LLukas22/scidocs huggingface dataset:
Analysis of n-Dimensional Quadtrees using the Hausdorff Fractal Dimension

There is mounting evidence [Man77, SchSI] that real datasets are statistically self-similar, and thus, ‘fractal’. This is an important insight since it permits a compact statistical description of spatial datasets; subsequently, as we show, it also forms the basis for the theoretical analysis of spatial access methods, without using the typical, but unrealistic, uniformity assumption. In this paper, we focus on the estimation of the number of quadtree blocks that a real, spatial dataset will require. Using the the wellknown Hausdorff fractal dimension, we derive some closed formulas which allow us to predict the number of quadtree blocks, given some few parameters. Using our formulas, it is possible to predict the space overhead and the response time of linear quadtrees/z-ordering [OM88], which are widely used in practice. In order to verify our analytical model, we performed *This work was partially supported by the National Science Foundation under Grants No. CDR8803012, EEC-94-02384, IRI-8958546 and IRI-9205273), with matching funds from Empress Software Inc. and Thinking Machines Inc. Some of the work was performed while he was visiting AT&T Bell Labor+ tories, Murray Hill, NJ. Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the VLDB copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Very Large Data Base Endowment. To copy otherwise, or to republish, requires a fee and/or special permission from the Endowment. Proceedings of the 22nd VLDB Conference Mumbai(Bombay), India, 1996 Volker Gaede Institut fiir Wirtschaftsinformatik Humboldt-Universitgt zu Berlin Spandauer Str. 1 10178 Berlin, Germany gaede@wiwi.hu-berlin.de an extensive experimental investigation using several real datasets coming from different domains. In these experiments, we found that our analytical model agrees well with our experiments as well as with older empirical observations on 2-d [Gae95b] and 3-d [ACF+94] data.
ELECTROACTIVE POLYMERS AS ARTIFICIAL MUSCLES-CAPABILITIES , POTENTIALS AND CHALLENGES

INTRODUCTION For many years, electroactive polymers (EAP) received relatively little attention due to the small number of available materials and their limited actuation capability. The recent emergence of EAP materials with large displacement response changed the paradigm of these materials and their potential capability. The main attractive characteristic of EAP is their operational similarity to biological muscles, particularly their resilience and ability to induce large actuation strains. Unique robotic components and miniature devices are currently being explored, where EAP serve as actuators to enable new capabilities. Generally, the low density and the relative ease of shaping them make polymers highly attractive materials and they are increasingly being chosen for aerospace applications. Early applications included components and structures, where composite materials made a significant impact on the construction of high performance aircraft. Increasingly, the resilience of polymers is finding applications in the emerging field of inflatable structures. Balloons were used to cushion the deployment of the Mars Pathfinder lander on July 4, 1997, paving the way for the recent large number of related initiatives. Inflatables are now being used to construct a rover (Figure l), aerial vehicles, telescopes (Figure 2), radar antennas, and others. Some of these applications have reached space flight experiments, whereas others are now at advanced stages of development. Polymers were also reported as construction elements of such actuators as: (a) McKibben muscle actuators [Schulte, 19611 These are air tubes with an angularly breaded fiber reinforcement that contract significantly when inflated, delivering a large force. (b) Shape memory polymers These materials sustain a volume change of over 40 times when subjected to pressure and heat, and a temperature rise causes the recovery of the pre-pressed shape [Sokolowski, et al, 19991; (c) Electrorhological fluids These are electroactive polymer liquids that that experience dramatic changes in rheological properties in the presence of an electric field. Willis M. Winslow first explained the effect in the 1940s using oil dispersions of fine powders [Winslow, 19491. The fluids are made from suspensions of an insulating base fluid and particles on the order of one tenth to one hundred microns in size. The electro-rheological effect is thought to arise from the difference in the dielectric constants of the fluid and particles. In the presence of an electric field, the particles, due to an induced dipole moment, will form chains along the field lines. This induced structure changes the E m ’ s viscosity, yield stress, and other properties, allowing the E W to change consistency from that of a liquid to something that is viscoelastic with response times on the order of milliseconds.
Effects of a hospital-based education programme on self-care behaviour, care dependency and quality of life in patients with heart failure--a randomised controlled trial.

