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This study presents the main motivation to investigate the COVID-19 pandemic, a major threat to the whole world from the day when it first emerged in China city of Wuhan. Predictions on the number of cases of COVID-19 are crucial in order to prevent and control the outbreak. In this research study, an artificial neural network with rectifying linear unit-based technique is implemented to predict the number of deaths, recovered and confirmed cases of COVID-19 in Pakistan by using previous data of 137 days of COVID-19 cases from the day 25 February 2020 when the first two cases were confirmed, until 10 July 2020. The collected data were divided into training and test data which were used to test the efficiency of the proposed technique. Furthermore, future predictions have been made by the proposed technique for the next 7 days while training the model on whole available data.
Introduction: Wait time predictions have become more common in emergency departments in Canada. These estimate the wait times a patient faces to see providers and they are usually provided in an accessible way such as through an online interface. One purpose of these trackers is to improve ED system efficiency. Patients can self-triage to alternative care such as their primary care physician, defer care until a later time or could move from oversubscribed to undersubscribed EDs. However, these mechanisms could also be abused. If providers can artificially influence the wait time this may provide a possible lever to change patients flows to an ED. I investigate whether there is evidence suggestive of manipulation of online wait time trackers at an ED system in Ontario. Methods: Inputs into the wait time prediction algorithm, like patient volumes are taken from the ED EMR. This is the most likely place where staff can manipulate the wait time tracker by retaining patients in the EMR system even after they are discharged. I examine two sets of data to assess whether the online tracker displays differences in patient volumes from “true” data. The first is scraped data of patient volumes from the wait times website. The second are the accurate patient volumes from administrative data which includes when a physician discharged patients from the ED. I compare values of the true patient volumes to the online values and plot distributions of these differences. I also employ measures of accuracy such as mean square error and root mean square error to provide a value of how accurate the online data is compared to the true data. I examine these by ED and over time. Results: There are differences between the number of patients that are posted online and those in the administrative data. The distributions of these differences are skewed towards positive values suggesting that the online data more often overcounts rather than undercounts patients. Measures of accuracy increase during times when EDs are congested but do not decrease when EDs become less congested. This inaccuracy persists for a period after EDs cease to be busy. Conclusion: ED wait time trackers have the potential to be manipulated. When staff have incentive to reduce patient volumes, online data becomes more inaccurate relative to true data. This suggests that wait time trackers may have unintended consequences and that the information that they provide may not be entirely accurate.
In many situations, incentives exist to acquire knowledge and make correct political decisions. We conduct an experiment that contributes to a small but growing literature on incentives and political knowledge, testing the effect of certain and uncertain incentives on knowledge. Our experiment builds on the basic theoretical point that acquiring and using information is costly, and incentives for accurate answers will lead respondents to expend greater effort on the task and be more likely to answer knowledge questions correctly. We test the effect of certain and uncertain incentives and find that both increase effort and accuracy relative to the control condition of no incentives for accuracy. Holding constant the expected benefit of knowledge, we do not observe behavioral differences associated with the probability of earning an incentive for knowledge accuracy. These results suggest that measures of subject performance in knowledge tasks are contingent on the incentives they face. Therefore, to ensure the validity of experimental tasks and the related behavioral measures, we need to ensure a correspondence between the context we are trying to learn about and our experimental design.
A clearly defined research question allows us to formulate hypotheses that propose possible answers to that question. From these hypotheses, we can then derive specific, unambiguous predictions that allow us to test their validity with empirical data. Hypotheses and predictions serve to narrow down the infinite possibilities for data collection and determine the data we need to collect. In this chapter I cover formulating hypotheses and predictions, then explain that we often use proxies to test predictions and how practical constraints influence our thinking.
All aspects of linguistic knowledge are ultimately based on speakers’ experience with lexical expressions, but of course, knowledge of language, notably, grammar, exceeds their memory of particular lexical tokens. It is a standard assumption of the usage-based approach that grammar involves a taxonomic network of constructions ranging from prefabricated strings of lexical expressions to highly abstract schemas. Chapter 4 describes the taxonomic organization of constructions and their development in L1 acquisition and language change. It includes a detailed discussion of current research on statistical grammar learning in infancy, the acquisition of constructions during the preschool years and two case studies on the rise of constructional schemas in language history.
