bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forming groups with 4 × 4 matrices
Authors: Harris J. R. 
Published: July 2016

The three Pauli matrices are normally given [1] as the 2 × 2 matrices:where ‘i’ is the usual complex number imaginary unit.These matrices obey the relations a2 = I = b2 = c2(where I is the 2 × 2 identity matrix), as well as the anticommutation relations:Within the quantities ia,ib and ic,i is a scalar multiplier of the 2 × 2 Pauli matrices and, of course, commutes with each of a, b, c.
Slide rules, nomograms and additive functions
Authors: Hopkins David 
Published: July 2016

Older readers will remember using a slide rule to carry out multiplication and division in the days before calculators. There was also a graphical tool called a nomogram, which was used for evaluating certain functions. Although such devices have little practical use nowadays, I was interested in investigating which classes of functions with two independent variables could be calculated using this type of device.Figure 1 shows how a slide rule was used to multiply 3 by 4 (or equivalently to divide 12 by 4). To do this, you align the 1 on the upper scale with the 3 on the lower scale and then read off the value below the 4 on the upper scale to get 12 (or, for division, you line up the 4 above the 12 and read off the answer 3 on the lower scale).
Pell Walks
Authors: Koshy Thomas 
Published: July 2016

Like Fibonacci and Lucas numbers, Pell and Pell-Lucas numbers are a fertile ground for creativity and exploration. They also have interesting applications to combinatorics [1], especially to the study of lattice paths [2, 3], as we will see shortly.Pell numbers Pn and Pell-Lucas numbers Qn are often defined recursively [4, 5]:where n ≥ 3. They can also be defined by Binet-like formulas:
A direct derivation of the Catalan formula
Authors: Leversha Gerry 
Published: July 2016

Many readers will be familiar with the sequence of Catalan numbers {Cn: n ≥ 0} and the formulawith its alternative formThese can be proved by using recurrence relations, generating functions or André's reflection principle. A good reference for all of these methods is Martin Griffiths' book [1].However, none of these approaches strikes me as being naturally combinatorial. A formula such as (1) is often derived by making a list of all the ways of doing something, and then subdividing this list into classes of equal size, so that either one class consists entirely of ‘valid’ cases or there is exactly one ‘valid’ case in each list.
Integrating expressions of the form and others
Authors: Trainin J. 
Published: July 2016

In an earlier communication to the Gazette [1], the authors in effect showed, in a somewhat complicated manner, how to evaluate the integral One can show in a simpler manner, however, how to evaluate, for integers n and m, a more general integral of the form where n ≥ m, provided that if m = 1, then n is odd.In addition, the final section to this article shows how to extend the procedure to include integrals for which m does not even have to be an integer, and also how to integrate where such an integral converges.
Rugby conversions: a 3-dimensional model
Authors: Crilly Tony , Pryor Alan 
Published: July 2016

From which position on a rugby pitch should a player choose to kick in order to convert a try? The problem is to find the optimal distance from the try-line conforming to a geometrical constraint: Law 13 of the Rugby Union code stipulates, ‘after a try has been scored, the scoring team has the right to take a place kick or drop kick at goal, on a line through the place where the try was scored’.The mathematical problem is not new and has been treated in the Gazette on several occasions [1, 2, 3], and in each case the modelling has been in two dimensions, taking a planar view of the pitch. Figure 1 represents this ‘planar model’.
Sums of powers of integers – how Fermat may have found them
Authors: Burn Bob 
Published: July 2016

On 22 September 1636, Fermat wrote to Roberval, [I, FO.II.XIII, p.71], saying that he had found the quadrature of an infinite number of curves. He named in particular the ‘solid parabola’, y = x3, and said that his method was different from Archimedes‘ quadrature of the parabola. He invited Roberval to share his thoughts on this and other matters.On 11th October 1636, Roberval replied to Fermat [1. FO.II.XIV, p.75], indicating his method for determining the quadrature of the ‘solid parabola’ and extending it to the quadrature of y = x4 and y = x5.
Reference gene selection and RNA preservation protocol in the cat flea, Ctenocephalides felis, for gene expression studies
Authors: MCINTOSH CATRIONA H. , BAIRD JOHN , ZINSER ERICH , WOODS DEBRA J. , CAMPBELL EWAN M. , BOWMAN ALAN S. 
Published: July 2016

