Electronic structure and transport properties of atomic NiO spinvalves

Ab-initio quantum transport calculations show that short NiO chains suspended in Ni nanocontacts present a very strong spin-polarization of the conductance. The generalized gradient approximation we use here predicts a similiar polarization of the conductance as the one previously computed with non-local exchange, confirming the robustness of the result. Their use as nanoscopic spinvalves is proposed.Comment: 2 pages, 1 figure; accepted in JMMM (Proceedings of ICM'06, Kyoto

Use of W-Boson Longitudinal-Transverse Interference in Top Quark Spin-Correlation Functions: II

This continuation of the derivation of general beam-referenced stage-two spin-correlation functions is for the analysis of top-antitop pair-production at the Tevatron and at the Large Hadron Collider. Both the gluon-production and the quark-production contributions are included for the charged-lepton-plus-jets reaction p p or p bar{p} --> t bar{t} --> (W^+ b)(W^- bar{b}) --> (l^{+} nu b)(W^- bar{b}). There is a simple 4-angle beam-referenced spin-correlation function for determination of the relative sign of, or for measurement of a possible non-trivial phase between the two dominant helicity amplitudes for t --> W^{+} b decay. There is an analogous function and tests for bar{t} --> W^{-} bar{b} decay. This signature requires use of the (t bar{t}) c.m.-energy of the hadronically decaying W-boson, or the kinematically equivalent cosine of the polar-angle of W-boson emission in the anti-top (top) decay frame. Spinors and their outer-products are constructed so that the helicity-amplitude phase convention of Jacob & Wick can be used throughout for the fixing of the signs associated with this large W-boson longitudinal-transverse interference effect.Comment: Continuation of hep-ph/0506240 to include gluon-production contribution; 3 "postscript" figures. Equation numbers as in published-on-line EPJ

Resolving Cosmic Neutrino Structure: A Hybrid Neutrino N-body Scheme

We present the first simulation capable of resolving the structure of neutrino clustering on Mpc scales. The method combines grid- and particle-based methods and achieves very good accuracy on both small and large scales, while keeping CPU consumption under control. Such simulations are not only ideal for calculating the non-linear matter power spectrum but also particularly relevant for studies of how neutrinos cluster in galaxy- or cluster-sized halos. We perform the largest neutrino N-body simulation to date, effectively containing 10 different neutrino hot dark matter components with different thermal properties.Comment: 13 pages, 6 figure

Ruptured abdominal aortic aneurysms: endovascular repair versus open surgery. A decision analytic approach

