scholarly journals Sediment underneath charophyte meadows is enriched in viable ephippia and enhances the benthic periphytic biofilm

Hydrobiologia ◽  
2021 ◽  
Author(s):  
María A. Rodrigo ◽  
Eric Puche ◽  
Matilde Segura ◽  
Adriana Arnal ◽  
Carmen Rojo
Keyword(s):  
Surficial Sediment ◽  
Aquatic Systems ◽  
Habitat Conservation ◽  
Design Experiment ◽  
Diverse Community ◽  
Sediment Layers ◽  
Periphytic Biofilm ◽  
Factorial Design Experiment ◽  
Outdoor Mesocosms

AbstractWe contribute to the knowledge of charophyte meadows as key components of aquatic systems by analysing how they affect wetland sediments. We performed a factorial-design experiment with limnocorrals (outdoor mesocosms) in a Mediterranean protected wetland with presence or absence of charophytes [Chara vulgaris (CV) and Chara hispida (CH), planted from cultures or recruited in situ from germination of their fructifications]. The first 1 cm-surficial and 2 cm-bottom sediment layers were analysed for cladoceran ephippia, ostracods valves, benthic community of bacteria and periphytic biofilm, and charophyte fructifications. In the surficial sediment, the ephippia density was fourfold higher in the conditions with charophytes than in sites with no-charophytes and higher apparent viability was found. The surficial sediment periphyton biofilm was composed mainly of diatoms, with tenfold higher biomass underneath charophytes, and a much diverse community. The specific microhabitat generated by each charophyte species was reflected in the different abundances and relationships between the analysed components, firstly establishing a divergence with the sediment without meadows and, secondly, a distinction between the meadows of CH and CV that exhibit particular morphology-architecture, might exudate different metabolites and might have different allelopathic capacities over microalgae and microinvertebrates. Thus, the charophyte–sediment tandem is relevant for biodiversity and habitat conservation.

The Effect of Money Denomination on Prosocial Behavior: Through the Perspective of Metaphorical Cognitive Theory

2021 ◽  
pp. 003329412110070
Author(s):  
Jianfeng Yang ◽  
Tao Xu ◽  
Yanhui Hou ◽  
Emily C. Monczynski ◽  
Xiaochuan Jiang
Keyword(s):  
Prosocial Behavior ◽  
Sample Size ◽  
Alternative Explanation ◽  
Cognitive Theory ◽  
Design Experiment ◽  
Single Factor ◽  
Behavior Study ◽  
Factor Design ◽  
Factorial Design Experiment ◽  
Practical Implications

Based on metaphorical cognitive theory, this research did four experiments to examine whether and how one important feature of money, denomination, could influence prosocial behavior. Study 1 was an experiment with a sample size of 209 undergraduates ( Mage = 18.97) showed that a larger denomination enhanced the probability of participants engaging in prosocial behavior rather than with a smaller denomination. Study 2 collecting data from 269 undergraduates ( Mage = 18.50) further showed that larger denominations condition inspired more prosocial behavior than the control condition; and the small denominations condition produced similar levels of prosocial behavior to the control condition. Study 3 used single factor design with a sample size of 192 undergraduates ( Mage = 20.49) repeated the results of Study 2. Furthermore, Study 3 excluded an important alternative explanation that the value rather than the denomination influenced prosocial behavior. Last, Study 4 applied a factorial design experiment with a sample size of 132 undergraduates ( Mage = 20.92) which demonstrated that generosity mediated the effect of denomination on prosocial behavior; the effect of denomination on prosocial behavior did not depend on money priming methods. Finally, theoretical and practical implications were discussed.

