bluuebunny/crossref_metadata_2025 huggingface dataset:
Functionalized Multiwalled Carbon Nanotube-Reinforced Polyimide Composite Films with Enhanced Mechanical and Thermal Properties
Authors: Chao Min , Li Yanming , Wu Guanglei , Zhou Zhenjun , Yan Luke
Published: August 2019

Polyimide- (PI-) based nanocomposites containing the 4,4′-diaminodiphenyl ether- (ODA-) modified multiwalled carbon nanotube (MWCNT) filler were successfully prepared. The PI/MWCNTs-ODA composite films exhibit high thermal conductivity and excellent mechanical property. The optimal value of thermal conductivity of the PI/MWCNTs-ODA composite film is 0.4397 W/mK with 3 wt.% filler loading, increased by 221.89% in comparison with that of the pure PI film. In addition, the tensile strength of the PI/MWCNTs-ODA composite film is 141.48 MPa with 3 wt.% filler loading, increased by 20.74% in comparison with that of the pure PI film. This work develops a new strategy to achieve a good balance between the high thermal conductivity and excellent mechanical properties of polyimide composite films by using functionalized carbon nanotubes as an effective thermal conductive filler.
Nonsyndromic Examples of Odontogenic Keratocysts: Presentation of Interesting Cases with a Literature Review
Authors: Hadziabdic Naida , Dzinovic Eda , Udovicic-Gagula Dalma , Sulejmanagic Nedim , Osmanovic Ahmed , Halilovic Sabina , Kurtovic-Kozaric Amina
Published: August 2019

The odontogenic keratocyst (OKC) may occur at any age. However, it mostly occurs during the second and third decades of life. Compared to other odontogenic cysts, this type occurs with a frequency of 5-15%. It is more common in the mandible region and in the male sex. Histologically, odontogenic keratocysts are characterized by the presence of an external connective tissue capsule, with keratinizing lining of the epithelium consisting of 5-8 cell layers with marked palisadisation of polarized basal cells and a corrugated parakeratin layer. The objective of this study is to present cases of odontogenic keratocysts, with reference to the latest classification and dilemmas in therapeutic doctrine. This project was realized in the form of descriptive studies, specifically in a series of cases. A collection of four individual cases was found at the Department of Oral Surgery. Due to the proper approach towards diagnosis, adequate and detailed histopathological analysis, and suitable therapeutic procedures, all cases of odontogenic keratocysts were successfully treated without complications. Enucleation of OKC, with a regular follow-up, proved to be the effective therapeutic choice for the patients described in this paper. Only in the case of recurrence would we consider other therapeutic options, primarily enucleation in combination with Carnoy’s solution.
Design of Multilayer Frequency-Selective Surfaces by Equivalent Circuit Method and Basic Building Blocks
Authors: Xu Yuan , He Mang
Published: August 2019

An equivalent circuit method (ECM) is proposed for the design of multilayer frequency-selective surfaces (FSSs). In contrast to the existing ECMs that were developed mainly for the analysis of the properties of a given FSS, the presented ECM aims at providing the initial design parameters of an FSS from the desired frequency response. In this method, four types of basic FSS structures are used as the building blocks to construct the multilayer FSSs, and their surface impedances in both the normal- and the oblique-incidence situations are studied in detail in order to achieve more accurate equivalent circuit (EC) representation of the entire FSS. For a general FSS design with expected frequency response, the EC parameters and the geometrical sizes of the required basic building blocks can be synthesized from a few typical S-parameter (S11/S12) samplings of the response curves via a simple least-square curve-fitting process. The effectiveness and accuracy of the method are shown by the designs of a band-pass FSS with steep falling edge and a miniaturized band-pass FSS with out-of-band absorption. The prototype of one design is fabricated, and the measured frequency response agrees well with the numerical results of the ECM and the full-wave simulations.
The Immunoscore: Colon Cancer and Beyond
Authors: Angell Helen K. , Bruni Daniela , Barrett J. Carl , Herbst Ronald , Galon Jérôme
Published: August 2019

Tumors evolve in close interaction with their microenvironment, which encompasses a continual tension between the developing tumor and the host immune system. Clinical trials have shown that appropriate enhancement of a tumor immune response can lead to long-lasting clinical responses and patient benefit. Understanding the contribution of the immune contexture, in addition to the molecular subtype across different tumor indications, is a significant knowledge gap with limited sagacity to drive rational immunotherapy combinations. To better inform clinical studies, we must first strive to understand the multifaceted elements of the tumor-immune interaction, the spatiotemporal interplay of numerous different immune cell types, in conjunction with an understanding of the oncogenic drivers and mutations that may lead to presentation of neoepitopes and could drive changes within the tumor microenvironment. In this review, we discuss the Immunoscore and its probable universal characteristic. The overlay of immune quantification with the molecular segments of disease and how this may benefit identification of patients at high risk of tumor recurrence will be discussed. The Immunoscore may translate to provide a tumor agnostic method to define immune fitness of a given tumor and predict and stratify patients who will benefit from certain therapies (in particular immune therapies) and, ultimately, help save the lives of patients with cancer.
Combination of Metformin and Gefitinib as First-Line Therapy for Nondiabetic Advanced NSCLC Patients with EGFR Mutations: A Randomized, Double-Blind Phase II Trial
Authors: Li Li , Jiang Liyan , Wang Yubo , Zhao Yizhuo , Zhang Xiao-Ju , Wu Guoming , Zhou Xiangdong , Sun Jianguo , Bai Jun , Ren Biyong , Tian Kun , Xu Zhi , Xiao Hua-liang , Zhou Qi , Han Rui , Chen Hengyi , Wang Haidong , Yang Zhenzhou , Gao Chan , Cai Shangli , He Yong
Published: August 2019

Purpose:

Preclinical and retrospective studies suggested a role for metformin in sensitizing patients who have diabetes with non–small cell lung cancer (NSCLC) to EGFR tyrosine kinase inhibitors (TKIs). We therefore examined its effects in combination with gefitinib in patients without diabetes harboring EGFR mutations (EGFRm).

