5,379 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
Meiotic behavior of two grapevine somatic mutants with ornamental potential
‘Niagara Steck’ and ‘Niagara Variegada’ are two grapevine varieties that arose spontaneously as somatic mutants of ‘Niagara Rosada’. Berries characterize ‘Niagara Steck’ at young stages exhibiting a remarkable brown reticulated structure on the epidermis which develops into a brown-bronze russet-like structure as the berries ripe. The mature berries have strongly acidic flesh. ‘Niagara Variegada’ shows notable variegation in leaves and berries. Meiotic studies were carried out to ascertain if the mutant phenotypes could be related to any change in chromosome number, structure or other irregularity. Floral buds of both varieties at different developmental stages were collected and fixed for cytological analyses. Chromosome counts at diakinesis/metaphase I showed n=19 bivalents for both varieties. Univalent, trivalent, tetravalent chromosomes or chain configuration were not recorded ruling out the possibility of any alteration in the chromosome number or structure in both mutant varieties. However, low percentages of meiotic irregularities were recorded such as chromosome stickiness, laggards, non-oriented chromosomes, precocious chromosome segregation, tetrads with one microcyte, microspore fusion, and tetrad degeneration. The total percentage of abnormalities was higher in ‘Niagara Variegada’ (19.68%) than in ‘Niagara Steck’ (14.40%) which may have contributed to a lower percentage of pollen fertility (79.80%) when compared to ‘Steck’ (90.74%). The aforementioned varieties can be propagated by hardwood cuttings and constitute an interesting option for ornamentation of home backyards, patios, and gardens with the advantage that ‘Niagara Variegada’ bearing sweet edible berries
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
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
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
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