Combatants used sexual violence in approximately half of all civil conflicts since 1989. We expect that when groups resort to sexual violence they are organizationally vulnerable, unlikely to win, ...and as such they are inclined to salvage something from the conflict by way of a settlement. Using quantitative analysis of data on civil conflicts in the post-Cold War period, we find that a higher prevalence of sexual violence perpetrated by government forces precipitates negotiated outcomes. This is particularly true in contexts where both government and rebel forces utilize comparable levels of wartime rape and other forms of sexual abuse.
The importance of human cell-based in vitro tools to drug development that are robust, accurate, and predictive cannot be understated. There has been significant effort in recent years to develop ...such platforms, with increased interest in 3D models that can recapitulate key aspects of biology that 2D models might not be able to deliver. We describe the development of a 3D human cell-based in vitro assay for the investigation of nephrotoxicity, using RPTEC-TERT1 cells. These RPTEC-TERT1 proximal tubule organoids 'tubuloids' demonstrate marked differences in physiologically relevant morphology compared to 2D monolayer cells, increased sensitivity to nephrotoxins observable via secreted protein, and with a higher degree of similarity to native human kidney tissue. Finally, tubuloids incubated with nephrotoxins demonstrate altered Na+/K+-ATPase signal intensity, a potential avenue for a high-throughput, translatable nephrotoxicity assay.
There has been a great deal of discussion about the large volumes of foreign fighters involved in civil conflicts in Syria and Iraq over recent years. Yet, there remains little systematic evidence ...about the effect, if any, that foreign fighters have upon the conflicts they join. Existing literature distinguishes between the resources fighters bring to rebel groups and the liability they represent in regards to campaign cohesion. We seek to establish preliminary evidence as to whether or not foreign fighters contribute to the success of the campaigns they join. Our multinomial logistic and competing risks regression analyses of civil conflicts between 1946 and 2013 suggest that foreign fighters are associated with a decreased likelihood of government victory. Furthermore, we offer partial evidence to suggest that foreign fighters from non-contiguous countries are more likely to help rebels achieve a negotiated settlement or to continue their struggle against the government, but not to directly help them achieve victory.
Human platelets express two protease-activated receptors (PARs), PAR1 (F2R) and PAR4 (F2RL3), which are activated by a number of serine proteases that are generated during pathological events and ...cause platelet activation. Recent interest has focused on PAR4 as a therapeutic target, given PAR4 seems to promote experimental thrombosis and procoagulant microparticle formation, without a broadly apparent role in hemostasis. However, it is not yet known whether PAR4 activity plays a role in platelet-leukocyte interactions, which are thought to contribute to both thrombosis and acute or chronic thrombo-inflammatory processes. We sought to determine whether PAR4 activity contributes to granule secretion from activated platelets and platelet-leukocyte interactions. We performed in vitro and ex vivo studies of platelet granule release and platelet-leukocyte interactions in the presence of PAR4 agonists including PAR4 activating peptide, thrombin, cathepsin G, and plasmin in combination with small-molecule PAR4 antagonists. Activation of human platelets with thrombin, cathepsin G, or plasmin potentiated platelet dense granule secretion that was specifically impaired by PAR4 inhibitors. Platelet-leukocyte interactions and platelet P-selectin exposure the following stimulation with PAR4 agonists were also impaired by activated PAR4 inhibition in either a purified system or in whole blood. These results indicate PAR4-specific promotion of platelet granule release and platelet-leukocyte aggregate formation and suggest that pharmacological control of PAR4 activity could potentially attenuate platelet granule release or platelet-leukocyte interaction-mediated pathological processes.
