1,181 research outputs found
An algebraic proof of Bogomolov-Tian-Todorov theorem
We give a completely algebraic proof of the Bogomolov-Tian-Todorov theorem.
More precisely, we shall prove that if X is a smooth projective variety with
trivial canonical bundle defined over an algebraically closed field of
characteristic 0, then the L-infinity algebra governing infinitesimal
deformations of X is quasi-isomorphic to an abelian differential graded Lie
algebra.Comment: 20 pages, amspro
Restoring an eroded legitimacy: the adaptation of nonfinancial disclosure after a scandal and the risk of hypocrisy
Purpose \u2013 This study contributes to the literature on hypocrisy in corporate social responsibility by
investigating how organizations adapt their nonfinancial disclosure after a social, environmental or
governance scandal.
Design/methodology/approach \u2013 The present research employs content analysis of nonfinancial
disclosures by 11 organizations during a 3-year timespan to investigate how they responded to major
scandals in terms of social, environmental and sustainability reporting and a content analysis of independent
counter accounts to detect the presence of views that contrast with the corporate disclosure and suggest
hypocritical behaviors.
Findings \u2013 Four patterns in the adaptation of reporting \u2013 genuine, allusive, evasive, indifferent \u2013 emerge from
information collected on scandals and socially responsible actions. The type of scandal and cultural factors can
influence the response to a scandal, as environmental and social scandal can attract more scrutiny than
financial scandals. Companies exposed to environmental and social scandals are more likely to disclose
information about the scandal and receive more coverage by external parties in the form of counter accounts.
Originality/value \u2013 Using a theoretical framework based on legitimacy theory and organizational hypocrisy,
the present research contributes to the investigation of the adaptation of reporting when a scandal occurs and
during its aftermath
Continental rift architecture and patterns of magma migration: a dynamic analysis based on centrifuge models.
Small-scale centrifuge models were used to investigate the role of continental rift structure in controlling patterns of magma migration and emplacement. Experiments considered the reactivation of weakness zones in the lower crust and the presence of magma at Moho depths. Results suggest that surface deformation, which reflects the weakness zone geometry, exerts a major control on patterns of magma migration. In the case of a single rift segment, the experimental lower crust and magma were both transferred in an extension-parallel direction toward the rift flanks. This lateral migration reflected the dominance of far-field stresses over extension-induced buoyancy forces. Local pressure gradients favored the raise of experimental magma in correspondence of marginal grabens. The lateral migration gave rise to major accumulations below the footwall of major boundary faults, providing the magma source able to feed off-axis volcanoes in nature, as inferred for the Main Ethiopian Rift. In the case of two offset rift segments, a major transfer zone developed. This transfer zone was characterized by prominent experimental lower crust doming and strong magma accumulation. Dynamic analysis showed that the transfer zone development caused a strong pressure difference in a rift-parallel direction, which dominated over the farfield thinning. Owing to this pressure gradient, almost all the underplated experimental magma collected below the lower crust dome, suggesting a rift-parallel (extension-orthogonal) migration. This process has a direct relevance for the localization of magmatic activity at transfer zones in natural continental rifts, such as in the Western Branch of the East African Rift System. Copyright 2004 by the American Geophysical Union
An all-glass microfluidic network with integrated amorphous silicon photosensors for on-chip monitoring of enzymatic biochemical assay
A lab-on-chip system, integrating an all-glass microfluidics and on-chip optical detection, was developed and tested. The microfluidic network is etched in a glass substrate, which is then sealed with a glass cover by direct bonding. Thin film amorphous silicon photosensors have been fabricated on the sealed microfluidic substrate preventing the contamination of the micro-channels. The microfluidic network is then made accessible by opening inlets and outlets just prior to the use, ensuring the sterility of the device. The entire fabrication process relies on conventional photolithographic microfabrication techniques and is suitable for low-cost mass production of the device. The lab-on-chip system has been tested by implementing a chemiluminescent biochemical reaction. The inner channel walls of the microfluidic network are chemically functionalized with a layer of polymer brushes and horseradish peroxidase is immobilized into the coated channel. The results demonstrate the successful on-chip detection of hydrogen peroxide down to 18 mu M by using luminol and 4-iodophenol as enhancer agent
From subduction- to strike slip-related volcanism: Miocene to Pliocene activity in Sivas-Malatya region, Central-Eastern Anatolia
Impaired implicit learning of syntactic structure in children with developmental language disorder:Evidence from syntactic priming
