Encodings of Range Maximum-Sum Segment Queries and Applications

Given an array A containing arbitrary (positive and negative) numbers, we consider the problem of supporting range maximum-sum segment queries on A: i.e., given an arbitrary range [i,j], return the subrange [i' ,j' ] \subseteq [i,j] such that the sum of the numbers in A[i'..j'] is maximized. Chen and Chao [Disc. App. Math. 2007] presented a data structure for this problem that occupies {\Theta}(n) words, can be constructed in {\Theta}(n) time, and supports queries in {\Theta}(1) time. Our first result is that if only the indices [i',j'] are desired (rather than the maximum sum achieved in that subrange), then it is possible to reduce the space to {\Theta}(n) bits, regardless the numbers stored in A, while retaining the same construction and query time. We also improve the best known space lower bound for any data structure that supports range maximum-sum segment queries from n bits to 1.89113n - {\Theta}(lg n) bits, for sufficiently large values of n. Finally, we provide a new application of this data structure which simplifies a previously known linear time algorithm for finding k-covers: i.e., given an array A of n numbers and a number k, find k disjoint subranges [i_1 ,j_1 ],...,[i_k ,j_k ], such that the total sum of all the numbers in the subranges is maximized.Comment: 19 pages + 2 page appendix, 4 figures. A shortened version of this paper will appear in CPM 201

Longest Common Extensions in Trees

The longest common extension (LCE) of two indices in a string is the length of the longest identical substrings starting at these two indices. The LCE problem asks to preprocess a string into a compact data structure that supports fast LCE queries. In this paper we generalize the LCE problem to trees and suggest a few applications of LCE in trees to tries and XML databases. Given a labeled and rooted tree $T$ of size $n$, the goal is to preprocess $T$ into a compact data structure that support the following LCE queries between subpaths and subtrees in $T$. Let $v_1$, $v_2$, $w_1$, and $w_2$ be nodes of $T$ such that $w_1$ and $w_2$ are descendants of $v_1$ and $v_2$ respectively. \begin{itemize} \item \LCEPP(v_1, w_1, v_2, w_2): (path-path \LCE) return the longest common prefix of the paths $v_1 \leadsto w_1$ and $v_2 \leadsto w_2$. \item \LCEPT(v_1, w_1, v_2): (path-tree \LCE) return maximal path-path LCE of the path $v_1 \leadsto w_1$ and any path from $v_2$ to a descendant leaf. \item \LCETT(v_1, v_2): (tree-tree \LCE) return a maximal path-path LCE of any pair of paths from $v_1$ and $v_2$ to descendant leaves. \end{itemize} We present the first non-trivial bounds for supporting these queries. For \LCEPP queries, we present a linear-space solution with $O(\log^{*} n)$ query time. For \LCEPT queries, we present a linear-space solution with $O((\log\log n)^{2})$ query time, and complement this with a lower bound showing that any path-tree LCE structure of size O(n \polylog(n)) must necessarily use $\Omega(\log\log n)$ time to answer queries. For \LCETT queries, we present a time-space trade-off, that given any parameter $\tau$, $1 \leq \tau \leq n$, leads to an $O(n\tau)$ space and $O(n/\tau)$ query-time solution. This is complemented with a reduction to the the set intersection problem implying that a fast linear space solution is not likely to exist

Amphipathic DNA polymers exhibit antiviral activity against systemic Murine Cytomegalovirus infection

<p>Abstract</p> <p>Background</p> <p>Phosphorothioated oligonucleotides (PS-ONs) have a sequence-independent, broad spectrum antiviral activity as amphipathic polymers (APs) and exhibit potent in vitro antiviral activity against a broad spectrum of herpesviruses: HSV-1, HSV-2, HCMV, VZV, EBV, and HHV-6A/B, and in vivo activity in a murine microbiocide model of genital HSV-2 infection. The activity of these agents against animal cytomegalovirus (CMV) infections in vitro and in vivo was therefore investigated.</p> <p>Results</p> <p>In vitro, a 40 mer degenerate AP (REP 9) inhibited both murine CMV (MCMV) and guinea pig CMV (GPCMV) with an IC₅₀of 0.045 μM and 0.16 μM, respectively, and a 40 mer poly C AP (REP 9C) inhibited MCMV with an IC₅₀of 0.05 μM. Addition of REP 9 to plaque assays during the first two hours of infection inhibited 78% of plaque formation whereas addition of REP 9 after 10 hours of infection did not significantly reduce the number of plaques, indicating that REP 9 antiviral activity against MCMV occurs at early times after infection. In a murine model of CMV infection, systemic treatment for 5 days significantly reduced virus replication in the spleens and livers of infected mice compared to saline-treated control mice. REP 9 and REP 9C were administered intraperitoneally for 5 consecutive days at 10 mg/kg, starting 2 days prior to MCMV infection. Splenomegaly was observed in infected mice treated with REP 9 but not in control mice or in REP 9 treated, uninfected mice, consistent with mild CpG-like activity. When REP 9C (which lacks CpG motifs) was compared to REP 9, it exhibited comparable antiviral activity as REP 9 but was not associated with splenomegaly. This suggests that the direct antiviral activity of APs is the predominant therapeutic mechanism <it>in vivo</it>. Moreover, REP 9C, which is acid stable, was effective when administered orally in combination with known permeation enhancers.</p> <p>Conclusion</p> <p>These studies indicate that APs exhibit potent, well tolerated antiviral activity against CMV infection in vivo and represent a new class of broad spectrum anti-herpetic agents.</p

GIS and spatial data analysis: Converging perspectives

We take as our starting point the state of geographic information systems (GIS) and spatial data analysis 50 years ago when regional science emerged as a new field of enquiry. In the late 1950s and 1960s advances in computing technology were making possible forms of automated cartography that in due course would lead to th

