170 research outputs found
Integrated Product and Process Development Using Case Studies: A Challenge to the Education of Science and Engineering Undergraduates
The education in integrated product and process development is a challenge for teachers, teaching assistants, as well as for students. At the Swiss Federal Institute of Technology, a new course in 'Safety and Environmental Protection Chemistry' has been established. To practise and
exercise the tools introduced in the lecture, four different case studies of chemical products and processes have been developed in collaboration with the chemical industry. The subjects of the case studies are the insecticide Pymetrozine, the reactive dye Cibachron-LS, the red pigment DPP,
and Perchloroethylene for dry cleaning. Various teams formed out of students from chemical engineering, chemistry, and environmental science work on topics like process safety, product safety, product risk assessment, and social responsibilities of manufactures. Different resource materials
and guidance by a teaching assistant were provided. Finally, the students presented their results to industrial experts and received at the same time valuable feedback about the industrial approach to such problems. The application of the tools for integrated product and process development
to actual case studies widened the students' scope of safety and environmental protection in a new proactive direction by a risk-oriented design of chemical technology
A broadband FFT spectrometer for radio and millimeter astronomy
The core architecture, tests in the lab and first results of a Fast Fourier
Transform (FFT) spectrometer are described. It is based on a commercially
available fast digital sampler (AC240) with an on-board Field Programmable Gate
Array (FPGA). The spectrometer works continuously and has a remarkable total
bandwidth of 1 GHz, resolved into 16384 channels. The data is sampled with 8
bits, yielding a dynamic range of 48 dB. An Allan time of more than 2000 s and
an SFDR of 37 dB were measured. First light observations with the KOSMA
telescope show a perfect spectrum without internal or external spurious
signals.Comment: Astronomy and Astrophysics, in pres
Cross-reactivity among iodinated contrast agents: should we be concerned?
Background
Although several papers deal with "cross-reactivity" in patients with iodinated contrast medium (ICM) hypersensitivity reactions (HSRs), there is no in-depth knowledge of this phenomenon. To define ICM-groups as potential reaction partners and to identify any potential clinical relevance in patients with ICM-HSRs.
Methods
The literature database PubMed was searched for eligible papers dealing with ICM-allergy and "cross-reactivity". The data presented by the papers was analyzed and individual patient data was extracted for re-evaluation based on a definition for both 'polyvalent reactivity' and 'cross-reactivity' as well as for chemical structure-dependent ICM-groups.
Results
Twenty-five original papers (with n=340 extracted patients) formed the study population. Incidences of polyvalent reactivity were non-significantly higher than incidences of cross-reactivity (both range from 0% to 100%). Crossover evaluation in reaction pairings (culprit ICM A with ICM B versus culprit ICM B with ICM A) showed concordance of only 30%. Data support rather non-cross-reactivity (individual reaction pattern) than cross-reactivity constellations.
Conclusions
The obtained results favour an individual reaction pattern, rather than a reactivity driven by chemical structures and so-called cross-reactivity
Are better communicators better readers? : an exploration of the connections between narrative language and reading comprehension
The association between receptive language skills and reading comprehension has been established in the research literature. Even when the importance of receptive skills for reading comprehension has been strongly supported, in practice lower levels of skills tend to go unnoticed in typically developing children. A potentially more visible modality of language, expressive skills using speech samples, has been rarely examined despite the longitudinal links between speech and later reading development, and the connections between language and reading impairments. Even fewer reading studies have examined expressive skills using a subgroup of speech samples â narrative samples â which are closer to the kind of language practitioners can observe in their classrooms, and are also a rich source of linguistic and discourse-level data in school-aged children. This thesis presents a study examining the relationship between expressive language skills in narrative samples and reading comprehension after the first two years of formal reading instruction, with considerable attention given to methodological and developmental issues. In order to address the main methodological issues surrounding the identification of the optimal linguistic indices in terms of reliability and the existence of developmental patterns, two studies of language development in oral narratives were carried out. The first of the narrative language studies drew data from an existing corpus, while the other analysed primary data, collected specifically for this purpose. Having identified the optimal narrative indices in two different samples, the main study examined the relationships between these expressive narrative measures along with receptive standardised measures, and reading comprehension in a monolingual sample of eighty 7- and 8-year-old children attending Year 3 in the UK. Both receptive and expressive oral language skills were assessed at three different levels: vocabulary, grammar and discourse. Regression analyses indicated that, when considering expressive narrative variables on their own, expressive grammar and vocabulary, in that order, contributed to explain over a fifth of reading comprehension variance in typically developing children. When controlling for receptive language however, expressive skills were not able to account for significant unique variance in the outcome measure. Nonetheless, mediation analyses revealed that receptive vocabulary and grammar played a mediating role in the relationship between expressive skills from narratives and reading comprehension. Results and further research directions are discussed in the context of this studyâs methodological considerations.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Young Measures Generated by Ideal Incompressible Fluid Flows
In their seminal paper "Oscillations and concentrations in weak solutions of
the incompressible fluid equations", R. DiPerna and A. Majda introduced the
notion of measure-valued solution for the incompressible Euler equations in
order to capture complex phenomena present in limits of approximate solutions,
such as persistence of oscillation and development of concentrations.
