bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of cold rolling deformation on mechanical properties and corrosion behavior of Ti-6Al-3Nb-2Zr-1Mo alloy
Authors: Guo Kai , Wang Tiansheng , Meng Kang , Yao Chuan , Wang Qingfeng
Published: May 2020

The effects of cold deformation on tensile properties and corrosion behavior of the Ti-6Al-3Nb-2Zr-1Mo alloy are investigated in the present work. The microstructure of the sample was characterized by means of x-ray diffractometry, scanning electron microscope and electron backscattered diffraction. The corrosion behavior of the alloy in HCl solution was characterized by potentiodynamic polarization test. The results show that the α laths became kinked after cold rolling and the interlamellar spacing decreased to about 0.45 μm at the rolling reduction of 50%. The kinking process closely linked with the development of shear bands within the colonies. EBSD investigations indicated that the α lath exhibited a (0001) texture in the 50% cold-rolled alloy. With the increase of cold deformation strain, the Yield strength of the alloy increases from 811 MPa to 943 MPa. The corrosion resistance of processed samples was higher than as-received sample. Experimental results showed that deformation substructure and texture had an influence on the corrosion rate of this alloy.
TiN-based organic-inorganic composite films with dual functions of solar control and low-emission for energy-saving coatings
Authors: Ma Yachao , Yang Daoyuan , Jiang Qiao , Zhu Kai , Yuan Huiyu , Cui Junyan , Yuan Lin
Published: May 2020

With the fast development of modern intelligent buildings, the demand for a comfortable environment and ‘low carbon’ technologies, for example, energy-saving buildings, becomes more intense. Thermal insulation coatings as one of the most promising routes to alleviate the energy consumption of buildings attract extensive attention in recent years. In this work, titanium nitride-based organic-inorganic composite films (TiN O/I films) were introduced as the thermal insulation coatings to window glass via blade coating method. Additionally, two different synthesis methods were adopted to prepare the inorganic TiN nanoparticle and its effect on the optical property of the coatings was studied detailedly via the ultraviolet-visible-near-infrared (UV–vis-IR) spectrophotometer and Fourier transform infrared spectrometer characterizations. In addition, the thermal insulation properties of the films were characterized by a system that simulates the natural environment. Various characterizations show that the synthesized TiN O/I films can not only pass through the visible light but also has high reflectance at the mid-infrared range, that is with the functions of solar control and low emission, well satisfying the requirements of the energy-saving coatings for window glass. These results demonstrated the good feasibility of TiN O/I films in thermal insulation coatings, and also provide a direction for the development of more novel thermal insulation materials with large-scale.
Microstructure and properties of B4Cp/Al composite prepared by microwave sintering with low temperature
Authors: Wang Hongming , Tang Feng , Li Guirong , Zhang De , Liu Ming , Kai Xizhou
Published: May 2020

In this study, B4Cp/Al composites were prepared by microwave sintering using 20 vol% B4C and Al powder as raw materials. The effects of sintering temperature and time on the microstructure and properties of B4Cp/Al composites were studied. The results show that in the presence of microwave field, the pores amount at the B4C/Al interface and the densification has been changed. When the sintering temperature is 580 °C and the sintering time is 45 min, the B4C particles are dispersed. At this time, the B4C/Al interface is clean and tight together with few transient phase Al3BC(s) that commonly generated in abnormally hyperthermal areas. When the temperature is enhanced or time prolonged, the liquid aluminum will appear in the composite, the fluidity of the aluminum matrix will increase greatly. A more serious aluminizing phenomenon will occur, resulting in the uneven distribution of B4C particles in the matrix. As for the properties, the optimized composite material exhibits the best compactness and Vickers hardness as 93.2% and 112.5HV1. The nanoindentation test reveals that the hardness and elastic modulus of interface are 8.494 GPa and 142.537 GPa.
Recent theory of traveling-wave tubes: a tutorial-review
Authors: Wong Patrick , Zhang Peng , Luginsland John
Published: May 2020

The traveling-wave tube (TWT), also known as the traveling-wave amplifier (TWA) or traveling-wave tube amplifier (TWTA), is a widely used amplifier in satellite communications and radar. An electromagnetic signal is inputted on one end of the device and is amplified over a distance until it is extracted downstream at the output. The physics behind this spatial amplification of an electromagnetic wave is predicated on the interaction of a linear DC electron beam with the surrounding circuit structure. Pierce, known as the ‘father of communications satellites,’ was the first to formulate the theory for this beam-circuit interaction, the basis of which has since been used to model other vacuum electronic devices such as free-electron lasers, gyrotrons, and Smith-Purcell radiators, just to name a few. In this paper, the traditional Pierce theory will first be briefly reviewed; the classic Pierce theory will then be extended in several directions: harmonic generation and the effect of high beam current on both the beam mode and circuit mode as well as ‘discrete effects’, giving a brief tutorial of recent theories of TWTs.
A note on the weak splitting number
Authors: Cavallo Alberto , Collari Carlo , Conway Anthony
Published: May 2020

The weak splitting number

wsp
⁡
(
L
)

