bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Power Spectrum Characteristics of Body Sway during a Static Upright Standing Posture in Healthy Elderly People and Young Adults
Authors: Demura Shinichi , Kitabayashi Tamotsu
Published: June 2007

This study was designed to compare peak frequency, mean power frequency, and power spectrum of each frequency band of body-sway time series and velocity time series power spectra between 30 healthy elderly people and 30 young adults and to clarify their frequency characteristics. Peak frequency and mean power frequency differed between groups, being higher for elderly persons, and the difference was marked in the front-back direction. When comparing power spectra of three domains (A: 0.02–0.2 Hz, B: 0.2–2.0 Hz, and C: 2.0–10.0 Hz) of an international standard, a significant age-group difference was found only in the front-back direction. Young adults were higher in the low frequency band (A domain) in sway time series, and the elderly group was higher in the high frequency band (C domain) in body-sway velocity time series. However, almost all power spectra of both groups appeared in the low frequency band. The present results suggested frequency characteristics of healthy people occur in the low frequency band, but the elderly group compared with the young adults had more characteristics in the high frequency band. Their frequency characteristics cannot be properly evaluated by the international standard established to screen disorders. It may be necessary for healthy people to have new evaluation frequency sections when considering power spectrum characteristics of sway time series and sway-velocity time series.
Performance on a Simple Reaction Time Task While Sleep Deprived
Authors: van den Berg Johannes , Neely Gregory
Published: June 2007

Divergent results have been reported on the effect of a night's sleep loss on performance of a single monotonous task. The present experiment examined the effect that partial sleep deprivation had on 10 participants' performance on a simple reaction time task requiring low responding for 120 min. compared to performance on the same task when well rested. Participants missed significantly more signals and had slower reaction times when sleep deprived. Reaction times increased with time when participants were both sleep deprived and rested, but the number of misses did not significantly change over time. Reaction time was significantly correlated with subjective ratings of sleepiness and heart rate in both conditions. EEG and heart-rate variability measures did not correlate significantly with reaction time. Misses correlated significantly with subjective ratings and heart rate but only in the rested condition.
Correlations for Number of Sunspots, Unemployment Rate, and Suicide Mortality in Japan
Authors: Otsu Akiko , Morgenthaler Stephan , Fujita Daisuke , Chinami Masanobu , Kaneko Yoshihiro , Shirakawa Taro
Published: June 2007

We studied the correlations among sunspot numbers, business cycles, and suicide mortalitites. Based on data from Japan between 1971 and 2001, a significant negative correlation between sunspot numbers and unemployment rate was found, R = −.17. The correlation between suicide mortality and unemployment rate was positive for males ( R =.46) and negative for females ( R= −.69). Both are statistically significant. The hypothesis that variation of sun activity may affect the economy and the unemployment rate and hence increase the male suicide mortality is raised.
The identification of QTLs associated with the in vitro response of rye (Secale cereale L.)
Authors: Bolibok Hanna , Gruszczyńska Anna , Hromada-Judycka Aneta , Rakoczy-Trojanowska Monika
Published: June 2007

This study was conducted in order to identify quantitative trait loci (QTLs) for the in vitro culture response of winter rye (Secale cereale L.) immature embryos and immature inflorescences. A genetic linkage map comprising 67 SSRs, 9 ISSRs, 13 SAMPLs, 7 RAPDs, 2 SCARs and one EST marker was created based on the analyses of 102 recombinant inbred lines from the cross between lines L318 (which has a good response in tissue cultures) and L9 (which is unable to regenerate plants from somatic tissues and anthers). The map spans 979.2 cM, and the average distance between markers is 9.9 cM. Two characteristics were evaluated: callus induction (CI) and somatic embryogenesis ability (SE). They were expressed as the percentage of immature embryos/inflorescences producing callus (designated ECI/ICI) and the percentage of explants producing somatic embryos (ESE/ISE). All the analysed traits showed continuous variation in the mapping population but a non-normal frequency distribution. We identified nine putative QTLs controlling the tissue culture response of rye, explaining up to 41.6% of the total phenotypic variation: two QTLs for ECI — eci-1, eci-2; 4 for ESE — ece-1, ese-2, ese-3, ese-4; 2 for ICI — ici-1, ici2; and 1 for ISE — ise-1. They were detected on chromosomes 1R, 4R, 5R, 6R and 7R.
Hydrogen Peroxide in the Troposphere
Authors: Pehnec Gordana
Published: June 2007

Vodikov Peroksid U Troposferi

Uloga vodikova peroksida (H2O2) u atmosferskoj kemiji i njegov doprinos u nastanku slobodnih radikala počeli su se proučavati tek posljednjih nekoliko desetljeća. Fotokemijskim reakcijama s ozonom i H2O2 nastaju oksidansi (slobodni radikali) koji mogu oksidirati biomolekule unutar stanica te dovesti do smrti stanica i ozljeda tkiva. Zbog toga se slobodni radikali smatraju uzrokom više od sto bolesti. H2O2 smatra se boljim indikatorom za atmosferski oksidacijski kapacitet od ozona. U atmosferi može biti prisutan u plinovitoj i tekućoj fazi te pokazuje tipične dnevne i sezonske varijacije. Međutim, zbog skupe i složene opreme, mjerenja H2O2 su rijetka i ograničena na samo nekoliko mjesta u svijetu. Mjerenja u slojevima leda na Grenlandu pokazala su da koncentracije H2O2 rastu posljednjih 200 godina. Značajan porast primijećen je upravo posljednjih dvaju desetljeća, a procjene pokazuju da će i dalje rasti zbog smanjene emisije sumporova dioksida. Mjerenja H2O2 u Hrvatskoj do sada još nisu bila provedena te će uporedo s već postojećim dugogodišnjim rezultatima mjerenja ozona i dušikovih oksida dati uvid u stanje i utjecaj na oksidativni stres.
Bronchial Hyperresponsiveness in Women Cooks and Cleaners
Authors: Karadžinska-Bislimovska Jovanka , Minov Jordan , Risteska-Kuc Snežana , Stoleski Sašo , Mijakoski Dragan
Published: June 2007

