Miracle-dz/UniFAR-FTUs huggingface dataset:
Value Creation in eBusiness: Exploring the Impacts of Internet-Enabled Business Conduct

This research seeks to explore value creation through e-business by emphasizing the impacts of Internet-enabled business conduct. We assume that firms may reap the benefits of engaging in e-business only if they are able to develop, adopt and use Internet-enabled business models (e-business models). Moreover, e-business value is created only if firms adopt e-business models that respond to relevant value drivers. Value drivers are certain key aspects of the business model that play a key role and possess the power of directly influencing e-business value creation. In this study, several economic and financial performance measures were used as value indicators. A survey was conducted in Norwegian enterprises. This research confirms that e-business is in its infancy. Moreover, in addition to a fairly limited e-business experience, the participating enterprises seem to have put all their efforts into relatively simple and primitive ebusiness solutions. Hence, the power of the Internet is wasted on solutions that basically support the automation of existing and traditional business processes. For a vast majority of the enterprises participating in this study, there have been no significant changes in key economic and financial indicators since they took up e-business. However, our research demonstrates that there is an association between value creation and e-business conduct. E-business value creation is associated with relevant e-business value drivers, namely efficiency, complementarities, customer retention, and innovation.
Approximation Algorithms for Hypergraph Small-Set Expansion and Small-Set Vertex Expansion

The expansion of a hypergraph, a natural extension of the notion of expansion in graphs, is defined as the minimum over all cuts in the hypergraph of the ratio of the number of the hyperedges cut to the size of the smaller side of the cut. We study the Hypergraph Small Set Expansion problem, which, for a parameter $\delta \in (0,1/2]$, asks to compute the cut having the least expansion while having at most $\delta$ fraction of the vertices on the smaller side of the cut. We present two algorithms. Our first algorithm gives an $\tilde O(\delta^{-1} \sqrt{\log n})$ approximation. The second algorithm finds a set with expansion $\tilde O(\delta^{-1}(\sqrt{d_{\text{max}}r^{-1}\log r\, \phi^*} + \phi^*))$ in a $r$--uniform hypergraph with maximum degree $d_{\text{max}}$ (where $\phi^*$ is the expansion of the optimal solution). Using these results, we also obtain algorithms for the Small Set Vertex Expansion problem: we get an $\tilde O(\delta^{-1} \sqrt{\log n})$ approximation algorithm and an algorithm that finds a set with vertex expansion $O\left(\delta^{-1}\sqrt{\phi^V \log d_{\text{max}} } + \delta^{-1} \phi^V\right)$ (where $\phi^V$ is the vertex expansion of the optimal solution). For $\delta=1/2$, Hypergraph Small Set Expansion is equivalent to the hypergraph expansion problem. In this case, our approximation factor of $O(\sqrt{\log n})$ for expansion in hypergraphs matches the corresponding approximation factor for expansion in graphs due to ARV.
Anthropomorphic Vs non-anthropomorphic software interface feedback for online factual delivery

We follow on from a group of internationally published papers in the area of investigating anthropomorphic user interface feedback. An experiment is described which aims to examine the effectiveness and user approval issues of anthropomorphic versus nonanthropomorphic user interface feedback. This experiment is highly relevant to the research community as computer scientists are not in agreement concerning the effectiveness and user approval of anthropomorphic user interfaces. The experiment described is in the context of online factual delivery. Specifically the area of direction finding was used to test anthropomorphic feedback against nonanthropomorphic feedback. Statistically significant results are presented for the benefit of the research community, where it is clear that in this context, the nonanthropomorphic user interface feedback was more effective and users tended to prefer this feedback.
Drivers of long-term variability in CO 2 net ecosystem exchange in a temperate peatland

