bluuebunny/crossref_metadata_2025 huggingface dataset:
Henson and Rubel's theorem for Zilber's pseudoexponentiation
Authors: Ahuva C. Shkop
Published: April 2012

In 1984, Henson and Rubel [2] proved the following theorem: If p(x1,…, xn) is an exponential polynomial with coefficients in ℂ with no zeroes in ℂ, then p(x1,…, xn) = eg(x1,…, xn) where g(x1,…, xn) is some exponential polynomial over C. In this paper, I will prove the analog of this theorem for Zilber's Pseudoexponential fields directly from the axioms. Furthermore, this proof relies only on the existential closedness axiom without any reference to Schanuel's conjecture.
Woodin's axiom (*), bounded forcing axioms, and precipitous ideals on ω1
Authors: Claverie Benjamin , Schindler Ralf
Published: April 2012

If the Bounded Proper Forcing Axiom BPFA holds, then Mouse Reflection holds at ℵ2 with respect to all mouse operators up to the level of Woodin cardinals in the next ZFC-model. This yields that if Woodin's ℙmax axiom (*) holds, then BPFA implies that V is closed under the “Woodin-in-the-next-ZFC-model” operator. We also discuss stronger Mouse Reflection principles which we show to follow from strengthenings of BPFA, and we discuss the theory BPFA plus “NSω1 is precipitous” and strengthenings thereof. Along the way, we answer a question of Baumgartner and Taylor, [2, Question 6.11].
ℙmax variations for separating club guessing principles
Authors: Ishiu Tetsuya , Larson Paul B.
Published: April 2012

In his book on ℙmax [7], Woodin presents a collection of partial orders whose extensions satisfy strong club guessing principles on ω1. In this paper we employ one of the techniques from this book to produce ℙmax variations which separate various club guessing principles. The principle (+) and its variants are weak guessing principles which were first considered by the second author [4] while studying games of length ω1. It was shown in [1] that the Continuum Hypothesis does not imply (+) and that (+) does not imply the existence of a club guessing sequence ω1. In this paper we give an alternate proof of the second of these results, using Woodin's ℙmax technology, showing that a strengthening of (+) does not imply a weakening of club guessing known as the Interval Hitting Principle. The main technique in this paper, in addition to the standard ℙmax machinery, is the use of condensation principles to build suitable iterations.
Consistent Directions of Effect for Established Type 2 Diabetes Risk Variants Across Populations
Authors: Haiman Christopher A. , Fesinmeyer Megan D. , Spencer Kylee L. , Bůžková Petra , Voruganti V. Saroja , Wan Peggy , Haessler Jeff , Franceschini Nora , Monroe Kristine R. , Howard Barbara V. , Jackson Rebecca D. , Florez Jose C. , Kolonel Laurence N. , Buyske Steven , Goodloe Robert J. , Liu Simin , Manson JoAnn E. , Meigs James B. , Waters Kevin , Mukamal Kenneth J. , Pendergrass Sarah A. , Shrader Peter , Wilkens Lynne R. , Hindorff Lucia A. , Ambite Jose Luis , North Kari E. , Peters Ulrike , Crawford Dana C. , Le Marchand Loic , Pankow James S.
Published: April 2012

Common genetic risk variants for type 2 diabetes (T2D) have primarily been identified in populations of European and Asian ancestry. We tested whether the direction of association with 20 T2D risk variants generalizes across six major racial/ethnic groups in the U.S. as part of the Population Architecture using Genomics and Epidemiology Consortium (16,235 diabetes case and 46,122 control subjects of European American, African American, Hispanic, East Asian, American Indian, and Native Hawaiian ancestry). The percentage of positive (odds ratio [OR] >1 for putative risk allele) associations ranged from 69% in American Indians to 100% in European Americans. Of the nine variants where we observed significant heterogeneity of effect by racial/ethnic group (Pheterogeneity < 0.05), eight were positively associated with risk (OR >1) in at least five groups. The marked directional consistency of association observed for most genetic variants across populations implies a shared functional common variant in each region. Fine-mapping of all loci will be required to reveal markers of risk that are important within and across populations.
Formulation and evaluation of delayed-onset extended-release tablets of metoprolol tartrate using hydrophilic-swellable polymers
Authors: Dadarwal Subhash , Madan Sarika , Agrawal Shyam
Published: April 2012

Formulation and evaluation of delayed-onset extended-release tablets of metoprolol tartrate using hydrophilic-swellable polymers

In view of the circadian rhythm of cardiovascular diseases, a delayed-onset extended-release (DOER) formulation of metoprolol tartrate (MT) was prepared. This was achieved through dissolution-guided optimization of the proportion of Methocel K4M and Methocel K15M. Core erosion ratio was greater than 50 %, thereby showing steady release of the drug after the lag time until complete dissolution. Optimized formulation produced a lag phase of 6 h followed by complete release of 98.7 ± 2.1 % in 24 h. Water uptake study revealed that Methocel K15M has lower water uptake (30 ± 1 %) than Methocel K4M (40 ± 2 %) after 24 h. Axial swelling of polymers was higher than swelling in the radial direction. Drug-polymer interaction study precludes any interaction between drug and polymer. Such a drug delivery system may provide a viable alternative for effective management of hypertension and other related disorders. This work also proposes an approach to attain DOER for a hydrophilic drug by using a hydrophilic swellable polymer in press coat.
An evaluation of kinesthetic differentiation ability in monofin swimmers
Authors: Rejman Marek , Klarowicz Andrzej , Zatoń Krystyna
Published: April 2012

Purpose

The aim of this study was to compare the ability of monofin swimmers in reproducing the bending forces that act on a monofin's surface through the specific leg movement present in swimming as well as the forces that the swimmers generated on a kinesthesiometer as part of a dry-land simulation trial.

