Automatic building detection from aerial images for mobile robot mapping

To improve mobile robot outdoor mapping, information about the shape and location of buildings is of interest. This paper describes a system for automatic detection of buildings in aerial images taken from a nadir view. The system builds two types of independent hypotheses based on the image contents. A segmentation process implemented as an ensemble of SOMs (Self Organizing Maps) is trained and used to create a segmented image showing different types of roofs, vegetation and sea. A second type of hypotheses is based on an edge image produced from the aerial photo. A line extraction process uses the edge image as input and extracts lines from it. From these edges, corners and rectangles that represent buildings are constructed. A classification process uses the information from both hypotheses to determine whether the rectangles are buildings, unsure buildings or unknown objects

A practical multirobot localization system

We present a fast and precise vision-based software intended for multiple robot localization. The core component of the software is a novel and efficient algorithm for black and white pattern detection. The method is robust to variable lighting conditions, achieves sub-pixel precision and its computational complexity is independent of the processed image size. With off-the-shelf computational equipment and low-cost cameras, the core algorithm is able to process hundreds of images per second while tracking hundreds of objects with a millimeter precision. In addition, we present the method's mathematical model, which allows to estimate the expected localization precision, area of coverage, and processing speed from the camera's intrinsic parameters and hardware's processing capacity. The correctness of the presented model and performance of the algorithm in real-world conditions is verified in several experiments. Apart from the method description, we also make its source code public at \emph{http://purl.org/robotics/whycon}; so, it can be used as an enabling technology for various mobile robotic problems

Photochemical Pump and NMR Probe to monitor the formation and kinetics of hyperpolarized metal dihydrides

On reaction of IrI(CO)(PPh 3) 21with para-hydrogen(p-H 2),Ir(H) 2I(CO)(PPh 3) 22 is formed which exhibits strongly enhanced 1H NMR signals for its hydride resonances. Complex 2 also shows similar enhancement of its NMR spectra when it is irradiated under p-H 2. We report the use of this photochemical reactivity to measure the kinetics of H 2 addition by laser-synchronized reactions in conjunction with NMR. The single laser pulse promotes the reductive elimination of H 2 from Ir(H) 2I(CO)(PPh 3) 22 in C 6D 6 solution to form the 16-electron precursor 1, back reaction with p-H 2 then reforms 2 in a well-defined nuclear spin-state. The build up of this product can be followed by incrementing a precisely controlled delay (τ), in millisecond steps, between the laser and the NMR pulse. The resulting signal vs. time profile shows a dependence on p-H 2 pressure. The plot of k obs against p-H 2 pressure is linear and yields the second order rate constant, k 2, for H 2 addition to 1 of (3.26 ± 0.42) × 10 2 M −1 s −1. Validation was achieved by transient-UV-vis absorption spectroscopy which gives k 2 of (3.06 ± 0.40) × 10 2 M −1 s −1. Furthermore, irradiation of a C 6D 6 solution of 2 with multiple laser shots, in conjunction with p-H 2 derived hyperpolarization, allows the detection and characterisation of two minor reaction products, 2a and 3, which are produced in such low yields that they are not detected without hyperpolarization. Complex 2a is a configurational isomer of 2, while 3 is formed by substitution of CO by PPh

Grasa bovina con un perfil de ácidos grasos mejorado: bajo contenido de grasas saturadas y alto de CLA cis-9, trans-11

