bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical and chest CT presentations from 27 patients with COVID-19 pneumonia in Mogadishu, Somalia: a descriptive study
Authors: Mohamed Yahye Garad , Mohamud Mohamed Farah Yusuf , Medişoğlu M. Sabri , Atamaca Ihsan Yavuz , Ali Ibrahim Hussein 
Published: September 2020

Abstract
Background
Coronavirus disease 2019 (COVID-19) is an acute viral pneumonia that had recently been found in humans. The first case was discovered in Wuhan, Hubei province, China, in December 2019. In this article, we aimed to demonstrate the clinical and radiological characteristics of COVID-19 patients in Somalia from 20 March 2020 to 20 April 2020.

Results
Twenty-seven patients that had a positive RT-PCR test between 20 March 2020 and 20 April 2020 were retrospectively observed. This study included 19 (70.4%) males and 8 (29.6%) females, and the mean age and range were 43 years (SD ± 14.0) and 27–70 years, respectively. The majority (59.3%) of COVID-19-infected patients had no obvious history of exposure to infected patients. The participants of our study mostly presented with dry cough 24 (88.9%) patients, fever 19 (70.4%), myalgia 18 (66.6%), and sore throat 16 (59.3%). Twenty-five of 27 patients had abnormal chest CT, while 2 (7.4%) patients had normal chest CT. The most common patterns of abnormality seen on chest CT in patients with COVID-19 were ground-glass opacity (GGO) 74.1%, crazy paving pattern 18.5%, consolidation 14.8%, and mixed GCO 11.1%. Also, the most common predominant lesion distributions were bilateral lung involvement (88.9%), peripheral distribution (77.8%), and lower lung predominance (63%). Particularly, lung cavitation, discrete pulmonary nodules, pleural effusion, and underlying pulmonary fibrosis or emphysema had not been observed.

Conclusion
Dry cough, fever, myalgia, and sore throat were the most clinical presentations. GGO, crazy paving pattern, patchy consolidation, and mixed GCO were the typical chest CT manifestations.
A Human Randomized Controlled Trial Comparing Metabolic Responses to Single and Repeated Hypoglycemia in Type 1 Diabetes
Authors: Bengtsen Mads Bisgaard , Støy Julie , Rittig Nikolaj Fibiger , Voss Thomas Schmidt , Magnusson Nils Erik , Svart Mads Vadsted , Jessen Niels , Møller Niels 
Published: September 2020

Abstract

Aims
Hypoglycemia hinders optimal glycemic management in type 1 diabetes (T1D). Long diabetes duration and hypoglycemia impair hormonal counter-regulatory responses to hypoglycemia. Our study was designed to test whether (1) the metabolic responses and insulin sensitivity are impaired, and (2) whether they are affected by short-lived antecedent hypoglycemia in participants with T1D.

Materials and Methods
In a randomized, crossover, 2x2 factorial design, 9 male participants with T1D and 9 comparable control participants underwent 30 minutes of hypoglycemia (p-glucose &lt; 2.9 mmol/L) followed by a euglycemic clamp on 2 separate interventions: with and without 30 minutes of hypoglycemia the day before the study day.

Results
During both interventions insulin sensitivity was consistently lower, while counter-regulatory hormones were reduced, with 75% lower glucagon and 50% lower epinephrine during hypoglycemia in participants with T1D, who also displayed 40% lower lactate and 5- to 10-fold increased ketone body concentrations following hypoglycemia, whereas palmitate and glucose turnover, forearm glucose uptake, and substrate oxidation did not differ between the groups. In participants with T1D, adipose tissue phosphatase and tensin homolog (PTEN) content, hormone-sensitive lipase (HSL) phosphorylation, and muscle glucose transporter type 4 (GLUT4) content were decreased compared with controls. And antecedent hypoglycemic episodes lasting 30 minutes did not affect counter-regulation or insulin sensitivity.