Furthermore, they gave several explicit examples exhibiting such phenomena. In
this paper we show that any measure-valued solution can be generated by a
sequence of exact weak solutions. In particular this gives rise to a very
large, arguably too large, set of weak solutions of the incompressible Euler
equations.Comment: 35 pages. Final revised version. To appear in Arch. Ration. Mech.
Ana
Fatal subarachnoid hemorrhage following ischemia in vertebrobasilar dolichoectasia.
Vertebrobasilar dolichoectasia (VBD) is a chronic disorder with various cerebrovascular and compressive manifestations, involving subarachnoid hemorrhage (SAH). Occurrence of SAH shortly after worsening of clinical VBD symptoms has occasionally been reported. The goal of the study was to examine this association, in particular its pathophysiology, clinical precursor signs, time course, and outcome.To this end, in a retrospective multicenter study, we analyzed 20 patients with VBD and SAH in regard to preceding clinical symptoms, presence of vertebrobasilar thrombosis and ischemia, outcome and neuropathological correlates.Median age of the 7 female and 13 male patients was 70 years (interquartile range [IQR] 18.3 years). Fourteen patients (70%) presented with new or acutely worsening posterior fossa signs at a median of 3 days prior to SAH (IQR 2, range 0.5-14). A thrombus within the VBD was detected in 12 patients (60%). Thrombus formation was associated with clinical deterioration (Ï = 4.38, P = 0.04) and ponto-cerebellar ischemia (Ï = 8.09, P = 0.005). During follow-up after SAH, 13 patients (65%) died, after a median survival time of 24âhours (IQR 66.2, range 2-264âhours), with a significant association between proven ponto-cerebellar ischemia and case fatality (Ï = 6.24, P = 0.01).The data establish an association between clinical deterioration in patients with VBD, vertebrobasilar ischemia, and subsequent SAH. Antithrombotic treatment after deterioration appears controversial and SAH outcome is frequently fatal. Our data also indicate a short window of 3 days that may allow for evaluating interventional treatment, preferably within randomized trials
Urban source term estimation for mercury using a boundary-layer budget method
Mercury is a heavy metal of particular concern due to its adverse effects on
human health and the environment. Recognizing this problem, the UN
Minamata Convention on Mercury was recently adopted, where signatory
countries agreed to reduce anthropogenic mercury emissions. To evaluate the
effectiveness of the convention, quantitative knowledge on mercury emissions
is crucial. So far, bottom-up approaches have successfully been applied to
quantify mercury emission â especially for point sources. Distributed
sources make up a large share of the emission; however, they are still
poorly characterized. Here, we present a top-down approach to estimate
mercury emissions based on atmospheric measurements in the city of Zurich,
Switzerland. While monitoring the atmospheric mercury concentrations during
inversion periods in Zurich, we were able to relate the concentration
increase to the mercury emission strength of the city using a box model. By
means of this boundary-layer budget approach, we succeeded in narrowing down
the emissions of Zurich to range between 41±8 kg aâ1 (upper bound) and 24±8 kg aâ1 (lower bound). Thereby, we could quantify emissions from
mixed, diffuse and point-like sources and derive an annual mercury per capita
emission of 0.06 to 0.10 g aâ1. The approach presented here has the
potential to support authorities in setting up inventories and to validate
emission estimations derived from the commonly applied bottom-up approaches.
