scholarly journals Tracheal Hypertrophy in Mealworms: Design and Plasticity in Oxygen Supply Systems

1989 ◽  
Vol 147 (1) ◽  
pp. 217-235 ◽  
Author(s):  
CATHERINE LOUDON
Keyword(s):  
Total Pressure ◽  
Oxygen Supply ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Tracheal System ◽  
Primary Mechanism ◽  
Ambient Oxygen ◽  
Supply Systems ◽  
Different Levels

Larval Tenebrio molitor L. (Insecta) were reared in three different levels of oxygen: 21 % (normal), 15 % and 10.5 %, all at 101.3 kPa (=1 atm) total pressure (remainder nitrogen). Some larvae were transferred from one oxygen level to another during development. The main tracheae (branching off from the spiracular tracheae) were of greater cross-sectional area in lower ambient oxygen. Compared to larvae of the same body mass reared in 21 % oxygen, larvae reared in 15 % oxygen had main tracheae 40% larger in cross-sectional area on average, and larvae in 10.5% oxygen had main tracheae 120% larger. This hypertrophy is not consistent with the widely accepted hypothesis that tracheae contribute an insignificant resistance to the net movement of oxygen in insect tracheal systems. The magnitude of the hypertrophy is consistent with predictions from Fick's law of diffusion and with the hypothesis that diffusion is the primary mechanism for oxygen movement in the larval tracheal system of holometabolous insects.

scholarly journals MARCADORES ANATÔMICOS DO PECÍOLO E A TOLERÂNCIA À SECA DE PONTEIROS E AO DÉFICIT HÍDRICO EM EUCALIPTO

Nativa ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 591-596
Author(s):  
Samyra Alves Condé ◽  
Edgard Augusto de Toledo Picoli ◽  
Thais Roseli Corrêa ◽  
Rodrigo Dal Sasso Lourenço
Keyword(s):  
Water Stress ◽  
Vascular Tissue ◽  
Relevant Information ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Physiological Disorder ◽  
Cross Sectional ◽  
Water Nutrients ◽  
Different Levels ◽  
Selection Of

A seca de ponteiros em Eucalipto é um distúrbio fisiológico, onde o estresse hídrico vem sendo associado como um dos fatores intensificadores de sua ocorrência. A seleção precoce de genótipos de eucalipto tolerantes a essas condições, podem fornecer informações relevantes quanto a esse distúrbio. Objetivou-se avaliar possíveis marcadores anatômicos, associados a tolerância ao déficit hídrico e à seca de ponteiros. Genótipos comerciais com diferentes graus de suscetibilidade a seca de ponteiros foram submetidos a diferentes níveis de estresse hídrico em condições de casa de vegetação. A duração do experimento foi de 75 dias. Amostras de pecíolos foram coletadas e avaliadas as características das áreas anatômicas de: seção transversal, tecido vascular, xilema, floema e do córtex. Os dados foram submetidos à análise da variância (ANOVA) e para comparação de médias foi adotado o teste Tukey (p<0,05). Os resultados mostraram que há a tendência de redução de todas as variáveis avaliadas com o aumento do déficit hídrico. Entretanto, o genótipo tolerante em condições de maior restrição hídrica apresenta maior área de seção transversal e de tecidos condutores em comparação ao suscetível. A maior proporção destes tecidos sugere que o clone tolerante apresenta condição mais favorável ao transporte de água, fotoassimilados e nutrientes. Palavras-chave: melhoramento florestal; silvicultura; seleção genômica.   ANATOMICAL MARKERS OF PETIOLE AND TOLERANCE TO DIE-BACK AND WATER STRESS IN EUCALYPTUS   ABSTRACT: Die-Back in Eucalyptus is a physiological disorder where the water stress has been associated as an intensifier of this occurrence. The early selection of tolerant Eucalyptus genotypes to water stress can provide relevant information to this disorder. The research aimed to evaluate possible anatomical markers associated with tolerance to water stress and Die-Back. Commercial genotypes with different levels of susceptibility to this disorder were submitted to different levels of water stress in a greenhouse condition. The experiment lasted 75 days. Petioles samples were collected and anatomical characteristics were evaluated: cross-sectional area, area of vascular tissue, xylem area, phloem area and cortical area. The data were submitted to analysis of variance (ANOVA) and for the comparison of means was adopted Tukey test (p <0.05). The results show us that there is a tendency to reduce all variables with increasing water deficit. However, the tolerant genotype in higher water stress conditions has greater cross-sectional area and conducting tissues compared to susceptible genotype. The major proportion of these tissues suggests that the tolerant clone presents more favorable condition for transport of water, nutrients and assimilates. Keywords: forest improvement; forestry; genomic selection.

