bluuebunny/crossref_metadata_2025 huggingface dataset:
Visualizing the splicing of single pre-mRNA molecules in whole cell extract
Authors: Crawford Daniel J. , Hoskins Aaron A. , Friedman Larry J. , Gelles Jeff , Moore Melissa J.
Published: November 2007

The excision of introns from nascent eukaryotic transcripts is catalyzed by the spliceosome, a highly complex and dynamic macromolecular machine composed of RNA and protein. Because of its complexity, biochemical analysis of the spliceosome has been previously limited to bulk assays in largely unfractionated cell extracts. We now report development of methodologies for studying the splicing of isolated single pre-mRNA molecules in real time. In this system, a fluorescently tagged pre-mRNA is tethered to a glass surface via its 3′-end. Splicing can be observed in Saccharomyces cerevisiae whole cell extract by monitoring loss of intron-specific fluorescence with a multi-wavelength total internal reflection fluorescence (TIRF) microscope. To prolong fluorophore lifetime, two enzyme-based O2 scavenging systems compatible with splicing were also developed. This work provides a powerful new approach for elucidating the mechanisms of spliceosome function and demonstrates the feasibility of utilizing TIRF microscopy for biochemical studies of single molecules in highly complex environments.
Discovering Generalized Profile-Association Rules for the Targeted Advertising of New Products
Authors: Hwang San-Yih , Yang Wan-Shiou
Published: November 2007

We propose a data-mining approach for the targeted marketing of new products that have never been rated or purchased by customers. This approach uncovers associations between customer types and product genres that frequently occurred in previous transaction records. Customer types are defined in terms of demographic attribute values that can be aggregated through concept hierarchies; product types can be generalized through product taxonomies. We use generalized profile-association rules (GP association rules) to identify the advertising targets for a given new product. In addition, we propose two algorithms—GP-Apriori and Merge-prune—to mine GP association rules and develop a value-based targeted advertising algorithm to select prospective customers of a new product on the basis of the discovered rules. We evaluate the proposed approach using both synthetic data and library-circulation data.
Scaling Limits for Cumulative Input Processes
Authors: Mikosch Thomas , Samorodnitsky Gennady
Published: November 2007

We study different scaling behavior of very general telecommunications cumulative input processes. The activities of a telecommunication system are described by a marked-point process ((Tn, Zn))n∈Z, where Tn is the arrival time of a packet brought to the system or the starting time of the activity of an individual source, and the mark Zn is the amount of work brought to the system at time Tn. This model includes the popular ON/OFF process and the infinite-source Poisson model. In addition to the latter models, one can flexibly model dependence of the interarrival times Tn−Tn−1, clustering behavior due to the arrival of an impulse generating a flow of activities, but also dependence between the arrival process (Tn) and the marks (Zn). Similarly to the ON/OFF and infinite-source Poisson model, we can derive a multitude of scaling limits for the input process of one source or for the superposition of an increasing number of such sources. The memory in the input process depends on a variety of factors, such as the tails of the interarrival times or the tails of the distribution of activities initiated at an arrival Tn, or the number of activities starting at Tn. It turns out that, as in standard results on the scaling behavior of cumulative input processes in telecommunications, fractional Brownian motion or infinite-variance Lévy stable motion can occur in the scaling limit. However, the fractional Brownian motion is a much more robust limit than the stable motion, and many other limits may occur as well.
On the Spanning Property of Risk Bonds Priced by Equilibrium
Authors: Horst Ulrich , Müller Matthias
Published: November 2007

We propose a method of pricing financial securities written on nontradable underlyings such as temperature or precipitation levels. To this end, we analyze a financial market where agents are exposed to financial and nonfinancial risk factors. The agents hedge their financial risk in the stock market and trade a risk bond issued by an insurance company. From the issuer's point of view the bond's primary purpose is to shift insurance risks related to noncatastrophic weather events to financial markets. As such, its terminal payoff and yield curve depend on an underlying climate or temperature process whose dynamics are independent of the randomness driving stock prices. We prove that if the bond's payoff function is monotone in the external risk process, it can be priced by an equilibrium approach. The equilibrium market price of climate risk and the equilibrium price process are characterized as solutions of nonlinear backward stochastic differential equations (BSDEs). Transferring the BSDEs into partial differential equations (PDEs), we represent the bond prices as smooth functions of the underlying risk factors. Our analytical results make the model amenable to a numerical analysis.
Workload Interpretation for Brownian Models of Stochastic Processing Networks
Authors: Harrison J. M. , Williams R. J.
Published: November 2007

