Abrupt Start Research Articles

Time Series Intervention Modelling Based on ESM and ARIMA Models: Daily Pakistan Rupee/Nigerian Naira Exchange Rate

The battered Nigerian economy has slipped into its second economic recession in five years due to the fallout of the coronavirus pandemic. And this has had a remarkable effect on the value of the Nigerian Naira that are exchanged for a unit of many other currencies of the world. Intervention modelling is used to assess the impact of this external event on the Pakistan Rupee to the Nigerian Naira exchange rates. The dataset for this study is the daily Nigerian Naira exchange rate with respect to the Pakistan Rupee from January–December 2020. The intervention point is marked on April 10, 2020, as a pulse function for the PKR/NGN series. Results revealed that the economic recession due to the fallout of the coronavirus pandemic increased the value of the Nigerian Naira by 3.38% against the Pakistan Rupee, which 1PKR is exchanged for 2.2042NGN compared to the periods before and after the intervention occurred. The intervention was felt at the point of intervention itself but the effect dies immediately after the intervention. Hence, the intervention response is described as an abrupt start and abrupt decay.

Federal Taxation: Comprehensive Topics

Federal Taxation: Comprehensive Topics

Bayesian modelling of integer-valued transfer function models

External events are commonly known as interventions that often affect times series of counts. This research introduces a class of transfer function models that include four different types of interventions on integer-valued time series: abrupt start and abrupt decay (additive outlier), abrupt start and gradual decay (transient shift), abrupt start and permanent effect (level shift) and gradual start and permanent effect. We propose integer-valued transfer function models incorporating a generalized Poisson, log-linear generalized Poisson or negative binomial to estimate and detect these four types of interventions in a time series of counts. Utilizing Bayesian methods, which are adaptive Markov chain Monte Carlo (MCMC) algorithms to obtain the estimation, we further employ deviance information criterion (DIC), posterior odd ratios and mean squared standardized residual for model comparisons. As an illustration, this study evaluates the effectiveness of our methods through a simulation study and application to crime data in Albury City, New South Wales (NSW) Australia. Simulation results show that the MCMC procedure is reasonably effective. The empirical outcome also reveals that the proposed models are able to successfully detect the locations and type of interventions.

Frequency-domain analysis of black-hole ringdowns

We propose a novel, frequency-domain approach to the analysis of the gravitational-wave ringdown signal of binary black holes and the identification of quasinormal mode frequencies of the remnant. Our approach avoids the issues of spectral leakage that would normally be expected (associated with the abrupt start of the ringdown) by modeling the inspiral and merger parts of the signal using a flexible sum of sine-Gaussian wavelets truncated at the onset of the ringdown. Performing the analysis in the frequency domain allows us to use standard (and by now well-established) Bayesian inference pipelines for gravitational-wave data as well as giving us the ability to readily search over the sky position and the ringdown start time, although we find that it is necessary to use an informative prior for the latter. We test our method by using it to analyze several simulated signals with varying signal-to-noise ratios injected into two- and three-detector networks. We find that our frequency-domain approach is generally able to place tighter constraints on the remnant black-hole mass and spin than a standard time-domain analysis.

