LLukas22/scidocs huggingface dataset:
A 660pW multi-stage temperature-compensated timer for ultra-low-power wireless sensor node synchronization

Recent work in ultra-low-power sensor platforms has enabled a number of new applications in medical, infrastructure, and environmental monitoring. Due to their limited energy storage volume, these sensors operate with long idle times and ultra-low standby power ranging from 10s of nW down to 100s of pW [1–2]. Since radio transmission is relatively expensive, even at the lowest reported power of 0.2mW [3], wireless communication between sensor nodes must be performed infrequently. Accurate measurement of the time interval between communication events (i.e. the synchronization cycle) is of great importance. Inaccuracy in the synchronization cycle time results in a longer period of uncertainty where sensor nodes are required to enable their radios to establish communication (Fig. 2.7.1), quickly making radios dominate the energy budget. Quartz crystal oscillators and CMOS harmonic oscillators exhibit very small sensitivity to supply voltage and temperature [4] but cannot be used in the target application space since they operate at very high frequencies and exhibit power consumption that is several orders of magnitude larger (>300nW) than the needed idle power. A gate-leakage-based timer was proposed [5] that leveraged small gate leakage currents to achieve power consumption within the required budget (< 1nW). However, this timer incurs high RMS jitter (1400ppm) and temperature sensitivity (0.16%/ºC). A 150pW program-and-hold timer was proposed [6] to reduce temperature sensitivity but its drifting clock frequency limits its use for synchronization. The quality of a timer is not captured well by RMS jitter since it ignores the averaging of jitter over multiple timer clock periods in a single synchronization cycle. Instead, we propose the uncertainty in a single synchronization cycle of length T as new metric and use this synchronization uncertainty (SU) to evaluate different timer approaches. The timer period is a random variable X(n), with mean and sigma, μ and σ. Given a synchronization cycle time T, consisting of N timer periods, we define SU as the standard deviation of T as given by √T/μ × σ, assuming X(n) is Gaussian. Note that a smaller clock period increases N and results in more averaging and a lower SU with fixed jitter (σ/μ).
Reliability and accuracy of cone-beam computed tomography dental measurements.

INTRODUCTION
Dental measurements are an integral part of the orthodontic records necessary for proper diagnosis and treatment planning. In this study, we investigated the reliability and accuracy of dental measurements made on cone-beam computed tomography (CBCT) reconstructions.


METHODS
Thirty human skulls were scanned with dental CBCT, and 3-dimensional reconstructions of the dentitions were generated. Ten measurements (overbite, overjet, maxillary and mandibular intermolar and intercanine widths, arch length available, and arch length required) were made directly on the dentitions of the skulls with a high-precision digital caliper and on the digital reconstructions with commercially available software. Reliability and accuracy were assessed by using intraclass correlation and paired Student t tests. A P value of < or = 0.05 was used to assign statistical significance.


RESULTS
Both the CBCT and the caliper measurements were highly reliable (r >0.90). The CBCT measurements tended to slightly underestimate the anatomic truth. This was statistically significant only for compounded measurements.


CONCLUSIONS
Dental measurements from CBCT volumes can be used for quantitative analysis. With the CBCT images, we found a small systematic error, which became statistically significant only when combining several measurements. An adjustment for this error allows for improved accuracy.
ANALYSIS OF FREQUENCY SELECTIVE SURFACES FOR RADAR ABSORBING MATERIALS

