bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enteropathogenic
Escherichia coli
Type III Effectors EspG and EspG2 Disrupt the Microtubule Network of Intestinal Epithelial Cells
Authors: Shaw Robert K. , Smollett Katherine , Cleary Jennifer , Garmendia Junkal , Straatman-Iwanowska Ania , Frankel Gad , Knutton Stuart 
Published: June 2005

ABSTRACT

Enteropathogenic
Escherichia coli
infection of intestinal epithelial cells leads to localized depletion of the microtubule cytoskeleton, an effect that is dependent on delivery of type III translocated effector proteins EspG and Orf3 (designated EspG2) to the site of depletion. Microtubule depletion involved disruption rather than displacement of microtubules.
KatA, the Major Catalase, Is Critical for Osmoprotection and Virulence inPseudomonas aeruginosaPA14
Authors: Lee Ji-Sun , Heo Yun-Jeong , Lee Jeong K. , Cho You-Hee 
Published: June 2005

ABSTRACTWe demonstrate that among the three monofunctional catalases ofPseudomonas aeruginosaPA14, KatA and, to a lesser extent, KatB, but not KatE, are required for resistance to peroxide and osmotic stresses. KatA is crucial for adaptation to H2O2stress and full virulence in bothDrosophila melanogasterand mice. This dismantling of catalase roles represents a specialized catalytic system primarily involving KatA in responses to adverse environmental conditions.
Adherence to and Invasion of Human Brain Microvascular Endothelial Cells Are Promoted by Fibrinogen-Binding Protein FbsA ofStreptococcus agalactiae
Authors: Tenenbaum Tobias , Bloier Christiane , Adam Rüdiger , Reinscheid Dieter J. , Schroten Horst 
Published: June 2005

ABSTRACTStreptococcus agalactiaeis a frequent cause of bacterial sepsis and meningitis in neonates. During the course of infection,S. agalactiaecolonizes and invades a number of host compartments, thereby interacting with different host tissues. Deletion of thefbsAgene, encoding the fibrinogen protein FbsA, significantly impaired the adherence and invasion of human brain microvascular endothelial cells (HBMEC) byS. agalactiae. The adherence and invasiveness of anfbsAdeletion mutant were restored by reintroducing thefbsAgene on an expression vector. Heterologous expression offbsAinLactococcus lactisenabled this bacterium to adhere to but not to invade HBMEC, suggesting that FbsA is a streptococcal adhesin. Finally, host cell adherence and invasion were significantly blocked in competition experiments with either purified FbsA fusion protein or a monoclonal antibody directed against the fibrinogen-binding epitope of FbsA. TheS. agalactiae fbsAmutant induced a release of the neutrophil chemoattractant interleukin-8 (IL-8) equal to that induced by the wild type. Taken together, our studies demonstrate that FbsA promotes the adherence ofS. agalactiaeto HBMEC but that FbsA neither mediates the bacterial invasion into host cells nor plays a role in IL-8 release for HBMEC.
Inhibition of Proteolytic Activity of a Chlamydial Proteasome/Protease-Like Activity Factor by Antibodies from Humans Infected with
Chlamydia trachomatis
Authors: Sharma Jyotika , Dong Feng , Pirbhai Mustak , Zhong Guangming 
Published: June 2005

ABSTRACT

We have previously shown that individuals infected with
Chlamydia trachomatis
can develop a robust antibody response to a chlamydia-secreted protein (designated chlamydial proteasome/protease-like activity factor [CPAF]). We now report that sera collected from these infected individuals neutralized the proteolytic activity of CPAF. Depletion of the serum sample with CPAF proteins to remove the CPAF-specific antibodies effectively blocked the neutralization, whereas similar depletion with the HSP60 proteins failed to do so. We further demonstrated that the CPAF central region covering residues 200 to 338 was predominantly recognized by the human neutralization antibodies. The significance of the CPAF neutralization antibodies generated in chlamydia-infected individuals is discussed.
Complement Depletion Renders C57BL/6 Mice Sensitive to the
Bacillus anthracis
Sterne Strain
Authors: Harvill Eric T. , Lee Gloria , Grippe Vanessa K. , Merkel Tod J. 
Published: June 2005

