bluuebunny/crossref_metadata_2025 huggingface dataset:
Dependency in the Twenty-First Century?
Authors: Stallings Barbara
Published: January 2020

The way external forces influence political and economic outcomes in developing countries is an ongoing concern of scholars and policymakers. In the 1970s and 1980s, dependency analysis was a popular way of approaching this topic, but it later fell into disrepute. This Element argues that it may be useful to revamp dependency to interpret China's new relationships with developing countries, including Latin America. Economic links with China have become important determinants of the region's development. Stallings discusses the dependency debates, reviews the way dependency operated in the US-Latin American case, and analyzes the growing Chinese presence within a dependency framework.
Dehn filling Dehn twists
Authors: Dahmani François , Hagen Mark , Sisto Alessandro
Published: January 2020

Let$\Sigma _{g,p}$be the genus–goriented surface withppunctures, with eitherg> 0 orp> 3. We show that$MCG(\Sigma _{g,p})/DT$is acylindrically hyperbolic whereDTis the normal subgroup of the mapping class group$MCG(\Sigma _{g,p})$generated by$K^{th}$powers of Dehn twists about curves in$\Sigma _{g,p}$for suitableK.

Moreover, we show that in low complexity$MCG(\Sigma _{g,p})/DT$is in fact hyperbolic. In particular, for 3g− 3 +p⩽ 2, we show that the mapping class group$MCG(\Sigma _{g,p})$is fully residually non-elementary hyperbolic and admits an affine isometric action with unbounded orbits on some$L^q$space. Moreover, if every hyperbolic group is residually finite, then every convex-cocompact subgroup of$MCG(\Sigma _{g,p})$is separable.

The aforementioned results follow from general theorems about composite rotating families, in the sense of [13], that come from a collection of subgroups of vertex stabilizers for the action of a groupGon a hyperbolic graphX. We give conditions ensuring that the graphX/Nis again hyperbolic and various properties of the action ofGonXpersist for the action ofG/NonX/N.
Improving rapid multiplication of sweetpotato (Ipomoea batatas L. (Lam) pre-basic seed using sandponics technology in East Africa
Authors: Wanjala Bramwel W. , Srinivasulu Rajendran , Makokha Phabian , Ssali Reuben T. , McEwan Margaret , Kreuze Jan F. , Low Jan W.
Published: January 2020

Sweetpotato (Ipomoea batatas, Convolvulaceae) is an important food crop in Sub-Saharan Africa (SSA). Lack of access to quality sweetpotato planting material after sweetpotato limits utilization of market oriented improved clones and new varieties. Obtaining clean planting material in the right quantity and quality is a challenge in the SSA region. Farmers often obtain planting materials from their own sources with multiple rooting, drawn from a previous crop or neighbors and face the risk of it being infected with sweetpotato viruses. The objective of this study was to examine the economic and physical yield performance of sandponics multiplication method by comparing with conventional soil method using optimal N-nutrient inputs. The performance of five sweetpotato cultivars (Irene, Delvia, Tanzania, Gweri, and Kabode) in the modified prototype sweetpotato nutrient media was evaluated. Vine production utilizing modified sandponics nutrient media with trellised plants was compared to the conventionally used soil media. Analysis of variance indicated that the main effects of cultivar and substrate were highly significant (p < 0.0001) for nodes produced, vine multiplication rate (VMR), number of cuttings produced, and vine length. In addition, cultivar by substrate interaction was highly significant at 0.01 probability level for nodes produced, VMR, and vine length. Vine multiplication rate was 33% higher in the sandponics system compared to the conventional soil method of multiplying sweetpotato vines. Among the cultivars studied, Irene was the most favorable cultivar with a VMR of 65.2 in sand and 45.5 in soil. The cost-effectiveness analysis indicates that the cost per cutting (i.e., 3–4 nodes) produced from sandponics method was 4.6 KSH (US$ 0.046) as compared to 3.1 KSH (US$ 0.031) per cutting produced from conventional method. Sandponics system is competitive due to its capability of increased VMRs. However, the optimal number of ratooning needs to be investigated to understand the economies of scale in future research.
DNA barcoding reveals cryptic diversity and peculiar phylogeographic patterns in mojarras (Perciformes: Gerreidae) from the Caribbean and South-western Atlantic
Authors: Jacobina Uedson Pereira , Torres Rodrigo Augusto , de Mello Affonso Paulo Roberto Antunes , dos Santos Ewerton Vieira , Calado Leonardo Luiz , de Araújo Bitencourt Jamille
Published: January 2020

The mojarras (Eucinostomus) are a widespread group of coastal fishes of controversial taxonomy because of similarities in their external morphology. In the present study, we assessed the genetic diversity of species and populations of Eucinostomus using DNA barcodes using a systematic and phylogeographic context. In total, 416 COI sequences of all valid Eucinostomus representatives were analysed based on public databases and collected specimens from the north-eastern coast of Brazil (Western South Atlantic). Several cases of misidentification were detected in the barcode dataset (E. argenteus, E. harengulus, E. gula, E. dowii and E. jonesii) that could account for the taxonomic issues in this genus. In contrast, we identified four molecular operational taxonomic units (MOTUs), with divergence above 2% in the Western Atlantic, that correspond to cryptic forms within E. argenteus, E. harengulus, E. gula and E. melanopterus. These data suggest that Plio-Pleistocene events (rise of the Panama isthmus, Amazonas outflow and sea-level fluctuations) played a major role in the diversification of mojarras. While subtle morphological differences have been used as proxies to discriminate Eucinostomus species, the genetic data proved to be efficient in differentiating them and revealing potentially undescribed taxa. Therefore, we recommend that further taxonomic studies in mojarras should incorporate DNA-based evidence.
Risk of psychotic disorders in migrants to Australia
Authors: O'Donoghue Brian , Downey Linglee , Eaton Scott , Mifsud Nathan , Kirkbride James B. , McGorry Patrick
Published: January 2020

Background

Certain migrant groups are at an increased risk of psychotic disorders compared to the native-born population; however, research to date has mainly been conducted in Europe. Less is known about whether migrants to other countries, with different histories and patterns of migration, such as Australia, are at an increased risk for developing a psychotic disorder. We tested this for first-generation migrants in Melbourne, Victoria.

