Positive and negative effects of allochthonous dissolved organic matter and inorganic nutrients on phytoplankton growth

2002 ◽  
Vol 59 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Jennifer L Klug
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Phytoplankton Community ◽  
Phytoplankton Growth ◽  
Inorganic Nutrients ◽  
Physiological Status ◽  
Negative Effects ◽  
Positive Effects ◽  
Negative Effect ◽  
Positive Effect

Dissolved organic matter (DOM) can have both positive and negative effects on phytoplankton growth. The magnitude of these effects may vary depending on the source of DOM and the composition of the phytoplankton community. Here, I address the relative importance of the positive and negative effects of DOM extracts on phytoplankton growth. In short-term experiments with phytoplankton from West Long Lake, a small, moderately coloured lake in northern Michigan, U.S.A., the net effect of doubling ambient DOM on phytoplankton growth was positive. Increasing DOM concentrations from ~10 mg C·L–1 to ~20 mg C·L–1 had a negative effect on total phytoplankton growth by reducing irradiance and thus reducing the depth to which growth was positive. However, inorganic nutrients in the DOM extracts increased growth at each irradiance level. The positive effect on phytoplankton growth owing to the nutrients associated with DOM was greater than the negative effect caused by shading. Although the positive effects of allochthonous DOM inputs outweighed the negative effects for the nutrient-limited phytoplankton in these experiments, the net effect depends on the concentration and availability of nutrients associated with allochthonous DOM as well as the physiological status of the phytoplankton community.

scholarly journals Machiavellianism dimensions, religiosity, social environment, and tax evasion

2021 ◽  
Vol 24 (1) ◽  
pp. 1-26
Author(s):  
Jean Stevany Matitaputty ◽  
Priyo Hari Adi
Keyword(s):  
Social Environment ◽  
Tax Evasion ◽  
Online Survey ◽  
Sampling Method ◽  
Sampling Technique ◽  
Snowball Sampling ◽  
Negative Effects ◽  
Positive Effects ◽  
Negative Effect ◽  
Positive Effect

This research aims to investigate the effects of Machiavellianism dimensions that consist of the use of manipulative tactics, cynical views, and disregard of conventional morality on tax evasion. Further, we also analyze the effects of religiosity and social environment as the variables that control Machiavellianism behavior. The population in this research are individual taxpayers, and the sampling technique used is an online survey with the snowball sampling method. The criteria used in sampling are taxpayers who are self-employed or entrepreneurs.  The data is then analyzed using the univariate and multivariate General Linear Model (GLM) methods. The results show that manipulative tactics and disregard of conventional morality have positive effects on tax evasion. Meanwhile, cynical views have a negative effect on tax evasion. Further, religiosity has negative effects on the use of manipulative tactics and disregard of conventional morality. Lastly, social environment has a positive effect on cynical views but no significant effects on the use of manipulative tactics and disregard of conventional morality.

Effect of biomanipulation on the structuring of the planktonic food web and water treatability by coagulation

1998 ◽  
Vol 37 (2) ◽  
pp. 105-112 ◽  
Author(s):  
J. Hejzlar ◽  
P. Dolejš ◽  
J. Komárková ◽  
J. Sed′a ◽  
K. Šimek ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Food Web ◽  
Planktivorous Fish ◽  
Zooplankton Grazing ◽  
Positive Effects ◽  
Planktonic Food ◽  
Plankton Community Structure ◽  
The Impact ◽  
Positive Effect

