Replacing energy by von Neumann entropy in quantum phase transitions

In the thermodynamic limit two distinct states of matter cannot be analytic continuations of each other. Classical phase transitions are characterized by non-analyticities of the free energy. For quantum phase transitions (QPTs) the ground state energy often assumes the role of the free energy. But in a number of important cases this criterion fails to predict a QPT, such as the three-dimensional metal-insulator transition of non-interacting electrons in a random potential (Anderson localization). It is therefore essential that we find alternative criteria that can track fundamental changes in the internal correlations of the ground state wavefunction. Here we propose that QPTs are generally accompanied by non-analyticities of the von Neumann (entanglement) entropy. In particular, the entropy is non-analytic at the Anderson transition, where it exhibits unusual fractal scaling. We also examine two dissipative quantum systems of considerable interest to the study of decoherence and find that non-analyticities occur if and only if the system undergoes a QPT.Comment: 8 pages, 6 figures; Annals of Physics, in press (2006

Critical evaluation of stents in coronary angioplasty: a systematic review

This is the final version. Available on open access from BMC via the DOI in this recordAvailability of data and materials: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.Background Coronary stents are routinely placed in the treatment and prophylaxis of coronary artery disease (CAD). Current coronary stent designs are prone to developing blockages: in-stent thrombosis (IST) and in-stent re-stenosis (ISR). This is a systematic review of the design of current coronary stent models, their structural properties and their modes of application, with a focus on their associated risks of IST and ISR. The primary aim of this review is to identify the best stent design features for reducing the risk of IST and ISR. To review the three major types of stents used in clinical settings today, determining best and relevant clinical practice by exploring which types and features of offer improved patient outcomes regarding coronary angioplasty. This information can potentially be used to increase the success rate of coronary angioplasty and stent technology in the future taking into account costs and benefits. Methods Scientific databases were searched to find studies concerning stents. After the exclusion criteria were applied, 19 of the 3192 searched literature were included in this review. Studies investigating three major types of stent design were found: bare-metal stents (BMS), drug-eluting stents (DES) and bioresorbable stents (BRS). The number of participants varied between 14 and 1264. On average 77.4% were male, with a mean age of 64 years. Results From the findings of these studies, it is clear that DES are superior in reducing the risk of ISR when compared to BMS. Conflicting results do not clarify whether BRS are superior to DES at reducing IST occurrence, although studies into newer BRS technologies show reducing events of IST to 0, creating a promising future for BRS showing them to be non-inferior. Thinner stents were shown to reduce IST rates, due to better re-endothelialisation. Scaffold material has also been shown to play a role with cobalt alloy stents reducing the risk of IST. This study found that thinner stents that release drugs were better at preventing re-blockages. Some dissolvable stents might be better at stopping blood clots blocking the arteries when compared to metal stents. The method and procedure of implanting the stent during coronary angioplasty influences success rate of these stents, meaning stent design is not the only significant factor to consider. Conclusions Positive developments in coronary angioplasty could be made by designing new stents that encompass all the most desirable properties of existing stent technology. Further work is needed to investigate the benefits of BRS in reducing the risk of IST compared to DES, as well as to investigate the effects of different scaffold materials on IST and ISR outcomes

Initial State Parton Broadening and Energy Loss Probed in d+Au at RHIC

The impact parameter and rapidity dependence of the Cronin effect for massless pions in $d+Au$ reactions at $\sqrt{s}_{NN}=200$ GeV at RHIC is computed in the framework of pQCD multiple elastic scattering on a nuclear target. We introduce a formalism to incorporate initial state energy loss in perturbative calculations and take into account the elastic energy loss in addition to the transverse momentum broadening of partons.We argue that the centrality dependence of the Cronin effect can distinguish between different hadron production scenarios at RHIC. Its magnitude and rapidity dependence are shown to carry important experimental information about the properties of cold nuclear matter up to the moderate- and large-$x$ antishadowing/EMC regions.Comment: 15 pages, 4 eps figures. Final version to appear in Phys.Lett.

