bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced levels of stimulated Brillouin reflectivity from non-Maxwellian plasmas
Authors: BAWA'ANEH M.S. , BOYD T.J.M.
Published: March 2006

A model that counts for temperature gradients in the target plasma, which leads to higher ion acoustic noise and enhanced levels of stimulated Brillouin scattering (SBS) gain and SBS reflectivity, has been adopted. Enhanced Brillouin gain leading to higher SBS reflectivity levels has been computed for non-homogeneous, non-Maxwellian plasmas. SBS reflectivity levels obtained are higher than those predicted by linear convective gain theory by several orders of magnitude and coincide with the high values of experimental data known in literature, which could not be interpreted by the linear convective gain theory.
The kH−3 and kH−5/3 energy spectra in stratified turbulence
Authors: Kitamura Y. , Matsuda Y.
Published: March 2006

Numerical experiments of stratified turbulence are conducted with a high‐resolution nonhydrostatic Boussinesq model to investigate the energy spectrum produced by synoptic scale forcings. The spectral slope obtained in our experiment with planetary rotation is close to −3 in the synoptic scales and −5/3 in the mesoscales, as observed in the troposphere. While the vortical modes are predominant in the −3 spectral range, magnitude of the divergent modes is greater than that of the vortical ones in the −5/3 range. The downscale energy cascade associated with the divergent modes plays an important role in the formation of the mesoscale kH−5/3 spectrum. In experiments without planetary rotation, the obtained spectral slope is steeper and energy transfer to larger vertical wavenumbers is increased.
A miniature electron-beam ion source for in-trap creation of highly charged ions
Authors: Alonso J. , Blaum K. , Djekic S. , Kluge H.-J. , Quint W. , Schabinger B. , Stahl S. , Verdú J. , Vogel M. , Werth G.
Published: March 2006

Measurements of the anomalous magnetic moment of the electron bound in hydrogen-like ions with spinless nuclei have proven to be highly sensitive tests of corresponding calculations based on bound-state quantum electrodynamics. Currently, an experiment on hydrogen-like calcium Ca19+40 is being prepared, which is expected to yield a precision in the 10−9 level for the electronic g factor. This experiment makes use of an in-trap electron-beam ion source with which the charge breeding of the ions is performed by electron-impact ionization.
Active-space coupled-cluster methods through connected quadruple excitations
Authors: Fan Peng-Dong , Hirata So
Published: March 2006

Coupled-cluster methods that include just a subset of all connected triple, quadruple, or both excitation amplitudes, according to the ansatz of and Adamowicz co-workers [Int. Rev. Phys. Chem. 12, 339 (1993); J. Chem. Phys. 99, 1875 (1993); 100, 5792 (1994)] and Piecuch et al. [J. Chem. Phys. 110, 6103 (1999)], have been implemented into parallel execution programs. They are applicable to closed- and open-shell species and they take advantage of real Abelian point-group symmetry. A symbol manipulation program has been invoked to automate the implementation. These methods have been applied to the singlet-triplet separations of five triatomic hydrides (CH2, NH2+, SiH2, PH2+, and AsH2+) with consideration of scalar relativistic effects. They have been shown to be remarkably effective with errors arising from the use of a very small subset of higher-order excitations being no more than a few tenths of 1kcal∕mol.
Positronium annihilation lifetimes and dielectric spectroscopy studies on diethyl phthalate: Phenomenological correlations and microscopic analyses in terms of the extended free volume model by Cohen-Grest
Authors: Pawlus S. , Bartoš J. , Šauša O. , Krištiak J. , Paluch M.
Published: March 2006

A combined positronium annihilation lifetime spectroscopy (PALS) and dielectric spectroscopy (DS) study on a typical van der Waals glass-former diethyl phthalate (DEP) was performed and the results were compared. From phenomenological point of view, the mutual relationships between the characteristic PALS temperatures, the glass temperature TgPALS, and the crossover temperatures Tb1L and Tb2L on the ortho-positronium (o-Ps) lifetime versus the temperature plot, have been discussed with respect to the characteristic DS temperatures, the glass temperature TgDS and the dynamic crossover temperature TBST, concerning the crossover behavior of primary α-relaxation times. Next, simultaneous application of the extended free volume (EFV) model by Cohen-Grest on the temperature dependence of both the mean free volume hole size data as extracted from PALS and the dielectric α-relaxation time revealed a good agreement between the experimental Tb1L and the characteristic EFV temperatures T0DS and T0PALS at which a free volume percolation should occur. These results indicate the important role of free volume in control of the primary (α) dynamics of supercooled DEP.
Highly designable phenotypes and mutational buffers emerge from a systematic mapping between network topology and dynamic output
Authors: Nochomovitz Yigal D. , Li Hao
Published: March 2006

Deciphering the design principles for regulatory networks is fundamental to an understanding of biological systems. We have explored the mapping from the space of network topologies to the space of dynamical phenotypes for small networks. Using exhaustive enumeration of a simple model of three- and four-node networks, we demonstrate that certain dynamical phenotypes can be generated by an atypically broad spectrum of network topologies. Such dynamical outputs are highly designable, much like certain protein structures can be designed by an unusually broad spectrum of sequences. The network topologies that encode a highly designable dynamical phenotype possess two classes of connections: a fully conserved core of dedicated connections that encodes the stable dynamical phenotype and a partially conserved set of variable connections that controls the transient dynamical flow. By comparing the topologies and dynamics of the three- and four-node network ensembles, we observe a large number of instances of the phenomenon of “mutational buffering,” whereby addition of a fourth node suppresses phenotypic variation amongst a set of three-node networks.
Relative spike timing in pairs of hippocampal neurons distinguishes the beginning and end of journeys
Authors: Shapiro Matthew L. , Ferbinteanu Janina
Published: March 2006