ABSTRACT

Concerns regarding safety and control of virulent
Bacillus anthracis
have created substantial hurdles to the study of anthrax. The Sterne strain is considered relatively safe to study, but this acapsular strain has a defect in normal mice and is often studied in A/J mice. A/J mice are highly susceptible to the Sterne strain, due to a defect in the Hc locus, which encodes complement factor 5 (C5). Here we show that normally resistant C57BL/6 mice become highly susceptible to the Sterne strain upon complement depletion with cobra venom factor. This generalizable approach should allow the virulence of anthrax to be studied under relatively safe conditions and using a wide variety of mouse strains.
Endogenous CD4+CD25+Regulatory T Cells Play No Apparent Role in the Acute Humoral Response to IntactStreptococcus pneumoniae
Authors: Lee Katherine S. , Sen Goutam , Snapper Clifford M. 
Published: June 2005

ABSTRACTImmunoglobulin G (IgG) antiprotein and antipolysaccharide responses to intactStreptococcus pneumoniaeare CD4+-T-cell dependent and therefore might be under the negative control of CD4+CD25+regulatory T cells. Injection of anti-interleukin 2 receptor α (anti-IL-2Rα) MAb to deplete regulatory T cells, injection of agonistic MAb against glucocorticoid-induced tumor necrosis factor receptor family-related protein to inhibit regulatory-T-cell function, and adoptive transfer of regulatory-T-cell-depleted CD4+T cells into athymic nude mice each had no effect on either the primary or secondary protein- or polysaccharide-specific IgG response to intactS. pneumoniae. Surprisingly, anti-IL-2Rα MAb also had no effect on the IgG response to intactS. pneumoniaein MyD88−/−mice or to a soluble protein-polysaccharide conjugate injected into wild-type mice in the absence of adjuvant. Collectively, these data are the first to suggest that, in contrast to their role in limiting chronic cell-mediated immunity, regulatory T cells may play no significant role in an acute humoral immune response to an intact extracellular bacterial pathogen.
Protective Immunization of Mice with an Active-Site Mutant of Subtilase Cytotoxin of Shiga Toxin-Producing
Escherichia coli
Authors: Talbot Ursula M. , Paton James C. , Paton Adrienne W. 
Published: June 2005

ABSTRACT

We have recently described a novel AB
5
cytotoxin produced by certain Shiga toxin-producing
Escherichia coli
strains. The A subunit of this toxin is a subtilase-like serine protease, while the B pentamer mediates binding to host cell glycolipid receptors. The subtilase cytotoxin is lethal for mice, causing extensive microvascular thrombosis as well as necrosis in the brain, kidneys, and liver. In the present study, we have immunized mice with a purified derivative of the toxin with a Ser
272
→ Ala mutation in the A subunit which abolishes cytotoxicity. This elicited strong antibody responses, as judged by enzyme-linked immunosorbent assay, which conferred protection against intraperitoneal challenge with purified toxin. Immunized mice were also protected from weight loss resulting from oral challenge with an
E. coli
K-12 clone expressing the active toxin.
The Order of Prime-Boost Vaccination of Neonatal Calves with
Mycobacterium bovis
BCG and a DNA Vaccine Encoding Mycobacterial Proteins Hsp65, Hsp70, and Apa Is Not Critical for Enhancing Protection against Bovine Tuberculosis
Authors: Skinner Margot A. , Wedlock D. Neil , de Lisle Geoffrey W. , Cooke Michèle M. , Tascon Ricardo E. , Ferraz Jose C. , Lowrie Douglas B. , Vordermeier H. Martin , Hewinson R. Glyn , Buddle Bryce M. 
Published: June 2005

