7,834 research outputs found
The Zeta Function Method and the Harmonic Oscillator Propagator
We show how the pre-exponential factor of the Feynman propagator for the
harmonic oscillator can be computed by the generalized -function method.
Besides, we establish a direct equivalence between this method and Schwinger's
propertime method.Comment: 12 latex pages, no figure
Use of functional fatty acids in animal nutrition to improve animal health status and derived products
Lo scopo della presente ricerca \ue8 stato quello di valutare degli effetti della somministrazione di differenti fonti di acidi grassi sulla salute animale e sulla qualit\ue0 dei prodotti derivati; non di meno, sono stati oggetto di analisi i possibili effetti benefici sulla salute umana. A tale scopo, sono state effettuate due distinte prove sperimentali, una su capre da latte e l\u2019altra su galline ovaiole.
La prima prova ha preso in considerazione lo studio dell\u2019espressione di geni e miRNA coinvolti nel metabolismo lipidico e nel processo infiammatorio a livello di tessuto epatico e adiposo sottocutaneo di nella capra da latte in transizione a seguito della somministrazione di fonti grassate apportanti acidi grassi saturi (SFA) o polinsaturi (PUFA) della serie omega 3 e 6 quali acido stearico e olio di pesce.
La seconda sperimentazione ha preso in considerazione le performance e la qualit\ue0 dell\u2019uovo prodotto in galline ovaiole la cui dieta \ue8 stata supplementata con Camelina sativa.
Negli ultimi decenni l\u2019integrazione della dieta con PUFA, in particolare con l\u2019acido eicosapentaenoico (EPA) e docosaesaenoico (DHA), si \ue8 dimostrata efficace in termini di salute sia a livello animale, attraverso la modulazione del metabolismo e del sistema immunitario, sia a livello dell\u2019uomo, con il consumo di alimenti animali arricchiti di acidi grassi essenziali.
Il primo caso di studio ha preso in esame 23 capre da latte di razza Alpina diagnosticate per un parto gemellare. La sperimentazione ha previsto l\u2019integrazione della dieta da una settimana prima (30 g/head/d di acidi grassi) a tre settimane dopo il parto (50 g/head/d di acidi grassi) di calcio stearato (ST, n= 7) o olio di pesce (FO, n= 8), e il confronto di questi due gruppi sperimentali con un gruppo di controllo (CON, n= 8), alimentato con una dieta base. Sono state effettuate biopsie di fegato e tessuto adiposo sottocutaneo a -7, 7 e 21 giorni dal parto al fine di determinare l\u2019espressione mRNA e miRNA di 38 geni implicati nel metabolismo lipidico di fegato e tessuto adipose e nella risposta infiammatoria a livello adiposo, mediante Polymerase Chain Reaction (PCR). Ad eccezione di Stearoyl-CoA desaturasi (SCD) (fegato), non abbiamo riscontrato variazioni significative nell\u2019espressione dei geni oggetto di studio a seguito della somministrazione dei trattamenti (FO e ST). Specificatamente, la supplementazione lipidica ha portato ad un aumento dell\u2019espressione di SCD nel gruppo ST e una riduzione nel FO. L\u2019effetto del tempo ha influenzato l\u2019andamento della maggior parte dei geni target per il metabolismo lipidico del fegato, vedendone l\u2019espressione aumentata da -7 a 7 giorni di lattazione e ridotta nella terza settimana di lattazione mentre, a livello di tessuto adiposo, \ue8 stata osservata una down regulation per tutta la