SUMMARYThe cat flea, Ctenocephalides felis, is a major pest species on companion animals thus of significant importance to the animal health industry. The aim of this study was to develop sampling and storage protocols and identify stable reference genes for gene expression studies to fully utilize the growing body of molecular knowledge of C. felis. RNA integrity was assessed in adult and larvae samples, which were either pierced or not pierced and stored in RNAlater at ambient temperature. RNA quality was maintained best in pierced samples, with negligible degradation evident after 10 days. RNA quality from non-pierced samples was poor within 3 days. Ten candidate reference genes were evaluated for their stability across four group comparisons (developmental stages, genders, feeding statuses and insecticide-treatment statuses). Glyceraldehyde 3 phosphate dehydrogenase (GAPDH), 60S ribosomal protein L19 (RPL19) and elongation factor-1α (Ef) were ranked highly in all stability comparisons, thus are recommended as reference genes under similar conditions. Employing just two of these three stable reference genes was sufficient for accurate normalization. Our results make a significant contribution to the future of gene expression studies in C. felis, describing validated sample preparation procedures and reference genes for use in this common pest.
Enjoying the third age! Discourse, identity and liminality in extra-care communities
Authors: WEST KAREN , SHAW RACHEL , HAGGER BARBARA , HOLLAND CAROL 
Published: July 2016

ABSTRACTExtra-care housing has been an important and growing element of housing and care for older people in the United Kingdom since the 1990s. Previous studies have examined specific features and programmes within extra-care locations, but few have studied how residents negotiate social life and identity. Those that have, have noted that while extra care brings many health-related and social benefits, extra-care communities can also be difficult affective terrain. Given that many residents are now ‘ageing in place’ in extra care, it is timely to revisit these questions of identity and affect. Here we draw on the qualitative element of a three-year, mixed-method study of 14 extra-care villages and schemes run by the ExtraCare Charitable Trust. We follow Alemàn in regarding residents' ambivalent accounts of life in ExtraCare as important windows on the way in which liminal residents negotiate the dialectics of dependence and independence. However, we suggest that the dialectic of interest here is that of the third and fourth age, as described by Gilleard and Higgs. We set that dialectic within a post-structuralist/Lacanian framework in order to examine the different modes ofenjoymentthat liminal residents procure in ExtraCare's third age public spaces and ideals, and suggest that their complaints can be read in three ways: as statements about altered material conditions; as inter-subjective bolstering of group identity; and as fantasmatic support for liminal identities. Finally, we examine the implications that this latter psycho-social reading of residents' complaints has for enhancing and supporting residents' wellbeing.
Reduced damage and epiphyll cover of leaves ofKorthalsiarattans that hostCamponotusants in the rain forest of Malaysian Borneo
Authors: Miler Krzysztof , Yahya Bakhtiar Effendi , Czarnoleski Marcin 
Published: July 2016

Abstract:Many species of palm produce chambers called domatia that are used by ants as nesting spaces. However, the ecological nature of this association is not well understood, and the information on palm–ant interactions is primarily anecdotal. Here, we conducted a field study in the secondary forest of the Danum Valley Conservation Area, Malaysian Borneo, on 41 individuals of the rattanKorthalsia furtadoana. All studied plants showed signs of a past or present partnership with domatia-nesting ants, as indicated by entry holes in domatia. In 14 plants, our physical disturbance of a stem provoked the appearance of patrolling ants ofCamponotussp. We compared the leaf conditions of rattans with and without patrolling ants, testing whether the presence of ants is linked to improved leaf health. The leaflets of plants with patrolling ants were significantly less physically damaged and less covered by epiphylls. On average, 19% of the leaflets of plants with patrolling ants were damaged (52% in plants without patrolling ants), and the epiphyll cover of their leaflets was 0.2 on our scale of 0–4 (1.3 in plants without patrolling ants). Our results suggest that this poorly studied plant–ant association has a mutualistic character. It seems that the ants take advantage of the nesting space created by the plant partner, while the plants gain protection for their photosynthetic apparatus against herbivores and epiphylls.
Effects of forest and cave proximity on fruit set of tree crops in tropical orchards in Southern Thailand
Authors: Sritongchuay Tuanjit , Kremen Claire , Bumrungsri Sara 
Published: July 2016

