In this paper, we present the implementation and evaluation of the
aerosol microphysics module SALSA2.0 in the framework of the
aerosol–chemistry–climate model ECHAM-HAMMOZ. It is an alternative
...microphysics module to the default modal microphysics scheme M7 in
ECHAM-HAMMOZ. The SALSA2.0 implementation within ECHAM-HAMMOZ is evaluated
against observations of aerosol optical properties, aerosol mass, and size
distributions, comparing also to the skill of the M7 implementation. The
largest differences between the implementation of SALSA2.0 and M7 are in the
methods used for calculating microphysical processes, i.e., nucleation,
condensation, coagulation, and hydration. These differences in the
microphysics are reflected in the results so that the largest differences
between SALSA2.0 and M7 are evident over regions where the aerosol size
distribution is heavily modified by the microphysical processing of aerosol
particles. Such regions are, for example, highly polluted regions and regions
strongly affected by biomass burning. In addition, in a simulation of the
1991 Mt. Pinatubo eruption in which a stratospheric sulfate plume was formed,
the global burden and the effective radii of the stratospheric aerosol are
very different in SALSA2.0 and M7. While SALSA2.0 was able to reproduce the
observed time evolution of the global burden of sulfate and the effective
radii of stratospheric aerosol, M7 strongly overestimates the removal of
coarse stratospheric particles and thus underestimates the effective radius
of stratospheric aerosol. As the mode widths of M7 have been optimized for
the troposphere and were not designed to represent stratospheric aerosol, the
ability of M7 to simulate the volcano plume was improved by modifying the
mode widths, decreasing the standard deviations of the accumulation and coarse
modes from 1.59 and 2.0, respectively, to 1.2 similar to what was observed
after the Mt. Pinatubo eruption. Overall, SALSA2.0 shows promise in improving
the aerosol description of ECHAM-HAMMOZ and can be further improved by
implementing methods for aerosol processes that are more suitable for the
sectional method, e.g., size-dependent emissions for aerosol species and size-resolved wet deposition.
Abstract
Biomass burning (BB) is a major source of aerosols that remain the most uncertain components of the global radiative forcing. Current global models have great difficulty matching observed ...aerosol optical depth (AOD) over BB regions. A common solution to address modelled AOD biases is scaling BB emissions. Using the relationship from an ensemble of aerosol models and satellite observations, we show that the bias in aerosol modelling results primarily from incorrect lifetimes and underestimated mass extinction coefficients. In turn, these biases seem to be related to incorrect precipitation and underestimated particle sizes. We further show that boosting BB emissions to correct AOD biases over the source region causes an overestimation of AOD in the outflow from Africa by 48%, leading to a double warming effect compared with when biases are simultaneously addressed for both aforementioned factors. Such deviations are particularly concerning in a warming future with increasing emissions from fires.
Winter quiescence in fishes is not uncommon, however understanding the mechanisms that cause dormancy are poorly understood. This study highlights the physiological stress temperature places on ...locomotor musculature and its consequences on whole organism locomotion. Cunner and tautog experience temperatures ranging from 0 to 25 °C and enter dormancy at ~10 °C. We aimed to address the question: how do winter temperatures affect steady swimming and muscle contraction kinetics in cunner? Fishes were collected and housed at 5, 10, 15, or 20 °C. Gait transition speed and fin beat frequency were measured at each acclimation temperature. Twitch and tetanus kinetics were recorded from the aerobic locomotor muscle, which is responsible for the power stroke during swimming. Fish acclimated to colder temperatures (5, 10 °C) demonstrated lower gait transition speeds than the warm temperature treatments. Similarly, twitch kinetics were slower in muscle acclimated at ≤10 °C. Locomotor muscle from tautog was significantly slower to contract and relax than cunner when tested at 5 and 10 °C. These results suggest that muscle acclimation differs in these closely related labrids from the same habitat. Additionally, these results suggest that cunner locomotor musculature can maintain greater performance at a wider range of temperatures. Cunner occupy more northern latitudes which likely allows for greater performance shifts in response to temperature. However, when temperatures get cold enough muscle function is reduced, perhaps contributing to their overwintering ecology.
Aim:
To report on prevalence of cerebral palsy (CP), severity rates, and types of brain lesions in children born preterm 2004 to 2010 by gestational age groups.
Methods:
Data from 12 population-based ...registries of the Surveillance of Cerebral Palsy in Europe network were used. Children with CP were eligible if they were born preterm (<37 weeks of gestational age) between 2004 and 2010, and were at least 4 years at time of registration. Severity was assessed using the impairment index. The findings of postnatal brain imaging were classified according to the predominant pathogenic pattern. Prevalences were estimated per 1,000 live births with exact 95% confidence intervals within each stratum of gestational age: ≤27, 28–31, 32–36 weeks. Time trends of both overall prevalence and prevalence of severe CP were investigated using multilevel negative binomial regression models.
