492 research outputs found

    A general framework for nonholonomic mechanics: Nonholonomic Systems on Lie affgebroids

    Get PDF
    This paper presents a geometric description of Lagrangian and Hamiltonian systems on Lie affgebroids subject to affine nonholonomic constraints. We define the notion of nonholonomically constrained system, and characterize regularity conditions that guarantee that the dynamics of the system can be obtained as a suitable projection of the unconstrained dynamics. It is shown that one can define an almost aff-Poisson bracket on the constraint AV-bundle, which plays a prominent role in the description of nonholonomic dynamics. Moreover, these developments give a general description of nonholonomic systems and the unified treatment permits to study nonholonomic systems after or before reduction in the same framework. Also, it is not necessary to distinguish between linear or affine constraints and the methods are valid for explicitly time-dependent systems.Comment: 50 page

    Regge Trajectories for Mesons in the Holographic Dual of Large-N_c QCD

    Full text link
    We discuss Regge trajectories of dynamical mesons in large-N_c QCD, using the supergravity background describing N_c D4-branes compactified on a thermal circle. The flavor degrees of freedom arise from the addition of N_f<<N_c D6 probe branes. Our work provides a string theoretical derivation, via the gauge/string correspondence, of a phenomenological model describing the meson as rotating point-like massive particles connected by a flux string. The massive endpoints induce nonlinearities for the Regge trajectory. For light quarks the Regge trajectories of mesons are essentially linear. For massive quarks our trajectories qualitatively capture the nonlinearity detected in lattice calculations.Comment: 21 pages, 4 figures. v2: typos corrected, references and acknowledgments adde

    Effects of dietary barley on rainbow trout exposed to an acute stress challenge

    Full text link
    Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.[EN] The present study evaluates the effect of dietary barley, based on its potential stress-relieving properties, on rainbow trout under acute stress challenge (hypoxia and crowding) and their recovery. Diets were formulated containing increasing barley concentrations (0, 4, 8, 16, 32%). Cortisol on plasma and fin, glucose and lactate plasma levels and malondialdehyde (MDA) in muscle were determined under normoxia before the stress test (basal levels), 30 min after the acute stress challenge and also during normoxia recovery (6 and 12 h after the stress). Results showed that at basal levels the inclusion of barley had no influence on cortisol, glucose nor on lactate values. After 30 min from the stress challenge, there was a significant increase in cortisol, glucose and lactate concentration in fish of all groups. Plasma cortisol showed the lowest levels in fish fed with diets at a medium (8%) of barley concentration and returned to basal levels 6 h after the stress stimulus with no differences between diets. Glucose values showed a less clear tendency 30 min after the stress challenge with lower levels in the control group, fish fed with 8% and 32% of barley in the diets and returned to basal levels in almost all the groups only 12 h after the stress challenge. Lactate showed the same trend as with glucose after the stress challenge but it returned to basal levels in 6 h. Interestingly, there was a significant decrease of lipid oxidation (MDA) in muscle soon after the stress test of fish fed with the highest barley levels. The present results suggest a potential positive effect of dietary barley on trout stress response.This work has been co-funded with FEDER and INIA funds. Julia Pinedo has been granted with the FPI-INIA grant number 21 (call 2012, BOE-2012-13337).Pinedo-Gil, J.; Martín-Diana, AB.; Bertotto, D.; Sanz-Calvo, M.; Jover Cerda, M.; Tomas-Vidal, A. (2019). Effects of dietary barley on rainbow trout exposed to an acute stress challenge. Aquaculture. 501:32-38. https://doi.org/10.1016/j.aquaculture.2018.10.070S323850

    Teaching medical students to express empathy by exploring patient emotions and experiences in standardized medical encounters.

