LLukas22/scidocs huggingface dataset:
Aerogels in Aerospace: An Overview

Aerogels are highly porous structures prepared via a sol-gel process and supercritical drying technology. Among the classes of aerogels, silica aerogel exhibits the most remarkable physical properties, possessing lower density, thermal conductivity, refractive index, and dielectric constant than any solids. Its acoustical property is such that it can absorb the sound waves reducing speed to 100m/s compared to 332m/s for air. However, when it comes to commercialization, the result is not as expected. It seems that mass production, particularly in the aerospace industry, has dawdled behind. This paper highlights the evolution of aerogels in general and discusses the functions and significances of silica aerogel in previous astronautical applications. Future outer-space applications have been proposed as per the current research trend. Finally, the implementation of conventional silica aerogel in aeronautics is argued with an alternative known as Maerogel.
The effect of prosthetic foot push-off on mechanical loading associated with knee osteoarthritis in lower extremity amputees.

Lower extremity amputation not only limits mobility, but also increases the risk of knee osteoarthritis of the intact limb. Dynamic walking models of non-amputees suggest that pushing-off from the trailing limb can reduce collision forces on the leading limb. These collision forces may determine the peak knee external adduction moment (EAM), which has been linked to the development of knee OA in the general population. We therefore hypothesized that greater prosthetic push-off would lead to reduced loading and knee EAM of the intact limb in unilateral transtibial amputees. Seven unilateral transtibial amputees were studied during gait under three prosthetic foot conditions that were intended to vary push-off. Prosthetic foot-ankle push-off work, intact limb knee EAM and ground reaction impulses for both limbs during step-to-step transition were measured. Overall, trailing limb prosthetic push-off work was negatively correlated with leading intact limb 1st peak knee EAM (slope=-.72±.22; p=.011). Prosthetic push-off work and 1st peak intact knee EAM varied significantly with foot type. The prosthetic foot condition with the least push-off demonstrated the largest knee EAM, which was reduced by 26% with the prosthetic foot producing the most push-off. Trailing prosthetic limb push-off impulse was negatively correlated with leading intact limb loading impulse (slope=-.34±.14; p=.001), which may help explain how prosthetic limb push-off can affect intact limb loading. Prosthetic feet that perform more prosthetic push-off appear to be associated with a reduction in 1st peak intact knee EAM, and their use could potentially reduce the risk and burden of knee osteoarthritis in this population.
Proportional representation and attitudes about politics: results from New Zealand

PR systems often are credited with producing more equitable outcomes between political parties and encouraging wider social group representation than majoritarian systems. Theory suggests that this should instill greater trust, efficacy, and faith in the political system. We assume that citizens disadvantaged by majoritarian rules (political minorities) will have a relatively greater shift toward positive attitudes about democracy following a transition from a majoritarian system to proportional representation. We employ panel data from the 1993–1996 New Zealand Election Study (NZES) to test hypotheses about the effects of electoral system change on attitudes about governmental responsiveness, trust in government, and political efficacy. We find that there is a general shift in mass opinion toward more positive attitudes on some measures of efficacy and responsiveness. Political minorities display a greater shift toward feelings of efficacy than other voters.  1999 Elsevier Science Ltd. All rights reserved.
Heterogeneous Beliefs and Momentum Profits

Recent theoretical models derive return continuation in a setting where investors have heterogeneous beliefs or receive heterogeneous information. This paper tests the link between heterogeneity of beliefs and return continuation in the cross-section of U.S. stock returns. Heterogeneity of beliefs about a firm’s fundamentals is measured by the dispersion in analyst forecasts of earnings. The results show that momentum profits are significantly larger for portfolios characterized by higher heterogeneity of beliefs. Predictive cross-sectional regressions show that heterogeneity of beliefs has a positive effect on return continuation after controlling for a stock’s visibility, the speed of information diffusion, uncertainty about fundamentals, information precision, and volatility. The results in this paper are robust to the potential presence of short-sale constraints and are not explained by arbitrage risk.
A Randomized Study on the Effectiveness of Prophylactic Clipping during Endoscopic Resection of Colon Polyps for the Prevention of Delayed Bleeding

BACKGROUNDS
The efficacy of clipping for preventing the delayed bleeding after the removal of colon polyps is still controversial. In order to clarify this efficacy, a randomized controlled study was performed.


