223 research outputs found
Development and Application of a Statistically-Based Quality Control for Crowdsourced Air Temperature Data
In urban areas, dense atmospheric observational networks with high-quality data are still a challenge due to high costs for installation and maintenance over time. Citizen weather stations (CWS) could be one answer to that issue. Since more and more owners of CWS share their measurement data publicly, crowdsourcing, i.e., the automated collection of large amounts of data from an undefined crowd of citizens, opens new pathways for atmospheric research. However, the most critical issue is found to be the quality of data from such networks. In this study, a statistically-based quality control (QC) is developed to identify suspicious air temperature (T) measurements from crowdsourced data sets. The newly developed QC exploits the combined knowledge of the dense network of CWS to statistically identify implausible measurements, independent of external reference data. The evaluation of the QC is performed using data from Netatmo CWS in Toulouse, France, and Berlin, Germany, over a 1-year period (July 2016 to June 2017), comparing the quality-controlled data with data from two networks of reference stations. The new QC efficiently identifies erroneous data due to solar exposition and siting issues, which are common error sources of CWS. Estimation of T is improved when averaging data from a group of stations within a restricted area rather than relying on data of individual CWS. However, a positive deviation in CWS data compared to reference data is identified, particularly for daily minimum T. To illustrate the transferability of the newly developed QC and the applicability of CWS data, a mapping of T is performed over the city of Paris, France, where spatial density of CWS is especially high.DFG, 322579844, Hitzewellen in Berlin, Deutschland - StadtklimamodifkationenBMBF, 01LP1602A, Verbundprojekt Stadtklima: Evaluierung von Stadtklimamodellen (Modul B), 3DO Teilprojekt 1: Dreidimensionales Monitoring atmosphärischer Prozesse in Berli
Depth-2 QAC circuits cannot simulate quantum parity
We show that the quantum parity gate on qubits cannot be cleanly
simulated by a quantum circuit with two layers of arbitrary C-SIGN gates of any
arity and arbitrary 1-qubit unitary gates, regardless of the number of allowed
ancilla qubits. This is the best known and first nontrivial separation between
the parity gate and circuits of this form. The same bounds also apply to the
quantum fanout gate. Our results are incomparable with those of Fang et al.
[3], which apply to any constant depth but require a sublinear number of
ancilla qubits on the simulating circuit.Comment: 21 pages, 2 figure
Occurrence and Coupling of Heat and Ozone Events and Their Relation to Mortality Rates in Berlin, Germany, between 2000 and 2014
Episodes of hot weather and poor air quality pose significant consequences for public health. In this study, these episodes are addressed by applying the observational data of daily air temperature and ozone concentrations in an event-based risk assessment approach in order to detect individual heat and ozone events, as well as events of their co-occurrence in Berlin, Germany, in the years 2000 to 2014. Various threshold values are explored so as to identify these events and to search for the appropriate regressions between the threshold exceedances and mortality rates. The events are further analyzed in terms of their event-specific mortality rates and their temporal occurrences. The results reveal that at least 40% of all heat events during the study period are accompanied by increased ozone concentrations in Berlin, particularly the most intense and longest heat events. While ozone events alone are only weakly associated with increased mortality rates, elevated ozone concentrations during heat events are found to amplify mortality rates. We conclude that elevated air temperatures during heat events are one major driver for increased mortality rates in Berlin, but simultaneously occurring elevated ozone concentrations act as an additional stressor, leading to an increased risk for the regional population.BMBF, 01LP1602, Verbundprojekt Stadtklima: Dreidimensionale Beobachtung atmosphärischer Prozesse in Städten, Modul B - 3D
Interation Between Introduced Rainbow Trout And Three Native Fishes For Food Resources In An Ozark Stream
Contrasting changes of urban heat island intensity during hot weather episodes
Cities typically exhibit higher air temperatures than their rural surroundings, a phenomenon known as the urban heat island (UHI) effect. Contrasting results are reported as to whether UHI intensity (UHII) is exacerbated or reduced during hot weather episodes (HWEs). This contrast is investigated for a four-year period from 2015 to 2018, utilising a set of observational data from high-quality meteorological stations, as well as from hundreds of crowdsourced citizen weather stations, located in the urban region of Berlin, Germany. It can be shown that if HWEs, defined here as the ten percent hottest days or nights during May–September, are identified via daytime conditions, or by night-time conditions at inner-city sites, then night-time UHII is exacerbated. However, if HWEs are identified via night-time conditions at rural sites, then night-time UHII is reduced. These differences in UHII change can be linked with prevalent weather conditions, namely radiation, cloud cover, wind speed, precipitation, and humidity. This highlights that, beside land cover changes, future changes in weather conditions due to climate change will control UHIIs, and thus heat-stress hazards in cities.BMBF, 01LP1602C , Verbundprojekt Stadtklima: Dreidimensionale Beobachtung atmosphärischer Prozesse in Städten, Modul B - 3DODFG, 322579844, Hitzewellen in Berlin, Deutschland - StadtklimamodifkationenDFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität Berli
Using the dendro-climatological signal of urban trees as a measure of urbanization and urban heat island
Using dendroclimatological techniques this study investigates whether inner city tree-ring width (TRW) chronologies from eight tree species (ash, beech, fir, larch, lime, sessile and pedunculate oak, and pine) are suitable to examine the urban heat island of Berlin, Germany. Climate-growth relationships were analyzed for 18 sites along a gradient of increasing urbanization covering Berlin and surrounding rural areas. As a proxy for defining urban heat island intensities at each site, we applied urbanization parameters such as building fraction, impervious surfaces, and green areas. The response of TRW to monthly and seasonal air temperature, precipitation, aridity, and daily air-temperature ranges were used to identify climate-growth relationships. Trees from urban sites were found to be more sensitive to climate compared to trees in the surrounding hinterland. Ring width of the deciduous species, especially ash, beech, and oak, showed a high sensitivity to summer heat and drought at urban locations (summer signal), whereas conifer species were found suitable for the analysis of the urban heat island in late winter and early spring (winter signal).
