bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors affecting the accuracy of forest clear-cut area estimation on medium spatial resolution satellite winter images
Authors: Budenkova Julia
Published: March 2011

Keskmise ruumilise lahutusega talvistelt satelliidipiltidelt tehtavate lageraiealade pindalahinnangute täpsust mõjutavad faktorid

The aim of this paper was to investigate the influence of attributes, describing clear-cut patch size, age, shape, nearest neighbours and habitat conditions on classification results of medium spatial resolution Landsat Thematic Mapper (TM) satellite images. The study area was Võru State Forest District in South-East Estonia and the satellite images used were made in late winter when the ground was covered with snow. Clear-cuts as significantly changed areas in forests were discerned from non-changed areas with thresholding of a two-date difference image. The results of the statistical analysis showed that clear-cut attributes had an influence on image classification results. The most influential variables (presented in decreasing order of significance) are the mean of clear-cut patch pixel values on the difference image, the relative boundary length with forest, the relative boundary length with coniferous forest and the clear-cut area to perimeter ratio. The age of clear-cut and habitat conditions had no statistically significant influence on classification results. The set of influential attributes remained the same when the classifications were performed on two more liberal and on two more conservative thresholding levels. Images in the visible and near infrared spectral region (Landsat TM bands 1-4) revealed appropriate for clear-cut mapping. The difference in the area of a single clear-cut patch represented in the forestry database to that classified from a Landsat TM image was about a sixth of the patch size. This implies the utility of medium resolution satellite images in clear-cut activity assessments in particular areas but not so much the applicability of these images for single patch area estimations.
Combining spatial and other objectives in forest design
Authors: Chen Bo , von Gadow Klaus
Published: March 2011

Combining spatial and other objectives in forest design

The paper presents a forest planning model for Northern Germany with an objective function which includes an economic, even flow and spatial component. The spatial modeling approach followed in this analysis relies on specific geographic relations among neighboring stands, including the distance between stand centroids and the length of the common boundary between adjacent compartments. To our knowledge, this is a new and more realistic approach in spatial optimization when compared with earlier approaches. The geographic data are derived from a GIS system and stored in a database. The database also includes details of all management regimes and the corresponding objective function coefficients. The method is first applied in a relatively small forest with only 41 compartments. The Simulated Annealing algorithm is used to identify the optimum combination of management regimes. Solutions are presented for different objective function components. When the even flow and spatial components were added in the objective function, the economic objective was only moderately reduced. The method is then also applied using a bigger example, a forest with 591 compartments. The results, obtained within a reasonable processing time, were similar and, because of the large number of compartments, the even flow was perfectly balanced.
The radial growth of pine stands in changing environmental conditions
Authors: Pärn Henn
Published: March 2011

Männipuistute radiaalkasvust muutuvates keskkonnatingimustes

The changes in the radial growth in two consecutive generations of pine stands was investigated. Two pure pine stands were selected for this study. The both stands were represented by two consecutive generations growing at the same location and in the same site conditions. For determining the differences in the radial growth of successive stand generations the constant cambial age method was used. In analysis the average tree ring widths of stands at age of 30, 40 and 50 years was compared. The analysis showed that the radial growth of the younger stands at present exceeded that of the stands of old age when young. The increased N deposition and elevated CO2 level during the second half of the last century may have some positive influence for the growth of the studied young stands. The average temperature of the winter months in 1950-2000 has increased by 1 °C compared to that in 1850-1900. Therefore it may be assumed that long-term continuous warming may cause the altered growth response of pines.
Assessment of changes in forest coverage based on historical maps
Authors: Raet Janar , Sepp Kalev , Kaasik Are
Published: March 2011

Assessment of changes in forest coverage based on historical maps

Forest has always been an important natural resource. Issues related to forest reserve, coverage area, distribution pattern and status have been important to the forest, nature protection, as well as to environment management specialists. The present studies have proved that it is not easy to find a clear and simple answer to the above-mentioned essential issues. The indicators of the importance of the forest coverage or the coverage area at a certain period of time depend on the applied assessment methodology, primary source used, etc. The main objectives of this study were to analyze the possibilities of using historical maps for studying the formation and changes of the forest coverage in the longer timely retrospect. The continuity of the forests and the possibilities of defining the variation of the areas covered with forest and open landscape were studied at the test area using the map material covering 150-year period (reference years were 1850, 1949 and 2002). The results of the analyses show that it is possible to reconstruct partially the formation of the forest in some areas and it is possible to define the areas, which have been covered with forests for tens or hundreds of years. It is possible to analyze from which land use classes the present forest community has been formed of and define the age of it. At the same time, several methodological questions arise in connection with the interpretation of the map information of the materials of the 19th century and definition of the term "forest". For example, one problematic issue is the vague definition of the class "Buschland" which in present terms could have at the time of mapping been either agricultural land or already a young forest. The comparison carried out at the test area showed that the coverage rate of the present forest areas with the areas covered with forests or such vague areas in 1850 is 75%.
About the heritability influence to the growth performance in Scots pine (Pinus sylvestris L.) progeny trials
Authors: Kurm Malle , Kaur Ursula , Maaten Tiit , Kiviste Andres
Published: March 2011