    Get PDF
    OBJECTIVES: To increase medical students’ ability to detect contextual and emotional cues and to respond empathetically to patients. METHODS: a training course in communication skills and patient-centered care with different teaching activities (didactic, reflective and interactive: workshops and encounters with simulated patients) was delivered to third-year medical students just before their clerckships. The program was evaluated by an external observer (OE) and simulated patients (SP) in 2 or 3 videotaped encounters. RESULTS: Students improved significantly from baseline to 3rd interview in all communicative skills and domains explored both in OE (32.4%) and SP (38.3%) measurement. At the end of the course students detected significantly more clues and made more empathetic expressions. CONCLUSIONS: The course seems to improve the ability of students to explore the illness experience, showing more empathy in a more genuine way. This was carried out in consultations lasting 10 minutes. PRACTICAL IMPLICATIONS: The program is effective and feasible to be applied as a regular formative activity. Further research is needed to assess whether this training program is applicable to students in more advanced educational levels and if it has any additional outcomes.pre-print432 K

    Effects of dietary inclusions of red beet and betaine on the acute stress response and muscle lipid peroxidation in rainbow trout

    Full text link
    [EN] This study evaluates the effects of red beet (RB) and betaine on rainbow trout submitted to an acute stress challenge. A control diet was compared with four experimental diets in which red beet (14 and 28%) and betaine (0.9 and 1.63%) were incorporated in different concentrations according to a factorial design. Cortisol in plasma and fin, glucose and lactate plasma levels, and malondialdehide (MDA) in muscle were all measured before the stress challenge and 30 min and 6 and 12 h after the stress challenge as parameters to determine the diet effects. RB and betaine had no effect on cortisol, glucose, and MDA basal levels. However, lactate basal levels were significantly lower on fish fed with RB and betaine. Thirty minutes after the stress challenge, there was a significant increase in plasma and fin cortisol, glucose and lactate concentrations, although fish fed with diets containing RB and betaine showed significantly higher plasma cortisol values. MDA values of fish fed with 14% RB and 0.9% betaine were significantly higher than MDA values from fish fed with 28% RB and 1.63% betaine. After 6 and 12 h, plasma and fin cortisol and lactate levels recovered in a similar trend. Glucose plasma levels recovered in almost all groups 12 h after the stress. Also, MDA values recovered basal levels after 6 and 12 h. RB and betaine did not enhance the tolerance to the stress challenge compared to the control group, although the presence of these ingredients had no negative effect on any of the stress indicators.Pinedo-Gil, J.; Martín-Diana, AB.; Bertotto, D.; Sanz-Calvo, MÁ.; Jover Cerda, M.; Tomas-Vidal, A. (2018). Effects of dietary inclusions of red beet and betaine on the acute stress response and muscle lipid peroxidation in rainbow trout. Fish Physiology and Biochemistry. 44(3):939-948. doi:10.1007/s10695-018-0483-3S939948443Aluru N, Vijayan MM (2006) Aryl hydrocarbon receptor activation impairs cortisol response to stress in rainbow trout by disrupting the rate limiting steps in steroidogenesis. Endocrinology 147:1895–1903Ashley PJ (2007) Fish welfare: current issues in aquaculture. Appl Anim Behav Sci 104:199–235Barton BA, Iwama GK (1991) Physiological changes in fish from stress in aquaculture with emphasis on the response and effects of corticosteroids. Annu Rev Fish Dis 1:3–26Bertotto D, Poltronieri C, Negrato E, Majolini D, Radaelli G, Simontacchi C (2010) Alternative matrices for cortisol measurement in fish. Aquac Res 41:1261–1267Bertotto D, Poltronieri C, Negrato E, Richard J, Pascoli F, Simontacchi C, Radaelli G (2011) Whole body cortisol and expression of HSP70, IGF-I and MSTN in early development of sea bass subjected to heat shok. Gen Comp Endocrinol 174:44–50Chagas EC, Val AL (2006) Ascorbic acid reduces