Three-coordinate iron(II) expanded ring N-heterocyclic carbene complexes

A sterically demanding seven-membered expanded ring N-heterocyclic carbene (NHC) ligand allows access to rare examples of three-coordinate iron(II)-NHC complexes incorporating only halide coligands of the general formula [Fe(NHC)X 2 ] (NHC = 7-DiPP; X = Br (1) Cl (2)). Reducing the steric influence of the ancillary NHC ligand through modulation of the N-aryl substituents leads to either four- or three-coordinate complexes of the general formula [Fe(NHC)Br 2 (THF)] (3) or [Fe(NHC)Br 2 ] (4) (NHC = 7-Mes), dependent upon the solvent of recrystallization. The further reduction of NHC steric influence results in four-coordinate geometries at iron in the form of the dimeric species [Fe(NHC)Br(μ-Br)] 2 (5) or [Fe(NHC)Br 2 (THF)] (6) (NHC = SDiPP), again dependent upon the solvent of recrystallization. Compounds 1-6 have been analyzed by 1 H NMR spectroscopy, X-ray crystallography, elemental microanalysis, Mössbauer spectroscopy (for 1 and 3-5), and Evans method magnetic susceptibility. In addition to these measurements the three-coordinate species 1 and 4 have been further analyzed by SQUID magnetometry and CASSCF calculations, which show significant magnetic anisotropy that is extremely sensitive to the coordination geometry

Towards correcting atmospheric beam wander via pump beam control in a down conversion process

Correlated photon pairs produced by a spontaneous parametric down conversion (SPDC) process can be used for secure quantum communication over long distances including free space transmission over a link through turbulent atmosphere. We experimentally investigate the possibility to utilize the intrinsic strong correlation between the pump and output photon spatial modes to mitigate the negative targeting effects of atmospheric beam wander. Our approach is based on a demonstration observing the deflection of the beam on a spatially resolved array of single photon avalanche diodes (SPAD-array)

The Mission Accessible Near-Earth Objects Survey: Four years of photometry

Over 4.5 years, the Mission Accessible Near-Earth Object Survey (MANOS) assembled 228 Near-Earth Object (NEO) lightcurves. We report rotational lightcurves for 82 NEOs, constraints on amplitudes and periods for 21 NEOs, lightcurves with no detected variability within the image signal to noise and length of our observing block for 30 NEOs, and 10 tumblers. We uncovered 2 ultra-rapid rotators with periods below 20s; 2016MA with a potential rotational periodicity of 18.4s, and 2017QG$_{18}$ rotating in 11.9s, and estimate the fraction of fast/ultra-rapid rotators undetected in our project plus the percentage of NEOs with a moderate/long periodicity undetectable during our typical observing blocks. We summarize the findings of a simple model of synthetic NEOs to infer the object morphologies distribution using the measured distribution of lightcurve amplitudes. This model suggests a uniform distribution of axis ratio can reproduce the observed sample. This suggests that the quantity of spherical NEOs (e.g., Bennu) is almost equivalent to the quantity of highly elongated objects (e.g., Itokawa), a result that can be directly tested thanks to shape models from Doppler delay radar imaging analysis. Finally, we fully characterized 2 NEOs as appropriate targets for a potential robotic/human mission: 2013YS$_{2}$ and 2014FA$_{7}$ due to their moderate spin periods and low $\Delta v$.Comment: Accepted for Publication, The Astrophysical Journal Supplement Serie

Impact of human foraging on tree diversity, composition, and abundance in a tropical rainforest

Tropical forest tree communities are structured by a range of large-scale drivers including elevation, certain high-impact anthropogenic activities (e.g., deforestation), and fires. However, low-impact human activities such as foraging may also be subtly but notably altering the composition of tropical forest tree communities. The study assessed the (i) differences in species diversity, patterns of relative abundance, and pairwise beta diversity between trees with edible and inedible fruits and seeds along an elevation gradient, and (ii) impact of human foraging on the forest tree communities in Oban Division of Cross River National Park, Nigeria. Fifteen permanent 40 by 40 m plots were established along an elevational gradient (120–460 m above mean sea level). All trees of 0.1 m diameter at breast height (dbh) and above were measured, identified, and, with the aid of structured questionnaires, classified into those with edible and inedible fruits/seeds. A total of 35 edible species with density of 128 stems/hectare and basal area of 11.99 m2/hectare, and 109 inedible species with density of 364 stems/hectare and basal area of 22.42 m2/hectare were sampled. However, the evenness of edible and inedible species was similar at pooled and plot levels. For inedible species, there was a positive relationship between pairwise beta diversity and elevation, and this was driven mainly by turnover. In contrast, edible species exhibited a non-significant trend between elevation and beta diversity. Thus, the study showed that human foraging of edible fruits may have subtly influenced patterns of species diversity and community structure in this tropical forest.FUNDING: Petroleum Technology Development Fund (PTDF), Nigeria, Grant/Award Number: PTDF/ED/PHD/ASA/1342/18.info:eu-repo/semantics/publishedVersio

Modelling chemistry in the nocturnal boundary layer above tropical rainforest and a generalised effective nocturnal ozone deposition velocity for sub-ppbv NOx conditions

