bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of Endoparasites in Faecal Samples of Cracids Bred in Captivity at the Parque Dois Irmãos, Recife, Pernambuco, Brazil
Authors: Cunha A. L. B. , Mendonça F. S. , Oliveira R. A. , Baratella-Evêncio L. , Oliveira-Filho R. M. , Simões R. S. , Simões M. J. , Evêncio-Neto J.
Published: October 2008

Among the many problems arising from poor sanitation that can affect wild birds maintained in captivity, parasitic afflictions are among the most frequent, and their effects can range from subclinical infections to death. Some of the most common cases involve endoparasites, principally if the species under consideration exists at a high population density. This being so, the aim of the current work was to report on the prevalence of endoparasites in faecal samples from cracids (curassows and allies) bred in captivity at the Parque Dois Irmãos, Recife, Pernambuco state in Brazil. To do this, faecal and sand samples were collected from the enclosures of birds of the family Cracidae belonging to the collection from the Parque Dois Irmãos, which originated from private collections from the Metropolitan Region and Forest Zone of the State of Pernambuco. Four lots of faecal and sand samples were collected over a 60-day period, giving a total of 84 faecal samples from 58 individuals of 21 species of cracids. The material collected was submitted for coproparasitological tests using the right method and spontaneous sedimentation. The results obtained were positive for Strongyloides sp., Ascaridia sp., Capillaria sp. and cysts of Entamoeba coli, as well as eggs belonging to the superfamily Strongyloidea.
A Study on the Epidemiology of Bovine Brucellosis in Punjab (India) Using Milk-ELISA
Authors: Aulakh H. K. , Patil P. K. , Sharma S. , Kumar H. , Mahajan V. , Sandhu K. S.
Published: October 2008

Bovine brucellosis, caused by Brucella abortus, is a serious zoonotic disease manifested by reproductive disorders resulting in huge economic losses to dairy farmers. A random survey was conducted to study the epidemiology of brucellosis in Punjab (India) using sampling software Survey toolbox. Two-stage sampling procedure was adopted; in the first step, villages were selected randomly from sampling frame of all the villages of Punjab followed by selection of owners, and animals in individual farms were identified using random sampling. In all, 32 villages were selected and then 345 animals (approximately 5%) were sampled from these villages. The milk samples collected were screened for brucella antibodies employing ELISA test. The overall apparent prevalence of brucellosis was found to be 18.26% (true prevalence - 17.68%). The prevalence in the central zone of the state was significantly higher, viz. 23.2% (chi square = 11.34, p < 0.01) compared to 14.2% in the sub-mountainous zone and 5.8% in the arid irrigated zone. The disease prevalence was found to be non-significantly higher (chi square 1.029, p = 0.310) in cattle (20.67%) compared to buffaloes (16.41%) and increased with age (chi square = 8.572, p < 0.05) in both species. There was significant association between disease and abortion (chi square = 22.322, p < 0.01) and maximum abortion cases due to brucellosis were found in > 6 month of gestation (95.7%). The disease was significantly associated with the retention of placenta (chi square = 8.477, p < 0.01), however there was no significant relationship of the disease with repeat breeding (chi square = 0.044, p = 0.834). The results of the study suggested that the accurate epidemiological scenario of the disease may be obtained by employing multistage sampling procedures using milk-based ELISA.
Analysis of Goat Milk by Near-Infrared Spectroscopy
Authors: Dračková M. , Hadra L. , Janštová B. , Navrátilová P. , Přidalová H. , Vorlová L.
Published: October 2008

The objective of this study was to determine protein, fat, lactose, total solids, non-fatty solids contents, freezing point, titratable acidity and pH using Fourier transform near infrared spectroscopy (FT-NIR). Sixty samples of goat milk were used to calibrate the instrument by the partial least squares (PLS) method. The spectra were measured on the integration sphere in the reflectance mode with the use of a 0.1 mm wide transflectance cell. The following statistical values were obtained: correlation coefficient (R) = 0.920 and standard error of calibration (SEC) = 0.094 for protein, R = 0.951 and SEC = 0.124 for fat, R = 0.997 and SEC = 0.011 for lactose, R = 0.940 and SEC = 0.260 for total solids, R = 0.873 and SEC = 0.159 for non-fatty solids, R = 0.935 and SEC = 0.003 for freezing point, R = 0.952 and SEC = 0.295 for titratable acidity and R = 0.835 and SEC = 0.057 for pH. The calibration models developed were verified by cross validation. The study showed that FT-NIR is a potentially useful technique for evaluating the composition of goat milk.
Influence of Thermally Treated and Untreated Lupin Meal on the Indicators of Performance and Health Condition of Broilers
Authors: Straková E. , Suchý P. , Steinhauser L. , Krejčí T. , Pospíšil R.
Published: October 2008

