LLukas22/scidocs huggingface dataset:
Performance evaluation for general queueing networks in manufacturing systems: Characterizing the trade-off between queue time and utilization

Performance evaluation plays a key role in manufacturing system design and productivity improvement. Characterizing performance objectively is the first step. Inspired by the underlying structure of tandem queues, we have derived an approximate model to characterize the system performance. The model decomposes system queue time and variability into bottleneck and non-bottleneck parts while capturing the dependence among workstations. Compared the new model with prior approaches, the new model not only is more accurate but also requires less information. The property of manufacturing system performance is given based on the insight from the model. 2012 Elsevier B.V. All rights reserved.
Role of reticulated platelets and platelet size heterogeneity on platelet activity after dual antiplatelet therapy with aspirin and clopidogrel in patients with stable coronary artery disease.

OBJECTIVES
The aim of this study was to evaluate the relationship between reticulated platelets (RPs), platelet size, and platelet function in patients with stable coronary artery disease (CAD) taking aspirin and clopidogrel.


BACKGROUND
Reticulated platelets are young platelets that are larger and possibly more active than non-RPs.


METHODS
Flow cytometry was used to measure RPs after staining with thiazole orange and to define the upper 20% and lower 20% of platelets by size. Platelet aggregation was measured with light transmission aggregometry (LTA); platelet activation was assessed by measuring activated platelet surface expression of P-selectin and glycoprotein (GP) IIb/IIIa.


RESULTS
Ninety patients were recruited and stratified into tertiles of %RPs. Patients in the upper tertile displayed greater platelet aggregation to 5-mumol/l adenosine diphosphate (ADP) (50.7 +/- 16.4% vs. 34.2 +/- 17.3%, p < 0.001), 1.5-mmol/l arachidonic acid (AA) (27.3 +/- 16.9% vs. 11.7 +/- 9.3%, p < 0.001), and 1-mug/ml collagen (18 +/- 11.6% vs. 12.1 +/- 8.7%, p < 0.05) and greater expression of GP IIb/IIIa (4.7 +/- 1.8% vs. 3.1 +/- 2.2%, p < 0.001). Frequency of low response to aspirin (AA LTA >20%) was higher in the upper tertile (53% vs. 17%, p < 0.001) compared with the lower tertile; low response to clopidogrel (ADP LTA >50%) was also elevated in the upper tertile (50% vs. 13%, p = 0.003). The larger platelet gate had a higher % of RPs compared with the smaller gate (15.4 +/- 16.7% vs. 1.7 +/- 2.3%, p < 0.001) and greater GP IIb/IIIa (5.7 +/- 3.1 vs. 2.1 +/- 1.2, p < 0.001) and P-selectin expression (7.8 +/- 4.9 vs. 4.6 +/- 2.7, p < 0.001).


CONCLUSIONS
The proportion of circulating RPs strongly correlates with response to antiplatelet therapy in patients with stable CAD. Large platelets exhibit increased reactivity despite dual antiplatelet therapy, compared with smaller platelets.
Pilot study of chronic maternal hyperoxygenation and effect on aortic and mitral valve annular dimensions in fetuses with left heart hypoplasia.

OBJECTIVE
Acute maternal hyperoxygenation (AMH) results in increased fetal left heart blood flow. Our aim was to perform a pilot study to determine the safety, feasibility and direction and magnitude of effect of chronic maternal hyperoxygenation (CMH) on mitral and aortic valve annular dimensions in fetuses with left heart hypoplasia (LHH) after CMH.


METHODS
Gravidae with fetal LHH were eligible for inclusion in a prospective evaluation of CMH. LHH was defined as: sum of aortic and mitral valve annuli Z-scores < -4.5, arch flow reversal and left-to-right or bidirectional atrial level shunting without hypoplastic left heart syndrome or severe aortic stenosis. Gravidae with an affected fetus and with ≥ 10% increase in aortic/combined cardiac output flow after 10 min of AMH at 8 L/min 100% fraction of inspired oxygen were offered enrollment. Nine gravidae were enrolled from February 2014 to January 2015. The goal therapy was ≥ 8 h daily CMH from enrollment until delivery. Gravidae who were cared for from July 2012 to October 2014 with fetal LHH and no CMH were identified as historical controls (n = 9). Rates of growth in aortic and mitral annuli over the final trimester were compared between groups using longitudinal regression.