Con el objetivo de reducir el riesgo de contraer enfermedades cardiovasculares la Organización Mundial de la Salud recomienda reducir el consumo en total de grasas, especialmente las grasas saturadas (WHO 2003). En el mismo sentido la OMS recomienda incrementar el consumo de ácidos grasos poli-insaturados (AGPI) n-3 y mantener la relación de AGPI dietarios n-6: n-3 por debajo de 4. Si bien el pescado es la principal fuente dietaría de AGPI n-3, en países como la Argentina donde el consumo per capita de pescado es bajo el aporte que realiza la carne vacuna adquiere especial relevancia; especialmente si la carne producida en sistemas pastoriles (McAfee et al. 2011). La grasa de animales provenientes de sistemas pastoriles se caracteriza por tener una mayor proporción de AGPI n-3 que la de animales provenientes de otros sistemas de engorde y por tener una relación AGPI n-6: n-3 cercana a 2 (Daley et al. 2010; Schor et al. 2008). Este tipo de grasa presenta, además, una proporción relativamente alta del ácido linoleico conjugado (CLA) cis-9, trans-11 (Schor et al. 2008); el que presentaría propiedades anti aterogénicas y anti carcinogénicas (Bhattacharya et al. 2006). Sin embargo, a pesar de estas características benéficas de la grasa vacuna proveniente de sistemas pastoril, al igual que en aquella proveniente de otros sistemas de producción, su proporción de ácidos grasos saturados es relativamente alta. La baja relación AGPI n-6: n-3 en la grasa de animales provenientes de sistemas pastoriles está asociada a la también baja relación entre estos ácidos grasos que existe en su dieta (pasto). En tanto que su mayor proporción de CLA cis-9, trans-11 en la grasa respecto a la de animales provenientes de sistemas de alimentación a base de concentrados se le atribuye a la mayor producción ruminal del ácido vaccénico trans-11 (TVA) con dietas fibrosas (Sackmann et al. 2003). El TVA producido en el rumen es luego utilizado en el tejido adiposo por la enzima stearoyl CoA desaturasa (SCD) para generar el CLA cis-9, trans- 11 (Sackmann et al. 2003). A diferencia de lo que ocurre en sistemas de alimentación a base de concentrado donde la principal limitante para la síntesis de CLA cis-9, trans-11 es la disponibilidad del precursor, en sistemas pastoriles la principal limitante es la conversión de TVA a CLA cis-9, trans-11 en el tejido adiposo por una menor restringida actividad de la enzima SCD (Daniel et al. 2004; Duckett et al. 2009). La enzima SCD es también responsable de la conversión de ácidos grasos saturados (AGS; ácidos palmítico y esteárico) a ácidos mono-insaturados (AGMI; ácidos palmitoleico y oleico). A diferencia de los ácidos grasos saturados los monoinsaturados, disminuirían el nivel de colesterol plasmático (Matthan et al. 2009; Ulbricht y Southgate 1991). Es así que una mayor actividad de la enzima SCD en animales en pastoreo sería deseable tanto para incrementar la conversión de conversión de TVA a CLA cis-9, trans-11, como para Grasa bovina con un perfil de ácidos grasos mejorado: bajo contenido de grasas saturadas y alto de CLA cis-9, trans-11 reducir las proporciones de ácidos grasos saturados. De esta forma se obtendría grasa vacuna con mejores propiedades para la salud: baja relación AGPI n-6: n-3, alta proporción de CLA cis-9, trans-11 y baja proporción de AGS totales. Existen evidencias de que la actividad de la enzima SCD sería mayor en vaquillonas que en toros (Barton et al. 2011) o que en novillos (Zembayashi et al. 1995). Por otra parte, Turk y Smith (2009) observaron que existiría una gran variabilidad en la actividad de la enzima en los distintos depósitos grasos del animal. El presente trabajo evalúa la composición de ácidos grasos de tres tejidos grasos de vaquillonas y novillos con el objetivo principal de determinar si el perfil de ácidos grasos de bovinos en pastoreo puede ser mejorado seleccionando una categoría de animales y determinados depósitos de grasa con mayor actividad de la SCD.Fil: De La Torre, M. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Pouzo, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Duckett, S.. University of Clemson; Estados UnidosFil: Pavan, E.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentin

Using structure-based organic chemistry online tutorials with automated correction for student practice and review

This article describes the development and implementation of an open-access organic chemistry question bank for online tutorials and assessments at University College Cork and Dublin Institute of Technology. SOCOT (structure-based organic chemistry online tutorials) may be used to supplement traditional small-group tutorials, thereby allowing students to develop essential problem-solving skills in organic chemistry. This online approach may be used for both formative and summative assessment. Students complete one problem set weekly or fortnightly, which consists of a number of questions of varying difficulty. A wide range of question types is possible; for example, prediction of reaction products, identification of reaction intermediates or reagents, and retrosynthetic analyses. Questions involving stereochemistry may be also be incorporated. The implementation is described, along with several sample questions and advice for creating questions. This approach is suitable for all levels of undergraduates, from introductory nonmajors to final-year chemistry students. Student feedback was overwhelmingly positive, and in particular, students found SOCOT to be a quite useful tool for review purposes. Our approach uses MarvinSketch, which is free for academic purposes, and the SMILES algorithm, which converts chemical structures into a text string and is compatible with any learning management system

Does habitat stability structure intraspecific genetic diversity? It’s complicated...

