Inherent Fragility Research Articles

Review: From Anti-Judaism to Anti-Semitism, Ancient and Medieval Christian Constructions of Jewish History, by Robert Chazan

Robert Chazan, From Anti-Judaism to Anti-Semitism, Ancient and Medieval Christian Constructions of Jewish History . Cambridge and New York: Cambridge University Press, 2016. 253 + xvi pp. ISBN 9781107152465. $30.99 (paperback). At the Council of Clermont in November 1095 Pope Urban II called the west to war. His speech was acerbic and vitriolic, religiously charged and filled with the alleged horrors suffered by Christians living in the east. It evoked in his audience a zeal and spirit that would be seen by later generations as the crusading ideal. However, it also exposed inherent political fragility, and deep seated racial biases, amongst elements of his audience, and upon those who took up the cross in the name of Christ. From April to July in 1096 the Ashkenazic Jews of Speyer, Worms and Mainz were targeted by elements of these Christian forces, facing either forced conversion or death. It is worryingly easy to see anti-Jewish sentiment in the central and later Middle Ages. But it is not enough simply to accept it, nor is it appropriate to simply see in medieval Christianity a consistent core of what would become anti-Semitism. The reality is of course much more complex and shifting than such a generalized image would dictate. Those in the People's Crusade who attacked these Jewish communities were engaging with Christian rhetoric and teaching, but also were exposing inherent social and political fear and resentment. Those who were attacked turned to one another for help, but also looked to episcopal authority to curb the horrific violence of the armed pilgrims and the local townsfolk who stood with them. A study that links the origins of anti-Jewish Christian sentiment to the manifestation of anti-Semitism in the modern period is both welcome and necessary. Robert Chazan asks challenging …

Flavor structure of GUTs and uncertainties in proton lifetime estimates

We study the flavour aspects of proton lifetime estimates in simple Grand unified models paying particular attention to their inherent fragility due to the notorious lack of control of some of the key parameters governing the relevant hard-process amplitudes. Among these, the theoretical uncertainties in the flavour structure of the baryon and lepton number violating charged currents due to the potential higher-order effects afflicting the matching of the underlying Yukawa couplings to the low-energy data often play a prominent role. Focusing on the minimal variants of the most popular unified models we study the potential instabilities of the corresponding proton lifetime estimates based on the renormalizable-level Yukawa fits with respect to the Planck-scale induced flavour effects. In particular, we perform a detailed numerical analysis of all minimal $SO(10)$ Yukawa sector fits available in the literature and show that the proton lifetime estimates based on these inputs exhibit a high degree of robustness with respect to moderate-size perturbations, well within the expected "improvement window" of the upcoming proton decay searches.

The Politics of Memory in South African Art

ABSTRACTThere is a saying attributed to Winston Churchill that goes, “History is written by the victors,” indicating that all histories are subjective and biased in some way. This was certainly true for South Africa under the Nationalist regime where the exploits of Afrikaner colonialism were glorified, and the majority of the population were mere “bit players” at best and vilified as savages at worst. Such traumatic histories have been interrogated by Penny Siopis in her “History Paintings” made in the early post-apartheid era which consider the residual effects of a dominant patriarchal and colonial discourse on the lives of black women in South Africa. Like Siopis, Paul Emmanuel and Diane Victor engage with the biased nature of history and memory in the light of post-apartheid dispensation in South Africa and the continuing after effects of our fraught past. This article considers the way these three artists engage with the inherent fragility and bias of memory through the materials they employ as much as the content of their works. I consider selected works by these artists and investigate how they engage with the politics of memory to expose fabrications and redress lacunae in the continuum of contested South African histories. I suggest that their works demonstrate how memories have been manipulated in service to a dominant ideology; in other words, they expose the “politics” of memory by using reconstituted/reworked memories to revisit and restore histories that might otherwise be lost.

