bluuebunny/crossref_metadata_2025 huggingface dataset:
Reference threshold sound pressure levels for the Welch Allyn AudioScopeTM
Authors: Bienvenue Gordon R. , Michael Paul L. , Chaffinch Janie O.
Published: October 2005

The Welch Allyn AudioScope has been evaluated as an audiometer screening instrument using a threshold, loudness balancing technique. Two sets of eartips have been compared to determine which eartip configuration would yield the most reliable audiometric data. The AudioScope has also been evaluated by the American National Standard Method for Coupler Calibration of Earphones using both sets of eartips, and reference threshold sound pressure levels for the AudioScope were developed by combining the coupler and loudness balance data. The most reliable eartip configuration for audiometric purposes is identified and guidelines for use of the audiometric screening instrument are proposed.
EGFR Activation Mediates Inhibition of Axon Regeneration by Myelin and Chondroitin Sulfate Proteoglycans
Authors: Koprivica Vuk , Cho Kin-Sang , Park Jong Bae , Yiu Glenn , Atwal Jasvinder , Gore Bryan , Kim Jieun A. , Lin Estelle , Tessier-Lavigne Marc , Chen Dong Feng , He Zhigang
Published: October 2005

Inhibitory molecules associated with myelin and the glial scar limit axon regeneration in the adult central nervous system (CNS), but the underlying signaling mechanisms of regeneration inhibition are not fully understood. Here, we show that suppressing the kinase function of the epidermal growth factor receptor (EGFR) blocks the activities of both myelin inhibitors and chondroitin sulfate proteoglycans in inhibiting neurite outgrowth. In addition, regeneration inhibitors trigger the phosphorylation of EGFR in a calcium-dependent manner. Local administration of EGFR inhibitors promotes significant regeneration of injured optic nerve fibers, pointing to a promising therapeutic avenue for enhancing axon regeneration after CNS injury.
A 5-Micron-Bright Spot on Titan: Evidence for Surface Diversity
Authors: Barnes Jason W. , Brown Robert H. , Turtle Elizabeth P. , McEwen Alfred S. , Lorenz Ralph D. , Janssen Michael , Schaller Emily L. , Brown Michael E. , Buratti Bonnie J. , Sotin Christophe , Griffith Caitlin , Clark Roger , Perry Jason , Fussner Stephanie , Barbara John , West Richard , Elachi Charles , Bouchez Antonin H. , Roe Henry G. , Baines Kevin H. , Bellucci Giancarlo , Bibring Jean-Pierre , Capaccioni Fabrizio , Cerroni Priscilla , Combes Michel , Coradini Angioletta , Cruikshank Dale P. , Drossart Pierre , Formisano Vittorio , Jaumann Ralf , Langevin Yves , Matson Dennis L. , McCord Thomas B. , Nicholson Phillip D. , Sicardy Bruno
Published: October 2005

Observations from the Cassini Visual and Infrared Mapping Spectrometer show an anomalously bright spot on Titan located at 80Â°W and 20Â°S. This area is bright in reflected light at all observed wavelengths, but is most noticeable at 5 microns. The spot is associated with a surface albedo feature identified in images taken by the Cassini Imaging Science Subsystem. We discuss various hypotheses about the source of the spot, reaching the conclusion that the spot is probably due to variation in surface composition, perhaps associated with recent geophysical phenomena.
Bottom-Feeding Plesiosaurs
Authors: McHenry Colin R. , Cook Alex. G. , Wroe Stephen
Published: October 2005

Elasmosaurid plesiosaurs were an important part of Cretaceous marine reptile communities and are generally considered to have been predators of small, agile, free-swimming fish and cephalopods. Two elasmosaurid specimens from Aptian and Albian deposits in Queensland, Australia, include fossilized gut contents dominated by benthic invertebrates: bivalves, gastropods, and crustaceans. Both specimens also contained large numbers of gastroliths (stomach stones). These finds point to a wider niche than has previously been supposed for these seemingly specialized predators and may also influence long-running controversy over the question of gastrolith function in plesiosaurs.
Retinoic Acid Signaling Affects Cortical Synchrony During Sleep
Authors: Maret Stéphanie , Franken Paul , Dauvilliers Yves , Ghyselinck Norbert B. , Chambon Pierre , Tafti Mehdi
Published: October 2005

Delta oscillations, characteristic of the electroencephalogram (EEG) of slow wave sleep, estimate sleep depth and need and are thought to be closely linked to the recovery function of sleep. The cellular mechanisms underlying the generation of delta waves at the cortical and thalamic levels are well documented, but the molecular regulatory mechanisms remain elusive. Here we demonstrate in the mouse that the gene encoding the retinoic acid receptor beta determines the contribution of delta oscillations to the sleep EEG. Thus, retinoic acid signaling, which is involved in the patterning of the brain and dopaminergic pathways, regulates cortical synchrony in the adult.
Transforming Growth Factor-β Signaling in Stem Cells and Cancer
Authors: Mishra Lopa , Derynck Rik , Mishra Bibhuti
Published: October 2005

