Non-exhaust traffic induced emissions are a major source of particle mass in most European countries. This is particularly important in Nordic and Alpine countries where winter time road traction ...maintenance occurs, e.g. salting and sanding, and where studded tyres are used. In this paper, Part 1, the road dust sub-model of a coupled road dust and surface moisture model (NORTRIP) is described. The model provides a generalised process based formulation of the non-exhaust emissions, with emphasis on the contribution of road wear, suspension, surface dust loading and the effect of road surface moisture (retention of wear particles and suspended emissions). The model is intended for use as a tool for air quality managers to help study the impact of mitigation measures and policies. We present a description of the road dust sub-model and apply the model to two sites in Stockholm and Copenhagen where seven years of data with surface moisture measurements are available. For the site in Stockholm, where studded tyres are in use, the model predicts the PM10 concentrations very well with correlations (R2) in the range of R2 = 0.76–0.91 for daily mean PM10. The model also reproduces well the impact of a reduction in studded tyres at this site. For the site in Copenhagen the correlation is lower, in the range 0.44–0.51. The addition of salt is described in the model and at both sites this leads to improved correlations due to additional salt emissions. For future use of the model a number of model parameters, e.g. wear factors and suspension rates, still need to be refined. The effect of sanding on PM10 emissions is also presented but more information will be required before this can be confidently applied for management applications.
•A coupled road dust and surface moisture model is presented and applied.•The surface moisture strongly determines the temporal variation of the road dust emissions.•The model predicts very well the temporal variation of suspended road dust emissions.•Time scales for suspension are significantly longer than previous estimates.•The model calculates the contribution of road salting to the emitted PM10 concentrations.
Y-receptor subtypes—how many more? Blomqvist, Anders G; Herzog, Herbert
Trends in neurosciences (Regular ed.),
07/1997, Letnik:
20, Številka:
7
Journal Article
Recenzirano
The Y-receptors belong to the G protein-coupled receptor superfamily and mediate a wide variety of physiological effects, such as regulation of blood pressure, anxiety, memory retention, hormone ...release and food intake. Since the first human Y-receptor was cloned in 1992, the search for additional subtypes has been an area of intense study. Recently four new NPY-receptor subtypes have been isolated, revealing surprisingly limited sequence identity with values as low as 30%. Several reports indicate further heterogeneity of this receptor family, for example a peripheral Y
2 receptor. However, since many studies have been carried out with different peptide analogs and radioligands in different species, there is substantial confusion regarding the pharmacological profile of the receptors. This may have led to an exaggeration of the potential number of discrete receptors.
Road dust emissions in Nordic countries still remain a significant contributor to PM10 concentrations mainly due to the use of studded tyres. A number of measures have been introduced in these ...countries in order to reduce road dust emissions. These include speed reductions, reductions in studded tyre use, dust binding and road cleaning. Implementation of such measures can be costly and some confidence in the impact of the measures is required to weigh the costs against the benefits. Modelling tools are thus required that can predict the impact of these measures. In this paper the NORTRIP road dust emission model is used to simulate real world abatement measures that have been carried out in Oslo and Stockholm. In Oslo both vehicle speed and studded tyre share reductions occurred over a period from 2004 to 2006 on a major arterial road, RV4. In Stockholm a studded tyre ban on Hornsgatan in 2010 saw a significant reduction in studded tyre share together with a reduction in traffic volume. The model is found to correctly simulate the impact of these measures on the PM10 concentrations when compared to available kerbside measurement data. Importantly meteorology can have a significant impact on the concentrations through both surface and dispersion conditions. The first year after the implementation of the speed reduction on RV4 was much drier than the previous year, resulting in higher mean concentrations than expected. The following year was much wetter with significant rain and snow fall leading to wet or frozen road surfaces for 83% of the four month study period. This significantly reduced the net PM10 concentrations, by 58%, compared to the expected values if meteorological conditions had been similar to the previous years. In the years following the studded tyre ban on Hornsgatan road wear production through studded tyres decreased by 72%, due to a combination of reduced traffic volume and reduced studded tyre share. However, after accounting for exhaust contributions and the impact of meteorological conditions in the model calculations then the net mean reduction in PM10 concentrations was only ∼50%, in agreement with observations. The NORTRIP model is shown to be able to reproduce the impacts of both traffic measures and meteorology on traffic induced PM10 concentrations, making it a unique and valuable tool for predicting the impact of measures for air quality management applications.