Bronchial Hyperresponsiveness in Women Cooks and Cleaners

The aim of this cross-sectional study was to assess the prevalence and characteristics of bronchial hyperresponsiveness (BHR) in 43 women cleaners (aged 26 to 57) and 37 women cooks (aged 29 to 55) and compare them with 45 controls (women office workers aged 27 to 58). The evaluation of all subjects included a questionnaire, skin prick tests to common aeroallergens, spirometry, and histamine challenge (PC20≤8 mg mL-1). We found higher BHR prevalence in cleaners and cooks than in office workers (30.2 % and 29.7 %, vs. 17.7 %, respectively), but statistical significance was not reached. The prevalence of mild and moderate to severe BHR was similar in all groups. Borderline BHR prevalence was significantly higher in cleaners than in controls (16.2 %vs. 6.6 %, P=0.032) whereas the difference was on the verge of significance in cooks (13.5 %vs. 6.6 %, P=0.081). Moderate to severe BHR was strongly associated with positive family history of asthma and atopy in all groups. Mild BHR was significantly associated with daily smoking in cleaners (P=0.031) and cooks (P=0.021), as well as with the duration of exposure in cleaners (P=0.038). Borderline BHR was closely related to daily smoking and duration of exposure in both cleaners and cooks. Our findings indicate an important role of workplace exposure in borderline BHR development, as well as the significant effect of smoking on mild BHR development in women cleaners and cooks.
Water dynamics in estuaries along the Polish Baltic coast
Authors: Jasińska Ewa , Massel Stanisław
Published: June 2007

Estuaries are areas where river and sea waters meet. Therefore, the hydrodynamical, hydrochemical, and hydrobiological processes in the estuaries are typical for both environments. The most important processes, which play leading roles in estuaries include the dynamics of water flow, water quality, and the mixing of water of different biochemical characteristics. This paper is divided into two parts. In the first, basic hydrodynamical processes are described and analytical and numerical methods of evaluating them are presented. Part two illustrates these processes using experimental data and the results of mathematical modeling for some estuaries along the Polish Baltic coast.
Arg16gly Polymorphism of the beta2-Adrenoceptor Gene (ADRBeta2) as a Susceptibility Factor for Nasal Polyposis
Authors: Bussu Francesco , Tiziano Francesco Danilo , Giorgio Arianna , Pinto Anna Maria , De Corso Eugenio , Angelozzi Carla , Brahe Christina , Paludetti Gaetano
Published: June 2007

Background

Nasal polyposis is probably a multifactorial disease, but so far, no genetic susceptibility factor has been identified. The observed associations between the ADRB2 arg16gly polymorphism and asthma-related phenotypes as well as those between nasal polyposis and asthma have prompted us to evaluate the potential involvement of this polymorphism in sinonasal polyposis.

Methods

We enrolled in our study, 56 patients and 47 sex- and age-matched controls. Genomic DNA from cases and controls was extracted and genotype was assessed by a polymerase chain reaction amplification/Nco I digestion assay. Statistical analysis was performed using JMP software (version 5.1).

Results

The “number of arg alleles” is significantly higher in cases than in controls (p = 0.0386 at t-test; substantially confirmed by nonparametric tests, p = 0.0396 by Wilcoxon/Kruskal-Wallis tests).

Conclusion

Although results of this study are preliminary because of the small size of the sample, the arg16 allele seems to be associated with an increased risk of sinonasal polyposis suggesting ADRB2 as a susceptibility gene. This finding, if confirmed, would have a clinical value in helping to assess the genetic risk for sinonasal polyposis thus opening new perspectives for the study of molecular factors underlying the development of nasal polyps.
Sudden Temperature Changes and Respiratory Symptoms—An Experimental Approach
Authors: Graudenz Gustavo Silveira , Oliveira Celso Henrique , Tribess Arlindo , Landgraf Richardt G. , Jancar Sonia , Kalil Jorge
Published: June 2007

Background

Exposure to air-conditioning systems and allergic phenotypes are consistent risk factors to develop indoor air quality (IAQ) respiratory complaints. The aim of this study was to compare the role of allergic rhinitis on respiratory complaints in individuals exposed to sudden temperature changes.

Methods

To address this question, a case-control challenge study was performed in a laboratory of thermal comfort evaluation with twin isolated chambers set at 14°C/57.2°F (cold) and 26°C/78.8°F (hot) temperatures. A groups of 32 patients with persistent allergic rhinitis (rhinitis group) and 16 control subjects (control group) were exposed for 30 minutes, three times alternately in the chambers. Symptoms were reported using an analog visual scale and nasal and pulmonary peak flow measurements were taken during baseline at hot and cold temperatures and after the challenge.