Background and aims Implicit learning mechanisms associated with detecting structural regularities have been proposed to underlie both the long-term acquisition of linguistic structure and a short-term tendency to repeat linguistic structure across sentences (structural priming) in typically developing children. Recent research has suggested that a deficit in such mechanisms may explain the inconsistent trajectory of language learning displayed by children with Developmental Learning Disorder. We used a structural priming paradigm to investigate whether a group of children with Developmental Learning Disorder showed impaired implicit learning of syntax (syntactic priming) following individual syntactic experiences, and the time course of any such effects. Methods Five- to six-year-old Italian-speaking children with Developmental Learning Disorder and typically developing age-matched and language-matched controls played a picture-description-matching game with an experimenter. The experimenter’s descriptions were systematically manipulated so that children were exposed to both active and passive structures, in a randomized order. We investigated whether children’s descriptions used the same abstract syntax (active or passive) as the experimenter had used on an immediately preceding turn (no-delay) or three turns earlier (delay). We further examined whether children’s syntactic production changed with increasing experience of passives within the experiment. Results Children with Developmental Learning Disorder’s syntactic production was influenced by the syntax of the experimenter’s descriptions in the same way as typically developing language-matched children, but showed a different pattern from typically developing age-matched children. Children with Developmental Learning Disorder were more likely to produce passive syntax immediately after hearing a passive sentence than an active sentence, but this tendency was smaller than in typically developing age-matched children. After two intervening sentences, children with Developmental Learning Disorder no longer showed a significant syntactic priming effect, whereas typically developing age-matched children did. None of the groups showed a significant effect of cumulative syntactic experience. Conclusions Children with Developmental Learning Disorder show a pattern of syntactic priming effects that is consistent with an impairment in implicit learning mechanisms that are associated with the detection and extraction of abstract structural regularities in linguistic input. Results suggest that this impairment involves reduced initial learning from each syntactic experience, rather than atypically rapid decay following intact initial learning. Implications Children with Developmental Learning Disorder may learn less from each linguistic experience than typically developing children, and so require more input to achieve the same learning outcome with respect to syntax. Structural priming is an effective technique for manipulating both input quality and quantity to determine precisely how Developmental Learning Disorder is related to language input, and to investigate how input tailored to take into account the cognitive profile of this population can be optimised in designing interventions
Cyclooxygenase-2 inhibitors. 1,5-diarylpyrrol-3-acetic esters with enhanced inhibitory activity toward cyclooxygenase-2 and improved cyclooxygenase-2/cyclooxygenase-1 selectivity.
he important role of cyclooxygenase-2 (COX-2) in the pathogenesis of inflammation and side effect limitations of current COX-2 inhibitor drugs illustrates a need for the design of new compounds based on alternative structural templates. We previously reported a set of substituted 1,5-diarylpyrrole derivatives, along with their inhibitory activity toward COX enzymes. Several compounds proved to be highly selective COX-2 inhibitors and their affinity data were rationalized through docking simulations. In this paper, we describe the synthesis of new 1,5-diarylpyrrole derivatives that were assayed for their in vitro inhibitory effects toward COX isozymes. Among them, the ethyl-2-methyl-5-[4-(methylsulfonyl)phenyl]-1-[3-fluorophenyl]-1H-pyrrol-3- acetate (1d), which was the most potent and COX-2 selective compound, also showed a very interesting in vivo anti-inflammatory and analgesic activity, laying the foundations for developing new lead compounds that could be effective agents in the armamentarium for the management of inflammation and pain
Cytokine Storm in COVID-19: Immunopathogenesis and Therapy
A cytokine storm is a hyperinflammatory state secondary to the excessive production of cytokines by a deregulated immune system. It manifests clinically as an influenza-like syndrome, which can be complicated by multi-organ failure and coagulopathy, leading, in the most severe cases, even to death. The term cytokine storm was first used in 1993 to describe the graft-versus-host disease following allogeneic hematopoietic stem cell transplantation. It was then reused to define the adverse syndromes secondary to the administration of immunostimulating agents, such as anti-CD28 antibodies or bioengineered immune cells, i.e., CAR T-cell therapy. Currently, the concept of cytokine storm has been better elucidated and extended to the pathogenesis of many other conditions, such as sepsis, autoinflammatory disease, primary and secondary hemophagocytic lymphohistiocytosis, and multicentric Castleman disease. Moreover, cytokine storm has recently emerged as a key aspect in the novel Coronavirus disease 2019, as affected patients show high levels of several key pro-inflammatory cytokines, such as IL-1, IL-2, IL-6, TNF-α, IFN-γ, IP-10, GM-CSF, MCP-1, and IL-10, some of which also correlate with disease severity. Therefore, since the onset of the pandemic, numerous agents have been tested in the effort to mitigate the cytokine storm in COVID-19 patients, some of which are effective in reducing mortality, especially in critically ill patients, and are now becoming standards of care, such as glucocorticoids or some cytokine inhibitors. However, the challenge is still far from being met, and other therapeutic strategies are being tested in the hope that we can eventually overcome the disease
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