\operatorname {wsp}(L)

of a link

L
L

is the minimal number of crossing changes needed to turn

L
L

into a split union of knots. We describe conditions under which certain

R

\mathbb {R}

-valued link invariants give lower bounds on

wsp
⁡
(
L
)

\operatorname {wsp}(L)

. This result is used both to obtain new bounds on

wsp
⁡
(
L
)

\operatorname {wsp}(L)

in terms of the multivariable signature and to recover known lower bounds in terms of the

τ
\tau

and

s
s

-invariants. We also establish new obstructions using link Floer homology and apply all these methods to compute

wsp
\operatorname {wsp}

for all but two of the

130
130

prime links with nine or fewer crossings.
Extremal growth of Betti numbers and trivial vanishing of (co)homology
Authors: Lyle Justin , Montaño Jonathan
Published: May 2020

A Cohen–Macaulay local ring

R
R

satisfies trivial vanishing if

Tor
i
R

⁡
(
M
,
N
)
=
0

\operatorname {Tor}_i^R(M,N)=0

for all large

i
i

implies that

M
M

or

N
N

has finite projective dimension. If

R
R

satisfies trivial vanishing, then we also have that

Ext
R
i

⁡
(
M
,
N
)
=
0

\operatorname {Ext}^i_R(M,N)=0

for all large

i
i

implies that

M
M

has finite projective dimension or

N
N

has finite injective dimension. In this paper, we establish obstructions for the failure of trivial vanishing in terms of the asymptotic growth of the Betti and Bass numbers of the modules involved. These, together with results of Gasharov and Peeva, provide sufficient conditions for

R
R

to satisfy trivial vanishing; we provide sharpened conditions when

R
R

is generalized Golod. Our methods allow us to settle the Auslander–Reiten conjecture in several new cases. In the last part of the paper, we provide criteria for the Gorenstein property based on consecutive vanishing of Ext. The latter results improve similar statements due to Ulrich, Hanes–Huneke, and Jorgensen–Leuschke.
Nek8445, a protein kinase required for microtubule regulation and cytokinesis inGiardia lamblia
Authors: Hennessey Kelly M. , Alas Germain C. M. , Rogiers Ilse , Li Renyu , Merritt Ethan A. , Paredez Alexander R.
Published: May 2020

Here we study the role of Nek8445 in regulating cell division and microtubule array organization in Giardia. Depletion of Nek8445 results in 87% of cells being stalled or blocked in cytokinesis. Nek8445 regulates ventral disk organization, funis formation, axoneme exit, and cell shape, all of which contribute to the observed cytokinesis defects.
High gene flow maintains wide-range species cohesion in a Neotropical epiphyte (Tillandsia aeranthos, Bromeliaceae)
Authors: Aoki-Gonçalves Felipe , Dantas De Queiroz Marcos Vinicius , De Beauclair Guimarães Thais , Solís Neffa Viviana , Palma-Silva Clarisse
Published: May 2020

Studies of patterns of genetic diversity, genetic structure and ecological data across geographical ranges of species allow us to test hypotheses about the evolutionary responses of organisms to fluctuations in habitat connectivity and availability. Here we present a study aiming to assess genetic diversity, population structure and breeding system across the geographical distribution of a subtropical epiphyte, Tillandsia aeranthos (Bromeliaceae), endemic to the Plata River basin (Pampa biome). Seven nuclear microsatellite markers were genotyped in 203 individuals from 13 localities across Brazil and Argentina and 14 plastid regions were sequenced for a subset of the individuals. Additionally, we performed controlled pollination experiments to discuss correlations between breeding system, genetic diversity and structure in the species. Nuclear diversity levels were high (HE = 0.806, HO = 0.745, allelic richness = 5.860) with no haplotype differentiation detected (c. 9 kpb sequenced). Bayesian assignment analysis, supported by principal coordinate analysis and analysis of molecular variance, show low genetic structure across the studied area (FST = 0.031, P < 0.001). Controlled pollination experiments indicated complete self-incompatibility in all localities analysed. Our results show effective gene flow maintaining low genetic structure between localities for T. aeranthos across an extensive area in the Pampa.
Less arterial stiffness in kidney transplant recipients than chronic kidney disease patients matched for renal function
Authors: Cheddani Lynda , Haymann Jean Philippe , Liabeuf Sophie , Tabibzadeh Nahid , Boffa Jean-Jacques , Letavernier Emmanuel , Essig Marie , Drüeke Tilman B , Delahousse Michel , Massy Ziad A ,   the NephroTest Study Group, Vrtovsnik Francois , Daugas Eric , Flamant Martin , Vidal-Petiot Emmanuelle , Jacquot Christian , Karras Alexandre , Thervet Eric , d’Auzac Christian , Houillier P , Courbebaisse M , Eladari D , Maruani G , Ronco Pierre , Fessi H , Rondeau Eric , Tabibzadeh Nahid , Livrozet Marine , Saint-Jacques Camille , Haymann Jean Philippe , Metzger M , Stengel B
Published: May 2020

Background

Chronic kidney disease is associated with a high cardiovascular risk. Compared with glomerular filtration rate–matched CKD patients (CKDps), we previously reported a 2.7-fold greater risk of global mortality among kidney transplant recipients (KTRs). We then examined aortic stiffness [evaluated by carotid–femoral pulse wave velocity (CF-PWV)] and cardiovascular risk in KTRs compared with CKDps with comparable measured glomerular filtration rate (mGFR).