Nowadays, applications of Frequency Selective Surfaces (FSS) for radar absorbing materials (RAM) are increasing, but it is still a challenge to select a proper FSS for a particular material as well as the dimensions of FSS for optimized absorption. Therefore, in this paper an attempt has been made to optimize the dimensions of FSS for microwave absorbing application using Genetic Algorithm (GA) approach. The considered frequency selective surfaces are composed of conducting patch elements pasted on the ferrite layer. FSS are used for filtration and microwave absorption. In this work, selection and optimization of FSS with radar absorbing material has been done for obtaining the maximum absorption at 8–12 GHz frequency. An equivalent circuit method has been used for the analysis of different FSS, which is further used to design fitness function of GA for optimizing the dimensions of FSS. Eight different available ferrite materials with frequency dependant permittivities and permeabilities have been used as material database. The GA optimization is proposed to select the proper material out of eight available materials with proper dimensions of FSS. The optimized results suggest the material from database and dimensions of FSS. The selected material is then mixed with epoxy and hardener, and coated over the aluminium sheet. Thereafter, all five FSS were fabricated on ferrite coated Al sheets using photolithographic method followed by wet etching. The absorption was measured for all FSS using absorption testing device (ATD) method at X-band. Absorption results showed that significant amount of absorption enhanced with the addition of proper FSS on radar absorbing coating. Received 16 December 2011, Accepted 17 January 2012, Scheduled 8 February 2012 * Corresponding author: Dharmendra Singh (dharmfec@gmail.com).
Rich Trades, Scarce Capabilities - Industrial Development Revisited

In the last decade of the sixteenth century, the Dutch republic underwent a dramatic economic transformation that laid the foundation of the country’s Golden Age. At the heart of this process was the rise of the “rich trades”, the network by which Dutch shipping came to dominate the lucrative trade routes to the East Indies, the Americas and the Levant (Israel, 1990). The rise of the “rich trades” provides me with an archetypal example of the economic process which I want to explore in what follows. Many of the themes which I develop below emerge clearly in the Dutch story: the steady displacement of an old and well established bulk-carrying trade in which the Dutch had so long excelled by this hugely more lucrative new activity; heavy fixed outlays in building up a network of supporting facilities; the growth and development of a series of domestic industries that could benefit from the export opportunities opened up by this new shipping activity; and, most importantly – a huge rise in real wages in the Dutch Republic, relative to levels in neighbouring countries. It is this last feature of the process, the rise in real wages, which forms my point of departure. It would seem that some kinds of economic activity are more lucrative than others; and countries specialising in such activities will enjoy a higher level of real wages than their neighbours. From the viewpoint of classical economic analysis, this line of argument invites a number of immediate objections. If some activities are more lucrative than others, will not new entrepreneurs, firms or countries flock to these activities, driving
Privacy and authentication: An introduction to cryptography

This paper presents a tutorial introduction to contemporary cryptography. The basic information theoretic and computational properties of classical and modern cryptographic systems are presented, followed by cryptanalytic examination of several important systems and an examination of the application of cryptography to the security of timesharing systems and computer networks. The paper concludes with a guide to the cryptographic literature.
The Moderating Role of Close Friends in the Relationship Between Conduct Problems and Adolescent Substance Use

PURPOSE
Conduct problems and peer effects are among the strongest risk factors for adolescent substance use and problem use. However, it is unclear to what extent the effects of conduct problems and peer behavior interact, and whether adolescents' capacity to refuse the offer of substances may moderate such links. This study was conducted to examine relationships between conduct problems, close friends' substance use, and refusal assertiveness with adolescents' alcohol use problems, tobacco, and marijuana use.


METHODS
We studied a population-based sample of 1,237 individuals from the Cardiff Study of All Wales and North West of England Twins aged 11-18 years. Adolescent and mother-reported information was obtained. Statistical analyses included cross-sectional and prospective logistic regression models and family-based permutations.


RESULTS
Conduct problems and close friends' substance use were associated with increased adolescents' substance use, whereas refusal assertiveness was associated with lower use of cigarettes, alcohol, and marijuana. Peer substance use moderated the relationship between conduct problems and alcohol use problems, such that conduct problems were only related to increased risk for alcohol use problems in the presence of substance-using friends. This effect was found in both cross-sectional and prospective analyses and confirmed using the permutation approach.


