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Article ; Online: Lipid mobilization, immune function and the paradigm of vitamin E in transition cows.

Ioannis Politis

International Journal of Health, Animal Science and Food Safety, Vol 3, Iss 1s (2016)

2016

Abstract: The number of metabolic disorders that dairy cows have to cope during the transition to lactation can be divided in three main categories. The first category includes disorders related to abnormal energy metabolism (ketosis, fatty liver, acidosis). The ... ...

Abstract	The number of metabolic disorders that dairy cows have to cope during the transition to lactation can be divided in three main categories. The first category includes disorders related to abnormal energy metabolism (ketosis, fatty liver, acidosis). The second and the third categories include disorders related to mineral metabolism (milk fever) and disorders related directly or indirectly to impaired immune function (mastitis, metritis, retained placenta), respectively. Among the many physiological changes during the transition period, perhaps the most crucial, is an increase in the concentration of plasma non-esterified fatty acids (NEFA). A portion of this increase in NEFA is obligatory and it is under hormonal control while another portion is the result of a situation known as negative energy balance (difference between energy consumed and energy spent). In this presentation I will present data from a collaborative study between the University of Milan and the Agricultural University of Athens which proves that negative correlations exist between blood concentrations of NEFA and β-hydroxybutyrate with α-tocopherol. The adipose tissue contains two main categories of cells: adipocytes and immunocompetent cells mainly monocytes/macrophages. Our research has tested the hypothesis that a cross-talk exists between adipocytes and monocytes/macrophages and this cross-talk is mediated by fatty acids released by adipocytes especially during the transition period. Results indicate that all fatty acids tested (myristic, palmitic, palmitoleic, stearic and oleic) upregulate the expression of numerous pro-inflammatory genes by both monocytes but neutrophils, as well. The longer the carbon chain, the most potent is the effect. Another hypothesis that we have tested is that vitamin E can interfere and block the cross talk between adipocytes and immunocompetent cells. Against this notion, α-tocopherol does not interfere with the effect of fatty acids on expression of pro-inflammatory genes. Thus, fatty acids compromise the ...
Keywords	lipid ; Vitamin E ; immune function ; lactation ; Animal culture ; SF1-1100 ; Ecology ; QH540-549.5 ; Genetics ; QH426-470 ; Economic biology ; QH705-705.5
Subject code	610
Language	English
Publishing date	2016-06-01T00:00:00Z
Publisher	Università degli Studi di Milano
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: A Route Choice Model for the Investigation of Drivers’ Willingness to Choose a Flyover Motorway in Greece

Ioannis Politis / Georgios Georgiadis / Aristomenis Kopsacheilis / Anastasia Nikolaidou / Chrysanthi Sfyri / Socrates Basbas

Sustainability, Vol 15, Iss 4614, p

2023 Volume 4614

Abstract: The constant evolution of many urban areas ultimately reaches a point where the current infrastructure cannot further serve the needs of citizens. In the case of transport networks, congested roads, increased delay, and low level of service are among the ...

Abstract	The constant evolution of many urban areas ultimately reaches a point where the current infrastructure cannot further serve the needs of citizens. In the case of transport networks, congested roads, increased delay, and low level of service are among the indicators of a need for road infrastructure upgrade. Thessaloniki is the second-largest city in Greece with a population of over 1 million inhabitants in its metropolitan area. Currently, a significant share of the city’s traffic demand is served via its ring road, whose capacity is set to be enhanced through the construction of a flyover highway with the simultaneous upgrade of the existing ring road. The current study aims at investigating the key factors determining the final route choice of drivers between the two road axes. To that end, data from a combined revealed and stated preference survey targeting car drivers were collected, which were later exploited as the basis for the development of binary route choice regression and machine learning models. The results reveal that drivers’ choice is affected by criteria such as total travel time, the probability of accident occurrence, and closure time due to accident. The results of this paper could prove beneficial to transport researchers in forecasting drivers’ behavior in terms of route choice and to practitioners during the planning phase of similar infrastructure projects.
Keywords	flyover ; route choice model ; stated preference ; machine learning ; ring road ; artificial neural network ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
Subject code	380
Language	English
Publishing date	2023-03-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Assessing the Environmental and Economic Footprint of Electronic Toll Collection Lanes