Patients and Methods:

A total of 224 patients without diabetes with treatment-naïve stage IIIB–IV EGFRm NSCLC were randomly assigned in a 1:1 ratio to receive gefitinib plus either metformin or placebo. The primary endpoint was progression-free survival (PFS) rate at 1 year and secondary endpoints included overall survival (OS), PFS, objective response rate (ORR), and safety. Serum levels of IL6 were also examined in an exploratory analysis.

Results:

The median duration of follow-up was 19.15 months. The estimated 1-year PFS rates were 41.2% [95% confidence interval (CI), 30.0–52.2] with gefitinib plus metformin and 42.9% (95% CI, 32.6–52.7) with gefitinib plus placebo (P = 0.6268). Median PFS (10.3 months vs. 11.4 months) and median OS (22.0 months vs. 27.5 months) were numerically lower in the metformin group, while ORRs were similar between the two arms (66% vs. 66.7%). No significant treatment group differences were detected across all subgroups with respect to PFS, including those with elevated levels of IL6. Metformin combined with gefitinib resulted in a remarkably higher incidence of diarrhea compared with the control arm (78.38% vs. 43.24%).

Conclusions:

Our study showed that addition of metformin resulted in nonsignificantly worse outcomes and increased toxicity and hence does not support its concurrent use with first-line EGFR-TKI therapy in patients without diabetes with EGFRm NSCLC.
Antitumor Activity and Mechanistic Characterization of APE1/Ref-1 Inhibitors in Bladder Cancer
Authors: Fishel Melissa L. , Xia Hanyu , McGeown Jack , McIlwain David W. , Elbanna May , Craft Ariel A. , Kaimakliotis Hristos Z. , Sandusky George E. , Zhang Chi , Pili Roberto , Kelley Mark R. , Jerde Travis J.
Published: August 2019

Bladder cancer is the ninth most common cause of cancer-related deaths worldwide. Although cisplatin is used routinely in treating bladder cancer, refractory disease remains lethal for many patients. The recent addition of immunotherapy has improved patient outcomes; however, a large cohort of patients does not respond to these treatments. Therefore, identification of innovative molecular targets for bladder cancer is crucial. Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein involved in both DNA repair and activation of transcription factors through reduction–oxidation (redox) regulation. High APE1/Ref-1 expression is associated with shorter patient survival time in many cancer types. In this study, we found high APE1/Ref-1 expression in human bladder cancer tissue relative to benign urothelium. Inhibition of APE1/Ref-1 redox signaling using APE1/Ref-1–specific inhibitors attenuates bladder cancer cell proliferation in monolayer, in three-dimensional cultures, and in vivo. This inhibition corresponds with an increase in apoptosis and decreased transcriptional activity of NF-κB and STAT3, transcription factors known to be regulated by APE1/Ref-1, resulting in decreased expression of downstream effectors survivin and Cyclin D1 in vitro and in vivo. We also demonstrate that in vitro treatment of bladder cancer cells with APE1/Ref-1 redox inhibitors in combination with standard-of-care chemotherapy cisplatin is more effective than cisplatin alone at inhibiting cell proliferation. Collectively, our data demonstrate that APE1/Ref-1 is a viable drug target for the treatment of bladder cancer, provide a mechanism of APE1/Ref-1 action in bladder cancer cells, and support the use of novel redox-selective APE1/Ref-1 inhibitors in clinical studies.

Significance:

This work identifies a critical mechanism for APE1/Ref-1 in bladder cancer growth and provides compelling preclinical data using selective redox activity inhibitors of APE1/Ref-1 in vitro and in vivo.
Lenalidomide Augments the Antitumor Activities of Eps8 Peptide-Specific Cytotoxic T Lymphocytes against Multiple Myeloma
Authors: Xie Xiaoling , Chen Yiran , Hu Yuxing , He Yanjie , Zhang Honghao , Li Yuhua
Published: August 2019