CONCLUSIONS
Reduced opportunities for interaction with alcohol-using peers may lower the risk of alcohol use problems in adolescents with conduct problems.
Acarbose treatment affects the serum levels of inflammatory cytokines and the gut content of bifidobacteria in Chinese patients with type 2 diabetes mellitus.

BACKGROUND
The effects of acarbose add-on therapy on gut microbiota and inflammatory cytokines were investigated in Chinese patients with type 2 diabetes mellitus (DM).


METHODS
Ninety-five DM patients were randomly allocated to two groups: 59 to Group A who received antidiabetic treatment that included acarbose 150 mg/day, and 36 to Group B who received similar treatment to Group A but without acarbose. Forty-five healthy volunteers were selected as a control group. Serum concentrations of inflammatory cytokines were determined by ELISA, and the contents of 16S rDNA of gut bacteria were determined by real-time quantitative polymerase chain reaction. General linear analysis for repeated measurements was used to analyze trend differences between the two diabetic groups.


RESULTS
After 4 weeks of antidiabetic treatment, the gut contents of Bifidobacterium longum and Enterococcus faecalis were significantly increased in both diabetes groups. The increase of Bifidobacterium longum (P = 0.004) and the decrease of lipopolysaccharides (LPS) (P < 0.001) and prothrombin activator inhibitor-1 (P = 0.003) were more significant in Group A. Decreases of monocyte chemoattractant protein-1 and LPS were more significant in patients whose HbA1c decrease was ≥1%, but there were no significant differences in the changes of other cytokines and gut bacteria between patients with HbA1c <7% and ≥7%. Pearson correlation analysis showed that changes of Enterococcus faecalis were negatively correlated with LPS, while multiple linear regression analysis showed a positive correlation of Bifidobacterium longum with acarbose treatment and the high-density lipoprotein cholesterol concentration.


CONCLUSIONS
Acarbose treatment can increase the content of gut Bifidobacterium longum in type 2 diabetes mellitus patients and decrease some inflammatory cytokines independently of its antihyperglycemic effects.
Shared Virtue: The Convergence of Valued Human Strengths Across Culture and History

Positive psychology needs an agreed-upon way of classifying positive traits as a backbone for research, diagnosis, and intervention. As a 1st step toward classification, the authors examined philosophical and religious traditions in China (Confucianism and Taoism), South Asia (Buddhism and Hinduism), and the West (Athenian philosophy, Judaism, Christianity, and Islam) for the answers each provided to questions of moral behavior and the good life. The authors found that 6 core virtues recurred in these writings: courage, justice, humanity, temperance, wisdom, and transcendence. This convergence suggests a nonarbitrary foundation for the classification of human strengths and virtues.
An examination of emergency department nurses' attitudes towards deliberate self-harm in an Irish teaching hospital.

PURPOSE
The purpose of this study was to examine emergency department (ED) nurses' attitudes towards individuals presenting with deliberate self-harm (DSH), including the relationship between attitudes and factors such as age, academic achievements, length of experience, and self-harm education.


METHOD
The study adopted a quantitative descriptive and correlational design. ED nurses' attitudes, working in a level 1 trauma ED in the Republic of Ireland, were surveyed, using an amended version of McAllister's et al. [McAllister, M., Creedy, D., Moyle, W., Farrugia, C., 2002. Nurses' attitudes towards clients who self-harm. Journal of Advanced Nursing 40(5), 578-586.] Attitude Towards Deliberate Self-Harm Questionnaire (ADSHQ). The survey yielded an 85% (n=68) response rate.


RESULTS
The study found that ED nurses held positive attitudes towards individuals presenting with DSH. No correlation was found between total scores and gender, ED experience, or a history of self-harm education, although older nurses and hospital trained nurses had less positive attitudes. Age and length of clinical experience produced a trend in which attitudes increased, reached a peak and then declined.


