bluuebunny/crossref_metadata_2025 huggingface dataset:
The anti-diabetic activities of natural sweetener plant Stevia: an updated review
Authors: Jan Sohail Ahmad , Habib Neeli , Shinwari Zabta Khan , Ali Muhammad , Ali Nasir
Published: March 2021

Diabetes mellitus is one of the key metabolic diseases cause due to defects in the secretion of insulin, insulin resistance in peripheral tissues, or both. Plants remained an important source of nutrition as well as medicine. Stevia rebaudiana Bertoni is one of the important high qualities non-caloric sugar substitute sweetener plants against diabetes disease. The compounds like steviol, rebaudioside A, stevioside, etc. can lower the sugar level many fold. In addition, it decreases oxidative stress, hence reduces the risk of diabetes. Its leaves have been used for the control and treatment of diabetes and many other metabolic diseases. In animal model experiments it reduces blood sugar level and promotes liver and kidney functions. In this review, we highlighted the most recent literature on the safe use of Stevia for the treatment of diabetes, its use as a functional food, and its mode of therapeutic action in different animal model experiments. However, keeping Stevia as a model plant; detailed investigations are needed for the identification of new metabolites and its use against diabetes and related diseases.
Manufacturing process design of high-pressure graphite-blasting for mechanical production of turbostratic graphene
Authors: Aokal Kamilia , Alami Abdul Hai , Cheaitou Ali , Abdelkareem Mohammad Ali
Published: March 2021

In this paper a manufacturing process is introduced to treat the bulk surfaces of surfaces via graphite powder blasting to directly produce an adherent layer of graphene. Subsequently, the study aims to correlate optical, thermal and electrochemical modifications with treatment parameters such as blasting pressure, nozzle distance and number of passes. After the treatment, the target surface has enhanced spectral, thermal and electrochemical properties because of the graphene’s turbostratic nature to adhesion to its surface. The thermal stability performance showed a consistent 5% increase relative to a bare aluminum substrate. A two-fold increase in corrosion resistance is seen in the sample compared to bare aluminum while diffuse absorbance values enhancement is around three-fold. This proposed manufacturing method provides straightforward and effective treatment at various degrees of automation. Since the deposited graphene substrate can cover a large area, it can be applied as a final layer on thermal collectors, PV panels and for other applications. It is possible to adopt this process to other well-established treatment plants without requiring high investments in the overhead expenses.
Lessons from long-run (1975–2017) structural change in Colombia's coffee production
Authors: Saenz Mariana , Alvarez Diego , Brock Gregory
Published: March 2021

Although coffee is still an important agricultural commodity in Colombia, the coffee share of GDP has significantly declined over the past 40 years. Controlling for changes in relative prices, factor endowments, and technological change, we analyze the coffee share decline in conjunction with other agricultural output by applying a Vector Error Correction model. The results indicate that while market liberalization policies contributed to the declining coffee share of GDP, the decline was partly offset by the end of coffee export quotas. Our results support policies in favor of assistance for farmers to compete in international markets.
30004 Examining Opioid Technical Assistance (TA) Requests for Hard-to-Reach Populations
Authors: Hagle Holly , Knabel Michael , Baker Michele , Krom Laurie , Campbell Aimee , Levin Frances , Cates-Wessel Kathryn
Published: March 2021

ABSTRACT IMPACT: Analyzing the types of technical assistance (basic, targeted or intensive) provided by the Opioid Response Network (ORN) to unique and hard-to-reach populations (UHRP) informs addiction health services and translational research by identifying technical assistance needs in these populations which may require a higher level of intensity. OBJECTIVES/GOALS: To improve ORN dissemination and implementation efforts, the project classifies TA requests into one of three categories: basic, targeted, and intensive. This TA Framework assists the ORN project team in understanding the level of TA required in the delivery of evidence-based practices to address opioids with communities with respect to UHRP. METHODS/STUDY POPULATION: TA requests from April 1, 2019, to April 1, 2020, were selected. The ORN classifies TA requests in one of three categories: basic (dissemination & brief consultation), targeted (services to enhance readiness and capacity), and intensive (full incorporation of innovation considering context, culture, and linguistics) (Fixsen, et. al., 2009; Becker, et al., 2020). Unique and hard-to-reach populations (UHRP) are defined based on physical location (i.e., remote or isolated), social position, or other vulnerabilities (i.e. member of an ethnic or racial minority group) (Thurman, & Harrison, 2020). ORN classifies 26 types of UHRP these types are not mutually exclusive. A frequency analysis of the UHRP types was conducted. Bivariate correlations between UHRP types that had a minimum of 30 cases were performed. RESULTS/ANTICIPATED RESULTS: Among 746 TA requests selected, 226 had missing information about UHRP types and 29 had missing information TA levels. These requests were excluded from the frequency analysis. The three most common UHRP types were people living in rural or remote areas (n=262, 50%), people who are uninsured or underinsured (n=162, 31%), and people who inject drugs (n=158, 30%). Most TA requests were targeted (69%), 23% were intensive, and 9% were basic. Bivariate correlations were performed between 21 UHRP types. Moderate (Pearson’s r=0.4-0.6) or strong correlations (r>0.6) were found for 11 occurrences for the UHRP type of ‘LGBT’, 8 for ‘Mental Illness’, and 7 for ‘Veterans’. Strong correlations were found between ‘Justice Involved’ and ‘Incarcerated’ (r=0.645), and between ‘Disabilities’ and ‘Chronic Pain’ (r=0.603). DISCUSSION/SIGNIFICANCE OF FINDINGS: There were more TA requests at targeted and intensive levels than basic levels suggesting the need for services to enhance readiness and build capacity. The moderate/strong correlations indicate that UHRP types were likely to coexist with other types. Future research can explore combining UHRP types that have moderate/strong correlations.
82032 Lessons learned from a virtual engagement salon amidst a pandemic
Authors: Khalil Pierre , Louis Jordan , Tafuto Barbara , Gordon Marsha
Published: March 2021