Results

The rhinitis group reported increased itching and stinging eyes when compared with the baseline during exposure to hot and cold temperatures and they also reported increased breathlessness during hot air exposure. In addition, there was a significant decrease in expiratory flow rates in this group during exposure to hot and cold temperatures that persisted for 24 hours after challenge.

Conclusion

This study suggests that individuals with allergic rhinitis have a lower threshold than controls to develop respiratory and ocular symptoms after air-conditioning–induced sudden temperature changes.
Fungal Allergens Induce Cathelicidin LL-37 Expression in Chronic Rhinosinusitis Patients in a Nasal Explant Model
Authors: Ooi Eng Hooi , Wormald Peter-John , Carney A. Simon , James Craig Lloyd , Tan Lor Wai
Published: June 2007

Background

Fungus is thought to play an important role in some subgroups of chronic rhinosinusitis (CRS) patients with eosinophilic mucus (EMCRS). The cathelicidin LL-37 is an important innate defense peptide with antimicrobial activity but its responses in CRS and EMCRS patients have not been established. We investigated the innate immune responses of LL-37 in nasal tissue from CRS and EMCRS patients to fungal allergen challenge.

Methods

The levels of LL-37 produced by nasal tissue and secreted in response to fungal allergen challenge were determined by a nasal tissue explant in vitro model. LL-37 mRNA and protein levels were quantified by real-time reverse-transcriptase–polymerase chain reaction and immunoassay methods.

Results

LL-37 mRNA expression in CRS, but not EMCRS patients, is significantly upregulated by Aspergillus (mean fourfold increase) and Alternaria (mean sixfold increase) extracts in a dose-response manner (p < 0.001). LL-37 peptide levels in the nasal tissue from CRS patients are increased in response to Alternaria (p < 0.05). In contrast, with EMCRS patients, the expression of LL-37 peptide in nasal tissue is increased with Aspergillus (p < 0.001) but is reduced with Alternaria. We also observed a trend where levels of secreted LL-37 were decreased with higher doses of Alternaria and Aspergillus extracts.

Conclusion

LL-37 is significantly up-regulated at the mRNA and protein level in CRS patients in response to fungal allergens. However, EMCRS patients do not show increased LL-37 at either the mRNA or the protein level in response to Alternaria.
Radiographic Signs of Elevated Intracranial Pressure in Idiopathic Cerebrospinal Fluid Leaks: A Possible Presentation of Idiopathic Intracranial Hypertension
Authors: Silver Ross I. , Moonis Gul , Schlosser Rodney J. , Bolger William E. , Loevner Laurie A.
Published: June 2007

Background

Traditionally, idiopathic cerebrospinal fluid (CSF) leaks have been associated with normal intracranial pressure (ICP). We speculate that at least one subset of these leaks may be associated with elevated ICP, more specifically, idiopathic intracranial hypertension (IIH). We sought to identify radiographic manifestations suggestive of elevated ICP in 14 patients with idiopathic CSF leaks who clinically and epidemiologically resembled patients with IIH.

Methods

We retrospectively reviewed high-resolution CT, MRI, and/or CT cisternography in 14 patients with elevated ICP and idiopathic CSF leaks for radiographic manifestations suggesting increased ICP.

Results

Arachnoid pits were seen in 79% of patients, empty sella was seen in 50% of patients, meningo(encephalo)celes were seen in 50% of patients, and dural ectasia was seen in 35% of patients, respectively. Optic nerve findings were not shown as commonly seen as described in the literature.

Conclusion

We show a subset of patients with idiopathic CSF leaks who display radiographic signs consistent with increased ICP who may represent an alternative presentation of IIH.
Comparison of the Hypoalgesic Efficacy of Low-Frequency and Burst-Modulated Kilohertz Frequency Currents
Authors: Ward Alex R , Oliver Warwick G
Published: June 2007

Background and Purpose

A within-subject randomized controlled trial was conducted to compare monophasic pulsed current (PC) with a frequency of 50 Hz and a phase duration of 500 microseconds with burst-modulated alternating current (BMAC) (1-kHz alternating current, burst modulated at a frequency of 50 Hz with a 20% duty cycle) to establish whether there were differences in hypoalgesic efficacy as assessed by cold pain threshold measurements.

Subjects

Twenty-two young adults who were healthy and drawn from a population of students of La Trobe University volunteered to participate in the study. Nineteen subjects (7 male, 12 female) met the inclusion criteria.

Method

Each participant experienced monophasic PC and BMAC. Time to cold pain threshold was measured before, during, and after the electrical stimulation intervention.

Results

Both PC and BMAC currents were effective at elevating the cold pain threshold, although there was no statistically significant difference between the 2 currents during stimulation.

Discussion and Conclusion

Pulsed current and BMAC appear to be equally effective at elevating the cold pain threshold. Analysis indicated that if any real difference exists, it would only be apparent with large (100) subject numbers. Any differences in hypoalgesic efficacy thus are not likely to be clinically important.
Financial Results of Selection Forest Enterprises with High Proportions of Valuable Timber – Results of an Empirical Study and their Application
Authors: Hanewinkel Marc
Published: June 2007

In order to analyse the financial consequences of a high proportion of selection forest and valuable timber, we compare private and communal forests with those run by the state. Enterprises run on a selection forest system clearly show more favourable economic indices which are a consequence of the high proportion of valuable timber harvested each year.