durata della prova. Per quanto riguarda l\u2019andamento dell\u2019espressione dei geni implicati nei fenomeni di infiammazione nel tessuto adiposo, i risultati del presente studio hanno evidenziato una up-regulation delle proteine di fase acuta nelle due settimane in prossimit\ue0 del parto, diminuita poi da 7 a 21 giorni di lattazione. Le interleuchine pro-infiammatorie (IL6 and IL8) hanno raggiunto un picco nella prima settimana dopo il parto, mentre abbiamo osservato una up-regulation di IL10 nelle ultime due settimane di prova. Considerando i microRNA, ad eccezione dell\u2019aumento dell\u2019espressione del miR-155 da -7 a 7 die dal parto, non \ue8 stato osservato nessun effetto del tempo. Analizzando l\u2019effetto interazione dieta*tempo nel metabolismo del fegato, Acyl-CoA Ossidasi 1 (ACOX1) ha visto aumentata la sua espressione nel gruppo ST, rispetto al CON al giorno 7 mentre SCD ha evidenziato una maggiore espressione da 7 a 21 giorni nel gruppo ST, se comparato al gruppo FO. Passando poi al tessuto adiposo, Lipin1 (LPIN1) ha mostrato valori di espressione maggiori per il FO a 7 giorni di lattazione (rispetto a ST) e l\u2019espressione di FASN ha raggiunto valori pi\uf9 elevati nel gruppo stearato a -7 DIM rispetto al controllo e al FO. L\u2019espressione di IL6 nel tessuto adiposo ha mostrato una down-regulation nel gruppo stearato rispetto al gruppo controllo al giorno 7. Il presente studio ha evidenziato limitati effetti dell\u2019espressione dei geni considerati, coinvolti nel metabolismo lipidico e nell\u2019infiammazione in fegato e tessuto adiposo, a seguito dell\u2019integrazione di acidi grassi saturi e polinsaturi in capre da latte vicine al parto. Nel contempo, \ue8 stato osservato un trend fisiologico nelle due settimane in prossimit\ue0 del parto, caratterizzato da un aumento della \u3b2-ossidazione nel fegato e da una diminuzione nella sintesi di acidi grassi, accompagnata da pi\uf9 intensi processi infiammatori, a livello di tessuto adiposo.
La successiva prova sperimentale si svolta con un numero totale di 32 galline ovaiole, assegnate in modo casuale a due gruppi oggetto di studio, con otto replicati per gruppo. Gli animali sono stati alimentati con una dieta base con (T) o senza (C) l\u2019inclusione del 7.5% di farina di camelina per un totale di 63 giorni. Le performance degli animali sono state valutate settimanalmente, mentre la qualit\ue0 dell\u2019uovo \ue8 stata determinata a 0, 28, 56 giorni e la shelf-life/TBARS a 0, 9, 21, 28 giorni. Si \ue8 visto come l\u2019integrazione della farina di camelina abbia migliorato il tasso di conversione dell\u2019alimento nelle galline (P<0.05). Inoltre, \ue8 stata osservata una riduzione del contenuto di acidi grassi saturi (SFA) nel tuorlo delle galline appartenenti al gruppo T (33.18 vs. 32.45 g/100g di acidi grassi totali; P\u2c2 0.01), concomitante ad un arricchimento in acido \u3b1-linolenico (1.05 vs. 1.47 g/100g di acidi grassi totali; P< 0.01). I risultati cos\uec ottenuti mostrano come sia possibile, integrando la dieta di galline ovaiole con farina di Camelina sativa, migliorare la qualit\ue0 del tuorlo, agendo sulla riduzione del contenuto in SFA e apportando un aumento di acidi grassi essenziali n-3.
Ne consegue che i PUFA possano avere un duplice impatto: sulla salute animale e, indirettamente, sulla salute del consumatore.