ABSTRACT IMPACT: This work is intended to improve community engagement salons both virtually and generally in order to maximize the benefit of this vital research tool. OBJECTIVES/GOALS: The Meharry-Vanderbilt Community Engaged Research Core (CERC) provides a protocol to maintain high standards in community engagement studios, even in a virtual setting amidst a pandemic. A virtual community engagement salon was selected as a case study to evaluate outcomes. METHODS/STUDY POPULATION: A virtual salon regarding sun safety in the Latinx community was observed live via Zoom and as a recording afterward. Following dissemination and completion of the post-meeting surveys, authors compiled and reviewed the results. An assessment was developed to determine the salon’s alignment with the Meharry-Vanderbilt CERC guidelines in a virtual setting; this was designated as the primary outcome. Data from the session were compared to the available literature on the topic, which produced three subheadings to the secondary outcome essential to the success of virtual community engagement salons: researcher preparedness, participant selection, and survey importance. RESULTS/ANTICIPATED RESULTS: The CERC guidelines of the community engagement salon were met and were effectively translated into a virtual setting. The presentation given by the researcher followed all technical instructions, yet it was clear that the researcher’s demeanor and conversational soft-skills were lacking. Instead of the recommended bi-directional flow of conversation, the conversation flow shifted to a unidirectional state controlled by the participants. Following the session, only three participants completed the survey along with the researcher. This completion rate of under 50% provides limited feedback on participants’ perspectives on the session’s quality and points to improve future sessions. DISCUSSION/SIGNIFICANCE OF FINDINGS: Pre-meeting researcher preparation is necessary to engage community stakeholders effectively. The lack of completed surveys from participants suggests potential fatigue from leading a majority of the conversation. Results demonstrate that solely meeting the requirements of the CERC does not suffice.
52350 PKM2 mediates anti-tumor immunity and T cell dysfunction
Authors: Markowitz Geoffrey , Ban Yi , Crowley Michael , Tavarez Diamile , Wong Stephen T.C. , Chang Kenneth , Schietinger Andrea , Altorki Nasser , Mittal Vivek
Published: March 2021

ABSTRACT IMPACT: T cell dysfunction is a dominant suppressor of anti-tumor immunity, reducing immunotherapeutic efficacy and benefit to patients; our work will identify novel mediators of this process for both therapeutic potential and underlying mechanism, allowing for both potential immediate clinical utility and identification of future targets based on new mechanistic insights. OBJECTIVES/GOALS: T cell dysfunction is a dominant suppressor of anti-tumor immunity, reducing immunotherapeutic efficacy and clinical benefit to the majority of patients. We aim to interrogate a novel mediator of dysfunction identified from transcriptome analyses, pyruvate kinase muscle isozyme isoform 2 (PKM2), for therapeutic utility and underlying mechanism. METHODS/STUDY POPULATION: Transcriptome analyses of CD8+ lymphocytes from tumor-bearing lungs from both murine KrasG12D p53-/- and human non-small cell lung cancer (NSCLC) patients were performed, and differentially expressed genes identified. Flow cytometric analyses for PKM isoform expression and effects of target knockdown on accumulation of dysfunctional characteristics, including checkpoint and transcription factor expression, proliferation, and cytokine production, were performed using an in vitro co-culture of murine antigen-specific T (OT-I) cells and antigen-expressing NSCLC (HKP1-ova) cells. In vivo examination of the same was performed using adoptive transfer of OT-I cells into immunocompetent recipient mice with engraftment of HKP1-ova cells, and subsequent evaluation of mouse survival and T cell phenotypes. RESULTS/ANTICIPATED RESULTS: Transcriptome analyses demonstrated that PKM expression was upregulated in dysfunctional T cells from both murine and human samples. This was confirmed both in vitro with co-culture and in vivo with adoptive transfer approaches, with both activated and dysfunctional OT-I cells expressing higher levels of isoform 2 of PKM than naive OT-I cells. Expression of PKM2 mimicked the kinetics of the transcription factor Tox, a known driver of dysfunction, and knockdown of PKM2 resulted in reduced granzyme B expression, and increased proportions of progenitors with fewer terminally differentiated dysfunctional cells. Knockdown of PKM2 in adoptively-transferred OT-I cells led to enhanced tumor control; results are being extended to other tumor models, and T cells metabolically profiled with PKM2 manipulation. DISCUSSION/SIGNIFICANCE OF FINDINGS: This work identified a novel mediator of dysfunction whose targeting has the potential to enhance anti-tumor immunity. Mechanistically, targeting PKM2 led to altered T cell differentiation to a dysfunctional state, linking metabolic phenotypes to these traits and underlining the importance and therapeutic potential of T cell metabolic pathways.
54101 Characterizing Microbiota Features of Clostridioides difficile Infections
Authors: Tomkovich Sarah , Rao Krishna , Young Vincent B. , Schloss Patrick D.
Published: March 2021