The summer and winter signals were strongest in tree-ring chronologies when the urban heat island intensities were based on an area of about 200 m to 3000 m centered over the tree locations, and thus reflect the urban climate at the scale of city quarters. For the summer signal, the sensitivity of deciduous tree species to climate increased with urbanity.
These results indicate that urban trees can be used for climate response analyses and open new pathways to trace the evolution of urban climate change and more specifically the urban heat island, both in time and space
Self-report of difficult defecation is associated with overactive bladder symptoms
Aims The association of dysfunctional bowel elimination with lower urinary tract symptoms is well known in children, but not in adults. It was our objective to assess lower urinary tract symptoms (LUTS) in women who report difficult defecation (DD). Methods This is a secondary analysis of 2,812 women, aged 35–64, who participated in a telephone interview. All subjects were asked “When you move your bowels, does the stool come out easily?” DD was considered present in those answering “no.” All subjects were queried regarding LUTS, urinary infections in the past year, self-perceived health status, medical history, and demographics. Symptoms of stress incontinence (five items), urge incontinence (five items), and the impact of these symptoms on their quality of life were solicited from subjects reporting more than 12 episodes of incontinence in 1 year. Results DD was reported by 10.4% (290/2,790) of women. Women with DD had higher LUTS than those who did not: nocturia (mean 1.8 ± 0.1 vs. 1.3 ± 0.0), urgency (47.6% vs. 29.2%), increased daytime frequency (mean 8.2 ± 0.3 vs. 7.2 ± 0.1), dysuria (22.9% vs. 13.7%), and a sensation of incomplete bladder emptying (55.6% vs. 28.2%). DD women were more often menopausal, reported a fair or poor self-reported health status, and had a higher number of comorbidities, less formal education, and lower annual household income. Conclusions Women with symptoms of DD have an increased rate of LUTS, consistent with the diagnosis of overactive bladder without incontinence. The pathophysiology underlying this association is worthy of future research. Neurourol. Urodynam. 29:1290–1294, 2010. © 2009 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78056/1/20839_ftp.pd
Evidence of horizontal urban heat advection in London using 6 years of data from a citizen weather station network
Recent advances in citizen weather station (CWS) networks, with data accessible via crowd-sourcing, provide relevant climatic information to urban scientists and decision makers. In particular, CWS can provide long-term measurements of urban heat and valuable information on spatio-temporal heterogeneity related to horizontal heat advection. In this study, we make the first compilation of a quasi-climatologic dataset covering six years (2015–2020) of hourly near-surface air temperature measurements obtained via 1560 suitable CWS in a domain covering south-east England and Greater London. We investigated the spatio-temporal distribution of urban heat and the influences of local environments on climate, captured by CWS through the scope of Local Climate Zones (LCZ)—a land-use land-cover classification specifically designed for urban climate studies. We further calculate, for the first time, the amount of advected heat captured by CWS located in Greater London and the wider south east England region. We find that London is on average warmer by about 1.0 ∘C–1.5 ∘C than the rest of south-east England. Characteristics of the southern coastal climate are also captured in the analysis. We find that on average, urban heat advection (UHA) contributes to 0.22 ± 0.96 ∘C of the total urban heat in Greater London. Certain areas, mostly in the centre of London are deprived of urban heat through advection since heat is transferred more to downwind suburban areas. UHA can positively contribute to urban heat by up to 1.57 ∘C, on average and negatively by down to −1.21 ∘C. Our results also show an important degree of inter- and intra-LCZ variability in UHA, calling for more research in the future. Nevertheless, we already find that UHA can impact green areas and reduce their cooling benefit. Such outcomes show the added value of CWS when considering future urban design
Vaginal support as determined by levator ani defect status 6 weeks after primary surgery for pelvic organ prolapse
ObjectiveTo evaluate whether major levator ani muscle defects were associated with differences in postoperative vaginal support after primary surgery for pelvic organ prolapse (POP).MethodsA retrospective chart review of a subgroup of patients in the Organ Prolapse and Levator (OPAL) study. Of the 247 women recruited into OPAL, 107 underwent surgery for prolapse and were the cohort for the present analysis. Major levator ani defects were diagnosed when more than 50% of the pubovisceral muscle was missing on MRI. Postoperative vaginal support was assessed via POPâ quantification system. Postoperative anatomic outcome was analyzed according to levator ani defect status, as determined by MRI.ResultsSupport of the anterior vaginal wall 2 cm above the hymen occurred among 62% of women with normal levator ani muscles/minor defects and 35% of those with major defects. Support of the anterior wall 1 cm above the hymen occurred among 32% women with normal muscles /minor defects and 59% of those with major defects. Levator ani defects were not associated with differences in postoperative apical/posterior vaginal support.ConclusionSix weeks after primary surgery for prolapse, women with normal levator ani muscles/minor defects had better anterior vaginal support than those with major levator defects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135557/1/ijgo141.pd
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