Studying the distributions of DTM derivatives of cinder cones: a statistical approach in volcanic morphometry

Author(s):  
Balázs Székely ◽  
Fanni Vörös

<p>In 2020 we celebrate the 40<sup>th</sup> anniversary of the seminal works of Wood (1980a,b) who was one of the first researchers who considered the shapes of volcanoes in a global point of view. These four decades have seen a number of new approaches that were made possible by the ever increasing computer power and the improvements in Digital Terrain Model (DTM) production. The improving resolution and accuracy of the DTMs of various volcanic fields (VF) opened the way of wide variations of volcanic geomorphometric considerations. However, the differences in approach and, even more importantly, the differences in DTM production technology and resolution make the comparative studies and especially global considerations very difficult.</p><p>We have envisioned a global geomorphometric analytical methodology to analyse cinder cone morphometry in terms of shape versus age: The aim is to establish a relationship between the age of scoria cones age and their morphometry. This is knowingly a rather difficult undertaking and we have made only the first steps yet, but our methodological advancements are always developed with this demand in mind.</p><p>For the sake of diversity, in the current study four volcanic areas were considered with different age ranges, four different resolution DEMs and different number of cones:  San Francisco Volcanic Field, Arizona, USA (SFVF, 30 m horizontal resolution, 313 pcs), the Chaîne des Puys, France (CdP,  0.5 m, 26 pcs), the central-eastern part of the Sierra Chichinautzin, Mexico (SCVF, 5 m, 152 pcs) and Kula Volcanic Field, Turkey (KVF, 12.5 m, 64 pcs). As age data we had either age ranges or measured ages of the individual cones.</p><p>A great number of derivatives (mostly related to slope angles) have been calculated for the individual cones. Their most important statistics and their distribution were computed. Irregularities and, especially, cone degradation modify the original statistical distribution; these distributions can be compared in statistical way. A quantitative distance (metric) has been introduced to study the similarity or dissimilarity of the cones.</p><p>For the comparison, we have grouped the cones in several ways – they have been observed individually, by areas and by age groups (based on previous researches). For every cone boxplot diagrams, histograms and cumulative histograms were made to detect differences together with average and median values. These age groups were subjects of the Mann – Whitney statistical test to discriminate statistically independent or dependent samples in the populations. The test showed some clear relations between erosion (shape) and age.</p><p>We created a cinder cone viewer for visualization purposes. This tool can display the aforementioned distributions and helps in picking pairs or groups of cinder cones to compare. As expected, the intra-VF comparisons are typically more successful as inter-VF comparisons. However, promising new morphometric derivatives (e.g., sectorial distributions) are under development.</p><p>Wood, C. A.: Morphometric evolution of cinder cones, J. Volcanol. Geoth. Res., 7, 387–413, 1980a.</p><p>Wood, C. A.: Morphometric analysis of cinder cone degradation, J. Volcanol. Geoth. Res., 8, 137–160, 1980b.</p>

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Malin Indremo ◽  
Richard White ◽  
Thomas Frisell ◽  
Sven Cnattingius ◽  
Alkistis Skalkidou ◽  
...  

AbstractThe aim of this study was to examine the validity of the Gender Dysphoria (GD) diagnoses in the Swedish National Patient Register (NPR), to discuss different register-based definitions of GD and to investigate incidence trends. We collected data on all individuals with registered GD diagnoses between 2001 and 2016 as well as data on the coverage in the NPR. We regarded gender confirming medical intervention (GCMI) as one proxy for a clinically valid diagnosis and calculated the positive predictive value (PPV) for receiving GCMI for increasing number of registered GD diagnoses. We assessed crude and coverage-adjusted time trends of GD during 2004–2015 with a Poisson regression, using assigned sex and age as interaction terms. The PPV for receiving GCMI was 68% for ≥ 1 and 79% for ≥ 4 GD-diagnoses. The incidence of GD was on average 35% higher with the definition of ≥ 1 compared to the definition of ≥ 4 diagnoses. The incidence of GD, defined as ≥ 4 diagnoses increased significantly during the study period and mostly in the age categories 10–17 and 18–30 years, even after adjusting for register coverage. We concluded that the validity of a single ICD code denoting clinical GD in the Swedish NPR can be questioned. For future research, we propose to carefully weight the advantages and disadvantages of different register-based definitions according to the individual study’s needs, the time periods involved and the age-groups under study.


2021 ◽  
Vol 83 (6) ◽  
Author(s):  
Gianmaria Tortelli ◽  
Anna Gioncada ◽  
Carolina Pagli ◽  
Mauro Rosi ◽  
Laura De Dosso ◽  
...  

