LLukas22/scidocs huggingface dataset:
Six Steps to a Successful COTS Implementation

F ederal organizations are relying more and more on commercial applications to supplement, enhance, or replace proprietary systems. This dependency is driven by the promise of improved functionality and reduced total ownership cost, as well as concern over the lack of capability to develop and maintain proprietary information technology applications. However, failure to successfully select, control, and implement these critical components continues to result in projects that are delivered late and over-budget or that fail entirely. The following six-step methodology highlights the important activities that should take place during a commercial off-the-shelf (COTS) implementation. Following this methodology throughout the software development life cycle will ensure that significant activities are not being ignored and will increase the chances of planning, executing, and deploying a successful COTS-based software solution. One of the biggest problems sighted in COTS-based projects is a disconnect between time and cost expectations during planning and those actually realized. During the planning stages, it is important to plan appropriately for all the major activities necessary to devise a well thought-out solution that will not fall apart with the first upgrade of one of its components. Research [1, 2, 3, 4, 5] has indicated the essential activities that must take place to ensure successful COTS-based projects: • Analyze software requirements. • Evaluate and select COTS solution(s). • Negotiate terms with COTS vendor. • Implement the COTS-based solution. • Maintain and upgrade the COTS-based solution. • Maintain license, subscription, and royalty fees. Figure 1 portrays an overview of the six steps outlined above and highlights the interactions that may occur throughout the execution of these steps. While this diagram implies a time dependency between these steps, it is important to realize that in certain cases this is neither strictly adhered to nor are all the steps necessarily performed by the organiza-tion(s) contracted to deliver a solution. Some requirements analysis and COTS evaluation are likely to occur in very early stages of a project as feasibility and affordability are analyzed. The following sections provide more details about each of these steps, along with a brief description of the factors to consider when evaluating the affordability and timeliness of a COTS-based solution. Specifics about the quantification and application of these factors can be found in [6]. Software requirements analysis is a critical part of the software development process, although too often this activity is overlooked or glossed over in the rush to start …
Machine Learning Methods for Spamdexing Detection

In this paper, we present recent contributions for the battle against one of the main problems faced by search engines: the spamdexing or web spamming. They are malicious techniques used in web pages with the purpose of circumvent the search engines in order to achieve good visibility in search results. To better understand the problem and finding the best setup and methods to avoid such virtual plague, in this paper we present a comprehensive performance evaluation of several established machine learning techniques. In our experiments, we employed two real, public and large datasets: the WEBSPAM-UK2006 and the WEBSPAM-UK2007 collections. The samples are represented by content-based, link-based, transformed link-based features and their combinations. The found results indicate that bagging of decision trees, multilayer perceptron neural networks, random forest and adaptive boosting of decision trees are promising in the task of web spam classification. Keywords—Spamdexing; web spam; spam host; classification, WEBSPAM-UK2006, WEBSPAM-UK2007.
Activation of Bacillus licheniformis alpha-amylase through a disorder-->order transition of the substrate-binding site mediated by a calcium-sodium-calcium metal triad.

BACKGROUND
The structural basis as to how metals regulate the functional state of a protein by altering or stabilizing its conformation has been characterized in relatively few cases because the metal-free form of the protein is often partially disordered and unsuitable for crystallographic analysis. This is not the case, however, for Bacillus licheniformis alpha-amylase (BLA) for which the structure of the metal-free form is available. BLA is a hyperthermostable enzyme which is widely used in biotechnology, for example in the breakdown of starch or as a component of detergents. The determination of the structure of BLA in the metal-containing form, together with comparisons to the apo enzyme, will help us to understand the way in which metal ions can regulate enzyme activity.


RESULTS
We report here the crystal structure of native, metal-containing BLA. The structure shows that the calcium-binding site which is conserved in all alpha-amylases forms part of an unprecedented linear triadic metal array, with two calcium ions flanking a central sodium ion. A region around the metal triad comprising 21 residues exhibits a conformational change involving a helix unwinding and a disorder-->order transition compared to the structure of metal-free BLA. Another calcium ion, not previously observed in alpha-amylases, is located at the interface between domains A and C.


