bluuebunny/crossref_metadata_2025 huggingface dataset:
ARE PRIVATE TRANSFERS ALTRUISTICALLY MOTIVATED? THE CASE OF THE REPUBLIC OF KOREA BEFORE AND DURING THE FINANCIAL CRISIS
Authors: KANG Sung Jin , SAWADA Yasuyuki
Published: March 2007

Using household panel data from Korea for 1995–98, this paper shows that private transfers of Korean households were altruistically motivated. Although the altruistic motive of households seemed to be reinforced during the financial crisis, the amount of private transfers was still not sufficient to support households living in urban areas. Also, there had been a strong crowding‐out relation between private and public transfers. This suggests that the Korean government should have designed its public transfer scheme carefully in order to improve the effectiveness and efficiency of its social safety net programs.
INTERRELATIONAL INCOME DISTRIBUTION IN BRAZIL
Authors: LENZEN MANFRED , SCHAEFFER ROBERTO
Published: March 2007

We extend Miyazawa and Masegi's original idea of disaggregated interrelational income multipliers with regard to three aspects. First, we examine the effect of system closure on the inter‐income‐group matrix. Second, we formally include inter‐household transactions, or the informal economy, into Miyazawa's calculus. Third, we extend the interrelational multiplier to environmental factors. These extensions are applied to the Brazilian economy of 1995. Multiplier matrices excluding and including the informal economy are presented and interpreted, and the redistributive process of transfer payments is traced through consecutive spending rounds for various scenarios. Finally, these redistributive processes are enumerated in terms of transport fuel and electricity use. Our results indicate that, because of the distribution of ownership of productive capital, the income formation process is heavily skewed toward the highest incomes. Whether the existing process and potential redistributive policies alleviate environmental pressure depends on the factors as well as the population segment appraised.
EFFICIENCY OF CHINESE TOWNSHIP AND VILLAGE ENTERPRISES IN THE 1990s BASED ON MICRO DATA FOR WUXI CITY, 1991–97
Authors: SHIRAISHI MAHO , YANO GO
Published: March 2007

We examine the (technical) efficiency of collective‐owned township and village enterprises (COTVEs) in Wuxi City, China, after 1990 to study whether the acknowledged success of township and village enterprises continued in the late 1990s. Our results suggest that COTVEs did not decline in relative efficiency compared with other types of enterprises in the late 1990s, but that their productivity leveled off or declined. Furthermore, we find that COTVEs faced with a more serious shortage of working capital had a lower efficiency after the mid‐1990s recession. These findings cast doubt on the view that the vaguely specified property rights of COTVEs are responsible for their declining performance problems during the period just before 1998 when massive privatization began. Privatization of COTVEs without other macroeconomic policy changes may now be insufficient to cope effectively with their declining productivity.
METHOD OF ANALYZING BUSINESS CYCLES IN A TRANSITION ECONOMY: THE CASE OF SLOVENIA
Authors: JAGRIč Timotej , OVIN Rasto
Published: March 2007

In this paper, we studied cyclical patterns in a transition economy. We introduced a dynamic perspective into the analysis by applying multivariate wavelet analysis. The wavelet covariance and wavelet correlation were defined and applied to the analysis of business cycles as an alternative to the traditional cross‐spectrum analysis. The main findings indicated that there is a significant business cycle component in aggregate economic activity and that business cycles are asymmetric and highly synchronized with the EU cycle. Additionally, it was found that three distinctive periods of business cycle synchronization exert an important impact on the properties of a business cycle.
DETERMINANTS OF DEMAND FOR FIJI'S EXPORTS: AN EMPIRICAL INVESTIGATION
Authors: NARAYAN Seema , NARAYAN Paresh Kumar
Published: March 2007

Fiji is no exceptin to the rule that exports are an important source of growth and development. In this light, it is important to know the determinants of exports. However, there is no empirical study on Fiji's export demand. This paper uses the modern econometric techniques—in particular, the autoregressive distributed lag approach to cointegration—to investigate whether the standard export demand variables, viz., trading partner income, export price, and competitor price, have a long‐run cointegration relationship with Fiji's real exports for the period 1970 to 1999. In addition, the long‐run results are also estimated by using the dynamic ordinary least squares and the fully modified ordinary least squares. The empirical results indicate the existence of a cointegration relationship among the variables. The long‐run foreign income, own‐price, and cross‐price elasticities are found to be 0.7 to 0.8, −1.3 to −1.5, and 2.1 to 2.2, respectively.
TAXONOMIC STATUS OF THE GENUSSOTALIA: SPECIES LEVEL RANKING FOR “TUCUXI” (SOTALIA FLUVIATILIS) AND “COSTERO” (SOTALIA GUIANENSIS) DOLPHINS
Authors: Caballero S. , Trujillo F. , Vianna J. A. , Barrios‐Garrido H. , Montiel M. G. , Beltrán‐Pedreros S. , Marmontel M. , Santos M. C. , Rossi‐Santos M. , Santos F. R. , Baker C. S.
Published: March 2007