The impact of planktivorous fish on the plankton community structure and character of aquatic organic matter was studied by a meso-scale enclosure experiment in a stratified reservoir. Aims of the study were (i) to examine the response of the communities with and without herbivorous zooplankton to an increased input of phosphorus and (ii) to determine the composition and coagulation properties of the organic matter produced by these communities. The concentration and composition of organic matter were affected both in the enclosure with planktivorous fish (F), where high algal biomass developed, and in the enclosure without fish (Z), where algae were maintained at a low concentration by zooplankton grazing. Although differences between the enclosures in concentrations of total dissolved organic matter and its hydrophobic, hydrophilic and neutral/basic fractions were relatively small, coagulation properties of the organics differed substantially. Particulate and dissolved organic matter produced in enclosure F had a positive effect on the efficiency of alum coagulation in contrast to the less readily separable organics produced in enclosure Z. The results indicate that pelagic food web manipulations to maintainin low phytoplankton biomass by zooplankton grazing may not always have positive effects on the treatability of water by coagulation.

scholarly journals Some do and some don’t? Accounting for variability of individual difference structures.

2017 ◽  
Author(s):  
Julia M. Haaf ◽  
Jeffrey Rouder
Keyword(s):  
Standard Deviation ◽  
Stroop Task ◽  
Hierarchical Models ◽  
Average Effect ◽  
Negative Effects ◽  
True Negative ◽  
Bayesian Hierarchical ◽  
Positive Effects ◽  
Negative Effect ◽  
Positive Effect

A prevailing notion in experimental psychology is that individuals' performance in a task varies gradually in a continuous fashion. In a Stroop task, for example, the true average effect may be 50ms with a standard deviation of say 30ms. In this case, some individuals will have greater effects than 50ms, some will have smaller, and some are fore-casted to have negative effects in sign - they respond faster to incongruent items than to congruent ones! But are there people who have a true negative effect in Stroop or any other task? We highlight three *qualitatively different* effects: negative effects, null effects, and positive effects. The main goal of this paper is to develop models that allow researchers to explore whether all three are present in a task: Do all individuals show a positive effect? Are there individuals with truly no effect? Are there any individuals with negative effects? We develop a family of Bayesian hierarchical models that capture a variety of these constraints. We apply this approach to Stroop interference experiments and a near-liminal priming experiment where the prime may be below and above threshold for different people. We show that most tasks people are quite alike - for example everyone has positive Stroop effects and nobody fails to Stroop or Stroops negatively. We also show a case that under very specific circumstances, we could entice some people to not Stroop at all.

scholarly journals Customer Value Co-Creation Intention, Practices and Experience in Self-Service Technologies

2021 ◽  
pp. 12-26
Author(s):  
Badra Sandamali Galdolage
Keyword(s):  
Customer Value ◽  
Service Providers ◽  
Service Encounters ◽  
Emotional Experiences ◽  
Negative Effects ◽  
Positive Effects ◽  
Negative Effect ◽  
Physical Interfaces ◽  
Self Service ◽  
Self Service Technology

Many service encounters are moving from traditional physical interfaces to technologically incorporated self-service options. However, it is surprising that very limited extant literature is devoted to understanding the movement towards self-service technologies. Therefore, this study aims at understanding customer value co-creation intention, practices including both the value co-creation and co-destruction and their co-creation experiences in self-service technology context. Based on the positivistic approach, a quantitative study carried out distributing self-administered questionnaires to 600 individuals chosen based on a non-probabilistic convenience sampling method. Study found that customer value co-creation intention has significant positive effects on customer value co-creation practices and significant negative effects on customer value co-destruction in SSTs. Value co-creation practices show a strong positive effect on customer functional experiences and ‘positive emotional experiences’ while having a negative effect on ‘negative emotional experiences. In contrast, co-destruction shows inverse relationships. This study assists practitioners to understand why customers collaborate with SSTs, what they do in co-creating value and how this links with their experience. Service providers can use this understanding to facilitate customer co-creation by securing positive customer experiences and achieving competitive advantage by designing and delivering value enhancing self-service technological interfaces from both strategic and operational perspectives.

scholarly journals Lagged Effect of Macroeconomic Variables on Stock Returns: A Case of Firm Size

