bluuebunny/crossref_metadata_2025 huggingface dataset:
A reliability study of the lightning locating network in British Columbia
Authors: Gilbert David E. , Johnson Bruce R. , Zala Cedric
Published: April 2008

To combat the major problem of lightning-caused forest fires in British Columbia, the British Columbia Ministry of Forests operates a lightning locating system developed by Lightning Location and Protection Inc. As of 1985, this network consisted of 18 magnetic direction finders located throughout the province. Lightning strike data collected by the network over three fire seasons (1983–1985) were analyzed to estimate the distribution of lightning signal strength and the component detection efficiencies. The analysis was based on more than 165 000 lightning strike records. In the mountainous terrain of British Columbia, the detection efficiencies of the lightning sensors were found to be somewhat lower than earlier results obtained from similar networks in Florida and Oklahoma. Corrective actions have been taken on five detector sites found to have significantly worse than average detection efficiencies. A long-range program to improve the system by refurbishing with upgraded equipment and adding several new detector sites is under way. The statistical results vividly demonstrate the importance of archiving and analyzing the lightning strike data to provide comprehensive local-environment field tests. In future years the data preparation and analysis techniques will be implemented annually.
Stem electrical capacitance and resistance measurements as related to total foliar biomass of balsam fir trees
Authors: MacDougall R. Glenn , Thompson R. G. , Piene Harald
Published: April 2008

Bioelectrical capacitance and resistance measurements of balsam fir trees were taken periodically over a 2-year study and correlated with total foliar biomass. Results indicate that both methods are useful in the estimation of foliar biomass when measurements are taken over a long period and then averaged. One time only measurements, or measurements performed during specific daily periods, results in better correlations between capacitance and foliar biomass than between resistance and foliar biomass.
Reactivation of vessel expansion in relation to budbreak in sycamore (Acerpseudoplatanus) trees
Authors: Denne M. P. , Atkinson C. J.
Published: April 2008

The origin and progress of production of the first vessels of the new growth ring has been followed within trees of sycamore (Acerpseudoplatanus L.) and compared with stages of bud and shoot development within the crown and with variation in temperature at bud level. Reactivation of vessel expansion originated at the bud base when the bud had elongated 50% over dormant length; this stage of budbreak was delayed by 2 days for each metre up the crown. Vessel expansion did not appear to progress actively down branches until the leaf tips began to emerge. Changes in carbon partitioning may suggest that this lag period is associated with the importing phase of bud growth, progress beginning when the leaves become self-sufficient in assimilates. After the lag period, progress of vessel expansion down the branches was estimated to be about 3 cm day−1. Expanding vessels reached the trunk first in upper or middle crown, while the predetermined leaves of the lower and middle crown buds were expanding. Vessel expansion progressed more rapidly down the trunk than down branches; the predetermined leaves of the lower to middle crown had fully expanded by the time vessel expansion reached the base of the trunk.
Germination and early growth of four pine species on soil treated with simulated acid rain
Authors: Schier George A.
Published: April 2008

The effect of simulated rain solutions of pH 5.6, 4.0, or 3.0 [Formula: see text] on seed germination and early seedling growth of pitch pine (Pinusrigida Mill.), shortleaf pine (P. echinata Mill.), loblolly pine (P. taeda L.), and eastern white pine (P. strobus L.) was observed in a growth chamber on unsterilized soil from the New Jersey Pine Barrens that had been treated for 1 year with the acid rain solutions. Damping-off caused the death of all seedlings in the pH 3.0 treatments. Autoclaving the soil controlled damping-off. However, chemical changes in the soil increased the solubilities of mineral elements, and at pH 3.0 Al toxicity inhibited root growth of pitch pine and shortleaf pine. In spite of suppressed root growth, seedling top growth was significantly greater at pH 3.0 than at less acid treatments possibly owing to greater inputs of N and increased availability of mineral nutrients.
Influence of humidity and temperature during exposure on SO2-induced leaf necrosis of Virginia pine and river birch
Authors: Umbach D. M. , Davis D. D.
Published: April 2008

River birch and Virginia pine seedlings were exposed to 0.8 or 1.0 ppm SO2 (approximately 2100 and 2600 μg m−3, respectively) for 4 h at temperatures of 16, 24, and 32 °C and at relative humidities of 60, 75, and 90%, in all combinations. Virginia pine seedlings exhibited increased SO2-induced leaf necrosis with increasing temperature and with increasing humidity. For greenhouse-grown Virginia pine seedlings, the relationship between leaf necrosis and vapor pressure deficit was linear with a common negative slope but with different intercepts for each temperature. For Virginia pine seedlings grown outdoors, the relationship between leaf necrosis and vapor pressure deficit was also linear, but both slope and intercept changed with temperature. For river birch, temperature did not greatly affect the overall level of injury; instead, the response to humidity was negligible, linear, or quadratic, depending on temperature and on the conditions under which seedlings were grown. The effects of temperature and humidity on injury to Virginia pine are consistent with an explanation based on changes in leaf conductance; however, such an explanation cannot easily account for the observed response of river birch.
Variation patterns and age relationships of wood density in families of jack pine and black spruce
Authors: Villeneuve M. , Morgenstern E. K. , Sebastian L. P.
Published: April 2008

