bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sampling Errors in Seasonal Forecasting
Authors: Cusack Stephen , Arribas Alberto 
Published: September 2008

Abstract
The limited numbers of start dates and ensemble sizes in seasonal forecasts lead to sampling errors in predictions. Defining the magnitude of these sampling errors would be useful for end users as well as informing decisions on resource allocation to minimize total system error. A numerical experiment has been designed to measure them, and results indicate that sampling errors are substantial in state-of-the-art seasonal forecast systems. The standard solution of increasing sample sizes is of limited benefit in seasonal forecasting because of restrictions imposed by resource costs and nonstationary observations. Alternative options, based on the postprocessing of forecast and hindcast data, are presented in this paper. The spatial and temporal aggregations of data together with the appropriate use of theoretical distributions can reduce the effect of sampling errors on forecast quantities by an amount equivalent to increasing samples sizes by a factor of 4 of more, with insignificant losses of forecast information. These postprocessing techniques can be viewed as cost-effective methods of reducing the effects of sampling errors in seasonal forecast quantities.
Analysis of a Dryline during IHOP: Implications for Convection Initiation
Authors: Wakimoto Roger M. , Murphey Hanne V. 
Published: September 2008

Abstract
A detailed analysis of a dryline that formed on 22 May 2002 during the International H2O Project (IHOP) is presented. The dryline was classified as a null case since air parcels lifted over the convergence boundary were unable to reach the level of free convection preventing thunderstorms from forming. A secondary dryline associated with a distinct moisture discontinuity developed to the west of the primary dryline. The primary dryline exhibited substantial along-frontal variability owing to the presence of misocyclones. This nonlinear pattern resembled the precipitation core/gap structure associated with cold fronts during one of the analysis times although the misocyclones were positioned within the gap regions. Radar refractivity has been recently shown to accurately retrieve the low-level moisture fields within the convective boundary layer; however, its use in forecasting the initiation of convection has been restricted to qualitative interpretations. This study introduces the total derivative of radar refractivity as a quantitative parameter that may improve nowcasts of convection. Although no storms developed on this day, there was a tendency for maxima of the total derivative to be near regions where cumulus clouds were developing near a convergence boundary.
Improving Incremental Balance in the GSI 3DVAR Analysis System
Authors: Kleist Daryl T. , Parrish David F. , Derber John C. , Treadon Russ , Errico Ronald M. , Yang Runhua 
Published: September 2008

Abstract
The gridpoint statistical interpolation (GSI) analysis system is a unified global/regional three-dimensional variational data assimilation (3DVAR) analysis code that has been under development for several years at the National Centers for Environmental Prediction (NCEP)/Environmental Modeling Center. It has recently been implemented into operations at NCEP in both the global and North American data assimilation systems (GDAS and NDAS, respectively). An important aspect of this development has been improving the balance of the analysis produced by GSI. The improved balance between variables has been achieved through the inclusion of a tangent-linear normal-mode constraint (TLNMC). The TLNMC method has proven to be very robust and effective. The TLNMC as part of the global GSI system has resulted in substantial improvement in data assimilation at NCEP.
Diabatically Induced Secondary Flows in Tropical Cyclones. Part I: Quasi-Steady Forcing
Authors: Pendergrass Angeline G. , Willoughby Hugh E. 
Published: September 2008

Abstract
The Sawyer–Eliassen Equation (SEQ) is here rederived in height coordinates such that the sea surface is also a coordinate surface. Compared with the conventional derivation in mass field coordinates, this formulation adds some complexity, but arguably less than is inherent in terrain-following coordinates or interpolation to the lower physical boundary. Spatial variations of static stability change the vertical structure of the mass flow streamfunction. This effect leads to significant changes in both secondary-circulation structure and intensification of the primary circulation. The SEQ is solved on a piecewise continuous, balanced mean vortex where the shapes of the wind profiles inside and outside the eye and the tilt of the specified heat source can be adjusted independently. A series of sensitivity studies shows that the efficiency with which imposed heating intensifies the vortex is most sensitive to intensity itself as measured by maximum wind and to vortex size as measured by radius of maximum wind. Vortex shape and forcing tilt have impacts 20%–25% as great as intensity and size, suggesting that the aspects of tropical cyclones that predispose them to rapid intensification are environmental or thermodynamic rather than kinematic.
Oxytocin enhances processing of positive versus negative emotional information in healthy male volunteers
Authors: Di Simplicio M , Massey-Chase R , Cowen PJ , Harmer CJ 
Published: September 2008