AbstractDuring continental rifting, strain and magmatism are believed to localize to narrow magmatic segments, while the rift margin is progressively abandoned. We integrate volcanological, geochemical, petrological and seismic data from the Ma’Alalta volcanic field (MVF) near the western margin of Afar, to show that the MVF is an active magmatic segment. Magmatism in MVF initiated with lava flows and large-volume, caldera-forming ignimbrites from a central edifice. However, the most recent magmatic activity shifted towards mafic lava fields, cinder cones and obsidian-rich silicic domes erupted from vents aligned NNW-SSE, defining a ~ 35-km-long magmatic segment. Along the same area, a NNW-SSE alignment of earthquakes was recorded by two local seismic networks (2005–2009 and 2011–2013). The geochemistry of the mafic rocks is similar to those of nearby axial volcanoes. Inferred magma storage depth from mineral geobarometry shows that a shallow, silicic chamber existed at ~ 5-km depth below the stratovolcano, while a stacked plumbing system with at least three magma storage levels between 9 and 24 km depth fed the recent basalts. We interpret the wide set of observations from the MVF as evidence that the area is an active magmatic segment, showing that localised axial extension can be heavily offset towards the rift margin.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A86-A86
Author(s):  
Michael Grandner ◽  
Naghmeh Rezaei

Abstract Introduction The COVID-19 pandemic has resulted in societal-level changes to sleep and other behavioral patterns. Objective, longitudinal data would allow for a greater understanding of sleep-related changes at the population level. Methods N= 163,524 deidentified active Fitbit users from 6 major US cities contributed data, representing areas particularly hard-hit by the pandemic (Chicago, Houston, Los Angeles, New York, San Francisco, and Miami). Sleep variables extracted include nightly and weekly mean sleep duration and bedtime, variability (standard deviation) of sleep duration and bedtime, and estimated arousals and sleep stages. Deviation from similar timeframes in 2019 were examined. All analyses were performed in Python. Results These data detail how sleep duration and timing changed longitudinally, stratified by age group and gender, relative to previous years’ data. Overall, 2020 represented a significant departure for all age groups and both men and women (P<0.00001). Mean sleep duration increased in nearly all groups (P<0.00001) by 5-11 minutes, compared to a mean decrease of 5-8 minutes seen over the same period in 2019. Categorically, sleep duration increased for some and decreased for others, but more extended than restricted. Sleep phase shifted later for nearly all groups (p<0.00001). Categorically, bedtime was delayed for some and advanced for others, though more delayed than advanced. Duration and bedtime variability decreased, owing largely to decreased weekday-weekend differences. WASO increased, REM% increased, and Deep% decreased. Additional analyses show stratified, longitudinal changes to sleep duration and timing mean and variability distributions by month, as well as effect sizes and correlations to other outcomes. Conclusion The pandemic was associated with increased sleep duration on average, in contrast to 2019 when sleep decreased. The increase was most profound among younger adults, especially women. The youngest adults also experienced the greatest bedtime delay, in line with extensive school-start-times and chronotype data. When given the opportunity, the difference between weekdays and weekends became smaller, with occupational implications. Sleep staging data showed that slightly extending sleep minimally impacted deep sleep but resulted in a proportional increase in REM. Wakefulness during the night also increased, suggesting increased arousal despite greater sleep duration. Support (if any) This research was supported by Fitbit, Inc.


2014 ◽  
Vol 143 (8) ◽  
pp. 1681-1691 ◽  
Author(s):  
M. E. ARNOLD ◽  
R. J. GOSLING ◽  
F. MARTELLI ◽  
D. MUELLER-DOBLIES ◽  
R. H. DAVIES

SUMMARYThere has been a rapid rise in the prevalence of cases of monophasic Salmonella Typhimurium (mST) in both humans and farm animals, and it has been found in pigs, cattle and poultry. It is therefore vital to have a good understanding of how to efficiently detect infected farms. The objective of this project was to determine sample type sensitivity in the detection of Salmonella to detect infected groups of animals on both pig (breeder, grower and finisher sites) and cattle (beef and dairy) farms, using data collected from a study investigating farms that were positive for mST, and to explore any variation between different age groups and management practices. A Bayesian approach in the absence of a gold standard was adopted to analyse the individual and pooled faecal sample data collected from each epidemiological group on each of the farms. The sensitivity of pooled sampling depended on the prevalence of infection in the group being sampled, with a higher prevalence leading to higher sensitivity. Pooled sampling was found to be more efficient at detecting positive groups of animals than individual sampling, with the probability of a random sample from a group of animals with 5% prevalence testing positive being equal to 15·5% for immature pigs (3·6% for an individual faecal sample, taking into account the sensitivity and infection prevalence), 7·1% for adult pigs (1·2% for individual sampling), 30% for outdoor cattle (2% for individual sampling) and 34% for indoor cattle (1% for individual sampling). The mean prevalence of each epidemiological group was higher in outdoor farms than indoor for both pigs and cattle (mean within-farm prevalence of 29·4% and 38·7% for outdoor pigs and cattle, respectively, compared to 19·8% and 22·1% for indoor pigs and cattle)


