A model to account for the consequences of host nutrition on the outcome of gastrointestinal parasitism in sheep: model evaluation

Parasitology ◽  
2007 ◽  
Vol 134 (9) ◽  
pp. 1279-1289 ◽  
Author(s):  
D. VAGENAS ◽  
S. C. BISHOP ◽  
I. KYRIAZAKIS
Keyword(s):  
Mathematical Model ◽  
Worm Burden ◽  
Management Strategies ◽  
Sensitivity Analyses ◽  
Sheep Model ◽  
Host Nutrition ◽  
Gastrointestinal Parasitism ◽  
Different Characteristics ◽  
Nutritional Strategies ◽  
Different Levels

SUMMARYThis paper describes sensitivity analyses and expectations obtained from a mathematical model developed to account for the effects of host nutrition on the consequences of gastrointestinal parasitism in sheep. The scenarios explored included different levels of parasitic challenge at different planes of nutrition, for hosts differing only in their characteristics for growth. The model was able to predict the consequences of host nutrition on the outcome of parasitism, in terms of worm burden, number of eggs excreted per gram faeces and animal performance. The model outputs predict that conclusions on the ability of hosts of different characteristics for growth to cope with parasitism (i.e. resistance) depend on the plane of nutrition. Furthermore, differences in the growth rate of sheep, on their own, are not sufficient to account for differences in the observed resistance of animals. The model forms the basis for evaluating the consequences of differing management strategies and environments, such as breeding for certain traits associated with resistance and nutritional strategies, on the consequences of gastrointestinal parasitism on sheep.

scholarly journals Nanotechnology and Reproductive Management of Farm Animals: Challenges and Advances

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1932
Author(s):  
Nesrein M. Hashem ◽  
Antonio Gonzalez-Bulnes
Keyword(s):  
Management Strategies ◽  
Farming Systems ◽  
Biological Molecules ◽  
Farm Animals ◽  
Physiological Status ◽  
Livestock Farming ◽  
Reproductive Management ◽  
Livestock Farming Systems ◽  
Reproductive Disease ◽  
Nutritional Strategies

Reproductive efficiency of farm animals has central consequences on productivity and profitability of livestock farming systems. Optimal reproductive management is based on applying different strategies, including biological, hormonal, nutritional strategies, as well as reproductive disease control. These strategies should not only guarantee sufficient reproductive outcomes but should also comply with practical and ethical aspects. For example, the efficiency of the biological- and hormonal-based reproductive strategies is mainly related to several biological factors and physiological status of animals, and of nutritional strategies, additional factors, such as digestion and absorption, can contribute. In addition, the management of reproductive-related diseases is challenged by the concerns regarding the intensive use of antibiotics and the development of antimicrobial resistant strains. The emergence of nanotechnology applications in livestock farming systems may present innovative and new solutions for overcoming reproductive management challenges. Many drugs (hormones and antibiotics), biological molecules, and nutrients can acquire novel physicochemical properties using nanotechnology; the main ones are improved bioavailability, higher cellular uptake, controlled sustained release, and lower toxicity compared with ordinary forms. In this review, we illustrate advances in the most common reproductive management strategies by applying nanotechnology, considering the current challenges of each strategy.

scholarly journals Step-by-step control of target efficiency indices of the control and measuring equipment stock applied in construction and housing and communal services

2018 ◽  
Vol 170 ◽  
pp. 01010 ◽  
Author(s):  
Rustam Khayrullin ◽  
Pavel Ivanov
Keyword(s):  
Mathematical Model ◽  
Finite Difference ◽  
Measuring Equipment ◽  
Technical Condition ◽  
Measuring Instruments ◽  
Finite Difference Equations ◽  
Target Values ◽  
The Mathematical Model ◽  
Step Control ◽  
Different Levels

The mathematical model is considered for the formation and implementation of development strategies of the stock of control and measuring instruments (CMI) applied in construction and housing and communal services(HCS), and step-by-step control of efficiency target values of the stock. The model is based on a system of finite - difference equations describing the change of number of the CMI samples with different levels of technical perfection and technical condition at each planning interval. The model allows calculating the required number of CMI for procurement and repairs in the various groups for provide target values of efficiency indices at each planning interval. Controller is number of modern CMI samples for procurement and number of modern and obsolete faulty CMI samples for the repairs. The results of calculations are presented.

