5,153 research outputs found
Sustainable forest management of miombo woodlands in Niassa National Reserve, northern Mozambique: a multidisciplinary approach of fire resistance analysis.
Poster presented at XIII World Forestry Congress. Buenos Aires (Argentina). 18 - 23 Oct 2009
Scattering and Trapping of Nonlinear Schroedinger Solitons in External Potentials
Soliton motion in some external potentials is studied using the nonlinear
Schr\"odinger equation. Solitons are scattered by a potential wall. Solitons
propagate almost freely or are trapped in a periodic potential. The critical
kinetic energy for reflection and trapping is evaluated approximately with a
variational method.Comment: 9 pages, 7 figure
The influence of metabolic profile of obese men on the severity of erectile dysfunction: Are metabolically healthy obese individuals protected?
Objective: To determine the prevalence of erectile dysfunction (ED) in metabolically healthy obese (MHO) individuals, and to compare ED severity and hypogonadism prevalence in MHO, metabolically unhealthy obese (MUO) and metabolically healthy non-obese individuals.Material and methods: ED patients (n=460) were evaluated by standardized protocol, that included clinical evaluation, abridged 5-item version of the International Index of Erectile Function (IIEF-5) questionnaire survey, and Penile Duplex Doppler Ultrasound (PDDU) exam. Patients were classified as obese [body mass index (BMI) =30.0 kg/m2] and non-obese (BMI <30.0 kg/m2), and metabolic health status was defined by National Cholesterol Education Program Adult Treatment Panel III (NCEP ATPIII) criteria. Statistical analysis was performed and statistical significance was considered at p-level <0.05.Results: The mean age of the subjects was 56.2±10.5 years. MHO was present in 40% of obese individuals (n=37). MUO had lower mean peak systolic velocity (mPSV) compared to MHO (28.1 cm/s vs. 36.9 cm/s; p=0.005), and IIEF-5 scores were also lower in MUO compared to MHO patients (10.2 vs. 13.1; p=0.018). No statistical differences in IIEF-5 score, mPSV and hypogonadism prevalence between MHO and metabolically healthy non-obese (MHNO) patients were observed.Conclusion: Our results lead us to conclude that healthy metabolic profile protects obese individuals from severity of ED. The strong association between obesity and ED may be otherwise attributed to metabolic abnormalities present in the obese
Chirocentrodon Bleekerianus (teleostei: Clupeiformes: Pristigasteridae), A Small Predaceous Herring With Folded And Distinctively Oriented Prey In Stomach.
Predaceous fish-eating species of the order Clupeiformes have a large mouth with well-developed teeth, and reach the greatest sizes within their families (up to 90 cm). We found that the pristigasterid Chirocentrodon bleekerianus, a small clupeiform (about 10 cm) from the tropical SW Atlantic, is able to prey on proportionally large clupeoid fishes and caridean shrimps. Fish preys are folded in the stomach of this herring, their heads and tails pointing toward the predator's head. This distinctive orientation of fish prey is also recorded for some small to medium-sized, fish-eating species of the tropical freshwater order Characiformes with canine-like teeth similar to those found in C. bleekerianus.64116516
Ground-state configurations in ferromagnetic nanotori
Magnetization ground states are studied in toroidal nanomagnets. The
energetics associated to the ferromagnetic, vortex and onion-like
configurations are explicitly computed. The analysis reveals that the vortex
appears to be the most prominent of such states, minimizing total energy in
every torus with internal radius (for Permalloy). For
the vortex remains the most favorable pattern whenever
( is the torus external radius and is
the exchange length), being substituted by the ferromagnetic state whenever
.Comment: 16 pages, 9 figures, 3 apendices, Revtex forma
Development of fluorescent nanocomposites based on CdTe quantum dots
Cadmium telluride (CdTe) quantum dots (QDs) are efficient fluorescence semiconductor nanoparticles with
unique optical and physicochemical properties. Their incorporation into polymer matrices allows the
development of materials with several applications such as in opto-eletronic devices. Nevertheless, one of the
most important prerequisite of these high-efficiency nanocomposites is the fluorescence efficiency of the QDs–
polymer, which is mainly related with the QDs dispersion. Even though many attempts have been made, there
are little work reporting the effect of different polymer matrices on QDs dispersion and therefore, the charge
transport in the final materials (Rakovich and Donegan 2013) 1 .
In this work, a strategy to develop QDs/polymer nanocomposites is presented. Highly fluorescent CdTe QDs
are embedded in different optically transparent commercial polymers, via solvent cast method.
To investigate the influence of each polymeric matrix on the final properties, optical, morphological and
electrical measurements were carried out. Furthermore, the results demonstrate that the addition of a surfactant
produce better dispersion of the CdTe QDs in the polymeric matrices and improve the electrical properties of
the resulting materials (Fig.1)
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