Transforming growth factor–β (TGF-β) and TGF-β–related proteins, such as the bone morphogenetic proteins, have emerged as key regulators of stem cell renewal and differentiation. These proteins have disparate roles in regulating the biology of embryonic stem cells and tumor suppression, and they help define the selection of cell fate and the progression of differentiation along a lineage. Here we illustrate their roles in embryonic stem cells and in the differentiation of neural, hematopoietic, mesenchymal, and gastrointestinal epithelial stem cells.
Characterization of the Reconstructed 1918 Spanish Influenza Pandemic Virus
Authors: Tumpey Terrence M. , Basler Christopher F. , Aguilar Patricia V. , Zeng Hui , Solórzano Alicia , Swayne David E. , Cox Nancy J. , Katz Jacqueline M. , Taubenberger Jeffery K. , Palese Peter , García-Sastre Adolfo
Published: October 2005

The pandemic influenza virus of 1918–1919 killed an estimated 20 to 50 million people worldwide. With the recent availability of the complete 1918 influenza virus coding sequence, we used reverse genetics to generate an influenza virus bearing all eight gene segments of the pandemic virus to study the properties associated with its extraordinary virulence. In stark contrast to contemporary human influenza H1N1 viruses, the 1918 pandemic virus had the ability to replicate in the absence of trypsin, caused death in mice and embryonated chicken eggs, and displayed a high-growth phenotype in human bronchial epithelial cells. Moreover, the coordinated expression of the 1918 virus genes most certainly confers the unique high-virulence phenotype observed with this pandemic virus.
Sensitivity and Specificity of a Monoclonal Antibody-Based Fluorescence Assay for Detecting
Enterocytozoon bieneusi
Spores in Feces of Simian Immunodeficiency Virus-Infected Macaques
Authors: Singh Inderpal , Sheoran Abhineet S. , Zhang Quanshun , Carville Angela , Tzipori Saul
Published: October 2005

Enterocytozoon bieneusi
is clinically the most significant among the microsporidia causing chronic diarrhea, wasting, and cholangitis in individuals with human immunodeficiency virus/AIDS. Microscopy with either calcofluor or modified trichrome stains is the standard diagnostic test for microsporidiosis and does not allow species identification. Detection of
E. bieneusi
infection based on PCR is limited to a few reference laboratories, and thus it is not the standard diagnostic assay. We have recently reported the development and characterization of a panel of monoclonal antibodies against
E. bieneusi
, and in this publication we evaluated the specificity and sensitivity of an immunofluorescence assay (IFA), compared with PCR, in simian immunodeficiency virus-infected macaques. The IFA, which correlated with the primary PCR method, with a detection limit of 1.5 ×10
5
spores per gram of feces, will simplify considerably the detection of
E. bieneusi
spores in clinical and environmental specimens and in laboratory and epidemiological investigations.
Psychosis in Parkinson’s disease
Authors: Thanvi B R , Lo T C N , Harsh D P
Published: October 2005

Psychosis is common in Parkinson’s disease (PD), particularly in its later stages. The symptoms range from comparatively minor illusions, vivid dreams, and occasional, non-disturbing visual hallucinations to frank psychosis. The pathogenesis of psychosis in PD is not fully known. Management of psychosis in PD requires a multidisciplinary approach. Some of the newer atypical antipsychotics are effective against psychosis with no significant worsening of PD. Psychosis in PD is associated with poor quality of life for patients and the carers.
Revisiting the ABC strategy: HIV prevention in Uganda in the era of antiretroviral therapy
Authors: Okware S , Kinsman J , Onyango S , Opio A , Kaggwa P
Published: October 2005

The ABC strategy is credited for bringing the HIV/AIDS epidemic under control in Uganda. By promoting abstinence, being faithful, and condom use, safe(r) behaviours have been identified that are applicable to people in different circumstances. However, scaling-up of antiretroviral therapy in the country raised concerns that HIV prevention messages targeting the uninfected population are not taking sufficient account of inherent complexities. Furthermore, there is debate in the country over relative importance of abstinence in reduction of HIV incidence as well as over the morality and effectiveness of condoms. The purpose of this paper is to examine each component of ABC in light of current developments. It is argued that there is still a strong justification for condom use to complement abstinence and being faithful. There is an urgent need to update and relaunch Uganda’s ABC strategy—its three elements are complementary, synergistic, and inseparable in the national HIV prevention programme.
BRST–VSUSY SUPERSPACE AND TWISTED SUPERFIELDS FOR D=4 BF SYSTEMS
Authors: AIDAOUI A. , TAHIRI M.
Published: October 2005

We propose to construct the off-shell supersymmetric structure present in quantized D=4 BF theories in terms of a BRST–VSUSY superspace formalism. The method is based on the introduction of constrained scalar superfields. We also discuss how to find the D=4 BF action from D=N=4 supersymmetric action by an appropriate twisting process.
A LIQUID CRYSTAL ANALOGUE OF THE COSMIC STRING
Authors: SÁTIRO CAIO , MORAES FERNANDO
Published: October 2005

We consider the propagation of light in an anisotropic medium with a topological line defect in the realm of geometrical optics. It is shown that the effective geometry perceived by light propagating in such medium is that of a spacial section of the cosmic string spacetime.
PHENOMENOLOGY OF GOLDSTINO COUPLINGS
Authors: LIU LU-XIN
Published: October 2005

A general coupling of the Goldstino to the matter field and the weak gravitational field is constructed based on the standard and nonlinear Volkov–Akulov realization of SUSY. The resulting Lagrangian, which is invariant under SUSY transformations, can give rise to explicit interactions which couple the helicity ±1/2 states of the gravitino with the gravitational field as well as the matter field.
WORLDLINE VARIATIONAL APPROXIMATION: A NEW APPROACH TO THE RELATIVISTIC BINDING PROBLEM
Authors: BARRO-BERGFLÖDT K. , ROSENFELDER R. , STINGL M.
Published: October 2005