Cancer immunotherapy is a promising new approach to cancer treatment. It has been demonstrated that a high number of tumor-specific cytotoxic T cells (CTL) is associated with increased survival in patients with multiple myeloma. Here, we focused on EGFR pathway substrate 8 (Eps8) as a candidate tumor-associated antigen (TAA) in multiple myeloma. Previous work has shown that Eps8-based immunotherapy in HLA-A2+ cancer patients may result in efficient antitumor immune responses against diverse tumor types. To improve immunotherapy for patients with multiple myeloma, we constructed a cocktail vaccine by combining several HLA-A2–restricted epitopes derived from Eps8 (Eps8cocktail), including Eps8101-2L (WLQDMILQV), Eps8276-1Y9V (YLDDIEFFV), and Eps8455-1Y (YLAESVANV). The CTLs induced by Eps8cocktail (Eps8cocktail-CTLs) showed highly effective anti–multiple myeloma activity, including Th1 cytokines production, cell proliferation, and cytotoxicity against HLA-A2+ multiple myeloma cells. This study highlights the importance of using a cocktail vaccine instead of a single-peptide vaccine to induce a robust response. Importantly, we revealed that lenalidomide effectively stimulated the antitumor activity of the Eps8cocktail-CTLs, with increasing expression trends for T-cell markers (CD28, CD40L, 41BB, and OX40). Compared with unstimulated CTLs and Eps8cocktail-CTLs, lenalidomide-treated Eps8cocktail-CTLs showed superior anti–multiple myeloma activity in humanized multiple myeloma models, including delaying tumor burden increases due to enhanced immune function. These results provide the framework for an Eps8 cocktail vaccination therapy to induce effective Eps8-specific CTLs in HLA-A2+ patients with multiple myeloma. Moreover, these studies further demonstrate that lenalidomide augments the immune response, providing a possibility for its use in combination with peptide vaccines to improve patient outcomes.
Overweight Proxies Are Associated with Atopic Asthma: A Matched Case–Control Study
Authors: Gramss Manuela , Lipek Tobias , Vogel Mandy , Remmler Johannes , Hiemisch Andreas , Jurkutat Anne , Genuneit Jon , Körner Antje , Kiess Wieland
Published: August 2019

Background: Many studies have documented a link between overweight and asthma in children with contradictory results regarding the best way to measure overweight. Moreover, often, the dynamic development of atopy, overweight, and asthma is controlled for age dependency insufficiently. Objective: This study assesses and compares the associations of overweight measured as waist circumference, waist to height ratio (WHtR), neck circumference, and body mass index with the occurrence of asthma – best possibly controlling for age-dependencies of these parameters. Methods: From a sample of 2,511 children aged 6–17 years, we matched 157 children with asthma with 2 controls (n = 471) according to age and atopy status and performed conditional logistic regression analyses. We further investigated the role of known influencing factors of asthma occurrence. Results: In children with atopy, all overweight proxies were consistently positively associated with asthma. Statistical significance was reached for WHtR-SD score (OR 1.26, 95% CI 1.03–1.54, p = 0.025) and persisted when further covariates, such as birth weight or social status, were added to the model. Groups of atopic versus nonatopic participants do not differ in levels of interleukin-6 or high-sensitivity C-reactive protein. Conclusion: In our cohort, overweight seems to carry a risk for asthma only if accompanied with atopy. We call for more strict age matching in pediatric cohort studies and longitudinal studies for a better understanding for causal links of overweight, atopy, and asthma.
Soluble Receptor for Advanced Glycation End Products and Its Correlation with Vascular Damage in Adolescents with Obesity
Authors: Rodríguez-Mortera Reyna , Luevano-Contreras Claudia , Solorio-Meza Sergio , Gómez-Ojeda Armando , Caccavello Russell , Bains Yasmin , Gugliucci Alejandro , Garay-Sevilla Ma. Eugenia
Published: August 2019

Objective: The aim of this study was to evaluate soluble receptor for advanced glycation end products (sRAGE) and advanced glycation end products (AGEs) in adolescents with and without obesity (OB) and their correlation with vascular damage. Methods: This is a cross-sectional study with 15–19 years old adolescents: 33 with OB and 33 with normal weight (NW), each group included 17 male and 16 female. Lipid profile, insulin, carboxymethylysine (CML), sRAGE, total AGEs, and dietary AGEs intake (dAGEs) were evaluated. Vascular damage was measured by flow-mediated vasodilation (FMD) and arterial stiffness index (Iβ). Homeostatic model assessment-insulin (HOMA-IR) and atherogenic index (AI) were calculated. Results: The group with OB had higher triglycerides (TG; p < 0.0001), AI (p < 0.001), HOMA-IR (p < 0.0001), dAGEs intake (p < 0.0001), lower CML (p = 0.05), total AGEs (p < 0.01), sRAGE (p < 0.001), and FMD (p < 0.002). In the total group, sRAGE correlated with AI (r = –0.26 p = 0.037); in the NW group, CML correlated with Iβ (r = –0.36; p = 0.037); and in the group of adolescents with OB, sRAGE correlated with FMD (r = –0.37; p = 0.037) and Iβ (r = 0.47; p = 0.006), while CML and total AGEs correlated with AI, p = 0.007 and p < 0.01, respectively). Conclusions: The group of adolescents with OB showed higher cardiometabolic risk as shown by higher TG, AI, HOMA-IR, and lower sRAGE and FMD. sRAGE correlated negatively with FMD and positively with Iβ, so it could be suggested as a biochemical marker of impaired endothelial function.
Association Between Baseline, Achieved, and Reduction of CRP and Cardiovascular Outcomes After LDL Cholesterol Lowering with Statins or Ezetimibe: A Systematic Review and Meta‐Analysis
Authors: Zhang Xin‐Lin , Lan Rong‐Fang , Zhang Xiao‐Wen , Xu Wei , Wang Lian , Kang Li‐Na , Xu Biao
Published: August 2019

Background

Several lipid‐lowering therapies reduce CRP (C‐reactive protein) independently of LDL‐C (low‐density lipoprotein cholesterol) reduction, but the association between
CRP
parameters and benefits from more‐intensive
LDL
‐C lowering is inconclusive. We aimed to determine whether the benefits of more‐ versus less‐intensive
LDL
‐C lowering on cardiovascular events related to baseline, achieved, or magnitude of reduction in
CRP
concentrations.

