1,180 research outputs found
Interactions between Economic Growth and Environmental Quality in Shenzhen, China's First Special Economic Zone
The relationship between economic development and environmental quality is a debated topic. Environmental Kuznets Curve (EKC) is one prominent hypothesis, positing an inverted U-shaped development-environment relationship. Here we test this hypothesis using data from Shenzhen, Peoples Republic of China. Established in 1980 as the first special economic zone in China, Shenzhen has developed from a small village into a large urban-industrial agglomeration with the highest income level in the country. The enormous expansion of infrastructure, industrial sites and urban settlements has profoundly changed the local environment. We utilize environmental monitoring data from Shenzhen on concentration of pollutants in ambient air, main rivers, and near shore waters from 1989 to 2003. The results show that production-induced pollutants support EKC while consumption-induced pollutants do not support it
Existence of axially symmetric static solutions of the Einstein-Vlasov system
We prove the existence of static, asymptotically flat non-vacuum spacetimes
with axial symmetry where the matter is modeled as a collisionless gas. The
axially symmetric solutions of the resulting Einstein-Vlasov system are
obtained via the implicit function theorem by perturbing off a suitable
spherically symmetric steady state of the Vlasov-Poisson system.Comment: 32 page
A Comparison of Machine Learning Algorithms for the Surveillance of Autism Spectrum Disorder
The Centers for Disease Control and Prevention (CDC) coordinates a
labor-intensive process to measure the prevalence of autism spectrum disorder
(ASD) among children in the United States. Random forests methods have shown
promise in speeding up this process, but they lag behind human classification
accuracy by about 5%. We explore whether more recently available document
classification algorithms can close this gap. We applied 8 supervised learning
algorithms to predict whether children meet the case definition for ASD based
solely on the words in their evaluations. We compared the algorithms'
performance across 10 random train-test splits of the data, using
classification accuracy, F1 score, and number of positive calls to evaluate
their potential use for surveillance. Across the 10 train-test cycles, the
random forest and support vector machine with Naive Bayes features (NB-SVM)
each achieved slightly more than 87% mean accuracy. The NB-SVM produced
significantly more false negatives than false positives (P = 0.027), but the
random forest did not, making its prevalence estimates very close to the true
prevalence in the data. The best-performing neural network performed similarly
to the random forest on both measures. The random forest performed as well as
more recently available models like the NB-SVM and the neural network, and it
also produced good prevalence estimates. NB-SVM may not be a good candidate for
use in a fully-automated surveillance workflow due to increased false
negatives. More sophisticated algorithms, like hierarchical convolutional
neural networks, may not be feasible to train due to characteristics of the
data. Current algorithms might perform better if the data are abstracted and
processed differently and if they take into account information about the
children in addition to their evaluations
User quality of experience of mulsemedia applications
User Quality of Experience (QoE) is of fundamental importance in multimedia applications and has been extensively studied for decades. However, user QoE in the context of the emerging multiple-sensorial media (mulsemedia) services, which involve different media components than the traditional multimedia applications, have not been comprehensively studied. This article presents the results of subjective tests which have investigated user perception of mulsemedia content. In particular, the impact of intensity of certain mulsemedia components including haptic and airflow on user-perceived experience are studied. Results demonstrate that by making use of mulsemedia the overall user enjoyment levels increased by up to 77%
A Characterisation of the Weylian Structure of Space-Time by Means of Low Velocity Tests
The compatibility axiom in Ehlers, Pirani and Schild's (EPS) constructive
axiomatics of the space-time geometry that uses light rays and freely falling
particles with high velocity, is replaced by several constructions with low
velocity particles only. For that purpose we describe in a space-time with a
conformal structure and an arbitrary path structure the radial acceleration, a
Coriolis acceleration and the zig-zag construction. Each of these quantities
give effects whose requirement to vanish can be taken as alternative version of
the compatibility axiom of EPS. The procedural advantage lies in the fact, that
one can make null-experiments and that one only needs low velocity particles to
test the compatibility axiom. We show in addition that Perlick's standard clock
can exist in a Weyl space only.Comment: to appear in Gen.Rel.Gra
Socioeconomic status, alcohol use disorders, and depression: A population-based study.
Depressive disorders (DD) and alcohol use disorders (AUD) frequently co-occur. They are key to understanding the current increases in "deaths of despair" among individuals with lower socioeconomic status (SES). The aim of this study was to assess the prospective bidirectional associations between AUD and DD, as well as the effect of SES on these two conditions.
