Expectation maximization (EM) algorithms using polar symmetries for computed tomography (CT) image reconstruction

We suggest a symmetric-polar pixellation scheme which makes possible a reduction of the computational cost for expectation maximization (EM) iterative algorithms. The proposed symmetric-polar pixellation allows us to deal with 3D images as a whole problem without dividing the 3D problem into 2D slices approach. Performance evaluation of each approach in terms of stability and image quality is presented. Exhaustive comparisons between all approaches were conducted in a 2D based image reconstruction model. From these 2D approaches, that showing the best performances were finally implemented and evaluated in a 3D based image reconstruction model. Comparison to 3D images reconstructed with FBP is also presented. Although the algorithm is presented in the context of computed tomography (CT) image reconstruction, it can be applied to any other tomographic technique as well, due to the fact that the only requirement is a scanning geometry involving measurements of an object under different projection angles. Real data have been acquired with a small animal (CT) scanner to verify the proposed mathematical description of the CT system.

Automatic intraductal breast carcinoma classification using a neural network-based recognition system

A contour-based automatic recognition system was applied to classify intraductal breast carcinoma into high nuclear grade and low nuclear grade in a digitized histologic image. The image discriminating characteristics were selected by their invariability condition to rotation and translation. They were acquired from cellular contours information. The totally interconnected multilayer perceptron network architecture was selected, and it was trained with the error back propagation algorithm. Forty cases were analyzed by the system and the diagnoses were compared with that of pathologist consensus, obtaining agreement in 97.5% (p < .00001 of cases). The system may become a very useful tool for the pathologist in the definitive classification of intraductal carcinoma.

First Report of Colletotrichum acutatum and C. fragariae Causing Bitter Rot of Apple in Uruguay

Almost 50% of deciduous fruit produced in Uruguay are apples and bitter rot is ubiquitous in the apple-production regions in Uruguay. In rainy and hot seasons (25 to 32°C by day), severe outbreaks of bitter rot occur. In summer 2010, when apple rot incidence reached 70% in some orchards, fruit with typical symptoms of bitter rot were collected from orchards in the south-central region, the main apple-production area. Symptoms included 0.5 to 6.0 cm in diameter, circular, sunken, light brown-to-brown lesions on the fruit surface that contained black, pinhead-sized fruiting structures that produced orange-to-brown conidial masses under high relative humidity. Each lesion progressed to the core of the fruit in a V-shaped pattern. Single-conidial isolates from lesions were examined morphologically (3), and based on sequences of the internal transcribed spacer (ITS) rDNA determined using ITS1/ITS4 primers (4), three species were identified: Colletotrichum acutatum with white-to-pale orange colonies and one-celled, hyaline, fusiform to cylindrical conidia that averaged 14.5 (9.3 to 17.8) × 5.0 (6.9 to 4.0) μm (isolates C11 and C18, GenBank Nos. JN413081 and JN413082, respectively); C. fragariae with white-to-pale gray and/or dark gray colonies and one-celled, hyaline, cylindrical to fusiform conidia that averaged 20.5 (14.3 to 22.9) × 6.0 (4.6 to 7.6) μm (isolate C15 and C37, GenBank Nos. JN413083 and JN413084, respectively); and C. gloeosporioides with white-to-pale gray or gray colonies and one-celled, hyaline, cylindrical to fusiform conidia that averaged 16.5 (13.1 to 20.3) × 6.5 (3.7 to 7.6) μm (isolates C5 and C29, GenBank Nos. JN413079 and JN413080) when grown on potato dextrose agar (PDA) at 25°C. To confirm pathogenicity, two isolates of each Colletotrichum spp. were inoculated onto mature, asymptomatic fruit of cv. Pink Lady (eight fruit per isolate). Each fruit was surface disinfested with 70% ethanol, wounded with a sterile needle, and inoculated with 10 μl of a spore suspension (5 × 10⁵ conidia/ml) of the appropriate isolate. Eight control fruit were each inoculated with 10 μl of sterile water. Inoculated fruit and the control fruit were placed in plastic bags (eight fruit per bag) and incubated at 25°C. Symptoms (sunken, brown lesions each with a V-shaped pattern extending to the core) developed on all inoculated fruit 2 to 4 days after inoculation. No lesions were observed on control fruit. When fungi were reisolated from lesions of inoculated fruit onto PDA and incubated at 25°C, colony and conidial morphology were identical to those of the original isolates, confirming Koch's postulates. This study confirms a previous report of C. gloeosporioides causing bitter rot on apple in Uruguay (1). C. acutaum and C. gloeosporioides are known to cause bitter rot on apple. C. fragariae has traditionally been associated with strawberry and recently with other host plants (2), but not with bitter rot of apple. To our knowledge, this is the first report of bitter rot of apple caused by C. fragariae, and the first report of this disease caused by C. acutatum and C. fragariae in Uruguay. References: (1) S. García. Page 49 in: Guía Para el Manejo Integrado de Plagas y Enfermedades en Frutales. INIA Las Brujas, Canelones, 1998. (2) S. J. MacKenzie et al. Plant Dis. 92:1432, 2008. (3) B. C. Sutton. The Coelomycetes. CAB International Publishing, New York, 1980. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

