Hybrids of carbon nanotube forests and gold nanoparticles for improved surface plasmon manipulation.

We report the fabrication and characterization of hybrids of vertically-aligned carbon nanotube forests and gold nanoparticles for improved manipulation of their plasmonic properties. Raman spectroscopy of nanotube forests performed at the separation area of nanotube-nanoparticles shows a scattering enhancement factor of the order of 1 × 10(6). The enhancement is related to the plasmonic coupling of the nanoparticles and is potentially applicable in high-resolution scanning near-field optical microscopy, plasmonics, and photovoltaics.

Carbon nanotube forests growth using catalysts from atomic layer deposition

We have grown carbon nanotubes using Fe and Ni catalyst films deposited by atomic layer deposition. Both metals lead to catalytically active nanoparticles for growing vertically aligned nanotube forests or carbon fibres, depending on the growth conditions and whether the substrate is alumina or silica. The resulting nanotubes have narrow diameter and wall number distributions that are as narrow as those grown from sputtered catalysts. The state of the catalyst is studied by in-situ and ex-situ X-ray photoemission spectroscopy. We demonstrate multi-directional nanotube growth on a porous alumina foam coated with Fe prepared by atomic layer deposition. This deposition technique can be useful for nanotube applications in microelectronics, filter technology, and energy storage. © 2014 AIP Publishing LLC.

Sublimation of snow from confierous forests in a climate model

Essery, R L H, Pomeroy, J W, Parvianen, J & Storck, P, Sublimation of snow from confierous forests in a climate model. Journal of Climate 16, pp 1855-1864 (2003).

Deer forests, game shooting and landed estates in the South West of Ireland, 1840 - 1970

This thesis is concentrated on the historical aspects of the elitist field sports of deer stalking and game shooting, as practiced by four Irish landed ascendancy families in the south west of Ireland. Four great estates were selected for study. Two of these were, by Irish standards, very large: the Kenmare estate of over 136,000 acres in the ownership of the Roman Catholic Earls of Kenmare, and the Herbert estate of over 44,000 acres in the ownership of the Protestant Herbert family. The other two were, in relative terms, small: the Grehan estate of c.7,500 acres in the ownership of the Roman Catholic Grehan family, and the Godfrey estate of c.5,000 acres, in the ownership of the Protestant Barons Godfrey. This mixture of contrasting estate size, owner's religions, nobleman, minor aristocrat and untitled gentry should, it is argued, yield a diversity of the field sports and lifestyles of their owners, and go some way to assess the contributions, good or bad, they have bequeathed to modern Ireland. Equally, it should help in assessing what importance, if any, applied to hunting. In this context, hunting is here used in its broadest meaning, and includes deer stalking and game shooting, as well as hunting with dogs and hounds on foot and horseback. Where a specific type of hunting is involved, it is so described; for example, fox hunting, stag hunting, hare hunting. Similarly, the term game is sometimes used in sporting literature to encompass all species of quarry killed, and can include deer, ground game (hares and rabbits), waterfowl, and various species of game birds. Where it refers to specific species, these are so described; for example grouse, pheasants, woodcork, wild duck, etc. Since two of these estates - the Kenmare and Herbert - each created a deer forest, unique in mid-19th century Ireland, they form the core study estates; the two smaller estates serve as comparative studies. And, equally unique, as these two larger estates held the only remnant population of native Irish red deer, the survival of that herd itself forms a concomitant core area of analysis. The numerary descriptions applied to these animals in popular literature are critically reassessed against prime source historical evidence, as are the so-called deer forest 'clearances'. The core period, 1840 to 1970, is selected as the seminal period, spanning 130 years, from the creation of the deer forests to when a fundamental change in policy and administration was introduced by the state. Comparison is made with similar estates elsewhere, in Britain and especially in Scotland. Their influence on the Irish methods and style of hunting is historically examined.