METHODS
One hundred and fifty-six patients with colon neoplasms (288 lesions) were enrolled in the study. The patients were randomly divided into two groups: clipping or nonclipping groups using a sealed envelope method before the endoscopic resections. Eight specialists and nine residents were invited to perform this procedure. The risk factors and the rates of delayed bleeding after the endoscopic resections in each group were investigated.


RESULTS
There were no significant differences in the bleeding rate between the clipping and nonclipping groups, while the length of the procedure was significantly longer and the cost was higher in the clipping group than in the nonclipping group. The rate of bleeding was significantly higher in cases with polyps 2 cm or larger and with a longer procedure time, while none of the other factors affected the bleeding rate.


CONCLUSIONS
This randomized controlled study revealed no significant effect of prophylactic clipping for preventing delayed bleeding after the endoscopic resection of colon polyps.
Internet of Things as a Service (iTaaS): Challenges and Solutions for Management of Sensor Data on the Cloud and the Fog

Building upon cloud, IoT and smart sensors technologies we design and develop an IoT as a Service (iTaaS) framework, that transforms a user’s mobile device (e.g. a smart phone) to an IoT gateway which allows for fast and efficient data streams transmission to the cloud. We develop a two-fold solution, based on micro-services for the IoT (users’ smart devices) and the cloud side (back-end services). iTaaS includes configurations for (a) the IoT side to support data collection from IoT devices to a gateway on a real time basis and, (b) the cloud back-end side to support data sharing, storage and processing. iTaaS provides the technology foreground to enable immediate application deployments in the domain of interest. An obvious and promising implementation of this technology is e-Health and remote health monitoring. As a proof of concept we implement a real time remote patient monitoring system that integrates the proposed framework and uses Bluetooth Low Energy (BLE) pulse oximeter and heart rate monitoring sensing devices. The experimental analysis shows fast data collection, as (for our experimental setup) data is transmitted from the IoT side (i.e. the gateway) to the cloud in less than 130 ms. We also stress the back-end system with high user concurrency (e.g. with 40 users per second) and high data streams (e.g. 240 data records per second) and we show that the requests are executed at around 1 s, a number that signifies a satisfactory performance by considering the number of requests, the network latency and the relatively small size of the Virtual Machines implementing services on the cloud (2 GB RAM, 1 CPU and 20 GB hard disk size). © 2018 Elsevier B.V. All rights reserved.
Image Features from Phase Congruency Image Features from Phase Congruency

Image features such as step edges, lines and Mach bands all give rise to points where the Fourier components of the image are maximally in phase. The use of phase congruency for marking features has signiicant advantages over gradient based methods. It is a dimension-less quantity that is invariant to changes in image brightness or contrast, hence it provides an absolute measure of the signiicance of feature points. This allows the use of universal threshold values that can be applied over wide classes of images. This paper presents a new way of calculating phase congruency through the use of wavelets. The existing theory that has been developed for 1D signals is extended to allow the calculation of phase congruency in 2D images. It is shown that for good localization it is important to consider the spread of frequencies present at a point of phase congruency. An eeective method for identifying, and compensating for, the level of noise in an image is presented. Finally, it is argued that high-pass ltering should be used to obtain image information at diierent scales. With this approach the choice of scale only aaects the relative signiicance of features without degrading their localization. Abstract Image features such as step edges, lines and Mach bands all give rise to points where the Fourier components of the image are maximally in phase. The use of phase congruency for marking features has signiicant advantages over gradient based methods. It is a dimensionless quantity that is invariant to changes in image brightness or contrast, hence it provides an absolute measure of the signiicance of feature points. This allows the use of universal threshold values that can be applied over wide classes of images. This paper presents a new way of calculating phase congruency through the use of wavelets. The existing theory that has been developed for 1D signals is extended to allow the calculation of phase congruency in 2D images. It is shown that for good localization it is important to consider the spread of frequencies present at a point of phase congruency. An eeective method for identifying, and compensating for, the level of noise in an image is presented. Finally, it is argued that high-pass ltering should be used to obtain image information at diierent scales. With this approach the choice of scale only aaects the relative signiicance of features without degrading their localization.
Community structure of the physical review citation network