RESULTS
There were no significant maternal or fetal complications in the CMH cohort. Mean gestational age at study initiation was 29.6 ± 3.2 weeks for the intervention group and 28.4 ± 1.8 weeks for controls (P = 0.35). Mean relative increase in aortic/combined cardiac output after AMH was 35.3% (range, 18.1-47.9%). Median number of hours per day on CMH therapy was 9.3 (range, 6.5-14.6) and median duration of CMH was 48 (range, 33-84) days. Mean mitral annular growth was 0.19 ± 0.05 mm/week compared with 0.14 ± 0.05 mm/week in CMH vs controls (mean difference 0.05 ± 0.05 mm/week, P = 0.33). Mean aortic annular growth was 0.14 ± 0.03 mm/week compared with 0.13 ± 0.03 mm/week in CMH vs controls (mean difference 0.01 ± 0.03 mm/week, P = 0.75). More than 9 h CMH daily (n = 6) was associated with better growth of the aortic annulus in intervention fetuses (0.16 ± 0.03 vs 0.08 ± 0.02 mm/week, P = 0.014).


CONCLUSIONS
CMH is both safe and feasible for continued research. In this pilot study, the effect estimates of annular growth, using the studied method of delivery and dose of oxygen, were small. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
The effect of lubrication on density distributions of roller compacted ribbons.

Roller compaction is a continuous dry granulation process for producing free flowing granules in order to increase the bulk density and uniformity of pharmaceutical formulations. It is a complicated process due to the diversity of powder blends and processing parameters involved. The properties of the produced ribbon are dominated by a number of factors, such as the powder properties, friction, roll speed, roll gap, feeding mechanisms and feeding speed, which consequently determine the properties of the granules (size distribution, density and flow behaviour). It is hence important to understand the influence of these factors on the ribbon properties. In this study, an instrumented roller press developed at the University of Birmingham is used to investigate the effect of lubrication on the density distribution of the ribbons. Three different cases are considered: (1) no lubrication, (2) lubricated press, in which the side cheek plates of the roller press are lubricated, and (3) lubricated powder, for which a lubricant is mixed into the powder. In addition, how the powders are fed into the entry region of the roller press and its influence on ribbon properties are also investigated. It is found that the method of feeding the powder into the roller press plays a crucial role in determining the homogeneity of the ribbon density. For the roller press used in this study, a drag angle (i.e., the angle formed when the powder is dragged into the roller press) is introduced to characterise the powder flow pattern in the feeding hopper. It is shown that a sharper drag angle results in a more heterogeneous ribbon. In addition, the average ribbon density depends upon the peak pressure and nip angle. The higher the peak pressure and nip angle are, the higher the average ribbon density is. Furthermore, the densification behaviour of the powder during roller compaction is compared to that during die compaction. It has been shown that the densification behaviour during these two processes is similar if the ribbons and the tablets have the same thickness.
Caveats for using statistical significance tests in research assessments

This article raises concerns about the advantages of using statistical significance tests in research assessments as has recently been suggested in the debate about proper normalization procedures for citation indicators by Opthof and Leydesdorff (2010). Statistical significance tests are highly controversial and numerous criticisms have been leveled against their use. Based on examples from articles by proponents of the use statistical significance tests in research assessments, we address some of the numerous problems with such tests. The issues specifically discussed are the ritual practice of such tests, their dichotomous application in decision making, the difference between statistical and substantive significance, the implausibility of most null hypotheses, the crucial assumption of randomness, as well as the utility of standard errors and confidence intervals for inferential purposes. We argue that applying statistical significance tests and mechanically adhering to their results are highly problematic and detrimental to critical thinking. We claim that the use of such tests do not provide any advantages in relation to deciding whether differences between citation indicators are important or not. On the contrary their use may be harmful. Like many other critics, we generally believe that statistical significance tests are overand misused in the empirical sciences including scientometrics and we encourage a reform on these matters. Highlights: We warn against the use of statistical significance tests (NHST) in research assessments. We introduce the controversial debate of NHST to the informetric community. We demonstrate some of the numerous flaws, misconceptions and misuses of NHST. We discuss potential alternatives and conclude that no "easy fixes" exist. We advocate informed judgment, free of the NHST-ritual, in decision processes. Acknowledgement. The author would like to thank the three anonymous reviewers for their very useful comments on previous drafts of this article.
Network performance evaluation of IPv4-v6 configured tunnel and 6to4 transition mechanisms on windows server operating systems