Methods

This study included all young people aged 15–24 years, residing in a geographically-defined catchment area of north western Melbourne who presented with a first episode of psychosis (FEP) to the Early Psychosis Prevention and Intervention Centre (EPPIC) between 1 January 2011 and 31 December 2016. Data pertaining to the at-risk population were obtained from the Australian 2011 Census and incidence rate ratios were calculated and adjusted for age, sex and social deprivation.

Results

In total, 1220 young people presented with an FEP during the 6-year study period, of whom 24.5% were first-generation migrants. We found an increased risk for developing psychotic disorder in migrants from the following regions: Central and West Africa (adjusted incidence rate ratio [aIRR] = 3.53, 95% CI 1.58–7.92), Southern and Eastern Africa (aIRR = 3.06, 95% CI 1.99–4.70) and North Africa (aIRR = 5.03, 95% CI 3.26–7.76). Migrants from maritime South East Asia (aIRR = 0.39, 95% CI 0.23–0.65), China (aIRR = 0.25, 95% CI 0.13–0.48) and Southern Asia (aIRR = 0.44, 95% CI 0.26–0.76) had a decreased risk for developing a psychotic disorder.

Conclusion

This clear health inequality needs to be addressed by sufficient funding and accessible mental health services for more vulnerable groups. Further research is needed to determine why migrants have an increased risk for developing psychotic disorders.
Revisiting McGovern-Fraser: Party Nationalization and the Rhetoric of Reform
Authors: SÁNCHEZ JAIME
Published: January 2020

The Democratic Party faced a crisis of political legitimacy in the late 1960s as distrust and protest permeated its electoral base. In response, the Democratic National Committee established the Commission on Party Structure and Delegate Selection, tasked with restructuring the party’s presidential nomination process. Contrary to the conventional historical narrative of the McGovern-Fraser Commission that has focused on a supposed displacement of the party’s old guard by radical insurgents, this article instead argues that the main impetus for reform came from national party leaders seeking to build up the legitimacy and authority of the National Committee. Commission Chair George McGovern and the DNC used a particular reform rhetoric that charged state parties with the corruption of the political process, necessitating rescue by an empowered national party. This focus on the nationalizing impulses behind McGovern-Fraser serves to shift our attention away from ideological struggles and toward institutional motives.
Interagency Cooperation in the Twilight of the Great Society: Telemedicine, NASA, and the Papago Nation
Authors: SIMPSON ANDREW T. , DOARN CHARLES R. , GARBER STEPHEN J.
Published: January 2020

NASA has put people in unique and extreme environments for over six decades. Supporting these individuals with a comprehensive health-care system has evolved over this period. As the Apollo program ended and NASA began to contemplate a space shuttle and space station program, societal pressures in the late 1960s and early 1970s caused federal agencies such as NASA to reconsider how to link the needs of the space program with a growing pressure to address societal needs by forging interagency partnerships. The Space Technology Applied to the Rural Papago Health Care (STARPAHC) project provides an example of how NASA sought to balance these two imperatives in an age of diminishing federal support. This project can provide lessons for today’s uncertain budgetary future for agencies such as NASA, which are once again being asked to find creative and innovative ways to support their missions while demonstrating their larger value to society.
Subduing the Mormons in Utah Territory: Foundation for theInsularCases
Authors: LINDBERG TIMOTHY
Published: January 2020

The conflict between the US government and the Mormons in Utah Territory during the second half of the nineteenth century reflected shifts in the American territorial system. Through a repudiation of religious practices and dismantling of the Latter-Day Saints’ Church as an institution, the federal government demonstrated a willingness and ability to interfere with and regulate traditional local issues such as marriage and religion. This provided a foundation for the changes to the territorial system outlined by the Supreme Court in the Insular Cases. Scholars have overlooked the continuities between earlier territorial policy and the post-Insular Cases colonial system. Linking the struggle over authority in Utah Territory with the outcome of the Insular Cases as a component of territorial policy history fills this gap and helps to illuminate the policy connections between continental expansion and overseas expansion.
The impact of the Pan-African-aged tectonothermal event on high-grade rocks at Mount Brown, East Antarctica
Authors: Liu Xiaochun , Fu Bin , Li Qiuli , Zhao Yue , Liu Jian , Chen Hong
Published: January 2020

