scholarly journals Burrowing crabs and physical factors hasten marsh recovery at panne edges

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0249330
Author(s):  
Kathryn Beheshti ◽  
Charlie Endris ◽  
Peter Goodwin ◽  
Annabelle Pavlak ◽  
Kerstin Wasson
Keyword(s):  
Salt Marsh ◽  
Global Climate ◽  
Field Investigation ◽  
Physical Factors ◽  
Key Factors ◽  
Negative Effects ◽  
Central California ◽  
Marsh Loss ◽  
Negative Effect ◽  
Positive Effect

Salt marsh loss is projected to increase as sea-level rise accelerates with global climate change. Salt marsh loss occurs along both lateral creek and channel edges and in the marsh interior, when pannes expand and coalesce. Often, edge loss is attributed to erosive processes whereas dieback in the marsh interior is linked to excessive inundation or deposition of wrack, but remains poorly understood. We conducted a two-year field investigation in a central California estuary to identify key factors associated with panne contraction or expansion. Our study explored how an abundant burrowing crab, shown to have strong negative effects on marsh biomass near creek edges, affects panne dynamics. We also explored which physical panne attributes best predicted their dynamics. To our knowledge, ours is the first study of panne dynamics in a California marsh, despite how ubiquitous pannes are as a feature of marshes in the region and how often extensive marsh dieback occurs via panne expansion. Overall, we found that pannes contracted during the study period, but with variable rates of marsh recovery across pannes. Our model incorporating both physical and biological factors explained 86% of the variation in panne contraction. The model revealed a positive effect of crab activity, sediment accretion, and a composite of depth and elevation on panne contraction, and a negative effect of panne size and distance to nearest panne. The positive crab effects detected in pannes contrast with negative effects we detected near creek edges in a previous study, highlighting the context-dependence of top-down and bioturbation effects in marshes. As global change continues and the magnitude and frequency of disturbances increases, understanding the dynamics of marsh loss in the marsh interior as well as creek banks will be critical for the management of these coastal habitats.

scholarly journals Burrowing crabs and physical factors hasten marsh recovery at panne edges

2021 ◽  
Author(s):  
Kathryn Beheshti ◽  
Charlie Endris ◽  
Peter Goodwin ◽  
Annabelle Pavlak ◽  
Kerstin Wasson
Keyword(s):  
Salt Marsh ◽  
Global Climate ◽  
Physical Factors ◽  
Severe Drought ◽  
Negative Effects ◽  
Central California ◽  
Marsh Loss ◽  
Negative Effect ◽  
Positive Effect ◽  
Burrowing Crab

Salt marsh loss is projected to increase as sea-level rise accelerates with global climate change. Salt marsh loss occurs along both lateral creek and channel edges and in the marsh interior, when pannes expand and coalesce. Often, edge loss is attributed to erosive processes whereas dieback in the marsh interior is linked to excessive inundation or deposition of wrack. We conducted a two-year field experiment (2016-2018) in a central California estuary, where, immediately preceding our study, marsh dieback at creek edges and panne expansion occurred during a period of severe drought and an overlapping warm water event. Our study explored how an abundant burrowing crab, shown to have strong negative effects on marsh biomass near creek edges, affects panne dynamics. We also explored which panne attributes best predicted their dynamics. Overall, we found that pannes contracted during the study period, but with variable rates of marsh recovery across pannes. Our model incorporating both physical and biological factors explained 86% of the variation in panne contraction. The model revealed a positive effect of crab activity, sediment accretion, and a composite of depth and elevation on panne contraction, and a negative effect of panne size and distance to nearest panne. The positive crab effects detected in pannes contrast with negative effects we had earlier detected near creek edges, highlighting the context-dependence of top-down and bioturbation effects in marshes. As global change continues and the magnitude and frequency of disturbances increases, understanding the dynamics of marsh loss in the marsh interior as well as creek banks will be critical for the management of these coastal habitats.

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.

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.