3 D printed replica of the human temporal bone intended for teaching gross anatomy.

The anatomy of the human temporal bone is complex and, therefore, poses unique challenges for students. Furthermore, temporal bones are frequently damaged from handling in educational settings due to their inherent fragility. This report details the production of a durable physical replica of the adult human temporal bone, manufactured using 3D printing technology. The physical replica was printed from a highly accurate virtual 3D model generated from CT scans of an isolated temporal bone. Both the virtual and physical 3D models accurately reproduced the surface anatomy of the temporal bone. Therefore, virtual and physical 3D models of the temporal bone can be used for educational purposes in order to supplant the use of damaged or otherwise fragile human temporal bones.

Harnessing region-specific neurovascular signaling to promote germinal matrix vessel maturation and hemorrhage prevention.

ABSTRACTGerminal matrix hemorrhage (GMH), affecting about 1 in 300 births, is a major perinatal disease with lifelong neurological consequences. Yet despite advances in neonatal medicine, there is no effective intervention. GMH is characterized by localized bleeding in the germinal matrix (GM), due to inherent vessel fragility unique to this developing brain region. Studies have shown that reduced TGFβ signaling contributes to this vascular immaturity. We have previously shown that a region-specific G-protein-coupled receptor pathway in GM neural progenitor cells regulates integrin β8, a limiting activator of pro-TGFβ. In this study, we use mice to test whether this regional pathway can be harnessed for GMH intervention. We first examined the endogenous dynamics of this pathway and found that it displays specific patterns of activation. We then investigated the functional effects of altering these dynamics by chemogenetics and found that there is a narrow developmental window during which this pathway is amenable to manipulation. Although high-level activity in this time window interferes with vessel growth, moderate enhancement promotes vessel maturation without compromising growth. Furthermore, we found that enhancing the activity of this pathway in a mouse model rescues all GMH phenotypes. Altogether, these results demonstrate that enhancing neurovascular signaling through pharmacological targeting of this pathway may be a viable approach for tissue-specific GMH intervention. They also demonstrate that timing and level are likely two major factors crucial for success. These findings thus provide critical new insights into both brain neurovascular biology and the intervention of GMH.

Reusable Enzymatic Fiber Mats for Neurotoxin Remediation in Water.

Highly effective and reusable organophosphorus hydrolase (OPH)-loaded fiber mats have been fabricated that are capable of degrading toxic organophosphates (OPs) over a broad range of relevant concentrations (from 8 to 8250 ppm). The inherent fragility of enzymes, a major impediment in their incorporation into technologically relevant materials, was overcome while retaining their high catalytic efficiency, selectivity, and sensitivity via a random heteropolymers (RHP) approach. Kinetic analysis guides the design of polycaprolactone matrix morphology from films to fibers, facilitating substrate diffusion in the material. The RHP-OPH fiber mats demonstrate excellent stability and reusability with minimal requirements for storage, retaining over 40% of their initial activity after repeated daily use for three months. Practically, present studies provide valuable guidance toward fabrication of enzyme-based functional materials.

Microencapsulation of beta cells in collagen micro-disks via circular pneumatically actuated soft micro-mold (cPASMO) device

The artificial pancreas provides a method for automatically managing insulin concentrations in patients with Type I diabetes. One strategy for fabricating an artificial pancreas is the encapsulation of beta cells in a collagen matrix, which can provide mechanical support. In addition, encapsulation of beta cells in small volumes and with high surface areas allows them to quickly sense glucose and secrete insulin for regulation. Currently, there is no such fabrication technique of encapsulating beta cells in a collagen matrix, due to their inherent fragility. Herein, we develop a novel technique called circular Pneumatic Actuated Soft Micromold (cPASMO) to produce collagen microdisks for encapsulating beta cells. cPASMO consists of a particle template, pneumatic channel, and buffer layer to control deformation. The actuation mechanism is simply to deform the template by increasing the inner pressure inside the channel. This deformation in the template generates a gap between the collagen microdisks and mold that can extract the collagen microdisks via buoyancy force. Thus, they can be released from their templates without damage. The position of the air channel determines the uniformity of the template deformation that leads to the high collagen microdisk extraction rate. Compared to the previous design (i.e., linear air channel), the extraction rate is four times faster. We demonstrated that beta cells encapsulated in collagen micro disks by a cPASMO device exhibit a biological function of rapidly sensing glucose and secreting insulin for regulation. The concentration of the secreted insulin from the encapsulated beta cells is three to six times higher than that of suspended cells. Also, smaller collagen micro disks release higher concentrations of insulin than those that are larger because the larger spaces between beta cells can degrade cellular communication. These breakthroughs in producing collagen microdisks will push the boundaries of treatment for Type I diabetic patients.

