116 research outputs found
What is the crisis of Western sciences?
© 2016, Springer Science+Business Media Dordrecht. This article is an attempt to formulate a clear definition of the concept of crisis of Western sciences introduced by Husserl in his last work. The attempt will be based on a reading of the Krisis, which will stress its underlying continuity with Husserl’s life-long concerns about the theoretical insufficiency of positive sciences, and downplay the novelty of the idea of crisis itself within Husserl’s work. After insisting on the fact that, according to Husserl, only an account of the shortcomings of the scientificity of Western sciences can justify the claim that they are undergoing a crisis, it will be argued that the common definition of the crisis of the sciences as the loss of their significance for life rests on a misunderstanding. The crisis of Western sciences will be characterized, instead, as the repercussion of the crisis of the scientificity of philosophy (and, specifically, of metaphysics) on the scientificity of positive sciences. The loss of significance of scientific knowledge for our existence will in turn appear as a further, inevitable consequence of the uprooting of the sciences from the soil of a universal philosophy culminating in metaphysics, and thus, as a phenomenon deeply intertwined with the crisis of Western sciences, but not identical to it
Dynamics of Dynamin during Clathrin Mediated Endocytosis in PC12 Cells
Members of the dynamin super-family of GTPases are involved in disparate cellular pathways. Dynamin1 and dynamin2 have been implicated in clathrin-mediated endocytosis. While some models suggest that dynamin functions specifically at the point of vesicle fission, evidence also exists for a role prior to fission during vesicle formation and it is unknown if there is a role for dynamin after vesicle fission. Although dynamin2 is ubiquitously expressed, dynamin1 is restricted to the nervous system. These two structurally similar endocytic accessory proteins have not been studied in cells that endogenously express both.The present study quantitatively assesses the dynamics of dynamin1 and dynamin2 during clathrin-mediated endocytosis in PC12 cells, which endogenously express both proteins. Both dynamin isoforms co-localized with clathrin and showed sharp increases in fluorescence intensity immediately prior to internalization of the nascent clathrin-coated vesicle. The fluorescence intensity of both proteins then decreased with two time constants. The slower time constant closely matched the time constant for the decrease of clathrin intensity and likely represents vesicle movement away from the membrane. The faster rate may reflect release of dynamin at the neck of nascent vesicle following GTP hydrolysis.This study analyses the role of dynamin in clathrin-mediated endocytosis in a model for cellular neuroscience and these results may provide direct evidence for the existence of two populations of dynamin associated with nascent clathrin-coated vesicles
A Severe Lack of Evidence Limits Effective Conservation of the World's Primates
Threats to biodiversity are well documented. However, to effectively conserve species and their habitats, we need to know which conservation interventions do (or do not) work. Evidence-based conservation evaluates interventions within a scientific framework. The Conservation Evidence project has summarized thousands of studies testing conservation interventions and compiled these as synopses for various habitats and taxa. In the present article, we analyzed the interventions assessed in the primate synopsis and compared these with other taxa. We found that despite intensive efforts to study primates and the extensive threats they face, less than 1% of primate studies evaluated conservation effectiveness. The studies often lacked quantitative data, failed to undertake postimplementation monitoring of populations or individuals, or implemented several interventions at once. Furthermore, the studies were biased toward specific taxa, geographic regions, and interventions. We describe barriers for testing primate conservation interventions and propose actions to improve the conservation evidence base to protect this endangered and globally important taxon
Nutrient Enrichment and Food Web Composition Affect Ecosystem Metabolism in an Experimental Seagrass Habitat
Food web composition and resource levels can influence ecosystem properties such as productivity and elemental cycles. In particular, herbivores occupy a central place in food webs as the species richness and composition of this trophic level may simultaneously influence the transmission of resource and predator effects to higher and lower trophic levels, respectively. Yet, these interactions are poorly understood.Using an experimental seagrass mesocosm system, we factorially manipulated water column nutrient concentrations, food chain length, and diversity of crustacean grazers to address two questions: (1) Does food web composition modulate the effects of nutrient enrichment on plant and grazer biomasses and stoichiometry? (2) Do ecosystem fluxes of dissolved oxygen and nutrients more closely reflect above-ground biomass and community structure or sediment processes? Nutrient enrichment and grazer presence generally had strong effects on biomass accumulation, stoichiometry, and ecosystem fluxes, whereas predator effects were weaker or absent. Nutrient enrichment had little effect on producer biomass or net ecosystem production but strongly increased seagrass nutrient content, ecosystem flux rates, and grazer secondary production, suggesting that enhanced production was efficiently transferred from producers to herbivores. Gross ecosystem production (oxygen evolution) correlated positively with above-ground plant biomass, whereas inorganic nutrient fluxes were unrelated to plant or grazer biomasses, suggesting dominance by sediment microbial processes. Finally, grazer richness significantly stabilized ecosystem processes, as predators decreased ecosystem production and respiration only in the zero- and one- species grazer treatments.Overall, our results indicate that consumer presence and species composition strongly influence ecosystem responses to nutrient enrichment, and that increasing herbivore diversity can stabilize ecosystem flux rates in the face of perturbations
Recommended from our members
Blocking and its response to climate change
Purpose of review: Atmospheric blocking events represent some of the most high-impact weather patterns in the mid-latitudes, yet they have often been a cause for concern in future climate projections. There has been low confidence in predicted future changes in blocking, despite relatively good agreement between climate models on a decline in blocking. This is due to the lack of a comprehensive theory of blocking and a pervasive underestimation of blocking occurrence by models. This paper reviews the state of knowledge regarding blocking under climate change, with the aim of providing an overview for those working in related fields.