Increment cores were analyzed in the laboratory to determine variation in wood density from pith to bark in plantations of black spruce (Piceamariana (Mill.) B.S.P.) and jack pine (Pinusbanksiana Lamb.). The sample consisted of 12 open-pollinated families of 20-year-old black spruce and 10 of 22-year-old jack pine. The prediction of future wood density appears possible at ages 6–7 in jack pine and 12–15 in black spruce. For jack pine, narrow-sense heritabilities ranged from 0.49 to 0.93 on an individual tree basis and from 0.55 to 0.73 on a family basis.
Partial cutting lodgepole pine stands to reduce losses to the mountain pine beetle
Authors: McGregor Mark D. , Amman Gene D. , Schmitz Richard F. , Oakes Robert D.
Published: April 2008

Partial cutting prescriptions were applied in the fall of 1978 through the early winter of 1980 to lodgepole pine stands (Pinuscontorta Douglas var. latifolia Engelmann) threatened by mountain pine beetle (Dendroctonusponderosae Hopkins) in the Kootenai and Lolo National Forests in western Montana, U.S.A. Partial cutting prescriptions consisted of removing from separate stands all trees 17.8, 25,4, and 30.5 cm and larger diameter at breast height (dbh), and prescriptions leaving 18.4, 23.0, and 27.6 m2 basal area per hectare. In thinned stands, the first 5 years' results following cutting showed greatly reduced tree losses to mountain pine beetle when compared with untreated stands (P < 0.01) on both forests. There were no significant differences in tree losses among partial cut treatments (P > 0.05). Post treatment mortality of lodgepole pine 12.7 cm and larger dbh to mountain pine beetle averaged 4.0 to 38.6% on the Kootenai and 6.0 to 17.1% on the Lolo in treated stands, compared with averages of 93.8 and 73.1% in untreated stands. Partial cutting appears to be useful for reducing lodgepole losses to mountain pine beetle.
Sample size for foliar analyses of coastal Douglas-fir
Authors: Marshall P. L. , Jahraus K.
Published: April 2008

Coefficients of variation were calculated for 17 foliar elements or element ratios in 10 stands of Pseudotsugamenziesii var. menziesii (Mirb.) Franco in the Vancouver Forest Region of British Columbia. These were found to vary widely between elements and, in some cases, between stands. Sample sizes necessary to produce estimates of mean foliar element concentrations within specified error limits under various α and β significance levels and estimates of coefficient of variation were calculated. Concentration of the least variable foliar elements (N, P, S, and K) could be estimated to within 10% with a sample of 21 trees and within 5% with a sample of 68 trees, assuming average coefficients of variation for each nutrient and α and β significance levels of 0.95. The variability reported in this study can be used to determine sample sizes for operational diagnoses of foliar element concentration if pilot samples are prohibitively expensive. A pilot sample should be used in conjunction with explicit β significance levels when determining foliar sample size for research purposes, especially if the samples are to be composited prior to chemical analysis. Analysis of the interrelationships between final sample size, pilot sample size, maximum desirable sampling error, and significance levels can provide the sample designer with information useful for the design of an efficient sample.
Genetic variation in response to soil types and phosphorus fertilizer levels in tamarack families
Authors: Wanyancha J. M. , Morgenstern E. K.
Published: April 2008

The response of 10 open-pollinated tamarack (Larixlaricina (Du Roi) K. Koch) families to three soil types and three phosphorus fertilizer levels was investigated in a greenhouse for 26 weeks. Characters assessed included height, root collar diameter, dry weights, and phosphorus concentration and accumulation. Estimates of variance components and stability parameters were made. Variation due to soil types, phosphorus treatments, and families was significant for all characters. The family × soil interaction was not significant for any character. The family × phosphorus interaction was significant in some cases, but its magnitude was relatively small. In comparison to earlier studies with nitrogen, genetic differentiation in response to phosphorus is less pronounced.
Coarse woody debris in mixed-conifer forests, Sequoia National Park, California
Authors: Harmon Mark E. , Cromack Jr. Kermit , Smith Bradley G.
Published: April 2008

The decay rate of Abiesconcolor (Gord. & Glend.) Lindl. logs and cover, mass, and volume of logs and snags in six midelevational forest stands of Sequoia National Park, California, are reported. Based on a chronosequence, Abiesconcolor boles have a decay rate-constant of 0.05 year−1 and a half-life of 14 years. A decay classification system was developed for Abiesconcolor, Calocedrusdecurrens (Torr.) Florin, Pinusjeffreyi Grev. & Balf., and Pinuslambertiana Dougl. logs. Dimensions taken from maps of six permanent plots were combined with decay-class information to estimate volume, mass, and projected cover of logs and snags. Total mass ranged from 29 Mg ha−1 in a Pinusjeffreyi forest to 400 Mg ha−1 in a Sequoiadendrongiganteum (Lindl.) Buchh. dominated stand. Volume, projected cover, and nitrogen storage exhibited patterns similar to mass, ranging from 84 to 1160 m3 ha−1, 3.1 to 9.3%, and 41 to 449 kg ha−1, respectively.
Growth losses from winter drying (red belt damage) in lodgepole pine stands on the east slopes of the Rockies in Alberta
Authors: Bella I. E. , Navratil S.
Published: April 2008

