311 research outputs found
The United States - China Rivalry and the BRI
The article describes the United States - China rivalry and Chinas Belt and Road Initiative (BRI) through a fine-grained review of primary materials such as major US policy documents and speeches by and media interviews with key American foreign policy decisionmakers, as well as the selective use of secondary materials such as think tank studies and articles in scholarly publications. It shows that the BRI has fueled the bilateral rivalry since its birth in 2013 and that the rivalry, in turn, has affected US views about the BRI. Under President Barack Obama, the US took a muted stance towards the BRI, expressing modestly cooperative sentiments regarding it. In contrast, under President Donald Trump, Washingtons posture towards the BRI dramatically changed with his administration frequently denigrating the BRI, raising it in major security and foreign policy documents, initiating competing development schemes such as the BUILD Act, and building closer cooperation with allies against Chinas venture. Despite its angst about the BRI, however, the Trump administration never launched any large-scale countermeasures. This article contributes to clarifying the situation by correcting some factual errors in past analyses and updating the general understanding about the Trump administrations response. It systematically contemplates how internal and external economic, political, and ideational factors affected the Obama and Trump administrations responses to the BRI, demonstrating that such factors shaped or shifted US policy or bounded its form and intensity. These factors, being similar to those stressed by neoclassical realists who emphasize the role of leaders as interpreters within limits of the external environment and responders to it subject to various domestic constraints, provide a foundation which is used to speculate about the USs probable response to the BRI under President Joseph Biden, Jr
A bi-TTF with a bipyridine spacer: 4,4′-bis[(3,6,7-trimethylsulfanyltetrathiafulvalen-2-yl)sulfanylmethyl]-2,2′-bipyridine
The title compound, C30H28N2S16, is a precursor to hybrid magnetic materials. The complete molecule is generated by a crystallographic inversion centre. In the crystal structure, the TTF core is not planar and adopts a chair conformation; the two C3S2 rings are folded around the S⋯S hinges, the dihedral angles being 17.14 (8) and 13.46 (7)°. There is a short S⋯S contact [3.4863 (14) Å] in the crystal structure
Limit Theorems and Coexistence Probabilities for the Curie-Weiss Potts Model with an external field
The Curie-Weiss Potts model is a mean field version of the well-known Potts
model. In this model, the critical line is explicitly
known and corresponds to a first order transition when . In the present
paper we describe the fluctuations of the density vector in the whole domain
and , including the conditional fluctuations
on the critical line and the non-Gaussian fluctuations at the extremity of the
critical line. The probabilities of each of the two thermodynamically stable
states on the critical line are also computed. Similar results are inferred for
the Random-Cluster model on the complete graph.Comment: 17 page
Cyclin A2 Mutagenesis Analysis: A New Insight into CDK Activation and Cellular Localization Requirements
Cyclin A2 is essential at two critical points in the somatic cell cycle: during S phase, when it activates CDK2, and during the G2 to M transition when it activates CDK1. Based on the crystal structure of Cyclin A2 in association with CDKs, we generated a panel of mutants to characterize the specific amino acids required for partner binding, CDK activation and subcellular localization. We find that CDK1, CDK2, p21, p27 and p107 have overlapping but distinct requirements for association with this protein. Our data highlight the crucial importance of the N-terminal α helix, in conjunction with the α3 helix within the cyclin box, in activating CDK. Several Cyclin A2 mutants selectively bind to either CDK1 or CDK2. We demonstrate that association of Cyclin A2 to proteins such as CDK2 that was previously suggested as crucial is not a prerequisite for its nuclear localization, and we propose that the whole protein structure is involved
Understanding the Use of Crisis Informatics Technology among Older Adults
Mass emergencies increasingly pose significant threats to human life, with a
disproportionate burden being incurred by older adults. Research has explored
how mobile technology can mitigate the effects of mass emergencies. However,
less work has examined how mobile technologies support older adults during
emergencies, considering their unique needs. To address this research gap, we
interviewed 16 older adults who had recent experience with an emergency
evacuation to understand the perceived value of using mobile technology during
emergencies. We found that there was a lack of awareness and engagement with
existing crisis apps. Our findings characterize the ways in which our
participants did and did not feel crisis informatics tools address human
values, including basic needs and esteem needs. We contribute an understanding
of how older adults used mobile technology during emergencies and their
perspectives on how well such tools address human values.Comment: 10 page
Porphyromonas gingivalis Participates in Pathogenesis of Human Abdominal Aortic Aneurysm by Neutrophil Activation. Proof of Concept in Rats
International audienceBACKGROUND: Abdominal Aortic Aneurysms (AAAs) represent a particular form of atherothrombosis where neutrophil proteolytic activity plays a major role. We postulated that neutrophil recruitment and activation participating in AAA growth may originate in part from repeated episodes of periodontal bacteremia. METHODS AND FINDINGS: Our results show that neutrophil activation in human AAA was associated with Neutrophil Extracellular Trap (NET) formation in the IntraLuminal Thrombus, leading to the release of cell-free DNA. Human AAA samples were shown to contain bacterial DNA with high frequency (11/16), and in particular that of Porphyromonas gingivalis (Pg), the most prevalent pathogen involved in chronic periodontitis, a common form of periodontal disease. Both DNA reflecting the presence of NETs and antibodies to Pg were found to be increased in plasma of patients with AAA. Using a rat model of AAA, we demonstrated that repeated injection of Pg fostered aneurysm development, associated with pathological characteristics similar to those observed in humans, such as the persistence of a neutrophil-rich luminal thrombus, not observed in saline-injected rats in which a healing process was observed. CONCLUSIONS: Thus, the control of periodontal disease may represent a therapeutic target to limit human AAA progression