Pelvic Canal Narrowing Caused by Triple Pelvic Osteotomy in the Dog

1994 ◽  
Vol 07 (03) ◽  
pp. 110-113 ◽  
Author(s):  
D. L. Holmberg ◽  
M. B. Hurtig ◽  
H. R. Sukhiani
Keyword(s):  
Postoperative Complications ◽  
Pelvic Osteotomy ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Canal Width ◽  
Operative Complications ◽  
Post Operative Complications

SummaryDuring a triple pelvic osteotomy, rotation of the free acetabular segment causes the pubic remnant on the acetabulum to rotate into the pelvic canal. The resulting narrowing may cause complications by impingement on the organs within the pelvic canal. Triple pelvic osteotomies were performed on ten cadaver pelves with pubic remnants equal to 0, 25, and 50% of the hemi-pubic length and angles of acetabular rotation of 20, 30, and 40 degrees. All combinations of pubic remnant lengths and angles of acetabular rotation caused a significant reduction in pelvic canal-width and cross-sectional area, when compared to the inact pelvis. Zero, 25, and 50% pubic remnants result in 15, 35, and 50% reductions in pelvic canal width respectively. Overrotation of the acetabulum should be avoided and the pubic remnant on the acetabular segment should be minimized to reduce postoperative complications due to pelvic canal narrowing.When performing triple pelvic osteotomies, the length of the pubic remnant on the acetabular segment and the angle of acetabular rotation both significantly narrow the pelvic canal. To reduce post-operative complications, due to narrowing of the pelvic canal, overrotation of the acetabulum should be avoided and the length of the pubic remnant should be minimized.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

Changes in the parameters of nasal breathing and parameters of the upper respiratory tract during orthognathic operations in patients with II and III skeletal class of jaw anomalies

2020 ◽  
pp. 22-27
Author(s):  
S.Sh. Gammadaeva ◽  
M.I. Misirkhanova ◽  
A.Yu. Drobyshev
Keyword(s):  
Respiratory Tract ◽  
Nasal Cavity ◽  
Nasal Septum ◽  
Cross Sectional Area ◽  
Upper Respiratory Tract ◽  
Sectional Area ◽  
Nasal Breathing ◽  
Cross Sectional ◽  
Skeletal Class ◽  
Upper Respiratory

The study analyzed the functional parameters of nasal breathing, linear parameters of the nasal aperture, nasal cavity and nasopharynx, volumetric parameters of the upper airways in patients with II and III skeletal class of jaw anomalies before and after orthognathic surgery. The respiratory function of the nose was assessed using a rhinomanometric complex. According to rhinoresistometry data, nasal resistance and hydraulic diameter were assessed. According to the data of acoustic rhinometry, the minimum cross-sectional area along the internal valve, the minimum cross-sectional area on the head of the inferior turbinate and nasal septum and related parameters were estimated. According to the CBCT data, the state of the nasal septum, the inferior turbinates, the nasal aperture, the state of the nasal cavity, and the linear values of the upper respiratory tract (nasopharynx) were analyzed. The patients were divided into 4 groups according to the classification of the patency of the nasal passages by

Unequal Probability Scheme for Fruit Count in a Guava Tree

2016 ◽  
Vol 3 (4) ◽  
Author(s):  
R. C. BHARATI
Keyword(s):  
Cross Sectional Area ◽  
Equal Probability ◽  
Sampling Scheme ◽  
Research Station ◽  
Sectional Area ◽  
Cross Sectional ◽  
Unequal Probability ◽  
Selection Probabilities ◽  
Horticultural Research ◽  
Number Of Branches

Data on fruit count corresponding to primary, secondary and tertiary branches of a randomly selected guava CV. Allahabad Safeda were recorded from the guava orchard of Horticultural Research Station, Birauli. The proposed sampling scheme in which the selection probabilities are based on length of braches between two forking points was compared with equal probability(PE), probability proportional to the number of branches(PPN), probability proportional to the cross sectional area (PPA) and probability proportional to volume (PPV) method of sampling and found to be more efficient.

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