Nutritional sensitivity of periparturient breakdown of immunity to gastrointestinal nematode parasites in mammals

Mammals usually develop immunity to gastrointestinal nematode parasites. However, during late pregnancy and lactation, this immunity often breaks down, resulting in elevated levels of parasitism. This periparturient relaxation of immunity (PPRI) renders lactating hosts main sources of infection for their parasite-naïve offspring, and may have a nutritional basis. Results of studies on parasitized hosts suggest that both crude protein (CP) and metabolizable energy (ME) supply may be important in regulating the degree of PPRI by affecting the immune response towards parasites. However there is a scarcity of data supporting such a role for ME in periparturient hosts, while there is sufficient evidence to support the view that CP in general, and amino acids are potent immunonutrients in various disease states (Chapter 1). In the first experiment (Chapter 2) I seperated effects of CP and ME on PPRI by feeding parasitized lactating rats at two levels of ME supply and one of three levels of CP supply. The results show that PPRI is sensitive to CP scarcity, and not to moderate ME scarcity. Increasing CP supply improved lactational performance and reduced PPRI, as observed by reduced worm burdens. In the second experiment (Chapter 3) I examined the rate at which improved nutrition can restore immunity by feeding low protein diets to rats nursing high number of pups, and then reduced litter size in a sub-group so that host nutritional status would change from scarce to adequate. The egg production of the parasite population of the latter group reduced within days to similarly low levels as rats that had always reared low number of pups and this was associated with an increased number of musosal mast cells and increased dam weight gain. Since host responses to dietary CP are almost by ii definition responses to essential amino acids, the third experiment assessed the sensitivity of PPRI to methionine and leucine deficiency (Chapter 4). The latter resulted in increased worm burdens and egg production to similar levels when low protein diets are fed and imposed penalties in lactational performance. Finally, in the fourth experiment it was investigated whether similar outcomes can be expected in periparturient ruminant hosts by supplementing sheep with field beans, which are deficient in methionine, instead of soybean meal (Chapter 5). Indeed, feeding high protein diets based on field beans was less effective in reducing the worm egg excretion and improving lactational performance. The data from this thesis (Chapter 6) provide novel information on the nutritional basis of PPRI, showing that the latter can be rapidly reduced through improved protein nutrition. This may be seen as a response to the protein quality of the diet and the supply of amino acids in optimum quantities. These results have implications for parasite control strategies in farm animals

Combined Ground Deformation Study Of Broader Area Of Patras Gulf (W. Greece) Using PSI-WAP, DGPS And Seismicity Analyses

Long-term ground deformation monitoring using the Persistent Scatterer Interferometry Wide Area Product (PSI-WAP) technique for the period 1992-2003, combined with Differential GPS measurements and seismicity analysis has provided useful information about the tectonic motions of the tectonically complex area of Patras Gulf (Western Greece), and lead to new insights on the geotectonic regime of this region. Descending ERS radar images were used to compile the PSI-WAP product that has been calibrated using the absolute velocity field of available GPS stations in the area. It has been found that the deformation of the southern part of Patras Gulf near the coastline has been characterized by considerable subsidence (>-5mm/yr), where unconsolidated sediments usually prevail, compared to the northern part of the gulf. Significant subsidence has also been identified in areas along the down-throw side of possible faults, as well as areas where extensive ground water pumping has occurred for irrigation. These results correlate well with local GPS and seismicity data

Diagnosis of sub-clinical coccidiosis in fast growing broiler chickens by MicroRNA profiling

Coccidiosis in broiler chickens, caused by infection with Eimeria spp. remains one of the most economically important production diseases. Development of a genetic biomarker panel of sub-clinical infection would be an important biological tool for the management of broiler flocks. We analysed expression of MicroRNAs (miRNAs) to determine the potential for these in diagnosing coccidiosis in broiler flocks. miRNA expression, in the ilea of Ross 308 broilers, was compared between chickens naturally clinically or sub-clinically infected with Eimeria maxima and Eimeria acervulina using NextSeq 500 sequencing. 50 miRNAs with greatest coefficient of variance were determined and principal component analysis showed that these miRNAs clustered within the clinical and sub-clinical groups much more closely than uninfected controls. Following false detection rate analysis and quantitative PCR we validated 3 miRNAs; Gallus gallus (gga)-miR-122-5p, gga-miR-205b and gga-miR-144-3p, which may be used to diagnose sub-clinical coccidiosis

Dietary vitamin D improves performance and bone mineralisation, but increases parasite replication and compromises gut health in Eimeria infected broilers

