The Structure of Marine Communities Over Time: Long and Short-Term Changes

1984 ◽  
pp. 384-413
Author(s):  
Ivan Valiela
Keyword(s):  
Short Term ◽  
Marine Communities ◽  
Over Time

The Short-Term and Long-Term Impacts of Sarbanes-Oxley Act on Composition and Characteristics of Corporate Board of Directors

2015 ◽  
Vol 5 (4) ◽  
Author(s):  
Halil Kaya ◽  
Gaurango Banerjee
Keyword(s):  
Board Composition ◽  
Corporate Boards ◽  
Corporate Accountability ◽  
Corporate Board ◽  
Short Term ◽  
Dual Roles ◽  
Board Characteristics ◽  
Sarbanes Oxley ◽  
Over Time

The paper examines the Sarbanes-Oxley (2002) Acts immediate impact on board composition and characteristics as well as possible reversals in its impact over time. Effects on directors age and tenure are analyzed over the 2001-06 sample period. Female participation in corporate boards is also studied in the pre-SOX and post-SOX periods. The dual roles of directors in being a member of the board as well as serving as either CEO, CFO, Chairman, Co-Chair, Founder, or Lead Director of their respective companies is also examined. We observe a short-term impact of SOX on board compositions due to changes seen in board characteristics between 2001 (pre-SOX), and 2003-05 short-term period (post-SOX). Also, we observe a reversal of board characteristics in 2006 to pre-SOX levels implying that the effects of SOX on board composition were short-lived, and needs to be monitored over time to ensure adherence to corporate accountability guidelines over the long-term.

scholarly journals Personality dynamics at work: The effects of form, time, and context of variability

2021 ◽  
pp. 089020702110173
Author(s):  
Nadin Beckmann ◽  
Damian P Birney ◽  
Amirali Minbashian ◽  
Jens F Beckmann
Keyword(s):  
Individual Differences ◽  
Cognitive Ability ◽  
Temporal Stability ◽  
Limited Evidence ◽  
Short Term ◽  
State Data ◽  
The Status ◽  
Over Time ◽  
Trait Variability

The study aimed to investigate the status of within-person state variability in neuroticism and conscientiousness as individual differences constructs by exploring their (a) temporal stability, (b) cross-context consistency, (c) empirical links to selected antecedents, and (d) empirical links to longer term trait variability. Employing a sample of professionals ( N = 346) from Australian organisations, personality state data together with situation appraisals were collected using experience sampling methodology in field and repeatedly in lab-like settings. Data on personality traits, cognitive ability, and motivational mindsets were collected at baseline and after two years. Contingent (situation contingencies) and non-contingent (relative SD) state variability indices were relatively stable over time and across contexts. Only a small number of predictive effects of state variability were observed, and these differed across contexts. Cognitive ability appeared to be associated with state variability under lab-like conditions. There was limited evidence of links between short-term state and long-term trait variability, except for a small effect for neuroticism. Some evidence of positive manifold was found for non-contingent variability. Systematic efforts are required to further elucidate the complex pattern of results regarding the antecedents, correlates and outcomes of individual differences in state variability.

scholarly journals Leaching Rate of Polychlorinated Biphenyls (PCBs) from Marine Paint Chips

2021 ◽  
Author(s):  
Allen D. Uhler ◽  
Jeffery H. Hardenstine ◽  
Deborah A. Edwards ◽  
Guilherme R. Lotufo
Keyword(s):  
Polychlorinated Biphenyls ◽  
Surface Waters ◽  
Leaching Rate ◽  
Short Term ◽  
Aroclor 1254 ◽  
Maintenance And Repair ◽  
Potential Source ◽  
Vessel Bottom ◽  
Dissolved Phase ◽  
Over Time

AbstractPolychlorinated biphenyls (PCBs) were added to certain marine vessel bottom paints as a plasticizer to improve the adhesion and durability of the paint. The most common PCB formulation used to amend such paints was Aroclor 1254. Fugitive Aroclor-containing paint chips generated from vessel maintenance and repair operations represent a potential source of PCB contamination to sediments. Limited published studies indicate that Aroclor-containing paint is largely inert and exhibits low PCB leaching into water; however, the rate and degree of leaching of PCBs from paint chips have not been directly studied. This laboratory-based study evaluated the rate and extent of leaching of PCBs from paint chips into freshwater. The results of this investigation demonstrate that the rate of PCB dissolution from paint chips decreased rapidly and exponentially over time. Based on this study, it is estimated that the rate of leaching of PCBs from paint chips would cease after approximately 3 years of exposure to water. When all leachable PCBs were exhausted, it is estimated that less than 1% of the mass of PCBs in the paint chips was amenable to dissolution. The results of this experiment suggest that Aroclor-containing paint chips found in sediments are likely short-term sources of dissolved-phase PCB to pore or surface waters and that the majority of the PCBs in paint chips remain in the paint matrix and unavailable for partitioning into water. Graphic Abstract

scholarly journals Investigating the Broken-Heart Effect: a Model for Short-Term Dependence between the Remaining Lifetimes of Joint Lives