Methods

We analysed CF-PWV in two cohorts: TransplanTest (KTRs) and NephroTest (CKDps). Propensity scores were calculated including six variables: mGFR, age, sex, mean blood pressure (MBP), body mass index (BMI) and heart rate. After propensity score matching, we included 137 KTRs and 226 CKDps. Descriptive data were completed by logistic regression for CF-PWV values higher than the median (>10.6 m/s).

Results

At 12 months post-transplant, KTRs had significantly lower CF-PWV than CKDps (10.1 versus 11.0 m/s, P = 0.008) despite no difference at 3 months post-transplant (10.5 versus 11.0 m/s, P = 0.242). A lower occurrence of high arterial stiffness was noted among KTRs compared with CKDps (38.0% versus 57.1%, P < 0.001). It was especially associated with lower mGFR, older age, higher BMI, higher MBP, diabetes and higher serum parathyroid hormone levels. After adjustment, the odds ratio for the risk of high arterial stiffness in KTRs was 0.40 (95% confidence interval 0.23–0.68, P < 0.001).

Conclusions

Aortic stiffness was significantly less marked in KTRs 1 year post-transplant than in CKDps matched for GFR and other variables. This observation is compatible with the view that the pathogenesis of post-transplant cardiovascular disease differs, at least in part, from that of CKD per se.
Transiently elevated estimated pulmonary pressures in a patient with complete heart block undergoing permanent pacing: a case report
Authors: Harvey Robert , Chong Adrian , Hill John , Korczyk Dariusz
Published: May 2020

Background

Complete heart block (CHB) is a frequent cause for acute admission in older patients with significant cardiac conduction disease. Common presenting symptoms are syncope and dyspnoea. Some patients may exhibit clinical and radiological signs of left ventricular (LV) decompensation, despite preserved LV ejection fraction on transthoracic echocardiography (TTE) and absent pre-existing LV dysfunction.

Case summary

In this clinical report, we present a case of CHB associated with transient but severe elevation in pulmonary artery systolic pressure, measured as the equivalent right ventricular systolic pressure (RVSP = 99 mmHg) by TTE in the absence of right ventricular outflow tract obstruction, that subsequently ‘normalized’ after implantation of a permanent pacemaker. After searching our echocardiogram database, we did find other cases with similar findings.

Discussion

There is limited literature describing transient acute elevation in estimated pulmonary pressures in the setting of new CHB that is subsequently reversed by permanent pacing. The true prevalence and mechanism of transient estimated pulmonary pressure as a result of CHB remains unknown. Based on our limited assessment, we postulate that the acute elevation in estimated pulmonary pressures is predominantly related to a compensatory augmentation of RV stroke volume and is caused by the underlying bradycardia and need to maintain forward cardiac output. This phenomenon may require further investigation and validation in future studies.
Utility of enhanced cardiac magnetic resonance imaging in Kounis syndrome: a case report
Authors: Matta Anthony , Elenizi Khaled , Bouisset Frederic , Roncalli Jerome
Published: May 2020

Background

Kounis syndrome is the occurrence of acute coronary syndrome precipitated by an allergic reaction in the presence or absence of underlying coronary artery disease. The syndrome is explained by the effect of released inflammatory mediators on the coronary arteries and platelets.

Case summary

We report an uncommon case of Kounis syndrome Type II in a 65-year-old man 24 h after being bitten by a hymenoptera. Clinical context, electrocardiogram, coronary angiography, and enhanced cardiac magnetic resonance imaging (MRI) imaging modality are presented.

Discussion

Awareness and understanding of this syndrome is essential for starting early and appropriate therapy, thereby preventing life-threatening events. Accordingly, we highlight the importance of enhanced cardiac MRI to complete the assessment of this entity.
Transcatheter aortic valve implantation facilitated by right common carotid cut-down and innominate artery angioplasty with simultaneous right coronary artery vein graft percutaneous coronary intervention in a patient with mid aortic syndrome: a case report
Authors: Ghobrial Mina S A , Khan Kamal , Baguneid Mohamed , Levy Richard D
Published: May 2020

Background

Transcatheter aortic valve implantation (TAVI) is most commonly performed via the femoral approach. Small caliber ilio-femoral arteries, severe calcification and tortuosity are often prohibitive reasons for TAVI via the femoral approach. Mid-aortic syndrome is a rare condition describing congenital or acquired coarctation of the abdominal aorta.

Case summary

To the best of our knowledge, this case report describes the world’s first TAVI in a patient with mid-aortic syndrome with challenging vascular access that would preclude conventional TAVI access routes. A 76-year-old woman with intermittent claudication, underwent work-up for axillo-bifemoral bypass, underwent a TAVI for incidental severe asymptomatic severe aortic stenosis via right common carotid TAVI facilitated by innominate artery angioplasty achieved vascular access for TAVI. Percutaneous coronary intervention to a right coronary artery vein graft was simultaneously performed via a left brachial artery cut down.

