7,037 research outputs found
The Objectivity of Ordinary Life
Metaethics tends to take for granted a bare Democritean world of atoms and the void, and then worry about how the human world that we all know can possibly be related to it or justified in its terms. I draw on Wittgenstein to show how completely upside-down this picture is, and make some moves towards turning it the right way up again. There may be a use for something like the bare-Democritean model in some of the sciences, but the picture has no standing as the basic objective truth about the world; if anything has that standing, it is ordinary life. I conclude with some thoughts about how the notion of bare, âthinâ perception of non-evaluative reality feeds a number of philosophical pathologies, such as behaviourism, and show how a âthickerâ, more value-laden, understanding of our perceptions of the world can be therapeutic against them
Evaluation of Psychoacoustic Sound Parameters for Sonification
Sonification designers have little theory or experimental evidence to guide the design of data-to-sound mappings. Many mappings use acoustic representations of data values which do not correspond with the listener's perception of how that data value should sound during sonification. This research evaluates data-to-sound mappings that are based on psychoacoustic sensations, in an attempt to move towards using data-to-sound mappings that are aligned with the listener's perception of the data value's auditory connotations. Multiple psychoacoustic parameters were evaluated over two experiments, which were designed in the context of a domain-specific problem - detecting the level of focus of an astronomical image through auditory display. Recommendations for designing sonification systems with psychoacoustic sound parameters are presented based on our results
Hyperbolic Kac Moody Algebras and Einstein Billiards
We identify the hyperbolic Kac Moody algebras for which there exists a
Lagrangian of gravity, dilatons and -forms which produces a billiard that
can be identified with their fundamental Weyl chamber. Because of the
invariance of the billiard upon toroidal dimensional reduction, the list of
admissible algebras is determined by the existence of a Lagrangian in three
space-time dimensions, where a systematic analysis can be carried out since
only zero-forms are involved. We provide all highest dimensional parent
Lagrangians with their full spectrum of -forms and dilaton couplings. We
confirm, in particular, that for the rank 10 hyperbolic algebra, , also known as the dual of , the
maximally oxidized Lagrangian is 9 dimensional and involves besides gravity, 2
dilatons, a 2-form, a 1-form and a 0-form.Comment: 33 page
Consumer responses to ethnic targeted marketing
__Abstract__
Marketing is impacted more than ever by demographic change,
to the extent that practitioners targeting ethnic groups should
re-think their approach depending upon the strength with which
different generations identify with their cultural heritage
Marine Phytoplankton Functional Types Exhibit Diverse Responses to Thermal Change
Marine phytoplankton generate half of global primary production, making them essential to ecosystem functioning and biogeochemical cycling. Though phytoplankton are phylogenetically diverse, studies rarely designate unique thermal traits to different taxa, resulting in coarse representations of phytoplankton thermal responses. Here we assessed phytoplankton functional responses to temperature using empirically derived thermal growth rates from four principal contributors to marine productivity: diatoms, dinoflagellates, cyanobacteria, and coccolithophores. Using modeled sea surface temperatures for 1950-1970 and 2080-2100, we explored potential alterations to each group\u27s growth rates and geographical distribution under a future climate change scenario. Contrary to the commonly applied Eppley formulation, our data suggest phytoplankton functional types may be characterized by different temperature coefficients (Q(10)), growth maxima thermal dependencies, and thermal ranges which would drive dissimilar responses to each degree of temperature change. These differences, when applied in response to global simulations of future temperature, result in taxon-specific projections of growth and geographic distribution, with low-latitude coccolithophores facing considerable decreases and cyanobacteria substantial increases in growth rates. These results suggest that the singular effect of changing temperature may alter phytoplankton global community structure, owing to the significant variability in thermal response between phytoplankton functional types. Phytoplankton communities are important players in biogeochemical processes, but are sensitive to global warming. Here, a meta-analysis shows how the varied responses of phytoplankton to rising temperatures could potentially alter growth dynamics and community structure in a future ocean
Light deflection in Weyl gravity: critical distances for photon paths
The Weyl gravity appears to be a very peculiar theory. The contribution of
the Weyl linear parameter to the effective geodesic potential is opposite for
massive and nonmassive geodesics. However, photon geodesics do not depend on
the unknown conformal factor, unlike massive geodesics. Hence light deflection
offers an interesting test of the Weyl theory.
In order to investigate light deflection in the setting of Weyl gravity, we
first distinguish between a weak field and a strong field approximation.
Indeed, the Weyl gravity does not turn off asymptotically and becomes even
stronger at larger distances.
We then take full advantage of the conformal invariance of the photon
effective potential to provide the key radial distances in Weyl gravity.