Infatti, questi acidi grassi non solo si sono dimostrati essere una fonte energetica ma anche una valida integrazione alla dieta animale durante i periodi pi\uf9 stressanti, quale, ad esempio il periparto. Di conseguenza, questo tipo di strategie alimentari possono agire su due fronti: da un lato migliorare la composizione acidica dei prodotti di origine animale, con un decremento nel contenuto di SFA e un aumento di acidi grassi monoinsaturi (MUFA) e PUFA, e, dall\u2019altro, arricchire la dieta del consumatore.The aim of the present thesis is to evaluate the effects of different dietary fatty acid sources on animal health and product quality, in addition, the possible beneficial effects on human health from animal product consumption was also a central motivation for this evaluation. With this purpose, two different trials were performed in dairy goats and laying hens respectively. Accounted for, were: (i) The expression of selected lipid metabolism and inflammation-related genes, and miRNA in the liver and adipose tissue of small ruminants around kidding which were fed saturated (SFA) or polyunsaturated (PUFA) fatty acid supplements in their diets from stearic acid or fish oil, (ii) The performance and egg quality of laying hens fed PUFA from Camelina sativa dietary supply. In the last decades PUFA supply, especially EPA and DHA among others, was reported to be effective in both the improvement of animal health, through the modulation of the metabolism and immune systems, and the enrichment of animal products with essential fatty acids that can lead to positive effects on human health.
The first trial considered twenty-three second-parity twin-diagnosed alpine dairy goats that were either fed from one week before (30 g/head/d fatty acids) to three weeks after kidding (50 g/head/d fatty acids) calcium stearate (ST, n= 7) or fish oil (FO, n= 8), and were compared to a control group fed a basal diet (CON, n= 8). Liver and adipose biopsies were collected on day -7, 7 and 21 from kidding. Quantitative PCR was used to measure mRNA and microRNA expression of 38 targets. Dietary treatments up-regulated (ST) and down-regulated (FO) Stearoyl-CoA desaturase (SCD) alone. Time around kidding strongly affected most of the target genes for lipid metabolism in liver, being mostly up-regulated from -7 to 7 DIM and down-regulated in the third week of lactation, while in adipose tissue a gradual down-regulation was observed throughout the trial. Acute-phase proteins were increased in adipose tissue in the two weeks around kidding and decreased from 7 to 21 DIM. Pro-inflammatory interleukins (IL6 and IL8) peaked in the first week after parturition, while IL10 was up-regulated in the last two weeks of the trial. With the exception of an up-regulation of miR-155 from -7 to 7 d from kidding, no effects of time were observed on miRNA expression in adipose tissue. Liver ACOX1 was greater in ST than CON on day 7 while SCD showed a higher expression from 7 to 21 DIM in ST compared to FO. Then, dealing with adipose tissue, LPIN1 had increase values in FO at 7 days after kidding (compared to ST) and FASN had the highest expression in stearate group 7 days before parturition, if compared to CON and FO. The expression of IL6 in adipose tissue had a down regulation in ST compared to control group at 7 DIM. The present trial revealed limited effects of dietary saturated or polyunsaturated supply around kidding on fatty acid metabolism - and inflammation - related genes in the liver and adipose tissue of dairy goats. At the same time, a physiological trend was observed in the two weeks around kidding with increased \u3b2-oxidation in the liver, and decreased fatty acid synthesis together with the higher inflammation processes in adipose tissue.
The second trial involved a total number of 32 laying hens that were randomly allocated to two experimental groups, with eight replicates per group. Animals were fed a common basal diet with (T) or without (C) inclusion of 7.5% Camelina meal for a total period of 63 days. Performance was evaluated weekly, while egg quality was determined at days 0, 28, 56 and shelf-life/TBARS at days 0, 9, 21, 28. Camelina meal supplementation improved feed conversion rate in laying hens (P<0.05). Moreover, reduced saturated fatty acids (SFA) content was observed in the yolk of T hens (33.18 vs. 32.45 g/100g total fatty acids; P\u2c2 0.01), with a concomitant enrichment in \u3b1-linolenic acid (1.05 vs. 1.47 g/100g total fatty acids; P< 0.01). Results of the present study show that it is possible to improve yolk quality by feeding Camelina sativa meal to laying hens, reducing egg SFA content and providing increased amount of beneficial n-3 fatty acids.
As a result, PUFA can exert a duplicate effect: on animal health and, indirectly, on human health.