Abstract. Land–atmosphere exchange of carbon dioxide (CO2) in peatlands exhibits marked seasonal and inter-annual variability, which subsequently affects the carbon (C) sink strength of catchments across multiple temporal scales. Long-term studies are needed to fully capture the natural variability and therefore identify the key hydrometeorological drivers in the net ecosystem exchange (NEE) of CO2. Since 2002, NEE has been measured continuously by eddy-covariance at Auchencorth Moss, a temperate lowland peatland in central Scotland. Hence this is one of the longest peatland NEE studies to date. For 11 years, the site was a consistent, yet variable, atmospheric CO2 sink ranging from −5.2 to −135.9 g CO2-C m−2 yr−1 (mean of −64.1 ± 33.6 g CO2-C m−2 yr−1). Inter-annual variability in NEE was positively correlated to the length of the growing season. Mean winter air temperature explained 87% of the inter-annual variability in the sink strength of the following summer, indicating an effect of winter climate on local phenology. Ecosystem respiration (Reco) was enhanced by drought, which also depressed gross primary productivity (GPP). The CO2 uptake rate during the growing season was comparable to three other sites with long-term NEE records; however, the emission rate during the dormant season was significantly higher. To summarise, the NEE of the peatland studied is modulated by two dominant factors: - phenology of the plant community, which is driven by winter air temperature and impacts photosynthetic potential and net CO2 uptake during the growing season (colder winters are linked to lower summer NEE), - water table level, which enhanced soil respiration and decreased GPP during dry spells. Although summer dry spells were sporadic during the study period, the positive effects of the current climatic trend towards milder winters on the site's CO2 sink strength could be offset by changes in precipitation patterns especially during the growing season.
Au Nanoparticle Synthesis Via Femtosecond Laser-Induced Photochemical Reduction of [AuCl4]−

Laser-assisted metallic nanoparticle synthesis is a versatile “green” method that has become a topic of active research. This chapter discusses the photochemical reaction mechanisms driving AuCl4 1⁄2 reduction using femtosecond-laser irradiation, and reviews recent advances in Au nanoparticle size-control. We begin by describing the physical processes underlying the interactions between laser pulses and the condensed media, including optical breakdown and supercontinuum emission. These processes produce a highly reactive plasma containing free electrons, which reduce AuCl4 1⁄2 , and radical species producing H2O2 that cause autocatalytic growth of Au nanoparticles. Then, we discuss the reduction kinetics of AuCl4 1⁄2 , which follow an autocatalytic rate law in which the firstand second-order rate constants depend on free electrons and H2O2 availability. Finally, we explain strategies to control the size of gold nanoparticles as they are synthesized; including modifications of laser parameters and solution compositions.
Derivation of Error Distribution in Least Squares Steganalysis

This paper considers the least squares method (LSM) for estimation of the length of payload embedded by least-significant bit replacement in digital images. Errors in this estimate have already been investigated empirically, showing a slight negative bias and substantially heavy tails (extreme outliers). In this paper, (approximations for) the estimator distribution over cover images are derived: this requires analysis of the cover image assumption of the LSM algorithm and a new model for cover images which quantifies deviations from this assumption. The theory explains both the heavy tails and the negative bias in terms of cover-specific observable properties, and suggests improved detectors. It also allows the steganalyst to compute precisely, for the first time, a p-value for testing the hypothesis that a hidden payload is present. This is the first derivation of steganalysis estimator performance
Endoplasmic Reticulum Stress Signaling Is Involved in Mitomycin C(MMC)-Induced Apoptosis in Human Fibroblasts via PERK Pathway

Endoplasmic reticulum (ER) stress-mediated cell apoptosis has been implicated in various cell types, including fibroblasts. Previous studies have shown that mitomycin C (MMC)-induced apoptosis occurs in fibroblasts, but the effects of MMC on ER stress-mediated apoptosis in fibroblasts have not been examined. Here, MMC-induced apoptosis in human primary fibroblasts was investigated by exposing cells to a single dose of MMC for 5 minutes. Significant inhibition of cell proliferation and increased apoptosis were observed using a cell viability assay, Annexin V/propidium iodide double staining, cell cycle analysis, and TUNEL (terminal deoxynucleotidyl transferase dUTP nick-end labeling) staining. Upregulation of proapoptotic factors, including cleaved caspase-3 and poly ADP-ribose polymerase (PARP), was detected by Western blotting. MMC-induced apoptosis was correlated with elevation of 78-kDa glucose-regulated protein (GRP78) and C/EBP homologous protein (CHOP), which are hallmarks of ER stress. Three unfolded protein response (UPR) sensors (inositol-requiring enzyme 1, IRE1; activating transcription factor 6, ATF6; and PKR-like ER kinase, PERK) and their downstream signaling pathways were also activated. Knockdown of CHOP attenuated MMC-induced apoptosis by increasing the ratio of BCL-2/BAX and decreasing BIM expression, suggesting that ER stress is involved in MMC-induced fibroblast apoptosis. Interestingly, knockdown of PERK significantly decreased ER stress-mediated apoptosis by reducing the expression of CHOP, BIM and cleaved caspase-3. Reactive oxygen species (ROS) scavenging also decreased the expression of GRP78, phospho-PERK, CHOP, and BIM. These results demonstrate that MMC-induced apoptosis is triggered by ROS generation and PERK activation.
Development and Evaluation of Online Estimation Methods for Feedback-Based Freeway Ramp Metering Strategy