Red belt damage (reddening and death of foliage) occurs frequently in lodgepole pine Pinuscontorta var. latifolia Engelm. stands between certain elevations and may affect tree growth and even cause mortality. We examined growth impact in four pine stands (10, 55, 90, and 115 years old) where nearly all trees showed symptoms of damage. On young trees, visible damage ranged from 0 to 80% of foliage, and averaged about 35%. A highly significant reduction in height growth and terminal bud length (p < 0.01) of young trees was proportional to the amount of damage. As much as two-thirds growth loss occurred in trees with 60% or more necrotized foliage. On intermediate and mature lodgepole pine, reduction of annual volume increment in the growing season following damage was variable and reached as high as 50%, with no further significant reduction occurring in subsequent years. Potential yield losses at rotation age and forest management prescriptions for susceptible stands are presented.
Performance in freezing tests and field experiments of full-sib families of Pinussylvestris (L.)
Authors: Nilsson Jan-Erik , Andersson Bengt
Published: April 2008

Full-sib families from plus trees of Pinussylvestris (L.) were tested in four 10-year field experiments and three 1-year experiments. Survival and height were assessed in the field experiments and plant height, dry matter content, and damage following artificial freeze testing during the hardening process in the 1-year experiments. Positive correlations between pairs of field experiments were found for breeding values for 10-year survival (rmean = +0.71) and 10-year height (rmean = +0.38). Positive correlations were also obtained between survival and height within field experiments. Breeding values for 10-year field survival and height were not correlated with the latitude of origin. Positive correlations were found between field mortality and both damage after freeze testing (0.61 < r < 0.85) and plant height (r = 0.75) for the 1-year-old seedlings. Results indicated that a low degree of damage after freeze testing of 1-year-old progenies is a better predictor of field survival than is northern geographical origin when establishing seed orchards of P. sylvestris for harsh areas in north Sweden.
Root systems of older immature hemlock, cedar, and Douglas-fir
Authors: Eis S.
Published: April 2008

Root systems of eight western hemlock (Tsugaheterophylla (Raf.) Sarg.), eight western red cedar (Thujaplicata Donn.), and six Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) trees, average age about 50 years, average dbh 26.3 cm, were hydraulically excavated. The sizes and shapes of the root systems are given and the root systems and roots are described. Fresh and dry weights of roots of all vegetation averaged 36 and 14 t/ha and were similar for all three species. Fine absorbing roots were distributed mainly in the organic horizon and immediately below it, i.e., in the top 10 or 15 cm of the soil; their turnover appears rapid. Their ovendry weight averaged 210 g/m2 and their length averaged 4 km/m2.
Top pruning Douglas-fir seedlings: morphology, physiology, and field performance
Authors: Duryea Mary L. , Omi Steven K.
Published: April 2008

Seedlings from nine Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seed sources were top pruned at six nurseries in the Pacific Northwest and then planted at field sites in their own seed zones and on one common site. Seedlings pruned tall (25 cm) and early in the growing season flushed again about 5 weeks after pruning and set bud 2 weeks later than unpruned controls. Nursery yield (number of shippable seedlings) was the same for tall–early pruned and control seedlings; however, pruning increased the number of seedlings with multiple leaders from 10 to 38%. Pruned seedlings were smaller than unpruned seedlings in height, stem diameter, bud length, and root and shoot weights at the time of field planting. First-year field survival and growth were the same for pruned and unpruned seedlings at all planting sites. Second-year field growth of pruned seedlings was generally greater than that of unpruned seedlings, and frequency of multiple leaders was reduced. However, pruned seedlings were still shorter than unpruned ones after 2 years. Field growth was greater when seedlings were pruned early rather than late (end of growing season) and tall rather than short (15 cm). Late–short pruning yielded shorter seedlings with smaller terminal buds and should be avoided. If pruning benefits nurseries by expediting grading, handling, and planting and, perhaps, enhancing growth later in the field, it should be continued as a cultural practice. However, longer-term measurements are needed for assessing the full effect of pruning on seedling growth.
Aboveground nutrient distribution within trees and stands in thinned and fertilized Douglas-fir
Authors: Pang P. C. , Barclay H. J. , McCullough K.
Published: April 2008

The aboveground distribution of five elemental nutrients (N, P, K, Ca, Mg) among seven tree components was studied in Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) 9 years after thinning and urea fertilization at Shawnigan Lake, British Columbia. Thinning increased the concentration of N but decreased Mg within trees and increased the total gain in weight per hectare of all elements. Fertilization reduced the concentration of N, P, and K within trees after 9 years but increased the total weight per hectare of all elements except P. Each element was distributed heterogeneously among seven components of the trees.
Growth intercepts for estimating site quality of young white spruce plantations in north central Ontario
Authors: Thrower James S.
Published: April 2008