2017 ◽  
Vol 39 (3) ◽  
pp. 541-567 ◽  
Author(s):  
MIKKEL BARSLUND ◽  
MARTEN VON WERDER ◽  
ASGHAR ZAIDI

ABSTRACTIn the context of emerging challenges and opportunities associated with population ageing, the study of inequality in active-ageing outcomes is critical to the design of appropriate and effective social policies. While there is much discussion about active ageing at the aggregate country level, little is known about inequality in active-ageing experiences within countries. Based on the existing literature on active ageing, this paper proposes an individual-level composite active ageing index based on Survey of Health, Ageing and Retirement in Europe (SHARE) data. The individual-level nature of the index allows us to analyse inequality in experiences of active ageing within selected European countries. One important motivation behind measuring active ageing at the individual level is that it allows for a better understanding of unequal experiences of ageing, which may otherwise be masked in aggregate-level measures of active ageing. Results show large differences in the distribution of individual-level active ageing across the 13 European countries covered and across age groups. Furthermore, there is a positive association between the country-level active ageing index and the equality of its distribution within a country. Hence, countries with the lowest average active ageing index tend to have the most unequal distribution in active-ageing experiences. For nine European countries, where temporal data are also available, we find that inequality in active-ageing outcomes decreased in the period 2004 to 2013.


Author(s):  
Dharma N. Bhatta ◽  
Jennifer Hecht ◽  
Shelley N. Facente

Background: Stigma and discrimination are major challenges faced by people living with HIV (PLWH), and stigma continues to be prevalent among PLWH. We conducted a cross-sectional study of 584 men who have sex with men (MSM) living with HIV between July 2018 and December 2020, designed to better understand which demographic and behavioral characteristics of MSM living with HIV in San Francisco, California are associated with experience of stigma, so that programs and initiatives can be tailored appropriately to minimize HIV stigma’s impacts. Methods: This analysis was conducted with data from San Francisco AIDS Foundation (SFAF) encompassing services from multiple different locations in San Francisco. Data about the level of HIV-related stigma experienced were collected through a single question incorporated into programmatic data collection forms at SFAF as part of the client record stored in SFAF’s electronic health record. We performed linear regression to determine the associations between self-reported experiences of HIV stigma and other characteristics among MSM living with HIV. Results: HIV stigma was low overall among MSM living with HIV who are actively engaged in HIV care in San Francisco; however, it was significantly higher for the age groups of 13–29 years (adjusted risk difference (ARD): 0.251, 95% CI: 0.012, 0.489) and 30–49 years (ARD: 0.205, 95% CI: 0.042, 0.367) when compared to the age group of 50 years and older, as well as people who were homeless (ARD: 0.844, 95% CI: 0.120, 1.568), unstably housed (ARD: 0.326, 95% CI: 0.109, 0.543) and/or having mental health concerns (ARD: 0.309, 95% CI: 0.075, 0.544), controlling for race, injection history, and viral load. Conclusions: These findings highlight an opportunity to develop culturally, socially, and racially appropriate interventions to reduce HIV stigma among MSM living with HIV, particularly for younger men and those struggling with housing stability and/or mental health.


2018 ◽  
Vol 46 (2) ◽  
pp. 35-42
Author(s):  
A. A. Tkachev ◽  
N. A. Tkacheva

This article describes burials of women at a Middle Bronze Age cemetery of Maytan—the only completely excavated Andronovo burial ground in the steppes of central Kazakhstan. On the basis of the location of ornaments in burials, an attempt is made to reconstruct details of costume with regard to age groups. The composition and arrangement of the individual elements of the costume indicate several decoration areas such as head; neck and chest; hands and feet. Exceptional areas are accessories (bags and boxes), belt, and lap of dress. Most ornaments mark the age category of women. There are two age groups: girls and adult women. Though many graves have been looted, a tentative reconstruction of the costume with regard to these groups is possible. Such a reconstruction is relevant to cultural tradition, ideas of beauty, and social status.


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