Conclusions
Participants with T1D displayed insulin resistance and impaired hormonal counter-regulation during hypoglycemia, whereas glucose and fatty acid fluxes were intact and ketogenic responses were amplified. We observed subtle alterations of intracellular signaling and no effect of short-lived antecedent hypoglycemia on subsequent counter-regulation. This plausibly reflects the presence of insulin resistance and implies that T1D is a condition with defective hormonal but preserved metabolic responsiveness to short-lived hypoglycemia.
Orchestrating morphogenesis: building the body plan by cell shape changes and movements
Authors: Perez-Vale Kia Z. , Peifer Mark 
Published: September 2020

ABSTRACTDuring embryonic development, a simple ball of cells re-shapes itself into the elaborate body plan of an animal. This requires dramatic cell shape changes and cell movements, powered by the contractile force generated by actin and myosin linked to the plasma membrane at cell-cell and cell-matrix junctions. Here, we review three morphogenetic events common to most animals: apical constriction, convergent extension and collective cell migration. Using the fruit fly Drosophila as an example, we discuss recent work that has revealed exciting new insights into the molecular mechanisms that allow cells to change shape and move without tearing tissues apart. We also point out parallel events at work in other animals, which suggest that the mechanisms underlying these morphogenetic processes are conserved.
Hedging the Brazilian stock index in the era of low interest rates: What has changed?
Authors: Aiube Fernando Antonio Lucena , Faquieri Winicius Botelho 
Published: September 2020

In this paper we analyze the ability of different asset classes to hedge the Brazilian stock index in periods of high and low interest rates in the Brazilian economy, using two multivariate GARCH models. Our analysis includes two categories of assets: those traded in domestic currency and those traded in U.S. dollars. From the perspective of a local investor, we find that the exchange rate (R$/US$) and gold are the assets least correlated with equities. From the standpoint of a foreign investor, commodity index and fixed-income assets are the most useful. These results prevail in the low- and high-interest-rate periods. Moreover, in the period of low interest rates, the standard deviation of the estimated conditional correlation time series decreases, suggesting that in this period investors are more confident about macroeconomic policies.
Relações entre índices preço-lucro e retornos dos títulos públicos
Authors: Amorim Daniel Penido de Lima , Camargos Marcos Antônio de 
Published: September 2020

Os índices P/E1 e P/E10 ou Índice Preço-lucro Ciclicamente Ajustado foram amplamente disseminados na literatura que tem como contexto o mercado de ações americano. Este artigo traz um método de construção de índices P/E para o mercado de ações brasileiro. Seu objetivo é analisar as relações de longo prazo entre tanto o P/E1 quanto o P/E10 e as taxas de juros correspondentes aos retornos de títulos públicos, de modo a testar a relação referente ao Modelo Fed. No geral, o período considerado foi de dezembro de 2004 a junho de 2018. Foram estimados modelos Autorregressivos de Defasagens Distribuídas, os quais podem ser representados como Modelos de Correção de Erros Condicionais. Os resultados evidenciaram relações de longo prazo significativas entre tanto o P/E1 quanto P/E10 e as referidas taxas de juros, sugerindo que o Modelo Fed está em linha com o comportamento do mercado financeiro brasileiro.
The CIPAZ study protocol: an open label randomised controlled trial of azithromycin versus ciprofloxacin for the treatment of children hospitalised with dysentery in Ho Chi Minh City, Vietnam
Authors: Darton Thomas C. , Thi Hong Chau Tran , Parry Christopher M. , Campbell James I. , Minh Ngoc Nguyen , Le Chau Ngoc Tang , Thanh Tuyen Ha , Thuy Duong Vu , Thanh Hoang Nhat Le , van Minh Pham , Kestelyn Evelyne , Thwaites Guy E. , Huu Tung Trinh , Baker Stephen 
Published: September 2020

Background: Diarrhoeal disease remains a common cause of illness and death in children <5 years of age. Faecal-oral infection by Shigella spp. causing bacillary dysentery is a leading cause of moderate-to-severe diarrhoea, particularly in low and middle-income countries. In Southeast Asia, S. sonnei predominates and infections are frequently resistant to first-line treatment with the fluoroquinolone, ciprofloxacin. While resistance to all antimicrobials is increasing, there may be theoretical and clinical benefits to prioritizing treatment of bacillary dysentery with the azalide, azithromycin. In this study we aim to measure the efficacy of treatment with azithromycin compared with ciprofloxacin, the current standard of care, for the treatment of children with bacillary dysentery. Methods and analysis: We will perform a multicentre, open-label, randomized controlled trial of two therapeutic options for the antimicrobial treatment of children hospitalised with dysentery. Children (6–60 months of age) presenting with symptoms and signs of dysentery at Children’s Hospital 2 in Ho Chi Minh City will be randomised (1:1) to treatment with either oral ciprofloxacin (15mg/kg/twice daily for 3 days, standard-of-care) or oral azithromycin (10mg/kg/daily for 3 days). The primary endpoint will be the proportion of treatment failure (defined by clinical and microbiological parameters) by day 28 (+3 days) and will be compared between study arms by logistic regression modelling using treatment allocation as the main variable. Ethics and dissemination: The study protocol (version 1.2 dated 27th December 2018) has been approved by the Oxford Tropical Research Ethics Committee (47–18) and the ethical review boards of Children's Hospital 2 (1341/NĐ2-CĐT). The study has also been approved by the Vietnamese Ministry of Health (5044/QĐ-BYT). Trial registration: Clinicaltrials.gov: NCT03854929 (February 26th 2019).
Can the results of a randomized controlled trial change the treatment preferences of orthopaedic surgeons?
Authors: Sonntag Jesper , Landale Keith , Brorson Stig , Harris Ian A 
Published: September 2020