“Simply No Worse and Simply No Better” May Simply Be Wrong: A Critique of Veenman’s Conclusion About Multigrade Classes

1996 ◽  
Vol 66 (3) ◽  
pp. 307-322 ◽  
Author(s):  
DeWayne A. Mason ◽  
Robert B. Burns
Keyword(s):  
Student Achievement ◽  
Selection Bias ◽  
Teacher Motivation ◽  
Key Factors ◽  
Negative Effects ◽  
Age Classes ◽  
Classroom Structure ◽  
Quality Instruction ◽  
Negative Effect ◽  
Classroom Structures

Although Simon Veenman’s (1995) synthesis of research on multigrade and multi-age classes contributes important definitions and findings to the literature, his assessment of the effects of multigrade classes—the more common of these classroom structures—ignores two key factors: (a) selection bias and (b) lower-quality instruction. The omission of these two key factors and Veenman’s implicit advocacy of multi-age classes and cross-grade grouping render his no-difference conclusion problematic. In this article, we critique Veenman’s conclusion and explanations, and argue that selection bias and lower-quality instruction should be included as part of the explanation for his no-difference finding. We conclude that multigrade classes have at least a small negative effect on achievement as well as potentially negative effects on teacher motivation. We suggest that researchers examine more carefully the conditions under which student achievement and affect may be fostered in this classroom structure.

A time-lagged study on the moderating role of overall satisfaction in perceived politics: Job outcomes relationships

2016 ◽  
Vol 23 (3) ◽  
pp. 321-336 ◽  
Author(s):  
Farooq Ahmed Jam ◽  
Magda B L Donia ◽  
Usman Raja ◽  
Chong Hui Ling
Keyword(s):  
Job Performance ◽  
Job Stress ◽  
Interpersonal Conflict ◽  
High Stress ◽  
Interactive Effects ◽  
Negative Effects ◽  
Negative Effect ◽  
Time Lagged ◽  
Positive Effect ◽  
High Politics

AbstractIn a time-lagged study with independent measures (N=115, paired responses), we examined the interactive effects of perceived organizational politics and overall satisfaction on job stress, interpersonal conflict, job performance, and creativity. The data were collected from a diverse sample of employees from various workplaces in Pakistan. The findings showed that perceived politics had a positive effect on job stress, while overall satisfaction had a negative effect on interpersonal conflict and a positive effect on creative performance. The results also revealed that in the face of high politics, highly satisfied individuals demonstrated higher levels of creativity and job performance. However, in this context of high politics negative effects were also observed, namely that highly satisfied individuals participated in interpersonal conflict and experienced high stress.

scholarly journals Optimizing the seismic effects of blasting in quarries by timing

2019 ◽  
pp. 48-62
Author(s):  
Ján Baulovič ◽  
Blažej Pandula ◽  
Julián Kondela ◽  
Marta Prekopová
Keyword(s):  
Natural Environment ◽  
Technical Problem ◽  
The Other ◽  
Negative Effects ◽  
Seismic Effects ◽  
Seismic Safety ◽  
Blasting Operation ◽  
Negative Effect ◽  
The Impact ◽  
Positive Effect

Recently, negative effects of the blasting operations and quantification of the seismic safety are regarded as very important technical problem in quarries. The impact of blasting operations is accompanied by both positive and negative seismic effects. For example, vibrations generated by explosion create very positive effect − when help to break the rocks, but, on the other hand, also result in negative effect − when affect constructions and natural environment in the vicinity of a blasting works site. If the vibrations are large enough, then the nearby objects could be damaged or destroyed. This article highlights the results of the blasting operation monitoring in limestone Lopušné Pažite quarry on Slovakia, which based on the rule that the negative effects depend on their range and strength. This method is applied in all quarries in Slovakia, which are close to settlements.

scholarly journals Designing for Packaging Sustainability. The Effects of Appearance and a Better Eco-Label on Consumers’ Evaluations and Choice

2019 ◽  
Vol 1 (1) ◽  
pp. 3251-3260 ◽  
Author(s):  
Sophie Krah ◽  
Tea Todorovic ◽  
Lise Magnier
Keyword(s):  
Negative Impact ◽  
Traffic Light ◽  
Negative Effects ◽  
User Perspective ◽  
Policy Makers ◽  
Negative Effect ◽  
Typical Appearance ◽  
Perceived Usability ◽  
Choice Intentions ◽  
Positive Effect