CONCLUSIONS
We present a structural description of a major conformational rearrangement mediated by metal ions. The metal induced disorder-->order transition observed in BLA leads to the formation of the extended substrate-binding site and explains on a structural level the calcium dependency of alpha-amylases. Sequence comparisons indicate that the unique Ca-Na-Ca metal triad and the additional calcium ion located between domains A and C might be found exclusively in bacterial alpha-amylases which show increased thermostability. The information presented here may help in the rational design of mutants with enhanced performance in biotechnological applications.
Rainfall-runoff models using artificial neural networks for ensemble streamflow prediction

Previous ensemble streamflow prediction (ESP) studies in Korea reported that modelling error significantly affects the accuracy of the ESP probabilistic winter and spring (i.e. dry season) forecasts, and thus suggested that improving the existing rainfall-runoff model, TANK, would be critical to obtaining more accurate probabilistic forecasts with ESP. This study used two types of artificial neural network (ANN), namely the single neural network (SNN) and the ensemble neural network (ENN), to provide better rainfall-runoff simulation capability than TANK, which has been used with the ESP system for forecasting monthly inflows to the Daecheong multipurpose dam in Korea. Using the bagging method, the ENN combines the outputs of member networks so that it can control the generalization error better than an SNN. This study compares the two ANN models with TANK with respect to the relative bias and the root-mean-square error. The overall results showed that the ENN performed the best among the three rainfall-runoff models. The ENN also considerably improved the probabilistic forecasting accuracy, measured in terms of average hit score, half-Brier score and hit rate, of the present ESP system that used TANK. Therefore, this study concludes that the ENN would be more effective for ESP rainfall-runoff modelling than TANK or an SNN. Copyright  2005 John Wiley & Sons, Ltd.
New directions in fluxgate sensors

Although fluxgates may have resolution of 50 pT and absolute precission of 1 nT, their accuracy is often degraded by crossfield response, non-linearities, hysteresis and perming effects. The trends are miniaturization, lower power consumption and production cost, non-linear tuning and digital processing. New core shapes and signal processing methods have been suggested.
Improvement of platelets after SVR among patients with chronic HCV infection and advanced hepatic fibrosis.

BACKGROUND AND AIMS
Patients with chronic hepatitis C virus (HCV) infection may develop cirrhosis with portal hypertension, reflected by decreased platelet count and splenomegaly. This retrospective cohort study aimed to assess changes in platelet counts after antiviral therapy among chronic HCV-infected patients with advanced fibrosis.


METHODS
Platelet counts and spleen sizes were recorded in an international cohort of patients with Ishak 4-6 fibrosis who started antiviral therapy between 1990 and 2003. Last measured platelet counts and spleen sizes were compared with their pre-treatment values (within 6 months prior to the start of therapy). All registered platelet count measurements from 24-week following cessation of antiviral therapy were included in repeated measurement analyses.


RESULTS
This study included 464 patients; 353 (76%) had cirrhosis and 187 (40%) attained sustained virological response (SVR). Among patients with SVR, median platelet count, increased by 35 × 10(9) /L (IQR 7-62, P < 0.001). In comparison, patients without SVR showed a median decline of 17 × 10(9) /L (IQR -5-47, P < 0.001). In a subgroup of 209 patients, median decrease in spleen size was 1.0 cm (IQR 0.3-2.0) for patients with SVR, while median spleen size increased with 0.6 cm (IQR -0.1-2.0, P < 0.001) among those without SVR. The changes in spleen size and platelet count were significantly correlated (R = -0.41, P < 0.001).


