bluuebunny/crossref_metadata_2025 huggingface dataset:
Successful management of hamstring injuries in Australian Rules footballers: two case reports
Authors: Hoskins Wayne T , Pollard Henry P
Published: April 2005

Hamstring injuries are the most prevalent injury in Australian Rules football. There is a lack of evidence based literature on the treatment, prevention and management of hamstring injuries, although it is agreed that the etiology is complicated and multi-factorial. We present two cases of hamstring injury that had full resolution after spinal manipulation and correction of lumbar-pelvic biomechanics. There was no recurrence through preventative treatment over a twelve and sixteen week period. The use of spinal manipulation for treatment or prevention of hamstring injury has not been documented in sports medicine literature and should be further investigated in prospective randomized controlled trials.
The differential contribution of tumour necrosis factor to thermal and mechanical hyperalgesia during chronic inflammation
Authors: Inglis Julia J , Nissim Ahuva , Lees Delphine M , Hunt Stephen P , Chernajovsky Yuti , Kidd Bruce L
Published: April 2005

Therapies directed against tumour necrosis factor (TNF) are effective for the treatment of rheumatoid arthritis and reduce pain scores in this condition. In this study, we sought to explore mechanisms by which TNF contributes to inflammatory pain in an experimental model of arthritis. The effects of an anti-TNF agent, etanercept, on behavioural pain responses arising from rat monoarthritis induced by complete Freund's adjuvant were assessed and compared with expression of TNF receptors (TNFRs) by dorsal root ganglion (DRG) cells at corresponding time points. Etanercept had no effect on evoked pain responses in normal animals but exerted a differential effect on the thermal and mechanical hyperalgesia associated with rat arthritis induced by complete Freund's adjuvant (CFA). Joint inflammation was associated with increased TNFR1 and TNFR2 expression on DRG cells, which was maintained throughout the time course of the model. TNFR1 expression was increased in neuronal cells of the DRG bilaterally after arthritis induction. In contrast, TNFR2 expression occurred exclusively on non-neuronal cells of the macrophage–monocyte lineage, with cell numbers increasing in a TNF-dependent fashion during CFA-induced arthritis. A strong correlation was observed between numbers of macrophages and the development of mechanical hyperalgesia in CFA-induced arthritis. These results highlight the potential for TNF to play a vital role in inflammatory hyperalgesia, both by a direct action on neurons via TNFR1 and by facilitating the accumulation of macrophages in the DRG via a TNFR2-mediated pathway.
CYP17 5'-UTR MspA1 polymorphism and the risk of premenopausal breast cancer in a German population-based case–control study
Authors: Verla-Tebit Emaculate , Wang-Gohrke Shan , Chang-Claude Jenny
Published: April 2005

Introduction

Studies on the association between the cytochrome P450c17α gene (CYP17) 5'-untranslated region MspA1 genetic polymorphism and breast cancer risk have yielded inconsistent results. Higher levels of estrogen have been reported among young nulliparous women with the A2 allele. Therefore we assessed the impact of CYP17 genotypes on the risk of premenopausal breast cancer, with emphasis on parity.

Methods

We used data from a population-based case–control study of women aged below 51 years conducted from 1992 to 1995 in Germany. Analyses were restricted to clearly premenopausal women with complete information on CYP17 and encompassed 527 case subjects and 904 controls, 99.5% of whom were of European descent. The MspA1 polymorphism was analyzed using PCR-RFLP (PCR–restriction fragment length polymorphism) assay.

Results

The frequencies of the variant allele among the cases and controls were 43% and 41%, respectively. Overall, CYP17 A1/A2 and A2/A2 genotypes compared with the A1/A1 genotype were not associated with breast cancer, with adjusted odds ratios (ORs) of 1.04 and 1.23, respectively. Among nulliparous women, however, breast cancer risk was elevated for the A1/A2 (OR = 1.31; 95% confidence interval (CI) 0.74 to 2.32) and the A2/A2 genotype (OR = 2.12; 95% CI 1.04 to 4.32) compared with the A1/A1 genotype, with a trend towards increasing risk associated with number of A2 alleles (P = 0.04). Otherwise, the CYP17 polymorphism was found neither to be an effect modifier of breast cancer risks nor to be associated with stage of disease.

Conclusion

Our results do not indicate a major influence of CYP17 MspA1 polymorphism on the risk of premenopausal breast cancer, but suggest that it may have an impact on breast cancer risk among nulliparous women. The finding, however, needs to be confirmed in further studies.
Book Reviews
Authors: Taylor Laura
Published: April 2005

An introduction to developmental psychology: Edited by A. Slater and G. Bremner Oxford, UK: Blackwells. 2003. Pp 632, Paperback, £20.99. ISBN 0631213961
Increased Capacity and Density of Choline Transporters Situated in Synaptic Membranes of the Right Medial Prefrontal Cortex of Attentional Task-Performing Rats
Authors: Apparsundaram Subbu , Martinez Vicente , Parikh Vinay , Kozak Rouba , Sarter Martin
Published: April 2005

