scholarly journals Antagonistic effects of long- and short-term environmental variation on species coexistence

2021 ◽  
Vol 288 (1958) ◽  
pp. 20211491
Author(s):  
Ming Liu ◽  
Dustin R. Rubenstein ◽  
Siew Ann Cheong ◽  
Sheng-Feng Shen
Keyword(s):  
Species Coexistence ◽  
Environmental Changes ◽  
Environmental Variation ◽  
Ecological Impacts ◽  
Short Term ◽  
Term Variation ◽  
Environmental Fluctuations ◽  
Time Periods ◽  
The Impact

Assessing the impact of environmental fluctuations on species coexistence is critical for understanding biodiversity loss and the ecological impacts of climate change. Yet determining how properties like the intensity, frequency or duration of environmental fluctuations influence species coexistence remains challenging, presumably because previous studies have focused on indefinite coexistence. Here, we model the impact of environmental fluctuations at different temporal scales on species coexistence over a finite time period by employing the concepts of time-windowed averaging and performance curves to incorporate temporal niche differences within a stochastic Lotka–Volterra model. We discover that short- and long-term environmental variability has contrasting effects on transient species coexistence, such that short-term variation favours species coexistence, whereas long-term variation promotes competitive exclusion. This dichotomy occurs because small samples (e.g. environmental changes over long time periods) are more likely to show large deviations from the expected mean and are more difficult to predict than large samples (e.g. environmental changes over short time periods), as described in the central limit theorem. Consequently, we show that the complex set of relationships among environmental fluctuations and species coexistence found in previous studies can all be synthesized within a general framework by explicitly considering both long- and short-term environmental variation.

scholarly journals An analysis of the long-term variation in stream water quality for three upland catchments at Loch Dee (Galloway, S.W. Scotland) under contrasting land management

2004 ◽  
Vol 8 (3) ◽  
pp. 422-435 ◽  
Author(s):  
S. J. Langan ◽  
D. Hirst
Keyword(s):  
Water Quality ◽  
Land Management ◽  
Stream Water ◽  
Base Flow ◽  
Sea Salt ◽  
Stream Water Quality ◽  
Short Term ◽  
Term Variation ◽  
The Impact

Abstract. A long term record of water chemistry, consisting of twenty years of weekly spot samples, from three sub-catchments draining into a loch and the loch outflow in Galloway, S.W. Scotland have been analysed. The analysis undertaken consisted of a three component statistical trend model. The technique allows the identification of long-term, seasonal and short-term trends, as well as differentiation between base flow and high flow responses. The land usage in the three sub-catchments is moorland, forest and forest plus lime. The results show that, since the mid-1980s, there has been a gradual decline in stream-water sulphate of the same order as reductions in the deposition of non-marine sulphate. Superimposed on this trend are somewhat random but considerable perturbations to this decline, caused by sea-salt deposition. There is no evidence of changes in surface water nitrate concentrations. The influence of different land management is evident in the sulphate, nitrate and pH data, whilst variations in calcium concentrations are also a product of differences in hydrological routing and the impact of sea-salt episodes. Keywords: trend analysis, acid deposition, land management, water quality, sea-salts, Galloway, S.W. Scotland

Pine forest lichens under eutrophication generated by a great cormorant colony

2014 ◽  
Vol 46 (2) ◽  
pp. 213-228 ◽  
Author(s):  
Jurga MOTIEJŪNAITĖ ◽  
Reda IRŠĖNAITĖ ◽  
Gražina ADAMONYTĖ ◽  
Mindaugas DAGYS ◽  
Ričardas TARAŠKEVIČIUS ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Transitional Zone ◽  
Pine Forest ◽  
Great Cormorant ◽  
Nest Density ◽  
Phalacrocorax Carbo ◽  
Short Term ◽  
Lichen Community ◽  
The Impact