Ioannis-Dimosthenis Ramandanis / Ioannis Politis / Socrates Basbas

Sustainability, Vol 12, Iss 9578, p

A Simulation Study

2020 Volume 9578

Abstract: Electronic toll collection (ETC) plays, as part of transport demand management (TDM) measures, an important role in preventing traffic congestion and improving the environmental conditions in urban and rural areas. An attempt is made in the framework of ... ...

Abstract	Electronic toll collection (ETC) plays, as part of transport demand management (TDM) measures, an important role in preventing traffic congestion and improving the environmental conditions in urban and rural areas. An attempt is made in the framework of this paper to evaluate the overall performance of a toll station when a lane is dedicated to ETC. The case study refers to a toll station in the Thessaloniki Metropolitan Area, Greece. Scenarios considered specific traffic characteristics, variable toll booth setups, and different penetration rates of the ETC tag users for car and heavy vehicles. The tool used in the evaluation process was the PTV Vissim traffic simulation software. The operation of the toll station during a specific peak-hour period was simulated with the aid of the specific software. In total, 39 alternative scenarios were developed and compared to determine the level of penetration rate for which the ETC lane would be effective for different toll booth setups. Results showed that when the right lane of the toll station is converted to ETC lane, the penetration rate of this lane must be greater the 15% for the private vehicles and 20% for the heavy goods vehicles (HGV) to reduce traffic congestion and to improve environmental conditions. It was also found that when an additional ETC lane was introduced to the existing toll station set up, traffic congestion and the associated environmental conditions were much improved even for low penetration rates. It must be noticed that the results from the use of discounted cash flow methods like internal rate of return (IRR), net present value (NPV) and benefit–cost ratio (BCR) showed that all economic indicators converge as penetration rate increases in all toll booth setups. Therefore, there is a specific penetration rate threshold above which the economic viability of the investment is secured. These findings can assist the design of an effective policy in terms of the optimized operation of a toll station and sustainable mobility planning.
Keywords	electronic toll collection ; transport demand management ; traffic simulation ; traffic congestion ; environmental conditions ; financial assessment ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
Subject code	380
Language	English
Publishing date	2020-11-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Trip and Personal Characteristics towards the Intention to Cycle in Larnaca, Cyprus

Paraskevas Nikolaou / Socrates Basbas / Ioannis Politis / Georgios Borg

Sustainability, Vol 12, Iss 4250, p

An EFA-SEM Approach

2020 Volume 4250

Abstract: Mobility is one of the most important and challenging aspects that influence climate change, air quality, and especially the quality of citizens’ lives. Therefore, creating sustainable transport solutions makes way for different modes of transport such ... ...

Abstract	Mobility is one of the most important and challenging aspects that influence climate change, air quality, and especially the quality of citizens’ lives. Therefore, creating sustainable transport solutions makes way for different modes of transport such as the bicycle, which is continuously gaining more supporters, due to the health, economic, and environmental benefits that it provides. However, cyclists are facing several barriers (e.g., lack of infrastructure), a fact that keeps away commuters from using a bicycle for their daily trips. Investigating the factors that reflect on the commuters’ intention to use a bicycle is a sine qua non for the promotion of sustainable mobility. Therefore, the objective of this paper is the investigation of the factors that prevent residents with low experience or with no cultural/lifestyle background in regards to cycling from cycling. The case study of the city of Larnaca (Cyprus) is deployed by exploring the socio-demographic and trip characteristics of the city’s residents and their relation with the intention to cycle. A two-step approach is developed, namely Explanatory Factor Analysis (EFA) and Structural Equation Modeling (SEM). Despite the promotion of cycling that education is attempting to do (successfully), other factors (such as age, distance, and time) appear to prevent Larnaca’s residents from cycling. Among the actions that local authorities should undertake is that of safety prevention of the vulnerable users of the road network. This group includes elderly people, who need major encouraging interventions by local policymakers and stakeholders.
Keywords	exploratory factor analysis ; structural equation modeling ; intention ; bicycle ; sustainable mobility ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
Subject code	710
Language	English
Publishing date	2020-05-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: How Does Operational Environment Influence Public Transport Effectiveness? Evidence from European Urban Bus Operators