ABSTRACT IMPACT: Our goal is to identify bacterial biomarkers of adverse Clostridioides difficile infection outcomes OBJECTIVES/GOALS: We characterized microbiota features of Clostridioides difficile infections (CDIs) and will investigate the association between bacterial taxa and adverse outcomes, which includes severe and recurrent CDIs. METHODS/STUDY POPULATION: 1,517 stool samples were collected from patients diagnosed with a CDI at the University of Michigan along with 1,516 unformed and 910 formed stool control samples. We characterized the microbiota of the 3,943 stool samples by sequencing the V4 region of the 16S rRNA gene and used the Dirichlet Multinomial Mixtures method to cluster samples into community types. Severe CDI cases were defined using the Infectious Diseases Society of America criteria and recurrent CDIs were defined as CDIs that occurred within 2-12 weeks of the primary CDI. We will use machine learning to examine whether specific bacterial taxa can predict severe or recurrent CDIs. We will test 5 machine learning models with 80% training and 20% testing data split. RESULTS/ANTICIPATED RESULTS: Similar to findings from a previous study with 338 samples, we found there was no difference in diversity between CDI cases and unformed controls (Inverse Simpson index, p > 0.5) and samples from the 3 groups (CDIs, unformed controls, and formed controls) clustered into 12 community types. To investigate the bacterial taxa that are important for predicting adverse CDI outcomes, we will select the best machine learning model based on performance and training time and examine how much each feature contributes to performance. We anticipate the large number of CDI cases in our cohort and robust machine learning approaches will enable us to identify more bacteria associated with adverse outcomes compared to other studies that have attempted to predict CDI recurrence with fewer CDI cases. DISCUSSION/SIGNIFICANCE OF FINDINGS: Adverse CDI outcomes are a significant source of the morbidities, mortalities, and healthcare costs associated with CDIs. Identifying bacterial biomarkers of severe and recurrent CDIs could enhance our ability to stratify patients into risk groups and may lead to the development of more targeted therapeutics.
77085 Impact of MYH6 Variants on Development and Clinical Course of Hypoplastic Left Heart Syndrome
Authors: Anfinson Melissa , Creighton Sara , James Jeanne , Goetsch Peter Frommeltry , Simpson Pippa , Mitchell Michael E , Tomita-Mitchell Aoy
Published: March 2021

ABSTRACT IMPACT: This work represents a novel way in which genetic information can be used to improve clinical decision making as it pertains to both treatment and management of congenital heart disease. OBJECTIVES/GOALS: Our lab found that MYH6 variants are both enriched in hypoplastic left heart syndrome (HLHS) and associated with decreased cardiac transplant-free survival. To elucidate the mechanisms of MYH6 variant pathogenicity, we are assessing their impact on atrial function during HLHS development and progression. METHODS/STUDY POPULATION: We are using 2D speckle-based tracking to retrospectively evaluate echocardiograms (echos) from 51 HLHS patients, 17 with MYH6 variants and 34 matched controls. Atrial function will be assessed by myocardial strain and strain rate at seven time points, beginning at the time of the patients’ earliest prenatal echo, and ending with their last available echo before death or cardiac transplant. Early left atrial function will examine the role of MYH6 variants in the development of HLHS in vivo, while longitudinal right atrial function will be assessed in order to look for differences that could be contributing to the decreased transplant-free survival seen in MYH6 variant carriers. RESULTS/ANTICIPATED RESULTS: We hypothesize that MYH6 variants cause HLHS by impairing early left atrial (LA) contractility, resulting in altered left ventricular hemodynamics and consequent hypoplasia. We therefore expect to find diminished prenatal LA function in HLHS patients with MYH6 variants. We also hypothesize that MYH6 variants continue to impair right atrial (RA) function in surgically-reconstructed HLHS hearts, necessitating earlier transplantation. Accordingly, we expect variant carriers to exhibit lower RA function at birth versus controls. We expect differences between groups to persist over time, and possibly increase in magnitude. In HLHS patients with MYH6 variants, we anticipate declining RA function will precede right ventricular function and therefore be an early indicator of transplant need. DISCUSSION/SIGNIFICANCE OF FINDINGS: This study represents a novel way in which genetic information can inform clinical decision-making. Identifying MYH6 variants as an early cause of HLHS offers chances for intervention. Understanding long-term effects of MYH6 on right atrial function in HLHS may aid in cardiac transplant risk stratification, thus improving patient outcomes.
The Built Environment and the Development of Intermediate Socio-Spatial Units at Los Guachimontones, Jalisco, Mexico
Authors: Heredia Espinoza Verenice Y.
Published: March 2021