The objective of the study was to test the productive effectiveness of complex feeding mixtures for broiler chickens containing lupin meal thermally treated or untreated and to assess their influence on the utility indicators and health condition of broilers. A total of 161 sexed broiler chickens of Ross 308 type were included in the experimental study. The group of cocks (LNM) and hens (LNF) fed a diet containing 10% untreated lupin meal reached a higher mean weight in comparison with the groups consuming a diet with the content of 10% meal treated by heat (LTM and LTF). The cocks in the LNM group reached a higher live weight (2 680.26 g) on day 42 compared with the cocks in the LTM group (2 591.28 g). A significantly higher weight (p ≤ 0.01) was proven in the hens in the LNF group (2 357.25 g) compared with the hens in the LTF group (2 241.22 g) on day 42. Blood was taken from vena basilica on day 42 in order to perform haematological and biochemical tests. In the native blood, the total numbers of erythrocytes (Er), the haematocrit value (Hc), haemoglobin (Hb), the mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), mean erythrocyte volume (MCV) and total leukocytes volume (Le) were determined. The assessed biochemical indicators in blood plasma included the total protein concentration (TP), glucose (Glu), cholesterol (Chol), catalytic concentration of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), plasmatic calcium (Ca), phosphorus (P) and magnesium (Mg). The results of haematological and biochemical tests ranged within physiological values. Some differences cannot be associated with the diets tested. The study results suggest the possibility of better utilization of thermally untreated lupin meal (compared with thermally treated lupin meal) for the nutrition of broiler chickens. The results achieved suggest both positive and economic effect (no costs for thermal treatment) in the case of no necessity of thermal treatment of lupin meal, when compared e.g. with soy meal, from the point of view of inactivation of anti-nutritional factors.
Nitrite Toxicity to Danio rerio: Effects of Subchronic Exposure on Fish Growth
Authors: Voslářová E. , Pištěková V. , Svobodová Z. , Bedáňová I.
Published: October 2008

The aim of this study was to investigate the long-term effects of subchronic exposure to sublethal levels of nitrite, ranging from 15 to 130 mg l-1 NO2-, on growth in aquarium fish Danio rerio. The juvenile growth test according to OECD 215 was used in the experiments. Fish weight was measured at the beginning of the experiment and then using the same method, fish weight was observed 28 days after fish stocking. Compared to the control, growth suppression was detected from the concentration of 73 mg l-1 NO2- (P < 0.05) and a significant inhibition of fish body growth was shown from 130 mg l-1 NO2- (P < 0.01). An exponential relationship between nitrite concentrations and specific growth rate (R2 = 0.896) was detected.
Oxytetracycline Assay in Pond Sediment
Authors: Nepejchalová L. , Svobodová Z. , Kolářová J. , Frgalová K. , Valová J. , Némethová D.
Published: October 2008

The fate of drug residues and their metabolites in the environment is relatively rarely investigated in the conditions of the Czech Republic, resulting in limited availability of scientific information. To demonstrate one example, we prepared a model study with medicated feedstuff containing oxytetracycline hydrochloride (OTC HCl), which was used in fish under normal conditions of use. The oxytetracycline (OTC) contents were determined in the sediments of the pond where the fish were treated. The ELISA method was used for OTC detection and the HPLC method was used for final quantification of OTC. The increasing contents of OTC in sediment depended on the repeated treatment and excretion of OTC by the fish. The concentration on day 59 after the last administration was 1516 μg kg-1 OTC in the sediment, which indicates a long-term persistence of the substance in the environment.
The Political Ethos of Palestinian Citizens of Israel: Critical Reading in the Future Vision Documents
Authors: Jamal Amal
Published: October 2008

In 2006-2007, several Arab nongovernmental organizations in Israel, led by a group of politicians and intellectuals, published future vision documents that summed up the needs, aspirations, hopes, and desires of Arab society in Israel. Despite the fact that the documents did not introduce any new ideas that were not on the Israeli political stage already, this article argues that the fact that the documents were a result of collective effort shows the deep changes that have been taking place among Arab society in general and its leadership in particular. The documents mark the rising tide of frustration and self-confidence, and as a result of oppositional consciousness among leaders and intellectuals of Arab society in Israel. The documents seek to redefine the relationship of Arab society with the Israeli state, demanding the transformation of Israel from an ethnic to a democratic state and calling the Jewish majority for a dialogue. The fact that several documents have emerged is a clear indication that the internal differences within Arab society are still stronger than the uniting forces within it.
Livelihood Choices and Returns among Pastoralists: Evidence from Southern Kenya
Authors: Radeny Maren , Nkedianye David , Kristjanson Patricia , Herrero Mario
Published: October 2008

Pastoral systems are rapidly changing in Africa and elsewhere, yet relatively little is known regarding what, and how well, households in these systems are now doing. This article addresses livelihood choices and income diversification strategies in a traditionally Maasai pastoral area of southern Kenya, and the factors influencing the returns to their diverse livelihood strategies. We explore how well household-level versus geographic factors explain the large variability in income and livestock wealth levels and the implications for wildlife conservation and poverty reduction strategies.
Making Pastoral Settlement Visible in China
Authors: Zukosky Michael L.
Published: October 2008

Seen in the built environment of village and towns, the plans of scientific texts and journals of modern animal husbandry, and in the programmes of state natural resource bureaucracies and international development projects, settlements constructed for nomadic peoples in China seem to index a historically and socially specific vision associated with modern political economic ideologies. Drawing on the work of James Scott (1996), one might argue that settlement is the vision of the Chinese state. Yet Scott's approach risks objectifying the embodied vision of the humans who constitute settlement. Indeed, many scholars have simplified the agency attributed to a range of actors within the experience of settlement. This article uses a phenomenological approach to make more complex our understandings of these phenomena by exploring perceptions of settlement among three distinct actors: officials from the Chinese states, personnel of international organizations which have funded and provided technical expertise in the implementation of settlements, and residents of settlements themselves - Chinese ethnic minority citizens. In conclusion, I offer three different but overlapping visions that make settlement as a totality possible, and yet distinct from an objectified vision of Chinese government officials.
Theoretical Conformational Analysis of Chemotactic Peptides Formyl-Met-Leu-Phe-OMe and Formyl-Met-Acc6-Phe-OMe
Authors: Wazady Youssef , Hassani Chakib  Ameziane , Lakhdar Mahjoub , Ezzamarty Aziz
Published: October 2008