Methods and Results

PubMed,
EMBASE
, and Cochrane were searched through July 2, 2018. We included randomized controlled cardiovascular outcome trials of
LDL
‐C lowering with statins or ezetimibe. Two reviewers independently extracted study data and rated study quality. Data were analyzed using meta‐analysis and metaregression analysis. Rate ratios of mortality and cardiovascular outcomes associated with baseline, achieved, and magnitude reduction of
CRP
concentration were calculated. Twenty‐four trials were included, with 171 250 patients randomly assigned to more‐ or less‐intensive
LDL
‐C–lowering treatments. Median follow‐up duration was 4.2 years. More‐intensive
LDL
‐C lowering resulted in a significant reduction in incidences of all outcomes. Compared with less‐intensive
LDL
‐C lowering, more‐intensive
LDL
‐C lowering was associated with less reductions in myocardial infarction with a higher baseline
CRP
concentration (change in rate ratios per 1‐mg/L increase in log‐transformed
CRP
, 1.12 [95%
CI
, 1.04–1.22;
P
=0.007]), but not other outcomes. Similar risk reductions occurred for more‐ versus less‐intensive
LDL
‐C–lowering therapy regardless of the magnitude of
CRP
reduction or the achieved
CRP
level for all outcomes.

Conclusions

Baseline
CRP
concentrations might be associated with the benefits of
LDL
‐C lowering on myocardial infarction, but no other outcomes, whereas the achieved and magnitude of reduction in
CRP
did not seem to have an important association.
Stroke Mechanisms in Symptomatic Intracranial Atherosclerotic Disease
Authors: Feng Xueyan , Chan Ka Lung , Lan Linfang , Abrigo Jill , Liu Jia , Fang Hui , Xu Yuming , Soo Yannie , Leng Xinyi , Leung Thomas W.
Published: August 2019

Background and Purpose—

In patients with symptomatic intracranial atherosclerotic stenosis, identifying the underlying stroke mechanisms may inform secondary prevention. We aimed to propose reproducible classification criteria for stroke mechanisms based on routine neuroimaging in symptomatic intracranial atherosclerotic stenosis and explore their clinical implications.

Methods—

We recruited patients with acute ischemic stroke attributed to 50% to 99% intracranial atherosclerotic stenosis in anterior circulation from 2 centers. Two investigators independently classified probable stroke mechanisms as parent artery atherosclerosis occluding penetrating artery, artery-to-artery embolism, hypoperfusion, and mixed mechanisms, with prespecified criteria based on infarct topography and magnetic resonance/computed tomography angiography. These stroke mechanisms were correlated with features of the patients at baseline and recurrent ischemic stroke in the same territory or relevant transient ischemic attack within 1 year.

Results—

Among 153 patients recruited, the most common stroke mechanisms were isolated hypoperfusion (35.3%) and mixed mechanism of artery-to-artery embolism and hypoperfusion (37.3%) that was associated with higher incidence of dyslipidemia (
P
=0.045) and hypertension (
P
=0.033) than patients with other stroke mechanisms. The proposed criteria showed substantial to excellent intrarater and interrater reproducibilities (κ, 0.791–0.908). Overall, 31 patients received interventional treatment of the diseased intracranial artery; 122 received medical treatment, among whom a mixed mechanism of artery-to-artery embolism and hypoperfusion at baseline was associated with higher risk of ischemic stroke in the same territory within 1 year (24.4% versus 7.8%; hazard ratio, 3.40; 95% CI, 1.25–9.20; log-rank
P
=0.010) than other mechanisms combined.

Conclusions—

Artery-to-artery embolism and hypoperfusion commonly coexist in ischemic stroke attributed to intracranial atherosclerotic stenosis, which may be associated with higher risk of stroke relapse.
Assessing the Impact of the South China Sea Arbitration on Small Island States: A Case Study of Kiribati
Authors: Kaye Stuart
Published: August 2019

The Annex VII Tribunal in the South China Sea Arbitration placed a high threshold on States seeking to claim an exclusive economic zone (EEZ) around small features. The implications of such an interpretation are potentially significant for the maritime jurisdiction of a number of States, particularly in the Pacific. This article considers the implications of the decision of the Tribunal, and applies it to Kiribati as a case study. It also considers possible ways States may minimize the risk associated with the Tribunal’s interpretation.
Revision of the Holarctic genus Gloma Meigen (Diptera: Empidoidea: Brachystomatidae: Trichopezinae)
Authors: SINCLAIR BRADLEY J. , CUMMING JEFFREY M. , BROOKS SCOTT E. , SAIGUSA TOYOHEI
Published: August 2019

The Holarctic genus Gloma Meigen is revised and includes five species (G. fuscipennis Meigen, G. fuscipes Melander, G. luctuosa Melander, G. pectinipes Melander, G. pyricornis Saigusa & Sinclair sp. nov.) and two undescribed species from China, presently known only from females. The monotypic Baltic amber genus Palaeoparamesia Meunier is discussed as possibly congeneric with Gloma. The Baltic amber species Gloma hirta Loew is considered a nomen dubium. A lectotype is designated for Gloma luctuosa. All species are described or diagnosed, and their geographic distributions mapped. A World key to the species of Gloma is provided. Phylogenetic placement of the genus, including a possible new relationship with Oreogeton Schiner is considered, and the relationships and zoogeographic history of the species are discussed based on a morphological cladistic analysis.
A taxonomic revision of the Strumigenys nitens and simulans groups (Hymenoptera: Formicidae), two Caribbean radiations of leaf litter ants
Authors: BOOHER DOUGLAS B. , PREBUS MATTHEW , LUBERTAZZI DAVID
Published: August 2019

