Can We Estimate the True Weight of Zooplankton Samples after Chemical Preservation?

1989 ◽  
Vol 46 (3) ◽  
pp. 522-527 ◽  
Author(s):  
Louis A. Giguère ◽  
J.-F. St-Pierre ◽  
B. Bernier ◽  
A. Vézina ◽  
j.-G. Rondeau
Keyword(s):  
Weight Loss ◽  
Body Length ◽  
Freeze Drying ◽  
Size Fraction ◽  
Dry Weight ◽  
Ash Content ◽  
Caloric Content ◽  
Size Fractions ◽  
Size Dependent ◽  
Weight Losses

Zooplankton are collected and sorted into two size fractions from which samples are randomly alloted to a battery of commonly used preservation techniques. We determine dry weight, ash content, and caloric content. We compute organic and inorganic losses of the samples to examine potential causes of variation in dry weight estimates. Treatments are: no preservation, preservation with one of three chemicals (75% ethanol, 5% or 10% buffered formaldehyde), preservation for 1 or 66 wk, and oven- or freeze-drying. Overall dry weight losses are independent of preservation methods. Chemical preservation reduces dry weight by 37 to 43%. Organic and inorganic losses range from 25 to 33% and 73 to 82%, respectively. Because inorganic losses are large, chemical preservation increases the caloric content of samples by 13 – 27%. Dry weight losses are somewhat size-dependent (37 versus 43% for the large and small size fraction respectively, after 66 wk of preservation). A regression of percent dry weight losses on body length (in millimetres) is obtained for our data, and published reports where formaldehyde is used as a preservative. It is: In[dry weight loss] = 4.149 − 0.576 length0.333. This relationship can be used to adjust the weight of zooplankton samples which have been preserved chemically. A survey of studies published in 1983 indicates that most authors did not adjust for dry weight losses due to preservation.

scholarly journals Configuration of flowsheet and reagent dosage for gilsonite flotation towards the ultra-low-ash concentrate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ataallah Bahrami ◽  
Fatemeh Kazemi ◽  
Mirsaleh Mirmohammadi ◽  
Yousef Ghorbani ◽  
Saghar Farajzadeh
Keyword(s):  
Sulfuric Acid ◽  
Sodium Silicate ◽  
Tannic Acid ◽  
Size Fraction ◽  
Sodium Cyanide ◽  
Ash Content ◽  
Drilling Fluids ◽  
Gas Oil ◽  
Size Fractions ◽  
Process Mineralogy

AbstractGilsonite has a wide variety of applications in the industry, including the manufacture of electrodes, paints and resins, as well as the production of asphalt and roof-waterproofing material. Gilsonite ash is a determining parameter for its application in some industries (e.g., gilsonite with ash content < 5% used as an additive in drilling fluids, resins). Due to the shortage of high grade (low ash) gilsonite reserves, the aim of this study is to develop a processing flowsheet for the production of ultra-low-ash gilsonite (< 5%), based on process mineralogy studies and processing tests. For this purpose, mineralogical studies and flotation tests have been performed on a sample of gilsonite with an average ash content of 15%. According to mineralogical studies, carbonates and clay minerals are the main associated impurities (more than 90 vol.%). Furthermore, sulfur was observed in two forms of mineral (pyrite and marcasite) and organic in the structure of gilsonite. Most of these impurities are interlocked with gilsonite in size fractions smaller than 105 µm. The size fraction of + 105 − 420 µm has a higher pure gilsonite (approximately 90%) than other size fractions. By specifying the gangue minerals with gilsonite and the manner and extent of their interlocking with gilsonite, + 75 − 420 µm size fraction selected to perform flotation tests. Flotation tests were performed using different reagents including collector (Gas oil, Kerosene and Pine oil), frother (MIBC) and depressant (sodium silicate, tannic acid, sulfuric acid and sodium cyanide) in different dosages. Based on the results, the use of kerosene collector, MIBC frother and a mixture of sodium silicate, tannic acid, sulfuric acid and sodium cyanide depressant had the most favorable results in gilsonite flotation in the rougher stage. Cleaner and recleaner flotation stages for the rougher flotation concentrate resulted in a product with an ash content of 4.89%. Due to the interlocking of gilsonite with impurities in size fractions − 105 µm, it is better to re-grinding the concentrate of the rougher stage beforehand flotation in the cleaner and recleaner stages. Finally, based on the results of mineralogical studies and processing tests, a processing flowsheet including crushing and initial granulation of gilsonite, flotation in rougher, cleaner and recleaner stages has been proposed to produce gilsonite concentrate with < 5% ash content.