Pärilikkuse mõjust hariliku männi (Pinus sylvestris L.) kasvuomadustele järglaskatsetes

The progeny trials of the Scots pine founded in Järvselja Training and Experimental Forest District in 1966 and 1967 by E. Pihelgas were analysed to estimate the heritability of height and diameter characteristics, and also the dependence of progeny properties on the plus tree and single tree phenotype. The data set consists of 513 height and 3707 breast height diameter measurements of 39-and 40-years-old progenies of 40 mother trees. The analysis was carried out with the SAS package, Release 9.1, mainly with ANOVA tools implemented SAS/MIXED procedure. Heritability h2 was calculated from the mother tree and residual variance components assuming a limited number of father trees for each progeny. Using the REML estimation procedures, the heritability of the stem height was found approximately equal to 1 and it was 0.19 for the DBH. Considering the mother tree characteristics, the age was significantly correlated with the progeny height.
Chemical characteristics of soils in Scots pine forests of Cladina and Vaccinium vitis-idaea site types on coastal dunes of Baltic Sea
Authors: Mandre Malle , Tilk Mari , Kõresaar Priit
Published: March 2011

Chemical characteristics of soils in Scots pine forests of Cladina and Vaccinium vitis-idaea site types on coastal dunes of Baltic Sea

The coastal dunes of Southwest Estonia have been undergoing a process of stabilisation and are today covered predominantly with Scots pine forests. For the investigation of soils on dunes sampling sites were selected according to topographical positions and forest site types: two sites in Cladina and two sites in Vaccinium vitis-idaea site types on dunes of different heights. The prevailing soils on dunes are Gleyic Podzols, which are generally poor in humus, water and mineral nutrients. Great differences in soil chemical components were found on the foots, slopes and tops of the dunes depending on the height of the dune. The study showed that the concentration of macronutrients (N, K, Ca, Mg) in soil decreased from the foot towards the top. On the other hand, a serious decrease in the nutrient concentration from the O horizon to the BC horizon was typical of the dunes. The soils were generally acidic, with the pH of 3.4-5.5 in the studied sampling sites. The soils were more acidic on the foots of the dune and in the O and A horizons.
Drought tolerance of Scots pine in diverse growth conditions on a dune estimated on the basis of carbohydrates and chlorophyll fluorescence in needles
Authors: Klõšeiko Jaan , Tilk Mari
Published: March 2011

Drought tolerance of Scots pine in diverse growth conditions on a dune estimated on the basis of carbohydrates and chlorophyll fluorescence in needles

Variation in the needle carbohydrate concentrations in Scots pine along the height profile on a forested dune in south-western Estonia were measured in spring. To assess the tolerance of trees, carbohydrate concentrations were compared with shoot morphology and photosystem II quantum efficiency (chlorophyll fluorescence). To test a potential effect of drought events on trees, chlorophyll fluorescence was measured in needles after drying and recovery, and dependcies of the treatment effects on the location on the dune were looked for. Water concentration in detached needles was reduced by a partial drying in laboratory. Needles were recovered by an addition of water. Carbohydrate concentrations were rather constant irrespective of shoot morphology and the tree location on the dune. The reduction in the photosynthetic efficiency, observed after the treatment, depended on the site. The results indicated that trees growing at lowest relative heights on the dune were potentially more vulnerable to drought than other trees on the dune at relative height of 5 to 25 m.
Variability of bryophytes and lichens on a forested coastal dune Tõotusemägi in Southwestern Estonia
Authors: Kösta Helen , Tilk Mari
Published: March 2011

Variability of bryophytes and lichens on a forested coastal dune Tõotusemägi in Southwestern Estonia

Bryophytes and lichens are important in all dry land ecosystems due to their ability to colonize different substrates which are not suitable for vascular plants. They have an important role in vertebrates and invertebrate's food chain and function as a habitat for invertebrates. Nitrogen and carbon cycles in the forest depend greatly on the local bryophyte and lichen flora. The aim of present study was to investigate the frequency and variety of different species of bryophytes and lichens on the forested sand dune Tõotusemägi. The study was carried out on a 183 m long transect running on the western slope of the dune. Identification of bryophyte and lichen species was carried out and zonality of forest ground vegetation was demonstrated. Species were observed on the ground, on litter, on stumps and on trees. On the slope, 26 bryophyte species and 38 lichen species were registered. Dominating bryophyte species were Pleurozium schreberi (Brid.) Mitt., Hylocomium splendens (Hedw.) Schimp., Polytrichum juniperinum Hedw., Polytrichum piliferum Hedw, Dicranum polysetum Sw., Dicranum scoparium Hedw. Dominating lichen species were Cladina rangiferina (L.) Nyl., Cladina arbuscula (Wallr.) Hale & W. L. Culb., Cladonia furcata (Huds.) Schrad, Cetraria islandica (L.) Ach. Dominating species of epiphytic lichens were Hypogymnia physodes (l.) Nyl., Parmelia sulcata Taylor, Pseudevernia furfuracea (L.) Zopf, Parmeliopsis ambigua (Wulfen) Nyl. and Imshaugia aleurites (Ach.) S. L. F. Meyer. On the slope of the dune 12 different ground vegetation zones were distinguished. Bryophyte species characteristic for humid habitats and tolerant to shade were observed on foot of the dune. This may be caused by a stream flowing nearby which creates a more moist and nutrient rich habitat. The top area of the dune is open to direct UV radiation, therefore lichens and only some bryophyte species tolerant to dryness were observed.
Growth response of young Scots pines to needle loss assessed from productive foliage
Authors: Kurkela Timo , Drenkhan Rein , Vuorinen Martti , Hanso Märt
Published: March 2011