CONCLUSIONS
Among chronic HCV-infected patients with advanced hepatic fibrosis, the platelet counts improved following SVR and the change in platelets correlated with the change in spleen size following antiviral therapy. These results suggest that HCV eradication leads to reduced portal pressure.
Adding Value: Learning Communities and Student Engagement

This study examines the relationships between participating in learning communities and student engagement in a range of educationally purposeful activities of first-year and senior students from 365 4-year institutions. The findings indicate that participating in a learning community is positively linked to engagement as well as student self-reported outcomes and overall satisfaction with college.
Modelling a Tidal Turbine in Unsteady Flow

A brief review of the literature is provided on the characteristics of marine currents and the approaches used for simulating tidal turbines. The feasibility of using CFD models to simulate time-dependent turbulent flow around a tidal turbine is then explored. Two different approaches for specifying the structure of the turbulent inflow conditions in CFD models are compared: the von Kármán spectral approach and the Synthetic Eddy Method (SEM) of Jarrin et al. (2006). The former model is commonly employed in the wind industry and is coded into Garrad Hassan’s Tidal Bladed and NREL’s TurbSim. Different approaches are also tested for decomposing the turbulence at the inlet into resolved and modelled components. The results from these tests indicate that the turbulence produced using the SEM inlet conditions is slightly less susceptible to decay with downstream distance than the von Kármán approach provided that the modelled turbulent kinetic energy accounts for only a small fraction of the total turbulence energy. Simulations of the unsteady flow around a tidal turbine, represented here as a simple porous disc, provide some insight into the effect of large-scale flow oscillations on the wake of the turbine. The wake structures obtained from unsteady CFD simulations are compared to those obtained using a steady approach. The results indicate that the presence of large coherent turbulent structures in the incident flow field produces a shorter wake than predicted by steady flow simulations. This work represents the first stage in the development of a unified model which will couple meta-scale simulations of flow in an estuary or complete channel to detailed small-scale simulations of the flow around tidal turbine devices.
Cross-Cultural Analysis of Students with Exceptional Talent in Mathematical Problem Solving

A t a conference held in January 2005, Lawrence Summers, then president of Harvard University, hypothesized that a major reason for the paucity of women mathematicians among the tenured faculty of elite research universities in the USA might be sex-based differences in “intrinsic aptitude” for mathematics, especially at the very high end of the distribution [36]. This commonly held belief is largely based upon data from standardized tests such as the quantitative section of the Scholastic Aptitude Test (SAT) I. This test, designed to determine mathematical proficiency of USA eleventh and twelfth graders, identifies students who have mastered grade-level material, but does not distinguish the profoundly gifted, that is, those who are four or more standard deviations above the mean, from the merely gifted who also score in the ninety-ninth percentile on this exam. To identify students who perform above grade level, the Study of Mathematically Precocious Youth (SMPY) administered the SAT I to children younger than thirteen years of age. The SMPY defined children as highly gifted in mathematics if they scored at least 700 (on a 200 to 800 scale) on the quantitative section of this test. Using this criterion, Benbow and Stanley reported in 1980 large gender differences in “mathematical reasoning ability” [4]. They concluded that “sex differences in achievement in and attitude towards mathematics result from superior male mathematical ability . . . [it] is probably an expression of a combination of both endogenous and exogenous variables.” Since these tests lack questions that require creative thinking and insight into higher-level mathematical concepts, they do not identify children with extremely high innate ability in mathematics, that is, ones who may go on to become top research mathematicians. They cannot differentiate between profoundly and moderately gifted children, regardless of age at which the examinations are administered. Thus, the SMPY identified thousands of children who, while quite bright and ambitious, were not necessarily profoundly gifted in mathematics. The SMPY also failed to identify many children with extreme ability in mathematics who lacked one or more of the socio-economically privileged environmental factors necessary to be recognized by this mechanism. Coincidentally, the ratio of boys to girls identified in the SMPY has dramatically declined during the past quarter century from the high of 13:1 originally reported in 1983 [5] to 2.8:1 in a 2005 report [6]. The fact that 29% of Ph.D.’s awarded to USA citizens in the mathematical sciences went to women in the 2006–2007 academic year [30] supports the idea that this latter ratio is a more accurate reflection of current Titu Andreescu is professor of science/mathematics education at the University of Texas, Dallas. His email address is txa051000@utdallas.edu.
Managing multiple generations: scenarios from the workplace.