Methods

Six men, members of the National Monofin Swimming Team, took part in the study. The level of the swimmers' kinesthetic response was defined by examining their repeatability in producing the bend forces that act on a monofin's surface as a reaction to water resistance and by investigation on the pressure force generated by a swimmer's lower limbs during dry-land tests on a kinesthesiometer.

Results and conclusions

It was established that a high level of kinesthetic response, estimated in the group of monofin swimmers, was the result of an adaptation evoked from the specificity of their sensory stimulus perception, received in the form of feedback from the monofin's large surface area.
The use of thermal imaging to evaluate body temperature changes of athletes during training and a study on the impact of physiological and morphological factors on skin temperature
Authors: Chudecka Monika , Lubkowska Anna
Published: April 2012

Purpose

The aim of this study was to assess the temperature changes of selected body surfaces (the arm and forearm) as a response to 90-minute physical exercise as well as to analyze the impact of physiological and morphological factors on the dynamics of temperature change.

Methods

A study group that consisted of 12 professional volleyball players was subjected to endurance training which lasted 90 minutes. Numerous physiological and morphological factors were measured, with mean temperatures registered from the body surface of the upper extremities before, immediately after, and ten min after physical effort by a thermal camera (SC500 ThermaCAM camera) at room temperature.

Results

After physical exercise, a fall in skin temperature resulting from prolonged sweating during the dynamic exercise tests was observed. The temperature changes in volleyball players, recorded in a series of tests, were found to be larger on the front surfaces of their upper extremities when compared to the rear. In addition, statistically significant positive correlation between maximum oxygen uptake (VO2max) and %HRmax, calculated with the decrease in skin temperatures, was found.

Conclusions

The strong and statistically significant influence of maximum oxygen uptake on the drop in surface temperature of the upper extremities (arm and forearm) immediately after the exercise indicates that thermography can be used as an additional, non-invasive method that provides information on a player's fitness level in comparison to other athletes.
The influence of the way of planning teaching content on the effectiveness of mastering self-defence techniques
Authors: Zalech Mirosław
Published: April 2012

Purpose

The improvement of a learning process through transferring a skill already acquired to another one which is being learnt is one of the factors contributing to increasing the effectiveness of teaching. The aim of this study was to compare the effectiveness of teaching performed on the basis of two plans, i.e. a traditional (intuitive) one and a network one.

Methods

A pedagogical experiment covering 13 weekly sessions of self-defence elements were taught. The control group was taught according to an algorithm developed in a traditional (intuitive) way, whereas the experimental group was taught according to a algorithm developed on the network model. After the sessions had been completed, five experts evaluated the acquisition level of three randomly selected elements. The results obtained by 32 men (average age 21.29 ± 0.76 years) from the experimental group and 32 men from the control group (average age 21.18 ± 0.87 years) were analysed statistically with the Student's t-test, two-way analysis of variance (ANOVA) and the Fisher post-hoc test.

Results

The experts did not differ in evaluating both groups (p < 0.05). Moreover, no interactions were revealed (p < 0.05) between the method of planning the teaching programme and the experts who evaluated the acquisition level of the taught elements. The only significant difference between the experimental group and the control group was observed in the method of planning the teaching programme, according to which self-defence elements were taught (p < 0.01).

Conclusions

The acquisition level of the taught self-defence elements according to the algorithm developed by basing it on the network model turned out to be significantly higher than in the case of those elements taught in the traditional (intuitive) planning process.
Usage of Information and Communication Technology in Micro Enterprises in the Last Decade
Authors: Žnidaršič Anja , Werber Borut
Published: April 2012

Usage of Information and Communication Technology in Micro Enterprises in the Last Decade

The paper presents the comparison of Information and Communication Technology (ICT) usage in Slovenian micro enterprises, using data derived from two studies carried out in years 1999 and 2009. Data for the studies were collected via structured interviews with owners or top managers of micro enterprises. We compared hardware and software equipment, business properties, characteristics of the interviewees and their impact on the successful use of ICT. The results show considerable changes in the ICT equipment, but that does not reflect in a better use of software compared to a decade ago. Key factors of successful use of ICT remain the same. The investment in ICT depends on owners' decisions and the most important factors are the owners' formal education and their skills and knowledge in ICT field. It was indicated that in recent years the investment of education in ICT field for both groups, owners and employees, was considerable lowered.
Effect of Olympic Weight Category on Performance in the Roundhouse Kick to the Head in Taekwondo
Authors: Estevan Isaac , Falco Coral , Álvarez Octavio , Molina-García Javier
Published: April 2012

Effect of Olympic Weight Category on Performance in the Roundhouse Kick to the Head in Taekwondo

