom duration &lt;6 hours and treated with percutaneous coronary intervention (PCI), were included. Blood samples for analysis of IL-6 and IL-6 receptor (IL-6R) were collected before PCI, immediately after PCI, at day 1 (median 18.3 hours after PCI), and at 4 months follow-up. Cardiac magnetic resonance imaging (CMR) was performed in the acute phase, median 2 days after admission, and repeated after 4 months. Clinical events and all-cause mortality were registered during 12 months' and 70 months' follow-up, respectively. Results There was a significant increase in IL-6 levels from admission to day 1 with a subsequent decline from day 1 to 4 months (Figure 1A). No significant change in IL-6R levels were found from admission to day 1 (Figure 1B). There was no difference between patients treated by postconditioning compared to routine PCI. High levels of IL-6 (&gt; median) at all sampling points were significantly associated with increased infarct size and reduced left ventricular ejection fraction (LVEF) measured by CMR. Additionally, high levels of IL-6 (&gt; median) at day 1 were associated with lower myocardial salvage, more presence of microvascular obstruction and larger increase in indexed LV end diastolic volume (LVEDVi). IL-6R measured during hospitalisation was significantly associated with change in LVEDVi, but did not associate with infarct size, LVEF or myocardial salvage. High levels of IL-6 (&gt;75th percentile) at all sampling points were associated with an increased risk of having an adverse clinical event during the first year and with long-term all-cause mortality (Figure 2), whereas there was no association between IL-6R and adverse clinical events. Conclusion Patients with high IL-6 levels during the acute phase of STEMI had larger infarct size, reduced myocardial salvage, reduced LV function and worse clinical outcome than patients with lower levels of IL-6. High levels of IL-6 measured after 4 months were associated with larger infarct size, reduced LVEF and increased all-cause mortality. IL-6R was significantly associated with increase in LVEDVi. The results add important information to the role of IL-6 in myocardial injury in acute STEMI and the IL-6 pathway as a potential treatment target. FUNDunding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Stein Erik Hagen Foundation for Clinical Heart Research, Oslo, Norway. Figure 1 Figure 2

Author(s):
Fei Zhao ◽
Ignacio Grossmann ◽
Stephen Stamatis
Keyword(s):

In this paper, we propose a novel solution strategy to explicitly describe the design space in which no recourse is considered for the realization of the parameters. First, to smooth the boundary of the design space, the Kreisselmeier-Steinhauser (KS) function is applied to aggregate all inequality constraints, and project them into the design space. Next, for creating a surrogate polynomial model of the KS function, we focus on finding the sampling points on the boundary of KS space. After testing the feasibility of Latin hypercube sampling points, two methods are presented to efficiently extend the set of boundary points. Finally, a symbolic computation method, cylindrical algebraic decomposition, is applied to transform the surrogate model into a series of explicit and triangular subsystems that can be further converted to describe the KS space. Two case studies are considered to show the efficiency of the proposed algorithm.

2021 ◽
Vol 2021 ◽
pp. 1-11
Author(s):
Xianglei Meng ◽
Nengjian Wang ◽
Qinhui Liu
Keyword(s):

To improve the safety and effectiveness of autonomous towing aircraft aboard the carrier deck, this study proposes a velocity-restricted path planner algorithm named as kinodynamic safety optimal rapidly exploring random tree (KS-RRT ∗ ) to plan a near time-optimal path. First, a speed map is introduced to assign different maximum allowable velocity for the sampling points in the workspace, and the traverse time is calculated along the kinodynamic connection of two sampling points. Then the near time-optimal path in the tree-structured search map can be obtained by the rewiring procedures, instead of a distance-optimal path in the original RRT ∗ algorithm. In order to enhance the planner’s performance, goal biasing scheme and fast collision checking technique are adopted in the algorithm. Since the sampling-based methods are sensitive to their parameters, simulation experiments are first conducted to determine the optimal input settings for the specific problem. The effectiveness of the proposed algorithm is validated in several common aircraft parking scenarios. Comparing with standard RRT ∗ and human heuristic driving, KS-RRT ∗ demonstrates a higher success rate, as well as shorter computation and trajectory time. In conclusion, KS-RRT ∗ algorithm is suitable to generate a near time-optimal safe path for autonomous high density parking in semistructured environment.