Iron speciation in aerosol dust influences iron bioavailability over glacial-interglacial timescales

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Bayesian Exponential Random Graph Models with Nodal Random Effects

We extend the well-known and widely used Exponential Random Graph Model (ERGM) by including nodal random effects to compensate for heterogeneity in the nodes of a network. The Bayesian framework for ERGMs proposed by Caimo and Friel (2011) yields the basis of our modelling algorithm. A central question in network models is the question of model selection and following the Bayesian paradigm we focus on estimating Bayes factors. To do so we develop an approximate but feasible calculation of the Bayes factor which allows one to pursue model selection. Two data examples and a small simulation study illustrate our mixed model approach and the corresponding model selection.Comment: 23 pages, 9 figures, 3 table

Halogen species record Antarctic sea ice extent over glacial–interglacial periods

Abstract. Sea ice is an integral part of the earth's climate system because it affects planetary albedo, sea-surface salinity, and the atmosphere–ocean exchange of reactive gases and aerosols. Bromine and iodine chemistry is active at polar sea ice margins with the occurrence of bromine explosions and the biological production of organoiodine from sea ice algae. Satellite measurements demonstrate that concentrations of bromine oxide (BrO) and iodine oxide (IO) decrease over sea ice toward the Antarctic interior. Here we present speciation measurements of bromine and iodine in the TALDICE (TALos Dome Ice CorE) ice core (159°11' E, 72°49' S; 2315 m a.s.l.) spanning the last 215 ky. The Talos Dome ice core is located 250 km inland and is sensitive to marine air masses intruding onto the Antarctic Plateau. Talos Dome bromide (Br−) is positively correlated with temperature and negatively correlated with sodium (Na). Based on the Br−/Na seawater ratio, bromide is depleted in the ice during glacial periods and enriched during interglacial periods. Total iodine, consisting of iodide (I−) and iodate (IO3−), peaks during glacials with lower values during interglacial periods. Although IO3− is considered the most stable iodine species in the atmosphere it was only observed in the TALDICE record during glacial maxima. Sea ice dynamics are arguably the primary driver of halogen fluxes over glacial–interglacial timescales, by altering the distance between the sea ice edge and the Antarctic plateau and by altering the surface area of sea ice available to algal colonization. Based on our results we propose the use of both halogens for examining Antarctic variability of past sea ice extent

Naturalness and theoretical constraints on the Higgs boson mass

Arbitrary regularization dependent parameters in Quantum Field Theory are usually fixed on symmetry or phenomenology grounds. We verify that the quadratically divergent behavior responsible for the lack of naturalness in the Standard Model (SM) is intrinsically arbitrary and regularization dependent. While quadratic divergences are welcome for instance in effective models of low energy QCD, they pose a problem in the SM treated as an effective theory in the Higgs sector. Being the very existence of quadratic divergences a matter of debate, a plausible scenario is to search for a symmetry requirement that could fix the arbitrary coefficient of the leading quadratic behavior to the Higgs boson mass to zero. We show that this is possible employing consistency of scale symmetry breaking by quantum corrections. Besides eliminating a fine-tuning problem and restoring validity of perturbation theory, this requirement allows to construct bounds for the Higgs boson mass in terms of $\delta m^2/m^2_H$ (where $m_H$ is the renormalized Higgs mass and $\delta m^2$ is the 1-loop Higgs mass correction). Whereas $\delta m^2/m^2_H<1$ (perturbative regime) in this scenario allows the Higgs boson mass around the current accepted value, the inclusion of the quadratic divergence demands $\delta m^2/m^2_H$ arbitrarily large to reach that experimental value.Comment: 6 pages, 4 figure

To the problem of doctor’s tactics in patients with pleuritis of uncertain genesis

Polyetiologic features of pleuritis lesions, doctors' particular speciality and the lack of standards give rise to inevitable difficulties in making diagnosis, while the introduction of modern research innovations solves only specific problems. All above mentioned issues require the introduction of new organizational technologies. Retrospective analysis of medical records of 968 patients performed at the centre of the Novokuznetsk State Clinical Tuberculous Hospital showed the efficacy of algorithm usage in specialized medical care and doctor's tactics. In 91% of patients the period for diagnosis verification was 10,4+2,0 days, and idiopathic pleuritis shared 4% of patients.Полиэтиологичность поражений плевры, узкая специализация врачей и отсутствие стандартов порождают неизбежные трудности диагностики, а внедрение наукоемких исследований решает лишь частные проблемы. Необходим пересмотр ситуации, использование новых организационных технологий. Данные ретроспективного анализа историй болезни 968 пациентов плеврального центра при ГУЗ «НКТБ», показали эффективность специализированной помощи и врачебной тактики, формализованной в виде алгоритма. Для 91% больных время верификации диагноза в среднем составляет 10,4+2,0 дней, а доля идиопатических плевритов — 4%

Clinical features of current, diagnostics of tuberculous and malignant pleurisies

