Fitting mixtures of Kent distributions to aid in joint set identification

When examining a rock mass, joint sets and their orientations can play a significant role with regard to how the rock mass will behave. To identify joint sets present in the rock mass, the orientation of individual fracture planer can be measured on exposed rock faces and the resulting data can be examined for heterogeneity. In this article, the expectation-maximization algorithm is used to lit mixtures of Kent component distributions to the fracture data to aid in the identification of joint sets. An additional uniform component is also included in the model to accommodate the noise present in the data.

Boosting Future Prospects or Softening Promises of Success? The Use of Emphatics and Hedging in the Letter to Shareholders Sections of Annual Reports

Tämä pro gradu -tutkielma käsittelee yritysten vuosikertomusten Toimitusjohtajan katsaus -osioissa esiintyvää metatekstiä. Erityisenä tutkimuskohteena ovat yrityksen tulevaisuutta käsittelevät lauseet ja niissä käytetty interpersonaalinen metateksti, jonka avulla kirjoittaja pyrkii joko vahvistamaan (emphatics-keinoin) tai heikentämään (hedging-keinoin) ilmaisujensa vahvuutta ja lukijalle niiden kautta välittyvää kuvaa viestin varmuudesta ja vakuuttavuudesta. Sijoittajille suunnattu Toimitusjohtajan katsaus käsittelee yleensä yrityksen edellisen vuoden tulosta, taloudellista asemaa sekä tulevaisuudennäkymiä. Tutkimuksen tarkoituksena oli selvittää, vaikuttaako yrityksen taloudellinen menestys vuosikertomuksen tässä osiossa käytetyn metatekstin määrään ja laatuun. Tutkimuksen teoriaosuudessa käsitellään ensiksi lyhyesti vuosikertomuksia ja niiden parissa tehtyä aiempaa kielitieteellistä tutkimusta, minkä jälkeen perehdytään tarkemmin metatekstin sekä hedging- ja emphatics-keinojen määrittelyyn. Näissä osioissa apuna toimivat muunmuassa Hylandin (1998) ja Cromptonin (1997) tutkimukset. Tutkimusaineistossa esiintyvien metatekstilajien määrittelyssä ja tunnistamisessa käytettiin apuna pääosin Crismore & Farnsworthin (1990) ja Grabe & Kaplanin (1997) tutkimuksia. Tutkimuksen aineistona oli yhteensä 23 yhdentoista amerikkalaisen yrityksen vuosikertomusta. Ne käsittivät esimerkkejä kunkin yhtiön talouden kannalta sekä erityisen hyviltä että huonoilta vuosilta. Aineistosta löydetty interpersonaalinen metateksti luokiteltiin viiteen eri ryhmään: modaaliverbit, hedging-verbit, muut hedging-keinot, emphatics-keinot ja evaluatives-keinot (eli kirjoittajan tekstistään tekemät subjektiiviset huomiot ja arviot). Tulokset osoittivat, että metatekstin käytössä ilmeni melkoista vaihtelua yksittäisten yritysten ja niiden hyvien ja huonojen vuosien välillä. Nämä eroavuudet eivät kuitenkaan vaikuttaneet merkittävästi koko aineiston kattaviin keskivertolukuihin, joiden avulla pyrittiin selvittämään hyvien ja huonojen vuosien välisiä yleisiä eroja. Tutkimuksen perusteella voidaan todeta, että Toimitusjohtajan katsaus –osioiden viittaukset yhtiön tulevaisuuteen heijastavat tavallisesti kirjoittajan varmuutta yrityksen menestyksekkäästä tulevaisuudesta riippumatta siitä, minkälainen vuosikertomuksessa käsitelty vuosi on ollut yhtiölle taloudellisesti. Yleisesti ottaen yhtiön taloudellisen tilan ei siis havaittu vaikuttavan Toimitusjohtajan katsauksessa käytetyn metadiskurssin määrään tai laatuun.