Discussion

We demonstrate that complex angioplasty to coronary artery bypass grafts and the innominate artery alongside TAVI via a variety of arterial access sites is both safe and feasible.
What drives pension reforms in the OECD?
Authors: Beetsma Roel , Klaassen Franc , Romp Ward , van Maurik Ron
Published: May 2020

Based on narrative identification, we construct a novel comprehensive dataset of pension reform measures in OECD countries from 1970 to 2017. We then study the timing of these measures. Our main and new result is that business cycle indicators are important for their timing: a worsening makes contractionary measures more likely and expansionary measures less likely. The demography matters only in the sense that the OECD-wide demography explains the general reform trend for a country. We find no evidence that country-specific or short-run demographic developments matter. We discuss a conceptual framework with adjustment costs of changing pension generosity that can account for both the reform responsiveness to the business cycle and the lack of responsiveness to changes in demographic forecasts. We also discuss potential policy implications of our findings.
Online searching platform for the antibiotic resistome in bacterial tree of life and global habitats
Authors: Zhang An Ni , Hou Chen-Ju , Negi Mishty , Li Li-Guan , Zhang Tong
Published: May 2020

Metagenomic analysis reveals that antibiotic-resistance genes (ARGs) are widely distributed in both human-associated and non-human-associated habitats. However, it is difficult to equally compare ARGs between samples without a standard method. Here, we constructed a comprehensive profile of the distribution of potential ARGs in bacterial tree of life and global habitats by investigating ARGs in 55 000 bacterial genomes, 16 000 bacterial plasmid sequences, 3000 bacterial integron sequences and 850 metagenomes using a standard pipeline. We found that >80% of all known ARGs are not carried by any plasmid or integron sequences. Among potential mobile ARGs, tetracycline and beta-lactam resistance genes (such as tetA, tetM and class A beta-lactamase gene) distribute in multiple pathogens across bacterial phyla, indicating their clinical relevance and importance. We showed that class 1 integrases (intI1) display a poor linear relationship with total ARGs in both non-human-associated and human-associated environments. Furthermore, both total ARGs and intI1 genes show little correlation with the degree of anthropogenicity. These observations highlight the need to differentiate ARGs of high clinical relevance. This profile is published on an online platform (ARGs-OSP, http://args-osp.herokuapp.com/) as a valuable resource for the most challenging topics in this field, i.e. the risk, evolution and emergence of ARGs.
Stress, Adaptation, and the Deep Genome: Why Transposons Matter
Authors: Hunter Richard G
Published: May 2020

Synopsis

Stress is a common, if often unpredictable life event. It can be defined from an evolutionary perspective as a force an organism perceives it must adapt to. Thus stress is a useful tool to study adaptation and the adaptive capacity of organisms. The deep genome, long neglected as a pile of “junk” has emerged as a source of regulatory DNA and RNA as well as a potential stockpile of adaptive capacity at the organismal and species levels. Recent work on the regulation of transposable elements (TEs), the principle constituents of the deep genome, by stress has shown that these elements are responsive to host stress and other environmental cues. Further, we have shown that some are likely directly regulated by the glucocorticoid receptor (GR), one of the two major vertebrate stress steroid receptors in a fashion that appears adaptive. On the basis of this and other emerging evidence I argue that the deep genome may represent an adaptive toolkit for organisms to respond to their environments at both individual and evolutionary scales. This argues that genomes may be adapted for what Waddington called “trait adaptability” rather than being purely passive objects of natural selection and single nucleotide level mutation.
Double Points of Free Projective Line Arrangements
Authors: Abe Takuro
Published: May 2020

We prove the Anzis–Tohăneanu conjecture, that is, the Dirac–Motzkin conjecture for supersolvable line arrangements in the projective plane over an arbitrary field of characteristic zero. Moreover, we show that a divisionally free arrangements of lines contain at least one double point that can be regarded as the Sylvester–Gallai theorem for some free arrangements. This is a corollary of a general result that if you add a line to a free projective line arrangement, then that line has to contain at least one double point. Also, we prove some conjectures and one open problems related to supersolvable line arrangements and the number of double points.
The COVID-19 pandemic: A call to action for health systems in Latin America to strengthen quality of care
Authors: Ezequiel Garcia Elorrio , Jafet Arrieta , Hugo Arce , Pedro Delgado , Ana Maria Malik , Carola Orrego Villagran , Sofia Rincon , Odet Sarabia , Teresa Tono , Jorge Hermida , Enrique Ruelas Barajas
Published: May 2020

