Proper Intervals Research Articles

A simple derivation of the relativistic Doppler effect in accelerated systems

Abstract The theory of the relativistic Doppler effect is well established and validated by several experiments. Most derivations, however, assume that both the reference frame of the source and the reference frame of the receiver are inertial, and the validity of the obtained formulas in the case of a non-inertial source and/or receiver is usually not clarified in higher physics education. As shown in this paper, if such formulas are carelessly applied to non-inertial cases, they can lead to contradictory results. This is probably what happened historically in the interpretation of experiments with a receiver in uniform circular motion around an inertial source, where some authors reported a shift towards the red, some others a shift towards the blue. This confusion points out the importance of establishing Doppler effect formulas that are valid in non-inertial cases. In this paper, we first set a rigorous definition of the relativistic Doppler shift, clarifying that it is the ratio between two proper time intervals relating to two different pairs of events. We then apply the definition to derive the relativistic Doppler shift in the case of a non-inertial source and/or receiver. The proposed derivations are very simple, provide important insights on the correct application of the time dilatation formula to accelerated systems, and highlight possible subtle mistakes that can lead to completely wrong results. This makes them a useful tool for teaching purposes, especially for graduate students.

The similative-pretence alternating pair and filler-slot relations

Abstract The present paper investigates the similative-pretence alternating pair in Mexican Spanish (como/igual que and como si constructions) based on the analysis of 1362 instances from The Corpus del Español NOW (News on the Web) corpus. We apply a revised version of distinctive collexeme analysis to our concordance data to explore the variety of different verbs that can occur in the first slot of similative and pretence constructions. Specifically, we use (i) a new measure that distinguishes the attraction that a verb lemma exerts on a construction from the attraction that a construction exerts on a verb lemma and (ii) bootstrapping on the level of files to, for the first time, provide proper confidence intervals in the context of collostructional studies. The from-verb lemma-to-construction analysis shows that there is a significant attraction of epistemic lemmas (e.g., parecer ‘to seem’) to occur in como ‘like’, and of mistaken identity lemmas (e.g., actuar ‘to act’) to appear in como si ‘as if’ constructions. The from-construction-to-verb lemma analysis, on the other hand, demonstrates that igual que ‘like’ significantly attracts epistemic perception verbs (e.g., ver ‘to look’), and como si ‘as if’ constructions significantly attract the verb lemma sentir ‘to feel.’

Construction Management by Controlling the Design and Curing Time of a Concrete Mix

Abstract The interval of time after pouring concrete is an important factor, which directly affects the timing and cost of construction. The case study that was investigated in this research, is a tunnel project located in Iran. Eighteen mix designs were prepared using properties such as different water-cement ratios and the use of two types of superplasticizer with different dosages. The optimal mix designs among the samples were separately specified. Concrete mix designs with different curing ages were made to specify the minimum curing time in which the concrete could gain the required compressive strength. Moreover, the concrete’s compressive strength was measured for different ages in order to determine the minimum time interval. For a better insight, two mathematical equations were derived to estimate the minimum curing time and time interval. Finally, a statistical analysis was conducted in order to determine the proper time intervals. Moreover, the analysis specified the impact rate of the research parameters (i.e. the type and dosage of superplasticizer, curing time, and water-cement ratio) on the compressive strength

Sequential sampling for functional estimation via Sieve

AbstractSequential sampling methods are often used to estimate functions describing models subjected to time‐intensive simulations or expensive experiments. These methods provide guidelines for point selection in the domain to capture maximum information about the function. However, in most sequential sampling methods, determining a new point is a time‐consuming process. In this paper, we propose a new method, named Sieve, to sequentially select points of an initially unknown function based on the definition of proper intervals. In contrast with existing methods, Sieve does not involve function estimation at each iteration. Therefore, it presents a greater computational efficiency for achieving a given accuracy in estimation. Sieve brings in tools from computational geometry to subdivide regions of the domain efficiently. Further, we validate our proposed method through numerical simulations and two case studies on the calibration of internal combustion engines and the optimal exploration of an unknown environment by a mobile robot.

A Novel Temperature Drift Error Estimation Model for Capacitive MEMS Gyros Using Thermal Stress Deformation Analysis.

