187 research outputs found
Preliminary Insights into Social Commerce Capability Development
The purpose of this paper is to explain how micro-entrepreneurs deploy, develop, and manage social media as a resource to create social commerce capabilities to achieve benefits. The paper uses a critical case sampling methodology to select a micro-entrepreneur who uses social media for advertising and retailing fashion items. Three findings emerge. First, in developing of social commerce capabilities, there is need to combine both technical and non-technical resources. Second, personal social capital is not immediately available for use in the development of social commerce capabilities especially when it is being translated for commercial purposes. Third, the level of social commerce capabilities developed is contingent on the affordances of the social media platform in use. This study uncovers the possibility of developing resources and capabilities concurrently i.e. resources do not necessarily have be inputs as identified in the theory. This paper is arguably one of the pioneering attempts at conceptualizing social commerce capabilities
Cardiac insulin-like growth factor-1 and cyclins gene expression in canine models of ischemic or overpacing cardiomyopathy
<p>Abstract</p> <p>Background</p> <p>Insulin-like growth factor-1 (IGF-1), transforming growth factor β (TGFβ) and cyclins are thought to play a role in myocardial hypertrophic response to insults. We investigated these signaling pathways in canine models of ischemic or overpacing-induced cardiomyopathy.</p> <p>Methods</p> <p>Echocardiographic recordings and myocardial sampling for measurements of gene expressions of IGF-1, its receptor (IGF-1R), TGFβ and of cyclins A, B, D1, D2, D3 and E, were obtained in 8 dogs with a healed myocardial infarction, 8 dogs after 7 weeks of overpacing and in 7 healthy control dogs.</p> <p>Results</p> <p>Ischemic cardiomyopathy was characterized by moderate left ventricular systolic dysfunction and eccentric hypertrophy, with increased expressions of IGF-1, IGF-1R and cyclins B, D1, D3 and E. Tachycardiomyopathy was characterized by severe left ventricular systolic dysfunction and dilation with no identifiable hypertrophic response. In the latter model, only IGF-1 was overexpressed while IGF-1R, cyclins B, D1, D3 and E stayed unchanged as compared to controls. The expressions of TGFβ, cyclins A and D2 were comparable in the 3 groups. The expression of IGF-1R was correlated with the thickness of the interventricular septum, in systole and diastole, and to cyclins B, D1, D3 and E expression.</p> <p>Conclusion</p> <p>These results agree with the notion that IGF-1/IGF-1R and cyclins are involved in the hypertrophic response observed in cardiomyopathies.</p
Left Ventricular Eccentricity Index for Assessment of Precapillary Pulmonary Hypertension in Dogs
peer reviewe
Graphical Models of Psychosocial Factors in Chronic Somatic Diseases
AbstractIn this paper we describe a graph, tree and forest model of psychosocial factors dependencies of chronically ill patients, called graphical models. Foundation of the study was the theory of meaningfulness of suffering by V. E. Frankl. 181 patients with either arterial hypertension or neoplasms with bad prognosis were examined thrice: 0-10 days from the time of diagnosis (stage I), about 5 weeks from the diagnosis (stage II) and at a follow-up about 5 months since stage II (stage III). 75 factors were available for consideration: 17 in stage I, 28 in stage II, 27 in stage III and 4 sets of data that describe populations: age, gender, education, number of stages executed. For both diseases graphs and trees are built under assumption that factors are vertices and significant correlations are edges, leading to model of dependencies between factors. Usefulness of this approach to analysis of difference between diseases is discussed
Cardiovascular biomarkers in dogs with systemic inflammatory response syndrome
To measure plasma N-terminal fragments of pro-B-type natriuretic peptides (NT-proBNP) and cardiac troponin T (cTnT) concentration in hospitalized dogs and relate these markers to underlying conditions and evaluate their potential as prognostic markers in dogs with systemic inflammatory response syndrome (SIRS).info:eu-repo/semantics/publishe
Interbreed variation in serum serotonin (5-hydroxytryptamine) concentration in updates healthy dogs
Introduction: Serotonin (5-hydroxytryptamine [5-HT]) has several biological functions. In different species, excessive 5-HT has been linked to valvular lesions, similar to those seen in dogs with myxomatous mitral valve disease. Previous studies suggest higher 5-HT in healthy Cavalier King Charles Spaniels (CKCSs), a breed highly affected by myxomatous mitral valve disease, compared to other breeds. Objective: To investigate potential interbreed variation in serum 5-HT in healthy dogs. Animals: 483 healthy dogs of nine breeds aged 1-7 years. Methods: Dogs were examined at five European centers. Absence of cardiovascular, organ-related, or systemic diseases was ensured by thorough clinical investigations including echocardiography. Serum was frozen and later analyzed by enzyme-linked immunosorbent assay (ELISA). Results: Median 5-HT concentration was 252.5 (interquartile range = 145.5-390.6) ng/mL. Overall breed difference was found (p Conclusions: Interbreed variation in serum 5-HT concentration was found in healthy dogs aged 1-7 years. These differences should be taken into account when designing clinical studies. (C) 2018 Elsevier B.V. All rights reserved.Peer reviewe
Effect of a magnetosphere compression on Jovian radio emissions: in situ case study using Juno data
During its 53-day polar orbit around Jupiter, Juno often crosses the
boundaries of the Jovian magnetosphere (namely the magnetopause and bow shock).