Strategically Equivalent Contests

Using a two-player Tullock-type contest, we show that intuitively and structurally different contests can be strategically equivalent. Strategically equivalent contests generate the same best response functions and, as a result, the same equilibrium efforts. However, strategically equivalent contests may yield different equilibrium payoffs. We propose a simple two-step procedure to identify strategically equivalent contests. Using this procedure, we identify contests that are strategically equivalent to the original Tullock contest, and provide new examples of strategically equivalent contests. Finally, we discuss possible contest design applications and avenues for future theoretical and empirical research

Do disempowered childbearing women give birth at home in Sierra Leone? A secondary analysis of the 2019 Sierra Leone demographic health survey

From Springer Nature via Jisc Publications RouterHistory: received 2022-09-02, registration 2023-11-14, accepted 2023-11-14, epub 2023-11-22, online 2023-11-22, collection 2023-12Acknowledgements: We want to thank the MEASURE DHS for granting us access to use the 2019 SLDHS data.Publication status: PublishedAbdulai Jawo Bah - ORCID: 0000-0002-3334-7882 https://orcid.org/0000-0002-3334-7882Background: A nationwide assessment of the link between women’s empowerment and homebirth has not been fully examined in Sierra Leone. Our study examined the association between women’s empowerment and homebirth among childbearing women in Sierra Leone using the 2019 Sierra Leone Demographic Health Survey (2019 SLDHS) data. Method: We used the individual file (IR) of the 2019 SLDHS dataset for our analysis. A total of 7377 women aged 15–49 years who gave birth in the five years preceding the survey were included. Outcome variable was “home birth of their last child among women in the five years preceding the 2019 SLDHS. Women’s empowerment parameters include women’s knowledge level, economic participation, decision-making ability and power to refuse the idea of intimate partner violence. We used the complex sample command on SPSS version 28 to conduct descriptive and multivariate logistic regression analyses. Results: Three in every 20 women had home childbirth (n = 1177; 15.3%). Women with low [aOR 2.04; 95% CI 1.43–2.92] and medium [aOR 1.44; 95%CI 1.05–1.97] levels of knowledge had higher odds of giving birth at home compared to those with high levels of knowledge. Women who did not have power to refuse the idea of intimate partner violence against women were more likely to had given birth at home [aOR 1.38; 95% CI1.09-1.74]. In addition, women with no [aOR 2.71; 95% CI1.34-5.46) and less than four antenatal care visits [aOR 2.08; 95% CI:1.51–2.88] and for whom distance to a health facility was a major problem [aOR 1.95; 95% CI1.49-2.56] were more likely to have had a homebirth. However, no statistically significant association was observed between a women’s decision-making power and home birth [aOR 1.11; 95% CI 0.86–1.41]. Conclusion: Despite improvements in maternal health indicators, homebirth by unskilled birth attendants is still a public health concern in Sierra Leone. Women with low knowledge levels, who did not have power to refuse the idea of intimate partner violence against women, had less than four ANC visits and considered distance to a health facility as a major problem had higher odds of giving birth at home. Our findings reflect the need to empower women by improving their knowledge level through girl child and adult education, increasing media exposure, changing societal norms and unequal power relations that promote gender-based violence against women, and improving roads and transport infrastructure.pubpu

Shopping externalities and retail concentration:Evidence from dutch shopping streets

Why do shops cluster in shopping streets? We argue that retail firms benefit from shopping externalities. We identify these externalities for the main Dutch shopping streets by estimating the effect of footfall – the number of pedestrians that pass by – and the number of shops in the vicinity on store owners’ rental income. We address endogeneity issues by exploiting spatial variation within shopping streets combined with historic long-lagged instruments. Our estimates imply an elasticity of rental income with respect to footfall as well as number of shops in the vicinity of (at least) 0.25. We show that these shopping externalities are unlikely to be internalised. It follows that substantial subsidies to shop owners are welfare improving, seemingly justifying current policies. Finally, we find limited evidence for heterogeneity between retail firms located in shopping streets in their willingness to pay for shopping externalities

