146 research outputs found

    Random planar graphs and the London street network

    Get PDF
    In this paper we analyse the street network of London both in its primary and dual representation. To understand its properties, we consider three idealised models based on a grid, a static random planar graph and a growing random planar graph. Comparing the models and the street network, we find that the streets of London form a self-organising system whose growth is characterised by a strict interaction between the metrical and informational space. In particular, a principle of least effort appears to create a balance between the physical and the mental effort required to navigate the city

    Toward Human-Carnivore Coexistence: Understanding Tolerance for Tigers in Bangladesh

    Get PDF
    Fostering local community tolerance for endangered carnivores, such as tigers (Panthera tigris), is a core component of many conservation strategies. Identification of antecedents of tolerance will facilitate the development of effective tolerance-building conservation action and secure local community support for, and involvement in, conservation initiatives. We use a stated preference approach for measuring tolerance, based on the ‘Wildlife Stakeholder Acceptance Capacity’ concept, to explore villagers’ tolerance levels for tigers in the Bangladesh Sundarbans, an area where, at the time of the research, human-tiger conflict was severe. We apply structural equation modeling to test an a priori defined theoretical model of tolerance and identify the experiential and psychological basis of tolerance in this community. Our results indicate that beliefs about tigers and about the perceived current tiger population trend are predictors of tolerance for tigers. Positive beliefs about tigers and a belief that the tiger population is not currently increasing are both associated with greater stated tolerance for the species. Contrary to commonly-held notions, negative experiences with tigers do not directly affect tolerance levels; instead, their effect is mediated by villagers’ beliefs about tigers and risk perceptions concerning human-tiger conflict incidents. These findings highlight a need to explore and understand the socio-psychological factors that encourage tolerance towards endangered species. Our research also demonstrates the applicability of this approach to tolerance research to a wide range of socio-economic and cultural contexts and reveals its capacity to enhance carnivore conservation efforts worldwide

    Platysma muscle additionally innervated by a variant anterior branch of the great auricular nerve

    Get PDF
    Damage to the great auricular nerve, with consequent clinical deficits, is a common surgical complication in facial aesthetic and in head and neck procedures such as parotidectomy, neck dissection, rhytidectomy and platysma flap operations. Hence, a thorough knowledge of nerve anatomy, particularly its potential variations, is critical in reducing the associated operative morbidity. Accordingly, we report an unusual variation of the anterior branch of the great auricular nerve noted in an 81-year-old female cadaver. The nerve was observed to course into the submandibular region anterior and superficial to the internal jugular vein, communicating with the cervical branch of the facial nerve, while independently innervating the platysma muscle. Although several anatomical variations of the branches of the cervical plexus have been documented, our report describes unique innervation of the platysma muscle by the great auricular nerve, which provides a new insight on the motor component of the nerve

    C2C— conflict to coexistence: A global approach to manage human–wildlife conflict for coexistence

    Get PDF
    Human–wildlife conflict (HWC) presents a growing challenge to conservation and development worldwide. World Wide Fund for Nature (WWF) and experts on human–wildlife coexistence strategies have responded to this challenge by developing a holistic, globally applicable approach to HWC management that can be tailored to specific local, regional, or national contexts. Its framework addresses the complexity of essential HWC management and long‐term coexistence strategies and is implemented in a structured yet contextualized step‐by‐step sequence by a team of facilitators and multiple stakeholders. The C2C: Conflict to Coexistence Approach centers on four principles (tolerance is maintained, responsibility is shared, resilience is built, holism is fundamental), four outcomes (wildlife thrives alongside human presence, habitat sufficient to maintain viable wildlife populations, people able and willing to live alongside wildlife, livelihoods/assets secured against presence of wildlife), and six HWC management elements (policy and governance, understanding interactions, prevention, response, mitigation, monitoring) that are to be implemented in an integrated way. It is currently undergoing testing in diverse pilot sites across three continents and demonstrating positive initial results. Here, we share the framework and methodology of the approach and initial results and experiences from these pilot sites

    More men than women make mucosal IgA antibodies to Human papillomavirus type 16 (HPV-16) and HPV-18: a study of oral HPV and oral HPV antibodies in a normal healthy population

    Get PDF
    BACKGROUND: We have previously shown the high prevalence of oral anti-human papillomavirus type 16 (HPV-16) antibodies in women with HPV-associated cervical neoplasia. It was postulated that the HPV antibodies were initiated after HPV antigenic stimulation at the cervix via the common mucosal immune system. The present study aimed to further evaluate the effectiveness of oral fluid testing for detecting the mucosal humoral response to HPV infection and to advance our limited understanding of the immune response to HPV. METHODS: The prevalence of oral HPV infection and oral antibodies to HPV types 16, 18 and 11 was determined in a normal, healthy population of children, adolescents and adults, both male and female, attending a dental clinic. HPV types in buccal cells were determined by DNA sequencing. Oral fluid was collected from the gingival crevice of the mouth by the OraSure method. HPV-16, HPV-18 and HPV-11 antibodies in oral fluid were detected by virus-like particle-based enzyme-linked immunosorbent assay. As a reference group 44 women with cervical neoplasia were included in the study. RESULTS: Oral HPV infection was highest in children (9/114, 7.9%), followed by adolescents (4/78, 5.1%), and lowest in normal adults (4/116, 3.5%). The predominant HPV type found was HPV-13 (7/22, 31.8%) followed by HPV-32 (5/22, 22.7%). The prevalence of oral antibodies to HPV-16, HPV-18 and HPV-11 was low in children and increased substantially in adolescents and normal adults. Oral HPV-16 IgA was significantly more prevalent in women with cervical neoplasia (30/44, 68.2%) than the women from the dental clinic (18/69, 26.1% P = 0.0001). Significantly more adult men than women displayed oral HPV-16 IgA (30/47 compared with 18/69, OR 5.0, 95% CI 2.09–12.1, P < 0.001) and HPV-18 IgA (17/47 compared with 13/69, OR 2.4, 95% CI 0.97–6.2, P = 0.04). CONCLUSION: The increased prevalence of oral HPV antibodies in adolescent individuals compared with children was attributed to the onset of sexual activity. The increased prevalence of oral anti-HPV IgA in men compared with women was noteworthy considering reportedly fewer men than women make serum antibodies, and warrants further investigation

