Foraging behavior of tyrant flycatchers (Aves, Tyrannidae) in Brazil

Este trabalho apresenta dados acerca do comportamento de forrageamento e substratos usados para a captura de presas por 28 espécies de tiranídeos (Tyrannidae) no Brasil. Para seis espécies: Arundinicola leucocephala Linnaeus, 1764, Fluvicola nengeta Linnaeus, 1766, Machetornis rixosa Vieillot, 1819, Myiozetetes similis Spix, 1825, Pitangus sulphuratus Linnaeus, 1766 e Tyrannus melancholicus Vieillot, 1819 -, também são apresentados dados sobre a altura do poleiro usado para caça, tempo de procura por presas, distância e ângulo de ataque. Com raras exceções, manobras do tipo sally strike foram as mais freqüentes, enquanto folhas vivas e o ar foram os substratos mais comumente usados para capturar presas. Para as seis espécies acima citadas três grupos de altura de forrageamento puderam ser discernidos: F. nengeta e M. rixosa forrageiam no chão, A. leucocephala e P. sulphuratus ocupam um estrato médio e T. melancholicus e M. similis formam um terceiro grupo e geralmente atacam suas presas a partir de poleiros situados a 3 m ou mais do chão. Com exceção de P. sulphuratus, que apresentou o tempo de procura mais longo, as outras cinco espécies não diferiram nesse aspecto. Três grupos foram também discernidos em relação à distância de ataque: F. nengeta e M. rixosa atacam presas próximas (< 2 m) a eles, A. leucocephala, P. sulphuratus e M. similis formam um grupo de média distância (3-4 m) e T. melancholicus apresentou as mais longas distâncias de ataque (até 12 m). As aves diferiram em alguns aspectos do ângulo de ataque que, juntamente com diferenças sutis em outros aspectos do comportamento de forrageamento podem levar a diferenças importantes na seleção de presas.

Os efeitos dos aparelhos funcionais sobre a dimensão transversal da maxila e mandíbula

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A respiração frenolabial na doença pulmonar obstrutiva crônica: revisão da literatura

Esta revisão teve por objetivo destacar os principais achados publicados nos últimos dez anos sobre os efeitos da respiração frenolabial (RFL) em pacientes com doença pulmonar obstrutiva crônica (DPOC). A busca dos artigos foi realizada nas bases de dados Lilacs, IBECS, MEDLINE e SciELO, por meio dos seguintes descritores da área da saúde (DeCS): doença pulmonar obstrutiva crônica, reabilitação, respiração, hiperinsuflação e dispneia, e suas respectivas versões na língua inglesa (MeSH), além do termo pursed-lip breathing. Após a eliminação dos títulos repetidos, foram selecionados somente os estudos que abordavam a RFL como tema principal, resultando em 12 artigos científicos, 10 ensaios clínicos e 2 revisões bibliográficas. Segundo os achados, a RFL proporciona: alterações sobre a gasometria arterial, caracterizada pelo aumento da saturação e pressão parcial de oxigênio; padrão ventilatório, com diminuição da frequência respiratória e aumento de tempo expiratório e do volume corrente; mecânica ventilatória, por meio do recrutamento de musculatura abdominal expiratória e dos músculos da caixa torácica e acessórios da inspiração; diminuição no consumo de oxigênio; alterações na modulação autonômica cardíaca induzida pelo aumento da atividade parassimpática e, por fim, melhora na qualidade de vida destes pacientes. A RFL é considerada uma manobra de grande importância, por repercutir de forma positiva em diversos sistemas e sobre a qualidade de vida de pacientes portadores da DPOC.

Intubação traqueal e o paciente com o estômago cheio

A aspiração pulmonar do conteúdo gástrico, apesar de pouco frequente, exige cuidados especiais para sua prevenção. A depressão da consciência durante a anestesia predispõe os pacientes a esta grave complicação pela diminuição na função do esfíncter esofágico e dos reflexos protetores das vias aéreas. Guias de jejum pré-operatório elaborados recentemente sugerem períodos menores de jejum, principalmente para líquidos, permitindo mais conforto aos pacientes e menor risco de hipoglicemia e desidratação, sem aumentar a incidência de aspiração pulmonar perioperatória. O uso rotineiro de agentes que diminuem a acidez e volume gástrico parece estar indicado apenas para pacientes de risco. A intubação traqueal após indução anestésica por meio da técnica de sequência rápida está indicada naqueles pacientes, com risco de aspiração gástrica, em que não há suspeita de intubação traqueal difícil. A indicação correta da técnica, sua aplicação criteriosa e a utilização racional das drogas disponíveis podem promover condições excelentes de intubação, com curto período de latência, rápido retorno da consciência e da respiração espontânea, caso haja falha na intubação traqueal.O presente artigo tem como objetivo discutir os métodos atualmente utilizados para controlar o volume e o pH do conteúdo gástrico, proteger as vias aéreas durante as manobras de intubação e reduzir o refluxo gastroesofágico.