AimsThe aim of this study was to investigate surgeons’ reported change of treatment preference in response to the results and conclusion from a randomized contolled trial (RCT) and to study patterns of change between subspecialties and nationalities.MethodsTwo questionnaires were developed through the Delphi process for this cross-sectional survey of surgical preference. The first questionnaire was sent out before the publication of a RCT and the second questionnaire was sent out after publication. The RCT investigated repair or non-repair of the pronator quadratus (PQ) muscle during volar locked plating of distal radial fractures (DRFs). Overall, 380 orthopaedic surgeons were invited to participate in the first questionnaire, of whom 115 replied. One hundred surgeons were invited to participate in the second questionnaire. The primary outcome was the proportion of surgeons for whom a treatment change was warranted, who then reported a change of treatment preference following the RCT. Secondary outcomes included the reasons for repair or non-repair, reasons for and against following the RCT results, and difference of preferred treatment of the PQ muscle between surgeons of different nationalities, qualifications, years of training, and number of procedures performed per year.ResultsOf the 100 surgeons invited for the second questionnaire, 74 replied. For the primary outcome, six of 32 surgeons (19%), who usually repaired the PQ muscle and therefore a change of treatment preference was warranted, reported a change of treatment preference based on the RCT publication. Of the secondary outcomes, restoring anatomy was the most common response for repairing the PQ muscle.ConclusionThe majority of the orthopaedic surgeons, where a change of treatment preference was warranted based on the results and conclusion of a RCT, did not report willingness to change their treatment preference. Cite this article: Bone Joint Open 2020;1-9:549–555.
Analysis of Variance and Correlation Study of Chlorophyll-a in North and South Coast of Lombok Island Using Aqua MODIS Image Data
Authors: Wibisana Hendrata , Zainab Siti , Kamandang Zetta Rasullia , Rusdi Muhammad 
Published: September 2020

Chlorophyll-a mapping is widely used in the coastal environment. The mapping results can be utilized as guidance for fishing activities. The presence of chlorophyll-a in phytoplankton is much investigated concerning the existence of fish as a source of livelihood for fishermen around the globe. One method extensively developed is the use of satellite imagery to map the chlorophyll-content in the coastal region from a small area to a global scale, such as Aqua MODIS image data. This study aims to monitor the distribution of chlorophyll-a on the north coast and south coast of Lombok island. Analysis of variance and parametric statistical tests with t-distribution was utilized to examine the correlation between the two types of chlorophyll-a distribution of the coast area, Lombok Island. The result shows that the distribution of chlorophyll-a concentrations on the north coast and the south of the coast is not the same abundance; the south coast of Lombok island has smaller variances, with the concentration distribution is relatively the same. It differs from the north part; the distribution shows less diversity. This result indicates that a reasonably wide interval wherein some coordinates has a relatively diffuse chlorophyll-a concentration with a sufficiently high distribution level. Analysis of variance result also shows that both the north and south coasts have different fertility levels for their coastal waters, which are characterized by the growth rate of chlorophyll-a on the surface water along the coastal region examined
Evaluation of forward reflectance models and empirical algorithms for
chlorophyll concentration of stratified waters
Authors: Lee Zhongping , Wang Yongchao , Yu Xiaolong , Shang Shaoling , Luis Kelly 
Published: September 2020

For waters with stratified chlorophyll concentration (Chl), numerical
simulations were carried out to gain insight into the forward models
of subsurface reflectance and empirical algorithms for Chl from the
ocean color. It is found that the Gordon and Clark (1980) forward
model for reflectance using an equivalent homogeneous water with a
weighted average Chl (