Episodic memory organizes experience in time, so that we can review past events and anticipate the future. In a hippocampus-dependent memory task, spike timing in pairs of simultaneously active CA1 neurons with overlapping place fields distinguished the start and end of trials. At the common starting point of different journeys, the relative spike timing of the neurons was highly correlated. As the rat approached a common goal from different starting points, however, temporal firing patterns were strongly modulated across journeys even if the cells fired in the same spatial locations within fields, implying that different processes influenced when and where cells fire. Spike timing within hippocampal ensembles may thereby help parse the beginning from the end of episodes in memory.
Cannibal crickets on a forced march for protein and salt
Authors: Simpson Stephen J. , Sword Gregory A. , Lorch Patrick D. , Couzin Iain D.
Published: March 2006

Swarming and mass migration are spectacular and sometimes devastating features of the biology of various animal species. These phenomena are typically associated with actual or anticipated depletion of food resources after an increase in population density, but the mechanisms driving such collective movements are poorly understood. Here we reveal that insects in large, coordinated migratory bands consisting of millions of Mormon crickets in western North America were deprived of two essential nutritional resources: protein and salt. The insects themselves provided a major source of these nutrients, and cannibalism was rife. We show that protein and salt satiation reduced cannibalism and that protein satiation inhibited walking. Additionally, experimentally reducing the motility or mobility of crickets substantially increased their risk of being cannibalized by other band members. As a result, the availability of protein and salt in the habitat will influence the extent to which bands march, both through the direct effect of nutrient state on locomotion and indirectly through the threat of cannibalism by resource-deprived crickets approaching from the rear. The crickets are, in effect, on a forced march. Migratory band formation and subsequent mass movement, therefore, are manifestations of specific tradeoffs between the costs and benefits of group living. Bands afford antipredator benefits to individual group members. Group movement then mitigates the resulting costs of intraspecific competition, namely local depletion of nutritional resources and the associated increased risk of cannibalism.
Genetic mosaics reveal both cell-autonomous and cell-nonautonomous function of murine p27
Kip1
Authors: Chien Wei-Ming , Rabin Stuart , Macias Everardo , Miliani de Marval Paula L. , Garrison Kendra , Orthel Jason , Rodriguez-Puebla Marcelo , Fero Matthew L.
Published: March 2006

Loss of the cyclin-dependent kinase inhibitor p27
Kip1
leads to an overall increase in animal growth, pituitary tumors, and hyperplasia of hematopoietic organs, yet it is unknown whether all cells function autonomously in response to p27
Kip1
activity or whether certain cells take cues from their neighbors. In addition, there is currently no genetic evidence that tumor suppression by p27
Kip1
is cell-autonomous because biallelic gene inactivation is absent from tumors arising in p27
Kip1
hemizygous mice. We have addressed these questions with tissue-specific targeted mouse mutants and radiation chimeras. Our results indicate that the suppression of pars intermedia pituitary tumors by p27
Kip1
is cell-autonomous and does not contribute to overgrowth or infertility phenotypes. In contrast, suppression of spleen growth and hematopoietic progenitor expansion is a consequence of p27
Kip1
function external to the hematopoietic compartment. Likewise, p27
Kip1
suppresses thymocyte hyperplasia through a cell-nonautonomous mechanism. The interaction of p27
Kip1
loss with epithelial cell-specific cyclin-dependent kinase 4 overexpression identifies the thymic epithelium as a relevant site of p27
Kip1
activity for the regulation of thymus growth.
Rapid, sequence-specific detection of unpurified PCR amplicons via a reusable, electrochemical sensor
Authors: Lai Rebecca Y. , Lagally Eric T. , Lee Sang-Ho , Soh H. T. , Plaxco Kevin W. , Heeger Alan J.
Published: March 2006

We report an electrochemical method for the sequence-specific detection of unpurified amplification products of the
gyrB
gene of
Salmonella typhimurium
. Using an asymmetric PCR and the electrochemical E-DNA detection scheme, single-stranded amplicons were produced from as few as 90 gene copies and, without subsequent purification, rapidly identified. The detection is specific; the sensor does not respond when challenged with control oligonucleotides based on the
gyrB
genes of either
Escherichia coli
or various
Shigella
species. In contrast to existing sequence-specific optical- and capillary electrophoresis-based detection methods, the E-DNA sensor is fully electronic and requires neither cumbersome, expensive optics nor high voltage power supplies. Given these advantages, E-DNA sensors appear well suited for implementation in portable PCR microdevices directed at, for example, the rapid detection of pathogens.
Investigation of Mediastinitis Due to Coagulase-Negative Staphylococci After Cardiothoracic Surgery
Authors: Van Kerkhove Maria D. , Parsonnet Julie , Weingart Michal , Tompkins Lucy S.
Published: March 2006

Six cases of coagulase-negative staphylococcal mediastinitis were identified in the latter half of 1999. A new preoperative cleansing solution was suspected by hospital staff to be a factor in the outbreak. We evaluated this possible risk factor along with other known and suspected surgical site infection risk factors in this case-control study.
Rosetta error model for gene expression analysis
Authors: Weng Lee , Dai Hongyue , Zhan Yihui , He Yudong , Stepaniants Sergey B. , Bassett Douglas E.
Published: March 2006

Motivation: In microarray gene expression studies, the number of replicated microarrays is usually small because of cost and sample availability, resulting in unreliable variance estimation and thus unreliable statistical hypothesis tests. The unreliable variance estimation is further complicated by the fact that the technology-specific variance is intrinsically intensity-dependent.

