Rational intuitionism

In this paper I give a critical overview of the views of the main Rational Intuitionists from 18th to 20th century.

A novel study of the polymerisation process involved in the formation of the network component of polymer-stabilised liquid crystals within electro-optic cells using high performance liquid chromatography

Polymer-stabilised liquid crystals are systems in which a small amount of monomer is dissolved within a liquid crystalline host, and then polymerised in situ to produce a network. The progress of the polymerisation, performed within electro-optic cells, was studied by establishing an analytical method novel to these systems. Samples were prepared by photopolymerisation of the monomer under well-defined reaction conditions; subsequent immersion in acetone caused the host and any unreacted monomer to dissolve. High performance liquid chromatography was used to separate and detect the various solutes in the resulting solutions, enabling the amount of unreacted monomer for a given set of conditions to be quantified. Longer irradiations cause a decrease in the proportion of unreacted monomer since more network is formed, while a more uniform LC director alignment (achieved by decreasing the sample thickness) or a higher level of order (achieved by decreasing the polymerisation temperature) promotes faster reactions.

Reconstruction of gusty wind speed time series from autonomous data logger records

The collection of wind speed time series by means of digital data loggers occurs in many domains, including civil engineering, environmental sciences and wind turbine technology. Since averaging intervals are often significantly larger than typical system time scales, the information lost has to be recovered in order to reconstruct the true dynamics of the system. In the present work we present a simple algorithm capable of generating a real-time wind speed time series from data logger records containing the average, maximum, and minimum values of the wind speed in a fixed interval, as well as the standard deviation. The signal is generated from a generalized random Fourier series. The spectrum can be matched to any desired theoretical or measured frequency distribution. Extreme values are specified through a postprocessing step based on the concept of constrained simulation. Applications of the algorithm to 10-min wind speed records logged at a test site at 60 m height above the ground show that the recorded 10-min values can be reproduced by the simulated time series to a high degree of accuracy.

Fine-root turnover rates of European forests revisited: an analysis of data from sequential coring and ingrowth cores

Background and Aims Forest trees directly contribute to carbon cycling in forest soils through the turnover of their fine roots. In this study we aimed to calculate root turnover rates of common European forest tree species and to compare them with most frequently published values. Methods We compiled available European data and applied various turnover rate calculation methods to the resulting database. We used Decision Matrix and Maximum-Minimum formula as suggested in the literature. Results Mean turnover rates obtained by the combination of sequential coring and Decision Matrix were 0.86 yr−1 for Fagus sylvatica and 0.88 yr−1 for Picea abies when maximum biomass data were used for the calculation, and 1.11 yr−1 for both species when mean biomass data were used. Using mean biomass rather than maximum resulted in about 30 % higher values of root turnover. Using the Decision Matrix to calculate turnover rate doubled the rates when compared to the Maximum-Minimum formula. The Decision Matrix, however, makes use of more input information than the Maximum-Minimum formula. Conclusions We propose that calculations using the Decision Matrix with mean biomass give the most reliable estimates of root turnover rates in European forests and should preferentially be used in models and C reporting.

Carbon management, local governance and community engagement

This article examines the role of communities in carbon management as it relates to both climate change and energy policy at the local level and as a seedbed for grassroots activity. The article considers some of the implications of recent policy developments, particularly the ways in which the ‘lines of responsibility’ are now being drawn at the local level. Drawing upon in-depth interviews with local authorities in the UK and the USA, the article examines the political distinctions that are evident between the two situations and the ramifications of these for practical community engagement in carbon management at the local level. Community engagement is likely to be central to the delivery of CO2 reductions, but evidence so far points to a series of challenges that will require a greater emphasis on partnership working between community groups and formal decision-making bodies.

Water quality trends in the Windrush catchment: Nitrogen speciation and sediment interactions

For the predominantly agricultural River Windrush catchment, spatial variations in concentrations of nitrogen species and suspended sediment were strongly related to geology and land use. Temporal patterns of NO3- and NO2- concentrations during the three year study were highly correlated with seasonal variations in baseflow. Suspended sediment concentrations were mainly controlled by storm discharge. Variations in total ammonium concentrations reflected both flow controls. Suspended sediment effects total ammonium and organic nitrogen transport to the aquatic system, and in-stream cycling processes. Organic nitrogen did not display consistent seasonal variations, but concentrations occasionally exceeding those of NO3-. Overall, NO3- and organic nitrogen were the most important at 60% and -40%, of total nitrogen load, respectively. Future assessments of agriculture impact on river water quality should consider the total nitrogen load, and not solely that of NO3-.

Towards a computationally efficient approach to modular classification rule induction

Induction of classification rules is one of the most important technologies in data mining. Most of the work in this field has concentrated on the Top Down Induction of Decision Trees (TDIDT) approach. However, alternative approaches have been developed such as the Prism algorithm for inducing modular rules. Prism often produces qualitatively better rules than TDIDT but suffers from higher computational requirements. We investigate approaches that have been developed to minimize the computational requirements of TDIDT, in order to find analogous approaches that could reduce the computational requirements of Prism.

Are gay rights Islamophobic? A critique of some uses of the concept of homonationalism in activism and academia

The concept of ‘homonationalism’ refers to deployments of gay rights for racist and Islamophobic ends, resulting in the consolidation of more sexually inclusive, but racially exclusionary, ideas of citizenship. This article critiques some of the analyses that the concept has inspired in both activist and academic contexts. The critique concentrates on two texts, showing that they make inappropriate rhetorical moves and inaccurate or unsubstantiated claims, and that rather than unearthing structural undercurrents of racism from certain texts or events, they project such structures onto them. While the validity of ‘homonationalism’ as an analytical category is not disputed, some of its propounders assume its explanatory power to be greater than it appears to be. The implications of this critique for gay rights activism and reform are explored.