This study presents monazite and rutile U–Pb and hornblende and biotite40Ar/39Ar geochronological data for high-grade rocks of the eastern Grenville-aged Rayner orogen at Mount Brown in order to analyse the extent and degree of Pan-African-aged reworking. Monazite from paragneiss yields U–Pb ages of 910 Ma for larger granular grains and 670–630 Ma for smaller globular beads around garnet porphyroblasts or hosted by symplectites. Rutile from leucogneiss yields U–Pb ages of 520–515 Ma. Hornblende and biotite from different rock types yield40Ar/39Ar plateau ages of 744 and 520–505 Ma, respectively. Combining these results with published zircon U–Pb age data suggests that granulite facies metamorphism occurred at 910 Ma, with a local low-temperature fluid flow event at 670–630 Ma and thermal reworking at 520–505 Ma. The older age of 744 Ma may reflect cooling or partial resetting of the hornblende40Ar/39Ar system, indicating that Pan-African-aged reworking did not exceed temperatures much higher than the hornblende Ar closure temperature. These data also suggest that the complete isotopic resetting of some minerals may occur without the growth of new mineral phases, providing an example of the style of reworking that is likely to occur in polymetamorphic terranes.
An ethnographic study exploring factors that minimize lunch waste in Tokyo elementary schools
Authors: Izumi Betty T , Akamatsu Rie , Byker Shanks Carmen , Fujisaki Kahori
Published: January 2020

Objective:

To explore factors that minimize lunch waste in Tokyo elementary schools and to consider how such factors can be modified and applied in US schools.

Design:

Focused ethnographic study using interviews, observation, participant observation and document review. Data were analysed using thematic analysis.

Setting:

Tokyo, Japan.

Participants:

Five school dietitians participated in the study. Data collection methods included in-depth interviews, observation of nutrition education lessons, participant observation of school lunchtime and review of relevant school documents (e.g. lunch menus, food waste records).

Results:

Five themes emerged from the analysis: (i) reinforcement of social norms to eat without waste; (ii) menu planning to increase exposure to unfamiliar and/or disliked foods; (iii) integration of food and nutrition education into the school curriculum; (iv) teacher lunchtime practices related to portion sizes, distributing leftover food and time management; and (v) engagement of students in reducing school lunch waste. Practical and tangible applications to US schools include measuring and reporting lunch waste to influence social norms, teaching students about the importance of reducing food waste, offering flexible school lunch portion sizes and providing students with meaningful opportunities to contribute to solving the problem of school lunch waste.

Conclusions:

Japan offers a model for minimizing school lunch waste through a holistic approach that includes factors that operate at and interact across multiple levels of society. Modifying and applying such an approach in US schools is worth considering given the urgent need to address food waste in order to support healthy diets and sustainable food systems.
Landscape positions dictating crop fertilizer responses in wheat-based farming systems of East African Highlands
Authors: Amede Tilahun , Gashaw Tadesse , Legesse Gizachew , Tamene Lulseged , Mekonen Kindu , Thorne Peter , Schultz Steffen
Published: January 2020

Improving fertilizer use efficiency has remained a challenge, particularly for small-scale farming in undulating ‘abnormal’ landscapes of East Africa. Milne's 1930s concept on ‘Catena’ was considered as a breakthrough in understanding soil variability and its implication on productivity in East African highlands. However, there is limited information on how the ‘Catena’ features could be used for fine tuning fertilizer recommendations. We initiated multiple on-farm replicated experiments in three wheat-growing districts (Endamohoni, Lemo and Worreilu) in the Ethiopian highlands in 2014, 2015 and 2016 to assess landscape positions affecting crop-nutrient responses, identify yield limiting nutrients across the ‘Catena’ (N, P, K, S and Zn) and quantify effects of landscape positions on resources use efficiency. We clustered farmlands across the ‘Catena’ (Hillslopes, Midslopes and Footslopes) based on land scape positions in the respective locations. Wheat yield was more strongly and significantly affected by landscape positions (P < 0.001) than by nutrient sources or rates. The crop response to fertilizers was 50 to 300% higher in foot slopes than in hillslopes, depending on locations and inputs levels. With increasing slope, there was a decrease in a crop fertilizer response due to a significant decrease in soil organic carbon, clay content and soil water content, with r2 of 0.95, 0.86 and 0.96, respectively. The difference in the crop response between landscape positions was significantly higher (P < 0.05) with higher rates of nutrient applications (>N92 P46) while differences between landscape positions diminish at lower rates. Yield benefits due to application of K was significant only in the dry years (P < 0.05), while there was hardly any yield benefit from the application of zinc and sulfur. The crop nitrogen recovery fraction and crop water productivity decreased with an increasing slope regardless of nutrient combinations. The results indicated that the landscape position could be considered as a proxy indicator for targeted fertilizer application, particularly in farms with undulating topographic features. Hillslopes are better served by the application of organic fertilizers along with conservation measures as applying higher rates of mineral fertilizer in hillslopes would rather increase the risk of downstream nutrient movement.
Plume‐Induced Subduction Initiation: Single‐Slab or Multi‐Slab Subduction?
Authors: Baes Marzieh , Sobolev Stephan , Gerya Taras , Brune Sascha
Published: January 2020

Initiation of subduction following the impingement of a hot buoyant mantle plume is one of the few scenarios that allow breaking the lithosphere and recycling a stagnant lid without requiring any preexisting weak zones. Here, we investigate factors controlling the number and shape of retreating subducting slabs formed by plume‐lithosphere interaction. Using 3‐D thermomechanical models we show that the deformation regime, which defines formation of single‐slab or multi‐slab subduction, depends on several parameters such as age of oceanic lithosphere, thickness of the crust and large‐scale lithospheric extension rate. Our model results indicate that on present‐day Earth multi‐slab plume‐induced subduction is initiated only if the oceanic lithosphere is relatively young (<30–40 Myr, but >10 Myr), and the crust has a typical thickness of 8 km. In turn, development of single‐slab subduction is facilitated by older lithosphere and pre‐imposed extensional stresses. In early Earth, plume‐lithosphere interaction could have led to formation of either episodic short‐lived circular subduction when the oceanic lithosphere was young or to multi‐slab subduction when the lithosphere was old.
The Relationship Between Magmatism and Deformation Along the Intra‐arc Strike‐Slip Atacama Fault System, Northern Chile
Authors: Seymour N. M. , Singleton J. S. , Mavor S. P. , Gomila R. , Stockli D. F. , Heuser G. , Arancibia G.
Published: January 2020