Indeed, they can act not just as a source of energy but also as an integral part of animal feed during stressing events such as peripartum. As a consequence, these nutritional strategies can also improve FA composition of animal products, with the decrease of SFA and increase of monounsaturated FA (MUFA) and PUFA contents, and a fortification of human diet
Advances in surface EMG signal simulation with analytical and numerical descriptions of the volume conductor
Surface electromyographic (EMG) signal modeling is important for signal interpretation, testing of processing algorithms, detection system design, and didactic purposes. Various surface EMG signal models have been proposed in the literature. In this study we focus on 1) the proposal of a method for modeling surface EMG signals by either analytical or numerical descriptions of the volume conductor for space-invariant systems, and 2) the development of advanced models of the volume conductor by numerical approaches, accurately describing not only the volume conductor geometry, as mainly done in the past, but also the conductivity tensor of the muscle tissue. For volume conductors that are space-invariant in the direction of source propagation, the surface potentials generated by any source can be computed by one-dimensional convolutions, once the volume conductor transfer function is derived (analytically or numerically). Conversely, more complex volume conductors require a complete numerical approach. In a numerical approach, the conductivity tensor of the muscle tissue should be matched with the fiber orientation. In some cases (e.g., multi-pinnate muscles) accurate description of the conductivity tensor may be very complex. A method for relating the conductivity tensor of the muscle tissue, to be used in a numerical approach, to the curve describing the muscle fibers is presented and applied to representatively investigate a bi-pinnate muscle with rectilinear and curvilinear fibers. The study thus propose an approach for surface EMG signal simulation in space invariant systems as well as new models of the volume conductor using numerical methods
One-dimensional symmetry and Liouville type results for the fourth order Allen-Cahn equation in R
In this paper, we prove an analogue of Gibbons' conjecture for the extended
fourth order Allen-Cahn equation in R N , as well as Liouville type results for
some solutions converging to the same value at infinity in a given direction.
We also prove a priori bounds and further one-dimensional symmetry and rigidity
results for semilinear fourth order elliptic equations with more general
nonlinearities
Drying kinetics and physico-chemical quality of mango slices
Mango (Mangifera indica L.) is an important tropical fruit consumed worldwide and grown in Italy only in Sicily, where the areas of the Tyrrhenian coast have proved to be suitable to produce valuable fruits. Mango fruit has a pleasant aroma and taste, which are important qualities for consumerâs sensorial acceptance. However, they are highly perishable, prone to progressive undesired changes if stored untreated, resulting in around 25% postharvest losses, which is further increased during storage and transportation. An alternative for reducing the above-mentioned undesired changes is the dehydration of the cut fruit, which reduce the fruit water activity, thereby avoiding the deteriorative process and extending the shelf-life. This study investigates the effect of dehydration at different temperatures (50, 60 and 70°C) on drying kinetics and volatile compounds of two cultivars (Keitt and Osteen) of mango fruits cultivated in Sicily. Significant losses of volatile constituents of fresh mango occurred at higher temperature, especially for the Osteen cultivar. A diffusion model including the effect of shrinkage is also proposed, which may be used to describe drying behaviour of fruits and to define the optimal drying conditions.. Experimental data of the moisture ratio during drying were well predicted by the model
Polymorphism, phonon dynamics and carrier-phonon coupling in pentacene
The crystal structure and phonon dynamics of pentacene is computed with the
Quasi Harmonic Lattice Dynamics (QHLD) method, based on atom-atom potential. We
show that two crystalline phases of pentacene exist, rather similar in
thermodynamic stability and in molecular density. The two phases can be easily
distinguished by Raman spectroscopy in the 10-100 cm-1 spectral region. We have
not found any temperature induced phase transition, whereas a sluggish phase
change to the denser phase is induced by pressure. The bandwidths of the two
phases are slightly different. The charge carrier coupling to low-frequency
phonons is calculated.Comment: 6 pages, 3 figures. Presented at ICFPAM-