In order to investigate the proper peptide backbone conformation that is biologically active, the chemotactic peptides formyl-Met-Leu-Phe-OMe and formyl-Met-Acc6-Phe-OMe (Acc6 is the a-a disubstituted amino acid l-aminocyclohexane-1-carboxylic acid) were studied by the theoretical method PEPSEA. This study shows that the parent peptide formyl-Met-Leu-Phe-OMe has a flexible structure, and that the other conformationally constrained peptide has a tendency to form the b turn structure. It also gives evidence against the hypothesis proposing the importance of a formyl group in the interaction with the receptor.
The Nature of the Chemical Process. 1. Symmetry Evolution – Revised Information Theory, Similarity Principle and Ugly Symmetry
Authors: Lin Shu-Kun
Published: October 2008

Symmetry is a measure of indistinguishability. Similarity is a continuous measure of imperfect symmetry. Lewis' remark that “gain of entropy means loss of information” defines the relationship of entropy and information. Three laws of information theory have been proposed. Labeling by introducing nonsymmetry and formatting by introducing symmetry are defined. The function L ( L=lnw, w is the number of microstates, or the sum of entropy and information, L=S+I) of the universe is a constant (the first law of information theory). The entropy S of the universe tends toward a maximum (the second law law of information theory). For a perfect symmetric static structure, the information is zero and the static entropy is the maximum (the third law law of information theory). Based on the Gibbs inequality and the second law of the revised information theory we have proved the similarity principle (a continuous higher similarity−higher entropy relation after the rejection of the Gibbs paradox) and proved the Curie-Rosen symmetry principle (a higher symmetry−higher stability relation) as a special case of the similarity principle. The principles of information minimization and potential energy minimization are compared. Entropy is the degree of symmetry and information is the degree of nonsymmetry. There are two kinds of symmetries: dynamic and static symmetries. Any kind of symmetry will define an entropy and, corresponding to the dynamic and static symmetries, there are static entropy and dynamic entropy. Entropy in thermodynamics is a special kind of dynamic entropy. Any spontaneous process will evolve towards the highest possible symmetry, either dynamic or static or both. Therefore the revised information theory can be applied to characterizing all kinds of structural stability and process spontaneity. Some examples in chemical physics have been given. Spontaneous processes of all kinds of molecular interaction, phase separation and phase transition, including symmetry breaking and the densest molecular packing and crystallization, are all driven by information minimization or symmetry maximization. The evolution of the universe in general and evolution of life in particular can be quantitatively considered as a series of symmetry breaking processes. The two empirical rules − similarity rule and complementarity rule − have been given a theoretical foundation. All kinds of periodicity in space and time are symmetries and contribute to the stability. Symmetry is beautiful because it renders stability. However, symmetry is in principle ugly because it is associated with information loss.
Improved Molecular Descriptors Based on the Optimization of Correlation Weights of Local Graph Invariants
Authors: Krenkel Germán , Castro Eduardo  A. , Toropov Andrey  A.
Published: October 2008

We report the calculation of boiling points for several alkyl alcohols through the use of improved molecular descriptors based on the optimization of correlation weights of local invariants of graphs. As local invariants we have used the presence of different chemical elements (i.e. C, H, and O) and the existence of different vertex degree values (i.e. 1, 2, 3 and 4). The inherent flexibility of the chosen molecular descriptor seems to be rather suitable to obtain satisfactory enough predictions of the property under study. Comparison with other similar approximation reveals a very good behavior of the present method. The use of higher order polynomials do not seem to be necessary to improve results regarding the simple linear fitting equations. Some possible future extensions are pointed out in order to achieve a more definitive conclusion about this approximation.
Molecular Approach to the Nyctinastic Movement of the Plant Controlled by a Biological Clock
Authors: Ueda Minoru , Takada Noboru , Yamamura Shosuke
Published: October 2008

Most leguminous plants close their leaves in the evening, as if to sleep, and open them early in the morning. This circadian rhythm is known to be controlled by the biological clock of such plants. Extensive studies on other nyctinastic plants led to the isolation of a variety of leaf-closing and leaf-opening substances. And, we found that the circadian rhythmic leaf-movement of these plants is controlled by a biological clock that regulates the balance of concentration between leaf-opening and -closing substances.
Papers from Euroconference on Molecular Mechanism of Heterogeneous Catalysis Held in San Feliu de Guixols (Spain) in June 2001
Authors: Illas Francesc , Ricart Josep
Published: October 2008

Heterogeneous catalysis is of immense technological and economic importance on a global scale because it provides the backbone of the world’s chemical and oil industries.[...]
Reaction Mechanism and Control of Selectivity in Catalysis by Oxides: Some Challenges and Open Questions
Authors: Centi Gabriele , Perathoner Siglinda
Published: October 2008

Some aspects of the reaction mechanisms in multistep selective (amm)oxidation reactions over oxide surfaces are discussed evidencing some of the challenges for surface science and theory in describing these reactions, and for applied catalysis in order to have a more in deep identification of the key factors governing surface reactivity and which may be used to improve catalytic performances. In particular, the role of chemisorbed species in the modification of the surface reactivity and the presence of multiple pathways of reaction are evidenced by comparing the behavior of V-based catalysts in C3-C4 alkanes and alkene oxidation.
Electronic Structure and Reactivity of TM-Doped La1-xSrxCoO3 (TM=Ni, Fe) Heterogeneous Catalysts
Authors: Grice S.  C. , Flavell W.   R. , Thomas A.   G. , Warren S. , Marr P.   G. D. , Jewitt D.   E. , Khan N. , Dunwoody P.   M. , Jones S.   A.
Published: October 2008