According to those, we analyze the weak and strong field regime for light
deflection. We further show some amazing features of the Weyl theory in the
strong regime.Comment: 20 pages, 9 figures (see published version for a better resolution,
or online version at stacks.iop.org/CQG/21/1897
Effects of Mitochondrial-Targeted Human Catalase in Skeletal Tissue of Mice Exposed to Simulated Spaceflight
During prolonged spaceflight, astronauts are exposed to both microgravity and space radiation and are at risk forincreased skeletal fragility due to bone loss, Evidence from rodent experiments has established that bothmicrogravity and ionizing radiation can cause bone loss due to increasd of bone-resorbing osteoclasts and decreasedin bone-forming osteoblasts, although the underlying molecular mechanisms for these changes are not fullyunderstood. We hypothesized that excess reactive oxidative species (ROS) produced by conditions that simulatedspaceflight alters the tight balance between osteoclast and osteoblast activities, leading to accelerated skeletalremodeling and culminating in loss of mineralized tissue. To begin to explore this hypothesis, we used the mCATmouse model [1]; these transgenic mice over-express the human catalase gene targeted to mitochondria, which arethe major organelle responsible for cellular production of free radicals. Catalase is an anti-oxidant that catalyzes theconversion of the reactive species, hydrogen peroxide (H202), into water and oxygen. This animal model wasselected as it displays extended lifespan, reduced cardiovascular disease and reduced central nervous systemradiosensitivity, consistent with elevated anti-oxidant activity conferred by the transgene. We reasoned that miceoverexpressing catalase the mitochondria of osteoblast and osteoclast lineage cells would be protected from the boneloss caused by simulated spaceflight
Assessing the effect of dynamics on the closed-loop protein-folding hypothesis
The closed-loop (loop-n-lock) hypothesis of protein folding suggests that loops of about 25 residues, closed through interactions between the loop ends (locks), play an important role in protein structure. Coarse-grain elastic network simulations, and examination of loop lengths in a diverse set of proteins, each supports a bias towards loops of close to 25 residues in length between residues of high stability. Previous studies have established a correlation between total contact distance (TCD), a metric of sequence distances between contacting residues (cf. contact order), and the log-folding rate of a protein. In a set of 43 proteins, we identify an improved correlation (
r
2
= 0.76), when the metric is restricted to residues contacting the locks, compared to the equivalent result when all residues are considered (
r
2
= 0.65). This provides qualified support for the hypothesis, albeit with an increased emphasis upon the importance of a much larger set of residues surrounding the locks. Evidence of a similar-sized protein core/extended nucleus (with significant overlap) was obtained from TCD calculations in which residues were successively eliminated according to their hydrophobicity and connectivity, and from molecular dynamics simulations. Our results suggest that while folding is determined by a subset of residues that can be predicted by application of the closed-loop hypothesis, the original hypothesis is too simplistic; efficient protein folding is dependent on a considerably larger subset of residues than those involved in lock formation.
</jats:p
Nitrogen cycle disruption through the application of de-icing salts on upland highways
It is hypothesized that episodic introductions of road salt severely disrupt the soil nitrogen cycle at a range of spatial and temporal scales. A field-scale study has confirmed impacts on the nitrogen cycle in soil, soil solution and river samples. There is evidence that ammonium-N retention on cation exchange sites has been reduced by the presence of sodium ions, and that ammonium-N has been flushed from the exchange sites. Increases in soil pH have been caused in naturally acidic uplands. These have enhanced mineralization of organic-N, especially nitrification, leading to a reduction in the mineralizable-N pool of roadside soils. There is evidence to support the hypothesis that organic matter content has been lowered over decades either through desorption or dispersal processes. Multiple drivers are identified that contribute to the disruption of nitrogen cycling processes, but their relative importance is difficult to quantify unequivocally. The influence of road salt on soil and soil solution declines with distance from the highway, but impacts on water chemistry in a local stream are still strongly evident at some distance from the road
Working practices and incomes of health workers : evidence from an evaluation of a delivery fee exemption scheme in Ghana
Background: This article describes a survey of health workers and traditional birth attendants (TBAs) which was carried out in 2005 in two regions of Ghana. The objective of the survey was to ascertain the impact of the introduction of a delivery fee exemption scheme on both health workers and those providers who were excluded from the scheme (TBAs). This formed part of an overall evaluation of the delivery fee exemption scheme. The results shed light not only on the scheme itself but also on the general productivity of a range of health workers in Ghana. Methods: A structured questionnaire was developed, covering individual and household characteristics, working hours and practices, sources of income, and views of the exemptions scheme and general motivation. After field testing, this was administered to 374 respondents in 12 districts of Central and Volta regions. The respondents included doctors, medical assistants (MAs), public and private midwives, nurses, community health nurses (CHNs), and traditional birth attendants, both trained and untrained. Results: Health workers were well informed about the delivery fee exemptions scheme and their responses on its impact suggest a realistic view that it was a good scheme, but one that faces serious challenges regarding financial sustainability. Concerning its impact on their morale and working conditions, the responses were broadly neutral. Most public sector workers have seen an increased workload, but counterbalanced by increased pay. TBAs have suffered, in terms of client numbers and income, while the picture for private midwives is mixed. The survey also sheds light on pay and productivity. The respondents report long working hours, with a mean of 54 hours per week for community nurses and up to 129 hours per week for MAs. Weekly reported client loads in the public sector range from a mean of 86 for nurses to 269 for doctors. Over the past two years, reported working hours have been increasing, but so have pay and allowances (for doctors, allowances now make up 66% of their total pay). The lowest paid public health worker now earns almost ten times the average gross national income (GNI) per capita, while the doctors earn 38.5 times GNI per capita. This compares well with average government pay of four times GNI per capita. Comparing pay with outputs, the relatively high number of clients reported by doctors reduces their pay differential, so that the cost per client â $1.09 â is similar to a nurse's (and lower than a private midwife's). Conclusion: These findings show that a scheme which increases demand for public health services while also sustaining health worker income and morale, is workable, if well managed, even within the relatively constrained human resources environment of countries like Ghana. This may be linked to the fact that internal comparisons reveal Ghana's health workers to be well paid from public sector sources.This work was undertaken as part of an international research programme â IMMPACT (Initiative for Maternal Mortality Programme Assessment) â funded by the Bill & Melinda Gates Foundation, the Department for International Development, the European Commission and USAID
- âŠ