Brownian networks are a class of stochastic system models that can arise as heavy traffic approximations for stochastic processing networks. In earlier work we developed the “equivalent workload formulation” of a generalized Brownian network: denoting by Z(t) the state vector of the generalized Brownian network at time t, one has a lower dimensional state descriptor W(t) = MZ(t) in the equivalent workload formulation, where M is an arbitrary basis matrix for a linear space ℳ that is orthogonal to the space of so-called “reversible displacements.” Here we use the special structure of a stochastic processing network to develop a more extensive interpretation of the equivalent workload formulation associated with its Brownian network approximation. In particular, we (i) characterize and interpret the notion of a reversible displacement, and (ii) show how the basis matrix M can be constructed from the basic optimal solutions of a certain dual linear program. The latter provides a mechanism for reducing the choices for M from an infinite set to a finite one (when the workload dimension exceeds one). We illustrate our results for an example of a closed stochastic processing network.
The Minisum Multipurpose Trip Location Problem on Networks
Authors: Berman Oded , Huang Rongbing
Published: November 2007

We investigate multipurpose trip location problems on networks with two different types of facilities and three groups of customers, two of which need only one type of service, while the third group needs both types of service in a single trip. The objective is to minimize the total weighted travel distance of all trips. We prove that there exists a dominating location set for the problem on a general network, propose a general binary programming model, and analyze the properties of optimal solutions on networks with simple topologies and one facility per type. We also investigate several heuristic approaches to the problem on general networks and present extensive computational experiments.
Whitehall and Roads: A Case Study of Sectoral Politics
Authors: Painter Martin
Published: November 2007

Trunk road policy in England is best seen as a case of sectoral policy making, that is the evolution of commitments within narrow conceptual and institutional boundaries. To build trunk roads it was necessary to construct and defend a self-contained world of roads policy and programme implementation. In the 1950s and 60s an internally accountable set of organisations and routines emerged, with their own logic and a seemingly inexorable momentum. This division of the world into sectoral specialities is a key part of government policy making, and the roads case demonstrates the pressures that exist towards fragmentation within government, while highlighting the artificiality of this fragmentation. Challenges were mounted from the outside world – from local communities and from environmentalists – which could not be contained or co-opted by the roads men. Governments were forced to react and the roads programme declined. However, this occurred as much by internal dissolution – the impossibility of implementation in the face of protest – as from an act of central co-ordination or reappraisal. It seems that such acts are severely limited by the political and administrative structures and logics of distinct policy sectors.
The Artificial Debate Between Rationalist and Incrementalist Models of Decision Making
Authors: Smith Gilbert , May David
Published: November 2007

The notion of decision making is central to studying the way in which policies are both formulated and implemented. This note discusses the relative merits of rationalistic as opposed to incrementalist models of decision making (together with attempts to provide a ‘third’ alternative). It concludes that in certain respects the debate is artificial since the approaches have features in common, the significance of which outweigh any specific points of variance. Firstly, on both sides of the debate the relationship between ‘is’ and ‘ought’ is confused and there are good grounds for suggesting that whereas incrementalist models may perform an explanatory function, rationalist models are largely confined to a prescriptive role. Secondly, the debate does not consider seriously the issue of what it takes to act in accord with any set of decision making rules and thus neglects the way in which policy makers and administrators may use ‘decision making’ as a gloss for a wide range of practices. Throughout, the paper is concerned with the implications of the terms of the dispute about different notions of ‘decision’ and ‘decision making’, for policy research.
The Royal Commission on the National Health Service
Authors: Farrell Christine
Published: November 2007

The Royal Commission on the NHS published its report in July 1979 after three years deliberation. This paper discusses developments taking place in the NHS prior to the appointment of the Royal Commission and identifies four major causes of unrest. Subsequently the article describes the way in which the Commission worked, the evidence submitted, the research commissioned and visits made in the UK and abroad. Some of the salient features of the report are identified and the immediate reactions to it assessed.
Proposition 13 and Its Impact on Local Government Programmes in California
Authors: Goodenough Richard
Published: November 2007

In July 1978 the California Legislature passed a far-reaching and controversial law, popularly known as Proposition 13, which greatly reduces the State revenue from property taxes. This article examines the reasons for the growing discontent with property taxation which has received nationwide support in recent years. Major changes in property taxation under Proposition 13 are reviewed and the implications of a declining property tax base are assessed for cities, counties and special districts in California. Proposition 13 has clearly resulted in a serious reduction of some services and the elimination of others depending on the priority which local governments give to the various services. There is also a trend for local governments to ensure that charges for services now reflect the true cost of providing them.

Although individual home-owners and businessmen have benefited considerably from reduced property taxes, the full impact of the revenue loss on programmes of local government spending has still to be felt because of the support funds supplied by the State Treasury. These funds have effectively shifted the tax burden from a local to a State level and temporarily delayed the time when local governments must come to terms with the real and very substantial revenue loss mandated by Proposition 13.
Policy Analysis in Mixed Economy: An Implementation Approach
Authors: Hull Chris. , Hjern Benny
Published: November 2007

‘Mixed economy’ we take to refer to the complex institutional arrangements of resource allocation in modern society; mixed economy policy analysis is concerned with a positive administrative theory for steering resource allocative processes. The present article reviews some basic definitions, dimensions and models of mixed economy and discusses several formal reasons for why so little progress has been made towards an administrative theory of mixed economy. A policy implementation perspective is used to provide an alternative conception of mixed economy allocative processes and a method for researching them. Data from a current research project on mixed economy strategies for ‘Helping Small Firms Grow’ are used to illustrate arguments in the article.
Can Regional Planning Work: Experiences from a Research Project on the Implementation of Spatial Policies in the Federal Republic of Germany
Authors: Konukiewitz Manfred
Published: November 2007