Localizing eloquent cortices is crucial for many neurosurgical applications, such as epilepsy and tumor resections. Clinicians may use non-invasive methods such as magnetoencephalography (MEG) to ...localize these cortical regions using equivalent current dipoles (ECDs). While dipoles are clinically validated, they provide the estimated strength, location, and orientation of only one or a few sources that best describe the recorded neuromagnetic data, requiring clinicians to make subjective decisions on the spatial extent of the underlying cortical area. More accurate delineation of eloquent cortical areas using distributed source localization methods would provide additional pre-surgical information on these regions’ location and spatial distribution, which could lead to reduced post-surgical complications associated with damage to or removal of eloquent cortices. Our objective in this paper was to present a method to post-process the distributed source localization results to yield a directly interpretable, distributed region of activation. As a test case, we selected somatosensory stimulation in a retrospective cohort of focal and multi-focal epilepsy patients. Our algorithm performs source localization using a distributed method (sLORETA), followed by post-processing and blind source separation to identify the area and boundary of the cortical tissue that primarily activates in response to somatosensory stimulation. We calculated the statistical significance of localization by comparing the identified region to an anatomical atlas and random chance. While examining patients who received left (upper left, UL) and right (upper right, UR) sided median nerve stimulation, the cortical areas identified by the algorithm were in anatomically appropriate areas with a median overlap of 97.6% and 94.7%, respectively. We observe that our algorithm localized somatosensory responses better than random chance in 57/58 (98%) patients who performed the UL task (p < 10 × 10−10, binomial test) and 49/50 (98%) patients who performed the UR task (p < 10 × 10−10, binomial test). We compared the localization of our algorithm to current clinical methods and found that our algorithm is not inferior to dipole localization. The algorithm can successfully localize somatosensory responses on the cortical surface in anatomically appropriate regions while providing the spatial extent of cortical activation, reducing subjectivity associated with dipole localization.
The methylotrophic yeast Pichia pastoris has been used extensively for expressing recombinant proteins because it combines the ease of genetic manipulation, the ability to provide complex ...posttranslational modifications and the capacity for efficient protein secretion. The most successful and commonly used secretion signal leader in Pichia pastoris has been the alpha mating factor (MATα) prepro secretion signal. However, limitations exist as some proteins cannot be secreted efficiently, leading to strategies to enhance secretion efficiency by modifying the secretion signal leader. Based on a Jpred secondary structure prediction and knob-socket modeling of tertiary structure, numerous deletions and duplications of the MATα prepro leader were engineered to evaluate the correlation between predicted secondary structure and the secretion level of the reporters horseradish peroxidase (HRP) and Candida antarctica lipase B. In addition, circular dichroism analyses were completed for the wild type and several mutant pro-peptides to evaluate actual differences in secondary structure. The results lead to a new model of MATα pro-peptide signal leader, which suggests that the N and C-termini of MATα pro-peptide need to be presented in a specific orientation for proper interaction with the cellular secretion machinery and for efficient protein secretion.
•Mutations were made in the MATα prepro leader to determine their effect on secretion.•Circular dichroism showed changes in secondary structure of the wild type vs. mutant pro-peptides.•CD results led to a model of the MATα pro-peptide different from that created by bioinformatics.•The model emphasizes the importance of the N and C termini in pro-peptide function.
Neutrophils, the most populous innate immune cell type, are the first responders to sites of infection and inflammation. Neutrophils can release their DNA to form extracellular traps (NETs), webs of ...DNA and granular proteases that contribute to pathogen clearance and promote thrombus formation. At present, the study of NETs is in part limited to the qualitative analysis of fluorescence microscopy-based images, thus quantification of the interactions between NETs and coagulation factors remains ill-defined.
Develop a quantitative method to measure the spatial distribution of DNA and colocalization of coagulation factor binding to neutrophils and NETs utilizing fluorescence-based microscopy.