A new method for evaluating decay: the effect of oxygen on Polyporuscompactus in red oak

1985 ◽  
Vol 15 (6) ◽  
pp. 1021-1024 ◽  
Author(s):  
T. J. Hall ◽  
Curt Leben
Keyword(s):  
Weight Loss ◽  
Continuous Flow ◽  
Constant Pressure ◽  
White Rot Fungi ◽  
Dry Weight ◽  
Ambient Air ◽  
White Rot ◽  
Weight Losses ◽  
Soil Block ◽  
Effect Of Oxygen

The effects of oxygen decay (weight loss) incited by Polyporuscompactus Overh. was studied using small fresh and dried wood blocks containing both sapwood and heartwood of similar radial position and age. A manifold was used to deliver hydrated gas mixtures of 1.0, 4.2, or 21% (ambient air) oxygen at constant pressure and continuous flow to jars containing inoculated or noninoculated blocks. Means (P = 0.05) for dry weight losses in inoculated blocks at 1.0, 4.2, and 21% oxygen were 3.3, 8.9, and 21.4%, respectively; losses may be comparable to decay by other white rot fungi using the soil-block procedure. Losses in noninoculated blocks at the above oxygen levels were 2.0, 4.6, and 7.0%, respectively. Differences in dry weight losses between fresh and dry blocks were found. In particular, losses in inoculated fresh blocks were significantly less than losses in inoculated dry blocks in ambient air. Native inhabitants occurring in fresh wood appear to interfere with the decay processes of P. compactus. Losses in noninoculated fresh blocks were significantly greater than in noninoculated dry blocks at 21% oxygen but not at 1.0 or 4.2% oxygen; losses were attributed to natural inhabitants in fresh wood.

scholarly journals Effects of formaldehyde preservation time on the length-weight relationship of the ubiquitous neotropical cladoceran Ceriodaphnia silvestrii

2021 ◽  
Vol 33 ◽  
Author(s):  
Rafael Lacerda Macêdo ◽  
Lorena Pinheiro-Silva ◽  
Adriana Lamanna Puga ◽  
Gabriel Klippel ◽  
Betina Kozlowsky-Suzuki ◽  
...  
Keyword(s):  
Body Length ◽  
Linear Models ◽  
Dry Weight ◽  
Total Body Length ◽  
Biomass Estimation ◽  
Biological Communities ◽  
Weight Losses ◽  
Major Interest ◽  
Total Body ◽  
Relationship Of

Abstract: Aim In this study, the effect of preservation time on total body length and dry weight of adult specimens of the neotropical cladoceran Ceriodaphnia silvestrii preserved with 4% formalin solution were examined. Methods The relationship between these variables was examined under increasing gradual time effects (i.e. 7, 30, and 60 days) after preservation using linear models and analysis of variance. Results Total body length did not statistically differ between fresh and preserved cladocerans at any preservation time, whereas dry weight was drastically reduced with increasing preservation time, with 15, 47 and 57% weight losses. Length-weight relationships were significantly and positively related in all treatments, though higher values of slope were found for fresh and 7 days samples. Conclusions We highlight that, for Ceriodaphnia silvestrii, the use of the formalin solution as a preservation fixative is not adequate when the major interest is biomass estimation. Also, we recommend that dry weight estimations from preserved samples should be done as soon as possible. Finally, considering the preservation losses and intra-specific composition of organisms, the application of correction factors is advised since preserved samples are important in the evaluation of long-term changes of biological communities.