The catalytic properties of LaCoO3 in aqueous oxidation are explored as a function of doping. Both Sr substitution for La and Fe/Ni substitution for Co are studied. The reaction of interest is the aqueous epoxidation of crotyl alcohol with hydrogen peroxide. The reaction products are measured using GC, and the decomposition of hydrogen peroxide is studied using the volume of oxygen evolved during reaction. Strong variations in the activity to epoxide formation are observed, with Fe-doped samples being rather inactive in the reaction. SR VUV photoemission is used to explore the surface reactivity of the ceramic catalysts in aqueous solution, using H2O as a probe molecule. These measurements are complemented by XANES measurements designed to probe the local defect structure and XPS measurements of surface composition. We relate the observed catalytic activity to the defect structure of the doped materials. In Ni-doped materials, oxygen vacancies appear to be the predominant defect, whereas in Fe-doped samples, electron holes are stabilized on Fe, leading to very different catalytic behaviour. Surface studies in combination with AA measurements reveal some dissolution of the catalyst into solution during the reaction. The surface reactivity to water is influenced by the TM d electron count, with water binding more strongly to Fe-doped materials than to those containing Ni. The influence of these factors on the rate of the unwanted hydrogen peroxide decomposition reaction and hence on activity in epoxidation is discussed.
Fundamentals of Quantum Chemistry: Molecular Spectroscopy and Modern Electronic Structure Computations
Authors: Lin Shu-Kun
Published: October 2008

I enjoyed reading this book. The message at the publisher's website [2] gives a very good introduction to this book. I copied and pasted the paragraphs here:[...]
Three-Dimensional Common-Feature Hypotheses for Octopamine Agonist 1-Arylimidazolidine-2-Thiones
Authors: Hirashima Akinori , Morimoto Masako , Ohta Hiroto , Kuwano Eiichi , Taniguchi Eiji , Eto Morifusa
Published: October 2008

Three-dimensional pharmacophore hypotheses were built from a set of 10 octopamine (OA) agonist 1-arylimidazole-2(3H)-thiones (AIHTs) and 1-arylimidazolidine-2-thiones (AITs). Among the ten common-featured models generated by program Catalyst/HipHop, a hypothesis including a hydrophobic aromatic (HpAr), three hydrophobic aliphatic (HpAl) and a hydrogen-bond acceptor lipid (HBAl) features was considered to be important in evaluating the OA-agonist activity. Active OA agonist 2,6-Et2 AIT mapped well onto all the HpAr, HpAl and HBAl features of the hypothesis. On the other hand, inactive compound 2,6-Et2 AIHT was shown to be difficult to achieve the energetically favorable conformation which is found in the active molecules in order to fit the 3D common-feature pharmacophore models. The present studies on OA agonists demonstrate that an HpAr, three HpAls and an HBAl sites located on the molecule seem to be essential for OA-agonist activity.
Dynamical Effects in the Optical Response of Carbon Chains
Authors: Berkus T. , Reinhard P.-G. , Suraud E.
Published: October 2008

We discuss the optical response of small carbon chains from the linear to the non linear domain in the framework of Time Dependent Local Density Approximation. We show that even for moderate ionizations, corresponding to a moderately intense excitation, the optical response exhibits significant alteration with respect to the truly linear domain response. This reflects non trivial dynamical effects at the level of electrons.
Electron Capture in Collisions of Slow Highly Charged Ions with an Atom and a Molecule: Processes and Fragmentation Dynamics
Authors: Frémont François , Laurent Guillaume , Rangama Jimmy , Sobocinski Przemyslaw , Tarisien Medhi , Adoui Lamri , Cassimi Amine , Chesnel Jean-Yves , Fléchard Xavier , Hennecart Dominique , Husson Xavier
Published: October 2008

Processes involved in slow collisions between highly charged ions (HCI) and neutral targets are presented. First, the mechanisms responsible for double electron capture are discussed. We show that, while the electron-nucleus interaction is expected to be dominant at projectile velocities of about 0.5 a.u., the electron-electron interaction plays a decisive role during the collision and gains importance when the projectile velocity decreases. This interaction has also to be invoked in the capture of core electrons by HCI. Finally, the molecular fragmentation of H2 following the impact of HCI is studied.
Rate Coefficient Determination in Charge Transfer Reactions
Authors: Bacchus-Montabonel Marie-Christine , Baloïtcha Ezinvi , Desouter-Lecomte Michèle , Vaeck Nathalie
Published: October 2008

The development of experimental ion-trap techniques provides the opportunity to compare directly theoretical rate coefficients to experimental data in the low-temperature regime. In the present work, we consider the ion-atom collisional systems, N2+, O2+, Si3+ and Si4+ on a He target, in order to examine the present status of the agreement between theory and experiment.
The Concept of Density Functional Theory Based Descriptors and its Relation with the Reactivity of Molecular Systems: A Semi-Quantitative Study
Authors: Chandrakumar K. R. S. , Pal Sourav
Published: October 2008