We determine the lowest bound-state pole of the density–density correlator in the scalar Wick–Cutkosky model where two equal-mass constituents interact via the exchange of mesons. This is done by employing the worldline representation of field theory together with a variational approximation as in Feynman's treatment of the polaron. Unlike traditional methods based on the Bethe–Salpeter equation, self-energy and vertex corrections are (approximately) included as are crossed diagrams. Only vacuum-polarization effects of the heavy particles are neglected. The well-known instability of the model due to self-energy effects leads to large qualitative and quantitative changes compared to traditional approaches which neglect them. We determine numerically the critical coupling constant above which no real solutions of the variational equations exist anymore and show that it is smaller than in the one-body case due to an induced instability. The width of the bound state above the critical coupling is estimated analytically.
Hypoxia of endothelial cells leads to MMP-2-dependent survival and death
Authors: Ben-Yosef Yaara , Miller Ariel , Shapiro Sarah , Lahat Nitza
Published: October 2005

Exposure of endothelial cells (ECs) to hypoxia has separately been shown to induce their angiogenesis or death. Matrix metalloproteinase (MMP)-2 is associated with EC angiogenesis, although recent studies also implicate this molecule in EC death. We studied the effect of hypoxia in the absence or presence of TNF-α (characteristic of the inflammatory microenvironment accompanying hypoxia) on MMP-2 expression and its role in angiogenesis (proliferation, migration, and tube formation) and in the death of primary human umbilical vein endothelial cells (HUVECs). Hypoxia alone (24–48 h in 0.3% O2 in the hypoxic chamber) and furthermore, when combined with TNF-α, significantly enhanced MMP-2 expression and activity. Hypoxia also led to a reduction in membrane type 1 MMP (MT1-MMP) and tissue inhibitor of metalloproteinase-2 mRNA and protein while enhancing the expression of αvβ3 integrin and the cytoskeletal protein phosphopaxillin. Moreover, hypoxia led to colocalization of αvβ3 and MMP-2, but not MT1-MMP, with phosphopaxillin in ECs. These results suggest MT1-MMP-independent activation of MMP-2 during hypoxia and support interactions between the ECM, integrins, and the cytoskeleton in hypoxia-induced MMP-2-related functions. Hypoxia enhanced EC migration in an MMP-2-dependent manner while leading to a reduction of cell number via their apoptosis, which was also dependent on MMP-2. In addition, hypoxia caused an aberrant tubelike formation on Matrigel that appeared to be unaffected by MMP-2. The hypoxia-induced, MMP-2-dependent migration of ECs is in accordance with the proangiogenic role ascribed to MMP-2, while the involvement of this protease in the hypoxia-related death of ECs supports an additional apoptotic role for this protease. Hence, in the hypoxic microenvironment, MMP-2 appears to have a dual autocrine role in determining the fate of ECs.
Nitric oxide induces [Ca2+]i oscillations in pituitary GH3 cells: involvement of IDR and ERG K+ currents
Authors: Secondo Agnese , Pannaccione Anna , Cataldi Mauro , Sirabella Rossana , Formisano Luigi , Di Renzo Gianfranco , Annunziato Lucio
Published: October 2005

The role of nitric oxide (NO) in the occurrence of intracellular Ca2+ concentration ([Ca2+]i) oscillations in pituitary GH3 cells was evaluated by studying the effect of increasing or decreasing endogenous NO synthesis with l-arginine and nitro-l-arginine methyl ester (l-NAME), respectively. When NO synthesis was blocked with l-NAME (1 mM) [Ca2+]i, oscillations disappeared in 68% of spontaneously active cells, whereas 41% of the quiescent cells showed [Ca2+]i oscillations in response to the NO synthase (NOS) substrate l-arginine (10 mM). This effect was reproduced by the NO donors NOC-18 and S-nitroso- N-acetylpenicillamine (SNAP). NOC-18 was ineffective in the presence of the L-type voltage-dependent Ca2+ channels (VDCC) blocker nimodipine (1 μM) or in Ca2+-free medium. Conversely, its effect was preserved when Ca2+ release from intracellular Ca2+ stores was inhibited either with the ryanodine-receptor blocker ryanodine (500 μM) or with the inositol 1,4,5-trisphosphate receptor blocker xestospongin C (3 μM). These results suggest that NO induces the appearance of [Ca2+]i oscillations by determining Ca2+ influx. Patch-clamp experiments excluded that NO acted directly on VDCC but suggested that NO determined membrane depolarization because of the inhibition of voltage-gated K+ channels. NOC-18 and SNAP caused a decrease in the amplitude of slow-inactivating ( IDR) and ether-à-go-go-related gene ( ERG) hyperpolarization-evoked, deactivating K+ currents. Similar results were obtained when GH3 cells were treated with l-arginine. The present study suggests that in GH3 cells, endogenous NO plays a permissive role for the occurrence of spontaneous [Ca2+]i oscillations through an inhibitory effect on IDR and on IERG.
Potent block of inactivation-deficient Na+channels by n-3 polyunsaturated fatty acids
Authors: Xiao Yong-Fu , Ma Li , Wang Sho-Ya , Josephson Mark E. , Wang Ging Kuo , Morgan James P. , Leaf Alexander
Published: October 2005