•The NORTRIP road dust emission model is applied to assess the impact of traffic measures.•The model reproduces the impacts of both traffic and meteorological conditions.•Road surface conditions have as significant an impact on road dust emissions as traffic abatement measures.•The model can be usefully applied to assess these measures in future air quality planning.
Non-exhaust traffic induced emissions are a major source of airborne particulate matter in most European countries. This is particularly important in Nordic and Alpine countries where winter time ...road traction maintenance occurs, e.g. salting and sanding, and where studded tyres are used. Though the total mass generated by wear sources is a key factor in non-exhaust emissions, these emissions are also strongly controlled by surface moisture conditions. In this paper, Part 2, the road surface moisture sub-model of a coupled road dust and surface moisture model (NORTRIP) is described. We present a description of the road surface moisture part of the model and apply the coupled model to seven sites in Stockholm, Oslo, Helsinki and Copenhagen over 18 separate periods, ranging from 3.5 to 24 months. At two sites surface moisture measurements are available and the moisture sub-model is compared directly to these observations. The model predicts the frequency of wet roads well at both sites, with an average fractional bias of −2.6%. The model is found to correctly predict the hourly surface state, wet or dry, 85% of the time. From the 18 periods modelled using the coupled model an average absolute fractional bias of 15% for PM10 concentrations was found. Similarly the model predicts the 90'th daily mean percentiles of PM10 with an average absolute bias of 19% and an average correlation (R2) of 0.49. When surface moisture is not included in the modelling then this average correlation is reduced to 0.16, demonstrating the importance of the surface moisture conditions. Tests have been carried out to assess the sensitivity of the model to model parameters and input data. The model provides a useful tool for air quality management and for improving our understanding of non-exhaust traffic emissions.
•A coupled road dust and surface moisture non-exhaust emission model is applied to seven sites over 18 different periods.•Surface moisture is shown to be the dominant cause of variability of the road dust emissions.•The model explains half the variability seen in roadside PM10 measurements.•Salt is found to have an impact on the surface moisture and on the variability of emissions.
Tick-borne encephalitis Valarcher, J F; Hägglund, S; Juremalm, M ...
Revue scientifique et technique (International Office of Epizootics),
08/2015, Letnik:
34, Številka:
2
Journal Article
Recenzirano
Tick-borne encephalitis (TBE), a zoonotic arbovirosis caused by tick-borne encephalitis virus (TBEV), is an increasing public health concern. Infections result in neurological symptoms in humans and ...the virus has rapidly expanded to new geographical areas. Three subtypes are currently present in different parts of Europe and Asia. The virus is transmitted by ticks, mainly Ixodes spp., between small mammals such as rodents, which serve as virus amplifying hosts. Humans are infected sporadically, either by a tick bite or by ingestion of infected milk or milk products. Other mammals (e.g. ruminants) can also be infected, but most of the time do not show clinical signs. In contrast to rodents, other wild and domestic mammals probably play only a very small direct role in maintaining TBEV in an area, but they might play an important role as hosts in sustaining a large tick population. Therefore, the virus prevalence and the occurrence of TBE can be influenced by several environmental, genetic and behavioural factors associated with the virus, the vectors or the hosts, and understanding these factors is essential for implementation of effective control measures. This article reviews virus characteristics and the epidemiological and clinical aspects of TBEV infections and examines pathogenesis, diagnostic approaches and control measures.
