extreme variation
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2022 ◽  
Vol 6 ◽  
pp. 1
Author(s):  
Darrel Ceballos ◽  
Albert Tine ◽  
Rakesh Varma ◽  
Husameddin El Khudari

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy. Approximately 8% of patients with HCC are not suitable candidates for curative options. Caudate lobe HCC presents technical challenges for interventional radiologists. Caudate lobe HCC has higher local recurrence and poorer survival rate than other segments. Transarterial treatments of caudate HCC are difficult due to extreme variation of arterial supply. We present a case of a caudate lobe HCC with supply from the proper hepatic artery, which underwent successful conventional transcatheter arterial chemoembolization (cTACE) by utilizing a Fogarty catheter to direct the embolic material. The patient presented 5 days following the procedure with duodenitis and pancreatitis, which were managed conservatively. Follow-up imaging at 1 month showed significant improvement of the ischemic duodenitis/pancreatitis with successful cTACE.


2021 ◽  
Vol 37 (4) ◽  
pp. 1059-1078
Author(s):  
Mengxuan Xu ◽  
Victoria Landsman ◽  
Barry I. Graubard

Abstract Misclassified frame records (also called stratum jumpers) and low response rates are characteristic for business surveys. In the context of estimation of the domain parameters, jumpers may contribute to extreme variation in sample weights and skewed sampling distributions of the estimators, especially for domains with a small number of observations. There is limited literature about the extent to which these problems may affect the performance of the ratio estimators with nonresponse-adjusted weights. To address this gap, we designed a simulation study to explore the properties of the Horvitz-Thompson type ratio estimators, with and without smoothing of the weights, under different scenarios. The ratio estimator with propensity-adjusted weights showed satisfactory performance in all scenarios with a high response rate. For scenarios with a low response rate, the performance of this estimator improved with an increase in the proportion of jumpers in the domain. The smoothed estimators that we studied performed well in scenarios with non-informative weights, but can become markedly biased when the weights are informative, irrespective of response rate. We also studied the performance of the ’doubled half’ bootstrap method for variance estimation. We illustrated an application of the methods in a real business survey.


2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Lila R. Gleitman ◽  
Claire Gleitman

The mid-twentieth century brought a radical change in how the linguistics community formulated its major goal, moving from a largely taxonomic science to Chomsky's revolution, which conceptualized language as a higher-order cognitive function. This article reviews the paths (not always direct) that brought Lila Gleitman into contact with that revolution, her contributions to it, and the evolution in her thinking about how language is learned by every child, regardless of extreme variation in the input received. To understand how that occurs, we need to discover what must be learned by the child and what is already there to guide that learning—what must be, in Plato's terms, “recollected.” The growing picture shows a learner equipped with information-processing mechanisms that extract evidence about word meanings using various evidential sources. Chief among these are the observational and linguistic-syntactic contexts in which words occur. The former is supported by a mechanism Gleitman and her collaborators call “propose but verify,” and the latter by a mechanism known as “syntactic boot-strapping.” Expected final online publication date for the Annual Review of Psychology, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Author(s):  
Anish A Sarma ◽  
Aartik Sarma ◽  
Marie Csete ◽  
Peter P Lee ◽  
John C Doyle

Dramatic variation in SARS-CoV-2 virulence and transmission between hosts has driven the COVID-19 pandemic. The complexity and dynamics of the immune response present a challenge to understanding variation in SARS-CoV-2 infections. To address this challenge, we apply control theory, a framework used to study complex feedback systems, to establish rigorous mathematical bounds on immune responses. Two mechanisms of SARS-CoV-2 biology are sufficient to create extreme variation between hosts: (1) a sparsely expressed host receptor and (2) potent, but not unique, suppression of interferon. The resulting model unifies disparate and unexplained features of the SARS-CoV-2 pandemic, predicts features of future viruses that threaten to cause pandemics, and identifies potential interventions.