The article outlines the principal strategic problems faced by comprehensive spatial planners in the German implementation system. These problems are rooted in a fragmented administrative structure with highly autonomous decision-making bodies in vertical (state and local authorities) as well as horizontal (strong sectoral linkages) dimensions. In drawing on research results from a comparative research project in three German states, the article discusses the influence of institutional arrangements on the ability of spatial planners to overcome these obstacles. It is found that procedural arrangements for day-to-day decision-making have a strong influence which so far has been widely neglected. The article also draws conclusions on the effectiveness of various implementation strategies, pointing out some reasons why ‘soft’ influence strategies are more likely to lead toward desired results.
Rational Planning and Politics: The Example of Local Authority Corporate Planning
Authors: Clapham David
Published: November 2007

This article examines one of the criticisms of local authority corporate planning which is that it is ill-suited to the local political process. The examination is in three parts. Firstly the corporate planning literature is reviewed to see what view of politics it reveals. Secondly an ideal corporate planning process based on the concept of rationality is compared with a political process which is made up of differences in perspective based on consumption cleavages. Thirdly the interaction of these two processes is examined by looking at the experience of corporate planning in two local authorities. The conclusion is that the criticism is a fair one and that in consequence local authority planning processes will in future be more closely integrated with the political system.
Capital Leakage from Owner-Occupied Housing
Authors: Kemeny Jim , Thomas Andrew
Published: November 2007

Capital leakage is defined as the conversion into disposable income of capital invested in housing assets. In debates on the capital demands of owner-occupation, one concern is the extent to which demand for mortgage finance results from the withdrawal of capital from owner-occupied housing and its expenditure elsewhere. The paper centres on an attempt to Quantify the likely dimensions of capital leakage using national statistical sources. Within severe data constraints it is estimated that capital release may fall in the range of £1,400–£2,600 million a year at 1980 prices. The paper concludes by considering policy implications in forms of any distorting effects on the savings and housing markets.
The Costs of Sixth-Form Rationalisation
Authors: Bailey S.J.
Published: November 2007

Many local education authorities are currently rationalising the institutional structure of sixth-form provision in their areas. This paper provides a brief review of the educational options available but its main emphasis is on the costs of rationalisation. The restructuring of sixth-form provision will have cost implications for the other parts of the educational system providing secondary and post 16 education. Hence the option which minimises sixth-form costs may cause an offsetting rise in costs in other areas, e.g. in 11 to 16 education. Such costs are examined by taking two case studies, namely Manchester and Newcastle Upon Tyne.
Housing Benefit: Some determinants of administrative performance
Authors: Walker Robert , Williams Julie
Published: November 2007

Social security administration has attracted little interest in academic circles despite its self-evident importance. Housing benefit is the only major social security scheme administered by local government and the apparent inability of some local authorities effectively to operate the scheme continues to attract media attention. In the absence of standardised local authority records an index of administrative performance was developed based on the subjective assessments of local officials. The analysis suggests that caseload composition and factors in the interactional environment are more important determinants of administrative performance (measured in this way) than are resource inputs.
Squaring the Circle: Reconciling predictive uncertainty with the control of public expenditure in the UK
Authors: Likierman Andrew
Published: November 2007

There are major uncertainties in forecasting the level of public expenditure in the UK. Yet there is a great deal of pressure on the government to be seen to be meeting its spending targets. This paper sets out to explain the ways in which predictive uncertainty has been reconciled with the need to be seen to be controlling public expenditure in the past few years. After first outlining the causes of uncertainty, the paper shows that there are a wide range of methods for dealing with it, more than might be supposed, and many of these have been used in recent years.
Urban Policy Contradictions: the market versus redistributive approaches
Authors: Moore Chris , Booth Simon
Published: November 2007

British urban policy emphasises the concept of partnership between different levels of government and the importance of institutional co-ordination for effective problem solving. This ignores underlying political and ideological conflicts between the objectives of central government and local authorities in the major conurbations. Examining the evolution of urban policy in Clydeside reveals two competing models of urban regeneration articulated by central and local government, reflecting different modes of interest representation and political accountability. This has particularly adverse consequences for certain communities within the conurbation. Policy prescriptions which fail to recognise these underlying conflicts are unlikely to succeed.
Time and Temperature Requirements for Weed Seed Thermal Death
Authors: Dahlquist Ruth M. , Prather Timothy S. , Stapleton James J.
Published: November 2007