Growth intercepts were used to estimate site index (defined as height of the trees 15 years after breast height (1.3 m) was attained) of dominant, planted white spruce (Piceaglauca (Moench) Voss) in north central Ontario. The growth intercepts were computed using four methods to select internode lengths from series of one through seven internodes, starting at each of eight heights from 0 to 3.0 m. Precision increased rapidly with more internodes and higher starting heights but quickly slowed to only marginal increases. Removing the smallest internode increased precision when growth intercepts started below 1.3 m. Removing the largest and both the smallest and largest internodes reduced precision from all starting heights. The most precise and practical growth intercepts used the average length of the first three, four, and five internodes above 2.0 m, explaining 83, 85, and 89% of the variation in site index, respectively.
The acceleration of jack pine seed development
Authors: Cecich Robert A. , Bauer Edmund O.
Published: April 2008

The time from emergence of an ovulate strobilus to collection of viable seeds can be reduced to as little as 9 months instead of the usual 16 months spread over two growing seasons. The procedure is called the "shortened reproductive cycle." Two-year-old jack pine (Pinusbanksiana Lamb.) seedlings, grown under accelerated growth conditions, were brought into a greenhouse in the fall, where the environment simulated natural photoperiod and temperature conditions encountered during a growing season, including the approach of fall and winter. Ovulate strobili that subsequently emerged were pollinated and "2nd-year" cones, derived from those strobili, were collected the following September. The yield of filled seeds per cone was low and germination success was variable. The seedlings derived from the shortened reproductive cycle appeared to be normal and produced their own ovulate strobili 14 months after germination. Exposure to the greenhouse environment stimulated pollen production but decreased production of ovulate strobili 1 year after transplanting to the nursery. Flowering during the shortened reproductive cycle procedure was further promoted with gibberellin A4/7 application at the end of terminal shoot elongation in the greenhouse during the winter. Ovulate strobili were observed 6 months later in the nursery.
Long-shoot bud development, shoot growth, and foliage production in provenances of lodgepole pine
Authors: O'Reilly Conor , Owens John N.
Published: April 2008

Long-shoot bud development, shoot growth, and foliage production were studied in seven provenances of Pinuscontorta Dougl. ssp. latifolia Engelm. from the major sites in British Columbia and one Yukon source growing in a provenance trial at Prince George, B.C. Branch terminal apical mitotic activity began in early March and continued until late September. Initiation of axillary buds began in May, about 2 weeks after the initiation of the subtending cataphyll. Differentiation of dwarf shoots began in early July to mid-August and continued until late October in some sources. Distal axillary buds had not always differentiated by late October in the southern sources. The duration of the period of apical growth and apical size during activity were related to final cataphyll numbers. Provenances with the widest, flattest, dormant apices produced the most cataphylls. The two northern provenances had more terminal sterile cataphylls but fewer sterile cataphylls lower in the long-shoot bud and shorter mean stem unit lengths than the others. Differences among provenances in shoot length were due mostly to variation in stem unit numbers. The large proportion of polycyclic long shoots in some provenances contributed to variation in dwarf shoot numbers.
Early progeny testing and evaluation of controlled crosses of black spruce
Authors: Williams Dianne J. , Dancik Bruce P. , Pharis Richard P.
Published: April 2008

Known parent F1 crosses of black spruce (Piceamariana (Mill) B.S.P.) were ranked in field progeny tests at ages 7 to 13 years for height and stem volume growth. Nine crosses, including two selfs, were chosen for early juvenile progeny testing in a glasshouse environment. Performance of early seedling growth for the same nine families grown under both field and glasshouse conditions were thus compared in a retrospective study. Juvenile–mature correlations were established between a number of traits associated with tree growth and vigor. Within the nine families there was a ranking from "fast"- to "slow"-growing family groups. Monthly measurements of morphological characters at ages 3 to 6 months in the glasshouse showed highly significant family variation for total height, root collar diameter, lateral branch number, needle number, volume, branch length, and shoot, root, and total seedling dry weights. Weekly application of gibberellin A4/7(GA4/7) beginning at age 3 months influenced 5- and 6-month shoot volume and shoot height, and final dry weight measurements (age 6 months). Height growth of the four slowest growing families (two outcrossed, two selfed) was significantly (P ≤ 0.05) increased by GA4/7 application, but the hormone had no significant effect on height growth of the five faster-growing families (all out-crossed). This may indicate that endogenous gibberellins are not limiting for height growth of faster growing families, but may be limiting for height growth of slower growing families. Simple correlations were highly significant between age 7 to 13 years for field height measurements, and 13-year field volume, versus glasshouse height, stem volume, and the several dry weight measurements at age 6 months. Similarly, Spearman rank order correlations were also significant. These strong correlations between early growth in the glasshouse environment and that of field growth (age 7 to 13 years) suggest that the poorest growing crosses can be identified in a juvenile growth progeny tets under glasshouse conditions by at least age 6 months. Rogueing of the poorest performers as a result of glasshouse testing would thus be at least as reliable as rogueing based on 13 years of field assessment. Selected families for such tests should of course come from similar latitudes and elevations
Interval estimation of operational availability of tree harvesting machines
Authors: Meng C. H. , Tang S. Z.
Published: April 2008

