Cost-effectiveness of diagnostic laparoscopy for assessing resectability in pancreatic and periampullary cancer.

Surgical resection is the only curative treatment for pancreatic and periampullary cancer, but many patients undergo unnecessary laparotomy because tumours can be understaged by computerised tomography (CT). A recent Cochrane review found diagnostic laparoscopy can decrease unnecessary laparotomy. We compared the cost-effectiveness of diagnostic laparoscopy prior to laparotomy versus direct laparotomy in patients with pancreatic and periampullary cancer with resectable disease based on CT scanning

Cost-Effectiveness Analysis of Endoscopic Ultrasound versus Magnetic Resonance Cholangiopancreatography in Patients with Suspected Common Bile Duct Stones.

Patients with suspected common bile duct (CBD) stones are often diagnosed using endoscopic retrograde cholangiopancreatography (ERCP), an invasive procedure with risk of significant complications. Using endoscopic ultrasound (EUS) or Magnetic Resonance CholangioPancreatography (MRCP) first to detect CBD stones can reduce the risk of unnecessary procedures, cut complications and may save costs

Quantum spacetime and the renormalization group: Progress and visions

The quest for a consistent theory which describes the quantum microstructure of spacetime seems to require some departure from the paradigms that have been followed in the construction of quantum theories for the other fundamental interactions. In this contribution we briefly review two approaches to quantum gravity, namely, asymptotically safe quantum gravity and tensor models, based on different theoretical assumptions. Nevertheless, the main goal is to find a universal continuum limit for such theories and we explain how coarse-graining techniques should be adapted to each case. Finally, we argue that although seemingly different, such approaches might be just two sides of the same coin.Comment: 14 pages, 4 figures, Proceedings of "Progress and Visions in Quantum Theory in View of Gravity: Bridging foundations of physics and mathematics", Leipzig, 201

Constraining Proton Lifetime in SO(10) with Stabilized Doublet-Triplet Splitting

We present a class of realistic unified models based on supersymmetric SO(10) wherein issues related to natural doublet-triplet (DT) splitting are fully resolved. Using a minimal set of low dimensional Higgs fields which includes a single adjoint, we show that the Dimopoulos--Wilzcek mechanism for DT splitting can be made stable in the presence of all higher order operators without having pseudo-Goldstone bosons and flat directions. The \mu term of order TeV is found to be naturally induced. A Z_2-assisted anomalous U(1)_A gauge symmetry plays a crucial role in achieving these results. The threshold corrections to alpha_3(M_Z), somewhat surprisingly, are found to be controlled by only a few effective parameters. This leads to a very predictive scenario for proton decay. As a novel feature, we find an interesting correlation between the d=6 (p\to e^+\pi^0) and d=5 (p\to \nu-bar K+) decay amplitudes which allows us to derive a constrained upper limit on the inverse rate of the e^+\pi^0 mode. Our results show that both modes should be observed with an improvement in the current sensitivity by about a factor of five to ten.Comment: 21 pages LaTeX, 2 figures, Few explanatory sentences and three new references added, minor typos corrected

Symmetries of degenerate center singularities of plane vector fields

Let $D$ be a closed unit $2$-disk on the plane centered at the origin $O$, and $F$ be a smooth vector field such that $O$ is a unique singular point of $F$ and all other orbits of $F$ are simple closed curves wrapping once around $O$. Thus topologically $O$ is a "center" singularity. Let also $\mathrm{Diff}(F)$ be the group of all diffeomorphisms of $D$ which preserve orientation and orbits of $F$. In arXiv:0907.0359 the author described the homotopy type of $\mathrm{Diff}(F)$ under assumption that the $1$-jet of $F$ at $O$ is non-degenerate. In this paper degenerate case is considered. Under additional "non-degeneracy assumptions" on $F$ the path components of $\mathrm{Diff}(F)$ with respect to distinct weak topologies are described.Comment: 21 page, 3 figure

Contraception needs and pregnancy termination in sub-Saharan Africa: a multilevel analysis of demographic and health survey data