Abstract Animal studies have shown the role of oxytocin in affiliation and attachment, and recent evidence suggests that oxytocin is also involved in human models of approach behaviour, possibly by modulating the processing of emotionally valenced stimuli. Although oxytocin administration has been reported to decrease neural responses to facial emotional information, the effects on a wider range of behavioural measures of emotional processing shown to be sensitive to antidepressant manipulation have not been examined. The aim of this study was to investigate whether intranasally administered oxytocin affects the processing of positive and negative affective information in healthy male volunteers across tasks measuring attention, perception and memory. Twenty-nine male healthy volunteers were randomly allocated to receive a single dose of oxytocin nasal spray (24 UI) or placebo. 50 min later, participants completed a battery of psychological tests measuring emotional processing. A single dose of intranasally administered oxytocin slowed reaction time to correctly identify fearful facial expressions and reduced the misclassification of positive emotions as negative ones. These effects occurred in the absence of significant differences in subjective ratings of mood and anxiety. These results suggest that oxytocin modulates emotion processing in healthy male volunteers. This action may contribute to the emerging role of the neuropeptide in promoting affiliative and approach behaviours by reducing the salience of potentially ambiguous and threatening social stimuli.
Estrogen inhibits dendritic cell maturation to RNA viruses
Authors: Escribese Maria M. , Kraus Thomas , Rhee Esther , Fernandez-Sesma Ana , López Carolina B. , Moran Thomas M. 
Published: September 2008

Abstract
Dendritic cells (DCs) play a central role in initiating and polarizing the immune response. Therefore, DC maturation represents a key control point in the shift from innate to adaptive immunity. It is suspected that during pregnancy, hormones are critical factors that modulate changes reported to occur in maternal immunity. Here we examined the effect of 17-β-estradiol (E2) on the maturational response triggered by virus in human DCs and its influence on their ability to activate naive T cells. We developed an in vitro system to measure the response of DCs to virus infection with Newcastle disease virus (NDV) after a 24-hour E2 treatment. Using this system, we demonstrated that E2 pretreatment down-regulated the antiviral response to RNA viruses in DCs by profoundly suppressing type I interferon (IFN) synthesis and other important inflammatory products. In addition, the DCs capacity to stimulate naive CD4 T cells was also reduced. These results suggest an important role for E2 in suppressing the antiviral response and provide a mechanism for the reduced immunity to virus infection observed during pregnancy.
Can semi-automated image cytometry on induced sputum become a screening tool for lung cancer?
Authors: Marek W. , Kotschy-Lang N. , Muti A. , Köhler Ch. , Nielsen L. , Topalidis Th. , Atay Z. , Nakhosteen J.A. 
Published: September 2008

The correlations between semi-automated sputum cytometry (ASC), conventional cytology and the final diagnosis was investigated in industrially-exposed workers. Slides of sputum samples from 201 former uranium miners with silicosis, 100 patients with asbestosis, 103 workers resected for lung cancer, and 200 controls (50% smokers), were stained using the Papanicolaou (Pap) method and the Feulgen reaction with thionin. Cytometry was performed using the Cyto-Savant automated system.Atypical nuclei were found in 72 of 404 patient samples, 327 samples were normal and five were inadequate for ASC analysis. Thirteen tumours (Pap IV, Pap V) and 11 cases of severe dysplasia were identified by cytology. Lung cancer was confirmed in 20 patients. Compared to the final diagnosis of lung cancer, the sensitivity of ASC was 75% (15 out of 20) and specificity 89.8% (520 out of 579). The results represent a diagnostic efficiency of 89.3%. The combination of ASC with cytology increased sensitivity to 80% (16 out of 20) without significant loss of specificity (89.7% or 523 out of 581).In this investigation of a limited number of patients with occupational radon or asbestos exposure, semi-automated sputum cytometry appears to be sensitive and reliable for the detection of malignant changes in the tracheobronchial mucosa. Together with conventional cytology, it would be reasonable to test the validity of the combined methods in a large-scale feasibility study of early lung cancer detection.
Human alveolar epithelial cells induce nitric oxide synthase‐2 expression in alveolar macrophages
Authors: Pechkovsky D.V. , Zissel G. , Stamme C. , Goldmann T. , Ari Jaffe H. , Einhaus M. , Taube C. , Magnussen H. , Schlaak M. , Müller­Quernheim J. 
Published: September 2008