We investigate the community structure of physics subfields in the citation network of all Physical Review publications between 1893 and August 2007. We focus on well-cited publications (those receiving more than 100 citations), and apply modularity maximization to uncover major communities that correspond to clearly identifiable subfields of physics. While most of the links between communities connect those with obvious intellectual overlap, there sometimes exist unexpected connections between disparate fields due to the development of a widely applicable theoretical technique or by cross fertilization between theory and experiment. We also examine communities decade by decade and also uncover a small number of significant links between communities that are widely separated in time. © 2010 Elsevier Ltd. All rights reserved.
Frequencies of Cytochrome P450 2B6 and 2C8 Allelic Variants in the Mozambican Population.

BACKGROUND
The cytochrome P450 enzymes (CYP) play an important role in the metabolism of many therapeutic agents. The activities of different enzymes exhibit variability in different populations, which causes variations in drug response or toxicity. The CYP2B6 and CYP2C8 enzymes are encoded by polymorphic genes characterised by different single nucleotide polymorphisms (SNPs). Several of these CYP variants are often associated with slow metabolism phenotypes. This study aimed to analyse the frequencies of allelic variants of CYP2B6 and CYP2C8 in the Mozambican population.


METHODS
Using a polymerase chain reaction and restriction fragment length polymorphism assay (PCR-RFLP), the frequencies of the allelic variants of CYP2B6 (c.64C>T, c.516G>T, c.777C>A, c.785A>G, c.1459C>T) and CYP2C8 (c.805A>T, c.416G>A, c.1196A>G, c.792C>G) were determined in 360 Mozambican blood donors.


RESULTS
The frequencies of the allelic variants of the CYP2B6 gene were 0.057, 0.426, 0.0, 0.410, and 0.004. For the CYP2C8 gene, the frequencies of the allelic variants were 0.160, 0.048, 0.0, and 0.005. No significant differences were observed between the gender and geographic distribution of volunteers around the country.


CONCLUSION
The frequencies of the allelic variants of the CYP2B6 and CYP2C8 genes were found to be homogeneously distributed in the Mozambican population and were comparable to other African populations. Further studies are required to explore the impact of these variants on the clinical response (efficacy and toxicity) of drugs, including antimalarials.
Analysing user physiological responses for affective video summarisation

Video summarisation techniques aim to abstract the most significant content from a video stream. This is typically achieved by processing low-level image, audio and text features which are still quite disparate from the high-level semantics that end users identify with (the ‘semantic gap’). Physiological responses are potentially rich indicators of memorable or emotionally engaging video content for a given user. Consequently, we investigate whether they may serve as a suitable basis for a video summarisation technique by analysing a range of user physiological response measures, specifically electro-dermal response (EDR), respiration amplitude (RA), respiration rate (RR), blood volume pulse (BVP) and heart rate (HR), in response to a range of video content in a variety of genres including horror, comedy, drama, sci-fi and action. We present an analysis framework for processing the user responses to specific sub-segments within a video stream based on percent rank value normalisation. The application of the analysis framework reveals that users respond significantly to the most entertaining video sub-segments in a range of content domains. Specifically, horror content seems to elicit significant EDR, RA, RR and BVP responses, and comedy content elicits comparatively lower levels of EDR, but does seem to elicit significant RA, RR, BVP and HR responses. Drama content seems to elicit less significant physiological responses in general, and both sci-fi and action content seem to elicit significant EDR responses. We discuss the implications this may have for future affective video summarisation approaches. 2008 Elsevier B.V. All rights reserved.
DIFFERENTIAL EQUATIONS, SPENCER COHOMOLOGY, AND COMPUTING RESOLUTIONS

We propose a new point of view of the Spencer cohomology appearing in the formal theory of dierential equations based on a dual approach via comodules. It allows us to relate the Spencer cohomology with standard constructions in homological algebra and, in particular, to express it as a Cotor. We discuss concrete methods for its construction based on homological perturbation theory.
Add-on rTMS for treatment of depression: a pilot study using stereotaxic coil-navigation according to PET data.