The results are interpreted in a manner that creates an instrument to help managers of forest companies to make decisions. Preference is given to a «benchmarking» approach over a comparative economic approach between even-aged forests and selection forests.
Strategie Wald und Wild für den Kanton Appenzell Ausserrhoden. Grundlagen zu einem kantonalen Konzept zur Verhütung von Wildschäden und zur Verbesserung der Lebensbedingungen der Wildtiere | Strategic plan for forest and game in the canton of Appenzell Ausserrhoden. Basis of a cantonal concept for the prevention of browsing damage and for the improvement of the habitat of game.
Authors: Meile Peter , Boschi Cristina , Sommerhalder Robert
Published: June 2007

The intensively used cultural landscape of the canton of Appenzell Ausserrhoden leaves only very limited resources for roe,chamois and deer. Copious feed in open green spaces is only available to ungulates for a very short space of time. A high rate of tourist activity on the slopes above the forest drives the game into the forest. Browsing damage is extremely high in forests at the foot of the Säntis massif. Rules governing the sustenance of the roe and chamois population are not always diligently kept. Our strategic plan calls for more extensively used green spaces including forest borders, hedges and brooksides, as well as the development of new hunting strategies.

A spatial reduction of tourist activities is called for, especially of ramblers and hikers, by path regulation. The organisation of the ecological surveillance of game and the decision-making process for the hunt need to be adjusted to meet the dual goals of enhancing the well-being of game and ensuring the natural regeneration of an indigenous composition of the forest.
Zur Rückkehr der Arve (Pinus cembra L.) in die Südalpen der Schweiz | The return of the Swiss stone pine (Pinus cembra L.) in the southern Alps of Switzerland
Authors: Keller Walter
Published: June 2007

The ecology and spread of the stone pine in the subalpine zone of southern Switzerland are discussed with reference to both vegetation relevés with Pinus cembra L. from Vergeletto valley(Canton Ticino) and forest history and botany publications. The ecograms and lists of tree species given in the recent literature are often contradictory, so that it is difficult to use them with confidence. This means that only verifiable and published relevés and analyses based on them may serve as a basis to evaluate the implementation and check the results of forest management in Switzerland.
Jahrringe als Archive für interdisziplinäre Umweltforschung | Annual rings as an archive for interdisciplinary environmental research
Authors: Cherubini Paolo , Gärtner Holger , Esper Jan , Dobbertin Michèle Kaennel , Kaiser Klaus Felix , Rigling Andreas , Treydte Kerstin , Zimmermann Niklaus E. , Bräker Otto Ulrich
Published: June 2007

The paper describes research in dendrochronological fields that was carried out at the Swiss Federal Research Institute WSL (Birmensdorf, Switzerland). After a short history of dendrochronology,we describe the applied materials and methods used, namely ring-width and wood density measurements,crossdating, stable isotopes measurement and wood anatomy.
Waldnutzung und Jahrringe | Forest use and tree-rings
Authors: Bräker Otto U. , Rigling Andreas
Published: June 2007

The present work describes tree-ring research related to the theory and practice of forest use carried out at the Swiss Federal Research Institute WSL. The effects of silvicultural practices and other, more indirect, human influence on tree and stand growth are demonstrated using a variety of examples from experiments and studies. Major timber harvestings significantly influence tree competition, stand structure and stand dynamics. Competition pressure in dense closed forests of uniform heights, short-term growth reactions from thinning and release,as well as weather and disease are easily recognizable. Medium to long-term changes in tree and stand growth reflect shifts in forest use, changes in water and nutrient cycles, or dynamics from anthropogenic emissions and depositions. These exam-ples are chosen to illustrate the effects of cultivation on current forest development and to assist the planning of future management practices. The results demonstrate the importance of tree-ring research to understand forest-dynamic processes and as a tool to develop forest management strategies.
Jahrringe als Indikatoren für extreme Standortsbedingungen im Gebirge: Schnee, Lawinen und Permafrost | Growth rings as indicators of extreme site conditions in the mountains: snow, avalanches and permafrost
Authors: Bebi Peter , Casteller Alejandro , Mayer Andrea Corinna , Stöckli Veronika
Published: June 2007

Snow, avalanches, and permafrost are extreme site conditions for plants. Reactions and adaptations to such extreme conditions can be reconstructed with growth ring analysis and linked with corresponding climate and disturbance data. On the basis of five case studies in and around the long-term research site Stillberg, near Davos, we discuss both the potential and the limits of dendroecology to understand the effect of such extreme site conditions. Despite some uncertainties in reliably assigning plant reactions, growth ring analysis is a valuable addition to better understand the effects of extreme site conditions on the survival and growth of plants. This can lead to improved management strategies associated with natural hazards, especially in the case of avalanches.
Stabile Isotope in der Dendroklimatologie | Stable isotopes and dendroclimatology
Authors: Treydte Kerstin , Esper Jan , Gärtner Holger
Published: June 2007