In this present paper, we have made an attempt to explain the theoretical basis for the empirical hardness/softness concepts to address the reactivity of molecular complexes in a semi-quantitative way within the framework of density functional theory. A model based on local hard-soft-acid-base principle has been proposed. The results obtained using some prototype charge transfer complexes, Lewis acid-base complexes and hydrogen-bonded complexes as examples, are in good agreement with the standard ab initio values. Although the model contains ad hoc parameters, it may form the basis of semi-quantitative description of inter-molecular interactions using hardness/softness parameters. The limitation, weakness and other critical issues of the present model are also discussed.
Time Dependent Coupled Cluster Approach to Resonance Raman Excitation Profiles from General Anharmonic Surfaces
Authors: Prasad M. Durga
Published: October 2008

A time dependent coupled cluster approach to the calculation of Resonance Raman excitation profiles on general anharmonic surfaces is presented. The vibrational wave functions on the ground electronic surface are obtained by the coupled cluster method (CCM). It is shown that the propagation of the vibrational ground state on the upper surface is equivalent to propagation of the vacuum state by an effective hamiltonian generated by the similarity transformation of the vibrational hamiltonian of that surface by the CCM wave operator of the lower surface up to a normalization constant. This time propagation is carried out by the time-dependent coupled cluster method in a time dependent frame. Numerical studies are presented to asses the validity of the approach.
Method of Moments of Coupled-Cluster Equations: Externally Corrected Approaches Employing Configuration Interaction Wave Functions
Authors: Piecuch Piotr , Kowalski Karol , Pimienta Ian S.O.
Published: October 2008

A new approach to the many-electron correlation problem, termed the method of moments of coupled-cluster equations (MMCC), is further developed and tested. The main idea of the MMCC theory is that of the noniterative energy corrections which, when added to the energies obtained in the standard coupled-cluster calculations, recover the exact (full configuration interaction) energy. The MMCC approximations require that a guess is provided for the electronic wave function of interest. The idea of using simple estimates of the wave function, provided by the inexpensive configuration interaction (CI) methods employing small sets of active orbitals to define higher–than–double excitations, is tested in this work. The CI-corrected MMCC methods are used to study the single bond breaking in HF and the simultaneous breaking of both O–H bonds in H2O.
Potential Functions of Al2 by the Relativistic Fock-Space Coupled Cluster Method
Authors: Landau Arie , Eliav Ephraim , Visscher Lucas , Kaldor Uzi
Published: October 2008

Potential functions of the ground and low excited states of Al2 are calculated by the relativistic Fock-space coupled cluster method in the framework of the projected Dirac-Coulomb Hamiltonian. A moderate-size basis [16s11p3d3f/6s6p3d2f] is used. 3Πu is confirmed as the ground state of the system. Its spin orbit splittings are reproduced well, with the Λ = 1, 2 states lying 32.5 and 66.1 cm−1, respectively, above the Λ = 0 minimum (experimental values are 30.4 and 63.4 cm−1). The bond is somewhat too weak, with De 0.14 eV below experiment, Re too high by 0.08 ˚A, and ωe 21 cm−1 too low. It is speculated that the better agreement obtained in earlier calculations may be due to neglect of basis set superposition errors. The description of bonding in the molecule may be improved by the use of a better basis and the inclusion of more correlation by the intermediate Hamiltonian coupled cluster method, which makes it possible to handle larger P spaces and extend the potential functions to the whole range of internuclear separations.
On the Use of Connected Moments Expansion with Coupled Cluster Reference
Authors: Noga Jozef , Szabados Agnes , Surján Péter
Published: October 2008

We examine the possibility of introducing a new class of so called noniterative corrections to coupled cluster energies, based on the connected moments expansion (CMX). Approximate Coupled Cluster (CC) wave functions are used as reference states and then the “improved energies” can be formally obtained either by CMX in terms of the moments of CC similarity transformed Hamiltonian, or in CMX of the usual Hamiltonian. Numerical results are given for some model systems that show the superiority of the latter approach.
State Selective Equation of Motion Coupled Cluster Theory: Some Preliminary Results
Authors: Nooijen Marcel
Published: October 2008

A multireference variant of coupled cluster theory is described that applies to systems that can qualitatively be described by deleting two electrons from a closed shell determinant, for example biradicals, single bond breaking processes, or valence excited states. The theory can be generalized to arbitrary open-shell systems and takes a form that is akin to equation-of-motion coupled cluster theory, but where all wave function parameters are explicitly optimized for the state of interest. The implementation of the present methods was accomplished in an automated fashion using the recently developed Automatic Program Generator (APG). We present benchmark results for the O2 and F2 molecules and investigate the behaviour of a number of closely related variants within the same general framework.
Reduction of Nitroaromatic Compounds on the Surface of Metallic Iron: Quantum Chemical Study
Authors: Zilberberg Igor , Pelmenschikov Alexander , Mcgrath Christian  J. , Davis William , Leszczynska Danuta , Leszczynski Jerzy
Published: October 2008