1 Department of Kinesiology, Pennsylvania State University, University Park, Pennsylvania; 2 Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center at ...Dallas and Presbyterian Hospital of Dallas, Dallas, Texas; 3 Department of Medicine, University of California at San Diego, La Jolla, California; 4 Department of Physiology, State University of New York at Buffalo, Buffalo, New York; 5 Hartford Hospital, Hartford; 6 Premise Development Corporation, Hartford, Connecticut; 7 Cardiology Division, Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
Submitted 2 October 2006
; accepted in final form 30 May 2007
Foreign and soluble gas rebreathing methods are attractive for determining cardiac output ( c ) because they incur less risk than traditional invasive methods such as direct Fick and thermodilution. We compared simultaneously obtained c measurements during rest and exercise to assess the accuracy and precision of several rebreathing methods. c measurements were obtained during rest (supine and standing) and stationary cycling (submaximal and maximal) in 13 men and 1 woman (age: 24 ± 7 yr; height: 178 ± 5 cm; weight: 78 ± 13 kg; O 2max : 45.1 ± 9.4 ml·kg –1 ·min –1 ; mean ± SD) using one-N 2 O, four-C 2 H 2 , one-CO 2 (single-step) rebreathing technique, and two criterion methods (direct Fick and thermodilution). CO 2 rebreathing overestimated c compared with the criterion methods (supine: 8.1 ± 2.0 vs. 6.4 ± 1.6 and 7.2 ± 1.2 l/min, respectively; maximal exercise: 27.0 ± 6.0 vs. 24.0 ± 3.9 and 23.3 ± 3.8 l/min). C 2 H 2 and N 2 O rebreathing techniques tended to underestimate c (range: 6.6–7.3 l/min for supine rest; range: 16.0–19.1 l/min for maximal exercise). Bartlett's test indicated variance heterogeneity among the methods ( P < 0.05), where CO 2 rebreathing consistently demonstrated larger variance. At rest, most means from the noninvasive techniques were ±10% of direct Fick and thermodilution. During exercise, all methods fell outside the ±10% range, except for CO 2 rebreathing. Thus the CO 2 rebreathing method was accurate over a wider range (rest through maximal exercise), but was less precise. We conclude that foreign gas rebreathing can provide reasonable c estimates with fewer repeat trials during resting conditions. During exercise, these methods remain precise but tend to underestimate c . Single-step CO 2 rebreathing may be successfully employed over a wider range but with more measurements needed to overcome the larger variability.
foreign gas rebreathing; physiological gas rebreathing; direct Fick; thermodilution
Address for reprint requests and other correspondence: J. A. Pawelczyk, 107 Noll Laboratory, Pennsylvania State Univ., Univ. Park, PA 16802 (e-mail: jap18{at}psu.edu )
To study mortality after appendectomy.
The management of patients with suspected appendicitis remains controversial, with advocates of early surgery as well as of expectant management. Mortality is ...not known.
The authors conducted a complete follow-up of deaths within 30 days after all appendectomies in Sweden (population 8.9 million) during the years 1987 to 1996 (n = 117,424) by register linkage. The case fatality rate (CFR) and the standardized mortality ratio (SMR) were analyzed by discharge diagnosis.
The CFR was 2.44 per 1,000 appendectomies. It was strongly related to age (0.31 per 1,000 appendectomies at 0-9 years of age, decreasing to 0.07 at 20-29 years, and reaching 164 among nonagenarians) and diagnosis at surgery (0.8 per 1,000 appendectomies after nonperforated appendicitis, 5.1 after perforated appendicitis, 1.9 after appendectomies for nonsurgical abdominal pain, and 10.0 for those with other diagnoses). The SMR showed a sevenfold excess rate of deaths after appendectomy compared with the general population. The relation to age was less marked (SMR of 44.4 at 0-9 years, decreasing to 2.4 in patients aged 20-29 years. and reaching 8.1 in nonagenarians). The SMR was doubled after perforation compared with nonperforated appendicitis (6.5 and 3.5, respectively). Nonsurgical abdominal pain and other diagnoses were associated with a high excess rate of deaths (9.1 and 14.9, respectively). The most common causes of deaths were appendicitis, ischemic heart diseases and tumors, followed by gastrointestinal diseases.
The CFR after appendectomy is high in elderly patients. The excess rate of death for patients with nonperforated appendicitis and nonsurgical abdominal pain suggests that the deaths may partly be caused by the surgical trauma. Increased diagnostic efforts rather than urgent appendectomy are therefore warranted among frail patients with an equivocal diagnosis of appendicitis.
