Spectral statistics of the quenched normal modes of a network-forming molecular liquid

We evaluate the density of states of the quenched normal modes of ST2 water, and their statistical fluctuations, for a range of densities spanning three regimes of behavior of a hydrogen bonded liquid: a lower-density regime of random tetrahedral network formation; in the vicinity of a liquid-liquid critical point; and in a higher-density regime of fragile glass-forming behavior. For all cases we find that the fluctuations around the mean spectral densities obey the predictions of the Gaussian orthogonal ensemble of random matrix theory. We also measure the participation ratio of the normal modes across the entire frequency range, and find behavior consistent with the majority of modes being of an extended nature, rather than localized.Comment: Accepted for publication in The Journal of Chemical Physic

Avaliação da Combinação de Microagulhamento com Tacrolimus no Tratamento de Vitiligo Estável

Introduction: Vitiligo is an amelanotic disorder that can manifest as localized patches to near total body depigmentation. It is considered a cosmetic disease but it is accompanied by extensive psychological effects. Multiple treatments have been tried until now but no single method has achieved the desired response. Tacrolimus is frequently used for vitiligo treatment with few adverse effects. Microneedling is a newer modality of therapeutic wounding that augments drug absorption. Combination of microneedling and tacrolimus have been tried to improve the repigmentation response in vitiligo. Our objective was to assess the safety and efficacy of this combined modality. Methods: Forty patients were subjected to combination of tacrolimus 0.1% ointment and microneedling at 2 week intervals for maximum 10 sessions with a follow-up period of 6 months. Assessment was based on grading of repigmentation and clinical improvement according to vitiligo noticeability scale. Results: Excellent repigmentation was observed in 30% cases. Improvement was significantly higher in lesions present on the head and neck. Mucosal vitiligo also showed good to excellent response. No severe side effects were reported. No complications or recurrences were observed during the follow-up period. Conclusion: Combination of microneedling and tacrolimus was found to be safe and efficacious in the treatment of stable vitiligo.Introdução: O vitiligo é uma doença amelanótica que pode se manifestar como manchas localizadas até quase à despigmentação total. É considerada uma doença cosmética, mas é acompanhada por extensos efeitos psicológicos. Vários tratamentos foram tentados até agora, mas nenhum método atingiu a resposta desejada. O tacrolimus é um agente frequentemente usado para o tratamento do vitiligo com um perfil mínimo de efeitos colaterais. O microagulhamento é uma modalidade mais recente de ferimento terapêutico que aumenta a absorção de fàrmacos. A combinação de microagulhamento e tacrolimus tem sido tentada para melhorar a resposta de repigmentação no vitiligo. Nosso objetivo foi avaliar a segurança e eficácia desta modalidade combinada. Métodos: Quarenta pacientes foram submetidos à combinação de tacrolimus 0,1% pomada e microagulhamento em intervalos de 2 semanas por um máximo de 10 sessões com um período de acompanhamento de 6 meses. A avaliação foi baseada na graduação de repigmentação e melhora clínica de acordo com a escala de perceptibilidade do vitiligo. Resultados: Excelente repigmentação foi observada em 30% dos casos. A melhora foi significativamente maior nas lesões presentes na cabeça e pescoço. O vitiligo mucoso também mostrou boa a excelente resposta. Não foram relatados efeitos colaterais graves. Nenhuma complicação ou recorrência foi observada durante o período de acompanhamento. Conclusão: A combinação de microagulhamento e tacrolimus é considerada segura e eficaz no tratamento do vitiligo estável. Compreender e estudar o risco de infeção na utilização de terapêutica imunossupressora permite a sua aplicação de forma mais informada e segura

Impact of borehole depths on reconstructed estimates of ground surface temperature histories and energy storage

Estimates of ground surface temperature changes and continental energy storage from geothermal data have become well-accepted indicators of climatic changes. These estimates are independent contributions to the ensemble of paleoclimatic reconstructions and have been used for the validation of general circulation models, and as a component of the energy budget accounting of the global climate system. Recent global and hemispheric analyses of geothermal data were based on data available in the borehole paleoclimatology database, which contains subsurface temperature profiles from a minimum depth of 200 m to about 600 m. Because of the nature of heat conduction, different depth ranges contain the record of past and persistent changes in the energy balance between the lower atmosphere and the ground for different time periods. Here we examine the dependency of estimated ground surface temperature histories and the magnitude of the subsurface heat content on the depth of borehole temperature profiles. Our results show that uncertainties in the estimates of the long-term surface temperature are in the range of ±0.5K. We conclude that previous estimates of ground surface temperature change remain valid for the period since industrialization, but longer-term estimates are subject to considerable uncertainties. The subsurface heat content shows a larger range of variability arising from differences in depth of the borehole temperature profiles, as well as from differences in the time of data acquisition, spanning four decades. These results indicate that estimates of subsurface heat should be carried out with caution to decrease cumulative errors in any spatial analysis

