1,460 research outputs found
Exit Ramp to Sustainability: the plenitude path
Juliet Schor, economista de renom i catedràtica de sociologia, identifica signes vitals de resistència iesperança en un món confrontat per desafiaments ecològics extrems. En el seu molt lúcid i documentattreball, l’autora mostra les interconnexions existents entre un amenaçant col·lapse ecològic, la pobresaglobal i les crisis econòmiques. Mentre les proves al voltant de la intensitat dels abusos humans globalssobre la nostra biosfera segueixen augmentant, les estructures, teories i polítiques econòmiqueshegemòniques, en lloc d’oferir solucions sensates, segueixen exacerbant la contribució humana a ladegradació del medi ambient del nostre planeta. Mentre els economistes de les societats riques segueixentractant el medi ambient com un be de luxe, les proves científiques ens diuen que la humanitat no potpermetre’s el luxe d’esperar que certs individus percebin que són novament rics abans de prendre accionsefectives. Segons explica l’autora, hi ha una necessitat urgent de trobar noves formes de reduir les nostrespetjades ecològiques i les emissions de gas d’efecte hivernacle mentre es resolen els problemes econòmicsdel Nord global i augmenten els estàndards de vida de la gent pobre del Sud global. Aquest és el problemareal del nostre temps i el nucli dels conflictes i canvis socials que tenim pel davant. Com demostra JulietSchor en el seu article, necessitem una rampa de sortida, una visió econòmica de transició cap a unaeconomia planetària sostenible que es fonamenti, no només en una comprensió clara del lloc on hem estat,sinó de la resistència d’un moviment emergent i en expansió de persones que estan forjant un camí cap auna nova plenitud.Juliet Schor, a well regarded economist and professor of sociology, identifies vital signs of resistance andhope in a world confronted by extreme ecological challenges. In her very lucid and well-documentedwork, the author shows the interconnection among a threatening ecological collapse, global poverty andeconomic crises. While evidence on the intensity of global stressors on our biosphere keeps mountingprevailing economic structures, theories and policies, rather than offering meaningful solutions, keepexacerbating human contribution to the degradation of our planet’s environment. While economists inwealthy societies keep treating the environment as a luxury good, scientific evidence tells us thathumanity does not have the luxury of waiting for some people to feel rich again before taking effectiveaction. There is an urgent need to find new ways to reduce our eco-footprints and green house gasemissions while solving the economic problems of the global north and raising the standard of living ofpoor people in the global south, she explains. This is the real problem of our time and the core of socialconflict and change ahead. As Juliet Schor demonstrates in her article, we need an exit ramp, an economicvision of the transition towards a sustainable planetary economy based not only on a clear understandingof where we have been, but on the resistance of an emerging and expanding movement of people who areforging a path to a new plenitude.Juliet Schor, economista de renombre y catedrática de sociología, identifica signos vitales de resistencia yesperanza en un mundo confrontado con desafíos ecológicos extremos. En su muy lúcido y documentadotrabajo, la autora muestra las interconexiones existentes entre un amenazante colapso ecológico, lapobreza global y las crisis económicas. Mientras que las pruebas acerca de la intensidad de los abusoshumanos globales sobre nuestra biosfera siguen aumentando, las estructuras, teorías y políticaseconómicas hegemónicas, en lugar de ofrecer soluciones sensatas, siguen exacerbando la contribuciónhumana a la degradación del medioambiente de nuestro planeta. Mientras que los economistas de lassociedades ricas siguen tratando el medioambiente como un bien de lujo, las pruebas científicas nos dicenque la humanidad no puede darse el lujo de esperar que ciertos individuos perciban que son de nuevoricos antes de tomar acciones efectivas. Según explica la autora, hay una necesidad urgente de encontrarformas nuevas de reducir nuestras huellas ecológicas y emisiones de gas de efecto invernadero mientrasse resuelven los problemas económicos del Norte global y aumentan los estándares de vida de la gentepobre del Sur global. Este es el problema real de nuestro tiempo y el núcleo de los conflictos y cambiossociales que tenemos por delante. Como demuestra Juliet Schor en su artículo, necesitamos una rampa desalida, una visión económica de transición hacia una economía planetaria sostenible que se base, no soloen una comprensión clara de dónde hemos estado, sino de la resistencia de un movimiento emergente yen expansión de personas que están forjando una senda hacia una nueva plenitud
Additivity of the Renyi entropy of order 2 for positive-partial-transpose-inducing channels
We prove that the minimal Renyi entropy of order 2 (RE2) output of a
positive-partial-transpose(PPT)-inducing channel joint to an arbitrary other
channel is equal to the sum of the minimal RE2 output of the individual
channels. PPT-inducing channels are channels with a Choi matrix which is bound
entangled or separable. The techniques used can be easily recycled to prove
additivity for some non-PPT-inducing channels such as the depolarizing and
transpose depolarizing channels, though not all known additive channels. We
explicitly make the calculations for generalized Werner-Holevo channels as an
example of both the scope and limitations of our techniques.Comment: 4 page
Human stereo matching is not restricted to epipolar lines
AbstractComputational approaches to stereo matching have often taken advantage of a geometric constraint which states that matching elements in the left and right eye images will always fall on “epipolar lines”. The use of this epipolar constraint reduces the search space from two dimensions to one, producing a tremendous saving in the computation time required to find the matching solution. Use of this constraint requires a precise knowledge of the relative horizontal, vertical and torsional positions of the two eyes, however, and this information may be unavailable in many situations. Experiments with dynamic random element stereograms reveal that human stereopsis can detect and identify the depth of matches over a range of both vertical and horizontal disparity. Observers were able to make accurate near/far depth discriminations when vertical disparity was as large as 45 arcmin, and were able to detect the presence of correlation over a slightly larger range. Thus, human binocular matching sensitivity is not strictly constrained to epipolar lines
Stimulation by a low-molecular-weight angiogenic factor of capillary endothelial cells in culture.