Cholinergic neurons innervating the cortex have been conceptualized as a major component of the attention system of the brain. Because of recent evidence indicating plastic mechanisms regulating choline transporter (CHT)-mediated high-affinity choline uptake, which is the rate-limiting step of acetylcholine synthesis, the present experiment determined the capacity of cholinergic terminals to transport choline, and the proportion of choline transporters localized in the membrane of synaptic terminals, in several brain regions of rats performing a cognitive vigilance task (CVT) and a simple reaction time task (SRTT) and nonperforming (NP) rats. Compared with evidence from NP rats, increased choline transporter capacity [as indicated by maximum transporter velocity (Vmax)] and an increased density of CHTs situated in synaptic plasma membrane, relative to intracellular locations, were observed in the medial prefrontal cortex of the right but not left hemisphere of CVT-performing animals. Furthermore, right medial prefrontalVmaxvalues of CVT-performing rats correlated positively and left medialVmaxvalues correlated negatively with the animals' performance in signal trials. Measures of CHT function in the brains of SRTT-performing animals did not differ significantly from those in NP rats. The present data support the hypothesis that an increased capacity of choline transporters in the right medial prefrontal cortex, primarily attributable to increased trafficking of transporters from intracellular compartments to the terminal membrane, represents a cellular mechanism contributing to the mediation of attentional performance.
Ric-8B, an Olfactory Putative GTP Exchange Factor, Amplifies Signal Transduction through the Olfactory-Specific G-Protein Gαolf
Authors: Von Dannecker Luiz Eduardo C. , Mercadante Adriana F. , Malnic Bettina
Published: April 2005

The olfactory system is able to detect a large number of chemical structures with a remarkable sensitivity and specificity. Odorants are first detected by odorant receptors present in the cilia of olfactory neurons. The activated receptors couple to an olfactory-specific G-protein (Golf), which activates adenylyl cyclase III to produce cAMP. Increased cAMP levels activate cyclic nucleotide-gated channels, causing cell membrane depolarization. Here we used yeast two-hybrid to search for potential regulators for Gαolf. We found that Ric-8B (for resistant to inhibitors of cholinesterase), a putative GTP exchange factor, is able to interact with Gαolf. Like Gαolf, Ric-8B is predominantly expressed in the mature olfactory sensory neurons and also in a few regions in the brain. The highly restricted and colocalized expression patterns of Ric-8B and Gαolf strongly indicate that Ric-8B is a functional partner for Gαolf. Finally, we show that Ric-8B is able to potentiate Gαolf-dependent cAMP accumulation in human embryonic kidney 293 cells and therefore may be an important component for odorant signal transduction.
Reluctant Vesicles Contribute to the Total Readily Releasable Pool in Glutamatergic Hippocampal Neurons
Authors: Moulder Krista L. , Mennerick Steven
Published: April 2005

The size of the readily releasable pool (RRP) of vesicles is critically important for determining the size of postsynaptic currents generated in response to action potentials. However, discrepancies in RRP estimates exist among methods designed to measure RRP size. In glutamatergic hippocampal neurons, we found that hypertonic sucrose application yielded RRP size estimates approximately fivefold larger than values obtained with high-frequency action potential trains commonly assumed to deplete the RRP. This discrepancy was specific for glutamatergic neurons, because no difference was found between sucrose and train estimates of RRP size in GABAergic neurons. A small component of the difference in excitatory neurons was accounted for by postsynaptic receptor saturation. Train estimates of vesicle pool size obtained using more stimuli revealed that action potential-elicited EPSCs did not truly reach a steady state during shorter trains, and RRP estimates were closer to sucrose estimates made in the same neurons. This suggested that reluctant vesicles may contribute to the total available pool. Two additional lines of evidence supported this hypothesis. First, RRP estimates from strongly depolarizing hyperkalemic solutions closely matched those obtained with sucrose. Second, when Ca2+influx was enhanced during trains, train estimates of pool size matched those obtained with sucrose. These data suggest that glutamatergic hippocampal neurons maintain a heterogeneous population of vesicles that can be differentially released with varying Ca2+influx, thereby increasing the range of potential synaptic responses.
Effect of leaf essential oil from Piper solmsianum C.DC. in mice behaviour
Authors: MOREIRA DAVYSON L. , SOUZA PATRÍCIA O. , KAPLAN MARIA AUXILIADORA C. , PEREIRA NUNO A. , CARDOSO GERALDO L. , GUIMARÃES ELSIE F.
Published: April 2005

The essential oil from Piper solmsianum leaves and its major compound (sarisan) were tested to verify their influences upon mice behaviour. The essential oil was obtained by hydrodistillation in a modified Clevenger extractor and analysed by GC/ MS. This analysis revealed in the oil the presence of monoterpenes, sesquiterpenes and of arylpropanoids. The compound sarisan, a myristicin analogue, was isolated from the oil to perform the pharmacological tests. Emulsions of the oil and of sarisan (5.0 and 10.0% v/v) were used in the tests. Pentobarbital (30 mg/ kg s.c.) or diazepam (2.5 mg/ kg s.c.) were tested as standard drugs to verify depressant or anxiolytic effects, respectively. Both essential oil and sarisan showed to have exciting and depressant effects in the tested animals.
Tangency quantum cohomology and characteristic numbers
Authors: KOCK JOACHIM
Published: April 2005