Coccidial infections may reduce fat soluble vitamin status and bone mineralisation in broiler chickens. We hypothesised that broilers infected with Eimeria maxima would benefit from increased dietary supplementation with vitamin D (vitD) or with 25-OH-D3 (25D3). Male Ross 308 chickens were assigned to diets with low (L) or commercial (M) vitD levels (1000 vs 4000 IU/kg) supplemented as D3 or 25D3. At d11 of age birds were inoculated with water (C) or 7000 E. maxima oocysts (I). Pen performance was calculated over the early (d1 - 6), acute (d7 - 10) and recovery periods (d11 - 14) post-infection (pi). At the end of each period 6 birds per treatment were dissected to assess long bone mineralisation, plasma levels of 25D3, calcium and phosphorus, and intestinal histomorphometry. Parasite replication and transcription of cytokines IL-10 and IFN-γ were assessed at d6 pi using quantitative PCR. Performance, bone mineralisation and plasma 25D3 levels were significantly reduced during infection (P < 0.05). M diets or diets with 25D3 raised plasma 25D3, improved performance and aspects of mineralisation (P < 0.05). Offering L diets compromised feed efficiency pi, reduced femur breaking strength and plasma phosphorous levels at d10 pi in I birds (P < 0.05). Contrastingly, offering M diets or diets with 25D3 resulted in higher parasite loads (P < 0.001) and reduced jejunal villi length at d10 pi (P < 0.01), with no effect on IL-10 or IFN-γ transcription. Diets with 4000 IU/kg vitD content or with 25D3 improved performance and mineralisation, irrespective of infection status, whilst 4000 IU/kg levels of vitD further improved feed efficiency and mineralisation in the presence of a coccidial infection

Effects of controlled dehydration on sleep quality and quantity: A polysomnographic study in healthy young adults

Dehydration is associated with several alternations in body homeostasis involving both physiological and mental aspects. In addition some studies have reported a negative effect of dehydration on subjectively assessed sleep-related parameters. The aim of the current study was to examine for the first time the effect of controlled dehydration on sleep quality and quantity using the gold-standard method of polysomnography. Twelve healthy male volunteers participated in this study (23.4 ± 0.8 years). Participants performed an in-house full polysomnographic assessment in two different occasions taking place in random order: (i) in a dehydrated state; and (ii) in a euhydrated state. In the dehydration scenario, the participants were allowed to consume only 1.25 L of non-caffeinated fluids, while during the euhydrated state participants had to drink at least 3 L of non-caffeinated fluids during the last 24 hr before the polysomnographic study. Urine specific gravity was assessed by refractrometry on collection day in order to assess hydration status. Participants who did not fulfil the hydration criteria were rescheduled. All participants successfully completed the two polysomnographic studies without any complaints or adverse effects reported. No significant differences were found in any of the examined indices of sleep quality and quantity between the dehydration and euhydration scenarios (p > .05). This is the first study to show that controlled mild dehydration does not seem to affect sleep quality and quantity in young healthy adults. More research is necessary to further verify these conclusions and assess whether other parameters are involved in the manifestation of sleep disturbances

Restless legs syndrome in Multiple Sclerosis patients: a contributing factor for fatigue, impaired functional capacity, and diminished health-related quality of life

Objectives Restless legs syndrome (RLS) symptoms are common in Multiple Sclerosis (MS) patients. The aim of the current study was to examine for the first time whether RLS could affect the functional capacity and various contributing parameters related to quality of life and fatigue in MS patients. Methods According to their RLS status, 50 relapsing-remitting MS patients were divided into the RLS (n = 10) and non-RLS groups (n = 40). Specific questionnaires were used in order to assess the health-related quality of life (HRQoL), fatigue levels, sleep quality, daily sleepiness, and depression symptoms of the patients. Functional capacity was examined using a battery of functional tests. Total body and visceral fat levels were assessed via bioelectrical impedance analyzers. Results Sleep quality, depression, fatigue, and HRQoL levels were found to be significantly worse in the patients with RLS compared to their free-RLS counterparts (P < 0.05). In addition, patients with RLS were found to exhibit further impairments in their performance in various functional tests related mainly with strength levels of lower extremities (P < 0.05). Finally, the patients with RLS were found to have significantly higher both total and trunk fat levels compared to patients without RLS (P < 0.05). A strong correlation was observed between the severity of RLS symptoms, sleep quality, fatigue, and QoL levels. Discussion It seems that RLS contributes even further to impairments on sleep quality, fatigue, functional capacity, and therefore HRQoL levels in relapsing-remitting MS patients, whilst for the first time a link between high fat levels has been revealed

Avaliação de um extrato vegetal na dieta sobre o comportamento produtivo de suínos estressados pelo calor

