Inhibition or Facilitation? Contrasted Inter-Specific Interactions in Sphagnum under Laboratory and Field Conditions

In a natural environment, plants usually interact with their neighbors predominantly through resource competition, allelopathy, and facilitation. The occurrence of the positive effect of allelopathy between peat mosses (Sphagnum L.) is rare, but it has been observed in a field experiment. It is unclear whether the stability of the water table level in peat induces positive vs. negative effects of allelopathy and how that is related to phenolic allelochemical production in Sphagnum. Based on field experiment data, we established a laboratory experiment with three neighborhood treatments to measure inter-specific interactions between Sphagnum angustifolium (Russ.) C. Jens and Sphagnum magellanicum Brid. We found that the two species were strongly suppressed by the allelopathic effects of each other. S. magellanicum allelopathically facilitated S. angustifolium in the field but inhibited it in the laboratory, and relative allelopathy intensity appeared to be positively related to the content of released phenolics. We conclude that the interaction type and intensity between plants are dependent on environmental conditions. The concentration of phenolics alone may not explain the type and relative intensity of allelopathy. Carefully designed combined field and laboratory experiments are necessary to reveal the mechanism of species interactions in natural communities.

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THE EFFECTS OF PHYSICAL ACTIVITY ON THE BALANCE OF THE ELDERLY

Facta Universitatis Series Physical Education and Sport ◽

10.22190/fupes190114002z ◽

2019 ◽

Vol 16 (2) ◽

pp. 761

Author(s):

Dobrica Živković ◽

Slađan Karaleić ◽

Ivana Anđelković ◽

Nikola Aksović

Keyword(s):

Physical Activity ◽

Exercise Program ◽

The Elderly ◽

Health It ◽

Negative Effects ◽

Cardio Vascular ◽

The Stability ◽

Risk Factors For Falls ◽

Positive Effect

Daily physical activity is necessary for good quality of life among the elderly. It usually happens that with the advent of years, the extent of exercise decreases among the elderly, which could have negative effects on their health. It is very important to point out that if the health results allow it, it is never too late to begin with programmed training and physical exercise. If it is carried out under supervision, the possibility of injury is significantly reduced. The subject matter of this research are studies published from 2000 to 2016, which focused on the effects of physical activity on the balance of individuals over the age of 60. The aim of this review is the compilation of the appropriate literature on physical activity, as well as the clarification on whether there are effects of the physical activity on the balance of the elderly. This overview included 24 research papers. The results of this study confirm the positive effect of physical activity on the balance of the elderly. It has been proven that several weeks of a standardized exercise program, based on the increase in joint mobility, cardio-vascular exercise, strengthening the stability of the pelvic region, and proprioceptive exercise can improve balance skills and reduce the perception of pain. For elderly individuals with specific risk factors for falls, the recommendation is specific aquatic exercise programs which will improve balance and strengthen the lower extremities.

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“Maybe It’s More Natural for Them to Have Been Out of Work for a Little While”

Making the Cut ◽

10.23943/princeton/9780691175102.003.0006 ◽

2020 ◽

pp. 103-112

Author(s):

David S. Pedulla

Keyword(s):

Field Experiment ◽

Racial Discrimination ◽

Statistical Test ◽

Job Applicants ◽

Compelling Evidence ◽

Negative Effects ◽

Experiment Data ◽

Negative Effect

This chapter turns to how the consequences of long-term unemployment vary with the race of the applicant. It presents results from field-experiment data to indicate that while certain groups of workers are severely penalized for a year of unemployment, others are not. This chapter probes those differences and develops an understanding of how and why race and experiences of unemployment interact in the ways that they do. It also examines whether the effects of unemployment differed in a statistically significantly way for white and black applicants. The results from this statistical test provide compelling evidence that this is indeed the case. While racial discrimination is strong and persistent, and long-term unemployment has negative effects for white job applicants, there is little additional negative effect of unemployment for black applicants.

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The effect of an additive on the aerobic stability and subsequent intake of grass silages

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600022698 ◽

1992 ◽

Vol 1992 ◽

pp. 159-159

Author(s):

O D Davies

Keyword(s):

Laboratory Method ◽

Negative Effects ◽

Laboratory Assessment ◽

Feeding Method ◽

Grass Silage ◽

Silage Fermentation ◽

Aerobic Stability ◽

The Stability ◽

Positive Effect ◽

Subsequent Intake

A major difficulty in producing detailed rations for ruminants, where grass silage is offered ad libitum lies in the accurate prediction of silage intake. It is well documented that ammonia and increased levels of acetic, butyric, caproic and valeric acids in grass silages have negative effects on intake, whilst increased organic matter digestibility has a positive effect. (Gill, Book and Thiago, 1988). A laboratory assessment of silage fermentation characteristics is usually determined from freshly cored samples. Depending on the stability of the silage, and the feeding method, results of such assessments may not be indicative of the silage on offer to stock.A laboratory method of determining the aerobic stability of silage has been developed by ADAS at Slough Laboratories between 1988 and 1990, (Brooks 1990).