ABSTRACT

Priming neonatal calves at birth with a
Mycobacterium bovis
bacillus Calmette-Guérin (BCG) vaccine and boosting with a DNA vaccine consisting of plasmids encoding mycobacterial antigens Hsp65, Hsp70, and Apa or the reverse prime-boost sequence induced similar levels of protection against experimental challenge with
Mycobacterium bovis
. When
M. bovis
was isolated from a thoracic lymph node following challenge, the two groups of calves given the prime-boost regimen had significantly lower numbers of
M. bovis
isolates than those vaccinated with BCG alone. These observations suggest that the exact sequence of administration of a prime-boost vaccination regimen in a neonatal animal model is not critical to the development of immunity.
A different analysis applied to a mathematical model on output of exhaled nitric oxide
Authors: Rottier Bart L. , Cohen Judith , van der Mark Thom W. , Douma W. Rob , Duiverman Eric J. , ten Hacken Nick H. T. 
Published: June 2005

The following is the abstract of the article discussed in the following letter: The relatively recent detection of nitric oxide (NO) in the exhaled breath has prompted a great deal of experimentation in an effort to understand the pulmonary exchange dynamics. There has been very little progress in theoretical studies to assist in the interpretation of the experimental results. We have developed a two-compartment model of the lungs in an effort to explain several fundamental experimental observations. The model consists of a nonexpansile compartment representing the conducting airways and an expansile compartment representing the alveolar region of the lungs. Each compartment is surrounded by a layer of tissue that is capable of producing and consuming NO. Beyond the tissue barrier in each compartment is a layer of blood representing the bronchial circulation or the pulmonary circulation, which are both considered an infinite sink for NO. All parameters were estimated from data in the literature, including the production rates of NO in the tissue layers, which were estimated from experimental plots of the elimination rate of NO at end exhalation (ENO) vs. the exhalation flow rate (V̇e). The model is able to simulate the shape of the NO exhalation profile and to successfully simulate the following experimental features of endogenous NO exchange: 1) an inverse relationship between exhaled NO concentration and V̇E, 2) the dynamic relationship between the phase III slope and V̇E, and 3) the positive relationship between ENO and V̇E. The model predicts that these relationships can be explained by significant contributions of NO in the exhaled breath from the nonexpansile airways and the expansile alveoli. In addition, the model predicts that the relationship between ENO and V̇E can be used as an index of the relative contributions of the airways and the alveoli to exhaled NO.
Can Reanalysis Have Anthropogenic Climate Trends without Model Forcing?
Authors: Cai Ming , Kalnay Eugenia 
Published: June 2005

Abstract
This paper shows analytically that a reanalysis made with a frozen model can detect the warming trend due to an increase of greenhouse gases within the atmosphere at its full strength (at least 95% level) after a short transient (less than 100 analysis cycles). The analytical proof is obtained by taking into consideration the following three possible deficiencies in the model used to create first-guess fields: (i) the physical processes responsible for the observed trend (e.g., an increase of greenhouse gases) are completely absent from the model, (ii) the first-guess fields are affected by an initial drift caused by the imbalance between the model equilibrium and the analysis that contains trends due to the observations, and (iii) the model used in the reanalysis has a constant model bias. The imbalance contributes to a systematic reduction in the reanalysis trend compared to the observations. The analytic derivation herein shows that this systematic reduction can be very small (less than 5%) when the observations are available for twice-daily assimilation. Moreover, the frequent analysis cycle is essential to compensate for the impact due to relatively poor space coverage of the observational network, which effectively yields smaller weights assigned to observations in a global data assimilation system.
Other major issues about using reanalysis for a long-term trend analysis, particularly the impact of the major changes in the global observing system that took place in the 1950s and in 1979, are not addressed. Here it is merely proven mathematically that using a frozen model in a reanalysis does not cause significant harm to the fidelity of the long-term trend in the reanalysis.
Interannual and Interdecadal Variability of Thailand Summer Monsoon Season
Authors: Singhrattna Nkrintra , Rajagopalan Balaji , Kumar K. Krishna , Clark Martyn 
Published: June 2005