The Scaffolding Protein Dlg1 Is a Negative Regulator of Cell-Free Virus Infectivity but Not of Cell-to-Cell HIV-1 Transmission in T Cells
Background: Cell-to-cell virus transmission of Human immunodeficiency virus type-1 (HIV-1) is predominantly mediated by cellular structures such as the virological synapse (VS). The VS formed between an HIV-1-infected T cell and a target T cell shares features with the immunological synapse (IS). We have previously identified the human homologue of the Drosophila Discs Large (Dlg1) protein as a new cellular partner for the HIV-1 Gag protein and a negative regulator of HIV-1 infectivity. Dlg1, a scaffolding protein plays a key role in clustering protein complexes in the plasma membrane at cellular contacts. It is implicated in IS formation and T cell signaling, but its role in HIV-1 cell-to-cell transmission was not studied before. Methodology/Principal Findings: Kinetics of HIV-1 infection in Dlg1-depleted Jurkat T cells show that Dlg1 modulates the replication of HIV-1. Single-cycle infectivity tests show that this modulation does not take place during early steps of the HIV-1 life cycle. Immunofluorescence studies of Dlg1-depleted Jurkat T cells show that while Dlg1 depletion affects IS formation, it does not affect HIV-1-induced VS formation. Co-culture assays and quantitative cell-to-cell HIV-1 transfer analyses show that Dlg1 depletion does not modify transfer of HIV-1 material from infected to target T cells, or HIV-1 transmission leading to productive infection via cell contact. Dlg1 depletion results in increased virus yield and infectivity of the viral particles produced. Particles with increased infectivity present an increase in their cholesterol content and during the first hours of T cell infection these particles induce higher accumulation of total HIV-1 DNA
Three Linked Vasculopathic Processes Characterize Kawasaki Disease: A Light and Transmission Electron Microscopic Study
Kawasaki disease is recognized as the most common cause of acquired heart disease in children in the developed world. Clinical, epidemiologic, and pathologic evidence supports an infectious agent, likely entering through the lung. Pathologic studies proposing an acute coronary arteritis followed by healing fail to account for the complex vasculopathy and clinical course.Specimens from 32 autopsies, 8 cardiac transplants, and an excised coronary aneurysm were studied by light (n=41) and transmission electron microscopy (n=7). Three characteristic vasculopathic processes were identified in coronary (CA) and non-coronary arteries: acute self-limited necrotizing arteritis (NA), subacute/chronic (SA/C) vasculitis, and luminal myofibroblastic proliferation (LMP). NA is a synchronous neutrophilic process of the endothelium, beginning and ending within the first two weeks of fever onset, and progressively destroying the wall into the adventitia causing saccular aneurysms, which can thrombose or rupture. SA/C vasculitis is an asynchronous process that can commence within the first two weeks onward, starting in the adventitia/perivascular tissue and variably inflaming/damaging the wall during progression to the lumen. Besides fusiform and saccular aneurysms that can thrombose, SA/C vasculitis likely causes the transition of medial and adventitial smooth muscle cells (SMC) into classic myofibroblasts, which combined with their matrix products and inflammation create progressive stenosing luminal lesions (SA/C-LMP). Remote LMP apparently results from circulating factors. Veins, pulmonary arteries, and aorta can develop subclinical SA/C vasculitis and SA/C-LMP, but not NA. The earliest death (day 10) had both CA SA/C vasculitis and SA/C-LMP, and an "eosinophilic-type" myocarditis.NA is the only self-limiting process of the three, is responsible for the earliest morbidity/mortality, and is consistent with acute viral infection. SA/C vasculitis can begin as early as NA, but can occur/persist for months to years; LMP causes progressive arterial stenosis and thrombosis and is composed of unique SMC-derived pathologic myofibroblasts
Clinical spectrum of MTOR-related hypomelanosis of Ito with neurodevelopmental abnormalities.
PURPOSE: Hypomelanosis of Ito (HI) is a skin marker of somatic mosaicism. Mosaic MTOR pathogenic variants have been reported in HI with brain overgrowth. We sought to delineate further the pigmentary skin phenotype and clinical spectrum of neurodevelopmental manifestations of MTOR-related HI. METHODS: From two cohorts totaling 71 patients with pigmentary mosaicism, we identified 14 patients with Blaschko-linear and one with flag-like pigmentation abnormalities, psychomotor impairment or seizures, and a postzygotic MTOR variant in skin. Patient records, including brain magnetic resonance image (MRI) were reviewed. Immunostaining (n = 3) for melanocyte markers and ultrastructural studies (n = 2) were performed on skin biopsies. RESULTS: MTOR variants were present in skin, but absent from blood in half of cases. In a patient (p.[Glu2419Lys] variant), phosphorylation of p70S6K was constitutively increased. In hypopigmented skin of two patients, we found a decrease in stage 4 melanosomes in melanocytes and keratinocytes. Most patients (80%) had macrocephaly or (hemi)megalencephaly on MRI. CONCLUSION: MTOR-related HI is a recognizable neurocutaneous phenotype of patterned dyspigmentation, epilepsy, intellectual deficiency, and brain overgrowth, and a distinct subtype of hypomelanosis related to somatic mosaicism. Hypopigmentation may be due to a defect in melanogenesis, through mTORC1 activation, similar to hypochromic patches in tuberous sclerosis complex
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