Mortality of weed seeds at temperatures of 39, 42, 46, 50, 60, and 70 C was recorded through time under controlled laboratory conditions similar to those of soil solarization for six weed species: annual sowthistle, barnyardgrass, black nightshade, common purslane, London rocket, and tumble pigweed. Time and temperature requirements for thermal death varied considerably among the species studied. Barnyardgrass, London rocket, and annual sowthistle were more susceptible to heat treatment than black nightshade, common purslane, and tumble pigweed. Temperatures of 50 C and above were lethal for seeds of all species. Common purslane seeds were unaffected at 46 C and below, tumble pigweed and barnyardgrass seeds were unaffected at 42 C and below, and black nightshade seeds were unaffected at 39 C. Nonlinear models for mortality as a function of duration of heat treatment were developed for each species at each temperature at which mortality occurred. These models provide an empirical relationship for the construction of field-applicable decision models that could predict the accumulation of time and temperature combinations for effective solarization of weed seeds.
Feeding Preferences of Weed Seed Predators and Effect on Weed Emergence
Authors: White Sharon S. , Renner Karen A. , Menalled Fabian D. , Landis Douglas A.
Published: November 2007

We determined feeding preferences of invertebrate seed predators and the effect of seed predation on weed emergence. Feeding choice studies were completed with three species of common ground beetles: (Amara aeneaDeGeer,Anisodactylus sanctaecrucisF., andHarpalus pensylvanicusDeGeer) (Coleoptera: Carabidae) and the northern field cricket (Gryllus pennsylvanicusDeGeer) (Orthoptera: Gryllidae).Anisodactylus sanctaecrucis,H. pensylvanicus, and the female and maleG. pennsylvanicusconsumed more redroot pigweed seeds compared with giant foxtail seeds;A. aeneaseed consumption did not differ between these two weed species. All invertebrates consumed fewer velvetleaf seeds compared with redroot pigweed and giant foxtail seeds; however, when seed biomass was compared,A. aeneaconsumed similar biomass of velvetleaf, giant foxtail, and redroot pigweed, whereasA. sanctaecrucisandH. pensylvanicusconsumed greater biomass of velvetleaf compared with giant foxtail seed. Seed burial depths of 0.5 or 1.0 cm reduced redroot pigweed and giant foxtail seed consumption byA. aeneaandA. sanctaecrucisbut not by the larger carabid beetle,H. pensylvanicus. In a greenhouse study,A. sanctaecrucisdecreased total weed emergence by 15%, andG. pennsylvanicusfemales and males decreased weed emergence by 16 and 5%, respectively. Emergence of redroot pigweed, but not velvetleaf or giant foxtail, decreased whenA. sanctaecrucisand the maleG. pennsylvanicuswere present, whereas the emergence of all three weed species decreased in the presence of the femaleG. pennsylvanicus. In field experiments, vertebrate access to velvetleaf seeds reduced emergence from 4 to 9% across field sites; invertebrate access reduced emergence 4 to 6%. Vertebrate access to giant foxtail seeds reduced emergence 3 to 7%, and invertebrate access reduced emergence 4 to 13%. These results suggest that predation of weed seeds by both vertebrates and invertebrates may reduce weed emergence and influence the weed community.
Screening and Identification of Glufosinate-Degrading Bacteria from Glufosinate-Treated Soils
Authors: Hsiao Chau-Ling , Young Chiu-Chung , Wang Ching-Yuh
Published: November 2007

In order to select efficient and competitive glufosinate-degrading bacteria, two soils which had been treated with glufosinate annually for more than 5 yr were screened. Three strains tolerant to this herbicide were identified by 16S rDNA analysis asBurkholderia sacchari,Serratia marcescens, andPseudomonas psychrotolerans. In addition, a moderately tolerant strain,P. citronellolis, was isolated from a soil which had received glufosinate treatment for only 6 mo. In culture medium containing high concentration of glufosinate, the former three strains showed significant ability to degrade this glutamine synthetase inhibitor, suggesting that glufosinate-degrading bacteria would be readily found in soils after a long-term induction or selection. A subsequent biodegradation experiment showed that 30 and 50% of glufosinate was degraded 7 and 21 d after treatment (DAT), respectively, in sterilized soils inoculated with the above-mentioned three tolerant strains. While more than 30% of the glufosinate in nonsterilized soils was degraded 7 DAT by the indigenous edaphic microbes, inoculation with the three selected strains enhanced glufosinate degradation to nearly 50%. A study on the competition from edaphic microorganisms in soils by polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) analysis revealed that within 21 d after inoculation (DAI), the propagation ofB. sacchariandP. psychrotoleranswas not affected, whereas that of the less tolerantP. citronelloliswas inhibited. This observation suggests that a long-term herbicide exposure is a promotive factor in generating bacterial strains having high degradation efficiency and showing vigorous propagation under the competition pressure arising from indigenous microbes.
Residual Herbicide Dissipation from Soil Covered with Low-Density Polyethylene Mulch or Left Bare
Authors: Grey Timothy L. , Vencill William K. , Mantripagada Nehru , Culpepper A. Stanley
Published: November 2007