AIMS AND OBJECTIVES
To evaluate the effects of a nurse-led, hospital-based heart failure specific education session with a three-month telephone follow-up on self-care behaviour, care dependency and quality of life for patients with chronic heart failure.


BACKGROUND
Patient education in patients with heart failure is able to promote heart failure-specific self-care, to reduce mortality, morbidity and rehospitalisation rates and to enhance quality of life, especially if heart failure education is embedded in a multidisciplinary approach. Evidence of the effect of a nurse-led self-care education, quality of life and care dependency in addition to standard medical treatment in Germany is lacking.


DESIGN
Nonblinded, prospective, single-centre, randomised controlled trial.


METHOD
Sixty-four patients were allocated either to the intervention group or to the control group. Patients in the intervention group received education about heart failure self-care with a consecutive telephone follow-up over three months in addition to standard medical treatment. Patients in the control group received standard medical treatment only.


RESULTS
Data of 110 patients (58 in the intervention group and 52 in the control group) with a mean age of 62 years and mean left ventricular ejection fraction of 28·2% could be analysed. Self-care education had a significant influence on overall heart failure self-care but not on quality of life and care dependency.


CONCLUSION
A single education session with a consecutive telephone follow-up is able to improve overall self-care behaviours but not quality of life. Care dependency was not influenced by the education session.


RELEVANCE TO CLINICAL PRACTICE
The easy to implement and short educational intervention has a positive effect on self-care behaviour for patients with heart failure. However, there was no effect on quality of life and care dependency. To improve quality of life and to influence care dependency, different measures have to be applied.
Heart rate variability as a prognostic tool in cardiology. A contribution to the problem from a theoretical point of view.

BACKGROUND
Recent clinical studies have proposed standard deviation of heart rate as a diagnostic tool for the outcome of cardiac infarction. Mathematical analysis of heart rate variability shows that heart rate is influenced by different frequency components derived from different parts of the autonomous nervous system. In the experimental part of this study, we investigated the possibility of calculating a variable describing the parasympathetic branch of the autonomous nervous system exclusively.


METHODS AND RESULTS
In 60 healthy volunteers, heart rate was measured to 1 millisecond during two different conditions: 5 minutes of rest, and 5 minutes of intermittent handgrip dynamometry; the latter is known to increase sympathetic arousal selectively. Heart rate was found to be lower at rest (65.9 +/- 9.7 beats per minute) than during dynamometry (72.8 +/- 10.4 beats per minute, P < .001). Respiratory sinus arrhythmia (RSA) calculated from the mean absolute differences between successive heart beats showed no significant change (3.01 +/- 1.62 beats per minute at rest versus 2.97 +/- 1.30 beats per minute during dynamometry). In contrast, standard deviation increased from 5.19 +/- 1.98 to 9.22 +/- 3.56 beats per minute (P < .001).


CONCLUSIONS
It can be concluded from these data as well as from other plots presented in this article that RSA is a measure of the parasympathetic vagal tone, whereas standard deviation is increased by both sympathetic and parasympathetic arousal. Clinical evidence and data from physiological experiments are presented to show that a selective measure of vagal tone like RSA may offer advantages over standard deviation as a prognostic tool in cardiology.
E-payment Gateway Model