OBJECTIVE
Repetitive transcranial magnetic stimulation (rTMS) is regarded as a potentially new tool to treat depression. In a double-blind, randomized, sham-controlled pilot study we investigated the efficacy of neuronavigated rTMS, guided according to the prefrontal metabolic state determined by positron emission tomography (PET).


METHODS
25 patients with major depression were included. Prior to rTMS, PET scans were obtained. For the real stimulation condition, the dorsolateral prefrontal cortex (DLPFC) with lower metabolic activity compared to the contralateral hemisphere was selected, if detected by prior PET. Stimulation parameters were 15 Hz, 110% motor threshold (MT), 3000 stimuli/day, for 10 days. A neuronavigational system was used to place the magnetic coil above each individuals' selected cortical region (real condition: DLPFC, sham: midline parieto-occipital, intensity 90% of MT). RTMS was administered add-on to medication. Depression-related symptoms were rated with Beck's, Hamilton's (HAM-D), and Montgomery-Asberg's (MADRS) depression rating scales.


RESULTS
Real stimulation improved depression according to HAM-D and MADRS moderately but significantly better compared to sham at the end of the stimulation sessions. In the real condition, four out of 13 patients responded with a mean improvement in HAM-D and/or MADRS of at least 50%, whereas none responded to sham. Antidepressant effects of stimulation of the relatively hypometabolic DLPFC were comparable to stimulation in absence of metabolic differences.


CONCLUSIONS
A moderate improvement of depressive symptoms after rTMS was observed. Our preliminary data show that stimulation of prefrontal hypometabolism may not be advantageous to stimulation irrespective of the metabolic state.
Cloud libraries: A novel application of cloud computing

Libraries all over the world suffer from common problems like flexibility associated with the digital data, lower levels of efficiency, and huge cost involved in managing the entire IT infrastructure themselves. Few options are available when it comes to collaborating with other libraries as well which is the prime reason for subordinate levels of efficiency. Cloud computing would help us in bridging the gap between digital libraries and IT. Sharing of data among the libraries will in principle reduce the overall cost and increase the efficiency. Capital expenditure done on infrastructure will chiefly be converted into operational expenditure. It will also enhance the users' experience and will help in making the libraries a lot more scalable.
Adaptive balanced hybrid data delivery for multi-channel data broadcast

With the proliferation of wireless information applications and services, data broadcasting known from radio networks has become an important mechanism for mobile data access in wireless communication networks. Two data delivery techniques, push and pull, and their hybrid combination had been introduced to satisfy mobile user demands. However, most previous research efforts were elaborated upon the premise of a single channel with static workload and access pattern. Recently the emergence of a multi-channel broadcast paradigm has attracted much research attention in the data broadcast community. In this paper, we design an adaptive balanced scheme (ABS) which performs a heuristic search in pursuit of a fair balance of access time for a hybrid data delivery in a multi-channel data broadcast environment. The experimental results show that at the balanced point exploited by ABS, the result of channel partition and data item classification is very close to the optimal balance, and consequently, we are able to obtain the lowest mean access time in both push and pull channels simultaneously. Keywords—Push, pull, data broadcast, mobile computing, wireless network.
Effects of a probiotic fermented milk on functional constipation: a randomized, double-blind, placebo-controlled study.

BACKGROUND AND AIM
Evidence suggests that probiotics reduce certain constipation-related symptoms. Lactobacillus casei strain Shirota has never been tested as treatment for functional constipation in otherwise-healthy subjects. To evaluate the efficacy of this probiotic among adults with functional constipation was aimed.