Field studies were conducted to examine the dissipation of three soil-applied residual herbicides for bare soil compared with soil under low-density polyethylene (LDPE) mulch in 2003 and 2004. Studies indicated that halosulfuron andS-metolachlor dissipation was more rapid for bare soil than soil under LDPE mulch. Sulfentrazone dissipation from bare soil was equal to soil under LDPE mulch in 2003. However, sulfentrazone dissipation in 2004 was more rapid for soil under LDPE mulch than for bare soil. The order for half-life, defined as time for 50% dissipation (DT50), varied by herbicide and soil exposure. Averaged across 2003 and 2004, metolachlor DT50was 2 d, halosulfuron 7 d, and sulfentrazone 16 d for bare soil.S-metolachlor DT50was 4 d, halosulfuron 10 d, and sulfentrazone 13 d for soil under LDPE mulch. Correlation between quantified herbicide dissipation and bioassay for bare soil compared with soil under LDPE mulch in 2004 indicated that assay species root dry weights were negatively correlated with herbicide concentration. Data indicated thatS-metolachlor and sulfentrazone bioassays, with oat and cotton, respectively, could be used to assess the level of dissipation for each herbicide.
An Ala205Val Substitution in Acetohydroxyacid Synthase of Eastern Black Nightshade (Solanum ptychanthum) Reduces Sensitivity to Herbicides and Feedback Inhibition
Authors: Ashigh Jamshid , Tardif François J.
Published: November 2007

Twelve populations of eastern black nightshade from different locations in Ontario are resistant to imazethapyr. This study aimed at determining the molecular basis of resistance in these populations and the activity of the resistant acetohydroxyacid synthase (AHAS) enzyme compared to that of the sensitive AHAS in response to different herbicides and branched-chain amino acid concentration. The results of partialAHASsequencing indicated that all resistant populations had a cytosine331to thymine substitution coding for an alanine205to valine substitution.In vitroAHAS enzyme assays of one resistant population showed that the specific activity of the resistant enzyme was 56% less than that of the susceptible enzyme. AHAS from the resistant population was 72-, 70-, and 64-fold less sensitive than that of the susceptible population to imazethapyr, imazamox, and primisulfuron, respectively. Furthermore, the resistant enzyme was less sensitive to feedback inhibition from branched-chain amino acids compared to the susceptible enzyme. Results confirmed that resistance in resistant populations of eastern black nightshade was conferred by target-site modification and that the Ala205Val substitution alters the kinetics and regulation of branched-chain amino acid biosynthesis.
Biological Control Agent for Rice Weeds from Protoplast Fusion betweenCurvularia lunataandHelminthosporium gramineum
Authors: Zhang Z. B. , Burgos N. R. , Zhang J. P. , Yu L. Q.
Published: November 2007

The advancement of biological weed control is limited by the slow development of effective, broader-spectrum biological control agents. Protoplast fusion was carried out between theHelminthosporium gramineumsubsp.echinochloae(HGE) strain, HM1, andCurvularia lunata(CL) to breed new strains with improved biocontrol efficiency. The HM1 strain was derived from HGE by ultraviolet (UV) treatment. Conditions for protoplast fusion were optimized, including lytic enzyme mixtures and incubation time. The efficacy of lytic enzyme mixtures on cell wall digestion was also compared. The most effective lytic enzyme mixture for CL was 2% lywallzyme plus 2% snailase and for HM1, 2% cellulase plus 2% snailase. The optimum incubation time was 16 h for CL and 24 h for HM1. All fusant strains exhibited similar morphological and conidial properties to the HM1 parent. A total of 1,360 fusant strains were produced, 136 of which were randomly selected for characterization. Seven fusant strains showed improved spore productivity and four fusant strains had increased production of the phytotoxin ophiobolin A, compared with HM1. Random amplified polymorphic DNA (RAPD) analysis of the fusant strains showed that the seven phytoactive fusant strains had a high similarity index (95 to 99%) to the parent HM1, but low similarity (22 to 26%) to the parent CL. Ethyl acetate extract of the culture broth and mycelia effectively controlled major weeds in rice production.
Influence of Neighboring Vegetation Height on Seed Dispersal: Implications for Invasive Plant Management
Authors: Davies Kirk W. , Sheley Roger L.
Published: November 2007

Controlling invasive plant infestations is very costly and often unsuccessful. Preventing invasions is more cost-effective than controlling invasive plants after they are established. Because prevention guidelines do not suggest any tools or methods to limit wind dispersal of invasive plant seeds, we investigated the influence of neighboring vegetation height on seed dispersal of a wind-dispersed (yellow salsify) and nonwind-dispersed (medusahead) species. To examine the influence of neighboring vegetation height on dispersal, seeds of both species were released in front of an artificial stand of desert wheatgrass in a modified wind tunnel. Treatments were a complete factorial design with two species, four vegetation heights (10, 30, 40, and 60 cm), three wind speeds (3, 5.5, and 10 km h−1), and three release distances from the neighboring vegetation (0, 15, and 30 cm). The ability of medusahead and yellow salsify seeds to disperse was influenced by the height of neighboring vegetation. Increasing height of neighboring vegetation decreased the number of yellow salsify seeds dispersing across neighboring vegetation. The greatest percentage of medusahead seeds dispersed across the neighboring vegetation was at the shortest height. Based on these results, we suggest that maintaining or promoting tall vegetation neighboring invasive plant infestations may reduce wind dispersal of seeds. More research is needed to investigate the influence of varying heights, densities, structural attributes, and composition of vegetation neighboring infestations and the dispersal of invasive plants.
The features of host immune response with respect to microsatellite status of colorectal cancer
Authors: Fenyvesi Attila
Published: November 2007