Measurements of atmospheric composition have been made over a remote rainforest landscape. A box model has previously been demonstrated to model the observed daytime chemistry well. However the box model is unable to explain the nocturnal measurements of relatively high [NO] and [O3], but relatively low observed [NO2]. It is shown that a one-dimensional (1-D) column model with simple O3 -NOx chemistry and a simple representation of vertical transport is able to explain the observed nocturnal concentrations and predict the likely vertical profiles of these species in the nocturnal boundary layer (NBL). Concentrations of tracers carried over from the end of the night can affect the atmospheric chemistry of the following day. To ascertain the anomaly introduced by using the box model to represent the NBL, vertically-averaged NBL concentrations at the end of the night are compared between the 1-D model and the box model. It is found that, under low to medium [NOx] conditions (NOx <1 ppbv), a simple parametrisation can be used to modify the box model deposition velocity of ozone, in order to achieve good agreement between the box and 1-D models for these end-of-night concentrations of NOx and O3. This parametrisation would could also be used in global climate-chemistry models with limited vertical resolution near the surface. Box-model results for the following day differ significantly if this effective nocturnal deposition velocity for ozone is implemented; for instance, there is a 9% increase in the following day’s peak ozone concentration. However under medium to high [NOx] conditions (NOx > 1 ppbv), the effect on the chemistry due to the vertical distribution of the species means no box model can adequately represent chemistry in the NBL without modifying reaction rate constants

Dyslexia-friendly schools and parent partnership: inclusion and home-school relationships

This is a postprint of an article whose final and definitive form has been published in the European Journal of Special Needs Education© 2005 Copyright Taylor & Francis; European Journal of Special Needs Education is available online at http://www.informaworld.comThis paper summarizes an action research project in five local areas in the south-west of England which aimed to support parents of children with dyslexic difficulties who were experiencing problems in obtaining appropriate provision in mainstream schools. It was based on the importance of effective parental partnership and quality inclusive practice for children having dyslexic difficulties. A development officer worked over two years in the five participating LEAs that were selected to represent a range of professional practice with a mix of urban and rural populations. As part of the evaluation, the authors also examined longitudinally the educational experiences of a sample of parents. The paper includes a conceptual framework of parental agency in this field in terms of knowledge, identity and parental strategies, and the conditions under which parents escalate their strategies to secure appropriate provision for their children. The support provided by the development officer is analysed in terms of the kinds of support requests received, the kinds of support offered and qualitative evidence of the impact of this support. This research is theorized in terms of current ideas about parent-partnership and theories about parent-teacher relations in terms of the diversity of parents. It highlights the significance of thinking about inclusive schooling and parent-school relations in terms of the interconnections between general systems for all, for those with special educational needs and those with specific difficulties. The policy and practice implications are interpreted in terms of the importance of a system of extended professionalism, which is inclusive of parents with learning difficulties and disabilities.The research project this paper summarises was funded by the British Dyslexia Association (BDA) and the Buttle Trust

Security governance and networks: New theoretical perspectives in transatlantic security

The end of the Cold War has not only witnessed the rise of new transnational threats such as terrorism, crime, proliferation and civil war; it has also seen the growing role of non-state actors in the provision of security in Europe and North America. Two concepts in particular have been used to describe these transformations: security governance and networks. However, the differences and potential theoretical utility of these two concepts for the study of contemporary security have so far been under-examined. This article seeks to address this gap. It proposes that security governance can help to explain the transformation of Cold War security structures, whereas network analysis is particularly useful for understanding the relations and interactions between public and private actors in the making and implementation of national and international security policies

A fungal pathogen in time and space: the population dynamics of Beauveria bassiana in a conifer forest

The fungal entomopathogen Beauveria bassiana is ubiquitous in below-ground systems; however, there is a dearth of information on the above-ground diversity, temporal and spatial distribution of this fungus. Therefore, we assessed its occurrence in a conifer forest (Pseudotsuga monziesii and Pinus nigra var. maritima) using selective media to isolate B. bassiana from soil, branch and bark samples collected in October 2005, March and June 2006. Fungal density was the highest at all locations in October, declining in March and June, and absent from conifer branches in June. This above-ground decline most likely resulted from more extreme environmental conditions compared with those below ground. Molecular analyses (ISSR-PCR) indicated that B. bassiana is genetically diverse, comprising both distinct microhabitat-specific and seasonal isolates. The occurrence of dissimilar above- and below-ground isolates suggests that B. bassiana occupies various overlapping niches in these systems

Exercise-induced improvements in liver fat and endothelial function are not sustained 12 months following cessation of exercise supervision in non-alcoholic fatty liver disease (NAFLD).

AIMS: Supervised exercise reduces liver fat and improves endothelial function, a surrogate of cardiovascular disease risk, in non-alcoholic fatty liver disease (NAFLD). We hypothesised that after a 16-week supervised exercise program, patients would maintain longer-term improvements in cardiorespiratory fitness, liver fat and endothelial function. MATHERIALS AND METHODS: Ten NAFLD patients [5/5 males/females, age 51±13years, BMI 31±3 kg.m(2) (mean±s.d.)] underwent a 16-week supervised moderate-intensity exercise intervention. Biochemical markers, cardiorespiratory fitness (VO2peak), subcutaneous, visceral and liver fat (measured by magnetic resonance imaging and spectroscopy respectively) and brachial artery flow-mediated dilation (FMD) were assessed at baseline, after 16 weeks supervised training and 12-months after ending supervision. RESULTS: Despite no significant change in body weight, there were significant improvements in VO2peak [6.5 ml.kg(-1).min(-1) (95% CI 2.8, 10.1); P=0.003], FMD [2.9% (1.5, 4.2); P=0.001], liver transaminases (P0.05) and liver fat [1.4% (-13.0, 15.9); P=0.83] were not significantly different from baseline. CONCLUSIONS: Twelve months following cessation of supervision, exercise-mediated improvements in liver fat and other cardiometabolic variables had reversed with cardiorespiratory fitness at baseline levels. Maintenance of high cardiorespiratory fitness and stability of body weight are critical public health considerations for the treatment of NAFLD.International Journal of Obesity accepted article preview online, 21 July 2016. doi:10.1038/ijo.2016.123