Regulation of Transpiration in the Clover Mite Bryobia Praetiosa Koch (Acarina: Tetranychidae)

1965 ◽  
Vol 43 (2) ◽  
pp. 257-269
Author(s):  
PAUL W. WINSTON ◽  
V. EUGENE NELSON
Keyword(s):  
Weight Loss ◽  
Water Content ◽  
Water Loss ◽  
Dry Weight ◽  
Total Weight ◽  
Total Weight Loss ◽  
Weight Losses ◽  
Before And After ◽  
The Face ◽  
Humidity Range

1. Groups of sixteen mites were starved for 48 hr. at 29% R.H. and then exposed for 18 or 24 hr. to one of nine humidities, from 0% to 93% R.H. They were weighed as groups before and after the treatments to determine total weight loss. Dry weights were also obtained to find water content and for the calculation of water and dry-weight losses. All work was done at 25° C. 2. Water loss, considered equivalent to total weight loss, was also obtained under several other conditions; and at all humidities it was found to be highest in mites killed in chloroform vapour while it was considerably less in those killed in HCN gas. Mites with spiracles kept open by air with 10% CO2 lost weight at rates midway between those for dead and those for living animals. 3. There is apparent regulation of body-water content as a percentage of the final weight over the whole humidity range. 4. Water loss is restricted by a CO2-sensitive mechanism, presumably the spiracles. 5. Active regulation of water loss by a cuticular mechanim was shown between 53% and 85% R.H., while at humidities below this, loss was actively restricted but not regulated. 6. It is postulated that both restriction and regulation are brought about by the same mechanism, which might be a form of active transport. 7. Uptake of water from unsaturated air was not found with any of the methods used. 8. Regulation such as was found here would help to maintain the internal environment of these mites as nearly constant as possible in the face of fluctuating humidities.

Size-dependent organo-mineral interactions and dynamics in a seasonally-flooded wetland

2020 ◽  
Author(s):  
Mohammad Afsar ◽  
Bruce Vasilas ◽  
Yan Jin
Keyword(s):  
Organic Matter ◽  
Size Fraction ◽  
Operational Definition ◽  
Organic C ◽  
Size Fractions ◽  
Size Dependent ◽  
Depressional Wetland ◽  
Mineral Associations ◽  
Delmarva Bay ◽  
Terrestrial Environments

&lt;p&gt;Understanding the mechanisms governing the composition and stability of organo-mineral associations is critical to predicting the dynamics of soil organic matter (SOC) and the related global carbon cycling. Redox-induced biogeochemical transformations are the key processes that control the stabilization of SOC via association with metal oxides in terrestrial environments such as wetlands. Despite its high C content (20-30% of terrestrial C), size-dependent organo-mineral associations and their dynamic changes in the redox-dynamic wetlands are poorly understood. Here we present size distribution, concentration, and composition of organo-mineral associations in pore water samples from a depressional wetland located at the Delmarva Bay in Delaware, USA, as influenced by seasonal fluctuations in water table level. The samples were collected from piezometers installed at multiple depths (50 cm, 100 cm, and 200 cm) and in three zones (upland, transitional, and wetland), respectively. Four size fractions were analyzed: dissolved (&lt;2.3 nm), natural nanoparticle (2.3-100 nm, NNP), fine colloid (100-450 nm), and particulate (450-100 nm). Our results revealed that dissolved, NNP, fine colloid and particulate fractions comprised 47 &amp;#177; 4%, 37 &amp;#177; 4%, 8 &amp;#177; 3% and 8 &amp;#177; 3% of&amp;#160; the bulk organic C (&lt;1000 nm) concentration, respectively. Relative percentages of respective Al, Mn, and Fe were 47 &amp;#177; 24%, 30 &amp;#177; 22%, 50 &amp;#177; 18% at 2.3-450 nm and 22 &amp;#177; 16%, 17 &amp;#177; 12%, 25 &amp;#177; 19% at 450-1000 nm size fraction. The main finding from this study are 1) dissolved and NNP fractions contain higher amount of C than colloidal and particulate fractions and 2) organo-mineral associations have significant differences in their elemental concentrations among different size fractions within colloidal size range. Additionally, the results clearly indicate that the commonly used operational definition for dissolved organic matter (DOM, &lt;450 nm) significantly overestimates the dissolved phase C concentration by including the NNP and colloidal fractions, which contain mineral-associated C. This has important implications in the estimation of SOC decomposition rate in soils, particularly in redox sensitive wetlands, thus in assessing terrestrial C cycling and the transport of OC as well as the associated elements.&lt;/p&gt;

