317 research outputs found
Potential energy surfaces and bound states for the open-shell van der Waals cluster BrâHF
Semiempiricalpotential energy surfaces for the lowest three electronic states of the open-shell complex BrâHF are constructed, based on existing empirical potentials for KrâHF and KrâNe and coupled-clusterelectronic structure calculations for BrâNe. Coupled cluster calculations are also described for HeâF, NeâF and ArâF. Electrostaticinteractions that arise from the quadrupole of the Br atom and the permanent multipoles of HF are also included in the BrâHF surfaces. The well depth of the lowest adiabatic surface is found to be 670 cmâ1 at a linear equilibrium geometry. The results of helicity decoupled and full close-coupling calculations of the bound states of the complex are also described. The ground state, with total angular momentum projection quantum number |P|=3/2, is found 435 cmâ1 below dissociation to Brâ(2P3/2)+HFâ(j=0). The lowest-frequency intermolecular bending and stretching vibrations are predicted around 145 and 211 cmâ1, respectively. Parity splittings are found to be extremely small for bound states with projection quantum number |P|=3/2. The relevance of the results to recently recorded spectra of BrâHF is discussed
Impact de l'introduction des panels gastro-intestinaux par PCR multiplex sur le traitement des infections digestives
Cette Ă©tude vise Ă Ă©valuer lâintĂ©rĂȘt des nouvelles PCR (Polymerase Chain Reaction) multiplex du
laboratoire microbiologique du CHUV (Centre Hospitalier Universitaire Vaudois) dans la prise en
charge clinique des gastroentérites. Les PCR sont actuellement implantée dans beaucoup de
laboratoire. Leur supériorité technique sur les méthodes de détections traditionnelles a été largement
Ă©tudiĂ©e. Cependant peu dâĂ©tudes se sont intĂ©ressĂ©es Ă lâinfluences des PCR sur la prise en charge
cliniques des patients. Nous avons voulu dans cette étude, analyser les différences de prises en charge
clinique en fonction de lâoutil diagnostique.
Deux groupes de patients consultant en ambulatoires pour des symptomes de gastroentérite les
urgences du CHUV ou de la PMU (Policlinique Médicale Universitaire) ont été comparés sur une
période de deux ans. Le premier groupe a été investigué par les méthodes de laboratoire
microbiologique traditionnelles (culture, test Elisa, microscopie, test dâantigĂšne ou de toxine) et le
second par PCR multiplex (panels de bactéries entéropathogÚnes, protozoaires digestif, C.difficile ou
Norovirus). Ces deux cohortes ont Ă©tĂ© comparĂ©es selon les rĂ©sultats dâexamens et les dĂ©cisions
cliniques des médecins, notamment en termes de traitement anti-infectieux.
Dans la cohorte de patients étant investigués par panels PCR, nous avons relevés trois changements
significatifs.
1. Une baisse de 44% du nombre de patients traités par traitements anti-infectieux prescrits dans
leur entier ;
2. Une augmentation de 80% du nombre de bactéries détectées ;
3. Une baisse de 64% du nombre de patients ayant reçu un résultat négatif qui avaient été traités
par traitement anti-infectieux empirique.
MalgrĂ© une augmentation de dĂ©tection des bactĂ©ries, il est observĂ© une baisse des prescriptions dâantiinfectieux.
Ce qui peut ĂȘtre expliquĂ© dâune part par le fait que les cliniciens, sachant quâils vont
obtenir rapidement un résultat, peuvent se permettre de ne pas traiter empiriquement certains patients
et de les rĂ©Ă©valuer lorsquâils auront obtenu le rĂ©sultat dâexamen de selle. Dâautre part, le fait dâobtenir
un rĂ©sultat prĂ©coce permet dâarrĂȘter les thĂ©rapies inutiles que ce soit chez les patients avec un rĂ©sultat
négatifs ou ceux positifs pour des pathogÚnes qui ne nécessitent pas forcément de traitement.
Globalement, les mĂ©decins prescrivent moins de traitements empiriques lorsquâils savent que les
rĂ©sultats de laboratoire seront rapidement disponibles et que la suspicion dâenteropathogĂšnes
bactériens est faible. Grùce au court délai des panels PCR, les traitements anti-infectieux prescrits
sont ainsi plus adĂ©quats, Ă©vitĂ©s ou interrompus prĂ©cocement lorsquâils sont inutiles ou mieux ciblĂ©s
lorsquâils sont nĂ©cessaires
Lâintroduction des panels PCR, a donc permis dâamĂ©liorer la prise en charge ambulatoire des
gastroentĂ©rites, tout en diminuant la prescription dâantibiotiques
The Phantom Urine: An Unexpected Finding during a Routine Cesarean Section.