Abstract

Dolphins of the genusSotaliaare found along the Caribbean and Atlantic coasts of Central and South America and in the Amazon River and most of its tributaries. At present, the taxonomy of these dolphins remains unresolved. Although five species were described in the late 1800s, only one species is recognized currently (Sotalia fluviatilis) with two ecotypes or subspecies, the coastal subspecies (Sotalia fluviatilis guianensis) and the riverine subspecies (Sotalia fluviatilis fluviatilis). Recent morphometric analyses, as well as mitochondrial DNA analysis, suggested recognition of each subspecies as separate species. Here we review the history of the classification of this genus and present new genetic evidence from ten nuclear and three mitochondrial genes supporting the elevation of each subspecies to the species level under the Genealogical/Lineage Concordance Species Concept and the criterion of irreversible divergence. We also review additional evidence for this taxonomic revision from previously published and unpublished genetic, morphological, and ecological studies. We propose the common name “costero” for the coastal species,Sotalia guianensis(Van Bénéden 1864), and accept the previously proposed “tucuxi” dolphin,Sotalia fluviatilis(Gervais, 1853), for the riverine species.
SUCKLING BEHAVIOR IN SPERM WHALE CALVES: OBSERVATIONS AND HYPOTHESES
Authors: Gero Shane , Whitehead Hal
Published: March 2007

Abstract

This study is the first to describe quantitatively the apparent suckling behavior of sperm whale, Physeter macrocephalus (Linnaeus, 1758), calves using observations from both above and below the surface. Peduncle dives are short (mean 14 s) dives made by sperm whale calves beside the peduncle of an adult female, which were previously assumed to be indicative of suckling. Photo‐identification and focal calf‐follows were used to collect data during 177 peduncle dive bouts from 22 different calves (11 calves from the Caribbean Sea, 11 from the Sargasso Sea), one of which was followed on forty different days. We found that peduncle diving in sperm whale calves is laterally asymmetrical with a bias to the left side of the escorting adult (69.8% of peduncle dives) and that calves generally do not switch sides during a bout of peduncle dives (switches occurred in only 10.8% of bouts). Further subsurface observations gave insight into potential alternative functions of peduncle diving. These alternative hypotheses, including nasal suckling, and the existing supporting evidence for each are discussed. It is likely that peduncle diving is related to suckling but that the exact function of the dives and manner in which sperm whale calves ingest milk remains unclear.
Continuing developments with the automated platelet count1
Authors: BRIGGS C. , HARRISON P. , MACHIN S. J.
Published: March 2007

The four main procedures for platelet counting are: manual phase contrast microscopy, impedance, optical light scatter/fluorescence and flow cytometry. Early methods to enumerate platelets were inaccurate and irreproducible. The manual count is still recognized as the gold standard or reference method, and until very recently the calibration of platelet counts by the manufacturers of automated cell counters and quality control material was performed by this method. However, it is time‐consuming and results in high levels of imprecision. The introduction of automated full blood counters using impedance technology resulted in a dramatic improvement in precision. However, impedance counts still have limitations as cell size analysis cannot discriminate platelets from other similar‐sized particles. More recently, light scatter or fluorescence methods have been introduced for automated platelet counting, but there are still occasional cases where an accurate platelet count remains a challenge. Thus, there has been interest in the development of an improved reference procedure to enable optimization of automated platelet counting. This method utilizes monoclonal antibodies to platelet cell surface antigens conjugated to a suitable fluorophore. This permits the possible implementation of a new reference method to calibrate cell counters, assign values to calibrators, and to obtain a direct platelet count on a variety of pathological samples. In future, analysers may introduce additional platelet parameters; a reliable method to quantify immature or reticulated platelets would be useful.
Functional infertility among territorial males in two passerine species, the willow warbler Phylloscopus trochilus and the bluethroat Luscinia svecica
Authors: T. Lifjeld Jan , Laskemoen Terje , Fossøy Frode , Johnsen Arild , Kleven Oddmund
Published: March 2007

Information about male infertility in free‐living birds is scarce, but anecdotal and circumstantial evidence suggests that it does occur regularly at a low frequency. In this paper we document three cases of azoospermia in two passerine species, the willow warbler Phylloscopus trochilus and the bluethroat Luscinia svecica at their breeding grounds in South Norway. In willow warblers, two males out of a sample of 50 territory holders had no sperm in their seminal glomera, the storage site of sperm ready for ejaculation. The two males also had very small testes. One out of 48 bluethroat males also had no sperm in the seminal glomera. This male had an extreme asymmetry of the testes, with the right testis being about twice as large as the left. He also failed to fertilize any eggs in his own nest, as well as in neighbouring nests, as revealed by microsatellite genotyping. Thus, the proportion of males without sperm seems to be at a magnitude of a few (2–4) percent in both species. These are among the first estimates of the frequency of azoospermia in wild birds. Our results indicate a significant risk for sexually monogamous females of laying unfertilized eggs, which could favour the evolution of extra‐pair copulation as a fertility insurance strategy in females.
Separation of components from impulses in reassigned spectrograms
Authors: Fulop Sean A. , Fitz Kelly
Published: March 2007

Two computational methods for pruning a reassigned spectrogram to show only quasisinusoidal components, or only impulses, or both, are presented mathematically and provided with step-by-step algorithms. Both methods compute the second-order mixed partial derivative of the short-time Fourier transform phase, and rely on the conditions that components and impulses are each well-represented by reassigned spectrographic points possessing particular values of this derivative. This use of the mixed second-order derivative was introduced by Nelson [J. Acoust. Soc. Am. 110, 2575–2592 (2001)] but here our goals are to completely describe the computation of this derivative in a way that highlights the relations to the two most influential methods of computing a reassigned spectrogram, and also to demonstrate the utility of this technique for plotting spectrograms showing line components or impulses while excluding most other points. When applied to speech signals, vocal tract resonances (formants) or glottal pulsations can be effectively isolated in expanded views of the phonation process.
Toward bias minimization in acoustic feedback cancellation systems
Authors: Boukis Christos , Mandic Danilo P. , Constantinides Anthony G.
Published: March 2007