In taekwondo, kick performance is generally measured using impact force and time. This study aimed to analyse performance in the roundhouse kick to the head according to execution distance between and within Olympic weight categories. The participants were 36 male athletes divided into three categories: featherweight (n = 10), welterweight (n = 15) and heavyweight (n = 11). Our results show that taekwondo athletes in all weight categories generate a similar relative impact force. However, the results indicate that weight has a large impact on kick performance, particularly in relation to total response time.
The Effect of Introducing a Smaller and Lighter Basketball on Female Basketball Players' Shot Accuracy
Authors: Podmenik Nadja , Leskošek Bojan , Erčulj Frane
Published: April 2012

The Effect of Introducing a Smaller and Lighter Basketball on Female Basketball Players' Shot Accuracy

Our study examined whether the introduction of a smaller and lighter basketball (no. 6) affected the accuracy of female basketball players' shots at the basket. The International Basketball Federation (FIBA) introduced a size 6 ball in the 2004/2005 season to improve the efficiency and accuracy of technical elements, primarily shots at the basket. The sample for this study included 573 European female basketball players who were members of national teams that had qualified for the senior women's European championships in 2001, 2003, 2005 and 2007. A size 7 (larger and heavier) basketball was used by 286 players in 1,870 matches, and a size 6 basketball was used by 287 players in 1,966 matches. The players were categorised into three playing positions: guards, forwards and centres. The results revealed that statistically significant changes by year occurred only in terms of the percentage of successful free throws. With the size 6 basketball, this percentage decreased. Statistically significant differences between the playing positions were observed in terms of the percentage of field goals worth three points (between guards and forwards) and two points (between guards and centres). The results show that the introduction of the size 6 basketball did not lead to improvement in shooting accuracy (the opposite was found for free throws), although the number of three-point shots increased.
Petrology of plagiogranite from Sjenica, Dinaridic Ophiolite Belt (southwestern Serbia)
Authors: Milovanović Dragan , Srećković-Batoćanin Danica , Savić Marija , Popovic Dana
Published: April 2012

Petrology of plagiogranite from Sjenica, Dinaridic Ophiolite Belt (southwestern Serbia)

The Sjenica plagiogranite occurs in the southern part of the Dinaridic Ophiolite Belt, 5 km northwest of Sjenica. The main minerals are albite with strongly altered biotite (replaced with chlorite), with occasional amphibole (magnesio hornblende to tschermakite) and quartz. An enclave of fine-grained granitic rocks with garnet grains was noted too. Secondary minerals are calcite and chlorite (daphnite). Major, trace and REE geochemistry coupled with field observations support a model by which the Sjenica plagiogranite could be formed by fractional crystallization of mantle origin mafic magma in a supra-subduction zone setting. Occurrences of calcite and chlorite nests in the Sjenica plagiogranites revealed that these rocks underwent hydrothermal alteration due to intensive sea water circulation in a sub-sea-floor environment.
Ichnology of Upper Cretaceous deep-sea thick-bedded flysch sandstones: Lower Istebna Beds, Silesian Unit (Outer Carpathians, southern Poland)
Authors: Rajchel Jacek , Uchman Alfred
Published: April 2012

Ichnology of Upper Cretaceous deep-sea thick-bedded flysch sandstones: Lower Istebna Beds, Silesian Unit (Outer Carpathians, southern Poland)

The Ophiomorpha rudis ichnosubfacies of the Nereites ichnofacies was recognized in thick- and very thick-bedded sandstones of the Lower Istebna Beds (Campanian-Maastrichtian), which were deposited mainly in deep-sea clastic ramps and aprons. It contains mainly Ophiomorpha rudis (produced by deeply burrowing decapod crustaceans) and rarely Zoophycos isp. and Chondrites isp. The impoverished Paleodictyon ichnosubfacies of the Nereites ichnofacies is present in the medium- and thin-bedded packages of flysch sandwiched between the thick- and very thick-bedded sandstones. They contain Chondrites isp., Phycosiphon incertum, Planolites isp., Arthrophycus strictus, Thalassinoides isp., Ophiomorpha annulata, O. rudis, Scolicia strozzii and Helminthorhaphe flexuosa. The relatively low diversity of this assemblage is influenced by limited areas covered by muddy substrate, which favours deep-sea tracemakers, and partly by a lowered oxygenation in the sediment.
Paleoecology of the Upper Eocene-Lower Oligocene Malcov Basin based on the calcareous nannofossils: a case study of the Leluchów section (Krynica Zone, Magura Nappe, Polish Outer Carpathians)
Authors: Oszczypko-Clowes Marta , Żydek Bartłomiej
Published: April 2012

Paleoecology of the Upper Eocene-Lower Oligocene Malcov Basin based on the calcareous nannofossils: a case study of the Leluchów section (Krynica Zone, Magura Nappe, Polish Outer Carpathians)

During the period of ca. 20 Ma (Middle Eocene-Chattian) the Leluchów Succession of the Magura Basin passed through drastic changes of sedimentary condition and paleobathymetry from well oxygened red shales withReticulofragmium amplectens, deposited beneath CCD, redGlobigerinaoozes, to oxygen depleted organic-rich menilite-type shales and finally to flysch deposition of open marine conditions. The biostratigraphic and lithostratigraphic scheme is well established with the Leluchów Marl Member — Zones NP19-20 to NP22 (Late Eocene-Early Oligocene), Smereczek Shale Member, Zone NP23 (Early Oligocene) and the Malcov Formation s.s., Zone NP24 (Early-Late Oligocene). The aim of the paper is to present the quantitative analyses as the basis for paleoecological changes in the Magura Basin during the Late Eocene-Late Oligocene period. The changes manifest themselves through a decrease in the water temperature and progressing eutrophication. Species typical of brackish water conditions and restricted to the Paratethys region were identified from the NP23 Zone.
Location of Processor Allocator and Job Scheduler and Its Impact on CMP Performance
Authors: Zydek Dawid , Chmaj Grzegorz , Shawky Alaa , Selvaraj Henry
Published: April 2012