Magmatic arcs may play a major role in the initiation, behavior, and abandonment of intra‐arc strike‐slip systems. Here we present zircon U‐Pb and (U‐Th)/He geochronology/thermochronology with new mapping to relate Coastal Cordillera arc magmatism to sinistral shear along the Atacama fault system (AFS) in northern Chile. New dates from 18 intrusions along the AFS between 24.6°S and 27°S compiled with published data record a minor Early Jurassic magmatic pulse (195–175 Ma), broad latest Jurassic to Early Cretaceous (150–120 Ma) pulse, and a minor younger (120–105 Ma) pulse. Mylonitization occurred only along the margins of Early Cretaceous plutons and surrounding Paleozoic metasedimentary rock, whereas Jurassic plutons and metasedimentary rocks away from Early Cretaceous plutons lack mylonitic fabrics. Early Cretaceous magmatism facilitated AFS deformation by thermally weakening the crust with elevated geothermal gradients that enabled mylonitization to take place at ~5‐ to 7‐km depths and low stresses. Spatial variability of pluton emplacement produced significant rheological heterogeneity, giving rise to a highly segmented fault system that did not originate as a regional‐scale shear zone. Synkinematic dikes (~120–117 Ma) cut mylonitic fabrics, and a postkinematic dike (~110 Ma) records the end stages of slip. The cessation of slip coincided with cooling below ~180 °C at ~116–99 Ma as arc magmatism migrated eastward and geothermal gradients relaxed, coeval with a major reorganization in plate motion and the onset of seafloor spreading in the south Atlantic.
Digital Rock Segmentation for Petrophysical Analysis With Reduced User Bias Using Convolutional Neural Networks
Authors: Niu Yufu , Mostaghimi Peyman , Shabaninejad Mehdi , Swietojanski Pawel , Armstrong Ryan T.
Published: January 2020

Pore‐scale digital images are usually obtained from microcomputed tomography data that has been segmented into void and grain space. Image segmentation is a crucial step in the process of digital rock analysis that can influence pore‐scale characterization studies and/or the numerical simulation of petrophysical properties. This is concerning since all segmentation methods have user‐selected parameters that result in biases. Convolutional neural networks (CNNs) provide a way forward since once trained, CNN can provide consistent and reliable image segmentation with no user‐defined inputs. In this paper, a CNN is used to segment digital sandstone data, and various ground truth data sets are tested. The ground truth images are created based on high‐resolution microcomputed tomography data and corresponding scanning electron microscope data. The results are evaluated in terms of porosity, permeability, and pore size distribution computed from the segmented data. We find that watershed‐based segmentation provides a wide range of possible petrophysical values depending on user‐selected thresholds, whereas CNN provides a smaller variance when trained on scanning electron microscope data. It can be concluded that CNN offers a reliable and consistent way to segment digital sandstone data for petrophysical analyses.
Daratumumab plus lenalidomide and dexamethasone in relapsed/refractory multiple myeloma: extended follow-up of POLLUX, a randomized, open-label, phase 3 study
Authors: Bahlis Nizar J. , Dimopoulos Meletios A. , White Darrell J. , Benboubker Lotfi , Cook Gordon , Leiba Merav , Ho P. Joy , Kim Kihyun , Takezako Naoki , Moreau Philippe , Kaufman Jonathan L. , Krevvata Maria , Chiu Christopher , Qin Xiang , Okonkwo Linda , Trivedi Sonali , Ukropec Jon , Qi Ming , San-Miguel Jesus
Published: January 2020

In POLLUX, daratumumab (D) plus lenalidomide/dexamethasone (Rd) reduced the risk of disease progression or death by 63% and increased the overall response rate (ORR) versus Rd in relapsed/refractory multiple myeloma (RRMM). Updated efficacy and safety after >3 years of follow-up are presented. Patients (N = 569) with ≥1 prior line received Rd (lenalidomide, 25 mg, on Days 1–21 of each 28-day cycle; dexamethasone, 40 mg, weekly) ± daratumumab at the approved dosing schedule. Minimal residual disease (MRD) was assessed by next-generation sequencing. After 44.3 months median follow-up, D-Rd prolonged progression-free survival (PFS) in the intent-to-treat population (median 44.5 vs 17.5 months; HR, 0.44; 95% CI, 0.35–0.55; P < 0.0001) and in patient subgroups. D-Rd demonstrated higher ORR (92.9 vs 76.4%; P < 0.0001) and deeper responses, including complete response or better (56.6 vs 23.2%; P < 0.0001) and MRD negativity (10–5; 30.4 vs 5.3%; P < 0.0001). Median time to next therapy was prolonged with D-Rd (50.6 vs 23.1 months; HR, 0.39; 95% CI, 0.31–0.50; P < 0.0001). Median PFS on subsequent line of therapy (PFS2) was not reached with D-Rd versus 31.7 months with Rd (HR, 0.53; 95% CI, 0.42–0.68; P < 0.0001). No new safety concerns were reported. These data support using D-Rd in patients with RRMM after first relapse.
Protein tyrosine phosphatase 4A3 (PTP4A3/PRL-3) drives migration and progression of T-cell acute lymphoblastic leukemia in vitro and in vivo
Authors: Wei M. , Haney M. G. , Rivas D. R. , Blackburn J. S.
Published: January 2020