Because the conventional Temperature Drift Error (TDE) estimation model for Capacitive MEMS Gyros (CMGs) has inadequate Temperature Correlated Quantities (TCQs) and inaccurate parameter identification to improve their bias stability, its novel model based on thermal stress deformation analysis is presented. Firstly, the TDE of the CMG is traced precisely by analyzing its structural deformation under thermal stress, and more key decisive TCQs are explored, including ambient temperature variation ∆T and its square ∆T2, as well its square root ∆T1/2; then, a novel TDE estimation model is established. Secondly, a Radial Basis Function Neural Network (RBFNN) is applied to identify its parameter accurately, which eliminates local optimums of the conventional model based on a Back-Propagation Neural Network (BPNN) to improve bias stability. By analyzing heat conduction between CMGs and the thermal chamber with heat flux analysis, proper temperature control intervals and reasonable temperature control periods are obtained to form a TDE precise test method to avoid time-consuming and expensive experiments. The novel model is implemented with an adequate TCQ and RBFNN, and the Mean Square Deviation (MSD) is introduced to evaluate its performance. Finally, the conventional model and novel model are compared with bias stability. Compared with the conventional model, the novel one improves CMG's bias stability by 15% evenly. It estimates TDE more precisely to decouple Si-based materials' temperature dependence effectively, and CMG's environmental adaptability is enhanced to widen its application under complex conditions.

Zastosowanie toksyny botulinowej w okuloplastyce

Botulinum toxin is one of the strongest functional organic toxins. Throughout history, detailed research has contributed to changing the perception of this substancefrom a toxin to a widely used medication. Botulinum toxin has found therapeutic use in many fields of medicine, and indications for its use are constantly widening in a variety of diseases that all characterize muscular hyperactivity. Intramuscular injection causes a transient paralysis, by acting on the motorend-plate of the neural axon and blocking a release of acetylcholine. In oculoplasty, it is used in treating localized dystonia such as :eyelid droop and facial hemiparesis, lower eyelid curl, eyelid retraction in cases of thyroid ophthalmopathy, treatment of non-healing corneal ulcers such as post-paresis upper eyelid insufficiency and dry-eye syndrome. In the general field of ophthalmology, the use of botulinum toxin successfully treats strabismus as well as otherextraocular muscle disorders that are present in nystagmus as well as Grave’s disease. The aim of this scientific study is to analyze the possibilities of botulinum toxin injections in various ophthalmic disorders, considering their potential as an alternativeto traditional surgeries, and discussing their benefits and risks. The research methodology relies on a systematic review of literature available in medical databases, analyzing publications and clinical studies related to botulinum toxin injections in ophthalmology. Since its discovery, botulinum toxin has undergone a remarkable transformation, from a deadly poison to a medicine used in various fields of medicine. When administered in appropriate doses, at proper intervals, and by qualified personnel, it becomes a safe form of the rapyfor numerous medical conditions characterized by excessive muscle activity.

A New Technique for Broadband Matching of Open-Ended Rectangular Waveguide Radiator.

The maximum reflection at an open end of a standard rectangular waveguide is about -10 dB in its operating frequency range. It is often used without matching. For critical applications, it is desirable to further reduce the reflection coefficient. In this paper, a new technique is presented for the broadband impedance matching of an open-ended rectangular waveguide. The proposed technique employs three thin capacitive matching elements placed at proper intervals via a low-loss dielectric material. The capacitance of, and distance between, the matching elements are optimized for broadband impedance matching using a simulation tool. Based on the proposed technique, two design examples are presented for the matching of a WR75 waveguide radiator. A reflection coefficient of less than -16 dB and -20 dB has been achieved over a ratio bandwidth of 2.13:1 and 1.62:1, respectively.

On the accumulation points of non-periodic orbits of a difference equation of fourth order

On the accumulation points of non-periodic orbits of a difference equation of fourth order

Controllable multi-scale hydrophobic structures on titanium alloy by polarization-dependent femtosecond laser fabrication and magnetron sputtering

Controllable multi-scale hydrophobic structures on titanium alloy by polarization-dependent femtosecond laser fabrication and magnetron sputtering

THU171 Reference Intervals For Bioavailable IGF-I Values In Dutch Healthy Children, Adolescents And Young Adults