Alternative distributions to estimate usual intake of nutrients for groups

When assessing food intake patterns in groups of individuals, a major problem is finding usual intake distribution. This study aimed at searching for a probability distribution to estimate the usual intake of nutrients using data from a cross-sectional investigation on nutrition students from a public university in São Paulo state, Brazil. Data on 119 women aged 19 to 30 years old were used. All women answered a questionnaire about their lifestyle, diet and demographics. Food intake was evaluated from a non-consecutive three-day 24-hour food record. Different probability distributions were tested for vitamins C and E, panthotenic acid, folate, zinc, copper and calcium where data normalization was not possible. Empirical comparisons were performed, and inadequacy prevalence was calculated by comparing with the NRC method. It was concluded that if a more realistic distribution for usual intake is found, results can be more accurate as compared to those achieved by other methods.

Engineering metal precipitate size distributions to enhance gettering in multicrystalline silicon

The extraction of metal impurities during phosphorus diffusion gettering (PDG) is one of the crucial process steps when fabricating high-efficiency solar cells using low-cost, lower-purity silicon wafers. In this work, we show that for a given metal concentration, the size and density of metal silicide precipitates strongly influences the gettering efficacy. Different precipitate size distributions can be already found in silicon wafers grown by different techniques. In our experiment, however, the as-grown distribution of precipitated metals in multicrystalline Si sister wafers is engineered through different annealing treatments in order to control for the concentration and distribution of other defects. A high density of small precipitates is formed during a homogenization step, and a lower density of larger precipitates is formed during extended annealing at 740º C. After PDG, homogenized samples show a decreased interstitial iron concentration compared to as-grown and ripened samples, in agreement with simulations.

Corporation annual reports to shareholders.

2nd ser. 1951-1970 v.1 Ac-Ac is oversize and is on the bottom shelf of locator 168. 2nd ser. 1951-1970 suppl. is located on top shelf of locator 170.

Using two dimensional sectional distributions to infer three dimensional volumetric distributions - Validation using tomography

The critical process parameter for mineral separation is the degree of mineral liberation achieved by comminution. The degree of liberation provides an upper limit of efficiency for any physical separation process. The standard approach to measuring mineral liberation uses mineralogical analysis based two-dimensional sections of particles which may be acquired using a scanning electron microscope and back-scatter electron analysis or from an analysis of an image acquired using an optical microscope. Over the last 100 years, mathematical techniques have been developed to use this two dimensional information to infer three-dimensional information about the particles. For mineral processing, a particle that contains more than one mineral (a composite particle) may appear to be liberated (contain only one mineral) when analysed using only its revealed particle section. The mathematical techniques used to interpret three-dimensional information belong, to a branch of mathematics called stereology. However methods to obtain the full mineral liberation distribution of particles from particle sections are relatively new. To verify these adjustment methods, we require an experimental method which can accurately measure both sectional and three dimensional properties. Micro Cone Beam Tomography provides such a method for suitable particles and hence, provides a way to validate methods used to convert two-dimensional measurements to three dimensional estimates. For this study ore particles from a well-characterised sample were subjected to conventional mineralogical analysis (using particle sections) to estimate three-dimensional properties of the particles. A subset of these particles was analysed using a micro-cone beam tomograph. This paper presents a comparison of the three-dimensional properties predicted from measured two-dimensional sections with the measured three-dimensional properties.

Forecasting Responses of Seagrass Distributions to Changing Water Quality Using Monitoring Data

Extensive data sets on water quality and seagrass distributions in Florida Bay have been assembled under complementary, but independent, monitoring programs. This paper presents the landscape-scale results from these monitoring programs and outlines a method for exploring the relationships between two such data sets. Seagrass species occurrence and abundance data were used to define eight benthic habitat classes from 677 sampling locations in Florida Bay. Water quality data from 28 monitoring stations spread across the Bay were used to construct a discriminant function model that assigned a probability of a given benthic habitat class occurring for a given combination of water quality variables. Mean salinity, salinity variability, the amount of light reaching the benthos, sediment depth, and mean nutrient concentrations were important predictor variables in the discriminant function model. Using a cross-validated classification scheme, this discriminant function identified the most likely benthic habitat type as the actual habitat type in most cases. The model predicted that the distribution of benthic habitat types in Florida Bay would likely change if water quality and water delivery were changed by human engineering of freshwater discharge from the Everglades. Specifically, an increase in the seasonal delivery of freshwater to Florida Bay should cause an expansion of seagrass beds dominated by Ruppia maritima and Halodule wrightii at the expense of the Thalassia testudinum-dominated community that now occurs in northeast Florida Bay. These statistical techniques should prove useful for predicting landscape-scale changes in community composition in diverse systems where communities are in quasi-equilibrium with environmental drivers.