Zootaxa ◽  
2021 ◽  
Vol 4942 (4) ◽  
pp. 583-591
Author(s):  
FABIANO STEFANELLO

The giant water bug fauna from tropical South America remains poorly known. Three species of Belostoma Latreille (Belostoma fittkaui De Carlo, B. sayagoi De Carlo and B. hirsutum Roback & Nieser) have been cited only a few times in the literature. These three species are remarkable since they represent an extreme variation for the genus, with article II of the labium distinctly shorter than article III. Here, the synonymy of B. hirsutum with B. sayagoi is proposed based on examination of type material and additional specimens. Further, B. fittkaui and B. sayagoi are redescribed, including discussion about comparative morphology with congeners. A new species group is proposed for these species and a key to the Belostoma species groups is provided. Distribution records are also updated. 


2021 ◽  
Vol 3 ◽  
Author(s):  
Florian U. Jehn ◽  
Lutz Breuer ◽  
Philipp Kraft ◽  
Konrad Bestian ◽  
Tobias Houska

Hydrological theory often assumes an exponential relationship between storage and discharge, but how often do we find such a behavior in real catchments? We analyze catchment attributes, discharge and weather conditions from 1992 to 2018 for 88 catchments in Hesse, Germany. All catchments have similar weather conditions, but a wide range of catchment characteristics. We find that only a fraction of catchments follow a roughly exponential behavior in their storage-discharge relationship. Far more catchments are complex and depict irregular patterns with even extreme variation from 1 year to another. This large set of catchments with similar weather conditions reveals that physical attributes that drive catchment complexity are diverse and include soil permeability, hydraulic conductivity, geology, and soil type. We link the examined simple and complex behavior to the fill and spill hypotheses and the interconnectedness of the catchments. Simpler catchments have more preferential flow and more connected hillslopes and thus lower runoff generation thresholds. This creates a more straightforward relationship between storage and discharge.


2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Abdullah Ali ◽  
Jeanette Azzaretto ◽  
Katie Moltz

The rise of popular music on a global scale has prompted researchers to predict standard features for creating the next hit songs. Previous studies have explored various acoustical/audio features and their relations to top-charting songs but fail to include the artists' voice in determining popular music patterns. As a result, this study had used a trend analysis to find consistent patterns over the selected period (1980-2019) by analyzing five distinct vocal features: vowel corruption, pitch, intensity, number of pulses, and voicing. Upon analyzation, a general increase in vowel corruption and a formant difference in vowels were observed. A stagnant level in intensity and extreme variation in pitch was also noted. Overall, this study was one of the first to find accurate trends, including vocal features in hit song prediction research. Among various implications, one would be introducing a new area of study regarding singing in contemporary music. 


2020 ◽  
Author(s):  
Suvi Ponnikas ◽  
Hanna Sigeman ◽  
Max Lundberg ◽  
Bengt Hansson

In the majority of bird species, recombination between the sex chromosome pairs in heterogametic females (ZW) is restricted to a small pseudoautosomal region (PAR), whereas recombination is ongoing along the entire Z chromosome in the homogametic males (ZZ). Recombination has a strong impact on the sequence evolution by affecting the extent of linkage, level of genetic diversity and efficacy of selection. Species within the Sylvioidea superfamily are unique among birds in having extended Z and W chromosomes (neo-sex chromosomes) formed by a fusion between the ancestral sex chromosomes and a part of chromosome 4A. So far the recombination landscape of the Sylvioidea neo-sex chromosomes remains unknown, despite its importance for understanding sequence evolution. Here, we use linkage mapping in a multi-generation pedigree to assemble, and assess the recombination rate along the entire Z chromosome of one Sylvioidea species, the great reed warbler (Acrocephalus arundinaceus). This resulted in an 87.54 Mbp and 90.19 cM large Z including the ancestral-Z, where the small PAR (0.89 Mbp) is located, and the added-Z. A striking result was an extreme variation in recombination rate along the Z in male great reed warblers with high rates at both telomeric ends, but an apparent lack of recombination over a substantial central section, covering 77% of the chromosome. This region showed a drastic loss of nucleotide diversity and accumulation of repeats compared to the highly recombining regions. Nonetheless, the evolutionary rate of genes (measured by dN/dS) did not differ between these regions, suggesting that the efficacy of selection on protein-coding sequences is not reduced by lack of recombination.


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