A novel technique for bias suppression within acoustic feedback cancellation systems is proposed. This is achieved based on the use of all-pass filters in the forward part of the hearing aid. The poles of these filters are made time-varying, which results in a frequency response with constant magnitude and varying phase. This is a desired feature of the proposed approach, since the results from human psychoacoustics show that the human ear is not sensitive to moderate phase perturbations. The derivation of the proposed algorithms for the time variation of the location of the poles of all pass filters is based on a rigorous analysis of the phenomenon of bias in acoustic systems. Practical issues, such as the dependence of the steady-state error on the order of the all-pass filter, the number of varying poles, and their standard deviation are examined and strategies for the variation of the poles are introduced. Results obtained from a simulated hearing aid are provided to support the analysis. The quality of the processed audio signals is evaluated through subjective tests.
Aberrations in materials with random inhomogeneities
Authors: Hernández J. A. , Clark M. , Sharples S. D. , Somekh M. G. , Lopez V. H.
Published: March 2007

Materials that consist of a random microstructure can affect ultrasonic measurements—reducing signal strength, increasing noise, and reducing measurement accuracy—through scattering and aberration of the acoustic field. To account for these adverse effects a phase screen model, alongside the stochastic wave equation, has been developed. This approach allows the field and study aberrations to be modeled from a statistical point of view. Experimental evidence of aberration and statistical properties of the measured acoustic field are shown. A measured correlation function of the acoustic field is interlinked to mean crystallite size by using a theoretical coherence function that can be mainly described by the correlation length and wave velocity variation of microstructure. The estimation of the mean crystallite size using this technique would provide some insight into material characterization.
Vortex sound due to a flexible boundary backed by a cavity in a low Mach number mean flow
Authors: Tang S. K. , Leung R. C. K. , So R. M. C.
Published: March 2007

Low frequency sound radiated due to the unsteady motion of an inviscid vortex in the proximity of a flexible membrane backed by an airtight cavity on an otherwise rigid plane is investigated theoretically. Results show that both monopole and dipole are created but the latter is important only when the vortex is traversing over the membrane. The monopole results from the membrane vibration and the dipole from the transverse motion of the vortex. It is also found that these sound fields tend to counteract each other. The increase in the mean flow speed in general results in a stronger acoustic power radiation, but sound attenuation may be possible if the membrane-cavity system is weak compared with the mean flow momentum.
Quantifying the effects of fast-acting compression on the envelope of speech
Authors: Stone Michael A. , Moore Brian C. J.
Published: March 2007

Fast-acting compression has several effects on the envelope of speech signals, especially when a target and a background are mixed together. Three measures of the envelope are described, which can be used to quantify these changes: (1) Within-signal modulation correlation or coherence, the degree of correlation (or coherence) of the envelope (on a dB scale) of a single source across different frequency regions, which is reduced by fast-acting compression; (2) fidelity of envelope shape, the degree to which the envelope shape of the target speech in different frequency channels is preserved following compression; and (3) across-signal modulation correlation or coherence (ASMC), the extent to which the target and background acquire a common component of modulation when they are compressed together, which becomes greater in absolute value (more negative) when the target and background are compressed together. Values of these measures are presented and compared with intelligibility scores obtained using stimuli processed (with a noise-vocoder) so as to preserve mainly envelope cues in a limited number of frequency channels. The results suggest that the dominant factor affecting intelligibility is ASMC.
A pseudo-inverse algorithm for simultaneous measurements using multiple acoustical sources
Authors: Xiang Ning , Li Shu
Published: March 2007

Simultaneous multiple acoustical sources measurement (SMASM) has been proposed for more effective and reliable identification of acoustical systems under critical conditions [N. Xiang and M. R. Schroeder, J. Acoust. Soc. Am. 113, 2754–2761 (2003); N. Xiang, J. N. Daigle, and M. Kleiner, J. Acoust. Soc. Am. 117, 1889–1894 (2005)]. This paper presents a pseudo-inverse algorithm for the SMASM correlation technique as an alternative way of extracting impulse responses of acoustical channels. Simulations and room acoustics experiments are carried out and the results prove the feasibility of the proposed algorithm.
Effects of stimulus variability and adult aging on adaptation to time-compressed speech
Authors: Golomb Julie D. , Peelle Jonathan E. , Wingfield Arthur
Published: March 2007

With as few as 10–20 sentences of exposure, listeners are able to adapt to speech that is highly distorted compared to that which is encountered in everyday conversation. The current study examines the extent to which adaptation to time-compressed speech can be impeded by disrupting the continuity of the exposure sentences, and whether this differs between young and older adult listeners when they are equated for starting accuracy. In separate sessions conducted one week apart, the degree of adaptation was assessed in four exposure conditions, all of which involved exposure to the same number of time-compressed sentences. A continuous exposure condition involved presentation of the time-compressed sentences without interruption. Two alternation conditions alternated time-compressed speech and uncompressed speech by single sentences or groups of four sentences. A fourth condition presented sentences that were separated by a period of silence but no uncompressed speech. For all conditions, neither young nor older adults’ overall level of learning was influenced by disruptions to the exposure sentences. In addition, participants’ performance showed reliable improvement across the first and subsequent sessions. These results support robust learning mechanisms in speech perception that remain functional throughout the lifespan.
Near-field ultrasound tomography
Authors: Mensah Serge , Franceschini Emilie
Published: March 2007