Clinical current, features of semiology and efficacy of diagnostic methods were studied on an example of 626 patients with a pleural pathology (401 - tuberculous, 225 - malignant pleurisies), examined at the specialized pleural department of Clinical Tuberculosis Hospital of Novokuznetsk. Typical cases of malignancies had the following characteristics: absence of inflammation symptoms, progressing dyspnoea and-or chest pain, inexhaustibility and haemorrhagic character of pleural effusion. In this group sensitivity and specificity of cytologic examination of pleural effusion was 51,9% and 98,0%, pleural needle biopsy (PNB) - 60,8% and 100% accordingly. 65% of tuberculous pleurisies were verified by PNB. Sensitivity PNB was accounted 80,8% at specificity 99,2%. Non-specific results of PNB in the cases high evidence of ТВ etiology pleurisy, using of another methods is necessary (test-therapy of a tuberculosis, organizational methods: algorithm, supervision).Клиническое течение, особенности симптоматики и эффективность диагностических методов рассмотрены на примере 626 больных с плевральной патологией (401 - туберкулезные, 225 - злокачественные плевриты), обследованных в специализированном плевральном отделении клинической туберкулезной больницы г. Новокузнецка. В типичных случаях злокачественность поражения плевры отличает отсутствие симптомов воспалительной интоксикации, прогрессирующая одышка и/или торакалгии, неиссякаемость и геморрагический характер экссудата. В этой группе отмечается высокая чувствительность и специфичность цитологического исследования плеврального выпота - 51,9% и 98,0%, игловой биопсии плевры (ПБ) - 60,8% и 100% соответственно. У 65% больных туберкулезом основным методом верификации плеврита является ПБ. Чувствительность ПБ составила 80,8% при специфичности 99,2%. Неспецифический результат ПБ при высокой вероятности туберкулезной этиологии плеврита предполагает использование других методов: тест-терапия туберкулеза, организационные (алгоритм, наблюдение)

Estimation of traffic matrices for LRD traffic

The estimation of traffic matrices in a communications network on the basis of a set of traffic measurements on the network links is a well known problem, for which a number of solutions have been proposed when the traffic does not show dependence over time, as in the case of the Poisson process. However, extensive measurements campaigns conducted on IP networks have shown that the traffic exhibits long range dependence. Here two methods are proposed for the estimation of traffic matrices in the case of long range dependence, their asymptotic properties are studied, and their relative merits are compared

Comparing composite likelihood methods based on pairs for spatial Gaussian random fields

In the last years there has been a growing interest in proposing methods for estimating covariance functions for geostatistical data. Among these, maximum likelihood estimators have nice features when we deal with a Gaussian model. However maximum likelihood becomes impractical when the number of observations is very large. In this work we review some solutions and we contrast them in terms of loss of statistical efficiency and computational burden. Specifically we focus on three types of weighted composite likelihood functions based on pairs and we compare them with the method of covariance tapering. Asymptotic properties of the three estimation methods are derived. We illustrate the effectiveness of the methods through theoretical examples, simulation experiments and by analyzing a data set on yearly total precipitation anomalies at weather stations in the United States.In the last years there has been a growing interest in proposing methods for estimating covariance functions for geostatistical data. Among these, maximum likelihood estimators have nice features when we deal with a Gaussian model. However maximum likelihood becomes impractical when the number of observations is very large. In this work we review some solutions and we contrast them in terms of loss of statistical efficiency and computational burden. Specifically we focus on three types of weighted composite likelihood functions based on pairs and we compare them with the method of covariance tapering. Asymptotic properties of the three estimation methods are derived. We illustrate the effectiveness of the methods through theoretical examples, simulation experiments and by analyzing a data set on yearly total precipitation anomalies at weather stations in the United States

How victim age affects the context and timing of child sexual abuse: applying the routine activities approach to the first sexual abuse incident

The aim of this study was to examine from the routine activities approach how victim age might help to explain the timing, context and nature of offenders’ first known contact sexual abuse incident. One-hundred adult male child sexual abusers (M = 45.8 years, SD = 12.2; range = 20–84) were surveyed about the first time they had sexual contact with a child. Afternoon and early evening (between 3 pm and 9 pm) was the most common time in which sexual contact first occurred. Most incidents occurred in a home. Two-thirds of incidents occurred when another person was in close proximity, usually elsewhere in the home. Older victims were more likely to be sexually abused by someone outside their families and in the later hours of the day compared to younger victims. Proximity of another person (adult and/or child) appeared to have little effect on offenders’ decisions to abuse, although it had some impact on the level of intrusion and duration of these incidents. Overall, the findings lend support to the application of the routine activities approach for considering how contextual risk factors (i.e., the timing and relationship context) change as children age, and raise questions about how to best conceptualize guardianship in the context of child sexual abuse. These factors should be key considerations when devising and implementing sexual abuse prevention strategies and for informing theory development