Results:
The sample comprised 2,273 children. 25.8% were born from multiple pregnancies. About 2-thirds had a bilateral spastic CP. 43.5% of children born ≤27 weeks had a high impairment index compared to 37.0 and 38.5% in the two other groups. Overall prevalence significantly decreased (incidence rate ratio per year: 0.96 0.92–1.00) in children born 32–36 weeks. We showed a decrease until 2009 for children born 28–31 weeks but an increase in 2010 again, and a steady prevalence (incidence rate ratio per year = 0.97 0.92–1.02 for those born ≤27 weeks. The prevalence of the most severely affected children with CP revealed a similar but not significant trend to the overall prevalence in the corresponding GA groups. Predominant white matter injuries were more frequent in children born <32 weeks: 81.5% (≤27 weeks) and 86.4% (28–31 weeks), compared to 63.6% for children born 32–36 weeks.
Conclusion:
Prevalence of CP in preterm born children continues to decrease in Europe excepting the extremely immature children, with the most severely affected children showing a similar trend.
Pharmacotherapy of Insomnia Neubauer, David N; Pandi-Perumal, Seithikurippu R; Spence, David Warren ...
Journal of Central Nervous System Disease,
2018, Letnik:
10
Book Review, Journal Article
Recenzirano
Odprti dostop
Insomnia remains a common clinical concern that is associated with negative daytime consequences for patients and represents a significant public health problem for our society. Although a variety of ...therapies may be employed to treat insomnia, the use of medications has been a dominant approach. Regulatory agencies have now classified insomnia medications into 4 distinct pharmacodynamics classes. Medications with indications approved for insomnia treatment include benzodiazepine receptor agonists, a melatonin receptor agonist, a selective histamine receptor antagonist, and a dual orexin/hypocretin receptor antagonist. Both pharmacodynamic and pharmacokinetic advances with hypnotic medications in recent years have expanded the pharmacopoeia to allow personalized treatment approaches for different patient populations and individual sleep disturbance patterns.
Abstract
Cirrus clouds are key modulators of Earth’s climate. Their dependencies on meteorological and aerosol conditions are among the largest uncertainties in global climate models. This work uses ...3 years of satellite and reanalysis data to study the link between cirrus drivers and cloud properties. We use a gradient-boosted machine learning model and a long short-term memory network with an attention layer to predict the ice water content and ice crystal number concentration. The models show that meteorological and aerosol conditions can predict cirrus properties with
R
2
= 0.49. Feature attributions are calculated with SHapley Additive exPlanations to quantify the link between meteorological and aerosol conditions and cirrus properties. For instance, the minimum concentration of supermicron-sized dust particles required to cause a decrease in ice crystal number concentration predictions is 2 × 10
−4
mg/m
3
. The last 15 hr before the observation predict all cirrus properties.
Neurotoxicity due to acute prenatal exposure to high-dose of mercury (Hg) is well documented. However, the effect of prenatal exposure to low Hg levels on child neurodevelopment and the question ...about “safety” of fish-eating during pregnancy remain controversial. International comparisons of Hg concentrations in mother-child biological samples and neurodevelopmental scores embedded in birth cohort studies may provide useful evidence to explore this issue.
The Mediterranean (Italy, Slovenia, Croatia, and Greece) cohort study included 1308 mother-child pairs enrolled in the Public Health Impact of long-term, low-level, Mixed Element exposure in a susceptible population EU Sixth Framework Programme (PHIME). Maternal hair and venous blood, cord blood and breast milk samples were collected, and total Hg (THg) levels were measured. Demographic and socioeconomic information, lifestyles and nutritional habits were collected through questionnaires at different phases of follow-up. Children at 18 months of age underwent neurodevelopmental testing using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Multivariate linear and logistic regressions were performed, for each country, to assess the association between THg and BSID-III scores, obtaining adjusted β coefficients and odds ratios (ORs). These values were used to conduct a meta-analysis, to explore possible heterogeneity among countries and to obtain combined estimates of the association between THg exposure and BSID-III scores.
Median THg (ng/g) was: 704 in maternal hair, 2.4 in maternal blood, 3.6 in cord blood, and 0.6 in breast milk. THg concentrations were highest in Greece and lowest in Slovenia. BSID-III neurodevelopmental scores were higher in Croatia and Slovenia. The meta-analysis of multivariate linear models found an overall positive association between language composite score and receptive communication scaled score and increasing THg in maternal hair (n = 1086; β = 0.55; 95%CI: 0.05–1.05 and n = 1075; β = 0.12; 95%CI: 0.02–0.22, respectively). The meta-analysis of logistic regression models showed that the overall adjusted OR between THg in cord blood and suboptimal gross motor score was borderline significant (n = 882; OR = 1.03; 95%CI: 1.00–1.07). Heterogeneity was found across the four sub-cohorts for language composite score in maternal blood, and for fine motor scaled score in cord blood and breast milk. Language composite score and THg concentrations in maternal venous blood were positively related (n = 58; β = 4.29; CI95% (−0.02, 8.60)) in Croatia and an increase of 1 ng/g of THg in maternal venous blood was associated with a reduced risk for children to fall in the lowest quintile of language score by 31% (n = 58; OR = 0.69; CI 95%: 0.37, 1.01). The comparison of β coefficients obtained by multiple linear regression model showed an inverse association between fine motor score and THg concentrations in cord blood for Croatia (n = 54; β = −0.53; CI 95%: −1.10, 0.04) and Slovenia (n = 225; β = −0.25; CI 95%: −0.49, −0.01). In Slovenia THg level in breast milk was associated with suboptimal fine motor performance (n = 195; OR = 5.25; CI 95%: 1.36, 21.10).
