Miracle-dz/UniFAR-FTUs huggingface dataset:
Purchasing a Service Online: Do Brazilians Perceive it as Risky?

ABSTRACT Marketing literature presents evidence that perceived risk may be one of the deterrents preventing the quicker spread of the Internet as a purchasing channel. This study investigates the relative importance of dimensions of risk when the consumer in Brazil is deciding on purchasing a service online. The results suggest that value for money (corresponding to a combination of financial and performance risks) and psychological risk were the only dimensions considered relevant by the respondents when making their online purchase decision. Time risk seemed to be mediated by these two dimensions. The implications of this study can be applied by both marketing professionals and academic researchers. RESUMEN. La literatura de mercadeo presenta pruebas de que el riesgo percibido puede ser uno de los obstáculos que previenen la diseminación acelerada de la Internet como un canal de compras. Este estudio investiga la importancia relativa de las dimensiones del riesgo inherentes al instante en que el consumidor en Brasil decide comprar un servicio en línea. Los resultados sugieren que el valor monetario (que corresponde a los riesgos financieros y de desempeño) así como el riesgo psicológico fueron las únicas dimensiones que los encuestados consideraron importantes durante la toma de decisión de efectuar compras en línea. El riesgo inherente al tiempo parecía estar atenuado por estas dos dimensiones. Las implicancias de este estudio pueden aplicarse tanto a los profesionales de mercado como a los investigadores académicos. RESUMO. A literatura sobre Marketing mostra evidências de que o risco considerado possa ser um dos obstáculos à expansão mais rápida da Internet como canal de compras. Este estudo analisa a importância relativa das dimensões do risco, no momento de o consumidor brasileiro decidir-se pela compra de um serviço online. Os resultados sugerem que o valor monetário (correspondente aos riscos financeiros e de desempenho) e o risco psicológico foram as únicas dimensões consideradas relevantes pelos respondentes, ao tomarem a decisão de fazer uma compra online. O risco do tempo parece atenuado por estas duas dimensões. As conclusões deste estudo podem ser utilizadas tanto pelos profissionais de marketing quanto pelos pesquisadores acadêmicos.
Stochastic Restricted Maximum Likelihood Estimator in Logistic Regression Model

In the presence of multicollinearity in logistic regression, the variance of the Maximum Likelihood Estimator (MLE) becomes inflated. Siray et al. (2015) [1] proposed a restricted Liu estimator in logistic regression model with exact linear restrictions. However, there are some situations, where the linear restrictions are stochastic. In this paper, we propose a Stochastic Restricted Maximum Likelihood Estimator (SRMLE) for the logistic regression model with stochastic linear restrictions to overcome this issue. Moreover, a Monte Carlo simulation is conducted for comparing the performances of the MLE, Restricted Maximum Likelihood Estimator (RMLE), Ridge Type Logistic Estimator(LRE), Liu Type Logistic Estimator(LLE), and SRMLE for the logistic regression model by using Scalar Mean Squared Error (SMSE).
Government Quality, Auditor Choice and Adoption of IFRS: A Cross Country Analysis

We examine the association between country-level government quality and firms’ choice of external auditors. Using a cross-sectional sample of 142,193 firm-year observations from 46 countries over 1998-2007, we show that the government quality of a country has a significant positive effect on the likelihood of choosing Big 4 auditors by firms in that country. We also show that firms in countries with strong governments that have adopted IFRS are more likely to choose Big 4 than non-Big 4 auditors. To our knowledge, this is the first study of its kind to provide direct evidence on the role of government quality in firms’ choice of external auditors. Choice of a Big 4 auditor may be regarded as a proxy for the demand for high quality financial reporting, and thus the results provide insights for policy makers on the importance of government quality improving financial reporting quality in a country.
A two-step Notch-dependant mechanism controls the selection of the polar cell pair in Drosophila oogenesis