2012 ◽  
Vol 7 (2) ◽  
pp. 236-257 ◽  
Author(s):  
Jaap Spreeuw ◽  
Iqbal Owadally
Keyword(s):  
Mortality Rates ◽  
Short Term ◽  
Numerical Work ◽  
Data Set ◽  
Multiple State ◽  
Multiple State Model ◽  
Insurance Data ◽  
Over Time ◽  
Assurance Contracts

AbstractWe analyze the mortality of couples by fitting a multiple state model to a large insurance data set. We find evidence that mortality rates increase after the death of a partner and, in addition, that this phenomenon diminishes over time. This is popularly known as a “broken-heart” effect and we find that it affects widowers more than widows. Remaining lifetimes of joint lives therefore exhibit short-term dependence. We carry out numerical work involving the pricing and valuation of typical contingent assurance contracts and of a joint life and survivor annuity. If insurers ignore dependence, or mis-specify it as long-term dependence, then significant mis-pricing and inappropriate provisioning can result. Detailed numerical results are presented.

Comparability and Short-Term Stability of Techniques to Assess Extension of Thinking about One's Personal Future

1983 ◽  
Vol 56 (2) ◽  
pp. 559-564 ◽  
Author(s):  
William Rakowski ◽  
Clifton E. Barber ◽  
Wayne C. Seelbach
Keyword(s):  
Data Collection ◽  
Life Events ◽  
Short Term ◽  
Life Event ◽  
Term Stability ◽  
The Future ◽  
Changes Over Time ◽  
Over Time

Three techniques for assessing extension of one's personal future (line-marking, open-ended report, life-events) were compared in a sample of 74 respondents. Two points of data collection were employed to examine short-term stability. At both administrations, correlations among indices suggested that techniques were only moderately comparable. Short-term stabilities were variable; correlations ranged from .42 to .79. Across subgroups of the sample, the direct, open-ended report of extension showed the greatest stability, while life-event extension showed the least. Apparently, extension of thinking about the future should be assessed by more than one technique to investigate potential relationships with other variables or changes over time in perspective about the future.

scholarly journals Macroeconomic Synchronization Between G3 Countries

2002 ◽  
Vol 3 (2) ◽  
pp. 137-153 ◽  
Author(s):  
Amado Peirό
Keyword(s):  
Business Cycle ◽  
Interest Rates ◽  
Short Term ◽  
The Us ◽  
Production Prices ◽  
Over Time

AbstractThis paper studies the existence of a world business cycle by examining quarterly and annual comovements in production, prices and interest rates in the three main world economies: Germany, Japan and the US. In accordance with earlier studies, contemporaneous relationships clearly dominate short-term dynamics. The evidence indicates the existence of strong comovements in prices and long-term interest rates, and, to a lesser degree, in GDP and short-term interest rates. They are, however, rather unstable over time.

scholarly journals Do Feelings of Defeat and Entrapment Change over Time? An Investigation of the Integrated Motivational—Volitional Model of Suicidal Behaviour Using Ecological Momentary Assessments

2020 ◽  
Vol 17 (13) ◽  
pp. 4685
Author(s):  
Jana-Sophie Stenzel ◽  
Inken Höller ◽  
Dajana Rath ◽  
Nina Hallensleben ◽  
Lena Spangenberg ◽  
...  
Keyword(s):  
Risk Factors ◽  
Suicidal Ideation ◽  
Real Time ◽  
Clinical Samples ◽  
Short Term ◽  
Change Over Time ◽  
Longitudinal Association ◽  
Ecological Momentary ◽  
Over Time ◽  
Short Term Variability

(1) Background. Defeat and entrapment have been highlighted as major risk factors of suicidal ideation and behavior. Nevertheless, little is known about their short-term variability and their longitudinal association in real-time. Therefore, this study aims to investigate whether defeat and entrapment change over time and whether defeat predicts entrapment as stated by the integrated motivational–volitional model of suicidal behavior. (2) Methods. Healthy participants (n = 61) underwent a 7-day smartphone-based ecological momentary assessment (EMA) on suicidal ideation/behavior and relevant risk factors, including defeat and entrapment and a comprehensive baseline (T0) and post (T2) assessment. (3) Results. Mean squared successive differences (MSSD) and intraclass correlations (ICC) support the temporal instability as well as within-person variability of defeat and entrapment. Multilevel analyses revealed that during EMA, defeat was positively associated with entrapment at the same measurement. However, defeat could not predict entrapment to the next measurement (approximately two hours later). (4) Conclusion. This study provides evidence on the short-term variability of defeat and entrapment highlighting that repeated measurement of defeat and entrapment—preferably in real time—is necessary in order to adequately capture the actual empirical relations of these variables and not to overlook significant within-person variability. Further research—especially within clinical samples—seems warranted.