The potential exhaustion of IPv4 addresses initiated the development of IPv6. The new version of the Internet Protocol offers substantially more network and host addresses, however transition from current to the new version has been remarkably slow. There are multiple reasons for the sluggish transition: complexity and enormousity being the forerunners. Thus for the interim, various transition mechanisms have been developed. Each mechanism has its associated benefits and weaknesses. In this paper two such mechanisms, namely configured tunnel and 6to4 transition mechanism, have been empirically evaluated for performance. Both mechanisms are implemented on two different Windows Server operating systems and performance related metrics like throughput, delay, jitter and CPU usage of the transition end nodes are measured. The results obtained on the test-bed show that TCP/UDP throughput and jitter values of the two mechanisms are similar, but delay and CPU reading are significantly different depending on the choice of transition mechanism and operating system.
Impact of a 2-year multimodal intervention for disruptive 6-year-olds on substance use in adolescence: randomised controlled trial.

BACKGROUND
Adolescent substance use is associated with both earlier childhood behavioural problems and serious lifetime addiction problems later in life.


AIMS
To examine whether, and through which mechanisms, targeting risk factors in early childhood prevents substance use across adolescence.


METHOD
Disruptive kindergarten boys (n = 172) living in Montreal were randomly allocated to a preventive intervention and a control condition. The intervention was delivered over 2 years (7-9 years of age) with two main components: (a) social and problem-solving skills training for the boys; and (b) training for parents on effective child-rearing skills.


RESULTS
Adolescent substance use, up to 8 years post-intervention, was reduced in those who received the intervention (d = 0.48-0.70). Of most interest, the intervention effects were explained partly by reductions in impulsivity, antisocial behaviour and affiliation with less deviant peers during pre-adolescence (11-13 years).


CONCLUSIONS
Adolescent substance use may be indirectly prevented by selectively targeting childhood risk factors that disrupt the developmental cascade of adolescent risk factors for substance use.
Ischemic preconditioning prior to intermittent Pringle maneuver in liver resections.

BACKGROUND/PURPOSE
Continuous inflow vascular occlusion during liver resections causes less severe ischemia and reperfusion injury (IRI) if it is preceded by ischemic preconditioning (IP) or if intermittent inflow occlusion is used during the resection. No previous clinical trial has studied the effects of adding IP to intermittent inflow occlusion.


METHODS
Consecutive patients (n = 32) with suspicion of malignant liver disease had liver resections (minimum 2 segments) performed with inflow occlusion (intermittent clamping in a manner of 15 min of ischemia and 5 min of reperfusion repetitively; 15/5). Half of the patients were randomized to receive IP (10 min of ischemia and 10 min of reperfusion before parenchymal transection; 10/10). The patients were stratified according to volume of resection and none had chronic liver disease. The patients were followed for 5 days with microdialysis (μD).


RESULTS
All patients completed the study and there were no deaths. No differences were seen between the groups regarding demographics or perioperative parameters (bleeding, duration of ischemia, resection volume, complications, and serum laboratory tests). There were no differences in alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, or prothrombin time (PT)-INR levels, but μD revealed lower levels of lactate, pyruvate, and glucose in the IP group having major liver resections (analysis of variance; ANOVA). Nitrite and nitrate levels in μD decreased postoperatively, but no differences were seen between the groups. In one patient an elevated μD-glycerol curve was seen before the diagnosis of a stroke was made.


