Covariant localizations in the torus and the phase observables

We describe all the localization observables of a quantum particle in a one-dimensional box in terms of sequences of unit vectors in a Hilbert space. An alternative representation in terms of positive semidefinite complex matrices is furnished and the commutative localizations are singled out. As a consequence, we also get a vector sequence characterization of the covariant phase observables.Comment: 16 pages, no figure, Latex2

Common mental disorders in young adults born late-preterm

Background Results of adulthood mental health of those born late-preterm (34 + 0–36 + 6 weeks + days of gestation) are mixed and based on national registers. We examined if late-preterm birth was associated with a higher risk for common mental disorders in young adulthood when using a diagnostic interview, and if this risk decreased as gestational age increased. Method A total of 800 young adults (mean = 25.3, s.d. = 0.62 years), born 1985–1986, participated in a follow-up of the Arvo Ylppö Longitudinal Study. Common mental disorders (mood, anxiety and substance use disorders) during the past 12 months were defined using the Composite International Diagnostic Interview (Munich version). Gestational age was extracted from hospital birth records and categorized into early-preterm (<34 + 0, n = 37), late-preterm (34 + 0–36 + 6, n = 106), term (37 + 0–41 + 6, n = 617) and post-term (≥42 + 0, n = 40). Results Those born late-preterm and at term were at a similar risk for any common mental disorder [odds ratio (OR) 1.11, 95% confidence interval (CI) 0.67–1.84], for mood (OR 1.11, 95% CI 0.54–2.25), anxiety (OR 1.00, 95% CI 0.40–2.50) and substance use (OR 1.31, 95% CI 0.74–2.32) disorders, and co-morbidity of these disorders (p = 0.38). While the mental disorder risk decreased significantly as gestational age increased, the trend was driven by a higher risk in those born early-preterm. Conclusions Using a cohort born during the advanced neonatal and early childhood care, we found that not all individuals born preterm are at risk for common mental disorders in young adulthood – those born late-preterm are not, while those born early-preterm are at a higher risk. Available resources for prevention and intervention should be targeted towards the preterm group born the earliest

Virtual Reality Relaxation to Decrease Dental Anxiety:Immediate Effect Randomized Clinical Trial

Introduction: Dental anxiety is common and causes symptomatic use of oral health services. Objectives: The aim was to study if a short-term virtual reality intervention reduced preoperative dental anxiety. Methods: A randomized controlled single-center trial was conducted with 2 parallel arms in a public oral health care unit: virtual reality relaxation (VRR) and treatment as usual (TAU). The VRR group received a 1- to 3.5-min 360° immersion video of a peaceful virtual landscape with audio features and sound supporting the experience. TAU groups remained seated for 3 min. Of the powered sample of 280 participants, 255 consented and had complete data. Total and secondary sex-specific mixed effects linear regression models were completed for posttest dental anxiety (Modified Dental Anxiety Scale [MDAS] total score) and its 2 factors (anticipatory and treatment-related dental anxiety) adjusted for baseline (pretest) MDAS total and factor scores and age, taking into account the effect of blocking. Results: Total and anticipatory dental anxiety decreased more in the VRR group than the TAU group (β = −0.75, P < .001, for MDAS total score; β = −0.43, P < .001, for anticipatory anxiety score) in patients of a primary dental care clinic. In women, dental anxiety decreased more in VRR than TAU for total MDAS score (β = −1.08, P < .001) and treatment-related dental anxiety (β = −0.597, P = .011). Anticipatory dental anxiety decreased more in VRR than TAU in both men (β = −0.217, P < .026) and women (β = −0.498, P < .001). Conclusion: Short application of VRR is both feasible and effective to reduce preoperative dental anxiety in public dental care settings (ClinicalTrials.gov NCT03993080). Knowledge Transfer Statement: Dental anxiety, which is a common problem, can be reduced with short application of virtual reality relaxation applied preoperatively in the waiting room. Findings of this study indicate that it is a feasible and effective procedure to help patients with dental anxiety in normal public dental care settings.Publisher PDFPeer reviewe

Semispectral measures as convolutions and their moment operators

The moment operators of a semispectral measure having the structure of the convolution of a positive measure and a semispectral measure are studied, with paying attention to the natural domains of these unbounded operators. The results are then applied to conveniently determine the moment operators of the Cartesian margins of the phase space observables.Comment: 7 page

The Standard Model of Quantum Measurement Theory: History and Applications

The standard model of the quantum theory of measurement is based on an interaction Hamiltonian in which the observable-to-be-measured is multiplied with some observable of a probe system. This simple Ansatz has proved extremely fruitful in the development of the foundations of quantum mechanics. While the ensuing type of models has often been argued to be rather artificial, recent advances in quantum optics have demonstrated their prinicpal and practical feasibility. A brief historical review of the standard model together with an outline of its virtues and limitations are presented as an illustration of the mutual inspiration that has always taken place between foundational and experimental research in quantum physics.Comment: 22 pages, to appear in Found. Phys. 199