The National Epidemiologic Survey on Alcohol and Related Conditions is a cohort study representative of the US adult population, which began in 2001-2002, with follow-up interviews conducted 3 years later. SES was primarily operationalized as educational attainment. AUD, DD, and their levels of severity were defined according to the DSM-5 criteria.
The risk of developing an incident DD increased gradually with the recency and the severity of AUD at baseline, but the converse was not observed. Lower SES was an independent risk for incident AUD or DD. SES did not modify the prospective association between AUD and DD.
The absence of interaction between SES and moderate or severe AUD for the incident DD must be considered with caution due to the limited number of DD cases reported in these AUD categories.
This result is consistent with a causal relationship between AUD and DD, and suggests that therapeutic interventions for AUD may also have beneficial effects to lower DD rates. The independent effects of a lower SES and AUD on DD may result in a vulnerable population cumulating disorders with heavy consequences on health and social well-being
Empirically modelled Pc3 activity based on solar wind parameters
It is known that under certain solar wind (SW)/interplanetary magnetic field (IMF) conditions (e.g. high SW speed, low cone angle) the occurrence of ground-level Pc3–4 pulsations is more likely. In this paper we demonstrate that in the event of anomalously low SW particle density, Pc3 activity is extremely low regardless of otherwise favourable SW speed and cone angle. We re-investigate the SW control of Pc3 pulsation activity through a statistical analysis and two empirical models with emphasis on the influence of SW density on Pc3 activity. We utilise SW and IMF measurements from the OMNI project and ground-based magnetometer measurements from the MM100 array to relate SW and IMF measurements to the occurrence of Pc3 activity. Multiple linear regression and artificial neural network models are used in iterative processes in order to identify sets of SW-based input parameters, which optimally reproduce a set of Pc3 activity data. The inclusion of SW density in the parameter set significantly improves the models. Not only the density itself, but other density related parameters, such as the dynamic pressure of the SW, or the standoff distance of the magnetopause work equally well in the model. The disappearance of Pc3s during low-density events can have at least four reasons according to the existing upstream wave theory: 1. Pausing the ion-cyclotron resonance that generates the upstream ultra low frequency waves in the absence of protons, 2. Weakening of the bow shock that implies less efficient reflection, 3. The SW becomes sub-Alfvénic and hence it is not able to sweep back the waves propagating upstream with the Alfvén-speed, and 4. The increase of the standoff distance of the magnetopause (and of the bow shock). Although the models cannot account for the lack of Pc3s during intervals when the SW density is extremely low, the resulting sets of optimal model inputs support the generation of mid latitude Pc3 activity predominantly through upstream waves
Empirically modelled Pc3 activity based on solar wind parameters
It is known that under certain solar wind (SW)/interplanetary magnetic
field (IMF) conditions (e.g. high SW speed, low cone angle) the occurrence of
ground-level Pc3–4 pulsations is more likely. In this paper we demonstrate
that in the event of anomalously low SW particle density, Pc3 activity is
extremely low regardless of otherwise favourable SW speed and cone angle. We
re-investigate the SW control of Pc3 pulsation activity through a statistical
analysis and two empirical models with emphasis on the influence of SW
density on Pc3 activity. We utilise SW and IMF measurements from the OMNI
project and ground-based magnetometer measurements from the MM100 array to
relate SW and IMF measurements to the occurrence of Pc3 activity. Multiple
linear regression and artificial neural network models are used in iterative
processes in order to identify sets of SW-based input parameters, which
optimally reproduce a set of Pc3 activity data. The inclusion of SW density
in the parameter set significantly improves the models. Not only the density
itself, but other density related parameters, such as the dynamic pressure of
the SW, or the standoff distance of the magnetopause work equally well in the
model. The disappearance of Pc3s during low-density events can have at least
four reasons according to the existing upstream wave theory: 1. Pausing the
ion-cyclotron resonance that generates the upstream ultra low frequency waves
in the absence of protons, 2. Weakening of the bow shock that implies less
efficient reflection, 3. The SW becomes sub-Alfvénic and hence it is not
able to sweep back the waves propagating upstream with the Alfvén-speed,
and 4. The increase of the standoff distance of the magnetopause (and of the
bow shock). Although the models cannot account for the lack of Pc3s during
intervals when the SW density is extremely low, the resulting sets of optimal
model inputs support the generation of mid latitude Pc3 activity
predominantly through upstream waves
Additional polymorphisms at marker loci D9S5 and D9S15 generate extended haplotypes in linkage disequilibrium with Friedreich ataxia.
- …