Abstract Disclosure: K. Pellikaan: None. M. Elizabeth: None. A.C. Hokken-Koelega: None. S.A. van den Berg: None. L. de Graaff-Herder: None. Background: Immunoreactive ‘total’ IGF-I is the main biochemical marker for titration of growth hormone (GH) treatment. However, in several endocrine disorders like Prader-Willi syndrome (PWS) and Silver-Russell syndrome, total IGF-I levels are often higher than expected based on GH dose and clinical effects. When patients reach total IGF-I concentrations above +2SDS, fear of negative long-term effects makes clinicians reduce GH dose. This dose reduction often leads to a deterioration in body composition, growth (in children) and quality of life, which suggests that bioavailability of IGF-I is reduced in patients with these disorders. Measurement of bioavailable IGF-I could improve GH dose titration. However, use of bioavailable IGF-I assays has been hindered by the lack of proper reference intervals. We report reference intervals of bioavailable IGF-I in a large group of healthy children, adolescents and adults. Methods: Serum was collected of 260 Dutch healthy controls aged 1-21 years. Total IGF-I and unbound, bioavailable IGF-I were measured manually using Ansh Labs total and free IGF-I assays. We calculated male and female age-related reference intervals for total and bioavailable IGF-I. Results: We present male and female age-related reference intervals. Both total and bioavailable IGF-I increased with age and were significantly higher in females than in males (p < 0.001). Conclusions: the reported reference intervals for bioavailable IGF-I concentrations will facilitate the use of bioavailable IGF-I levels as an alternative marker for GH dose titration in patients with disorders in which total IGF-I levels are unreliable. Presentation: Thursday, June 15, 2023

Psychometric properties of the Chinese version of the PROMIS-Cancer-Anxiety item bank assessed using a graded response model

ObjectiveThis study aimed to examine the psychometric properties of the Chinese version of the Patient-Reported Outcome Measurement Information System (PROMIS)-Cancer-Anxiety item bank using a graded response model in a sample of patients with cancer. MethodsA cross-sectional study was conducted and the Chinese version of the PROMIS-Cancer-Anxiety item bank was used to measure anxiety in patients with cancer. The unidimensional structure of the item bank was evaluated using principal component analysis. Residual correlations and the graphs of item mean scores conditional on the rest scores were examined to evaluate the local independence and monotonicity of the items, respectively. Item characteristics were described using item parameter estimates and item information. Operating characteristic curves (OCCs) and test information curve (TIC) were also plotted. Measurement invariance across age, gender, and education level was assessed to identify possible differential item functioning (DIF). ResultsA total of 1075 patients with cancer were enrolled. Under the assumptions of unidimensionality, local independence, and monotonicity, the discrimination parameters a ranged from 2.30 to 5.47, and the threshold parameters b ranged from b1 = −2.87 to b4 = 3.21 with proper intervals. Completely overlapped category curves were not observed among the OCCs of any items. Item information and TIC showed that the item bank had a wide measurement range. The DIFs for age, gender, and education level for all items were not remarkable. ConclusionsThe results supported using the Chinese version of the PROMIS-Cancer-Anxiety item bank to measure anxiety and develop a computerized adaptive testing (CAT) system for anxiety in patients with cancer.

Association of interpregnancy interval and risk of adverse pregnancy outcomes in woman by different previous gestational ages.

With an increasing proportion of multiparas, proper interpregnancy intervals (IPIs) are urgently needed. However, the association between IPIs and adverse perinatal outcomes has always been debated. This study aimed to explore the association between IPIs and adverse outcomes in different fertility policy periods and for different previous gestational ages. We used individual data from China's National Maternal Near Miss Surveillance System between 2014 and 2019. Multivariable Poisson models with restricted cubic splines were used. Each adverse outcome was analyzed separately in the overall model and stratified models. The stratified models included different categories of fertility policy periods (2014-2015, 2016-2017, and 2018-2019) and infant gestational age in previous pregnancy (<28 weeks, 28-36 weeks, and ≥37 weeks). There were 781,731 pregnancies enrolled in this study. A short IPI (≤6 months) was associated with an increased risk of preterm birth (OR [95% CI]: 1.63 [1.55, 1.71] for vaginal delivery [VD] and 1.10 [1.03, 1.19] for cesarean section [CS]), low Apgar scores and small for gestational age (SGA), and a decreased risk of diabetes mellitus in pregnancy, preeclampsia or eclampsia, and gestational hypertension. A long IPI (≥60 months) was associated with an increased risk of preterm birth (OR [95% CI]: 1.18 [1.11, 1.26] for VD and 1.39 [1.32, 1.47] for CS), placenta previa, postpartum hemorrhage, diabetes mellitus in pregnancy, preeclampsia or eclampsia, and gestational hypertension. Fertility policy changes had little effect on the association of IPIs and adverse maternal and neonatal outcomes. The estimated risk of preterm birth, low Apgar scores, SGA, diabetes mellitus in pregnancy, and gestational hypertension was more profound among women with previous term births than among those with preterm births or pregnancy loss. For pregnant women with shorter or longer IPIs, more targeted health care measures during pregnancy should be formulated according to infant gestational age in previous pregnancy.