In this study, we revise two groups of cryptic leaf litter ants, the Strumigenys nitens and Strumigenys simulans species groups. These two groups are restricted to the Greater Antilles and the Bahamas. We redefine the species groups, provide a key for the five species in the S. nitens group, and differentiate the two species in the S. simulans group. Four new species are described: Strumigenys caiman sp. nov., S. economoi sp. nov., S. hubbewatyorum sp. nov., and S. zemi sp. nov. We review and provide a key for the Strumigenys fauna of Hispaniola, which comprises the two endemic species S. economoi and S. zemi, six more broadly distributed Neotropical species, and three pan-tropical “tramp” species.
A new species of Camelobaetidius Demoulin, 1966 (Ephemeroptera: Baetidae), from the Colombian Orinoco River basin
Authors: SALINAS-JIMENEZ LUIS GONZALO , BOLDRINI R. , OSORIO-RAMIREZ DIANA PAOLA , CARO CLARA INES , ROJAS-PEÑA JOSE ISMAEL
Published: August 2019

Three species of Camelobaetidius Demoulin, 1966 have been reported from Colombia until now, based on nymphs. We describe a fourth species based on nymphs from the Colombian Orinoco river basin. The new species can be recognized by: 1) labrum narrowly rounded anteriorly; 2) segment II of labial palp with a short rounded distomedial projection; 3) incisors of right mandible with eleven denticles; 4) gills absent from the bases of coxae; 5) tarsal claws with ten denticles; 6) outer margin of forefemur with a row of about 23 long, spine-like setae; 7) posterior margin of tergum IV with truncate spines, and 8) terminal filament almost as long as cerci. [Zoobank URL: urn:lsid:zoobank.org:act:500CF998-8EF3-43E3-BA8B-F062B92768F3]
Stratiform and Convective Radar Reflectivity–Rain Rate Relationships and Their Potential to Improve Radar Rainfall Estimates
Authors: Kirsch Bastian , Clemens Marco , Ament Felix
Published: August 2019

The variability of the raindrop size distribution (DSD) contributes to large parts of the uncertainty in radar-based quantitative rainfall estimates. The variety of microphysical processes acting on the formation of rainfall generally leads to significantly different relationships between radar reflectivity Z and rain rate R for stratiform and convective rainfall. High-resolution observation data from three Micro Rain Radars in northern Germany are analyzed to quantify the potential of dual Z–R relationships to improve radar rainfall estimates under idealized rainfall type identification and separation. Stratiform and convective rainfall are separated with two methods, establishing thresholds for the rain rate-dependent mean drop size and the α coefficient of the power-law Z–R relationship. The two types of dual Z–R relationships are tested against a standard Marshall–Palmer relationship and a globally adjusted single relationship. The comparison of DSD-based and reflectivity-derived rain rates shows that the use of stratiform and convective Z–R relationships reduces the estimation error of the 6-month accumulated rainfall between 30% and 50% relative to a single Z–R relationship. Consistent results for neighboring locations are obtained at different rainfall intensity classes. The range of estimation errors narrows by between 20% and 40% for 10-s-integrated rain rates, dependent on rainfall intensity and separation method. The presented technique also considerably reduces the occurrence of extreme underestimations of the true rain rate for heavy rainfall, which is particularly relevant for operational applications and flooding predictions.
Parameterization of Directional Absorption of Orographic Gravity Waves and Its Impact on the Atmospheric General Circulation Simulated by the Weather Research and Forecasting Model
Authors: Xu Xin , Xue Ming , Teixeira Miguel A. C. , Tang Jianping , Wang Yuan
Published: August 2019

In this work, a new parameterization scheme is developed to account for the directional absorption of orographic gravity waves (OGWs) using elliptical mountain-wave theory. The vertical momentum transport of OGWs is addressed separately for waves with different orientations through decomposition of the total wave momentum flux (WMF) into individual wave components. With the new scheme implemented in the Weather Research and Forecasting (WRF) Model, the impact of directional absorption of OGWs on the general circulation in boreal winter is studied for the first time. The results show that directional absorption can change the vertical distribution of OGW forcing, while maintaining the total column-integrated forcing. In general, directional absorption inhibits wave breaking in the lower troposphere, producing weaker orographic gravity wave drag (OGWD) there and transporting more WMF upward. This is because directional absorption can stabilize OGWs by reducing the local wave amplitude. Owing to the increased WMF from below, the OGWD in the upper troposphere at midlatitudes is enhanced. However, in the stratosphere of mid- to high latitudes, the OGWD is still weakened due to greater directional absorption occurring there. Changes in the distribution of midlatitude OGW forcing are found to weaken the tropospheric jet locally and enhance the stratospheric polar night jet remotely. The latter occurs as the adiabatic warming (associated with the OGW-induced residual circulation) is increased at midlatitudes and suppressed at high latitudes, giving rise to stronger thermal contrast. Resolved waves are likely to contribute to the enhancement of polar stratospheric winds as well, because their upward propagation into the high-latitude stratosphere is suppressed.
Trends in Persistent Seasonal-Scale Atmospheric Circulation Patterns Responsible for Seasonal Precipitation Totals and Occurrences of Precipitation Extremes over Canada
Authors: Tan Xuezhi , Gan Thian Yew , Chen Shu , Horton Daniel E. , Chen Xiaohong , Liu Bingjun , Lin Kairong
Published: August 2019