High power rapidly tunable system for laser cooling

We present a laser configuration capable of fast frequency changes with a high power output and a large tuning range. The system integrates frequency tuning with an acousto-optic modulator with a double pass tapered amplifier. A compensation circuit keeps the seed power constant and prevents damage to the amplifier. A single mode fiber decouples the modulation and amplification sections and keeps the alignment fixed. The small power required to saturate the amplifier makes the system very reliable. We use the system to obtain a dipole trap that we image using a beam derived from the same configuration.

[Musculoskeletal chronic pain: Latin-American expert panel review based on scientific evidence]

Based on the continual medical education, in the first trimester of 2010 an expert in pain meeting has being made at Mexico City. The priority of the research was on educate residents of medical school or at their post graduate years, and the priority was on investigate of how our residents use adequate pain medication. In that first meeting at Mexico City, from different countries, the agreement was on inadequate use of pain treatment caused from inadequate education of the proper indication of drugs and other therapies for muscle skeletal pain. We decided to make a Latin American expert recommendation in chronic muscle pain where we include: epidemiological and socioeconomic pain data, actual classification of NSAIDs, pharmacological and other treatment in pain, and side effects of most popular drugs with actual recommendations. We include Medline guides, reviews, randomized studies and meta-analysis from 2001 to 2010.

Clinical presentation and outcome of venous thromboembolism in COPD

Chronic obstructive pulmonary disease (COPD) is a moderate risk factor for venous thromboembolism (VTE), but neither the clinical presentation nor the outcome of VTE in COPD patients is well known. The clinical presentation of VTE, namely pulmonary embolism (PE) or deep venous thrombosis (DVT), and the outcome at 3 months (death, recurrent VTE or bleeding) were compared between 2,984 COPD patients and 25,936 non-COPD patients included in the RIETE (Registro Informatizado de la Enfermedad TromboEmbólica) registry. This ongoing international, multi-centre registry includes patients with proven symptomatic PE or DVT. PE was the more frequent VTE presentation in COPD patients (n = 1,761, 59%). PE presentation was more significantly associated with COPD patients than non-COPD patients (OR 1.64, 95% CI 1.49-1.80). During the 3-month follow-up, mortality (10.8% versus 7.6%), minor bleeding (4.5% versus 2.3%) or first VTE recurrences as PE (1.5% versus 1.1%) were significantly higher in COPD patients than in non-COPD patients. PE was the most common cause of death. COPD patients presented more frequently with PE than DVT. It may explain the worse prognosis of COPD patients, with a higher risk of death, bleeding or VTE recurrences as PE compared with non-COPD patients. Further therapeutic options are needed.