The effect of changes in nutrient demand on gastrointestinal parasitism in lactating rats

2005 ◽  
Vol 2005 ◽  
pp. 12-12 ◽  
Author(s):  
H. N. Normanton ◽  
J. G. M. Houdijk ◽  
N. S. Jessop ◽  
D. P. Knox ◽  
I. Kyriazakis
Keyword(s):  
Food Intake ◽  
Immune Responses ◽  
Worm Burden ◽  
Nutrient Supply ◽  
Rodent Model ◽  
Nutrient Demand ◽  
Per Se ◽  
Immunological Changes ◽  
Gastrointestinal Parasitism ◽  
Protein Supply

A recent study carried out by Houdijk et al (2005), used a rodent model to assess whether a reduction in protein scarcity during lactation resulted in a reduced degree of parasitism. Feeding high protein foods resulted in a reduced worm burden, but was confounded with increased food intake per se. Therefore, effects observed on parasitism may not necessarily have been associated with an increased protein supply, but with changes in the gut environment due to the increased food intake. Before this model can be used to assess the underlying immune responses, further work is needed to verify that the effects observed are indeed related to changes in nutrient supply. This experiment aimed to provide further evidence on the nutritional control of parasitism during lactation by manipulating nutrient demand. It was expected that the latter would not be associated with changes in food intake per se and results could therefore be used to exclude the influence of non-immunological changes in the gut environment as a contributing factor of reduced parasitism.

scholarly journals Efecto de la Escolarización en la Producción de Relaciones Causales y Contracausales: Evidencia Psicolingüística para el Ámbito Educativo

2016 ◽  
Vol 6 (3) ◽  
pp. 258
Author(s):  
Gabriela Mariel Zunino
Keyword(s):  
Empirical Evidence ◽  
Language Processing ◽  
Formal Education ◽  
Educational Process ◽  
Semantic Relations ◽  
Practical Application ◽  
Discourse Comprehension ◽  
Educational Processes ◽  
Different Characteristics ◽  
Different Levels

In order to promote the practical application of psycholinguistic data in educational fields and expecting that this transfer would enhance the development of both the pedagogical field and the investigation in experimental psycholinguistics, we present two experiments to analyse the production of semantic relations in discourse, especially the causality/countercausality dimension. We found that the pattern of causal advantage is cross-wise and consistent in subjects with different levels of formal education, so it could be a suitable scaffold to develop other aspects of discourse comprehension and production. We compare our results with previous findings about discourse comprehension and interpret the data in the framework of educational processes. To use of empirical evidence about language processing on educational fields allows not only to review specific issues such as the characteristics of teaching materials, but also to improve educational process in a comprehensive way, making possible to adapt different approaches to populations with different characteristics.

Simulation of COVID-19 indoor emissions from coughing and breathing with air conditioning and mask protection effects

2021 ◽  
pp. 1420326X2110395 ◽  
Author(s):  
Carlo Cravero ◽  
Davide Marsano
Keyword(s):  
Air Conditioning ◽  
Vaccination Campaign ◽  
Ventilation System ◽  
Management Strategies ◽  
Air Conditioning System ◽  
Beneficial Effects ◽  
Mass Vaccination Campaign ◽  
Future Events ◽  
System Configurations ◽  
Different Characteristics

The COVID-19 infection has emerged as a disruptive pandemic at worldwide level. The study of the mechanism of contagion is one of the greatest challenges before a mass vaccination campaign that would protect populations. The study can support the development of knowledge and tools to develop possible strategies for containing its spread in future events. The saliva droplet aerosol expelled during breathing or coughing is the main cause for the propagation of the SARS-Cov-2. In this work, a URANS CFD approach was used to simulate the dispersion from the mouth of these particles in closed environments. The air conditioning system was considered. The conditions were varied to determine their impact on the diffusion of the aerosol. Lagrangian and Eulerian numerical approaches were used to model the coughing and the breathing events. These were validated with the puff theory, numerical and experimental results. A realistic case of a meeting room with two persons was simulated. Different characteristics of the expulsed aerosols and different ventilation system configurations were considered to demonstrate how these simulations can support management strategies for indoor occupation. Finally, the effect of the protective mask was introduced to quantify its beneficial effects to support safe indoor occupation.

