Size structure and body condition of Ponto-Caspian gammarids in the Vistula estuary (Poland)

2019 ◽  
Vol 48 (1) ◽  
pp. 23-30
Author(s):  
Aldona Dobrzycka-Krahel ◽  
Anna Tarała ◽  
Wojciech Majkowski
Keyword(s):  
Body Condition ◽  
Size Structure ◽  
Experimental Studies ◽  
Biological Indicators ◽  
Vistula Lagoon ◽  
Low Salinity ◽  
Colonization Process ◽  
Wet Weight ◽  
Vistula Delta ◽  
Positive Effect

Abstract Over the past few decades, Ponto-Caspian gammarids Pontogammarus robustoides, Obesogammarus crassus and Dikerogammarus haemobaphes have colonized the European inland and coastal brackish waters. Previous experimental studies of P. robustoides, O. crassus and D. haemobaphes indicated that the salinity optimum for the species is about 7 PSU. We examined whether salinities below 5 PSU in the Vistula estuary – the Vistula Lagoon and the Vistula Delta, create a favorable environment and have a positive effect on Ponto-Caspian gammarids. The objective of this work was to determine the population parameters (size structure) and biological indicators (condition) of the studied gammarid species at a low salinity level. Length–weight relationships can be considered as their body condition in the environment. These relationships were calculated for each gammarid species according to the exponential equation y = axb, where: y – wet weight, x – total length, a – intercept, b – slope. The results clearly show responses of Ponto-Caspian gammarids to the low salinity habitat and indicate that such environment provides excellent conditions. The results of analysis show that the condition of gammarids is good. The optimal strategy of the examined alien gammarids may help them to maintain a strong competitive position in the environment and affect the colonization process in non-native waters with low salinity.

scholarly journals Influence of Pre-Sowing Operations on Soil-Dwelling Fauna in Soybean Cultivation

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 474
Author(s):  
Darija Lemic ◽  
Ivana Pajač Živković ◽  
Marija Posarić ◽  
Renata Bažok
Keyword(s):  
Cover Crop ◽  
Soil Fauna ◽  
Biological Indicators ◽  
Conventional Tillage ◽  
Pitfall Traps ◽  
Beneficial Insects ◽  
The Family ◽  
Negative Effect ◽  
Natural Equilibrium ◽  
Positive Effect

The aim of this study was to determine the effects of different pre-sowing operations on the abundance and composition of total soil fauna in soybean cultivation, with special attention to carabids as biological indicators of agroecosystem quality. The study was conducted in central Croatia with six different pre-sowing activities (cover crop, mulching, ploughing, glyphosate, fertiliser removal, conventional tillage). Pitfall traps were used to collect soil fauna in April, June and September. After determining the abundance and composition of the fauna, their coenological characteristics were calculated and statistical analysis was performed. During the study, 7836 individuals of soil fauna were collected. The composition consisted of 84% beneficial, 8% harmful and 8% indifferent fauna. Class Insecta was the most numerous with a proportion of 56%, with most members of the family Carabidae (1622 individuals), followed by the class Arachnida (40%). The number of fauna collected was influenced by the interaction between pre-seeding intervention and sampling date. Pre-seeding interventions that did not involve soil activities did not affect the number and composition of soil fauna at the beginning of vegetation. Mechanical interventions in the soil and warmer and drier weather have a negative effect on the number and composition of soil fauna. As the season progresses, the influence of pre-sowing activities on soil fauna in soybean crops decreases. It seems that a reduction in mechanical activities in the shallow seed layer of the soil has a positive effect on species richness or diversity. Of particular note is the large proportion of beneficial insects that currently colonise the study area, characterising soil richness and stable natural equilibrium.

scholarly journals Implementation Intentions to Reduce Smoking: A Systematic Review of the Literature

2020 ◽  
Author(s):  
Charlotte J Hagerman ◽  
Rebecca K Hoffman ◽  
Sruthi Vaylay ◽  
Tonya Dodge
Keyword(s):  
Systematic Review ◽  
Implementation Intentions ◽  
Experimental Studies ◽  
Implementation Intention ◽  
Promising Tool ◽  
Current Systematic Review ◽  
Long Term Follow Up ◽  
Positive Effect