The extraordinary growth of interconnected computer network & pervasive trends of using this network as new field for conducting Business process are stimulating the demand for new payment methods. These new methods attain high level of security, speed, privacy, decentralization & internationalization. This seminar surveys the state of art in payment technology & we proposed model for electronic payment gateway, On the basis of requirement of electronic payment gateway. E-payment is now one of most central research areas in E-commerce. E-payment system the automated process of exchanging monetary values among parties in business transactions. In this paper a brief overview of electronic payment gateway is provided. This, addresses the requirements for an electronic payment gateway from both the customers and the merchants' point of view. Most of the population doesn’t trust on the local existing online payment gateway because it is not very secure. Mostly people want to adopt electronic payment system as it has lots of advantages. They need such a gateway that fulfil their all requirements and provide security, privacy etc. On the basis of these requirements and the local infrastructure, we propose an electronic payment gateway for local environment.. Keywords— E-payment, Gateway
Long-term efficacy of darunavir/ritonavir monotherapy in patients with HIV-1 viral suppression: week 96 results from the MONOI ANRS 136 study.

OBJECTIVES
Long-term results at week 96 are needed to evaluate the capacity of the darunavir/ritonavir monotherapy strategy to maintain a sustained control of the HIV-1 viral load.


METHODS
MONOI is a prospective, open-label, non-inferiority, randomized, 96 week trial comparing darunavir/ritonavir monotherapy versus a darunavir/ritonavir triple-therapy strategy to maintain HIV-1 viral load suppression in HIV-1-infected patients.


CLINICAL TRIAL REGISTRATION
NCT00412551.


RESULTS
From 225 randomized patients, 219 patients reached the 48 week follow-up and 211 reached the 96 week follow-up (106 patients in the darunavir monotherapy arm and 105 in the darunavir triple-therapy arm). Baseline characteristics were well balanced between the two treatment groups. At week 96, in intent-to-treat analysis, 91/103 patients (88%, 95% CI 81-94) allocated to the darunavir/ritonavir monotherapy arm and 87/104 patients (84%, 95% CI 75-90) allocated to the darunavir triple-therapy arm achieved an HIV-1 viral load <50 copies/mL, with no statistical difference between the two groups. Throughout the 96 week follow-up, 66/112 patients (59%, 95% CI 49-68) and 79/113 patients (70%, 95% CI 61-78) consistently had HIV-1 RNA <50 copies/mL with darunavir/ritonavir monotherapy and darunavir/ritonavir triple therapy, respectively.


CONCLUSIONS
The MONOI study establishes darunavir/ritonavir monotherapy as durable and efficacious for maintaining virological suppression in HIV-1 patients. Darunavir/ritonavir monotherapy should be considered as a (tailored) treatment option for standard triple-therapy patients who have had a substantial period of viral suppression.
Impact of fatigue on everyday life among older people with chronic heart failure.

AIM
To explore the relationship between fatigue and performance of activities of daily living (ADL), use of assistive devices, home-help service and community mobility services in older clients with chronic heart failure.


METHODS
A cross-sectional descriptive study of 40 patients was performed using the Multidimensional Fatigue Inventory, the Staircase of ADL, Assessment of Motor and Process Skills and a demographic checklist.


RESULTS
We found high levels of general fatigue, physical fatigue and reduced activity. Greater fatigue was associated significantly with increased dependence and decreased quality of ADL, but not for shopping. Use of community mobility services and assistive devices was frequent and home help less frequent. Use of assistive devices and home help were associated significantly with greater fatigue, but not the use of community mobility services.


CONCLUSIONS
Fatigue had a negative impact on ADL mainly from physical rather than from mental causes. Improved energy conservation strategies to reduce the consequences of fatigue are needed.
The study of regional geography in Southern Europe

Abstract This essay begins by suggesting that the regional geography of Southern Europe has been needlessly neglected in recent years. The literature, maps and atlases that are now available on the area are then briefly reviewed, to demonstrate that people and places there are worthy of more professional interest. Finally the methodological challenges that stem from the differences between home‐based and foreign fieldwork are indicated.
Safety of Daily Co-Trimoxazole in Pregnancy in an Area of Changing Malaria Epidemiology: A Phase 3b Randomized Controlled Clinical Trial