AbstractSummer monsoon rains are a critical factor in Thailand’s water resources and agricultural planning and management. In fact, they have a significant impact on the country’s economic health. Consequently, understanding the variability of the summer monsoon rains over Thailand is important for instituting effective mitigating strategies against extreme rainfall fluctuations. To this end, the authors systematically investigated the relationships between summer monsoon precipitation from the central and northern regions of Thailand and large-scale climate features. It was found that Pacific sea surface temperatures (SSTs), in particular, El Niño–Southern Oscillation (ENSO), have a negative relationship with the summer monsoon rainfall over Thailand in recent decades. However, the relationship between summer rainfall and ENSO was weak prior to 1980. It is hypothesized that the ENSO teleconnection depends on the SST configuration in the tropical Pacific Ocean, that is, an eastern Pacific–based El Niño pattern, such as is the case in most of the post-1980 El Niño events, tends to place the descending limb of the Walker circulation over the Thailand–Indonesian region, thereby significantly reducing convection and consequently, rainfall over Thailand. It is believed that this recent shift in the Walker circulation is instrumental for the nonstationarity in ENSO–monsoon relationships in Thailand. El Niños of 1997 and 2002 corroborate this hypothesis. This has implications for monsoon rainfall forecasting and, consequently, for resources planning and management.
Avoiding Inhomogeneity in Percentile-Based Indices of Temperature Extremes
Authors: Zhang Xuebin , Hegerl Gabriele , Zwiers Francis W. , Kenyon Jesse 
Published: June 2005

AbstractUsing a Monte Carlo simulation, it is demonstrated that percentile-based temperature indices computed for climate change detection and monitoring may contain artificial discontinuities at the beginning and end of the period that is used for calculating the percentiles (base period). This would make these exceedance frequency time series unsuitable for monitoring and detecting climate change. The problem occurs because the threshold calculated in the base period is affected by sampling error. On average, this error leads to overestimated exceedance rates outside the base period. A bootstrap resampling procedure is proposed to estimate exceedance frequencies during the base period. The procedure effectively removes the inhomogeneity.
A Distinctly Interdecadal Signal of Pacific Ocean–Atmosphere Interaction
Authors: Frauenfeld Oliver W. , Davis Robert E. , Mann Michael E. 
Published: June 2005

Abstract
A new and distinctly interdecadal signal in the climate of the Pacific Ocean has been uncovered by examining the coupled behavior of sea surface temperatures (SSTs) and Northern Hemisphere atmospheric circulation. This interdecadal Pacific signal (IPS) of ocean–atmosphere interaction exhibits a highly statistically significant interdecadal component yet contains little to no interannual (El Niño scale) variability common to other Pacific climate anomaly patterns. The IPS thus represents the only empirically derived, distinctly interdecadal signal of Pacific Ocean SST variability that likely also represents the true interdecadal behavior of the Pacific Ocean–atmosphere system. The residual variability of the Pacific’s leading SST pattern, after removal of the IPS, is highly correlated with El Niño anomalies. This indicates that by simply including an atmospheric component, the leading mode of Pacific SST variability has been decomposed into its interdecadal and interannual patterns. Although the interdecadal signal is unrelated to interannual El Niño variability, the interdecadal ocean–atmosphere variability still seems closely linked to tropical Pacific SSTs. Because prior abrupt changes in Pacific SSTs have been related to anomalies in a variety of physical and biotic parameters throughout the Northern Hemisphere, and because of the persistence of these changes over several decades, isolation of this interdecadal signal in the Pacific Ocean–atmosphere system has potentially important and widespread implications to climate forecasting and climate impact assessment.
Ocean–Atmosphere Interactions in the Tropical and Subtropical Atlantic Ocean
Authors: Huang Bohua , Shukla J. 
Published: June 2005