The exposure of pigs to heat stress (HS) affects the integrity of intestinal epithelia, compared to thermal neutral (TN) pigs, partially due to overproduction of free radicals. Herbal extracts (HE) from Capsicum spp., Pipper nigrum y Zingiber officinales possess antioxidant activity. The effect of adding this HE to the diet was analyzed on performance of 42 pigs (27±3 kg). The treatments were: TN-C, TN pigs with control diet, TN-P, pigs with control diet plus 0.02% HE; HS-C, HS pigs with control diet; and HS-P, HS pigs with control diet plus 0.02% HE. The experiment consisted of two periods; in period 1, all pigs were adapted to the control diet during 8 days under TN conditions, followed by a 7-day experimental period. Daily weight gain and feed intake were higher (P &lt;0.05), and feed conversion ratio tended (P&lt;0.10) to improve in HS-HE pigs compared to HS-C pigs. In conclusion, adding HE to the diet can improve some productive parameters in pigs exposed to HS conditions.La exposición de cerdos a estrés por calor (EC), en comparación con termo neutralidad (TN) afecta la integridad del epitelio intestinal, en parte debido a la sobreproducción de radicales libres. Extractos de hierbas (EH) como Capsicum spp., Pipper nigrum y Zingiber officinales poseen actividad antioxidante. Se evaluó el efecto de adicionar un extracto EH a la dieta en el desempeño productivo de 42 cerdos (27±3 kg) en EC. Los tratamientos fueron: TN-T, cerdos en TN alimentados con dieta testigo; EC-T y EC-EH, cerdos en EC alimentados con dieta testigo sin o con 0.2 % de EH. El experimento consistió de dos periodos; en periodo 1, todos los cerdos tuvieron 8 días de adaptación a la dieta testigo en TN, seguido del periodo experimental de 7 días. La ganancia de peso y consumo de alimento fueron mayores (P &lt;0.05), y la conversión alimenticia tendió a ser mejor (P&lt;0.10) en cerdos EC-EH que en cerdos EC-T. En conclusión, la adición del EH puede contribuir a mejorar algunos parámetros productivos cuando los cerdos están expuestos a EC.A exposição de suínos ao estresse térmico (CE), em comparação com a termoneutralidade (TN), afeta a integridade do epitélio intestinal, em parte devido à superprodução de radicais livres. Extratos de ervas (EH) como Capsicum spp., Pipper nigrum e Zingiber officinales possuem atividade antioxidante. Avaliou-se o efeito da adição de extrato de EH à dieta sobre o desempenho produtivo de 42 suínos (27±3 kg) em EC. Os tratamentos foram: TN-T, suínos em TN alimentados com dieta controle; EC-T e EC-EH, suínos em EC alimentados com dieta controle sem ou com 0,2% de EH. O experimento consistiu em dois períodos; No período 1, todos os suínos tiveram 8 dias de adaptação à dieta controle em TN, seguido do período experimental de 7 dias. O ganho de peso e o consumo de ração foram maiores (P &lt; 0,05) e a conversão alimentar tendeu a ser melhor (P &lt; 0,10) em porcos EC-EH do que em porcos EC-T. Em conclusão, a adição de EH pode contribuir para melhorar alguns parâmetros produtivos quando os suínos são expostos a CE

Μελέτη της συμβολής τεχνολογιών υδρογόνου στη βελτίωση της ποιότητας ισχύος αιολικού πάρκου διασυνδεδεμένου στο δίκτυο και στην αποθήκευση ενέργειας υβριδικού σταθμού παραγωγής