Background: The genetic alterations in colorectal cancer (CRC) progression are determined by two separate pathways, chromosomal and microsatellite instability (MSI). The CRCs with MSI have distinct clinicopathological characteristics with pronounced tumor-associated immune responses. The aim of our study was to investigate the intensity of host immune response in CRC tissue by comparing microsatellite stable (MSS) and instable tumors. Methods: The study was performed on CRC specimens from 28 patients with MSI and compared with 30 MSS tumors. The microsatellite status was evaluated with two markers by PCR and melting point analysis. The immunostaining with anti-CD3 pan-T cell antibody was used to quantify the number of tumor infiltrating lymphocytes. The lymphocytes in peritumoral stromal and the Crohn?s-like peritumoral reaction were counted on H&E slides. Results: No significant differences were found in the average number of lymphocytes in peritumoral stroma and in clinicopathological characteristics of CRCs. The conspicuous Crohn?s-like lymphoid reactions were present in 67.86% of CRCs with MSI versus 26.66% of MSS cases. The CRCs with MSI cases carried significantly higher numbers of tumor infiltrating T-lymphocytes (13.21 versus 7.47) (p<0.0001). Conclusion: The presences of peritumoral Crohn?s-like lymphoid and intraepithelial lymphocytic reaction were intensive markers for MSI in colorectal carcinomas in our study. The peculiar genetic instability in MSI tumors may lead to a continuous production of abnormal peptides, which act as neoantigens. They could induce specific antitumor immune responses effective in limiting tumor growth and spread. Abnormal peptides are potentially promising in immunotherapy advancing and in the design of a vaccine against colorectal tumors with MSI.
The glow duration time influence on the ionization rate detected in the diodes filled with noble gases on mbar pressures
Authors: Stepanovic Olivera , Radovic Miodrag , Maluckov Cedomir
Published: November 2007

The results of the glow current duration time (glowing-time) influence on the ionization rate detected in the gas filled diodes are presented. The electrical breakdown was detected as the minimal current impulse. After that diode glow from the minimal glowing-time (10-3 s), up to the maximal 103 s which overlap the time of the stationary regime formation in the gas diode tube. The diodes were with volumes of 300 cm3, but with a diode gap volume of about 1 cm3 and filled with helium, neon, argon or krypton, at the pressures of the order of mbar. The ionization rates were detected as the residual ionization after the glowing was interrupted, using the electrical breakdown time delay measuring method. The influence of the gap distance stationary current values and the relaxation period were also investigated. The result shows that the stationary regime in such a gas diode is established after the glowing time of 1-3 s, although the breakdown formative times were smaller then 1 ms.
Wiedemann-Franz ratio in plasmas in the mixtures of xenon, argon and cesium
Authors: Novakovic Nadezda , Stojilkovic S.M. , Gajic Dragan
Published: November 2007

In the present paper, the xenon plasmas containing argon and cesium as additive and pertaining to the above mentioned type (high-pressure low-temperature, LIE) are studied, and a theoretical evaluation of their basic transport parameters is presented. The numerical calculations were based on the assumption that the system is kept under constant pressure and temperature and that it attained local thermo dynamical equilibrium. Some results of a theoretical study which embraced numerical evaluations of the plasma composition, electron collision frequency, electrical and thermal conductivities and Wiedemann-Franz ratio, all regarded as functions of pressure and temperature, are given for high-pressure (from 0,1 MPa to 1,5 MPa) and low-temperature (from 2 000 K to 20 000 K). A previously derived modified expression for the Debye radius, offering the possibility to treat the plasmas considered as weakly non-ideal in the whole temperature range of interest, is used in the evaluations, in combination with the Saha equations for the relevant ionization stages of xenon, argon and cesium. .
Investigation of the impact of grape cultivars on the grape brandies quality
Authors: Rankovic Vesna , Palic Radosav , Zivkovic Jelena , Mosic Ivana , Stankovic Snezana , Stojanovic Gordana
Published: November 2007

The results of the four-year investigation of the grape cultivars impact of the first Yugoslav interspecies hybrids Lucija and Mediana on the grape brandies quality are presented. The experiment was carried out with reference to the standard grape cultivars Smederevka intended for production of grape brandies. Investigation covered a procedure for establishing parameters, which determine the quality of strong alcoholic beverages and organoleptic rating. Higher presence of methanol with reference to standard cultivars was not established in the investigated hybrids brandies, which demonstrates properties similar to that of precious cultivars. The highest average content of higher alcohols was found out with the Mediana grape brandy, which amounts to 3295.3 mg/Laa, followed by the Smederevka grape brandy with 3261.8 mg/Laa, the Mediana/Lucija grape brandy with 3130.0 mg/Laa and the Lucija grape brandy with 2940.0 mglLaa of higher alcohols. The concentration of higher alcohols positively affects aroma of the beverage. The Mediana grape brandy and the variant where fermentation of the Mediana and Lucija grapes in the 50:50 ratio was carried out possess better organoleptic characteristics than those of Smederevka, while the Lucija grape brandy shows worse organoleptic characteristics.
Antimicrobial activity of bioactive component from flower of linum capitatum kit
Authors: Ilic Slavica , Konstantinovic Sandra , Todorovic Zoran
Published: November 2007