Growth response of young Scots pines to needle loss assessed from productive foliage

The amount of productive foliage was assessed with the help of the relative significance of each annual needle set in their contribution to the growth of young Scots pines (Pinus sylvestris). The number of needles in the subsequent needle sets was studied retrospectively in twelve-year-old stand, and the worst needle loss years were detected. The growth rate of trees was compared with the number of needles in the annual needle sets and with the loss of needles from the assessed productive foliage. Needles in the 4th and older needle sets remaining in the trees were interpreted as useless or less important if their amount did not correlate with the growth. The second and third needle sets supported both radial and height growth. Most variation in the needle loss during 1999-2002, caused mainly by summer drought and by fungal needle cast due to Lophodermium seditiosum, occurred in the third annual needle set. Decrease in both radial and height increments in relation to the needle loss were apparent in the total material for 1997-2004, but needle loss reduced the annual growth significantly only in two-three years inside that period.
Forest development on Kihnu Island and the role of the human factor in it
Authors: Meikar Toivo
Published: March 2011

Kihnu saare metsade areng ja inimfaktori osa selles

Of the total area of Kihnu Island (16.38 km2), 26% is under a 420-ha pine forest growing on sandy soils and dunes. The forest was estimated to cover about 130 ha (8%) in the early 19th century and 180 ha (11%) in 1949. In 1829-1935 the island's forest was managed predominantly by means of clear cuttings of 1.1 ha in size. Thereafter, it was treated as protection forest. In parallel with clear cutting, clear-cut areas and bare sandy zones were afforested where necessary. Altogether, 210 ha of forest plantations were established in 1829-1949. Intensive forest management and collateral use of forest (grazing on woodlands, gathering of forest litter) led to the impoverishment of the forest soils and stand diversity and deterioration of the forest growth conditions. In the last 75 years the island's forest has effectively enjoyed the status of protection forest, and its area has increased due to shrinking farming activity.
Growth Differences in the Progeny Trials of the Scots Pine (Pinus sylvestris L.)
Authors: Kurm Malle , Kiviste Andres , Kaur Ursula , Maaten Tiit
Published: March 2011

Kasvuomaduste erinevused hariliku männi (Pinus sylvestris L.) järglaskatsetes

The progeny trials of Scots pine founded in Järvselja Training and Experimental Forest District in 1967 and 1968 by E. Pihelgas were analysed to estimate the dependence of progeny growth variables on mother tree or mother stand origin and age. Our progeny data set consists of 4622 DBH and 486 height measurements of the 41- and 42-year-old progeny trials. In 2008 and in 1995 all trees of the progeny trial were callipered and height of nine sample trees was measured on each plot. The analysis was carried out with the SAS/GLM procedure. It was proved that height of inland-originated progeny stands was significantly higher than height of progeny stands originated from maritime regions. Plus-tree progeny stands exceeded single tree and mixture-of-seeds progeny stands in height, diameter, basal area and volume.
New woodland beetle species (Coleoptera) in Estonian fauna
Authors: Süda Ilmar
Published: March 2011

Metsamardikate (Coleoptera) uued liigid Eestis

The article presents faunistic data on 85 species of Coleoptera new to the Estonian fauna. Most of the material has been collected within the framework of various research and monitoring projects carried out in Estonian nature reserves (1998-2009). A new type of trunk window trap, designed by the author in 2004 mainly for monitoring purposes, has been successfully used. 17 of the 85 species are new for the fauna of whole Baltic region: Pseudeuglenes pentatomus (Ths.) (Aderidae), Caenocara subglobosum (Muls. & Rey), Xyletinus tremulicola Y. Kangas (Anobiidae), Choragus sheppardi Kirby (Anthribidae), Cryptocephalus saliceti Zebe (Chrysomelidae), Dirrhagofarsus attenuatus (Mäklin), Hylis cariniceps (Rtt.), Microrhagus emyi (Rouget) (Eucnemidae), Gnathoncus communis (Marseul) (Histeridae), Notolaemus unifasciatus (Latr.) (Laemophloeidae), Agathidium discoideum Er. (Leiodidae), Anisoxya fuscula (Ill.) (Melandryidae), Mordellistena neuwaldeggiana (Pz.) (Mordellidae), Ripidius quadriceps Abeille de Perrin (Rhipiphoridae), Lissodema cursor (Gyll.) (Salpingidae), Aphodius quadrimaculatus (L.) (Scarabaeidae) and Eutheia schaumii Kiesw. (Scydmaenidae). One of the species, Caenocara subglobosum (Muls. & Rey) (Anobiidae), is new for the whole Northern Europe. Specimens of this species were collected from eastern and southern Estonia: most were caught in window traps but some also emerged from the collected fruiting bodies of Common Puffball (Lycoperdon perlatum). For 21 new species, Estonia lies on the northern edge of their range. Three of these, Triphyllus bicolor (F.), Mycetophagus ater (Rtt.) and Glischrochilus grandis (Tournier) that were collected from 6-10 sites, have a wider distribution in Estonia. Two species, Xyletinus tremulicola Y. Kangas (Anobiidae) and Stephanopachys linearis (Kug.) (Bostrichidae), have been listed on Annex II of the EU Habitats Directive. Two new species (Lymantor aceris (Lindemann) and Xyleborinus saxesenii (Ratz.)) were also added to the list of Estonian bark beetles (Curculionidae: Scolytinae).
The first reported outbreak of the great web-spinning pine-sawfly, Acantholyda posticalis (Mats.) (Hymenoptera, Pamphiliidae), in Estonia
Authors: Voolma Kaljo , Pilt Enn , Õunap Heino
Published: March 2011