Human neutrophils were purified from peripheral blood, bound to fibronectin and treated with the PKC-activator phorbol myristate acetate (PMA) to induce neutrophil activation and NETs formation. Samples were incubated with purified coagulation factors or plasma before staining with a DNA-binding dye and coagulation factor-specific antibodies. The spatial distribution of DNA and coagulation factors was imaged via fluorescence microscopy and quantified via a custom-built MATLAB-based image analysis algorithm. The algorithm first established global thresholding parameters on a training set of fluorescence image data and then systematically quantified intensity profiles across treatment conditions. Quantitative comparison of treatment conditions was enabled through the normalization of fluorescent intensities using the number of cells per image to determine the percent and area of DNA and coagulation factor binding per cell.
Upon stimulation with PMA, NETs formation resulted in an increase in the area of DNA per cell. The coagulation factor fibrinogen bound to both the neutrophil cell body as well as NETs, while prothrombin, FX and FVIIa binding was restricted to the neutrophil cell body. The Gla domain of FX was required to mediate FX-neutrophil binding. Activated protein C (APC), but not Gla-less APC, bound to neutrophil cell bodies and NETs in a punctate manner. Neither FXIIa nor FXIa were found to bind either neutrophil cell bodies or NETs. Fibrinogen binding was dependent on extracellular DNA, while FX and APC required phosphatidylserine exposure for binding to activated neutrophils.
We have developed a quantitative measurement platform to define the spatial localization of fluorescently-labeled coagulation factor binding to neutrophils and extracellular DNA during NETosis.
•The coagulation factor fibrinogen binds DNA-rich NETs.•Coagulation factors prothrombin, FX and FVIIa bind activated neutrophils during NETosis.•The anticoagulant activated protein C (APC) binds activated neutrophils and DNA-rich NETs.•Binding of FX and APC to activated neutrophils is dependent on the Gla-domain and exposure of phosphatidylserine.
In the contact activation pathway of the coagulation, zymogen factor XII (FXII) is converted to FXIIa, which triggers activation of FXI leading to the activation of FIX and subsequent thrombin ...generation and fibrin formation. Feedback activation of FXI by thrombin has been shown to promote thrombin generation in a FXII-independent manner and FXIIa can bypass FXI to directly activate FX and prothrombin in the presence of highly negatively charged molecules, such as long-chain polyphosphates (LC polyP). We sought to determine whether activation of FXII or FXI differentially regulate the physical biology of fibrin formation. Fibrin formation was initiated with tissue factor, ellagic acid (EA), or LC polyP in the presence of inhibitors of FXI and FXII. Our data demonstrated that inhibition of FXI decreased the rate of fibrin formation and fiber network density, and increased the fibrin network strength and rate of fibrinolysis when gelation was initiated
via
the contact activation pathway with EA. FXII inhibition decreased the fibrin formation and fibrin density, and increased the fibrinolysis rate only when fibrin formation was initiated
via
the contact activation pathway with LC polyP. Overall, we demonstrate that inhibition of FXI and FXII distinctly alter the biophysical properties of fibrin.
This article contextualizes the trope of cannibalism as it developed in modern and contemporary Chinese literature. Tracking the trajectory of this trope, so the article argues, illuminates the ...colonially-driven, hierarchy-induced violence demonstrating China's modernity (re)entering into crisis even after a century of revolution and modernization. In the shadow of Western colonial invasions and domestic disorder, May Fourth intellectuals realized China's need to modernize to survive the threat of being colonized--or consumed. This existential crisis, in turn, drove a desire to consume and colonize others; thus, modern subjectivity came to be built on consumption, becoming, in essence, a "consuming identity." This consuming identity reflects violence in various forms of hierarchy, be it feudalistic, revolutionary, or capitalistic. May Fourth literatures of cannibalism envision the potential salvation of awakening modern subjects by portraying modern subjects' ambiguity in, and anxieties about, cannibalism. Contemporary literatures of cannibalism, in contrast, present a doomed conception according to which consuming identities and desires for objectification and cannibalistic consumption prevail over--or consume--all. Keywords cannibalism; modernity; hierarchy; coloniality; May Fourth
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