Abstract:Deforestation and forest fragmentation are contributing to declines in crop pollinator populations worldwide. Several studies have examined the impact of forest proximity on plant pollination ecology, but concentrated on single crop species. However, it can be more informative to investigate multiple crop and pollinator species in a community, because different pollinator groups may respond differently to forest distance. We evaluated flower visitor diversity, visitation frequency, and fruit set for three crop species (rambutan, durian and mango) in 10 pairs of mixed fruit orchards. Each pair consisted of one orchard near to (< 1 km) and one orchard far from (> 7 km) the forest edge. Rambutan fruit set was significantly influenced by distance to forest. The main visitors of rambutan flowers were stingless bees. In contrast, the dominant visitors to durian and mango flowers were nectarivorous bats and flies, respectively, and the fruit set of these crops were not significantly influenced by distance to forest. However, durian fruit set was negatively affected by distance to the nearest cave inhabited by nectarivorous bats. This study demonstrates that both caves and forests can be important pollinator sources for agricultural crops, and that the dispersal success of pollinators is related to isolation from source habitats. Maintaining forest patches and limestone karsts may provide stepping stones across fragmented landscapes, and attract greater numbers of pollinators to agricultural areas.
Exploratory social network analysis and gene sequencing in people who inject drugs infected with hepatitis C virus
Authors: WANG Y. , TAN X. D. , ZHOU C. , ZHOU W. , PENG J. S. , REN Y. S. , NI Z. L. , LIU B. , YANG F. , GAO X. D. 
Published: July 2016

SUMMARYSocial networks facilitate the transmission of hepatitis C virus (HCV) in people who inject drugs (PWID). The aim of this study was to assess how certain network structural characteristics are related to HCV infections in PWID and to determine the most susceptible individuals for HCV transmission in a network of PWID. PWID (N= 80) from central China were recruited from a previous follow-up case-control study. Demographic and behavioural information was obtained from a computerized database for each group. HCV RNA was extracted from blood specimens. Sequences were used to construct a phylogenetic tree and to determine genetic distances. Socio-metric social links were established between participants. Network measures were calculated using UCINET. Three HCV genotypes were identified, covering five subtypes. The density of the social networks for the whole sample (N= 80), case group (n= 31) and control group (n= 49) was 0.038, 0.054 and 0.008, respectively. PWID infected with HCV were in frequent contact with others within their group. There were four pairs of nodes with genotypic distances of 0.000 that were identified and clustered in subtypes 6a and 1b; each subject pair was linked and found in one clique. Three of the five most active nodes were infected with HCV. These three nodes served as a bridge, contributing to the connection of other nodes. These findings identify susceptible individuals for HCV transmission in PWID based on their frequent contact with others in the network. These results provide data that could be used for modelling HCV transmission patterns and in public health policies.
Current evidence on the association of the metabolic syndrome and dietary patterns in a global perspective
Authors: Hosseini Zeinab , Whiting Susan J. , Vatanparast Hassan 
Published: July 2016

AbstractThe metabolic syndrome (MetS) is a key indicator of two main causes of death worldwide: CVD and diabetes. The present paper aimed to perform a review of the population-based research on the association of dietary patterns and the MetS in terms of methodology and findings. For the purpose of the present study, a scoping literature review was conducted using MEDLINE and EMBASE databases and hand searching in Google Scholar. Thirty-nine population-based studies were selected. Most of these studies used the factor analysis method and thea prioridietary approach, which had been initially extracted viaa posteriorimethods such as using the Mediterranean dietary pattern. The main finding was that following the Mediterranean or similar ‘healthy’ pattern reduced risk of the MetS, while following a ‘Western’ pattern increased risk of the MetS. The methodological approach in determining the dietary pattern of a population, whethera prioriora posteriori, should be chosen based on the purpose of the research. Overall, evidence suggests a diet based on the components of the Mediterranean diet and the avoidance of the ‘Western’ diet can aid in preventing the MetS.
Conflicting visions of renewal in Pittsburgh’s Hill District, 1950–1968
Authors: GRANTMYRE LAURA 
Published: July 2016