Organisers control the patterning and growth of many tissues and organs. Correctly regulating the size of these organisers is crucial for proper differentiation to occur. Organiser activity in the epithelium of the Drosophila ovarian follicle resides in a pair of cells called polar cells. It is known that these two cells are selected from a cluster of equivalent cells. However, the mechanisms responsible for this selection are still unclear. Here, we present evidence that the selection of the two cells is not random but, by contrast, depends on an atypical two-step Notch-dependant mechanism. We show that this sequential process begins when one cell becomes refractory to Notch activation and is selected as the initial polar cell. This cell then produces a Delta signal that induces a high level of Notch activation in one other cell within the cluster. This Notch activity prevents elimination by apoptosis, allowing its selection as the second polar cell. Therefore, the mechanism used to select precisely two cells from among an equivalence group involves an inductive Delta signal that originates from one cell, itself unable to respond to Notch activation, and results in one other cell being selected to adopt the same fate. Given its properties, this two-step Notch-dependent mechanism represents a novel aspect of Notch action.
High levels of histone H3 acetylation at the CMV promoter are predictive of stable expression in Chinese hamster ovary cells

Chinese hamster ovary cells (CHO) are widely used in the production of glycosylated therapeutic proteins such as antibodies. During expansion and maintenance, CHO cell lines are prone to production instability, which may be caused by promoter silencing, loss of transgene copies, or post‐transcriptional effects. Silencing of recombinant genes may be accompanied by DNA methylation and histone modification. Previously, we demonstrated that cytosine methylation of the human cytomegalovirus major immediate early promoter/enhancer (hCMV‐MIE) can be used to predict instability of antibody‐producing CHO cell lines. However, the high rate of false prediction motivates the search for further markers of stable promoter activity. To this end, we correlated a variety of histone modifications in the vicinity of hCMV‐MIE with production stability over time. Our results suggest that acetylation of histone H3 (H3ac) is a more effective indicator of production stability than DNA methylation. Selecting cell lines with highest CMV promoter H3ac levels enriches stable expressors and improves the average stability of production cell lines. For histone H3 acetylation measurement we employed a method based on chromatin immunoprecipitation (ChIP). In its current form, the method is suitable to evaluate 10−20 cell lines within a few days. We propose to determine H3 acetylation once the number of candidate cell lines has been narrowed based on productivity and product quality. © 2016 American Institute of Chemical Engineers Biotechnol. Prog. , 32:776–786, 2016
Compared effects of serotonin on cervical and hypoglossal inspiratory activities: an in vitro study in the newborn rat.

1. Experiments were performed on the brain stem‐spinal cord preparation of newborn rats, in which the phrenic and hypoglossal nerves continue to show rhythmic respiratory activity in vitro, in order to compare the effects of serotonin (5‐HT) on both activities and to analyse the mechanisms responsible for the depression by 5‐HT of the hypoglossal activity. 2. Under control conditions, simultaneous recordings of the inspiratory discharges of hypoglossal and cervical roots showed that the two bursts did not start simultaneously and had different patterns (time‐to‐peak and peak values); this suggests that both pools of motoneurons did not share the same central drive(s). 3. Adding 5‐HT and related agents to the bathing medium delayed and depressed the hypoglossal inspiratory discharge via activation of 5‐HT2 receptors since these effects were elicited by 5‐HT2 agonists (alpha‐methyl‐5‐HT and 1‐(2,5‐dimethoxy‐4‐iodophenyl)‐2‐aminopropane‐HCl (DOI)) but not by 5‐HT1 agonists (RU 24969 and (+/‐)‐8‐hydroxy‐2‐(di‐N‐propylamino)tetralin hydrobromide (8‐OH‐DPAT)). The 5‐HT depression of the hypoglossal discharge was prevented by applying a pretreatment with a specific 5‐HT2 antagonist (ketanserin). Parallel to the hypoglossal discharge decrease, 5‐HT elicited a permanent cervical root discharge along with a persistent inspiratory bursting. Adding the 5‐HT precursor L‐tryptophan to the bathing medium depressed the hypoglossal (XII) discharge without affecting the cervical one. 4. Local application of 5‐HT within the hypoglossal motor nucleus decreased the hypoglossal output, revealing that the 5‐HT depression of the hypoglossal discharge was at least partly mediated by the 5‐HT effects at the level of the motoneurons. Local application of 5‐HT within the cervical motor nucleus elicited a permanent firing in the cervical root with a persistent inspiratory bursting. 5. Intracellular analysis confirmed the existence of differences in central respiratory drive between cervical and hypoglossal motoneurons under control conditions, as well as differences in response to 5‐HT. All the hypoglossal motoneurons became silent under 5‐HT bathing, and showed no change in the input membrane resistance, a moderate depolarization, and a delayed central respiratory drive with a decreased amplitude. The cervical motoneurons became more active during inspiration, despite a decrease in the amplitude of the central respiratory drive, which was compensated for by a large depolarization and an increased input membrane resistance. Some cervical motoneurons even fired at a low rate during expiration. (ABSTRACT TRUNCATED AT 400 WORDS)
Differences in ventilatory inefficiency between pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension.