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive blood cancer. There are no immunotherapies and few molecularly targeted therapeutics available for treatment of this malignancy. The identification and characterization of genes and pathways that drive T-ALL progression are critical for the development of new therapies for T-ALL. Here, we determined that the protein tyrosine phosphatase 4A3 (PTP4A3 or PRL-3) plays a critical role in T-ALL initiation and progression by promoting leukemia cell migration. PRL-3 is highly expressed in patient T-ALL samples at both the mRNA and protein levels compared to normal lymphocytes. Knock-down of PRL-3 expression using short-hairpin RNA (shRNA) in human T-ALL cell lines significantly impeded T-ALL cell migration capacity in vitro and reduced their ability to engraft and proliferate in vivo in xenograft mouse models. Additionally, PRL-3 overexpression in aMyc-induced zebrafish T-ALL model significantly accelerated disease onset and shortened the time needed for cells to enter blood circulation. Reverse-phase protein array (RPPA) and gene set enrichment analysis (GSEA) revealed that the SRC signaling pathway is affected by PRL-3. Immunoblot analyses validated that manipulation of PRL-3 expression in T-ALL cells affected the SRC signaling pathway, which is directly involved in cell migration, although Src was not a direct substrate of PRL-3. More importantly, T-ALL cell growth and migration were inhibited by small molecule inhibition of PRL-3, suggesting that PRL-3 has potential as a therapeutic target in T-ALL. Taken together, our study identifies PRL-3 as an oncogenic driver in T-ALL both in vitro and in vivo and provides a strong rationale for targeted therapies that interfere with PRL-3 function.
Two faces of bivalent domain regulate VEGFA responsiveness and angiogenesis
Authors: Chen Jiahuan , Liang Xiaodong , Zhang Shasha , Wang Shiyan , Garcia Sara P. , Yan Pengyi , Yu Huijing , Li Zixuan , Liu Li , Zhang Fang , Wei Weiting , Le Huangying , Zhang Yan , Yuan Guo-cheng , Chen Sun , Chen Yingwei , Sun Kun , Pu William T. , Zhang Bing
Published: January 2020

The bivalent domain (BD) at promoter region is an unique epigenetic feature poised for activation or repression during cell differentiation in embryonic stem cell. However, the function of BDs in already differentiated cells remains exclusive. By profiling the epigenetic landscape of endothelial cells during VEGFA (vascular endothelial growth factor A) stimulation, we discovered that BDs are widespread in endothelial cells and preferentially marked genes responsive to VEGFA. The BDs responsive to VEGFA have more permissive chromatin environment comparing to other BDs. The initial activation of bivalent genes depends on RNAPII pausing release induced by EZH1 rather than removal of H3K27me3. The later suppression of bivalent gene expression depended on KDM5A recruitment by its interaction with PRC2. Importantly, EZH1 promoted both in vitro and in vivo angiogenesis by upregulating EGR3, whereas KDM5A dampened angiogenesis. Collectively, this study demonstrates a novel dual function of BDs in endothelial cells to control VEGF responsiveness and angiogenesis.
Inhibition of AIM2 inflammasome activation alleviates GSDMD-induced pyroptosis in early brain injury after subarachnoid haemorrhage
Authors: Yuan Bin , Zhou Xiao-ming , You Zong-qi , Xu Wei-dong , Fan Jie-mei , Chen Shu-juan , Han Yan-ling , Wu Qi , Zhang Xin
Published: January 2020

Only a few types of inflammasomes have been described in central nervous system cells. Among these, the absent in melanoma 2 (AIM2) inflammasome is primarily found in neurons, is highly specific and can be activated only by double-stranded DNA. Although it has been demonstrated that the AIM2 inflammasome is activated by poly(deoxyadenylic-deoxythymidylic) acid sodium salt and leads to pyroptotic neuronal cell death, the role of AIM2 inflammasome-mediated pyroptosis in early brain injury (EBI) after subarachnoid haemorrhage (SAH) has rarely been studied. Thus, we designed this study to explore the mechanism of gasdermin D(GSDMD)-induced pyroptosis mediated by the AIM2 inflammasome in EBI after SAH. The level of AIM2 from the cerebrospinal fluid (CSF) of patients with SAH was detected. The pathway of AIM2 inflammasome-mediated pyroptosis, the AIM2/Caspase-1/GSDMD pathway, was explored after experimental SAH in vivo and in primary cortical neurons stimulated by oxyhaemoglobin (oxyHb) in vitro. Then, we evaluated GSDMD-induced pyroptosis mediated by the AIM2 inflammasome in AIM2 and caspase-1- deficient mice and primary cortical neurons generated through lentivirus (LV) knockdown. Compared with that of the control samples, the AIM2 level in the CSF of the patients with SAH was significantly increased. Pyroptosis-associated proteins mediated by the AIM2 inflammasome were significantly increased in vivo and in vitro following experimentally induced SAH. After AIM2 and caspase-1 were knocked down by an LV, GSDMD-induced pyroptosis mediated by the AIM2 inflammasome was alleviated in EBI after SAH. Intriguingly, when caspase-1 was knocked down, apoptosis was significantly suppressed via impeding the activation of caspase-3. GSDMD-induced pyroptosis mediated by the AIM2 inflammasome may be involved in EBI following SAH. The inhibition of AIM2 inflammasome activation caused by knocking down AIM2 and caspase-1 alleviates GSDMD-induced pyroptosis in EBI after SAH.
Laminated self-standing covalent organic framework membrane with uniformly distributed subnanopores for ionic and molecular sieving
Authors: Li Yang , Wu Qianxun , Guo Xinghua , Zhang Meicheng , Chen Bin , Wei Guanyi , Li Xing , Li Xiaofeng , Li Shoujian , Ma Lijian
Published: January 2020