Results: The Rosetta error model captures the variance-intensity relationship for various types of microarray technologies, such as single-color arrays and two-color arrays. This error model conservatively estimates intensity error and uses this value to stabilize the variance estimation.

We present two commonly used error models: the intensity error-model for single-color microarrays and the ratio error model for two-color microarrays or ratios built from two single-color arrays. We present examples to demonstrate the strength of our error models in improving statistical power of microarray data analysis, particularly, in increasing expression detection sensitivity and specificity when the number of replicates is limited.

Availability: Rosetta error models are available in the Rosetta Resolver® system for gene expression analysis. These technology-specific error models are designed and optimized for different microarray technologies, such as Affymetrix® and Agilent Technologies.

Contact:  lee_weng@rosettabio.com

Supplementary information:  Supplementary data and Appendices are available at Bioinformatics online.
ArabidopsisTEBICHI, with Helicase and DNA Polymerase Domains, Is Required for Regulated Cell Division and Differentiation in Meristems
Authors: Inagaki Soichi , Suzuki Takamasa , Ohto Masa-aki , Urawa Hiroko , Horiuchi Takashi , Nakamura Kenzo , Morikami Atsushi
Published: March 2006

In plant meristems, each cell divides and differentiates in a spatially and temporally regulated manner, and continuous organogenesis occurs using cells derived from the meristem. We report the identification of the Arabidopsis thaliana  TEBICHI (TEB) gene, which is required for regulated cell division and differentiation in meristems. The teb mutants show morphological defects, such as short roots, serrated leaves, and fasciation, as well as defective patterns of cell division and differentiation in the meristem. The TEB gene encodes a homolog of Drosophila MUS308 and mammalian DNA polymerase θ, which prevent spontaneous or DNA damage–induced production of DNA double strand breaks. As expected from the function of animal homologs, teb mutants show constitutively activated DNA damage responses. Unlike other fasciation mutants with activated DNA damage responses, however, teb mutants do not activate transcriptionally silenced genes. teb shows an accumulation of cells expressing cyclinB1;1:GUS in meristems, suggesting that constitutively activated DNA damage responses in teb lead to a defect in G2/M cell cycle progression. Furthermore, other fasciation mutants, such as fasciata2 and tonsoku/mgoun3/brushy1, also show an accumulation of cells expressing cyclinB1;1:GUS in meristems. These results suggest that cell cycle progression at G2/M is important for the regulation of the pattern of cell division and of differentiation during plant development.
Nuclear Photosynthetic Gene Expression Is Synergistically Modulated by Rates of Protein Synthesis in Chloroplasts and Mitochondria
Authors: Pesaresi Paolo , Masiero Simona , Eubel Holger , Braun Hans-Peter , Bhushan Shashi , Glaser Elzbieta , Salamini Francesco , Leister Dario
Published: March 2006

Arabidopsis thaliana mutants prors1-1 and -2 were identified on the basis of a decrease in effective photosystem II quantum yield. Mutations were localized to the 5′-untranslated region of the nuclear gene PROLYL-tRNA SYNTHETASE1 (PRORS1), which acts in both plastids and mitochondria. In prors1-1 and -2, PRORS1 expression is reduced, along with protein synthesis in both organelles. PRORS1 null alleles (prors1-3 and -4) result in embryo sac and embryo development arrest. In mutants with the leaky prors1-1 and -2 alleles, transcription of nuclear genes for proteins involved in photosynthetic light reactions is downregulated, whereas genes for other chloroplast proteins are upregulated. Downregulation of nuclear photosynthetic genes is not associated with a marked increase in the level of reactive oxygen species in leaves and persists in the dark, suggesting that the transcriptional response is light and photooxidative stress independent. The mrpl11 and prpl11 mutants are impaired in the mitochondrial and plastid ribosomal L11 proteins, respectively. The prpl11 mrpl11 double mutant, but neither of the single mutants, resulted in strong downregulation of nuclear photosynthetic genes, like that seen in leaky mutants for PRORS1, implying that, when organellar translation is perturbed, signals derived from both types of organelles cooperate in the regulation of nuclear photosynthetic gene expression.
Reactive Oxygen Species Play a Role in Regulating a Fungus–Perennial Ryegrass Mutualistic Interaction
Authors: Tanaka Aiko , Christensen Michael J. , Takemoto Daigo , Park Pyoyun , Scott Barry
Published: March 2006

