1,148 research outputs found

    Branched covers of the sphere and the prime-degree conjecture

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    To a branched cover between closed, connected and orientable surfaces one associates a "branch datum", which consists of the two surfaces, the total degree d, and the partitions of d given by the collections of local degrees over the branching points. This datum must satisfy the Riemann-Hurwitz formula. A "candidate surface cover" is an abstract branch datum, a priori not coming from a branched cover, but satisfying the Riemann-Hurwitz formula. The old Hurwitz problem asks which candidate surface covers are realizable by branched covers. It is now known that all candidate covers are realizable when the candidate covered surface has positive genus, but not all are when it is the 2-sphere. However a long-standing conjecture asserts that candidate covers with prime degree are realizable. To a candidate surface cover one can associate one Y -> X between 2-orbifolds, and in a previous paper we have completely analyzed the candidate surface covers such that either X is bad, spherical, or Euclidean, or both X and Y are rigid hyperbolic orbifolds, thus also providing strong supporting evidence for the prime-degree conjecture. In this paper, using a variety of different techniques, we continue this analysis, carrying it out completely for the case where X is hyperbolic and rigid and Y has a 2-dimensional Teichmueller space. We find many more realizable and non-realizable candidate covers, providing more support for the prime-degree conjecture

    Efficacy and microbiota modulation induced by limpial 2.5%, a new medical device for the inverse psoriasis treatment

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    (1) Inverse psoriasis (IP), also known as intertriginous, typically affects the groin, armpits, navel, intergluteal fissure, and external genitalia. Skin lesions are erythematous plaques of inflammatory nature, smooth, well-delimited, non-scaly, and non-infiltrated. Lesions may be accompanied by itching, pain, or burning sensation. The aim of this study is both to investigate the modulation of the skin microbiota induced by IP and, on the other hand, to test the effectiveness of the new biotechnological product LimpiAL 2.5%. (2) Patients affected by IP were recruited in a private practice and treated for 4 weeks with LimpiAL 2.5% exclusively. The clinical effects on the lesion skin were evaluated, and the skin microbiotas before and after treatment were compared. (3) The clinical outcomes reveled a significant beneficial effect of the tested product. At the same time, LimpiAL increased the biological diversity of the skin microbiota and exerted a significant decrease of some Corynebacterium species, and the increase of some Staphylococcus species. (4) Together, the clinical outcomes and the microbiota analysis suggest that LimpiAL treatment improves the skin condition of affected patients, basically restoring the eubiosis conditions of the affected sites and modulating the bacterial composition of the resident microbiota

    Evaporating waterbody effects in a simplified urban neighbourhood: A RANS analysis

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    The incorporation of nature-based solutions comprising green and blue infrastructure is often touted as a way to cool cities and enhance pollutant removal. However, there is little agreement between different methodologies to measure the effect of any single intervention. Here, we present 3D steady RANS simulations to investigate the influence of waterbody on in-canyon flow structure, temperature (T*) and water vapour (!*) distribution in a simplified urban neighbourhood. A novel solver that captures evaporation effects is developed and validated against wind tunnel experiments. Simulations are performed under neutral atmospheric conditions for forced -and mixed-convection cases and different air-water temperature differences, indicative of either daytime or night-time conditions. Results under forced convection show minimal impact on the flow structure, whilst T* and !* effects are distributed primarily over and around the water surface. However, the mixed-convection case shows that a cooler waterbody weakens the principal vortex in the open square, whilst T* and !* effects reach further upwind and are more widely distributed in the spanwise direction. A warmer waterbody is shown to disrupt the skimming flow structure, indicating a possible heat and pollutant removal mechanism from around the waterbody and also downwind canyons

    Sub-Nyquist Field Trial Using Time Frequency Packed DP-QPSK Super-Channel Within Fixed ITU-T Grid

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    Sub-Nyquist time frequency packing technique was demonstrated for the first time in a super channel field trial transmission over long-haul distances. The technique allows a limited spectral occupancy even with low order modulation formats. The transmission was successfully performed on a deployed Australian link between Sydney and Melbourne which included 995 km of uncompensated SMF with coexistent traffic. 40 and 100 Gb/s co-propagating channels were transmitted together with the super-channel in a 50 GHz ITU-T grid without additional penalty. The super-channel consisted of eight sub-channels with low-level modulation format, i.e. DP-QPSK, guaranteeing better OSNR robustness and reduced complexity with respect to higher order formats. At the receiver side, coherent detection was used together with iterative maximum-a-posteriori (MAP) detection and decoding. A 975 Gb/s DP-QPSK super-channel was successfully transmitted between Sydney and Melbourne within four 50GHz WSS channels (200 GHz). A maximum potential SE of 5.58 bit/s/Hz was achieved with an OSNR=15.8 dB, comparable to the OSNR of the installed 100 Gb/s channels. The system reliability was proven through long term measurements. In addition, by closing the link in a loop back configuration, a potential SE*d product of 9254 bit/s/Hz*km was achieved