The preparation of subnanoporous covalent-organic-framework (COF) membranes with high performance for ion/molecule sieving still remains a great challenge. In addition to the difficulties in fabricating large-area COF membranes, the main reason is that the pore size of 2D COFs is much larger than that of most gas molecules and/or ions. It is urgently required to further narrow their pore sizes to meet different separation demands. Herein, we report a simple and scalable way to grow large-area, pliable, free-standing COF membranes via a one-step route at organic–organic interface. The pore sizes of the membranes can be adjusted from >1 nm to sub-nm scale by changing the stacking mode of COF layers from AA to AB stacking. The obtained AB stacking COF membrane composed of highly-ordered nanoflakes is demonstrated to have narrow aperture (∼0.6 nm), uniform pore distribution and shows good potential in organic solvent nanofiltration, water treatment and gas separation.
Macrophages directly contribute collagen to scar formation during zebrafish heart regeneration and mouse heart repair
Authors: Simões Filipa C. , Cahill Thomas J. , Kenyon Amy , Gavriouchkina Daria , Vieira Joaquim M. , Sun Xin , Pezzolla Daniela , Ravaud Christophe , Masmanian Eva , Weinberger Michael , Mayes Sarah , Lemieux Madeleine E. , Barnette Damien N. , Gunadasa-Rohling Mala , Williams Ruth M. , Greaves David R. , Trinh Le A. , Fraser Scott E. , Dallas Sarah L. , Choudhury Robin P. , Sauka-Spengler Tatjana , Riley Paul R.
Published: January 2020

Canonical roles for macrophages in mediating the fibrotic response after a heart attack include extracellular matrix turnover and activation of cardiac fibroblasts to initiate collagen deposition. Here we reveal that macrophages directly contribute collagen to the forming post-injury scar. Unbiased transcriptomics shows an upregulation of collagens in both zebrafish and mouse macrophages following heart injury. Adoptive transfer of macrophages, from either collagen-tagged zebrafish or adult mouse GFPtpz-collagen donors, enhances scar formation via cell autonomous production of collagen. In zebrafish, the majority of tagged collagen localises proximal to the injury, within the overlying epicardial region, suggesting a possible distinction between macrophage-deposited collagen and that predominantly laid-down by myofibroblasts. Macrophage-specific targeting of col4a3bpa and cognate col4a1 in zebrafish significantly reduces scarring in cryoinjured hosts. Our findings contrast with the current model of scarring, whereby collagen deposition is exclusively attributed to myofibroblasts, and implicate macrophages as direct contributors to fibrosis during heart repair.
Pattern generation and symbolic dynamics in a nanocontact vortex oscillator
Authors: Yoo Myoung-Woo , Rontani Damien , Létang Jérémy , Petit-Watelot Sébastien , Devolder Thibaut , Sciamanna Marc , Bouzehouane Karim , Cros Vincent , Kim Joo-Von
Published: January 2020

Harnessing chaos or intrinsic nonlinear behaviours of dynamical systems is a promising avenue toward unconventional information processing technologies. In this light, spintronic devices are promising because of the inherent nonlinearity of magnetization dynamics. Here, we demonstrate experimentally the potential for chaos-based schemes using nanocontact vortex oscillators by unveiling and characterizing their waveform patterns and symbolic dynamics using time-resolved electrical measurements. We dissociate nonlinear deterministic patterns from thermal fluctuations and show that the emergence of chaos results in the unpredictable alternation of well-defined patterns. With phase-space reconstruction techniques, we perform symbolic analyses of the time series and show that the oscillator exhibits maximal entropy and complexity at the centre of its incommensurate region. This suggests that such vortex-based systems are promising nanoscale sources of entropy that could be exploited for information processing.
Cerebrospinal fluid lipocalin 2 as a novel biomarker for the differential diagnosis of vascular dementia
Authors: Llorens Franc , Hermann Peter , Villar-Piqué Anna , Diaz-Lucena Daniela , Nägga Katarina , Hansson Oskar , Santana Isabel , Schmitz Matthias , Schmidt Christian , Varges Daniela , Goebel Stefan , Dumurgier Julien , Zetterberg Henrik , Blennow Kaj , Paquet Claire , Baldeiras Inês , Ferrer Isidro , Zerr Inga
Published: January 2020

The clinical diagnosis of vascular dementia (VaD) is based on imaging criteria, and specific biochemical markers are not available. Here, we investigated the potential of cerebrospinal fluid (CSF) lipocalin 2 (LCN2), a secreted glycoprotein that has been suggested as mediating neuronal damage in vascular brain injuries. The study included four independent cohorts with a total n = 472 samples. LCN2 was significantly elevated in VaD compared to controls, Alzheimer’s disease (AD), other neurodegenerative dementias, and cognitively unimpaired patients with cerebrovascular disease. LCN2 discriminated VaD from AD without coexisting VaD with high accuracy. The main findings were consistent over all cohorts. Neuropathology disclosed a high percentage of macrophages linked to subacute infarcts, reactive astrocytes, and damaged blood vessels in multi-infarct dementia when compared to AD. We conclude that CSF LCN2 is a promising candidate biochemical marker in the differential diagnosis of VaD and neurodegenerative dementias.
Reversible interconversion between methanol-diamine and diamide for hydrogen storage based on manganese catalyzed (de)hydrogenation
Authors: Shao Zhihui , Li Yang , Liu Chenguang , Ai Wenying , Luo Shu-Ping , Liu Qiang
Published: January 2020