Note: fast, small, and low vibration mechanical laser shutters

We present three novel mechanical laser shutter designs based, respectively, on a stepper motor, a relay, and a piezoelectric actuator. Each shutter type is ideally suited to a specific shuttering application. The stepper motor is well suited for applications requiring low vibrations, the relay is compact and capable of rapid bursts, and the piezoelectric is 2 orders of magnitude faster than other available mechanical shutters.

A selective spectrofluorimetric method for carbendazim determination in oranges involving inclusion-complex formation with cucurbit[7]uril

The increase in fluorescence intensity with respect to carbendazim that occurs as a result of supramolecular-complex formation between carbendazim and cucurbit[7]uril has been studied. This host-guest interaction has been employed to develop a sensitive and selective method for benzoimidazole-type pesticide determination in fruit samples. The association constant and stoichiometry of the complex formed are reported herein, and the influence of experimental variables, such as the pH or ionic strength of the solution, on complex formation and the presence of interfering substances is also discussed. Under the optimal conditions found, the developed method allows the detection of carbendazim at a 5.0x10(-9)M level. To test the method, matrix solid phase dispersion was employed as a sample preparation method for carbendazim determination in orange samples with an RSD (%) (n=3) value of 5%. The LOD and LOQ values calculated for real samples were 0.10 and 0.52mg/kg, respectively, thus showing that the proposed method is sensitive enough to meet legal requirements.

[The extent of knowledge about strokes among the population of a rural area in the province of Lleida]

INTRODUCTION

Although stroke continues to be a significant cause of morbidity and mortality, the knowledge of warning signs and risk factors among general population is still insufficient.

AIM

To assess the current knowledge of stroke (terminology, signs and symptoms, risk factors and attitude) among rural population of Baix Segria in Lleida in order to the best target and message, prior to educational campaigns.

SUBJECTS AND METHODS

A structured interview using closeended questions was conducted among 153 users of Primary Health Centers.

RESULTS

In our cohort, 6.5% ignored the disease, while 48 (31,4%) had good knowledge of risk factors (more than three risk factors) and 62 (40,5%) identified more than three warnings signs correctly. Only 31,1% would correctly act if stroke occurred. Transient ischemic attack was not considered as emergency. Most participants, 78,5%, would contact to primary care. Surprisingly, knowledge of stroke symptoms and risk factors was not associated with an increased chance of calling 061 or going to the hospital. Older respondents were less likely to recognize symptoms and to consider stroke as an emergency, while the university education was associated with good knowledge and actuation.

CONCLUSION

The level of knowledge of established stroke risk factors, warning signs, and treatment in rural population of Lleida is low. Our data suggested not only that a community-based education program to increase public knowledge of stroke among rural population is necessary, but also we need to inform the people stroke is treatable.

Luxación recidivante postraumática del tendón extensor carpi ulnaris (ECU) en la muñeca: a propósito de un caso

La luxación o subluxación del tendón del extensor carpi ulnaris es uno de los diagnósticos diferenciales, a tener en cuenta, ante la existencia de dolor en el lado cubital de la muñeca, siendo rara su lesión aislada, por lo que su diagnóstico, puede pasar, con frecuencia, desapercibido.

La lesión ocurre durante una hipersupinación del antebrazo, desviación cubital y flexión palmar de la muñeca. Manifestando el paciente la sintomatología dolorosa tras la reducción del tendón con la pronación, dolor que puede llegar a ser muy incapacitante, con disminución del movimiento de pronosupinación de la muñeca, y disminución de fuerza. Debido a su mecanismo de producción y aparición de los síntomas, el diagnóstico es clínico, pues las pruebas complementarias pueden ser normales. La luxación del tendón, sólo ocurre, ante la ruptura o desinserción de su vaina osteofibrosa propia, o capa profunda del sexto compartimento extensor, a pesar de que el ligamento anular dorsal, o capa superficial del retináculo extensor, permanezca intacto. El tratamiento ha de ser quirúrgico, para reconstruir la vaina o corredera osteofibrosa, obteniéndose resultados satisfactorios.