Evolution and Adaptation of Forest and Crop Pathogens in the Anthropocene

2020 ◽  
pp. PHYTO-08-20-035
Author(s):  
Pauline Hessenauer ◽  
Nicolas Feau ◽  
Upinder Gill ◽  
Benjamin Schwessinger ◽  
Gurcharn S. Brar ◽  
...  
Keyword(s):  
Population Genomics ◽  
Production Systems ◽  
Management Strategies ◽  
Forest Trees ◽  
Forest Production ◽  
Population Genomic ◽  
Genomic Studies ◽  
Pathogen Populations ◽  
Different Characteristics ◽  
Global Food

Anthropocene marks the era when human activity is making a significant impact on earth, its ecological and biogeographical systems. The domestication and intensification of agricultural and forest production systems have had a large impact on plant and tree health. Some pathogens benefitted from these human activities and have evolved and adapted in response to the expansion of crop and forest systems, resulting in global outbreaks. Global pathogen genomics data including population genomics and high-quality reference assemblies are crucial for understanding the evolution and adaptation of pathogens. Crops and forest trees have remarkably different characteristics, such as reproductive time and the level of domestication. They also have different production systems for disease management with more intensive management in crops than forest trees. By comparing and contrasting results from pathogen population genomic studies done on widely different agricultural and forest production systems, we can improve our understanding of pathogen evolution and adaptation to different selection pressures. We find that in spite of these differences, similar processes such as hybridization, host jumps, selection, specialization, and clonal expansion are shaping the pathogen populations in both crops and forest trees. We propose some solutions to reduce these impacts and lower the probability of global pathogen outbreaks so that we can envision better management strategies to sustain global food production as well as ecosystem services.

scholarly journals Improving the Measurement of Functional Somatic Symptoms With Item Response Theory

Assessment ◽  
2020 ◽  
pp. 107319112094715 ◽  
Author(s):  
Angélica Acevedo-Mesa ◽  
Jorge Nunes Tendeiro ◽  
Annelieke Roest ◽  
Judith G. M. Rosmalen ◽  
Rei Monden
Keyword(s):  
Item Response Theory ◽  
Item Response ◽  
Somatic Symptoms ◽  
Sensitivity Analyses ◽  
Symptom Checklist ◽  
Methodological Issues ◽  
Response Theory ◽  
Adult Participants ◽  
Severity Levels ◽  
Different Levels

More than 40 questionnaires have been developed to assess functional somatic symptoms (FSS), but there are several methodological issues regarding the measurement of FSS. We aimed to identify which items of the somatization subscale of the Symptom Checklist–90 (SCL-90) are more informative and discriminative between persons at different levels of severity of FSS. To this end, item response theory was applied to the somatization scale of the SCL-90, collected from a sample of 82,740 adult participants without somatic conditions in the Lifelines Cohort Study. Sensitivity analyses were performed with all the participants who completed the somatization scale. Both analyses showed that Items 11 “feeling weak physically” and 12 “heavy feelings in arms or legs” were the most discriminative and informative to measure severity levels of FSS, regardless of somatic conditions. Clinicians and researchers may pay extra attention to these symptoms to augment the assessment of FSS.

scholarly journals Symposium 5: Joint BAPEN and Nutrition Society Symposium on ‘Feeding size 0: the science of starvation’ Severe malnutrition: therapeutic challenges and treatment of hypovolaemic shock