Endogenous Endophthalmitis in COVID-19 Patients

Intrinsic endophthalmitis is indeed behavior that causes eye disease that spreads into the bloodstream from a distant primary site. The intraocular disease caused by hematogenous microbial proliferation is known as indigenous endophthalmitis. Extrinsic and intrinsic endophthalmitis are the two types of endophthalmitis that exist. The presence of an external point of entry is linked to extrinsic endophthalmitis. Intrinsic endophthalmitis is a kind of septicemia caused by a blood-borne infection. Endophthalmitis is a disease of all the inner coating of the eyeball except the sclera and cornea, which is accompanied by substantial, increasing vitreous swelling. Endophthalmitis is a severe ocular crisis with severe visual and general consequences. An exterior injury of the entrance, such as injury, operation, or an inflamed cornea, is the most prevalent route of entry for potential pathogens. Endophthalmitis has a complex etiology, with many pathogenic species and substantial regional heterogeneity. The treatment of endophthalmitis has evolved dramatically during the last century. Endophthalmitis induced by direct inoculation dissemination of pathogenic microbes is a rare occurrence that occurs most commonly in sick or disadvantaged people. Intravenous medication usage, diabetes mellitus, immunological impairment, cancer, prolonged hospitalization, or systemic antibiotic therapy have all been linked to a 0.04 percent incidence rate. Haden described metastatic endophthalmitis in a seriously sick patient with pneumococcal cerebrospinal encephalopathy treated with intravenously anti-meningococcal serum in the 1918 volume of the Journal Ophthalmology. Endogenous endophthalmitis, unlike extrinsic endophthalmitis, needs comprehensive systemic antibiotic treatment. In indigenous endophthalmitis, the illness originates not in the eye but elsewhere in the body. As a result, it is necessary to obtain comprehensive cultures. Patients are sometimes unable to carry out their functions in society or household. As a rest, the person cannot cope financially and socially in his environment. Many social and influential factors are disturbed, and the patients are often depressed. Cosmetically the surgeries are not satisfying. Artificial prosthetics can be used, but they're seldom of minimum functional importance. Such interventions can be helpful for the patient. The focus should be made to deliberately save the patients and not just the cosmetic value of the surgery. Persons with chronic endophthalmitis had more excellent eyesight than people with symptomatic or subacute endophthalmitis. Improvements in eyesight were observed in individuals with persistent or subacute keratitis several months after the surgery more frequently than in people with symptomatic endophthalmitis. Nevertheless, in 40 percent of the overall all instances with an abrupt start, there have been no improvements or even decrease in visual acuity.

Analyzing the Underlying Structure of Online Teaching During the COVID-19 Pandemic Period: An Empirical Investigation of Issues of Students.

The aim of the study is to reveal the underlying structure of issues of university students taking online classes during the COVID-19 pandemic period. The overall design of the study includes a review of contemporary literature and field survey for data collection and analysis. Discourse of literature coupled with expert opinion has been employed for identification of issues. Interpretive Structural Modeling (ISM) is used for the determination of intra-issue relationships and analyzing the underlying structure. Cross impact matrix multiplication applied to classification (MICMAC analysis) is used as a technique for classifying issues on the basis of driving–dependence power. Results of the literature show that there are 21 major issues faced by the students taking online classes. ISM shows that lack of institutional guidelines, lack of regulators’ guidelines, stress of pandemic situation, and abrupt (not planned) start of online classes are the most critical issues. MICMAC analysis reveals that there is no autonomous issue, 4 (i.e., connectivity issue, shy to use technology, lack of institutional guidelines, and stress of pandemic situation) are independent, 6 other issues are dependent, and the remaining 11 are linking. This is a valuable study having practical implications for regulators, students, parents, and society to understand the current problem. It is an original attempt that contributes toward literature in the form of a structural model and a diagram of classification of issues.

COVID19 ve Grafiksel Veri Analizi

Covid-19 salgını 2019 yılının son ayları ile 2020 yılının ilk aylarında tüm dünyanın gündemine hızla giriş yapmıştır. Hastalığın, çıkış noktası kabul edilen Çin’in Wuhan bölgesinden dünyanın diğer bölgelerine ulaşması birkaç ay içinde gerçekleşmiştir. Covid-19 ile ilgili derlenen bilgiler ilk günlerde sayısal tablolar olarak ortaya çıkmıştır. Ancak ilerleyen günler ile birlikte özellikle farklı ülkelerin değerlerinin karşılaştırılması için grafiklere başvurulmuştur. Grafikler verinin genel özelliklerini hedef kitleye iletmede çok etkili araçlardır. Modern teknoloji ile beraber grafik çeşitliliği de artmıştır. Bu çalışmada son 6 ay içerisinde Covid-19 kapsamında kullanılan bazı grafik teknikleri incelenmiştir. Çalışma sonunda özellikle mekânsal analizleri içeren haritaların ve konuya ilişkin farklı bilgileri bir arada aktaran gösterge panosunun tıp araştırmalarında daha fazla kullanılmasının, ileride ortaya çıkabilecek yeni salgın hastalıkların tahmin edilmesinde faydalı olabileceği önerilmiştir.