The Canadian Pulp and Paper Association has defined the operational availability of a piece of logging equipment as A = (T − M − D)/T, where T denotes total scheduled machine hours per day, M denotes maintenance hours per day, and D denotes machine downtime per day. The existing literature on logging machines contains only point estimates of the mean operational availability. This paper propounds interval estimation as a preferable alternative since, unlike point estimation, it provides an indication of the uncertainty involved. Two methods of interval estimation are developed: (i) an analytical approach derived from basic theories and (ii) a Monte Carlo simulation. A detailed example is given to demonstrate the application of both methods to the same logging machine. For situations in which theoretical distributions for downtimes and repair times can be assumed, analytical solutions provide general and exact answers for the interval estimate of machine operational availability. However, if theoretical distributions cannot be reasonably assumed and if the integration involved is difficult, the analytical procedures become difficult. In such cases, operational availability can be approximated by the method of Monte Carlo simulation.
Allozyme variation in Piceamariana from Newfoundland: Discussion
Authors: Critchfield William B.
Published: April 2008

not available
LEARNING BY CRITERION OPTIMIZATION ON A UNITARY UNIMODULAR MATRIX GROUP
Authors: FIORI SIMONE
Published: April 2008

The present manuscript aims at illustrating fundamental challenges and solutions arising in the design of learning theories by optimization on manifolds in the context of complex-valued neural systems. The special case of a unitary unimodular group of matrices is dealt with. The unitary unimodular group under analysis is a low dimensional and easy-to-handle matrix group. Notwithstanding, it exhibits a rich geometrical structure and gives rise to interesting speculations about methods to solve optimization problems on manifolds. Also, its low dimension allows us to treat most of the quantities involved in computation in closed form as well as to render them in graphical format. Some numerical experiments are presented and discussed within the paper, which deal with complex-valued independent component analysis.
GLOBAL DYNAMICS OF A CLASS OF COMPLEX VALUED NEURAL NETWORKS
Authors: SREE HARI RAO V. , MURTHY GARIMELLA RAMA
Published: April 2008

In this paper activation dynamics of a complex valued neural network has been studied. Sufficient conditions for global exponential stability of a unique equilibrium are obtained. Our results show that in the serial mode of operation, the network converges to a stable state.
FREQUENCY-MULTIPLEXING ABILITY OF COMPLEX-VALUED HEBBIAN LEARNING IN LOGIC GATES
Authors: KAWATA SOTARO , HIROSE AKIRA
Published: April 2008

Lightwave has attractive characteristics such as spatial parallelism, temporal rapidity in signal processing, and frequency band vastness. In particular, the vast carrier frequency bandwidth promises novel information processing. In this paper, we propose a novel optical logic gate that learns multiple functions at frequencies different from one another, and analyze the frequency-domain multiplexing ability in the learning based on complex-valued Hebbian rule. We evaluate the averaged error function values in the learning process and the error probabilities in the realized logic functions. We investigate optimal learning parameters as well as performance dependence on the number of learning iterations and the number of parallel paths per neuron. Results show a trade-off among the learning parameters such as learning time constant and learning gain. We also find that when we prepare 10 optical path differences and conduct 200 learning iterations, the error probability completely decreases to zero in a three-function multiplexing case. However, at the same time, the error probability is tolerant of the path number. That is, even if the path number is reduced by half, error probability is found almost zero. The results can be useful to determine neural parameters for future optical neural network systems and devices that utilize the vast frequency bandwidth for frequency-domain multiplexing.
ONLINE DETECTION OF THE MODALITY OF COMPLEX-VALUED REAL WORLD SIGNALS
Authors: MANDIC DANILO P. , VAYANOS PHEBE , CHEN MO , GOH SU LEE
Published: April 2008

A novel method for the online detection of the modality of complex-valued nonlinear and nonstationary signals is introduced. This is achieved using a convex combination of complex nonlinear adaptive filters with different transient characteristics. To facilitate the online mode of operation, the convex mixing parameter λ within the proposed architecture is made gradient adaptive. Our focus is on the most important aspect of complex nonlinear modeling, that is, the identification of the split-complex and fully-complex nature of the signal in hand. The algorithms derived are robust and capable of tracking the changes in the modality of both benchmark and real world radar and wind complex vector fields.
EXISTENCE OF FINITE ENERGY SOLUTIONS FOR ELLIPTIC SYSTEMS WITH L1-VALUED NONLINEARITIES
Authors: BOCCARDO LUCIO , ORSINA LUIGI , PORRETTA ALESSIO
Published: April 2008

In this paper, we are going to study the following elliptic system: [Formula: see text] where Ω is a bounded open subset of ℝN, a(x, s) and b(x, s) are positive and coercive Carathéodory functions, and f ∈ LM(Ω). The main purpose of this paper is to prove existence and regularity results with an improved regularity of the function z in the class of Sobolev spaces, and the existence of solutions (u, z) both with finite energy.
A MULTICRITERIA SYSTEM USING GRADUAL FUZZY RULES AND FUZZY ARITHMETIC
Authors: SANDRI SANDRA , SIBERTIN-BLANC CHRISTOPHE
Published: April 2008

We present a multicriteria fuzzy system that uses fuzzy gradual rules bases to model the user's preferences and fuzzy arithmetic to aggregate the results issued by the bases. We first present a multicriteria problem and its solution for the case of precise information. Then we extend the model to treat pieces of information that may involve imprecision/vagueness. We show that the use of residuated implication operators (employed by gradual rules), coupled with similarity relations (to guarantee consistency), offer a better treatment of the problem than a Mamdani-like approach. We illustrate the various features of the system by means of a simple example and describe an application of the formalism to social games.
ON THE COMPARISON OF GENERIC INFORMATION LOSS MEASURES AND CLUSTER-SPECIFIC ONES
Authors: LADRA SUSANA , TORRA VICENÇ
Published: April 2008

Masking methods are to protect data bases prior to their public release. They mask an original data file so that the new file ensures the privacy of data respondents. Information loss measures have been developed to evaluate in which extent the masked file diverges from the corresponding original file, and in what extent the same analyses on both files lead to the same results.

