Subsampling Reduces Sorting Effort for Waterfowl Foods in Salt-Marsh Core Samples

2014 ◽  
Vol 5 (2) ◽  
pp. 380-386 ◽  
Author(s):  
Mark C. Livolsi ◽  
Kevin M. Ringelman ◽  
Christopher K. Williams
Keyword(s):  
Salt Marsh ◽  
Food Availability ◽  
Carrying Capacity ◽  
Processing Time ◽  
Soil Core ◽  
Habitat Types ◽  
Core Samples ◽  
Large Numbers ◽  
Significant Difference ◽  
Time Savings

Abstract Waterfowl researchers often use soil core samples to estimate food availability in foraging habitats, and these estimates are needed for bioenergetic models of carrying capacity. However, core sampling is frequently a time- and resource-intensive process, and some researchers have suggested that subsampling may be a valuable way to reduce processing time. We evaluated whether 10% and 25% by mass subsampling are appropriate techniques for reducing core-sorting effort while maintaining precision for samples taken in six separate habitat types along the Delaware bayshore. We found no significant difference between biomass found in 100% sorted cores and estimated biomass obtained by 10% and 25% subsampling. We found that 10% subsampling offered the greatest time savings, reducing mean sorting times by 77% (from 13.7 hours to 3.3 hours) from 100% sorted cores. We recommend that researchers consider subsampling to reduce core-sorting effort and cost, particularly when processing large numbers of cores.

Assessing Uncertainty in Coastal Marsh Core Sampling for Waterfowl Foods

2015 ◽  
Vol 6 (1) ◽  
pp. 238-246 ◽  
Author(s):  
Kevin M. Ringelman ◽  
Christopher K. Williams ◽  
John M. Coluccy
Keyword(s):  
Energy Density ◽  
Habitat Type ◽  
Coastal Marsh ◽  
Energy Estimates ◽  
Large Animal ◽  
Soil Core ◽  
Habitat Types ◽  
Food Items ◽  
Core Samples ◽  
Landscape Scales

Abstract Quantifying foraging resources available to waterfowl in different habitat types is important for estimating energetic carrying capacity. To accomplish this, most studies collect soil-core samples from the marsh substrate, sieve and sort food items, and extrapolate energy values to wetland or landscape scales. This is a costly and time-intensive process; furthermore, extrapolation methods yield energy estimates with large variances relative to the mean. From both research and management perspectives, it is important to understand sources of this variation and estimate the number of soil cores needed to reduce the variance to desired levels. Using 2,341 cores collected from freshwater and salt marsh habitats at four sites along the Atlantic Coast, we examined sampling variation and biological variation among sites and habitats. When we removed extreme outliers in the data caused by large animal food items found in a small core sample, estimates of energy density decreased by an order of magnitude for most habitats. After removing outliers, we found inconsistent geographical variation among habitat types that was especially pronounced in freshwater and no evidence for within-season temporal depletion of food resources for any site or habitat. We used a Monte Carlo simulation approach to estimate the optimal number of cores (minimizing both cost and estimated variance) sampled in each habitat type. Across most contexts, a reduction in the coefficient of variation reached diminishing returns near 40 core samples. We recommend that researchers explicitly address outliers in the data and managers acknowledge the imprecision that can arise from including or excluding outliers when estimating energy density at landscape scales. Our results suggest that collecting 40–50 cores per habitat type was sufficient to reduce the variance to acceptable levels while minimizing overall sampling costs.

Extraction and Quantification of Eugenol from Clove Buds Using HPLC

2020 ◽  
Vol 7 (1) ◽  
pp. 17-23
Author(s):  
Khadiza Fitri Shafira ◽  
Abul Kalam Azad ◽  
Zubair Khalid Labu ◽  
Abul Bashar Mohammed Helal Uddin
Keyword(s):  
Processing Time ◽  
Soxhlet Extraction ◽  
Extraction Methods ◽  
Past Study ◽  
Solvent Ratio ◽  
Clove Oil ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Significant Difference ◽  
Clove Essential Oil