The Covid-19 and other recent pandemics has highlighted existing weakness in health systems across the Latin-America and the Caribbean (LAC) region to effectively prepare for and respond to Public Health Emergencies. It has been stated that quality of care will be among the most influential factors on Covid 19 mortality rates and low systems performance is the common case in these countries. More comprehensive and system level strategies are required to address the challenges. These must focus on redesigning and strengthening health systems to make them more resilient to the changing needs of populations and based on quality improvement methods that have shown rigorously evaluated positive effects in previous local and regional experiences. A call to action is being made by the Latin American Consortium for Quality, Patient Safety and Innovation (CLICSS) and they provide specific recommendations for decision makers.
Prognostic value of lymphocyte-to-C-reactive protein ratio in patients with gastric cancer after surgery: a multicentre study
Authors: Cheng Chuan-bing , Zhang Qu-xia , Zhuang Lv-Ping , Sun Jian-wei
Published: May 2020

Objective

The immune inflammation-based score is recognized as a prognostic marker for cancer. However, the most accurate prognostic marker for patients with gastric cancer remains undetermined. We aimed to evaluate the predictive value of the lymphocyte-to-C-reactive protein ratio for outcomes in gastric cancer patients after radical gastrectomy.

Methods

A total of 607 gastric cancer patients treated at three Chinese institutions were included. Receiver operating characteristic curves were generated, and the areas under the curve were calculated to compare the predictive value among the inflammation-based score, lymphocyte-to-C-reactive protein ratio, C-reactive protein/albumin and neutrophil-lymphocyte, platelet-lymphocyte and lymphocyte-monocyte ratios. Cox regression was performed to determine the prognostic factors for overall survival.

Results

The median follow-up time was 63 months (range: 1–84 months). The optimal cut-off value for lymphocyte-to-C-reactive protein ratio was 0.63. The patients were divided into the LCR <0.63 (LLCR, n = 294) group and the LCR ≥0.63 (HLCR, n = 313) group. LLCR was significantly correlated with poor clinical characteristics. Compared with inflammation-based score, lymphocyte-to-C-reactive protein ratio had the highest areas under the curve (0.695). Patients with LLCR experienced more post-operative complications than the HLCR group (20.4 vs. 12.1%, P = 0.006). Multivariate analysis showed that a higher lymphocyte-to-C-reactive protein ratio (HR: 0.545, 95%CI: 0.372–0.799, P = 0.002) was associated with better overall survival. The HLCR group had higher 5-year overall survival rate than the LLCR group (80.5 vs. 54.9%, P < 0.001).

Conclusions

Preoperative lymphocyte-to-C-reactive protein ratio levels can effectively predict the short-term and oncological efficacy of gastric cancer patients after radical gastrectomy with a predictive value significantly better than other inflammation-based score.
Successful use of ligamentum teres hepatis for perforated duodenal ulcer following omentectomy: a case report
Authors: Takahashi Yusuke , Kobayashi Akira , Seki Hitoshi
Published: May 2020

Our patient was a 59-year-old woman with past history of hysterectomy, bilateral salpingo-oophorectomy, regional lymphadenectomy and omentectomy performed for advanced ovarian cancer. She was experiencing abdominal pain over the past 2 days and visited our hospital owing to pain exacerbation. Contrast-enhanced computed tomography revealed free air around the liver, ascites and duodenal perforation; thus, emergent abdominal surgery was performed. The 5-mm duodenal perforation at the anterior wall of the duodenal bulb was sutured with absorbable thread. We used ligamentum teres hepatis (LTH) as a patch for the sutured site as the greater omentum could not be used. The postoperative course was uneventful, and she was discharged on postoperative Day 8. There were no complications 1 month after surgery. Although the greater omentum is conventionally used for upper gastrointestinal perforation, the LTH was a plausible alternative with good indication in our case.
Estimating the Population Health Impact of Recently Introduced Modified Risk Tobacco Products: A Comparison of Different Approaches
Authors: Lee Peter N , Abrams David , Bachand Annette , Baker Gizelle , Black Ryan , Camacho Oscar , Curtin Geoffrey , Djurdjevic Smilja , Hill Andrew , Mendez David , Muhammad-Kah Raheema S , Murillo Jose Luis , Niaura Raymond , Pithawalla Yezdi B , Poland Bill , Sulsky Sandra , Wei Lai , Weitkunat Rolf
Published: May 2020

Introduction

Various approaches have been used to estimate the population health impact of introducing a Modified Risk Tobacco Product (MRTP).

Aims and Methods

We aimed to compare and contrast aspects of models considering effects on mortality that were known to experts attending a meeting on models in 2018.

Results

Thirteen models are described, some focussing on e-cigarettes, others more general. Most models are cohort-based, comparing results with or without MRTP introduction. They typically start with a population with known smoking habits and then use transition probabilities either to update smoking habits in the “null scenario” or joint smoking and MRTP habits in an “alternative scenario”. The models vary in the tobacco groups and transition probabilities considered. Based on aspects of the tobacco history developed, the models compare mortality risks, and sometimes life-years lost and health costs, between scenarios. Estimating effects on population health depends on frequency of use of the MRTP and smoking, and the extent to which the products expose users to harmful constituents. Strengths and weaknesses of the approaches are summarized.