Location of Processor Allocator and Job Scheduler and Its Impact on CMP Performance

High Performance Computing (HPC) architectures are being developed continually with an aim of achieving exascale capability by 2020. Processors that are being developed and used as nodes in HPC systems are Chip Multiprocessors (CMPs) with a number of cores. In this paper, we continue our effort towards a better processor allocation process. The Processor Allocator (PA) and Job Scheduler (JS) proposed and implemented in our previous works are explored in the context of its best location on the chip. We propose a system, where all locations on a chip can be analyzed, considering energy used by Network-on-Chip (NoC), PA and JS, and processing elements. We present energy models for the researched CMP components, mathematical model of the system, and experimentation system. Based on experimental results, proper placement of PA and JS on a chip can provide up to 45% NoC energy savings.
Sensor-Actor Network Solution for Scalable Ad-hoc Sensor Networks
Authors: Chaczko Zenon , Chiu Christopher , Aslanzadeh Shahrzad , Dune Toby
Published: April 2012

Sensor-Actor Network Solution for Scalable Ad-hoc Sensor Networks

Architects of ad-hoc wireless Sensor-Actor Networks (SANETS) face various problems and challenges. The main limitations relate to aspects such as the number of sensor nodes involved, low bandwidth, management of resources and issues related to energy management. In order for these networks to be functionally proficient, the underlying software system must be able to effectively handle unreliable and dynamic distributed communication, power constraints of wireless devices, failure of hardware devices in hostile environments and the remote allocation of distributed processing tasks throughout the wireless network. The solution must be solved in a highly scalable manner. This paper provides the requirements analysis and presents the design of a software system middleware that provides a scalable solution for ad-hoc sensor network infrastructure made of both stationary and mobile sensors and actuators.
Aphids (Hemiptera: Aphididae) of midfield thickets in an agricultural landscape
Authors: Bennewicz Janina
Published: April 2012

Aphids (Hemiptera: Aphididae) of midfield thickets in an agricultural landscape

The occurrence and structure of associations and communities of aphids (Hemiptera: Aphididae) in different types of midfield thickets (boundaries, bushes and "forest islands") characteristic of the Lower Vistula River Valley region are described. The study shows that midfield thickets in an agricultural environment are more attractive to aphids than those in a landscape park. It indicates that aphids choose sites with a superior availability and quantity of food and where midfield thickets border a large area of fields under cultivation. Midfield thickets are habitats which are either not inhabited by aphid species considered to be plant pests, or are treated by them as sites for further dispersal. Moreover, the aphids are often subspecies not regarded as pests, as in the case of Aphis fabae, or they feed mainly on herbaceous plants, like Hyalopterus pruni, which is most commonly recorded on common reed.
Five tortricines from Malaysia and New Caledonia (Lepidoptera: Tortricidae)
Authors: Razowski Józef
Published: April 2012

Five tortricines from Malaysia and New Caledonia (Lepidoptera: Tortricidae)

Aoupinieta gen. n. and Homalernis mankoboi sp. n., H. jeriau sp. n., Peraglyphis silvana sp. n., Aoupinieta hollowayi sp. n., A. novaecaledoniae sp. n. are described as new. Arotrophora crustata Meyrick is transferred to Peraglyphis Common. Peraglyphis is new to the Oriental region.
Tortricines in the fauna of Nepal (Lepidoptera: Tortricidae)
Authors: Razowski Józef
Published: April 2012

Tortricines in the fauna of Nepal (Lepidoptera: Tortricidae)

Five species of Tortricini and one Polyorthini are reported from Nepal. Acleris ganesia, A. gothena and Sociosa nesima are described as new. The hitherto unknown female genitalia of A. monagma Diakonoff are described, and data on the external variation in some species are provided.
The Influence of the Type of Soil Management on Their Buffer Properties
Authors: Brągiel Piotr
Published: April 2012

Wpływ Sposobu Użytkowania Na Właściwości Buforowe Gleb
Data Matrix in the PCB production
Authors: Marchewka Adam , Zdrojewski Jarosław
Published: April 2012

Data Matrix in the PCB production

This article presents an approach to Data Matrix code analysis used during preparation of the exposure machine. Tasks realized by the machine are described in a defined way. The choice of description and the verification of film choice correctness are performed automatically, based on data from camera images. This method allows automating the settings and transmission of specific data for the performed task.
Analytical, Numerical and Experimental Examination of Reinforced Composites Beams Covered with Carbon Fiber Reinforced Plastic
Authors: Kasimzade A. , Tuhta S.
Published: April 2012

Analytical, Numerical and Experimental Examination of Reinforced Composites Beams Covered with Carbon Fiber Reinforced Plastic