It was hypothesized that cell­to­cell interaction between human alveolar macrophages (AM) and alveolar epithelium, might be an important factor leading to nitric oxide synthase‐2 (NOS2) messenger ribonucleic acid (mRNA) and protein expression by constituent cells of the alveolar wall and/or AM.NOS2 mRNA and the protein expression patterns of human AM and alveolar epithelial cells type II (AEC­II) isolated from normal parts of lung resections of patients with pulmonary malignancies were determined. In addition, NOS2 mRNA expression in human AM co­cultured with autologous AEC­II in the presence of pro­inflammatory cytokines interleukin (IL)‐1β, tumour necrosis factor (TNF)‐α, interferon (IFN)‐γ or lipopolysaccharide (LPS) was investigated. The effect of human surfactant protein‐A (SP‐A) on IFN‐γ‐mediated NOS2 mRNA expression in human AM was also studied.Neither NOS2 mRNA nor protein could be detected in freshly isolated, unstimulated or cytokine­stimulated AEC­II. In contrast, freshly isolated AM from bronchoalveolar lavage or lung tissue samples expressed immunoreactivity for NOS2 protein, but no NOS2 mRNA could be detected by reverse transcriptase polymerase chain reaction. All stimuli tested failed to induce NOS2 mRNA expression in human AMin vitro. Only AM­AEC­II co­culture in the presence of IFN‐γ led to NOS2 mRNA and protein expression.In situhybridization of NOS2 mRNA on lung tissue explants and immunohistochemical staining of cytospin preparations of AM­AEC­II co­cultures demonstrated that NOS2 is expressed in AM but not in AEC­II. This co­culture effect could not be reproduced by substitution of AEC­II with SP‐A.These data give evidence of a regulatory network controlling human nitric oxide synthase‐2 expression in the lower respiratory tract.
Identification of a new cystic fibrosis transmembrane regulator mutation in a severely affected patient
Authors: Spitzer E. , Staab D. , Hanke R. , Wahn U. , Grosse R. 
Published: September 2008

By using a combination of multiplex polymerase chain reaction and allele­specific labelled probes, the oligo­ligation assay is designed to detect known cystic fibrosis transmembrane regulator mutations. This study shows that this assay may also be useful to detect new mutations.The second child of a family of Bosnic origin showed all the symptoms of intestinal and pulmonary manifestations of cystic fibrosis. No signal could be obtained for the allele­specific probe 1898+1G>A. This could be explained by a nearby localized sequence change that prevented polymerase chain reaction primers or oligonucleotide probes from binding to the target sequence. Indeed, sequence analysis revealed a new 1894G>T exchange (Glu587Stop). Both parents and the healthy brother carried this mutation. Thus, the index patient was homozygous for 1894G>T, which was inherited from both parents.
Sleep and breathing in neuromuscular disease
Authors: Bourke S.C. , Gibson G.J. 
Published: September 2008