INTRODUCTION
Antibiotic therapy during pregnancy may be beneficial and impacts positively on the reduction of adverse pregnancy outcomes. No studies have been done so far on the effects of daily Co-trimoxazole (CTX) prophylaxis on birth outcomes. A phase 3b randomized trial was conducted to establish that daily CTX in pregnancy is not inferior to SP intermittent preventive treatment (IPT) in reducing placental malaria; preventing peripheral parasitaemia; preventing perinatal mortality and also improving birth weight. To establish its safety on the offspring by measuring the gestational age and birth weight at delivery, and compare the safety and efficacy profile of CTX to that of SP.


METHODS
Pregnant women (HIV infected and uninfected) attending antenatal clinic were randomized to receive either daily CTX or sulfadoxine-pyrimethamine as per routine IPT. Safety was assessed using standard and pregnancy specific measurements. Women were followed up monthly until delivery and then with their offspring up to six weeks after delivery.


RESULTS
Data from 346 pregnant women (CTX = 190; SP = 156) and 311 newborns (CTX = 166 and SP = 145) showed that preterm deliveries (CTX 3.6%; SP 3.0%); still births (CTX 3.0%; SP 2.1%), neonatal deaths (CTX 0%; SP 1.4%), and spontaneous abortions (CTX 0.6%; SP 0%) were similar between study arms. The low birth weight rates were 9% for CTX and 13% for SP. There were no birth defects reported. Both drug exposure groups had full term deliveries with similar birth weights (mean of 3.1 Kg). The incidence and severity of AEs in the two groups were comparable.


CONCLUSION
Exposure to daily CTX in pregnancy may not be associated with particular safety risks in terms of birth outcomes such as preterm deliveries, still births, neonatal deaths and spontaneous abortions compared to SP. However, more data are required on CTX use in pregnant women both among HIV infected and un-infected individuals.


TRIAL REGISTRATION
Clinicaltrials.gov NCT00711906.
Some remarks on singularities in quantum cosmology

Abstract We discuss to what extent classical singularities persist upon quantization in two simple cosmological models.
Role of Nanoparticles in Photocatalysis

The aim of this review paper is to give an overview of the development and implications of nanotechnology in photocatalysis. The topics covered include a detailed look at the unique properties of nanoparticles and their relation to photocatalytic properties. Current applications of and research into the use of nanoparticles as photocatalysts has also been reviewed. Also covered is the utilization of nanoparticles in doped, coupled, capped, sensitized and organic– inorganic nanocomposite semiconductor systems, with an effort to enhance photocatalytic and/or optical properties of commonly used semiconductor materials. The use of nanocrystalline thin films in electrochemically assisted photocatalytic processes has been included. Finally, the use of nanoparticles has made a significant contribution in providing definitive mechanistic information regarding the photocatalytic process. Background on photocatalysis The photocatalytic process Organic chemicals which may be found as pollutants in wastewater effluents from industrial or domestic sources, must be removed or destroyed before discharge to the environment. Such pollutants may also be found in ground and surface waters which also require treatment to achieve acceptable drinking water quality (Lindner et al., 1995). The increased public concern with these environmental pollutants has prompted the need to develop novel treatment methods (Zeltner et al., 1996) with photocatalysis gaining a lot of attention in the field of pollutant degradation. Much of the natural purification of aqueous system lagoons, ponds, streams, rivers and lakes is caused by sunlight initiating the breakdown of organic molecules into simpler molecules and ultimately to carbon dioxide and other mineral products. There are various natural sensitizers that accelerate the process. The utilization of ‘colloidal semiconductors’ and the introduction of catalysts to promote specific redox processes on semiconductor surfaces were developed in 1976 (Kalyanasundaram, 1983). Since then, laboratory studies have confirmed that naturally occurring semiconductors could enhance this solar driven purification process (Matthews, 1993). The photocatalytic detoxification of wastewater is a process that combines heterogeneous catalysis with solar technologies (Zhang et al., 1994a). Semiconductor photocatalysis, with a primary focus on TiO 2, has been applied to a variety of problems of environmental interest in addition to water and air purification. The application of illuminated semiconductors for degrading undesirable organics dissolved in air or water is well documented and has been successful for a wide variety of compounds (Hoffmann et al., 1995).
Design and evaluation of incremental data structures and algorithms for dynamic query interfaces

