Slope-aspect color shading for parametric surfaces

The invention is a method for generating an image of a parametric surface, such as the compass direction toward which each surface element of terrain faces, commonly called the slope-aspect azimuth of the surface element. The method maximizes color contrast to permit easy discrimination of the magnitude, ranges, intervals or classes of a surface parameter while making it easy for the user to visualize the form of the surface, such as a landscape. The four pole colors of the opponent process color theory are utilized to represent intervals or classes at 90 degree angles. The color perceived as having maximum measured luminance is selected to portray the color having an azimuth of an assumed light source and the color showing minimum measured luminance portrays the diametrically opposite azimuth. The 90 degree intermediate azimuths are portrayed by unique colors of intermediate measured luminance, such as red and green. Colors between these four pole colors are used which are perceived as mixtures or combinations of their bounding colors and are arranged progressively between their bounding colors to have perceived proportional mixtures of the bounding colors which are proportional to the interval's angular distance from its bounding colors

Continuous hierarchical slope-aspect color display for parametric surfaces

A method for generating an image of a parametric surface, such as the aspect of terrain which maximizes color contrast to permit easy discrimination of the magnitude, ranges, intervals or classes of a surface parameter while making it easy for the user to visualize the form of the surface, such as a landscape. The four pole colors of the opponent process color theory are utilized to represent intervals or classes at 90 degree angles. The color perceived as having maximum measured luminance is selected to portray the color having an azimuth of an assumed light source and the color showing minimum measured luminance portrays the diametrically opposite azimuth. The 90 degree intermediate azimuths are portrayed by unique colors of intermediate measured luminance, such as red and green. Colors between these four pole colors are used which are perceived as mixtures or combinations of their bounding colors and are arranged progressively between their bounding colors to have perceived proportional mixtures of the bounding colors which are proportional to the interval's angular distance from its bounding colors

Protecting biodiversity and economic returns in resource-rich tropical forests.

In pursuit of socioeconomic development, many countries are expanding oil and mineral extraction into tropical forests. These activities seed access to remote, biologically rich areas, thereby endangering global biodiversity. Here we demonstrate that conservation solutions that effectively balance the protection of biodiversity and economic revenues are possible in biologically valuable regions. Using spatial data on oil profits and predicted species and ecosystem extents, we optimise the protection of 741 terrestrial species and 20 ecosystems of the Ecuadorian Amazon, across a range of opportunity costs (i.e. sacrifices of extractive profit). For such an optimisation, giving up 5% of a year's oil profits (US$221 million) allows for a protected area network that retains of an average of 65$ 1.7 billion), and uses only marginally less land, to achieve equivalent levels of ecological protection. Applying spatial statistics to remotely sensed, historic deforestation data, we further focus the optimisation to areas most threatened by imminent forest loss. We identify Emergency Conservation Targets: areas that are essential to a cost-effective conservation reserve network and at imminent risk of destruction, thus requiring urgent and effective protection. Governments should employ the methods presented here when considering extractive led development options, to responsibly manage the associated ecological-economic trade-offs and protect natural capital. Article Impact Statement: Governments controlling resource extraction from tropical forests can arrange production and conservation to retain biodiversity and profits. This article is protected by copyright. All rights reserved

The synthesis, characterization and targeting ability of nano-scale enrichment polymer layers

Thin polymer films have been utilized as enrichment layers for evanescent waveguide chemical sensors and other analytical techniques. This is due to the fact that the chemical nature of polymers is ideal for trapping chemically similar organic molecules making analysis more convenient. Specifically, research in this area of volatile organic compounds (VOCs) detection, focused has been given to identifying a single polymer film of micron scale thickness to target one analyte. This work focuses on the design and use of multiple polymers in one enrichment layer to target VOCs to facilitate detection. Two distinct layered enrichment systems were synthesized via the “grafting to” approach. The end application is to apply these polymers onto mid-infrared transparent evanescent wave micro-disk or micro-ring resonators. Analysis of the polymer affinity to VOCs and to act as enrichment layers is determined by the thickness increase caused by swelling of the film when exposed to the analyte vapor. Detection analysis was done using attenuated total reflection (ATR) FT-IR spectroscopy. The polymer layered systems were characterized by atomic force microscopy, ellipsometry and infrared spectroscopy. Studies of pure analyte vapors and mixtures were conducted in saturated conditions

Diagnostic Accuracy and Acceptability of the Primary Care Posttraumatic Stress Disorder Screen for the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) among US Veterans