In this paper, a near-field tomographic solution is introduced to solve the imaging problem of fluid objects assumed to be weakly heterogeneous (Born approximation) and excited by spherical waves. The solution to the forward problem is based on the Huygens-Fresnel principle which describes the scattered field as the result of the interference scheme of all the secondary spherical waves. From the derivation of the scattered field, a new Fourier transform that has been called the elliptical Fourier transform is defined: It differs from the standard Fourier transform in that instead of a plane wave decomposition, a harmonic ellipsoidal wave decomposition is obtained. Based on this spectral analysis, a near-field Radon transform is designed that complements the “far-field tools” published in diffraction tomography literature. Then, assuming that the measuring distance is greater than one wavelength, the feasibility of reconstructing either the impedance or the velocity maps of an acoustical (perfect fluid) model is demonstrated. Numerical simulations were performed which confirmed the validity of the theory presented here; a theory which has many potential applications in future wave theory research.
Threshold and channel interaction in cochlear implant users: Evaluation of the tripolar electrode configuration
Authors: Bierer Julie Arenberg
Published: March 2007

The efficacy of cochlear implants is limited by spatial and temporal interactions among channels. This study explores the spatially restricted tripolar electrode configuration and compares it to bipolar and monopolar stimulation. Measures of threshold and channel interaction were obtained from nine subjects implanted with the Clarion HiFocus-I electrode array. Stimuli were biphasic pulses delivered at 1020pulses∕s. Threshold increased from monopolar to bipolar to tripolar stimulation and was most variable across channels with the tripolar configuration. Channel interaction, quantified by the shift in threshold between single- and two-channel stimulation, occurred for all three configurations but was largest for the monopolar and simultaneous conditions. The threshold shifts with simultaneous tripolar stimulation were slightly smaller than with bipolar and were not as strongly affected by the timing of the two channel stimulation as was monopolar. The subjects’ performances on clinical speech tests were correlated with channel-to-channel variability in tripolar threshold, such that greater variability was related to poorer performance. The data suggest that tripolar channels with high thresholds may reveal cochlear regions of low neuron survival or poor electrode placement.
Artemisinins Inhibit
Trypanosoma cruzi
and
Trypanosoma brucei rhodesiense
In Vitro Growth
Authors: Mishina Yuliya V. , Krishna Sanjeev , Haynes Richard K. , Meade John C.
Published: March 2007

Artemisinin compounds inhibit in vitro growth of cultured
Trypanosoma cruzi
and
Trypanosoma brucei rhodesiense
at concentrations in the low micromolar range. Artemisinin also inhibits calcium-dependent ATPase activity in
T. cruzi
membranes, suggesting a mode of action via membrane pumps. Artemisinins merit further investigation as chemotherapeutic options for these pathogens.
Requirements for Assembly of PtlH with the Pertussis Toxin Transporter Apparatus of
Bordetella pertussis
Authors: Verma Anita , Burns Drusilla L.
Published: March 2007

PtlH is an essential component of the Ptl system, the type IV transporter responsible for secretion of pertussis toxin (PT) across the outer membrane of
Bordetella pertussis
. The nine Ptl proteins are believed to interact to form a membrane-spanning apparatus through which the toxin is secreted. In this study, we monitored the subcellular localization of PtlH in strains of
B. pertussis
lacking PT, lacking other Ptl proteins, or from which ATP has been depleted in order to gain insight into the requirements for assembly of PtlH with the remainder of the Ptl transporter complex that is thought to be tightly embedded in the membrane. We found that PtlH is exclusively localized to the inner membrane fraction of the cell in a wild-type strain of
B. pertussis
. In contrast, PtlH localized to both the cytoplasmic and inner membrane fractions of a mutant strain of
B. pertussis
that does not produce PT. In comparison to how it localized in wild-type strains of
B. pertussis
, PtlH exhibited aberrant localization in strains lacking PtlD, PtlE, PtlF, and PtlG. We also found that localization of PtlH was perturbed in
B. pertussis
strains that were treated with carbonyl cyanide
m
-chlorophenylhydrazone and sodium arsenate, which are capable of depleting cellular ATP levels, and in strains of
B. pertussis
that produce an altered form of PtlH that lacks ATPase activity. When taken together, these results indicate that tight association of PtlH with the membrane, likely through interactions with components of the transporter-PT complex, requires the toxin substrate, a specific subset of the Ptl proteins, and ATP. Based on these data, a model for the assembly of the Ptl transporter-PT complex is presented.
Immunogenicity of
Anaplasma marginale
Type IV Secretion System Proteins in a Protective Outer Membrane Vaccine
Authors: Lopez Job E. , Palmer Guy H. , Brayton Kelly A. , Dark Michael J. , Leach Stephanie E. , Brown Wendy C.
Published: March 2007

