scholarly journals Temperature effects on individual-level parasitism translate into predictable effects on parasitism in populations

2020 ◽  
Author(s):  
Devin Kirk ◽  
Mary I. O’Connor ◽  
Erin A. Mordecai
Keyword(s):  
Temperature Effects ◽  
Positive Relationship ◽  
Mechanistic Model ◽  
Parasite Burden ◽  
Population Level ◽  
Parasite Transmission ◽  
Individual Level ◽  
Strong Positive Relationship ◽  
General Rules

ABSTRACTParasitism – the interaction between a parasite and its host – is expected to change in a warmer future, but the direction and magnitude of this change is uncertain. One challenge is understanding whether warming effects will be similar on individual hosts (e.g., parasite burden) compared to on population-level parasitism (e.g., prevalence, R0). Examining thirteen empirical systems, we found a strong positive relationship between the thermal optima of individual- and population-level parasitism. We also found that parasitism thermal optima were close to host performance thermal optima in mosquito – parasite systems but not in non-mosquito – parasite systems. A simple mechanistic model showed how population-level parasitism thermal optima can be similar to individual-level parasitism thermal optima even under conditions where parasite transmission has a considerably higher thermal optimum. These results provide a key step towards finding general rules for how warming temperatures should affect parasitism in individuals, populations, and ecosystems.

Branchiobdellidan infestation on endangered white-clawed crayfish (Austropotamobius pallipes) in the UK

Parasitology ◽  
2012 ◽  
Vol 139 (6) ◽  
pp. 774-780 ◽  
Author(s):  
P. J. ROSEWARNE ◽  
R. J. G. MORTIMER ◽  
A. M. DUNN
Keyword(s):  
Positive Relationship ◽  
Parasite Burden ◽  
Gill Tissue ◽  
Parasite Prevalence ◽  
Sister Group ◽  
Freshwater Crayfish ◽  
Taxonomic Identification ◽  
Austropotamobius Pallipes ◽  
Strong Positive Relationship ◽  
The Uk

SUMMARYBranchiobdellidans or crayfish worms are clitellate annelids and ectosymbionts of freshwater crayfish. An investigation of branchiobdellidan infestation was undertaken in a population of endangered white-clawed crayfish (Austropotamobius pallipes) in the river Aire, UK. Thirty two percent of animals were infested either by the adult parasite or their cocoons (n=107). Parasite burden increased with host size, but did not differ with sex. Observations of crayfish gill tissue revealed a strong positive relationship between melanization of filaments and parasite prevalence and burden. Taxonomic identification revealed that 1 species of branchiobdellidan was present, Branchiobdella astaci. The first sequences were generated for this species and phylogenetically analysed alongside published sequences for 5 other branchiobdellidan species in Europe. The position of B. astaci within the genus Branchiobdella was confirmed, and it was found to cluster as a sister group to B. parasita.

scholarly journals Linking Bioenergetics and Parasite Transmission Models Suggests Mismatch Between Snail Host Density and Production of Human Schistosomes

2019 ◽  
Vol 59 (5) ◽  
pp. 1243-1252 ◽  
Author(s):  
Matthew Malishev ◽  
David J Civitello
Keyword(s):  
Host Density ◽  
Population Level ◽  
Immune Defense ◽  
Parasite Transmission ◽  
Host Snail ◽  
Individual Level ◽  
High Resource ◽  
Parasite Ecology ◽  
The Individual ◽  
Host Parasite

Abstract The consequences of parasite infection for individual hosts depend on key features of host–parasite ecology underpinning parasite growth and immune defense, such as age, sex, resource supply, and environmental stressors. Scaling these features and their underlying mechanisms from the individual host is challenging but necessary, as they shape parasite transmission at the population level. Translating individual-level mechanisms across scales could inherently improve the way we think about feedbacks among parasitism, the mechanisms driving transmission, and the consequences of human impact and disease control efforts. Here, we use individual-based models (IBMs) based on general metabolic theory, Dynamic Energy Budget (DEB) theory, to scale explicit life-history features of individual hosts, such as growth, reproduction, parasite production, and death, to parasite transmission at the population level over a range of resource supplies focusing on the major human parasite, Schistosoma mansoni, and its intermediate host snail, Biomphalaria glabrata. At the individual level, infected hosts produce fewer parasites at lower resources as competition increases. At the population level, our DEB–IBM predicts brief, but intense parasite peaks early during the host growth season when resources are abundant and infected hosts are few. The timing of these peaks challenges the status quo that high densities of infected hosts produce the highest parasite densities. As expected, high resource supply boosts parasite output, but parasite output also peaks at modest to high host background mortality rates, which parallels overcompensation in stage-structured models. Our combined results reveal the crucial role of individual-level physiology in identifying how environmental conditions, time of the year, and key feedbacks within host–parasite ecology interact to define periods of elevated risk. The testable forecasts from this physiologically-explicit epidemiological model can inform disease management to reduce human risk of schistosome infection.