In recent years, botulism type C has become a serious problem in poultry flocks in Sweden. A real-time PCR assay for Clostridium botulinum (C. botulinum) type C neurotoxin (BoNTC) gene was developed ...as an alternative to the mouse bioassay for detection and identification of C. botulinum type C. The complete method consists of an optimized enrichment protocol followed by automated DNA extraction prior to real-time PCR. The sensitivity of the PCR assay was determined with purified DNA to approximately 50 copies per PCR reaction. The specificity of the PCR assay was evaluated on a panel of about thirty relevant bacteria and on samples of caecum from birds collected in connection with botulism outbreaks on Swedish poultry farms. The PCR assay also covers a previously reported chimeric C/D sequence of the gene. Caecum samples from the outbreaks were positive by real-time PCR. Some of these samples were also examined with a set of conventional PCR methods, to distinguish the gene for the chimeric form from the conserved type C gene. Interestingly, the caecum samples were found to be positive for the chimeric C/D sequence. This is the first study in Europe demonstrating the chimeric C/D sequence. When the toxin gene in two of the samples was sequenced, it was closely identical (99–100%) with several previously reported C/D chimeric sequences. DNA extraction and the real-time PCR assay were both performed in a 96-well format, facilitating for future large-scale detection in outbreak situations and prevalence studies.
The maintenance of pregnancy requires suppression of the maternal immune system which would naturally recognize the developing fetus as an allograft and seek to destroy it by mounting a Th1 regulated ...cytotoxic immune response. During pregnancy a range of soluble factors are produced by the placenta which switch maternal immune regulation towards a protective Th2 phenotype. These factors also influence the developing fetal immune system and all newborns initially have an immunological milieu skewed towards Th2 immunity. Vaccination during the neonatal period must therefore overcome the dual challenge of the inhibitory effect of maternally derived antibody and this natural Th2 regulatory environment. One means of overcoming these obstacles is by the use of adjuvant systems that can redirect the neonatal immune response towards an appropriate Th1 regulated reaction that affords protection from infectious disease. In this overview, experiments are described in which viral antigens incorporated into immune stimulatory complexes (ISCOMs) are able to induce immune responses with balanced Th1 and Th2 regulation in neonatal mice, as evidenced by the nature of the IgG subclass response and cytokine profile, and the induction of cytotoxic lymphocytes. ISCOM adjuvanted vaccines are able to induce similar protective immunity in the newborn of larger animal species including cattle, horses and dogs.
Orthostatic intolerance after spaceflight Buckey, J. C., Jr; Lane, L. D; Levine, B. D ...
Journal of applied physiology (1985),
07/1996, Letnik:
81, Številka:
1
Journal Article
Recenzirano
J. C. Buckey Jr, L. D. Lane, B. D. Levine, D. E. Watenpaugh, S. J. Wright, W. E. Moore, F. A. Gaffney and C. G. Blomqvist
Department of Internal Medicine, University of Texas Southwestern Medical ...Center, Dallas 75235-9034, USA.
Orthostatic intolerance occurs commonly after spaceflight, and important
aspects of the underlying mechanisms remain unclear. We studied 14
individuals supine and standing before and after three space shuttle
missions of 9-14 days. After spaceflight, 9 of the 14 (64%) crew members
could not complete a 10-min stand test that all completed preflight. Pre-
and postflight supine hemodynamics were similar in both groups except for
slightly higher systolic and mean arterial pressures preflight in the
finishers 15 +/- 3.7 and 8 +/- 1.2 (SE) mmHg, respectively; P < 0.05.
Postflight, finishers and nonfinishers had equally large postural
reductions in stroke volume (-47 +/- 3.7 and -48 +/- 3.3 ml, respectively)
and increases in heart rate (35 +/- 6.6 and 51 +/- 5.2 beats/min,
respectively). Cardiac output during standing was also similar (3.6 +/- 0.4
and 4.1 +/- 0.3 l/min, respectively). However, the finishers had a greater
postflight vasoconstrictor response with higher total peripheral resistance
during standing (22.3 +/- 1.2 units preflight and 29.4 +/- 2.3 units
postflight) than did the nonfinishers (20.1 +/- 1.1 units preflight and
19.9 +/- 1.4 units postflight). We conclude that 1) the primary systemic
hemodynamic event, i.e., the postural decrease in stroke volume, was
similar in finishers and nonfinishers and 2) the heart rate response and
cardiac output during standing were not significantly different, but 3) the
postural vasoconstrictor response was significantly greater among the
finishers (P < 0.01).
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