⟨

C
h
l

⟩

) as the input works well, but
depending on the contribution of gelbstoff, the difference in
reflectance between stratified and the equivalent homogeneous water
can be more than 10%. Further, the attenuation of upward light is
better approximated as

∼

1.5

t
i
m
e
s

that of the diffuse attenuation
coefficient of downwelling irradiance. On the other hand, although the
forward model for reflectance developed in Zaneveld et al. [Opt.
Express 13, 9052 (2005)] using equivalent
homogeneous water with a weighted average of the backscattering to
absorption ratio as the input also works well, this model cannot be
used to obtain equivalent

⟨

C
h
l

⟩

for reflectance. Further, for
empirical Chl algorithms designed for “Case 1” waters, it has been
discovered that, for surface Chl in a range of

∼

0.06

−

22.0

m
g

/

m

3

, the predictability of surface Chl is
basically the same as that of

⟨

C
h
l

⟩

from the blue-green band ratio or the
band difference of reflectance. Because

⟨

C
h
l

⟩

is wavelength and weighting-formula
dependent, and it is required to have profiles of both Chl and the
optical properties, these results emphasize that for empirical Chl
algorithms, it is easier, less ambiguous, and certainly more
straightforward and simple to use surface Chl for algorithm
development and then its evaluation, rather than to use

⟨

C
h
l

⟩

, regardless of whether or not the
water is stratified.
X-ray attenuation models to account for beam hardening in computed tomography
Authors: Yang Q. , Fullagar W. K. , Myers G. R. , Latham S. J. , Varslot T. , Sheppard A. P. , Kingston A. M. 
Published: September 2020

We introduce a beam-hardening correction method for lab-based X-ray computed tomography (CT) by modifying existing iterative tomographic reconstruction algorithms. Our method simplifies the standard Alvarez–Macovski X-ray attenuation model [Phys. Med. Biol. 21, 733 (1976)] and is compatible with conventional (i.e., single-spectrum) CT scans. The sole modification involves a polychromatic projection operation, which is equivalent to applying a weighting that more closely matches the attenuation of polychromatic X-rays. Practicality is a priority, so we only require information about the X-ray spectrum and some constants relating to material properties. No other changes to the experimental setup or the iterative algorithms are necessary. Using reconstructions of simulations and several large experimental datasets, we show that this method is able to remove or reduce cupping, streaking, and other artefacts from X-ray beam hardening and improve the self-consistency of projected attenuation in CT. When the assumptions made in the simplifications are valid, the reconstructed tomogram can even be quantitative.
Cost-effective demonstration of fiber-optic frequency transfer
Authors: Zhang Hao 
Published: September 2020

In this paper, we demonstrate a cost-effective solution for fiber-optic
frequency transfer. By employing the commercially available small form
pluggable (SFP) transceivers and other components for telecom, the
scheme is compatible with the existing telecom networks. An experiment
testbed based on the common round trip frequency
transfer is carried out to investigate the corresponding performance
in detail. Compared with the conventional analog electro-optic
interconversion scheme, the optical modulation and demodulation
employing SFP transceiver has an inferior performance in terms of
additive phase noise. However, the scheme enables a much larger
operation range of receiving optical power for an optimal system
performance, which indicates the certain capability of adapting to
different fiber transmission links. On the basis of the established
testbed, fiber-optic frequency transfer with a frequency of 1 GHz is
demonstrated over a 50 km dispersion-compensated fiber link.
Furthermore, the additive phase noise of

−

84

d
B
c

/

H
z

@1 Hz and

−

130

d
B
c

/

H
z

@10 kHz is achieved. Simultaneously,
the Allan deviation (ADEV) of

9.6

×

1

0

−
14

/

s

and

8.4

×

1

0

−
17

/

10

4

s

is reached, respectively. The scheme
can provide a relatively feasible solution to implement fiber-optic
frequency transfer over the existing telecom network
infrastructure.
On supporting efficient snapshot isolation for hybrid workloads with multi-versioned indexes
Authors: Sun Yihan , Blelloch Guy E. , Lim Wan Shen , Pavlo Andrew 
Published: September 2020