Rickettsial pathogens in the genera
Anaplasma
and
Ehrlichia
cause acute infection in immunologically naive hosts and are major causes of tick-borne disease in animals and humans. Immunization with purified outer membranes induces protection against acute
Anaplasma marginale
infection and disease, and a proteomic and genomic approach recently identified 21 proteins within the outer membrane immunogen in addition to the well-characterized major surface proteins MSP1 to MSP5. Among the newly described proteins were the type IV secretion system (TFSS) proteins VirB9, VirB10, and conjugal transfer protein (CTP). In other gram-negative bacteria, TFSS proteins form channels, facilitate secretion of molecules, and are required for intracellular survival. However, TFSS proteins have not been explored as vaccine antigens. In this study we demonstrate that in
Anaplasma marginale
outer membrane-vaccinated cattle, VirB9, VirB10, and CTP are recognized by serum immunoglobulin G2 (IgG2) and stimulate memory T-lymphocyte proliferation and gamma interferon secretion. VirB9 induced the greatest proliferation in CD4
+
T-cell lines, and VirB9-specific CD4
+
T-cell clones responded to three
A. marginale
strains, confirming the VirB9-specific T-cell responses are directed against epitopes in the native protein. The three TFSS proteins are highly conserved with orthologous proteins in
Anaplasma phagocytophilum
,
Ehrlichia chaffeensis
, and
Ehrlichia canis
. Recognition of TFSS antigens by CD4
+
T cells and by IgG2 from cattle immunized with the protective outer membrane fraction provides a rationale for including these proteins in development of vaccines against
A. marginale
and related pathogens.
CpG Oligodeoxynucleotide Treatment Enhances Innate Resistance and Acquired Immunity to African Trypanosomes
Authors: Harris Tajie H. , Mansfield John M. , Paulnock Donna M.
Published: March 2007

Relative resistance to African trypanosomiasis is based on the development of a type I cytokine response, which is partially dependent on innate immune responses generated through MyD88 and Toll-like receptor 9 (TLR9). Therefore, we asked whether enhancement of the immune response by artificial stimulation with CpG oligodeoxynucleotide (ODN), a TLR9 agonist, would result in enhanced protection against trypanosomes. In susceptible BALB/c mice, relative resistance to infection was significantly enhanced by CpG ODN treatment and was associated with decreased parasite burden, increased cytokine production, and elevated parasite-specific B- and T-cell responses. In relatively resistant C57BL/6 mice, survival was not enhanced but early parasitemia levels were reduced 100-fold and the majority of the parasites were nondividing, short stumpy (SS) forms. CpG ODN treatment of lymphocyte-deficient C57BL/6-scidand BALB/cByJ-scidmice also enhanced survival and reduced parasitemia, indicating that innate resistance to trypanosome infection can be enhanced. In C57BL/6-scidand BALB/cByJ-scidmice, the parasites were also predominantly SS forms during the outgrowth of parasitemia. However, the effect of CpG ODN treatment on parasite morphology was not as marked in gamma interferon (IFN-γ)-knockout mice, suggesting that downstream effects of IFN-γ production may play a discrete role in parasite cell differentiation. Overall, these studies provide the first evidence that enhancement of resistance to African trypanosomes can be induced in susceptible animals in a TLR9-dependent manner and that CpG ODN treatment may influence the developmental life cycle of the parasites.
Niche-Specific Activation of the Oxidative Stress Response by the Pathogenic FungusCandida albicans
Authors: Enjalbert Brice , MacCallum Donna M. , Odds Frank C. , Brown Alistair J. P.
Published: March 2007

Candida albicansis a major opportunistic pathogen of humans. The pathogenicity of this fungus depends upon its ability to deal effectively with the host defenses and, in particular, the oxidative burst of phagocytic cells. We have explored the activation of the oxidative stress response inC. albicansin ex vivo infection models and during systemic infection of a mammalian host. We have generatedC. albicansstrains that contain specific green fluorescent protein (GFP) promoter fusions and hence act as biosensors of environmental oxidative stress at the single-cell level. Having confirmed thatCTA1-,TRX1-, andTTR1/GRX2-GFPreporters respond specifically to oxidative stress, and not to heat shock, nitrosative, or osmotic stresses, we used these reporters to show that individualC. albicanscells activate an oxidative stress response following phagocytosis by neutrophils, but not by macrophages. Significantly, only a small proportion ofC. albicanscells (about 4%) activated an oxidative stress response during systemic infection of the mouse kidney. The response of these cells was generally equivalent to exposure to 0.4 mM hydrogen peroxide in vitro. We conclude that mostC. albicanscells are exposed to an oxidative stress when they come into contact with neutrophils in the bloodstream of the host but that oxidative killing is no longer a significant threat once an infection has been established in the kidney.
Immunomodulatory Effects of theLutzomyia longipalpisSalivary Gland Protein Maxadilan on Mouse Macrophages
Authors: Brodie Tess M. , Smith Matthew C. , Morris Robin V. , Titus Richard G.
Published: March 2007

Infection withLeishmania majoris enhanced when the sand flyLutzomyia longipalpissalivary peptide maxadilan (MAX) is injected along with the parasite. Here we determined the effect that MAX has on the secretion of cytokines and nitric oxide (NO) and on parasite survival in macrophages (MΦs). The cytokines produced by MΦs can enhance a type 1 response, which will increase NO and the killing of intracellular pathogens such asL. major, or a type 2 response, leading to antibody production that is ineffective against intracellular pathogens such asL. major. A mouse macrophage cell line (RAW 264.7) was stimulated with various concentrations of MAX and lipopolysaccharide (LPS), and the supernatants were collected after 1, 2, and 3 days. Supernatants were assayed for interleukin-12p70 (IL-12p70), IL-10, IL-6, transforming growth factor β (TGF-β), NO, and tumor necrosis factor alpha (TNF-α). Our results indicate that the addition of MAX upregulates the cytokines associated with a type 2 response (IL-10, IL-6, and TGF-β) but downregulates type 1 cytokines (IL-12p70 and TNF-α) and NO. MAX was also added toL. major-infected mouse peritoneal exudate cells (PECs), and the parasite load increased significantly. The enhanced parasite load correlated with decreased NO production by PECs that were stimulated with LPS and gamma interferon in the presence of MAX. The ability of MAX to foster a type 2 response, to enhance parasite survival, and to decrease NO argues that MAX may be crucial for the early survival ofLeishmaniain the vertebrate host, and therefore, MAX holds considerable promise as an antigenic component for a vaccine againstLeishmania.
QseA Directly Activates Transcription of
LEE1
in Enterohemorrhagic
Escherichia coli
Authors: Sharp Faith C. , Sperandio Vanessa
Published: March 2007