Background: Eugenol is the main constituent of clove essential oil. Past studies have found that clove oil has diverse uses in the pharmaceutical field due to its antioxidant, antibacterial and anesthetic properties. Objective: This work compares the performance of different extraction methods and factors and identifies the effect of the treatments on oil yields and eugenol content. Materials and Methods: Maceration, Hydro distillation, microwave-assisted extraction (MAE), and Soxhlet were performed. The best technique was identified according to yield and content. Further studies were conducted to examine the effects of different factors, such as solvent types (ethanol and methanol) and sample-to-solvent ratio (1:10 and 1:15). HPLC UV-Vis was utilized in the analysis of eugenol concentration. Results and Discussion: Soxhlet extraction provided the highest yield (39.98%) and eugenol content (15.83%), compared to other methods. The results observed from several Soxhlet extraction factors showed that there is no significant difference between the different factors. In the meantime, methanol 1:15 provided the greatest amount of yields (57.83%) and eugenol content (22.21%). In this regard, the higher ratio resulted in higher eugenol content. Conclusion: The results obtained are less comparable because the processing time, the working solvent, and the separation technique were carried out differently for each method. In the meantime, as there is no past study that compared the selected methods and factors, this study’s findings will contribute substantially to fill the gap in this field.

scholarly journals Responses of Bat Communities (Mammalia: Chiroptera) to Forest Loss and Habitat Conversion in Southern Cameroon

2021 ◽  
Vol 14 ◽  
pp. 194008292110103
Author(s):  
Patrick Jules Atagana ◽  
Eric Moïse Bakwo Fils ◽  
Sevilor Kekeunou
Keyword(s):  
Secondary Forest ◽  
Biosphere Reserve ◽  
Abundant Species ◽  
Primary Forest ◽  
Habitat Types ◽  
Habitat Transformation ◽  
Significant Difference ◽  
Southern Cameroon ◽  
Habitat Conversion ◽  
Species Specific

We aimed to assess how bats are affected by habitat transformation by comparing bat assemblages in four habitat types: primary forest, secondary forest, cocoa plantations and human habitations in the Dja Biosphere Reserve of southern Cameroon. Bats were sampled in the four habitat types using mist nets. During 126 nights, a total of 413 bats were captured, belonging to four families, 16 genera and 24 species. Ninety three individuals (17 species) were captured in the primary forest, followed by plantations (105 individuals, 14 species), human habitations (159 individuals, 10 species), and secondary forest (55 individuals, eight species). Megaloglossus woermanni was recorded in all the four habitats, and was the most abundant species (105 individuals). The analysis of bat assemblage between habitat types showed a statistically significant difference in species composition. The distribution of the six most abundant species ( Epomops franqueti, Megaloglossus woermanni, Rousettus aegyptiacus, Dohyrina cyclops, Hipposideros cf. caffer and Hipposideros cf. ruber) was influenced by habitat types. Our results suggest that the decrease in species richness observed in disturbed habitats may be due to habitat perturbations of primary forest habitats. Therefore, it is important to examine the effects of habitat conversion at species level, as responses are often species-specific.

scholarly journals Limit theorems for multi-type general branching processes with population dependence

2020 ◽  
Vol 52 (4) ◽  
pp. 1127-1163
Author(s):  
Jie Yen Fan ◽  
Kais Hamza ◽  
Peter Jagers ◽  
Fima C. Klebaner
Keyword(s):  
Carrying Capacity ◽  
Population Model ◽  
General Framework ◽  
Limit Theorems ◽  
Mating Systems ◽  
Law Of Large Numbers ◽  
Branching Processes ◽  
Special Section ◽  
Large Numbers ◽  
Type Population

AbstractA general multi-type population model is considered, where individuals live and reproduce according to their age and type, but also under the influence of the size and composition of the entire population. We describe the dynamics of the population as a measure-valued process and obtain its asymptotics as the population grows with the environmental carrying capacity. Thus, a deterministic approximation is given, in the form of a law of large numbers, as well as a central limit theorem. This general framework is then adapted to model sexual reproduction, with a special section on serial monogamic mating systems.

Simplified estimation of unsaturated soil hydraulic conductivity using bulk electrical conductivity and particle size distribution

Soil Research ◽  
2013 ◽  
Vol 51 (1) ◽  
pp. 23 ◽  
Author(s):  
Mohammad Reza Neyshabouri ◽  
Mehdi Rahmati ◽  
Claude Doussan ◽  
Boshra Behroozinezhad
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Hydraulic Conductivity ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Unsaturated Soil ◽  
Soil Core ◽  
Soil Hydraulic Conductivity ◽  
Core Samples ◽  
Soil Hydraulic