ABSTRACT:Visual representations of the Lower Hill District created by Pittsburgh's redevelopment coalition and by neighbourhood insiders reveal the conflicting ways redevelopers and residents understood older neighbourhoods and their redevelopment. Redevelopers’ maps and photographs of the Lower Hill documented the neighbourhood's densely built-up blocks and intermixture of land uses as definitive examples of blight that threatened downtown's economic health. Models and architectural sketches of the Civic Arena – the jewel of the Lower Hill's redevelopment plan – promised to wipe away blight and renew the city. Redevelopers distributed their imagery through brochures and the city's daily press. Framed by captions labelling the Lower Hill a ‘blight’ and the Civic Arena a ‘wonder of the modern world’, these images helped sell the public on redevelopment. Lower Hill insiders, most notably the city's African American newspaper, the Pittsburgh Courier, and the Courier’s lead photographer, Charles ‘Teenie’ Harris, envisioned the Lower Hill and its redevelopment differently. Harris and the Courier criticized the neighbourhood's dilapidated housing but celebrated its thriving social life. They also supported redevelopment but saw it primarily as a route to new jobs and improved housing for Hill residents. After the Civic Arena opened in 1961, redevelopment failed to deliver more jobs or better housing because redevelopers’ worldview prioritized the built over the social environment. Hill District residents, led by the Courier, reacted to these shortcomings with visual protests pairing redevelopers’ favourite symbol of progress – the brand new Civic Arena – with symbols of racial injustice. By spotlighting the inequalities that undergirded redevelopers’ vision for the city, these protests stopped redevelopment from spreading further into the Hill in 1968.
Do not hear, see, or speak: views of older residents and their adult children about the nursing unit in the continuing care retirement community
Authors: Ayalon Liat 
Published: July 2016

ABSTRACTBackground:The present study evaluated views of continuing care retirement community (CCRC) residents and their adult children concerning the nursing unit (NU) within the CCRC.Methods:Qualitative interviews with older adults and their adult children were conducted. Analysis consisted of 187 interviews with older adults and their adult children over a period of up to six years. Analysis relied on constant comparisons within the same interview, over interviews of the same person over time, and between CCRC residents and their adult children. Major themes were identified to construct a coherent storyline.Results:The NU was viewed as a different universe that should be avoided at all costs. This was attributed to: (1) the association of the NU with one's impending decline and dependence and (2) beliefs about substandard care in the NU.Conclusions:The findings point to the ambivalence expressed by CCRC residents and their adult children concerning the NU, even though to some degree, the NU represents the main reason for the transition to a CCRC.
Frontal and Temporal Structural Connectivity Is Associated with Social Communication Impairment Following Traumatic Brain Injury
Authors: Rigon Arianna , Voss Michelle W. , Turkstra Lyn S. , Mutlu Bilge , Duff Melissa C. 
Published: July 2016

AbstractObjectives:Although it has been well documented that traumatic brain injury (TBI) can result in communication impairment, little work to date has examined the relationship between social communication skills and structural brain integrity in patients with TBI. The aim of the current study was to investigate the association between self- and other-perceived communication problems and white matter integrity in patients with mild to severe TBI.Methods:Forty-four individuals (TBI=24) and people with whom they frequently communicate, as well as demographically matched normal healthy comparisons (NC) and their frequent communication partners, were administered, respectively, the La-Trobe Communication Questionnaire Self form (LCQ-SELF) and Other form (LCQ-OTHER). In addition, diffusion tensor imaging data were collected, and fractional anisotropy (FA) measures were extracted for each lobe in both hemispheres.Results:Within the TBI group, but not within the NC group, participants who were perceived by their close others as having more communication problems had lower FA in the left frontal and temporal lobes (p<.01), but not in other brain regions.Conclusions:Frontotemporal white matter microstructural integrity is associated with social communication abilities in adults with TBI. This finding contributes to our understanding of the mechanisms leading to communication impairment following TBI and can inform the development of new neuromodulation therapies as well as diagnostic tools. (JINS, 2016,22, 705–716)
Energy intake, energy required and mortality in an older population
Authors: Lee Paul H , Chan Choi-Wan 
Published: July 2016