On the unsteady rotating fluid flow in a uniformly rotating or fixed vertical cylinder

In this paper we consider the properties of the transient process that always precedes (or completes) the onset (cessation) of steady fluid flow in a uniformly rotating vertical cylinder. First, we give an elementary (without using the Navier–Stokes equations) and detailed derivation of the equation describing the space and time distribution of angular speeds in a rotating viscous fluid. This expression is used further for the numerical construction of the dynamic surface profiles. We find that in the case of an abrupt stop of cylinder rotation, these profiles have an inflection point, while for an abrupt start of cylinder rotation such a peculiarity is absent. We provide a simple physical explication of this fact. The issues outlined in this article will be useful for undergraduate students studying the basics of fluid mechanics.

Revealing the perovskite formation kinetics during chemical vapour deposition

High control chemical vapour deposition of (Cs,FA)PbI3 perovskite provides insights into CVD kinetics and perovskite phase evolution.

Filling the gap in a double seismic zone: Intraslab seismicity in Northern Chile

Double seismic zones (DSZs) of intermediate-depth intraslab seismicity are observed in many subduction zones around the globe, and have been related to dehydration reactions in the downgoing crust and mantle lithosphere. These reactions occur at, to first order, constant temperatures, which explains the observed linear arrangements of seismicity that appear to follow isotherms of thermal models.Intermediate-depth seismicity in Northern Chile, however, exhibits a pattern of intraslab seismicity that substantially deviates from a classical DSZ. Whereas two parallel seismicity planes are present in the updip part of the slab, these abruptly change into a 25–30 km thick, homogeneously seismogenic volume at a depth of ∼80–100 km. Seismicity rate and moment release significantly increase in this depth interval. In order to understand which processes evoke this configuration and what distinguishes the Northern Chile subduction zone from more conventional subduction zone settings (e.g. Japan), we performed a detailed seismological investigation of slab seismicity in Northern Chile using data from the IPOC permanent network. We determined >600 moment tensors of intraslab earthquakes, processed and evaluated location uncertainties for 8 years of high-resolution earthquake hypocenter data, and performed statistical analysis of the different seismicity populations.We observe that earthquakes both in the highly active cluster and the DSZ above exhibit consistently downdip extensive source mechanisms that align with the dip angle and direction of the slab. This implies strong slab pull, which is also evident from slab steepening outlined by hypocenters towards the downdip termination of the highly active cluster. Moreover, events in the cluster show a very weak aftershock productivity and a high background event rate, which leads to a temporal distribution of seismicity that is close to a purely random process. We find that the position of the highly seismogenic volume spatially coincides with: 1) the disappearance of the velocity contrast between oceanic crust and the underlying mantle in receiver function images, 2) the transition from the “cold nose” (i.e. the stagnant part) to the hot part of the mantle wedge, as evidenced by seismic attenuation images, and 3) with an increase of the slab dip angle. Based on these different pieces of evidence, we speculate that high tensile stresses and heat input from above could lead to a sudden burst of kinetically delayed metamorphic reactions there that then enables the observed increased seismicity rates. Since these reactions have overall a negative volume change that leads to slab densification and hence further increases slab pull, the spatial pattern of seismicity we observe could result from a runaway-type process, which would explain its abrupt start and high moment release rates.

Apnea events in neonatal age: A case report and literature review

BackgroundAmong the most common autonomic signs visible in preterm neonates, apnea can represent the first sign of several neurologic and non-neurologic disorders, and seizure is a relatively infrequent cause. Herein authors present a case of neonatal autonomic apnea, discussing the polygraphic video-EEG features of this pathological entity and the differential diagnosis with central apnea and autonomic apnea. Case reportA female preterm Caucasian infant (29 + 4 weeks' gestational age (GA)), first twin of a twin pregnancy, at birth was intubated and surfactant administration was performed. She was ventilated via invasive ventilation for three days, with subsequent weaning with non-invasive ventilation for other two days, when she stopped requiring any ventilator support. After one week the ventilation weaning, the child presented episodes of cyanosis associated with sudden oxygen desaturation, skin pallor, apnea, and bradycardia. Therefore, the child underwent a continuous video-eeg recording with polygraphic study. The exam showed the presence of apneic episodes with an abrupt and clear start, associated with oxygen desaturation at 70%, with minimal thoracic effort at onset, and then evolving into central apnea. Central apnea lasted about 16 s and presented clear start- and end-points. These episodes were also associated with suppression of the EEG trace in frequency and amplitude, and after about 10 s of central apnea an abrupt decrease of the child's heart rate (more than 50% variation, from 160 bpm to 65 bpm) was recorded. In the suspect of epileptic apneas of autonomic origin, a therapy with oral Levetiracetam, at a starting dose of 10 mg/Kg/day, then increased up to 40 mg/Kg/day, was initiated, and after about 48 h the first administration of the anticonvulsant therapy, no new episodes of cyanosis or electrical apneas were recorded. HypothesisHerein the authors suggest to consider the diagnosis of autonomic seizures in those neonates with apneic events associated with EEG suppression.Considering that apnea events are not only present in preterm infants but also in term neonates, it is mandatory to diagnose in this context neonatal seizures for a correct diagnosis and a proper therapeutic choice.