Respiratory muscle weakness in neuromuscular disease causes significant morbidity and mortality. The published data on respiratory muscle activity and breathing during sleep in normal subjects, the impact of respiratory muscle weakness on sleep and breathing and the relations to daytime respiratory function in neuromuscular disease are reviewed here. In normal subjects during sleep upper airway resistance increases, chemosensitivity is reduced and the wakefulness drive to breathe is lost, resulting in a fall in ventilation. During rapid eye movement (REM) sleep, ribcage and accessory breathing muscles are suppressed, particularly during bursts of eye movements, and breathing is more irregular, rapid and shallow, with a further fall in ventilation.In subjects with respiratory muscle weakness sleep is fragmented, with shorter total sleep time, frequent arousals, an increase in stage 1 sleep and a reduction in, or complete suppression of, REM sleep. Sleep­disordered breathing and nocturnal desaturation are common and most severe during REM sleep. Correlations between daytime respiratory function and nocturnal desaturation are moderate or weak, but daytime respiratory function has greater prognostic value than nocturnal measurements.Noninvasive ventilation improves sleep quality and breathing in subjects with respiratory muscle weakness. However, the optimal criteria for initiation of ventilation and its role in rapidly progressive neuromuscular diseases are unclear.
Oxidant metabolism in chronic obstructive pulmonary disease
Authors: Boots A.W. , Haenen G.R.M.M. , Bast A. 
Published: September 2008

The development and progression of chronic obstructive pulmonary disease (COPD) have been associated with increased oxidative stress or reduced antioxidant resources. Several indicators of oxidative stress, such as hydrogen peroxide exhalation, lipid peroxidation products and degraded proteins, are indeed elevated in COPD patients. As a result, the antioxidant capacity decreases in COPD patients.The fall in antioxidant capacity of blood from COPD patients should not only be regarded as a reflection of the occurrence of oxidative stress but also as evidence that oxidative stress spreads out to the circulation and can therefore generate a systemic effect.COPD is linked to weight loss and in particular to loss in fat­free mass by skeletal muscle wasting. This systemic effect can be mediated by both oxidative stress and oxidative stress­mediated processes like apoptosis and inflammation. Furthermore, COPD is a predisposition for lung cancer through several mechanisms including oxidative stress and oxidative stress­mediated processes such as inflammation and disruption of genomic integrity.Current therapeutic interventions against the far­reaching consequences of the systemic oxidative stress in chronic obstructive pulmonary disease are not yet optimised. A diet designed to reduce chronic metabolic stress might form an effective therapeutic strategy in chronic obstructive pulmonary disease.
Fluid homeostasis in chronic obstructive lung disease
Authors: de Leeuw P.W. , Dees A. 
Published: September 2008

Chronic obstructive pulmonary disease (COPD) often leads to massive oedema and the development of what is usually called cor pulmonale. The mechanisms by which patients with COPD retain salt and water are not completely understood. Several abnormalities have been found including reduced renal blood flow with relatively preserved glomerular filtration rate and elevated levels of renin, aldosterone, arginine vasopressin and atrial natriuretic peptide. Generally, these abnormalities worsen with the severity of COPD and are most marked during the oedematous phases.Cardiac output is remarkably normal, suggesting that “cor pulmonale” is not primarily a cardiac disorder but rather a condition of volume overload due to activation of sodium­retaining mechanisms. The stimulus for this activation could be underfilling of the arterial system (reduced effective circulating volume) secondary to a fall in total peripheral vascular resistance. The latter is caused by hypercapnia­induced dilation of the precapillary sphincters. Apparently, the massive sodium retention by the kidney is not able to restore the circulating volume and a vicious cycle ensues ultimately leading to a clinical picture which resembles right­sided heart failure. Predictably, only blockade of the effects of carbon dioxide at the level of the precapillary sphincters would be able to halt this process.
Incidence and short-term outcome of acute lung injury in mechanically ventilated children
Authors: Dahlem P. , van Aalderen W.M.C. , Hamaker M.E. , Dijkgraaf M.G.W. , Bos A.P. 
Published: September 2008