Unsaturated soil hydraulic conductivity K is a fundamental transfer property of soil but its measurement is costly, difficult, and time-consuming due to its large variations with water content (θ) or matric potential (h). Recently, C. Doussan and S. Ruy proposed a method/model using measurements of the electrical conductivity of soil core samples to predict K(h). This method requires the measurement or the setting of a range of matric potentials h in the core samples—a possible lengthy process requiring specialised devices. To avoid h estimation, we propose to simplify that method by introducing the particle-size distribution (PSD) of the soil as a proxy for soil pore diameters and matric potentials, with the Arya and Paris (AP) model. Tests of this simplified model (SM) with laboratory data on a broad range of soils and using the AP model with available, previously defined parameters showed that the accuracy was lower for the SM than for the original model (DR) in predicting K (RMSE of logK = 1.10 for SM v. 0.30 for DR; K in m s–1). However, accuracy was increased for SM when considering coarse- and medium-textured soils only (RMSE of logK = 0.61 for SM v. 0.26 for DR). Further tests with 51 soils from the UNSODA database and our own measurements, with estimated electrical properties, confirmed good agreement of the SM for coarse–medium-textured soils (<35–40% clay). For these textures, the SM also performed well compared with the van Genuchten–Mualem model. Error analysis of SM results and fitting of the AP parameter showed that most of the error for fine-textured soils came from poorer adequacy of the AP model’s previously defined parameters for defining the water retention curve, whereas this was much less so for coarse-textured soils. The SM, using readily accessible soil data, could be a relatively straightforward way to estimate, in situ or in the laboratory, K(h) for coarse–medium-textured soils. This requires, however, a prior check of the predictive efficacy of the AP model for the specific soil investigated, in particular for fine-textured/structured soils and when using previously defined AP parameters.

A modified hydropneumo‐elutriation apparatus for quantitative root separation from large soil core samples

1995 ◽  
Vol 26 (15-16) ◽  
pp. 2703-2709 ◽  
Author(s):  
J.L. Chotte ◽  
J.Y. Laurent ◽  
J.P. Rossi
Keyword(s):  
Soil Core ◽  
Core Samples ◽  
Large Soil

Digital manometry to measure cerebrospinal fluid pressure during lumbar puncture

2021 ◽  
pp. 197140092110551
Author(s):  
Robert Heider ◽  
Peter G Kranz ◽  
Erin Hope Weant ◽  
Linda Gray ◽  
Timothy J Amrhein
Keyword(s):  
Cerebrospinal Fluid ◽  
Lumbar Puncture ◽  
Pressure Measurement ◽  
Fluid Pressure ◽  
Cerebrospinal Fluid Pressure ◽  
Pressure Measurements ◽  
Csf Pressure ◽  
Left Lateral Decubitus Position ◽  
Significant Difference ◽  
Time Savings

Rationale and Objectives Accurate cerebrospinal fluid (CSF) pressure measurements are critical for diagnosis and treatment of pathologic processes involving the central nervous system. Measuring opening CSF pressure using an analog device takes several minutes, which can be burdensome in a busy practice. The purpose of this study was to compare accuracy of a digital pressure measurement device with analog manometry, the reference gold standard. Secondary purpose included an assessment of possible time savings. Materials and Methods This study was a retrospective, cross-sectional investigation of 71 patients who underwent image-guided lumbar puncture (LP) with opening CSF pressure measurement at a single institution from June 2019 to September 2019. Exclusion criteria were examinations without complete data for both the digital and analog measurements or without recorded needle gauge. All included LPs and CSF pressures were measured with the patient in the left lateral decubitus position, legs extended. Acquired data included (1) digital and analog CSF pressures and (2) time required to measure CSF pressure. Results A total of 56 procedures were analyzed in 55 patients. There was no significant difference in mean CSF pressures between devices: 22.5 cm H2O digitally vs 23.1 analog ( p = .7). Use of the digital manometer resulted in a time savings of 6 min (438 s analog vs 78 s digital, p < .001). Conclusion Cerebrospinal fluid pressure measurements obtained with digital manometry demonstrate comparable accuracy to the reference standard of analog manometry, with an average time savings of approximately 6 min per case.

scholarly journals Cladocera remains and vegetation types to assess the state of oxbows

2018 ◽  
Vol 29 ◽  
pp. 27-39
Author(s):  
István Gyulai ◽  
Csilla Lakatos ◽  
János Tamás Kundrát ◽  
Zsuzsanna Balogh ◽  
Edina Simon ◽  
...  
Keyword(s):  
Surface Sediment ◽  
Ecological Status ◽  
Open Water ◽  
Vegetation Types ◽  
Freshwater Lakes ◽  
Chemical Parameters ◽  
Habitat Types ◽  
Cladocera Remains ◽  
Significant Difference ◽  
Physical And Chemical