Teaching childbirth with high-fidelity simulation. Is it better observing the scenario during the briefing session?

The design of optimal courses for obstetric undergraduate teaching is a relevant question. This study evaluates two different designs of simulator-based learning activity on childbirth with regard to respect to the patient, obstetric manoeuvres, interpretation of cardiotocography tracings (CTG) and infection prevention. This randomised experimental study which differs in the content of their briefing sessions consisted of two groups of undergraduate students, who performed two simulator-based learning activities on childbirth. The first briefing session included the observations of a properly performed scenario according to Spanish clinical practice guidelines on care in normal childbirth by the teachers whereas the second group did not include the observations of a properly performed scenario, and the students observed it only after the simulation process. The group that observed a properly performed scenario after the simulation obtained worse grades during the simulation, but better grades during the debriefing and evaluation. Simulator use in childbirth may be more fruitful when the medical students observe correct performance at the completion of the scenario compared to that at the start of the scenario.Impact statementWhat is already known on this subject? There is a scarcity of literature about the design of optimal high-fidelity simulation training in childbirth. It is known that preparing simulator-based learning activities is a complex process. Simulator-based learning includes the following steps: briefing, simulation, debriefing and evaluation. The most important part of high-fidelity simulations is the debriefing. A good briefing and simulation are of high relevance in order to have a fruitful debriefing session.What do the results of this study add? Our study describes a full simulator-based learning activity on childbirth that can be reproduced in similar facilities. The findings of this study add that high-fidelity simulation training in childbirth is favoured by a short briefing session and an abrupt start to the scenario, rather than a long briefing session that includes direct instruction in the scenario.What are the implications of these findings for clinical practice and/or further research? The findings of this study reveal what to include in the briefing of simulator-based learning activities on childbirth. These findings have implications in medical teaching and in medical practice.

ANALYSIS IN AUDITING: SOME QUESTIONS FOR APPLICATION

In the difficult period of the country's economic structure functioning, investment forms the future of technical, financial and economic security. The legally regulated institutional framework creates opportunities for an abrupt innovation start. However, the low positions, which are caused by the economy of war, do not provide opportunities for its implementation. Consequently, the full and rational use of existing chances becomes a guarantee of at least a slow implementation of the strategies of innovative development of enterprises. In this way, the system of auditor consulting and formation of audit opinion about the effectiveness of innovative processes and projects is a priority. Available analysis tools, system approach and cash flow modelling, provide investors with confidence and generate interest from shareholders and owners. The calculation of a number of indicators characterizing the effectiveness of innovation projects becomes a guarantee of their implementation and achievement of management objectives. Therefore, the application of analytical techniques in the process of audit of innovative projects allows the auditor to form an independent opinion on their convenience.

Director (a) por primera vez: Un estudio sobre la experiencia y socialización de los directores noveles en establecimientos municipales de Chile

Taking the role of a school principal for the first time is a critical period in their job performance, issue that has been sparsely studied in Chile despite of the increasing renovation of school leaders at the time. Based on 12 case studies and a survey administered to 76 principals, this article explores the experience and socialization of beginning principals at public schools, capturing their professional development needs as well. The main results include: a profile of beginning principals; the confirmation of an abrupt start at school organization; focus on short term actions emphasizing school climate and institutional management actions (delaying focus on pedagogical management); experiencing external and internal school difficulties combined with a lack of personal competencies to overcome challenges; the absence of institutional support during this initial period, which is compensated by school internal actors’ support and individuals’ personal networks with other principals; and the need to differentiate between the experiences of beginning principals depending on whether they are insiders or outsiders to the school organization or the municipal sector.