Injectable acrylic bone cements for vertebroplasty based on a radiopaque hydroxyapatite. Formulation and rheological behaviour

The utilization of injectable acrylic bone cement is crucial to the outcome of vertebroplasty and kyphoplasty. However, only a few cements that are in clinical use today are formulated specifically for use in these procedures and even these formulations are not regarded as "ideal" injectable bone cements. The aim of this work is to prepare bioactive bone cements by adding strontium hydroxyapatite (SrHA) to a cement formulation based on polymethylmethacrylate. Thus, the cement combines the immediate mechanical support given by the setting of the acrylic matrix with optimum radiopacity and bioactivity due to the incorporation of the SrHA. Formulations of bioactive cement were prepared with 10 and 20 wt% of SrHA as synthesised and after a surface treatment with the monomer. Cements loaded with treated particles showed an enhancement of their handling properties, and hence, an improvement on their rheological behaviour, injectabilities and compressive parameters. Further experiments were also carried out to determine their bioactivity and biocompatibility and results appear in other publication.

Diffraction by a circular aperture: an application of the vectorial theory of Huygens's principle in the near field

A vectorial theory that brings new insight into the nature of diffraction is used to obtain mathematical expressions that evaluate diffraction patterns in the near field. The equations allow us to discriminate between the contributions of the vectorial and the scalar approaches. In the near field we studied the pattern of light diffracted through a circular aperture, and it was proved that the vectorial approach is significant in a region very near the circular aperture. In spite of the obvious differences between the circular aperture and other obstacles, the present theory may also be used with other geometries.

Phenotypic diversity of Triatoma infestans at the microgeographic level in the Gran Chaco of Argentina and the Andean valleys of Bolivia

Triatoma infestans (Klug) is the main vector of Trypanosoma cruzi, etiologic agent of Chagas disease. The phenotype of the species varies at different geographic scales. The objective of this study was to compare the antennal phenotype of spatially close T. infestans populations and to evaluate its usefulness as a marker of exchange of individuals between populations. The antennal phenotype of 190 T. infestans from Argentina and Bolivia was analyzed using uni- and multivariate techniques. This study shows heterogeneity of the antennal phenotypes of closely related T. infestans populations living in different habitats. Specimens collected in a goat corral and a rabbit cage in La Rioja (Argentina) were dissimilar to the specimens collected in the nearby intradomestic environment. Similarly, specimens from peridomestic corrals in Cochabamba (Bolivia) were different from the intradomestic and sylvatic specimens, indicating some degree of isolation between these populations. In contrast, T. infestans collected in chicken coops and the intradomestic environment were similar, in all studied regions, suggesting a frequent exchange of individuals between the two habitats and/or because of the similarity of the habitat due to the presence of chickens in the intradomestic environment. We propose that each habitat affects in a particular mode the insect morphology and these changes could be used to identify recolonizing T. infestans. These results support the hypothesis of different degrees of isolation between intradomestic and peridomestic habitats. Within this context, special attention should be given to chicken coops and other close peridomestic structures in relation to the recolonization process of domestic habitats by T. infestans.

SodERF3, a novel sugarcane ethylene responsive factor (ERF), enhances salt and drought tolerance when overexpressed in tobacco plants

The molecular signals and pathways that govern biotic and abiotic stress responses in sugarcane are poorly understood. Here we describe SodERF3, a sugarcane (Saccharum officinarum L. cv Ja60-5) cDNA that encodes a 201-amino acid DNA-binding protein that acts as a transcriptional regulator of the ethylene responsive factor (ERF) superfamily. Like other ERF transcription factors, the SodERF3 protein binds to the GCC box, and its deduced amino acid sequence contains an N-terminal putative nuclear localization signal (NLS). In addition, a C-terminal short hydrophobic region that is highly homologous to an ERF-associated amphiphilic repression-like motif, typical for class II ERFs, was found. Northern and Western blot analysis showed that SodERF3 is induced by ethylene. In addition, SodERF3 is induced by ABA, salt stress and wounding. Greenhouse-grown transgenic tobacco plants (Nicotiana tabacum L. cv. SR1) expressing SodERF3 were found to display increased tolerance to drought and osmotic stress.