This paper expounds the basics of isotope fixation in tree rings and relevant field and laboratory procedures. Examples from high mountain regions show both the potential and limits of employing these methods in dendroclimatological studies. Carbon isotopes yield seasonally resolved information on temperature,precipitation and relative humidity, whilst oxygen isotopes provide information on the isotope values of the source water,and thus, on precipitation. Inter-annual and decadal variations, in particular, reflect a strong common climatic signal that extends across a wide range of site ecologies. However, low frequency trends are masked by a non-climatic, human induced long-term trend, especially where carbon isotopes are concerned. At present,detrending methods are of a provisional nature and set a limit to stable isotopes for paleoclimatic questions. Highly resolved plant physiological and biochemical investigations should provide more insight into these unsolved problems.
Monitoring und Erfolgskontrolle in WWF-Naturwaldflächen im Kanton Bern | Monitoring and evaluating success in WWF natural forest areas in Canton Berne
Authors: Loser Erika , Bebié Nicole , Niggli-Luder Simone , Bürkler Felix
Published: June 2007

In order to evaluate success in six areas of protected forest,WWF Berne depends on simple indicators that measure biological diversity. The diversity potential of the forested areas,covering between two and 78 hectares, is estimated by the means of a quantitative and a qualitative determination of old and deadwood structures, which is consequently compared with the threshold value of 30 m3 deadwood per hectare for xylobionte insects as one of the most widespread species. In addition to rough estimations covering larger areas, detailed studies were carried out on a few selected sites. The resulting data will serve as the basis for long-term comparisons and are available for further studies. The approach presented here is to be understood as a cost-effective, practical application to evaluate success in other protected areas of forest.
Multifunctional regional forestry planning – Good practices and lessons learnt in Bulgaria
Authors: Stiptzov Vassil , Duerr Christoph
Published: June 2007

The present experiences with multifunctional regional forestry planning in six pilot areas of Bulgaria clearly indicate how different interest groups can actively participate in long-term forestry planning. These processes can play a guiding role for the general democratisation of municipalities, for a constructive collaboration with civil society, the private sector and state institutions. One condition for the effective implementation of the plans is the political will to set clear priorities for the multifunctionality of forests in order to provide appropriate financial resources for implementation together with a consistent controlling mechanism. Bilateral development cooperation between Bulgaria and Switzerland seeks to promote awareness amongst the actors, develop appropriate methodologies and educate and train stakeholders. What is still lacking in Bulgaria is the formulation of appropriate forestry legislation and guidelines for the preparation and implementation of the plans, an efficient monitoring system as well as the carefully formulated coordination with regional spatial development planning.
Untersuchungen zum Einfluss der thermischen Vorbehandlung auf das Sorptionsverhalten und ausgewählte mechanische Eigenschaften von Fichtenholz | Examinations of the influence of thermal treatment on certain mechanical properties of spruce (reviewed paper)
Authors: Bächle Fritz , Niemz Peter
Published: June 2007

A range of mechanical, physical and chemical properties were tested on spruce, which had been subjected to diverse thermal treatments. The results of the examination are presented in tables and graphic figures.
Von der waldbezogenen Umweltbildung zu einer waldbezogenen Bildung für eine nachhaltige Entwicklung – neue Wege für die Waldpädagogik | From a forest oriented environmental education to a forest-oriented education for sustainable development: New ways for forestry pedagogics (reviewed paper)
Authors: Kohler Beate , Bittner Alexander , Bögeholz Susanne
Published: June 2007

This paper analyses the requirements and the potential of forest education, taking into account the current discussions about Education for Sustainable Development(ESD).
Untersuchungen zur Feuchteverteilung und Spannungsausbildung in Holzbauteilen bei Wechselklimalagerung | Investigation of moisture distribution and stress formation in timber construction materials under changing climatic conditions
Authors: Niemz Peter , Bärtschi Hans , Howald Martin
Published: June 2007

The work examined the behaviour of moisture in three-layered,massive, 60 to 70 mm thick wood panels using various methods or diverse structures under climatic stress. In a first test samples were subjected to an alternating wet/dry climate,whereby the moisture was continuously measured for resistance in the outer and middle layer using an electric charge. At the end of each humid and dry phase the tension between the layers on some panels was determined by cutting them open. In addition the occurrence of cracks in the outer layers was recorded. In a second test a climatic difference with a cold and a warm side were carried out, whereby the moisture distribution in the three layers was continuously measured using an electric charge.
Untersuchungen zum Diffusionswiderstand von Holzwerkstoffen | Diffusion resistance of timber materials
Authors: Popper Rudolf , Niemz Peter , Eberle Gerhild
Published: June 2007

The water vapour diffusion resistance of timber materials were tested in a wet climate (relative humidity ranging from 100%to 65% at 20 °C) and in a dry climate (relative humidity ranging from 0% to 65% and from 0% to 35% at 20 °c) with variation by relative humidity and vapour pressure gradient. The diffusion resistance of multilayer solid wood panels lies under or within the range of the solid wood (spruce), tending even to a lower range. This can be attributed to the loosely inserted middle lamella of the used solid wood panels, which were not correctly glued by the manufacturer. The diffusion resistance of the solid wood panels increases with decreasing moisture content and decreasing panel thickness, as well as with increasing water vapour gradient from 818 to 1520 Pa. There were clear differences between the tested timber materials. The diffusion resistance of particle composites is strongly dependent on the specific gravity. Due to laminar particles OSBs(Oriented Strand Boards) have a larger diffusion resistance than chipboards. The water vapour diffusion resistance of OSBs lies within the range of plywood.
La sylviculture favorable au chêne, facteur majeur de la progression du Pic mar Dendrocopos medius en Suisse: Exemple du Bois du Devens (canton de Neuchâtel) | Silviculture that favours oak as a major factor in the expansion of the middle-spotted-woodpecker in Switzerland. Example of Bois du Devens (Canton Neuchâtel)
Authors: Junod Pascal , Mulhauser Blaise
Published: June 2007