We assessed the usefulness of Cladocera remains for establishing the ecological status of oxbows and also tested the association of Cladocera species with various vegetation types. Cladocera remains were collected from the surface sediment of four habitat types (tangled vegetation, open water, reeds and tunnels) and 15 physical and chemical parameters of surface water were studied. In the surface sediment samples, we identified 32 Cladocera taxa. There was a significant difference in the number of species amongst habitat types as per ANOVA. The benthic and plant associated Cladocera communities of reeds, tangled vegetation, open water and tunnels were clearly separated from each other by NMDS ordination. CCA showed that habitat types had characteristic Cladocera species: Pleuroxus species were frequent in the tangled vegetation habitat, while Chydorus species were frequent in the open water. Remarkably, in reeds, Bosmina species were frequent, although these species are usually common in open water. Specimens of the Alona genus were found everywhere. Our findings suggest that the remains of Cladocera species may be useful indicators to assess and monitor the structure of freshwater lakes.

scholarly journals Effects of enhanced hydrological connectivity on Mediterranean salt marsh fish assemblages with emphasis on the endangered Spanish toothcarp (Aphanius iberus)

2016 ◽  
Author(s):  
Patricia Prado ◽  
Carles Alcaraz ◽  
Lluis Jornet ◽  
Nuno Alberto Caiola ◽  
Carles Ibáñez
Keyword(s):  
Salt Marsh ◽  
Fish Community ◽  
Fish Assemblages ◽  
Fish Population ◽  
Important Variable ◽  
Hydrological Connectivity ◽  
Local Diversity ◽  
Large Numbers ◽  
Negative Effect ◽  
Migratory Movements

The hydrological connectivity between the salt marsh and the sea was partially restored in a Mediterranean wetland containing isolated ponds resulting from former salt extraction and aquaculture activities. A preliminary assessment provided evidence that ponds farther from the sea hosted very large numbers of the endangered Spanish toothcarp, Aphanius iberus, suggesting that individuals had been trapped and consequently reach unnaturally high densities. In order to achieve both habitat rehabilitation and toothcarp conservation, efforts were made to create a gradient of hydrologically connected areas, including isolated fish reservoirs, semi-isolated, and connected salt marsh–sea areas that could allow migratory movements of fish and provide some protection for A. iberus. The fish community was monitored prior to, and for three years after rehabilitation. Results showed an increase in the number of fish species within semi-isolated areas (Zone A), relative to connected areas (Zone B), while at the assemblage level, structural differences between zones were higher than interannual variability. GLMs evidenced that distance to the sea was the most important variable explaining the local diversity of the fish community after restoration, with occasional influence of other factors such as temperature, and depth. The abundance of A. iberus was consistently higher in semi-isolated areas at greater distances from the sea, but a decline occurred in both zones and in isolated reservoir ponds after restoration efforts, which may be attributable to dispersal to adjacent habitats, and to interannual differences in recruitment success. A negative effect of restoration works on fish population cannot be excluded, but the final outcome of the intervention likely needs a longer period .

Field evaluation of plaster-based temephos pellets for residual control of midge larvae (Diptera: Chironomidae) in establishing rice crops

1994 ◽  
Vol 34 (5) ◽  
pp. 659 ◽  
Author(s):  
MM Stevens ◽  
GN Warren
Keyword(s):  
Water Column ◽  
Water Samples ◽  
Field Evaluation ◽  
Application Rate ◽  
Control Agent ◽  
Fourth Instar ◽  
Soil Core ◽  
Potential Control ◽  
Core Samples ◽  
Application Rates

A pelletised formulation of temephos (5% a.i.) was evaluated as a potential control agent for chironomid midge larvae in establishing rice crops. Four application rates between 0.03 and 0.53 mg a.i./L (42-732 g a.i./ha) were applied to 80 m2 experimental rice bays immediately after flooding. Water samples and soil core samples were taken at regular intervals until 29 days post-treatment. Larvae were extracted from core samples using magnesium sulfate (MgSO4) flotation, whilst laboratory-reared fourth instar Chironomus tepperi Skuse larvae were used in bioassays with field-collected water samples to determine pesticide activity in the water column. All treatments significantly suppressed C. tepperi-type larvae in the field for at least 13 days. Some suppression of non-C. tepperi-type larvae was obtained at 0.27 mg a.i./L, whilst at 0.53 mg a.i./L all chironomids were reduced to negligible levels for the full period of the trial. In bioassays, significant levels of water column toxicity to fourth instar C. tepperi larvae were only recorded for 2 days after treatment at the highest application rate. Our results indicate that plaster-based temephos pellets have the potential to provide effective, single application control of chironomid larvae in establishing rice crops without the risk of spray drift inherent in the aerial application of liquid insecticides.

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