Dynamic query interfaces (DQIs) form a recently developed method of database access that provides continuous realtime feedback to the user during the query formulation process. Previous work shows that DQIs are elegant and powerful interfaces to small databases. Unfortunately, when applied to large databases, previous DQI algorithms slow to a crawl. We present a new approach to DQI algorithms that works well with large databases.
Natural Products in Drug Discovery: Impacts and Opportunities — An Assessment

Nature stands as an inexhaustible source of novel chemotypes and pharmacophores, and has been a source of medicinal agents for thousands of years, and an impressive number of modern drugs find their origin in natural products. Natural product chemistry has experienced explosive and diversified growth, making natural products the subject of much interest and promise in the present day research directed towards drug design and discovery. It is noteworthy that natural products are a source of new compounds with diversified structural arrangements possessing interesting biological activities. Natural products, thus, have played and continue to play an invaluable role in the drug discovery process. Recently, there has been a renewed interest in natural products research due to the failure of alternative drug discovery methods to deliver many lead compounds in key therapeutic areas such as immunosuppression, anti-infective, and metabolic diseases. However, continuing improvements in natural products research are needed to continue to be competitive with other drug discovery methods, and also to keep pace with the ongoing changes in the drug discovery process. Faithful drives are needed in a more intensified fashion to explore “Nature” as a source of novel and active agents that may serve as the leads and scaffolds for elaboration into urgently needed efficacious drugs for a multitude of disease indications. Natural products have provided considerable value to the pharmaceutical industry over the past half century. In particular, the therapeutic
Accuracy of colposcopy in the diagnostic setting compared with the screening setting.

OBJECTIVE
To estimate the accuracy of colposcopy to identify cervical precancer in screening and diagnostic settings.


METHODS
As part of a larger clinical trial to evaluate the diagnostic accuracy of optical spectroscopy, we recruited 1,850 patients into a diagnostic or a screening group depending on their history of abnormal findings on Papanicolaou tests. Colposcopic examinations were performed and biopsies specimens obtained from abnormal and normal colposcopic sites for all patients. The criterion standard of test accuracy was the histologic report of biopsies. We calculated sensitivities, specificities, likelihood ratios, receiver operating characteristic curves, and areas under the receiver operating characteristic curves.


RESULTS
The prevalence of high-grade squamous intraepithelial lesions (HSIL) or cancer was 29.0% for the diagnostic group and 2.2% for the screening group. Using a disease threshold of HSIL, colposcopy had a sensitivity of 0.983 and a specificity of 0.451 in the diagnostic group when the test threshold was low-grade squamous intraepithelial lesions (LSIL), and a sensitivity of 0.714 and a specificity of 0.813 when the test threshold was HSIL. Using the same HSIL disease threshold, in the screening group, colposcopy had a sensitivity of 0.286 and a specificity of 0.877 when the test threshold was LSIL, and a sensitivity of 0.191 and a specificity of 0.961 when the threshold was HSIL. The colposcopy area under the receiver operating characteristic curve was 0.821 (95% confidence interval 0.79-0.85) in the diagnostic setting compared with 0.587 (95% confidence interval 0.56-0.62) in the screening setting. Changing the disease threshold to LSIL demonstrated similar patterns in the tradeoff of sensitivity and specificity and measure of accuracy.


CONCLUSION
Colposcopy performs well in the diagnostic setting and poorly in the screening setting. Colposcopy should not be used to screen for cervical intraepithelial neoplasia.


LEVEL OF EVIDENCE
II.