Maxillary canine-first premolar transposition - Restoring normal tooth order with segmented mechanics

Tooth transpositions present at a relatively low incidence in the world population and primarily affect maxillary canines and premolars. Treatment of this disturbance should take into account aspects such as facial pattern, age, malocclusion, tooth-size discrepancy, stage of eruption, and magnitude of the transposition. Mechanics for correction should be entirely individualized, reducing the risks and adverse effects. Practitioners often select simpler options, indicating extraction of permanent teeth, which is an irreversible procedure that may bring about damages to the patient. This study presents a case report and treatment of unilateral transposition of maxillary canine and premolar with repositioning of affected teeth to their respective normal positions.

CHARACTERISTICS OF ARTERIAL-HYPERTENSION IN RESPONSE TO BOLUS INJECTION OF PHENYLEPHRINE IN ATROPINIZED PATIENTS

The changes of arterial pressure promoted by bolus injection of 50 mg phenylephrine (PHE) were studied in 20 atropinized patients (5 normal subjects, 13 patients with mitral valve disease, 1 patient with essential arterial hypertension and 1 patient with hypertrophic cardiomyopathy) submitted to routine catheterism. Patients with aortic valve disease, left ventricular outflow tract obstruction and intracardiac shunt were excluded from the study. All patients were in sinus rhythm, without heart failure. Arterial pressure started to increase at 14.8 +/- 5.4 s (range, 5.6 to 27 s; mean +/- SD) after PHE. There was an increase of 37.8 +/- 16.7 mmHg (range, 12.5 to 70 mmHg) in systolic pressure and of 26.6 +/- 11.1 mmHg (range, 7.5 to 42.5 mmHg) in diastolic pressure. Peak hypertension was attained at 36.6 +/- 16.4 s (range, 10.8 to 64.9 s) and hypertension continued for 176 +/- 92 s (range, 11 to 365 s). Heart rate was 114 +/- 21 bpm before PHE and 111 +/- 21 bpm (P<0.05) after PHE. There were no adverse events associated with intravenous PHE injection in any patient, in accordance with the general view that bolus injection of PHE is a safe and practical maneuver to promote arterial hypertension.

Role of roscovitine and IBMX on kinetics of nuclear and cytoplasmic maturation of bovine oocytes in vitro

The 3-isobutyl-1-methylxanthine (IBMX) is able to prevent resumption of meiosis by maintaining elevated cyclic AMP (cAMP) concentrations in the oocyte, and roscovitine, a purine known to specifically inhibit MPF kinase activity, maintains bovine oocytes at the germinal vesicle (GV) stage. The present study was conducted to analyze whether cytoplasmic maturation (examined by the pattern of cortical granule (CG) distribution) of bovine oocytes is improved during meiotic arrest with IBMX and roscovitine. Oocytes were matured in vitro in a 10% Knockout(SR) supplemented TCM-199 medium (Control) with either 0.5 mM IBMX or 25 mu M roscovitine (ROSC). Oocytes were stained with fluorescein isothiocyanate conjugated Lens culinaris agglutinin (FITC-LCA) for CG evaluation and with Hoechst 33342 for nuclear stage assessment. At 16 h of culture, the percentage of oocytes remaining in the GV stage was higher (P < 0.05) in the ROSC group (32.41%) compared with the Control and IBMX groups (8.61% and 9.73%, respectively). At 24h of culture, progression of meiosis to M II stage was retarded (P < 0.05) in the ROSC group (24.05%) compared to the Control (60.20%), whereas the IBMX group (33.88%) showed no significant difference to the other two groups. At 16h of maturation, the proportion of oocytes with CG in clusters (immature cytoplasm) was similar between the groups, as was the percentage of peripheral CG (mature) at 24h of maturation. The results of the present study demonstrated that the meiotic inhibitors IBMX and roscovitine delay the progression of nuclear maturation without affecting cytoplasmic maturation, assessed by the analysis of CG repositioning. (c) 2006 Elsevier B.V. All rights reserved.

An analytical and numerical study of plane change maneuvers using aerodynamic force

The goal of the present work is to analyze space missions that use the terrestrial atmosphere to accomplish orbital maneuvers that involve a plane change. A set of analytical solutions is presented for the variation of the orbital elements due to a single passage through the atmosphere, assuming that the interval the spacecraft travels through the atmosphere is not too large. The study considers both the lift influence on the spacecraft orbit as well as drag. The final equations are tested with numerical integration and can be considered in accordance with the numerical results whenever the perigee height is larger than a critical value. Next, a numerical study of the ratio between the velocity increment required to correct the semimajor axis decay due to the atmospheric passage and the velocity variation required to obtain the change in the inclination is also presented. This analysis can be used to decide if a maneuver passing through the atmosphere can decrease the fuel consumption of the mission and, in the cases where this technique can be used, if a multiple passage is more efficient than a single passage.