The development of cost-effective, sustainable, and efficient catalysts for liquid organic hydrogen carrier systems is a significant goal. However, all the reported liquid organic hydrogen carrier systems relied on the use of precious metal catalysts. Herein, a liquid organic hydrogen carrier system based on non-noble metal catalysis was established. The Mn-catalyzed dehydrogenative coupling of methanol and N,N’-dimethylethylenediamine to form N,N’-(ethane-1,2-diyl)bis(N-methylformamide), and the reverse hydrogenation reaction constitute a hydrogen storage system with a theoretical hydrogen capacity of 5.3 wt%. A rechargeable hydrogen storage could be achieved by a subsequent hydrogenation of the resulting dehydrogenation mixture to regenerate the H2-rich compound. The maximum selectivity for the dehydrogenative amide formation was 97%.
Rewiring of endogenous signaling pathways to genomic targets for therapeutic cell reprogramming
Authors: Krawczyk Krzysztof , Scheller Leo , Kim Hyojin , Fussenegger Martin
Published: January 2020

Rewiring cellular sensors to trigger non-natural responses is fundamental for therapeutic cell engineering. Current designs rely on engineered receptors that are limited to single inputs, and often suffer from high leakiness and low fold induction. Here, we present Generalized Engineered Activation Regulators (GEARs) that overcome these limitations by being pathway-specific rather than input-specific. GEARs consist of the MS2 bacteriophage coat protein fused to regulatory or transactivation domains, and work by rerouting activation of the NFAT, NFκB, MAPK or SMAD pathways to dCas9-directed gene expression from genomic loci. This system enables membrane depolarization-induced activation of insulin expression in β-mimetic cells and IL-12 expression in activated Jurkat cells, as well as IL-12 production in response to the immunomodulatory cytokines TGFβ and TNFα in HEK293T cells. Engineered cells with the ability to reinterpret the extracellular milieu have potential for applications in immunotherapy and in the treatment of metabolic diseases.
Structure of the prefusion-locking broadly neutralizing antibody RVC20 bound to the rabies virus glycoprotein
Authors: Hellert Jan , Buchrieser Julian , Larrous Florence , Minola Andrea , de Melo Guilherme Dias , Soriaga Leah , England Patrick , Haouz Ahmed , Telenti Amalio , Schwartz Olivier , Corti Davide , Bourhy Hervé , Rey Félix A.
Published: January 2020

Rabies virus (RABV) causes fatal encephalitis in more than 59,000 people yearly. Upon the bite of an infected animal, the development of clinical disease can be prevented with post-exposure prophylaxis (PEP), which includes the administration of Rabies immunoglobulin (RIG). However, the high cost and limited availability of serum-derived RIG severely hamper its wide use in resource-limited countries. A safe low-cost alternative is provided by using broadly neutralizing monoclonal antibodies (bnAbs). Here we report the X-ray structure of one of the most potent and most broadly reactive human bnAbs, RVC20, in complex with its target domain III of the RABV glycoprotein (G). The structure reveals that the RVC20 binding determinants reside in a highly conserved surface of G, rationalizing its broad reactivity. We further show that RVC20 blocks the acid-induced conformational change required for membrane fusion. Our results may guide the future development of direct antiviral small molecules for Rabies treatment.
The role of photon recycling in perovskite light-emitting diodes
Authors: Cho Changsoon , Zhao Baodan , Tainter Gregory D. , Lee Jung-Yong , Friend Richard H. , Di Dawei , Deschler Felix , Greenham Neil C.
Published: January 2020

Perovskite light-emitting diodes have recently broken the 20% barrier for external quantum efficiency. These values cannot be explained with classical models for optical outcoupling. Here, we analyse the role of photon recycling (PR) in assisting light extraction from perovskite light-emitting diodes. Spatially-resolved photoluminescence and electroluminescence measurements combined with optical modelling show that repetitive re-absorption and re-emission of photons trapped in substrate and waveguide modes significantly enhance light extraction when the radiation efficiency is sufficiently high. In this manner, PR can contribute more than 70% to the overall emission, in agreement with recently-reported high efficiencies. While an outcoupling efficiency of 100% is theoretically possible with PR, parasitic absorption losses due to absorption from the electrodes are shown to limit practical efficiencies in current device architectures. To overcome the present limits, we propose a future configuration with a reduced injection electrode area to drive the efficiency toward 100%.
Network-induced multistability through lossy coupling and exotic solitary states
Authors: Hellmann Frank , Schultz Paul , Jaros Patrycja , Levchenko Roman , Kapitaniak Tomasz , Kurths Jürgen , Maistrenko Yuri
Published: January 2020