Effects of cavitation on performance of automotive torque converter

Cavitation is a phenomenon whereby vapor bubbles of a flowing liquid are formed in a local region where the pressure of the liquid is below its vapor pressure. It is well known that cavitation in torque converters occurs frequently when a car with an automatic transmission makes an abrupt start. Cavitation is closely related to a performance drop and noise generation at a specific operating condition in a car and a torque converter itself. This study addressed the relation between cavitation and performance in an automotive torque converter in a quantitative and qualitative manner using numerical simulations. The cavitation was calculated at various operating conditions using a commercial flow solver with the homogeneous cavitation model, and the torque converter performance was compared with the experimental data. Numerical results well match to the data and indicate that the cavitation causes significant performance drop, as the pump speed increases or both speed ratio and reference pressure decrease.

Individual trial analysis evidences clock and non-clock based conditioned suppression behaviors in rats

We analyzed the temporal pattern of conditioned suppression of lever-pressing for food in rats conditioned with tone-shock pairings using either a 10 or 15s conditioned stimulus (CS)-unconditioned stimulus (US) interval with a CS duration that was three times the CS-US interval. The analysis of average suppression and of individual trials was performed during Probe CS-alone trials and when a short gap was inserted during the CS. The pattern of suppression followed the classical temporal rules: (1) scalar property, (2) a shift in peak suppression due to a gap, compatible with a Stop rule, (3) a three-state pattern of lever-pressing in individual trials, with abrupt start and stop of suppression. The peak of the average suppression curve, but not the middle time, was anticipatory to the programmed US time. The pattern of lever-pressing in individual trials unraveled two types of start of suppression behavior: a clock-based biphasic responding, with a burst of lever-pressing before suppression, and a non-clock based monophasic reduction of lever-pressing close to the CS onset. The non-clock based type of behavior may be responsible for the anticipatory peak time, and the biphasic pattern of lever-pressing may reflect the decision stage described in clock models.

Persistent intermediate water warming during cold stadials in the southeastern Nordic seas during the past 65 k.y.

In the Nordic seas, conversion of inflowing warm Atlantic sur face water to deep cold water through convection is closely linked with climate. During the last glacial period, climate underwent rapid millennial-scale variability known as Dansgaard-Oeschger (DO) events, consisting of warm interstadials and cold stadials. Here we present the first benthic foraminiferal Mg/Ca- d 18 O record from the Nordic seas in order to reconstruct the ocean circulation on DO time scales. The record confirms that convection similar to modern took place in the Nordic seas during interstadials with cold bottom water temperatures (BWTs) close to modern temperatures. The results show gradual and pronounced BWT increases of 2–5 °C during stadials, indicating a stop or near stop in convection. The BWT peaks are followed by an abrupt drop in temperature at the onset of interstadials, indicating the abrupt start of convection and renewed generation of cold deep water. The rise in BWT during stadials confirms earlier interpretations of subsurface inflow of warm Atlantic water below a halocline reaching >1.2 km water depth. The results suggest that warm Atlantic water never ceased to flow into the Nordic seas during the glacial period; inflow at the surface during the Holocene and warm interstadials changed to subsurface and intermediate inflow during cold stadials. Our results suggest that it is the vertical shifts in the position of the warm Atlantic water that cause the abrupt surface warmings.

Optimal Execution in Presence of Short-Term Trading

Starting from basic hypotheses on how footprints from hidden orders are interpreted by short-term traders, we derive a fair price model that predicts market impact for non-uniform participation rate schedules. We use this model to derive an optimal execution schedule for a risk-averse trader. The optimal schedule delays front-loading to avoid the information shock of an abrupt start. We also consider optimal strategies with respect to the Volume-Weighted Average Price (VWAP) benchmark. We show that the VWAP-optimized schedule for a large order is similar to the risk-averse one. In an example, we compute the cost of front-loading, and the additional cost of the information shock that results from an aggressive trade start.