This work establishes a connection between gravitational quantum cohomology and enumerative geometry of rational curves (in a projective homogeneous variety) subject to conditions of infinitesimal nature like, for example, tangency. The key concept is that of modified psi classes, which are well suited for enumerative purposes and substitute the tautological psi classes of 2D gravity. The main results are two systems of differential equations for the generating function of certain top products of such classes. One is topological recursion while the other is Witten-Dijkgraaf-Verlinde-Verlinde. In both cases, however, the background metric is not the usual Poincaré metric but a certain deformation of it, which surprisingly encodes all the combinatorics of the peculiar way modified psi classes restrict to the boundary. This machinery is applied to various enumerative problems, among which characteristic numbers in any projective homogeneous variety, characteristic numbers for curves with cusp, prescribed triple contact, or double points.
Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers
Authors: FERNANDES-DE-LIMA VERA M. , KOGLER JOÃO E. , BENNATON JOCELYN , HANKE WOLFGANG
Published: April 2005

The brain is an excitable media in which excitation waves propagate at several scales of time and space. ''One-dimensional'' action potentials (millisecond scale) along the axon membrane, and spreading depression waves (seconds to minutes) at the three dimensions of the gray matter neuropil (complex of interacting membranes) are examples of excitation waves. In the retina, excitation waves have a prominent intrinsic optical signal (IOS). This optical signal is created by light scatter and has different components at the red and blue end of the spectrum. We could observe the wave onset in the retina, and measure the optical changes at the critical transition from quiescence to propagating wave. The results demonstrated the presence of fluctuations preceding propagation and suggested a phase transition. We have interpreted these results based on an extrapolation from Tasaki's experiments with action potentials and volume phase transitions of polymers. Thus, the scatter of red light appeared to be a volume phase transition in the extracellular matrix that was caused by the interactions between the cellular membrane cell coat and the extracellular sugar and protein complexes. If this hypothesis were correct, then forcing extracellular current flow should create a similar signal in another tissue, provided that this tissue was also transparent to light and with a similarly narrow extracellular space. This control tissue exists and it is the crystalline lens. We performed the experiments and confirmed the optical changes. Phase transitions in the extracellular polymers could be an important part of the long-range correlations found during wave propagation in central nervous tissue.
Campo Belo Metamorphic Complex: tectonic evolution of an Archean sialic crust of the southern São Francisco Craton in Minas Gerais (Brazil)
Authors: OLIVEIRA ARILDO H. , CARNEIRO MAURÍCIO A.
Published: April 2005

Systematic geological studies performed in the study area allowed the characterization of six lithodemic units: three gneissic, one amphibolitic, one supracrustal and one fissure mafic. The mineral assemblage and the structural record of these lithodemic units indicate that the study area was affected by five tectonothermal events. The structural pattern of the first and oldest event occurred under granulite facies conditions and reveals essentially a sinistral kinematic pattern. The second event, showing dominant extensional characteristics, is related to the generation of an ensialic basin filled by the volcano-sedimentary sequence of the supracrustal lithodemic unit. The third event, which is the most expressive in the study region, is characterized by a vigorous regional migmatization process and by the generation of the Claudio Shear Zone, presenting dextral kinematic movement. The fourth event is represented by a fissure mafic magmatism (probably two different mafic dike swarms) and finally, the fifth event is a regional metamorphic re-equilibration that reached the greenschist facies, closing the main processes of the tectonic evolution of the Campo Belo Metamorphic Complex.
Supramolecular ionics: electric charge partition within polymers and other non-conducting solids
Authors: GALEMBECK FERNANDO , COSTA CARLOS A. R. , GALEMBECK ANDRÉ , SILVA MARIA DO CARMO V. M.
Published: April 2005

Electrostatic phenomena in insulators have been known for the past four centuries, but many related questions are still unanswered, for instance: which are the charge-bearing species in an electrified organic polymer, how are the charges spatially distributed and which is the contribution of the electrically charged domains to the overall polymer properties? New scanning probe microscopies were recently introduced, and these are suitable for the mapping of electric potentials across a solid sample thus providing some answers for the previous questions. In this work, we report results obtained with two of these techniques: scanning electric potential (SEPM) and electric force microscopy (EFM). These results were associated to images acquired by using analytical electron microscopy (energy-loss spectroscopy imaging in the transmission electron microscope, ESI-TEM) for colloid polymer samples. Together, they show domains with excess electric charges (and potentials) extending up to hundreds of nanometers and formed by large clusters of cations or anions, reaching supramolecular dimensions. Domains with excess electric charge were also observed in thermoplastics as well as in silica, polyphosphate and titanium oxide particles. In the case of thermoplastics, the origin of the charges is tentatively assigned to their tribochemistry, oxidation followed by segregation or the Mawell-Wagner-Sillars and Costa Ribeiro effects.
Adapted Gaussian basis sets for atoms from Li through Xe generated with the generator coordinate Hartree-Fock method
Authors: CASTRO EUSTÁQUIO V. R. DE , JORGE FRANCISCO E.
Published: April 2005

The generator coordinate Hartree-Fock method is used to generate adapted Gaussian basis sets for the atoms from Li (Z=3) through Xe (Z=54). In this method the Griffin-Hill-Wheeler-Hartree-Fock equations are integrated through the integral discretization technique. The wave functions generated in this work are compared with the widely used Roothaan-Hartree-Fock wave functions of Clementi and Roetti (1974), and with other basis sets reported in the literature. For all atoms studied, the errors in our total energy values relatively to the numerical Hartree-Fock limits are always less than 7.426 mhartree.
Embryonic hybrid cells: a powerful tool for studying pluripotency and reprogramming of the differentiated cell chromosomes
Authors: SEROV OLEG , MATVEEVA NATALIA , KUZNETSOV SERGEY , KAFTANOVSKAYA ELENA , MITTMANN JOSANE
Published: April 2005