Abstract Implementation intentions are a goal-setting technique in which an individual commits to perform a particular behavior when a specific context arises. Recently, researchers have begun studying how implementation intention (II) interventions can facilitate antismoking efforts. The current systematic review synthesized results of experimental studies that tested the effect of an II intervention on smoking cognitions and behavior. Of 29 reviewed articles, 11 studies met inclusion criteria. Nine studies (81.8%) tested an II intervention as a cessation tool for current smokers, whereas two tested II interventions as a tool to prevent smoking among predominantly nonsmoking adolescents. A majority of the studies (66.7%) testing II interventions as a cessation tool reported a positive effect on cessation at long-term follow-up. Of the two studies testing II interventions as a tool for prevention, one study found a positive effect on long-term follow-up. Methodology varied between the studies, highlighting the discrepancies between what researchers consider “implementation intentions” to be. II interventions are a promising tool for antismoking efforts, but more research is necessary to determine the best methodology and the populations for whom this intervention will be most effective. Implications Brief, free, and easily scalable, II interventions to prevent smoking are highly attractive for antismoking efforts. This review outlines the circumstances under which II interventions have demonstrated effectiveness in helping people resist smoking cigarettes. We illuminate gaps in the existing literature, limitations, methodological discrepancies between studies, and areas for future study.

scholarly journals MEKANISME RESPON STRES: KONSEPTUALISASI INTEGRASI ISLAM DAN BARAT

2019 ◽  
Vol 5 (1) ◽  
pp. 48-61
Author(s):  
Syahidah Rena
Keyword(s):  
Body Condition ◽  
Qualitative Approach ◽  
Natural State ◽  
Human Beings ◽  
Response Mechanism ◽  
Modern Life ◽  
System Sensitivity ◽  
Psychological Concept ◽  
Natural Reaction ◽  
Positive Effect

Essentially, stress is a prevalent event used to occur. Nowadays, the society experienced stress as an attribute of modern life, since it became an inevitable part of human’s life. Causally, stress appeared as an individual's response to stressors that are perceived as causing threat both internal and external balance disorders.This paper aimed to discuss stress phenomena and individual’s response mechanism to stress based on integrative perspectives of Western and Islam. As a library study, this research used a qualitative approach. Furthermore the study analyzed main sources of literature such as books, journals and various researches related to the topic. This study discovered that good stress/eustress which was explained in western psychological concept would give positive effect such as fostering tough personality was consistent to the message of Qur’an which explained that stress is a natural state in human life.Allah has created human beings having anxiety and complaint as a natural reaction of the body's system sensitivity towards unpleasant things. Within islamic perspective, stress which was organized with positive spirit could turn body condition became better and stronger. 

Study of the Impact of Protective Process Agents with Carbon Nanopowder Additives on Chip Forming Processes

2021 ◽  
Vol 887 ◽  
pp. 319-324
Author(s):  
E.A. Petrovsky ◽  
K.A. Bashmur ◽  
Vadim S. Tynchenko
Keyword(s):  
Experimental Studies ◽  
Cutting Speed ◽  
Optimal Composition ◽  
Cooling Process ◽  
Shrinkage Ratio ◽  
Nickel Chromium ◽  
Chromium Alloys ◽  
On Chip ◽  
The Impact ◽  
Positive Effect

The present study describes the impact of various protective process agents on chip forming processes. The research was conducted on NiCr20TiAl and 34NiCrMoV14-5 nickel-chromium alloys. New lubricant-cooling process agents with carbon nanopowder additives are studied. The optimal composition of the nanopowder additive and its effect during alloy cutting is examined. Experiments reveal the dependence of shrinkage ratio on cutting speed and various protective process agents. The values of H50 microhardness are also defined when cutting these alloys using protective process agents. Experimental studies found the positive effect of developed agents with nanopowder additives on the processes of NiCr20TiAl and 34NiCrMoV14-5 alloys chip formation.

scholarly journals Do You Get the Picture? A Meta-Analysis of the Effect of Graphics on Reading Comprehension

AERA Open ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 233285842090169 ◽  
Author(s):  
Daibao Guo ◽  
Shuai Zhang ◽  
Katherine Landau Wright ◽  
Erin M. McTigue
Keyword(s):  
Reading Comprehension ◽  
Grade Level ◽  
Text Comprehension ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Future Research ◽  
Significant Difference ◽  
Flow Diagrams ◽  
Positive Effect ◽  
Mixed Format