Generic information loss measures ignore the intended data use of the file. These are the standard measures when data has to be released (e.g. published in the web) and there is no control on what kind of analyses users would perform. In this paper we study generic information loss measures, and we compare such measures with respect to cluster-specific ones. That is, measures specifically defined for the case in which the user will do clustering with the original data. To do so, we define such measures and then we do an extensive comparison of the two measures.

The paper shows that the generic measures can cope with the information loss related to clustering.
HOW TO GROUP ATTRIBUTES IN MULTIVARIATE MICROAGGREGATION
Authors: NIN JORDI , HERRANZ JAVIER , TORRA VICENÇ
Published: April 2008

Microaggregation is one of the most employed microdata protection methods. It builds clusters of at least k original records, and then replaces these records with the centroid of the cluster. When the number of attributes of the dataset is large, one usually splits the dataset into smaller blocks of attributes, and then applies microaggregation to each block, successively and independently. In this way, the effect of the noise introduced by microaggregation is reduced, at the cost of losing the k-anonymity property.

In this work we show that, besides the specific microaggregation method, the value of the parameter k and the number of blocks in which the dataset is split, there exists another factor which influences the quality of the microaggregation: the way in which the attributes are grouped to form the blocks. When correlated attributes are grouped in the same block, the statistical utility of the protected dataset is higher. In contrast, when correlated attributes are dispersed into different blocks, the achieved anonymity is higher, and so, the disclosure risk is lower. We present quantitative evaluations of such statements based on different experiments on real datasets.
LARGE AREA GaN METAL SEMICONDUCTOR METAL (MSM) PHOTODIODE USING A THIN LOW TEMPERATURE GaN CAP LAYER
Authors: CHUAH L. S. , HASSAN Z. , ABU HASSAN H. , CHIN C. W. , THAHAB S. M.
Published: April 2008

Small area metal semiconductor metal (MSM) photodiode (PD) has been one of the most favoured detector choices for high speed optoelectronics integrated circuits due to their low parasitic capacitance and simple planar device structure, which is compatible with FETs. Large MSM PDs, on the other hand, can also be useful in many network and interconnect applications such as fibre distributed data interfaces.

An MBE grown GaN metal semiconductor metal photodiode with a thin low temperature GaN (50nm) barrier enhancement layer is reported, which has low dark current. The detector using Nickel ( Ni ) Schottky metal fingers with 400 μm spacing on a large active area exhibit a low dark current of 1.23 mA at 10 V bias, which is about three orders of magnitude lower than that of the normal GaN Schottky photodiode.
BAND NARROWING AND GAIN SPECTRA OF LASER DYE SOLUTIONS WITH SCATTERING TiO2 NANOPARTICLES
Authors: BLINOV L. M. , CHIDICHIMO G. , CIPPARRONE G. , PAGLIUSI P. , RUGIERO T.
Published: April 2008

The spectra of amplified spontaneous emission (ASE) intensity and gain have been measured for solutions of laser dye Rhodamine-640 in glycerin with light scattering TiO 2 nanoparticles. Such solutions typically manifest random lasing in backscattering geometry. In this work, the conventional transverse pump geometry is used, and the ASE gain spectra are measured using a variation of the length of the illuminated (pumped) stripe. In this geometry, with increasing concentration of nanoparticles, the "unidirectional" gain along the stripe decreases dramatically. At the same time, strong narrowing of the ASE bandwidth is observed even in the absence of net gain. The experimental results help one to understand the role of the scattering particles in the light amplification. On the one hand, the particles increase a zigzag type of the light path within the amplifying medium, which results in bandwidth narrowing and strong amplification of chaotic light beams. On the other hand, the amplification of a seed beam propagating in a selected direction is dramatically suppressed. The results are discussed using simple modeling of ASE amplification and qualitative arguments.
ELECTRICAL SPIN INJECTION FROM AN IRON-RICH IRON–PLATINUM THIN FILM INTO GALLIUM ARSENIDE
Authors: SINSARP ASAWIN , MANAGO TAKASHI , TAKANO FUMIYOSHI , AKINAGA HIRO
Published: April 2008

We fabricated an FePt / MgO tunneling junction ( Fe 55 atomic %) on a GaAs -based light-emitting-diode structure. The out-of-plane magnetization of the FePt thin film was confirmed by a magneto-optical measurement. The electrical spin injection from FePt into GaAs at room temperature was studied using the technique of spin-polarized electroluminescence. The spin polarization of the injected electrons under the magnetic field of 1 T was at least 6.0%. The remnant polarization at 0 T, which indicates the spin injection without a magnetic field, was at least 3.3%.
NASH EQUILIBRIA IN UNCONSTRAINED STOCHASTIC GAMES OF RESOURCE EXTRACTION
Authors: BALBUS ŁUKASZ , NOWAK ANDRZEJ S.
Published: April 2008

