Diversidad y abundancia de primates en hábitats del área de influencia de la carretera Iquitos–Nauta, Amazonía Peruana

En este artículo se proporciona información sobre la diversidad, tamaño de grupo y densidad poblacional de primates para cada hábitat diferenciado en el área de estudio. En 556 km de transectos recorridos de setiembre a octubre del 2011 y luego de febrero a mayo y julio a octubre del 2012, se  registró 200 grupos de nueve especies de primates y otras dos fueron observadas fuera de los censos, alcanzando el registro a 11 especies. Grupos más pequeños correspondieron a <em>Pithecia aequatorialis</em>, <em>Callicebus torquatus</em> y <em>Callicebus discolor</em>, cuyo tamaño de acuerdo al tipo de hábitat varió  entre  2 y 6 individuos y la más grande  fue para <em>Saimiri sciureus</em> (12 a 42 individuos). Las densidades poblacionales fueron más altas para <em>Saguinus lagonotus</em> (55,8 individuos/km²) y <em>S. sciureus</em> (52 individuos/km²) y la más baja para <em>C. torquatus</em> (0,4 individuos/km²). Grupos de <em>S. sciureus</em>, <em>S. lagonotus</em> y <em>P. aequatorialis</em> fueron los más frecuentemente observados (78% de los avistamientos) en los tres tipos de hábitats diferenciados. Entre las especies,  <em>Lagothrix poeppigii</em>, <em>Alouatta seniculus </em>y <em>C. torquatus </em> estuvieron ausentes en el lado oriental de la carretera Iquitos-Nauta; la extinción local de estas especies estarían relacionadas con la alta presión de caza y deforestación.

Intermediate-energy differential and integral cross sections for vibrational excitation in α-tetrahydrofurfuryl alcohol

Differential and integral cross section measurements, for incident electron energies in the 20-50 eV range, are reported for excitation of several composite vibrational modes in α-tetrahydrofurfuryl alcohol (THFA). Optimisation and frequency calculations, using GAUSSIAN 09 at the B3LYP/aug-cc-pVDZ level, were also undertaken for the two most abundant conformers of THFA, with results being reported for their respective mode classifications and excitation energies. Those calculations assisted us in the experimental assignments of the composite features observed in our measured energy loss spectra. There are, to the best of our knowledge, no other experimental or theoretical data currently available in the literature against which we can compare the present results.

Computer-supported diagnosis for endotension cases in endovascular aortic aneurysm repair evolution

An abdominal aortic aneurysm (AAA) is a localized abnormal enlargement of the abdominal aorta with fatal consequences if not treated on time. The endovascular aneurysm repair (EVAR) is a minimal invasive therapy that reduces recovery times and improves survival rates in AAA cases. Nevertheless, post-operation difficulties can appear influencing the evolution of treatment. The objective of this work is to develop a pilot computer-supported diagnosis system for an automated characterization of EVAR progression from CTA images. The system is based on the extraction of texture features from post-EVAR thrombus aneurysm samples and on posterior classification. Three conventional texture-analysis methods, namely the gray level co-occurrence matrix (GLCM), the gray level run length matrix (GLRLM), the gray level difference method (GLDM), and a new method proposed by the authors, the run length matrix of local co-occurrence matrices (RLMLCM), were applied to each sample. Several classification schemes were experimentally evaluated. The ensembles of a k-nearest neighbor (k-NN), a multilayer perceptron neural network (MLP-NN), and a support vector machine (SVM) classifier fed with a reduced version of texture features resulted in a better performance (Az=94.35±0.30), as compared to the classification performance of the other alternatives.

Potassium-uracil/thymine ring cleavage enhancement as studied in electron transfer experiments and theoretical calculations

We report experimental and theoretical studies on ring cleavage enhancement in collisions of potassium atoms with uracil/thymine to further increase the understanding of the complex mechanisms yielding such fragmentation pathways. In these electron transfer processes time-of-flight (TOF) negative ion mass spectra were obtained in the collision energy range 13.5-23.0 eV. We note that CNO(-) is the major ring breaking anion formed and its threshold formation is discussed within the collision energy range studied. Such a decomposition process is supported by the first theoretical calculations to clarify how DNA/RNA pyrimidine base fragmentation is enhanced in electron transfer processes yielding ion-pair formation.

Increased exhaled breath temperature in subjects with uncontrolled asthma

BACKGROUND

Increased vascularity of the airway mucosa in asthma potentially increases heat loss in the airways.

OBJECTIVE

To determine if the inflamed airways of subjects with uncontrolled asthma show increased exhaled breath temperature (EBT).

PATIENTS AND METHODS

In 100 patients with persistent asthma and 50 healthy volunteers, we measured lung function by post-bronchodilator forced spirometry, the asthma control test (ACT) and EBT.

RESULTS

Patients with asthma, of whom 49 (49%) were female, with a mean (± standard error of the mean) age of 44 (±17) years and a predicted forced expiratory volume in one second of 71% (±16), had a significantly increased EBT, particularly those with uncontrolled asthma (n = 50, ACT ≤ 19, EBT 34.9 ± 0.8°C), compared to patients with controlled asthma (n = 50, ACT ≥ 20, EBT 33.7 ± 0.8°C) and healthy volunteers (n = 50, EBT 33.2 ± 0.2°C, P < 0.001).

CONCLUSION

We observed a higher temperature on exhaled breath in subjects with uncontrolled asthma than in subjects with controlled asthma and healthy controls. The increase in exhaled breath temperature may be a proxy for a raised airway inflammatory state in asthma patients.

N-site de-methylation in pyrimidine bases as studied by low energy electrons and ab initio calculations

Electron transfer and dissociative electron attachment to 3-methyluracil (3meU) and 1-methylthymine (1meT) yielding anion formation have been investigated in atom-molecule collision and electron attachment experiments, respectively. The former has been studied in the collision energy range 14-100 eV whereas the latter in the 0-15 eV incident electron energy range. In the present studies, emphasis is given to the reaction channel resulting in the loss of the methyl group from the N-sites with the extra charge located on the pyrimidine ring. This particular reaction channel has neither been approached in the context of dissociative electron attachment nor in atom-molecule collisions yet. Quantum chemical calculations have been performed in order to provide some insight into the dissociation mechanism involved along the N-CH3 bond reaction coordinate. The calculations provide support to the threshold value derived from the electron transfer measurements, allowing for a better understanding of the role of the potassium cation as a stabilising agent in the collision complex. The present comparative study gives insight into the dynamics of the decaying transient anion and more precisely into the competition between dissociation and auto-detachment.