Furthermore, our method is applicable to other compounds and to a wide range
of cities or other areas, where sources or sinks for mercury and
other atmospheric pollutants are presumed.</p
Combined biological and chemical assessment of estrogenic activities in wastewater treatment plant effluents
Five wastewater treatment plant effluents were analyzed for known endocrine disrupters and estrogenicity. Estrogenicity was determined by using the yeast estrogen screen (YES) and by measuring the blood plasma vitellogenin (VTG) concentrations in exposed male rainbow trout (Oncorhynchus mykiss). While all wastewater treatment plant effluents contained measurable concentrations of estrogens and gave a positive response with the YES, only at two sites did the male fish have significantly increased VTG blood plasma concentrations after the exposure, compared to pre-exposure concentrations. Estrone (E1) concentrations ranged up to 51ngLâ1, estradiol (E2) up to 6ngLâ1, and ethinylestradiol (EE2) up to 2ngLâ1 in the 90samples analyzed. Alkylphenols, alkylphenolmonoethoxylates and alkylphenoldiethoxylates, even though found at ”gLâ1 concentrations in effluents from wastewater treatment plants with a significant industrial content, did not contribute much to the overall estrogenicity of the samples taken due to their low relative potency. Expected estrogenicities were calculated from the chemical data for each sample by using the principle of concentration additivity and relative potencies of the various chemicals as determined with the yeast estrogen screen. Measured and calculated estradiol equivalents gave the same order of magnitude and correlated rather well (R 2=0.6
Ergebnis der selektiven Verpaarung beim Entlebucher Sennenhund zur Reduktion der ureteralen Ektopie
Outcome of selective mating in the Entlebucher Mountain Dog for reduction of ureteral ectopia
The Entlebucher Mountain Dog is predisposed to ureteral ectopia and associated diseases of the urinary tract as well as the kidneys, which can have severe to lethal consequences. Due to the clustered occurrence of clinical signs in 11â% of Entlebucher Mountain dogs in the absence of a genetic test for ureteral ectopia, screening was introduced in 2008 to allow phenotype-based breeding selection. The ureteral orifices of the dogs are visualized by ultrasound and existing urinary retention or urinary incontinence is documented. The diagnostic findings were evaluated centrally with assignment to one of five phenotypes depending on the localization of the ureteral orifices and the renal and ureteral shape. Breeding approval and mating restrictions are the responsibility of the respective breeding associations and predominantly Entlebucher Mountain Dogs with extravesical ectopic ureters and/or clinical signs were excluded from breeding. The effect of phenotype-based selective mating on the incidence of ureteral ectopia and its clinical signs, as well as possible factors influencing the expression of the phenotype, were determined in the birth cohorts after the introduction of screening. Analysis of the data set of 1456 phenotyped Entlebucher Mountain Dogs showed, that at 11â% versus 5â%, males were more frequently assigned to the extravesical phenotype than females. The effect of phenotype-based breeding selection was examined in a subpopulation consisting of phenotyped parents and their offspring (n = 876). The prevalence of the extravesical phenotype decreased from 24â% in the 2005 to 2007 birth cohorts to 1,4â% in the 2015 to 2017 birth cohorts. Since 2015 almost no Entlebucher Mountain Dogs with incontinence, hydroureter or hydronephrosis have been recorded. It was feared that the additional selection measures to control ureteral ectopia in the small Entlebucher Mountain Dog population would intensify the inbreeding increase. However, this has so far remained absent. Therefore, as long as no genetic test is available, it is recommended to continue phenotype-based breeding selection with exclusion of dogs with extravesical ureteral ectopia and/or hydroureter/hydronephrosis/urinary incontinence, while keeping an eye on the development of the inbreeding coefficient.
