1,217 research outputs found
EVALUATION OF SOLIDS CARRYING CAPACITY IN AERATED FLUID DRILLING: REAL SCALE TESTS AND MODELING
This paper summarizes the results of two sets of experimental tests performed at PETROBRAS real scale test facility aiming the evaluation of solids return times in aerated fluid drilling. The effect of the following parameters was studied: liquid and gas injection rates, particle diameter and depth. Results indicate that the gas has a major effect in accelerating the liquid phase, which would be responsible for carrying the particles to the surface. The concept of effective liquid velocity coupled with an adequate procedure for particle sedimentation velocity calculation reproduced the experimental results adequately
National culture and earnings management in developed and emerging countries
Purpose
This study investigates how the association between national culture and earnings management compares between developed and emerging countries.
Design/methodology/approach
The empirical analysis relies on a sample of 6,313 firm-year observations from 11 emerging markets and 27,605 firm-year observations from 22 developed countries. The authors use ordinary least squares regression methods to test the hypotheses of the study.
Findings
Based on Hofstede's (2011) cultural dimensions, the authors find that firms from countries with a higher level of uncertainty avoidance and individualism are less likely to engage in earnings management, but the effect of uncertainty avoidance (individualism) is more (less) pronounced in the emerging countries. Moreover, the authors demonstrate that firms from emerging (developed) countries with higher levels of power distance and masculinity are less (more) likely to engage in earnings management. Finally, the authors find evidence of a trade-off between accruals-based and real earnings management in firms from countries with greater long-term orientation and an indulgence cultural dimension.
Originality/value
This paper adds to the literature by theoretically discussing and empirically analysing the role that developed and emerging countries' development plays on the effect of national culture on earnings management.info:eu-repo/semantics/acceptedVersio
Narrowing the gap of personalized medicine in emerging countries: the case of multiple endocrine neoplasias in Brazil
The finished version of the human genome sequence was completed in 2003, and this event initiated a revolution in medical practice, which is usually referred to as the age of genomic or personalized medicine. Genomic medicine aims to be predictive, personalized, preventive, and also participative (4Ps). It offers a new approach to several pathological conditions, although its impact so far has been more evident in mendelian diseases. This article briefly reviews the potential advantages of this approach, and also some issues that may arise in the attempt to apply the accumulated knowledge from genomic medicine to clinical practice in emerging countries. The advantages of applying genomic medicine into clinical practice are obvious, enabling prediction, prevention, and early diagnosis and treatment of several genetic disorders. However, there are also some issues, such as those related to: (a) the need for approval of a law equivalent to the Genetic Information Nondiscrimination Act, which was approved in 2008 in the USA; (b) the need for private and public funding for genetics and genomics; (c) the need for development of innovative healthcare systems that may substantially cut costs (e.g. costs of periodic medical followup); (d) the need for new graduate and postgraduate curricula in which genomic medicine is emphasized; and (e) the need to adequately inform the population and possible consumers of genetic testing, with reference to the basic aspects of genomic medicine
Activation profile of pro-inflammatory cytokines in acute cardiac overload
INTRODUCTION:Pro-inflammatory cytokines have been implicated in ventricular remodeling during heart failure progression. In the present study, we investigated the effects of acute volume and RV pressure overload on biventricular hemodynamics and myocardial gene expression of IL-6 and TNF-alpha.METHODS:Male Wistar rats (n = 45) instrumented with RV and LV tip micromanometers were randomly assigned to one of three protocols: i) acute RV pressure overload (PrOv) induced by pulmonary trunk banding in order to double RV peak systolic pressure, for 120 or 360 min; ii) acute volume overload (VolOv) induced by dextran40 infusion (5 ml/h), for 120 or 360 min; iii) Sham. Free wall samples from the RV and LV were