Spark Plasma Sintered Zirconia Ceramic Composites with Graphene-Based Nanostructures

The addition of graphene-based nanostructures (GBNs) can improve the inherent fragility of ceramics and provide them with improved electrical and thermal conductivities. However, both the starting material (ceramic matrix and GBNs) and the processing/sintering approach are crucial for the final composite microstructure and properties. This work focuses on the influence of the content and dimensions of the GBN filler (10 and 20 vol%; 3 and ~150 layers), the powder-processing conditions (dry versus wet), and the homogenization method (ultrasound sonication versus high-energy planetary ball milling) on GBN/tetragonal zirconia (3YTZP) composites. The microstructure and electrical properties of the spark plasma sintered (SPS) composites were quantified and analyzed. The highest microstructural homogeneity with an isotropic microstructure was achieved by composites prepared with thicker GBNs milled in dry conditions. A high content (20 vol%) of few-layered graphene as a filler maximizes the electrical conductivity of the composites, although it hinders their densification.

Novel GO/silica composite aerogels with enhanced mechanical and thermal insulation properties prepared at ambient pressure

ABSTRACTNovel graphene oxide (GO)/silica composite aerogels were fabricated to strengthen the nanostructure and overcome inherent fragility of silica aerogels by a sol-gel method using tetraethyl orthosilicate (TEOS) and low concentration of graphene oxide solution as the main materials, followed by an environmentally friendly ambient pressure drying (APD). The interaction between GO nanosheets and silica matrix was investigated by using FTIR and SEM. Meanwhile, the mechanical properties and thermal conductivity of aerogels were also studied. The results showed that GO were uniformly dispersed in the silica aerogel, and there is a good physico-chemical combination between GO and silica matrix. The addition of GO can enhance the mechanical of the composite aerogels, and when the GO content is increased from 0 to 3wt%, the mechanical strength is improved from 0.04 MPa to 0.65 MPa. Meanwhile, the thermal conductivity of composite aerogels first decreases and then increases with increasing GO content, and the optimal value is 0.018 W/m K. The composites with outstanding properties prepared by APD are potential for insulation applications.

Bank Utilization, Institutions, and Run Behavior in Newly Enfranchised Populations: Evidence from the Freedman's Bank and Trust

Using a novel dataset from the Freedman's Savings Bank, we examine how societal trust impacts policy makers' goals of increased financial participation and economic integration. We find that events that impact trust in political representation and public safety also impact financial participation. The same factors that make communities resilient to racial violence also influence the reactions to financial panics, which increases the likelihood of having wealth destroyed in a collapse, particularly as compared to white depositors. Our results demonstrate how the inherent fragility of financial institutions can cause disproportionate damage to the stability of disenfranchised communities.