Nõmme-võrgendivaablase (Acantholyda posticalis (Mats.), Hymenoptera: Pamphiliidae) esmakordne hulgisigimine Eestis

The great web-spinning pine-sawfly, Acantholyda posticalis (Matsumura 1912) (Hymenoptera, Pamphiliidae), is a common and widespread species, occurring throughout the pine forests of Europe and Asia. In the recorded history of forest entomology of Estonia, no mass outbreaks of this species have been reported before. In 2008, an outbreak of A. posticalis was recorded on the island of Saaremaa, Estonia. About 250 hectares of Scots pine (Pinus sylvestris) stands growing on sandy soils were defoliated. In 2009, no flight of A. posticalis was observed, the larvae remain in diapause in soil. An overview about distribution and outbreaks of A. posticalis is given and its impact on pine stands is discussed.
Biomass production and carbon accumulation in silver birch stands in Oxalis site type
Authors: Varik Mats , Aosaar Jürgen , Uri Veiko
Published: March 2011

Biomassi produktsioon jänesekapsa kasvukohatüübi arukaasikutes

Present study was carried out in three silver birch (Betula pendula Roth.) stands in the Oxalis site type in South-Estonia. The above-ground biomass, above-ground biomass production and foliar characteristics of 14-, 32- and 45-year-old silver birch natural stands were studied. The above-ground biomass and production of the stand was estimated in August 2008 using dimension analysis (model tree method). The above-ground biomasses in the 14-, 32- and 45-year-old silver birch stands growing on forest land were 39.9; 140.3 and 224.3 t ha-1 respectively. All results are given in dry mass (DM). Current annual production (CAP) of stem mass ranged 4.7-7.5 t ha-1. Leaf area index (LAI) ranged 2.5-4.4 m2 m-2 in the studied stands. Based on these results, stands of silver birch growing in Oxalis site type are very productive and may exceed the respective values presented in yield tables used in Estonian forestry.
Morphometric parameters of pine needles in Tolkuse bog in the dune field in Southwest Estonia
Authors: Ots Katri , Tilk Mari
Published: March 2011

Männiokaste morfomeetriast Edela-Eesti luitemaastikku ilmestavas Tolkuse rabas

Needle characteristics of Scots pines (Pinus sylvestris L.) in Tolkuse bog (SW Estonia) their length, dry weight and area are discussed. Samples of needles and peat were collected from seven small forest stands in Tolkuse bog in summer 2004. The sampling sites were selected from transect across the bog margin towards its centre (site I - bog margin, site VII - bog centre). Sample branches (n = 30) were collected from the southern sides of the crowns of three trees at heights of 1.5 and 3.0 m. Soil analysis of the samples showed that the pH of peat in Tolkuse bog was in the range 3.3-4.2. The nutrient concentrations of Tolkuse bog peat (% of dry mass) varied as follows: total N 0.7-1.5, total P 0.07-0.14, total K 0.02-0.06, Ca 0.14-0.51 and Mg 0.06-0.22. As compared with other sampling sites a significantly higher concentration of nutrients was observed in the peat at site V. This may explain the best growth of the needles at this site. Site VII, located in the centre of the bog between hollows where bog water is closest to the surface, had the smallest measurements of needles. This indicates that this site has the least favourable conditions for pine growth. Needles growing in the crown at a height of 3 m from the ground had a considerably smaller needle area than those at a height of 1.5 m from the ground.
About management and research of forest genetic resources
Authors: Maaten Tiit , Kurm Malle
Published: March 2011

Metsageneetiliste ressursside majandamisest ja uurimisest

Conservation and management as well research on forest genetic resources are getting more important around the world including Europe and Estonia. There are two main cornerstones by the increasing relevance: international agreements and rapidly developed methods for investigation of genetic structure and diversity by different organisms, including forest trees. In light of given background an overview about recent developments as well historical overview about movements in the past will be given in this paper. This review focuses on (i) genetical aspects by different silvicultural systems (ii) history and results of provenance trials (iii) tree breeding theory and results (iiii) in situ conservation of forest genetic resources (iiiii) development of methods for gene technology in the past and nowadays, including development of genetically modified trees (iiiiii) international processes influencing management and conservation of forest genetic resources.
Threatened forest lichen Lobaria pulmonaria - its past, present and future in Estonia
Authors: Jüriado Inga , Liira Jaan
Published: March 2011