The middle-spotted-woodpecker Dendrocopos medius, which was deemed to have disappeared from the littoral of Neuchâtel,is a species in full expansion today, particularly in the Bois du Devens (MULHAUSER & BLANT en prép.). Without differentiated silvicultural interventions-i.e. differentiated according to area-today this region would be dominated largely by the beech. The article presents the evolution of the forest Bois du Devens, the development of silvicultural practice during the 20th century and its effect on the expansion of the middlespotted-woodpecker. The analysis of the silviculture practised in this forest since 1920, fleshed out with the numerical basis of the silvicultural inventories, provides confirmation of the dependence of the middle-spotted-woodpecker on oaks of major dimensions, with a preference for highly fertile habitats and underlines the importance of mature forest stands. Such heterogeneous stands are rich in microstructures, cavity trees,big trees, trees that accomplish their full life cycle, as well as entire crowns that are left on the ground after trees have been cut.
KnowForAlp: Übergreifender Wissenstransfer zu Waldthemen im Alpenraum | KnowForAlp: Overlapping exchange of know-how on forestry in Alpine regions
Authors: Lässig Reinhard , Huber Gerhard , Detten Roderich Von , Hanewinkel Marc , Feichter Helmut , Moritzi Martin , Streckfuss Michael
Published: June 2007

The cold wind blowing in the face of forestry in many countries in Europe grows ever fiercer. 19 partner organisations from seven Alpine nations aim to counter this trend with a new initiative for an active transfer and exchange of know-how that crosses national borders. The concept of the KnowForAlp Initiative is a network that connects forest proprietors, research and practice. The new Internet portal, www.waldwissen.net,provides a wide circle of users interested in the forest-both within and from outside the Alpine regions-with results of the exchange of experience and information.
Der Einfluss von Aufnahmefehlern und Wachstumsvorgängen auf die Stammzahlverteilung in Buchennaturverjüngungen unter Altholzschirm: Vergleich eines naturnahen Buchenbestandes im Sihlwald, Schweiz, mit einem Bestand im Buchen-Urwald Uholka, Ukraine | The influence of survey errors and growth processes on stem distribution in young growth under old beech growth. Comparison of a close-to-nature beech stand in the Sihlwald, Switzerland and a virgin beech stand in the Uholka forest, Ukraine (reviewed paper)
Authors: Bachofen Hansheinrich
Published: June 2007

The young growth stem distributions in a 115 year old beech stand in the Sihlwald (Switzerland) and in a virgin beech stand in Uholka (Ukraine) show conspicuous sinks in the 130,0 to 169,9 cm tree height range. A model shows, that these sinks can be the result of height growth differences be tween trees in different height classes. Technical reasons of the surveys may accentuate the sinks. There may be more reasons which could play a role but these were not investigated.
FSC in der Schweiz: Über den Markt zu Nachhaltigkeit oderüber Nachhaltigkeit zum Markt? | FSC in Switzerland: Sustainability via the market,or the market via sustainability? (reviewed paper)
Authors: Bieri Luzia , Binder Claudia , Stauffacher Michael
Published: June 2007

At international level, FSC certification aims at a sustainable management of the forest. However, forest owners in Switzerland do not perceive it in this way, as Swiss forest law already regulates sustainable forestry. Interviews with forest owners and managers of the canton Zurich sho wed that the main reason for certifying the forest in Switzerland seems to be an economic one, namely to prevent future discrimination against own forest products in the market.
Die Entwicklung der Wälder auf der Schwägalp im 20. Jahrhundert und ihre Bedeutung für den Lebensraum des Auerhuhns (Tetrao urogallus L.) | Forest development on the Schwägalp in the 20th century and its significance for the habitat of capercaillie (Tetrao urogallus L.) (reviewed paper)
Authors: Fritsche Beat , Bollmann Kurt , Graf Roland F. , Bugmann Harald
Published: June 2007

Capercaillie populations in Switzerland declined significantly during the 20th century. The loss of suitable habitats is considered to be the main reason for this decline. For the Pre-Alpine region of the Schwägalp, aerial photographs and a statistic model were used to quantify changes in the availability and distribution of capercaillie habitat. We detected a loss of suitable habitats. However, this loss alone can not explain the extensive decline in the population of this endangered species.
Schälungen durch den Rothirsch: eine Fallstudie in den Nordostschweizer Voralpen | Bark stripping by red deer: a case study in the Pre-Alps of northeastern Switzerland
Authors: Rheinberger Christoph , Suter Werner
Published: June 2007