Both large-scale atmospheric circulation and moisture content in the atmosphere govern regional precipitation. We partition recent changes in mean, heavy, and extreme precipitation for all seasons over Canada to changes in synoptic circulation patterns (dynamic changes) and in atmospheric moisture conditions (thermodynamic changes) using 500-hPa geopotential height and precipitation data over 1979–2014. Using the self-organizing map (SOM) cluster analysis, we identify statistically significant trends in occurrences of certain synoptic circulation patterns over the Canadian landmass, which have dynamically contributed to observed changes in precipitation totals and occurrence of heavy and extreme precipitation events over Canada. Occurrences of circulation patterns such as westerlies and ridges over western North America and the North Pacific have considerably affected regional precipitation over Canada. Precipitation intensity and occurrences of precipitation extremes associated with each SOM circulation pattern also showed statistically significant trends resulting from thermodynamic changes in the atmospheric moisture supply for precipitation events. A partition analysis based on the thermodynamic–dynamic partition method indicates that most (~90%) changes in mean and extreme precipitation over Canada resulted from changes in precipitation regimes occurring under each synoptic circulation pattern (thermodynamic changes). Other regional precipitation changes resulted from changes in occurrences of synoptic circulation patterns (dynamic changes). Because of the high spatial variability of precipitation response to changes in thermodynamic and dynamic conditions, dynamic contributions could offset thermodynamic contributions to precipitation changes over some regions if thermodynamic and dynamic contributions are in opposition to each other (negative or positive), which would result in minimal changes in precipitation intensity and occurrences of heavy and extreme precipitation events.
Variations in the Frequency of Winter Extreme Cold Days in Northern China and Possible Causalities
Authors: Yuan Chaoxia , Li Wenmao
Published: August 2019

Weather and climate extremes often cause devastating disasters and motivate research to improve their understanding. Here, the spatiotemporal variations in the frequency of winter extreme cold days (WECDs) in northern China (NC) were investigated. The results show that the first EOF mode reflects the spatially consistent anomalies and explains 39% of the total variance. The second EOF mode represents the east–west contrasted anomalies and explains 17% of the total variance. In the winter, when the negative Arctic Oscillation (AO) co-occurs with the stronger Siberian high (SH), cold air from the polar region is more easily advected southward, causing the increased number of WECDs in all of NC. The co-occurrence of negative AO and stronger SH may be related to excessive snow in the preceding autumn over northeastern Eurasia through the local positive feedback between the snow and surface air temperatures and the tropospheric–stratospheric interaction. On the other hand, in the winter when the negative AO co-occurs with the weaker SH, eastern NC is still under the influence of cold-air intrusion from the polar region relevant to the negative AO, whereas western NC is impacted by the anomalous warm-air advection related to the weaker SH. The weakening of the SH may be caused by the El Niño teleconnection. The reproducibility of the observed variations and possible causalities of WECDs in NC by 10 coupled models participating in CMIP5 has been assessed. All the models can reproduce the observed dominant EOF modes. The relevant large-scale circulation anomalies and possible causalities can also be well simulated by the multimodel ensemble.
Recent Increased Covariability of Tropical Cyclogenesis Latitude and Longitude over the Western North Pacific during the Extended Boreal Summer
Authors: Zhao Haikun , Zhang Jie , Klotzbach Philip J. , Chen Shaohua
Published: August 2019

This study examines interdecadal changes in the interannual relationship between the extended boreal summer (May–November) tropical cyclogenesis (TCG) latitude and longitude over the western North Pacific Ocean (WNP) during 1979–2016. Increasing covariability of WNP TCG latitude and longitude is observed since 1998, which is found to be closely linked to shifting ENSO conditions and a tropical Pacific climate regime shift. Accompanied by an increasing occurrence in central Pacific (CP) ENSO events during recent decades, there has been a more consistent northwestward or southeastward shift of WNP TCG location since 1998. These coherent latitude and longitude shifts were generally not evident during 1979–97, a period characterized by a more conventional eastern Pacific (EP) ENSO pattern. Our statistical results show a robust relationship between TCG latitude and the Hadley circulation and between longitude and the Walker circulation during the period prior to and since the regime shift, and a possible physical explanation for the recent increased covariability of TCG latitude and longitude is given. During 1998–2016, there is a significant association of CP ENSO events with the intensity of both the Hadley and Walker circulations that likely caused the recent increase in the covariability of TCG latitude and longitude. However, the strong association of EP ENSO events with the intensity of the Hadley circulation but not with the Walker circulation during 1979–97 weakened the covariability of TCG latitude and longitude. In addition, changes in tropical Indian Ocean sea surface temperatures appear to also importantly contribute to the recent increased covariability of WNP TCG location.
Rising Temperatures Increase Importance of Oceanic Evaporation as a Source for Continental Precipitation
Authors: Findell Kirsten L. , Keys Patrick W. , van der Ent Ruud J. , Lintner Benjamin R. , Berg Alexis , Krasting John P.
Published: August 2019

