On the efficacy of anti-parasite behaviour: a case study of tadpole susceptibility to cercariae of Echinostoma trivolvis

2006 ◽  
Vol 84 (11) ◽  
pp. 1623-1629 ◽  
Author(s):  
Janet Koprivnikar ◽  
Mark R. Forbes ◽  
Robert L. Baker
Keyword(s):  
Environmental Factors ◽  
Wood Frog ◽  
Green Frog ◽  
Wood Frogs ◽  
Behavioural Responses ◽  
Frog Tadpoles ◽  
Low Levels ◽  
Host Behaviour ◽  
Echinostoma Trivolvis

Many animals respond behaviourally to the infective stages of parasites, but the efficacy of such responses in reducing risk of parasitism often is not established. It was found that tadpoles of Rana clamitans Latr., 1801 (green frogs) and R. sylvatica LeConte, 1825 (wood frogs) increased their activity when exposed to live infective stages (cercariae) of the trematode Echinostoma trivolvis Rudolphi, 1809. The susceptibility to parasitism for green frog tadpoles subjected to three different treatments was compared. Tadpoles were housed at 20 °C and allowed to respond to cercariae, held at 6–8 °C and showing reduced behavioural responses, or anesthetized and showing no responses. Low levels of parasitism were found for tadpoles that responded behaviourally to cercariae; such responses are expected to occur under normal field conditions in the absence of factors suppressing activity of tadpoles. We also demonstrate that infectivity of E. trivolvis cercariae to non-responding (anesthetized) wood frog tadpoles was higher at warm than at cool temperatures. Thus, lowered parasitism at warm temperatures in the first experiment likely resulted from host behavioural responses and not from low infectivity of cercariae. These results have implications for observing effects of environmental factors on susceptibility to parasitism where susceptibility is thought or known to be mediated by host behaviour.

Carryover effects of phenotypic plasticity: embryonic environment and larval response to predation risk in Wood Frogs (Lithobates sylvaticus) and Northern Leopard Frogs (Lithobates pipiens)

2015 ◽  
Vol 93 (11) ◽  
pp. 867-877 ◽  
Author(s):  
A.M. Bennett ◽  
D.L. Murray
Keyword(s):  
Predation Risk ◽  
Wood Frog ◽  
Leopard Frog ◽  
Carryover Effects ◽  
Wood Frogs ◽  
Lithobates Sylvaticus ◽  
Northern Leopard Frog ◽  
Leopard Frogs ◽  
Frog Tadpoles ◽  
Northern Leopard Frogs

Limitations of phenotypic plasticity affect the success of individuals and populations in changing environments. We assessed the plasticity-history limitation on predator-induced defenses in anurans (Wood Frogs, Lithobates sylvaticus (LeConte, 1825), and Northern Leopard Frogs, Lithobates pipiens (Schreber, 1782)), predicting that plastic responses to predation risk by dragonfly larvae (family Aeshnidae) in the embryonic environment would limit the defensive response to predators in the larval environment. Predator-conditioned Wood Frog embryos increased relative tail depth in response to those same cues as larvae, whereas predator-naive tadpoles did not. However, no carryover effect was noted in the behavioural response of Wood Frog tadpoles to predation risk. Predator-naive Northern Leopard Frog tadpoles increased relative tail depth in response to predation risk in the larval environment. Predator-conditioned Northern Leopard Frog embryos hatched with, and maintained, a marginal increase in tail depth as larvae in the absence of predation risk. Predator-conditioned Northern Leopard Frog embryos exposed to predation risk as larvae showed no morphological response. While we find no strong support for the plasticity-history limitation per se, carryover effects across embryonic and larval life-history stages were noted in both Wood Frog and Northern Leopard Frog, suggesting that predation risk early in ontogeny can influence the outcome of future interactions with predators.

Low Temperature Fault Isolation Using Soft Defect Localization

2012 ◽  
Author(s):  
Kristopher D. Staller
Keyword(s):  
Low Temperatures ◽  
Laser Scanning ◽  
Low Cost ◽  
Fault Isolation ◽  
Laser Scanning Microscopy ◽  
Cold Temperature ◽  
Multiple Point ◽  
Defect Localization ◽  
Low Levels

Abstract Cold temperature failures are often difficult to resolve, especially those at extreme low levels (< -40°C). Momentary application of chill spray can confirm the failure mode, but is impractical during photoemission microscopy (PEM), laser scanning microscopy (LSM), and multiple point microprobing. This paper will examine relatively low-cost cold temperature systems that can hold samples at steady state extreme low temperatures and describe a case study where a cold temperature stage was combined with LSM soft defect localization (SDL) to rapidly identify the cause of a complex cold temperature failure mechanism.