Recent Findings: Several avenues have been identified by which blocking can be improved in numerical models, though a fully reliable simulation remains elusive (at least, beyond a few days lead time). Models are therefore starting to provide some useful information on how blocking and its impacts may change in the future, although deeper understanding of the processes at play will be needed to increase confidence in model projections. There are still major uncertainties regarding the processes most important to the onset, maintenance and decay of blocking and advances in our understanding of atmospheric dynamics, for example in the role of diabatic processes, continue to inform the modelling and prediction efforts.
Summary: The term ‘blocking’ covers a diverse array of synoptic patterns, and hence a bewildering range of indices has been developed to identify events. Results are hence not considered fully trustworthy until they have been found using several different methods. Examples of such robust results are the underestimation of blocking by models, and an overall decline in future occurrence, albeit with a complex regional and seasonal variation. In contrast, hemispheric trends in blocking over the recent historical period are not supported by different methods, and natural variability will likely dominate regional variations over the next few decades
Uniendo ingenierÃa y ecologÃa: la protección costera basada en ecosistemas
En un contexto de crecientes impactos y riesgos socio-económicos en las costas del planeta, la
protección costera basada en ecosistemas surge como un nuevo paradigma que une los principios
de protección, sostenibilidad y resiliencia, a la vez que proporciona múltiples beneficios. Este
artÃculo ofrece una perspectiva sobre qué son y cómo se pueden utilizar las defensas naturales en
el diseño, planificación y gestión de costas. La polÃtica pública muestra un creciente interés por su
implementación general y el cuerpo de conocimiento y experiencia alrededor de la también
denominada infraestructura ?verde? es creciente, pero aún existen importantes barreras que
salvar. Una de ellas es estandarizar su diseño en términos ingenieriles, asà como reconocer los
aspectos que los diferencian respecto a enfoques tradicionales. La adaptación climática y la
reducción de riesgos son áreas en las que su utilización puede ser más significativa, debido a
la variedad de servicios que ofrecen. Tanto desde el punto de vista técnico como económico,
existen argumentos sólidos para evitar la degradación de los ecosistemas, avanzando su
restauración y conservación, como también desde la perspectiva de la defensa de las costas.In a context of increasing socio-economic impacts and risks in the coastal areas of the planet,
coastal protection based on ecosystem features becomes a new paradigm that combines the
principles of conservation, sustainability and resilience, while providing multiple benefits. This
paper provides a perspective on what these are and how they can be used in the design,
planning and management of the coastal zones. Policy-makers are calling for further uptake
and implementation across the board and the body of knowledge and experience around the socalled
?green? infrastructure is growing, but there are still major barriers for a widespread uptake.
One of them is to standardize designs in engineering terms, recognizing the different characteristics
compared to traditional engineering solutions. Climate adaptation and risk reduction are
areas where its use may be more significant, for the variety of services they offer. Both technically
and economically, there are strong arguments to prevent degradation of ecosystems and to
advance in their restoration and conservation, as well as from a coastal defense perspective
Arthropathies Associated with Basic Calcium Phosphate Crystals
Basic calcium phosphate (BCP) crystals refer to a family of crystals including partially carbonate substituted hydroxyapatite, octacalcium phosphate, and tricalcium phosphate. These crystals have been found in and around joints and have been associated with several forms of arthritis and periarthritis. Identification of BCP crystals remains problematic because of the lack of a simple, reliable analytic procedure. Methods currently in use include alizarin red S staining, labelled diphosphonate binding, scanning and transmission electron microscopy with energy dispersive X-ray microanalysis, X-ray diffraction, and atomic force microscopy. Periarthropathies associated with BCP crystals include calcific tendinitis and bursitis. Intra-articular BCP crystal deposition is common in osteoarthritis, often found together with calcium pyrophosphate dihydrate crystals. Uncommon conditions in which BCP crystals are found include destructive shoulder arthropathies, acute inflammatory attacks of arthritis, and erosive arthritis. Secondary deposition of BCP crystals has been observed in chronic renal failure, in patients with collagen vascular diseases, following neurologic injury and after local corticosteroid injection
- …