A class of nonzero-sum symmetric stochastic games of capital accumulation/resource extraction is considered. It is shown that Nash equilibria in the games with some natural constraints are also equilibrium solutions in unconstrained games and dominate in the Pareto sense an equilibrium leading to exhausting the entire resource stock in the first period of the game.
THE KLEIN-4 DIAGRAM ALGEBRAS
Authors: PARVATHI M. , SIVAKUMAR B.
Published: April 2008

In this paper we study a new class of diagram algebras, the Klein-4 diagram algebras denoted by Rk(n). These algebras are the centralizer algebras of the group Gn := (ℤ2 × ℤ2)≀Sn acting on V⊗k, where V is the signed permutation module for Gn These algebras have been realized as subalgebras of the extended G-vertex colored partition algebras introduced by Parvathi and Kennedy in [7]. In this paper we give a combinatorial rule for the decomposition of the tensor powers of the signed permutation representation of Gn by explicitly constructing the basis for the irreducible modules. In the process we also give the basis for the irreducible modules appearing in the decomposition of V⊗k in [5]. We then use this rule to describe the Bratteli diagram of Klein-4 diagram algebras.
Sensitive Items in Privacy Preserving — Association Rule Mining
Authors: Duraiswamy K. , Maheswari N.
Published: April 2008

Privacy-preserving has recently been proposed in response to the concerns of preserving personal or sensible information derived from data-mining algorithms. For example, through data-mining, sensible information such as private information or patterns may be inferred from non-sensible information or unclassified data. As large repositories of data contain confidential rules that must be protected before published, association rule hiding becomes one of important privacy preserving data-mining problems. There have been two types of privacy concerning data-mining. Output privacy tries to hide the mining results by minimally altering the data. Input privacy tries to manipulate the data so that the mining result is not affected or minimally affected. For some applications certain sensitive predictive rules are hidden that contain given sensitive items. To identify the sensitive items an algorithm SENSITEM is proposed. The results of the work have been given.
The Location of Events Producing Potential Transients During Pitting of Freely Corroding Al and Its Alloys
Authors: Isaacs Hugh S. , Scheffey Carl , Huang Ruoshuang
Published: April 2008

The behavior of a number of Al alloys have been studied using open circuit potential transients in conjunction with current density mapping, imaging, and time-delay of arrival of potential changes. Generally, potential transients are analyzed as noise relating to initiation and repassivation of metastable pits, a behavior demonstrated for stainless steels. However, measurements on pure Al, using segmented electrodes and imaging methods, show that most transients emanate from growing pits. Comparing behaviors of alloys shows that AA1100 and AA2024 are similar to pure Al. AA7075 shows similar transients but only a thin highly deformed surface layer is locally attacked along the abrasion direction. AA5083 in contrast first shows transients dominated by metastable pitting and only after hours of exposure do events within growing pits dominate the production of transients.
Investigations of Cut-edge Corrosion of Galvanized Steels by the Scanning Vibrating Electrode Technique
Authors: Thebault Florian , Vuillemin Bruno , Oltra Roland , Allely Christian , Ogle Kevin , Tada Eiji
Published: April 2008

Local electrochemical probes, the Scanning Vibrating Electrode Technique, the electrochemical capillary cell and a pH sensor have been used to study the corrosion behavior of zinc coated low alloy carbon steel cut-edges immersed in 0.03 M NaCl solution. Experimental results show an inhibition of cathodic reactions on a limited area of the steel surface. Hypothesis of self-healing on cut-edge has been tested and validated by two complementary numerical models of the corrosion behavior. Then a self-healing mechanism is proposed that explains obtained observations.
Use of a hanging-weight system for liver ischemic preconditioning in mice
Authors: Hart Melanie L. , Much Chressen , Köhler David , Schittenhelm Jens , Gorzolla Iris C. , Stahl Gregory L. , Eltzschig Holger K.
Published: April 2008

Ischemic preconditioning (IP) represents a powerful experimental strategy to identify novel molecular targets to attenuate hepatic injury during ischemia. As a result, murine studies of hepatic IP have become an important field of research. However, murine IP is technically challenging, and experimental details can alter the results. Therefore, we systematically tested a novel model of hepatic IP by using a hanging-weight system for portal triad occlusion. This system has the benefit of applying intermittent hepatic ischemia and reperfusion without manipulation of a surgical clamp or suture, thus minimizing surgical trauma. Systematic evaluation of this model revealed a close correlation of hepatic ischemia time with liver damage as measured by alanine (ALT) and aspartate (AST) aminotransferase serum levels. Using different numbers of IP cycles and times intervals, we found optimal liver protection with four cycles of 3 min ischemia/3 min reperfusion as measured by ALT, AST, lactate dehydrogenase, and interleukin-6. Similarly, ischemia-associated increases in hepatic infarct size, neutrophil infiltration, and histological injury were maximally attenuated with the above regimen. To demonstrate transcriptional consequences of liver IP, we isolated RNA from preconditioned liver and confirmed transcriptional modulation of known target genes (equilibrative nucleoside transporters, acute-phase complement genes). Taken together, these studies confirm highly reproducible liver injury and protection by IP when using the hanging-weight system for hepatic ischemia and intermittent reperfusion. Further studies of murine IP may consider this technique.
Mechanism of leukotriene D4inhibition of Na-alanine cotransport in intestinal epithelial cells
Authors: Talukder Jamilur R. , Kekuda Ramesh , Saha Prosenjit , Sundaram Uma
Published: April 2008