the effects of hypoxia on the Amazon fish tambaqui. J Fish Biol 69:608–612Cui XJ, Zhou QC, Liang HO, Yang J, Zhao LM (2010) Effects of dietary carbohydrate sources on the growth performance and hepatic carbohydrate metabolic enzyme activities of juvenile cobia (Rachycentron canadum Linnaeus.) Aquac Res 42:99–107Dabrowski K, Lee KJ, Guz L, Verlhac V, Gabaudan J (2004) Effects of dietary ascorbic acid on oxygen stress (hypoxia or hyperoxia), growth and tissue vitamin concentration in juvenile rainbow trout (Oncorhynchus mykiss). Aquaculture 233:383–392Enes P, Panserat S, Kaushik S, Oliva-Teles A (2006) Rapid metabolic adaptation of European sea beass (Dicentrarchus labrax) juveniles fed different carbohydrate sources after heat shock stress. Comp Biochem Physiol A 145:73–81Fast MD, Hosoya S, Johnson SC, Alfonso LOB (2008) Cortisol response and immune-related effects of Atlantic salmon (Salmo salar Linnaeus) subjected to short- and long-term stress. Fish Shellfish Immunol 24:194–204Francis G, Makkar HPS, Becker K (2001) Antinutritional factors present in plant-derived alternate fish feed ingredients and their effects in fish. Aquaculture 199:197–227Ganessan B, Anandan R, Lakshmanan PT (2011) Studies on the protective effects of betaine against oxidative damage during experimentally induced restraint stress in Wistar albino rats. Cell Stress Chaperones 16:641–652Gesto M, López-Patiño MA, Hernández J, Soengas JL, Míguez JM (2013) The response of brain serotonergic and dopaminergic systems to an acute stressor in rainbow trout: a time course study. J Exp Biol 216:4435–4442Gesto M, López-Patiño MA, Hernández J, Soengas JL, Míguez JM (2015) Gradation of the stress response in rainbow trout exposed to stressors of different severity: the role of brain serotonergic and dopaminergic systems. J Neuroendocrinol 27:131–141Hemre GI, Mommsen TP, Krogdahl Å (2002) Carbohydrates in fish nutrition: effects on growth, glucose metabolism and heptic enzymes. Aquac Nutr 8:175–194Ings JS, Vijayan MM, Servos MR (2012) Tissue-specific metabolic changes in response to an acute handling disturbance in juvenile rainbow trout exposed to municipal wastewater effluent. Aquat Toxicol 108:53–59Janssens PA, Waterman J (1988) Hormonal regulation of gluconeogenesis and glycogenolysis in carp (Cyprinus carpio) liver pieces cultured in vitro. Comp Biochem Physiol 91A:451–457Jeney G, Galeotti M, Volpatti D, Anderson DP (1997) Prevention of stress in rainbow trout (Oncorhynchus mykiss) fed diets containing different doses of glucan. Aquaculture 154:1–15Kaplan LA, Pesce AJ (1984) Clinical chemistry: theory, analysis and correlation. Mosby, St. Louis, pp 1032–1036Krogdahl Å, Sundby A, Olli JJ (2004) Atlantic salmon (Salmon salar) and rainbow trout (Oncorhynchus mykiss) digest and metabolize nutrients differently. Effects of water salinity and dietary starch levels. Aquaculture 229:335–360Kujala TS, Vienola MS, Klika KD, Loponen JM, Pihlaja K (2002) Betalain and phenolic composition of four beetroot (Beta vulgaris) cultivars. Eur Food Res Technol 214:505–510Kumar N, Jadhao SB, Chandan NK, Kumar K, Jha AK, Bhushan S, Kumar S, Rana RS (2012) Dietary choline, betaine and lecithin mitigate endosulfan-induced stress in Labeo rohita fingerlings. Fish Physiol Biochem 38:989–1000Leveelahti L, Rytkönen KT, Renshaw GMC, Nikinmaa M (2014) Revisiting redox-active antioxidant defences in response to hypoxic challenge in both hypoxia-tolerant and hypoxia-sensitive fish species. Fish Physiol Biochem 40:183–191Lushchak VI, Bagnyukova TV, Lushchak OV, Storey JM, Storey KB (2005) Hypoxia and recovery perturb free radical processes and antioxidant potential in common carp (Cyprinus carpio) tissues. Int J Bichem Cell Biol 37:1319–1330Lushchak VI, Bagnyukova TV (2006) Temperature increase results in oxidative stress in goldfish tissues. 