Critical density of a freeway link is subject to changes over time due to circumstances such as environmental conditions (snow, rain, etc.), traffic incidents. Because of its impacts on the performance of some ramp metering strategies that make use of critical density as a threshold value for control action, it is necessary to trace the real value of the critical density. Hence, methodologies for the on-line estimation of critical density using Extended Kalman Filtering (EKF) and Kalman Filtering (KF) were proposed in this paper. Basically, critical density was chosen as the state variable to be determined using system output, measurement of traffic flow on the downstream freeway link. Then, these methods are evaluated using microscopic simulation environment, PARAMICS. The results indicate that both methods (using KF and EKF) provide better performance in terms of tracing time-dependent changes of real critical occupancy effectively for all the scenarios tested compared with the case where constant critical occupancy used.
The receptive‐field spatial structure of cat retinal Y cells.

1. Y‐type ganglion cells in the cat's retina were stimulated with bars of light and grating patterns at photopic luminances. Stimuli were stationary, and luminance at each point was varied sinusoidally in time at 2 Hz. Impulse rates were recorded from single cells. 2. When the stimulus was a narrow bar of light, the impulse rate approached a sinusoidal function of time as contrast was reduced. The linear behaviour of each cell was therefore characterized by taking the limit of response parameters as contrast approached zero. 3. The ratio of surround strength to centre strength varied widely between cells but the two strengths were approximately equal on average. The difference between surround phase and centre phase averaged 168 deg. 4. As contrast increased, responses became rectified. Rectifier output was well described by a power law of stimulus amplitude, where the power was usually 1.4 or 1.5. 5. Response phase advanced with increasing contrast, and at high response amplitudes grew less than proportionally with contrast. These effects were assumed due to the contrast gain control described by Shapley & Victor (1978). 6. Gratings in which luminance varied sinusoidally with distance were used to determine Y cell spatial resolution. The second‐harmonic amplitude of the response diminished rapidly with increasing spatial frequency: the radius of the best‐fitting Gaussian mechanism was about 0.25 deg for a cell at 10 deg eccentricity. 7. This spatial resolution is close to the linear resolution of X cells as determined by Linsenmeier, Frishman, Jakiela & Enroth‐Cugell (1982). 8. A receptive field model incorporating both linear and non‐linear elements is described. The model consists of an array of subunit pathways, each of which has a centre‐surround organization followed by a rectifier; a pool weights and sums subunit outputs, and signals are then passed through a contrast gain control. 9. The model accounts qualitatively for the over‐all centre‐surround organization of Y cell linear responses, the dependence of frequency‐doubled responses on spatial frequency, and impulse rate as a function of time for a variety of bar and grating stimuli.
Motion characterization from temporal cooccurrences of local motion-based measures for video indexing

This paper describes an original approach for motion interpretation with a view to content-based video indexing. We exploit a statistical analysis of the temporal distribution of appropriate local motion-based measures to perform a global motion characterization. We consider motion features extracted from temporal cooccurrence matrices, and related to properties of homogeneity, acceleration or complexity. Results on various real video sequences are reported and provide a first validation of the approach.
The relationship between occupational psychological stress and female fertility.