A voltage-gated, small, persistent Na+current ( INa) has been shown in mammalian cardiomyocytes. Hypoxia potentiates the persistent INathat may cause arrhythmias. In the present study, we investigated the effects of n-3 polyunsaturated fatty acids (PUFAs) on INain HEK-293t cells transfected with an inactivation-deficient mutant (L409C/A410W) of the α-subunit (hH1α) of human cardiac Na+channels (hNav1.5) plus β1-subunits. Extracellular application of 5 μM eicosapentaenoic acid (EPA; C20:5n-3) significantly inhibited INa. The late portion of INa( INa late, measured near the end of each pulse) was almost completely suppressed. INareturned to the pretreated level after washout of EPA. The inhibitory effect of EPA on INawas concentration dependent, with IC50values of 4.0 ± 0.4 μM for INapeak ( INa peak) and 0.9 ± 0.1 μM for INa late. EPA shifted the steady-state inactivation of INa peakby −19 mV in the hyperpolarizing direction. EPA accelerated the process of resting inactivation of the mutant channel and delayed the recovery of the mutated Na+channel from resting inactivation. Other polyunsaturated fatty acids, docosahexaenoic acid, linolenic acid, arachidonic acid, and linoleic acid, all at 5 μM concentration, also significantly inhibited INa. In contrast, the monounsaturated fatty acid oleic acid or the saturated fatty acids stearic acid and palmitic acid at 5 μM concentration had no effect on INa. Our data demonstrate that the double mutations at the 409 and 410 sites in the D1–S6 region of hH1αinduce inactivation-deficient INaand that n-3 PUFAs inhibit mutant INa.
Splenic baroreceptors control splenic afferent nerve activity
Authors: Moncrief Karli , Kaufman Susan
Published: October 2005

Stenosis of either the portal or splenic vein increases splenic afferent nerve activity (SANA), which, through the splenorenal reflex, reduces renal blood flow. Because these maneuvers not only raise splenic venous pressure but also reduce splenic venous outflow, the question remained as to whether it is increased intrasplenic postcapillary pressure and/or reduced intrasplenic blood flow, which stimulates SANA. In anesthetized rats, we measured the changes in SANA in response to partial occlusion of either the splenic artery or vein. Splenic venous and arterial pressures and flows were simultaneously monitored. Splenic vein occlusion increased splenic venous pressure (9.5 ± 0.5 to 22.9 ± 0.8 mmHg, n = 6), reduced splenic arterial blood flow (1.7 ± 0.1 to 0.9 ± 0.1 ml/min, n = 6) and splenic venous blood flow (1.3 ± 0.1 to 0.6 ± 0.1 ml/min, n = 6), and increased SANA (1.7 ± 0.4 to 2.2 ± 0.5 spikes/s, n = 6). During splenic artery occlusion, we matched the reduction in either splenic arterial blood flow (1.7 ± 0.1 to 0.7 ± 0.05, n = 6) or splenic venous blood flow (1.2 ± 0.1 to 0.5 ± 0.04, n = 5) with that seen during splenic vein occlusion. In neither case was there any change in either splenic venous pressure (−0.4 ± 0.9 mmHg, n = 6 and +0.1 ± 0.3 mmHg, n = 5) or SANA (−0.11 ± 0.15 spikes/s, n = 6 and −0.05 ± 0.08 spikes/s, n = 5), respectively. Furthermore, there was a linear relationship between SANA and splenic venous pressure ( r = 0.619, P = 0.008, n = 17). There was no such relationship with splenic venous ( r = 0.371, P = 0.236, n = 12) or arterial ( r = 0.275, P = 0.413, n = 11) blood flow. We conclude that it is splenic venous pressure, not flow, which stimulates splenic afferent nerve activity and activates the splenorenal reflex in portal and splenic venous hypertension.
Daily, intermittent intravenous infusion of peptide YY(3-36) reduces daily food intake and adiposity in rats
Authors: Chelikani Prasanth K. , Haver Alvin C. , Reeve Joseph R. , Keire David A. , Reidelberger Roger D.
Published: October 2005

The gut hormone peptide YY(3-36) [PYY(3-36)] decreases food intake when administered by intravenous infusion to lean and obese humans and rats. Whether chronic administration of PYY(3-36) produces a sustained reduction in food intake and adiposity is the subject of intense debate. Batterham et al. (R. L. Batterham, M. A. Cowley, C. J. Small, H. Herzog, M. A. Cohen, C. L. Dakin, A. M. Wren, A. E. Brynes, M. J. Low, M. A. Ghatei, R. D. Cone, and S. R. Bloom. Nature 418: 650–654, 2002) first reported that PYY(3-36) reduces food intake and weight gain in rats when injected into the peritoneal cavity twice daily for 7 days. Numerous laboratories have failed to confirm that daily injections of PYY(3-36) decrease body weight. Continuous subcutaneous administration of PYY(3-36) by osmotic minipump has been reported to reduce daily food intake in rodents but only during the first 3–4 days of administration. Here we show the effects of different daily patterns of intravenous infusion of PYY(3-36) on food intake, body weight, and adiposity in rats tethered via infusion swivels to computer-controlled pumps. Measurement of food bowl weight recorded by computer every 20 s permitted daily assessment of the instantaneous effects of PYY(3-36) administration on food intake and meal patterns. One-hour intravenous infusions of PYY(3-36) at 30 pmol·kg−1·min−1 every other hour for 10 days produced a sustained reduction in daily food intake of ∼20% and decreased body weight and adiposity by 7 and 35%, respectively. Thus dosage pattern is critical for producing a sustained effect of PYY(3-36) on food intake and adiposity.
Haptic Identification of Surfaces as Fields of Force
Authors: Chib Vikram S. , Patton James L. , Lynch Kevin M. , Mussa-Ivaldi Ferdinando A.
Published: October 2005