Using Bird Distributions to Assess Extinction Risk and Identify Conservation Priorities in Biodiversity Hotspots

Habitat loss, fragmentation, and degradation threaten the World’s ecosystems and species. These, and other threats, will likely be exacerbated by climate change. Due to a limited budget for conservation, we are forced to prioritize a few areas over others. These places are selected based on their uniqueness and vulnerability. One of the most famous examples is the biodiversity hotspots: areas where large quantities of endemic species meet alarming rates of habitat loss. Most of these places are in the tropics, where species have smaller ranges, diversity is higher, and ecosystems are most threatened.

Species distributions are useful to understand ecological theory and evaluate extinction risk. Small-ranged species, or those endemic to one place, are more vulnerable to extinction than widely distributed species. However, current range maps often overestimate the distribution of species, including areas that are not within the suitable elevation or habitat for a species. Consequently, assessment of extinction risk using these maps could underestimate vulnerability.

In order to be effective in our quest to conserve the World’s most important places we must: 1) Translate global and national priorities into practical local actions, 2) Find synergies between biodiversity conservation and human welfare, 3) Evaluate the different dimensions of threats, in order to design effective conservation measures and prepare for future threats, and 4) Improve the methods used to evaluate species’ extinction risk and prioritize areas for conservation. The purpose of this dissertation is to address these points in Colombia and other global biodiversity hotspots.

In Chapter 2, I identified the global, strategic conservation priorities and then downscaled to practical local actions within the selected priorities in Colombia. I used existing range maps of 171 bird species to identify priority conservation areas that would protect the greatest number of species at risk in Colombia (endemic and small-ranged species). The Western Andes had the highest concentrations of such species—100 in total—but the lowest densities of national parks. I then adjusted the priorities for this region by refining these species ranges by selecting only areas of suitable elevation and remaining habitat. The estimated ranges of these species shrank by 18–100% after accounting for habitat and suitable elevation. Setting conservation priorities on the basis of currently available range maps excluded priority areas in the Western Andes and, by extension, likely elsewhere and for other taxa. By incorporating detailed maps of remaining natural habitats, I made practical recommendations for conservation actions. One recommendation was to restore forest connections to a patch of cloud forest about to become isolated from the main Andes.

For Chapter 3, I identified areas where bird conservation met ecosystem service protection in the Central Andes of Colombia. Inspired by the November 11th (2011) landslide event near Manizales, and the current poor results of Colombia’s Article 111 of Law 99 of 1993 as a conservation measure in this country, I set out to prioritize conservation and restoration areas where landslide prevention would complement bird conservation in the Central Andes. This area is one of the most biodiverse places on Earth, but also one of the most threatened. Using the case of the Rio Blanco Reserve, near Manizales, I identified areas for conservation where endemic and small-range bird diversity was high, and where landslide risk was also high. I further prioritized restoration areas by overlapping these conservation priorities with a forest cover map. Restoring forests in bare areas of high landslide risk and important bird diversity yields benefits for both biodiversity and people. I developed a simple landslide susceptibility model using slope, forest cover, aspect, and stream proximity. Using publicly available bird range maps, refined by elevation, I mapped concentrations of endemic and small-range bird species. I identified 1.54 km2 of potential restoration areas in the Rio Blanco Reserve, and 886 km2 in the Central Andes region. By prioritizing these areas, I facilitate the application of Article 111 which requires local and regional governments to invest in land purchases for the conservation of watersheds.