BACKGROUND Measures of ventilatory efficiency during cardiopulmonary exercise testing (CPX) are increasingly being used as prognostic markers in heart failure and pulmonary hypertension (PH). Little is known about whether these measures can be applied to all forms of PH, in particular chronic thromboembolic pulmonary hypertension (CTEPH), wherein thrombotic vascular occlusion has an impact on gas exchange. METHODS One hundred twenty-seven patients, 50 with CTEPH and 77 with pulmonary arterial hypertension (PAH), underwent incremental CPX. RESULTS Physiologic ventilatory dead space fraction (Vd/Vtphys) measured at peak exercise with arterial blood gas analysis was higher in CTEPH than PAH (52.9% vs 41.8%, P < .001). The V(E)/V(CO(2)) slope was higher in patients with CTEPH than in patients with PAH (50.7 L/min/L/min vs 44.4 L/min/L/min, P = .024) and was mirrored by similar changes in the ventilatory equivalent for CO(2) at anaerobic threshold (Eqco(2)_AT) (47.7 L/min/L/min vs 42.0 L/min/L/min, P = .008). In a multivariate linear regression analysis, disease subtype was found to be an independent predictor of Vd/Vtphys (P < .001), V(E)/V(CO(2)) slope (P = .003), and Eqco(2)_AT (P < .001). These three measures could distinguish between World Health Organization functional classes I/II and III/IV in PAH but not CTEPH. CONCLUSION Significant differences in gas exchange exist between CTEPH and PAH, due to differences in Vd/Vtphys likely as a result of vascular occlusion due to thromboembolic disease. This dissociates measures of ventilatory efficiency from disease severity and also contributes to our understanding of the differences in exercise limitation and breathlessness in PAH and CTEPH. Common prognostic end points from CPX cannot be applied to all forms of PH.
THE NOVEMBER EFFECT AND TAX LOSS SELLING: AN EMPIRICAL INVESTIGATION

The January Effect is a well-documented stock market anomaly that is characterized by abnormally high stock returns in the first couple of weeks of the New Year. The predominant explanation of why this January Effect exists is the tax loss-selling hypothesis, which states that stocks are sold towards the end of the year for tax reasons and subsequently re-bought at the first of the year. The passage of the Tax Reform Act of 1986, which changed the fiscal year end for institutional investors from December 31st to October 31st, allows the authors to test in isolation the tax loss-selling hypothesis. Two things should be expected as a result of the Tax Reform Act: First, the existence of a so-called "November Effect" post 1986, and second, the dissipation of the January Effect. The evidence presented in the paper cooborates neither.
B Cell Antigen Receptor-Induced Rac1 Activation and Rac1-Dependent Spreading Are Impaired in Transitional Immature B Cells Due to Levels of Membrane Cholesterol1

The BCR-triggered responses of mature and transitional immature B cells differ at both the biochemical and functional level. In this study, we show that in mature B cells, BCR signaling triggers Vav phosphorylation and Rac1 activation. Furthermore, we demonstrate that although downstream actin-dependent BCR capping is independent of Rac1 activation, actin-dependent membrane ruffling and cell spreading are Rac1-dependent processes. In contrast, BCR-induced Vav phosphorylation and Rac1 activation is impaired in transitional immature B cells, resulting in defects in actin polymerization-dependent spreading and membrane ruffling while Rac1-independent BCR capping remains intact. Because transitional immature murine B cells maintain lower steady-state levels of plasma membrane cholesterol, we augmented their levels to that of mature B cells and found that BCR-induced Rac1 activation and Rac1-dependent membrane ruffling and cell spreading were restored. These studies provide a direct link between B cell cholesterol levels and downstream cellular signaling processes.
Sphingosine Kinase and Sphingosine-1-Phosphate Regulate Migration, Endocytosis and Apoptosis of Dendritic Cells