Mortality in Young Adults following in Utero and Childhood Exposure to Arsenic in Drinking Water

Background: Beginning in 1958, the city of Antofagasta in northern Chile was exposed to high arsenic concentrations (870 µg/L) when it switched water sources. The exposure abruptly stopped in 1970 when an arsenic-removal plant commenced operations. A unique exposure scenario like this—with an abrupt start, clear end, and large population (125,000 in 1970), all with essentially the same exposure—is rare in environmental epidemiology. Evidence of increased mortality from lung cancer, bronchiectasis, myocardial infarction, and kidney cancer has been reported among young adults who were in utero or children during the high-exposure period.Objective: We investigated other causes of mortality in Antofagasta among 30- to 49-year-old adults who were in utero or ≤ 18 years of age during the high-exposure period.Methods: We compared mortality data between Antofagasta and the rest of Chile for people 30–49 years of age during 1989–2000. We estimated expected deaths from mortality rates in all of Chile, excluding Region II where Antofagasta is located, and calculated standardized mortality ratios (SMRs).Results: We found evidence of increased mortality from bladder cancer [SMR = 18.1; 95% confidence interval (CI): 11.3, 27.4], laryngeal cancer (SMR = 8.1; 95% CI: 3.5, 16.0), liver cancer (SMR = 2.5; 95% CI: 1.6, 3.7), and chronic renal disease (SMR = 2.0; 95% CI: 1.5, 2.8).Conclusions: Taking together our findings in the present study and previous evidence of increased mortality from other causes of death, we conclude that arsenic in Antofagasta drinking water has resulted in the greatest increases in mortality in adults < 50 years of age ever associated with early-life environmental exposure.

A detailed semiologic analysis of childhood psychogenic nonepileptic seizures

Psychogenic nonepileptic seizure (PNES) is an important differential diagnostic problem in patients with or without epilepsy. There are many studies that have analyzed PNES in adults; currently, however, there is no systematic assessment of purely childhood PNES semiology. Our study based on a large pediatric video-electroencephalography (EEG) monitoring (VEM) cohort, provides a detailed analysis of childhood PNES and assesses the usability of the current classification system described in adults. Medical and video-EEG records of 568 consecutive children (younger than 18 years) who underwent video-EEG monitoring (VEM) at our hospital were reviewed. Aura, type of movement, anatomic distribution, synchrony, symmetry, eye movement, responsiveness, vocalization, hyperventilation, vegetative and emotional signs, presence of eyewitness, and duration of the event were recorded among children with the diagnosis of PNES. We also compared our data with those of earlier adult studies. Seventy-five archived PNES of 27 children (21 girls; age 8-18 years) were reanalyzed. Nine children (33%) had the diagnosis of epilepsy currently or in the past. Mean age at the time of PNES onset was 11.6 (standard deviation 3.2) years. Mean duration of PNES was longer (269 s) compared to seizures of the epileptic group (83 s; p = 0.002). Eyewitnesses (mostly parents) were present in 89% of cases. Eighty percent of PNES had an abrupt start, with 68% also ending abruptly. In only 15% of events were the patients eyes closed at the beginning of the attack. Patients were unresponsive in 34%. The most frequent motor sign was tremor (25%) with the upper, rather than lower limbs more frequently involved. Pelvic thrusting was seen in only two attacks. Emotional-mostly negative-signs were observed during 32 PNES (43%). Based on Seneviratne et al.'s classification, 18 events (24%) were classified as rhythmic motor PNES, only half the frequency of that previously described in adults. No hypermotor PNES was found. The frequency of complex motor PNES (13%) and mixed PNES (4%) showed similar frequency in children as in adults. Dialeptic PNES was found more frequently among younger children. All PNES belonged to the same semiologic type in 23 patients (85%). Because homogeneity of PNES within a patient was high in the pediatric population, we found it useful to classify PNES into different semiologic categories. Dialeptic PNES seems to be more frequent among younger children. Tremor is the most frequent motor sign and usually accompanied by preserved responsiveness in childhood. Negative emotion is commonly seen in pediatric PNES, but pelvic thrusting is a rare phenomenon. We, therefore, suggest a modification of the present classification system in which PNES with motor activity is divided into minor and major motor PNES, and the latter group is subdivided into synchron rhythmic motor and asynchron motor PNES. We believe that our study, a detailed analysis on the semiology and classification of purely childhood PNES might assist the early and precise diagnosis of nonepileptic paroxysmal events.