Life History of Female Preferences for Male Faces: A Comparison of Pubescent Girls, Nonpregnant and Pregnant Young Women, and Middle-aged Women

Although scientific interest in facial attractiveness has developed substantially in recent years, few studies have contributed to our understanding of the ontogeny of facial preferences. In this study, attractiveness of 30 male faces was evaluated by four female groups: girls at puberty, nonpregnant and pregnant young women, and middle-aged women. The main findings are as follows: (1) Preference for sexy-looking faces was strongest in young, nonpregnant women. (2) Biologically more mature girls displayed more adultlike preferences. (3) The intragroup consistency for postmenopausal women was relatively low. (4) In terms of the preference pattern, pregnant women were more similar to perimenopausal women than they were to their nonpregnant peers. (5) Preference for youthful appearance decreased with the age of the women. I argue that the life history of female preferences for male faces is, to a large extent, hormone-driven and underpinned by a set of evolutionary adaptations

GroundsWell: Community-engaged and data-informed systems transformation of Urban Green and Blue Space for population health – a new initiative

This is the published version. Available on open access from F1000 Research via the DOI in this record[version 1; peer review: 1 approved].Data availability: No data are available with this article.Natural environments, such as parks, woodlands and lakes, have positive impacts on health and wellbeing. Urban Green and Blue Spaces (UGBS), and the activities that take place in them, can significantly influence the health outcomes of all communities, and reduce health inequalities. Improving access and quality of UGBS needs understanding of the range of systems (e.g. planning, transport, environment, community) in which UGBS are located. UGBS offers an ideal exemplar for testing systems innovations as it reflects place-based and whole society processes, with potential to reduce non-communicable disease (NCD) risk and associated social inequalities in health. UGBS can impact multiple behavioural and environmental aetiological pathways. However, the systems which desire, design, develop, and deliver UGBS are fragmented and siloed, with ineffective mechanisms for data generation, knowledge exchange and mobilisation. Further, UGBS need to be co-designed with and by those whose health could benefit most from them, so they are appropriate, accessible, valued and used well. This paper describes a major new prevention research programme and partnership, GroundsWell, which aims to transform UGBS-related systems by improving how we plan, design, evaluate and manage UGBS so that it benefits all communities, especially those who are in poorest health. We use a broad definition of health to include physical, mental, social wellbeing and quality of life. Our objectives are to transform systems so that UGBS are planned, developed, implemented, maintained and evaluated with our communities and data systems to enhance health and reduce inequalities. GroundsWell will use interdisciplinary, problem-solving approaches to accelerate and optimise community collaborations among citizens, users, implementers, policymakers and researchers to impact research, policy, practice and active citizenship. GroundsWell will be shaped and developed in three pioneer cities (Belfast, Edinburgh, Liverpool) and their regional contexts, with embedded translational mechanisms to ensure that outputs and impact have UK-wide and international application.UK Prevention Research PartnershipHSC Research and Development Office Northern Irelan

The supernatural characters and powers of sacred trees in the Holy Land

This article surveys the beliefs concerning the supernatural characteristics and powers of sacred trees in Israel; it is based on a field study as well as a survey of the literature and includes 118 interviews with Muslims and Druze. Both the Muslims and Druze in this study attribute supernatural dimensions to sacred trees which are directly related to ancient, deep-rooted pagan traditions. The Muslims attribute similar divine powers to sacred trees as they do to the graves of their saints; the graves and the trees are both considered to be the abode of the soul of a saint which is the source of their miraculous powers. Any violation of a sacred tree would be strictly punished while leaving the opportunity for atonement and forgiveness. The Druze, who believe in the transmigration of souls, have similar traditions concerning sacred trees but with a different religious background. In polytheistic religions the sacred grove/forest is a centre of the community's official worship; any violation of the trees is regarded as a threat to the well being of the community. Punishments may thus be collective. In the monotheistic world (including Christianity, Islam and Druze) the pagan worship of trees was converted into the worship/adoration of saints/prophets; it is not a part of the official religion but rather a personal act and the punishments are exerted only on the violating individual

The effects of exposure to objective coherence on perceived meaning in life: a preregistered direct replication of Heintzelman, Trent & King (2013)

Having a sense of meaning in life (MIL) has been acknowledged as a catalyst to psychological flourishing. As such, understanding ways to promote MIL represents a worthy goal for those interested in bolstering positive outcomes. This study sought to replicate the findings of Heintzelman, Trent & King (2013 Psychol. Sci. 24, 991–998 (doi:10.1177/0956797612465878)), who found that MIL could be influenced by external stimulation. Their findings suggest that exposure to coherent stimuli produces significantly higher MIL scores than exposure to incoherent stimuli. Using materials and methodology provided by the corresponding author of the original paper, this study attempted to directly test this manipulation under conditions with increased statistical power. All tests, however, failed to replicate. Possible explanations for these discrepant findings are discussed, and potential future directions for this area of the literature are proposed

A New Linear-Time Algorithm for Centroid Decomposition

The centroid of a tree is a node that, when removed, breaks the tree in connected components of size at most half of that of the original tree. By recursing this procedure on the components, one obtains the centroid decomposition of the tree, also known as centroid tree. The centroid tree has logarithmic height and its construction is a powerful pre-processing step in several tree-processing algorithms. The folklore recursive algorithm for computing the centroid tree runs in time. To the best of our knowledge, the only result claiming O(n) time is unpublished and relies on (dynamic) heavy path decomposition of the original tree. In this short paper, we describe a new simple and practical linear-time algorithm for the problem based on the idea of applying the folklore algorithm to a suitable decomposition of the original tree