Keywords: Ectopic ureter, Dog, Inbreeding, Phenotype, Breeding selection
Deutsch
Ergebnis der selektiven Verpaarung beim Entlebucher Sennenhund zur Reduktion der ureteralen Ektopie
Der Entlebucher Sennenhund ist prĂ€disponiert fĂŒr die ureterale Ektopie und damit fĂŒr assoziierte Erkrankungen der Harnwege sowie der Nieren, was schwerwiegende bis letale Folgen haben kann. Aufgrund des gehĂ€uften Auftretens klinischer Symptome bei 11â% der Entlebucher Sennenhunde wurde in Ermangelung eines Gentests auf ureterale Ektopie 2008 ein Screening eingefĂŒhrt, um eine PhĂ€notyp-basierte Zuchtselektion zu ermöglichen. Die UretermĂŒndungen der Hunde werden in der Regel mittels Ultraschall lokalisiert und bestehender HarnrĂŒckstau oder Harninkontinenz wird dokumentiert. Die Befundung erfolgte zentral mit einer Zuordnung zu einem von fĂŒnf PhĂ€notypen in AbhĂ€ngigkeit von der Lokalisation der UretermĂŒndungen sowie der Nieren â und Ureterengestalt. Die Zuchtzulassung und VerpaarungsbeschrĂ€nkungen obliegen den jeweiligen ZuchtverbĂ€nden, wobei ĂŒberwiegend Entlebucher Sennenhunde mit extravesikal ektopischen Ureteren und/oder klinischen Symptomen von der Zucht ausgeschlossen wurden. Die Auswirkung der PhĂ€notyp-basierten selektiven Verpaarung auf das Auftreten der ureteralen Ektopie und deren klinischen Symptome sowie mögliche Einflussfaktoren auf die AusprĂ€gung des PhĂ€notyps wurden in den Geburtsjahren nach EinfĂŒhrung des Screenings ermittelt. Die Analyse des Datensatzes mit 1456 phĂ€notypisierten Entlebucher Sennenhunden zeigte, dass mit 11â% versus 5â% RĂŒden hĂ€ufiger als HĂŒndinnen dem extravesikalen PhĂ€notyp zugeteilt wurden. Die Auswirkung der PhĂ€notyp-basierten Zuchtselektion wurde an einer Teilpopulation, bestehend aus phĂ€notypisierten Elterntieren und ihren Nachkommen (n = 876), untersucht. Die PrĂ€valenz des extravesikalen PhĂ€notyps nahm von 24â% bei den Geburtsjahren 2005 bis 2007 auf 1,4â% bei den Geburtsjahren 2015 bis 2017 ab. Seit 2015 wurden nahezu keine Entlebucher Sennenhunde mehr mit Inkontinenz, Hydroureter oder Hydronephrose erfasst. BefĂŒrchtet wurde, dass die zusĂ€tzlichen Selektionsmassnahmen zur BekĂ€mpfung der ureteralen Ektopie in der kleinen Entlebucher Sennenhundepopulation den Inzuchtanstieg verstĂ€rken wĂŒrde. Dies blieb bisher jedoch aus. Daher wird, solange kein genetischer Test zur VerfĂŒgung steht, empfohlen, die PhĂ€notyp-basierte Zuchtselektion mit Ausschluss von Hunden mit extravesikaler ureteraler Ektopie und/oder Hydroureter/Hydronephrose/Harninkontinenz vorerst weiterzufĂŒhren und gleichzeitig die Entwicklung des Inzuchtkoeffizienten im Auge zu behalten.
SchlĂŒsselwörter: Ektopischer Ureter, Hund, Inzucht, PhĂ€notyp, Zuchtselektion
Français
RĂ©sultat de lâaccouplement sĂ©lectif chez le bouvier de lâEntlebuch pour rĂ©duire lâectopie urĂ©tĂ©rale
Le Bouvier de lâEntlebuch est prĂ©disposĂ© Ă lâectopie urĂ©tĂ©rale et aux maladies associĂ©es des voies urinaires ainsi que des reins, ce qui peut entraĂźner des consĂ©quences fatales. En raison de lâapparition de signes cliniques chez 11â% des chiens et en lâabsence dâun test gĂ©nĂ©tique pour lâectopie urĂ©tĂ©rale, un dĂ©pistage a Ă©tĂ© introduit en 2008 pour permettre une sĂ©lection dâĂ©levage basĂ©e sur le phĂ©notype. Les orifices urĂ©traux des chiens ont Ă©tĂ© visualisĂ©s par Ă©chographie et la rĂ©tention ou lâincontinence urinaire existante documentĂ©e. Les rĂ©sultats du diagnostic ont Ă©tĂ© Ă©valuĂ©s de maniĂšre centralisĂ©e avec attribution Ă lâun des cinq phĂ©notypes en fonction de la localisation des orifices urĂ©tĂ©raux ainsi que de la forme des reins et des uretĂšres. Lâapprobation pour la reproduction et les restrictions dâaccouplement relĂšvent de la responsabilitĂ© des associations dâĂ©levage respectives et les bouviers de lâEntlebuch prĂ©sentant des uretĂšres ectopiques extravĂ©sicaux et/ou des signes cliniques ont majoritairement Ă©tĂ© exclus de la reproduction. Lâeffet de cet accouplement sĂ©lectif basĂ© sur le phĂ©notype sur lâincidence de lâectopie urĂ©tĂ©rale et de ses signes cliniques ainsi que les facteurs possibles influençant