The stability of synchronised networked systems is a multi-faceted challenge for many natural and technological fields, from cardiac and neuronal tissue pacemakers to power grids. For these, the ongoing transition to distributed renewable energy sources leads to a proliferation of dynamical actors. The desynchronisation of a few or even one of those would likely result in a substantial blackout. Thus the dynamical stability of the synchronous state has become a leading topic in power grid research. Here we uncover that, when taking into account physical losses in the network, the back-reaction of the network induces new exotic solitary states in the individual actors and the stability characteristics of the synchronous state are dramatically altered. These effects will have to be explicitly taken into account in the design of future power grids. We expect the results presented here to transfer to other systems of coupled heterogeneous Newtonian oscillators.
Optogenetic regulation of endogenous proteins
Authors: Redchuk Taras A. , Karasev Maksim M. , Verkhusha Polina V. , Donnelly Sara K. , Hülsemann Maren , Virtanen Jori , Moore Henna M. , Vartiainen Maria K. , Hodgson Louis , Verkhusha Vladislav V.
Published: January 2020

Techniques of protein regulation, such as conditional gene expression, RNA interference, knock-in and knock-out, lack sufficient spatiotemporal accuracy, while optogenetic tools suffer from non-physiological response due to overexpression artifacts. Here we present a near-infrared light-activatable optogenetic system, which combines the specificity and orthogonality of intrabodies with the spatiotemporal precision of optogenetics. We engineer optically-controlled intrabodies to regulate genomically expressed protein targets and validate the possibility to further multiplex protein regulation via dual-wavelength optogenetic control. We apply this system to regulate cytoskeletal and enzymatic functions of two non-tagged endogenous proteins, actin and RAS GTPase, involved in complex functional networks sensitive to perturbations. The optogenetically-enhanced intrabodies allow fast and reversible regulation of both proteins, as well as simultaneous monitoring of RAS signaling with visible-light biosensors, enabling all-optical approach. Growing number of intrabodies should make their incorporation into optogenetic tools the versatile technology to regulate endogenous targets.
Carbon doping switching on the hydrogen adsorption activity of NiO for hydrogen evolution reaction
Authors: Kou Tianyi , Chen Mingpeng , Wu Feng , Smart Tyler J. , Wang Shanwen , Wu Yishang , Zhang Ying , Li Shengtong , Lall Supriya , Zhang Zhonghua , Liu Yi-Sheng , Guo Jinghua , Wang Gongming , Ping Yuan , Li Yat
Published: January 2020

Hydrogen evolution reaction (HER) is more sluggish in alkaline than in acidic media because of the additional energy required for water dissociation. Numerous catalysts, including NiO, that offer active sites for water dissociation have been extensively investigated. Yet, the overall HER performance of NiO is still limited by lacking favorable H adsorption sites. Here we show a strategy to activate NiO through carbon doping, which creates under-coordinated Ni sites favorable for H adsorption. DFT calculations reveal that carbon dopant decreases the energy barrier of Heyrovsky step from 1.17 eV to 0.81 eV, suggesting the carbon also serves as a hot-spot for the dissociation of water molecules in water-alkali HER. As a result, the carbon doped NiO catalyst achieves an ultralow overpotential of 27 mV at 10 mA cm−2, and a low Tafel slope of 36 mV dec−1, representing the best performance among the state-of-the-art NiO catalysts.
Valley phonons and exciton complexes in a monolayer semiconductor
Authors: He Minhao , Rivera Pasqual , Van Tuan Dinh , Wilson Nathan P. , Yang Min , Taniguchi Takashi , Watanabe Kenji , Yan Jiaqiang , Mandrus David G. , Yu Hongyi , Dery Hanan , Yao Wang , Xu Xiaodong
Published: January 2020

The coupling between spin, charge, and lattice degrees of freedom plays an important role in a wide range of fundamental phenomena. Monolayer semiconducting transitional metal dichalcogenides have emerged as an outstanding platform for studying these coupling effects. Here, we report the observation of multiple valley phonons – phonons with momentum vectors pointing to the corners of the hexagonal Brillouin zone – and the resulting exciton complexes in the monolayer semiconductor WSe2. We find that these valley phonons lead to efficient intervalley scattering of quasi particles in both exciton formation and relaxation. This leads to a series of photoluminescence peaks as valley phonon replicas of dark trions. Using identified valley phonons, we also uncover an intervalley exciton near charge neutrality. Our work not only identifies a number of previously unknown 2D excitonic species, but also shows that monolayer WSe2 is a prime candidate for studying interactions between spin, pseudospin, and zone-edge phonons.
Vibronic coherence contributes to photocurrent generation in organic semiconductor heterojunction diodes
Authors: Bian Qingzhen , Ma Fei , Chen Shula , Wei Qi , Su Xiaojun , Buyanova Irina A. , Chen Weimin M. , Ponseca Carlito S. , Linares Mathieu , Karki Khadga J. , Yartsev Arkady , Inganäs Olle
Published: January 2020

Charge separation dynamics after the absorption of a photon is a fundamental process relevant both for photosynthetic reaction centers and artificial solar conversion devices. It has been proposed that quantum coherence plays a role in the formation of charge carriers in organic photovoltaics, but experimental proofs have been lacking. Here we report experimental evidence of coherence in the charge separation process in organic donor/acceptor heterojunctions, in the form of low frequency oscillatory signature in the kinetics of the transient absorption and nonlinear two-dimensional photocurrent spectroscopy. The coherence plays a decisive role in the initial ~200 femtoseconds as we observe distinct experimental signatures of coherent photocurrent generation. This coherent process breaks the energy barrier limitation for charge formation, thus competing with excitation energy transfer. The physics may inspire the design of new photovoltaic materials with high device performance, which explore the quantum effects in the next-generation optoelectronic applications.