A new type of carbon resistance thermometer with excellent thermal contact at millikelvin temperatures

Using a new brand of commercially available carbon resistor we built a cryogenic thermometer with an extremely good thermal contact to its thermal environment. Because of its superior thermal contact the thermometer is insensitive to low levels of spurious radio frequency heating. We calibrated our thermometer down to 5mK using a quartz tuning fork He-3 viscometer and measured its thermal resistance and thermal response time.Comment: 5 pages, 4 figure

Empirical Evidence on the Use of Credit Scoring for Predicting Insurance Losses with Psycho-social and Biochemical Explanations

An important development in personal lines of insurance in the United States is the use of credit history data for insurance risk classification to predict losses. This research presents the results of collaboration with industry conducted by a university at the request of its state legislature. The purpose was to see the viability and validity of the use of credit scoring to predict insurance losses given its controversial nature and criticism as redundant of other predictive variables currently used. Working with industry and government, this study analyzed more than 175,000 policyholders’ information for the relationship between credit score and claims. Credit scores were significantly related to incurred losses, evidencing both statistical and practical significance. We investigate whether the revealed relationship between credit score and incurred losses was explainable by overlap with existing underwriting variables or whether the credit score adds new information about losses not contained in existing underwriting variables. The results show that credit scores contain significant information not already incorporated into other traditional rating variables (e.g., age, sex, driving history). We discuss how sensation seeking and self-control theory provide a partial explanation of why credit scoring works (the psycho-social perspective). This article also presents an overview of biological and chemical correlates of risk taking that helps explain why knowing risk-taking behavior in one realm (e.g., risky financial behavior and poor credit history) transits to predicting risk-taking behavior in other realms (e.g., automobile insurance incurred losses). Additional research is needed to advance new nontraditional loss prediction variables from social media consumer information to using information provided by technological advances. The evolving and dynamic nature of the insurance marketplace makes it imperative that professionals continue to evolve predictive variables and for academics to assist with understanding the whys of the relationships through theory development.IC2 Institut

Dark mammoth trunks in the merging galaxy NGC 1316 and a mechanism of cosmic double helices

NGC 1316 is a giant, elliptical galaxy containing a complex network of dark, dust features. The morphology of these features has been examined in some detail using a Hubble Space Telescope, Advanced Camera for Surveys image. It is found that most of the features are constituted of long filaments. There also exist a great number of dark structures protruding inwards from the filaments. Many of these structures are strikingly similar to elephant trunks in H II regions in the Milky Way Galaxy, although much larger. The structures, termed mammoth trunks, generally are filamentary and often have shapes resembling the letters V or Y. In some of the mammoth trunks the stem of the Y can be resolved into two or more filaments, many of which showing signs of being intertwined. A model of the mammoth trunks, related to a recent theory of elephant trunks, is proposed. Based on magnetized filaments, the model is capable of giving an account of the various shapes of the mammoth trunks observed, including the twined structures.Comment: Accepted for publication in Astrophysics & Space Scienc

Quantum lattice fluctuations in a frustrated Heisenberg spin-Peierls chain

As a simple model for spin-Peierls systems we study a frustrated Heisenberg chain coupled to optical phonons. In view of the anorganic spin-Peierls compound CuGeO3 we consider two different mechanisms of spin-phonon coupling. Combining variational concepts in the adiabatic regime and perturbation theory in the anti-adiabatic regime we derive effective spin Hamiltonians which cover the dynamical effect of phonons in an approximate way. Ground-state phase diagrams of these models are determined, and the effect of frustration is discussed. Comparing the properties of the ground state and of low-lying excitations with exact diagonalization data for the full quantum spin phonon models, good agreement is found especially in the anti-adiabatic regime.Comment: 9 pages, 7 figures included, submitted to Phys. Rev.

Using a socially-engaged arts approach to exploring how diverse socio-cultural groups accessed, valued, engaged with and benefited from an urban treescape during the COVID-19 Pandemic

This paper presents a socially-engaged arts approach to exploring the variety and specificity of cultural benefits urban park-users associated with its treescape during the COVID-19 pandemic. Drawing on the cultural ecosystem services framework, cultural benefits are understood in terms of positive impacts to ‘experiences’ (our relational interactions with the environment), ‘capabilities’ (our knowledge and abilities in relation to environmental interaction) and ‘identities’ (our perceptions of our relationship with the environment). The research captured evidence of a broad range of people’s interactions with the human and non-human world, whilst opening up an inclusive space for respondents to reflect on and share feelings about the significance of these experiences. The methods employed attracted a range of ‘quieter voices’ to participate, particularly more vulnerable park-users. They also attended to the multiple levels at which people connected with treescapes during this time, from less conscious material engagements to more emotionally and culturally driven transactions. This case study research highlights the important role of the park’s treescape in supporting people to feel better during the COVID-19 crisis and their cultural associations and ties to it. However, it also explores feelings of concern for and perceived lack of influence over this valued resource as potentially disbenefiting wellbeing. It identifies experiences of environmental anxiety, emerging from a lack of certainty over and agency within urban green spaces and treescapes and the benefits they can provide. It concludes that management of treescapes and greenspaces should be sensitive to impacts on environmental emotion