Although much is known about the signals and mechanisms that lead to pathogenic interactions between plants and fungi, comparatively little is known about fungus–plant mutualistic symbioses. We describe a novel role for reactive oxygen species (ROS) in regulating the mutualistic interaction between a clavicipitaceous fungal endophyte, Epichloë festucae, and its grass host, Lolium perenne. In wild-type associations, E. festucae grows systemically in intercellular spaces of leaves as infrequently branched hyphae parallel to the leaf axis. A screen to identify symbiotic genes isolated a fungal mutant that altered the interaction from mutualistic to antagonistic. This mutant has a single-copy plasmid insertion in the coding region of a NADPH oxidase gene, noxA. Plants infected with the noxA mutant lose apical dominance, become severely stunted, show precocious senescence, and eventually die. The fungal biomass in these associations is increased dramatically, with hyphae showing increased vacuolation. Deletion of a second NADPH oxidase gene, noxB, had no effect on the E. festucae–perennial ryegrass symbiosis. ROS accumulation was detected cytochemically in the endophyte extracellular matrix and at the interface between the extracellular matrix and host cell walls of meristematic tissue in wild-type but not in noxA mutant associations. These results demonstrate that fungal ROS production is critical in maintaining a mutualistic fungus–plant interaction.
The D-Type Cyclin CYCD3;1 Is Limiting for the G1-to-S-Phase Transition inArabidopsis
Authors: Menges Margit , Samland Anne K. , Planchais Séverine , Murray James A.H.
Published: March 2006

The G1-to-S-phase transition is a key regulatory point in the cell cycle, but the rate-limiting component in plants is unknown. Overexpression of CYCLIN D3;1 (CYCD3;1) in transgenic plants increases mitotic cycles and reduces endocycles, but its effects on cell cycle progression cannot be unambiguously determined. To analyze the cell cycle roles of plant D-type cyclins, we overexpressed CYCD3;1 in Arabidopsis thaliana cell suspension cultures. Changes in cell number and doubling time were insignificant, but cultures exhibited an increased proportion of G2- over G1-phase cells, as well as increased G2 arrest in response to stationary phase and sucrose starvation. Synchronized cultures confirm that CYCD3;1-expressing (but not CYCD2;1-expressing) cells show increased G2-phase length and delayed activation of mitotic genes such as B-type cyclins, suggesting that CYCD3;1 has a specific G1/S role. Analysis of putative cyclin-dependent kinase phosphorylation sites within CYCD3;1 shows that mutating Ser-343 to Ala enhances CYCD3;1 potency without affecting its rate of turnover and results in a fivefold increase in the level of cell death in response to sucrose removal. We conclude that CYCD3;1 dominantly drives the G1/S transition, and in sucrose-depleted cells the decline in CYCD3;1 levels leads to G1 arrest, which is overcome by ectopic CYCD3;1 expression. Ser-343 is likely a key residue in modulating CYCD3;1 activity in response to sucrose depletion.
A family of oligopeptide transporters is required for growth of Candida albicans on proteins
Authors: Reuß Oliver , Morschhäuser Joachim
Published: March 2006

The human fungal pathogen Candida albicans can use proteins as the sole source of nitrogen for growth. The secretion of aspartic proteinases, which have been shown to contribute to virulence of C. albicans, allows the fungus to digest host proteins to produce peptides that must be taken up into the cell by specific transporters. To understand in more detail how C. albicans utilizes proteins as a nitrogen source, we undertook a comprehensive analysis of oligopeptide transporters encoded in the C. albicans genome. We identified eight OPT genes encoding putative oligopeptide transporters, almost all of which are represented by polymorphic alleles in strain SC5314. Expression of these genes was differentially induced when C. albicans was grown in YCB‐BSA medium, which contains bovine serum albumin as the sole nitrogen source. Whereas deletion of single OPT genes in strain SC5314 did not affect its ability to utilize proteins as a nitrogen source, opt123Δ triple mutants had a severe growth defect in YCB‐BSA which was rescued by reintroduction of a single copy of OPT1, OPT2 or OPT3. In addition, forced expression of OPT4 or OPT5 under control of the ADH1 promoter also restored growth of an opt123Δ mutant, demonstrating that at least OPT1‐OPT5 encode functional peptide transporters. The various oligopeptide transporters differ in their substrate preferences, as shown by the ability of strains expressing specific OPT genes to grow on peptides of defined length and sequence. We present evidence that in addition to the known role of oligopeptide transporters in the uptake of tetra‐ and pentapeptides these proteins can also transport longer peptides up to at least eight amino acids in length, ensuring an efficient utilization of the various peptides produced via endoproteolytic digestion of proteins by the secreted aspartic proteinases. As even transporters encoded by polymorphic alleles of a single gene exhibited differences in their efficiency to take up specific peptides, the oligopeptide transporters represent an example for how the evolution of gene families containing differentially expressed and functionally optimized members increases the nutritional versatility and, presumably, the adaptation of C. albicans to different host niches.
Evaluation of a Burdizzo Castrator for Neutering of Dogs
Authors: Ortega‐Pacheco A , Bolio‐González ME , Colin‐Flores RF , Sauri‐Arceo CH , Gutiérrez‐Blanco E , Jiménez‐Coello M , Linde Forsberg C
Published: March 2006

