scholarly journals Variable Slope Forecasting Methods and COVID-19 Risk

2021 ◽  
Vol 14 (10) ◽  
pp. 467
Author(s):  
Jonathan Leightner ◽  
Tomoo Inoue ◽  
Pierre Lafaye de Micheaux
Keyword(s):  
Confidence Interval ◽  
Moving Average ◽  
Estimation Methods ◽  
Reduced Form ◽  
Omitted Variables ◽  
Total Derivative ◽  
Derivative Estimate ◽  
The Usa ◽  
The Uk ◽  
Over Time

There are many real-world situations in which complex interacting forces are best described by a series of equations. Traditional regression approaches to these situations involve modeling and estimating each individual equation (producing estimates of “partial derivatives”) and then solving the entire system for reduced form relationships (“total derivatives”). We examine three estimation methods that produce “total derivative estimates” without having to model and estimate each separate equation. These methods produce a unique total derivative estimate for every observation, where the differences in these estimates are produced by omitted variables. A plot of these estimates over time shows how the estimated relationship has evolved over time due to omitted variables. A moving 95% confidence interval (constructed like a moving average) means that there is only a five percent chance that the next total derivative would lie outside that confidence interval if the recent variability of omitted variables does not increase. Simulations show that two of these methods produce much less error than ignoring the omitted variables problem does when the importance of omitted variables noticeably exceeds random error. In an example, the spread rate of COVID-19 is estimated for Brazil, Europe, South Africa, the UK, and the USA.

scholarly journals Topological and Morphological Controls on Morphodynamics of Salt Marsh Interiors

2021 ◽  
Vol 9 (3) ◽  
pp. 311
Author(s):  
Ben R. Evans ◽  
Iris Möller ◽  
Tom Spencer
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
East Coast ◽  
Marsh Surface ◽  
Coastal Environments ◽  
Coastal System ◽  
Morphological Segmentation ◽  
The Usa ◽  
The Uk ◽  
Over Time

Salt marshes are important coastal environments and provide multiple benefits to society. They are considered to be declining in extent globally, including on the UK east coast. The dynamics and characteristics of interior parts of salt marsh systems are spatially variable and can fundamentally affect biotic distributions and the way in which the landscape delivers ecosystem services. It is therefore important to understand, and be able to predict, how these landscape configurations may evolve over time and where the greatest dynamism will occur. This study estimates morphodynamic changes in salt marsh areas for a regional domain over a multi-decadal timescale. We demonstrate at a landscape scale that relationships exist between the topology and morphology of a salt marsh and changes in its condition over time. We present an inherently scalable satellite-derived measure of change in marsh platform integrity that allows the monitoring of changes in marsh condition. We then demonstrate that easily derived geospatial and morphometric parameters can be used to determine the probability of marsh degradation. We draw comparisons with previous work conducted on the east coast of the USA, finding differences in marsh responses according to their position within the wider coastal system between the two regions, but relatively consistent in relation to the within-marsh situation. We describe the sub-pixel-scale marsh morphometry using a morphological segmentation algorithm applied to 25 cm-resolution maps of vegetated marsh surface. We also find strong relationships between morphometric indices and change in marsh platform integrity which allow for the inference of past dynamism but also suggest that current morphology may be predictive of future change. We thus provide insight into the factors governing marsh degradation that will assist the anticipation of adverse changes to the attributes and functions of these critical coastal environments and inform ongoing ecogeomorphic modelling developments.

scholarly journals Ongoing challenges to understanding multidrug and rifampicin-resistant tuberculosis in children versus adults

2020 ◽  
pp. 2002504
Author(s):  
C. Finn McQuaid ◽  
Ted Cohen ◽  
Anna S. Dean ◽  
Rein M.G.J. Houben ◽  
Gwenan M. Knight ◽  
...  
Keyword(s):  
Soviet Union ◽  
Former Soviet Union ◽  
Odds Ratio ◽  
Western Europe ◽  
Resistant Tuberculosis ◽  
The Usa ◽  
The Uk ◽  
Tuberculosis In Children ◽  
Over Time ◽  
Country Specific

Previous analyses suggest children with tuberculosis (TB) are no more or no less likely to have multidrug- or rifampicin-resistant TB (MDR/RR-TB) than adults. However, the availability of new data, particularly for high MDR/RR-TB burden countries, suggest updates of country-specific estimates are warranted.We used data from population-representative surveys and surveillance collected between 2000 and 2018 to compare the odds ratio (OR) of MDR/RR-TB among children (<15 years) with TB, compared to the odds of MDR/RR-TB among adults (≥15 years) with TB.In most settings (45/55 countries), and globally as a whole, there is no evidence that age is associated with odds of MDR/RR-TB. However, in some settings such as former Soviet Union countries in general, and Georgia, Kazakhstan, Lithuania, Tajikistan and Uzbekistan in particular, as well as Peru, MDR/RR-TB is positively associated with age ≥15. Meanwhile, in Western Europe in general, and the UK, Poland, Finland and Luxembourg in particular, MDR/RR-TB is positively associated with age <15. Sixteen countries had sufficient data to compare over time between 2000–2011 and 2012–2018, with evidence for decreases in the OR in children compared to adults in Germany, Kazakhstan and the USA.Our results support findings that in most settings a child with TB is as likely as an adult with TB to have MDR/RR-TB. However, setting-specific heterogeneity requires further investigation. Further, the OR for MDR/RR-TB in children compared to adults is generally either stable or decreasing. There are important gaps in detection, recording and reporting of drug resistance among paediatric TB cases, limiting our understanding of transmission risks and measures needed to combat the global TB epidemic.