The properties of embryonic hybrid cells obtained by fusion of embryonic stem (ES) or teratocarcinoma (TC) cells with differentiated cells are reviewed. Usually, ES-somatic or TC-somatic hybrids retain pluripotent capacity at high levels quite comparable or nearly identical with those of the pluripotent partner. When cultured in vitro, ES-somatic- and TC-somatic hybrid cell clones, as a rule, lose the chromosomes derived from the somatic partner; however, in some clones the autosomes from the ES cell partner were also eliminated, i.e. the parental chromosomes segregated bilaterally in the ES-somatic cell hybrids. This opens up ways for searching correlation between the pluripotent status of the hybrid cells and chromosome segregation patterns and therefore for identifying the particular chromosomes involved in the maintenance of pluripotency. Use of selective medium allows to isolate in vitro the clones of ES-somatic hybrid cells in which "the pluripotent" chromosome can be replaced by "the somatic" counterpart carrying the selectable gene. Unlike the TC-somatic cell hybrids, the ES-somatic hybrids with a near-diploid complement of chromosomes are able to contribute to various tissues of chimeric animals after injection into the blastocoel cavity. Analysis of the chimeric animals showed that the "somatic" chromosome undergoes reprogramming during development. The prospects for the identification of the chromosomes that are involved in the maintenance of pluripotency and its cis- and trans-regulation in the hybrid cell genome are discussed.
Microporosity of BIF hosted massive hematite ore, Iron Quadrangle, Brazil
Authors: VARAJÃO CÉSAR A.C. , BRUAND ARY , RAMANAIDOU ERICK R. , GILKES ROBERT J.
Published: April 2005

Massive hematite ore (MHO) is a special high-grade iron ore, used as lump ore in the process of obtaining direct reduction iron (DRI). The influence of porosity on the reducibility of MHO from the Capitão do Mato Mine (Iron Quadrangle, Brazil) was investigated using optical and scanning electron microscopes on drill core and open pit samples. Hematite is the main component of the samples and occurs as granular crystals (10 mum), microplates (1 mum) and euhedral martite (10 to 30 mum). Quartz, maghemite, kenomagnetite and goethite are minor components. Primary micropores (Å to 1 mum) are associated with microplaty crystals that fill cavities between granular hematite. Secondary micropores (Å to 5 mum) related to euhedral martite crystals, are the most important. The total porosity of weathered samples, measured using nitrogen adsorption and mercury injection, attains values up to 11%, whereas unweathered samples have a porosity less than 2.5%. Reducibility is strongly enhanced by porosity, but inhibited by structure (bedding).
Shamanism or science?
Authors: GOTTLIEB OTTO R. , BORIN MARIA RENATA DE M.B.
Published: April 2005

The interconnection of the three organismic levels, metabolism, morphology, and biogeography, can now be amplified into a multipart architecture, introducing plant bioactivity through ethnobotany-oriented descriptions. Only via such an integrative model, the diverse organismic levels can be connected within a more holistic, realistic scheme. Construction of qualitative and quantitative models via evolutionarily conceived implantation into dahlgrenograms and Sporne indices, allows ethnobotany to acquire predictive validity. The coherence of such systems was demonstrated by comparison of the vast ethnobotanical Brazilian database by Pio Corrêa with relatively very minute databases referring to three Amazonian Indian societies.
Nonextensive statistical mechanics: a brief review of its present status
Authors: TSALLIS CONSTANTINO
Published: April 2005

We briefly review the present status of nonextensive statistical mechanics. We focus on (i) the central equations of the formalism, (ii) the most recent applications in physics and other sciences, (iii) the a priori determination (from microscopic dynamics) of the entropic index q for two important classes of physical systems, namely low-dimensional maps (both dissipative and conservative) and long-range interacting many-body hamiltonian classical systems.
Weak convergence under nonlinearities
Authors: MOREIRA DIEGO R. , TEIXEIRA EDUARDO V. O.
Published: April 2005

In this paper, we prove that if a Nemytskii operator maps Lp(omega, E) into Lq(omega, F), for p, q greater than 1, E, F separable Banach spaces and F reflexive, then a sequence that converge weakly and a.e. is sent to a weakly convergent sequence. We give a counterexample proving that if q = 1 and p is greater than 1 we may not have weak sequential continuity of such operator. However, we prove that if p = q = 1, then a weakly convergent sequence that converges a.e. is mapped into a weakly convergent sequence by a Nemytskii operator. We show an application of the weak continuity of the Nemytskii operators by solving a nonlinear functional equation on W1,p(omega), providing the weak continuity of some kind of resolvent operator associated to it and getting a regularity result for such solution.
Modulation by context of a scene in monkey anterior inferotemporal cortex during a saccadic eye movement task
Authors: LIMA BRUSS , FIORANI MARIO , GATTASS RICARDO
Published: April 2005