CONCLUSIONS
IP before intermittent vascular occlusion does not reduce the serum parameters used to assess IRI. IP seems to improve aerobic glucose metabolism, as the levels of glucose, pyruvate, and lactate locally in the liver were reduced, compared to controls, in patients having >3 segments resected. μD may be used to monitor metabolism locally.
Video streaming performance under proportional fair scheduling

In this paper, we study the performance of the proportional fair scheduler, which has been proposed for some of the emerging radio access systems. It maximizes the spectral efficiency of the systems, which is a strong incentive for network providers to use it. Our goal is to investigate how the proportional fair scheduling affects the performance of streaming users. Focus is on the throughput-delay trade-offs associated with proportional fair scheduling in CDMA/HDR systems. Special attention is devoted to defining appropriate performance measures and creating a realistic simulation environment. Our results indicate that the opportunistic scheduling may face difficulties in providing the user-level performance in cases where streaming flows constitute a significant share of the traffic load.
A new use of operators in the algebraic mode of REDUCE

It is apparent for many users of REDUCE [1] that in the algebraic mode many facilities available in the symbolic mode are lacking. Consequently, the programming of nontrivial problems very soon becomes unnecessarily complicated. This situation is unsatisfactory mainly for two reasons:1) Though some users will turn to the symbolic mode, many of them do not have the time to master it and are not supposed to know LISP.
Cardiac effects of antiretroviral therapy in HIV-negative infants born to HIV-positive mothers: NHLBI CHAART-1 (National Heart, Lung, and Blood Institute Cardiovascular Status of HAART Therapy in HIV-Exposed Infants and Children cohort study).

OBJECTIVES
The aim of this study was to investigate the possible effects of antiretroviral therapy (ART) in utero on cardiac development and function in human immunodeficiency virus (HIV)-negative children.


BACKGROUND
ART reduces vertical HIV transmission. Long-term cardiotoxicity after in utero exposure to ART is unknown in children but has occurred in young animals.


METHODS
Using a prospective multisite cohort study design, echocardiograms taken between birth and 24 months were compared in 2 groups of HIV-negative infants of HIV-positive mothers: 136 infants exposed to ART (ART+) and 216 unexposed infants (ART-).


RESULTS
Mean left ventricular (LV) mass z-scores were consistently lower in ART+ girls than in ART- girls: differences in mean z-scores were -0.46 at birth (p = 0.005), -1.02 at 6 months (p < 0.001), -0.74 at 12 months (p < 0.001), and -0.79 at 24 months (p < 0.001). Corresponding differences in z-scores for boys were smaller: 0.13 at 1 month (p = 0.42), -0.44 at 6 months (p = 0.01), -0.15 at 12 months (p = 0.37), and -0.21 at 24 months (p = 0.21). Septal wall thickness and LV dimension were smaller than expected in ART+ infants, but LV contractility was consistently about 1 SD higher at all ages (p < 0.001). In ART+ infants, LV fractional shortening was higher than in ART- infants; girls showed a greater difference.


CONCLUSIONS
Fetal exposure to ART is associated with reduced LV mass, LV dimension, and septal wall thickness z-scores and increased LV fractional shortening and contractility up to age 2 years. These effects are more pronounced in girls than in boys. Fetal ART exposure may impair myocardial growth while improving depressed LV function.
The foundations of photo-realistic rendering: from quantum electrodynamics to Maxwell's equations

Rendering techniques simulate 3D light transport. The typical algorithms only approximate electromagnetic wave interactions. The classical theory of electrodynamics is itself a macroscopic manifestation of the elemental quantum theory of electrodynamics (QED), which describes how individual photons behave. In this paper we explain how QED leads to Maxwell's equations.
Age and National Institutes of Health Stroke Scale Score within 6 hours after onset are accurate predictors of outcome after cerebral ischemia: development and external validation of prognostic models.

BACKGROUND AND PURPOSE
To date, no validated, comprehensive, and practicable model exists to predict functional recovery within the first hours of cerebral ischemic symptoms. The purpose of this study was to externally validate 2 prognostic models predicting functional outcome and survival at 100 days within the first 6 hours after onset of acute cerebral ischemia.


