1,388 research outputs found
Spiral model, jamming percolation and glass-jamming transitions
The Spiral Model (SM) corresponds to a new class of kinetically constrained
models introduced in joint works with D.S. Fisher [8,9]. They provide the first
example of finite dimensional models with an ideal glass-jamming transition.
This is due to an underlying jamming percolation transition which has
unconventional features: it is discontinuous (i.e. the percolating cluster is
compact at the transition) and the typical size of the clusters diverges faster
than any power law, leading to a Vogel-Fulcher-like divergence of the
relaxation time. Here we present a detailed physical analysis of SM, see [5]
for rigorous proofs. We also show that our arguments for SM does not need any
modification contrary to recent claims of Jeng and Schwarz [10].Comment: 9 pages, 7 figures, proceedings for StatPhys2
Assessing direct contributions of morphological awareness and prosodic sensitivity to childrenâs word reading and reading comprehension
We examined the independent contributions of prosodic sensitivity and morphological awareness to word reading, text reading accuracy, and reading comprehension. We did so in a longitudinal study of English-speaking children (N = 70). At 5 to 7 years of age, children completed the metalinguistic measures along with control measures of phonological awareness and vocabulary. Children completed the reading measures two years later. Morphological awareness, but not prosodic sensitivity made a significant independent contribution to word reading, text reading accuracy and reading comprehension. The effects of morphological awareness on reading comprehension remained after controls for word reading. These results suggest that morphological awareness needs to be considered seriously in models of reading development and that prosodic sensitivity might have primarily indirect relations to reading outcomes.
Keywords: Morphological Awareness; Prosody; Word Reading; Reading Comprehension
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Evidence: Biofilter performance and operation as related to commercial composting
This report provides a critical review of available evidence as to how effectively the various categories and configurations of biofilter reduce bioaerosol and odour emissions from composting facilities
Ergot: A New Disease Threat to Sorghum in the Americas and Australia
Sorghum, Sorghum bicolor (L.) Moench, is the worldâs fifth most important cereal crop, cultivated on about 45 million hectares for food, feed, beverage, and fodder. The most significant technological change since the 1960s has been the development and use of F1 hybrid seed (14), which has lead to a dramatic
improvement in the cropâs productivity. Sorghum cultivation in intensive, commercialized systems where yields average 3 to 5 t ha-1 relies almost totally on hybrid seed. In contrast, yields vary widely and average less than 1 t ha-1 in low-input production systems
B-Amyloid of Alzheimer\u27s Disease Induces Reactive Gliosis that Inhibits Axonal Outgrowth
Pathological lesions in the brains of patients with Alzheimer\u27s disease (AD) are characterized by dense deposits of the protein ,B-amyloid. The link between the deposition of B-amyloid in senile plaques and AD-associated pathology is, at present, controversial since there have been conflicting reports on whether the 39- 43 amino acid B-amyloid sequence is toxic or trophic to neurons. In this report, we show that B-amyloid peptide when presented as an insoluble substrate which mimics its conformation in vivo can induce cortical glial cells in vitro and in vivo to locally deposit chondroitin sulfate containingproteoglycan. In vitro the proteoglycan-containing matrix deposited by glia on B-amyloid blocks the usual ability of the peptide to allow cortical neurons to adhere and grow. Chondroitin sulfate-containing proteoglycan was also found in senile plaques of human AD tissue. We suggest that an additional effect of B-amyloid in the brain, which compounds the direct effects of ,8- amyloid on neurons, is mediated by the stimulation of astroglia to become reactive. Once in the reactive state, glial cells deposit large amounts of growth-inhibitory molecules within the neuropil which could impair neuronal process survival and regeneration leading to neurite retraction and/or dystrophy around senile plaques in AD
The Effects of Reputation and Ethics on Budgetary Slack
This experimental study tests the effects on budgetary slack of two potential controls for opportunistic self-interestĂłreputation and ethics. I manipulate the level of information asymmetry between the subordinate and the superior regarding productive capability and measure the subordinateĂs reputation and ethical concerns regarding budgetary slack. In this setting, I examine how information asymmetry affects reputation and ethical concerns, and test the effects of these concerns on budgetary slack. Consistent with prior findings, subordinates restrict the slack in their budgets to well below the maximum under a slackinducing pay scheme, even after five periods of experience. Budgetary slack is negatively associated with a measure of ethical responsibility from a pre-experiment personality questionnaire as well as reputation and ethical concerns expressed in an exit questionnaire. Subordinates express lower reputation concerns as information asymmetry regarding productive capability increases, thereby reducing the superiorĂs ability to monitor the slack in their budget. Ethical concerns, however, are not diminished with increases in information asymmetry. These results suggest that reputation is a socially mediated control, whereas ethics is an internally mediated control for opportunistic self-interest
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Index insurance and climate risk management: addressing social equity
Motivation Fair distribution of benefits from index insurance matters. Lack of attention to social equity can reinforce inequalities and undermine the potential index insurance holds as a tool for climate risk management that is also pro-poor.