AbstractObjectivesThe present study evaluated the association between energy intake, energy required and mortality in older adults.DesignA cohort study with a mean of 10·67 (sd 4·74) years of follow-up. Participants completed a 24 h dietary recall. Energy required per day was computed by BMR. Deaths through 2006 were identified from the National Death Index. A Cox regression was used to estimate the hazard ratios (HR) of quantiles of energy intake and energy required on all-cause and CVD mortality, adjusting for demographics, socio-economic status and co-morbidity.SettingThe National Health and Nutrition Examination Survey (NHANES) III, 1988–1994.SubjectsA total of 4846 participants aged 60 years or above were analysed.ResultsWithin the follow-up period, there were a total of 2954 deaths (61·0 %), 51·9 % were caused by CVD. Relative to those in quartile 1 of energy intake, only quartile 4 was associated with all-cause mortality and CVD mortality with HR of 0·86 (95 % CI 0·77, 0·96, P=0·006) and 0·76 (95 % CI 0·65, 0·89, P=0·001), respectively. On the other hand, relative to those in quartile 1 of energy required, all quartiles of participants had a lower risk of all-cause mortality and CVD mortality. The interaction effects between energy intake and energy required with all-cause and CVD mortality were insignificant (P=0·70 and 0·61, respectively).ConclusionsIndependent of energy required, higher energy intake was associated with lower HR of both all-cause and CVD mortality in older adults.
Food insecurity and diabetes self-management among food pantry clients
Authors: Ippolito Matthew M , Lyles Courtney R , Prendergast Kimberly , Marshall Michelle Berger , Waxman Elaine , Seligman Hilary Kessler 
Published: July 2016

AbstractObjectiveTo examine the association between level of food security and diabetes self-management among food pantry clients, which is largely not possible using clinic-based sampling methods.DesignCross-sectional descriptive study.SettingCommunity-based food pantries in California, Ohio and Texas, USA, from March 2012 through March 2014.SubjectsConvenience sample of adults with diabetes queuing at pantries (n1237; 83 % response). Sampled adults were stratified as food secure, low food secure or very low food secure. We used point-of-care glycated Hb (HbA1c) testing to determine glycaemic control and captured diabetes self-management using validated survey items.ResultsThe sample was 70 % female, 55 % Latino/Hispanic, 25 % white and 10 % black/African American, with a mean age of 56 years. Eighty-four per cent were food insecure, one-half of whom had very low food security. Mean HbA1cwas 8·1 % and did not vary significantly by food security status. In adjusted models, very-low-food-secure participants, compared with both low-food-secure and food-secure participants, had poorer diabetes self-efficacy, greater diabetes distress, greater medication non-adherence, higher prevalence of severe hypoglycaemic episodes, higher prevalence of depressive symptoms, more medication affordability challenges, and more food and medicine or health supply trade-offs.ConclusionsFew studies of the health impact of food security have been able to examine very low food security. In a food pantry sample with high rates of food insecurity, we found that diabetes self-management becomes increasingly difficult as food security worsens. The efficacy of interventions to improve diabetes self-management may increase if food security is simultaneously addressed.
MOMA: the challenge to search for organics and biosignatures on Mars
Authors: Goetz W. , Brinckerhoff W. B. , Arevalo R. , Freissinet C. , Getty S. , Glavin D. P. , Siljeström S. , Buch A. , Stalport F. , Grubisic A. , Li X. , Pinnick V. , Danell R. , van Amerom F. H. W. , Goesmann F. , Steininger H. , Grand N. , Raulin F. , Szopa C. , Meierhenrich U. , Brucato J. R. ,   the MOMA Science Team
Published: July 2016

AbstractThis paper describes strategies to search for, detect, and identify organic material on the surface and subsurface of Mars. The strategies described include those applied by landed missions in the past and those that will be applied in the future. The value and role of ESA's ExoMars rover and of her key science instrument Mars Organic Molecule Analyzer (MOMA) are critically assessed.