Conclusions

Despite methodological differences, most modellers have assumed the increase in risk of mortality from MRTP use, relative to that from cigarette smoking, to be very low and have concluded that MRTP introduction is likely to have a beneficial impact. Further model development, supplemented by preliminary results from well-designed epidemiological studies, should enable more precise prediction of the anticipated effects of MRTP introduction.

Implications

There is a need to estimate the population health impact of introducing modified risk nicotine-containing products for smokers unwilling or unable to quit. This paper reviews a variety of modeling methodologies proposed to do this, and discusses the implications of the different approaches. It should assist modelers in refining and improving their models, and help toward providing authorities with more reliable estimates.
Water Politics in Asia
Authors: Xie Lei
Published: May 2020

Transboundary water courses abound in Asia, which is experiencing risks with regards to the use of water and the sustainability of water ecology. Many of the Asian states are facing growing pressures to react to global change, with a high level of both poverty and population growth. Asia’s water politics have been explored from a range of perspectives, reflecting the complicated discourses, processes, and narratives when the global South respond to water-related challenges. Within these nations, the low economic development level and the underdevelopment of key democratic institutions as well as limited knowledge in water management have posed challenges to the region to setting up efficient institutional arrangements to promote sustainable development. The geographical conditions make the sharing of international rivers more complicated. Large-scale rivers are often found to run through a number of countries, resulting in each state possessing asymmetric interests in the shared water resources. Vulnerability in the river basin is often unevenly spread among riparian states, adding to the difficulty of countries’ peacefully resolving tensions over the shared water resources. Moreover, regional security in South Asia is considered to be unstable and rapidly changing. Some international rivers run near national borders, complicating the existing border disputes in some places. Questions are raised if the region has developed strong resilience when faced with water-related risks such as water scarcity and degradation.
Educational Policy and Race
Authors: Stewart Mahala Dyer
Published: May 2020

Policies are crucial for understanding the way that racial inequalities persist within contemporary society. Educational policies include those official and unofficial guidelines that are developed by policymakers, school administrators, and educators to influence the way that schools both directly and indirectly provide education to students. In the United States, these policies include a variety of state and federal laws and regulations that govern students’ pre-kindergarten, primary (K–8), and secondary schooling (high school), as well as policies affecting higher education (college and beyond). Scholars studying education show that examining how policies are created—who creates it and for what purpose—and also how the policy is put into practice at the state and district level is crucial for understanding inequalities. This entry focuses on K–12 educational policy and race in the United States. More specifically, the focus is primarily on influential policies in schools since the 1954 Brown vs. Board of Education decision, with particular attention on two crucial types of race-based educational policy: desegregation and school choice programs. There are many other educational policies not addressed here that could be examined for their influence in racial schooling inequities. This piece focuses on K–12 educational policies, but policies related to race in pre-K as well as institutions of higher education are also areas in which educational policies are impacted by race relations. Examining those formal and informal guidelines for the way that they shape children’s schooling is crucial for understanding how racial inequalities persist within contemporary society. As a practice of power, education policy has the potential to be used as a tool for positive social change and disrupt white supremacy within the context of schooling. Yet doing so requires first recognizing the way that race and racism have been written into school policies.
Alaska Native Education
Authors: Hyslop Polly , Leonard Beth
Published: May 2020

This bibliography presents foundational studies in Alaska Native education, as well as more current articles, book chapters, dissertations, media sources, and other key resources that explore Alaska Native education from the precolonization era to the present. As there have been a number of publications about Alaska Natives, rather than with and for Alaska Natives, this bibliography privileges Alaska Native voices and scholarship. Although Alaska Natives are often grouped with American Indian peoples in educational statistical analyses, the contexts of these groups are distinct with historical and current challenges that, although not completely dissimilar, diverge in significant ways. Currently Alaska Native students represent 22 percent of the total K-12 population in Alaska (Alaska Department of Education & Early Development,), and 16 percent of all students enrolled in the University of Alaska system. Education continues to be a priority for Alaska Native organizations and communities. Current issues include low numbers of Alaska Native teachers and appropriate Indigenous teacher preparation, high teacher turnover, and Alaska Native retention and graduation rates in K-12 and higher education. As well, many scholars seek to reorient ideologies around academic “success” beyond diplomas and degrees (Barnhardt and Kawagley 2010; Barnhardt and Kawagley 2011). Many sources in this bibliography envision the potential for Alaska Native education, diverging from the discourses of Alaska Native student failure[s]; rather, these sources focus on how K-12 and higher education institutions might be better prepared to serve these students. Bibliography categories are broad in scope and there is significant thematic overlap among the sources. Websites with significant content on Alaska Native education include the Alaska Native Knowledge Network and Alaskool. In addition, there are a number of locally based curriculum initiatives by Alaska Native teacher organizations, including the Association of Interior Native Educators who have developed culturally based curriculum units, teacher resource books, and learning styles videos.
Peer Victimization and Bullying in Childhood and Adolescence
Authors: Schmidt Michelle , Bagwell Catherine
Published: May 2020