2009 ◽  
Vol 68 (3) ◽  
pp. 274-280 ◽  
Author(s):  
Kathryn Maitland
Keyword(s):  
District Hospital ◽  
Fluid Management ◽  
Management Strategies ◽  
Case Fatality ◽  
Antimicrobial Treatment ◽  
Severe Malnutrition ◽  
Society Symposium ◽  
Life Threatening ◽  
Systematic Failure ◽  
Nutritional Strategies

The systematic failure to recognise and appropriately treat children with severe malnutrition has been attributed to the elevated case-fatality rates, often as high as 50%, that still prevail in many hospitals in Africa. Children admitted to Kilifi District Hospital, on the coast of Kenya, with severe malnutrition frequently have life-threatening features and complications, many of which are not adequately identified or treated by WHO guidelines. Four main areas have been identified for research: early identification and better supportive care of sepsis; evidence-based fluid management strategies; improved antimicrobial treatment; rational use of nutritional strategies. The present paper focuses on the identification of children with sepsis and on fluid management strategies.

A simple approach for dealing with dynamics and uncertainty in fisheries with heterogeneous resource and effort distribution

2004 ◽  
Vol 55 (3) ◽  
pp. 249 ◽  
Author(s):  
J. C. Seijo ◽  
E. P. Pérez ◽  
J. F. Caddy
Keyword(s):  
Risk Aversion ◽  
Negative Binomial ◽  
Management Strategies ◽  
Spatial Allocation ◽  
Surf Clam ◽  
Spatially Distributed ◽  
Imperfect Knowledge ◽  
States Of Nature ◽  
Allocation Decisions ◽  
Different Levels

Most fisheries models are based on dynamic pool assumptions. For sedentary and sessile species, these assumptions are inadequate, because they are spatially distributed in patches that vary in size, density and age structure. A simple bioeconomic model, negative binomial (NEGBIN), is proposed; this model relaxes the dynamic pool assumption without entering into the complexities of a geographically structured model. NEGBIN assumes a probability density function (the negative binomial), to describe heterogeneity in the density distribution over the population range. The model incorporates decision theory and different levels of risk aversion in resource management. The uncertainty associated with alternative fishing strategies, given imperfect knowledge about virgin stock biomass, is also included in the analysis. The model is applied to the Mesodesma donacium (surf clam) fishery in the central northern zone of Chile (South America). Alternative management strategies are evaluated with different levels of risk aversion. In the fisheries literature to date, this approach to evaluating the uncertainty associated with spatial allocation decisions has been rare. It is suggested that this kind of analysis, whether accompanied by quantitative probabilities of alternative states of nature or not, is an alternative way of dealing with risk and uncertainty in spatial allocation decisions.

The use of service channels by citizens in the Netherlands: implications for multi-channel management

2008 ◽  
Vol 74 (1) ◽  
pp. 95-110 ◽  
Author(s):  
Willem Pieterson ◽  
Wolfgang Ebbers
Keyword(s):  
Empirical Studies ◽  
Management Strategies ◽  
Personal Characteristics ◽  
Channel Management ◽  
Service Channel ◽  
Channel Integration ◽  
Governmental Organizations ◽  
Traditional Service ◽  
Different Characteristics ◽  
Service Channels

Many governmental organizations are changing their service channel management strategies to multi-channel management. However, very few empirical studies exist that explore how these multi-channel strategies should be shaped. In this article we test a number of hypotheses on citizens' channel use behaviour and the determinants of this behaviour. Further, we take into account the differences between citizens with and without a personal computer. In our conclusions we call for multi-channel strategies that do not only incorporate the features of service channels and the front—back office integration, but also deal with personal characteristics and task characteristics. Further, digital divide issues still influence channel usage by citizens, so it is necessary to keep all channels open for citizens. Finally, our study reveals that multi-channelling is a very complex subject on which research is still in its infancy. Points for practitioners • Multi-channel management may benefit most from channel integration. • Channels have different characteristics that render them suitable for different (parts of) services. • Computer `have-nots' still rely on traditional service channels, so these should remain accessible.

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