Contents

A Burdizzo castrator was evaluated for the neutering of dogs. Histological and morphological changes of spermatic cells and peripheral serum testosterone after challenge with a GnRH‐analogue (gonadorelin) were assessed. There was a control group (G1), a surgically castrated group (G2) and a Burdizzo group (G3) divided in two, G3a receiving two crunches in each spermatic cord and G3b receiving one crunch in each spermatic cord. Sixteen days after application of the Burdizzo blood samples were taken from the dogs at 30 min interval during 2 h; after the second sample the dogs were treated with 1 μg/kg body weight of gonadorelin i.v. The same protocol of gonadorelin challenge was performed in G1 and G2 dogs. The G2 dogs were surgically castrated after the second blood sample, before the gonadorelin treatment, and the G1 dogs after the last blood sample. The excised gonads were examined histologically, and sperm smears were prepared from the caudae epididymidis. The testes and plexus pampiniformis of the G1 and G2 dogs had a normal histological appearance, and they had morphologically normal epididymal sperm cells. In all G3 dogs, there was an acute fibrosis with an inflammatory reaction in the plexus pampiniformis. The testes from the G3a dogs showed diffuse areas of infarction and degeneration of the parenchyma. Similar but less diffuse lesions were seen in group 3b dogs. The deferent ducts from all G3 dogs showed vasitis and/or sperm granulomas. Azoospermia or sperm malformations were observed in the epididymal smears from the G3 dogs. Testosterone concentration in the G1 dogs increased after gonadorelin application (p < 0.0001). The G2 dogs had basal testosterone levels after castration (p < 0.001) and did not respond to gonadorelin. Groups 3a and b showed a slight but non‐significant increase in testosterone concentration after gonadorelin challenge, supposedly due to the reduction of testicular blood flow and loss of testicular interstitial tissue.
Tephrostratigraphy and paleoenvironmental variation in late Quaternary core sediments of the southwestern Ulleung Basin, East Sea (Sea of Japan)
Authors: Kim Il‐Soo , Park Myong‐Ho , Ryu Byong‐Jae , Yu Kang‐Min
Published: March 2006

Abstract  Data on the late Quaternary tephra layers, tephrostratigraphy, geochemistry and environment were determined in two sediment cores from the southwestern part of Ulleung Basin (East Sea/Sea of Japan), representing marine‐oxygen isotope stages 1–3. The cores consist mainly of muddy sediments that are partly interbedded with silty sands, lapilli tephra and ash layers. The lapilli tephra layers (Ulleung‐Oki tephra, 9.3 ka) originating from Ulleung Island consist mainly of massive‐type glass shards, whereas the ash layers (Aira‐Tanzawa ash, 22.0–24.7 ka) derived from southern Kyushu Island are mainly composed of typical plane‐type and bubble‐wall glasses that are higher in SiO2 and lower in Na2O + K2O than the lapilli tephra layers. Except for the tephra layers, fine‐grained sediments throughout the core sections are mostly of marine origin based on geochemical data (C/N ratios, hydrogen index, S2 peak) and Tmax. In particular, organic carbon contents increased during Termination I, probably as a result of an influx of the deglacial Tsushima Current through the Korea Strait.
Suppressed oxytocin neuron responses to immune challenge in late pregnant rats: a role for endogenous opioids
Authors: Brunton Paula J. , Sabatier Nancy , Leng Gareth , Russell John A.
Published: March 2006

Cytokine challenge (mimicking infection) with systemic interleukin‐1β (IL‐1β) stimulates oxytocin neurons via a noradrenergic brainstem pathway similar to that involved in parturition. As the responses of oxytocin neurons to several stimuli are reduced in late pregnancy, we have investigated whether responses to IL‐1β are also suppressed. In virgin Sprague–Dawley rats, IL‐1β (500 ng/kg i.v.) rapidly increased oxytocin secretion (3.2‐fold), via a central action as the firing rate of oxytocin neurons in the supraoptic nucleus was increased. In contrast, IL‐1β had no significant effect on the electrical or secretory activity of oxytocin neurons in late pregnant rats. In pregnancy activation of a central inhibitory opioid mechanism restrains oxytocin neuron responses to various stimuli. Accordingly, we tested the effects of the opioid antagonist, naloxone, on oxytocin neuron responses to IL‐1β in pregnancy. Naloxone (5 mg/kg i.v.) did not affect the oxytocin secretory response to IL‐1β in virgin rats, whereas in late pregnant rats naloxone revealed a greater oxytocin secretory response to IL‐1β (3.5‐fold) than in virgin rats. In virgin rats, naloxone decreased oxytocin neuron firing rate after IL‐1β, however, in pregnant rats naloxone increased the firing rate response to IL‐1β to the level seen in virgin rats. Thus, systemic IL‐1β acts centrally to increase oxytocin secretion. In pregnancy this response is suppressed by endogenous opioids, thus preserving neurohypophysial oxytocin stores for parturition and minimizing the risk of preterm labour. The exaggerated oxytocin secretory response to IL‐1β in pregnancy after naloxone reflects increased oxytocin stores and/or increased efficiency of excitation‐secretion coupling at the posterior pituitary.
Estimation of microbial cover distributions at Mammoth Hot Springs using a multiple clone library resampling method
Authors: Martín Héctor García , Goldenfeld Nigel
Published: March 2006

We propose the use of cover as a quick, low‐resolution proxy for the abundance of microbial species, which reduces polymerase chain reaction bias. We showcase this concept in a computation that uses clone library information from travertine‐forming hot springs in Yellowstone National Park to provide estimates of relative covers at different locations within the spring system. Samples were used from two media: the water column and the travertine substrate. The cover distribution is found to approximate a power law for samples within the water column. Significant commonality of species with the highest cover is observed in the water column for all locations, but not for species present in the substrate at different locations or between media at the same location.
Site‐specific variation in Antarctic marine biofilms established on artificial surfaces
Authors: Webster Nicole S. , Negri Andrew P.
Published: March 2006