AbstractLichen community changes were investigated on trees within a colony of great cormorants (Phalacrocorax carbo sinensis) established in a pine forest on the Curonian Spit, western Lithuania. The impact of birds on the forest has altered the number and characteristics of substrata available to lichens. The lowest number of lichen species and occurrences was registered on trees in the most active part of the colony with the highest nest density. Lichen community patterns were most strongly related to P and Ca content in substrata and pH values. Some acidophytic species showed negative correlations, both with long-term and short-term ornithogenic influence. However, three acidophytes (Chaenotheca ferruginea, Lepraria incana, Coenogonium pineti) demonstrated an affinity for the transitional zone and recently occupied trees, and furthermore,C. pinetiapparently reacted positively to a short-term ornithogenic influence but negatively to a long-term one. These three lichens, along with algae, were the main, and often the only, components of epiphytic communities on trees at the edge of the colony and apparently indicated the crucial point of the acidophytic community under the increasing load of nutrients. All nitrophytic species showed an affinity for a long-term bird influence and reacted negatively to a short-term influence. Only free-living algae (predominating speciesDesmococcus olivaceus) showed a clear affinity for trees occupied by bird nests.Hypogymnia physodeswas found to be an indicator for early environmental changes following eutrophication. The study also showed that high concentrations of P did not have a mitigating effect on the detrimental impact brought about by increases in N and pH levels, but was possibly equally detrimental to acidophytic lichens.

SUMBER-SUMBER RESILIENSI PADA REMAJA AKHIR YANG MENGALAMI KEKERASAN DARI ORANGTUA PADA MASA KANAK-KANAK

Psibernetika ◽  
2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Devina Calista ◽  
Garvin Garvin
Keyword(s):  
Late Adolescents ◽  
Long Term Effects ◽  
Short Term ◽  
Parental Affection ◽  
Resilience Factors ◽  
Childhood Violence ◽  
Past Experiences ◽  
The Impact ◽  
Depth Interviews

<p><em>Child abuse by parents is common in households. The impact of violence on children will bring short-term effects and long-term effects that can be attributed to their various emotional, behavioral and social problems in the future; especially in late adolescence that will enter adulthood. Resilience factors increase the likelihood that adolescents who are victims of childhood violence recover from their past experiences</em><em>,</em><em> become more powerful individuals and have a better life. The purpose of this study was to determine the source of resilience in late adolescents who experienced violence from parents in their childhood. This research uses qualitative research methods with in-depth interviews as a method of data collection. The result shows that the three research participants have the aspects of "I Have", "I Am", and "I Can"; a participant has "I Can" aspects as a source of resilience, and one other subject has no source of resilience. The study concluded that parental affection and acceptance of the past experience have role to the three sources of resilience (I Have, I Am, and I Can)</em></p><p><em> </em></p><p><strong><em>Keyword : </em></strong><em>Resilience, adolescence, violence, parents</em></p>

Designing a CRM Framework for online & offline sports footwear retailers

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Rodrigo Cueva ◽  
Guillem Rufian ◽  
Maria Gabriela Valdes
Keyword(s):  
Environmental Changes ◽  
Customer Relationship ◽  
Business Strategies ◽  
Economic Sectors ◽  
Running Shoes ◽  
Brick And Mortar ◽  
Key Factor ◽  
On Line ◽  
The Impact

The use of Customer Relationship Managers to foster customers loyalty has become one of the most common business strategies in the past years.  However, CRM solutions do not fill the abundance of happily ever-after relationships that business needs, and each client’s perception is different in the buying process.  Therefore, the experience must be precise, in order to extend the loyalty period of a customer as much as possible. One of the economic sectors in which CRM’s have improved this experience is retailing, where the personalized attention to the customer is a key factor.  However, brick and mortar experiences are not enough to be aware in how environmental changes could affect the industry trends in the long term.  A base unified theoretical framework must be taken into consideration, in order to develop an adaptable model for constructing or implementing CRMs into companies. Thanks to this approximation, the information is complemented, and the outcome will increment the quality in any Marketing/Sales initiative. The goal of this article is to explore the different factors grouped by three main domains within the impact of service quality, from a consumer’s perspective, in both on-line and off-line retailing sector.  Secondly, we plan to go a step further and extract base guidelines about previous analysis for designing CRM’s solutions focused on the loyalty of the customers for a specific retailing sector and its product: Sports Running Shoes.