Abstract
A 110-yr simulation is conducted using a specially designed coupled ocean–atmosphere general circulation model that only allows air–sea interaction over the Atlantic Ocean within 30°S–60°N. Since the influence from the Pacific El Niño–Southern Oscillation (ENSO) over the Atlantic is removed in this run, it provides a better view of the extratropical influences on the tropical air–sea interaction within the Atlantic sector. The model results are compared with the observations that also have their ENSO components subtracted.
The model reproduces the two major anomalous patterns of the sea surface temperature (SST) in the southern subtropical Atlantic (SSA) and the northern tropical Atlantic (NTA) Ocean. The SSA pattern is phase locked to the annual cycle. Its enhancement in austral summer is associated with atmospheric disturbances from the South Atlantic during late austral spring. The extratropical atmospheric disturbances induce anomalous trade winds and surface heat fluxes in its northern flank, which generate SST anomalies in the subtropics during austral summer. The forced SST anomalies then change the local sea level pressure and winds, which in turn affect the northward shift of the atmospheric disturbance and cause further SST changes in the deep Tropics during austral fall.
The NTA pattern is significant throughout a year. Like the SSA pattern, the NTA pattern in boreal winter–spring is usually associated with the heat flux change caused by extratropical atmospheric disturbances, such as the North Atlantic Oscillation. The SST anomalies then feed back with the tropical atmosphere and expand equatorward. From summer to fall, however, the NTA SST anomalies are likely to persist within the subtropics for more than one season after it is generated. Our model results suggest that this feature is associated with a local feedback between the NTA SST anomalies and the atmospheric subtropical anticyclone from late boreal summer to early winter. The significance of this potential feedback in reality needs to be further examined with more observational evidence.
The Nonlinear Patterns of North American Winter Temperature and Precipitation Associated with ENSO
Authors: Wu Aiming , Hsieh William W. , Shabbar Amir 
Published: June 2005

Abstract
Nonlinear projections of the tropical Pacific sea surface temperature anomalies (SSTAs) onto North American winter (November–March) surface air temperature (SAT) and precipitation anomalies have been performed using neural networks. During El Niño, the linear SAT response has positive anomalies centered over Alaska and western Canada opposing weaker negative anomalies centered over the southeastern United States. In contrast, the nonlinear SAT response, which is excited during both strong El Niño and strong La Niña, has negative anomalies centered over Alaska and northwestern Canada and positive anomalies over much of the United States and southern Canada.
For precipitation, the linear response during El Niño has a positive anomaly area stretching from the east coast to the southwest coast of the United States and another positive area in northern Canada, in opposition to the negative anomaly area over much of southern Canada and northern United States, and another negative area over Alaska. In contrast, the nonlinear precipitation response, which is excited during both strong El Niño and strong La Niña, displays positive anomalies over much of the United States and southern Canada, with the main center on the west coast at around 45°N and a weak center along the southeast coast, and negative anomalies over northwestern Canada and Alaska.
The nonlinear response accounts for about one-fourth and one-third as much variance as the linear response of the SAT and precipitation, respectively. A polynomial fit further verifies the nonlinear response of both the SAT and precipitation to be mainly a quadratic response to ENSO. Both the linear and nonlinear response patterns of the SAT and precipitation are basically consistent with the circulation anomalies (the 500-mb geopotential height anomalies), detected separately by nonlinear projection. A cross-validation test shows that including the nonlinear (quadratic) response can potentially contribute to additional forecast skill over North America.
A Generalized Energy Balance Climate Model with Parameterized Dynamics and Diabatic Heating
Authors: Shell Karen M. , Somerville Richard C. J. 
Published: June 2005

Abstract
Energy balance models have proven useful in understanding mechanisms and feedbacks in the climate system. An original global energy balance model is presented here. The model is solved numerically for equilibrium climate states defined by zonal average temperature as a function of latitude for both a surface and an atmospheric layer. The effects of radiative, latent, and sensible heating are parameterized. The model includes a variable lapse rate and parameterizations of the major dynamical mechanisms responsible for meridional heat transport: the Hadley cell, midlatitude baroclinic eddies, and ocean circulation. The model reproduces both the mean variation of temperature with latitude and the global average heat budget within the uncertainty of observations.
The utility of the model is demonstrated through examination of various climate feedbacks. One important feedback is the effect of the lapse rate on climate. When the planet warms as a result of an increase in the solar constant, the lapse rate acts as a negative feedback, effectively enhancing the longwave emission efficiency of the atmosphere. The lapse rate is also responsible for an increase in global average temperature when the meridional heat transport effectiveness is increased. The water vapor feedback enhances temperature changes, while the latent and sensible heating feedback reduces surface temperature changes.