186,484 research outputs found
Early endosomes associated with dynamic F-actin structures are required for late trafficking of H. pylori VacA toxin
No full textGlycosylphosphatidylinositol-anchored proteins
(GPI-APs) are endocytosed by a clathrinindependent
pathway into vesicles named GPIAP–
enriched early endosomal compartments (GEECs).
We recently showed that the vacuolating toxin VacA
secreted by Helicobacter pylori is endocytosed into the
GEECs (Gauthier, N.C., P. Monzo, V. Kaddai, A. Doye,
V. Ricci, and P. Boquet. 2005. Mol. Biol. Cell. 16:4852–
4866). Unlike GPI-APs that are mostly recycled back
to the plasma membrane, VacA reaches early endosomes
(EEs) and then late endosomes (LEs), where vacuolation
occurs.
In this study, we used VacA to study the traffi cking
pathway between GEECs and LEs. We found that VacA
routing from GEECs to LEs required polymerized actin.
During this traffi cking, VacA was transferred from GEECs
to EEs associated with polymerized actin structures. The
CD2-associated protein (CD2AP), a docking protein implicated
in intracellular traffi cking, bridged the fi lamentous
actin (F-actin) structures with EEs containing VacA.
CD2AP regulated those F-actin structures and was required
to transfer VacA from GEECs to LEs. These results
demonstrate that sorting from GEECs to LEs requires dynamic
F-actin structures on EEs
Numerical generation of the temperature response factors for a Borehole Heat Exchangers field
No full textGround Coupled Heat Pump (GCHP) systems connected to a set of vertical ground heat exchangers require short and long term dynamic analysis of the surrounding ground for an optimal operation. The thermal response of the ground for a multiple Borehole Heat Exchanger (BHE) field can be described by proper temperature response factors or “g-functions”. This concept was firstly introduced by Eskilson (1987). The g-functions are a family of solutions of the transient heat conduction equation and each of them refer to a given borehole field geometry. Furthermore the g-functions are the core of many algorithms for simulating the ground response to a GCHP system, including the well-known commercial software EED.
Analytical approaches based on the Finite Line Source (FLS) model have been developed by Eskilson (1987), Zeng et al. (2002) and later by Lamarche (2007). Such solutions can be in principle applied together with space superposition to infer the thermal response for any BHE configuration.
This study is a continuation of the previous work presented in Acuña et al. (2012), and a further investigation is devoted to optimize a numerical model of a squared configuration of 64 boreholes using the commercial software Comsol Multiphysics©. Symmetry conditions and different Fourier numbers have been applied and explored together with the effects related to the dimensions of the calculation domain with respect to the BHE depth and BHE field width. Furthermore, a parametric analysis is addressed to boundary conditions, which points out possible limits on the calculation domain extension. The results of the proposed numerical model are compared with the g-functions embedded within the EED software as well as those calculated by FLS method through the spatial superposition. In a closer approximation to reality, the numerical model is also studied accounting for an adiabatic part at the top of the BHE
Association of patient-reported outcomes and heart rate trends in heart failure. a report from the chiron project
No full textPatient-reported outcomes (PROs) have been previously considered “soft” end-points because of the lack of association of the reported outcome to measurable biological parameters. The present study aimed to assess whether electrocardiographic measures are associated to PROs changes. We evaluated the association between heart rate (HR), QRS and QT/QTc durations and PROs, classified as “good” or “bad” according to the patients’ overall feeling of health, in patients from the Chiron project. Twenty-four chronic heart failure (HF) patients were enrolled in the study (71% male, mean age 62.9 ± 9.4 years, 42% ischemic etiology, 15 NYHA class II and 9 class III) providing 1086 days of usable physiological recordings (4 hours/day). The mean HR was significantly higher in the “bad” than in the “good” PROs class (74.0 ± 6.4 bpm vs 68.0 ± 7.2 bpm; p < 0.001). Conversely, the ratio between movement and rest activities showed significantly higher values in “good” compared to “bad” PROs. We also found significantly longer QTc and QRS durations in patients with “bad” PROs compared to patients with “good” PROs. That in patients with mild to moderate HF, higher HR, wider QRS and longer QTc, as well as a reduced HR ratio between movement and rest, were associated with “bad” PROs is clinically noteworthy because the association of worse PROs with measurable variations of biological parameters may help physicians in evaluating PROs reliability itself and in their clinical decisions. Whether a timely intervention on these biological parameters may prevent adverse outcomes is important and deserves to be investigated in further studies
Neurodevelopmental parent-infant psychotherapy and mindfulness: Complementary approaches in work with parents and babies
No full textThis innovative book explains and introduces the use of mindfulness in therapeutic work with parents and babies, covering issues such as feeding, crying, sleeping and relating, as well as other developmental challenges which affect family life, as practiced in both clinical sessions and in the home.