2021 ◽  
Vol 19 (1) ◽  
Keyword(s):  
Stock Returns ◽  
Firm Size ◽  
Small Firms ◽  
Size Group ◽  
Negative Effects ◽  
Macroeconomic Factors ◽  
Large Size ◽  
Negative Effect ◽  
Positive Effect ◽  
Lagged Effect

The evidence of lagged effect regarding firm size between macroeconomic factors and stock returns is found with GARCH model for the UAE firms. More precisely, exchange rate showed a significant effect on stock returns irrespective of size group and lag level. However, a positive effect is observed at lag four and a negative effect is observed on lag five and two for small and large size firms respectively. For majority of the firms in small size, the risk-free rate showed a negative lagged effect on stock returns; however, for the majority of the firms in large size, it showed a positive lagged effect on stock returns. Inflation also showed a significant effect on stock returns on each lag level except for large firms where at lag five it is insignificant. Moreover, as the lags increase from 1- 4 and size from small to large, the negative effect of inflation converts to positive effect on stock returns. The lag effect of real activity showed both positive and negative effects on relatively larger stock returns of small firms than big firms. Money supply showed positive significant effect on stock returns of all firms irrespective of the size group; however, this relationship is even more prominent at lag five. Finally, the oil prices showed a positive effect on stock returns (large size) which further maximizes at lag two; whereas, a negative maximization takes place at lag three. Hence, investors can make informed and effective decisions and UAE policymakers developed effective measures to control and promote macroeconomic growth and stability.

Sanctuary Cities, Crime, and Incorporation

2019 ◽  
pp. 118-152
Author(s):  
Loren Collingwood ◽  
Benjamin Gonzalez O’Brien
Keyword(s):  
Voter Turnout ◽  
Crime Rates ◽  
Police Force ◽  
Crime Reporting ◽  
Immigrant Communities ◽  
Negative Effects ◽  
Positive Effects ◽  
Chief Complaints ◽  
Negative Effect

One of the chief complaints raised against sanctuary cities is that they can increase crime, while one argument in their favor is that they can increase the incorporation of Latino and immigrant communities. This chapter analyzes both the positive and negative effects of sanctuary polices, finding that these policies have no effect on crime rates when comparable cities are compared to one another and when crime rates pre/post sanctuary are examined. The findings show that sanctuary policies can have positive effects, potentially increasing both Latino voter turnout and police force representation. While sanctuary policies are found to have few downsides and potential positive benefits, antisanctuary legislation like Texas’s SB4 are found to have a negative effect. In high-immigrant areas, antisanctuary legislation is found to depress the number of 911 calls, suggesting that antisanctuary legislation does in fact reduce crime reporting, as opponents claim.

scholarly journals Evaluation of the lipid fraction of pyrochars organic matter in the aspect of negative effects on soil

2020 ◽  
Vol 17 ◽  
pp. 00156
Author(s):  
Rodion Okunev ◽  
Elena Smirnova ◽  
Kamil Giniyatullin ◽  
Irina Guseva
Keyword(s):  
Organic Matter ◽  
Low Temperature ◽  
Pyrolysis Temperature ◽  
Lipid Fraction ◽  
Total Content ◽  
Negative Effects ◽  
Polycyclic Aromatic ◽  
Negative Effect ◽  
Pahs Concentration ◽  
Low Temperature Pyrolysis

The evaluation of the possible negative effect of pyrochars on soils based on the analysis of the content of lipid fraction and polycyclic aromatic hydrocarbons (PAHs) of organic matter was evaluated. Eight species of pyrochar were obtained from the crop and wood residues (linden, willow, corn, millet) by two pyrolysis regimes: low-temperature pyrolysis (<400°C) and high-temperature pyrolysis (400–600°C). The largest amount of lipid fraction (from 0.54 to 2.78%) and PAHs were found in pyrochars obtained at a low pyrolysis temperature. The total content of PAHs in the studied samples ranged from 8.49 to 603.21 μg/kg. According to the PAHs content, pyrochar was the most adverse for application to the soil, obtained from the residues of millet of low-temperature pyrolysis, however, at a high pyrolysis temperature, the safest product with the lowest PAHs concentration and a significant amount of lipid fraction was formed. Using an incubation experiment by measuring substrate-induced respiration in soil-pyrochar mixtures, it was shown that the application of this meliorant can also increase the emission of carbon dioxide from soils in a short time. The results of the experiments showed that it is necessary to precisely control the conditions of pyrolysis and carefully select the material for pyrochar in order to obtain the products with most favourable amounts of lipid fraction and PAHs content.