Optically induced coherent intra-band dynamics in disordered semiconductors

On the basis of a tight-binding model for a strongly disordered semiconductor with correlated conduction- and valence band disorder a new coherent dynamical intra-band effect is analyzed. For systems that are excited by two, specially designed ultrashort light-pulse sequences delayed by tau relatively to each other echo-like phenomena are predicted to occur. In addition to the inter-band photon echo which shows up at exactly t=2*tau relative to the first pulse, the system responds with two spontaneous intra-band current pulses preceding and following the appearance of the photon echo. The temporal splitting depends on the electron-hole mass ratio. Calculating the population relaxation rate due to Coulomb scattering, it is concluded that the predicted new dynamical effect should be experimentally observable in an interacting and strongly disordered system, such as the Quantum-Coulomb-Glass.Comment: to be published in Physical Review B15 February 200

Childbirth after adolescent and young adult cancer: a population-based study

Purpose: Annually, > 45,000 US women are diagnosed with cancer during adolescence and young adulthood (AYA). Since 2006, national guidelines have recommended fertility counseling for cancer patients. We examined childbirth after AYA cancer by calendar period, cancer diagnosis, and maternal characteristics. Methods: We identified a cohort of women with an incident invasive AYA cancer diagnosis at ages 15–39 during 2000–2013 in North Carolina. Cancer records were linked with statewide birth certificates through 2014. Hazard ratios (HR) and 95% confidence intervals (CI) for first post-diagnosis live birth were calculated using Cox proportional hazards regression. Results: Among 17,564 AYA cancer survivors, 1989 had ≥ 1 birth after diagnosis during 98,397 person-years. The 5- and 10-year cumulative incidence of live birth after cancer was 10 and 15%, respectively. AYA survivors with a post-diagnosis birth were younger at diagnosis, had lower stage disease, and had less often received chemotherapy than those without a birth. The 5-year cumulative incidence of post-diagnosis birth was 10.0% for women diagnosed during 2007–2012, compared to 9.4% during 2000–2005 (HR = 1.01; 0.91, 1.12), corresponding to periods before and after publication of American Society of Clinical Oncology fertility counseling guidelines in 2006. Conclusions: Despite advances in fertility preservation options and recognition of fertility counseling as a part of high-quality cancer care, the incidence of post-diagnosis childbirth has remained stable over the last 15 years. Implications for Cancer Survivors: Our study uses statewide data to provide recent, population-based estimates of how often AYA women have biological children after a cancer diagnosis

Birth outcomes among adolescent and young adult cancer survivors

IMPORTANCE: Cancer diagnosis and treatment may adversely affect reproductive outcomes among female cancer survivors. OBJECTIVE: To compare the birth outcomes of adolescent and young adult cancer survivors (AYA [diagnosed at ages 15-39 years]) with those of women without a cancer diagnosis. DESIGN, SETTING, AND PARTICIPANTS: The North Carolina Central Cancer Registry (CCR) was used to identify female AYA cancer survivors diagnosed from January 2000 to December 2013; CCR records were linked to statewide birth certificate files from January 2000 to December 2014 to identify postdiagnosis live births to AYA survivors (n = 2598). A comparison cohort of births to women without a recorded cancer diagnosis was randomly selected from birth certificate files (n = 12 990) with frequency matching on maternal age and year of delivery. MAIN OUTCOMES AND MEASURES: Prevalence of preterm birth, low birth weight, small-for-gestational-age births, cesarean delivery, and low Apgar score. RESULTS: Overall, 2598 births to AYA cancer survivors (mean [SD] maternal age, 31 [5] years) were included. Births to AYA cancer survivors had a significantly increased prevalence of preterm birth (prevalence ratio [PR], 1.52; 95% CI, 1.34-1.71), low birth weight (PR, 1.59; 95% CI, 1.38-1.83), and cesarean delivery (PR, 1.08; 95% CI, 1.01-1.14) relative to the comparison cohort of 1299. The higher prevalence of these outcomes was most concentrated among births to women diagnosed during pregnancy. Other factors associated with preterm birth and low birth weight included treatment with chemotherapy and a diagnosis of breast cancer, non-Hodgkin lymphoma, or gynecologic cancers. The prevalence of small-for-gestational-age births and low Apgar score (<7) did not differ significantly between groups. CONCLUSIONS AND RELEVANCE: Live births to AYA cancer survivors may have an increased risk of preterm birth and low birth weight, suggesting that additional surveillance of pregnancies in this population is warranted. Our findings may inform the reproductive counseling of female AYA cancer survivors

Reversed anisotropies and thermal contraction of FCC (110) surfaces

The observed anisotropies of surface vibrations for unreconstructed FCC metal (110) surfaces are often reversed from the "common sense" expectation. The source of these reversals is investigated by performing ab initio density functional theory calculations to obtain the surface force constant tensors for Ag(110), Cu(110) and Al(110). The most striking result is a large enhancement in the coupling between the first and third layers of the relaxed surface, which strongly reduces the amplitude of out-of-plane vibrations of atoms in the first layer. This also provides a simple explanation for the thermal contraction of interlayer distances. Both the anisotropies and the thermal contraction arise primarily as a result of the bond topology, with all three (110) surfaces showing similar behavior.Comment: 13 pages, in revtex format, plus 1 postscript figur

Analysis of a spatial Lotka-Volterra model with a finite range predator-prey interaction

We perform an analysis of a recent spatial version of the classical Lotka-Volterra model, where a finite scale controls individuals' interaction. We study the behavior of the predator-prey dynamics in physical spaces higher than one, showing how spatial patterns can emerge for some values of the interaction range and of the diffusion parameter.Comment: 7 pages, 7 figure