Understanding vulnerabilities of continental precipitation to changing climatic conditions is of critical importance to society at large. Terrestrial precipitation is fed by moisture originating as evaporation from oceans and from recycling of water evaporated from continental sources. In this study, continental precipitation and evaporation recycling processes in the Earth system model GFDL-ESM2G are shown to be consistent with estimates from two different reanalysis products. The GFDL-ESM2G simulations of historical and future climate also show that values of continental moisture recycling ratios were systematically higher in the past and will be lower in the future. Global mean recycling ratios decrease 2%–3% with each degree of temperature increase, indicating the increased importance of oceanic evaporation for continental precipitation. Theoretical arguments for recycling changes stem from increasing atmospheric temperatures and evaporative demand that drive increases in evaporation over oceans that are more rapid than those over land as a result of terrestrial soil moisture limitations. Simulated recycling changes are demonstrated to be consistent with these theoretical arguments. A simple prototype describing this theory effectively captures the zonal mean behavior of GFDL-ESM2G. Implications of such behavior are particularly serious in rain-fed agricultural regions where crop yields will become increasingly soil moisture limited.
Cloud Influence on ERA5 and AMPS Surface Downwelling Longwave Radiation Biases in West Antarctica
Authors: Silber Israel , Verlinde Johannes , Wang Sheng-Hung , Bromwich David H. , Fridlind Ann M. , Cadeddu Maria , Eloranta Edwin W. , Flynn Connor J.
Published: August 2019

The surface downwelling longwave radiation component (LW↓) is crucial for the determination of the surface energy budget and has significant implications for the resilience of ice surfaces in the polar regions. Accurate model evaluation of this radiation component requires knowledge about the phase, vertical distribution, and associated temperature of water in the atmosphere, all of which control the LW↓ signal measured at the surface. In this study, we examine the LW↓ model errors found in the Antarctic Mesoscale Prediction System (AMPS) operational forecast model and the ERA5 model relative to observations from the ARM West Antarctic Radiation Experiment (AWARE) campaign at McMurdo Station and the West Antarctic Ice Sheet (WAIS) Divide. The errors are calculated separately for observed clear-sky conditions, ice-cloud occurrences, and liquid-bearing cloud-layer (LBCL) occurrences. The analysis results show a tendency in both models at each site to underestimate the LW↓ during clear-sky conditions, high error variability (standard deviations > 20 W m−2) during any type of cloud occurrence, and negative LW↓ biases when LBCLs are observed (bias magnitudes >15 W m−2 in tenuous LBCL cases and >43 W m−2 in optically thick/opaque LBCLs instances). We suggest that a generally dry and liquid-deficient atmosphere responsible for the identified LW↓ biases in both models is the result of excessive ice formation and growth, which could stem from the model initial and lateral boundary conditions, microphysics scheme, aerosol representation, and/or limited vertical resolution.
Tracer Transport within Abyssal Mixing Layers
Authors: Holmes R. M. , de Lavergne Casimir , McDougall Trevor J.
Published: August 2019

Mixing layers near sloped topography in the abyss are thought to play a critical role in the global overturning circulation. Yet the behavior of passive tracers within sloping boundary layer systems has received little attention, despite the extensive use of tracer observations to understand abyssal circulation. Here, we investigate the behavior of a passive tracer released near a sloping boundary within a flow governed by one-dimensional boundary layer theory. The spreading rate of the tracer across isopycnals is influenced by factors such as the bottom-intensification of mixing, the dipole of upwelling (in the boundary layer) and downwelling (in the outer mixing layer), and along-isopycnal diffusion. For isolated near-boundary tracer releases, the bulk diffusivity, proportional to the rate of increase of the variance of the tracer distribution in buoyancy space, is much less than what would be expected from averaging the diapycnal diffusivity over the tracer patch. This stems from the presence of the bottom boundary that prevents tracer diffusion through it. Furthermore, when along-isopycnal diffusion is weak, the boundary tends to drive the tracer up the slope toward less dense fluid on average due to asymmetries between boundary layer and interior flows. With strong along-isopycnal diffusion this upslope movement is reduced, while at the same time the average diapycnal spreading rate is increased due to a reduced influence of the bottom boundary. These results have implications for what can be learned about the characteristics of mixing near sloping boundaries from past and future tracer-release experiments.
A Method for Identifying Kolmogorov’s Inertial Subrange in the Velocity Variance Spectrum
Authors: Ortiz-Suslow David G. , Wang Qing , Kalogiros John , Yamaguchi Ryan
Published: August 2019

Kolmogorov’s inertial subrange is one of the most recognized concepts in fluid turbulence. However, the practical application of this theory to turbulent flows requires identifying subrange bandwidth. In the atmospheric boundary layer, decades of investigation support Kolmogorov’s theory, but the techniques used to identify the subrange vary and no systematic approach has emerged. The algorithm for robust identification of the inertial subrange (ARIIS) has been developed to facilitate empirical studies of the turbulence cascade. ARIIS systematically and robustly identifies the most probable subrange bandwidth in a given velocity variance spectrum. The algorithm is a novel approach in that it directly uses the expected 3/4 ratio between streamwise and transverse velocity components to locate the onset and extent of the inertial subrange within a single energy density spectrum. Furthermore, ARIIS does not assume a −5/3 power law but instead uses a robust, iterative statistical fitting technique to derive the slope over the identified range. This algorithm was tested using a comprehensive micrometeorological dataset obtained from the Floating Instrument Platform (FLIP). The analysis revealed substantial variation in the inertial subrange bandwidth and spectral slope, which may be driven, in part, by mechanical wind–wave interactions. Although demonstrated using marine atmospheric data, ARIIS is a general approach that can be used to study the energy cascade in other turbulent flows.
Trust and the city: Linking urban upbringing to neural mechanisms of trust in psychosis
Authors: Lemmers-Jansen Imke LJ , Fett Anne-Kathrin J , van Os Jim , Veltman Dick J , Krabbendam Lydia
Published: August 2019

Objective:

Elevated prevalence of non-affective psychotic disorders is often found in densely populated areas. This functional magnetic resonance imaging study investigates if reduced trust, a component of impaired social functioning in patients with psychotic disorder, is associated with urban upbringing.