Background: Women in sub-Saharan Africa (SSA) have a higher risk of unintended pregnancies that are more likely to be terminated, most of which are unsafe with associated complications. Unmet need for contraception is highest in SSA and exceeds the global average. This study investigates the association between unmet/met need for contraception and pregnancy termination SSA. Methods: We used pooled data from Demographic and Health Surveys conducted from January 2010 to December 2018 in 32 countries in SSA. Our study involved 265,505 women with diverse contraception needs and with complete data on all variables of interest. Multilevel logistic regression at 95% CI was used to investigate the association between individual and community level factors and pregnancy termination. Results: We found an overall pregnancy termination rate of 16.27% ranging from 9.13% in Namibia to 38.68% in Gabon. Intriguingly, women with a met need for contraception were more likely to terminate a pregnancy [aOR = 1.11; 95% CI 1.07–1.96] than women with unmet needs. Women with secondary education were more likely to terminate a pregnancy as compared to those without education [aOR = 1.23; 95% CI 1.19–1.27]. With regards to age, we observed that every additional age increases the likelihood of terminating a pregnancy. At the contextual level, the women with female household heads were less likely to terminate a pregnancy [aOR = 0.95; 95% CI 0.92–0.97]. The least socio-economically disadvantaged women were less likely to terminate a pregnancy compared to the moderately and most socio-economically disadvantaged women. Conclusions: Our study contributes towards the discussion on unmet/met need for contraception and pregnancy termination across SSA. Women with met need for contraception have higher odds of terminating a pregnancy. The underlying cause of this we argued could be poor adherence to the protocols of contraceptives or the reluctance of women to utilise contraceptives after experiencing a failure. Governments of SSA and non-governmental organisations need to take pragmatic steps to increase met needs for contraception and also utilise mass media to encourage women to adhere to the prescription of contraceptives in order to reduce the incidence of unplanned pregnancies and unsafe abortions

Form-field gauge symmetry in M-theory

We show how to cast an interacting system of M‐branes into manifestly gauge‐invariant form using an arrangement of higher‐dimensional Dirac surfaces. Classical M‐theory has a cohomologically nontrivial and noncommutative set of gauge symmetries when written using a “doubled” formalism containing 3‐form and 6‐form gauge fields. We show how the arrangement of Dirac surfaces allows an integral subgroup of these symmetries to be preserved at the quantum level. The proper context for discussing these large gauge transformations is relative cohomology, in which the 3‐form transformation parameters become exact when restricted to the five‐brane worldvolume. This structure yields the correct lattice of M‐theory brane charges

No two gangs are alike: The digital divide in street gangs’ differential adaptations to social media

© 2020 The Authors Social media provide novel opportunities for street gangs to operate beyond their traditional borders to sell drugs, recruit members and control their territory, virtually and physically. Although social media have contributed to the means available to street gangs today, it does not mean that every gang agrees on their use. Drawing on different perspectives (ex-gang members, law enforcement) on gangs using a multi-method design in a London borough, the current study shows that social media have polarized gangs, resulting in two distinct types of digital adaptation. The proposed division of ‘digitalist’ and ‘traditionalist’ gangs is rooted in Thrasher's (1927) dictum that no two gangs are alike and explains how some gangs prefer to keep a low profile, thus, avoiding social media use. ‘Digitalists’, by contrast, prefer to use social media as a way to gain reputation and territorial expansion. They use it to brand themselves and to appear attractive for recruits and customers alike. These differences can be theoretically explained firstly as a generational gap, meaning that younger gang members prefer the use of social media; and secondly, by how well established a gang already is, as newer gangs need more attention to establish themselves

Induced innovation in clean energy technologies from foreign environmental policy stringency?

In this paper, we re-conceptualize the meaning of policy-induced innovations in clean technologies by taking a cross-border approach. Previously, empirical research has shown how domestic climate and environmental policies induce firms in the same country to innovate in clean and environmental technologies. This phenomenon has become known as the Porter Hypothesis. However, most research focuses strictly on domestic inducement effects and, if foreign effects are accounted for, they are assumed to be either “knowledge” or “technology” spillovers. We, however, propose that policy spillovers might also induce innovations in other countries. In order to test this hypothesis, we construct a “foreign” environmental policy stringency proxy. This proxy is used as the main explanatory variable, with the outcome variable clean technologies, defined here as all renewable energy technologies as well as electrical energy storage, because these technologies are predominantly defined within the scope of climate and environmental policies as necessary to combat climate change and set forth as paramount to stemming pollutant causing climate change in the United Nations Framework Convention on Climate Change founding documents. Our results show that foreign environmental policy stringency does, indeed, induce clean-technology innovation at home, but this effect varies with different lag structures in our three models

Abstract Interpretation of Stateful Networks

Modern networks achieve robustness and scalability by maintaining states on their nodes. These nodes are referred to as middleboxes and are essential for network functionality. However, the presence of middleboxes drastically complicates the task of network verification. Previous work showed that the problem is undecidable in general and EXPSPACE-complete when abstracting away the order of packet arrival. We describe a new algorithm for conservatively checking isolation properties of stateful networks. The asymptotic complexity of the algorithm is polynomial in the size of the network, albeit being exponential in the maximal number of queries of the local state that a middlebox can do, which is often small. Our algorithm is sound, i.e., it can never miss a violation of safety but may fail to verify some properties. The algorithm performs on-the fly abstract interpretation by (1) abstracting away the order of packet processing and the number of times each packet arrives, (2) abstracting away correlations between states of different middleboxes and channel contents, and (3) representing middlebox states by their effect on each packet separately, rather than taking into account the entire state space. We show that the abstractions do not lose precision when middleboxes may reset in any state. This is encouraging since many real middleboxes reset, e.g., after some session timeout is reached or due to hardware failure