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Effects of marine reserves on predator-prey interactions in central California kelp forests

Marine Ecology Progress Series ◽

10.3354/meps13526 ◽

2020 ◽

Vol 655 ◽

pp. 139-155

Author(s):

DC Yates ◽

SI Lonhart ◽

SL Hamilton

Keyword(s):

Species Interactions ◽

Size Structure ◽

Marine Reserves ◽

Mortality Rates ◽

Kelp Forests ◽

Negative Effects ◽

Central California ◽

Invertebrate Predators ◽

Predatory Fishes ◽

Density And Biomass

Marine reserves are often designed to increase density, biomass, size structure, and biodiversity by prohibiting extractive activities. However, the recovery of predators following the establishment of marine reserves and the consequent cessation of fishing may have indirect negative effects on prey populations by increasing prey mortality. We coupled field surveys with empirical predation assays (i.e. tethering experiments) inside and outside of 3 no-take marine reserves in kelp forests along the central California coast to quantify the strength of interactions between predatory fishes and their crustacean prey. Results indicated elevated densities and biomass of invertebrate predators inside marine reserves compared to nearby fished sites, but no significant differences in prey densities. The increased abundance of predators inside marine reserves translated to a significant increase in mortality of 2 species of decapod crustaceans, the dock shrimp Pandalus danae and the cryptic kelp crab Pugettia richii, in tethering experiments. Shrimp mortality rates were 4.6 times greater, while crab mortality rates were 7 times greater inside reserves. For both prey species, the time to 50% mortality was negatively associated with the density and biomass of invertebrate predators (i.e. higher mortality rates where predators were more abundant). Video analyses indicated that macro-invertivore fishes arrived 2 times faster to tethering arrays at sites inside marine reserves and began attacking tethered prey more rapidly. The results indicate that marine reserves can have direct and indirect effects on predators and their prey, respectively, and highlight the importance of considering species interactions in making management decisions.

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Long-term Archive of the DUCK94 Nearshore Field Experiment Data

10.21236/ada630859 ◽

1999 ◽

Author(s):

William Birkemeier ◽

Kent Hathaway ◽

Ravi Sinha ◽

Kossi Edoh ◽

Awatif Amin ◽

...

Keyword(s):

Field Experiment ◽

Experiment Data

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Determinants of Corporate Anti-Corruption Disclosure: The Case of the Emerging Economics

Sustainability ◽

10.3390/su13063462 ◽

2021 ◽

Vol 13 (6) ◽

pp. 3462

Author(s):

Maider Aldaz Odriozola ◽

Igor Álvarez Etxeberria

Keyword(s):

Empirical Studies ◽

Geographical Area ◽

Control Variable ◽

Emerging Countries ◽

Point Of View ◽

Press Freedom ◽

Negative Effects ◽

Key Factor ◽

Using Data ◽

Positive Effect

Corruption is a key factor that affects countries’ development, with emerging countries being a geographical area in which it tends to generate greater negative effects. However, few empirical studies analyze corruption from the point of view of disclosure by companies in this relevant geographical area. Based on a regression analysis using data from the 96 large companies from 15 emerging countries included in the 2016 International Transparency Report, this paper seeks to understand what determinants affect such disclosure. In that context, this paper provides empirical evidence to understand the factors that influence reporting on anti-corruption mechanisms in an area of high economic importance that has been little studied to date, pointing to the positive effect of press freedom in a country where the company is located and with the industry being the unique control variable that strengthens this relationship.