This thesis describes studies on the evaluation of endovascular repair versus open surgery in patients with ruptured abdominal aortic aneurysm (AAA). In chapter 1, the rationale for this research is presented. Since in the western world, the population is aging, it is expected that the incidence of abdominal aortic aneurysms will increase and consequently, ruptured AAAs. Ruptured AAA is a life threatening condition that requires immediate intervention. The condition can be treated with endovascular repair or open surgery. Therefore, the aim of this thesis was to investigate whether endovascular repair or open surgery would be the preferred treatment in this group of patients from a decision analytic approach, taking clinical effectiveness as well as costs into account. To enable comparison of the results of endovascular repair with open surgery in patients with a ruptured AAA from the literature, it is important to systemically evaluate the published studies and to adjust for differences in inclusion criteria among the studies. In chapter 2, we performed a systematic review of studies that compared endovascular repair with open surgery in the treatment of patients with a ruptured AAA. We found that, after adjustment for patients’ hemodynamic condition upon presentation, a benefit in 30-day mortality for endovascular repair compared with open surgery for patients with a ruptured AAA was observed but was not statistically significant. In chapter 3, we compared the clinical outcomes of treatment after endovascular repair and open surgery in patients with ruptured infrarenal AAAs including one-year follow-up. It turned out that in our study with a highly selective population, mortality and morbidity might be similar for patients with a ruptured infrarenal AAA treated with endovascular repair compared with open surgery, even after one- year follow-up. In addition to the aneurysm anatomy, other criteria may be needed for endovascular repair to improve clinical outcomes. The Glasgow Aneurysm Score (GAS) is a prediction rule to predict in- hospital mortality after open surgery for patients with ruptured and unruptured AAA. The GAS, however, was developed in patients treated with open surgery only, whereas nowadays, endovascular repair is the preferred treatment for repair of ruptured AAA in many European hospitals. In chapter 4, the GAS was validated in patients with ruptured AAA treated with endovascular repair or open surgery. In addition, our aim was to modify the GAS into an updated prediction rule that predicts 30-day mortality after endovascular repair or open surgery. We found that the GAS showed limited discriminative ability in our patient population. In addition, we showed that, considering the included risk factors, 30-day mortality was always lower if patients with ruptured AAA were treated with endovascular repair instead of with open surgery. To evaluate the incurred costs of both endovascular repair and open surgery, it is important to calculate both in-hospital costs and costs during follow-up after the procedure. Chapter 5 describes the retrospectively assessment of in-hospital costs and costs of one-year follow-up of endovascular repair and open surgery in patients with an acute infrarenal AAA, using the resource utilization approach. We found that total costs including in-hospital costs and one-year follow-up in patients with acute infrarenal AAA were lower for endovascular repair than for open surgery. From a health policy perspective, it should be questioned whether current available evidence justifies today’s policy to treat patients with ruptured AAA with endovascular repair if anatomically suitable. In addition, it is of interest whether additional information is required to inform the decision making process for patients with ruptured AAA in the future. Therefore, in chapter 6, we evaluated the cost-effectiveness of endovascular repair compared with open surgery in patients with ruptured AAA and investigated whether performing future research to obtain additional information is justified. We concluded that endovascular repair was more effective and less costly compared with open surgery in patients with ruptured AAA. Therefore, current available evidence does justify today’s policy to treat patients with ruptured AAA with endovascular repair if anatomically suitable. In addition, further research is justified and should concentrate on short-term costs and clinical! effectiveness of endovascular repair versus open surgery in patients with ruptured AAA. In chapter 7 the main findings were summarized of the preceding chapters and placed in a broader context. In addition, methodological considerations and future research were discussed

Glucocorticoids, vitamin D and bone : a pathophysiologic and therapeutic study of glucocorticoid-induced bone disease

Mooser's report ( 1921) of a patient with osteoporosis and obesity is one of the first descriptions of endogenous hypercortisolism. Later Cushing (1932) described the syndrome as a clinical entity and Albright et al. (1941) reported 9 patients who at autopsy all appeared to have sustained a severe degree of cortical and trabecular bone loss. In 1949 glucocorticoids (GC) became available as therapeutic agents. in addition to their favourable antiinflammatory action deleterious side effects (e.g. on bone mass) have become apparent (Kjellstrand, 1975). A diminished bone mass, measured as trabecular bone volume of iliac crest biopsies (Birkenhager et al., 1967) or by total body Ca with neutron activation analysis (Aloia et al., 1974), is a typical hallmark in patients with endogenous hypercortisolism. The impact of exogenous GC excess on bone mass is more difficult to evaluate. In the quantification of the amount of bone in such patients by several techniques one has to take into account not only the physiological age related bone loss (see Chapter II), but also the underlying disease for which GC are prescribed. This is illustrated by Stresemann & Krokowski ( 1967) who found signs of a decreased bone mineral content on X-rays of the vertebral column (using a quantitative measurement technique) in 32% of patients treated with varying doses of GC for chronic obstructive lung disease, but similar signs were observed in an equal percentage of patients who never had used steroids. However, Adinof & Hollister (1983) described a significant loss of trabecular bone mass at the metaphysis of the radius with single photonabsorptiometry only in asthmatic subjects on long-term daily steroids. Measurement of total body Ca with neutron activation analysis showed lower values in patients with rheumatoid arthritis treated with non steroidal antiinflammatory drugs than controls, but even lower values in rheumatic patients treated with steroids (Reid et a!., 1982). Similar findings were reported by Hahn et al. (J 973) with photonabsortiometry of the metaphyseal mass of the forearm. The decreased mineral content was correlated with the duration of GC therap