Originary Humanicity: Locating Anthropos

Originary HumanicityLocating Anthropos Vicki Kirby First of all, I didn't say that there was no center, that we could get along without the center. I believe that the center is a function, not a being—a reality, but a function. And this function is absolutely indispensable. The subject is absolutely indispensable. I don't destroy the subject; I situate it. That is to say, I believe that at a certain level both of experience and of philosophical and scientific discourse one cannot get along without the notion of subject. It is a question of knowing where it comes from and how it functions. —Jacques Derrida Structure, Sign, and Play in the Discourse of the Human Sciences. Discussion The need to understand human behavior will all too often make a quick appeal to individual intention and personal motivation as the explanatory cause of conduct. However, within certain areas of Western academic thinking, especially over the last forty years, the assumption that the individual authors his own life, or that "the agential subject" is, indeed, an autonomous individual whose decisions are properly her own, is significantly compromised. Close analysis of the agential subject through psychoanalysis, poststructuralism, various forms of discourse and media theories, or even classical sociological methodologies that focus on the problematic relationship between the individual and society, discover a subject whose identity is more conceded than [End Page 43] substantive. However, as this agent/subject has continued to function as an anchor for social and political analysis despite myriad revelations of its inherent fragility, and for some, impossibility, we need to ask what might be going on in its preservation. The mystery of agency—what it is, if it is, how and when it can be relied upon, why it fails, or even if it ever fails completely—exercises all of us because these are existential questions about what it means to be . . . oneself. Given the vagaries and even failures of willpower, the common perception of the agential subject goes something like this: a subject-self can exert power over an object-self who, or is it which, appears powerless. This representation sits well with an everyday understanding of motivation lost or gained, as we see in self-help books that equate personal application with control and potential success in life. Such readings in popular culture assume that an individual possesses an enduring ability to express and realize an intention even when evidence to the contrary is in abundance: it seems that a sense of personal autonomy and a capacity for self-direction operate as organizational and judgmental touchstones in everyday experience and belief. But are more nuanced analyses of the subject that operate as a vernacular in critical and social theory so very different from quotidian understandings, and does the latter's reliance on the individual's foreclosed identity, and its corollary—the assumption that agency is an isolatable capacity, a self-possession—reappear surreptitiously as fact rather than analytical necessity in the former? If we concede that the integrity of the subject and the very notion of agency are undeniably slippery in both everyday understandings as well as more theorized elaborations of the problematic, then the danger of the subject's dissolution is surely minimized if we represent the problem as one of splitting, division, or vacillation between two alternatives. There will be less risk that the self/individual is confounded if the constitutive disunity within the subject is read as a play between two different states of being (for example, passive or active, submissive or purposeful). Although the conundrum involves the subject being both, we content ourselves that if we could stop the clock and freeze-frame a particular moment then we would see that the subject is only ever one at a time. Unity restored. Importantly, to suggest that the subject is both at the same time undoes any sense of option or even splitting, for the difference between these states of being disappears, as does the identity of someone who chooses between them.1 In response to this terrifying prospect, an admission that the subject "wobbles," or vacillates, can effectively retain a conventional notion of agency as an authoring force: although...

Design process robustness: a bipartite network analysis reveals the central importance of people

Design processes require the joint effort of many people to collaborate and work on multiple activities. Effective techniques to analyse and model design processes are important for understanding organisational dynamics, for improving collaboration, and for planning robust design processes, reducing the risk of rework and delays. Although there has been much progress in modelling and understanding design processes, little is known about the interplay between people and the activities they perform and its influence on design process robustness. To analyse this interplay, we model a large-scale design process of a biomass power plant with $100+$ people and ${\sim}150$ activities as a bipartite network. Observing that some people act as bridges between activities organised to form nearly independent modules, in order to evaluate process fragility, we simulate random failures and targeted attacks to people and activities. We find that our process is more vulnerable to attacks to people rather than activities. These findings show how the allocation of people to activities can obscure an inherent fragility, making the process highly sensitive and dependent on specific people. More generally, we show that the behaviour of robustness is determined by the degree distributions, the heterogeneity of which can be leveraged to improve robustness and resilience to cascading failures. Overall, we show that it is important to carefully plan the assignment of people to activities.