scholarly journals Solving the Omitted Variables Problem of Regression Analysis Using the Relative Vertical Position of Observations

2012 ◽  
Vol 2012 ◽  
pp. 1-25 ◽  
Author(s):  
Jonathan E. Leightner ◽  
Tomoo Inoue
Keyword(s):  
Regression Analysis ◽  
Government Spending ◽  
Reduced Form ◽  
Vertical Position ◽  
Annual Data ◽  
Theoretical Argument ◽  
Omitted Variables ◽  
The Third ◽  
The Usa ◽  
The Government

The omitted variables problem is one of regression analysis’ most serious problems. The standard approach to the omitted variables problem is to find instruments, or proxies, for the omitted variables, but this approach makes strong assumptions that are rarely met in practice. This paper introduces best projection reiterative truncated projected least squares (BP-RTPLS), the third generation of a technique that solves the omitted variables problem without using proxies or instruments. This paper presents a theoretical argument that BP-RTPLS produces unbiased reduced form estimates when there are omitted variables. This paper also provides simulation evidence that shows OLS produces between 250% and 2450% more errors than BP-RTPLS when there are omitted variables and when measurement and round-off error is 1 percent or less. In an example, the government spending multiplier, , is estimated using annual data for the USA between 1929 and 2010.

Contact in Adoption: The Experience of Adoptive Families in the USA

2003 ◽  
Vol 27 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Gretchen Miller Wrobel ◽  
Harold D Grotevant ◽  
Jerica Berge ◽  
Tai Mendenhall ◽  
Ruth McRoy
Keyword(s):  
Decision Making ◽  
Longitudinal Study ◽  
Family Communication ◽  
Adoptive Families ◽  
Complex Issue ◽  
The Usa ◽  
The Uk ◽  
Changes Over Time ◽  
Over Time

Contact in adoption is a complex issue that adoption professionals frequently negotiate. Today most adoption placements include an initial plan for contact that in many instances changes over time. By understanding contact as an issue that presents itself over the course of an adopted person's lifetime, the complexities it brings to the adoption experience can be seen. Gretchen Miller Wrobel, Harold D Grotevant, Jerica Berge, Tai Mendenhall and Ruth McRoy discuss contact from a US perspective using findings from the Minnesota/Texas Adoption Project, a longitudinal study of openness in adoption. They examine how curiosity, satisfaction with adoptive contact, family communication and searching influence decision-making about the extent of contact. Implications for adoption professionals in the USA and the UK are also presented.

scholarly journals Longitudinal analysis of the utility of liver biochemistry in hospitalised COVID-19 patients as prognostic markers

2020 ◽  
Author(s):  
Tingyan Wang ◽  
David A Smith ◽  
Cori Campbell ◽  
Steve Harris ◽  
Hizni Salih ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Clinical Utility ◽  
Prognostic Markers ◽  
Clinical Syndrome ◽  
Rt Pcr ◽  
Large Teaching Hospital ◽  
The Usa ◽  
The Uk ◽  
Normal Albumin ◽  
Over Time

Background: COVID-19, the clinical syndrome caused by infection with SARS-CoV-2, has been associated with deranged liver biochemistry in studies from China, Italy and the USA. However, the clinical utility of liver biochemistry as a prognostic marker of outcome for COVID-19 is currently debated. Methods: We extracted routinely collected clinical data from a large teaching hospital in the UK, matching 585 hospitalised SARS-CoV-2 RT-PCR-positive patients to 1165 hospitalised SARS-CoV-2 RT-PCR-negative patients for age, gender, ethnicity and pre-existing comorbidities. Liver biochemistry was compared between groups over time to determine whether derangement was associated with outcome. Results: 26.8% (157/585) of COVID-19 patients died, compared to 11.9% (139/1165) in the non-COVID-19 group (p<0.001). At presentation, a significantly higher proportion of the COVID-19 group had elevated alanine aminotransferase (20.7% vs. 14.6%, p=0.004) and hypoalbuminaemia (58.7% vs. 35.0%, p<0.001), compared to the non-COVID-19 group. Within the COVID-19 group, those with hypoalbuminaemia at presentation had 1.83-fold increased hazards of death compared to those with normal albumin (adjusted hazard ratio [HR] 1.83, 95% CI 1.25-2.67), whilst the hazard of death was ~4-fold higher in those aged ≥75 years (adjusted HR 3.96, 95% CI 2.59-6.04) and ~3-fold higher in those with pre-existing liver disease (adjusted HR 3.37, 95% CI 1.58-7.16). In the COVID-19 group, alkaline phosphatase increased (R=0.192, p<0.0001) and albumin declined (R=-0.123, p=0.0004) over time in patients who died. We did not find a significant association between other liver biochemistry and death. Conclusion: In this UK population, liver biochemistry is commonly deranged in patients with COVID-19 but only baseline low albumin and a rising alkaline phosphatase over time are prognostic markers for death.