The ability to discriminate an object's shape and mechanical properties from touch is one of the most fundamental somatosensory functions. When exploring physical properties of an object, such as stiffness and curvature, humans probe the object's surface and obtain information from the many sensory receptors in their upper limbs. This sensory information is critical for the guidance of actions. We studied how humans acquire an internal representation of the shape and mechanical properties of surfaces and how this information affects the execution of trajectories over the surface. Experiments involved subjects executing trajectories while holding a planar manipulandum that renders planar virtual objects with variable shape and mechanical properties. Subjects were instructed to make reaching movements with the hand between points on the boundary of a curved virtual disk of varying stiffness and curvature. The results suggest two classifications of adaptive responses: force perturbations and object boundaries. In the first case, a rectilinear hand movement is enforced by opposing the interaction forces. In the second case, the trajectory conforms to the object boundary so as to reduce interaction forces. While this dichotomy is evident for very rigid and very soft objects, the likelihood of an object boundary classification depended, in a smooth and monotonic way, on the average force experienced during the initial movements. Furthermore, the observed response across a variety of stiffness values lead to a constant average interaction force after adaptation. This suggests that the nervous system may select from the two responses through a mechanism that attempts to establish a constant interaction force.
Terrestrial habitat preferences of the natterjack toad during and after the breeding season in a landscape of intensive agricultural activity
Authors: Miaud Claude , Sanuy Delfi
Published: October 2005

Nineteen adult toads equipped with transmitters were followed during and after the breeding period (January to September) in order to estimate their home range area and habitat use in a landscape of cereal agriculture. Median home range area was 0.5 ha (range 0.1-11 ha) during the breeding season (January-April). Home range areas increase during the post-breeding season (April-September) e.g., median minimum concave polygon of 4.1 ha. No relation between home range and toads' body size was observed. Six habitat types were described in the studied area. The proportion of habitats used (i.e. proportion of the pooled positions of 11 toads during the post-breeding season in each habitat) was significantly different from the proportion of available habitats: while crops represented 85% of the available habitat, only 43% of the toads' positions were recorded in this type of habitat. A compositional analysis of habitat preference was performed. At both landscape and individual home range levels, the toads preferred the stone embankments and ditches above all, while the crops were the least preferred habitat. This study highlights the role of habitat linkage and marginal habitats for the persistence of amphibian populations in intensive agricultural and arid landscapes.
Ecological patterns of distribution on gradients of elevation and species diversity of snakes in southern Taiwan
Authors: Lee Tsung Hung
Published: October 2005

The study was conducted in southern Taiwan, along a road traversing the study area from 287 to 1680 m a.s.l. from May to October 2003 to investigate the distribution patterns and species diversity of the snakes. A total of 69 individual snakes belonging to 16 species were recorded. The Shannon's index and evenness index of the full study area were 2.4337 and 0.8777, respectively. Moreover, evenness index was 401 to 700 m > 1001 to 1300 m > 701 to 1000 m > 1301 to 1600 m altitudinal zone. The Shannon's index, DMG, and the reciprocal form of the Berger-Parker index (1/d) were 1001 to 1300 m > 401 to 700 m > 701 to 1000 m > 1301 to 1600 m altitudinal zone. Thirty-seven snakes were found in natural forest, 12 in plantation forest, 8 in secondary forest, and 12 in agricultural lands. I concluded that the highest species richness and diversity are found in mid-altitudinal mountains in southern Taiwan.
Discrepancy in mitochondrial and nuclear polymorphism in meadow vipers (Vipera ursinii) questions the unambiguous use of mtDNA in conservation studies
Authors: Ujvari Beata , Olsson Mats , Madsen Thomas
Published: October 2005

The sequence diversity of the entire mitochondrial control region (CR) of three meadow viper (Vipera ursinii) populations was analysed and compared to previously documented nuclear genetic variability at the major histocompatibility complex (MHC) Class I loci. One of the populations, a small and inbred Hungarian population, exhibited no MHC polymorphism, whereas the two other, sampled from large viper populations in Ukraine, shoved very high MHC diversity. In spite of the great difference in population size and nuclear (MHC) diversity, all of the vipers from the three populations exhibited a CR haplotype diversity of zero. The dramatic discrepancy in nuclear vs. mitochondrial variability in the Ukrainian viper populations suggest that the lack of CR diversity was not caused by a population bottleneck, but rather by slow CR evolutionary rate, which has been documented in numerous other vertebrate taxa. Thus, due to the large taxonomic differences in CR rate of evolution, population genetic diversity estimates based on CR heterogeneity (and conservation management decisions that spring from those estimates) may depend as much upon the taxa being investigated, as upon the underlying pattern of genetic variation within the study population.
The Response of Tropospheric Circulation to Perturbations in Lower-Stratospheric Temperature
Authors: Haigh Joanna D. , Blackburn Michael , Day Rebecca
Published: October 2005

A multiple regression analysis of the NCEP–NCAR reanalysis dataset shows a response to increased solar activity of a weakening and poleward shift of the subtropical jets. This signal is separable from other influences, such as those of El Niño–Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO), and is very similar to that seen in previous studies using global circulation models (GCMs) of the effects of an increase in solar spectral irradiance. The response to increased stratospheric (volcanic) aerosol is found in the data to be a weakening and equatorward shift of the jets.