Active bio-monitoring of contamination in aquatic systems—An in situ translocation experiment applying the PICT concept

2011 ◽  
Vol 101 (1) ◽  
pp. 228-236 ◽  
Author(s):  
Stefanie Rotter ◽  
Frédéric Sans-Piché ◽  
Georg Streck ◽  
Rolf Altenburger ◽  
Mechthild Schmitt-Jansen
Keyword(s):  
Aquatic Systems ◽  
Translocation Experiment ◽  
Bio Monitoring

In situ measurement of perfluoroalkyl substances in aquatic systems using diffusive gradients in thin-films technique

2018 ◽  
Vol 144 ◽  
pp. 162-171 ◽  
Author(s):  
Dong-Xing Guan ◽  
Ya-Qing Li ◽  
Nan-Yang Yu ◽  
Guang-Hui Yu ◽  
Si Wei ◽  
...  
Keyword(s):  
Thin Films ◽  
In Situ Measurement ◽  
Aquatic Systems ◽  
Perfluoroalkyl Substances ◽  
Diffusive Gradients

A factorial design experiment as a pilot study for noninvasive genetic sampling

2012 ◽  
Vol 12 (6) ◽  
pp. 1040-1047 ◽  
Author(s):  
SHARON RENAN ◽  
EDITH SPEYER ◽  
NAAMA SHAHAR ◽  
TOMER GUETA ◽  
ALAN R. TEMPLETON ◽  
...  
Keyword(s):  
Pilot Study ◽  
Factorial Design ◽  
Design Experiment ◽  
Noninvasive Genetic Sampling ◽  
Genetic Sampling ◽  
Factorial Design Experiment

Sodium Propionate To Control Clostridium botulinum Toxigenesis in a Shelf-Stable Beef Product Prepared by Using Combined Processes Including Irradiation

1997 ◽  
Vol 60 (7) ◽  
pp. 771-776 ◽  
Author(s):  
M. PAULA SUÁREZ REBOLLO ◽  
H. RICARDO RODRÍGUEZ ◽  
MARCELO O. MASANA ◽  
JORGE A. LASTA
Keyword(s):  
Factorial Design ◽  
Clostridium Botulinum ◽  
Meat Products ◽  
Design Experiment ◽  
Combined Processes ◽  
Sodium Propionate ◽  
Safety Level ◽  
Shelf Stable ◽  
Processing Factors ◽  
Factorial Design Experiment

The antibotulinal effect of sodium propionate was evaluated by a factorial-design experiment and by an inoculated-pack study on a shelf-stable beef product. Processing of samples involved curing, cooking, vacuum packing, and gamma irradiation. The factorial-design experiment involved 240 samples treated with 0, 0.8, 2.0, and 3.3% sodium propionate, challenged with 101 to 105 spores of type A Clostridium botulinum per package, irradiated with 2.5, 5, 7.5, and 10 kGy, and stored at 28°C for up to 4 months. In the pack study, 110 samples with 2% added sodium propionate were challenged with 108 spores of C. botulinum per package, irradiated with 12.5 kGy, and stored (28°C) for 8 months. Addition of 0.8% sodium propionate resulted in a delay (compared to control samples) in toxigenesis of 18 (5 kGy), 34 (2.5 kGy), and 34 (7.5 kGy) days, while no toxin was detected in samples irradiated with 10 kGy. Samples containing 2 and 3.3% sodium propionate were not toxic at any irradiation dose assayed. A safety level, expressed as the number of decimal reductions (DR = log 1/P) for the combination 0.8% sodium propionate and 10 kGy, was estimated to be >4.4. In the inoculated pack study, 2 of 107 samples became toxic, and the safety level treatment resulted in 10.7 DR. Sodium propionate in combination with other processing factors was very effective in preventing C. botulinum toxigenesis: it can be used as a further safety hurdle in the development of shelf-stable meat products.

The effect of type of silage and level of concentrate supplementation offered during early lactation on total lactation performance of January/February calving cows

1980 ◽  
Vol 30 (3) ◽  
pp. 341-354 ◽  
Author(s):  
R. W. J. Steen ◽  
F. J. Gordon
Keyword(s):  
Significant Interaction ◽  
Live Weight ◽  
Milk Composition ◽  
Design Experiment ◽  
Early Lactation ◽  
Lactation Performance ◽  
Concentrate Supplementation ◽  
Grass Silage ◽  
Factorial Design Experiment ◽  
Friesian Cows