scholarly journals A Century of Peer-reviewed Australian Zoological Research: Prominent Authors, Themes and Usage of Papers from Australian Zoologist

2021 ◽  
Author(s):  
Michael C. Calver ◽  
Heather M. Crawford ◽  
Douglas Fletcher
Keyword(s):  
New Zealand ◽  
Citation Impact ◽  
Environmental Sciences ◽  
Publication History ◽  
The Usa ◽  
History Of ◽  
International Profile ◽  
The Uk ◽  
Over Time ◽  
Highly Cited

ABSTRACT The peer-reviewed Australian Zoologist, first published in 1914, is Australia’s longest-lived zoological journal. Its publication history shows changes in the zoological topics covered over the last 100 years, including the animals studied, characteristics of the authors and readership, and the influence of the databases used to study the journal on information retrieval. Searches in different databases retrieved different numbers of papers; Scopus (including secondary documents not in the database but cited by documents that are in the database) was the most comprehensive. Although authors from 22 countries contributed papers over the history of the Australian Zoologist, over 90% of authors were Australian. Most international authors came from the USA, the UK, Canada and New Zealand. Approximately two-thirds of authors citing Australian Zoologist were Australian-based, but there were still 10 or more authors from each of thirty-four other countries citing Australian Zoologist: while regional, the journal has an international profile. Highly cited papers in Australian Zoologist had high mean Scopus percentile ranks (20th century 83.9, 21st century 73.7), indicating that in comparison to their fields globally, these papers are used well above average. Considering all papers published in Australian Zoologist, over time the proportion of papers in the categories ‘Biodiversity & Conservation’ and ‘Environmental Sciences & Ecology’ rose significantly, reflecting the increased research in these areas. Between 2013 and 2019, when relevant metrics are available in Scopus, Australian Zoologist declined in no metric measured while improving significantly in CiteScore, Highest Percentile, and % Cited, indicating increasing references to Australian Zoologist papers by other peer-reviewed publications. Between 2010 and 2019, 2.1% of Australian Zoologist papers were ranked within the top 10% in their fields globally, based on citation impact. Authors considering publishing in Australian Zoologist should note that longer papers are acceptable, colour imagery (including photographs) is encouraged, the journal is visible in major databases, it is cited internationally and there are no page charges.

An early mainstream economist from Hungary: István Varga (1897–1962)

2003 ◽  
Vol 53 (2) ◽  
pp. 195-213 ◽  
Author(s):  
K. Majoros
Keyword(s):  
Austrian Economic ◽  
National Income ◽  
Anglo Saxon ◽  
Turbulent Times ◽  
The Usa ◽  
New Ideas ◽  
Modern Economic ◽  
The Uk ◽  
Economic Thinking ◽  
Lasting Influence

The study introduces a Hungarian economic thinker, István Varga*, whose valuable activity has remained unexplored up to now. He became an economic thinker during the 1920s, in a country that had not long before become independent of Austria. The role played by Austria in the modern economic thinking of that time was a form of competition with the thought adhered to by the UK and the USA. Hungarian economists mainly interpreted and commented on German and Austrian theories, reasons for this being that, for example, the majority of Hungarian economists had studied at German and Austrian universities, while at Hungarian universities principally German and Austrian economic theories were taught. István Varga was familiar not only with contemporary German economics but with the new ideas of Anglo-Saxon economics as well — and he introduced these ideas into Hungarian economic thinking. He lived and worked in turbulent times, and historians have only been able to appreciate his activity in a limited manner. The work of this excellent economist has all but been forgotten, although he was of international stature. After a brief summary of Varga’s profile the study will demonstrate the lasting influence he has had in four areas — namely, business cycle research and national income estimations, the 1946 Hungarian stabilisation program, corporate profit, and consumption economics — and will go on to summarise his most important achievements.

Neurosurgical activity during COVID-19 pandemic: an experts' opinion from China, South Korea, Italy, the USA, Colombia, and the UK

2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Marco M. Fontanella ◽  
Giorgio Saraceno ◽  
Ting Lei ◽  
Joshua B. Bederson ◽  
Namkyu You ◽  
...  
Keyword(s):  
South Korea ◽  
The Usa ◽  
The Uk
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