Methods:

In total, 39 patients (22 first episode and 17 clinical high risk) and 30 healthy controls, aged 16–29, performed two multi-round trust games, with a cooperative and unfair partner during functional magnetic resonance imaging scanning. Baseline trust was operationalized as the first investment made, and changes of trust as changes in investments made over the 20 trials during the games. Urban exposure during upbringing (0–15 years) was defined as higher urban (≥2500 inhabitants/km2) or lower urban (<2500 inhabitants/km2).

Results:

Patients displayed lower baseline trust (first investment) than controls, regardless of urbanicity exposure. During cooperative interactions, lower-urban patients showed increasing investments. In addition, during cooperative interactions, group-by-developmental urbanicity interactions were found in the right and left amygdalae, although for the latter only at trend level. Higher urbanicity was associated with decreased activation of the left amygdala in patients and controls during investments and with increased activation of the right and left amygdalae in patients only, during repayments. During unfair interactions, no associations of urbanicity with behavior or brain activation were found.

Conclusion:

Urban upbringing was unrelated to baseline trust. Associations with urbanicity were stronger for patients compared to controls, suggesting greater susceptibility to urbanicity effects during the developmental period. Higher-urban patients failed to compensate for the initial distrust specifically during repeated cooperative interactions. This finding highlights potential implications for social functioning. Urban upbringing was linked to differential amygdala activation, suggesting altered mechanisms of feedback learning, but this was not associated with trust game behavior.
An Experimental Validation of Masking in IEC 60601-1-8:2006-Compliant Alarm Sounds
Authors: Bolton Matthew L. , Zheng Xi , Li Meng , Edworthy Judy Reed , Boyd Andrew D.
Published: August 2019

Objective

This research investigated whether the psychoacoustics of simultaneous masking, which are integral to a model-checking-based method, previously developed for detecting perceivability problems in alarm configurations, could predict when IEC 60601-1-8-compliant medical alarm sounds are audible.

Background

The tonal nature of sounds prescribed by IEC 60601-1-8 makes them potentially susceptible to simultaneous masking: where concurrent sounds render one or more inaudible due to human sensory limitations. No work has experimentally assessed whether the psychoacoustics of simultaneous masking accurately predict IEC 60601-1-8 alarm perceivability.

Method

In two signal detection experiments, 28 nursing students judged whether alarm sounds were present in collections of concurrently sounding standard-compliant tones. The first experiment used alarm sounds with single-frequency (primary harmonic) tones. The second experiment’s sounds included the additional, standard-required frequencies (often called subharmonics). T tests compared miss, false alarm, sensitivity, and bias measures between masking and nonmasking conditions and between the two experiments.

Results

Miss rates were significantly higher and sensitivity was significantly lower for the masking condition than for the nonmasking one. There were no significant differences between the measures of the two experiments.

Conclusion

These results validate the predictions of the psychoacoustics of simultaneous masking for medical alarms and the masking detection capabilities of our method that relies on them. The results also show that masking of an alarm’s primary harmonic is sufficient to make an alarm sound indistinguishable.

Application

Findings have profound implications for medical alarm design, the international standard, and masking detection methods.
How Homelands Change
Authors: Shelef Nadav G.
Published: August 2019

Under what conditions do nations give up parts of their national homeland? This article answers this question using novel data that traces systematically the inclusion of lost homeland territory in discursive definitions of the homeland for all ethnic nationalist homelands truncated between 1945 and 1996. A survival analysis of the continued homeland status of lost lands shows that longer-lasting democracies are significantly less likely to continue to include lost lands within the homeland’s scope, even after controlling for other factors thought to shape the inclusion of territory in the homeland. Since the desire for the control of territory is at the heart of much international conflict, understanding the conditions under which the scope of that territory is redefined contributes to addressing an especially refractory aspect of international politics.
Adolescent Technology, Sleep, and Physical Activity Time in Two U.S. Cohorts
Authors: Fomby Paula , Goode Joshua A. , Truong-Vu Kim-Phuong , Mollborn Stefanie
Published: August 2019

The advent of Internet-enabled mobile digital devices has transformed U.S. adolescent technology use over the last decade, yet little is known about how these changes map onto other health-related behaviors. We provide a national profile of how contemporary technology use fits into adolescents’ daily health lifestyles compared with the previous generation, with particular attention to whether and for whom technology use displaces time spent in sleep or physical activity. Time diaries were collected from 11- to 17-year-olds in 2002-2003 ( N = 1,139) and 2014-2016 ( N = 527) through the U.S. Panel Study of Income Dynamics Child Development Supplement. Contemporary adolescents spent 40 minutes more per week in technology-focused activities, but their composition was more varied compared with the earlier cohort. Contemporary technology use was predictive of less time in physical activity, and adolescents who engaged in frequent video game play spent less time in physical activity compared with peers with other technology use profiles.