Given the wide-reaching implications of peer bullying and victimization for children and adolescents as well as increasing public attention to this topic, research in this area has grown during the late 20th and early 21st centuries. Beginning with efforts in Norway in the 1970s, research on bullying and victimization has expanded to include an abundance of research in the United States, Canada, Europe, Australia, and other countries. Regardless of geographic area, important targets of research include defining the constructs (e.g., what is aggression and when does it become bullying or victimization behavior? Are there bullying or victimization behaviors that are more characteristic of males or females?) and understanding the degree to which the problem affects youth (e.g., What are prevalence rates for preschoolers versus school-aged children versus adolescents?). Some studies distinguish between physical or overt forms and social or relational forms of bullying and victimization, but others include measures of general bullying and victimization that do not distinguish among different types. Even with more agreement on definitions, researchers still use different methodologies and measures to study bullying and victimization. A fundamental goal of much of the research literature is to identify predictors and consequences of both bullying and victimization. The correlates and predictors of bullying and victimization exist within multiple contexts and can be grouped into several categories, such as Individual-Level Risk Factors, Family- and Home-Level Risk Factors, Social-Level Risk Factors, and School-Level Risk Factors. Considerable attention has been given to Internalizing Distress and externalizing behavior problems as key outcomes or consequences of bullying and victimization. In addition, other consequences include peer problems and school-related problems. Both cross-sectional and longitudinal studies explore these topics, and a number of useful review articles and meta-analyses provide additional evidence. As researchers have considered more complex models involving risk factors and outcomes associated with bullying and victimization, many have focused on identifying protective factors that might moderate the link between risk factors and victimization or that might function as a buffer against negative outcomes associated with victimization and bullying. Friendship is one such moderator variable with considerable evidence that it disrupts both of these links. The ultimate goal of much of the research on bullying and victimization is to inform the development of effective prevention and intervention efforts. With regard to intervention, research efforts are most often school-based with objectives that include, for example, reducing bullying behaviors, empowering victims, educating teachers, and effectively engaging bystanders.
Transfer of Sciatic Nerve Motor Branches in High Femoral Nerve Injury: A Cadaver Feasibility Study and Clinical Case Report
Authors: Chen Huihao , Meng Depeng , Xie Zheng , Yin Gang , Hou Chunlin , Lin Haodong
Published: May 2020

BACKGROUND

Femoral nerve injury causes knee dysfunction, and high femoral nerve injury is difficult to repair.

OBJECTIVE

To evaluate the anatomic feasibility of transferring the sciatic nerve motor branches in high femoral nerve injury.

METHODS

The femoral nerve was exposed in both lower extremities of 3 adult fresh-frozen cadavers; each branch was noninvasively dissected to its proximal nerve fiber intersection point and distal muscle entry point. The branches of the sciatic nerve were also exposed. The length, diameter, and number of myelinated fibers were measured in each femoral and sciatic nerve branch. The feasibility of tension-free direct suture between the femoral and sciatic nerve branches was evaluated. One patient was treated with transfer of a nerve branch innervating the semitendinosus muscle to the femoral nerve branch and was followed up for 18 mo.

RESULTS

The diameters and numbers of myelinated fibers in the femoral nerve branches matched those of the sciatic nerve branches. In the single patient, a combined femoral nerve bundle (comprising the rectus femoris and vastus lateralis branches) was used as a graft. The branch of the sciatic nerve was sutured with the muscle branch of the femoral by using a sural nerve as a nerve graft. The knee joint straightening strength reached medical research council grade 4+.

CONCLUSION

The proximal motor branches of the sciatic nerve may be transferred as donor nerves to repair high femoral nerve injury. A femoral nerve bundle comprising the rectus femoris and vastus lateralis branches may be used as the receptor nerve.
Probing cosmic rays with Fe Kα line structures generated by multiple ionization process
Authors: Okon Hiromichi , Imai Makoto , Tanaka Takaaki , Uchida Hiroyuki , Tsuru Takeshi Go
Published: May 2020

Supernova remnants (SNRs) have been regarded as major acceleration sites of Galactic cosmic rays. Recent X-ray studies revealed neutral Fe Kα line emission from dense gas in the vicinity of some SNRs, which can be best interpreted as K-shell ionization of Fe atoms in the gas by sub-relativistic particles accelerated in the SNRs. In this Letter, we propose a novel method of constraining the composition of particles accelerated in SNRs, which is currently unknown. When energetic heavy ions collide with target atoms, their strong Coulomb field can easily cause simultaneous ejection of multiple inner-shell electrons of the target. This results in shifts in characteristic X-ray line energies, forming distinctive spectral structures. Detection of such structures in the neutral Fe Kα line strongly supports the particle ionization scenario, and furthermore provides direct evidence of heavy ions in the accelerated particles. We construct a model for the Fe Kα line structures by various projectile ions utilizing atomic-collision data.
Alcohol consumption is associated with a later need for ICU admission: a Northern Finland Birth Cohort 1966—study
Authors: Hietanen Siiri , Kaakinen Timo , Ala-Kokko Tero , Herajärvi Johanna , Auvinen Juha , Niittyvuopio Miikka , Liisanantti Janne
Published: May 2020

Background

Alcohol-related problems are common in intensive care unit (ICU) admitted patients. The aim of the present study is to assess the impact of alcohol consumption on the need of intensive care in 19 years follow-up period.