Dendritic cells (DC) are inducers of primary immune responses and represent an attractive vector for cancer immunotherapy. Sphingosine kinase (SphK) and its product sphingosine-1-phosphate (S1P) play an important role in the regulation of immune cells and cancer, affecting processes such as differentiation, growth or migration. We studied the role of SphK and S1P on migration of DC. RT-PCR showed mRNA expression of SphK in DC, declining from immature (iDC) to mature DC (mDC) to antigen-loaded mDC. Expression of S1P receptors was S1P1 > S1P2 = S1P3, unrelated to maturation or antigen uptake. In transwell assays, iDC migrated towards SDF-1, MIP-1α, MCP and S1P, whereby S1P combined with a chemokine had a synergistic effect. mDC migrated towards 6Ckine and MIP-3β, but not towards S1P. The SphK-inhibitor dihydro-sphingosine (DHS) reduced migration of iDC but not of mDC. In addition S1P3-inhibitor suramin inhibited DC migration in response to S1P. DHS had a reverse effect on endocytosis, enhancing the uptake of FITC dextran. We also observed an anti-apoptotic effect of S1P on mDC for the first time. This indicates that SphK/S1P may play a role in accumulation of peripheral iDC at the location of antigen and subsequent antigen-uptake. These findings may help to optimise DC-based cancer immunotherapy by modulation of SphK/S1P.
Heparin is required for cell-free binding of basic fibroblast growth factor to a soluble receptor and for mitogenesis in whole cells

Heparin is required for the binding of basic fibroblast growth factor (bFGF) to high-affinity receptors on cells deficient in cell surface heparan sulfate proteoglycan. So that this heparin requirement could be evaluated in the absence of other cell surface molecules, we designed a simple assay based on a genetically engineered soluble form of murine FGF receptor 1 (mFR1) tagged with placental alkaline phosphatase. Using this assay, we showed that FGF-receptor binding has an absolute requirement for heparin. By using a cytokine-dependent lymphoid cell line engineered to express mFR1, we also showed that FGF-induced mitogenic activity is heparin dependent. Furthermore, we tested a series of small heparin oligosaccharides of defined lengths for their abilities to support bFGF-receptor binding and biologic activity. We found that a heparin oligosaccharide with as few as eight sugar residues is sufficient to support these activities. We also demonstrated that heparin facilitates FGF dimerization, a property that may be important for receptor activation.
Interactions in Insurance Classifications

California developed territorial boundaries for the California Automobile Assigned Risk Plan on the basis of the "driver performance composite index" (DPCI), a summary measure of the experience of drivers residing in each of some 1800 Zip Codes in that State. This paper discusses some of the shortcomings of the DPCI and suggests other measures that could be useful in recognizing real differences in experience among geographic units. The paper also discusses the effects due to correlation with other rating variables. The ultimate impact of these problems cannot be measured because the process by which boundaries were drawn was subjective. The potential impact, assessed by measuring the correlation between indices which correct for other rating variables the original index, could be substantial.
Y-Configuration Stent Placement (Crossing and Kissing) for Endovascular Treatment of Wide-Neck Cerebral Aneurysms Located at 4 Different Bifurcation Sites

BACKGROUND AND PURPOSE: The Y-stent technique, including crossing-Y and kissing-Y, is a promising therapeutic option for some complex bifurcation aneurysms. Here, its efficacy and safety are evaluated on the basis of 11 bifurcation aneurysms. MATERIALS AND METHODS: A retrospective review was conducted for all patients who underwent endovascular treatment of aneurysms in our department between January 2009 and June 2011 to identify and analyze cases with bifurcation aneurysms reconstructed by using Y-stents. RESULTS: Eleven patients (4 ruptured and 7 unruptured aneurysms) were identified (4 men, 7 women) with a mean age of 60.4 years. Nine aneurysms (2 AcomAs, 3 MCA-Bifs, 1 PcomA, 3 BA apexes) were treated by using the crossing-Y technique, and 2 (both BA apexes) were treated with the kissing-Y technique, achieving complete occlusion in 6 aneurysms, residual neck in 4, and partial occlusion in 1. Perioperatively, a single thromboembolic event occurred in 1 case without neurologic deficit, which required a salvaging second stent implantation. Means of 9.9 months of angiographic and 13.7 months of clinical follow-up were available. As a result, 9 (81.8) aneurysms were completely occluded, 1 with a residual neck remained stable, and 1 residual aneurysm sac was recanalized, which was retreated and achieved a complete occlusion. All patients were independent with an mRS score of 0–1 at discharge and follow-up. CONCLUSIONS: In selected patients, the reconstruction of bifurcation aneurysms by using the Y-stent can be successfully achieved with satisfactory midterm results.
Lack of sex difference in cerebrospinal fluid (CSF) leptin levels and contribution of CSF/plasma ratios to variations in body mass index in children.