Ground surface temperature and continental heat gain: uncertainties from underground

Temperature changes at the Earthʼs surface propagate and are recorded underground as perturbations to the equilibrium thermal regime associated with the heat flow from the Earthʼs interior. Borehole climatology is concerned with the analysis and interpretation of these downward propagating subsurface temperature anomalies in terms of surface climate. Proper determination of the steady-state geothermal regime is therefore crucial because it is the reference against which climate-induced subsurface temperature anomalies are estimated. Here, we examine the effects of data noise on the determination of the steady-state geothermal regime of the subsurface and the subsequent impact on estimates of ground surface temperature (GST) history and heat gain. We carry out a series of Monte Carlo experiments using 1000 Gaussian noise realizations and depth sections of 100 and 200 m as for steady-state estimates depth intervals, as well as a range of data sampling intervals from 10 m to 0.02 m. Results indicate that typical uncertainties for 50 year averages are on the order of ±0.02 K for the most recent 100 year period. These uncertainties grow with decreasing sampling intervals, reaching about ±0.1 K for a 10 m sampling interval under identical conditions and target period. Uncertainties increase for progressively older periods, reaching ±0.3 K at 500 years before present for a 10 m sampling interval. The uncertainties in reconstructed GST histories for the Northern Hemisphere for the most recent 50 year period can reach a maximum of ±0.5 K in some areas. We suggest that continuous logging should be the preferred approach when measuring geothermal data for climate reconstructions, and that for those using the International Heat Flow Commission database for borehole climatology, the steady-state thermal conditions should be estimated from boreholes as deep as possible and using a large fitting depth range (~100 m)

Impact of maximum borehole depths on inverted temperature histories in borehole paleoclimatology

A quantitative assessment is presented for the impact of the maximum depth of a temperature-depth profile on the estimate of the climatic transient and the resultant ground surface temperature (GST) reconstruction used in borehole paleoclimatology. The depth of the profile is important because the downwelling climatic signal must be separated from the quasi-steady state thermal regime established by the energy in the Earth's interior. This component of the signal is estimated as a linear increase in temperature with depth from the lower section of a borehole temperature profile, which is assumed to be unperturbed by recent changes in climate at the surface. The validity of this assumption is dependent on both the subsurface thermophysical properties and the character of the downwelling climatic signal. Such uncertainties can significantly impact the determination of the quasi-steady state thermal regime, and consequently the magnitude of the temperature anomaly interpreted as a climatic signal. The quantitative effects and uncertainties that arise from the analysis of temperature-depth profiles of different depths are presented. Results demonstrate that widely different GST histories can be derived from a single temperature profile truncated at different depths. Borehole temperature measurements approaching 500-600 m depths are shown to provide the most robust GST reconstructions spanning 500 to 1000 yr BP. It is further shown that the bias introduced by a temperature profile of depths shallower than 500-600 m remains even if the time span of the reconstruction target is shortened

On the static length of relaxation and the origin of dynamic heterogeneity in fragile glass-forming liquids

The most puzzling aspect of the glass transition observed in laboratory is an apparent decoupling of dynamics from structure. In this paper we recount the implication of various theories of glass transition for the static correlation length in an attempt to reconcile the dynamic and static lengths associate with the glass problem. We argue that a more recent characterization of the static relaxation length based on the bond ordering scenario, as the typical length over which the energy fluctuations are correlated, is more consistent with, and indeed in perfect agreement with the typical linear size of the dynamically heterogeneous domains observed in deeply supercooled liquids. The correlated relaxation of bonds in terms of energy is therefore identified as the physical origin of the observed dynamic heterogeneity.Comment: 6 pages, 1 figur

Biobanking from the patient perspective

Biobanks and biobanking research plays an increasingly important role in healthcare research and delivery as health systems become more patient-centred and medicine becomes more personalised. There is also growing acceptance and appreciation of the value that patients, patient advocacy organisations and the public can bring as stakeholders in biobanking and more generally in research. Therefore, the importance of active, early and sustained engagement and involvement of patient and public representatives in biobanks will become increasingly relevant. Organising and facilitating patient and public involvement in biobanking takes considerable time and effort for all stakeholders involved. Therefore, for any biobank operator considering involving patients and the public in their biobanking activities, consideration of best practices, current guidance, ethical issues and evaluation of involvement will be important. In this article, we demonstrate that patients are much more than donors to biobanks—they are collaborators at the heart of biobanking with an important voice to identify perspective, which can be an extremely valuable resource for all biobanks to utilise. The case studies herein provide examples of good practice of patient involvement in biobanking as well as outcomes from these practices, and lessons learned. Our aim is to provide useful insights from these efforts and potential future strategies for the multiple stakeholders that work with patients and the public involved in biobank-based research