Threatened forest lichen Lobaria pulmonaria - its past, present and future in Estonia

Lobaria pulmonaria is a conspicuous and widely known epiphytic lichen species which mainly occurs on mature hardwood trees in old forests. The distribution of L. pulmonaria has become highly fragmented, showing a decline across Europe. Lobaria pulmonaria is unevenly distributed among ca. 600 localities in Estonia. Most localities are in north-eastern and south-western Estonia (50% and 21% of records respectively). 86% of L. pulmonaria localities are in nature reserves, national parks or woodland key habitats (WKH). In 81% of historical localities known until 1992, L. pulmonaria could be considered extinct. 6% of L. pulmonaria localities have become destroyed in the period from 1993 to 2010 due to clear cutting; in 19% of localities the species could be considered endangered, as its neighbourhood is affected by forest management activities. 40% of destroyed localities are located in forests designated as WKHs in north-eastern Estonia, and most of the endangered populations are also within WKHs. In forest management and conservation planning, WKHs should be preserved with surrounding buffer areas in order to avoid abrupt changes in environmental condition and natural disturbance regimes. There is also a necessity to develop specific management methods to recover reforested wooded meadows, to ensure that species of semi-open habitats are retained, e.g. by reducing the density of spruce.
The management and protection of soil cover: an ecosystem approach
Authors: Kõlli Raimo , Kanal Arno
Published: March 2011

The management and protection of soil cover: an ecosystem approach

There is need for increased societal awareness of the importance of soil management for varying specific uses and for protection of the environment. The main purpose of the study was to analyze the role of soils in the formation and function of ecosystems, to elucidate the properties and mechanisms which play the main role in plant-soil mutual relationships, and to generalize the pedoecological principles of soil management and protection in conditions of Estonia. The treatment is a departure from the pedocentric viewpoint and is based on an ecosystem approach. The relationships between soil and plant covers are tested quantitatively on the basis of the ecosystems' phytoproductivity and fluxes of organic carbon, and qualitatively on the ground of humus forms and site types. On the basis of personal research and data available in literature, the constraints limiting soil cover functioning, the soil degradation features which occurred in actual time and the measures and activities for prevention of soil degradation are analyzed. Problems connected with biodiversity and soil environment protection ability as they relate to soil cover management and protection are discussed. For sustainable land use and to avoid deterioration of soil properties, the experience of local farmers, scientific research and monitoring of degradation features are needed. The soil cover is protected (or sustainable land use is attained) in circumstances when soil fertility and functioning is maintained adequately for the soil types' characteristics. Soil cover should be considered as a medium through which it is possible to improve the environmental status of the area.
Incivilités, logements sociaux et modes de gouvernance
Authors: Ouellet Frédéric , Lemieux Frédéric , Sauvêtre Nadège
Published: March 2011

Est-ce que le mode de gouvernance adopté influence les perceptions, les représentations et l'intervention face à des ruptures de l'ordre social ? Cette étude s'intéresse à cette question et met en relief deux types de logements sociaux dont le mode de gestion est passablement différent. Le premier est géré par les autorités municipales (habitation à loyer modique [HLM]) et le deuxième est administré collectivement par les communautés qui y habitent (coopérative d'habitation [COOP]). La comparaison met en évidence le rôle du mode de gouvernance quant au jugement et à la fréquence des incivilités. L'étude porte sur un sondage effectué auprès de 364 résidents de logements sociaux qui se situent à l'intérieur de cinq quartiers de la ville de Montréal. Les résultats démontrent que le niveau de cohésion et de contrôle social informel est plus élevé dans les coopératives que dans les HLM et ils expliquent la fréquence des incivilités qui s'y produisent, les jugements que les résidents portent sur leur gravité relative et les stratégies d'intervention qu'ils privilégient.
La dynamique de la criminalité à Montréal : l'écologie criminelle revisitée
Authors: Boivin Rémi , Ouellet Frédéric
Published: March 2011

Cette étude de géographie criminelle urbaine explore la possibilité de combiner le concept de désorganisation sociale et la notion d'opportunités criminelles dans un même cadre théorique. À l'aide de modèles linéaires hiérarchiques (MLH), il est démontré que le nombre de crimes commis, tant contre la personne que contre les biens, est mieux prédit par la présence simultanée de délinquants motivés et d'opportunités criminelles. Mais la théorie des opportunités criminelles n'explique pas la présence de délinquants motivés. La théorie de la désorganisation sociale explique beaucoup mieux la distribution géographique de délinquants motivés dans l'espace urbain. Suivant la formulation initiale de Shaw & McKay, les résultats de l'étude indiquent qu'il n'existe pas un lien direct entre la composition des populations résidentes et la criminalité commise dans un quartier. Son effet est indirect et passe par la concentration urbaine de délinquants potentiels.
Criminalization and Off-Street Sex Work in Canada
Authors: O'Doherty Tamara
Published: March 2011