The structural basis for pyrophosphatase catalysis

AbstractBackground Soluble inorganic pyrophosphatase (PPase), an essential enzyme central to phosphorus metabolism, catalyzes the hydrolysis of the phosphoanhydride bond in inorganic pyrophosphate. Catalysis requires divalent metal ions which affect the apparent pKas of the essential general acid and base on the enzyme, and the pKa of the substrate. Three to five metal ions are required for maximal activity, depending on pH and enzyme source. A detailed understanding of catalysis would aid both in understanding the nature of biological mechanisms of phosphoryl transfer, and in understanding the role of divalent cations. Without a high-resolution complex structure such a model has previously been unobtainable.Results We report the first two high-resolution structures of yeast PPase, at 2.2 and 2.0 å resolution with R factors of around 17%. One structure contains the two activating metal ions; the other, the product (MnPi)2 as well. The latter structure shows an extensive network of hydrogen bond and metal ion interactions that account for virtually every lone pair on the product phosphates. It also contains a water molecule/hydroxide ion bridging two metal ions and, uniquely, a phosphate bound to four Mn2+ ions.Conclusions Our structure-based model of the PPase mechanism posits that the nucleophile is the hydroxide ion mentioned above. This aspect of the mechanism is formally analogous to the ‘two-metal ion’ mechanism of alkaline phosphatase, exonucleases and polymerases. A third metal ion coordinates another water molecule that is probably the required general acid. Extensive Lewis acid coordination and hydrogen bonds provide charge shielding of the electrophile and lower the pKa of the leaving group. This ‘three-metal ion’ mechanism is in detail different from that of other phosphoryl transfer enzymes, presumably reflecting how ancient the reaction is

Modelling spatial patterns in host-associated microbial communities

Microbial communities exhibit spatial structure at different scales, due to constant interactions with their environment and dispersal limitation. While this spatial structure is often considered in studies focusing on free-living environmental communities, it has received less attention in the context of host-associated microbial communities or microbiota. The wider adoption of methods accounting for spatial variation in these communities will help to address open questions in basic microbial ecology as well as realize the full potential of microbiome-aided medicine. Here, we first overview known factors affecting the composition of microbiota across diverse host types and at different scales, with a focus on the human gut as one of the most actively studied microbiota. We outline a number of topical open questions in the field related to spatial variation and patterns. We then review the existing methodology for the spatial modelling of microbiota. We suggest that methodology from related fields, such as systems biology and macro-organismal ecology, could be adapted to obtain more accurate models of spatial structure. We further posit that methodological developments in the spatial modelling and analysis of microbiota could in turn broadly benefit theoretical and applied ecology and contribute to the development of novel industrial and clinical applications.Peer reviewe

Kulmahampaan aiheuttaman juuriresorption tarkastelu KKTT menetelmällä

Tiivistelmä. Kulmahammas on varsinaisista pysyvistä hampaista yleisin puhkeamatta jäävä hammas. Sen etiologia on monitekijäinen ja edelleen hieman epäselvä, mutta joitakin mahdollisia syitä puhkeamishäiriölle on onnistuttu löytämään. Kulmahampaan poikkeava puhkeaminen on yleisempää naisilla ja sitä esiintyy enemmän ylä- kuin alaleuassa. Poikkeava puhkeaminen on usein unilateraalista. Kulmahampaan poikkeavaa puhkeamista ennustavat useat kliiniset löydökset. Kulmahammas on palpoitavissa bukkaalisesta huulipoimusta 1.5 vuotta ennen puhkeamistaan, ja sen palpoiminen tulisi aloittaa toisten yläinkisiivien puhjettua suuhun. Kliinisen tutkimuksen lisäksi puhkeamatonta kulmahammasta tulee tutkia radiologisten tutkimusmenetelmien avulla. Yleisimpiä menetelmiä ovat PTG- ja KKTT-kuvaus. Poikkeavasti puhkeavan kulmahampaan hoitomuotoja ovat varhaishoito sekä ortodonttinen ja kirurginen hoito. Poikkeavasti puhkeava kulmahammas aiheuttaa eniten juuriresorptiota viereisissä hampaissa, kun sen puhkeamissuunta on bukkaalinen tai palatinaalinen. Juuriresorptiota esiintyy usein lateraali-inkisiiveissä, mutta myös sentraali-inkisiivien juuriresorptio on mahdollista. Juuriresorptiota esiintyy eniten juuren apikaali- ja keskikolmanneksessa. Oma tutkimuksemme käsitti 33 potilasta, jotka oli kuvattu KKTT-menetelmällä poikkeavasti puhkeavan kulmahampaan vuoksi vuosina 2011–2014. Tutkimuksessa havaitsimme, että poikkeavia kulmahampaita esiintyy enemmän tytöillä kuin pojilla. Hampaan puhkeamissuunta vaikuttaa sen aiheuttamaan juuriresorptioon, vakavuuteen ja sijaintiin

A dilemma in representing observables in quantum mechanics

There are self-adjoint operators which determine both spectral and semispectral measures. These measures have very different commutativity and covariance properties. This fact poses a serious question on the physical meaning of such a self-adjoint operator and its associated operator measures.Comment: 10 page