    Noncyclic covers of knot complements

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    Hempel has shown that the fundamental groups of knot complements are residually finite. This implies that every nontrivial knot must have a finite-sheeted, noncyclic cover. We give an explicit bound, Φ(c)\Phi (c), such that if KK is a nontrivial knot in the three-sphere with a diagram with cc crossings and a particularly simple JSJ decomposition then the complement of KK has a finite-sheeted, noncyclic cover with at most Φ(c)\Phi (c) sheets.Comment: 29 pages, 8 figures, from Ph.D. thesis at Columbia University; Acknowledgments added; Content correcte

    A Conceptual Model of the Role of Communication in Surrogate Decision Making for Hospitalized Adults

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    OBJECTIVE: To build a conceptual model of the role of communication in decision making, based on literature from medicine, communication studies and medical ethics. METHODS: We proposed a model and described each construct in detail. We review what is known about interpersonal and patient-physician communication, described literature about surrogate-clinician communication, and discussed implications for our developing model. RESULTS: The communication literature proposes two major elements of interpersonal communication: information processing and relationship building. These elements are composed of constructs such as information disclosure and emotional support that are likely to be relevant to decision making. We propose these elements of communication impact decision making, which in turn affects outcomes for both patients and surrogates. Decision making quality may also mediate the relationship between communication and outcomes. CONCLUSION: Although many elements of the model have been studied in relation to patient-clinician communication, there is limited data about surrogate decision making. There is evidence of high surrogate distress associated with decision making that may be alleviated by communication-focused interventions. More research is needed to test the relationships proposed in the model. PRACTICE IMPLICATIONS: Good communication with surrogates may improve both the quality of medical decisions and outcomes for the patient and surrogate

    From building regulations and local health rules to the new local building codes. A national survey in Italy on the prescriptive and performance requirements for a new performance approach

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    BACKGROUND: World Health Organization has highlighted the need to strengthen the relationship between health and built environment factors, such as inappropriate housing conditions. Building Regulations and Local Health Rules provide safety and building hygiene in construction practices. Currently the Italian Government is giving rise to a Building Regulation Type and the paper aims to verify the present contents of recent innovative Local Health Rules and Building Regulations of several Italian municipalities for supporting the performance approach of the future Building Regulations including hygienic issues. METHODS: The analysis examines both Building Regulations and Local Health Rules of a sample of about 550 cities, analysing some specific fields of interest: urban field, outdoor issues, housing features, housing restrictions, and qualitative aspects. RESULTS: The analysis focuses on some specific aspects defining the general data reported in Building Regulations and Local Health Rules, in particular around surfaces, heights, lighting and aeration ratio, basements and semi-basements, gas radon, building greenery, etc. CONCLUSION: The investigation permitted to have a wide vision on the present State of the Art in order to highlight some innovative aspects and design approaches of Building Regulations and Local Health Rules. New perspectives in the new regulations should have a performance approach, starting also from the recent SARS-CoV-2 pandemic

    Communicating with Clinicians: The Experiences of Surrogate Decision‐Makers for Hospitalized Older Adults

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    OBJECTIVES: To describe communication experiences of surrogates who had recently made a major medical decision for a hospitalized older adult. DESIGN: Semistructured interviews about a recent hospitalization. SETTING: Two hospitals affiliated with one large medical school: an urban public hospital and a university-affiliated tertiary referral hospital. PARTICIPANTS: Surrogates were eligible if they had recently made a major medical decision for a hospitalized individual aged 65 and older and were available for an interview within 1 month (2-5 months if the patient died). MEASUREMENTS: Interviews were audio-recorded, transcribed, and analyzed using methods of grounded theory. RESULTS: Thirty-five surrogates were interviewed (80% female, 44% white, 56% African American). Three primary themes emerged. First, it was found that the nature of surrogate-clinician relationships was best characterized as a relationship with a "team" of clinicians rather than individual clinicians because of frequent staff changes and multiple clinicians. Second, surrogates reported their communication needs, including frequent communication, information, and emotional support. Surrogates valued communication from any member of the clinical team, including nurses, social workers, and physicians. Third, surrogates described trust and mistrust, which were formed largely through surrogates' communication experiences. CONCLUSION: In the hospital, surrogates form relationships with a "team" of clinicians rather than with individuals, yet effective communication and expressions of emotional support frequently occur, which surrogates value highly. Future interventions should focus on meeting surrogates' needs for frequent communication and high levels of information and emotional support

    Timing of Do‐Not‐Resuscitate Orders for Hospitalized Older Adults Who Require a Surrogate Decision‐Maker

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    OBJECTIVES: To examine the frequency of surrogate decisions for in-hospital do-not-resuscitate (DNR) orders and the timing of DNR order entry for surrogate decisions. DESIGN: Retrospective cohort study. SETTING: Large, urban, public hospital. PARTICIPANTS: Hospitalized adults aged 65 and older over a 3-year period (1/1/2004–12/31/2006) with a DNR order during their hospital stay. MEASUREMENTS: Electronic chart review provided data on frequency of surrogate decisions, patient demographic and clinical characteristics, and timing of DNR orders
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