scholarly journals Session 3 (Joint with the British Dietetic Association): Management of obesity Weight-loss interventions in the treatment of obesity

2009 ◽  
Vol 69 (1) ◽  
pp. 34-38 ◽  
Author(s):  
C. R. Hankey
Keyword(s):  
Physical Activity ◽  
Weight Loss ◽  
Energy Expenditure ◽  
Energy Intake ◽  
Weight Maintenance ◽  
Dietary Advice ◽  
Excess Body Weight ◽  
Lifestyle Interventions ◽  
Post Intervention ◽  
Weight Losses

Treatments to induce weight loss for the obese patient centre on the achievement of negative energy balance. This objective can theoretically be attained by interventions designed to achieve a reduction in energy intake and/or an increase in energy expenditure. Such ‘lifestyle interventions’ usually comprise one or more of the following strategies: dietary modification; behaviour change; increases in physical activity. These interventions are advocated as first treatment steps in algorithms recommended by current clinical obesity guidelines. Medication and surgical treatments are potentially available to those unable to implement ‘lifestyle interventions’ effectively by achieving losses of between 5 kg and 10 kg. It is accepted that the minimum of 5% weight loss is required to achieve clinically-meaningful benefits. Dietary treatments differ widely. Successful weight loss is most often associated with quantification of energy intake rather than macronutrient composition. Most dietary intervention studies secure a weight loss of between 5 kg and 10 kg after intervention for 6 months, with gradual weight regain at 1 year where weight changes are 3–4 kg below the starting weight. Some dietary interventions when evaluated at 2 and 4 years post intervention report the effects of weight maintenance rather than weight loss. Specific anti-obesity medications are effective adjuncts to weight loss, in most cases doubling the weight loss of those given dietary advice only. Greater physical activity alone increases energy expenditure by insufficient amounts to facilitate clinically-important weight losses, but is useful for weight maintenance. Weight losses of between half and three-quarters of excess body weight are seen at 10 years post intervention with bariatric surgery, making this arguably the most effective weight-loss treatment.

scholarly journals Long term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland. III. Distribution and kinetics of soil organic carbon in particle size fractions

Soil Research ◽  
1986 ◽  
Vol 24 (2) ◽  
pp. 293 ◽  
Author(s):  
RC Dalal ◽  
RJ Mayer
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Size Fraction ◽  
Organic C ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Clay Size Fraction ◽  
Sand Size

Distribution of soil organic carbon in sand-, silt- and clay-size fractions during cultivation for periods ranging from 20 to 70 years was studied in six major soils used for cereal cropping in southern Queensland. Particle-size fractions were obtained by dispersion in water using cation exchange resin, sieving and sedimentation. In the soils' virgin state no single particle-size fraction was found to be consistently enriched as compared to the whole soil in organic C in all six soils, although the largest proportion (48%) of organic C was in the clay-size fraction; silt and sand-size fractions contained remaining organic C in equal amounts. Upon cultivation, the amounts of organic C declined from all particle-size fractions in most soils, although the loss rates differed considerably among different fractions and from the whole soil. The proportion of the sand-size fraction declined rapidly (from 26% to 12% overall), whereas that of the clay-size fraction increased from 48% to 61% overall. The proportion of silt-size organic C was least affected by cultivation in most soils. It was inferred, therefore, that the sand-size organic matter is rapidly lost from soil, through mineralization as well as disintegration into silt-size and clay-size fractions, and that the clay fraction provides protection for the soil organic matter against microbial and enzymic degradation.