Although convergent research demonstrates that well-designed graphics can facilitate readers’ understanding of text, there are select situations where graphics have been shown to have no effect on learners’ overall text comprehension. Therefore, the current meta-analytic study examined 39 experimental studies published between 1985 and 2018 measuring graphics’ effects on readers’ comprehension. We first quantified the overall effect on reading comprehension. Then, we considered interactions with learners’ characteristics, graphic types, and assessment formats. Our analysis revealed that the inclusion of graphics had a moderate overall positive effect (Hedges’s g = 0.39) on students’ reading comprehension, regardless of grade level. Regarding graphic type, we did not find a significant difference among pictures, pictorial diagrams, and flow diagrams. Only when compared to mixed graphics, pictures had a greater effect on comprehension. Additionally, compared with true and false assessments, graphics differentially benefited students’ comprehension on open-ended comprehension assessments and mixed format assessments. Implications for future research are presented.

scholarly journals Evidence for benthic body size miniaturization in the deep sea

2006 ◽  
Vol 86 (6) ◽  
pp. 1339-1345 ◽  
Author(s):  
Janne I. Kaariainen ◽  
Brian J. Bett
Keyword(s):  
Body Size ◽  
Deep Sea ◽  
Size Structure ◽  
Size Class ◽  
The Body ◽  
Significant Shift ◽  
Individual Biomass ◽  
Wet Weight ◽  
Accumulation Curves ◽  
Average Individual

The benthic body size miniaturization hypothesis states that deep-sea communities are dominated by organisms of smaller body size, although some field studies have produced contradictory results. Using appropriate sample sets, this study tests this hypothesis by contrasting the benthic communities of the Fladen Ground (North Sea, 150 m) and the Faroe–Shetland Channel (1600 m). Samples were collected for large (500 μm) and small macrofauna (250–355 μm), meiofauna (45 μm) as well as an intermediate sized ‘mesofauna’ (180 μm) to ensure comprehensive coverage of the full meio- and macro-faunal body size-range. The body size structure of the benthos was compared using two methods. The more widely used average individual biomass method involves dividing the total sample biomass by sample abundance. Additionally, body size accumulation curves were constructed by assigning all specimens into a logarithmic size-class and then plotting the cumulative percentage of individuals present in each size-class. The results seem to support the hypothesis that the deep-sea environment is a small organism habitat. Although these findings only represent two locations, the overall body size accumulation curves clearly display a statistically significant shift towards smaller body sizes at the deeper site. The magnitude of the effect is appreciable with median metazoan body size reducing from 14.3 μg wet weight in the Fladen Ground to 3.8 μg wet weight in the Faroe–Shetland Channel. The average individual biomass measurements are shown to be of limited value and can lead to potentially misleading conclusions if the underlying size structure is not analysed in detail.

The Effects of Using Colored Paper to Boost Response-Rates to Surveys and Questionnaires

2003 ◽  
Vol 33 (1) ◽  
pp. 29-40 ◽  
Author(s):  
James Hartley ◽  
Andrew Rutherford
Keyword(s):  
Surveys And Questionnaires ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Response Rates ◽  
Colored Paper ◽  
Positive Effect

Many people have speculated over the last 80 years or so about the possibilities of using colored paper to boost response-rates to surveys and questionnaires, and several studies have been carried out. Most of these enquiries report no significant effects from using colored paper, although there have been some exceptions. In this investigation we pooled together the results from all of the experimental studies known to us on the topic and we carried out a meta-analysis to see if there might be a positive effect for colored paper overall. The results indicated that this was not the case, for we found no significant differences between the response rates to white and to colored paper in general. However, when we considered separately the most common colors used, it appeared that pink paper had the greatest effect.

scholarly journals Complex Analyses of Plankton Structure and Function

2001 ◽  
Vol 1 ◽  
pp. 119-132 ◽  
Author(s):  
Karl E. Havens
Keyword(s):  
Size Structure ◽  
Experimental Studies ◽  
Structure And Function ◽  
Size Spectrum ◽  
Phytoplankton Productivity ◽  
Resource Managers ◽  
Carbon Transfer ◽  
And Function ◽  
Freshwater Plankton ◽  
Plankton Communities