The research presented in this article examines women's perceptions of how the criminal laws relating to prostitution affect the experience of working in the off-street Canadian sex industry. The results of interviews with 10 women indicate that the criminalization of prostitution has numerous effects on the health and safety of indoor workers: the workers are alienated from the protective services of police; they are often misinformed about their legal rights in Canada; they face personal, legal, and social consequences for association with a criminalized activity; their abilities to mitigate risk are severely limited by the criminalization of ancillary activities related to prostitution; and their health is directly affected by the isolation and stress that accompany marginalized labour. The participants share their advice for future regulation of the sex industry in Canada and strongly encourage the removal of adult consensual sex work from the realm of criminal behaviour in Canada.
Driving under the Influence of Cannabis or Alcohol in a Cohort of High-frequency Cannabis Users: Prevalence and Reflections on Current Interventions
Authors: McGuire Fraser , Dawe Meghan , Shield Kevin D. , Rehm Jürgen , Fischer Benedikt
Published: March 2011

Driving under the influence of alcohol or cannabis is a major public health concern, as both are major risk factors for motor vehicle accidents (MVAs). Prevalence levels for both driving-risk behaviours have increased in Canada in recent years, despite punitive laws and enforcement aimed at impaired driving. Young drivers are a major risk group, due to their common substance use and MVA involvement. Data from a cohort of N=102 high-frequency cannabis users [18–28 years old, 70 males and 32 females] who were also active alcohol users, recruited by mass advertising from university student populations in Toronto, indicated that a significantly (p=0.009) higher proportion of the sample [35.0%] had driven a car while under the influence of cannabis than had driven while under the influence of alcohol [4.9%] or of a combination of cannabis and alcohol [3.9%] in the 30 days prior to the assessment. Multiple explanations of this finding are possible. First, law-enforcement and practical deterrence effects for alcohol- versus cannabis-impaired driving in Canada may be substantially different. Second, cannabis users may generally believe that the impairment effects of cannabis are limited, and frequent users may specifically believe in their ability to control cannabis's effects on driving. Implications for interventions and policy are discussed.
Factors predicting the feasibility of monitoring lower-limb muscle motor evoked potentials in patients undergoing excision of spinal cord tumors
Authors: Rajshekhar Vedantam , Velayutham Parthiban , Joseph Mathew , Babu K. Srinivasa
Published: March 2011

Object

This prospective study on intraoperative muscle motor evoked potentials (MMEPs) from lower-limb muscles in patients undergoing surgery for spinal cord tumors was performed to: 1) determine preoperative clinical features that could predict successful recording of lower-limb MMEPs; 2) determine the muscle in the lower limb from which MMEPs could be most consistently obtained; 3) assess the need to monitor more than 1 muscle per limb; and 4) determine the effect of a successful baseline MMEP recording on early postoperative motor outcome.

Methods

Of 115 consecutive patients undergoing surgery for spinal cord tumors, 110 were included in this study (44 intramedullary and 66 intradural extramedullary tumors). Muscle MEPs were generated using transcranial electrical stimulation under controlled anesthesia and were recorded from the tibialis anterior, quadriceps, soleus, and external anal sphincter muscles bilaterally. The effect of age (≤ 20 or > 20 years old), location of the tumor (intramedullary or extramedullary), segmental location of the tumor (cervical, thoracic, or lumbar), duration of symptoms (≤ 12 or > 12 months), preoperative functional grade (Nurick Grades 0–3 or 4–5), and muscle power (Medical Research Council Grades 0/5–3/5 or 4/5–5/5) on the success rate of obtaining MMEPs was studied using multiple regression analysis. The effect of the ability to monitor MMEPs on motor outcome at discharge from the hospital was also analyzed.

Results

The overall success rate for obtaining baseline lower-limb MMEPs was 68.2% (75 of 110 patients). Eighty-nine percent of patients with Nurick Grades 0–3 had successful MMEP recordings. Muscle MEPs could not be obtained in any patient in whom muscle power was 2/5 or less, but were obtained from 91.4% of patients with muscle power of 4/5 or more. Analysis showed that only preoperative Nurick grade (p ≤ 0.0001) and muscle power (p < 0.0001) were significant predictors of the likelihood of obtaining MMEPs. Responses were most consistently obtained from the tibialis anterior muscle (68%), but in the other 32% MMEPs could not be recorded from the tibialis anterior but could be recorded from another muscle. The ability to monitor MMEPs was associated with better motor outcome at discharge from the hospital (p = 0.052).

Conclusions

The likelihood of obtaining lower-limb MMEPs is significantly greater in patients with better functional grades and higher motor power. Muscle MEPs are most consistently obtained from the tibialis anterior muscle but other muscles should also be monitored to optimize the chances of obtaining MMEP responses from the lower limbs.
Use of cerebrospinal fluid amyloid-β and total tau protein to predict favorable surgical outcomes in patients with idiopathic normal pressure hydrocephalus
Authors: Tarnaris Andrew , Toma Ahmed. K. , Chapman Miles D. , Keir Geoff , Kitchen Neil D. , Watkins Laurence D.
Published: March 2011

Object

The prognostic value of CSF biomarkers in patients with idiopathic normal pressure hydrocephalus (iNPH) has not been adequately studied to date. The aim of this study was to identify CSF markers of favorable surgical outcome in patients with iNPH undergoing the insertion of a ventriculoperitoneal shunt.