CONCLUSION
Although ED nurses in this study hold positive attitudes, ongoing continuing education, which was identified as a key theme in the study, remains an important strategy to maintain and further improve attitudes. The need for research into aspects of care such as knowledge, awareness and empathy is recommended, as is the need to evaluate the extent to which the National Strategy for Suicide Prevention 2005-2014 recommendations [Department of Health and Children, Health Service Executive, National Suicide Review Group 2005. Reach Out - Irish National Strategy for Action on Suicide Prevention 2005-2014.  (accessed 22.02.08)] have been implemented.
Cancellation of operations on the day of intended surgery at a major Australian referral hospital.

OBJECTIVE
To establish the rate of and reasons for cancellations of surgery on the scheduled day in an Australian hospital.


DESIGN
Prospective survey.


SETTING
Major metropolitan tertiary hospital, 13 May to 15 November 2002.


MAIN OUTCOME MEASURES
Proportion of operations cancelled on the day of surgery, obtained each day from the operating theatre list and a separate list of additions and cancellations compiled on the day; reasons for cancellations from the cancellation list, extended or confirmed, as necessary, by questioning of bookings and ward staff, or members of the surgical team; estimated and actual duration of each operation and patient information from hospital clinical records.


RESULTS
7913 theatre sessions were scheduled by 133 surgeons in the study period; 941 of these (11.9%) were cancelled on the day, including 724 of 5472 (13.2%) elective procedures on working weekdays. Main reasons for cancellation were: no theatre time due to over-run of previous surgery (18.7%); no postoperative bed (18.1%); cancelled by patient (17.5%); and change in patient clinical status (17.1%). Procedural reasons (including patient not ready, no surgeon, list error, administrative cause, and communication failure) totalled 21.0%. Ear, nose and throat surgery experienced the most cancellations (19.6%), followed by cardiothoracic surgery (15.8%).


CONCLUSIONS
There were five major reasons of similar magnitude for on-the-day surgery cancellations. We estimated that 60% of cancellations of elective procedures were potentially avoidable. Change of one factor leading to cancellation (eg, provision of more postoperative beds) is not likely to lead to improvement unless the other major factors are also tackled.
A general framework for comparing automatic testing techniques of Android mobile apps

As an increasing number of new techniques are developed for quality assurance of Android applications (apps), there is a need to evaluate and empirically compare them. Researchers as well as practitioners will be able to use the results of such comparative studies to answer questions such as, “What technique should I use to test my app?” Unfortunately, there is a severe lack of rigorous empirical studies on this subject. In this paper, for the first time, we present an empirical study comparing all existing fully automatic “online” testing techniques developed for the Android platform. We do so by first reformulating each technique within the context of a general framework. We recognize the commonalities between the techniques to develop the framework. We then use the salient features of each technique to develop parameters of the framework. The result is a general recasting of all existing approaches in a plug-in based formulation, allowing us to vary the parameters to create instances of each technique, and empirically evaluate them on a common set of subjects. Our results show that (1) the ∗Anna Rita Fasolino Preprint submitted to Elsevier December 21, 2016
Poor nutritional status of schoolchildren in urban and peri-urban areas of Ouagadougou (Burkina Faso)

BACKGROUND
Malnutrition is still highly prevalent in developing countries. Schoolchildren may also be at high nutritional risk, not only under-five children. However, their nutritional status is poorly documented, particularly in urban areas. The paucity of information hinders the development of relevant nutrition programs for schoolchildren. The aim of this study carried out in Ouagadougou was to assess the nutritional status of schoolchildren attending public and private schools.


METHODS
The study was carried out to provide baseline data for the implementation and evaluation of the Nutrition Friendly School Initiative of WHO. Six intervention schools and six matched control schools were selected and a sample of 649 schoolchildren (48% boys) aged 7-14 years old from 8 public and 4 private schools were studied. Anthropometric and haemoglobin measurements, along with thyroid palpation, were performed. Serum retinol was measured in a random sub-sample of children (N = 173). WHO criteria were used to assess nutritional status. Chi square and independent t-test were used for proportions and mean comparisons between groups.