Regional phylogeographic studies have long been conducted in the southeastern United States for a variety of species. With some exceptions, many of these studies focus on single species or single clades of organisms, and those considering multiple species tend to focus on deep historical breaks causing differentiation. However, in many species more recent factors may be influencing genetic diversity. To understand the roles of historic and contemporary processes in structuring genetic diversity, we reanalyzed existing genetic data from Southeast of North America using approaches gleaned from phylogeographic and landscape genetic literature that were implemented across species including AMOVAs, PCoAs, Species Distribution Modelling, and tests of isolation by distance, environment, and habitat instability. Genetic variance was significantly partitioned by ecoregions, watersheds, and across phylogeographic breaks in the majority of species. Similarly, genetic variation was significantly associated with some combination of geographic or environmental distance or habitat instability in most species. Patterns of genetic variation were largely idiosyncratic across species. While habitat instability over time is significantly correlated with genetic diversity in some species, it appears generally less important than isolation by geographic or environmental distance. Our results suggest that many factors, both historical and contemporary, impact genetic diversity within a species, and more so, that these patterns aren’t always similar in closely related species. This supports the importance of species- specific factors and cautions against assumptions that closely related species will respond to historical and contemporary forces in similar ways

Altered urothelial ATP signaling in a major subset of human overactive bladder patients with pyuria

Overactive Bladder (OAB) is an idiopathic condition, characterized by urgency, urinary frequency, and urgency incontinence, in the absence of routinely traceable urinary infection. We have described microscopic pyuria (≥10 wbc/μl) in patients suffering from the worst symptoms. It is established that inflammation is associated with increased ATP release from epithelial cells, and extracellular ATP originating from the urothelium following increased hydrostatic pressure is a mediator of bladder sensation. Here, using bladder biopsy samples, we have investigated urothelial ATP signaling in OAB patients with microscopic pyuria. Basal, but not stretch-evoked, release of ATP was significantly greater from the urothelium of OAB patients with pyuria than from non-OAB patients or OAB patients without pyuria (<10 wbc/μl). Basal ATP release from the urothelium of OAB patients with pyuria was inhibited by the P2 receptor antagonist suramin and abolished by the hemichannel blocker carbenoxolone, which differed from stretch-activated ATP release. Altered P2 receptor expression was evident in the urothelium from pyuric OAB patients. Furthermore, intracellular bacteria were visualized in shed urothelial cells from ∼80% of OAB patients with pyuria. These data suggest that increased ATP release from the urothelium, involving bacterial colonization, may play a role in the heightened symptoms associated with pyuric OAB patients

Universities Confront ‘Tech Disruption’: Perceptions of Student Engagement Online Using Two Learning Management Systems

This article is a teaching note on the experiences of students and professors as they adapted to the use of a new learning management system (LMS). Using pedagogical theories of student engagement and the online learning process, we explore how the design of an LMS affects student satisfaction and interaction with peers and the instructor. This descriptive, qualitative study reports student and instructor experiences in four hybrid sociology courses that used Google Classroom as an experimental LMS. These same students also used Blackboard, a more traditional LMS, in their other sociology classes, establishing a quasi within-subject point of comparison for these two systems. A survey (n=72) and four focus groups (n=54) were conducted among students to determine how student engagement is experienced differently on Classroom and Blackboard. Eighty-three percent of students reported feeling satisfied with Classroom over Blackboard. Focus groups revealed themes relating to usability and learnability; interaction and individuality; and facilitation of learning. Students and instructors responded more positively, with some exceptions, to Classroom’s reliability and interface, but claims about the transformative power of online tools are not wholly supported by student or instructor experiences. The study advances our understanding of how the LMS interface, design, and functionality play a role in student engagement online. Further research is needed to understand the full extent of Classroom’s impact on learning in the higher education landscape