The GCM studies of the solar influence also showed an impact on tropospheric mean meridional circulation with a weakening and expansion of the tropical Hadley cells and a poleward shift of the Ferrel cells. To understand the mechanisms whereby the changes in solar irradiance affect tropospheric winds and circulation, experiments have been carried out with a simplified global circulation model. The results show that generic heating of the lower stratosphere tends to weaken the subtropical jets and the tropospheric mean meridional circulations. The positions of the jets, and the extent of the Hadley cells, respond to the distribution of the stratospheric heating, with low-latitude heating forcing them to move poleward, and high-latitude or latitudinally uniform heating forcing them equatorward. The patterns of response are similar to those that are found to be a result of the solar or volcanic influences, respectively, in the data analysis.

This demonstrates that perturbations to the heat balance of the lower stratosphere, such as those brought about by solar or volcanic activity, can produce changes in the mean tropospheric circulation, even without any direct forcing below the tropopause.
Circumglobal Teleconnection in the Northern Hemisphere Summer*
Authors: Ding Qinghua , Wang Bin
Published: October 2005

Analysis of the 56-yr NCEP–NCAR reanalysis data reveals a recurrent circumglobal teleconnection (CGT) pattern in the summertime midlatitude circulation of the Northern Hemisphere. This pattern represents the second leading empirical orthogonal function of interannual variability of the upper-tropospheric circulation. The CGT, having a zonal wavenumber-5 structure, is primarily positioned within a waveguide that is associated with the westerly jet stream. The spatial phases of CGT tend to lock to preferred longitudes. The geographically phase-locked patterns bear close similarity during June, August, and September, but the pattern in July shows shorter wavelengths in the North Pacific–North America sector. The CGT is accompanied by significant rainfall and surface air temperature anomalies in the continental regions of western Europe, European Russia, India, east Asia, and North America. This implies that the CGT may be a source of climate variability and predictability in the above-mentioned midlatitude regions.

The CGT has significant correlations with the Indian summer monsoon (ISM) and El Niño–Southern Oscillation (ENSO). However, in normal ISM years the CGT–ENSO correlation disappears; on the other hand, in the absence of El Niño or La Niña, the CGT–ISM correlation remains significant. It is suggested that the ISM acts as a “conductor” connecting the CGT and ENSO. When the interaction between the ISM and ENSO is active, ENSO may influence northern China via the ISM and the CGT. Additionally, the variability of the CGT has no significant association with the Arctic Oscillation and the variability of the western North Pacific summer monsoon. The circulation of the wave train shows a barotropic structure everywhere except the cell located to the northwest of India, where a baroclinic circulation structure dominates. Two possible scenarios are proposed. The abnormal ISM may excite an anomalous west-central Asian high and downstream Rossby wave train extending to the North Pacific and North America. On the other hand, a wave train that is excited in the jet exit region of the North Atlantic may affect the west-central Asian high and, thus, the intensity of the ISM. It is hypothesized that the interaction between the global wave train and the ISM heat source may be instrumental in maintaining the boreal summer CGT.
A Statistical Model of Cloud Vertical Structure Based on Reconciling Cloud Layer Amounts Inferred from Satellites and Radiosonde Humidity Profiles
Authors: Rossow William B. , Zhang Yuanchong , Wang Junhong
Published: October 2005

To diagnose how cloud processes feed back on weather- and climate-scale variations of the atmosphere requires determining the changes that clouds produce in the atmospheric diabatic heating by radiation and precipitation at the same scales of variation. In particular, not only the magnitude of these changes must be quantified but also their correlation with atmospheric temperature variations; hence, the space–time resolution of the cloud perturbations must be sufficient to account for the majority of these variations. Although extensive new global cloud and radiative flux datasets have recently become available, the vertical profiles of clouds and consequent radiative flux divergence have not been systematically measured covering weather-scale variations from about 100 km, 3 h up to climate-scale variations of 10 000 km, decadal inclusive. By combining the statistics of cloud layer occurrence from the International Satellite Cloud Climatology Project (ISCCP) and an analysis of radiosonde humidity profiles, a statistical model has been developed that associates each cloud type, recognizable from satellite measurements, with a particular cloud vertical structure. Application of this model to the ISCCP cloud layer amounts produces estimates of low-level cloud amounts and average cloud-base pressures that are quantitatively closer to observations based on surface weather observations, capturing the variations with latitude and season and land and ocean (results are less good in the polar regions). The main advantage of this statistical model is that the correlations of cloud vertical structure with meteorology are qualitatively similar to “classical” information relating cloud properties to weather. These results can be evaluated and improved with the advent of satellites that can directly probe cloud vertical structures over the globe, providing statistics with changing meteorological conditions.
Elimination of the Greenland Ice Sheet in a High CO2 Climate
Authors: Ridley J. K. , Huybrechts P. , Gregory J. M. , Lowe J. A.
Published: October 2005