PROBLEM
The current nursing workforce is composed of multigenerational staff members creating challenges and at times conflict for managers.


METHODS
Generational cohorts are defined and two multigenerational scenarios are presented and discussed using the ACORN imperatives and Hahn's Five Managerial Strategies for effectively managing a multigenerational staff.


FINDINGS
Communication and respect are the underlying key strategies to understanding and bridging the generational gap in the workplace.


CONCLUSION
Embracing and respecting generational differences can bring strength and cohesiveness to nursing teams on the managerial or unit level.
More Accurate Student Modeling through Contextual Estimation of Slip and Guess Probabilities in Bayesian Knowledge Tracing

Modeling students’ knowledge is a fundamental part of intelligent tutoring systems. One of the most popular methods for estimating students’ knowledge is Corbett and Anderson’s [6] Bayesian Knowledge Tracing model. The model uses four parameters per skill, fit using student performance data, to relate performance to learning. Beck [1] showed that existing methods for determining these parameters are prone to the Identifiability Problem: the same performance data can be fit equally well by different parameters, with different implications on system behavior. Beck offered a solution based on Dirichlet Priors [1], but, we show this solution is vulnerable to a different problem, Model Degeneracy, where parameter values violate the model’s conceptual meaning (such as a student being more likely to get a correct answer if he/she does not know a skill than if he/she does). We offer a new method for instantiating Bayesian Knowledge Tracing, using machine learning to make contextual estimations of the probability that a student has guessed or slipped. This method is no more prone to problems with Identifiability than Beck’s solution, has less Model Degeneracy than competing approaches, and fits student performance data better than prior methods. Thus, it allows for more accurate and reliable student modeling in ITSs that use knowledge tracing.
Differential Impacts of Copepods and Cladocerans on Lake Seston, and Resulting Effects on Zooplankton Growth

In an enclosure study in Schöhsee, a small mesotrophic lake in Northern Germany, the impact of copepods and daphniids on the seston community was studied. In general, these two guilds differ in their feeding behaviour. Copepods actively select their food, with a preference for larger particles, whereas most cladocerans are unselective filter-feeders. In this study we investigate how the impact of the two different grazers affects zooplankton growth. We combine results obtained in the laboratory with results measured in situ in the enclosures. Copepods and cladocerans were cultured on seston from enclosures that were inhabited by density gradients of copepods or daphniids. We observed that Daphnia grew faster on seston that was pre-handled by copepods than on seston that was pre-handled by daphniids, and that somatic growth decreased with increasing densities of daphniids in the enclosures. In contrast, we observed no differences in development rates for copepods grown on the different media. The population growth rates of Daphnia in the Daphnia treatments were determined in the enclosures. Growth differences in both somatic- and population growth of Daphnia were correlated to food quality aspects of the seston. In the laboratory we found that Daphnia growth was correlated with several fatty acids. The strongest regression was with the concentration of 20:4ω3 (r 2= 0.37). This particular fatty acid also showed the highest correlation with growth after normalisation of the fatty acids to the carbon content of the enclosures (r 2= 0.33). On the other hand, in the enclosure the population growth correlated most to the particulate nitrogen content (r 2= 0.78) and only to the N:C ratio, when normalised to carbon (r 2= 0.51).
Whole-body-vibration training increases knee-extension strength and speed of movement in older women.

OBJECTIVES
To investigate the effects of 24 weeks of whole-body-vibration (WBV) training on knee-extension strength and speed of movement and on counter-movement jump performance in older women.


DESIGN
A randomized, controlled trial.


SETTING
Exercise Physiology and Biomechanics Laboratory, Leuven, Belgium.


PARTICIPANTS
Eighty-nine postmenopausal women, off hormone replacement therapy, aged 58 to 74, were randomly assigned to a WBV group (n=30), a resistance-training group (RES, n=30), or a control group (n=29).