METHODS
On admission to a participating hospital, patients were registered prospectively and included according to defined criteria. Follow-up was performed 100 days after the event. With the use of prospectively collected data, 2 prognostic models were developed and internally calibrated in 1079 patients and externally validated in 1307 patients. By means of age and National Institutes of Health Stroke Scale (NIHSS) score as independent variables, model I predicts incomplete functional recovery (Barthel Index <95) versus complete functional recovery, and model II predicts mortality versus survival.


RESULTS
In the validation data set, model I correctly predicted 62.9% of the patients who were incompletely restituted or had died and 83.2% of the completely restituted patients, and model II correctly predicted 57.9% of the patients who had died and 91.5% of the surviving patients. Both models performed better than the treating physicians' predictions made within 6 hours after admission.


CONCLUSIONS
The resulting prognostic models are useful to correctly stratify treatment groups in clinical trials and should guide inclusion criteria in clinical trials, which in turn increases the power to detect clinically relevant differences.
How reader perception of capsule affects interpretation of washout in hypervascular liver nodules in patients at risk for hepatocellular carcinoma.

PURPOSE
To determine whether reader perception of a capsule affects reader interpretation of washout in hypervascular liver nodules at dynamic magnetic resonance imaging (MRI) in patients at risk for hepatocellular carcinoma (HCC).


MATERIALS AND METHODS
This retrospective study was Institutional Review Board (IRB)-approved and Health Insurance Portability and Accountability Act (HIPAA)-compliant, with waiver of informed consent. MRI reports for 111 hypervascular liver nodules (median 2.0 cm, range 1.0-17.8 cm) in 62 patients were reviewed, and the presence/absence of capsule and washout were recorded for one reading. A second independent study reading was also performed. The signal intensity ratio (SIR) for each nodule and liver parenchyma was measured. An objective SIR threshold was identified for nodules without capsules that correctly classified the presence/absence of washout, then applied to nodules with capsules to classify them as having / not having objective washout. Nodules were categorized as definite / not definite HCC using subjective and objective washout, based on LI-RADS, OPTN, AASLD, and EASL criteria, and proportions compared using McNemar's test.


RESULTS
Agreement on nodule features was high for Readings 1 and 2 (κ = 0.70-0.82). For Reading 1, 71 nodules lacked capsules (43 with and 28 without subjective washout); an SIR threshold of 0.88 classified the presence/absence of washout correctly in 94% (67/71, P < 0.001). Forty nodules had capsules; although all had subjective washout (100%, 40/40), 75% (30/40) had objective washout (P < 0.05). Using objective washout caused 4.5% (3/66; LI-RADS, OPTN) and 12% (10/83; AASLD, EASL) of nodules to be recategorized from definite HCC to not definite HCC.


CONCLUSION
Reader perception of capsule affects interpretation of washout. This effect can influence nodule categorization using imaging-based diagnostic systems. J. Magn. Reson. Imaging 2016;43:1337-1345.
The energetics and structure of nickel clusters: Size dependence

The energetics of nickel clusters over a broad size range are explored within the context of the many-body potentials obtained via the embedded atom method. Unconstrained local minimum energy configurations are found for single crystal clusters consisting of various truncations of the cube or octahedron, with and without ( 110) faces, as well as some monotwinnings of these. We also examine multitwinned structures such as icosahedra and various truncations of the decahedron, such as those of Ino and Marks. These clusters range in size from 142 to over 5000 atoms. As in most such previous studies, such as those on Lennard-Jones systems, we find that icosahedral clusters are favored for the smallest cluster sizes and that Marks’ decahedra are favored for intermediate sizes (all our atomic systems larger than about 2300 atoms). Of course very large clusters will be single crystal face-centered-cubic (fee) polyhedra: the onset of optimally stable single-crystal nickel clusters is estimated to occur at 17 000 atoms. We find, via comparisons to results obtained via atomistic calculations, that simple macroscopic expressions using accurate surface, strain, and twinning energies can usefully predict energy differences between different structures even for clusters of much smaller size than expected. These expressions can be used to assess the relative energetic merits of various structural motifs and their dependence on cluster size.