Finally, Chapter 11 is concerned with alternating pairs of constructions, such as active and passive clauses and singular and plural nouns, which are commonly analyzed as paradigmatic alternatives of particular grammatical categories such as voice and number. Crucially, paradigmatic alternatives of this type are often asymmetrical in the sense that the less frequent member of an alternating pair of constructions is marked by an extra morpheme (e.g., a voice or number marker). Linguistic typologists refer to this asymmetry by the notion of markedness and have argued that frequency accounts for the occurrence of the extra marker. Chapter 11 presents a network analysis of the encoding asymmetries of grammatical categories based on research from typology and psycholinguistics. While the proposed account applies to a large number of categories (e.g., voice, number, tense, aspect, case), the chapter is primarily concerned with a phenomenon known as differential object marking, which has played a key role in recent typological and psycholinguistic research on grammatical relations.
Every construction has a particular ecological location in the grammar network that is defined by its relationship to other constructions in the system. Since the relationships between constructions are similar to those between lexemes, Chapter 10 begins with a short discussion of psycholinguistic research on the mental lexicon, which is commonly analyzed as an activation network (Dell 1986). There is abundant evidence that lexical access is influenced by several interacting factors including frequency, priming, similarity and neighborhood density, or family size. Considering research on sentences processing, L1 acquisition and language change, the chapter argues that the availability, or accessibility, of constructions is influenced by the same factors as lexical access, that is, by frequency, priming, similarity and neighborhood density, supporting the hypothesis that lexemes and constructions are organized in similar ways. Specifically, the chapter argues that grammar includes “construction families” that influence the use and the development of syntactic patterns (Diessel and Tomasello 2005; Wells et al. 2009).
All linguistic elements, e.g., words, phrases and clauses, occur in sequential order. The sequential arrangement of linguistic elements is motivated by conceptual and pragmatic factors, but the strength of sequential relations is primarily determined by automatization or chunking. Since automatization is a gradual process driven by frequency of occurrence, sequential relations vary on a continuum. Moreover, since language unfolds in time, sequential relations have an inherent forward orientation, which is reflected in the fact that listeners are able to “predict” upcoming elements in the unfolding speech stream. Chapter 5 considers the effect of automatization and chunking on the development of linguistic structure and the cognitive organization of grammar. The chapter is divided into two parts. The first part is concerned with research on lexical prefabs and the organization of morphological network models, and the second part considers sequential aspects of constructional schemas and the gradience of constituency.
In this chapter, we introduce the bare-bones model of electoral interventions in elections. The theoretical argument we develop produces a rich variety of comparative statics. We amend many aspects of the conventional wisdom. A state which acts as a liberal hegemon in a foreign election does not always promote more democratic elections. Two liberal outsiders in conflict are better for democratic elections. Conflicts between liberal and illiberal powers do produce some of the worst outcomes as far as clean elections go.
This article reflects on a double interpretation of English constructions containing the combined expression will have to. As I will show, illocutions involving sentences of the type ‘NP will have to VP’ can be interpreted as either (i) predicting future enforcing circumstances that trigger a future obligation or (ii) reporting such circumstances as currently in force at speech time. Once I sketch the different semantic elements at play in a Kratzerian framework, I cast doubt on some current views on the so-called modal–tense interaction. As I will show, one way to fully account for the availability of both readings is by assuming a semantic temporal underspecification as to when the triggering circumstances in the conversational background are initially in force. This raises important theoretical caveats for semantic analyses in the field, particularly for those that equate the semantics of the future with prediction. As the article shows, such a widespread assumption can be contended by a dynamic account of obligational ascriptions, according to which their different illocutionary forces can be derived from the contextual change potential of its primitive (and admittedly underspecified) future semantics. Ultimately, the paper voices support for the view that future semantics must not be equated with prediction.
Irrigation according to reliable estimates of crop water requirements (CWR) is one of the key strategies to ensure long-term sustainability of irrigated agriculture. In southern Mediterranean regions, during the irrigation season, CWR is almost totally controlled by the potential evapotranspiration of the irrigated crop. An innovative system for forecasting crop potential evapotranspiration (ETp) has been implemented recently in the Campania region (southern Italy). The system produces ETp forecasts with a lead time of up to 5 days, by coupling the visible and near-infrared crop imagery with numerical weather prediction outputs of a limited area model. The forecasts are delivered to farmers with a simple and intuitive web app interface, which makes daily real-time ETp maps accessible from desktop computers, tablets and smartphones. Forecast performances were evaluated for maize fields of two farms in two irrigation seasons (2014–2015). The mean absolute bias of the forecasted ETp was <0.3 mm/day and the RMSE was <0.6 mm/day, both for lead times up to 5 days.