Chapter 4 dealt with elevational ranges of montane birds and the impact of lowland deforestation on their ranges in the Western Andes of Colombia, an important biodiversity hotspot. Using point counts and mist-nets, I surveyed six altitudinal transects spanning 2200 to 2800m. Three transects were forested from 2200 to 2800m, and three were partially deforested with forest cover only above 2400m. I compared abundance-weighted mean elevation, minimum elevation, and elevational range width. In addition to analyzing the effect of deforestation on 134 species, I tested its impact within trophic guilds and habitat preference groups. Abundance-weighted mean and minimum elevations were not significantly different between forested and partially deforested transects. Range width was marginally different: as expected, ranges were larger in forested transects. Species in different trophic guilds and habitat preference categories showed different trends. These results suggest that deforestation may affect species’ elevational ranges, even within the forest that remains. Climate change will likely exacerbate harmful impacts of deforestation on species’ elevational distributions. Future conservation strategies need to account for this by protecting connected forest tracts across a wide range of elevations.

In Chapter 5, I refine the ranges of 726 species from six biodiversity hotspots by suitable elevation and habitat. This set of 172 bird species for the Atlantic Forest, 138 for Central America, 100 for the Western Andes of Colombia, 57 for Madagascar, 102 for Sumatra, and 157 for Southeast Asia met the criteria for range size, endemism, threat, and forest use. Of these 586 species, the Red List deems 108 to be threatened: 15 critically endangered, 29 endangered, and 64 vulnerable. When ranges are refined by elevational limits and remaining forest cover, 10 of those critically endangered species have ranges < 100km2, but then so do 2 endangered species, seven vulnerable, and eight non-threatened ones. Similarly, 4 critically endangered species, 20 endangered, and 12 vulnerable species have refined ranges < 5000km2, but so do 66 non-threatened species. A striking 89% of these species I have classified in higher threat categories have <50% of their refined ranges inside protected areas. I find that for 43% of the species I assessed, refined range sizes fall within thresholds that typically have higher threat categories than their current assignments. I recommend these species for closer inspection by those who assess risk. These assessments are not only important on a species-by-species basis, but by combining distributions of threatened species, I create maps of conservation priorities. They differ significantly from those created from unrefined ranges.

Use of Coarse-resolution models of species' distributions to guide local conservation inferences

Distribution models are used increasingly for species conservation assessments over extensive areas, but the spatial resolution of the modeled data and, consequently, of the predictions generated directly from these models are usually too coarse for local conservation applications. Comprehensive distribution data at finer spatial resolution, however, require a level of sampling that is impractical for most species and regions. Models can be downscaled to predict distribution at finer resolutions, but this increases uncertainty because the predictive ability of models is not necessarily consistent beyond their original scale. We analyzed the performance of downscaled, previously published models of environmental favorability (a generalized linear modeling technique) for a restricted endemic insectivore, the Iberian desman (Galemys pyrenaicus), and a more widespread carnivore, the Eurasian otter ( Lutra lutra), in the Iberian Peninsula. The models, built from presence–absence data at 10 × 10 km resolution, were extrapolated to a resolution 100 times finer (1 × 1 km). We compared downscaled predictions of environmental quality for the two species with published data on local observations and on important conservation sites proposed by experts. Predictions were significantly related to observed presence or absence of species and to expert selection of sampling sites and important conservation sites. Our results suggest the potential usefulness of downscaled projections of environmental quality as a proxy for expensive and time-consuming field studies when the field studies are not feasible. This method may be valid for other similar species if coarse-resolution distribution data are available to define high-quality areas at a scale that is practical for the application of concrete conservation measures

Osingonjako ja omien osakkeiden hankinta varojenjakokeinoina – veroseuraamusten tarkastelu