Georgios Georgiadis / Ioannis Politis / Panagiotis Papaioannou

Sustainability, Vol 12, Iss 4919, p

2020 Volume 4919

Abstract: Public transport systems’ effectiveness is a well-recognized pillar of their sustainability. In this study, we employed order-m efficiency estimators to investigate the effectiveness of 57 bus public transport operators that provide services in both ... ...

Abstract	Public transport systems’ effectiveness is a well-recognized pillar of their sustainability. In this study, we employed order-m efficiency estimators to investigate the effectiveness of 57 bus public transport operators that provide services in both large and medium sized European cities. Their effectiveness was simulated through a tailored production model and was evaluated against critical exogenous variables, which were mostly extracted from Eurostat database. Results showed that the effectiveness of the examined operators is generally satisfactory. Our research suggests that certain exogenous factors significantly affect operators’ effectiveness and thus create either advantageous or disadvantageous operational environments for maintaining public transport sustainability. Among these factors, household size, unemployment and car ownership rates were found to be unfavorable to bus public transport operations. Contrary to them, the presence of university students and metro systems in cities create a favorable operational environment for bus public transport effectiveness. These findings assist in the identification of sustainable development policies that would both contribute to public transport sustainability and to the fulfillment of wider community goals. Our findings also rationalize benchmarking exercises in the public transport industry, since they enable fair performance comparisons between systems that seek to incorporate successful management practices to improve their sustainability.
Keywords	public transport ; conditional non-parametric analysis ; data envelopment analysis ; performance ; exogenous factors ; benchmarking ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
Subject code	380
Language	English
Publishing date	2020-06-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Capturing Twitter Negativity Pre- vs. Mid-COVID-19 Pandemic

Ioannis Politis / Georgios Georgiadis / Aristomenis Kopsacheilis / Anastasia Nikolaidou / Panagiotis Papaioannou

Sustainability, Vol 13, Iss 13356, p

An LDA Application on London Public Transport System

2021 Volume 13356

Abstract: The coronavirus pandemic has affected everyday life to a significant degree. The transport sector is no exception, with mobility restrictions and social distancing affecting the operation of transport systems. This research attempts to examine the effect ...

Abstract	The coronavirus pandemic has affected everyday life to a significant degree. The transport sector is no exception, with mobility restrictions and social distancing affecting the operation of transport systems. This research attempts to examine the effect of the pandemic on the users of the public transport system of London through analyzing tweets before (2019) and during (2020) the outbreak. For the needs of the research, we initially assess the sentiment expressed by users using the SentiStrength tool. In total, almost 250,000 tweets were collected and analyzed, equally distributed between the two years. Afterward, by examining the word clouds of the tweets expressing negative sentiment and by applying the latent Dirichlet allocation method, we investigate the most prevalent topics in both analysis periods. Results indicate an increase in negative sentiment on dates when stricter restrictions against the pandemic were imposed. Furthermore, topic analysis results highlight that although users focused on the operational conditions of the public transport network during the pre-pandemic period, they tend to refer more to the effect of the pandemic on public transport during the outbreak. Additionally, according to correlations between ridership data and the frequency of pandemic-related terms, we found that during 2020, public transport demand was decreased while tweets with negative sentiment were being increased at the same time.
Keywords	COVID-19 ; Twitter ; sentiment analysis ; public transport ; latent Dirichlet allocation ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
Subject code	380
Language	English
Publishing date	2021-12-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Shifting to Shared Wheels

Ioannis Politis / Ioannis Fyrogenis / Efthymis Papadopoulos / Anastasia Nikolaidou / Eleni Verani

Sustainability, Vol 12, Iss 8205, p

Factors Affecting Dockless Bike-Sharing Choice for Short and Long Trips

2020 Volume 8205

Abstract: In this paper, we explore users’ intentions to use bike-sharing systems (BSS) compared to traditional competitive transport modes—private car, bus and walking. Fueled by the increasingly rampant growth of shared economy and Information and Communication ... ...