Quorum sensing (QS) in enterohemorrhagic
Escherichia coli
(EHEC) regulates the expression of the locus of enterocyte effacement (LEE). The LEE contains five major operons named
LEE1
through
LEE5
. QseA was previously shown to be activated through QS and to activate the transcription of
LEE1
. The
LEE1
operon encodes Ler, the transcription activator of all other LEE genes, and has two promoters: a distal promoter (P1) and a proximal promoter (P2). We have previously reported that QseA acts on P1 and not P2. To identify the minimal region of
LEE1
that is necessary for QseA-mediated activation, a series of nested-deletion constructs of the
LEE1
promoter fused to a
lacZ
reporter were constructed in both the EHEC and
E. coli
K-12 backgrounds. In an EHEC background, QseA-dependent activation of
LEE1
can be observed for the entire regulatory region (beginning at nucleotide −393 and ending at nucleotide −123). In contrast to what occurred in EHEC, in K-12 there was no QseA-dependent activation of
LEE1
transcription between base pairs −393 and −343. These data indicate that a QseA-dependent EHEC-specific regulator is required for the activation of transcription in this region. We also observed QseA-dependent
LEE1
activation from nucleotides −218 to −123 in K-12, similar to results of the nested-deletion analysis performed with EHEC. Electrophoretic mobility shift assays established that QseA directly binds to the region of
LEE1
from bp −173 to −42 and not to the region from bp −393 to −343. These studies suggest that QseA activates the transcription of
LEE1
by directly binding upstream of its P1 promoter region.
THE REAL GENUS OF 2-GROUPS
Authors: MAY COY L.
Published: March 2007

Let G be a finite group. The real genus ρ(G) is the minimum algebraic genus of any compact bordered Klein surface on which G acts. Here we consider 2-groups acting on bordered Klein surfaces. The main focus is determining the real genus of each of the 51 groups of order 32. We also obtain some general results about the partial presentations that 2-groups acting on bordered surfaces must have. In addition, we obtain genus formulas for some families of 2-groups and show that if G is a 2-group with positive real genus, then ρ(G) ≡ 1 mod 4.
THE HAMILTONIAN APPROACH TO GENERAL RELATIVITY AND CMB PRIMORDIAL SPECTRUM
Authors: BARBASHOV B. M. , PERVUSHIN V. N. , ZAKHAROV A. F. , ZINCHUK V. A.
Published: March 2007

Approaches to solutions of problems of the energy, time, Hamiltonian operator quantization of the General Relativity, the creation of the Universe from vacuum are considered in the frame of reference associated with the CMB radiation in order to describe parameters of this radiation in terms of the parameters of the Standard Model of elementary particles.
QUANTUM GRAVITY AND HIGHER CURVATURE ACTIONS
Authors: BOJOWALD MARTIN , SKIRZEWSKI AURELIANO
Published: March 2007

Effective equations are often useful to extract physical information from quantum theories without having to face all technical and conceptual difficulties. One can then describe aspects of the quantum system by equations of classical type, which correct the classical equations by modified coefficients and higher derivative terms. In gravity, for instance, one expects terms with higher powers of curvature. Such higher derivative formulations are discussed here with an emphasis on the role of degrees of freedom and on differences between Lagrangian and Hamiltonian treatments. A general scheme is then provided which allows one to compute effective equations perturbatively in a Hamiltonian formalism. Here, one can expand effective equations around any quantum state and not just a perturbative vacuum. This is particularly useful in situations of quantum gravity or cosmology where perturbations only around vacuum states would be too restrictive. The discussion also demonstrates the number of free parameters expected in effective equations, used to determine the physical situation being approximated, as well as the role of classical symmetries such as Lorentz transformation properties in effective equations. An appendix collects information on effective correction terms expected from loop quantum gravity and string theory.
THE VARIATIONAL APPROACH TO ALTERNATIVE THEORIES OF GRAVITY
Authors: ALLEMANDI GIANLUCA , FRANCAVIGLIA MAURO
Published: March 2007

This paper is based on lectures given in Ladek-Zdroj, Poland during the 42nd edition of the Karpac winter school on Theoretical Physics. The aim of these lectures was to give an introduction to a rigorous, mathematically well based, variational approach to alternative theories of Gravity, in view of their very interesting recent applications in the framework of Cosmology. We discuss alternative theories of Gravity both in the metric, purely affine and Palatini formalism, stressing differences and analogies both from a physical and mathematical viewpoint. Moreover we give and introduction to almost all the alternative theories of Gravity, that have been recently studied in view of their physical interest (higher order theories of Gravity, including Lovelock and Chern-Simons Lagrangians). Finally we skip to one of the most striking recent applications of alternative theories of Gravity in the framework of cosmological models: alternative theories of Gravity have been proven to provide a consistent model for accelerating universes.
NEFA-glucose comodulation model of β-cell insulin secretion in 24-h multiple-meal test
Authors: Salinari Serenella , Bertuzzi Alessandro , Manco Melania , Mingrone Geltrude
Published: March 2007