This study showed an inverse relation between THg levels and developmental motor scores at 18 months, although the evidence was weak and partially internally and externally inconsistent. No evidence of detrimental effects of THg was found for cognitive and language outcomes at these concentrations and age.
Characterization of the exposome, the totality of all environmental factors that one is exposed to from conception onwards, has been recommended to better evaluate the role of environmental ...influences on developmental programming and life-course vulnerability to major chronic diseases. In the framework of the Health and Environment-wide Associations based on Large population Surveys (HEALS) project we considered the pregnancy exposome exploiting two databases (PHIME and REPRO_PL) that include birth cohorts from three EU countries (Croatia, Slovenia and Poland). The databases contained information on several chemical exposures, socio-demographic, lifestyle and health related factors from conception to child birth, and neuropsychological scores assessed by the Bayley Scales of Infant and Toddler Development in the first two years of life. Our main goal was to assess consistency of environmental influences on neurodevelopment, if any, across European countries differing for geographical, socio-demographic characteristics and levels of chemical exposures to metals such as lead (Pb), mercury (Hg), cadmium (Cd) and trace elements, including micronutrients such as zinc (Zn) and selenium (Se). To this aim, we first selected variables common to the different databases, then applied univariate and multivariate regression analyses to identify factors linked to neurodevelopment, and finally performed meta-analysis to detect potential heterogeneity among cohorts and pooled estimates. Significant differences in exposure levels among the three sub-cohorts were observed as for Hg and Se; exposure levels under study were relatively low and within the range described in existing EU biomonitoring studies. The univariate analyses did not show any common pattern of association as only in the Polish cohort chemical exposure had an impact on neuropsychological outcome. In the meta-analysis, some consistent trends were evident, relative to the adverse influence of Pb on children's language and cognition and the positive influence of Se on language abilities. The effects of the neurotoxic metal Hg positively influenced the motor scores in the Polish cohorts, while it decreased the motor scores in the Slovenia and Croatian sub-cohorts. The only socio-demographic factor consistently associated to the outcome among cohorts was child's sex, with females performing better than males on cognitive and language scores. These findings point to the need of harmonizing existing cohorts or creating prospective study designs that facilitate comparisons in the exposome over time, places and kind of environmental exposures.
•The exposome paradigm allows to evaluate the impact of multiple exposures on child neurodevelopment.•Statistical methods are needed to cope with heterogeneity in levels of exposure and outcome among different study populations.•Our results support complexity of early life exposome and identify both heterogeneous and consistent effects across cohorts.
Chronic Insomnia Disorder Avidan, Alon Y; Neubauer, David N
Continuum,
08/2017, Letnik:
23, Številka:
4, Sleep Neurology
Journal Article
Odprti dostop
Neurologists, along with all health care providers, commonly encounter patients with insomnia, which is a condition that impacts patients' underlying neurologic conditions in a bidirectional manner. ...While chronic insomnia is one of the most common sleep disturbances, only a small proportion of individuals with this condition discuss their sleep problems with their providers. When insomnia is described, it is more often in relationship to another medical problem, as opposed to an independent condition. In neurology practice, multiple factors including pain, movement disorders, sleep apnea, and medications that act on the central nervous system often contribute to insomnia. An all-inclusive approach is necessary when evaluating sleep problems in patients with insomnia.
The US Food and Drug Administration (FDA) has approved several medications for the treatment of insomnia that target specific receptor systems in the brain and incorporate several unique pharmacodynamic and pharmacokinetic profiles that can represent customized therapy for specific insomnia phenotypes. FDA-approved medications for insomnia include γ-aminobutyric acid (GABA)-modulating benzodiazepine receptor agonists, a melatonin receptor agonist, a histamine receptor antagonist, and the newest approved option, a hypocretin (orexin) receptor antagonist.
This article provides an evidence-based multidisciplinary approach to the treatment of insomnia, highlighting the rationale and utility of cognitive-behavioral therapy and pharmacologic interventions. Neurologists should be proactive in assessing the impact of underlying comorbidities on insomnia, particularly in the setting of psychiatric conditions such as depression, sleep disorders such as circadian rhythm disorders, and medical problems such as nocturia.
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