1. Indices of oxidative stress. Comp Biochem Physiol C 143:30–35Madaro A, Olsen RE, Kristiansen TS, Ebbeson LOE, Nilsen TO, Flik G, Gorissen M (2015) Stress in Atlantic salmon: response to unpredictable chronic stress. J Exp Biol 218:2538–2550Ming J, Xie J, Xu P, Ge X, Liu W, Ye J (2012) Effects of emodin and vitamin C on growth performance, biochemical parameters and two HSP70s mRNA expression of Wuchang bream (Megalobrama amblycephala Yih) under high temperature stress. Fish Shellfish Immunol 32:651–661Mommsen TP, Vijayan MM, Moon TW (1999) Cortisol in teleosts: dynamics, mechanisms of action, and metabolic regulation. Rev Fish Biol Fish 9:211–268Montero D, Tort L, Robaina L, Vergara JM, Izquierdo MS (2001) Low vitamin E in diet reduces stress resistance of gilthead seabream (Sparus aurta) juveniles. Fish Shellfish Immunol 11:473–490Ortuño J, Esteban MA, Meseguer J (2003) Effect of dietary intake of vitamins C and E on the stress response of gilthead seabream (Sparus aurata L.) Fish Shellfish Immunol 14:145–156Øverli Ø, Sørensen C, Kiessling A, Pottinger TG, Gjøen HM (2006) Selection for improved stress tolerance in rainbow trout (Oncorhynchus Mykiss) leads to reduced feed waste. Aquaculture 261:776–781Pérez-Jiménez A, Peres H, Rubio VC, Oliva-Teles A (2012) The effect of hypoxia on intermediary metabolism and oxidative status in gilthead sea bream (Sparus aurata) fed on diets supplemented with methionine and white tea. Comp Biochem Physiol C 155:506–516Pichavant K, Maxime V, Thébault MT, Ollivier H, Garnier JP, Bousquet B, Diouris M, Boeuf G, Nonnotte G (2002) Effects of hypoxia and subsequent recovery on turbot (Scophthalmus maximus): hormonal changes and anaerobic metabolism. Mar Ecol Prog Ser 225:275–285Pinedo-Gil J, Tomás-Vidal A, Larrán-García AM, Tomás-Almenar C, Jover-Cerdá M, Sanz-Calvo MA, Martín-Diana AB (2017a) Enhancement of quality of rainbow trout (Oncorhynchus mykiss) flesh incorporating barley on diet without negative effect on rearing parameters. Aquacult Int 25:1005–1023. https://doi.org/10.1007/s10499-016-0091-0Pinedo-Gil J, Tomás-Vidal A, Jover-Cerdá M, Tomás-Almenar C, Sanz-Calvo MA, Martín-Diana AB (2017b) Red beet and betaine as ingredients in diets of rainbow trout (Oncorhynchus mykiss): effects on growth performance, nutrient retention and flesh quality. Arch Anim Nutr 71:486–505. https://doi.org/10.1080/1745039X.2017.1391503Rabeh NM (2015) Effect of red beetroot (Beta vulgaris L.) and its fresh juice against carbon tetrachloride induced hepatotoxicity in rats. World Appl Sci J 33(6):931–938Rollo A, Sulpizio R, Nardi M, Silvi S, Orpianesi C, Caggiano M, Cresci A, Carnevalli O (2006) Live microbial feed supplement in aquaculture for improvement of stress tolerance. Fish Physiol Biochem 32:167–177Sadoul B, Leguen I, Colson V, Friggens NC, Prunet P (2015) A multivariate analysis using physiology and behaviour to characterize robustness in two isogenic lines of rainbow trout exposed to a confinement stress. Physiol Behav 140:139–147Tan Q, Xie S, Zhu X, Lei W, Yang Y (2006) Effect of dietary carbohydrates sources on growth performance and utilization for gibel carp (Carassius auratus) and Chinese longsnout catfish (Leiocassis Longirostris Günther). Aquac Nutr 12:61–70Tintos A, Míguez JM, Mancera JM, Soengas JL (2006) Development of a microtitre plate indirect ELISA for measuring cortisol in teleosts, and evaluation of stress responses in rainbow trout and gilthead sea bream. J Fish Biol 68:251–263Van Anholt RD, Spanings FAT, Koven WM, Nixon O, Wendelaar Bonga SE (2004) Arachidonic acid reduces the stress response of gilthead seabream, Sparus aurata L. J Exp Biol 207:3419–3430Virtanen E (1995) Piecing together the betaine puzzle. Feed Min 3:12–17Wu XY, Liu YJ, TIan LX, Mai KS, Yang HJ (2007) Utilization of several different carbohydrate sources by juvenile yellowfin seabream (Sparus latus). J Fish China 31(4):463–471Yoshida Y, Itoh N, Hayakawa M, Piga R, Cynshi O, Jishage K, Niki E (2005) Lipid peroxidation induced by carbon tetrachloride and its inhibition by antioxidant as evaluated by an oxidative stress marker, HODE. Toxicol Appl Pharmacol 208:87–97Zeng L, Wang YH, Ai CX, Zheng JL, Wu CW, Cai R (2016) Effects of β-glucan on ROS production and energy metabolism in yellow croaker (Pseudosciaena crocea) under acute hypoxic stress. Fish Physiol Biochem 42:1395–1405Zolderdo AJ, Algera DA, Lawrence MJ, Gilmour KM, Fast MD, Thuswaldner J, Willmore WG, Cooke SJ (2016) Stress, nutrition and parental care in a teleost fish: exploring mechanisms with supplemental feeding and cortisol manipulation. J Exp Biol 219:1237–124