A low-mol.-wt compound isolated from rat Walker 256 carcinoma and found to induce neovascularization in vivo was tested on cultures of cow brain-derived endothelial cells (CBEC) growing on plastic and collagen substrates. This factor had a mitogenic effect on CBEC cultured on native collagen gels and for this reason has been called "endothelial-cell-stimulating angiogenesis factor" (ESAF). CBEC growing on plastic culture dishes or denatured collagen films were not stimulated by ESAF. The mitogenic effect of ESAF was equally apparent when added to cells already attached to the native collagen substrate or when the collagen substrate was pre-incubated with ESAF before plating the cells. A floating collagen gel pre-incubated with ESAF in cultures of CBEC growing on plastic dishes did not stimulate cell growth. Our data indicate that the substrate influences cell behaviour and that CBEC only respond to ESAF when growing on a native collagen substrate
The prescribing of prisms in clinical practice
The use of prisms in cases of decompensated heterophoria is an established treatment modality. The clinical literature lacks consensus upon the appropriate use of prisms, and fails to provide the necessary evidence base. While the experimental literature can guide the practitioner, the lack of double-blind, placebo-controlled clinical studies needs to be addressed
The bacterial hydrophobin BslA is a switchable ellipsoidal Janus nanocolloid
BslA
is an amphiphilic protein that forms a highly hydrophobic
coat around <i>Bacillus subtilis</i> biofilms, shielding
the bacterial community from external aqueous solution. It has a unique
structure featuring a distinct partition between hydrophilic and hydrophobic
surfaces. This surface property is reminiscent of synthesized Janus
colloids. By investigating the behavior of BslA variants at water-cyclohexane
interfaces through a set of multiscale simulations informed by experimental
data, we show that BslA indeed represents a biological example of
an ellipsoidal Janus nanoparticle, whose surface interactions are,
moreover, readily switchable. BslA contains a local conformational
toggle, which controls its global affinity for, and orientation at,
water–oil interfaces. This adaptability, together with single-point
mutations, enables the fine-tuning of its solvent and interfacial
interactions, and suggests that BslA could be a basis for biotechnological
applications
High glucose concentration stimulates intracellular renin activity and angiotensin II generation in rat mesangial cells
Increased intrarenal renin-angiotensin system activity contributes to diabetic nephropathy. ANG II generation in mesangial cells (MC) is increased by high-glucose (HG) exposure. This study assessed the mechanisms involved in the glucose-induced ANG II generation in rat MC. Under basal conditions, MC mainly secreted prorenin. HG decreased prorenin secretion and induced a striking 30-fold increase in intracellular renin activity. After 72 h of HG exposure, only the mRNA levels for angiotensinogen and angiotensin-converting enzyme (ACE) were significantly elevated. However, after shorter periods of 24 h of HG stimulation the mRNA levels of the enzymes prorenin and cathepsin B, besides that for ACE, were significantly increased. the results suggest that the HG-induced increase in ANG II generation in MC results from an increase in intracellular renin activity mediated by at least three factors: a time-dependent stimulation of ( pro) renin gene transcription, a reduction in prorenin enzyme secretion, and an increased rate of conversion of prorenin to active renin, probably mediated by cathepsin B. the increase in angiotensinogen mRNA in parallel to increased renin activity indicates that HG also increased the availability of the renin substrate. the consistent upregulation of ACE mRNA suggests that, besides renin, ACE is directly involved in the increased mesangial ANG II generation induced by HG.UNIFESP, Div Renal, BR-04023900 São Paulo, BrazilUNIFESP, Div Renal, BR-04023900 São Paulo, BrazilWeb of Scienc
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