Lessons from a comparison of work domain models: representational choices and their implications

As methods in cognitive work analysis become more widely applied, questions regarding the impact of modeling choices and similarities in modeling efforts across projects and domains are increasingly relevant. However, no explicit comparison of models of similar systems has been reported. This paper compares independently developed work domain analysis (WDA) models of two command and control environments. Similarities in model content and the types of nodes included provide evidence that WDA techniques can capture fundamental elements regarding purposes and constraints. These points of agreement provide a common starting point for developing work domain representations of military command and control systems. The comparison also revealed differences between the models. Although differences in content reflected differences in scope of coverage and level of detail, other differences corresponded to more fundamental choices in modeling approach. These included the treatment of sensors, level of integration in the model, and representation of particular abstract constraints. Examination of these more fundamental differences pointed to important degrees of freedom in how to represent a WDA and clarified the implications of these modeling choices for guiding design. Actual or potential applications of this research include aiding analysts in making work domain modeling choices as well as producing work domain models of command and control environments.     

Dietary phytoestrogens dampen female sexual behavior in mice with a disrupted aromatase enzyme gene.

Aromatization of testosterone (T) to estradiol (E2) during perinatal development in male rodents plays a significant role in sexual differentiation of the brain and adult behaviors. Exposure to estrogens during development can enhance masculine behaviors in adult females and reduce expression of female-typical behaviors in adult males. Previous studies have shown that, in addition to naturally occurring estrogens, dietary phytoestrogens can affect sexual differentiation. To distinguish between the effects of endogenous T-derived E2 and exogenous phytoestrogens, the authors used an aromatase knockout (ArKO) mouse that cannot produce E2 but is responsive to E2 via estrogen receptors α and β. Dams and their litters were maintained either on a standard mouse chow that was rich in phytoestrogens or on a chow nearly devoid of phytoestrogens. Mice were maintained on their perinatal diets after weaning. Adults of both sexes were gonadectomized and tested for lordosis behavior. In the ArKO females raised on a diet high in phytoestrogens, lordosis was reduced in comparison with females of both genotypes on the low phytoestrogen diet. The authors' findings suggest that dietary phytoestrogen consumption may partially defeminize adult female sexual behavior in the mouse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

FcRn as a Transporter for Nasal Delivery of Biologics: A Systematic Review

FcRn plays a major role in regulating immune homeostasis, but it is also able to transport biologics across cellular barriers. The question of whether FcRn could be an efficient transporter of biologics across the nasal epithelial barrier is of particular interest, as it would allow a less invasive strategy for the administration of biologics in comparison to subcutaneous, intramuscular or intravenous administrations, which are often used in clinical practice. A focused systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. It was registered on the international prospective register of systematic reviews PROSPERO, which helped in identifying articles that met the inclusion criteria. Clinical and preclinical studies involving FcRn and the nasal delivery of biologics were screened, and the risk of bias was assessed across studies using the Oral Health Assessment Tool (OHAT). Among the 12 studies finally included in this systematic review (out of the 758 studies screened), 11 demonstrated efficient transcytosis of biologics through the nasal epithelium. Only three studies evaluated the potential toxicity of biologics’ intranasal delivery, and they all showed that it was safe. This systematic review confirmed that FcRn is expressed in the nasal airway and the olfactory epithelium, and that FcRn may play a role in IgG and/or IgG-derived molecule-transcytosis across the airway epithelium. However, additional research is needed to better characterize the pharmacokinetic and pharmacodynamic properties of biologics after their intranasal delivery.     

Circular RNA,the Key for Translation

It was thought until the 1990s that the eukaryotic translation machinery was unable to translate a circular RNA. However internal ribosome entry sites (IRESs) and m⁶A-induced ribosome engagement sites (MIRESs) were discovered, promoting 5′ end-independent translation initiation. Today a new family of so-called “noncoding” circular RNAs (circRNAs) has emerged, revealing the pivotal role of 5′ end-independent translation. CircRNAs have a strong impact on translational control via their sponge function, and form a new mRNA family as they are translated into proteins with pathophysiological roles. While there is no more doubt about translation of covalently closed circRNA, the linearity of canonical mRNA is only theoretical: it has been shown for more than thirty years that polysomes exhibit a circular form and mRNA functional circularization has been demonstrated in the 1990s by the interaction of initiation factor eIF4G with poly(A) binding protein. More recently, additional mechanisms of 3′–5′ interaction have been reported, including m⁶A modification. Functional circularization enhances translation via ribosome recycling and acceleration of the translation initiation rate. This update of covalently and noncovalently closed circular mRNA translation landscape shows that RNA with circular shape might be the rule for translation with an important impact on disease development and biotechnological applications.     

Development of a Selective Americium Separation Process Using H4TPAEN as Water-Soluble Stripping Agent

ABSTRACT

Recycling americium from spent nuclear fuel is considered as an important option for a future sustainable nuclear fuel cycle. The PUREX solvent extraction process allows to separate uranium and plutonium from a solution of spent fuel dissolved in nitric acid. In a second step, it would be desirable to separate americium from fission products, and especially lanthanides, but also from curium in order to further transmute americium in future fast neutron reactors. For this purpose, we report the investigation of a new solvent extraction process based on the use of TODGA as an extractant in the organic phase and H₄TPAEN as a selective Am(III) stripping agent in the aqueous phase. With this promising system it is possible to co-extract Am, Cm and lanthanides at high acidity and then selectively strip americium from the loaded organic phase at pH around 1 with H₄TPAEN. Batch extraction data were acquired to evaluate best conditions to develop a liquid-liquid extraction flow sheet. The influence of several parameters like concentration of ligand, cations and temperature on Am(III)/Cm(III) and Am/lanthanides separation was evaluated. Especially, the ability of H₄TPAEN complexing agent to strip macro-concentrations of Am was demonstrated.     

The Likeness of Fugitivity: William Notman's Carte-de-visite Portrait of John Anderson

In 1861, in his Montreal studio, the Canadian photographer William Notman (1826–1891) took a carte-de-visite portrait of the fugitive African-American John Anderson, who had fled to Canada to escape slavery in the US. Subsequently, examples of this portrait had been sold at abolitionist events. This essay explores visual strategies underlying the production of this image, at a time when Anderson had become the focus of a transatlantic extradition case that received extensive international media attention. The paper argues that the carte-de-visite functioned strategically to situate Anderson among free subjects by using a visual language of composure and stability, while relying also on a certain societal distance between Anderson and his many advocates. It shows too how Anderson, when posing for the carte-de-visite, negotiated the tensions between ‘objecthood’ and ‘subjecthood’ within a transatlantic context. Finally, it compares Notman's carte-de-visite with other examples of antislavery visual culture, such as the Wedgwood slave medallion, a daguerreotype abolitionist button and other depictions of Anderson.