Tämän tutkielman tarkoituksena on perehtyä osingon ja omien osakkeiden hankinnan eroihin varojenjakokeinoina ja erityisesti tarkastella niihin liittyviä veroseuraamuksia. Veroseuraamuksia arvioidaan niin listaamattomista, kuin listatuista yhtiöistä saaduista varoista ja niitä selvennetään laskuesimerkein. Näiden lisäksi tutkielmassa käsitellään peitellyn osingon säännöksen soveltamista erityisesti omien osakkeiden hankintaan liittyen. Peiteltyyn osinkoon liittyvät ennakkopäätökset, joita tutkielmassa esitellään runsaasti, ovat avain asemassa säännöksen soveltamisen ymmärtämisessä. Koska tutkielman perustana on voimassa olevan oikeuden sisältö ja tarkoituksena on tulkita lainsäädäntöä, on kyseessä lainopillinen tutkimus. Tutkielmassa todetaan osingon ja omien osakkeiden hankinnan olevan toistensa kaltaisia varojenjakokeinoja, kun asiaa katsotaan osakeyhtiölain näkökulmasta. Kun asiaa tarkastellaan verotuksen näkökulmasta, lainsäädäntö kannustaa yleensä jakamaan osinkoa etenkin listaamattomista yhtiöistä. Pörssiyhtiöissä myös omien osakkeiden hankinta voi olla tarkoituksen mukainen keino saada varoja yhtiöstä.

S Corporations Can Benefit Many Closely-Held Hospitality Firms

In his discussion - S Corporations Can Benefit Many Closely-Held Hospitality Firms - by John M. Tarras, Assistant Professor, School of Hotel, Restaurant & Institutional Management at Michigan State University, Assistant Professor Tarras initially offers: “Organization as an S corporation has many advantages for hospitality firms since passage of the Tax Reform Act of 1986. The author discusses those advantages and lists the disadvantages as well.” In the opening paragraphs Tarras alludes to the relationship between hospitality firms, S corporations, and the Tax Reform Act of 1986, and then defines what an S corporation is. “An S corporation is a form of business entity that combines many of the tax advantages of partnerships with the legal attributes of a corporation, including limited liability for its shareholders. Its name is obtained from a subchapter of the Internal Revenue Code. Except for tax purposes, the S corporation is treated in the same manner as any regular corporation. Like a partnership, income and losses for an S corporation are generally passed through directly to shareholders for inclusion on their individual returns. An S corporation thus avoids the double tax problem facing regular corporations.” There are certain criteria to be met and caveats to be avoided in qualifying for S corporation status. Tarras lists and cites these for you. “Due to the complicated nature of S corporations, the election may be inadvertently terminated if the eligibility requirements are violated,” Tarras expands and cites. As the article suggests at the outset, there are advantages and disadvantages to S corporation status; the author outlines some examples for you. “Traditionally, the S corporation has been used by hospitality firms wishing to avoid the "double tax" problem of a regular corporation,” Tarras informs you. “Regular corporations are taxed once at the corporate level, and again at the shareholder level when income is distributed to shareholders in the form of dividends.” Tarras advises you as to why an S corporation is an advantage in this situation. “Since the S corporation generally is not subject to any corporate taxes, it generally makes no difference whether distributions to shareholders of S corporations are characterized as compensation or dividends,” thus the double tax is avoided. This is just one such positive illustration. Assistant Professor Tarras wants you to know: “Perhaps the most important reason to consider the S corporation has to do with the downward revision of tax rates for both individuals and corporations.” He highlights a case study for you. Some of the disadvantages of S corporation affiliation are the caveats alluded to earlier. They include, “the limitation of an S corporation of 35 shareholders,” Tarras cites. “Also, there are limits as to who may own stock in an S corporation.” These are but two of the limitations of an S corporation. Tarras closes with a further glimpse of the down-sides of an S corporation.

Application of density functional theory to capillary phenomena in cylindrical mesopores with radial and longitudinal density distributions

In this paper, we applied a version of the nonlocal density functional theory (NLDFT) accounting radial and longitudinal density distributions to study the adsorption and desorption of argon in finite as well as infinite cylindrical nanopores at 87.3 K. Features that have not been observed before with one-dimensional NLDFT are observed in the analysis of an inhomogeneous fluid along the axis of a finite cylindrical pore using the two-dimensional version of the NLDFT. The phase transition in pore is not strictly vapor-liquid transition as assumed and observed in the conventional version, but rather it exhibits a much elaborated feature with phase transition being complicated by the formation of solid phase. Depending on the pore size, there are more than one phase transition in the adsorption-desorption isotherm. The solid formation in finite pore has been found to be initiated by the presence of the meniscus. Details of the analysis of the extended version of NLDFT will be discussed in the paper. (C) 2004 American Institute of Physics.