Projections of future global sea level depend on reliable estimates of changes in the size of polar ice sheets. Calculating this directly from global general circulation models (GCMs) is unreliable because the coarse resolution of 100 km or more is unable to capture narrow ablation zones, and ice dynamics is not usually taken into account in GCMs. To overcome these problems a high-resolution (20 km) dynamic ice sheet model has been coupled to the third Hadley Centre Coupled Ocean–Atmosphere GCM (HadCM3). A novel feature is the use of two-way coupling, so that climate changes in the GCM drive ice mass changes in the ice sheet model that, in turn, can alter the future climate through changes in orography, surface albedo, and freshwater input to the model ocean. At the start of the main experiment the atmospheric carbon dioxide concentration was increased to 4 times the preindustrial level and held constant for 3000 yr. By the end of this period the Greenland ice sheet is almost completely ablated and has made a direct contribution of approximately 7 m to global average sea level, causing a peak rate of sea level rise of 5 mm yr−1 early in the simulation. The effect of ice sheet depletion on global and regional climate has been examined and it was found that apart from the sea level rise, the long-term effect on global climate is small. However, there are some significant regional climate changes that appear to have reduced the rate at which the ice sheet ablates.
SST-Induced Surface Wind Variations over the Brazil–Malvinas Confluence: Satellite and In Situ Observations*
Authors: Tokinaga Hiroki , Tanimoto Youichi , Xie Shang-Ping
Published: October 2005

The confluence of the Brazil–Malvinas Currents maintains strong sea surface temperature (SST) fronts in the midlatitude southwestern Atlantic year-round. SST effects on near-surface stability and surface wind variations are examined in this region using satellite and in situ datasets. Satellite observations show strong (weak) surface wind speeds over the warm Brazil (cold Malvinas) Current. A novel feature of this study is the construction of a high-resolution surface meteorological dataset that is based on historical ship observations. Analysis of this new in situ dataset reveals an increased (reduced) sea–air temperature difference over the Brazil (Malvinas) Current, indicating destabilization (stabilization) in the atmospheric boundary layer. These results are consistent with the SST-induced vertical mixing mechanism for wind adjustment. The SST effect on the near-surface atmosphere is observed both in the climatology and on interannual time scales in the Brazil–Malvinas confluence. Along a zonal SST front at 49°S northeast of the Malvinas/Falkland Islands, there is a collocated line of surface wind divergence, with moderate convergence to the north. Vertical mixing does not explain this divergence pattern because the prevailing surface winds are westerly, blowing in parallel with the front. An additional mechanism is proposed for boundary layer wind adjustment.
A New FSU Winds Climatology
Authors: Bourassa Mark A. , Romero Rosario , Smith Shawn R. , O’Brien James J.
Published: October 2005

A new objective time series of in situ–based monthly surface winds has been developed as a replacement for the subjective tropical Pacific Florida State University (FSU) winds. The new time series begins in January 1978, and it is ongoing. The objective method distinguishes between observations from volunteer observing ships (VOSs) and buoys, allowing different weights for these different types of observations. An objective method is used to determine these weights and accounts for the differences in error characteristics and in spatial/temporal sampling. A comparison is made between the objective and subjective products, as well as scatterometer winds averaged monthly on the same grid. The scatterometer fields are a good proxy for truth. These three sets of fields have similar magnitudes, directions, and derivative fields. Both in situ wind products underestimate convergence about the intertropical convergence zone; however, the objective FSU product is a much better match to the scatterometer observations. Furthermore, the objective winds have smaller month-to-month variation than the subjective winds. Composites of ENSO phases are also examined and show minor differences between the subjective and objective wind products. The strengths and weaknesses of the objective and subjective winds are discussed.
Simulated and Observed Preindustrial to Modern Vegetation and Climate Changes*
Authors: Notaro Michael , Liu Zhengyu , Gallimore Robert , Vavrus Stephen J. , Kutzbach John E. , Prentice I. Colin , Jacob Robert L.
Published: October 2005

Rising levels of carbon dioxide since the preindustrial era have likely contributed to an observed warming of the global surface, and observations show global greening and an expansion of boreal forests. This study reproduces observed climate and vegetation trends associated with rising CO2 using a fully coupled atmosphere–ocean–land surface GCM with dynamic vegetation and decomposes the effects into physiological and radiative components. The simulated warming trend, strongest at high latitudes, was dominated by the radiative effect, although the physiological effect of CO2 on vegetation (CO2 fertilization) contributed to significant wintertime warming over northern Europe and central and eastern Asia. The net global greening of the model was primarily due to the physiological effect of increasing CO2, while the radiative and physiological effects combined to produce a poleward expansion of the boreal forests. Observed and simulated trends in tree ring width are consistent with the enhancement of vegetation growth by the physiological effect of rising CO2.
Duty, Honor, Country: The Social Identity of West Point Cadets
Authors: Franke Volker C.
Published: October 2005

This article explores the extent to which military socialization at the United States Military Academy (USMA) shapes the identity of West Point cadets. Building on social identity theory, the article examines the relationship between the strength of cadets' military and national identifications, their levels of patriotism and warriorism, their attitudes toward the United Nations and peacekeeping operations, and their commitment to a military career. The underlying assumption is that commitment to different social identities affects the preparedness of military professionals for increasingly complex global security needs. The analysis reveals that, although successful in enhancing cadets' identification with military reference groups and boosting their warriorism scores, USMA socialization appears neither to affect cadets' patriotism scores or the potency of their national identifications, nor to strengthen their level of support for the United Nations or their commitment to peacekeeping. In addition, the data provide preliminary evidence, that West Point might be less effective in enhancing the military identity of its female than of its male cadets.
Conscription in Scandinavia During the Last Quarter Century: Developments and Arguments
Authors: Sorensen Henning
Published: October 2005