OBJECTIVE To investigate the association between occupational psychological stress and female fertility. METHODS This was a case-control study including consecutive working female patients attending fertility and in vitro fertilization clinics in the Soroka University Medical Center. We compared occupational stress between 64 working patients who had attended the clinics due to female infertility (case group) and 106 working patients who had attended the clinics due to their partner's reproductive impairment (control group). RESULTS Patients from the female infertility group were older (31.9 +/- 6.2 versus 30.2 +/- 4.6, P = 0.047) and tended to participate more in sporting activity [23.4 versus 10.4%, odds ratio (OR) = 2.6, 95% confidence interval (CI) = 1.05-6.73, P = 0.022] as compared with patients from the male infertility group. Patients from the case group tended to work more weekly hours as compared with the controls (33.6 +/- 16.8 versus 26.9 +/- 17.4, P = 0.028). High reliability was found, as demonstrated by Cronbach's alpha of 0.81-0.90 for the four burnout parameters. Patients from the female infertility group had significantly lower listlessness scores as compared with the control group, using the Mann-Whitney test (2.6 +/- 1.1 versus 3.1 +/- 1.2, P = 0.013). CONCLUSIONS Patients admitted due to female infertility tended to have lower listlessness scores as compared with patients admitted due to their partner's infertility problem. No significant association was found between other burnout, job strain and job satisfaction scores and women's fertility status.
Pebble Games, Proof Complexity, and Time-Space Trade-offs

Pebble games were extensively studied in the 1970s and 1980s in a number of different contexts. The last decade has seen a revival of interest in pebble games coming from the field of proof complexity. Pebbling has proven to be a useful tool for studying resolution-based proof systems when comparing the strength of different subsystems, showing bounds on proof space, and establishing size-space trade-offs. This is a survey of research in proof complexity drawing on results and tools from pebbling, with a focus on proof space lower bounds and trade-offs between proof size and proof space.
Complete system of analytic invariants for unfolded differential linear systems with an irregular singularity of Poincar\'e rank 1

In this, paper, we give a complete system of analytic invariants for the unfoldings of nonresonant linear differential systems with an irregular singularity of Poincar\'e rank 1 at the origin over a fixed neighborhood $D_r$. The unfolding parameter $\epsilon $ is taken in a sector S pointed at the origin of opening larger than $2 \pi$ in the complex plane, thus covering a whole neighborhood of the origin. For each parameter value in S, we cover $D_r$ with two sectors and, over each sector, we construct a well chosen basis of solutions of the unfolded linear differential systems. This basis is used to find the analytic invariants linked to the monodromy of the chosen basis around the singular points. The analytic invariants give a complete geometric interpretation to the well-known Stokes matrices at $\epsilon =0$: this includes the link (existing at least for the generic cases) between the divergence of the solutions at $\epsilon =0$ and the presence of logarithmic terms in the solutions for resonance values of the unfolding parameter. Finally, we give a realization theorem for a given complete system of analytic invariants satisfying a necessary and sufficient condition, thus identifying the set of modules.
Evaluation of small bowel bleeding

Purpose of reviewThe review focuses on the latest techniques that are evolving in the management of small bowel bleeding. Recent findingsVideo capsule endoscopy has the highest yield of diagnosis when it is performed within 48 h of the bleeding event (78 versus 48%). The pooled detection rate of double balloon endoscopy was noted to be 68.1% for obscure gastrointestinal bleeding according to a systematic review of 66 studies in the last 10 years. Also a recent review, which focused on analysis of 68 studies found that the procedural characteristics were comparable for double balloon, single balloon and spiral enteroscopy though the procedure time was fastest for the spiral enteroscopy group. Medical therapy for vascular lesions is in its infancy but shows promise. SummaryAdvanced diagnostic and therapeutic endoscopic techniques are changing the paradigm of care for patients with small bowel bleeding.
Contribution of Somatic and Dendritic SK Channels in the Firing Rate of Deep Cerebellar Nuclei: Implication in Cerebellar Ataxia