The aim of this study was to determine the incidence and short-term outcome of mechanically ventilated children suffering from acute lung injury (ALI) on a paediatric intensive care unit (PICU).Between January 1 1998 and January 1 2000, all mechanically ventilated children were evaluated using the criteria of an American-European Consensus Conference.Of the 443 children eligible for analysis, 44 (9.9%) were diagnosed as suffering from ALI. Of these, 79.5% developed the acute respiratory distress syndrome (ARDS); 54.5% (24 of 44) fulfilled the ARDS criteria at inclusion and 25% (11 of 44) later. PICU mortality for ALI was 27.3% (12 of 44) and within the ARDS subgroup 31.4% (11 of 35). Of the 12 children who died, 11 had ARDS; the main cause of death was cerebral damage (seven of 12).Acute lung injury and acute respiratory distress syndrome are rare diseases on apaediatric intensive care unit with a high mortality. Most of the children with acutelung injury develop acute respiratory distress syndrome. In the acute respiratory distress syndrome subgroup, mortality is higher than in the acute lung injury nonacute respiratory distress syndrome subgroup. Further investigations should confirm prognostic factors (e.g.respiratory parameters) for prediction of outcome.
Systemic inflammation in chronic obstructive pulmonary disease
Authors: Oudijk E­J.D. , Lammers J­W.J. , Koenderman L. 
Published: September 2008

Chronic obstructive pulmonary disease (COPD) is characterised by a chronic inflammation in the pulmonary tissue. The disease is associated with a switch from a self­limiting inflammatory response, mainly initiated by smoke inhalation, to a chronic persistent inflammatory response after prolonged interaction with cigarette smoke. The extent of the inflammatory reaction is correlated with the severity of the disease.Chronic inflammation in the pulmonary tissue is also associated with systemic effects. These effects range from cytokine­induced priming of peripheral leukocytes, to muscle wasting induced by cytokines such as tumour necrosis factor‐α. Despite a general consensus that chronic inflammation is a characteristic phenomenon of the disease, surprisingly little is known regarding the underlying pathogenetic mechanisms.A clear communication is present between the disease mechanisms in the pulmonary compartment and peripheral tissues, leading to the concept of COPD as a systemic inflammatory disease. This communication can be mediated by: 1) leakage of reactive oxygen species and stress­induced cytokines directly into the peripheral blood, 2) (pre)activation of peripheral blood leukocytes that can result in aberrant homing and activation of inflammatory cells in distant tissues, and 3) the liberation of pro­inflammatory mediators by leukocytes and/or stromal cells present in the pulmonary tissues during progression of the disease.The current authors hypothesise that the occurrence of a chronic inflammatory response after prolonged interaction of the pulmonary tissue with cigarette smoke causes aberrant homing of leukocytes to the tissue and delayed apoptosis. This leads to the autonomous characteristic of the inflammatory response in patients with chronic obstructive pulmonary disease.
Structure and function of the respiratory muscles in patients with COPD: impairment or adaptation?: Fig. 1.—
Authors: Orozco-Levi M. 
Published: September 2008

Respiratory muscles are essential to alveolar ventilation. These muscles work against increased mechanical loads due to airflow limitation and geometrical changes of the thorax derived from pulmonary hyperinflation. Respiratory muscle fibres show several degrees of impairment in cellular and subcellular structures which, in many cases, are proportional to the severity of the disease and accompanying conditions (ageing, deconditioning, starvation, comorbidity). This structural impairment translates, from the functional point of view, to a loss of strength (capacity to generate tension) and an increased susceptibility to failure in the face of a particular load (early onset of fatigue).On the other hand, there is accumulating evidence that the diaphragm and other respiratory muscles are also able to express adaptive changes in response to the chronic mechanical load imposed by the disease. In most cases, impairment and adaptation of the respiratory muscles reaches a balance that permits enough ventilation for patients' survival. However, this balance can be altered for additional increments of the mechanical or metabolic load on the muscles (e.g.abdominal or thoracic surgeries, pneumonia, pulmonary embolism,etc.). Moreover, loss of balance is not always associated with extreme situations. Many patients develop ventilatory failure and require hospital admission even if the cause of the exacerbation is less dramatic (bronchial infections, pain of any nature, electrolyte disturbances,etc.).Although the physiopathology of chronic obstructive pulmonary disease exacerbations is multifactorial, the above-mentioned fragility suggests the existence of a “fragile balance” between respiratory muscle overload and respiratory muscle adaptations. Assessment of respiratory muscle function through specific tests evaluating the strength and endurance could offer valuable information about this particular susceptibility to muscle imbalance. Identification of patients possessing a fragile respiratory muscle balance could have important implications for the application of specific strategies such as respiratory muscle training, nutrition, or anabolic treatment.