Invertebrate diversity in Irish and British forests

Ireland and Britain were once covered in natural forest, but extensive anthropogenic deforestation reduced forest cover to less than 1% and 5 %, respectively, by the beginning of the 20th century. Large-scale afforestation has since increased the level of forest cover to 11% in Ireland and 12% in Britain, with the majority of planted forests comprising small monoculture plantations, many of which are of non - native conifer tree species. At present the forest cover of Ireland and Britain generally consists of small areas of remnant semi-natural woodland and pockets of these plantation forests within a predominantly agricultural landscape. Invertebrates comprise a large proportion of the biodiversity found within forested habitats. In particular, spiders and carabid beetles play an important role in food webs as both predators and prey and respond to small-scale changes in habitat structure, meaning they are particularly sensitive to forest management. Hoverflies play an important role in control and pollination and have been successfully used as indicators of habitat disturbance and quality. This research addressed a number of topics pertinent to the forest types present in the contemporary Irish and British landscapes and aimed to investigate the invertebrate diversity of these forests. Spiders and carabid beetles were sampled using pitfall trapping and hoverflies were sampled using Malaise net trapping. Topics included the impacts of afforestation, the importance of open space, the choice of tree species, and the use of indicators for biodiversity assessment, as well as rare native woodlands and the effect of grazing on invertebrate diversity. The results are discussed and evidence-based recommendations are made for forest policy and management to protect and enhance invertebrate biodiversity in order to promote sustainable forest management in Ireland and Britain.

Gene selection using iterative feature elimination random forests for survival outcomes.

Although many feature selection methods for classification have been developed, there is a need to identify genes in high-dimensional data with censored survival outcomes. Traditional methods for gene selection in classification problems have several drawbacks. First, the majority of the gene selection approaches for classification are single-gene based. Second, many of the gene selection procedures are not embedded within the algorithm itself. The technique of random forests has been found to perform well in high-dimensional data settings with survival outcomes. It also has an embedded feature to identify variables of importance. Therefore, it is an ideal candidate for gene selection in high-dimensional data with survival outcomes. In this paper, we develop a novel method based on the random forests to identify a set of prognostic genes. We compare our method with several machine learning methods and various node split criteria using several real data sets. Our method performed well in both simulations and real data analysis.Additionally, we have shown the advantages of our approach over single-gene-based approaches. Our method incorporates multivariate correlations in microarray data for survival outcomes. The described method allows us to better utilize the information available from microarray data with survival outcomes.

Conversion of natural forests to managed forest plantations decreases tree resistance to prolonged droughts

© 2015 Published by Elsevier B.V.Throughout the southern US, past forest management practices have replaced large areas of native forests with loblolly pine plantations and have resulted in changes in forest response to extreme weather conditions. However, uncertainty remains about the response of planted versus natural species to drought across the geographical range of these forests. Taking advantage of a cluster of unmanaged stands (85-130year-old hardwoods) and managed plantations (17-20year-old loblolly pine) in coastal and Piedmont areas of North Carolina, tree water use, cavitation resistance, whole-tree hydraulic (Ktree) and stomatal (Gs) conductances were measured in four sites covering representative forests growing in the region. We also used a hydraulic model to predict the resilience of those sites to extreme soil drying. Our objectives were to determine: (1) if Ktree and stomatal regulation in response to atmospheric and soil droughts differ between species and sites; (2) how ecosystem type, through tree water use, resistance to cavitation and rooting profiles, affects the water uptake limit that can be reached under drought; and (3) the influence of stand species composition on critical transpiration that sets a functional water uptake limit under drought conditions. The results show that across sites, water stress affected the coordination between Ktree and Gs. As soil water content dropped below 20% relative extractable water, Ktree declined faster and thus explained the decrease in Gs and in its sensitivity to vapor pressure deficit. Compared to branches, the capability of roots to resist high xylem tension has a great impact on tree-level water use and ultimately had important implications for pine plantations resistance to future summer droughts. Model simulations revealed that the decline in Ktree due to xylem cavitation aggravated the effects of soil drying on tree transpiration. The critical transpiration rate (Ecrit), which corresponds to the maximum rate at which transpiration begins to level off to prevent irreversible hydraulic failure, was higher in managed forest plantations than in their unmanaged counterparts. However, even with this higher Ecrit, the pine plantations operated very close to their critical leaf water potentials (i.e. to their permissible water potentials without total hydraulic failure), suggesting that intensively managed plantations are more drought-sensitive and can withstand less severe drought than natural forests.