collected for mRNA quantification.RESULTS:In the RV, acute overload induced IL-6 and TNF-alpha gene expression, higher in VolOv (IL-6: + 669.7 +/- 263.4%; TNF-alpha: + 5149.9 +/- 1099.0%; 360 min) than in PrOv (IL-6: + 64.9 +/- 44.2%; TNF-alpha: + 628.1 +/- 229.3%; 360 min). In PrOv, TNF-alpha mRNA levels in the LV were increased, in the absence of ventricular overload. IL-6 and TNF-alpha mRNA levels did not correlate in the LV, while in the RV a positive correlation was found (r = 0.574; p < 0.001).CONCLUSIONS:Acute cardiac overload induces overexpression of pro-inflammatory cytokines. This gene activation is not uniform, being higher in volume overload and involving both load-dependent and load-independent mechanisms
Post-surgical follow-up of primary hyperparathyroidism associated with multiple endocrine neoplasia type 1
The bone mineral density increments in patients with sporadic primary hyperparathyroidism after parathyroidectomy have been studied by several investigators, but few have investigated this topic in primary hyperparathyroidism associated with multiple endocrine neoplasia type 1. Further, as far as we know, only two studies have consistently evaluated bone mineral density values after parathyroidectomy in cases of primary hyperparathyroidism associated with multiple endocrine neoplasia type 1. Here we revised the impact of parathyroidectomy (particularly total parathyroidectomy followed by autologous parathyroid implant into the forearm) on bone mineral density values in patients with primary hyperparathyroidism associated with multiple endocrine neoplasia type 1. Significant increases in bone mineral density in the lumbar spine and femoral neck values were found, although no short-term (15 months) improvement in bone mineral density at the proximal third of the distal radius was observed. Additionally, short-term and medium-term calcium and parathyroid hormone values after parathyroidectomy in patients with primary hyperparathyroidism associated with multiple endocrine neoplasia type 1 are discussed. In most cases, this surgical approach was able to restore normal calcium/parathyroid hormone levels and ultimately lead to discontinuation of calcium and calcitriol supplementation
Biochemical, bone and renal patterns in hyperparathyroidism associated with multiple endocrine neoplasia type 1
Primary hyperparathyroidism associated with multiple endocrine neoplasia type I (hyperparathyroidism/multiple endocrine neoplasia type 1) differs in many aspects from sporadic hyperparathyroidism, which is the most frequently occurring form of hyperparathyroidism. Bone mineral density has frequently been studied in sporadic hyperparathyroidism but it has very rarely been examined in cases of hyperparathyroidism/multiple endocrine neoplasia type 1. Cortical bone mineral density in hyperparathyroidism/multiple endocrine neoplasia type 1 cases has only recently been examined, and early, severe and frequent bone mineral losses have been documented at this site. Early bone mineral losses are highly prevalent in the trabecular bone of patients with hyperparathyroidism/multiple endocrine neoplasia type 1. In summary, bone mineral disease in multiple endocrine neoplasia type 1related hyperparathyroidism is an early, frequent and severe disturbance, occurring in both the cortical and trabecular bones. In addition, renal complications secondary to sporadic hyperparathyroidism are often studied, but very little work has been done on this issue in hyperparathyroidism/multiple endocrine neoplasia type 1. It has been recently verified that early, frequent, and severe renal lesions occur in patients with hyperparathyroidism/multiple endocrine neoplasia type 1, which may lead to increased morbidity and mortality. In this article we review the few available studies on bone mineral and renal disturbances in the setting of hyperparathyroidism/multiple endocrine neoplasia type 1. We performed a meta-analysis of the available data on bone mineral and renal disease in cases of multiple endocrine neoplasia type 1-related hyperparathyroidism
Endogenous production of ghrelin and beneficial effects of its exogenous administration in monocrotaline-induced pulmonary hypertension