107 σ.Οι τεχνολογίες υδρογόνου αποτελούν μια εναλλακτική δυνατότητα υπό εξέταση για την επίλυση των σύγχρονων ενεργειακών προβλημάτων. Η ηλεκτρόλυση μπορεί να παράξει υδρογόνο κατάλληλης καθαρότητας ώστε να αξιοποιηθεί από κυψέλες καυσίμου και ο συνδυασμός τους με ανανεώσιμες πηγές ενέργειας συνιστούν αντικείμενο διερεύνησης διεθνώς. Με τη ραγδαία ανάπτυξη των αιολικών πάρκων στα σύγχρονα συστήματα ηλεκτρικής ενέργειας, ο συνδυασμός ανεμογεννητριών και ηλεκτρολυτών προσελκύει σημαντικό ενδιαφέρον. Η αυξανόμενη διείσδυση αιολικής ενέργειας συνοδεύεται με την επίλυση προβλημάτων στην ποιότητα της αποδιδόμενης ισχύος προς το δίκτυο. Σε περιπτώσεις υψηλής διακύμανσης του ανέμου και γρήγορων μεταβολών στην ταχύτητά του, η ισχύς εξόδου ενός αιολικού πάρκου και η τάση στο σημείο σύνδεσης μπορεί να εμφανίσουν σημαντικές διακυμάνσεις, με αποτέλεσμα να πρέπει να εξετασθεί η δυνατότητα αξιοποίησης της αιολικής ενέργειας. Ειδικότερα σε απομονωμένα δίκτυα ή/και σε περιπτώσεις πολύ υψηλής διείσδυσης αιολικής ενέργειας, καθίσταται σοβαρότερης σημασίας η εξομάλυνση της αποδιδόμενης ισχύος στο δίκτυο. Η παρούσα εργασία προτείνει μία μέθοδο για την εξομάλυνση της ισχύος εξόδου ενός αιολικού πάρκου (Α/Π), χρησιμοποιώντας γεννήτρια παραγωγής υδρογόνου με ηλεκτρόλυση νερού. Για να επιτευχθεί κατάλληλη εξομάλυνση προσδιορίζεται η ισχύς εξόδου αναφοράς, η οποία προσφέρεται στο δίκτυο, ενώ η υπόλοιπη ισχύς απορροφάται από τους ηλεκτρολύτες της γεννήτριας υδρογόνου. Για τον υπολογισμό της ισχύος αναφοράς υιοθετείται η μέθοδος του κινούμενου εκθετικού μέσου. Επίσης αναπτύσσεται κατάλληλη στρατηγική διαχείρισης της γεννήτριας υδρογόνου που επιδιώκει τόσο την ελαχιστοποίηση των διακυμάνσεων της αποδιδόμενης ισχύος στο δίκτυο όσο και την επέκταση ζωής των ηλεκτρολυτών. Η προσομοίωση του συστήματος αναπτύχθηκε σε περιβάλλον λογισμικού Matlab/Simulink. Η μεθοδολογία που αναπτύχθηκε εφαρμόσθηκε στη διερεύνηση των επιπτώσεων εγκατάστασης υβριδικού σταθμού παραγωγής ηλεκτρικής ενέργειας σε μη διασυνδεδεμένο νησιωτικό σύστημα που περιλαμβάνει συμβατικές μονάδες παραγωγής. Στόχος είναι να συγκριθούν διαφορετικές τεχνολογικές λύσεις ώστε να επιτευχθεί κατά το δυνατόν απεξάρτηση από τις συμβατικές μονάδες παραγωγής με ταυτόχρονη διείσδυση συστημάτων παραγωγής ανανεώσιμων πηγών ενέργειας (ΑΠΕ) και επικουρικών συστημάτων αποθήκευσης ηλεκτρικής ενέργειας που χρησιμοποιούν τεχνολογίες υδρογόνου. Τα δεδομένα που χρησιμοποιήθηκαν προέρχονται από το νησιωτικό σύστημα του Αγ. Ευστρατίου του νομού Λέσβου. Η τεχνικοοικονομική αποτίμηση των εναλλακτικών τοπολογιών βασίζεται στο λογισμικό HOMER.Hydrogen technologies constitute nowadays an attractive possibility under consideration to solve energy problems. Water electrolysis enables production of hydrogen sufficiently pure to be implemented in fuel cells and their combination with renewable energy sources is a preferential research subject internationally. Due to the fast penetration of wind energy in the modern power systems, the combination of wind generators and electrolyzers acquires important interest. The important integration of wind energy raises problems of power quality to be solved. In cases of high fluctuations of wind and abrupt changes in its speed, the power output of a wind park and the voltage at the interconnection point present also fluctuations. Therefore, the problem of the integration of wind systems in the grid necessitates investigation. Especially in cases of isolated grids or/and very high penetration of wind energy in the grid, the need of wind power conditioning is of crucial importance. The present work proposes a methodology for minimizing the output power fluctuations of a wind farm (WF) connected to the grid, using a hydrogen generator with multiple electrolyzers. In order to achieve appropriate power quality, the reference power to be delivered to the grid is determined. The remaining power produced is consumed by the hydrogen generator. The calculation of the power reference value is based on the method of the exponential moving average (EMA). Moreover, a particular strategy is developed managing the operation of the hydrogen generator achieving a compromise in the minimization of power fluctuations and the life extension of the electrolyzers. The system modelling has been developed in the software environment of Matlab/Simulink. The developed methodology has been applied to investigate the impact of a hybrid station integration, in the case of an isolated island system incorporating diesel generators. The objective is to consider different technical solutions enabling minimization of the use of diesel generators through penetration of renewable energy sources combined to hydrogen energy storage systems. The system data implemented correspond to the island Agios Eystratios of Lesvos prefecture. The technical and economical investigation is based on HOMER software.Νικόλαος-Παναγιώτης Κ. Σακκά