A mixture model-based approach to the clustering of microarray expression data

Motivation: This paper introduces the software EMMIX-GENE that has been developed for the specific purpose of a model-based approach to the clustering of microarray expression data, in particular, of tissue samples on a very large number of genes. The latter is a nonstandard problem in parametric cluster analysis because the dimension of the feature space (the number of genes) is typically much greater than the number of tissues. A feasible approach is provided by first selecting a subset of the genes relevant for the clustering of the tissue samples by fitting mixtures of t distributions to rank the genes in order of increasing size of the likelihood ratio statistic for the test of one versus two components in the mixture model. The imposition of a threshold on the likelihood ratio statistic used in conjunction with a threshold on the size of a cluster allows the selection of a relevant set of genes. However, even this reduced set of genes will usually be too large for a normal mixture model to be fitted directly to the tissues, and so the use of mixtures of factor analyzers is exploited to reduce effectively the dimension of the feature space of genes. Results: The usefulness of the EMMIX-GENE approach for the clustering of tissue samples is demonstrated on two well-known data sets on colon and leukaemia tissues. For both data sets, relevant subsets of the genes are able to be selected that reveal interesting clusterings of the tissues that are either consistent with the external classification of the tissues or with background and biological knowledge of these sets.

Will climate change drive alien invasive plants into areas of high protection value? An improved model-based regional assessment to prioritise the management of invasions.

Species distribution models (SDMs) studies suggest that, without control measures, the distribution of many alien invasive plant species (AIS) will increase under climate and land-use changes. Due to limited resources and large areas colonised by invaders, management and monitoring resources must be prioritised. Choices depend on the conservation value of the invaded areas and can be guided by SDM predictions. Here, we use a hierarchical SDM framework, complemented by connectivity analysis of AIS distributions, to evaluate current and future conflicts between AIS and high conservation value areas. We illustrate the framework with three Australian wattle (Acacia) species and patterns of conservation value in Northern Portugal. Results show that protected areas will likely suffer higher pressure from all three Acacia species under future climatic conditions. Due to this higher predicted conflict in protected areas, management might be prioritised for Acacia dealbata and Acacia melanoxylon. Connectivity of AIS suitable areas inside protected areas is currently lower than across the full study area, but this would change under future environmental conditions. Coupled SDM and connectivity analysis can support resource prioritisation for anticipation and monitoring of AIS impacts. However, further tests of this framework over a wide range of regions and organisms are still required before wide application.

Experimental plant communities develop phylogenetically overdispersed abundance distributions during assembly

The importance of competition between similar species in driving community assembly is much debated. Recently, phylogenetic patterns in species composition have been investigated to help resolve this question: phylogenetic clustering is taken to imply environmental filtering, and phylogenetic overdispersion to indicate limiting similarity between species. We used experimental plant communities with random species compositions and initially even abundance distributions to examine the development of phylogenetic pattern in species abundance distributions. Where composition was held constant by weeding, abundance distributions became overdispersed through time, but only in communities that contained distantly related clades, some with several species (i.e., a mix of closely and distantly related species). Phylogenetic pattern in composition therefore constrained the development of overdispersed abundance distributions, and this might indicate limiting similarity between close relatives and facilitation/complementarity between distant relatives. Comparing the phylogenetic patterns in these communities with those expected from the monoculture abundances of the constituent species revealed that interspecific competition caused the phylogenetic patterns. Opening experimental communities to colonization by all species in the species pool led to convergence in phylogenetic diversity. At convergence, communities were composed of several distantly related but species-rich clades and had overdispersed abundance distributions. This suggests that limiting similarity processes determine which species dominate a community but not which species occur in a community. Crucially, as our study was carried out in experimental communities, we could rule out local evolutionary or dispersal explanations for the patterns and identify ecological processes as the driving force, underlining the advantages of studying these processes in experimental communities. Our results show that phylogenetic relations between species provide a good guide to understanding community structure and add a new perspective to the evidence that niche complementarity is critical in driving community assembly.