The fragility of community security in Damascus and its environs

AbstractThe organizational errors of Syrian urban planning have been a major cause of the escalation of the Syrian crisis and its continuation. Syrian cities, including Damascus and its environs, have suffered from the fragility of social security, which is manifested in the form of cohesive human groups in closed communities, influenced by religion, culture, family, class, place of origin of the population, occupation, etc. This article examines the fragility of security during the crisis of 2011–18, with the aim of clarifying the impact of the organizational problems and the processing delay that has generated social security fragility because these closed communities are looking for their own security and safety outside the control of local administrations. The article proposes that the inherent fragility of security in Damascus and its environs should be associated with poverty, organizational errors and slums as a model for the fragility of all Syrian cities.

After Bauman

After Bauman

Die "unermessliche Leichtigkeit und Zerbrechlichkeit des menschlichen Faktums." Jan Patočka und die Krise des Humanismus

The "immeasurable lightness and fragility of the human fact." Jan Patočka and the Crisis of HumanismThe article addresses Jan Patočka’s writings in the immediate aftermath of the Second World War. The paper’s title – "The Immense Lightness and Fragility of the Human Fact" – is taken from a short, yet immensely crucial 1946 text of his that formulates a severe criticism of ideology/ideologies and eventually offers a profound questioning of humanist ideals. Accentuating his critique against the backdrop of Sartre's and Heidegger's contemporaneous challenges to humanism, the paper argues that Patočka debunks a misconceived "cult of the human being" and ideologies of progress while insisting on the integrity of a human life in confrontation with its inherent weakness and fragility.

Pneumatically Actuated Soft Micromold Device for Fabricating Collagen and Matrigel Microparticles.

Collagen microparticles have recently gained more attention as viable cell confinement blocks in many biomedical research fields. Small volume and high surface area of collagen structure improve cell confinement, viability, and proliferation. Moreover, dense collagen fiber structure can protect cells from immune destruction. The ability to produce collagen microparticles in an accurate and reliable way is of upmost importance to the advancement of many biomedical researches, especially cancer research and tissue engineering. Currently, no such fabrication technique exists due to inherent fragility of collagen. Herein, we report the very first platform, pneumatically actuated soft micromold (PASMO) device, which addresses challenges in collagen microparticle production. Our new platform uses a soft micromold with a pneumatic actuator that can produce arbitrary shapes of collagen microstructures precisely from 100 μm to over 2 mm in range and can encapsulate cells inside without damaging the shape. The duplication accuracy of more than 96% in dimensions and 90% in depth has been demonstrated. The density of collagen fiber distribution is determined to be 86.57%, which is higher than that of collagen microparticles produced by other methods. We have confirmed cell viability in collagen microparticles. We also produce Matrigel™ particles as tool to develop a xenograft cancer model. The results demonstrate that Matrigel particles created by the PASMO device can reduce cell scattering for the xenograft model and the uniformity of tumors developed in mice is 12-fold improved, which can lead to an increased accuracy of cancer metastasis studies and drug screening research. These breakthroughs in the production of modular microparticles will push the boundaries of cancer research in the near future.

Harsh‐Environment‐Resistant OH‐Vibrations‐Sensitive Mid‐Infrared Water‐Ice Photonic Sensor

State‐of‐the‐art ultrahigh‐sensitivity photonic sensing schemes rely on exposing the evanescent field of tightly confined light to the environment. Yet, this renders an inherent fragility to the device, and since adding a protective layer disables light exposure, there exists a technology gap for highly sensitive harsh‐environment‐resistant surface photonic sensors. Here, a novel type of mid‐infrared waveguide sensors is reported which exploit vibrational resonance‐driven directional coupling effects besides absorption, with optical sensing elements that can be buried (≈1–10 µm) and resist systematic exposure to industrial environments without failure. A harsh‐environment‐resistant, fiber‐coupled, surface sensor for monitoring the structural phase of water (liquid‐supercooled‐solid), as well as the type of ice microstructure (clear rime), is shown. It is demonstrated how this type of sensor can be designed to detect ice layers with nanometric (≈100 nm) to microscopic (≈30 µm or higher) thicknesses, and the first experimental tests both in optical laboratory and in icing wind tunnel inflight aircraft simulation tests are reported.