Effects of Financial Innovations on Profitability for Deposit Taking Microfinancing Institutions in Kenya

2018 ◽  
Vol 9 (6) ◽  
pp. 529-536
Author(s):  
Martin Khoya Odipo ◽  
Keyword(s):  
Financial Institutions ◽  
Positive Relationship ◽  
Financial Institution ◽  
Secondary Data ◽  
Financial Statements ◽  
Descriptive Statistics ◽  
Primary Data ◽  
Microfinance Institutions ◽  
Financial Innovations ◽  
Strong Positive Relationship

Recent studies have documented that innovations improve profitability of firms. This article documents that deposit taking micro financial institutions that have adopted financial innovations have increased their profitability. The study covered five years between 2009-2013. Both primary and secondary data were used in the study. Primary data was obtained through administration of drop and pick questionnaires to selected employees of the institutions. Secondary data was obtained from financial statements and management reports of these deposit taking microfinance institutions. Data was analyzed using descriptive statistics, return on asset and multi-liner regression model to determine the effect of each financial innovation applied on profitability on the micro-financial institution. The results showed that most deposit taking microfinance institutions adopted these financial innovations in their current operations. There was strong positive relationship between individual innovations and profitability. In line with profitability ROA also showed improvement each year after the adoption of these financial innovations.

INTERCONNECTION OF SUSTAINABLE DEVELOPMENT COMPONENTS FOR THE INDIGENOUS PEOPLES OF THE NORTH

2020 ◽  
Vol 2 (8) ◽  
pp. 101-110
Author(s):  
N. N. ILYSHEVA ◽  
◽  
E. V. KARANINA ◽  
G. P. LEDKOV ◽  
E. V. BALDESKU ◽  
...  
Keyword(s):  
Climate Change ◽  
Sustainable Development ◽  
Economic Development ◽  
Indigenous Peoples ◽  
Ecological Footprint ◽  
Positive Relationship ◽  
The North ◽  
Strong Positive Relationship ◽  
The Face ◽  
The Relationship

The article deals with the problem of achieving sustainable development. The purpose of this study is to reveal the relationship between the components of sustainable development, taking into account the involvement of indigenous peoples in nature conservation. Climate change makes achieving sustainable development more difficult. Indigenous peoples are the first to feel the effects of climate change and play an important role in the environmental monitoring of their places of residence. The natural environment is the basis of life for indigenous peoples, and biological resources are the main source of food security. In the future, the importance of bioresources will increase, which is why economic development cannot be considered independently. It is assumed that the components of resilience are interrelated and influence each other. To identify this relationship, a model for the correlation of sustainable development components was developed. The model is based on the methods of correlation analysis and allows to determine the tightness of the relationship between economic development and its ecological footprint in the face of climate change. The correlation model was tested on the statistical materials of state reports on the environmental situation in the Khanty-Mansiysk Autonomous Okrug – Yugra. The approbation revealed a strong positive relationship between two components of sustainable development of the region: economy and ecology.

scholarly journals Blood Pressure Trajectories Across the Life Course

2021 ◽  
Vol 34 (3) ◽  
pp. 234-241
Author(s):  
Norrina B Allen ◽  
Sadiya S Khan
Keyword(s):  
Blood Pressure ◽  
Measurement Errors ◽  
Clinical Care ◽  
Population Level ◽  
Cumulative Exposure ◽  
Older Adulthood ◽  
Individual Level ◽  
The Life Course ◽  
Level Group ◽  
Improve Health

Abstract High blood pressure (BP) is a strong modifiable risk factor for cardiovascular disease (CVD). Longitudinal BP patterns themselves may reflect the burden of risk and vascular damage due to prolonged cumulative exposure to high BP levels. Current studies have begun to characterize BP patterns as a trajectory over an individual’s lifetime. These BP trajectories take into account the absolute BP levels as well as the slope of BP changes throughout the lifetime thus incorporating longitudinal BP patterns into a single metric. Methodologic issues that need to be considered when examining BP trajectories include individual-level vs. population-level group-based modeling, use of distinct but complementary BP metrics (systolic, diastolic, mean arterial, mid, and pulse pressure), and potential for measurement errors related to varied settings, devices, and number of readings utilized. There appear to be very specific developmental periods during which divergent BP trajectories may emerge, specifically adolescence, the pregnancy period, and older adulthood. Lifetime BP trajectories are impacted by both individual-level and community-level factors and have been associated with incident hypertension, multimorbidity (CVD, renal disease, cognitive impairment), and overall life expectancy. Key unanswered questions remain around the additive predictive value of BP trajectories, intergenerational contributions to BP patterns (in utero BP exposure), and potential genetic drivers of BP patterns. The next phase in understanding BP trajectories needs to focus on how best to incorporate this knowledge into clinical care to reduce the burden of hypertensive-related outcomes and improve health equity.