This paper critically evaluates some complex methods that have been used to characterize the structure and function of freshwater plankton communities. The focus is on methods related to plankton size structure and carbon transfer. The specific methods reviewed are 1) size spectrum analysis, 2) size-fractionated phytoplankton productivity, 3) size-fractionated zooplankton grazing, 4) plankton ecological transfer efficiency, and 5) grazer effects on phytoplankton community structure. Taken together, these methods can provide information on community ecological properties that are directly related to practical issues including water quality and fisheries productivity. However, caution is warranted since application without a complete understanding of assumptions and context of the manipulations could lead to erroneous conclusions. As an example, experimental studies involving the addition or removal of zooplankton, especially when coupled with nutrient addition treatments, could provide information on the degree of consumer vs. resource control of phytoplankton. Resource managers subsequently could use this information in developing effective measures for controlling nuisance algal biomass. However, the experiments must be done critically and with sufficient safeguards and other measurements to ensure that treatments (e.g., zooplankton exclosure by screening of water) actually are successful and do not introduce other changes in the community (e.g., removal of large algae). In all of the methods described here, the investigator must take care when generalizing results and, in particular, carry out a sufficient number of replications to encompass both the major seasonal and spatial variation that occurs in the ecosystem.

The influence of politeness on the perception of product recall notices

2001 ◽  
Vol 2 (3) ◽  
pp. 272-279 ◽  
Author(s):  
Luuk Van Waes ◽  
Carel van Wijk
Keyword(s):  
Experimental Studies ◽  
Corporate Image ◽  
The Other ◽  
Product Recalls ◽  
Product Recall ◽  
Politeness Strategies ◽  
Negative Effect ◽  
Commercial Relation ◽  
Positive Effect ◽  
Clear Information

When companies decide — or are forced — to publish a product recall notice, their aim is to give consumers clear information on how to handle the problem and to warn them of a possible danger. On the other hand companies try to preserve their corporate image in order to guarantee a (commercial) relation in the future. This article deals with the question whether politeness strategies lead to differences in the appreciation, acceptance and perception of product recall notices. In two experimental studies we evaluated the effect of positive and negative politeness strategies in different conditions. The results show that the use of elaborated negative politeness strategies positively influences the appreciation and acceptance of the message, and has a positive effect on the perception of the corporate image. However in a context where the product recall warns of a severe risk, writers of product recalls should use politeness strategies more cautiously. In this context the use of politeness strategies even seems to have a negative effect on the acceptability of the recall message.

scholarly journals Fibrin Glue Does Not Improve Healing of Gastrointestinal Anastomoses: A Systematic Review

2014 ◽  
Vol 54 (1-2) ◽  
pp. 1-13 ◽  
Author(s):  
Tyge Nordentoft ◽  
Hans-Christian Pommergaard ◽  
Jacob Rosenberg ◽  
Michael Patrick Achiam
Keyword(s):  
Systematic Review ◽  
Fibrin Glue ◽  
Healing Process ◽  
Gastrointestinal Surgery ◽  
Experimental Studies ◽  
Positive Influence ◽  
Qualitative Synthesis ◽  
Negative Effect ◽  
The Difference ◽  
Positive Effect

Background/Aim: Anastomotic leakage remains a frequent and serious complication in gastrointestinal surgery. In order to reduce its incidence, several clinical and experimental studies on anastomotic sealing have been performed. In a number of these studies, the sealing material has been fibrin glue (FG), and the results in individual studies have been varying. The positive effect of anastomotic sealing with FG might be due to the mechanical/physical properties, the increased healing of the anastomoses or both. The aim of this systematic review was to evaluate the existing evidence on the healing effects of FG on gastrointestinal anastomoses. Methods: PubMed, EMBASE and the Cochrane databases were searched for studies evaluating the healing process of gastrointestinal anastomoses after any kind of FG application. The search period was from 1953 to December 2013. Results: Twenty-eight studies were included in the qualitative synthesis. These studies were all experimental studies, since no human studies used histological or biochemical evaluation of healing. In 7 of the 28 studies, a positive effect of FG on healing was found, while 8 studies reported a negative effect and 11 studies found no effect. Furthermore, 2 studies reported unclear results. The difference in the study outcome was independent of the study design and the type of FG used. Conclusion: In the available studies, FG did not consistently have a positive influence on the healing of gastrointestinal anastomoses. It is consequently plausible that the positive effect of FG sealing of gastrointestinal anastomoses, if there is any, may be due to a mechanical sealing effect rather than due to improved healing per se.

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