Intermediate socio-spatial units (ISUs), materialized as neighborhoods and districts, were important elements in the ordering of the built environment in large ancient settlements. They are indicative of an increasing vertical and horizontal complexity because they lie between households and the governing authority. Collective action theory holds that ISUs can take many forms and can be created through bottom-up, top-down, or top-down/bottom-up processes. The distribution of ISUs in the context of other architectural elements illuminates the degree to which collective policies shaped urban landscapes. This article identifies districts and neighborhoods, two types of ISUs, at the site of Los Guachimontones (Jalisco, Mexico) through a study of its internal spatial organization. Intensive survey and mapping have identified thousands of architectural elements, including the circular complexes known as guachimontones. Thiessen polygon analysis reveals that guachimontones are an important feature of the site's spatial organization, as well as to the materialization of ISUs and other socio-spatial units. Broadly speaking, the organization of these built spaces reveals that their growth can be attributed to collectively oriented political strategies.
Business Model Innovation in Transforming Economies: A Co-evolutionary Perspective for a Global and Digital World
Authors: Mihalache Oli R. , Volberda Henk W.
Published: March 2021

Although transforming economies offer many examples of business model innovation, they have been largely overlooked in academic research, with most studies focusing on what happens in developed countries. However, in their push to become innovation economies, transforming economies have become experimentation arenas for new ways of doing business. This special issue addresses the gap in business model innovation research in several ways. First, we develop a co-evolutionary framework in which we consider what type of business model innovation occurs in transforming economies (adoption, adaptation, or creation) and who the central players are (indigenous firms or MNEs). We show how, through business model innovation, indigenous firms have begun to challenge global industry leaders – despite not having the same resource advantages, proprietary technology, or market power – and we highlight the consequences of this for the domestic and global environment. Second, we discuss how the articles in this special issue advance research by contributing to a co-evolutionary perspective on business model innovation for a global and digital world. Third, to guide future research on business model innovation in the fascinating context of transforming economies we outline various directions that could build on our framework and the articles presented here.
Taxing the Tails in a Global Economy: How Electoral, Party and Wage Bargaining Systems Interact to Determine the Taxes Paid by the Poor and Rich
Authors: Hays Jude C.
Published: March 2021

A prominent line of research on electoral systems and income redistribution argues that proportional representation (PR) leads to tax-and-transfer policies that benefit the poor at the expense of the rich. This is because PR produces encompassing center-left coalitions that protect the poor and middle classes. Yet countries with PR electoral systems tend to rely heavily on consumption taxes and tax profits lightly, both of which are inconsistent with this expectation. Both policies are regressive and seem to benefit the rich at the expense of the poor. This article argues that PR electoral institutions, when combined with trichotomous multipartism, are not as hostile to the rich as commonly believed, and that it is important to understand how electoral and party systems interact with labor market institutions in order to explain the puzzling pattern of taxation that is observed. The author develops a theoretical model and evaluates its empirical implications for a world in which production has become multinational.
The Press Bureau, ‘D’ Notices, and Official Control of the British Press's Record of the First World War
Authors: Monger David
Published: March 2021

Concerns about fake news and media manipulation are commonplace in contemporary society, and, throughout the twentieth century, historians regularly presented the First World War as an era of manipulated public messages. Yet, despite broad statements about the impact of press censorship in First World War Britain, publication of an official history of the ‘D’ notice system, and growing revision of historical understanding of the interaction between the state, the press, propaganda, and the public during the war, no thorough assessment of the content of the D notices issued by the Press Bureau to newspaper editors has been undertaken. This article provides a thorough analysis of the more than seven hundred notices issued during the war years. While drawing attention to several exceptions which exceeded plausible claims of a threat to security, it argues that most notices genuinely sought to protect potentially dangerous information and that casual assumptions about misleading state press management are not borne out by a close reading of the actual notices issued.
Using GPS tracking for fruit bat conservation
Authors: Mandl Isabella , Houmadi Amelaid , Said Ishaka , Abdou Badrane Ben Ali , Fardane Abdoul-Kader , Egger-Peitler Kilian , Oleksy Ryszard , Doulton Hugh , Chaihane Sourette Said Ali
Published: March 2021

Understanding the ecology of species is key to the development of effective conservation measures. For many fruit bat species, however, even baseline knowledge of ecology and behaviour is lacking. To identify feeding sites of the Critically Endangered Livingstone's flying fox Pteropus livingstonii on the island of Anjouan, Comoros, we piloted the use of GPS loggers. Two bats (one female, one male) were tagged in early 2019, and data collected for 217 and 35 days, respectively. Acceleration data facilitated the classification of location points into behavioural categories. Potential feeding sites were located by cluster analysis of all location points that were attributed to a behavioural category in which feeding could occur. One important feeding site was located in an agricultural area. This is the first time quantitative behavioural data have been collected for Livingstone's flying foxes, providing insight into the ecological needs of this threatened species. These findings have the potential to inform applied conservation management decisions for protecting the resources required for the survival of this species.
Looking for Agency in Transnational Refugee Trajectories during the Second World War
Authors: de Jong Rosa
Published: March 2021

The authors of three recent monographs,The Escape Line, Escape from Vichy, andNearly the New World, highlight in particular the relevance of transnational refugee and resistance networks. These books shed new light on the trajectories of refugees through war-torn Europe and their routes out of it. Megan Koreman displays inThe Escape Linethe relevance of researching one line of resistance functioning in several countries and thereby shifts from the common nationalistic approach in resistance research. InEscape from VichyEric Jennings researches the government-endorsed flight route between Marseille and Martinique and explores the lasting impact of encounters between refugees and Caribbean Negritude thinkers. Joanna Newman explores the mainly Jewish refugees who found shelter in the British West Indies, with a focus on the role of aid organisations in this flight.
Relational revolution and relationality in IR: New conversations
Authors: Kurki Milja
Published: March 2021