METHODS
Subjects with functional constipation (Rome II-defined) were randomized to intake L.  casei strain Shirota fermented milk or placebo once daily for 4 weeks under double-blind condition. Primary outcomes were constipation severity and stool frequency; secondary outcomes were stool consistency and quantity.


RESULTS
In intent-to-treat population, compared with baseline, constipation severity and stool frequency improved in both probiotic (n = 47) and control groups (n = 43), but improvements were comparable in both groups at week 4 (α = 5% level). In probiotic group, stool consistency and quantity at week 4 improved significantly versus baseline but not versus control. Considering that the study agent is non-pharmaceutical and the purpose of supplementation is for long-term effect, re-evaluation at α = 10% was conducted, which showed significant improvement in constipation severity at week 4 (P = 0.058). Magnitude of the probiotic effect on stool consistency was small but grew over time, d = 0.19, 95% confidence interval 0.00-0.35 (Week 4), d = 0.29, 95% confidence interval 0.11-0.52 (postintervention). Post-hoc exploratory analysis suggests incomplete evacuation may decrease with probiotic intake.


CONCLUSIONS
Four-week administration of L.  casei strain Shirota did not alleviate constipation severity or stool frequency, consistency, and quantity when compared with control. With re-evaluation at α = 10% level, improvement in constipation severity was significant at week 4. To obtain conclusive results, further studies with longer intervention are warranted.
The Logical Essentials of Bayesian Reasoning

This chapter offers an accessible introduction to the channel-based approach to Bayesian probability theory. This framework rests on algebraic and logical foundations, inspired by the methodologies of programming language semantics. It offers a uniform, structured and expressive language for describing Bayesian phenomena in terms of familiar programming concepts, like channel, predicate transformation and state transformation. The introduction also covers inference in Bayesian networks, which will be modelled by a suitable calculus of string diagrams. 1998 ACM Subject Classification Probabilistic computation, F. 1.2 Digital Object Identifier 10.4230/LIPIcs...
Aspirin Reduces Plasma Concentrations of the Oncometabolite 2-Hydroxyglutarate: Results of a Randomized, Double-Blind, Crossover Trial.

BACKGROUND
Aspirin use is an effective strategy for the chemoprevention of colorectal cancer, even at low doses. However, in order to implement aspirin interventions, risk-benefit balances and biologic mechanisms need to be better defined; to further this aim, we used a metabolomics approach.


METHODS
We metabolically profiled 40 healthy, nonsmoking men and women ages 20 to 45 years enrolled in a randomized, double-blind, crossover trial of 325 mg aspirin/day over a period of 60 days. Gas and liquid chromatography-mass spectrometry were used to comprehensively profile participants' plasma samples after aspirin and placebo interventions.


RESULTS
A total of 363 metabolites, covering most human biochemical pathways, were measured. Compared with placebo-treated participants, plasma concentrations of the oncometabolite 2-hydroxyglutarate (R+S) decreased after aspirin treatment in both men and women (P = 0.005). This signal proved robust during 20-fold random splitting of the data using 80% of the samples in each split. We subsequently performed functional follow-up studies using targeted, enantiospecific detection in human colorectal cancer cell lines and observed an aspirin-induced reduction of (R)-2-hydroxyglutarate. We further showed that salicylate, the primary aspirin metabolite, inhibits the hydroxyacid-oxoacid transhydrogenase mediated production of (R)-2-hydroxyglutarate, thereby providing mechanistic evidence for the clinically observed effects of aspirin on total-2-hydroxyglutarate.


CONCLUSIONS
Using a metabolomics approach with functional follow-up, we propose that a decrease in the oncometabolite (R)-2-hydroxyglutarate may identify an additional mechanism for aspirin or its metabolites in cancer prevention.


IMPACT
Reduction of the oncometabolite (R)-2-hydroxyglutarate identifies a novel, non-COX-inhibition-mediated mechanism of aspirin.