Impact of processing methods on microbial load of reared and wild-caught edible crickets (Scapsipedus icipe and Gryllus bimaculatus) in Kenya

2019 ◽  
Vol 5 (3) ◽  
pp. 171-183 ◽  
Author(s):  
J.W. Gatheru ◽  
F.M. Khamis ◽  
F.L.O. Ombura ◽  
J. Nonoh ◽  
C.M. Tanga ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Dry Weight ◽  
Microbial Load ◽  
Deep Frying ◽  
Fresh Weight ◽  
Gryllus Bimaculatus ◽  
Microbial Composition ◽  
Processing Methods ◽  
Microbial Counts ◽  
Fungal Populations

The microbial composition of farmed and wild Scapsipedus icipe and Gryllus bimaculatus is presented. The aim of this study is to determine the microbial load of the two cricket species and evaluate the efficiency of processing methods (boiling, sun-drying, freeze-drying, snap-freezing and deep-frying) in reducing microbial counts. Farmed and wild species were compared based on microbial diversity. Fresh crickets had high microbial counts, bacterial and fungal populations ranged from 4.26-4.58 log cfu/g and 3.48-4.48 log cfu/g fresh weight, respectively. Upon processing, microbial counts reduced, bacterial counts ranged from 1.00-2.08 log cfu/g dry weight (boiled) and 2.70-3.34 log cfu/g dry weight (sun-dried). Fungal counts ranged from1.85-1.95 log cfu/g dry weight (boiled) and 2.95-3.51 log cfu/g dry weight (sun-dried). Deep-frying, freeze-drying and snap-freezing emerged as the best processing methods. Although there is no alarm in consuming fresh crickets, a processing method is advisable to minimize any possible risks.

scholarly journals Soft bodies make estimation hard: correlations among body dimensions and weights of multiple species of sea cucumbers

2015 ◽  
Vol 66 (10) ◽  
pp. 857 ◽  
Author(s):  
James Prescott ◽  
Shijie Zhou ◽  
Andhika P. Prasetyo
Keyword(s):  
Power Function ◽  
Body Length ◽  
Sea Cucumber ◽  
Dry Weight ◽  
Basic Knowledge ◽  
Small Scale ◽  
Body Width ◽  
Sea Cucumbers ◽  
Body Dimensions ◽  
Wet Weight

Tropical sea cucumbers are commonly exploited by small-scale, poorly managed fisheries. A fundamental problem in managing sea cucumber fisheries is the lack of basic knowledge of important life history characteristics for most species. As a result of plastic body dimensions, biological research on this group of animals becomes exceptionally challenging. To improve our understanding of essential biological parameters, we conducted a study to investigate correlations among various body measurements. We analysed a total of 18 sea cucumber species and more than 6600 individuals collected at Scott Reef in the Timor Sea, north-west Australia. We used hierarchical Bayesian errors-in-variables models to specifically take into account measurement errors that are obviously unavoidable. The measures included three types of weights (wet weight, gutted weight and dry weight) and two body dimensions (length and width). The modelling reveals that using both body length and width as independent variables, wet weight increases approximately linearly with body length, but is a power function (~1.6) of body width, although variability exists among species. Dry weight tends to increase more slowly with body length, but has a similar power function of body width. Linear relationships are established between the three types of weights. On average, ~11% of a live specimen and ~16% of a gutted specimen is processed to the commercially traded dry body wall. Our results can be applied to sea cucumbers in other areas and can be useful for data standardisation and size-based fisheries management.

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