Forecasting Revenue Impacts from COVID-19: The Case of Florida Municipalities

2021 ◽  
pp. 0160323X2110120
Author(s):  
Hai (David) Guo ◽  
Can Chen
Keyword(s):  
Local Government ◽  
Short Term ◽  
Fiscal Planning ◽  
Revenue Structure ◽  
Municipal Managers ◽  
The Impact

Early in the pandemic, Florida municipal managers indicated that forecasting the impact on local revenues was one of their top priorities in responding to the pandemic, yet such a tool has not been widely available. This study offers simple and straightforward fiscal planning guides for assessing the short-term and long-term impacts of the COVID 19 recession on local government revenues by estimating the revenue declines among 411 Florida municipalities from FY 2021 to FY 2023. The forecast results predict revenues will be reduced by $5.11 billion from 2019 pre-pandemic levels for Florida cities in fiscal years 2021 through 2023. The decline is forecast to be 3.54 percent in FY 2021, 4.02 percent in FY 2022, and 3.29 percent in FY 2023. The revenue structure matters for estimating the revenue decline.

scholarly journals Paleolithic Diet—Effect on the Health Status and Performance of Athletes?

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 1019
Author(s):  
Barbara Frączek ◽  
Aleksandra Pięta ◽  
Adrian Burda ◽  
Paulina Mazur-Kurach ◽  
Florentyna Tyrała
Keyword(s):  
Blood Pressure ◽  
Body Mass ◽  
Positive Impact ◽  
Model Assessment ◽  
Paleolithic Diet ◽  
Short Term ◽  
Positive Effects ◽  
Short And Long Term ◽  
The Impact

The aim of this meta-analysis was to review the impact of a Paleolithic diet (PD) on selected health indicators (body composition, lipid profile, blood pressure, and carbohydrate metabolism) in the short and long term of nutrition intervention in healthy and unhealthy adults. A systematic review of randomized controlled trials of 21 full-text original human studies was conducted. Both the PD and a variety of healthy diets (control diets (CDs)) caused reduction in anthropometric parameters, both in the short and long term. For many indicators, such as weight (body mass (BM)), body mass index (BMI), and waist circumference (WC), impact was stronger and especially found in the short term. All diets caused a decrease in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG), albeit the impact of PD was stronger. Among long-term studies, only PD cased a decline in TC and LDL-C. Impact on blood pressure was observed mainly in the short term. PD caused a decrease in fasting plasma (fP) glucose, fP insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) and glycated hemoglobin (HbA1c) in the short run, contrary to CD. In the long term, only PD caused a decrease in fP glucose and fP insulin. Lower positive impact of PD on performance was observed in the group without exercise. Positive effects of the PD on health and the lack of experiments among professional athletes require longer-term interventions to determine the effect of the Paleo diet on athletic performance.

Methods to Reduce Traffic Speed in High-Pedestrian Rural Areas

2003 ◽  
Vol 1828 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Ali Kamyab ◽  
Steve Andrle ◽  
Dennis Kroeger ◽  
David S. Heyer
Keyword(s):  
Rural Areas ◽  
Speed Limit ◽  
Single Word ◽  
Short Term ◽  
Speed Reduction ◽  
Traffic Calming ◽  
Reduction Strategies ◽  
Long Term Impact ◽  
The Impact

Many Minnesota counties are faced with the problem of high vehicle speeds through towns or resort areas that have significant pedestrian traffic. The impact of speed reduction strategies in high-pedestrian areas in rural counties of Minnesota was investigated. Speed data were collected at two selected study sites under their existing conditions ("no-treatment" or "before" condition) and after the proposed speed reduction strategies were installed. Second "after" data conditions were collected to study the short-term and long-term impact of the implemented strategies. The traffic-calming techniques employed at the Twin Lakes site consisted of removable pedestrian islands and pedestrian crossing signs. A dynamic variable message sign that sent a single-word message ("Slow") to motorists traveling over the speed limit was installed at the Bemidji site. The research study shows that the traffic-calming strategy deployed in Twin Lakes was effective in significantly reducing the mean speed and improving speed limit compliance in both the short term and long term. Despite proven effectiveness, the deployed speed reduction treatment in Bemidji Lake failed to lower the speed at the study site. The single-word message on the sign and the location of the sign, as well as a lack of initial enforcement, were the primary reasons for such failure.

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