Methods

The study population consists of Northern Finland Birth Cohort 1966 participants, who responded alcohol-related questions at 31 years of age and Intensive Care Unit (ICU admissions from 1997 to 2016.

Results

There were a total of 8379 assessed people and 136 (1.6%) of them were later admitted to ICU. A total of 44 (32.4%) of the ICU-admitted persons had their alcohol consumption at the highest quartile of the cohort (P = 0.047). These patients had a lower number of malignancy-related admissions (3.6% versus 14.0%, P = 0.027), neurological admissions (14.3 versus 30.6%, P = 0.021), and were more often admitted due to poisonings (12.5% versus 5.0%, P = 0.07). There were no differences in 28-day post-ICU mortality but long-term mortality of ICU-admitted patients with lower alcohol consumption was higher than non–ICU-admitted population.

Conclusion

Among ICU-admitted population, there was higher alcohol consumption at age of 31 years. People in the lower alcohol consumption quartiles were more often admitted to ICU due to malignancy-related causes and they had higher long-term mortality.
0006 The Role of Stress in Sleep in Night Shift Workers: Going Beyond Circadian Misalignment
Authors: Schaap E , Sagong C , Cuamatzi Castelan A S , Sayed J , Roth T , Drake C L , Cheng P
Published: May 2020

Introduction

Despite a growing need for nighttime work, few studies have characterized the causes of sleep disturbance in night shift workers beyond circadian misalignment. Recent research suggest that high sleep reactivity to stress (a predisposition for sleep disturbance due to stress) may also lead to sleep difficulties in shift workers. This study investigated if sleep reactivity is an independent predictor of daytime sleep disturbances after controlling for circadian phase.

Methods

Night shift workers (N= 48) completed an 8 hour polysomnography (PSG) during the daytime following a night shift (9am - 4pm). Circadian phase was measured using melatonin assays of saliva samples collected over 24 hours under dim light (<10 lux; Dim Light Melatonin Onset [DLMO]). Sleep reactivity was measured using the Ford Insomnia Response to Stress Test (FIRST). Linear regressions were conducted with PSG sleep parameters as outcome variables: difficulty falling asleep (Sleep Onset Latency [SOL] and Latency to Persistent Sleep [LPS]), difficulty staying asleep (Wake After Sleep Onset [WASO]), and sleep duration (Total Sleep Time [TST]). FIRST was tested as a predictor controlling for DLMO.

Results

After controlling for circadian phase, higher FIRST scores was associated with more difficulty staying asleep (WASO: t[45]=4.059, p<0.001) and shorter sleep duration (TST: t[45] = -4.403, p<0.0001), but not predictive of difficulty falling asleep (SOL: p>0.05). However, higher FIRST scores did predict a longer latency to persistent sleep (LPS: t[45]=2.272, p<0.05).

Conclusion

These results suggest that sleep reactivity to stress and circadian misalignment are independent processes that are both associated with disrupted daytime sleep in night shift workers. Given that night shift work can also cause psychosocial stress, treatments focused on circadian misalignment alone may not be sufficient. Our study highlights the need to consider sleep reactivity in the clinical management of shift work disorder.

Support

Support for this study was provided to PC by NHLBI (K23HL138166).
0012 REM Sleep in Ostrich Chicks
Authors: Lyamin O , Borshenko V , Bakhchina A , Siegel J
Published: May 2020

Introduction

It was reported that adult ostriches displayed the longest REM sleep episodes (up to 5 min) and more REM sleep (24% of the nighttime) than any other avian species. In all mammals studied so far REM sleep predominates at early age suggesting it promotes development of the brain. The aim of this study was to examine REM sleep in ostrich chicks.

Methods

EEG, electrooculogram and electromyogram of the neck muscles were recorded in 4 chronically implanted 2–3 month old ostrich chicks over 3 nights. The last night was scored in 4-sec epochs for waking, nonREM and REM sleep.

Results

NonREM sleep and REM sleep in the ostrich chicks occurred when they were sitting or lying with the head held above the ground or rested on the ground. REM sleep was characterized by distinct rapid eye movements, head drops and eye closure. The amplitude of the EEG during episodes of REM sleep ranged between low voltage EEG, as recorded during quiet waking and high voltage slow waves, as recorded during nonREM sleep EEG. The ostrich chicks spent on average 70.7 + 2.2% of the nighttime in nonREM sleep and 12.3 + 3.9% in REM sleep. The episodes of REM sleep lasted on average 9 + 1 sec and ranged between 4 and 36 sec.

Conclusion

Similar to adult birds, 2–3 mo old ostrich chicks displayed a “mixed” sleep state which has features of both slow wave sleep / nonREM and REM sleep, as we have described in the platypus and echidna. An unexpected result of this study is the total amount and duration of episodes of REM were considerably smaller than has been reported in adult ostriches. More studies need to be done on the developmental and environmental determinants of REM sleep in the ostrich.

Support

The Russian Foundation for Basic Research (18-04-01252) and HL148574