There is a multifaceted relational revolution afoot in International Relations (IR) and in the social sciences more widely. This article suggests, via engagement with varied forms of relational thought and practice in IR, but in particular via engagement with ‘relational cosmology’ associated with the ‘natural’ as well as the ‘social’ sciences, that there are important reasons for relational thought and practice in IR and around it to be more attentive to dialogues on relationality across natural and social sciences. If relational thought in IR has challenged the colonial and bifurcated ontologies of the field, relational cosmology too assists in shifting ‘modern’ understandings of science and the cosmos by facilitating engagement with situated knowledges and deep-going relationalities across ‘nature’ and ‘society’, ‘human’ and ‘non-human’ communities. Relational cosmology may be productive in joining, and perhaps even in facilitating, conversations across multiple relationalities emerging from different parts of the world and in different fields of inquiry, and yet – reflecting its relational and pluriversal orientations – it is not proposed here as a new ‘meta-‘ or ‘grand-’ narrative for relational theorising or IR.
Knowledge as a Revenue Driver, Not a Cost Centre: the LexisNexis GLP and How to Use Market Intelligence to Make Knowledge a Vital Growth Engine for Law Firms
Authors: O'Connor Christopher
Published: March 2021

This article by the LexisNexis Segment Marketing team explains the approach, methodology and findings of the LexisNexis Gross Legal Product (GLP) report, first presented at the BIALL's Virtual Conference in June 2020. The GLP is a quantitative measure of underlying demand for legal services in the UK, comprised of 250 individual metrics which serve as proxies for legal activity. The article outlines the methodology and sources used to build the GLP; headline findings for Q2 2020 YTD; and provides suggestions for how firm leaders and knowledge professionals could use the information in their work. The GLP Q2 model found that demand for legal activity has declined by 7% since the start of 2020.
Economic freedom reform: does culture matter?
Authors: Moellman Nicholas , Tarabar Danko
Published: March 2021

We analyse the role of culture in economic freedom reform and dispersion in an unbalanced panel of up to 80 countries, and in dyadic models with up to 3,003 unique country pairs. We find that a sense of individualism strengthens the effectiveness of democracy in promoting economic freedom within countries over 1950–2015, and that institutional distance between countries increases in their cultural distance, suggesting an important role of culture in determining long-run institutional equilibria. Our results are robust to a large variety of socio-economic controls, measures of institutions and measures of bilateral geographic, economic and demographic distances.
Psychotraumatologie des Kindesalters
Authors: Landolt Markus A.
Published: March 2021

Gewalterleben, Vernachlässigung, Unfälle, Naturkatastrophen und lebensbedrohliche Krankheiten gehören zu den häufigsten Ursachen für die Entwicklung von Traumafolgestörungen bei Kindern und Jugendlichen. Wie entstehen solche Störungen? Wie können sie erfasst werden? Welche Möglichkeiten der Prävention gibt es und welche therapeutischen Behandlungen sind geeignet und wirksam? Mit diesen und weiteren Fragen beschäftigt sich die Kinderpsychotraumatologie, über deren aktuelle Entwicklungen dieses Buch einen Überblick gibt. Die vorliegende Neuauflage geht auf die Klassifikation von Traumafolgestörungen nach DSM-5 und ICD-11 ein und informiert über neue Methoden und Weiterentwicklungen im Bereich der Diagnostik und Behandlung solcher Störungsbilder. Aktuelle Forschungsbefunde, u.a. in Hinblick auf Entstehungsmodelle und biologische Faktoren, werden dargestellt, und es wird ein Überblick über Interventionsmöglichkeiten in der Notfallpsychologie und in der Behandlung von Traumafolgestörungen gegeben. Der Band bietet somit eine wertvolle Hilfe für alle, die mit traumatisierten Kindern und Jugendlichen arbeiten.
Intensifying Australian Heatwave Trends and Their Sensitivity to Observational Data
Authors: Jyoteeshkumar reddy P. , Perkins‐Kirkpatrick Sarah E. , Sharples Jason J.
Published: March 2021

Heatwaves are an accustomed extreme event of the Australian climate, which can cause catastrophic impacts on human health, agriculture, and urban and natural systems. We have analyzed the trends in Australia‐wide heatwave metrics (frequency, duration, intensity, number, cumulative magnitude, timing, and season duration) across 69 extended summer seasons (i.e., from November‐1951 to March‐2020). Our findings not only emphasize that heatwaves are becoming hotter, longer, and more frequent, but also signify that they are occurring with excess heat, commencing much earlier, and expanding their season over many parts of Australia in recent decades. The Australian heatwave trends have strengthened since last observed Australian study was conducted. We also investigated the heatwave and severe heatwave trends at a local city‐scale using three different observational products (AWAP and SILO gridded datasets and ACORN_SATV2 station data) over selected time periods (1911–2019, 1911–1964, and 1965–2019). Results suggest that heatwave trends are noticeably different amongst the three datasets. However, the results highlight that the severe heatwave cumulative magnitude and their season duration have been increasing significantly in recent decades over Australia's southern coastal cities (like Melbourne and Adelaide). The climatological mean of the most heatwave and severe heatwave metrics is substantially higher in recent decades compared to earlier periods across all the cities considered. The findings of our study have significant implications for the development of advanced heatwave planning and adaptation strategies.
Meteorological and Electrical Conditions of Two Mid‐latitude Thunderstorms Producing Blue Discharges
Authors: Liu Feifan , Zhu Baoyou , Lu Gaopeng , Lei Jiuhou , Shao Jun , Chen Yanling , Huang Anjing , Ma Ming , Qin Zilong , Zhong Jiahao , Ren Huan , Wang Zhongru , Wan Zerun , Liu Guojin , Peng Changzhi , Peng Kang‐Ming , Zhou Helin
Published: March 2021