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SHELL MATERIAL'S PERFORMANCE OF THE MICROCAPSULE FOR ELECTROLYTIC CO-DEPOSITION

International Journal of Modern Physics B ◽

10.1142/s0217979210066197 ◽

2010 ◽

Vol 24 (15n16) ◽

pp. 3124-3130 ◽

Cited By ~ 1

Author(s):

HUI CONG LIU ◽

XIU QING XU ◽

WEI PING LI ◽

YAN HONG GUO ◽

LI-QUN ZHU

Keyword(s):

Composite Coating ◽

Methyl Cellulose ◽

Water Vapor Permeability ◽

Core Material ◽

Vapor Permeability ◽

Shell Material ◽

The Core ◽

Surface Performance ◽

The Stability ◽

Positive Effect

The shell material of microcapsules has an important effect on the electrolytic co-deposition behavior, the release of core material and the surface performance of composite coating. This paper discussed the tensile property and the stability of three shell materials including polyvinyl alcohol (PVA), gelatin and methyl cellulose (MC). It is found that these three shell materials have good mechanical strength and flexibility which are favorable to electrolytic co-deposition and stability of microcapsules in composite coating and that MC has well permeability and porosity which has a positive effect on the release of the core material in composite coating. Moreover, the study of the thermal properties and water vapor permeability of the three shell materials showed that their permeability improved with increase of temperature and humidity. In addition, the composite copper coating containing microcapsules with PVA, gelatin or MC as shell material was prepared respectively.

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Social capital and national innovation system: a cross-country analysis

Cross Cultural Management An International Journal ◽

10.1108/ccm-10-2013-0154 ◽

2014 ◽

Vol 21 (4) ◽

pp. 453-475 ◽

Cited By ~ 9

Author(s):

Sepehr Ghazinoory ◽

Ali Bitaab ◽

Ardeshir Lohrasbi

Keyword(s):

Social Capital ◽

National Level ◽

Innovation System ◽

Negative Effects ◽

Content Type ◽

Research Findings ◽

Different Dimensions ◽

The Impact ◽

Positive Effect

Purpose – In the last two decades, researchers have paid much attention to the role of cultural values on economic and social development. In particular, the crucial role of different aspects of culture on the development of innovation has been stressed in the literature. Consequently, it is vital to understand how social capital, as a core cultural value, affects the innovation process and the innovative performance at the national level. However, to date, the impact of different dimensions of social capital and innovation has not been properly portrayed or explained. Thus, the purpose of this paper is to investigate the influence of four different dimensions of social capital (institutional and interpersonal, associational life and norms) on two of the main functions of national innovation system (NIS) (entrepreneurship and knowledge creation) based on over 50,000 observations in 34 countries. Design/methodology/approach – In this regard, national-level data from the World Values Survey database was employed to quantify social capital. Entrepreneurship is, in turn, assumed to consist of three sub-indexes and 14 indicators based on the Global Entrepreneurship Index. Knowledge creation is also measured through US Patent Office applications. Also, exploratory factor analysis and structural equation modeling approach were used to build the measurement model and investigate the impact that each factor of social capital had on entrepreneurship and knowledge application, respectively. Measurement and structural models were built and their reliability and validity were tested using various fit indices. Research findings suggest the strong positive effect of institutional trust and networking on entrepreneurship. Also, interpersonal trust and networks were shown to have high influence on knowledge development at the national level. Norms appear to have naïve to medium negative effects on both functions. Findings – Research findings suggest the strong positive effect of institutional trust and networking on entrepreneurship. Also, interpersonal trust and networks were shown to have high influence on knowledge development at the national level. Norms appear to have naïve to medium negative effects on both functions. Originality/value – However, to date, the impact of different dimensions of social capital and innovation has not been properly portrayed or explained.

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Numerical Studies of the Effects of Water Capsules on Self-Healing Efficiency and Mechanical Properties in Cementitious Materials

Advances in Materials Science and Engineering ◽

10.1155/2016/8271214 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Haoliang Huang ◽

Guang Ye

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Elastic Modulus ◽

Cementitious Materials ◽

Self Healing ◽

Negative Effects ◽

Numerical Studies ◽

Healing Efficiency ◽

The Impact ◽

Positive Effect

In this research, self-healing due to further hydration of unhydrated cement particles is taken as an example for investigating the effects of capsules on the self-healing efficiency and mechanical properties of cementitious materials. The efficiency of supply of water by using capsules as a function of capsule dosages and sizes was determined numerically. By knowing the amount of water supplied via capsules, the efficiency of self-healing due to further hydration of unhydrated cement was quantified. In addition, the impact of capsules on mechanical properties was investigated numerically. The amount of released water increases with the dosage of capsules at different slops as the size of capsules varies. Concerning the best efficiency of self-healing, the optimizing size of capsules is 6.5 mm for capsule dosages of 3%, 5%, and 7%, respectively. Both elastic modulus and tensile strength of cementitious materials decrease with the increase of capsule. The decreasing tendency of tensile strength is larger than that of elastic modulus. However, it was found that the increase of positive effect (the capacity of inducing self-healing) of capsules is larger than that of negative effects (decreasing mechanical properties) when the dosage of capsules increases.

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