RESULTS
Mean age of the children (48% boys) was 11.5 ± 1.2 years. Micronutrient malnutrition was highly prevalent, with 38.7% low serum retinol and 40.4% anaemia. The prevalence of stunting was 8.8% and that of thinness, 13.7%. The prevalence of anaemia (p = 0.001) and vitamin A deficiency (p < 0.001) was significantly higher in public than private schools. Goitre was not detected. Overweight/obesity was low (2.3%) and affected significantly more children in private schools (p = 0.009) and younger children (7-9 y) (p < 0.05). Thinness and stunting were significantly higher in peri-urban compared to urban schools (p < 0.05 and p = 0.004 respectively). Almost 15% of the children presented at least two nutritional deficiencies.


CONCLUSION
This study shows that malnutrition and micronutrient deficiencies are also widely prevalent in schoolchildren in cities, and it underlines the need for nutrition interventions to target them.
A double-blinded randomized multicentre study to investigate the effect of changes in stimulation parameters on sacral nerve stimulation for constipation.

AIM
Sacral nerve stimulation (SNS) may be offered to patients with constipation who have failed to improve with conservative treatment. The response to SNS is variable, with a significant loss of efficacy in some patients. An increased frequency of stimulation may improve the efficacy of SNS for faecal incontinence. This study aimed to see if alteration of the pulse width or frequency improved the outcome for those with constipation.


METHOD
Eleven patients with constipation currently being treated by SNS were recruited from three centres. They were randomized to five different protocols of stimulation each applied for 5 weeks. Group 1 used standard settings (pulse width 210 μs, frequency 14 Hz); in the other four groups (Groups 2-5) the pulse width and/or frequency were halved or doubled. Patients and investigators were blinded to the group allocation.


RESULTS
The Cleveland Clinic constipation score varied significantly between the five groups. Group 1 achieved the lowest score mean (± SD) 13.4 (± 4.4) (P = 0.03). The number of digitations per defaecation was the lowest in Group 4, 90 μs and 14 Hz (P < 0.01). No other variable changed significantly. Standard settings were the most preferred by the recruited patients.


CONCLUSION
Alteration of pulse width or frequency of stimulation had no significant effect on the outcome of SNS for constipation.
Language networks: Their structure, function, and evolution

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A survey of unmanned aerial vehicles (UAVs) for traffic monitoring

The focus of this paper is on surveying UAV-based systems for traffic monitoring and management. Although there has been voluminous research on the subject, unmanned aerial vehicles (UAVs) are proven to be a viable and less time-consuming alternative to real-time traffic monitoring and management, providing the eye-in-the-sky solution to the problem.
Experiments in Rainfall Estimation with a Polarimetric Radar in a Subtropical Environment

A unique dataset consisting of high-resolution polarimetric radar measurements and dense rain gauge and disdrometer observations collected in east-central Florida during the summer of 1998 was examined. Comparison of the radar measurements and radar parameters computed from the disdrometer observations supported previous studies, which indicate that oscillating drops in the free atmosphere have more spherical apparent shapes in the mean than equilibrium shapes. Radar–disdrometer comparisons improved markedly when using an empirical axis ratio relation developed from observational studies and representing more spherical drop shapes. Fixedform power-law rainfall estimators for radar reflectivity (ZH), specific differential phase (KDP), specific differential phase–differential reflectivity (KDP, ZDR), and radar reflectivity–differential reflectivity (ZH, ZDR) were then determined using the disdrometer observations. Relations were produced for both equilibrium shapes and the empirical axis ratios. Polarimetric rainfall estimators based on more spherical shapes gave significantly improved performance. However, the improvement was largely in bias mitigation. Rainfall estimates with the ZH–ZDR measurement pair had the highest correlation with rain gauge observations, the smallest range in bias factors from storm to storm, and the smallest root-mean-square error.