We present here an atypical finding during an elective repeat cesarean section. Despite urine flow through an indwelling bladder catheter, bladder remains distended during the whole procedure. Unexpected anatomical variations and malformations can make routine surgery challenging. Urinary tract anomalies should be suspected in cases of unexpected difficult bladder catheterization
On the Effect of Aleatoric and Epistemic Errors on the Learnability and Quality of NN-based Potential Energy Surfaces
The effect of noise in the input data for learning potential energy surfaces
(PESs) based on neural networks for chemical applications is assessed. Noise in
energies and forces can result from aleatoric and epistemic errors in the
quantum chemical reference calculations. Statistical (aleatoric) noise arises
for example due to the need to set convergence thresholds in the self
consistent field (SCF) iterations whereas systematic (epistemic) noise is due
to, {\it inter
alia}, particular choices of basis sets in the calculations. The two
molecules considered here as proxies are HCO and HONO which are examples
for single- and multi-reference problems, respectively, for geometries around
the minimum energy structure. For HCO it is found that adding noise to
energies with magnitudes representative of single-point calculations does not
deteriorate the quality of the final PESs whereas increasing the noise level
commensurate with electronic structure calculations for more complicated, e.g.
metal-containing, systems is expected to have a more notable effect. However,
the effect of noise on the forces is more noticeable. On the other hand, for
HONO which requires a multi-reference treatment, a clear correlation between
model quality and the degree of multi-reference character as measured by the
amplitude is found. It is concluded that for chemically "simple" cases
the effect of aleatoric and epistemic noise is manageable without evident
deterioration of the trained model - although the quality of the forces is
important. However, considerably more care needs to be exercised for situations
in which multi-reference effects are present
Losing your virginity safely? A Swiss national survey.
Good practice and knowledge in terms of contraception at first sexual intercourse may lead adolescents to a safer sexual life. To date, research studies have mostly focused on women when investigating contraception use or on condom use only when addressing both genders.
The present study adds to the current knowledge by offering a more in-depth view of contraception use at first intercourse among youths. This is achieved through a large selection of variables, the fact that we address both males and females and that we have considered a wide range of contraceptive means.
To determine the rate of contraception use at first intercourse by youth in Switzerland and its association with social and personal characteristics.
Data were obtained from a self-administrated national survey on sexual behaviour among young adults (mean age 26 years). Participants (n = 4036) were divided into three groups based on the means of contraception used at first intercourse: condom, with or without contraceptive (86.4%), contraceptive only (8.3%) and non-use (5.3%).
Only 5.3% did not use any contraception. Compared with the condom group, individuals in the non-use group were more likely to report a lower family socioeconomic status, to be foreign born, to have foreign-born parents, to have a non-intact family and to live in a Catholic canton. They were also more likely to have had their first intercourse in the context of a casual relationship, to have been intoxicated at the time and more likely to regret it. Participants in the contraceptive group reported a higher family socioeconomic status, had intact families, did not live in Catholic cantons, were older and in a steady relationship at first intercourse.
Contraception is generally used at first intercourse in Switzerland. Improvements can still be made concerning contraception use in the most vulnerable social strata such as low income families or foreign status
Collisional excitation rate coefficients of N2H+ by He
Using a recoupling technique with close-coupling spin-free calculations de-excitation rate coefficients are obtained among hyperfine transitions for He colliding with N2H+. A recently determined potential energy surface suitable for scattering calculations is used to investigate rate coefficients for temperatures between 5 and 50 K, and for the seven lowest rotational levels of N2H+. Fitting functions are provided for the Maxwellian averaged opacity tensors and for the rotational de-excitation collisional rate coefficients. The fitting functions for the opacity tensors can be used to calculate hyperfine (de)-excitation rate coefficients among elastic and inelastic rotational levels, and among the corresponding magnetic sublevels of the hyperfine structure. Certain dynamical approximations are investigated and found to be invali
Assignment of the evidential value of a fingermark general pattern using a Bayesian network
Abstract: When visible on a fingermark, the general pattern maintains its importance in the fingerprint examination procedure, since the difference between the general pattern of a fingermark and a fingerprint is sufficient for exclusion. In the current work, the importance of the general pattern is extended by evaluating the strength of evidence of a match given corresponding general pattern. In current practice (due to the lack of statistical support for the general pattern evidence) the fingerprint examiners assign personal probabilities to the general pattern evidence based on their knowledge and experience, while in this work the probabilities are calculated using a Bayesian Network which is fed by empirical data. 1
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