Analysis of species hyper-diversity in the tropical rain forests of Indonesia: the problem of non-observance

The main interest in the assessment of forest species diversity for conservation purposes is in the rare species. The main problem in the tropical rain forests is that most of the species are rare. Assessment of species diversity in the tropical rain forests is therefore often concerned with estimating that which is not observed in recorded samples. Statistical methodology is therefore required to try to estimate the truncated tail of the species frequency distribution, or to estimate the asymptote of species/diversity-area curves. A Horvitz-Thompson estimator of the number of unobserved (“virtual”) species in each species intensity class is proposed. The approach allows a definition of an extended definition of diversity, ( or generalised Renyi entropy). The paper presents a case study from data collected in Jambi, Sumatra, and the “extended diversity measure” is used on the species data.

Towards the sustainable use of Europe’s forests: a centre for European forest science! – Some missing catalytic elements?

The Symposium, “Towards the sustainable use of Europe’s forests”, with sub-title “Forest ecosystem and landscape research: scientific challenges and opportunities” lists three fundamental substantive areas of research that are involved: Forest management and practices, Ecosystem processes and functional ecology, and Environmental economics and sociology. This paper argues that there are essential catalytic elements missing! Without these elements there is great danger that the aimed-for world leadership in the forest sciences will not materialize. What are the missing elements? All the sciences, and in particular biology, environmental sciences, sociology, economics, and forestry have evolved so that they include good scientific methodology. Good methodology is imperative in both the design and analysis of research studies, the management of research data, and in the interpretation of research finding. The methodological disciplines of Statistics, Modelling and Informatics (“SMI”) are crucial elements in a proposed Centre of European Forest Science, and the full involvement of professionals in these methodological disciplines is needed if the research of the Centre is to be world-class. Distributed Virtual Institute (DVI) for Statistics, Modelling and Informatics in Forestry and the Environment (SMIFE) is a consortium with the aim of providing world-class methodological support and collaboration to European research in the areas of Forestry and the Environment. It is suggested that DVI: SMIFE should be a formal partner in the proposed Centre for European Forest Science.

Contributions to the bryological flora of the tropical and subtropical forests from the Argentina (Bryophyta, Musci).

The authors present here a list of 32 mosses belonging to 15 families: Brachytheciaceae, Cryphaeaceae, Entodontaceae, Hedwigiaceae, Hypnaceae, Leptodontaceae, Meteoriaceae, Neckeraceae, Pilotrichaceae, Polytrichaceae, Pterobryaceae, Racopilaceae, Rigodiaceae, Stereophyllaceae, and Trachypodaceae, all collected in the mountainous forests of the Yungas of the NW of the Argentina (Jujuy, Salta, Catamarca and Tucumán provinces), and also in the rainforests from the NE of the country (Misiones province). Eight species: Atrichum polycarpum, Chrysohypnum elegantulum, Pilosium chlorophyllum, Pilotrichella flexilis, Porotrichodendron lindigii, Pseudotrachypus martinicensis, Steerecleus scariosus, and Thamnobryum fasciculatum are new records for the bryologic flora from Argentina. Braunia imberbis and Squamidium brasiliense are two new records for the bryophytic flora of the Catamarca province; Porotrichodendron superbum is new for the Salta province, while Forsstroemia coronata is the first record for the Catamarca and Jujuy provinces. Aerolindigia capillacea, Braunia reflexifolia, Chryso-hypnum diminutivum, Meteorium deppei and Meteoridium remotifolium are five new citations for the Jujuy province, and Schoenobryum concavifolium is new for the bryophytic flora of the Misiones province. Many studied species occur more frequently in the Yungas than in the NE rainforests; others show separated distribution but live in both areas, the Yungas and Paranaense area, and others are more or less restricted to the Paranaense rainforest of the NE of Argentina. The taxonomy of species is updated, and comments are included on bibliographical precedents, ecology and chorology of each taxon.