    Impact of sensor-augmented pump therapy with predictive low-glucose management on hypoglycemia and glycemic control in patients with type 1 diabetes mellitus : 1-year follow-up

    Get PDF
    Q2Artículo original2625-2631AIMS: To describe real-life experience with sensor-augmented pump therapy with predictive low-glucose management (SAPT-PLGM), in terms of hypoglycemia and glycemic control after one year of follow-up in T1D patients with hypoglycemia as the main indication of therapy. METHODS: Retrospective cohort study under real life conditions. Baseline and one-year follow-up variables of glycemic control, hypoglycemia and glycemic variability were compared. RESULTS: Fifty patients were included, 31 on prior treatment with SAPT with low-glucose suspend (LGS) feature and 19 on multiple dose insulin injections (MDI). Mean HbA1c decreased in the MDI group (8.24%-7.08%; p = 0.0001). HbA1c change was not significant in the SAPT-LGS group. Area under the curve (AUC) below 70 mg/dl improved in both SAPT-LGS and MDI groups while AUC, %time and events below 54 mg/dl decreased in SAPT-LGS group. Glycemic variability improved in the MDI group. Less patients presented severe hypoglycemia with SAPT-PLGM in both groups, however the change was non-significant. CONCLUSIONS: Under real life conditions, SAPT-PLGM reduced metrics of hypoglycemia in patients previously treaded with MDI and SAPT-LGS without deteriorating glycemic control in SAPT-LGS patients, while improving it in patients treated with MDI

    Red beet and betaine as ingredients in diets of rainbow trout (Oncorhynchus mykiss): effects on growth performance, nutrient retention and flesh quality

    Full text link
    [EN] The objective of the study was to evaluate the impact of different concentrations of dietary red beet and betaine on the growth performance and fish flesh quality of rainbow trout. Therefore, a control diet was compared with four diets in which two levels of red beet (14% and 28%) and betaine (0.9% and 1.63%) were incorporated in combination. The study was set up with an average body weight of 69 ± 2.2 g and finished when fish reached commercial weight (175¿250 g) after 105 d. The impact of the diets was studied based on the growth performance, biometric indexes, proximal composition, protein and fat retention efficiencies and apparent nutrient digestibility by fish reared on a recirculation system. Further estimates were the effect of red beet and betaine on the flesh proximate composition and quality of the final product (water activity, colour, texture, thiobarbituric acid reactive substances and sensory characteristics). Results showed that inclusion of 14% red beet and 0.9% betaine did not affect growth, nutritive or biometric parameters and nutrient retention when compared with the control diet. However, higher levels of red beet and betaine had negative effects on growth and nutritive parameters. The tested ingredients enhanced quality parameters regardless of the concentration used. After feeding the red beet and betaine, fish flesh showed lower water activity and better textural and colour properties than the control and also a dose-dependent effect on lipid oxidation was observed.This work has been co-funded with FEDER and INIA funds. Julia Pinedo has been granted with the FPI-INIA grant number 21 [call 2012, BOE-2012-13337].Pinedo-Gil, J.; Tomas-Vidal, A.; Jover Cerda, M.; Tomás-Almenar, C.; Sanz-Calvo, MÁ.; Martín-Diana, AB. (2017). Red beet and betaine as ingredients in diets of rainbow trout (Oncorhynchus mykiss): effects on growth performance, nutrient retention and flesh quality. Archives of Animal Nutrition. 71(6):486-505. doi:10.1080/1745039X.2017.1391503S48650571