scholarly journals Disentangling niche theory and beta diversity change

2021 ◽  
Author(s):  
William Godsoe ◽  
Peter J Bellingham ◽  
Elena Moltchanova
Keyword(s):  
Beta Diversity ◽  
Price Equation ◽  
Short Term ◽  
Before And After ◽  
Environmental Requirements ◽  
Habitat Specialists ◽  
Montane Tropical Forest ◽  
Ecological Drift ◽  
Over Time

Beta diversity describes the differences in species composition among communities. Changes in beta diversity over time are thought to be due to selection based on species' niche characteristics. For example, theory predicts that selection that favours habitat specialists will increase beta diversity. In practice, ecologists struggle to predict how beta diversity changes. To remedy this problem, we propose a novel solution that formally measures selection's effects on beta diversity. Using the Price equation, we show how change in beta diversity over time can be partitioned into fundamental mechanisms including selection among species, variable selection among communities, drift, and immigration. A key finding of our approach is that a species' short-term impact on beta diversity cannot be predicted using information on its long-term environmental requirements (i.e. its niche). We illustrate how our approach can be used to partition causes of diversity change in a montane tropical forest before and after an intense hurricane. Previous work in this system highlighted the resistance of habitat specialists and the recruitment of light-demanding species but was unable to quantify the importance of these effects on beta diversity. Using our approach, we show that changes in beta diversity were consistent with ecological drift. We use these results to highlight the opportunities presented by a synthesis of beta diversity and formal models of selection.

Opening the black box: soil microcosm experiments reveal soot-black carbon short-term oxidation and influence on organic carbon mineralisation

2021 ◽  
Author(s):  
Marta Crispo ◽  
Duncan D. Cameron ◽  
Will Meredith ◽  
Aaron Eveleigh ◽  
Nicos Ladommatos ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Black Carbon ◽  
Fossil Fuels ◽  
Isotope Ratio Mass Spectrometry ◽  
Soil Microcosm ◽  
Short Term ◽  
Carbon Mineralisation ◽  
Significant Difference ◽  
Global Carbon ◽  
Over Time

<p>Black carbon (BC), the product of the incomplete combustion of fossil fuels and biomass, is ubiquitous in soils globally. Although BC is a major soil carbon pool, its effects on the global carbon cycle have not yet been resolved. It is deemed to represent a large stable pool in soils turning over on geological timescales, but research suggests it can alter soil biogeochemical cycling including that of ecosystem-derived organic carbon. Here, we established two soil microcosm chamber experiments: experiment one added <sup>13</sup>C organic carbon to soil with and without added BC (soot and biochar) to investigate whether it suppressed organic carbon mineralisation; experiment two added <sup>13</sup>C BC (soot) to soil to establish whether it is mineralised in soil over a short timescale. Gases were sampled over six-months and analysed using isotope ratio mass spectrometry. In experiment one we found that the efflux of <sup>13</sup>C organic carbon from the soil decreased over time, but the addition of soot to soil significantly reduced the mineralisation of organic carbon from 32% of the total supplied without soot to 14% of the total supplied with soot. In contrast, there was not a significant difference after the addition of biochar in the flux of δ <sup>13</sup>CO<sub>2 </sub>from the organic carbon added to the soil. In experiment two, we found that the efflux <sup>13</sup>C from soil with added <sup>13</sup>C labelled soot significantly differed from the control, but this efflux declined over time. There was a cumulative loss of 0.17% <sup>13</sup>C from soot over the experiment.These experimental results represent a step-change in understanding the influence of BC continuum on carbon dynamics, which has major consequences for the way we measure, monitor and manage soils for carbon storage and sequestration in the future.</p>

The Learning Impact of Violent Video Games

2010 ◽  
pp. 312-325
Author(s):  
Alice Ireland ◽  
Nathaniel Payne
Keyword(s):  
Video Games ◽  
Strong Evidence ◽  
Research Evidence ◽  
Aggressive Behaviors ◽  
Negative Effects ◽  
Short Term ◽  
Violent Video Games ◽  
Thinking Processes ◽  
Over Time

There is strong research evidence to suggest that exposure to violent video games is related to an increase in aggressive behaviors in children. Violent video games trigger short-term bursts of aggression, but more importantly they can actually change the user’s thinking processes over time. However, there is also strong evidence to the contrary. This chapter presents an overview of recent evidence for and against the argument on violent games and aggression, together with suggestions for ways that parents can help to mitigate negative effects.

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