This article describes the empirical changes of conscription in Scandinavia since 1970 from four perspectives, i.e., the demography, economy, organization, and personnel that give Denmark, Sweden, and Norway a quite different conscription profile. No easy explanations are given for these changes which are products of complex and sometimes even contradictory decisions made at the national and organizational levels. Instead, the present conscription profiles of Denmark, and Sweden, and Norway are identified as one of three ideal reasons for using conscripts: Democracy, Deterrence, and Deployment abroad, the DDD-model. This theoretical model suggests both national and international reasons for the continuation of conscription and thus argues against reducing or abolishing conscription due to the end of the Cold War and relying, instead, on a professional army. In addition, conscripts may be better qualified for international peacekeeping missions than regulars because they can more easily identify with the local civil population. The announcement of the end of conscription as a result of the end of the Cold War, therefore, seems somewhat premature.
Decision-Makers or Decision-Takers? Military Missions and Civilian Control in Democratic South America
Authors: Pion-Berlin David , Arceneaux Craig
Published: October 2005

The conclusion of the Cold War and the re-emergence of democracy in South America has removed principal enemies, both internal and external, while economic integration has softened contentious border disputes. This changed environment has led the military to rethink its role and search for new missions. While many purportedly `new' missions were not unheard of in the past, they have recently taken on greater importance. Are some of these activities intrinsically more detrimental than others for the development of civilian control over the military? Most scholars have customarily thought so, assuming that internal, role expansive operations would allow the armed forces undue political influence and erode the base of civilian supremacy. In our examination of 23 missions and 33 operations across 7 South America countries, we find sufficient grounds to question these assumptions. The evidence suggests that the character of the military mission alone does not dictate the fate of civilian control. Rather, only by revealing the principal decision-makers behind the military campaigns can we assess the longer-term impact of military activity upon political overseers.
The Military and the Consolidation of Democracy: The Recent Turkish Experience
Authors: Heper Metin , Guney Aylin
Published: October 2005

Turkey's recent success in dealing with the threat of political Islam without the military taking power into its own hands cannot be explained by either of the two contending theories about the military's role in the consolidation of democracy, that of the "mode-of-transition" or that of "electoral dynamics." Following the transition to democracy, officers in Latin America have evinced politically elite characteristics and have been in a tug of war with civilian politicians; officers in Eastern Europe have shown non-elite (professional) characteristics and have been subordinated to civilian politicians; officers in Turkey, not unlike their counterparts in France and Germany of earlier decades, have displayed state-elite characteristics and maintained their privileged position in the polity. Thus, while it is possible to use the dichotomy of politicized versus professional militaries to explain the fortunes of democracy in Latin America and Eastern Europe, respectively, in Turkey it is necessary to analyze the factors determining the orientation of officers toward democracy.
Citizenship and Compulsory Military Service: The Revolutionary Origins of Conscription in the United States
Authors: Kestnbaum Meyer
Published: October 2005

This article seeks to clarify the origins of citizen service in the United States. It departs from the premise that military service compelled by the state and performed as an obligation of citizenship may be understood as constitutive of citizen service. Based on this analytic distinction, the article develops one central argument. Citizen service was first realized in the United States during the American Revolution, but not, as might be expected, in the compulsory militia dating from the colonial period. Rather, citizen service was realized first in the form of the federally mandated conscription of American national citizens into the Continental Army, a peculiarly Revolutionary contribution to the War of Independence. Citizen service's Revolutionary birth in national conscription, then, helps to recast the very roots of the American military tradition.
Th1e Impact of Multiple Deployments on Soldiers' Peacekeeping Attitudes, Morale, and Retention
Authors: Reed Brian J. , Segal David R.
Published: October 2005

In the post-Cold War era, the United States Army has undergone a dramatic transformation. In this new security era, the Army is increasingly participating in nontraditional operations. Also during this period, the frequency with which American service members have been operationally deployed (OPTEMPO) has increased. In this article, we analyze the impact of multiple deployments on peacekeeping attitudes, personal morale, and reenlistment intentions. In terms of peacekeeping attitudes, the greatest effects were on judgments of the appropriateness of alternative personnel to perform peacekeeping operations. With respect to morale and reenlistment intentions, we found support for the negative impact of multiple deployments on personal morale. However, we found no statistical support for the relationship between number of deployments and reenlistment intentions.
Motivation in U.S. Narrative Accounts of the Ground War in Vietnam
Authors: Vaughan David K. , Schum William A.
Published: October 2005

This study applied a content analysis methodology to eighteen narrative nonfiction accounts written by men who saw combat in the Vietnam ground war. The narratives were examined for evidence of the motivational factors, derived from a comparative study of experts in the field, that provided the basis for their authors' actions in a combat environment. This exploratory investigation found that the most important motivational factors were primary group allegiance, combat survival, leadership, and duty, factors traditionally ranked high in previous studies. However, it also revealed noticeable differences in motivational factors correlated with the authors' rank, previous military experience, and period of Vietnam service. While the sample size was small, the results indicate a promising area for further research.