Menstrual cycle phase and sexual arousability in women

__Abstract__ Sexual arousability of women has not been consistently found to vary significantly over phases of the menstrual cycle. We studied changes in the temperature of a labium minus and subjective sexual and genital arousal recorded on semantic scales while watching erotic video in 12 women with natural menstrual cycles and 12 women using low-dose estrogen oral contraceptive pills. Natural cycle phase was ascertained by blood progesterone. Subjects were tested twice, with an interval of about 2 weeks. Half of each group had their first test during their luteal phase, the others during their follicular phase. Women tested for the first time in their follicular phase were sexually more aroused than women tested for the first time during their luteal phase. This was true for both objective (i.e., a labium minus change in temperature) and subjective genital arousal. When these women were retested in their alternative phase of the menstrual cycle, those who were then follicular did not score higher than those who were then luteal. On the contrary, the latter group scored as high as when tested during their follicular phase. This phenomenon was observed both in women with and without oral contraception. The nature of the menstrual phase (i.e., natural or pill-induced) seems irrelevant in this respect. Sexual arousal achieved during the first session appeared to be correlated with an increase in desire for making love during the rest of the day and night. Only 1 of 12 women tested during their luteal phase indicated an increase in desire to make love, while 6 of 12 women tested during their follicular phase indicated an increase. Apparently the menstrual cycle phase during the first test determines the immediate response and indirectly affects the response during the second test approximately 10 days later. In a random block design the difference in sexual response between follicular and luteal phase of the menstrual cycle disappears

Experimental determination of the eutectic temperature in air of the CuO-TiO2 pseudobinary system

Eutectic temperature and composition in the CuO–TiO2 pseudobinary system have been experimentally determined in air by means differential thermal analysis (DTA), thermogravimetry (TG) and hot-stage microscopy (HSM). Samples of the new eutectic composition treated at different temperatures have been characterized by X-ray diffraction (XRD) and X-ray absorption near-edge structural spectroscopy (XANES) to identify phases and to determine the Cu valence state, respectively. The results show that the eutectic temperature in air is higher by 100 °C (∼1000 °C) for a Ti-richer composition (XTiO2=25 mol%) than the one calculated in the literature. The reduction of Cu2+ to Cu+ takes places at about 1030 °C. The existence of Cu2TiO3 and Cu3TiO4 has been confirmed by XRD in the temperature range between 1045 and 1200 °C

Cumulative Head Impact Burden in High School Football

Impacts to the head are common in collision sports such as football. Emerging research has begun to elucidate concussion tolerance levels, but sub-concussive impacts that do not result in clinical signs or symptoms of concussion are much more common, and are speculated to lead to alterations in cerebral structure and function later in life. We investigated the cumulative number of head impacts and their associated acceleration burden in 95 high school football players across four seasons of play using the Head Impact Telemetry System (HITS). The 4-year investigation resulted in 101,994 impacts collected across 190 practice sessions and 50 games. The number of impacts per 14-week season varied by playing position and starting status, with the average player sustaining 652 impacts. Linemen sustained the highest number of impacts per season (868); followed by tight ends, running backs, and linebackers (619); then quarterbacks (467); and receivers, cornerbacks, and safeties (372). Post-impact accelerations of the head also varied by playing position and starting status, with a seasonal linear acceleration burden of 16,746.1g, while the rotational acceleration and HIT severity profile burdens were 1,090,697.7-rad/sec2 and 10,021, respectively. The adolescent athletes in this study clearly sustained a large number of impacts to the head, with an impressive associated acceleration burden as a direct result of football participation. These findings raise concern about the relationship between sub-concussive head impacts incurred during football participation and late-life cerebral pathogenesis, and justify consideration of ways to best minimize impacts and mitigate cognitive declines.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90454/1/neu-2E2011-2E1825.pd