lâexpression du phĂ©notype ont Ă©tĂ© dĂ©terminĂ©s dans les cohortes de naissance aprĂšs lâintroduction du dĂ©pistage. Lâanalyse de lâensemble des donnĂ©es de 1456 Bouviers de lâEntlebuch phĂ©notypĂ©s a montrĂ© que, Ă 11â% contre 5â%, les mĂąles Ă©taient plus frĂ©quemment affectĂ©s au phĂ©notype extravĂ©sical que les femelles. Lâeffet de la sĂ©lection dâĂ©levage basĂ©e sur le phĂ©notype a Ă©tĂ© examinĂ© dans une sous-population composĂ©e de parents phĂ©notypĂ©s et de leur progĂ©niture (n = 876). La prĂ©valence du phĂ©notype extravĂ©sical est passĂ©e de 24â% dans les cohortes de naissance de 2005 Ă 2007 Ă 1,4â% dans les cohortes de naissance de 2015 Ă 2017. Depuis 2015, presque aucun bouvier dâEntlebuch prĂ©sentant une incontinence, un hydrouretĂšre ou une hydronĂ©phrose nâa Ă©tĂ© enregistrĂ©. Une possible augmentation de la consanguinitĂ© due aux mesures de sĂ©lection supplĂ©mentaires visant Ă contrĂŽler lâectopie urĂ©tĂ©rale ne sâest pas produite. Par consĂ©quent, tant quâaucun test gĂ©nĂ©tique nâest disponible, il est recommandĂ© de poursuivre la sĂ©lection dâĂ©levage basĂ©e sur le phĂ©notype avec exclusion des chiens prĂ©sentant une ectopie urĂ©tĂ©rale extravĂ©sicale et/ou une hydrouretĂšre/hydronĂ©phrose/incontinence urinaire, tout en surveillant lâĂ©volution du coefficient de consanguinitĂ©.
Mots-clĂ©s: auretĂšre ectopique, chien, consanguinitĂ©, phĂ©notype, sĂ©lection dâĂ©levage
Italiano
Risultato dell'accoppiamento selettivo nel cane da montagna Entlebuch per ridurre l'ectopia ureterale
Il bovaro dellâEntlebuch Ăš predisposto allâectopia ureterale e quindi alle malattie che sono correlate al tratto urinario e renale con possibili conseguenze letali. A causa della frequente comparsa di segni clinici nellâ11â% dei cani e in assenza di un test genetico per lâectopia ureterale, nel 2008 Ăš stato introdotto uno screening per consentire la selezione fenotipica dei riproduttori. Gli orifizi ureterali dei cani sono solitamente localizzato tramite ecografia e viene documentata la presenza di ritenzione o incontinenza urinaria. I risultati sono stati valutati in modo centralizzato e si Ăš assegnato il risultato a uno dei cinque fenotipi a seconda della localizzazione degli orifizi ureterali e della forma dei reni e degli ureteri. Lâautorizzazione allâallevamento e le restrizioni allâaccoppiamento sono di competenza delle rispettive associazioni di allevatori e i bovari dellâEntlebuch con ureteri ectopici extravescicali e/o con segni clinici sono stati prevalentemente esclusi dalla riproduzione. Lâeffetto dellâaccoppiamento selettivo, basato sul fenotipo per rapporto allâincidenza dellâectopia ureterale e dei suoi segni clinici, nonchĂ© dei possibili fattori che influenzano lâespressione del fenotipo, Ăš stato determinato nelle coorti di nascita dopo lâintroduzione dello screening. Lâanalisi del set di dati di 1456 bovari dellâEntlebuch fenotipizzati ha dimostrato che, con una percentuale dellâ11â% rispetto al 5â%, i maschi erano piĂč frequentemente assegnati al fenotipo extravescicale rispetto alle femmine. Lâeffetto della selezione riproduttiva basata sul fenotipo Ăš stato esaminato in una subpopolazione composta da genitori fenotipizzati e dalla loro discendenza (n = 876). La prevalenza del fenotipo extravescicale Ăš diminuita dal 24â% nelle coorti di nascita dal 2005 al 2007 allâ1,4â% nelle coorti di nascita dal 2015 al 2017. Dal 2015 non sono stati registrati quasi piĂč bovari dellâEntlebuch con incontinenza, idrouretere o idronefrosi. Non si Ăš riscontrato un possibile aumento della consanguineitĂ dovuto alle misure di selezione aggiuntive per controllare lâectopia ureterale. Pertanto, finchĂ© non Ăš disponibile un test genetico, si raccomanda di continuare la selezione fenotipica con lâesclusione dei cani con ectopia ureterale extravescicale e/o idrouretere/idronefrosi/incontinenza urinaria, facendo particolare attenzione allâandamento del coefficiente di consanguineitĂ .
Parole chiavi: Uretere ectopico, cane, consanguineitĂ , fenotipo, selezione riproduttiv
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