The initial reduction steps of nitroaromatic compounds on the surface of metallic iron have been studied theoretically using nitrobenzene (NB) as a representative of nitroaromatic compounds. The quantum chemical cluster approximation within the semiempirical Neglect of Diatomic Differential Overlap for Metal Compounds method was applied to model the Fe(110) crystallographic surface, taken as a representative reactive surface for granular iron. This surface was modeled as a 39-atom two-layer metal cluster with rigid geometry. The associative and dissociative adsorption of nitrobenzene was considered. Based on our quantum chemical analysis, we suggest that the direct electron donation from the metal surface into the π* orbital of NB is a decisive factor responsible for subsequent transformation of the nitro group. Molecularly adsorbed NB interacts with metal iron exclusively through nitro moiety oxygens which occupy tri-coordinated positions on surface The charge transfer from metal to NB of approximately 2 atomic units destablizes the nitro group. As a result, the first dissociation of the N-O bond goes through a relatively low activation barrier. The adsorbed nitrosobenzene is predicted to be a stable surface species, though still quiet labile.
Proton NMR Chemical Shift Behavior of Hydrogen-Bonded Amide Proton of Glycine-Containing Peptides and Polypeptides as Studied by ab initio MO Calculation
Authors: Hori S. , Yamauchi K. , Kuroki S. , Ando I.
Published: October 2008

NMR chemical shifts of the amide proton of a supermolecule, an Nmethylacetamide hydrogen-bonded with a formamide, were calculated as functions of hydrogen-bond length RN…O and hydrogen-bond angles by FPT-GIAO method within the framework of HF/STO 6-31++G(d,p) ab initio MO method. The calculations explained reasonably the experimental data reported previously that the isotropic proton chemical shifts move downfield with a decrease in RN…O. Further, the behavior of proton chemical shift tensor components depending on the hydrogen-bond length and hydrogen-bond angle was discussed.
Genotoxic Pyrrolizidine Alkaloids — Mechanisms Leading to DNA Adduct Formation and Tumorigenicity
Authors: Fu Peter P. , Xia Qingsu , Lin Ge , Chou Ming W.
Published: October 2008

Plants that contain pyrrolizidine alkaloids are widely distributed in the world. Although pyrrolizidine alkaloids have been shown to be genotoxic and tumorigenic in experimental animals, the mechanisms of actions have not been fully understood. The results of our recent mechanistic studies suggest that pyrrolizidine alkaloids induce tumors via a genotoxic mechanism mediated by 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5Hpyrrolizine (DHP)-derived DNA adduct formation. This mechanism may be general to most carcinogenic pyrrolizidine alkaloids, including the retronecine-, heliotridine-, and otonecinetype pyrrolizidine alkaloids. It is hypothesized that these DHP-derived DNA adducts are potential biomarkers of pyrrolizidine alkaloid tumorigenicity. The mechanisms that involve the formation of DNA cross-linking and endogenous DNA adducts are also discussed.
Detection of Riddelliine-Derived DNA Adducts in Blood of Rats Fed Riddelliine
Authors: Yan Jian , Nichols Jasyl , Yang Ya-Cheng , Fu Peter P. , Chou Ming W.
Published: October 2008

We have previously shown that riddelliine, a naturally occurring genotoxic pyrrolizidine alkaloid, induces liver tumors in rats and mice through a genotoxic mechanism mediated by the formation of a set of eight 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5Hpyrrolizine ( DHP)-derived DNA adducts. In this study we report the formation of these DHP-derived DNA adducts in blood DNA of rats fed riddelliine. In an adduct formation and removal experiment, male and female F344 rats (8 weeks of age) were administered riddelliine by gavage at a single dose of 10.0 mg/kg body weight in 0.1 M phosphate buffer. At 8, 24, 48, and 168 hrs after dosing, the levels of DHP-derived DNA adduct in blood and liver were determined by 32P-postlabeling/HPLC. Maximum DNA adduct formation occurred at 48 hr after treatment. From 48 to 168 hours, the adduct levels in female rat blood were 4-fold greater than those in male rats. In a dose response experiment, female rats were gavaged 0.1 and 1.0 mg/kg doses of riddelliine for three consecutive days and the DHPderived DNA adducts in blood DNA were assayed. The levels of the DHP-derived DNA adducts in blood of rats receiving 0.1 and 1.0 mg/kg doses were 12.9 and 51.8 adducts/107 nucleotides. These results suggest that: (i) leucocyte DNA can bind with DHP to form a set of DHP-derived DNA adducts generated in liver; (ii) DHP-derived DNA adducts in blood can serve as a potential non-invasive biomarkers for assessing the exposure to riddelliine.
SELDI-TOF-MS Analysis of Transcriptional Activation Protein Binding to Response Elements Regulating Carcinogenesis Enzymes
Authors: Bischoff Steve R. , Kahn Mahfuz B. , Powell Michael D. , Kirlin Ward G.
Published: October 2008

The risk from chemical carcinogens and environmental toxins is dependent on the metabolic balance between bioactivation and detoxification enzymes. Therefore, agents that alter enzyme expression are critical factors in toxicity. Enhancement or suppression of enzyme activities through gene expression is in part regulated by interactions between specific DNA promoter response elements and specific transcription proteins. DNA-protein interactions are dependent upon translocation of proteins from the cytoplasm to the nucleus and the affinity of proteins for binding to transcription promoter sequences. A key factor in both processes is the intracellular redox state, which influences protein-protein interactions and protein-DNA binding and can be altered by exposure to electrophiles, antioxidants and oxidative stress. Oxidative stress levels can be readily detected by measurable effects on the intracellular glutathione (GSH):glutathione disulfide redox potential, the major intracellularredox buffer. Alterations in the GSH redox pool can directly affect enzyme activity by altering disulfide bonds in the transcription factors regulating enzyme expression. These may affect: 1) specific DNA-protein and protein-protein interactions, 2) cyst(e)ine redox state within transcriptional proteins and 3) translocation of transcription proteins from cytoplasmic to nuclear compartments within the cell. The studies reported here are designed to investigate the relative changes in enzyme expression in response to cellular redox potential changes using the new proteomics technology of surface enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI). Treatment of HeLa and HT29 human cell lines to increase the expression of enzymes that are upregulated by oxidative stress was used as a model system to determine the efficacy of the SELDI technology in measuring changes in transcriptional protein binding to transcriptional response elements. An important goal is to determine whether the SELDI will allow simultaneous studies of multiple transcriptional protein-DNA interactions in response to controlled oxidative stress. This will provide a better understanding of the effect of electrophilic carcinogens and oxidants on the balance between activation and detoxification mechanisms in chemical carcinogenesis.
Effect of Dissolved Humic Substances on the Photochemical Degradation Rate of 1-Aminopyrene and Atrazine
Authors: Zeng Kui , Hwang Huey-min , Yuzuri Hongtao
Published: October 2008