Methods

Ventricular CSF was collected intraoperatively from 22 patients with iNPH and enzyme-linked immunosorbent assay was used to analyze the levels of amyloid-β 1–42 (Aβ1–42) and total tau protein. The Black grading scale was used to assess outcomes at 6 months. Receiver operating characteristic (ROC) curves were obtained and discriminant function analysis was undertaken to provide sensitivity and specificity figures for each marker as well as their combination.

Results

The mean age of the patients was 71.45 years (± 9.5 years [SD]). Follow-up was achieved in 21 patients. Seventeen patients had a favorable outcome and 4 patients had unfavorable outcome at 6 months. An Aβ1–42 level of 180 pg/ml had a sensitivity of 35% and a specificity of 20% for predicting a favorable outcome at 6 months. A total tau level of 767 pg/ml will have a sensitivity of 17% and a specificity of 20% for predicting a favorable outcome at 6 months. A combination of Aβ1–42 and total tau levels predicted favorable outcomes with a sensitivity of 80% and specificity of 82.4%.

Conclusions

In this pilot study a combination of Aβ1–42 levels and total tau protein levels predicted favorable surgical outcomes at 6 months with adequate accuracy to be of clinical use. Further study in a larger group with longer follow-up is warranted.
Compressed Matching in Dictionaries
Authors: Klein Shmuel T. , Shapira Dana
Published: March 2011

The problem of compressed pattern matching, which has recently been treated in many papers dealing with free text, is extended to structured files, specifically to dictionaries, which appear in any full-text retrieval system. The prefix-omission method is combined with Huffman coding and a new variant based on Fibonacci codes is presented. Experimental results suggest that the new methods are often preferable to earlier ones, in particular for small files which are typical for dictionaries, since these are usually kept in small chunks.
Overexpression of CYP3A4 in a COLO 205 Colon Cancer Stem Cell Model in vitro
Authors: Olszewski Ulrike , Liedauer Richard , Ausch Christoph , Thalhammer Theresia , Hamilton Gerhard
Published: March 2011

Cancer stem cells (CSCs) seem to constitute a subpopulation of tumor cells that escape from chemotherapy and cause recurrent disease. Low proliferation rates, protection in a stem cell niche and overexpression of drug resistance proteins are considered to confer chemoresistance. We established an in vitro colon CSC-like model using the COLO 205 cell line, which revealed transiently increased expression of CD133 when transferred to serum-free stem cell culture medium. Assessment of global gene expression of COLO 205 cells under these conditions identified a set of upregulated genes including cytochrome P450 3A4 (CYP3A4) and aldehyde dehydrogenase 1A1 (ALDH1A1), as confirmed by real-time qPCR. ALDH1A1 is a CSC marker for certain tumor entities and confers resistance to cyclophosphamide. CYP3A4 is expressed in liver and colon and its overexpression seems particularly relevant in colon cancer, since it inactivates irinotecan and other xenobiotics, such as taxols and vinca alkaloids. In conclusion, this COLO 205 model provides evidence for CD133 induction concomitant with overexpression of CYP3A4, which, together with ATP-binding cassette, subfamily G, member 2 (ABCG2) and others, may have a role in chemoresistant colon CSCs and a negative impact on disease-free survival in colon cancer patients.
Role of Methionine Adenosyltransferase Genes in Hepatocarcinogenesis
Authors: Ramani Komal , Mato José M. , Lu Shelly C.
Published: March 2011

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. Detection of HCC can be difficult, as most of the patients who develop this tumor have no symptoms other than those related to their longstanding liver disease. There is an urgent need to understand the molecular mechanisms that are responsible for the development of this disease so that appropriate therapies can be designed. Methionine adenosyltransferase (MAT) is an essential enzyme required for the biosynthesis of S-adenosylmethionine (AdoMet), an important methyl donor in the cell. Alterations in the expression of MAT genes and a decline in AdoMet biosynthesis are known to be associated with liver injury, cirrhosis and HCC. This review focuses on the role of MAT genes in HCC development and the scope for therapeutic strategies using these genes.
Small Molecule Inhibitors of Bcl-2 Family Proteins for Pancreatic Cancer Therapy
Authors: Masood Ashiq , Azmi Asfar S. , Mohammad Ramzi M.
Published: March 2011

Pancreatic cancer (PC) has a complex etiology and displays a wide range of cellular escape pathways that allow it to resist different treatment modalities. Crucial signaling molecules that function downstream of the survival pathways, particularly at points where several of these pathways crosstalk, provide valuable targets for the development of novel anti-cancer drugs. Bcl-2 family member proteins are anti-apoptotic molecules that are known to be overexpressed in most cancers including PC. The anti-apoptotic machinery has been linked to the observed resistance developed to chemotherapy and radiation and therefore is important from the targeted drug development point of view. Over the past ten years, our group has extensively studied a series of small molecule inhibitors of Bcl-2 against PC and provide solid preclinical platform for testing such novel drugs in the clinic. This review examines the efficacy, potency, and function of several small molecule inhibitor drugs targeted to the Bcl-2 family of proteins and their preclinical progress against PC. This article further focuses on compounds that have been studied the most and also discusses the anti-cancer potential of newer class of Bcl-2 drugs.
Analysis of Resource and Emission Impacts: An Emergy-Based Multiple Spatial Scale Framework for Urban Ecological and Economic Evaluation
Authors: Liu Gengyuan , Yang Zhifeng , Chen Bin , Zhang Lixiao
Published: March 2011

