4,034 research outputs found
Pursuing positionality in design
In the context of a complex social matrix that we find ourselves in, described by the continuous flux of power relations and asymmetries; design as a practice, their practitioners and researchers carry the responsibility in the mindful shaping of the future. As mediators within the design system, designers carry the conversation between the design program, a hypothesis, the stakeholders, and the effects of the resulting conclusions. Within their practice and the reflexive process upon it, designers can question, critique, and dismantle oppressive systems of status quo perpetuation. A first approach to a critical dialogue in design suggests reviewing one’s identity to discover possible privileges and biases. This is done through the revision of positionality as a conscious way of understanding who we are regarding an other; identity remains fundamental in the axiological description of our ethical values, preconceptions, and the essence of our being, modifying and steering our ways of knowing and doing. Defining positionality impacts the design process and research, affecting methodologies and findings. This manuscript searches to display the nuances of design and the relevance of achieving the situated conception of our identity, i.e. positionality, through reflexivity. Intersecting designerly research and critical social studies to analyse the role of the self enables reflexivity. Giving a comprehensive overview of how to achieve this by overlapping Decolonial theory and Pluriverse, Thirdwave feminist theories such as Intersectionality, Standpoint theory, and Critical race theory; research methodologies such as Autoethnography and Participatory action research are presented under this theoretical framework
Stabilizing Superconductivity in Nanowires by Coupling to Dissipative Environments
We present a theory for a finite-length superconducting nanowire coupled to
an environment. We show that in the absence of dissipation quantum phase slips
always destroy superconductivity, even at zero temperature. Dissipation
stabilizes the superconducting phase. We apply this theory to explain the
"anti-proximity effect" recently seen by Tian et. al. in Zinc nanowires.Comment: 4 pages, 3 figure
Bulk viscosity of the massive Gross-Neveu model
A calculation of the bulk viscosity for the massive Gross-Neveu model at zero
fermion chemical potential is presented in the large- limit. This model
resembles QCD in many important aspects: it is asymptotically free, has a
dynamically generated mass gap, and for zero bare fermion mass it is scale
invariant at the classical level (broken through the trace anomaly at the
quantum level). For our purposes, the introduction of a bare fermion mass is
necessary to break the integrability of the model, and thus to be able to study
momentum transport. The main motivation is, by decreasing the bare mass, to
analyze whether there is a correlation between the maximum in the trace anomaly
and a possible maximum in the bulk viscosity, as recently conjectured. After
numerical analysis, I find that there is no direct correlation between these
two quantities: the bulk viscosity of the model is a monotonously decreasing
function of the temperature. I also comment on the sum rule for the spectral
density in the bulk channel, as well as on implications of this analysis for
other systems.Comment: v2: 3->3 processes included, conclusions unchanged. Comments and
references added. Typos corrected. To appear in Phys. Rev.
Coexistence of pion condensation and color superconductivity in two flavor quark matter
We show that the superconducting 2SC phase at high density and normal chiraly
broken quark phase at low density is separated by the mixed non-uniform phase
along the baryon density line.Comment: Change of the title. Journal-ref adda
Visualizing polymeric components that define distinct root barriers across plant lineages
Hydrophobic cell wall depositions in roots play a key role in plant development and interaction with the soil environment, as they generate barriers that regulate bidirectional nutrient flux. Techniques to label the respective polymers are emerging, but are efficient only in thin roots or sections. Moreover, simultaneous imaging of the barrier constituents lignin and suberin remains problematic owing to their similar chemical compositions. Here, we describe a staining method compatible with single- and multiphoton confocal microscopy that allows for concurrent visualization of primary cell walls and distinct secondary depositions in one workflow. This protocol permits efficient separation of suberin- and lignin-specific signals with high resolution, enabling precise dissection of barrier constituents. Our approach is compatible with imaging of fluorescent proteins, and can thus complement genetic markers or aid the dissection of barriers in biotic root interactions. We further demonstrate applicability in deep root tissues of plant models and crops across phylogenetic lineages. Our optimized toolset will significantly advance our understanding of root barrier dynamics and function, and of their role in plant interactions with the rhizospheric environment
Fracton pairing mechanism for "strange" superconductors: Self-assembling organic polymers and copper-oxide compounds
Self-assembling organic polymers and copper-oxide compounds are two classes
of "strange" superconductors, whose challenging behavior does not comply with
the traditional picture of Bardeen, Cooper, and Schrieffer (BCS)
superconductivity in regular crystals. In this paper, we propose a theoretical
model that accounts for the strange superconducting properties of either class
of the materials. These properties are considered as interconnected
manifestations of the same phenomenon: We argue that superconductivity occurs
in the both cases because the charge carriers (i.e., electrons or holes)
exchange {\it fracton excitations}, quantum oscillations of fractal lattices
that mimic the complex microscopic organization of the strange superconductors.