AbstractThe environmental burden of packaging is huge. However, redesigning packaging to make it more sustainable without damaging its other functions is not always easy and can have a negative impact on consumers’ choice. In this paper, we adopt a user-perspective and test the effects of packaging appearance and a better eco-label on consumers’ responses. Based on the literature, we designed an eco- label using a traffic light system with an objective sustainability score enabling to compare the sustainability of different packages. The results of our experimental study (N=120) show that while a sustainable (vs. typical) appearance in packaging has a positive effect on perceived sustainability, it has a negative effect on perceived usability. However, we demonstrate that the presence of a high score on the eco-label positively impacts the perceived sustainability of both the sustainable and the typical packages and the choice intentions. This eco-label also enabled to mitigate the negative effects of the sustainable appearance on perceived usability. Designers and policy-makers can use the results of this paper to positively influence evaluations of and choice for sustainable packaging.

The effects of the antecedents of service purchase intention in the context of monetary sales promotion

2014 ◽  
Vol 64 (Supplement-2) ◽  
pp. 177-197
Author(s):  
Cheng-Chen Chiang
Keyword(s):  
Perceived Risk ◽  
Purchase Intention ◽  
Positive Impact ◽  
Perceived Value ◽  
Perceived Quality ◽  
Sales Promotion ◽  
Negative Effects ◽  
Perceived Price ◽  
Negative Effect ◽  
Positive Effect

This study investigated the correlations among variables for credence service in the context of monetary sales promotion. The findings suggested that perceived price directly affected perceived quality, with a negative effect. Perceived price had a positive effect directly on perceived value. Perceived quality directly affected perceived value. Perceived value was found as a key predictor of purchase intention. In addition, perceived quality had indirect and positive impact on purchase intention via value. The results of this study also suggested that there was a negative effect of perceived price on perceived risk. Moreover, it was also noted that perceived risk had negative effects on perceived value and purchase intention.

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.

Ejection has both positive and negative effects on left ventricular isovolumic relaxation

1997 ◽  
Vol 273 (6) ◽  
pp. H2696-H2707 ◽  
Author(s):  
David S. Berger ◽  
Katherine Vlasica ◽  
Christopher M. Quick ◽  
Kimberly A. Robinson ◽  
Sanjeev G. Shroff
Keyword(s):  
Steady State ◽  
Underlying Mechanism ◽  
Multiple Regression Model ◽  
Left Ventricular ◽  
Negative Effects ◽  
Active Stress ◽  
Relaxation Effects ◽  
Negative Effect ◽  
Positive Effect ◽  
Isovolumic Relaxation

In isovolumically beating hearts, the speed of left ventricular (LV) relaxation is uniquely determined by peak active stress (ςmax). In contrast, such a succinct description of relaxation is lacking for the ejection beats, although ejection is generally thought to hasten relaxation. We set out to determine how ejection modifies the relaxation-ςmax relationship obtained in the isovolumically beating hearts. Experiments were performed on five isolated rabbit hearts subjected to various loading conditions. Instantaneous LV pressure and volume were recorded and converted to active stress, from which isovolumic relaxation time ( T r) was defined as the time for stress to fall from 75 to 25% of ςmax (isovolumic beats) or its end-ejection value (ejection beats). Steady-state and transient isovolumic beat and steady-state ejection beat data were used to develop a multiple regression model. This model identified stress, current beat ejection, and previous beat ejection history as independent predictor variables of T r and fit the data well in all hearts ( r 2 > 0.98). Furthermore, this model could predict relaxation in transient ejection beats ( r 2 = 0.80 for all hearts). Whereas the coefficient for the current beat ejection was negative (i.e., negative effect or hastening relaxation), the ejection history coefficient was positive (i.e., positive effect or slowing relaxation). The sum of these two coefficients was negative, corresponding to the commonly observed net negative effect of ejection on relaxation. The expected positive inotropic effect of ejection was also observed. The dissipations of both positive inotropic and relaxation effects were slow, suggesting a nonmechanical underlying mechanism(s). We postulate that these two effects are linked and caused by ejection-mediated changes in myofilament Ca2+ sensitivity.

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