In the article, analytical, numerical (Finite Element Method) and experimental investigation results of beam that was strengthened with fiber reinforced plastic-FRP composite has been given as comparative, the effect of FRP wrapping number to the maximum load and moment capacity has been evaluated depending on this results. Carbon FRP qualitative dependences have been occurred between wrapping number and beam load and moment capacity for repair-strengthen the reinforced concrete beams with carbon fiber. Shown possibilities of application traditional known analysis programs, for the analysis of Carbon Fiber Reinforced Plastic (CFRP) strengthened structures.
Dong Hai Bridge – Wave Load Study for Low Pier Foundations of 70m Spans
Authors: Huangfu Xi , Yan Aihua , Liu Hongyan
Published: April 2012

Horizontal force from wave to foundations is one of the critical design loads in foundation design of sea-crossing bridges. It can essentially control the design of the bridge. This paper describes the study and verification of wave load on low pier foundations of 70m spans in Dong Hai Bridge (also known as East Ocean Bridge or East Sea Bridge), including determination of design wave conditions, selection of calculation methods, wave physical modelling test, etc.
A Full-scale Experiment on Vibration Mitigation of Stay Cable
Authors: Sun Limin , Shi Chen , Zhou Haijun , Cheng Wei
Published: April 2012

Mechanical dampers are often installed near to anchorages of stay cables for mitigating vibrations due to wind or wind/rain. However, the optimal damping estimated by a linear theory is hard to be obtained and an efficiency factor between the designed damping and the practical one has to be considered for design. In this study, experiments of cable-damper system were conducted by using a 215 meters long full-scale stay cable. 7 types of mechanical dampers, including oil damper, viscous damper and MR damper, were adopted. The experimental results show that an inner type damper provided an additional damping (log decrement) 0.013, other outer type dampers provided additional damping larger than 0.030. Based on the experimental results, the authors suggest that the efficiency factor should be 0.3 for an inner type damper, and 0.5 for an outer type damper. The nonlinear design theory was also preliminarily studied.
Dong Hai Bridge – Design and Test of 10,000DWT Collision Protection for Piers on Main Navigational Channel
Authors: Huang Rong , Deng Qing'er , Yan Aihua
Published: April 2012

Design of Dong Hai Bridge (also known as East Ocean Bridge or East Sea Bridge) considers collision of up to 10,000DWT ships in the main navigational channel. Collision protective dolphins are installed at main piers. This paper describes the design concept and corresponding tests on collision protection for the project. Fixed dolphins are at main piers installed in the transverse direction to the bridge alignment and steel pipe piles are used as foundation. Physical ship collision modelling was made by simulation of the dolphin and ship stiffnesses, which determined the design standard for collision force and provided basis for the shape and design of the dolphins. Integration of dolphins and piers was also proposed Dolphins consisting of a steel spatial structure are at main piers installed as protection along the bridge axis. Mathematical modelling and physical model tests were also undertaken in order to identify the influence of dolphins to wave load on piers, and in order to verify the feasibility and give guidance to design of the steel dolphins.
Hong Kong-Shenzhen Western Corridor and Deep Bay Link: Design Development and Environmental Challenges
Authors: Lee Joseph , Kong Alex , Chan Eric
Published: April 2012

The Hong Kong-Shenzhen Western Corridor (HK-SWC) and the Deep Bay Link (DBL) are two highway projects located near the north-western boundary of the Hong Kong Special Administrative Region (HKSAR). The HK-SWC will be the fourth vehicular boundary crossing between two of the most prosperous cities in the southern part of China: Hong Kong and Shenzhen. The DBL will link the HK-SWC to Hong Kong's strategic highway system via the Yuen Long Highway. This Paper describes some of the main challenges of these two projects at the planning and design stages, notably the necessary environmental protection measures and how these have been addressed in conjunction with design development of the bridgework, as well as the special challenges posed by the design liaison with the Shenzhen side.
Radiolabelling Studies of Free Radicals Using Muonium (The Second Hydrogen Radioisotope)
Authors: Rhodes Christopher J.
Published: April 2012

An overview is presented of the way various spectroscopic/radioisotopic-labelling methods (MuSR), in which free radicals are labelled with the light hydrogen radioisotope muonium, may be employed in the study of free radical reaction kinetics and dynamics. Specifically considered are: the reaction rates of thiyl radicals and related species in relation to biological membrane damage; the dynamics of radicals sorbed in solid catalysts and in activated carbons and other porous particulate materials of environmental significance; reacting gas-phase systems; mechanisms for the formation of muon (muonium) labelled radicals, and the study of radical stabilisation and reactivity.
Proton Transfer in Bacterial Reaction Centers and Bacteriorhodopsin in the Presence of Dipyridamole
Authors: Knox P.P. , Lukashev E.P. , Mamedov M.D. , Semenov A. Yu. , Borissevitch G.P.
Published: April 2012

Dipyridamole, 2,6-bis(diethanolamino)-4,8-dipiperidinopyrimido[5,4-d]pyrimidine (DIP), a well known vasodilator and inhibitor of membrane peroxidation has recently been shown a potential co-activator (modulator) in the MDR phenomenon in cancer therapy. It inhibits P-glycoprotein (Pgp) which is a efflux pump of anticancer drugs in tumor cells. For the first time it is shown that dipyridamole, markedly slows down the kinetics of the electrogenic phase of the photoelectric response in Rb. sphaeroides chromatophores which is due to the proton transfer from the external medium to the secondary quinone acceptor in the reaction center. In purple membranes from H. salinarium containing bacteriorhodopsin (bR) dipyridamole (in its charged state) significantly slows down the kinetics of the proton transfer to the Schiff base from the primary donor Asp-96 (in wild type bacteria) or from the surrounding (in D96N mutant). Dipyridamole is supposed to affect the proton-transfer via changes in structural dynamics of membrane proteins including modification of their system of hydrogen-bonds.
Photochemistry of 1,N-Diiodoalkanes
Authors: Miranda Miguel A. , Pérez-Prieto Julia , Font-Sanchis Enrique , Scaiano J. C.
Published: April 2012