Introduction: Loss of inhibitory output from Purkinje cells leads to hyperexcitability of the Deep Cerebellar Nuclei (DCN), which results in cerebellar ataxia. Also, inhibition of small-conductance calcium-activated potassium (SK) channel increases firing rate of DCN, which could cause cerebellar ataxia. Therefore, SK channel activators can be effective in reducing the symptoms of this disease, and used for the treatment of cerebellar ataxia. In this regard, we hypothesized that blockade of SK channels in different compartments of DCN would increase firing rate with different value. The location of these channels has different effects on increasing firing rate. Methods: In this study, multi-compartment computational model of DCN was used. This computational stimulation allowed us to study the changes in the firing activity of DCN neuron without concerns about interfering parameters in the experiment. Results: The simulation results demonstrated that blockade of somatic and dendritic SK channel increased the firing rate of DCN. In addition, after hyperpolarization (AHP) amplitude increased with blocking SK channel, and its regularity and resting potential changed. However, action potentials amplitude and duration had no significant changes. The simulation results illustrated a more significant contribution of SK channels on the dendritic tree to the DCN firing rate. SK channels in the proximal dendrites have more impact on firing rate compared to distal dendrites. Discussion: Therefore, inhibition of SK channel in DCN can cause cerebellar ataxia, and SK channel openers can have a therapeutic effect on cerebellar ataxia. In addition, the location of SK channels could be important in therapeutic goals. Dendritic SK channels can be a more effective target compared to somatic SK channels.
A simplified approach to recovery conditions for low rank matrices

Recovering sparse vectors and low-rank matrices from noisy linear measurements has been the focus of much recent research. Various reconstruction algorithms have been studied, including ℓ1 and nuclear norm minimization as well as ℓp minimization with p &#60; 1. These algorithms are known to succeed if certain conditions on the measurement map are satisfied. Proofs for the recovery of matrices have so far been much more involved than in the vector case. In this paper, we show how several classes of recovery conditions can be extended from vectors to matrices in a simple and transparent way, leading to the best known restricted isometry and nullspace conditions for matrix recovery. Our results rely on the ability to “vectorize” matrices through the use of a key singular value inequality.
Lower bounds for the total stopping time of 3x + 1 iterates

The total stopping time σ∞(n) of a positive integer n is the minimal number of iterates of the 3x + 1 function needed to reach the value 1, and is +∞ if no iterate of n reaches 1. It is shown that there are infinitely many positive integers n having a finite total stopping time σ∞(n) such that σ∞(n) γBP ≈ 41.677647, a search of all 3x + 1 trees to sufficient depth could produce a proof that there are infinitely many n such that σ∞(n) < γ log n. It would require a very large computation to search 3x + 1 trees to a sufficient depth to produce a proof that the expected behavior of a "random" 3x + 1 iterate, which is γ = 2/log4/3 ≈ 6.95212, occurs infinitely often.
Effects of lovastatin on biliary lipid secretion and bile acid metabolism in humans.

Lovastatin, an inhibitor of HMG-CoA reductase, lowers cholesterol saturation of bile. To determine the mechanism of this effect and further define the role of cholesterol synthesis in regulation of biliary lipid metabolism, we studied ten human volunteers in a control period and again after 5-6 weeks on lovastatin, 40 mg b.i. d. Mean sterol production from acetate in mononuclear leukocytes fell from 1.18 to 0.84 pmol/min per 10(6) cells on lovastatin (P less than 0.02). Concomitantly there was reduction in mean biliary secretion of cholesterol from 143 to 96 mumol/h (P less than 0.02). On lovastatin, mean pool size of bile acids by the Lindstedt method fell from 3193 to 2917 mumol (one-sided P = 0.05) and mean pool size by the one-sample method fell from 5158 to 4091 mumol (P less than 0.002). Lovastatin had no effect on mean fractional turnover rate of either cholic acid (0.77 vs. 0.74 day-1) or chenodeoxycholic acid (0.51 vs. 0.54 day-1). Mean total bile acid synthesis was lower on lovastatin (1443 vs. 1240 mumol/day), but the difference did not quite achieve statistical significance. In humans, inhibition of cholesterol synthesis by lovastatin lowers biliary cholesterol saturation by reducing cholesterol secretion into bile. Bile acid pool size, and perhaps bile acid synthesis, are also reduced by this inhibition.