Different extracts containing bioactive components and etheric oil of the flowers of Linum capitation kit. (Linacea) of Serbian origin were tested for an Antimicrobial activity against four bacteria (Staphylococcus aureus Escherichia coli, Bacillus subtilus, Pseudomonas aeruginosa), one mold (Aspergillus niger) and one yeast (Candida albicans). The isolated Flavonoids were also tested against Staphylococcus aureus, Escherichia coli Bacillus anhtracis, Pseudomonas aeruginosa, Aspergillus niger, Candida albicans and Herpes simplex virus type.
The application of scanning electronic microscopy: The study of the surface structures of the upper layers of dyed polyester fiber samples in the ostacet yellow E-L5R
Authors: Miljkovic Milena , Purenovic Milovan , Zarubica Aleksandra
Published: November 2007

Scanning electronic microscope JSM-5300 (JEOL, Japan) has been used to investigate the structure of the PES fibers upper layers. Preparation of samples was performed by placing them on an aluminium support, with a glue or double-sided adhesive tape. The tool for spreading the conductive layer on the sample's surface, used in this work, was JFC-1100E ION SPUTTER (JEOL Co., Japan). Potential difference of electron acceleration was 30 kV, and multiplication of the samples was 3500 times. ORWO NP 20 DIN films were used for taking the photos. The samples were dyed with C.I.D. Yellow 23, in concentration of l%, at pH = 4.5, with the following acids added: acetic formic and oxalic. The results show absence of any internal damage in fiber structure. On the surface however, groups of particles have been observed varying in shape, magnitude and spacing density. Organic (acetic, formic and oxalic) acids used in the experiments caused differences in upper layers structures of dyed PES fibers. This is the main reason to induce differences in color (DE), chromaticity (DH) and lightness (DL), among the samples (with the all acids included) and a standard (addition of acetic acid only).
Detection limits for radioactivity counting
Authors: Manic G. , Manic Vesna , Vesic D.
Published: November 2007

In this paper, the detection limits for radioactivity counting are determined. Several decision rules are presented and applied to calculate the critical value. The value obtained by the best approximation for the alpha particles counting was used to evaluate the minimum detectable concentration in water, soil and air.
Methods of radon measurement
Authors: Forkapic S. , Bikit I. , Conkic Lj , Veskovic M. , Slivka J. , Krmar M. , Zikic-Todorovic N. , Varga E. , Mrdja D.
Published: November 2007

Several important international scientific organizations have designated radon as a carcinogenic and serious health problem. As a chemically inert gas, it is easily released from soil, building materials, and water, to emanate to the atmosphere. Since 1992, Laboratory for Nuclear Physics of the Department of Physics, Faculty of Sciences in Novi Sad has been involved in measurements of radon concentration in air, using several different techniques. Last year, systematic radon measurements in drinking waters began, too. The work presented here gives a survey and discussion of the results of the both series of measurements.
A pan-European classification of the Skadar lake according to environmental standards
Authors: Mijovic S.R. , Vukovic Z. , Mazgalj A.
Published: November 2007

Nowadays, the values of natural fresh-water resources are increasing and a Pan-European methodology for water quality assessment was applied in the case of the Skadar Lake eco-system. The main goal of this paper was to classify Skadar Lake according to the environmental quality standards, prescribed in the EC directives and EUROWATERNET requirements. Basically, the criteria enable to classify the water as belonging to one of, usually, five classes with respect to a number of physicochemical and biological parameters. To determine the reference state, that could be expected if they were not significantly affected by human activities, was the second most important task. Some modeling was done to support interpretation of the measured data taken seasonally from May to October in the 2002-2004 period. A clear picture of the current state of the Skadar Lake was created and the classification will facilitate the interpretation of the environmental data relating to the Skadar Lake ecosystem. As a general conclusion it could be stated that the lake ecosystem is still in good conditions, although a small care has been done to it in the past.
Atmospheric aerosols and their influence on air quality in urban areas
Authors: Tasic Mirjana , Rajsic Slavica , Novakovic Velibor , Mijic Zoran
Published: November 2007