Purpose The aims are to: (i) examine social equity concerns raised by index insurance in the context of climate risk management; (ii) consider how greater attention can be given to social equity in index insurance initiatives; and (iii) reflect on the policy challenges raised by seeking to take social equity into account as a mechanism for climate risk reduction.
Approach and methods The article draws on learning from the CGIARâs Research Program on Climate Change, Agriculture and Food Security (CCAFS) and presents the cases of the Index Based Livelihoods Insurance (IBLI) and Agriculture and Climate Risk Enterprise Ltd. (ACRE) in East Africa. It proposes a framework for unpacking social equity related to equitable access, procedures, representation and distribution within index insurance schemes
Findings Systematically addressing social equity raises hard policy choices for index insurance initiatives without straightforward solutions. Attention to how benefits and burdens of index insurance are distributed raises the unpalateable truth for development policy that the poorest members of rural society can be excluded. Nevertheless, a focus on social equity may open up opportunities to ensure index insurance is linked to more socially just climate risk management. At the very least, it may prevent index insurance from generating greater inequality. Taking social equity into account thus, shifts the focus from agricultural systems in transition per se to systems with potential to incorporate societal transformation through distributive justice.
Policy implications A framework is presented for unpacking different dimensions of social equity in index insurance schemes. It is intended to facilitate identification of opportunities for building outcomes that are more equitable, with greater potential for inclusion and fairer distribution
Locked and Unlocked Chains of Planar Shapes
We extend linkage unfolding results from the well-studied case of polygonal
linkages to the more general case of linkages of polygons. More precisely, we
consider chains of nonoverlapping rigid planar shapes (Jordan regions) that are
hinged together sequentially at rotatable joints. Our goal is to characterize
the families of planar shapes that admit locked chains, where some
configurations cannot be reached by continuous reconfiguration without
self-intersection, and which families of planar shapes guarantee universal
foldability, where every chain is guaranteed to have a connected configuration
space. Previously, only obtuse triangles were known to admit locked shapes, and
only line segments were known to guarantee universal foldability. We show that
a surprisingly general family of planar shapes, called slender adornments,
guarantees universal foldability: roughly, the distance from each edge along
the path along the boundary of the slender adornment to each hinge should be
monotone. In contrast, we show that isosceles triangles with any desired apex
angle less than 90 degrees admit locked chains, which is precisely the
threshold beyond which the inward-normal property no longer holds.Comment: 23 pages, 25 figures, Latex; full journal version with all proof
details. (Fixed crash-induced bugs in the abstract.
Goats or wolves? Private sector managers in the public sector
Public administration reforms have propagated the use of private sector management skills in the public sector, and an increased openness to managers with a private sector background. This has created a debate between those who think private sector experience improves public institutions by bringing core managerial values such as results orientation, efficiency, or openness to innovation, and those who argue that private sector experience can damage core public sector values, such as impartiality and equity. Despite the abundant anecdotal evidence, broad empirical evidence on the effects of private sector experience on public managers' values remains limited. Using data from a survey among central government top managers in 18 European countries, we show that public managers with private sector experience have, as expected, more core managerial values. Yet, unlike the conventional view, core public values do not suffer.The politics and administration of institutional chang
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