Insights into the structure of liquid water from nuclear quantum effects on density and compressibility of ice polymorphs

Nuclear quantum effects lead to an anomalous shift of the volume of hexagonal ice; heavy ice has a larger volume than light ice. This anomaly in ice increases with temperature and persists in liquid water up to the boiling point. We study nuclear quantum effects on the density and compressibility of several ice-like structures and crystalline ice phases. By calculating the anisotropic contributions to the stain tensor, we analyze how the compressibility changes along different directions in hexagonal ice, and find that hexagonal ice is softer along the x-y plane than the z-direction. Furthermore, by performing ab initio density functional theory calculations with a van der Waals functional and with the quasiharmonic approximation, we find an anomalous isotope effect in the bulk modulus of hexagonal ice: heavy ice has a smaller bulk modulus than light ice. In agreement with the experiments, we also obtain an anomalous isotope effect for clathrate hydrate structure I. For the rest of the ice polymorphs, the isotope effect is: i) anomalous for ice IX, Ih, Ic, clathrate, and low density liquid-like amorphous ice; ii) normal at T=0 K and becomes anomalous with increasing temperature for ice IX, II, high density liquid-like amorphous ices, and ice XV; iii) normal for ice VIII up to the melting point. There is a transition from an anomalous isotope effect to a normal isotope effect for both the volume and bulk modulus, as the density (compressibility) of the structures increases (decreases). This result can explain the anomalous isotope effect in liquid water: as the compressibility decreases from melting point to the compressibility minimum temperature, the difference between the volumes of the heavy and light water rapidly decreases, but the effect stays anomalous up to the boiling temperature as the hydrogen bond network is never completely broken by fully filling all the interstitial sites.Comment: 17 pages, 15 figure

Between a rock and a hard place: corporate elites in the context of religion and secularism in Turkey

Drawing on discourse analyses of 36 in-depth interviews with elite business people from Turkey, the study identifies the networking patterns of new and established business elites in the context of economic liberalization and socioreligious transformation of the country. Through a comparative analysis of the so-called secular and religious elite networks, we demonstrate the role of institutional actors such as the government, and identity networks, based on religion and place of birth in shaping the form and content of social networks among business elites in Turkey. In order to achieve this, we operationalize Bourdieu's notion of theory of practice and Granovetter's theory of social networks, illustrating the utility of combining these approaches in explicating the form and content of social networks in their situated contexts, in which power and divergent interests are negotiated.Galatasaray University Research Fund [grant number 12.102.005]

Anomalous Nuclear Quantum Effects in Ice

One striking anomaly of water ice has been largely neglected and never explained. Replacing hydrogen ($^1$H) by deuterium ($^2$H) causes ice to expand, whereas the "normal" isotope effect is volume contraction with increased mass. Furthermore, the anomaly increases with temperature $T$, even though a normal isotope shift should decrease with $T$ and vanish when $T$ is high enough to use classical nuclear motions. In this study, we show that these effects are very well described by {\it ab initio} density functional theory. Our theoretical modeling explains these anomalies, and allows us to predict and to experimentally confirm a counter effect, namely that replacement of $^{16}$O by $^{18}$O causes a normal lattice contraction.Comment: 5 pages, 3 figure

The Future Mortality of High Mortality Countries: A Model Incorporating Expert Arguments

This paper examines the future of mortality in the 65 countries still experiencing high mortality in 2010, as defined by a cutoff of 40 deaths before age five per thousand live births. Mortality declines in several countries stagnated or reversed in the last two decades of the twentieth century due mainly to HIV/AIDS. The forces underlying past mortality trends and affecting the future course of mortality are examined by reviewing the existing literature and reporting the results of the global survey and invited meeting, both involving mortality experts. The experts assessed the likelihood and weight of forces hypothesized to influence mortality. A statistical model is combined with these expert assessments to produce a set of mortality assumptions that are incorporated into the projections reported in this paper. This paper also addresses the limited availability of reliable data on age-specific mortality rates

Leptin and resistin levels in serum of patients with hematologic malignancies: correlation with clinical characteristic