In adults, leptin seems to cross the blood-brain barrier by a saturable transporter. This may contribute to the development of obesity. The present study in healthy children investigates leptin levels in plasma and cerebrospinal fluid (CSF) in relation to body constitution. This prospective study analyzed leptin levels in plasma and CSF samples (stored at -80 C) of patients without CNS infection or blood-brain barrier dysfunction. Inclusion criteria included temperature less than 38.5 C, C-reactive protein levels below 10 mg/L, CSF leukocyte levels less than 10(7)/L, no need for neurosurgical or oncological treatment, and no history of trauma. Four groups were designated according to body mass index. Sixty-five children (28 girls and 37 boys) entered the study. Plasma leptin (median) was 7.4 in girls and 2.6 ng/mL in boys. , CSF leptin was 0.273 and 0.204 ng/mL, respectively, leading to CSF/plasma ratios of 0.045 and 0.071, respectively. Ratios were clearly dependent on body mass index percentiles (r = -0.484; P < 0.01, significant differences between groups by ANOVA). Median plasma leptin levels in the 4 groups (body mass index, <10th, 10th-50th, 50th-90th, and >90th percentile) were 2.0, 2.3, 4.1, and 8.8 ng/mL; CSF/plasma ratios were inversely related: 8.2%, 7.6%, 5.5% and 3.6%. In healthy children, CSF leptin levels account for approximately 5% of plasma levels. CSF/plasma ratios in girls are lower than those in boys, explaining why calorie intake and energy expenditure are not grossly different despite large differences in circulating plasma leptin concentrations. CSF/plasma ratios of lean children are higher than those in obese children. The dynamic changes in the CSF/plasma ratios are more pronounced in lean children, i.e. the nonlinear transport characteristics of the leptin system amplifies the information about changes in body energy stores in this population, indicating that leptin is part of a mechanism to protect the body from critical weight loss rather than to avoid obesity.
Output and Employment Input-Output Multipliers on the basis of Use and Make Matrices

In the literature, the construction of technical coefficients is linked to flow data (use and make matrices), but stochastics are imposed on the coefficients when multipliers are calculated, by means of the Leontief inverse. Due the nonlinearity of this operation, the multiplier estimates are biased (it is generally argued that the Leontief inverse underestimates input-output multipliers). By going back to the flow data, this paper provides unbiased and consistent employment and output multipliers input-output estimates for the Andalusian economy. Rectangular use and make matrices are accommodated and technical coefficients, the Leontief inverse, and associated problems (such as negative coefficients) are circumvented.
Coexistence Gaps in Space: Cross-Technology Interference-Nulling for Improving LTE-U/WiFi Coexistence

To avoid the foreseeable spectrum crunch, LTE operators have started to explore the option to directly use 5 GHz unlicensed spectrum band being used by IEEE 802.11 (WiFi). However, as LTE is not designed with shared spectrum access in mind, there is a major issue of coexistence with WiFi networks. Current coexistence schemes to be deployed at the LTE-U BS create coexistence gaps only in one domain (e.g., time, frequency, or space) and can provide only incremental gains due to the lack of coordination among the coexisting WiFi and LTE-U networks. Therefore, we propose a coordinated coexistence scheme which relies on cooperation between neighboring LTE-U and WiFi networks. Our proposal suggests that LTE-U BSs equipped with multiple antennas can create coexistence gaps in space domain in addition to the time domain gaps by means of cross-technology interference nulling towards WiFi nodes in the interference range. In return, LTE-U can increase its own airtime utilization while trading off slightly its antenna diversity. The cooperation offers benefits to both LTE-U and WiFi in terms of improved throughput and decreased channel access delay. More specifically, system-level simulations reveal a throughput gain up to 221% for LTE-U network and 44% for WiFi network depending on the setting, e.g., the distance between the two cell, number of LTE antennas, and WiFi users in the LTE-U BS neighborhood. Our proposal provides significant benefits especially for moderate separation distances between LTE-U/WiFi cells where interference from a neighboring network might be severe due to the hidden network problem.