Importance: Posttraumatic stress disorder (PTSD) is a serious mental health disorder that can be effectively treated with empirically based practices. PTSD screening is essential for identifying undetected cases and providing patients with appropriate care. Objective: To determine whether the Primary Care PTSD screen for the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (PC-PTSD-5) is a diagnostically accurate and acceptable measure for use in Veterans Affairs (VA) primary care clinics. Design, Setting, and Participants: This cross-sectional, diagnostic accuracy study enrolled participants from May 19, 2017, to September 26, 2018. Participants were recruited from primary care clinics across 2 VA Medical Centers. Session 1 was conducted in person, and session 2 was completed within 30 days via telephone. A consecutive sample of 1594 veterans, aged 18 years or older, who were scheduled for a primary care visit was recruited. Data analysis was performed from March 2019 to August 2020. Exposures: In session 1, participants completed a battery of questionnaires. In session 2, a research assistant administered the PC-PTSD-5 to participants, and then a clinician assessor blind to PC-PTSD-5 results conducted a structured diagnostic interview for PTSD. Main Outcomes and Measures: The range of PC-PTSD-5 cut points overall and across gender was assessed, and diagnostic performance was evaluated by calculating weighted κ values. Results: In total, 495 of 1594 veterans (31%) participated, and 396 completed all measures and were included in the analyses. Participants were demographically similar to the VA primary care population (mean [SD] age, 61.4 [15.5] years; age range, 21-93 years) and were predominantly male (333 participants [84.1%]) and White (296 of 394 participants [75.1%]). The PC-PTSD-5 had high levels of diagnostic accuracy for the overall sample (area under the receiver operating characteristic curve [AUC], 0.927; 95% CI, 0.896-0.959), men (AUC, 0.932; 95% CI, 0.894-0.969), and women (AUC, 0.899, 95% CI, 0.824-0.974). A cut point of 4 ideally balanced false negatives and false positives for the overall sample and for men. However, for women, this cut point resulted in high numbers of false negatives (6 veterans [33.3%]). A cut point of 3 fit better for women, despite increasing the number of false positives. Participants rated the PC-PTSD-5 as highly acceptable. Conclusions and Relevance: The PC-PTSD-5 is an accurate and acceptable screening tool for use in VA primary care settings. Because performance parameters will change according to sample, clinicians should consider sample characteristics and screening purposes when selecting a cut point

Use of anti-retroviral therapy in tuberculosis patients on second-line anti-TB regimens: a systematic review

Introduction: Use of antiretroviral therapy (ART) during treatment of drug susceptible tuberculosis (TB) improves survival. However, data from HIV infected individuals with drug resistant TB are lacking. Second line TB drugs when combined with ART may increase drug interactions and lead to higher rates of toxicity and greater noncompliance. This systematic review sought to determine the benefit of ART in the setting of second line drug therapy for drug resistant TB. Methods: We included individual patient data from studies that evaluated treatment of drug-resistant tuberculosis in HIV-1 infected individuals published between January 1980 and December of 2009. We evaluated the effect of ART on treatment outcomes, time to smear and culture conversion, and adverse events. Results: Ten observational studies, including data from 217 subjects, were analyzed. Patients using ART during TB treatment had increased likelihood of cure (hazard ratio (HR) 3.4, 95% CI 1.6–7.4) and decreased likelihood of death (HR 0.4, 95% CI 0.3–0.6) during treatment for drug resistant TB. These associations remained significant in patients with a CD4 less than 200 cells/mm3 and less than 50 cells/mm3, and when correcting for drug resistance pattern. Limitations: We identified only observational studies from which individual patient data could be drawn. Limitations in study design, and heterogeneity in a number of the outcomes of interest had the potential to introduce bias. Discussion: While there are insufficient data to determine if ART use increases adverse drug interactions when used with second line TB drugs, ART use during treatment of drug resistant TB appears to improve cure rates and decrease risk of death. All individuals with HIV appear to benefit from ART use during treatment for TB

Modelling of photonic wire Bragg Gratings

Some important properties of photonic wire Bragg grating structures have been investigate. The design, obtained as a generalisation of the full-width gap grating, has been modelled using 3D finite-difference time-domain simulations. Different types of stop-band have been observed. The impact of the grating geometry on the lowest order (longest wavelength) stop-band has been investigated - and has identified deeply indented configurations where reduction of the stop-bandwidth and of the reflectivity occurred. Our computational results have been substantially validated by an experimental demonstration of the fundamental stop-band of photonic wire Bragg gratings fabricated on silicon-on-insulator material. The accuracy of two distinct 2D computational models based on the effective index method has also been studied - because of their inherently much greater rapidity and consequent utility for approximate initial designs. A 2D plan-view model has been found to reproduce a large part of the essential features of the spectral response of full 3D models

Effect of antiretroviral therapy on the diagnostic accuracy of symptom screening for intensified tuberculosis case finding in a South African HIV clinic.

BACKGROUND: Current symptom screening algorithms for intensified tuberculosis case finding or prior to isoniazid preventive therapy (IPT) in patients infected with human immunodeficiency virus (HIV) were derived from antiretroviral-naive cohorts. There is a need to validate screening algorithms in patients on antiretroviral therapy (ART). METHODS: We performed cross-sectional evaluation of the diagnostic accuracy of symptom screening, including the World Health Organization (WHO) algorithm, to rule out tuberculosis in HIV-infected individuals pre-ART and on ART undergoing screening prior to IPT. RESULTS: A total of 1429 participants, 54% on ART, had symptom screening and a sputum culture result available. Culture-positive tuberculosis was diagnosed in 126 patients (8.8%, 95% confidence interval [CI], 7.4%-10.4%). The WHO symptom screen in the on-ART compared with the pre-ART group had a lower sensitivity (23.8% vs 47.6%), but higher specificity (94.4% vs 79.8%). The effect of ART was independent of CD4(+) count in multivariable analyses. The posttest probability of tuberculosis following a negative WHO screen was 8.9% (95% CI, 7.4%-10.8%) and 4.4% (95% CI, 3.7%-5.2%) for the pre-ART and on-ART groups, respectively. Addition of body mass index to the WHO screen significantly improved discriminatory ability in both ART groups, which was further improved by adding CD4 count and ART duration. CONCLUSIONS: The WHO symptom screen has poor sensitivity, especially among patients on ART, in a clinic where regular tuberculosis screening is practiced. Consequently, a significant proportion of individuals with tuberculosis would inadvertently be placed on isoniazid monotherapy despite high negative predictive values. Until more sensitive methods of ruling out tuberculosis are established, it would be prudent to do a sputum culture prior to IPT where this is feasible