Humic substances (HS) are ubiquitous in the environment, and can act as photosensitizers in the redox reactions of some photochemical processes. The influence of HS in these reactions varies with the HS type and concentration. The total organic carbon content (TOC) of some commercial HS (such as soil and river humic acid, and fulvic acid) was studied. 1-Aminopyrene (1-AP) and 1-hydoxypyrene (1-HP) are carcinogenic and slightly water-soluble polycyclic aromatic hydrocarbons (PAH). The impact of PAH on natural environment is related to their photolysis rates and photoproducts; therefore, it is of interest to study the photolysis of these compounds. Our previous study showed that the photolysis rate of 1-HP was inhibited by HS. In this study, photolysis of 1-AP was conducted with pure water, natural river water, and pure water containing commercial HS. It was found that the photolysis rate of 1-AP can be inhibited or enhanced by HS, depending on the type and concentration. The first order photolysis rate constant of 1-AP (10 μM) in phosphate buffer (pH 7.0, 1 mM) containing a humic acid (20-80 ppm) was enhanced by up to 5 folds. With a fulvic acid (20-80 ppm), it was enhanced by about 2 folds. With a soil humic acid, it was enhanced by about 2 folds at the concentration of 20 ppm and was inhibited by up to 4 folds at the concentration of 80 ppm. Atrazine (2-chloro-4-ethylamine-6-isopropylamino-s-triazine) is a widely used herbicide. It is toxic, often bioaccumulative and persistent. In this study, the effect of HS on the photochemical fate of atrazine was also studied. The results showed that photolysis of atrazine can be enhanced by humic acid, depending on the type and concentration of humic acid. The fulvic acid has no effect on its photolysis within 10 days.
The Influence of Environmental Temperatures on Neurotoxicity Induced by Methamphetamine in Male Rats
Authors: Mohaghegh Rymond A. , Singleton Jeurel , Shockley Dolores
Published: October 2008

Methamphetamine (MAMPH) increases core body temperature at room temperature and decreases it in the cold room. MAMPH at doses ≥ 5.0 mg/kg also induces neural toxicity at room temperature, but not in the cold room. We hypothesized that the neural toxicity of the MAMPH is heat related. Thus, the objectives of these experiments were to investigate the dynamics of heat dissipation and conservation at various ambient temperatures. Forty male Sprague-Dawley rats were divided into four equal groups. Groups 1, 2 and 3 were injected intraperitoneally (i.p.) with saline and one hour later with an equivolume of MAMPH in doses of 2.5, 5.0, or 7.5 mg/kg bwt. Group four was injected with saline/saline. Core body (Tc) and tail skin (Ts) temperatures were recorded with thermistors (YSI series 700) at room temperature (21 ± 1°C) or in a cold room (7 ± 0.5°C) every five minutes for four hours. Tc was used as an index for total body heat, and Ts was used as an index for blood flow to the tail (a measure of heat dissipation /conservation) at various times during the experiment. Analysis of the data (ANOVA and post-hoc) showed that MAMPH at doses of 5.0 and 7.5 mg/kg bwt increased the Tc at room temperature, and decreased the Tc at doses of 2.5, 5.0 and 7.5 mg/kg bwt in the cold room in a dose dependent manner. Analysis of the tail effector mechanism for heat dissipation at room temperature, and for heat conservation in the cold room, demonstrated that Ts does not follow Tc at room temperature, but follows Tc in the cold room. In the cold room, MAMPH treated animals decreased Ts, or probably vasoconstricted the tail as the Tc falls. In contrast, at room temperature, although MAMPH raised the Tc of the animals, there was no evidence for a change in Ts, or no tail vasodilatation. Based on these data, we suggest that MAMPH (i.p.) impair heat dissipation, but not heat conservation. Hence, the accumulated heat in neural tissue may account, in part, for the reported neural toxicity of MAMPH.
Differential Cytotoxicity and Gene Expression in Human Liver Carcinoma (HepG2) Cells Exposed to Arsenic Trioxide, and Monosodium Acid Methanearsonate (MSMA)
Authors: Tchounwou P. B. , Wilson B. A. , Abdelghani A. A. , Ishaque A. B. , Patlolla A. K.
Published: October 2008