We investigated the effect of a scene on the activity of cells in the anterior inferotemporal (AIT) cortex while the monkey performed a saccadic eye movement (SEM) task with and without the context of a scene (gray frame). Most neurons did not code for the presence of a scene when it appeared alone (monkey free viewing) or when the monkey was fixating. Nevertheless, when a peripheral target was turned on and the monkey had to make a SEM to it, some cells were capable of differentially coding the presence of the scene before and after the saccade.
Spatial distribution of organic matter in the surface sediments of Ubatuba Bay (Southeastern - Brazil)
Authors: BURONE LETICIA , MUNIZ PABLO , PIRES-VANIN ANA MARIA S. , RODRIGUES MARCELO
Published: April 2005

Analyses of organic matter content, organic carbon, nitrogen, sulfur and granulometric variables were performed on 101 surface sediment samples from Ubatuba Bay in order to investigate the spatial distribution of organic matter, its origin and the relationships among its components. The samples were obtained with a manual corer, from water depths between 1 and 15m during 5 cruises of the R/V "Veliger II'', two months apart. Pearson correlation, regression and Principal Component Analysis (PCA) statistical methods were used to analyze the data. Strong correlations between organic matter and fine sediment fractions were obtained. The PCA revealed at least two main sample groups that reflect the different environmental conditions prevalent in the bay. There is a simple linear relationship between organic carbon content and the organic matter content determined by the calcination technique. Taking into account that the analysis of organic matter content is less expensive and less time consuming than the analysis of organic carbon, the present method of estimation can be useful when fast evaluation of the organic carbon content is needed for samples from similar environments.
Photoelectrochemical solar cell using extract of Eugenia jambolana Lam as a natural sensitizer
Authors: Garcia Christian G. , Polo André S. , Iha Neyde Y. Murakami
Published: April 2005

The extract of Jambolão (java plum), Eugenia jambolana Lam, was used as a natural sensitizer of a wide band-gap semiconductor (TiO2) in photoelectrochemical solar cells. The natural dye, adsorbed onto the semiconductor surface, absorbs visible light and promotes electron transfer across the dye/semiconductor interface. Photogenerated current and voltage as high as 2.3 mA and 711 mV, respectively, were obtained and effective conversion of visible light into electricity was achieved. The use of a natural product as the semiconductor sensitizer enables a faster and simpler production of cheaper and environmentally friendly solar cells.
Somatic pairing, endomitosis and chromosome aberrations in snakes (Viperidae and Colubridae)
Authors: Beçak Maria Luiza , Beçak Willy , Pereira Alexandre
Published: April 2005

The positioning of macrochromosomes of Bothrops jararaca and Bothrops insularis (Viperidae) was studied in undistorted radial metaphases of uncultured cells (spermatogonia and oogonia) not subjected to spindle inhibitors. Colchicinized metaphases from uncultured (spleen and intestine) and cultured tissues (blood) were also analyzed. We report two antagonic non-random chromosome arrangements in untreated premeiotic cells: the parallel configuration with homologue chromosomes associated side by side in the metaphase plate and the antiparallel configuration having homologue chromosomes with antipolar distribution in the metaphase ring. The antiparallel aspect also appeared in colchicinized cells. The spatial chromosome arrangement in both configurations is groupal size-dependent and maintained through meiosis. We also describe, in untreated gonia cells, endomitosis followed by reductional mitosis which restores the diploid number. In B. jararaca males we observed that some gonad regions present changes in the meiotic mechanism. In this case, endoreduplicated cells segregate the diplochromosomes to opposite poles forming directly endoreduplicated second metaphases of meiosis with the suppression of first meiosis. By a successive division, these cells form nuclei with one set of chromosomes. Chromosome doubling in oogonia is known in hybrid species and in parthenogenetic salamanders and lizards. This species also presented chromosome rearrangements leading to aneuploidies in mitosis and meiosis. It is suggested that somatic pairing, endomitosis, meiotic alterations, and chromosomal aberrations can be correlated processes. Similar aspects of nuclei configurations, endomitosis and reductional mitosis were found in other Viperidae and Colubridae species.
Use of synthetic aperture radar for recognition of Coastal Geomorphological Features, land-use assessment and shoreline changes in Bragança coast, Pará, Northern Brazil
Authors: Souza-Filho Pedro W. M. , Paradella Waldir R.
Published: April 2005

Synthetic Aperture Radar (SAR) images are being used more extensively than ever before for geoscience applications in the moist tropics. In this investigation, a RADARSAT1-1 C-HH SAR image acquired in 1998 was used for coastal mapping and land-cover assessment in the Bragança area, in the northern Brazil. The airborne GEMS 1000 X-HH radar image acquired in 1972 during the RADAM Project was also used for evaluating coastal changes occurring over the last three decades. The research has confirmed the usefulness of RADARSAT-1 image for geomorphological mapping and land-cover assessment, particularly in macrotidal mangrove coasts. It was possible to map mangroves, salt marshes, chenier sand ridges, dunes, barrier-beach ridges, shallow water morphologies and different forms of land-use. Furthermore, a new method to estimate shoreline changes based on the superimposition of vectors extracted from both sources of SAR data has indicated that the shoreline has been subjected to severe coastal erosion responsible for retreat of 32 km² and accretion of 20 km², resulting in a mangrove land loss of almost 12 km². In an application perspective, orbital and airborne SAR data proved to be a fundamental source of information for both geomorphological mapping and monitoring coastal changes in moist tropical environments.
On the pterosaur remains from the Río Belgrano formation (Barremian), Patagonian Andes of Argentina
Authors: Kellner Alexander W.A. , Aguirre-Urreta María B. , Ramos Victor A.
Published: April 2005