There is experimental evidence that a source of fatty acids (FAs) that is either exogenous or endogenous is necessary to support normal insulin secretion. Therefore, FAs comodulate the glucose-induced pancreatic insulin secretion. To assess the role of FAs, 16 morbidly obese nondiabetic patients and 6 healthy volunteers were studied. The controls and the obese subjects, before and after diet-induced weight loss, spent 24 h in a calorimetric chamber, where they consumed standardized meals. Hourly blood samples were drawn from a central venous catheter for the measurement of glucose, C-peptide, and nonesterified fatty acid (NEFA) concentrations. Insulin sensitivity was measured (as the M value) by euglycemic hyperinsulinemic clamp. In the present study, we propose a mathematical model in which insulin secretion rate (ISR) is expressed as a function of both plasma glucose and NEFA concentrations. Model parameters, obtained by fitting the individual experimental data of plasma C-peptide concentration, gave an estimated ISR comparable with that obtained by the deconvolution method. To evaluate the performance of the model in an experimental condition in which incretin effect was minimized, previous data on insulin secretion following a butter load and subsequent hyperglycemic clamp were reanalyzed. This model of nutrient-stimulated insulin secretion is the first attempt to represent in a simple way the interaction between glucose and NEFA in the regulation of insulin secretion in the β-cell and explains, at least in part, the “potentiation factor” used in previous models to account for other control factors different from glucose after either an intravenous infusion of glucose or a mixed meal.
Design of a Nonlinear Finite-Time Converging Observer for a Class of Nonlinear Systems
Authors: Sauvage Frédéric , Guay Martin , Dochain Denis
Published: March 2007

This paper proposes a nonlinear finite-time converging observer for a class of nonlinear systems. The estimate is recovered from the present and delayed estimates provided by two independent dynamical systems converging to a function of the state with linear error dynamics. The estimation is carried out using only the Jacobian matrix of both transformations determined by solving two systems of partial derivative equations. The results are illustrated on a bioreactor model.
Flow Rate and Interference Studies for Copper Bindingto a Silica‐Immobilized Humin Polymer Matrix:Column and Batch Experiments
Authors: Gardea-Torresdey Jorge L. , Contreras Carolina , de la Rosa Guadalupe , Peralta-Videa Jose R.
Published: March 2007

Batch and column experiments were performed to determine the Cu(II) binding capacity of silica‐immobilized humin biomass. For column studies, 500 bed volumes of a 0.1 mM Cu(II) solution were passed through humin packed columns at the flow rates of 1, 1.5, 2, and 3 mL/min. The biopolymer showed an average Cu binding capacity of 12 ± 1.5 mg/g and a Cu recovery of about 96.5 % ± 1.5. The breakthrough points for Cu(II) alone were approximately 420, 390, 385, and 300 bed volumes for the flow rates of 1, 1.5, 2 and 3 mL/min, respectively. The interference studies demonstrated that at low concentrations, the hard cations Ca(II) and Mg(II) did not seem to represent a major interference on Cu(II) binding to the humin biopolymer. The selectivity showed by this biopolymer was Cu(II)>Ca(II)>Mg(II). On the other hand, batch experiments showed that Ca(II) + Mg(II) at 100mM each reduced the Cu(II) binding to 73 %. However, 1000 mM concentrations of Ca(II) and Mg(II), separately and in mixture, reduced the Cu(II) binding to 47 %, 44 % and 31 %, respectively. The results of this study showed that immobilized humin in a silica matrix could represent an inexpensive bio‐source for Cu removal from contaminated water, even in the presence of low concentrations of the hard cations Ca(II) and Mg(II).
Chemistry of Organophosphonate Scale Growth Inhibitors: 2. Structural Aspects of 2‐Phosphonobutane‐1,2,4‐Tricarboxylic Acid Monohydrate (PBTC.H2O)
Authors: Demadis Konstantinos D. , Raptis Raphael G. , Baran Peter
Published: March 2007

Industrial water systems often suffer from undesirable inorganic deposits, such as calcium carbonate,
calcium phosphate(s), magnesium silicate, and others. Synthetic water additives such as phosphonates and
phosphonocarboxylates are the most important and widely utilized scale inhibitors in a plethora of industrial
applications. The design of efficient and cost‐effective inhibitors, as well as the study of their structure and
function at the molecular level are important areas of research. This study reports the crystal and molecular
structure of PBTC (PBTC = 2‐phosphonobutane‐1,2,4‐tricarboxylic acid), one of the most widely used scale
inhibitors in the cooling water treatment industry. Triclinic PBTC monohydrate crystallizes in the P 1 space
group with cell dimesions, a =7.671(1) Å, b = 8.680(1) Å, c = 9.886(1) Å, α = 65.518(2) deg, β = 71.683(2) deg, γ = 76.173(2) deg, V = 564.20(11) Å3, and Z = 2. Bond distances in the ‐PO3 moiety are 1.4928(10) Å for the P=O double bond and 1.5294(10) Å and 1.5578(10) Å for the two ‐P‐O(H) groups. P‐C and C‐O bond lengths fall in the normal range. A network of hydrogen bonds are formed between the water molecule of crystallization, the ‐P‐OH and the ‐COOH groups.
Chemistry of Organophosphonate Scale Growthlnhibitors: 3. Physicochemical Aspects of 2‐Phosphonobutane‐1,2,4‐Tricarboxylate (PBTC) And ItsEffect on CaCO3 Crystal Growth
Authors: Demadis Konstantinos D. , Lykoudis Panos
Published: March 2007