Improved lower bound on the on-line chain partitioning of semi-orders with representation

Improved lower bound on the on-line chain partitioning of semi-orders with representation

Machine Learning for Exposure-Response Analysis: Methodological Considerations and Confirmation of Their Importance via Computational Experimentations.

Exposure-response (E-R) is a key aspect of pharmacometrics analysis that supports drug dose selection. Currently, there is a lack of understanding of the technical considerations necessary for drawing unbiased estimates from data. Due to recent advances in machine learning (ML) explainability methods, ML has garnered significant interest for causal inference. To this end, we used simulated datasets with known E-R "ground truth" to generate a set of good practices for the development of ML models required to avoid introducing biases when performing causal inference. These practices include the use of causal diagrams to enable the careful consideration of model variables by which to obtain desired E-R relationship insights, keeping a strict separation of data for model-training and for inference generation to avoid biases, hyperparameter tuning to improve the reliability of models, and estimating proper confidence intervals around inferences using a bootstrap sampling with replacement strategy. We computationally confirm the benefits of the proposed ML workflow by using a simulated dataset with nonlinear and non-monotonic exposure-response relationships.

Key quality indicators in colonoscopy.

Many quality indicators have been proposed for colonoscopy, but most colonoscopists and endoscopy groups focus on measuring the adenoma detection rate and the cecal intubation rate. Use of proper screening and surveillance intervals is another accepted key indicator but it is seldom evaluated in clinical practice. Bowel preparation efficacy and polyp resection skills are areas that are emerging as potential key or priority indicators. This review summarizes and provides an update on key performance indicators for colonoscopy quality.

1309. Adherence to Short-Term Antibiotic Therapy in Children – a Blinded, Prospective, Electronically-Monitored Study

Abstract Background Non-adherence to short-term antibiotic treatment in children can lead to treatment failure and development of drug resistance. To develop effective interventional programs reliable adherence data is needed, but previous studies are scarce and have mostly used parental self-reports. We aimed to determine true adherence rates of pediatric patients treated for acute infections with antibiotic suspensions. Secondary goals were to evaluate patient and treatment characteristics influencing adherence rates and whether the prescriber can predict adherence rates of patients. Methods A prospective, blinded, electronically monitored, observational study. Patients aged 2 months to 5 years diagnosed with an acute bacterial infection requiring short (5-10 days) oral antibiotic monotherapy were enrolled. Parents were told they received a new "childproof" cap for evaluation, but unknowingly were provided with an electronically monitored medication bottle recording every manipulation of the cap. At the end of treatment study purpose was disclosed and, if approved, cap data and patient and treatment information collected. Results 100 infants (49 boys, mean [range] age 1.87 years [0.2-5.1]) were included in the final analysis. Only 11 participants received all the recommended doses. Overall adherence (defined as administration of &amp;gt;75% of prescribed doses) was 62%, while timing adherence (administration of &amp;gt;75% of doses within ±20% of the prescribed interval) was only 21%. After applying a logistic regression model, the only factor significantly associated with non-adherence was being a single parent [OR=5.7 95%CI (1.07-30.3)]. Prescribers overestimated adherence, defining 49/62 (77.7%) participants as likely adherent. Patient/parent pairs that were predicted to be adherent were not more likely to be overall or timing adherent than those predicted to be non-adherent (31/47 vs. 6/16, p=0.77). Conclusion Adherence of children to short-term antimicrobial treatment for an acute infection is suboptimal, with only 62% showing good adherence and 21% with good adherence at proper timing intervals. Providers were unable to predict patient adherence. This data is important when considering recommended treatment durations and developing interventional programs to increase adherence. Disclosures All Authors: No reported disclosures.