The community structure and composition of marine microbial biofilms established on glass surfaces was investigated across three differentially contaminated Antarctic sites within McMurdo Sound. Diverse microbial communities were revealed at all sites using fluorescence in situ hybridization (FISH) and denaturing gradient gel electrophoresis (DGGE) techniques. Sequencing of excised DGGE bands demonstrated close affiliation with known psychrophiles or undescribed bacteria also recovered from the Antarctic environment. The majority of bacterial sequences were affiliated to the Gammaproteobacteria, Cytophaga/Flavobacteria of Bacteroidetes (CFB), Verrucomicrobia and Planctomycetales. Principal components analysis of quantitative FISH data revealed distinct differences in community composition between sites. Each of the sites were dominated by different bacterial groups: Alphaproteobacteria, Gammaproteobacteria and CFB at the least impacted site, Cape Armitage; green sulfur and sulfate reducing bacteria near the semi‐impacted Scott Base and Planctomycetales and sulfate reducing bacteria near the highly impacted McMurdo Station. The highest abundance of archaea was detected near Scott Base (2.5% of total bacteria). Multivariate analyses (non‐metric multidimensional scaling and analysis of similarities) of DGGE patterns revealed greater variability in community composition between sites than within sites. This is the first investigation of Antarctic biofilm structure and FISH results suggest that anthropogenic impacts may influence the complex composition of microbial communities.
Steering, Supporting, Enabling: The Role of Law in Local Government Reforms
Authors: MEHDE VEITH
Published: March 2006

Reforms in local government often follow decisions that are taken by central governments. To initiate these changes, law is the most important mechanism. This article analyzes the different regulative strategies legislators can apply in this context. Since local governments have a variety of options at hand to resist orders for change, a strict steering approach is not necessarily the most promising mechanism. Contrariwise, to play a purely enabling role might not be a satisfactory option for central governments that want to express their commitment to a multilevel reform agenda.
Videoconferencing in Criminal Proceedings: Legal and Empirical Issues and Directions for Research
Authors: JOHNSON MOLLY TREADWAY , WIGGINS ELIZABETH C.
Published: March 2006

State and federal courts are increasingly using videoconferencing to hold proceedings in criminal cases, including first appearances and arraignments. However, little systematic information is available about the extent of its use, the proceedings for which it is used, how it is implemented, and, most importantly, whether videoconferencing affects the behavior or perceptions of participants in a way that violates a defendant's fundamental rights. In this article we review the legal and empirical issues raised by the use of videoconferencing in criminal cases and describe empirical research that could and, we argue, should, inform policy decisions concerning its use.
Relocating People Out of Private Reserves Voluntary Resettlement as a Conservation Tool in Guatamala
Authors: Margolius Cheryl , Beavers John , Paiz Marie Claire
Published: March 2006

Most resettlement projects throughout the world have been, and continue to be, non‐voluntary. The voluntary nature of the Guatemalan initiative makes it fundamentally different than earlier efforts‐and it may be the key to resettlement finding its place among conservation strategies.
The Analysis of Illicit Methaqualone Containing Preparations by Gas Chromatography–Mass Spectrometry for Forensic Purposes
Authors: Grové Alida A. , Rohwer Egmont R. , Laurens Johannes B. , Vorster Barend C.
Published: March 2006

ABSTRACT: A validated gas chromatographic–mass spectrometric method for quantitative analysis of methaqualone (MTQ) in illicit preparations is reported. The method proved to have a coefficient of variation of below 5%. Four batches of seized tablets, two pairs with similar imprints, were analyzed. It was found that the average MTQ concentration in all four batches of tablets differed significantly (p=0.01) rendering it impossible to conclude that, on the basis of MTQ concentration alone, the batches with a similar logo originated from the same manufacturer or manufacturing batch. Conversely, it can be said that in this case, the four batches originated from either different clandestine laboratories or manufacturing batches.
Probability of Exclusion in Paternity Testing: Time to Reassess*
Authors: Cifuentes Lucía O. , Martínez Eliseo H. , Acuña Mónica P. , Jonquera Hugo G.
Published: March 2006

ABSTRACT: The average exclusion probability is a measure of efficiency in paternity testing; it refers to the a priori ability of a battery of tests to detect paternity inconsistencies. This parameter measures the capacity of the system to detect a false accusation of paternity. Traditionally, this average exclusion probability has been estimated as the probability of excluding a man who is not the father by an inconsistency in at least one of the studied loci. We suggest that this criterion should be corrected, as currently the presumed father is excluded when at least three genetic inconsistencies are found with the child being tested, not just one. This change of criterion has occurred because of the use of microsatellite loci, whose mutation rates are much greater than those of the coding genes used previously in paternity studies. We propose the use of the average probability of exclusion for at least three loci (not only one), as an honest measure of the combined probability of exclusion of several loci, and we propose an algebraic expression to calculate it.
Allele Frequency Data for 19 Short Tandem Repeats (PowerPlex® 16 and FFFl) in a Belgian Population Sample
Authors: Decorte Ronny , Verhoeven Elke , Vanhoutte Elisabeth , Knaepen Katleen , Cassiman Jean‐Jacques
Published: March 2006

POPULATION: Belgian Caucasians (Dutch speaking; n=198).
Considerations in the revision of previous surgical procedures
Authors: SAUNDERS WILLIAM P.
Published: March 2006