    Pseudomonas aeruginosa That Specifically Mediates Chemotaxis Toward α-Ketoglutarate

    Get PDF
    Pseudomonas aeruginosa is an ubiquitous pathogen able to infect humans, animals, and plants. Chemotaxis was found to be associated with the virulence of this and other pathogens. Although established as a model for chemotaxis research, the majority of the 26 P. aeruginosa chemoreceptors remain functionally un-annotated. We report here the identification of PA5072 (named McpK) as chemoreceptor for α-ketoglutarate (αKG). High-throughput thermal shift assays and isothermal titration calorimetry studies (ITC) of the recombinant McpK ligand binding domain (LBD) showed that it recognizes exclusively α-ketoglutarate. The ITC analysis indicated that the ligand bound with positive cooperativity (Kd1 = 301 μM, Kd2 = 81 μM). McpK is predicted to possess a helical bimodular (HBM) type of LBD and this and other studies suggest that this domain type may be associated with the recognition of organic acids. Analytical ultracentrifugation (AUC) studies revealed that McpK-LBD is present in monomer-dimer equilibrium. Alpha-KG binding stabilized the dimer and dimer self-dissociation constants of 55 μM and 5.9 μM were derived for ligand-free and αKG-bound forms of McpK-LBD, respectively. Ligand-induced LBD dimer stabilization has been observed for other HBM domain containing receptors and may correspond to a general mechanism of this protein family. Quantitative capillary chemotaxis assays demonstrated that P. aeruginosa showed chemotaxis to a broad range of αKG concentrations with maximal responses at 500 μM. Deletion of the mcpK gene reduced chemotaxis over the entire concentration range to close to background levels and wild type like chemotaxis was recovered following complementation. Real-time PCR studies indicated that the presence of αKG does not modulate mcpK expression. Since αKG is present in plant root exudates it was investigated whether the deletion of mcpK altered maize root colonization. However, no significant changes with respect to the wild type strain were observed. The existence of a chemoreceptor specific for αKG may be due to its central metabolic role as well as to its function as signaling molecule. This work expands the range of known chemoreceptor types and underlines the important physiological role of chemotaxis toward tricarboxylic acid cycle intermediates. [EN]FEDER funds and Fondo Social Europeo through grants from the Junta de Andalucía (grant CVI-7335) and the Spanish Ministry for Economy and Competitiveness (grant BIO2013-42297). MM was supported by the Spanish Ministry of Economy and Competitiveness Postdoctoral Research Program, Juan de la Cierva (JCI-2012-11815).Peer reviewe

    Risk of Acute Myocardial Infarction Among New Users of Allopurinol According to Serum Urate Level: A Nested Case-Control Study

    Get PDF
    Abstract: Objectives: To test the hypothesis that allopurinol reduces the risk of acute myocardial infarction (AMI) in hyperuricemic patients and to assess whether the effect is dependent on dose, duration and serum uric acid (SUA) level attained after treatment. Methods: Nested case-control study over the period 2002?2015. From a cohort of patients aged 40?99 years old, we identified incident AMI cases and randomly selected five controls per case, matched for exact age, sex and index date. Adjusted odds ratios (AOR) and 95% CI were computed through unconditional logistic regression. Only new users of allopurinol were considered. Results: A total of 4697 AMI cases and 18,919 controls were included. Allopurinol use was associated with a reduced risk of AMI mainly driven by duration of treatment (AOR ?180 days = 0.71; 95% CI: 0.60?0.84). Among long-term users (>180 days), the reduced risk was only observed when the SUA level attained was below 7 mg/dL (AOR7mg/dL = 1.04; 95% CI: 0.75?1.46; p for trend = 0.001). A dose-effect was observed but faded out once adjusted for the SUA level attained. The reduced risk of AMI occurred in both patients with gout and patients with asymptomatic hyperuricemia. Conclusions: The results confirm a cardioprotective effect of allopurinol which is strongly dependent on duration and SUA level attained after treatment
    corecore