Blue discharges are one type of rarely observed upward discharge emerging from the top of thunderstorms. The favorable meteorological conditions and charge structures needed to produce this marvelous phenomenon are still poorly understood. In this study, we report on two midlatitude thunderstorms producing 13 blue discharges observed simultaneously by the Imager of Sprites and Upper Atmospheric Lightning (ISUAL) and ground‐based lightning detection array. In these two thunderstorms, blue discharges always occurred in the vicinity of the coldest cloud top (∼195 K) and clustered within a bounded area near the convective surge, leading to the overshooting thundercloud top (reaching about 18 km) into the stratosphere. The parent thunderstorms were normally electrified with a main midlevel negative and an upper positive charge layer centered at about 15 km as inferred from source heights of narrow bipolar events (NBEs). The associated negative NBEs near the tropopause indicated that they are upward positive discharges initiated between the upper positive charge layer and the negative screening layer at the cloud top. In addition, the outbreak of negative NBEs in the altitude range of 16–18 km was observed in conjunction with blue discharges observed from space. This suggests that there exists a strong upper positive layer with an intense convection at this altitude of the thunderstorm. It is inferred that an overshooting thundercloud top with intense convective updraft could lead to a strong and high upper positive charge layer and therefore create favorable charge structures for initiating upward positive blue discharges.
Development and Evaluation of Chemistry‐Aerosol‐Climate Model CAM5‐Chem‐MAM7‐MOSAIC: Global Atmospheric Distribution and Radiative Effects of Nitrate Aerosol
Authors: Zaveri Rahul A. , Easter Richard C. , Singh Balwinder , Wang Hailong , Lu Zheng , Tilmes Simone , Emmons Louisa K. , Vitt Francis , Zhang Rudong , Liu Xiaohong , Ghan Steven J. , Rasch Philip J.
Published: March 2021

An advanced aerosol treatment, with a focus on semivolatile nitrate formation, is introduced into the Community Atmosphere Model version 5 with interactive chemistry (CAM5‐chem) by coupling the Model for Simulating Aerosol Interactions and Chemistry (MOSAIC) with the 7‐mode Modal Aerosol Module (MAM7). An important feature of MOSAIC is dynamic partitioning of all condensable gases to the different fine and coarse mode aerosols, as governed by mode‐resolved thermodynamics and heterogeneous chemical reactions. Applied in the free‐running mode from 1995 to 2005 with prescribed historical climatological conditions, the model simulates global distributions of sulfate, nitrate, and ammonium in good agreement with observations and previous studies. Inclusion of nitrate resulted in ∼10% higher global average accumulation mode number concentrations, indicating enhanced growth of Aitken mode aerosols from nitrate formation. While the simulated accumulation mode nitrate burdens are high over the anthropogenic source regions, the sea‐salt and dust modes respectively constitute about 74% and 17% of the annual global average nitrate burden. Regional clear‐sky shortwave radiative cooling of up to −5 W m−2 due to nitrate is seen, with a much smaller global average cooling of −0.05 W m−2. Significant enhancements in regional cloud condensation nuclei (at 0.1% supersaturation) and cloud droplet number concentrations are also attributed to nitrate, causing an additional global average shortwave cooling of −0.8 W m−2. Taking into consideration of changes in both longwave and shortwave radiation under all‐sky conditions, the net change in the top of the atmosphere radiative fluxes induced by including nitrate aerosol is −0.7 W m−2.
Impact of Sea‐Ice Model Complexity on the Performance of an Unstructured‐Mesh Sea‐Ice/Ocean Model under Different Atmospheric Forcings
Authors: Zampieri Lorenzo , Kauker Frank , Fröhle Jörg , Sumata Hiroshi , Hunke Elizabeth C. , Goessling Helge F.
Published: March 2021

We have equipped the unstructured‐mesh global sea‐ice and ocean model FESOM2 with a set of physical parameterizations derived from the single‐column sea‐ice model Icepack. The update has substantially broadened the range of physical processes that can be represented by the model. The new features are directly implemented on the unstructured FESOM2 mesh, and thereby benefit from the flexibility that comes with it in terms of spatial resolution. A subset of the parameter space of three model configurations, with increasing complexity, has been calibrated with an iterative Green's function optimization method to test the impact of the model update on the sea‐ice representation. Furthermore, to explore the sensitivity of the results to different atmospheric forcings, each model configuration was calibrated separately for the NCEP‐CFSR/CFSv2 and ERA5 forcings. The results suggest that a complex model formulation leads to a better agreement between modeled and the observed sea‐ice concentration and snow thickness, while differences are smaller for sea‐ice thickness and drift speed. However, the choice of the atmospheric forcing also impacts the agreement of the FESOM2 simulations and observations, with NCEP‐CFSR/CFSv2 being particularly beneficial for the simulated sea‐ice concentration and ERA5 for sea‐ice drift speed. In this respect, our results indicate that parameter calibration can better compensate for differences among atmospheric forcings in a simpler model (i.e., sea‐ice has no heat capacity) than in more realistic formulations with a prognostic sea‐ice thickness distribution and sea ice enthalpy.
Ancient, Acidic Lakes May Have Harbored Life
Authors: Kemeny Richard
Published: March 2021