scholarly journals Examining the Effects of the Sacramento Dockless E-Bike Share on Bicycling and Driving

2021 ◽  
Vol 13 (1) ◽  
pp. 368
Author(s):  
Dillon T. Fitch ◽  
Hossain Mohiuddin ◽  
Susan L. Handy
Keyword(s):  
Travel Behavior ◽  
Regression Models ◽  
Population Level ◽  
Panel Survey ◽  
Multilevel Regression ◽  
Combine Data ◽  
Cross Sectional ◽  
Individual Level ◽  
Before And After ◽  
Bike Share

One way cities are looking to promote bicycling is by providing publicly or privately operated bike-share services, which enable individuals to rent bicycles for one-way trips. Although many studies have examined the use of bike-share services, little is known about how these services influence individual-level travel behavior more generally. In this study, we examine the behavior of users and non-users of a dockless, electric-assisted bike-share service in the Sacramento region of California. This service, operated by Jump until suspended due to the coronavirus pandemic, was one of the largest of its kind in the U.S., and spanned three California cities: Sacramento, West Sacramento, and Davis. We combine data from a repeat cross-sectional before-and-after survey of residents and a longitudinal panel survey of bike-share users with the goal of examining how the service influenced individual-level bicycling and driving. Results from multilevel regression models suggest that the effect of bike-share on average bicycling and driving at the population level is likely small. However, our results indicate that people who have used-bike share are likely to have increased their bicycling because of bike-share.

Medication Adherence: Expanding the Conceptual Framework

2021 ◽  
Author(s):  
Marie Krousel-Wood ◽  
Leslie S Craig ◽  
Erin Peacock ◽  
Emily Zlotnick ◽  
Samantha O’Connell ◽  
...  
Keyword(s):  
Older Adults ◽  
Medication Adherence ◽  
Conceptual Framework ◽  
Clinical Outcomes ◽  
Implicit Attitudes ◽  
Explanatory Power ◽  
Population Level ◽  
Time Preferences ◽  
Adherence Behavior ◽  
Individual Level

Abstract Interventions targeting traditional barriers to antihypertensive medication adherence (AHMA) have been developed and evaluated, with evidence of modest improvements in adherence. Translation of these interventions into population-level improvements in adherence and clinical outcomes among older adults remains suboptimal. From the Cohort Study of Medication Adherence among Older adults (CoSMO), we evaluated traditional barriers to AHMA among older adults with established hypertension (N=1544; mean age=76.2 years, 59.5% women, 27.9% Black, 24.1% and 38.9% low adherence by proportion of days covered (i.e., PDC<0.80) and the 4-item Krousel-Wood Medication Adherence Scale (i.e., K-Wood-MAS-4≥1), respectively), finding that they explained 6.4% and 14.8% of variance in pharmacy refill and self-reported adherence, respectively. Persistent low adherence rates, coupled with low explanatory power of traditional barriers, suggest that other factors warrant attention. Prior research has investigated explicit attitudes toward medications as a driver of adherence; the roles of implicit attitudes and time preferences (e.g., immediate versus delayed gratification) as mechanisms underlying adherence behavior are emerging. Similarly, while associations of individual-level social determinants of health (SDOH) and medication adherence are well-reported, there is growing evidence about structural SDOH and specific pathways of effect. Building on published conceptual models and recent evidence, we propose an expanded conceptual framework that incorporates implicit attitudes, time preferences and structural SDOH, as emerging determinants that may explain additional variation in objectively and subjectively measured adherence. This model provides guidance for design, implementation and assessment of interventions targeting sustained improvement in implementation medication adherence and clinical outcomes among older women and men with hypertension.

Are leaders with postgraduate degrees perceived to be more transformational? A quasi-experimental field study

2019 ◽  
Vol 40 (2) ◽  
pp. 259-273 ◽  
Author(s):  
Morris Mendelson ◽  
Jasmine Alam ◽  
Chris Cunningham ◽  
Adam Totton ◽  
Carrie Smith
Keyword(s):  
Transformational Leadership ◽  
Field Study ◽  
Positive Relationship ◽  
Master's Degree ◽  
Leadership Qualities ◽  
Content Type ◽  
Experimental Field ◽  
Strong Positive Relationship ◽  
Quasi Experimental ◽  
Master’S Degree

PurposeTransformational leadership has been shown to have a positive impact on a host of employee level and organizational performance indicators. However, little research has sought to understand some of the antecedents of this style of leadership. The purpose of this paper is to examine the link between having a post-secondary education and perceptions of transformational leadership.Design/methodology/approachData were collected from two surveys issued in a mid-sized energy company located on the eastern seaboard of North America. One-way ANOVA comparing employees’ perceptions of transformational leadership exhibited by their supervisors that either did or did not have a post-graduate degree demonstrated a strong, positive relationship between the attainment of a Master’s degree and perceived levels of transformational leadership qualities.FindingsThe findings of this quasi-experimental field study demonstrated a strong, positive relationship between the attainment of a Master’s degree and perceived levels of transformational leadership qualities.Originality/valueThis study is the first of its kind to demonstrate that more educated managers are generally perceived to be more transformational in their leadership style.