This article reviews the photochemistry of 1,n-diiodoalkanes, with special emphasis on the involved intermediates. Photolysis of 1,1-diiodomethane produces homolytic cleavage of the C–I bond to give the α-iodo radical, which in solid matrix cannot dissociate but collapses to isodiiodomethane. However, in solution subsequent electron-transfer produces the α-iodo cation, which is able to achieve cyclo-propanation of olefins. In the case of 1,2-diiodides, their photolysis gives rise to β-iodoalkyl radicals which usually lose iodine very rapidly, forming a carbon-carbon double bond. Homolytic cleavage of 1,n-diiodoalkanes (n>2) affords n-iodo radicals which are stabilized by participation of the remaining iodine atom. The cyclic hypervalent iodine radicals thus generated have low reactivity towards oxygen and characteristic UV spectra whose λmax depends on the ring size. These intermediates can be photolyzed, with iodine extrusion and formation of 1,2-diphenylcycloalkanes. On the other hand, photoinduced electron-transfer between carbanionic nucleophiles and 1,n-diiodoalkanes produces n-iodo radicals, which couple with the nucleophile leading to radical anions. Intramolecular electron-transfer from the radical anion to the σ* MO of the remaining C–I bond may compete with intermolecular electron-transfer to the substrate. This type of processes have been used for the synthesis of mono- and disubstituted adamantane derivatives. Finally, photoinduced electron-transfer between aromatic amines and 1,n-diiodoperfluoroalkanes (n>2) allows the preparation of fluorine containing heteroaromatic compounds.
Radical Pairs in Solution
Authors: Woodward J. R.
Published: April 2012

Radical pairs (RPs) are important reaction intermediates generated whenever two radicals encounter one another, a bond is cleaved homolytically or electron transfer between non-radical species takes place. The concept of a radical pair as a reaction intermediate is introduced and developed through simple pictorial analogies, indicating how RP behaviour is governed by interplay of spin and spatial motion. Such analogies are then extended to describe the experimental consequences of RPs in magnetic resonance and magnetochemistry experiments, including reference to the relevance of RPs in biological systems. Finally experimental techniques by which RPs can be observed directly are introduced and described in the context of the developed models.
Chemical, Biological and Medical Controversies Surrounding the Fenton Reaction
Authors: Burkitt Mark J.
Published: April 2012

A critical evaluation is made of the role of the Fenton reaction (Fe2+ + H2O2 → Fe3+ + •OH + OH-) in the promotion of oxidative damage in mammalian systems. Following a brief, historical overview of the Fenton reaction, including the formulation of the Haber–Weiss cycle as a mechanism for the catalysis of hydroxyl radical production, an appraisal is made of the biological relevance of the reaction today, following recognition of the important role played by nitric oxide and its congers in the promotion of biomolecular damage. In depth coverage is then given of the evidence (largely from EPR studies) for and against the hydroxyl radical as the active oxidant produced in the Fenton reaction and the role of metal chelating agents (including those of biological importance) and ascorbic acid in the modulation of its generation. This is followed by a description of the important developments that have occurred recently in the molecular and cellular biology of iron, including evidence for the presence of ‘free’ iron that is available in vivo for the Fenton reaction. Particular attention here is given to the role of the iron-regulatory proteins in the modulation of cellular iron status and how their functioning may become dysregulated during oxidative and nitrosative stress, as well as in hereditary haemochromatosis, a common disorder of iron metabolism. Finally, an assessment is made of the biological relevance of ascorbic acid in the promotion of hydroxyl radical generation by the Fenton reaction in health and disease.
Kinetic Isotope Effects as Probes for Hydrogen Tunneling, Coupled Motion and Dynamics Contributions to Enzyme Catalysis
Authors: Kohen Amnon
Published: April 2012

Since the early days of enzymology attempts have been made to deconvolute the various contributions of physical phenomena to enzyme catalysis. Here we present experimental and theoretical studies that examine the possible role of hydrogen tunneling, coupled motion, and enzyme dynamics in catalysis. In this review, we first introduce basic concepts of enzyme catalysis from a physical chemistry point of view. Then, we present several recent developments in the application of experimental tools that can probe tunneling, coupled motion, dynamic effects and other possible physical phenomena that may contribute to catalysis. These tools include kinetic isotope effects (KIEs), their temperature dependency and H/D/T mutual relations (the Swain–Schaad relationship). Several theories and models that assist in understanding those phenomena are also described. The possibility that these models invoke a direct role for the enzyme's dynamics (environmental fluctuations and rearrangements) is discussed. Finally, the need to compare the enzymatic reaction to the uncatalyzed one while investigating contributions to catalysis is emphasised.
On the Chemistry of Inorganic Free Radicals in Cloud Water
Authors: Buxton George V. , Salmon G. Arthur
Published: April 2012