The microbial etiology of periradicular periodontitis requires that efforts must be made to eliminate infection from the root canal system and the periradicular tissues. Periradicular surgery is an option of endodontic re‐treatment when non‐surgical root canal treatment and re‐treatment fails. Unfortunately, surgery is not always successful for a number of reasons including, extraradicular infection, associated marginal periodontal disease, inability to seal the root canal system from the periradicular tissues, anatomical anomalies and poor surgical technique. This paper reviews the use of re‐surgery in the treatment of failed surgical cases, discussing some of the problems that may be encountered and how they may be managed.
Hard tissue management: osseous access, curettage, biopsy and root isolation
Authors: HOSKINSON ANTHONY E.
Published: March 2006

Following adequate tissue incision, reflection and retraction to expose the surgical site, the next stages of periradicular surgery consist of osseous access through the cortical bone, if still intact, and subsequent removal of any soft tissue lesion surrounding the apical and/or lateral aspects of the associated root to provide unimpeded access to these sites. The soft tissue lesion may on occasions encapsulate foreign material that may perpetuate the lesion if left in situ. Any excised lesion should be sent for histopathologic examination to confirm the clinical diagnosis and exclude other pathoses.
Mutational Analysis of the
Saccharomyces cerevisiae
Cytochrome
c
Oxidase Assembly Protein Cox11p
Authors: Banting Graham S. , Glerum D. Moira
Published: March 2006

Cox11p is an integral protein of the inner mitochondrial membrane that is essential for cytochrome
c
oxidase assembly. The bulk of the protein is located in the intermembrane space and displays high levels of evolutionary conservation. We have analyzed a collection of site-directed and random
cox11
mutants in an effort to further define essential portions of the molecule. Of the alleles studied, more than half had no apparent effect on Cox11p function. Among the respiration deficiency-encoding alleles, we identified three distinct phenotypes, which included a set of mutants with a misassembled or partially assembled cytochrome oxidase, as indicated by a blue-shifted cytochrome
aa
3
peak. In addition to the shifted spectral signal, these mutants also display a specific reduction in the levels of subunit 1 (Cox1p). Two of these mutations are likely to occlude a surface pocket behind the copper-binding domain in Cox11p, based on analogy with the
Sinorhizobium meliloti
Cox11 solution structure, thereby suggesting that this pocket is crucial for Cox11p function. Sequential deletions of the matrix portion of Cox11p suggest that this domain is not functional beyond the residues involved in mitochondrial targeting and membrane insertion. In addition, our studies indicate that Δ
cox11
, like Δ
sco1
, displays a specific hypersensitivity to hydrogen peroxide. Our studies provide the first evidence at the level of the cytochrome oxidase holoenzyme that Cox1p is the in vivo target for Cox11p and suggest that Cox11p may also have a role in the response to hydrogen peroxide exposure.
ALTERNATING GROUPS AS AUTOMORPHISM GROUPS OF RIEMANN SURFACES
Authors: ETAYO GORDEJUELA J. J. , MARTÍNEZ E.
Published: March 2006

In this work we give pairs of generators (x, y) for the alternating groups An, 5 ≤ n ≤ 19, such that they determine the minimal genus of a Riemann surface on which An acts as the automorphism group. Using these results we prove that A15 is the unique of these groups that is an H*-group, i.e., the groups achieving the upper bound of the order of an automorphism group acting on non-orientable unbordered surfaces.
The JAK/STAT pathway is essential for opioid-induced cardioprotection: JAK2 as a mediator of STAT3, Akt, and GSK-3β
Authors: Gross Eric R. , Hsu Anna K. , Gross Garrett J.
Published: March 2006

We examined the role for the JAK/STAT signaling pathway in acute opioid-induced cardioprotection (OIC) and whether opioid-induced glycogen synthase kinase-3β (GSK-3β) inhibition is mediated by the JAK/STAT pathway. Rats underwent 30 min of ischemia and either 5 min or 2 h of reperfusion, followed by tissue isolation for molecular analysis or infarct size assessment, respectively. Rats were treated with vehicle, morphine (300 μg/kg), the δ-opioid agonist fentanyl isothiocynate (FIT, 10 μg/kg), or the GSK inhibitor SB-216763 (SB21, 600 μg/kg) 10 min before ischemia. Five minutes before opioid or SB21 treatment, some rats received the putative JAK2 inhibitor AG-490 (3 mg/kg) or the putative JAK3 inhibitor ZM-449829 (3 mg/kg). H9C2 cardiomyoblast cells were also used to investigate FIT-induced signaling (1 μM) in vitro via molecular analysis. Morphine induced the phosphorylation of JAK2, yet not JAK1, in the area at risk. Morphine, FIT, and SB21 also reduced infarct size compared with vehicle (water) when administered before ischemia [43.0 ± 2.8, 39.1 ± 3.1, and 42.1 ± 2.5 (* P < 0.001, respectively) vs. 58.1 ± 1.3%, respectively]. AG-490 abrogated OIC, whereas ZM-449829 had no effect on OIC. Cardioprotection was afforded by SB21 even in the presence of AG-490. Morphine phosphorylated STAT3, Akt, and GSK-3β, and phosphorylation was abrogated by AG-490. FIT stimulation of H9C2 cells also caused a time-dependent phosphorylation of STAT3, Akt, and GSK-3β, and this effect was abrogated by AG-490. STAT3 phosphorylation was also dependent on phosphatidylinositol 3-kinase (PI3K) activation in both tissue and H9C2 cells. These data suggest that OIC occurs via the JAK2 regulation of PI3K pathway-dependent STAT3, Akt, and GSK-3β, with GSK-3β contributing a central role in acute OIC.
Regulatory role of ovarian sex hormones in calcium uptake activity of cardiac sarcoplasmic reticulum
Authors: Bupha-Intr Tepmanas , Wattanapermpool Jonggonnee
Published: March 2006

