Hierarchical strategies for efficient fault recovery on the reconfigurable PAnDA device

A novel hierarchical fault-tolerance methodology for reconfigurable devices is presented. A bespoke multi-reconfigurable FPGA architecture, the programmable analogue and digital array (PAnDA), is introduced allowing fine-grained reconfiguration beyond any other FPGA architecture currently in existence. Fault blind circuit repair strategies, which require no specific information of the nature or location of faults, are developed, exploiting architectural features of PAnDA. Two fault recovery techniques, stochastic and deterministic strategies, are proposed and results of each, as well as a comparison of the two, are presented. Both approaches are based on creating algorithms performing fine-grained hierarchical partial reconfiguration on faulty circuits in order to repair them. While the stochastic approach provides insights into feasibility of the method, the deterministic approach aims to generate optimal repair strategies for generic faults induced into a specific circuit. It is shown that both techniques successfully repair the benchmark circuits used after random faults are induced in random circuit locations, and the deterministic strategies are shown to operate efficiently and effectively after optimisation for a specific use case. The methods are shown to be generally applicable to any circuit on PAnDA, and to be straightforwardly customisable for any FPGA fabric providing some regularity and symmetry in its structure

The high hydraulic conductivity of three wooded tropical peat swamps in northeast Peru : measurements and implications for hydrological function

This research was supported by a NERC PhD studentship to the lead author, as well as by a Dudley Stamp Memorial Award from the Royal Geographical Society.The form and functioning of peatlands depend strongly on their hydrological status, but there are few data available on the hydraulic properties of tropical peatlands. In particular, the saturated hydraulic conductivity (K) has not previously been measured in neotropical peatlands. Piezometer slug tests were used to measure K at two depths (50 and 90 cm) in three contrasting forested peatlands in the Peruvian Amazon: Quistococha, San Jorge and Buena Vista. Measured K at 50 cm depth varies between 0.00032 and 0.11 cm s−1, and at 90 cm, it varies between 0.00027 and 0.057 cm s−1. Measurements of K taken from different areas of Quistococha showed that spatial heterogeneity accounts for ~20% of the within-site variance and that depth is a good predictor of K. However, K did not vary significantly with depth at Buena Vista and San Jorge. Statistical analysis showed that ~18% of the variance in the K data can be explained by between-site differences. Simulations using a simple hydrological model suggest that the relatively high K values could lead to lowering of the water table by >10 cm within ~48 m of the peatland edge for domed peatlands, if subjected to a drought lasting 30 days. However, under current climatic conditions, even with high K, peatlands would be unable to shed the large amount of water entering the system via rainfall through subsurface flow alone. We conclude that most of the water leaves these peatlands via overland flow and/or evapotranspiration.PostprintPeer reviewe

An assessment of vouchered records and field observations of the rare anguid, Dopasia buettikoferi (Lidth de Jeude, 1905) in Borneo

We report recent observations, two new locality records and an updated overview of the distribution of Dopasia buettikoferi (Lidth de Jeude, 1905) from Borneo, as well as photographic documentation of this species showing colouration and patterns in living individuals and the holotype. This note represents the first complete compilation of distributional knowledge of this rarely-encountered member of the family Anguidae

An assessment of vouchered records and field observations of the rare anguid, Dopasia buettikoferi (Lidth de Jeude, 1905) in Borneo

We report recent observations, two new locality records and an updated overview of the distribution of Dopasia buettikoferi (Lidth de Jeude, 1905) from Borneo, as well as photographic documentation of this species showing colouration and patterns in living indi-viduals and the holotype. This note represents the first complete compilation of distributional knowledge of this rarely-encountered member of the family Anguidae

An assessment of vouchered records and field observations of the rare anguid, Dopasia buettikoferi (Lidth de Jeude, 1905) in Borneo

We report recent observations, two new locality records and an updated overview of the distribution of Dopasia buettikoferi (Lidth de Jeude, 1905) from Borneo, as well as photographic documentation of this species showing colouration and patterns in living indi-viduals and the holotype. This note represents the first complete compilation of distributional knowledge of this rarely-encountered member of the family Anguidae

The presence of peat and variation in tree species composition are under different hydrological controls in Amazonian wetland forests

This research was funded by the Gordon and Betty Moore Foundation, through grant #5349 ‘Monitoring protected areas in Peru to increase forest resilience to climate change’, and NERC standard grant ‘Carbon Storage in Amazonian Peatlands: Distribution and Dynamics’(NE/R000751/1).The peat-forming wetland forests of Amazonia are characterised by high below-carbon stocks and supply fruit, fibres and timber to local communities. Predicting the future of these ecosystem services requires understanding how hydrological conditions are related to tree species composition and the presence, or absence, of peat. Here, we use continuous measurements of water table depth over 2.5 years and manual measurements of pore-water pH and electrical conductivity to understand the ecohydrological controls of these variables across the large peatland complex in northern Peruvian Amazonia. Measurements were taken in permanent forest plots in four palm swamps, four seasonally flooded forests and four peatland pole forests. All trees ≥10 cm diameter were also measured and identified in the plots to assess floristic composition. Peat occurs in eight of these twelve sites; three seasonally flooded forests and one palm swamp are not associated with peat. Variation in tree species composition among forest types was linked to high flood levels (maximum flooding height) and pH: seasonally flooded forests experience high flood levels (up to 3.66 m from the ground surface) and have high pH values (6?7), palm swamps have intermediate flood levels (up to 1.34 m) and peatland pole forests experience shallow flooding (up to 0.28 m) and have low pH (4). In contrast, the presence of peat was linked to variation in maximum water table depth (ie the depth to which the water table drops below the ground surface). Surface peat is found in all forest types where maximum water table depth does not fall >0.55 m below the ground surface at any time. Peat formation and variation in tree species composition therefore have different ecohydrological controls. Predicted increases in the frequency and strength of flooding events may alter patterns of tree species composition, whereas increases in drought severity and declines in minimum river levels may pose a greater risk to the belowground carbon stores of these peatland ecosystems.Publisher PDFPeer reviewe