The chemistry by which the inorganic free radicals •OH, HO2•, O2•-, SOx•- (x = 3, 4, 5), NO3•, Cl• and Cl2•- lead to the formation of acid rain by the oxidation of sulfur dioxide and organic pollutants in cloud water is discussed in detail. Also considered are the sources of the radicals, their relative reactivities, their inter-conversion and the origins of the pollutants with which they react.
Intermolecular and Intramolecular Transamidation Reactions
Authors: González-Rosende M. Eugenia , Castillo Encarna , Lasri Jamal , Sepúlveda-Arques Jose
Published: April 2012

The amide functional group is resonance stabilised and direct reaction with amines is known to be difficult. Facile amide exchange reactions would enable the synthesis of important new amide based molecules, therefore transamidation reactions represent an important step in this direction. In order to ensure a transamidation reaction takes place, special requirements and conditions are required. According to the different structural characteristics of the carbox-amide group and types of activation, the most relevant examples of this reaction will be reviewed.
The 2-Norbornyl Cation is not a Single Minimum Energy System
Authors: Mamantov Andrew
Published: April 2012

Simple and dual variable linear regression equations are presented which can estimate the sensitivity constants ρ for the solvolysis reactions of hundreds of bicyclic and tricyclic compounds. These are the first QSARs which utilize dihedral angles to estimate/predict ρ constants. These QSARs and other analyses herein support the new theory that the bridgehead hydrogen bond orbital assists the displacement of the exo leaving group in the solvolyses of 2-norbornyl derivatives. Alternative interpretions of the 1H NMR and 13C NMR spectra indicate that C1 is hypercoordinated rather than C6. Consequently, in normal hydroxylic solvents the 2-norbornyl cation is not symmetrical, does not require C—C σ-bond bridging and is not a single minimum energy system, i.e. it is a pair of rapidly equilibrating cations, eq 1, structure 2b. At ≤ −158°C, the 2-norbornyl cation is proposed to be an H—C1—H σ-bond delocalized resonance hybrid structure 16/16’. Hypotheses are presented which suggest that the norbornane system can be viewed as a saturated counterpart of a conjugated π system, e.g. benzene. This new delocalization and bond concept, sigma aromaticity, can also help to explain the preferential “exo'’ reactions of norbornane and norbornene systems, the unusual stability of the 2-norbornyl cation, and perhaps provide new insight concerning the ubiquitousness of six-membered rings. Sigma aromaticity may also help account for the greater efficiency of singlet energy transfer between chromophores when the molecular spacer group is rigid rather than flexible, and electron transfer in DNA.
Molecular Dynamics Simulations of Dna and Its Complexes
Authors: Khalid Syma , Rodger P.Mark
Published: April 2012

This article describes how classical molecular simulation methods are being used to gain a molecular-level understanding of the interaction mechanisms responsible for DNA–ligand recognition, and that govern the response of DNA to ligand binding. Case studies using a variety of different ligands—including small pharmaceutical drugs, proteins and lipids—are used to illustrate the power of modern molecular dynamics simulation methods for understanding how we may control the function and structure of DNA.
Kinetic Studies of Atomic Carbon, C[2p2 (3PJ)], with Thiols by Time-Resolved Atomic Resonance Absorption Spectroscopy in the Vacuum Ultraviolet
Authors: Deeyamulla Mahendra P. , Husain David
Published: April 2012

Reaction rates of atomic carbon in its electronic ground state, C[2p2 (3PJ)], with a range of large sulfur-containing molecules have been investigated using time-resolved atomic spectroscopy in the vacuum ultraviolet following pulsed irradiation. Absolute rate data for the collisional removal at 300 K of C(23PJ) by the gases 1-propanethiol, 1-butanethiol, 1-pentanethiol, 2-propanethiol, 2-methyl-1-propanethiol, 2-methyl-2-propanethiol and dimethyl sulfide are reported. All processes proceed at rates of the order of the collision numbers, supporting an overall mechanism of C-atom insertion into the S–H bond following initial addition, which is energetically favourable, a mechanism demonstrated analogously hitherto with H2S and where H-atom abstraction would also be endothermic.
Studies on the Thermodynamic and Kinetic Properties of Reactions of Bo(Bs) with H2
Authors: Yin Ping , Hu Yucai , Zheng Hegen , Du Qingjun , Liu Bing , Jiang Wei
Published: April 2012

The thermodynamic and kinetic properties of reactions of BO (BS) with H2 have been investigated within the temperature range of 200 – 1200 K using general statistical thermodynamics and transition state theory with the Wigner correction. It is concluded that the orders of their equilibrium constants and reaction rate constants are similar, especially at high temperature. Moreover, reaction 2 and reaction 4 have both thermodynamic and kinetic advantages over the whole temperature range for the BO=H2 and BS=H2 system, respectively.
Converging Environmental Knowledge: Re-evaluating the Birth of Modern Environmentalism in Finland
Authors: Räsänen Tuomas
Published: April 2012