Factors Affecting on Entrepreneurial Intention of University Students (Case Study on Wollo University)

2021 ◽  
Author(s):  
Abdu Kamil
Keyword(s):  
Environmental Factors ◽  
University Students ◽  
Family Background ◽  
Secondary Data ◽  
Entrepreneurial Intention ◽  
Primary Data ◽  
Personal Factors ◽  
Factors Affecting ◽  
College Of Business

Abstract Background: Entrepreneurship is essential in creating, fulfilling and forming a healthy economy. This study is conducted to investigate Factor Affecting on Entrepreneurial Intention: The case study on Wollo University Students. Some studies have been done in this area but only a few were conducted in Ethiopia. This research aims to address the gap that exists due to the weakness of previous studies to verify the factors that affect entrepreneurial intention and provide more clarification on the topic. Methods: For the purpose of this study explanatory research design was employed. The researcher used stratified random sampling to classify all participants into seven colleges and one school of law. From each stratum proportionally by using purposive sampling to select 226 respondents with graduate students from college of business and economics for the desire of the study. Both primary and secondary data were collected. Primary data were collected through structured questionnaire from 210 students. Secondary data were collected from previous studies and used as reference. Results: The correlation and regression analysis has been applied to see the relationship and how independent variables influence entrepreneurial intention. From the analyses it is confirmed that demographic factors have statistically insignificant effect on entrepreneurial intention, while personal factors, environmental factors and family background have a statistically significant effect on entrepreneurial intention. Conclusions: Based on the findings it is concluded that demographic factor does not affect entrepreneurial intention while personal factors, environmental factors and family background affect entrepreneurial intention.

scholarly journals Dealing with Interval DEA Based on Error Propagation and Entropy: A Case Study of Energy Efficiency of Regions in China Considering Environmental Factors

2015 ◽  
Vol 3 (6) ◽  
pp. 538-548 ◽  
Author(s):  
Jianping Fan ◽  
Weizhen Yue ◽  
Meiqin Wu
Keyword(s):  
Energy Efficiency ◽  
Environmental Factors ◽  
Error Propagation ◽  
Interval Data ◽  
Data Envelopment ◽  
Exact Data ◽  
Dea Models ◽  
Traditional Approaches ◽  
Decision Making Units

AbstractThe conventional data envelopment analysis (DEA) measures the relative efficiency of decision making units (DMUs) consuming multiple inputs to produce multiple outputs under the assumption that all the data are exact. In the real world, however, it is possible to obtain interval data rather than exact data because of various limitations, such as statistical errors and incomplete information, et al. To overcome those limitations, researchers have proposed kinds of approaches dealing with interval DEA, which either use traditional DEA models by transforming interval data into exact data or get an efficiency interval by using the bound of interval data. In contrast to the traditional approaches above, the paper deals with interval DEA by combining traditional DEA models with error propagation and entropy, uses idea of the modified cross efficiency to get the ultimate cross efficiency of DMUs in the form of error distribution and ranks DMUs using the calculated ultimate cross efficiency by directional distance index. At last we illustrate the feasibility and effectiveness of the proposed method by applying it to measure energy efficiency of regions in China considering environmental factors.

scholarly journals Genetic or Psychogenic? A Case Study of “Folie à Quatre” Including Twins

2015 ◽  
Vol 2015 ◽  
pp. 1-3 ◽  
Author(s):  
Tohru Ohnuma ◽  
Heii Arai
Keyword(s):  
Environmental Factors ◽  
Social Isolation ◽  
Schizophrenia Patient ◽  
Monozygotic Twins ◽  
The Other ◽  
Positive Symptoms ◽  
Short Period ◽  
The Common ◽  
Shared Psychotic Disorder

Shared psychotic disorder, characterized by shared delusion among two or more subjects (termed “Folie à deux,” “trois,” etc.), is often associated with strong religious beliefs or social isolation, factors creating strong psychological sympathy. Recently, we treated a rare familial case of “Folie à quatre” in central Tokyo without such influences. The proband was a schizophrenia patient and younger brother within monozygotic twins. Positive symptoms were “transmitted” to remaining family members, his elder brother, mother, and father father, in a relatively short period of three months. Although the pathophysiology of these positive symptoms (delusions and hallucinations) remains unclear, the transmission pattern suggests the primacy of social and environmental factors (and/or their interaction), while genetics appeared less influential in this “Folie à famille.” Although undiagnosed psychoses in the whole family cannot be excluded, they did not share the other negative schizophrenia symptoms of the proband. A strong familial connection appeared to be the most important factor for the common delusion and hallucination.

scholarly journals Personal, Socio-Cultural and Environmental Factors Associated with Smoking Among Female Students at University of Lusaka, Zambia

2021 ◽  
Vol 3 (1) ◽  
pp. 93-103
Author(s):  
Francesca Chishimba Kasonka ◽  
◽  
Diana Mannan ◽  
Theresa Lesa Chisoso ◽  
Brian Chanda Chiluba ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Peer Influence ◽  
Premature Death ◽  
Female Students ◽  
Family Influence ◽  
Snowball Sampling ◽  
Adverse Health Effects ◽  
Younger Age ◽  
The University

Tobacco use is one of the most preventable causes of premature death globally, yet statistics show that there has been an increase of female smokers. Hence a need to understand why smoking prevalence continues despite the overwhelming data on adverse health effects. The aim of this study was to explore personal, socio-cultural, and environmental factors that are associated with smoking among female university students of University of Lusaka. A qualitative case study design was conducted with a sample 12 female students from the University of Lusaka. Snowball sampling was utilized. Female students smoking tobacco were predominantly associated with the desire for personal gratification, to feel accepted by their peers who smoke, to express female independenceand freedom and exposure to a male family member who smokes at younger age. Socio-cultural factors such as such as peer influence, family influence and female modernity in society were the major influencers of smoking in the female students, and environmental factors such as the lack of responsiveness to Zambia’s anti-smoking campaigns and a gap in the enforcement of anti-smoking legislation in Zambia also played an indirect role in facilitating smoking among female student. Anti-smoking campaigns could try and consider evaluating interventions from a male and female perspective respectively.

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