ABSTRACTA 3 × 2 factorial design experiment using 84 British Friesian cows was conducted to assess the effect of offering three types of grass silage and two levels of concentrate supplementation during early lactation on the total lactation performance of cows which calve during January and February. The three types of silage were early-cut wilted (ECW), early-cut unwilted (ECU) and late-cut unwilted (LCU), and the two levels of concentrate supplementation were 538 kg (LC) and 738 kg (HC) during a mean post-calving period of 71 days. The animals had a mean calving date of 29 January and were blocked according to calving date, and allocated at random to the treatments within each block on day 7 of lactation. The treatments were applied from day 7 of lactation until the animals were turned out to pasture on 18 April. Mean milk yields for the indoor period were: HC treatments 1963 (ECW), 1979 (ECU) and 1830 (LCU); LC treatments 1938 (ECW), 1942 (ECU) and 1731 (LCU) ± 41·3 kg; and for the total lactation were: HC treatments 5375 (ECW), 5438 (ECU) and 5284 (LCU); LC treatments 5509 (ECW), 5529 (ECU) and 5316 (LCU) ± 184·1 kg. There was no significant interaction between silage type and level of concentrate supplementation.Milk composition, animal live weight and body condition were not significantly affected by either silage type or level of concentrate supplementation.

Effect of fescue toxicosis on whole body energy and nitrogen balance, in situ degradation and ruminal passage rates in Holstein steers

2015 ◽  
Vol 55 (8) ◽  
pp. 988 ◽  
Author(s):  
A. F. Koontz ◽  
D. H. Kim ◽  
K. R. McLeod ◽  
J. L. Klotz ◽  
D. L. Harmon
Keyword(s):  
Energy Balance ◽  
Whole Body ◽  
Fescue Toxicosis ◽  
Design Experiment ◽  
Feeding Level ◽  
Structure Factors ◽  
In Situ Degradation ◽  
Body Energy ◽  
Treatment Structure

This study was designed to examine alteration of ruminal kinetics, as well as N and energy balance during fescue toxicosis. Six ruminally cannulated Holstein steers (bodyweight (BW) = 217 ± 7 kg) were weight matched into pairs and pair fed throughout a crossover design experiment with a 2×2 factorial treatment structure. Factors were endophyte (infected, E+ vs. uninfected, E−) and feeding level (1100 (L) or 1800 (H) kJ/kG BW.75). During each period, after 8 days of feeding level adaptation, animals were ruminally dosed twice daily with ground fescue seed for the remainder of the period. One steer per pair was dosed with ground endophyte infected fescue seed (E+), the other with ground endophyte free fescue seed. In situ degradation of ground alfalfa was determined on Days 13–16. Total faecal and urinary collections were performed on Days 17–21, with animals placed into indirect calorimetry head-boxes during Days 20 and 21. Heat production (HP) was calculated using the Brower equation. Retained energy (RE) was calculated as intakeE – (faecalE + urinaryE + gaseousE + HP). Liquid and particulate passage rates were evaluated using Cr:EDTA and iADF respectively on Days 22 and 23. There was no difference (P > 0.9) in dry matter intake (DMI)/kg.75 between endophyte treatments, and DMI/kg.75 was different (P < 0.01) between H and L intake by design. Animals on H feeding had higher (P < 0.01) water, N and energy intakes. Energy and N excretion, as well as retained DE, ME, RE, and HP were higher (P < 0.03) for H versus L. There was no difference in retained N, DE, ME, or HP (P > 0.15) between endophyte treatments. Neither rate nor extent of in situ degradation was altered by intake level or endophyte treatment (P > 0.3). DM percentage and DM weight of rumen contents were increased (P < 0.01) by E+ dosing. Particulate passage increased (P = 0.0002) during H intake and decreased (P = 0.02) with E+ dosing. Ruminal liquid passage decreased (P < 0.03) with H feeding, while liquid flow rate tended to be reduced (P < 0.14) with E+ dosing. Total VFA concentration increased with both H feeding (P < 0.01) and E+ dosing (P < 0.0001). Despite these differences, the N and energy balance data indicate that the reductions in weight gain and productivity seen during fescue toxicosis are primarily due to reduced intake.

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