Pterosaur remains from the Río Belgrano Formation, Santa Cruz Province, Argentina, were found close to the Estancia Río Roble, along with several ammonoids that indicate a Barremian age for those strata. The specimens (MACN-SC 3617) consist of one ulna and one element tentatively identified as a portion of a wing metacarpal. The ulna shows morphological affinities with the Pteranodontoidea (sensu Kellner 1996), particularly with the members of the Anhangueridae by having a well developed ventral crest close to the proximal articulation, and is tentatively referred to this pterosaur clade. The oldest record of the Anhangueridae, previously limited to the Aptian/Albian, is therefore extended to the Barremian. The Argentinean material is preserved in three dimensions, an unusual condition for pterosaur fossils from that country, indicating that the site situated near the Estancia Río Roble has a great potential for new and well preserved specimens.
The length of the second fundamental form, a tangency principle and applications
Authors: Fontenele Francisco X. , Silva Sérgio L.
Published: April 2005

In this paper we prove a tangency principle (see Fontenele and Silva 2001) related with the length of the second fundamental form, for hypersurfaces of an arbitrary ambient space. As geometric applications, we make radius estimates of the balls that lie in some component of the complementary of a complete hypersurface into Euclidean space, generalizing and improving analogous radius estimates for embedded compact hypersurfaces obtained by Blaschke, Koutroufiotis and the authors. The basic tool established here is that some operator is elliptic at points where the second fundamental form is positive definite.
Organic matter composition in the sediment of three Brazilian coastal lagoons: district of Macaé, Rio de Janeiro (Brazil)
Authors: Zink Klaus-Gerhard , Furtado André L. S. , Casper Peter , Schwark Lorenz
Published: April 2005

Freshwater lagoons comprise important coastal ecosystems and natural buffers between urbanized land areas and open ocean in the Rio de Janeiro State, Brazil. Studies of sediment and water chemistry, zooplankton and bacterial communities to assess the extent of anthropogenic disturbance are available. Here we contribute with an organic-geochemical approach supplemented by some microbiological aspects to complete the characterization of these lagoonal ecosystems. Bulk organic matter and extractable lipids (aliphatic hydrocarbons, alcohols and fatty acids, sterols) were investigated from two locations per lagoon: at the seaward site and landward ends - and at two depth intervals (0-3 and 3-6 cm) per site. Urbanized Imboacica Lagoon received increased anthropogenic input over the most recent years represented by the topmost 3 cm of sediment, whereas deeper sediment layers are less affected by human influence. Eutrophication or nutrient availability favored enhanced algal/cyanobacterial growth. In remote Cabiúnas and Comprida Lagoons pristine conditions are preserved. Organic matter from vascular plants dominates (chain length of free lipids up to C36), which is exceptionally well preserved by acidic lagoonal waters. Differentiation between landward and seaward sites in these two lagoons is less well established due to much smaller surface/volume to catchment ratios. No anthropogenic influences are yet detectable in sediments of Cabiúnas and Comprida Lagoons.
Apoptotic cell and phagocyte interplay: recognition and consequences in different cell systems
Authors: Moreira Maria Elisabete C. , Barcinski Marcello A.
Published: April 2005

Cell death by apoptosis is characterized by specific biochemical changes, including the exposure of multiple ligands, expected to tag the dying cell for prompt recognition by phagocytes. In non-pathological conditions, an efficient clearance is assured by the redundant interaction between apoptotic cell ligands and multiple receptor molecules present on the engulfing cell surface. This review concentrates on the molecular interactions operating in mammalian and non-mammalian systems for apoptotic cell recognition, as well as on the consequences of their signaling. Furthermore, some cellular models where the exposure of the phosphatidylserine (PS) phospholipid, a classical hallmark of the apoptotic phenotype, is not followed by cell death will be discussed.
Strategies that facilitate or counter eavesdropping on vocal interactions in songbirds
Authors: Dabelsteen Torben
Published: April 2005

Most territorial songbirds live in communication networks where eavesdropping on vocal interactions may constitute an important option for gathering information regarding the relative dominance, condition and quality of individuals being eavesdropped upon. The relatively low costs and risks of eavesdropping, together with the obvious advantages of gaining such comparative information about other individuals, predict eavesdropping to be a widespread phenomenon even though it is not necessarily advantageous for the participants to be eavesdropped upon. Special eavesdropper strategies that facilitate eavesdropping (how best to eavesdrop) may therefore have evolved together with strategies for interacting that either co-facilitate (public signaling) or counter eavesdropping directly (private signaling) or indirectly by preventing any subsequent negative consequences of being eavesdropped upon (anonymity). This paper reviews the predictions for the strategies and also gives examples supporting their use by territorial songbirds in connection with vocal interactions.
Modulation by steroid hormones of a ''sexy'' acoustic signal in an Oscine species, the Common Canary Serinus canaria
Authors: Rybak Fanny , Gahr Manfred
Published: April 2005