What happens to precocious readers’ performance by the age of 11 years?

This paper reports on the progress made by a group of fourteen 11-year-old children who had been originally identified as being precocious readers before they started primary school at the age of 5-years. The data enable comparisons to be made with the performance of the children when they were younger so that a six year longitudinal analysis can be made. The children who began school as precocious readers continued to make progress in reading accuracy, rate and comprehension, thereby maintaining their superior performance relative to a comparison group. However, their progress appeared to follow the same developmental trajectory as that of the comparison group. Measures of phonological awareness showed that there are long term, stable individual differences which correlated with all measures of reading. The children who were reading precociously early showed significantly higher levels of phonological awareness than the comparison children. In addition, they showed the same levels of performance on this task as a further group of high achieving young adults. A positive effect of being able to read at precociously early age was identified in the significantly higher levels of receptive vocabulary found amongst the these children. The analyses indicated that rises in receptive vocabulary resulted from reading performance rather than the other way round

Earthworm-produced calcite granules: a new terrestrial palaeothermometer?

In this paper we show for the first time that calcite granules, produced by the earthworm Lumbricus terrestris, and commonly recorded at sites of archaeological interest, accurately reflect temperature and soil water δ18O values. Earthworms were cultivated in an orthogonal combination of two different (granule-free) soils moistened by three types of mineral water and kept at three temperatures (10, 16 and 20 ºC) for an acclimatisation period of three weeks followed by transfer to identical treatments and cultivation for a further four weeks. Earthworm-secreted calcite granules were collected from the second set of soils. δ18O values were determined on individual calcite granules (δ18Oc) and the soil solution (δ18Ow). The δ18Oc values reflect soil solution δ18Ow values and temperature, but are consistently enriched by 1.51 (±0.12) ‰ in comparison to equilibrium in synthetic carbonates. The data fit the equation 1000 ln α = [20.21 ± 0.92] (103 T-1) - [38.58 ± 3.18] (R2 = 0.95; n = 96; p < 0.0005). As the granules are abundant in modern soils, buried soils and archaeological contexts, and can be dated using U-Th disequilibria, the developed palaeotemperature relationship has enormous potential for application to Holocene and Pleistocene time intervals.

Diversity of cultivars and other plant resources used at habitation sites in the Llanos de Mojos, Beni, Bolivia: Evidence from macrobotanical remains, starch grains, and phytoliths

Although sparsely populated today, the Llanos de Mojos, Bolivia, sustained large sedentary societies in the Late Holocene (ca. 500 to 1400 AD). In order to gain insight into the subsistence of these people, we undertook macrobotanical and phytolith analyses of sediment samples, and starch grain and phytolith analyses of artifact residues, from four large habitation sites within this region. Macrobotanical remains show the presence of maize (Zea mays), squash (Cucurbita sp.), peanut (Arachis hypogaea), cotton (Gossypium sp.), and palm fruits (Arecaceae). Microbotanical results confirm the widespread use of maize at all sites, along with manioc (Manihot esculenta), squash, and yam (Dioscorea sp.). These integrated results present the first comprehensive archaeobotanical evidence of the diversity of plants cultivated, processed, and consumed, by the pre-Hispanic inhabitants of the Amazonian lowlands of Bolivia.

Identifying and recording every casualty of armed conflict

This article discusses the international legal obligation to identify and record every casualty of armed conflict that finds its basis in the treaties and customs of international humanitarian law and international human rights law. The article applies the various facets of the legal obligation to the armed conflicts in Iraq and Sri Lanka and argues that the parties in these conflicts failed in their international legal responsibility to civilians.

Compliant Multi-electrode Micro-channel Array for Recording Afferent Nerve Activity

We have fabricated a compliant neural interface to record afferent nerve activity. Stretchable gold electrodes were evaporated on a polydimethylsiloxane (PDMS) substrate and were encapsulated using photo-patternable PDMS. The built-in microstructure of the gold film on PDMS allows the electrodes to twist and flex repeatedly, without loss of electrical conductivity. PDMS microchannels (5mm long, 100μm wide, 100μm deep) were then plasma bonded irreversibly on top of the electrode array to define five parallel-conduit implants. The soft gold microelectrodes have a low impedance of ~200kΩ at the 1kHz frequency range. Teased nerves from the L6 dorsal root of an anaesthetized Sprague Dawley rat were threaded through the microchannels. Acute tripolar recordings of cutaneous activity are demonstrated, from multiple nerve rootlets simultaneously. Confinement of the axons within narrow microchannels allows for reliable recordings of low amplitude afferents. This electrode technology promises exciting applications in neuroprosthetic devices including bladder fullness monitors and peripheral nervous system implants.

Flow-induced morphological instability of a mushy layer

A morphological instability of a mushy layer due to a forced flow in the melt is analysed. The instability is caused by flow induced in the mushy layer by Bernoulli suction at the crests of a sinusoidally perturbed mush–melt interface. The flow in the mushy layer advects heat away from crests which promotes solidification. Two linear stability analyses are presented: the fundamental mechanism for instability is elucidated by considering the case of uniform flow of an inviscid melt; a more complete analysis is then presented for the case of a parallel shear flow of a viscous melt. The novel instability mechanism we analyse here is contrasted with that investigated by Gilpin et al. (1980) and is found to be more potent for the case of newly forming sea ice.