Bark stripping by deer and other mammals may not only impair the future quality of wood but also influence tree survival. Large-scale bark stripping can thus impact forest functions such as wood production and protection against natural hazards. As for now, research into causes of bark stripping behaviour has not led to a coherent functional understanding, although the behaviour is more common in artificial stands offering poor forage. The present study of intensive bark stripping in ash stands shows that such behaviour may also occur in deer wintering areas where habitat quality is supposed to be good.
Reboisement de sites pollués – Enseignements tirés d'une étude de cas avec des métaux lourds | Reforestation of polluted soils – results of a case study on heavy metals
Authors: Steiner Laure , Rosselli Walter , Combe Jean , Barbezat Vincent , Buttler Alexandre
Published: June 2007

Les Abattes (Le Locle, Canton Neuchâtel) is an ancient dump contaminated by metals, like thousands of others in Switzerland,which, according to the law, does not require a reclaiming. Local trees have been grown on this site and data have been collected for 15 years between 1991 and 2005. Lessons grown from this experience are mixed. The plantation has stabilised the soil physically and immobilised the metals more rapidly than natural pioneer plants would. However growing trees have not been able to extract enough metals from soil. The risk of a diffuse metal contamination of surface water and food chain is still present. Therefore reforestation of low-contaminated sites has to be seen as a temporary solution requiring a continuous supervision in a longterm. At best it could provide timber under certain conditions. It is recommended to clearly indicate these constraints in the forest guiding plans which are now being elaborated.
Robust predictive control of switched systems: Satisfying uncertain schedules subject to state and control constraints
Authors: Mhaskar Prashant , El‐Farra Nael H. , Christofides Panagiotis D.
Published: June 2007

In this work, we consider robust predictive control of switched uncertain nonlinear systems required to satisfy a prescribed switching sequence with uncertainty in the switching times subject to state and input constraints. To illustrate our approach, we consider first the problem of satisfying a prescribed schedule subject to uncertainty only in the switching times. Predictive controllers that guarantee the satisfication of state and input constraints from an explicitly characterized set of initial conditions are first designed. The performance and constraint‐handling capabilities of the predictive controllers are subsequently utilized in ensuring the satisfaction of the switching schedule while preserving stability. The results are then generalized to address the problem in the presence of parametric uncertainty and exogenous time‐varying disturbances in the dynamics of the constituent modes. The proposed control method is demonstrated through application to a scheduled chemical process example. Copyright © 2007 John Wiley & Sons, Ltd.
A nonlinear adaptive speed tracking control for sensorless permanent magnet step motors with unknown load torque
Authors: Tomei P. , Verrelli C. M.
Published: June 2007

Assuming that only stator currents and voltages are available for feedback, a nonlinear adaptive speed tracking control algorithm is proposed for a permanent magnet step motor with unknown constant load torque. It relies on three new theoretical results: the ‘s‐alignment’ and ‘c‐alignment’ procedures, in which the motor is forced to reach certain known equilibrium points, and an output feedback controller which guarantees asymptotic speed tracking for every initial condition belonging to an explicitly computed domain of attraction (global exponential convergence is achieved in the case of known constant load torque). Numerical simulation results illustrate the effectiveness of the proposed solution. Copyright © 2007 John Wiley & Sons, Ltd.
Ambipolar Transport in Organic Conjugated Materials
Authors: Cornil J. , Brédas J.‐L. , Zaumseil J. , Sirringhaus H.
Published: June 2007

The relative mobility of holes versus electrons in π‐conjugated materials is a long‐standing issue in the field of organic electronics. In this Progress Report, we first argue on the basis of theoretical considerations that in general organic semiconductors are intrinsically as good electron transporters as they are hole transporters. Then, in the light of selected experimental works, we discuss the origin of the features that prevent the observation of intrinsic electron transport, and the strategies that have been developed to promote ambipolar transport in field‐effect transistors.
Life history traits and parental care in Lepilemur ruficaudatus
Authors: Hilgartner Roland , Zinner Dietmar , Kappeler Peter M.
Published: June 2007

In this study we investigated the importance of biparental care for the evolution and/or maintenance of pair‐living in red‐tailed sportive lemurs (Lepilemur ruficaudatus), a nocturnal folivorous lemur. Between 2000 and 2005, we collected data on life history traits from a total of 14 radio‐collared pairs of adults and their offspring in Kirindy forest, western Madagascar. Predation rate varied between years with a minimum of 0% and a maximum of 40% per year. Patterns of parental care were quantified during simultaneous focal observations of both pair‐partners in 2003 and 2004. Mating activity was limited to the months of May and June, as indicated by conspicuous changes of vulval morphology and male mate guarding behavior. After a gestation length of about 5 months, which is much longer than expected for a lemur of this body mass, single infants were born in November. Lactation lasted for about 50 days. Apart from lactation, females provided infant care by warming, grooming and transporting infants orally. Infants were parked in dense vegetation while females foraged. Males were seen only rarely in proximity to infants and we found no evidence for direct infant care provided by social fathers. We conclude that the necessity of direct infant care cannot explain the evolution and/or maintenance of pair‐living in Lepilemur ruficaudatus. Am. J. Primatol. 70:2–11, 2008. © 2007 Wiley‐Liss, Inc.
Sex, age, and family differences in the chemical composition of owl monkey (Aotus nancymaae) subcaudal scent secretions
Authors: MacDonald Edith A. , Fernandez‐duque Eduardo , Evans Sian , Hagey Lee R.
Published: June 2007