scholarly journals People’s attitudes towards deadwood in forest: evidence from the Ukrainian Carpathians

2019 ◽  
Vol 65 (No. 5) ◽  
pp. 171-182 ◽  
Author(s):  
Oksana Pelyukh ◽  
Alessandro Paletto ◽  
Lyudmyla Zahvoyska
Keyword(s):  
Local Community ◽  
Sustainable Forest Management ◽  
Managed Forests ◽  
Negative Effects ◽  
Face To Face ◽  
The Face ◽  
Negative Effect ◽  
Intensively Managed ◽  
People’S Attitudes ◽  
Positive Effect

People’s attitudes towards forest stand characteristics including deadwood are becoming increasingly relevant in sustainable forest management. The aim of this study is to investigate people’s attitudes towards deadwood in forest. The study was carried out in the Rakhiv region (Ukraine) characterized by high importance of forest resources for the local community and economy. People’s opinions were collected through the face-to-face administration of a questionnaire to 308 respondents. The survey investigated three aspects: importance of deadwood in forest; people’s perceptions of positive and negative effects of deadwood in forest; effects of presence and amount of deadwood in different types of forest on people’s aesthetical preferences. The results show that the majority of respondents consider deadwood as an important component of the forest, but generally they prefer intensively managed forests without deadwood. According to the respondents’ opinions, the most important positive effect of deadwood is a contribution to stand dynamics, while the most important negative effect is an increasing risk of insects and diseases.

Comparison of lactational responses of dairy cows in Georgia and Israel to heat load and photoperiod

2002 ◽  
Vol 75 (3) ◽  
pp. 469-476 ◽  
Author(s):  
Y. Aharoni ◽  
O. Ravagnolo ◽  
I. Misztal
Keyword(s):  
Milk Yield ◽  
Heat Load ◽  
Protein Concentration ◽  
Day Length ◽  
Seasonal Effects ◽  
Good Match ◽  
Negative Effects ◽  
Positive Effects ◽  
Daily Change ◽  
Positive Effect

AbstractThe seasonal effects of heat load and photoperiod on yield and composition of milk from primiparous cows in the course of lactation were studied using test day records from 8968 primiparous cows on 76 farms in Georgia, collected from 1990 through 1997. The effect of prepartum photoperiod on milk production in the subsequent lactation of these cows was also evaluated. These estimated seasonal effects were compared with those estimated for 4728 primiparous cows on 13 farms, and for 1538 multiparous cows on three farms during consecutive lactations in Israel from 1994 through 1996. During lactation, the day length had a positive effect on milk yield and negative effects on fat and protein concentrations in the milk, but the daily change in day length had positive effects on milk yield and fat concentration, and a smaller positive effect on protein concentration. The day length during the prepartum period had negative effects on milk yield and fat and protein concentrations. The heat load during lactation had negative effects on milk yield and fat and protein concentrations. Most of the effects were highly (P < 0·001) significant. There was a very good match between the results obtained for primiparous cows in Georgia and Israel, for the combined effects of heat load and photoperiod during lactation on milk yield and protein and fat concentrations. The match between primiparous and multiparous cows in Israel was better for milk yield and protein concentration than for fat concentration. The estimated effects of pre-partum photoperiod were higher for multiparous cows in Israel than for primiparous cows in either country.

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