INTERVENTION
The WBV group and the RES group trained three times a week for 24 weeks. The WBV group performed unloaded static and dynamic knee-extensor exercises on a vibration platform, which provokes reflexive muscle activity. The RES group trained knee-extensors by performing dynamic leg-press and leg-extension exercises increasing from low (20 repetitions maximum (RM)) to high (8RM) resistance. The control group did not participate in any training.


MEASUREMENTS
Pre-, mid- (12 weeks), and post- (24 weeks) isometric strength and dynamic strength of knee extensors were measured using a motor-driven dynamometer. Speed of movement of knee extension was assessed using an external resistance equivalent to 1%, 20%, 40%, and 60% of isometric maximum. Counter-movement jump performance was determined using a contact mat.


RESULTS
Isometric and dynamic knee extensor strength increased significantly (P<.001) in the WBV group (mean+/-standard error 15.0+/-2.1% and 16.1+/-3.1%, respectively) and the RES group (18.4+/-2.8% and 13.9+/-2.7%, respectively) after 24 weeks of training, with the training effects not significantly different between the groups (P=.558). Speed of movement of knee extension significantly increased at low resistance (1% or 20% of isometric maximum) in the WBV group only (7.4+/-1.8% and 6.3+/-2.0%, respectively) after 24 weeks of training, with no significant differences in training effect between the WBV and the RES groups (P=.391; P=.142). Counter-movement jump height enhanced significantly (P<.001) in the WBV group (19.4+/-2.8%) and the RES group (12.9+/-2.9%) after 24 weeks of training. Most of the gain in knee-extension strength and speed of movement and in counter-movement jump performance had been realized after 12 weeks of training.


CONCLUSION
WBV is a suitable training method and is as efficient as conventional RES training to improve knee-extension strength and speed of movement and counter-movement jump performance in older women. As previously shown in young women, it is suggested that the strength gain in older women is mainly due to the vibration stimulus and not only to the unloaded exercises performed on the WBV platform.
Dysphagia bedside screening for acute-stroke patients: the Gugging Swallowing Screen.

BACKGROUND AND PURPOSE
Acute-onset dysphagia after stroke is frequently associated with an increased risk of aspiration pneumonia. Because most screening tools are complex and biased toward fluid swallowing, we developed a simple, stepwise bedside screen that allows a graded rating with separate evaluations for nonfluid and fluid nutrition starting with nonfluid textures. The Gugging Swallowing Screen (GUSS) aims at reducing the risk of aspiration during the test to a minimum; it assesses the severity of aspiration risk and recommends a special diet accordingly.


METHODS
Fifty acute-stroke patients were assessed prospectively. The validity of the GUSS was established by fiberoptic endoscopic evaluation of swallowing. For interrater reliability, 2 independent therapists evaluated 20 patients within a 2-hour period. For external validity, another group of 30 patients was tested by stroke nurses. For content validity, the liquid score of the fiberoptic endoscopic evaluation of swallowing was compared with the semisolid score.


RESULTS
Interrater reliability yielded excellent agreement between both raters (kappa=0.835, P<0.001). In both groups, GUSS predicted aspiration risk well (area under the curve=0.77; 95% CI, 0.53 to 1.02 in the 20-patient sample; area under the curve=0.933; 95% CI, 0.833 to 1.033 in the 30-patient sample). The cutoff value of 14 points resulted in 100% sensitivity, 50% specificity, and a negative predictive value of 100% in the 20-patient sample and of 100%, 69%, and 100%, respectively, in the 30-patient sample. Content validity showed a significantly higher aspiration risk with liquids compared with semisolid textures (P=0.001), therefore confirming the subtest sequence of GUSS.


CONCLUSIONS
The GUSS offers a quick and reliable method to identify stroke patients with dysphagia and aspiration risk. Such a graded assessment considers the pathophysiology of voluntary swallowing in a more differentiated fashion and provides less discomfort for those patients who can continue with their oral feeding routine for semisolid food while refraining from drinking fluids.