Modern data-driven applications require that databases support fast analytical queries while undergoing rapid updates---often referred to as Hybrid Transactional Analytical Processing (HTAP). Achieving fast queries and updates in a database management system (DBMS) is challenging since optimizations to improve analytical queries can cause overhead for updates. One solution is to use snapshot isolation (SI) for multi-version concurrency control (MVCC) to allow readers to make progress regardless of concurrent writers.
In this paper, we propose the Parallel Binary Tree (P-Tree) index structure to achieve SI and MVCC for multicore in-memory HTAP DBMSs. At their core, P-Trees are based on pure (immutable) data structures that use path-copying for updates for fast multi-versioning. They support tree nesting to improve OLAP performance while still allowing for efficient updates. The data structure also enables parallel algorithms for bulk operations on indexes and their underlying tables. We evaluate P-Trees on OLTP and OLAP benchmarks, and compare them with state-of-the-art data structures and DBMSs. Our experiments show that P-Trees outperform many concurrent data structures for the YCSB workload, and is 4--9 x faster than existing DBMSs for analytical queries, while also achieving reasonable throughput for simultaneous transactional updates.
Deep unsupervised cardinality estimation
Authors: Yang Zongheng , Liang Eric , Kamsetty Amog , Wu Chenggang , Duan Yan , Chen Xi , Abbeel Pieter , Hellerstein Joseph M. , Krishnan Sanjay , Stoica Ion 
Published: September 2020

Cardinality estimation has long been grounded in statistical tools for density estimation. To capture the rich multivariate distributions of relational tables, we propose the use of a new type of high-capacity statistical model: deep autoregressive models. However, direct application of these models leads to a limited estimator that is prohibitively expensive to evaluate for range or wildcard predicates. To produce a truly usable estimator, we develop a Monte Carlo integration scheme on top of autoregressive models that can efficiently handle range queries with dozens of dimensions or more.Like classical synopses, our estimator summarizes the data without supervision. Unlike previous solutions, we approximate the joint data distribution without any independence assumptions. Evaluated on real-world datasets and compared against real systems and dominant families of techniques, our estimator achieves single-digit multiplicative error at tail, an up to 90x accuracy improvement over the second best method, and is space- and runtime-efficient.
Cardiac involvement in children with community-acquired pneumonia and respiratory failure
Authors: Nimdet Kachaporn , Techakehakij Win 
Published: September 2020

Abstract

Background
Pneumonia causes significant incidence in children younger than 5 years. Most fatalities are resulted from complications. High rates of cardiac events were detected in adult studies but usually related to underlying diseases.

Objective
To study the cardiac effects of community-acquired pneumonia (CAP) with respiratory failure (RF) in healthy children.

Methods
The prospective cohort study was conducted in children aged 2–59 months with CAP and RF. Cardiac enzyme assessments, chest radiography, electrocardiography, and echocardiography were performed at the admission date and 2 weeks after admission. t-test and chi-square test were used for comparison between first and second investigations, and the statistically significance level was a P <0.05.

Results
Of the 135 patients, pericardial effusion occurred in 80 (59%), valvular regurgitation in 30 (22%), ST/T changes in 66 (49%), cardiac arrhythmia in 7 (5%), and myocardial injury in 83 (62%). Significant improvement of cardiothoracic-ratio, heart rate, ST/T changes, cardiac arrhythmia, troponin T, myocardial performance, and left-ventricular ejection fraction was demonstrated at second investigations. Three mortality cases exhibited evidence of congestive heart failure (CHF).

Conclusion
Children with CAP and RF had several cardiac effects even in healthy children. Most cardiac effects were mild and transient. Mortality cases were revealed evidence of congestive heart failure (CHF). Future research should be designed to find out the characteristics and predictors of CHF for early recognition and therapeutic strategy.
A new extension of Srivastava’s triple hypergeometric functions and their associated properties
Authors: Saboor Abdus , Rahman Gauhar , Anjum Zunaira , Nisar Kottakkaran Sooppy , Araci Serkan 
Published: September 2020

AbstractIn this paper, we define a new extension of Srivastava’s triple hypergeometric functions by using a new extension of Pochhammer’s symbol that was recently proposed by Srivastava, Rahman and Nisar [H. M. Srivastava, G. Rahman and K. S. Nisar, Some extensions of the Pochhammer symbol and the associated hypergeometric functions, Iran. J. Sci. Technol. Trans. A Sci. 43 2019, 5, 2601–2606]. We present their certain basic properties such as integral representations, derivative formulas, and recurrence relations. Also, certain new special cases have been identified and some known results are recovered from main results.