Assessing the impact that patterns of Na intake may have on gastric cancer will provide a more comprehensive estimation of Na reduction as a primary prevention approach. We aimed to estimate the proportion of gastric cancer cases that are attributable to Na intake above the recommendation by the WHO (≤2 g/d) throughout the world in 2010, as well as expected values for 2030. Population attributable fractions (PAF) were computed for 187 countries, using Na intakes in 1990 and 2010 and estimates of the association between Na intake and gastric cancer, assuming a time lag of 20 years. Median PAF ranged from 10·1% in low to 22·5 % in very high Human Development Index (HDI) countries in men (P<0·001) and from 7·2 to 16·6 %, respectively, among women (P<0·001). An increase in median PAF until 2030 is expected in most settings, except for countries classified as low HDI, in both sexes. High Na intakes account for a large proportion of gastric cancer cases, and proportions are expected to increase in almost all of the countries. Intensified efforts to diminish Na intake in virtually all populations are needed to further reduce gastric cancer burden.
An assessment is made of the ability of the Coupled Model Intercomparison Project 5 (CMIP5) models to represent the seasonal cycles of biogeochemistry of the Ross Sea over the late twentieth century. In particular, sea surface temperature, sea ice concentration, surface chlorophyll a, nitrate, phosphate and silicate, and the depth of the seasonal thermocline (measuring vertical mixing) are examined to quantify the physical-biogeochemical capabilities of each model, and to provide for ‘ranked’ model ensembles. This permits critical assessment of modelled Ross Sea biogeochemical cycling, including less well observed variables such as iron and vertically integrated primary production. The assessment enables determination of model output confidence limits; these confidence limits are used to examine future model scenario projections for consideration of potential ecosystem changes. The future scenarios examined are the representative concentration pathways rcp4.5 and rcp8.5. Our study suggests that by the end of the twenty-first century under rcp4.5 and/or rcp8.5 that there will be average increases in sea surface temperature, surface chlorophyll a, integrated primary production and iron, average decreases in surface nitrate, phosphate and silicate, and relatively large decreases in the depth of the seasonal thermocline and percentage coverage by sea ice in the Ross Sea.
The regional and temporal variation in patterns of fruit and vegetable intake contributes to differences in the impact on gastric cancer burden across regions and over the years. We aimed to estimate the proportion and absolute number of gastric cancer cases that could have been prevented in 2012 with an increase in fruit and vegetable intake up to the levels defined by the Global Burden of Disease as the theoretical minimum-risk exposure distribution (300 and 400 g/d, respectively), as well as the corresponding figures expected for 2025. Preventable fractions (PF) were computed for 161 countries, using data on fruit and vegetable availability in 1997 and 2010 and published estimates of the magnitude of the association between fruit and vegetable intake and gastric cancer, assuming a time lag of approximately 15 years. Countries classified as very high Human Development Index (HDI) presented median PF in 2012 much lower than low-HDI countries for both fruits (3·0 v. 10·2 %, P<0·001) and vegetables (6·0 v. 11·9 %, P<0·001). For vegetables only, PF significantly decreased until 2025 in most settings; however, this corresponded to a reduction in the absolute number of preventable gastric cancer cases in less than half of the countries. Increasing fruit and vegetable intake would allow preventing a relatively high proportion of gastric cancer cases, mostly in developing countries. Although declines in PF are predicted in the near future, changes in order to achieve healthier lifestyles may be insufficient to overcome the load of demographic variation to further reduce the gastric cancer burden.
In this paper, we use unique data from the market for Bordeaux wine to test the hypothesis that consumers are willing to pay for expert opinion because it is accurate. Using proprietary indicators of the quality of the vintage, which are based on both publicly and privately available information, we find that additional publicly available information on the weather improves the expert's predictions of subsequent prices. This establishes that the expert opinions are not efficient, in the sense that they can be easily improved, and that these opinions must be demanded, at least in part, for some purpose other than their accuracy. (JEL Classification: D8, Q13)
The aims of the present study were to propose a multivariate model for predicting simultaneously body, trunk and appendicular fat and lean masses from easily measured variables and to compare its predictive capacity with that of the available univariate models that predict body fat percentage (BF%). The dual-energy X-ray absorptiometry (DXA) dataset (52 % men and 48 % women) with White, Black and Hispanic ethnicities (1999–2004, National Health and Nutrition Examination Survey) was randomly divided into three sub-datasets: a training dataset (TRD), a test dataset (TED); a validation dataset (VAD), comprising 3835, 1917 and 1917 subjects. For each sex, several multivariate prediction models were fitted from the TRD using age, weight, height and possibly waist circumference. The most accurate model was selected from the TED and then applied to the VAD and a French DXA dataset (French DB) (526 men and 529 women) to assess the prediction accuracy in comparison with that of five published univariate models, for which adjusted formulas were re-estimated using the TRD. Waist circumference was found to improve the prediction accuracy, especially in men. For BF%, the standard error of prediction (SEP) values were 3·26 (3·75) % for men and 3·47 (3·95) % for women in the VAD (French DB), as good as those of the adjusted univariate models. Moreover, the SEP values for the prediction of body and appendicular lean masses ranged from 1·39 to 2·75 kg for both the sexes. The prediction accuracy was best for age < 65 years, BMI < 30 kg/m2 and the Hispanic ethnicity. The application of our multivariate model to large populations could be useful to address various public health issues.