The development of the complex and multi-dimensional urban socio-economic system creates impacts on natural capital and human capital, which range from a local to a global scale. An emergy-based multiple spatial scale analysis framework and a rigorous accounting method that can quantify the values of human-made and natural capital losses were proposed in this study. With the intent of comparing the trajectory of Beijing over time, the characteristics of the interface between different scales are considered to explain the resource trade and the impacts of emissions. In addition, our improved determination of emergy analysis and acceptable management options that are in agreement with Beijing’s overall sustainability strategy were examined. The results showed that Beijing’s economy was closely correlated with the consumption of nonrenewable resources and exerted rising pressure on the environment. Of the total emergy use by the economic system, the imported nonrenewable resources from other provinces contribute the most, and the multi‑scale environmental impacts of waterborne and airborne pollution continued to increase from 1999 to 2006. Given the inputs structure, Beijing was chiefly making greater profits by shifting resources from other provinces in China and transferring the emissions outside. The results of our study should enable urban policy planners to better understand the multi-scale policy planning and development design of an urban ecological economic system.
Static Isolated Horizons: SU(2) Invariant Phase Space, Quantization, and Black Hole Entropy
Authors: Perez Alejandro , Pranzetti Daniele
Published: March 2011

We study the classical field theoretical formulation of static generic isolated horizons in a manifestly SU(2) invariant formulation. We show that the usual classical description requires revision in the non-static case due to the breaking of diffeomorphism invariance at the horizon leading to the non-conservation of the usual pre-symplectic structure. We argue how this difficulty could be avoided by a simple enlargement of the field content at the horizon that restores diffeomorphism invariance. Restricting our attention to static isolated horizons we study the effective theories describing the boundary degrees of freedom. A quantization of the horizon degrees of freedom is proposed. By defining a statistical mechanical ensemble where only the area aH of the horizon is fixed macroscopically—states with fluctuations away from spherical symmetry are allowed—we show that it is possible to obtain agreement with the Hawkings area law (S = aH /(4l 2p)) without fixing the Immirzi parameter to any particular value: consistency with the area law only imposes a relationship between the Immirzi parameter and the level of the Chern-Simons theory involved in the effective description of the horizon degrees of freedom.
Pluripotent Stem Cell Studies Elucidate the Underlying Mechanisms of Early Embryonic Development
Authors: Li Lingyu , Jing Naihe
Published: March 2011

Early embryonic development is a multi-step process that is intensively regulated by various signaling pathways. Because of the complexity of the embryo and the interactions between the germ layers, it is very difficult to fully understand how these signals regulate embryo patterning. Recently, pluripotent stem cell lines derived from different developmental stages have provided an in vitro system for investigating molecular mechanisms regulating cell fate decisions. In this review, we summarize the major functions of the BMP, FGF, Nodal and Wnt signaling pathways, which have well-established roles in vertebrate embryogenesis. Then, we highlight recent studies in pluripotent stem cells that have revealed the stage-specific roles of BMP，FGF and Nodal pathways during neural differentiation. These findings enhance our understanding of the stepwise regulation of embryo patterning by particular signaling pathways and provide new insight into the mechanisms underlying early embryonic development.
Recent Advances in Conjugated Polymers for Light Emitting Devices
Authors: AlSalhi Mohamad Saleh , Alam Javed , Dass Lawrence Arockiasamy , Raja Mohan
Published: March 2011

A recent advance in the field of light emitting polymers has been the discovery of electroluminescent conjugated polymers, that is, kind of fluorescent polymers that emit light when excited by the flow of an electric current. These new generation fluorescent materials may now challenge the domination by inorganic semiconductor materials of the commercial market in light-emitting devices such as light-emitting diodes (LED) and polymer laser devices. This review provides information on unique properties of conjugated polymers and how they have been optimized to generate these properties. The review is organized in three sections focusing on the major advances in light emitting materials, recent literature survey and understanding the desirable properties as well as modern solid state lighting and displays. Recently, developed conjugated polymers are also functioning as roll-up displays for computers and mobile phones, flexible solar panels for power portable equipment as well as organic light emitting diodes in displays, in which television screens, luminous traffic, information signs, and light-emitting wallpaper in homes are also expected to broaden the use of conjugated polymers as light emitting polymers. The purpose of this review paper is to examine conjugated polymers in light emitting diodes (LEDs) in addition to organic solid state laser. Furthermore, since conjugated polymers have been approved as light-emitting organic materials similar to inorganic semiconductors, it is clear to motivate these organic light-emitting devices (OLEDs) and organic lasers for modern lighting in terms of energy saving ability. In addition, future aspects of conjugated polymers in LEDs were also highlighted in this review.