Abstract	In this paper, we explore users’ intentions to use bike-sharing systems (BSS) compared to traditional competitive transport modes—private car, bus and walking. Fueled by the increasingly rampant growth of shared economy and Information and Communication Technology (ICT), shared mobility is gaining increasing traction. The numbers of shared mobility schemes are rapidly growing worldwide and are accompanied by changes in the traditional vehicle ownership model. In order to pinpoint the factors that strongly affect the willingness to use BSS, a stated preference survey among car and bus users as well as pedestrians was designed and conducted. Binary logit models of the choice between the currently preferred transportation modes and BSSs were developed, for short and long-duration trips, respectively. The results highlight a distinctive set of factors and patterns affecting the willingness to adopt bike-sharing: choice is most sensitive to travel time and cost of the competitive travel options. In general, users are more willing to make the switch to a BSS, especially for short trip durations, when their typical mode of transport becomes more expensive. Bike-sharing also seems to be a more attractive option for certain user socio-demographic groups per mode and trip duration (age, education level, employment status, household income). Trip characteristics such as trip purpose and frequency were also found to affect the willingness to choose BSS. In general, BSS seem to mainly attract bus users and pedestrians, while car users may use BSS more sparingly, mainly for commuting purposes.
Keywords	sharing economy ; bike-sharing ; stated preference ; discrete choice models ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
Subject code	380
Language	English
Publishing date	2020-10-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Dilemma Zone

Panagiotis Papaioannou / Efthymis Papadopoulos / Anastasia Nikolaidou / Ioannis Politis / Socrates Basbas / Eleni Kountouri

Safety, Vol 7, Iss 1, p

Modeling Drivers’ Decision at Signalized Intersections against Aggressiveness and Other Factors Using UAV Technology

2021 Volume 11

Abstract: Intersection safety and drivers’ behavior are strongly interrelated, especially when the latter are located in dilemma zone. This paper explores, among others, the main factors affecting driver behavior, such as distance to stop line, approaching speed ... ...

Abstract	Intersection safety and drivers’ behavior are strongly interrelated, especially when the latter are located in dilemma zone. This paper explores, among others, the main factors affecting driver behavior, such as distance to stop line, approaching speed and acceleration/deceleration, and two additional factors, namely, driver’s aggressiveness and driver’s relative position at the onset of the yellow signal. Field data were collected using unmanned aerial vehicle (UAV) technology. Two binary choice models were developed, the first relying on observed data and the latter enriched by the latent factor drivers’ aggressiveness and the vehicles’ relative position. Drivers were classified to aggressive and non-aggressive ones using a latent class model that combined approaching speed and acceleration/deceleration data. Drivers were further grouped according to their expected reaction/decision to stop or cross the intersection in relation to their relative position. Both models equally explain drivers’ decisions adequately, but the second one offers additional explanatory power attributed to aggressiveness. Being able to identify the level of aggressiveness among the drivers enables the calculation of the probability that drivers will cross the intersection even if caught in a dilemma zone or in a zone in which the obvious decision is to stop. Such findings can be valuable when designing a signalized intersection and the traffic time settings, as well as the posted speed limit.
Keywords	UAV video-observed vehicle trajectory data ; driver behavior ; signalized intersection ; dilemma zone ; choice model ; latent class model ; Industrial safety. Industrial accident prevention ; T55-55.3 ; Medicine (General) ; R5-920
Subject code	380
Language	English
Publishing date	2021-02-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Utilization of 2D and 3D cell cultures for the modelling of intramammary infection in sheep

Eleni Dalaka / Demetrios Vassilakos / Georgios C. Stefos / Aphrodite I. Kalogianni / Irida Palamidi / Athanasios I. Gelasakis / Ioannis Politis / Georgios Theodorou

Frontiers in Animal Science, Vol

2022 Volume 3

Abstract: Ovine mastitis is defined as the inflammation of the sheep udder, most commonly caused in response to intramammary infections. Based on the occurrence of clinical signs, mastitis is characterized as either clinical or subclinical (SCM). The impact of ... ...