    Network Structure and City Size

    Get PDF
    Network structure varies across cities. This variation may yield important knowledge about how the internal structure of the city affects its performance. This paper systematically compares a set of surface transportation network structure variables (connectivity, hierarchy, circuity, treeness, entropy, accessibility) across the 50 largest metropolitan areas in the United States. A set of scaling parameters are discovered to show how network size and structure vary with city size. These results suggest that larger cities are physically more inter-connected. Hypotheses are presented as to why this might obtain. This paper then consistently measures and ranks access to jobs across 50 US metropolitan areas. It uses that accessibility measure, along with network structure variables and city size to help explain journey-to-work time and auto mode share in those cities. A 1 percent increase in accessibility reduces average metropolitan commute times by about 90 seconds each way. A 1 percent increase in network connectivity reduces commute time by 0.1 percent. A 1 percent increase in accessibility results in a 0.0575 percent drop in auto mode share, while a 1 percent increase in treeness reduces auto mode share by 0.061 percent. Use of accessibility and network structure measures is important for planning and evaluating the performance of network investments and land use changes

    Using vital statistics to estimate the population-level impact of osteoporotic fractures on mortality based on death certificates, with an application to France (2000-2004)

    Get PDF
    Abstract Background We developed a methodology using vital statistics to estimate the impact of osteoporotic fractures on the mortality of an entire population, and applied it to France for the period 2000-2004. Methods Current definitions of osteoporotic fractures were reviewed and their components identified. We used the International Classification of Diseases with national vital statistics data for the French adult population and performed cross-classifications between various components: age, sex, I-code (site) and E-code (mechanism of fracture). This methodology allowed identification of appropriate thresholds and categorization for each pertinent component. Results 2,625,743 death certificates were analyzed, 2.2% of which carried a mention of fracture. Hip fractures represented 55% of all deaths from fracture. Both sexes showed a similar pattern of mortality rates for all fracture sites, the rate increased with age from the age of 70 years. The E-high-energy code (present in 12% of death certificates with fractures) was found to be useful to rule-out non-osteoporotic fractures, and to correct the overestimation of mortality rates. Using this methodology, the crude number of deaths associated with fractures was estimated to be 57,753 and the number associated with osteoporotic fractures 46,849 (1.85% and 1.78% of all deaths, respectively). Conclusion Osteoporotic fractures have a significant impact on overall population mortality.</p

    Fontan-Associated Liver Disease (FALD) in the EUROFontan experience: an insight into European awareness

    Get PDF
    Fontan-Associated Liver Disease (FALD) is a dramatically emerging problem even if not precisely defined in term of debated diagnosis and surveillance protocols. We analyze FALD prevalence, clinical impact and implications in a European cohort of patients. It's a retrospective observational multicenter study including Fontan patients operated between 1990 and 2022. Anatomical, clinical, surgical and liver-related data were collected, defining FALD as a spectrum of time-related structural-functional liver modifications due to congestive hepatopathy (from mild liver fibrosis to liver cirrhosis and hepatocellular carcinoma) diagnosed through multiparametric evaluations. 14 centers routinely conducted liver assessment after Fontan completion. Out of 2141 patients, 343 (16%) were diagnosed with FALD (M/F = 198/145; median age 18 years, IQR 15-26) with a median follow-up time of 14 years (IQR 9-20) from Fontan surgery. Among these, there were 19 (5.5%) deaths, 5 (26.3%) of whom related to advanced liver disease/cancer. FALD showed no significant association with gender (p = 0.4, adjusted p-value = 0.5), dominant ventricular morphology (p = 0.060, adjusted p-value = 0.086) nor surgery type (p = 0.3, adjusted p-value = 0.4). Significant association emerged between FALD and fenestration absence (p = 22 kPa on transient elastography (p < 0.001, adjusted p-value < 0.001). The analysis demonstrated no significant association between FALD and abnormal liver function tests (p = 0.2), heart transplantation (p = 0.6, adjusted p-value = 0.6), worse survival (p = 0.38). This study shows significant mortality related to FALD, which is also associated to clinical signs of failing Fontan circulation, stressing the pressing need of universally shared diagnostic criteria and surveillance protocols, to prevent and/or early-identify FALD and its more lethal complications.Thoracic Surger
    corecore