The book is divided into two parts. Part 1 introduces: (1) what parent-infant psychotherapy is, its origin and evolution; (2) mindfulness, which consists in paying attention in a purposeful way in the present moment and not judgementally; and (3) the development and maturation of the brain and nervous system and how they are affected by the environment in utero and after birth. Part 2 then goes on to explore a range of topics such as parental mental illnesses, immigration, dislocation, loss, guilt, substance misuse, abuse, post-natal depression, congenital malformations and the role of fathers. It describes how these factors impact the parental relationship with, and the healthy development of the infant, drawing from relevant research to demonstrate the effectiveness of parent-infant psychotherapy and mindfulness.
The practice of psychoanalytic psychotherapy aided by mindfulness is a useful intervention for distressed families with infants, while a mindful approach to oneself and one’s baby can ease parental anxiety and free-loving capacities. Neurodevelopmental Parent-Infant Psychotherapy and Mindfulness is an essential resource for clinicians and researchers working on parent and infant relations and will also appeal to curious new or future parents
Myocardial metabolism evaluation and ketones utilization in the failing human heart
No full textBackground: Under normal circumstances, free fatty acids (FFAs) are the predominant energetic substrate of the heart. In experimental and end-stage models of heart failure (HF) a quantitative switch from a predominance of FFAs utilization to the more energy favourable ketone bodies has been demonstrated. The aim of this study was to identify and quantify the heart substrates utilization in mild to moderate human HF.
Methods: β-hydroxybutyrate, lactate, triacyclglycerols, glucose and FFAs concentrations in arterial, coronary sinus (CS), and central venous beds were measured after an overnight fast to derive myocardial substrates utilization in HF patients and controls scheduled for cardiac device implanting procedures.
Results: A total of 15 HF patients and 11 controls were enrolled. Arterial and CS metabolites concentration were similar between the groups. A significant reduction in the myocardial FFAs extraction was showed in HF patients compared to controls (HF 0.07 +- 0.23 mmol/L vs non-HF 0.25 +- 0.16 mmol/L, p=0.03), together with an inverse association between FFAs and neurohormonal and echocardiographic HF hallmarks. Opposite, β-hydroxybutyrate, lactate, triacyclglycerols and glucose extractions were relatively unchanged between groups. The net cardiac extraction of β-hydroxybutyrate was directly associated to HF duration. When diabetic and non-diabetic patients were compared among HF population, the results were substantially similar, with a slight trend in reduction of FFAs net extraction (HF 0.03 +- 0.30 mmol/L vs non-HF 0.26 +- 0.12 mmol/L, p=0.09).
Conclusions: In our study ketone bodies utilization was unchanged between mild to moderate HF patients and controls. We showed a reduced myocardial FFAs extraction consistent with a downregulation of beta-oxidation in the failing heart in HF population. Future studies are needed to clarify mechanisms that regulate the metabolic switch and its timing
Coupling short-term (B2G model) and long-term (g-function) models for ground source heat exchanger simulation in TRNSYS. Application in a real installation
No full textGround-source heat pump (GSHP) systems represent one of the most promising techniques for heating and cooling in buildings. These systems use the ground as a heat source/sink, allowing a better efficiency thanks to the low variations of the ground temperature along the seasons. The ground-source heat exchanger (GSHE) then becomes a key component for optimizing the overall performance of the system. Moreover, the short-term response related to the dynamic behaviour of the GSHE is a crucial aspect, especially from a regulation criteria perspective in on/off controlled GSHP systems. In this context, a novel numerical GSHE model has been developed at the Instituto de Ingeniería Energética, Universitat Politècnica de València. Based on the decoupling of the short-term and the long-term response of the GSHE, the novel model allows the use of faster and more precise models on both sides. In particular, the short-term model considered is the B2G model, developed and validated in previous research works conducted at the Instituto de Ingeniería Energética. For the long-term, the g-function model was selected, since it is a previously validated and widely used model, and presents some interesting features that are useful for its combination with the B2G model. The aim of the present paper is to describe the procedure of combining these two models in order to obtain a unique complete GSHE model for both short- and long-term simulation. The resulting model is then validated against experimental data from a real GSHP installation
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Helicobacter pylori VacA cytotoxin: a probe for a clathrin-independent and Cdc42-dependent pinocytic pathway routed to late endosomes.
No full textAppropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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