From the boundary locations, the upstream solar wind dynamic pressure can be
inferred, which in turn illustrates the state of compression or relaxation of
the system. The aim of this study is to examine Jovian radio emissions during
magnetospheric compressions, in order to determine the relationship between the
solar wind and Jovian radio emissions. In this paper, we give a complete list
of bow shock and magnetopause crossings (from June 2016 to August 2022), along
with some extra informations (e.g. solar wind dynamic pressure and position of
the standoff distances inferred from Joy et al. (2002)). We then select two
compression events that occur in succession (inferred from magnetopause
crossings) and we present a case study of the response of the Jovian radio
emissions. We demonstrate that magnetospheric compressions lead to the
activation of new radio sources. Newly activated broadband kilometric emissions
are observed almost simultaneously to compression of the magnetosphere, with
sources covering a large range of longitudes. Decametric emission sources are
seen to be activated more than one rotation later only at specific longitudes
and dusk local times. Finally, the activation of narrowband kilometric
radiation is not observed during the compression phase, but when the
magnetosphere is in its expansion phase
Utility of Computed Tomographic Angiography for Pulmonary Hypertension Assessment in a Cohort of West Highland White Terriers With or Without Canine Idiopathic Pulmonary Fibrosis
West Highland white terriers (WHWTs) affected with canine idiopathic pulmonary fibrosis (CIPF) are at risk of developing precapillary pulmonary hypertension (PH). In humans, thoracic computed tomography angiography (CTA) is commonly used to diagnose and monitor patients with lower airway diseases. In such patients, CTA helps to identify comorbidities, such as PH, that could negatively impact prognosis. Diameter of the pulmonary trunk (PT), pulmonary trunk-to-aorta ratio (PT/Ao), and right ventricle-to-left ventricle ratio (RV/LV) are CTA parameters commonly used to assess the presence of PH. Pulmonary vein-to-right pulmonary artery ratio (PV/PA) is a new echocardiographic parameter that can be used in dogs to diagnose PH. The primary aim of this study was to evaluate the use of various CTA parameters to diagnose PH. An additional aim was to evaluate the correlation of RV/LV measurements between different CTA planes. CTA and echocardiography were prospectively performed on a total of 47 WHWTs; 22 affected with CIPF and 25 presumed healthy control dogs. Dogs were considered to have PH if pulmonary vein-to-right pulmonary artery ratio (PV/PA) measured on 2D-mode echocardiography was less than to 0.7. WHWTs affected with CIPF had higher PT/Ao compared with control patients. In WHWTs affected with CIPF, PT size was larger in dogs with PH (15.4 mm) compared with dogs without PH (13 mm, p = 0.003). A cutoff value of 13.8 mm predicted PH in WHWTs affected with CIPF with a sensitivity of 90% and a specificity of 87% (AUC = 0.93). High correlations were observed between the different CTA planes of RV/LV. Results suggest that diameter of the PT measured by CTA can be used to diagnose PH in WHWTs with CIPF
The prevalence of pulmonary hypertension assessed using the pulmonary vein‐to‐right pulmonary artery ratio and its association with survival in West Highland white terriers with canine idiopathic pulmonary fibrosis
Background: Pulmonary hypertension (PH) is a known co-morbidity in West Highland white terriers (WHWTs)
affected with canine idiopathic pulmonary fibrosis (CIPF). The pulmonary vein-to-right pulmonary artery ratio (PV/
PA) has recently been described for the detection of pre-capillary PH in dogs. The objective of the present study
was to estimate the prevalence of PH at diagnostic, in WHWTs affected with CIPF, by using PV/PA, in comparison
with a group of healthy breed-matched controls (CTRLs). Additional study objective was to expl
Effects of hyperoxia and cardiovascular risk factors on myocardial ischaemia-reperfusion injury: a randomized, sham-controlled parallel study.
peer reviewedThe beneficial effects of supplemental oxygen in patients with acute myocardial infarction are still uncertain: what are the effects of ischaemia-reperfusion injury during hyperoxia and normoxia in mature rats with and without cardiovascular risk factors? What is the main finding and its importance? Despite elevated baseline oxidative stress in rodents with cardiovascular risk factors, hyperoxic reperfusion limited myocardial necrosis and anti/pro-oxidant imbalance in spontaneously hypertensive and Zucker rats. In contrast, this effect was exacerbated in healthy Wistar rats. These results suggest that oxygen supplementation may not be harmful in patients with acute myocardial injury.
ABSTRACT: Recent studies on O2 supplementation in acute coronary syndrome patients are equivocal. We tested the hypothesis that oxidative stress is increased in rodents with cardiovascular risk factors and enhances ischaemia-reperfusion injury in the presence of hyperoxia. A total of 43 Wistar rats (WR), 30 spontaneously hypertensive rats (SHR) and 33 obese Zucker rats (ZR) were randomized in a sham procedure (one-third) or underwent a left anterior descending ligation of the coronary artery for 60 min (two-thirds). This was followed by 3 h of reperfusion while animals were randomized either in a hyperoxic (HR) or a normoxic reperfusion (NR) group. Myocardial infarction size and oxidative stress biomarkers (myeloperoxidase (MPO), malondialdehyde and total free thiols) were assessed in blood samples. Baseline troponin T was higher in SHR and ZR than in WR (both P < 0.001). Baseline total MPO was elevated in ZR in comparison to SHR and WR (both P < 0.001). SHR had lower thiol concentration compared to WR and ZR (P < 0.000001). HR was associated with a lower troponin T rise in SHR and ZR than in NR (both P < 0.001), while the reverse occurred in WR (P < 0.001). In SHR, HR limited total MPO increase as compared to NR (P = 0.0056) and the opposite effect was observed with total MPO in WR (P = 0.013). NR was associated with a drastic reduction of total thiols as compared to HR both in SHR and in ZR (both P < 0.001). Despite a heightened baseline oxidative stress level, HR limited myocardial necrosis and anti/pro-oxidant imbalance in SHR and ZR whereas this effect was exacerbated in healthy WR
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