Counter-monumentality and the vulnerability of memory

Monuments have been a staple of archaeology since the beginning of the discipline and have been used as case-studies for a diverse range of topics. In recent years, monuments have been considered particularly often in studies of social memory. By materializing memorial ambitions, however, the creation of monuments provides a venue for collective memories to be challenged. Despite their outward appearance of strength and permanence, monuments additionally render the memory of their creators vulnerable and open to contestation. In particular, the practice of counter-monumentality, or active and deliberate interventions in traditional monuments, illustrates how the erection of monuments exposes the inherent fragility of memory. Examples from the present and the past demonstrate these points: a statue of Confederate generals Robert E. Lee and Thomas “Stonewall” Jackson in Baltimore, Maryland, and a corpus of monumental statues from southeastern Anatolian and northern Syria during the Iron Age.

Development of a Proximity Labeling System to Map the Chlamydia trachomatis Inclusion Membrane.

Chlamydia grows within a membrane-bound vacuole termed an inclusion. The cellular processes that support the biogenesis and integrity of this pathogen-specified parasitic organelle are not understood. Chlamydia secretes integral membrane proteins called Incs that insert into the chlamydial inclusion membrane (IM). Incs contain at least two hydrophobic transmembrane domains flanked by termini, which vary in size and are exposed to the host cytosol. In addition, Incs are temporally expressed during the chlamydial developmental cycle. Data examining Inc function are limited because of (i) the difficulty in working with hydrophobic proteins and (ii) the inherent fragility of the IM. We hypothesize that Incs function collaboratively to maintain the integrity of the chlamydial inclusion with small Incs organizing the IM and larger Incs interfacing with host cell machinery. To study this hypothesis, we have adapted a proximity-labeling strategy using APEX2, a mutant soybean ascorbate peroxidase that biotinylates interacting and proximal proteins within minutes in the presence of H2O2 and its exogenous substrate, biotin-phenol. We successfully expressed, from an inducible background, APEX2 alone, or fusion proteins of IncATM (TM = transmembrane domain only), IncA, and IncF with APEX2 in Chlamydia trachomatis serovar L2. IncF-APEX2, IncATM-APEX2, and IncA-APEX2 localized to the IM whereas APEX2, lacking a secretion signal, remained associated with the bacteria. We determined the impact of overexpression on inclusion diameter, plasmid stability, and Golgi-derived sphingomyelin acquisition. While there was an overall impact of inducing construct expression, IncF-APEX2 overexpression most negatively impacted these measurements. Importantly, Inc-APEX2 expression in the presence of biotin-phenol resulted in biotinylation of the IM. These data suggest that Inc expression is regulated to control optimal IM biogenesis. We subsequently defined lysis conditions that solubilized known Incs and were compatible with pulldown conditions. Importantly, we have created powerful tools to allow direct examination of the dynamic composition of the IM, which will provide novel insights into key interactions that promote chlamydial growth and development within the inclusion.

Transparent Flexible Electrodes Based on Junctionless Copper Nanowire Network via Selective Electroless Metallization of Electrospun Nanofibers

A component that is able to transport charges while being transparent to light is fundamental in many devices, including LCD screens, touch panels and solar cells. The most common transparent electrode material is Indium Tin Oxide (ITO) due to its high performance, but the costly production techniques, the rarity of indium and its inherent fragility are pushing the market to look for alternatives. In this work, a facile method for the creation of a junctionless metal nanowire network as transparent electrodes using electrospinning and selective electroless deposition is proposed, without annealing steps or vacuum processes which is needed in conventional nanowire production. The method exploits the insertion of the electroless sensitizing agent into the electrospinning solution for selectively catalyzed metallization of the electrospun nanofiber template without hydrophobic treatments to substrates. The best optoelectronic properties are adequate to replace ITO: Rs = 35 Ω/□ and T = 90% with a very flat transmittance window.