Research in our laboratory has demonstrated that a trivalent form of arsenic such as arsenic trioxide (AT) has the ability to cause significant cytotoxicity, and induction of a significant number of stress genes in human liver carcinoma cells (HepG2). However, the literature also indicates that the toxicity of arsenic depends on its chemical form. To test this hypothesis, we further evaluated the cellular and molecular responses of HepG2 cells following exposure to monosodium acid methanearsonate (MSMA), a pentavalent and organic form of arsenic. Cytotoxicity was evaluated using the MTT-assay for cell viability, while the gene profile assay was performed to measure the degree of gene induction in 13 different recombinant cell lines generated from a parental HepG2 cell line. Cytotoxicity experiments yielded LC50 values of 11.9 + 2.6 μg/mL for AT, and 257.3 + 51.4μg/mL for MSMA; indicating that AT was about 20 times more toxic than MSMA. Exposure of HepG2 cells to MSMA also resulted in a significant reduction (p < 0.05) in the number of stress genes induced, compared to AT. Upon MSMA exposure, only 2 (HMTIIA and HSP70) out of the 13 constructs evaluated yielded inductions to statistically significant levels (p < 0.05), compared to 11 (GSTYa, XRE, HMTIIA, c-fos, NF-kBRE, HSP70, p53RE, GADD153, GADD45, and GRP78) for AT. These results greatly support the hypothesis that the toxicity of arsenic compounds highly depends on their chemical forms; with the inorganic forms being more potent than the organic ones.
Differential Gene Expression of Fibroblasts: Keloid versus Normal
Authors: Cohly Hari H. P. , Scott Heath , Ndebele Kenneth , Jenkins John K. , Angel Michael F.
Published: October 2008

This study investigated gene regulation and unique gene products in both keloid (KDF) and normal (NDF) dermal fibroblasts in established cell lines. For gene regulation, NDF versus KDF were compared using Clontech's Atlas™ Human cDNA Expression Array while unique gene products were studied using RNA Fingerprinting Kit. RNA from each sample was converted to cDNA using oligo-dT primers. Down-regulated genes using Atlas Array in KDF were 1) 60 S ribosomal protein, 2) Thioredoxin dependent peroxidase, 3) Nuclease sensitive element DNA binding protein, 4) c-myc purine-binding transcription factor, 5) c-AMP dependent protein kinase, and, 6) Heat Shock Protein 90 kDa. Genes that are up regulated in KDF were 1) Tubulin and 2) Heat Shock Protein 27 kDa. With the differential display, we found 17 bands unique to both KDF and NDF. The specific gene and the manner in which they were differentially regulated have direct implications to understanding keloid fibroblast proliferation.
Expression of Chemokines, MIP-1alpha and RANTES in Caprine Lentiviral Infection and Their Influence on Viral Replication
Authors: Punna S. , Jones A. K. , Reddy P. G.
Published: October 2008

Chemokines belong to a super family of inducible and secreted, pro-inflammatory cytokines. They act primarily as chemoattractants and activators of specific types of leukocytes and are involved in a variety of immune and inflammatory responses. The status and role of chemokines, macrophage inflammatory protein (MIP-1α) and RANTES (Regulated upon Activation Normal T-cell Expressed and Secreted) in the immunopathogenesis by caprine arthritis-encephalitis virus (CAEV) are not fully elucidated. The objectives of this study were to, 1) determine the expression MIP-1α in goat synovial membrane cells (GSM cells) infected in vitro, and peripheral blood mononuclear cells (PBMC) of CAEV infected goats by RT-PCR, and 2) effect of exogenous MIP-1α and on replication of CAEV in GSM cells in vitro. RT-PCR results indicated higher expression of MIP-1α in PBMC of CAEV-infected goats as compared to controls. Similarly, higher expression of MIP-1α was observed in GSMC infected in vitro with CAEV as compared to that in uninfected cells. Exogenous MIP-1α (20 ng/ml) and RANTES (20 ng/ml) significantly inhibited CAEV replication in GSM cells by 75% and 65%, respectively as compared to the replication in GSM cells not treated with the chemokines. Results of this study suggest that CAEV infection may alter the expression of chemokines in goats, which may suppress the replication of the virus.
Effect of Antioxidant (Turmeric, Turmerin and Curcumin) on Human Immunodeficiency Virus
Authors: Cohly H. H. P. , Asad S. , Das S. K. , Angel M. F. , Rao M.
Published: October 2008

Oxidative stress is implicated in HIV-infection. It has been suggested that plant antioxidants may offer protection from viral replication and cell death associated with oxidative stress in patients with HIV/AIDS. Because of inherent antioxidant properties of turmeric (T) and its derivatives, water-soluble extract turmerin (Tm) and lipid soluble curcumin (Cu), their potential efficacy as anti-HIV drugs were examined. Cell viability and p-24 antigen release by CEMss-T cells (1 x 105 cells/ml) infected with HIV-IIIB strain, used as an acute model of infection, were tested in the presence of 3’azido-3’deoxythmidine (AZT). Proliferative responses of human mononuclear cells derived from HIV patients (chronic model) stimulated with phyohemagglutinin (PHA), concanavalin A (ConA), and pokeweed mitogen (PWM) were also examined in the presence of AZT and Tm. In the infection assay, T, Tm and Cu individually did not reduce p-24 antigen release or improve cell viability. AZT (5μM) + Tm (800 ng/ml) inhibited infection by 37 % and increased cell numbers by 30%; whereas, Tm (80 ng/ml) inhibited infection by 26% and increased cell number by 60%. In the proliferation assay, lymphocytes from HIV-infected patients showed better inhibition of mitogen responsiveness to Tm (800 ng/ml) when compared to AZT at 5 μM or Tm at 80 ng/ml. Turmerin inhibited HIV-infected T-cell proliferation and, in combination with AZT, decreased T-cell infection and increased cell viability. These data provide evidence suggesting that efficacious anti-HIV therapy may be possible using lower, less toxic doses of AZT in the presence of turmerin.