The quality and pollution of air and its impact on the environment and particularly on human health, is an issue of significant public and governmental concern. The emission of the main air pollutants (sulfur dioxide, nitrogen oxides) has declined significantly but the trends in concentrations of a particulate matter are less clear and this pollutant still pose a risk to human health. The studies on the quality of air in urban atmosphere related to suspended particles PM10 and PM2.5, and first measurements of their mass concentrations have been initiated in our country in 2002, and are still in progress. The results of preliminary investigations revealed the need for the continuous and long-term systematical sampling measurements and analysis of interaction of the specific pollutants ? PM10 and PM2.5 as well as ozone, heavy metals in the ground level. Survey of some basic knowledge and features of atmospheric particles will be given and the results of air quality assessment in Belgrade will be presented as well.
Synthesis of new condensed coumarin derivatives
Authors: Dekic Stojadin , Dekic Vidoslav , Vucic Branimirka , Dekic Biljana , Dekic Milan
Published: November 2007

Reactions of 4-chloro-2-oxo-2H-chromene-3-carbonitrile (1) with 4-methylpyridin- 2-ylamine (2) and 6-methoxy-benzothiazol-2-ylamine (3) in acetonitrile containing a catalytic amount of triethylamine gave the new coumarin derivatives 7-imino-10-methyl-7H- 5-oxa-7a,12-diaza-benzo[a]anthracen-6-one (4) and 7-imino-10-methoxy-7H-5-oxa-12- thia-7a,13-diaza-indeno[1,2-b]phenanthren-6-one (5) in 52 and 39% yields, respectively. The novel compounds were subjected to acid hydrolysis giving the corresponding oxoderivatives 10-methyl-5-oxa-7a,12-diaza-benzo[a]anthracene-6,7-dione (6) and 10- methoxy-5-oxa-12-thia-7a,13-diaza-indeno[1,2-b]phenanthrene-6,7-dione (7) in 64 and 58% yields, respectively. The structural assignments of the synthesized compounds were based on elemental analyses, IR and proton NMR spectra. .
Metal complexes of Schiff’s bases derived from 3-(arylazo)-2,4- -pentanediones with 2-aminophenol and 2-aminothiophenol
Authors: Krishnankutty K. , Sayudevi P. , Ummathur Basheer
Published: November 2007

Phenylazo- and thiazolylazo-2,4-pentanediones on reaction with 2-aminophenol and 2-aminothiophenol yielded a new series of polydentate Schiff?s base ligands. The structure and tautomeric nature of these compounds and their metal complexes were established on the basis of their IR, 1H-NMR and mass spectral data. The spectral and analytical data revealed the condensation of both carbonyl groups of 3-(2-thiazolylazo)- 2,4-pentanedione with 2-aminophenol to form an N2O2 tetradentate ligand. Details on the formation of its [ML] complexes with Ni(II), Cu(II) and Zn(II) and the nature of their bonding are discussed based on analytical, IR, 1H-NMR and mass spectral data.
The charge percolation mechanism and simulation of Ziegler-Natta polymerizations, part VI: Mechanism of ethylene polymerization by supported chromium oxide
Authors: Stoiljkovic Dragoslav , Pilic Branka , Bulajic Misa , Djurasovic Nebojsa , Ostrovski Nikolaj
Published: November 2007

Despite intensive research over the last 50 years, many questions concerning ethylene polymerization by supported chromium oxide are still unanswered. Hence, the very fundamental issues of this polymerization are discussed in this paper. It is shown that a charge percolation mechanism (CPM) of olefin polymerization by Ziegler-Natta transition metal complexes, recently proposed by us, can give the answers in this case, too.
Mode of delivery and neurosonographic findings in premature infants
Authors: Velisavljev-Filipovic Gordana
Published: November 2007

Introduction Fetal and preterm infant brain is especially vulnerable to hemorrhagic and ischemic damage at the end of the second and at the beginning of the third trimester. This is due to vascular, cellular and anatomic characteristics of the brain during development. In premature babies, there is a physiological instability and limited autoregulation of cerebral circulation. Hemorrhagic and ischemic damages often occur together, though pathophysiological processes leading to lesions are different. Material and methods The paper deals with a detailed analysis of 860 ultrasound brain scans of prematurely born children. The examinations were performed at the Ultrasound Department of the Institute of Child and Youth Health Care in Novi Sad. 707 vaginally born premature infants and 153 premature infants born by Cesarean section were examined. The bleeding was graded according to the Papile classification. Results and Discussion Out of 384 children with diagnosed grade I hemorrhage, 75 premature infants (19.5%) were born by Cesarean section. In the group of children with grade II hemorrhage, operative deliveries account for 14.7%. From the total of 85 children with grade III hemorrhage, (intraventricular bleeding with chamber dilatation), only 6 premature infants were born by Cesarean section (7%). Intra-parenchymal bleeding was diagnosed in a very small number of premature infants; 0.32% of all diagnosed hemorrhages were grade IV hemorrhages. In this group there were no children born by Cesarean section. The increase of hemorrhage grade is accompanied by a greater rate of pelvic presentation and manual assistance by Bracht. There were 240 prematurely born children with no echosonographically diagnosed hemorrhage, 38% of all examined premature infants. From this number, 13.3% of neonates were born by Cesarean section. Conclusion In the etiology of neonatal intracranial hemorrhage, especially prematurely born ones, apart from the trauma, which plays a major role, other factors are also important, above all fetal distress, perinatal hypoxia and functional immaturity of all organs.