The respective influence of testosterone and estradiol on the structure of the Common Canary Serinus canaria song was studied by experimentally controlling blood levels of steroid hormones in males and analyzing the consequent effects on acoustic parameters. A detailed acoustic analysis of the songs produced before and after hormonal manipulation revealed that testosterone and estradiol seem to control distinct song parameters independently. The presence of receptors for testosterone and estradiol in the brain neural pathway controlling song production strongly suggests that the observed effects are mediated by a steroid action at the neuronal level.
Isolation induced changes in Guinea Pig Cavia porcellus pup distress whistles
Authors: Monticelli Patrícia F. , Tokumaru Rosana S. , Ades César
Published: April 2005

Guinea Pig Cavia porcellus pups emit high-pitched distress whistles when separated from their mother. In order to assess the influence of the duration of a brief isolation period on whistle acoustic structure, werecorded the distress whistles of six 8-day old pups separated for 15 min from their group in a novel environment and compared the mean values of the first and last 30 whistle notes. Acoustic analysis revealed, throughout the session, a significant decrease in whistle duration, an increase in mean frequency and a tendency for a decrease in number of harmonics in the first part of the note. Results demonstrate that, throughout a brief isolation period, the vocal response of Guinea Pig pups to isolation undergoes structural changes possibly related to time-dependent changes in motivational state.
Analysis of whistles produced by the Tucuxi Dolphin Sotalia fluviatilis from Sepetiba Bay, Brazil
Authors: Erber Claudia , Simão Sheila M.
Published: April 2005

From July 2001 to June 2002, we recorded a total of 2h55min of Tucuxi Dolphin Sotalia fluviatilis vocalizations from Sepetiba Bay, Brazil (22º35'S-44º03'W). A total of 3350 whistles were analyzed quantitative and qualitatively and were divided into 124 types, by visual inspection of sonograms. The following parameters were measured: Initial Frequency, Final Frequency, Minimum Frequency, Maximum Frequency, Duration, Number of Inflections, Frequency at the Inflection Points, Frequency at 1/2, 1/4, and 3/4 of whistle duration, Presence of Frequency Modulation and Harmonics. Ascending type whistles (N=2719) were most common, representing 82% of the total. Dolphin behavior and average group size observed during recording influenced the whistle's quantitative and qualitative parameters. The results demonstrate the great diversity of whistles emitted and indicate a functional role of these vocalizations during the observed behaviors.
Vocal sequential exchanges and intragroup spacing in the Northern Muriqui Brachyteles arachnoides hypoxanthus
Authors: Mendes Francisco D.C. , Ades César
Published: April 2005

Sequential exchanges of vocalizations (staccatos and neighs) emitted by Northern Muriquis Brachyteles arachnoides hypoxanthus were recorded at the Biological Station of Caratinga, Minas Gerais State, Brazil. Staccatos and neighs containing larger proportion of short elements were preferentially produced during short-range exchanges; neighs, produced by a larger number of participants, were typical of long-range exchanges. Staccatos emitted by animals feeding in a dispersed manner contained a larger proportion of tonal elements than those emitted by muriquis feeding in a cohesive manner. Sequential exchanges seem thus to be constituted by two inter-related subsystems of calls that aid muriquis to coordinate intragroup spacing, despite the poor visibility of the habitat.
Species richness and relative abundance of birds in natural and anthropogenic fragments of Brazilian Atlantic forest
Authors: Anjos Luiz dos
Published: April 2005

Bird communities were studied in two types of fragmented habitat of Atlantic forest in the State of Paraná, southern Brazil; one consisted of forest fragments that were created as a result of human activities (forest remnants), the other consisted of a set of naturally occurring forest fragments (forest patches). Using quantitative data obtained by the point counts method in 3 forest patches and 3 forest remnants during one year, species richness and relative abundance were compared in those habitats, considering species groups according to their general feeding habits. Insectivores, omnivores, and frugivores presented similar general tendencies in both habitats (decrease of species number with decreasing size and increasing isolation of forest fragment). However, these tendencies were different, when considering the relative abundance data: the trunk insectivores presented the highest value in the smallest patch while the lowest relative abundance was in the smallest remnant. In the naturally fragmented landscape, time permitted that the loss of some species of trunk insectivores be compensated for the increase in abundance of other species. In contrast, the remnants essentially represented newly formed islands that are not yet at equilibrium and where future species losses would make them similar to the patches.
Genes and chromosomes: control of development
Authors: Serov Oleg , Serova Irina
Published: April 2005

The past decade has witnessed immense progress in research into the molecular basis behind the developmental regulation of genes. Sets of genes functioning under hierarchical control have been identified, evolutionary conserved systems of genes effecting the cell-to-cell transmission of transmembrane signals and assigned a central role in morphogenesis have been intensively studied; the concept of genomic regulatory networks coordinating expression of many genes has been introduced, to mention some of the major breakthroughs. It should be noted that the temporal and tissue-specific parameters of gene expression are correctly regulated in development only in the context of the chromosome and that they are to a great extent dependent on the position of the gene on the chromosome or the interphase nucleus. Moreover epigenetic inheritance of the gene states through successive cell generations has been conducted exclusively at the chromosome level by virtue of cell or chromosome memory. The ontogenetic memory is an inherent property of the chromosome and cis-regulation has a crucial role in its maintenance.
Inactivation of yeast inorganic pyrophosphatase by organic solvents
Authors: Grazinoli-Garrido Rodrigo , Sola-Penna Mauro
Published: April 2005