A new analysis of South African sediments hints that acidic lakes may have leached minerals necessary for biotic life.
Sea Surface Height Variability in the 30–120 km Wavelength Band From Altimetry Along‐Track Observations
Authors: Chen Shuiming , Qiu Bo
Published: March 2021

Reprocessed altimetry along‐track sea surface height (SSH) observations from multiple missions are analyzed for the SSH variability in the 30–120 km wavelength band. This band of variability is missing in the widely used global multi‐mission mapped SSH data set, known as the Archiving, Validation and Interpretation of Satellite Oceanographic Data SSH product. The SSH variability is derived from along‐track SSH variance spectra after subtracting noise floors, and its global spatial patterns are consistent among the missions and the output of a high‐resolution ocean general circulation model simulation. High SSH variability in the 30–120 km wavelength band is found in the intratropics of all ocean basins (25°S–25°N), the western boundary current outflow regions, and in five regions along the Antarctic Circumpolar Current: Agulhas Retroflection zone, Kerguelen Plateau, Macquarie Ridge, Pacific Antarctic Ridge, and Drake Passage. The average slope of the along‐track SSH spectra in the 30–120 km wavelength band in the intratropics falls between −2.14 and −1.56, consistent with the Garrett‐Munk spectral slope. The spatial patterns of the SSH variability could be used as a metric to evaluate high‐resolution numerical models and to shed light on what to expect from future high‐resolution altimetry missions.
Quantum engineering of non-equilibrium efficient p-doping in ultra-wide band-gap nitrides
Authors: Jiang Ke , Sun Xiaojuan , Shi Zhiming , Zang Hang , Ben Jianwei , Deng Hui-Xiong , Li Dabing
Published: March 2021

Ultra-wide band-gap nitrides have huge potential in micro- and optoelectronics due to their tunable wide band-gap, high breakdown field and energy density, excellent chemical and thermal stability. However, their application has been severely hindered by the low p-doping efficiency, which is ascribed to the ultrahigh acceptor activation energy originated from the low valance band maximum. Here, a valance band modulation mode is proposed and a quantum engineering doping method is conducted to achieve high-efficient p-type ultra-wide band-gap nitrides, in which GaN quantum-dots are buried in nitride matrix to produce a new band edge and thus to tune the dopant activation energy. By non-equilibrium doping techniques, quantum engineering doped AlGaN:Mg with Al content of 60% is successfully fabricated. The Mg activation energy has been reduced to about 21 meV, and the hole concentration reaches higher than 1018 cm−3 at room temperature. Also, similar activation energies are obtained in AlGaN with other Al contents such as 50% and 70%, indicating the universality of the quantum engineering doping method. Moreover, deep-ultraviolet light-emission diodes are fabricated and the improved performance further demonstrates the validity and merit of the method. With the quantum material growth techniques developing, this method would be prevalently available and tremendously stimulate the promotion of ultra-wide band-gap semiconductor-based devices.
2D materials for conducting holes from grain boundaries in perovskite solar cells
Authors: You Peng , Tang Guanqi , Cao Jiupeng , Shen Dong , Ng Tsz-Wai , Hawash Zafer , Wang Naixiang , Liu Chun-Ki , Lu Wei , Tai Qidong , Qi Yabing , Lee Chun-Sing , Yan Feng
Published: March 2021

Grain boundaries in organic–inorganic halide perovskite solar cells (PSCs) have been found to be detrimental to the photovoltaic performance of devices. Here, we develop a unique approach to overcome this problem by modifying the edges of perovskite grain boundaries with flakes of high-mobility two-dimensional (2D) materials via a convenient solution process. A synergistic effect between the 2D flakes and perovskite grain boundaries is observed for the first time, which can significantly enhance the performance of PSCs. We find that the 2D flakes can conduct holes from the grain boundaries to the hole transport layers in PSCs, thereby making hole channels in the grain boundaries of the devices. Hence, 2D flakes with high carrier mobilities and short distances to grain boundaries can induce a more pronounced performance enhancement of the devices. This work presents a cost-effective strategy for improving the performance of PSCs by using high-mobility 2D materials.
Prostate cancer prognosis after initiation of androgen deprivation therapy among statin users. A population-based cohort study
Authors: Peltomaa A. I. , Raittinen P. , Talala K. , Taari K. , Tammela T. L. J. , Auvinen A. , Murtola T. J.
Published: March 2021

Purpose

Statins’ cholesterol-lowering efficacy is well-known. Recent epidemiological studies have found that inhibition of cholesterol synthesis may have beneficial effects on prostate cancer (PCa) patients, especially patients treated with androgen deprivation therapy (ADT). We evaluated statins’ effect on prostate cancer prognosis among patients treated with ADT.