Numerous behavioral studies have shown that animals use olfactory cues as inbreeding avoidance or kin avoidance mechanisms, implying that scent is unique to families. However, few studies have analyzed the chemical profile of a scent and ascertained the messages that are conveyed in scent secretions. Owl monkeys (Aotus nancymaae) are socially monogamous primates that utilize scent when interacting with foreign conspecifics. This suggests there is a difference in the chemical composition of scent marks. We chemically analyzed sub‐caudal gland samples from three families of captive owl monkeys (Aotus nancymaae). Samples were analyzed by capillary GC‐MS and relative retention time and fragment pattern was compared with known standards. Gland samples were high in large plant‐based shikikate metabolites and fatty ketones; alcohols, acids, and acetates were virtually absent. Gender, age, and family could be reliably classified using discriminant analysis (92.9, 100, and 100%, respectively). Female scent profiles were greater in concentration of aromatic plant metabolites, possibly the result of a different diet or physiological differences in female metabolism as compared to male. Offspring of adult age still living in their natal group showed a less complex chemical profile than their parents. Finally, each family had its own unique and complex chemical profile. The presence of family scent may play a role in mediating social interactions. Am. J. Primatol. 70:12–18, 2007. © 2007 Wiley‐Liss, Inc.
Female ovarian cycle phase affects the timing of male sexual activity in free‐ranging Barbary macaques (Macaca sylvanus) of Gibraltar
Authors: Heistermann Michael , Brauch Katrin , Möhle Ulrike , Pfefferle Dana , Dittami John , Hodges Keith
Published: June 2007

Although all macaques have a multimale multifemale mating system, the degree of promiscuity shown by the Barbary macaque is considered to be extreme in terms of both mating frequency and number of mating partners. How mating activity is distributed throughout the female menstrual cycle and whether or not copulations are concentrated around the fertile phase as in other members of the genus is, however, not known. To examine this, we collected data on rates of copulation throughout 29 ovarian cycles from 13 free‐ranging females of the Gibraltar Barbary macaque population and related them to the time of ovulation and the female fertile phase as determined from fecal hormone analysis. In addition, patterns of male inspection of females and time spent in consortship, both indicators of female attractivity, were also analyzed. The results indicate that both mating behavior and female attractivity vary predictably with ovarian cycle stage. Rates of copulation were found to increase toward the time of ovulation, with a distinct peak of ejaculatory (but not non‐ejaculatory) copulations occurring in the fertile phase. Additionally, we show that frequency of inspection of females by males and time spent in consortship were also highest during the fertile phase and that ejaculatory copulations and male pericopulatory behaviors were significantly correlated with levels of female sex hormones. Our findings indicate that the Barbary macaque shows a mating pattern during the cycle similar to that described for other members of the genus. More importantly, however, our study provides clear evidence that despite an extreme degree of promiscuity Barbary macaque males concentrate their reproductive effort to the fertile phase, implying that they are able to discern this period and that thus timing of ovulation is not concealed from them. Estrogen‐related cues appear to be involved in the process of recognition of female reproductive status by males, but the exact nature of these cues and how male Barbary macaques use them remains to be clarified. Am. J. Primatol. 70:44–53, 2008. © 2007 Wiley‐Liss, Inc.
Nonlinear surface electrical resistivity of graphite–polyurethane composite films
Authors: Kannarpady Ganesh K. , Mohan Bharath , Bhattacharyya Abhijit
Published: June 2007

In this article, we study the surface resistivity of graphite–polyurethane composites using voltage–current characteristics. The evolution of the percolation network of graphite in polyurethane is qualitatively studied using optical micrographs. As expected, the surface resistivity decreases as a function of graphite concentration. In particular, the surface resistivity of the 69% graphite–polyurethane composite is about four orders of magnitude lower than the surface resistivity of the 27% graphite–polyurethane composite. The electrical resistivity of the composite is found to be highly nonlinear with respect to an increasing voltage at a low graphite weight fraction. On the other hand, the nonlinearity is significantly milder at higher weight fractions. The reasons behind the nonlinearity are discussed. Very preliminary studies indicate that very low weight fractions of single wall carbon nanotubes (e.g. 2.5%) are sufficient to generate electrical conductivities comparable to much higher loading fractions (∼ 60% and higher) of the heavier graphite particles. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Dielectric studies of conductive carbon black reinforced microcellular ethylene–propylene–diene monomer vulcanizates
Authors: Mahapatra S. P. , Sridhar V. , Tripathy D. K.
Published: June 2007

The alternating‐current and electrical conductivity of conductive, carbon black reinforced, microcellular ethylene–propylene–diene monomer vulcanizates was measured in the frequency range of 100 Hz to 1 MHz. The effects of variations in the filler and blowing‐agent loadings on the dielectric constant and percolation behavior were studied. The phenomenon of percolation was examined on the basis of measured changes in the electrical conductivity and morphology of composites with different concentrations of the filler. Scanning electron microphotographs showed the agglomeration of the filler above these concentrations and the formation of a continuous network structure. The experimental results were not in agreement with the predictions of the statistical percolation theory; this deviation was explained in light of the formation of an interphase or mesostructure in the composites. The variation of the dielectric constant with the filler and blowing‐agent loadings was explained on the basis of polarization of the filler in the polymer matrix. Additionally, the use of dielectric mixture laws in describing the dielectric constants of both solid and microcellular composites was investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007