Industrial water systems often suffer from undesirable inorganic deposits, such as calcium carbonate,
calcium phosphates, calcium sulfate, magnesium silicate, and others. Synthetic water additives, such as
phosphonates and phosphonocarboxylates, are the most important and widely utilized scale inhibitors in a plethora of industrial applications including cooling water, geothermal drilling, desalination, etc. The design
of efficient and cost‐effective inhibitors, as well as the study of their structure and function at the molecular
level are important areas of research. This study reports various physicochemical aspects of the chemistry of
PBTC (PBTC = 2‐phosphonobutane‐1,2,4‐tricarboxylic acid), one of the most widely used scale inhibitors in
the cooling water treatment industry. These aspects include its CaCO3 crystal growth inhibition and
modification properties under severe conditions of high CaCO3 supersaturation, stability towards oxidizing
microbiocides and tolerance towards precipitation with Ca2+. Results show that 15 ppm of PBTC can inhibit
the formation of by ∼35 %, 30 ppm by ∼40 %, and 60 ppm by ∼44 %. PBTC is virtually stable to the effects
of a variety of oxidizing microbiocides, including chlorine, bromine and others. PBTC shows excellent
tolerance towards precipitation as its Ca salt. Precipitation in a 1000 ppm Ca2+ (as CaCO3) occurs after 185
ppm PBTC are present.
DNA Interactions with Ruthenium(II) Polypyridine Complexes Containing Asymmetric Ligands
Authors: Chao Hui , Ji Liang-Nian
Published: March 2007

In an attempt to probe nucleic acid structures, numerous Ru(II) complexes with different ligands have been synthesized and investigated. In this contribution we focus on the DNA‐binding properties of
ruthenium(II) complexes containing asymmetric ligands that have attracted little attention in the past decades.
The influences of the shape and size of the ligand on the binding modes, affinity, enantioselectivities and photocleavage of the complexes to DNA are described.
Synthesis, Characterization, Spectral Studies andAntifungal Activity of Mn(II), Fe(II), Co(II), Ni(II),Cu(II) and Zn(II) Complexes with 2‐(4‐Sulphophenylazo)‐1,8‐Dihydroxy‐3,6‐NapthaleneDisulphonic Acid Trisodium Salt
Authors: Pandey Gajanan , Narang K. K.
Published: March 2007

Complexes of the type Na6[M(HL)2(H2O)2], where M= Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)
and Na3H2L= 2‐(4‐sulphophenylazo)‐1,8‐dihydroxy 3,6 naphthalene disulphonic acid trisodium salt, have
been synthesized and characterized by physico‐chemical (elemental analyses, solubility, electrolytic
conductance, magnetic susceptibility measurement) and spectral (UV‐Visible, IR, ESR, powder x‐ray
diffraction) techniques for their structure and studied for their antifungal activity against ten fungi. The
anionic 1:2 metal:ligand complexes show octahedral geometry around M(II), a significant antifungal activity
against Curvularia lunata and Alternaria triticina and a moderate activity against Alternaria brassicicola,
Alternaria brassicae, Alternaria solanae, Curvularia species, Helminthosporium oryzae, Collectotrichum
capsici, Aspergillus niger, Aspergillus flavus and Fusarium udum.
Gold Binding by Native and Chemically ModifiedHops Biomasses
Authors: López M. Laura , Gardea-Torresdey J. L. , Peralta-Videa J. R. , de la Rosa G. , Armendáriz V. , Herrera I. , Troiani H. , Henning J.
Published: March 2007

Heavy metals from mining, smelting operations and other industrial processing facilities pollute
wastewaters worldwide. Extraction of metals from industrial effluents has been widely studied due to the
economic advantages and the relative ease of technical implementation. Consequently, the search for new
and improved methodologies for the recovery of gold has increased. In this particular research, the use of
cone hops biomass (Humulus lupulus) was investigated as a new option for gold recovery. The results
showed that the gold binding to native hops biomass was pH dependent from pH 2 to pH 6, with a maximum
percentage binding at pH 3. Time dependency studies demonstrated that Au(III) binding to native and
modified cone hops biomasses was found to be time independent at pH 2 while at pH 5, it was time
dependent. Capacity experiments demonstrated that at pH 2, esterified hops biomass bound 33.4 mg Au/g of
biomass, while native and hydrolyzed hops biomasses bound 28.2 and 12.0 mg Au/g of biomass,
respectively. However, at pH 5 the binding capacities were 38.9, 37.8 and 11.4 mg of Au per gram of native,
esterified and hydrolyzed hops biomasses, respectively.
Structural Features of Antitumor Titanium Agents andRelated Compounds
Authors: Caruso Francesco , Rossi Miriam , Opazo Cristian , Pettinari Claudio
Published: March 2007

Previous studies established some Ti compounds as having marked activity against tumors of the
gastrointestinal tract and lack of side effects common to widely used cytostatic agents. We describe pertinent
structural features of known antitumor Ti agents and other potentially active compounds. Particularly
noteworthy features are that Ti‐O bonds are short and Ti‐O‐Ti bond angles are large, demonstrating that in
these compounds the O binding has high s‐character approaching sp hybridization.