The validity of consumer-level activity monitors in healthy older adults in free-living conditions
Consumer-level activity monitors, such as Fitbit and Misfit devices, are a popular and low-cost means of measuring physical activity. This study aims to compare the accuracy of step counts from two consumer-level activity monitors against two reference devices in healthy, community dwelling older adults in free-living conditions. Twenty-five older adults (aged 65-84) simultaneously wore 5 devices (e.g. Misfit Shine and Fitbit Charge HR) over 7 consecutive days. All consumer-level activity monitors positively correlated with reference devices (p<0.001). There was also substantial to near perfect agreement between all consumer-level activity monitors and reference devices. Compared to the Actigraph GT3X+, the waist worn Misfit Shine displayed the highest agreement amongst the devices worn (ICC=0.96, 95% 0.91 to 0.99). The wrist worn devices showed poorer agreement to reference devices. Future research needs to consider that not all consumer-level activity monitors are equal in terms of accuracy, design and function
Epstein-Barr virus lytic infection promotes activation of Toll-like receptor 8 innate immune response in systemic sclerosis monocytes
BACKGROUND: Monocytes/macrophages are activated in several autoimmune diseases, including systemic sclerosis (scleroderma; SSc), with increased expression of interferon (IFN)-regulatory genes and inflammatory cytokines, suggesting dysregulation of the innate immune response in autoimmunity. In this study, we investigated whether the lytic form of Epstein-Barr virus (EBV) infection (infectious EBV) is present in scleroderma monocytes and contributes to their activation in SSc.
METHODS: Monocytes were isolated from peripheral blood mononuclear cells (PBMCs) depleted of the CD19+ cell fraction, using CD14/CD16 negative-depletion. Circulating monocytes from SSc and healthy donors (HDs) were infected with EBV. Gene expression of innate immune mediators were evaluated in EBV-infected monocytes from SSc and HDs. Involvement of Toll-like receptor (TLR)8 in viral-mediated TLR8 response was investigated by comparing the TLR8 expression induced by infectious EBV to the expression stimulated by CL075/TLR8/agonist-ligand in the presence of TLR8 inhibitor in THP-1 cells.
RESULTS: Infectious EBV strongly induced TLR8 expression in infected SSc and HD monocytes in vitro. Markers of activated monocytes, such as IFN-regulated genes and chemokines, were upregulated in SSc- and HD-EBV-infected monocytes. Inhibiting TLR8 expression reduced virally induced TLR8 in THP-1 infected cells, demonstrating that innate immune activation by infectious EBV is partially dependent on TLR8. Viral mRNA and proteins were detected in freshly isolated SSc monocytes. Microarray analysis substantiated the evidence of an increased IFN signature and altered level of TLR8 expression in SSc monocytes carrying infectious EBV compared to HD monocytes.
CONCLUSION: This study provides the first evidence of infectious EBV in monocytes from patients with SSc and links EBV to the activation of TLR8 and IFN innate immune response in freshly isolated SSc monocytes. This study provides the first evidence of EBV replication activating the TLR8 molecular pathway in primary monocytes. Immunogenicity of infectious EBV suggests a novel mechanism mediating monocyte inflammation in SSc, by which EBV triggers the innate immune response in infected cells
Social health insurance: can we ever make a case for Pakistan
Social Health Insurance has been used as an approach to increase efficiency of healthcare system and consumer satisfaction in provision of healthcare services. Many developed countries have successfully planned and implemented insurance models which provide almost universal coverage and addresses issues of equity. The phenomenon is established however, developing countries especially Eastern Mediterranean region is still struggling to present one successful model of social health insurance which can be compared with European or Scandinavian countries. Pakistan likewise faces huge challenges in public sector healthcare provision and considerable proportion of population prefers to go to private sector. Quality of care, access and rising costs make healthcare, somehow, a luxury. Rising national economy, political will to carry out health sector reforms and the creation of district health system after devolution presents an opportunity to launch at least some pilot initiatives of social health insurance. This will give us some food for thought to further up scale and replicate the model all over the country
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