We investigated the endogenous production of ghrelin as well as cardiac and pulmonary vascular effects of its administration in a rat model of monocrotaline (MCT)-induced pulmonary hypertension (PH). Adult Wistar rats randomly received a subcutaneous injection of MCT (60 mg/kg) or an equal volume of vehicle. One week later, animals were randomly assigned to receive a subcutaneous injection of ghrelin (100 mug/kg bid for 2 wk) or saline. Four groups were analyzed: normal rats treated with ghrelin (n = 7), normal rats injected with saline (n = 7), MCT rats treated with ghrelin (n = 9), and MCT rats injected with saline (n = 9). At 22-25 days, right ( RV) and left ventricular (LV) pressures were measured, heart and lungs were weighted, and samples were collected for histological and molecular analysis. Endogenous production of ghrelin was almost abolished in normal rats treated with ghrelin. In MCT-treated animals, pulmonary expression of ghrelin was preserved, and RV myocardial expression was increased more than 20 times. In these animals, exogenous administration of ghrelin attenuated PH, RV hypertrophy, wall thickening of peripheral pulmonary arteries, and RV diastolic disturbances and ameliorated LV dysfunction, without affecting its endogenous production. In conclusion, decreased tissular expression of ghrelin in healthy animals but not in PH animals suggests a negative feedback in the former that is lost in the latter. A selective increase of ghrelin mRNA levels in the RV of animals with PH might indicate distinct regulation of its cardiac expression. Finally, ghrelin administration attenuated MCT-induced PH, pulmonary vascular remodeling, and RV hypertrophy, indicating that it may modulate PH
Testing and modeling of a traditional timber mortise and tenon joint
The structural safety and behaviour of traditional timber structures depends significantly on the performance of their connections. The behaviour of a traditional mortise and tenon timber joint is addressed using physical testing of full-scale specimens. New chestnut wood and old chestnut wood obtained from structural elements belonging to ancient buildings is used. In addition, the performance of different semi and non-destructive techniques for assessing global strength is also evaluated. For this purpose, ultrasonic testing, micro-drilling and surface penetration are considered, and the possibility of their application is discussed based on the application of simple linear regression models. Finally, nonlinear finite element analysis is used to better understand the behaviour observed in the full-scale experiments, in terms of failure mode and ultimate load. The results
show that the ultrasonic pulse velocity through the joint provides a reasonable estimate for the effective-
ness of the assembly between the rafter and brace and novel linear regressions are proposed. The failure mechanism and load–displacement diagrams observed in the experiments are well captured by the proposed non-linear finite element analysis, and the parameters that affect mostly the ultimate load of the timber joint
are the compressive strength of wood perpendicular to the grain and the normal stiffness of the interface elements representing the contact between rafter and brace
Is there a proximal shift in the distribution of colorectal adenomas?
INTRODUCTION:
Several studies have shown a proximal shift of colorectal cancer (CRC) during the last decades. However, few have analyzed the changing distribution of adenomas over time.
AIM:
The aim of this study was to compare the site and the characteristics of colorectal adenomas, in a single center, during two periods.
METHODS:
We conducted a retrospective, observational study in a single hospital of adenomas removed during a total colonoscopy in two one-year periods: 2003 (period 1) and 2012 (period 2). Patients with inflammatory bowel disease, familial adenomatous polyposis, hereditary non-polyposis colorectal cancer syndrome, or history of CRC were excluded from the study. The χ(2) statistical test was performed. P values less than 0.05 were considered statistically significant.
RESULTS:
During the two considered periods, a total of 864 adenomas from 2394 complete colonoscopies were analyzed: 333 adenomas from 998 colonoscopies during period 1 and 531 adenomas from 1396 colonoscopies during period 2. There was a significant increase in the proportion of adenomatous polyps in the proximal colon from period 1 to 2 (30.6% to 38.8% (p = 0.015)). Comparing the advanced features of adenomas between the two periods, it was noted that in period 2, the number of adenomas with size ≥1 cm (p = 0.001), high-grade dysplasia (p = 0.001), and villous features (p < 0.0001) had a significant increase compared to period 1.
CONCLUSION:
Incidence of adenomatous polyps in the proximal colon as well as adenomas with advanced features has increased in the last years. This finding may have important implications regarding methods of CRC screening
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