In a rabbit model of chronic intestinal inflammation, we previously demonstrated inhibition of neutral Na-amino acid cotransport. The mechanism of the inhibition was secondary to a decrease in the affinity for amino acid rather than the number of cotransporters. Since leukotriene (LT)D4is known to be elevated in enterocytes during chronic intestinal inflammation, we used rat intestinal epithelial cell (IEC-18) monolayers to determine the mechanism of regulation of Na-alanine cotransport (alanine, serine, cysteine transporter 1: ASCT1) by LTD4. Na-alanine cotransport was inhibited by LTD4in IEC-18 cells. The mechanism of inhibition of ASCT1 (solute carrier, SLC1A4) by LTD4is secondary to a decrease in the affinity of the cotransporter for alanine without a significant change in cotransporter numbers and is not secondary to an alteration in the Na+extruding capacity of the cells. Real-time quantitative PCR and Western blot analysis results indicate that ASCT1 message and protein levels are also unchanged in LTD4-treated IEC-18 cells. These results indicate that LTD4inhibits Na-dependent neutral amino acid cotransport in IEC. The mechanism of inhibition is secondary to a decrease in the affinity for alanine, which is identical to that seen in villus cells from the chronically inflamed rabbit small intestine, where LTD4levels are significantly increased.
Identification and characterization of rabbit small intestinal villus cell brush border membrane Na-glutamine cotransporter
Authors: Talukder Jamilur R. , Kekuda Ramesh , Saha Prosenjit , Arthur Subha , Sundaram Uma
Published: April 2008

Glutamine, the primary metabolic fuel for the mammalian small intestinal enterocytes, is primarily assimilated by Na-amino acid cotransporters. Although Na-solute cotransport has been shown to exist in the brush border membrane (BBM) of the absorptive villus cells, the identity of Na-glutamine cotransport in rabbit small intestinal villus cells was unknown. Na-dependent glutamine uptake is present in villus BBM vesicles. An intravesicular proton gradient did not stimulate this Na-dependent glutamine uptake, whereas Li+did not significantly suppress this uptake. These observations in concert with amino acid substitution studies suggested that Na-glutamine cotransporter in the villus cell BBM was the newly identified cotransporter B0AT1 (SLC6A19). Quantitative real-time PCR identified the message for this cotransporter in villus cells. Thus a full-length cDNA of B0AT1 was cloned and expressed in MDA-MB-231 cells. This expressed cotransporter exhibited characteristics similar to those observed in villus cells from the rabbit small intestine. Antibody was generated for B0AT1 that demonstrated the presence of this cotransporter protein in the villus cell BBM. Kinetic studies defined the kinetic parameters of this cotransporter. Thus this study describes the identification, cloning, and characterization of the Na-amino acid cotransporter responsible for the assimilation of a critical amino acid by the absorptive villus cells in the mammalian small intestine.
Angiotensin converting enzyme-2 is protective but downregulated in human and experimental lung fibrosis
Authors: Li Xiaopeng , Molina-Molina Maria , Abdul-Hafez Amal , Uhal Victor , Xaubet Antonio , Uhal Bruce D.
Published: April 2008

Earlier work from this laboratory showed that local generation of angiotensin (ANG) II is required for the pathogenesis of experimental pulmonary fibrosis and that ANG peptides are expressed robustly in the lungs of patients with idiopathic pulmonary fibrosis (IPF). Angiotensin converting enzyme-2 (ACE-2) degrades the octapeptide ANG II to form the heptapeptide ANG1-7 and thereby limits ANG II accumulation. On this basis, we hypothesized that ACE-2 would be protective against experimental lung fibrogenesis and might be downregulated in human and experimental lung fibrosis. In lung biopsy specimens from patients with IPF, ACE-2 mRNA and enzyme activity were decreased by 92% ( P < 0.01) and 74% ( P < 0.05), respectively. ACE-2 mRNA and activity were also decreased similarly in the lungs of bleomycin-treated rats and C57-BL6 mice. In mice exposed to low doses of bleomycin, lung collagen accumulation was enhanced by intratracheal administration of either ACE-2-specific small interfering RNAs (siRNAs) or the peptide DX600, a competitive inhibitor of ACE-2 ( P < 0.05). Administration of either ACE-2 siRNA or DX600 significantly increased the ANG II content of mouse lung tissue above the level induced by bleomycin alone. Coadministration of the ANG II receptor antagonist saralasin blocked the DX600-induced increase in lung collagen. Moreover, purified recombinant human ACE-2, delivered to mice systemically by osmotic minipump, attenuated bleomycin-induced lung collagen accumulation. Together, these data show that ACE-2 mRNA and activity are severely downregulated in both human and experimental lung fibrosis and suggest that ACE-2 protects against lung fibrogenesis by limiting the local accumulation of the profibrotic peptide ANG II.