Activity-Based Funding of Hospitals and Its Impact on Mortality, Readmission, Discharge Destination, Severity of Illness, and Volume of Care: A Systematic Review and Meta-Analysis

Background: Activity-based funding (ABF) of hospitals is a policy intervention intended to re-shape incentives across health systems through the use of diagnosis-related groups. Many countries are adopting or actively promoting ABF. We assessed the effect of ABF on key measures potentially affecting patients and health care systems: mortality (acute and post-acute care); readmission rates; discharge rate to post-acute care following hospitalization; severity of illness; volume of care. Methods: We undertook a systematic review and meta-analysis of the worldwide evidence produced since 1980. We included all studies reporting original quantitative data comparing the impact of ABF versus alternative funding systems in acute care settings, regardless of language. We searched 9 electronic databases (OVID MEDLINE, EMBASE, OVID Healthstar, CINAHL, Cochrane CENTRAL, Health Technology Assessment, NHS Economic Evaluation Database, Cochrane Database of Systematic Reviews, and Business Source), hand-searched reference lists, and consulted with experts. Paired reviewers independently screened for eligibility, abstracted data, and assessed study credibility according to a pre-defined scoring system, resolving conflicts by discussion or adjudication. Results: Of 16,565 unique citations, 50 US studies and 15 studies from 9 other countries proved eligible (i.e. Australia, Austria, England, Germany, Israel, Italy, Scotland, Sweden, Switzerland). We found consistent and robust differences between ABF and no-ABF in discharge to post-acute care, showing a 24% increase with ABF (pooled relative risk = 1.24, 95% CI 1.18–1.31). Results also suggested a possible increase in readmission with ABF, and an apparent increase in severity of illness, perhaps reflecting differences in diagnostic coding. Although we found no consistent, systematic differences in mortality rates and volume of care, results varied widely across studies, some suggesting appreciable benefits from ABF, and others suggesting deleterious consequences. Conclusions: Transitioning to ABF is associated with important policy- and clinically-relevant changes. Evidence suggests substantial increases in admissions to post-acute care following hospitalization, with implications for system capacity and equitable access to care. High variability in results of other outcomes leaves the impact in particular settings uncertain, and may not allow a jurisdiction to predict if ABF would be harmless. Decision-makers considering ABF should plan for likely increases in post-acute care admissions, and be aware of the large uncertainty around impacts on other critical outcomes

HIV-related travel restrictions: trends and country characteristics

Introduction: Increasingly, HIV-seropositive individuals cross international borders. HIV-related restrictions on entry, stay, and residence imposed by countries have important consequences for this mobile population. Our aim was to describe the geographical distribution of countries with travel restrictions and to examine the trends and characteristics of countries with such restrictions. Methods: In 2011, data presented to UNAIDS were used to establish a list of countries with and without HIV restrictions on entry, stay, and residence and to describe their geographical distribution. The following indicators were investigated to describe the country characteristics: population at mid-year, international migrants as a percentage of the population, Human Development Index, estimated HIV prevalence (age: 15&#x2013;49), presence of a policy prohibiting HIV screening for general employment purposes, government and civil society responses to having non-discrimination laws/regulations which specify migrants/mobile populations, government and civil society responses to having laws/regulations/policies that present obstacles to effective HIV prevention, treatment, care, and support for migrants/mobile populations, Corruption Perception Index, and gross national income per capita. Results: HIV-related restrictions exist in 45 out of 193 WHO countries (23%) in all regions of the world. We found that the Eastern Mediterranean and Western Pacific Regions have the highest proportions of countries with these restrictions. Our analyses showed that countries that have opted for restrictions have the following characteristics: smaller populations, higher proportions of migrants in the population, lower HIV prevalence rates, and lack of legislation protecting people living with HIV from screening for employment purposes, compared with countries without restrictions. Conclusion: Countries with a high proportion of international migrants tend to have travel restrictions &#x2013; a finding that is relevant to migrant populations and travel medicine providers alike. Despite international pressure to remove travel restrictions, many countries continue to implement these restrictions for HIV-positive individuals on entry and stay. Since 2010, the United States and China have engaged in high profile removals. This may be indicative of an increasing trend, facilitated by various factors, including international advocacy and the setting of a UNAIDS goal to halve the number of countries with restrictions by 2015