Materials and methods

Our study population consisted of 8253 PCa patients detected among the study population of the Finnish randomized study of screening for prostate cancer. These were limited to 4428 men who initiated ADT during the follow-up. Cox proportional regression model adjusted for tumor clinical characteristics and comorbidities was used to estimate hazard ratios for risk of PSA relapse after ADT initiation and prostate cancer death.

Results

During the median follow-up of 6.3 years after the ADT initiation, there were 834 PCa deaths and 1565 PSA relapses in a study cohort. Statin use after ADT was associated with a decreased risk of PSA relapse (HR 0.73, 95% CI 0.65–0.82) and prostate cancer death (HR 0.82; 95% CI 0.69–0.96). In contrast, statin use defined with a one-year lag (HR 0.89, 95% CI 0.76–1.04), statin use before ADT initiation (HR 1.12, 95% CI 0.96–1.31), and use in the first year on ADT (HR 1.02, 95% CI 0.85–1.24) were not associated with prostate cancer death, without dose dependency.

Conclusion

Statin use after initiation of ADT, but not before, was associated with improved prostate cancer prognosis.
Gut microbial taxa elevated by dietary sugar disrupt memory function
Authors: Noble Emily E. , Olson Christine A. , Davis Elizabeth , Tsan Linda , Chen Yen-Wei , Schade Ruth , Liu Clarissa , Suarez Andrea , Jones Roshonda B. , de La Serre Claire , Yang Xia , Hsiao Elaine Y. , Kanoski Scott E.
Published: March 2021

Emerging evidence highlights a critical relationship between gut microbiota and neurocognitive development. Excessive consumption of sugar and other unhealthy dietary factors during early life developmental periods yields changes in the gut microbiome as well as neurocognitive impairments. However, it is unclear whether these two outcomes are functionally connected. Here we explore whether excessive early life consumption of added sugars negatively impacts memory function via the gut microbiome. Rats were given free access to a sugar-sweetened beverage (SSB) during the adolescent stage of development. Memory function and anxiety-like behavior were assessed during adulthood and gut bacterial and brain transcriptome analyses were conducted. Taxa-specific microbial enrichment experiments examined the functional relationship between sugar-induced microbiome changes and neurocognitive and brain transcriptome outcomes. Chronic early life sugar consumption impaired adult hippocampal-dependent memory function without affecting body weight or anxiety-like behavior. Adolescent SSB consumption during adolescence also altered the gut microbiome, including elevated abundance of two species in the genus Parabacteroides (P. distasonis and P. johnsonii) that were negatively correlated with hippocampal function. Transferred enrichment of these specific bacterial taxa in adolescent rats impaired hippocampal-dependent memory during adulthood. Hippocampus transcriptome analyses revealed that early life sugar consumption altered gene expression in intracellular kinase and synaptic neurotransmitter signaling pathways, whereas Parabacteroides microbial enrichment altered gene expression in pathways associated with metabolic function, neurodegenerative disease, and dopaminergic signaling. Collectively these results identify a role for microbiota “dysbiosis” in mediating the detrimental effects of early life unhealthy dietary factors on hippocampal-dependent memory function.
Statistics of pathogenic bacteria in the search of host cells
Authors: Otte Stefan , Ipiña Emiliano Perez , Pontier-Bres Rodolphe , Czerucka Dorota , Peruani Fernando
Published: March 2021

A crucial phase in the infection process, which remains poorly understood, is the localization of suitable host cells by bacteria. It is often assumed that chemotaxis plays a key role during this phase. Here, we report a quantitative study on how Salmonella Typhimurium search for T84 human colonic epithelial cells. Combining time-lapse microscopy and mathematical modeling, we show that bacteria can be described as chiral active particles with strong active speed fluctuations, which are of biological, as opposed to thermal, origin. We observe that there exists a giant range of inter-individual variability of the bacterial exploring capacity. Furthermore, we find Salmonella Typhimurium does not exhibit biased motion towards the cells and show that the search time statistics is consistent with a random search strategy. Our results indicate that in vitro localization of host cells, and also cell infection, are random processes, not involving chemotaxis, that strongly depend on bacterial motility parameters.
Genome-wide binding potential and regulatory activity of the glucocorticoid receptor’s monomeric and dimeric forms
Authors: Johnson Thomas A. , Paakinaho Ville , Kim Sohyoung , Hager Gordon L. , Presman Diego M.
Published: March 2021

A widely regarded model for glucocorticoid receptor (GR) action postulates that dimeric binding to DNA regulates unfavorable metabolic pathways while monomeric receptor binding promotes repressive gene responses related to its anti-inflammatory effects. This model has been built upon the characterization of the GRdim mutant, reported to be incapable of DNA binding and dimerization. Although quantitative live-cell imaging data shows GRdim as mostly dimeric, genomic studies based on recovery of enriched half-site response elements suggest monomeric engagement on DNA. Here, we perform genome-wide studies on GRdim and a constitutively monomeric mutant. Our results show that impairing dimerization affects binding even to open chromatin. We also find that GRdim does not exclusively bind half-response elements. Our results do not support a physiological role for monomeric GR and are consistent with a common mode of receptor binding via higher order structures that drives both the activating and repressive actions of glucocorticoids.