For the copper oxides, the superconducting transition temperature as
predicted by the fracton mechanism is of the order of K. We suggest
that the marginal ingredient of the high-temperature superconducting phase is
provided by fracton coupled holes that condensate in the conducting
copper-oxygen planes owing to the intrinsic field-effect-transistor
configuration of the cuprate compounds. For the gate-induced superconducting
phase in the electron-doped polymers, we simultaneously find a rather modest
transition temperature of K owing to the limitations imposed by
the electron tunneling processes on a fractal geometry. We speculate that
hole-type superconductivity observes larger onset temperatures when compared to
its electron-type counterpart. This promises an intriguing possibility of the
high-temperature superconducting states in hole-doped complex materials. A
specific prediction of the present study is universality of ac conduction for
.Comment: 12 pages (including separate abstract page), no figure
Developing transferable management skills through Action Learning
There has been increasing criticism of the relevance of the Master of Business Administration (MBA) in developing skills and competencies. Action learning, devised to address problem-solving in the workplace, offers a potential response to such criticism. This paper offers an insight into one university’s attempt to integrate action learning into the curriculum. Sixty-five part-time students were questioned at two points in their final year about their action learning experience and the enhancement of relevant skills and competencies. Results showed a mixed picture. Strong confirmation of the importance of selected skills and competencies contrasted with weaker agreement about the extent to which these were developed by action learning. There was, nonetheless, a firm belief in the positive impact on the learning process. The paper concludes that action learning is not a panacea but has an important role in a repertoire of educational approaches to develop relevant skills and competencies
Optical absorption and photoluminescence spectroscopy of the growth of silver nanoparticles
Results obtained from the optical absorption and photoluminescence (PL)
spectroscopy experiments have shown the formation of excitons in the
silver-exchanged glass samples. These findings are reported here for the first
time. Further, we investigate the dramatic changes in the photoemission
properties of the silver-exchanged glass samples as a function of postannealing
temperature. Observed changes are thought to be due to the structural
rearrangements of silver and oxygen bonding during the heat treatments of the
glass matrix. In fact, photoelectron spectroscopy does reveal these chemical
transformations of silver-exchanged soda glass samples caused by the thermal
effects of annealing in a high vacuum atmosphere. An important correlation
between temperature-induced changes of the PL intensity and thermal growth of
the silver nanoparticles has been established in this Letter through precise
spectroscopic studies.Comment: 15 pages,4 figures,PDF fil
Mitochondrial nucleoids maintain genetic autonomy but allow for functional complementation
Mitochondrial DNA (mtDNA) is packaged into DNA-protein assemblies called nucleoids, but the mode of mtDNA propagation via the nucleoid remains controversial. Two mechanisms have been proposed: nucleoids may consistently maintain their mtDNA content faithfully, or nucleoids may exchange mtDNAs dynamically. To test these models directly, two cell lines were fused, each homoplasmic for a partially deleted mtDNA in which the deletions were nonoverlapping and each deficient in mitochondrial protein synthesis, thus allowing the first unequivocal visualization of two mtDNAs at the nucleoid level. The two mtDNAs transcomplemented to restore mitochondrial protein synthesis but were consistently maintained in discrete nucleoids that did not intermix stably. These results indicate that mitochondrial nucleoids tightly regulate their genetic content rather than freely exchanging mtDNAs. This genetic autonomy provides a molecular mechanism to explain patterns of mitochondrial genetic inheritance, in addition to facilitating therapeutic methods to eliminate deleterious mtDNA mutations
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