Sensitivity and uncertainty analysis for structural health monitoring with crack propagation under random loads: A numerical framework in the frequency domain

AbstractThe quantification of uncertainties in a system and the ability to identify the most influential parameters for a given structural health monitoring (SHM) strategy constitutes an important step for an in‐depth analysis of the problem. It is used in reliability assessment and for the definition of proper inspection intervals. In a recent paper, the authors proposed a methodology for SHM and fatigue life estimations of structures under random loads. This paper expands over those concepts and presents a framework for sensitivity and uncertainty analysis for SHM of structures in the frequency domain. The structure is an Euler–Bernoulli beam, which is modeled with the Ritz method. The conceptual simplicity of the Ritz model keeps the computational cost low. The results showed that the Walker parameter for the crack propagation law, ; the modal damping factor; and the input acceleration are important parameters affecting the variance of the remaining useful life.

Broadly Tunable Erbium-Doped Fiber Ring Laser Based on Tapered Polarization Maintaining Fiber

A broadly tunable erbium-doped fiber ring laser is proposed and demonstrated based on the tapered polarization maintaining fiber (PMF) Sagnac interferometer, in which the Sagnac and intermodal interferences are superimposed to generate one localized peak over a wide wavelength range in its transmission spectrum. By heating the tapered PMF, the localized peak may be discretely tuned with the temperature at the step, depending on the intermodal interference. Tunability may become continuous when additional stress is exerted longitudinally on the tapered PMF. The tapered PMF Sagnac interferometer is inserted into the laser cavity to achieve broadly and continuously tunable output. Specifically, by optimizing the PMF length and its tapering section to obtain proper channel intervals of the Sagnac and intermodal interference, the lasing wavelength is continuously tuned over 60 nm covering from 1565.1 nm to 1625.2 nm with sidemode suppression ratio higher than 50 dB and power uniformity better than 1 dB. The tuning responses to temperature and axial stress are both linear with sensitivity of −1.1 nm/°C and −29.4 pm/μϵ. Most importantly, the temperature and axial stress affect the Sagnac and intermodal interferences, respectively, which makes it convenient to set the lasing wavelength beforehand during operation.

Impact of the COVID-19 Pandemic on Pulmonary Hypertension Patients: Insights from the BNP-PL National Database.

We aimed to evaluate the clinical course and impact of the SARS-CoV-2 pandemic on the rate of diagnosis and therapy in the complete Polish population of patients (pts) with pulmonary arterial hypertension (PAH-1134) and CTEPH (570 pts) treated within the National Health Fund program and reported in the national BNP-PL database. Updated records of 1704 BNP-PL pts collected between March and December 2020 were analyzed with regard to incidence, clinical course and mortality associated with COVID-19. Clinical characteristics of the infected pts and COVID-19 decedents were analyzed. The rates of new diagnoses and treatment intensification in this period were studied and collated to the proper intervals of the previous year. The incidence of COVID-19 was 3.8% (n = 65) (PAH, 4.1%; CTEPH, 3.2%). COVID-19-related mortality was 28% (18/65 pts). Those who died were substantially older and had a more advanced functional WHO class and more cardiovascular comorbidities (comorbidity score, 4.0 ± 2.1 vs. 2.7 ± 1.8; p = 0.01). During the pandemic, annualized new diagnoses of PH diminished by 25–30% as compared to 2019. A relevant increase in total mortality was also observed among the PH pts (9.7% vs. 5.9% pre-pandemic, p = 0.006), whereas escalation of specific PAH/CTEPH therapies occurred less frequently (14.7% vs. 21.6% pre-pandemic). The COVID-19 pandemic has affected the diagnosis and treatment of PH by decreasing the number of new diagnoses, escalating therapy and enhancing overall mortality. Pulmonary hypertension is a risk factor for worsened course of COVID-19 and elevated mortality.

Discriminating 1D new physics solutions in b → sℓℓ decays * *Partly supported by the National Natural Science Foundation of China (11735003, 11975041, 11961141004), and the fundamental Research Funds for the Central Universities. Rui-Xiang Shi is supported by the National Natural Science Foundation of China (12147145) and Project funded by China Postdoctoral Science Foundation (2021M700343)

The recent measurements of , , , , a set of CP-averaged angular observables for the decay and its isospin partner by the LHCb Collaboration consistently hint at lepton universality violation in the transitions. In this work, we first perform global fits to the data and show that five one-dimensional scenarios, i.e, , , , , and can best explain the so-called B anamolies. Furthermore, we explore how these scenarios can be distinguished from each other. For this purpose, we first study the combinations of four angular asymmetries and find that they cannot distinguish the five new physics scenarios. We then show that a newly constructed ratio can uniquely discriminate the five new physics scenarios in proper intervals of if it can be measured with percent-level precision.