Effects of the eccentricity on the primaries in the gravitational capture phenomenon

Gravitational capture is a characteristic of some dynamical systems in celestial mechanics, as in the elliptic restricted three-body problem that is considered in this paper. The basic idea is that a spacecraft (or any particle with negligible mass) can change a hyperbolic orbit with a small positive energy around a celestial body into an elliptic orbit with a small negative energy without the use of any propulsive system. The force responsible for this modification in the orbit of the spacecraft is the gravitational force of the third body involved in the dynamics. In this way, this force is used as a zero cost control, equivalent to a continuous thrust applied in the spacecraft. One of the most important applications of this property is the construction of trajectories to the Moon. The objective of the present paper is to study in some detail the effects of the eccentricity of the primaries in this maneuver.

Strategies for plane change of Earth orbits using lunar gravity and derived trajectories of family G

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Alternative Transfers to the NEOs 99942 Apophis, 1994 WR12, and 2007 UW1 via Derived Trajectories from Periodic Orbits of Family G

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of the eccentricity on the primames in the gravitational capture phenomenon

Gravitational capture is a characteristic of some dynamical systems in celestial mechanics, as in the elliptic restricted three-body problem that is considered in this paper. The basic idea is that a spacecraft (or any particle with negligible mass) can change a hyperbolic orbit with a small positive energy around a celestial body into an elliptic orbit with a small negative energy without the use of any propulsive system. The force responsible for this modification in the orbit of the spacecraft is the gravitational force of the third body involved in the dynamics. In this way, this force is used as a zero cost control, equivalent to a continuous thrust applied in the spacecraft. One of the most important applications of this property is the construction of trajectories to the Moon. The objective of the present paper is to study in some detail the effects of the eccentricity of the primaries in this maneuver.

Maxillary canine - First premolar transposition: Restoring normal tooth order with segmented mechanics

Tooth transpositions present at a relatively low incidence in the world population and primarily affect maxillary canines and premolars. Treatment of this disturbance should take into account aspects such as facial pattern, age, malocclusion, tooth-size discrepancy, stage of eruption, and magnitude of the transposition. Mechanics for correction should be entirely individualized, reducing the risks and adverse effects. Practitioners often select simpler options, indicating extraction of permanent teeth, which is an irreversible procedure that may bring about damages to the patient. This study presents a case report and treatment of unilateral transposition of maxillary canine and premolar with repositioning of affected teeth to their respective normal positions. © 2006 by The EH Angle Education and Research Foundation, Inc.

Mandible protrusion and decrease of TMJ sounds: An electrovibratographic examination

This study quantified by, electrovibratography, the amount of mandible protrusion required to decrease significantly temporomandibular joint (TMJ) vibratory energy as an aid in the diagnosis of the recapture of anteriorly displaced disk. Eighteen patients diagnosed as having anterior disk displacement with reduction and TMJ clicking were submitted to electrovibratographic examination at the first appointment and treated with a stabilizing appliance and anterior positioning appliance with 1 to 5 mm protrusion. Vibratory energy was checked in each of these positions. Baseline data were used as control. At the first appointment, the patients had vibrations with more elevated intensities at the middle and late phases of the mouth opening cycle. At only one clinical step, mandible protrusion was obtained with the anterior repositioning appliance, ranging from 1 to 5 mm protusion. At each new position, a new electrovibratographic exam was made. After the 5-mm mandibular projection, only 2 patients presented vibration, with means between 0.6 and 2.8 Hz. Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). The outcomes of this study indicate that 3 mm is the minimum amount of mandible protrusion to significantly decrease the TMJ vibratory energy and to recapture the displaced articular disk.

Interplanetary natural routes via Moon and Lagrangiam points L1 and L2

Swing-by techniques are extensively used in interplanetary missions to minimize fuel consumption and to raise payloads of spaceships. The effectiveness of this type of maneuver has been proven since the beginning of space exploration. According to this premise, we have explored the existence of a natural and direct links between low Earth orbits and the lunar sphere of influence, to obtain low-energy interplanetary trajectories through swing-bys with the Moon and the Earth. The existence of these links are related to a family of retrograde periodic orbits around the Lagrangian equilibrium point L1 predicted for the circular, planar, restricted three-body Earth-Moon-particle problem. The trajectories in these links are sensitive to small disturbances. This enables them to be conveniently diverted reducing so the cost of the swing-by maneuver. These maneuvers allow us a gain in energy sufficient for the trajectories to escape from the Earth-Moon system and to stabilize in heliocentric orbits between the Earth and Venus or Earth and Mars. On the other hand, still within the Earth sphere of influence, and taking advantage of the sensitivity of the trajectories, is possible to design other swing-bys with the Earth or Moon. This allows the trajectories to have larger reach, until they can reach the orbit of other planets as Venus and Mars.(3σ)Broucke, R.A., Periodic Orbits in the Restricted Three-Body Problem with Earth-Moon Masses, JPL Technical Report 32-1168, 1968.