Free classification of large sets of everyday objects is more thematic than taxonomic

Traditionally it has been thought that the overall organisation of categories in the brain is taxonomic. To examine this assumption, we had adults sort 140–150 diverse, familiar objects from different basic-level categories. Almost all the participants (80/81) sorted the objects more thematically than taxonomically. Sorting was only weakly modulated by taxonomic priming, and people still produced many thematically structured clusters when explicitly instructed to sort taxonomically. The first clusters that people produced were rated as having equal taxonomic and thematic structure. However, later clusters were rated as being increasingly thematically organised. A minority of items were consistently clustered taxonomically, but the overall dominance of thematically structured clusters suggests that people know more thematic than taxonomic relations among everyday objects. A final study showed that the semantic relations used to sort a given item in the initial studies predicted the proportion of thematic to taxonomic word associates generated to that item. However, unlike the results of the sorting task, most of these single word associates were related taxonomically. This latter difference between the results of large-scale, free sorting tasks versus single word association tasks suggests that thematic relations may be more numerous, but weaker, than taxonomic associations in our stored conceptual network. Novel statistical and numerical methods for objectively measuring sorting consistency were developed during the course of this investigation, and have been made publicly available

Emerging Infectious Disease leads to Rapid Population Decline of Common British Birds

Emerging infectious diseases are increasingly cited as threats to wildlife, livestock and humans alike. They can threaten geographically isolated or critically endangered wildlife populations; however, relatively few studies have clearly demonstrated the extent to which emerging diseases can impact populations of common wildlife species. Here, we report the impact of an emerging protozoal disease on British populations of greenfinch Carduelis chloris and chaffinch Fringilla coelebs, two of the most common birds in Britain. Morphological and molecular analyses showed this to be due to Trichomonas gallinae. Trichomonosis emerged as a novel fatal disease of finches in Britain in 2005 and rapidly became epidemic within greenfinch, and to a lesser extent chaffinch, populations in 2006. By 2007, breeding populations of greenfinches and chaffinches in the geographic region of highest disease incidence had decreased by 35% and 21% respectively, representing mortality in excess of half a million birds. In contrast, declines were less pronounced or absent in these species in regions where the disease was found in intermediate or low incidence. Also, populations of dunnock Prunella modularis, which similarly feeds in gardens, but in which T. gallinae was rarely recorded, did not decline. This is the first trichomonosis epidemic reported in the scientific literature to negatively impact populations of free-ranging non-columbiform species, and such levels of mortality and decline due to an emerging infectious disease are unprecedented in British wild bird populations. This disease emergence event demonstrates the potential for a protozoan parasite to jump avian host taxonomic groups with dramatic effect over a short time period

Global, local and focused geographic clustering for case-control data with residential histories

BACKGROUND: This paper introduces a new approach for evaluating clustering in case-control data that accounts for residential histories. Although many statistics have been proposed for assessing local, focused and global clustering in health outcomes, few, if any, exist for evaluating clusters when individuals are mobile. METHODS: Local, global and focused tests for residential histories are developed based on sets of matrices of nearest neighbor relationships that reflect the changing topology of cases and controls. Exposure traces are defined that account for the latency between exposure and disease manifestation, and that use exposure windows whose duration may vary. Several of the methods so derived are applied to evaluate clustering of residential histories in a case-control study of bladder cancer in south eastern Michigan. These data are still being collected and the analysis is conducted for demonstration purposes only. RESULTS: Statistically significant clustering of residential histories of cases was found but is likely due to delayed reporting of cases by one of the hospitals participating in the study. CONCLUSION: Data with residential histories are preferable when causative exposures and disease latencies occur on a long enough time span that human mobility matters. To analyze such data, methods are needed that take residential histories into account

Naturalizing Institutions: Evolutionary Principles and Application on the Case of Money

In recent extensions of the Darwinian paradigm into economics, the replicator-interactor duality looms large. I propose a strictly naturalistic approach to this duality in the context of the theory of institutions, which means that its use is seen as being always and necessarily dependent on identifying a physical realization. I introduce a general framework for the analysis of institutions, which synthesizes Searle's and Aoki's theories, especially with regard to the role of public representations (signs) in the coordination of actions, and the function of cognitive processes that underly rule-following as a behavioral disposition. This allows to conceive institutions as causal circuits that connect the population-level dynamics of interactions with cognitive phenomena on the individual level. Those cognitive phenomena ultimately root in neuronal structures. So, I draw on a critical restatement of the concept of the meme by Aunger to propose a new conceptualization of the replicator in the context of institutions, namely, the replicator is a causal conjunction between signs and neuronal structures which undergirds the dispositions that generate rule-following actions. Signs, in turn, are outcomes of population-level interactions. I apply this framework on the case of money, analyzing the emotions that go along with the use of money, and presenting a stylized account of the emergence of money in terms of the naturalized Searle-Aoki model. In this view, money is a neuronally anchored metaphor for emotions relating with social exchange and reciprocity. Money as a meme is physically realized in a replicator which is a causal conjunction of money artefacts and money emotions