Career Plateau and Turnover Intention in Chinese Employees: Career Anchor as Moderator

2015 ◽  
Vol 43 (5) ◽  
pp. 757-766 ◽  
Author(s):  
Yueran Wen ◽  
Liu Liu
Keyword(s):  
Turnover Intention ◽  
Positive Relationship ◽  
Management Practices ◽  
Career Anchor ◽  
Career Plateau ◽  
Strong Positive Relationship ◽  
High Level ◽  
The Relationship ◽  
Moderating Role

Based on a survey of 147 Chinese employees, we examined the relationship between perceived career plateau and turnover intention, and the moderating role of career anchor in challenge in this process. We hypothesized that perceived career plateau would be positively related to turnover intention, and that this relationship would be stronger in employees with a higher level of career anchor in challenge than in those with a lower level. The results showed that perceived career plateau had a strong positive relationship with turnover intention, especially in employees with a high level of career anchor in challenge. These findings have implications for research in career development and turnover intention, as well as in management practices.

Hubungan Budaya Pengamanan dan Kinerja Bandar Udara dengan Kepuasan Penumpang Angkutan Udara di Bandar Udara Internasional Soekarno - Hatta

WARTA ARDHIA ◽  
2013 ◽  
Vol 39 (2) ◽  
pp. 128-145
Author(s):  
Siti Masrifah
Keyword(s):  
Significant Relationship ◽  
Positive Relationship ◽  
Service Performance ◽  
Air Transport ◽  
Cultural Relations ◽  
Security Culture ◽  
International Airport ◽  
Passenger Satisfaction ◽  
Strong Positive Relationship ◽  
And Performance

This study examined the association of security culture (X1) and the performance of airport services (X2) with air transport passenger satisfaction (Y), either individually or jointly.This study with a sample of 100 respondents passenger air transport, the distribution of questionnaires to terminal 2F domestic at Soekarno Hatta International Airport Cengkareng.Calculation results show a positive and significant relationship shown in securing cultural relations (X1) to the satisfaction of passenger air transport (Y). Airport service performance (X2) to the satisfaction of passenger air transport (Y). The relation security culture and performance of airport service to the satisfaction of the air transport of passengers together.The final results of this study have a strong positive relationship between security culture in air transport passenger satisfaction. Strong positive relationship between performance of airport services in air transport passenger satisfaction. And a strong positive relationship between culture security and performance of airport services to the satisfaction of the air transport of passengers together.Penelitian ini untuk mengetahui hubungan budaya pengamanan (X1) dan kinerja pelayanan bandar udara (X2) dengan kepuasan penumpang angkutan udara (Y), baik secara sendiri-sendiri maupun secara bersama-sama. Penelitian ini dengan jumlah sampel sebanyak 100 responden penumpang angkutan udara, dengan melakukan sebaran kuesioner di terminal 2F domestik Bandar Udara International Soekarno Hatta Cengkareng. Hasil perhitungan menunjukkan hubungan yang positif dan signifikan pada budaya pengamanan (X1) dengan kepuasan penumpang angkutan, hubungan positif dan signifikan antara kinerja pelayanan bandar udara (X2) dengan kepuasan penumpang angkutan udara (Y), serta menghasilkan hubungan positif dan signifikan antara budaya pengamanan (X1) dan kinerja pelayanan Bandar udara (X2) dengan kepuasan penumpang angkutan udara (Y) secara bersama-sama. Hasil akhir penelitian ini mempunyai hubungan positif dan kuat antara budaya pengamanan dengan kepuasan penumpang angkutan udara. Hubungan positif dan kuat antara kinerja pelayanan Bandar udara dengan kepuasan penumpang angkutan udara. Hubungan positif dan kuat antara budaya pengamanan dan kinerja pelayanan Bandar udara dengan kepuasan penumpang angkutan udara secara bersama-sama. Implikasi bagi penyelenggara bandar udara dalam tercapainya kepuasan penumpang angkutan udara dengan memberikan rasa aman, lancar, tertib, dan selamat dalam suatu penerbangan, serta jasa pelayanan bandar udara dengan kebersihan terminal dan ketersediaan fasilitas yang cukup dan baik.

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