In this article I wish to challenge the current scholarly consensus on the origins of modern environmentalism in Finland. Finnish environmental history literature has emphasised the assumption that Rachel Carson's Silent Spring transformed environmental ideas and policy in Finland, as it allegedly did in some other countries. Basing the argument on the scientific research on toxic pollution in Finland and Sweden in the 1960s and early 1970s, I argue that the decisive and transforming influence originated instead from Swedish science. It was only after Swedish scientists had presented evidence that the Swedish environment was severely contaminated by toxic chemicals that Finns launched their own research projects verifying these findings in Finland too. This caused a sense of anxiety among the Finnish public and galvanised not only the Finnish environmental movement but also Finnish society as a whole. The article concludes by sketching a preliminary model for further research on the birth of modern environmentalism.
Biologists Bridging Science and the Conservation Movement: The Rise of Nature Conservation and Nature Management in the Netherlands, 1850-1950
Authors: van der Wint Henny J.
Published: April 2012

This paper investigates the importance and various roles of amateur naturalists and biologists in the conservation movement between 1850 and 1950, in particular in the Netherlands. It is concluded that biological sciences were important resources for Dutch nature conservation, although the extent of their importance and the approaches taken varied considerably over the course of decades. Early on, amateur naturalists were leading 'movement intellectuals' who combined different types of knowledge, arguments for the protection of nature and practices in a new way. Later, after the institutionalisation of biology, the rise of ecology and the societal recognition of nature conservation, professional scientists developed new approaches and became more influential. They gave nature conservation more status and greater legitimacy. The founding of networks with scientists and other actors turned out to be of great importance. So a new societal role for biologists was created, but also a niche for ecological research. In the Netherlands, biologists had different strategies, some of them more appropriate for practical and political aims and for cooperation with amateurs than others. The Dutch interactions between scientists and conservation resemble those in Germany and the UK, but were quite different from those in Belgium.
Registration of ‘Kharoba’: A Bread Wheat Cultivar Developed through Doubled Haploid Breeding
Authors: Elhaddoury J. , Lhaloui S. , Udupa S.M. , Moatassim B. , Taiq R. , Rabeh M. , Kamlaoui M. , Hammadi M.
Published: April 2012

‘Kharoba’ (Reg. No. CV‐1068, PI 664028), a hard red spring wheat (Triticum aestivum L.) cultivar developed using doubled haploid technology by the Institut National de la Recherche Agronomique (INRA), Morocco, and tested as 00DHBW300, was approved for release in 2010 by the Office National de Sécurité Sanitaire des Produits Alimentaires (ONSSA), Morocco. Kharoba was selected from the doubled haploids derived from the cross ‘Altar 84’/Aegilops squarrosa 221//‘Pastor’/3/k134(6)/‘Veery’//‘Bobwhite’/‘Pavon’/4/‘Tilila’. Kharoba is a widely adapted, high‐yielding, short, erect cultivar having good end‐use qualities. Kharoba is resistant to leaf rust (caused by Puccinia triticina Eriks.), yellow rust (caused by P. striiformis Westend f. sp. tritici), the Hessian fly [Mayetiola destructor (Say)], and Fusarium head blight (caused by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schwein.) Petch]). Kharoba has been released for cultivation under both rainfed and irrigated conditions. Kharoba is the first bread wheat cultivar developed through doubled haploid breeding in Morocco.
Challenges in ductal carcinoma in situ risk communication and decision‐making
Authors: Partridge Ann H. , Elmore Joann G. , Saslow Debbie , McCaskill‐Stevens Worta , Schnitt Stuart J.
Published: April 2012

In September 2010, the American Cancer Society and National Cancer Institute convened a conference to review current issues in ductal carcinoma in situ (DCIS) risk communication and decision‐making and to identify directions for future research. Specific topics included patient and health care provider knowledge and attitudes about DCIS and its treatment, how to explain DCIS to patients given the heterogeneity of the disease, consideration of nomenclature changes, and the usefulness of decision tools/aids. This report describes the proceedings of the workshop in the context of the current literature and discusses future directions. Evidence suggests that there is a lack of clarity about the implications and risks of a diagnosis of DCIS among patients, providers, and researchers. Research is needed to understand better the biology and mechanisms of the progression of DCIS to invasive breast cancer and the factors that predict those subtypes of DCIS that do not progress, as well as efforts to improve the communication and informed decision‐making surrounding DCIS. CA Cancer J Clin 2012. © 2012 American Cancer Society.
Putative Population of Adipose-Derived Stem Cells Isolated from Mediastinal Tissue during Cardiac Surgery
Authors: Patel Amit N. , Yockman James , Vargas Vanessa , Bull David A.
Published: April 2012

Mesenchymal stem cells have been isolated from various adult human tissues and are valuable for not only therapeutic applications but for the study of tissue homeostasis and disease progression. Subcutaneous adipose depots have been shown to contain large amounts of stem cells. There is little information that has been reported to date describing the isolation and characterization of mesenchymal stem cells from visceral adipose tissue. In this study, we describe a mesenchymal stem cell population isolated from mediastinal adipose depots. The cells express CD44, CD105, CD166, and CD90 and are negative for hematopoietic markers CD34, CD45, and HLA-DR. In addition, the cells have a multilineage potential, with the ability to differentiate into adipogenic, osteogenic, and chondrogenic cell types. The biological function of visceral adipose tissue remains largely unknown and uncharacterized. However, the proximity of adipose tissue to the heart suggests a potential role in the pathogenesis of cardiovascular disease in obesity. In addition, with the ability of fat to regulate metabolic activity in humans, this novel stem cell source may be useful to further study the mechanisms involved in metabolic disorders.