Aim:To evaluate leptin and resistin levels in patients with various hematologic malignancies. Methods: We included 21 patients with lymphoma, 14 with multiple myeloma (MM), 14 with acute leukemia, 13 with chronic lymphocytic leukemia (CLL), and 25 healthy control subjects into our study. The subjects’ body mass indexes (BMI) were calculated; hematological and acute phase response parameters, serum lipid were determined; serum leptin and resistin levels were determined by ELISA. Results: Serum leptin level was significantly increased in CLL and MM groups when compared to the control group (p < 0.01). Resistin level was significantly higher in lymphoma patients than in CLL, acute leukemia and control groups (p < 0.01). In the control group, leptin level was negatively correlated with hemoglobin level (r = –0.44, p = 0.047); and in all patients with hematologic malignancies, leptin level was correlated with BMI (r = 0.32, p = 0.02). Leptin in lymphoma subjects correlated with hemoglobin level (r = 0.64, p = 0.005), resistin level correlated with the platelet count in patients with hematologic malignancies (r = 0.26, p = 0.044). In addition, leptin level had negative correlations with international prognostic score (IPS) in Hodgkin lymphoma (r = –0.9, p = 0.002) and with international prognostic index (IPI) in non-Hodgkin lymphoma (r = –0.77, p = 0.03). In CLL patients, leptin level had a correlation with the poor prognostic marker — CD38 level (r = 0.68, p = 0.03). Conclusion: We found higher leptin levels in MM and CLL patients, and higher resistin levels in lymphoma patients: this fact demonstrates that changes in adipose tissue and metabolism occur in these disease states.Цель: определить уровни содержания лептина и резистина в сыворотке крови больных с различными онкогематологическими заболеваниями. Методы: обследован 21 больной лимфомой, 14 — множественной миеломой (ММ), 14 — острой лейкемией, 13 — хронической лимфоцитарной лейкемией (ХЛЛ), и 25 здоровых доноров. У пациентов определены такие характеристики: индекс массы тела (ИМТ), гематологические параметры, содержание липидов в сыворотке крови. Содержание лептина и резистина в сыворотке крови определяли иммуноферментным методом. Результаты: уровень лептина в сыворотке крови был значительно выше у больных с ХЛЛ и ММ, чем таковой у контрольной группы (р < 0,01). Уровень резистина был значительно выше в группе больных с лимфомами по сравнению с ХЛЛ, острой лейкемией и контрольной группами (р < 0,01). В контрольной группе уровень лептина отрицательно коррелировал с уровнем гемоглобина (r = –0,44, р = 0,047), а во всех группах больных уровень лептина коррелировал с ИМТ (r = 0,32, р = 0,02). Уровень лептина при лимфомах коррелировал с уровнем гемоглобина (r = 0,64, р = 0,005), уровень резистина коррелировал с количеством тромбоцитов у больных всех групп (r = 0,26, р = 0,044). При лимфоме Ходжкина выявлена отрицательная корреляция между уровнем лептина и величиной международной прогностической шкалы (r = -0,9, р = 0,002), при неходжкинской лимфоме — величиной международного прогностического индекса (r = –0,77, р = 0,03), у больных ХЛЛ — с уровнем экспрессии CD38 (r = 0,68, р = 0,03). Выводы: у больных ММ и ХЛЛ выявлен высокий уровень лептина, а с лимфомами — высокий уровень резистина: этот факт указывает на то, что у больных указанными онкогематологическими заболеваниями могут возникать изменения в структуре жировой ткани и обмене веществ

Lymphocyte subsets and the role of Th1/Th2 balance in stressed chronic pain patients

Background: The complex regional pain syndrome (CRPS) and fibromyalgia (FM) are chronic pain syndromes occurring in highly stressed individuals. Despite the known connection between the nervous system and immune cells, information on distribution of lymphocyte subsets under stress and pain conditions is limited. Methods: We performed a comparative study in 15 patients with CRPS type I, 22 patients with FM and 37 age- and sex-matched healthy controls and investigated the influence of pain and stress on lymphocyte number, subpopulations and the Th1/Th2 cytokine ratio in T lymphocytes. Results: Lymphocyte numbers did not differ between groups. Quantitative analyses of lymphocyte subpopulations showed a significant reduction of cytotoxic CD8+ lymphocytes in both CRPS (p < 0.01) and FM (p < 0.05) patients as compared with healthy controls. Additionally, CRPS patients were characterized by a lower percentage of IL-2-producing T cell subpopulations reflecting a diminished Th1 response in contrast to no changes in the Th2 cytokine profile. Conclusions: Future studies are warranted to answer whether such immunological changes play a pathogenetic role in CRPS and FM or merely reflect the consequences of a pain-induced neurohumoral stress response, and whether they contribute to immunosuppression in stressed chronic pain patients. Copyright (c) 2008 S. Karger AG, Basel