Little information exists regarding how accurately emergency physicians (EPs) predict the probability of acute coronary syndrome (ACS). Our objective was to determine if EPs can accurately predict ACS in a prospectively identified cohort of emergency department (ED) patients who met enrolment criteria for a study of coronary computed tomographic angiography (CCTA) and were admitted for a “rule out ACS” protocol.
A prospective observational pilot study in an academic medical centre was carried out. EPs caring for patients with chest pain provided whole-number estimates of the probability of ACS after clinical review. This substudy was part of the now published Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) study, a study of CCTA and admission of patients for a rule out ACS protocol after a nondiagnostic evaluation. Predictions were grouped into probability groups based on the validated Goldman criteria. ACS was determined by an adjudication committee using American Heart Association/American College of Cardiology/European Society of Cardiology guidelines.
A total of 334 predictions were obtained for a study population with a mean age of 54 (SD 12) years, 63% of whom were male. There were 35 ACS events. EPs predicted ACS better than by chance, and increasingly higher estimates were associated with a higher incidence of ACS (p = 0.0004). The percentage of patients with ACS was 0%, 6%, 7%, and 17%, respectively, for very low, low, intermediate, and high probability groups. EPs' estimates had a sensitivity of 63% using a > 20% probability of ACS to define a positive test. Lowering this threshold to > 7% to define a test as positive increased the sensitivity of physician estimates to 89% but lowered specificity from 65% to 24%
Our data suggest that for a selected ED cohort meeting eligibility criteria for a study of CCTA, EPs predict ACS better than by chance, with an increasing proportion of patients proving to have ACS with increasing probability estimates. Lowering the estimate threshold does not result in an overall sensitivity level that is sufficient to send patients home from the ED and is associated with a poor specificity.
This chapter shows that format and categorical organization of semantic representations are strictly intermingled and that the study of the anatomical lesions underlying category-specific semantic disorders can contribute to clarifying the nature of these intimate relationships. It determines whether the anatomical locus of lesion is different in patients with a category-specific impairment for action names and object names and whether the neuroanatomical correlates of these category-specific disorders are consistent with the predictions based on the sensorymotor model of semantic knowledge. The chapter focuses on predictions based on the sensory-functional and the domains of knowledge hypothesis, rather than on those based on the intercorrelations among semantic features hypothesis, since the latter assumes that the severity of brain damage plays the major role in the pathophysiology of category-specific disorders. It presents the results of investigations which have checked the neuroanatomical predictions of the intercorrelations among semantic features hypothesis.
Exact tidal study extends back to a fourteenth century record containing sexagesimal times. Earlier commentators have taken these times to be high water. This study shows they are for the later moment of when the flood ends; and, that eighteenth and nineteenth century elevation measurements formed a completely different way of considering the tide, leading directly to reliable predictions. The result shows the Thames tide to have been more consistent than previously stated; and consequently the actual change more accelerated. Therefore tidal current predictions are shown to have a longer history than have water surface elevation levels.
In this study, a method is presented to maintain real-time positioning at the decimetre-level accuracy during breaks in reception of the measurement corrections from multiple reference stations. The method is implemented at the rover by estimating prediction coefficients of the corrections during normal RTK positioning, and uses these coefficients to predict the corrections when reception of the corrections is temporarily lost. The paper focuses on one segment of this method, the on-the-fly prediction of orbital corrections. Frequently, only a few minutes of data representing short orbit ‘arcs’ are available to the user before losing radio transmission. Thus, it would be hard for the rover to predict the satellite positions using equations of motion. An alternative method is proposed. In this method, GPS orbital corrections are predicted as a time series and are added to the initial positions computed from the broadcast ephemeris to compute relatively accurate satellite positions. Different prediction approaches were investigated. Results show that the double exponential smoothing method and Winters' method can be successfully applied. The latter, however, has a better performance. The impact of the data length used for estimation of the prediction coefficients and the selection of seasonal lengths in Winters' method were investigated and some values were recommended. In general, the method can give orbital correction estimation accuracy of less than 5 cm after 15 minutes of prediction. This will result in a positioning accuracy better than 5 cm.