Alterations in the intracellular Ca2+handling in cardiomyocytes may underlie the cardiac dysfunction observed in the ovarian sex hormone-deprived condition. To test the hypothesis that ovarian sex hormones had a significant role in the cardiac intracellular Ca2+mobilization, the sarcoplasmic reticulum (SR) Ca2+uptake and SR Ca2+-ATPase (SERCA) activity were determined in 10-wk ovariectomized rat hearts. With the use of left ventricular homogenate preparations, a significant suppression of maximum SR Ca2+uptake activity, but with an increase in SR Ca2+responsiveness, was demonstrated in ovariectomized hearts. In parallel measurements of SERCA activity in SR-enriched membrane preparations from ovariectomized hearts, a suppressed maximum SERCA activity with a leftward shift in the relationship between pCa (-log molar free Ca2+concentration) and SERCA activity was also detected. A significant downregulation of SERCA proteins and reduction in the SERCA mRNA level were observed in association with suppressed maximum SERCA activity. While there were no changes in total phospholamban and phosphorylated Ser16phospholamban levels, a decrease in phosphorylated Thr17phospholamban as well as an increase in the suprainhibitory, monomeric form of phospholamban stoichiometry was found. Estrogen and progesterone supplementations were equally effective in preventing changes in ovariectomized hearts. Our data showed for the first time that female sex hormones played an important role in the regulation of the cardiac SR Ca2+uptake. Under hormone-deficient conditions, there was an adaptive response of SERCA that escaped the regulatory effect of phospholamban.
Hemodynamic effects of acute and repeated exposure to raloxifene in ovariectomized sheep
Authors: Zoma Willie D. , Baker R. Scott , Mershon John L. , Clark Kenneth E.
Published: March 2006

We hypothesize that administration of acute and daily doses of raloxifene will have significant effects on ovine coronary and uterine hemodynamics and that these changes are estrogen receptor dependent. Eleven ovariectomized sheep were instrumented to measure mean arterial pressure, heart rate (HR), cardiac output (CO), and coronary (CBF) and uterine artery blood flows (UBF). A dose-response curve was generated for raloxifene (1, 3, and 10 μg/kg) and compared with a standard dose of estradiol-17β (1 μg/kg) given intravenously. In a second group of animals, raloxifene (10 μg·kg−1·day−1) was administered intravenously for 14 consecutive days, and cardiovascular responses were compared with a group of animals administered estradiol-17β (10 μg/kg) daily for the same period. To determine whether raloxifene-related vascular responses were estrogen receptor (ER) mediated, the animals were pretreated with estrogen antagonist ICI-182,780 given intravenously. Finally, RT-PCR was preformed to determine the presence of ERα and ERβ mRNA in ovine coronary and uterine vessels. Raloxifene increased CBF and UBF dose dependently with a parallel decrease in the associated vascular resistances. Acute cardiovascular responses to daily doses of raloxifene and estradiol-17β were sustainable. In contrast to estradiol-17β, which significantly increases CO by increasing HR but not stroke volume, raloxifene significantly increased stroke volume without a significant parallel increase in HR. ICI-182,780 abolished raloxifene-induced hemodynamic responses, and ERα and ERβ mRNA are present in both ovine coronary and uterine vessels. Hence, the hemodynamic effects of raloxifene are dose dependent, sustainable, and estrogen receptor mediated.
Leukocyte-platelet aggregate adhesion and vascular permeability in intact microvessels: role of activated endothelial cells
Authors: He Pingnian , Zhang Hong , Zhu Longkun , Jiang Yanyan , Zhou Xueping
Published: March 2006

Leukocyte-platelet aggregation and aggregate adhesion have been indicated as biomarkers of the severity of tissue injury during inflammation or ischemic reperfusion. The objective of this study is to investigate the mechanisms of the aggregate adhesion and quantitatively evaluate its relationship with microvessel permeability. A combined autologous blood perfusion with single microvessel perfusion technique was employed in rat mesenteric venular microvessels. The aggregate adhesion was induced by systemic application of TNF-α plus local application of platelet-activating factor (PAF). Changes in permeability were determined by measurements of hydraulic conductivity ( Lp) before and after aggregate adhesion in the same individually perfused microvessels. The compositions of the adherent aggregates were identified with fluorescent labeling and confocal imaging. In contrast to leukocyte adhesion as single cells resulting in no increase in microvessel permeability, aggregate adhesion induced prolonged increases in microvessel Lp(6.1 ± 0.9 times the control, n = 9) indicated by the initial Lpmeasurements after 3 h of blood perfusion, which is distinct from the transient Lpincrease caused by PAF-induced endothelial activation in the absence of blood. Isoproteronol (Iso) attenuated aggregate adhesion-mediated Lpincreases if applied after autologous blood perfusion and prevented the aggregate adhesion if the initial endothelial activation is inhibited by applying Iso before PAF administration but showed less effect on single leukocyte adhesion. This study demonstrated that leukocyte-platelet aggregate adhesion via a mechanism different from that of single leukocyte adhesion caused a prolonged increase in microvessel permeability. Our results also indicate that the initial activation of endothelial cells by PAF plays a crucial role in the initiation of leukocyte-platelet aggregate adhesion.