Abstract	Ovine mastitis is defined as the inflammation of the sheep udder, most commonly caused in response to intramammary infections. Based on the occurrence of clinical signs, mastitis is characterized as either clinical or subclinical (SCM). The impact of ovine SCM on the overall sustainability of dairy sheep farms has been substantially documented underpinning the significance of efficient diagnosis. Although SCM can be detected in cows, the performance and the validity of the methods used do not transfer in dairy sheep. This fact challenges the development of evidence-based ovine udder health management protocols and renders the detection and control of ovine mastitis rather problematic. Currently, cell culture-based models are being successfully used in biomedical studies and have also been effectively used in the case of bovine mastitis. The objective of the present study was to culture ovine primary mammary cells for the development of 2D and 3D cell culture-based models for the study of ovine mammary gland and to focus on the first stages of the intramammary infection by common mastitis-inducing pathogens. Cells were infected by E. coli and S. aureus mimicking the first stages of natural intramammary infections. The secreted proteins were subjected to mass-spectrometry resulting in the identification of a total of 79 distinct proteins. Among those, several had already been identified in healthy or mastitic milk, while others had not been previously detected for in the ovine mammary secretome. Our results suggest that the development of cell-based models for studying specific stages of intramammary infection has the potential to be beneficial for the udder health management in dairy sheep.
Keywords	cell culture models ; ovine ; in vitro infection ; proteomics ; intramammary infections ; Veterinary medicine ; SF600-1100
Subject code	630
Language	English
Publishing date	2022-11-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: The Effects of Replacing Soybean Meal with Rapeseed Meal, Cottonseed Cake, and Fava Beans on the Milk Yield and Quality Traits in Milking Ewes

Aphrodite I. Kalogianni / Marios Moschovas / Foteini Chrysanthakopoulou / Thomai Lazou / Georgios Theodorou / Ioannis Politis / Ioannis Bossis / Athanasios I. Gelasakis

Animals, Vol 12, Iss 274, p

2022 Volume 274

Abstract: The replacement of soybean meal (SBM) from intensively reared dairy sheep diets has emerged as a significant challenge for sustainable production. However, the effects of this replacement on milk production have not been sufficiently elucidated. The ... ...

Abstract	The replacement of soybean meal (SBM) from intensively reared dairy sheep diets has emerged as a significant challenge for sustainable production. However, the effects of this replacement on milk production have not been sufficiently elucidated. The objective of this study was to prospectively assess the effects of replacing SBM with a mixture of alternative protein sources on the milk yield (MY) and the milk quality traits (MQT) in intensively reared dairy sheep. A total of 112 multiparous, purebred milking ewes of the Chios and Frizarta breeds, from two intensive dairy sheep farms, were involved in the study, postweaning, and were assigned to either the control (CR) or the experimental ration (ER) group. In the ER, 3/4 of the SBM was replaced by a mixture of rapeseed meal, cottonseed cake, and fava beans, producing a ration of a similar nutritional value. MY, MQT, and body condition scores were recorded for each individual ewe monthly for a period of 4 months during lactation. The experimental ration was associated with beneficial effects on daily and 100-day fat yields and on the electrical conductivity of milk as an improved udder health status indicator, with no adverse effects on any of the rest of the studied milk production traits.
Keywords	soybean meal ; fava beans ; rapeseed meal ; cottonseed cake ; dairy sheep ; milk yield ; Veterinary medicine ; SF600-1100 ; Zoology ; QL1-991
Subject code	630
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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