A number of application for enzymes in organic solvents have been developed in chemical processing, food related conversions and analyses. The only unsolved problem related to nonaqueous enzymology is the notion that enzymes in organic solvent are mostly far less active than in water. Therefore, studies concerning the mechanisms by which enzymes are inactivated by organic solvents would reveal a clear understanding of the structure-function relationship of this phenomenon. Here we analyzed the effects of a series of alcohols (methanol, ethanol, 1-propanol and 2-propanol) and acetone on the activity of yeast inorganic pyrophosphatase. We observed that solvents inactivated the enzyme in a dose-dependent manner. This inactivation is also dependent on the hydrophobicity of the solvent, where the most hydrophobic solvent is also the most effective one. The I50 for inactivation by n-alcohols are 5.9±4, 2.7±1 and 2.5±1 M for methanol, ethanol and 1-propanol, respectively. Inactivation was less effective at 37C than at 5C, when the I50 for inactivation by methanol, ethanol and 1-propanol are 4.5±2, 2.1±2 and 1.7±1 M, respectively. Our proposal is that solvent binds to the enzyme structure promoting the inactivation by stabilizing an unfolded structure, and that this binding is through the hydrophobic regions of either the protein or the solvent.
The 1590-1520 Ma Cachoeirinha magmatic arc and its tectonic implications for the Mesoproterozoic SW Amazonian craton crustal evolution
Authors: Ruiz Amarildo S. , Geraldes Mauro C. , Matos João B. , Teixeira Wilson , Van Schumus William R. , Schmitt Renata S.
Published: April 2005

Isotopic and chemical data of rocks from the Cachoeirinha suite provide new insights on the Proterozoic evolution of the Rio Negro/Juruena Province in SW Amazonian craton. Six U-Pb and Sm-Nd analyses in granitoid rocks of the Cachoeirinha suite yielded ages of 1587-1522 Ma and T DM model ages of 1.88-1.75 Ga (EpsilonNd values of -0.8 to +1.0). In addition, three post-tectonic plutonic rocks yielded U-Pb ages from 1485-1389 Ma (T DM of 1.77-1.74 Ga and EpsilonNd values from -1.3 to +1.7). Variations in major and trace elements of the Cachoeirinha suite rocks indicate fractional crystallization process and magmatic arc geologic setting. These results suggest the following interpretations: (1) The interval of 1590-1520 Ma represents an important magmatic activity in SW Amazonian craton. (2) T DM and arc-related chemical affinity supportthe hypothesis that the rocks are genetically associated with an east-dipping subduction zone under the older (1.79-1.74 Ga) continental margin. (3) The 1590-1520 Ma age of intrusive rocks adjacent to an older crust represents similar geological framework along the southern margin of Baltica, corroborating the hypothesis of tectonic relationship at that time.
Mammalian cell invasion and intracellular trafficking by Trypanosoma cruzi infective forms
Authors: Mortara Renato A. , Andreoli Walter K. , Taniwaki Noemi N. , Fernandes Adriana B. , Silva Claudio V. da , Fernandes Maria Cecília D.C. , L'abbate Carolina , Silva Solange da
Published: April 2005

Trypanosoma cruzi, the etiological agent of Chagas’ disease, occurs as different strains or isolates that may be grouped in two major phylogenetic lineages: T. cruzi I, associated with the sylvatic cycle and T. cruzi II, linked to the human disease. In the mammalian host the parasite has to invade cells and many studies implicated the flagellated trypomastigotes in this process. Several parasite surface components and some of host cell receptors with which they interact have been identified. Our work focused on how amastigotes, usually found growing in the cytoplasm, can invade mammalian cells with infectivities comparable to that of trypomastigotes. We found differences in cellular responses induced by amastigotes and trypomastigotes regarding cytoskeletal components and actin-rich projections. Extracellularly generated amastigotes of T. cruzi I strains may display greater infectivity than metacyclic trypomastigotes towards cultured cell lines as well as target cells that have modified expression of different classes of cellular components. Cultured host cells harboring the bacterium Coxiella burnetii allowed us to gain new insights into the trafficking properties of the different infective forms of T. cruzi, disclosing unexpected requirements for the parasite to transit between the parasitophorous vacuole to its final destination in the host cell cytoplasm.
Coricladus quiteriensis gen. et sp. nov., a new conifer in Southern-Brazil Gondwana (Lower Permian, Paraná Basin)
Authors: Jasper André , Ricardi-Branco Fresia , Guerra-Sommer Margot
Published: April 2005

A new taxon of conifers (Coricladus quiteriensis) is described based on megafloristic remains from the roofshale level at the Quitéria Outcrop (Rio Bonito Formation - Lower Permian - Southern Paraná Basin - Rio Grande do Sul - Brazil). This megafloristic community is included in the Botrychiopsis Zone - Botrychiopsis valida Sub-Zone (Kungurian/Roadian). The assemblage, preserved as impressions, do not present remains of epidermic characters, and is composed mainly of isolated vegetative branches with spirally disposed acicular leaves, presenting a conspicuous central vein and also isolated fertile branches with sparse and irregular leaves and terminal cones. Leafless principal branches, organically connected with sterile and fertile branches, are rare. Reproductive feminine scales, disposed in a plane, are organized in lax terminal cones on branches, composed by 4 (four) distal ovuliferous scales, and 8 (eight) elliptical-elongated anatropous seeds. Paleoecological data pointed out to a mesophylous to higrophylous habitat in swampy environments.