Prognostic and predictive value of clinical and biochemical factors in breast cancer patients with bone metastases receiving "metronomic" zoledronic acid

<p>Abstract</p> <p>Background</p> <p>To assess prognostic and predictive effects of clinical and biochemical factors in our published randomized study of a weekly low dose (metronomic arm) versus a conventional dosage of zoledronic acid (conventional arm) in breast cancer patients with bone metastases.</p> <p>Methods</p> <p>Treatment outcome of 60 patients with bone metastases were used to assess impacts of following potential prognostic factors, estrogen receptor status, lymph node status, 2 year-disease free interval (DFI), numbers of chemotherapy regimens administered, interventions, and serum levels of VEGF, N-telopeptide of type I collagen (NTx), CEA, and CA 15-3.</p> <p>Results</p> <p>In univariate analyses, patients pretreated with 2 or fewer chemotherapy regimens, ER-positive tumors, 3 or fewer lymph nodes, DFI of more than 2 years, serum VEGF of less than 500 pg/mL after 3 months of intervention, serum CEA and CA 15-3 of less than ULN, and baseline serum NTx of less than 18 nM BCE had significantly longer progression free survival (PFS). The multivariate analysis showed that ER positivity (hazard ratio [HR], 0.295; 95% confidence interval [CI], 0.141-0.618; P = 0.001), serum VEGF of less than 500 pg/mL after 3 months of intervention (HR, 2.220; 95% CI, 1.136-4.338; P = 0.020), baseline serum NTx of less than 18 nM BCE (HR, 2.842; 95% CI, 1.458-5.539; P = 0.001), and 2 or fewer chemotherapy regimens received (HR, 7.803; 95% CI, 2.884-21.112; P = 0.000) were associated with a better PFS. When evaluating the predictive effect of the biochemical factors, an interaction between NTx and zoledronic acid intervention was shown (P = 0.005). The HR of weekly low dose versus a conventional dosage of zoledronic acid was estimated to be 2.309 (99% CI, 1.067-5.012) in patients with baseline serum NTx of more than 18 nM BCE, indicating a superiority of weekly low dose of zoledronic acid.</p> <p>Conclusions</p> <p>ER, serum VEGF level after intervention, and numbers of chemotherapy regimens administered are prognostic but not predictive factors in breast cancer patients with bone metastases. Patients with baseline serum NTx of more than 18 nM BCE might benefit more from weekly low-dose of zoledronic acid.</p> <p>Trial registration</p> <p>ClinicalTrials.gov unique identifier: ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00524849">NCT00524849</a></p

Unravelling the mechanisms that determine the uptake and metabolism of magnetic single and multicore nanoparticles in a Xenopus laevis model.

Multicore superparamagnetic nanoparticles have been proposed as ideal tools for some biomedical applications because of their high magnetic moment per particle, high specific surface area and long term colloidal stability. Through controlled aggregation and packing of magnetic cores it is possible to obtain not only single-core but also multicore and hollow spheres with internal voids. In this work, we compare toxicological properties of single and multicore nanoparticles. Both types of particles showed moderate in vitro toxicity (MTT assay) tested in Hep G2 (human hepatocellular carcinoma) and Caco-2 (human colorectal adenocarcinoma) cells. The influence of surface chemistry in their biological behavior was also studied after functionalization with O,O′-bis(2-aminoethyl) PEG (2000 Da). For the first time, these nanoparticles were evaluated in a Xenopus laevis model studying their whole organism toxicity and their impact upon iron metabolism. The degree of activation of the metabolic pathway depends on the size and surface charge of the nanoparticles which determine their uptake. The results also highlight the potential of Xenopus laevis model bridging the gap between in vitro cell-based assays and rodent models for toxicity assessment to develop effective nanoparticles for biomedical applications