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81.
Acoustic rhinometry in humans: accuracy of nasal passage area estimates, and ability to quantify paranasal sinus volume and ostium size. 总被引:2,自引:0,他引:2
Erkan Tarhan Mehmet Coskun Ozcan Cakmak Hüseyin Celik Mehmet Cankurtaran 《Journal of applied physiology》2005,99(2):616-623
A comprehensive study that compared acoustic rhinometry (AR) data to computed tomography (CT) data was performed to evaluate the accuracy of AR measurements in estimating nasal passage area and to assess its ability of quantifying paranasal sinus volume and ostium size in live humans. Twenty nasal passages of 10 healthy adults were examined by using AR and CT. Actual cross-sectional areas of the nasal cavity, sinus ostia sizes, and maxillary and frontal sinus volumes were determined from CT sections perpendicular to the curved acoustic axis of the nasal passage. Nasal cavity volume (from nostril to choana) calculated from the AR-derived area-distance curve was compared with that from the CT-derived area-distance curve. AR measurements were also done on pipe models that featured a side branch (Helmholtz resonator of constant volume but two different neck diameters) simulating a paranasal sinus. In the anterior nasal cavity, there was good agreement between the cross-sectional areas determined by AR and CT. However, posterior to the sinus ostia, AR overestimated cross-sectional area. The difference between AR nasal volume and CT nasal volume was much smaller than the combined volume of the maxillary and frontal sinuses. The results suggest that AR measurements of the healthy adult nasal cavity are reasonably accurate to the level of the paranasal sinus ostia. Beyond this point, AR overestimates cross-sectional area and provides no quantitative data for sinus volume or ostium size. The effects of paranasal sinuses and acoustic resonances in the nasal cavity are not accounted for in the present AR algorithms. 相似文献
82.
Variation in phosphorus efficiency among 73 bread and durum wheat genotypes grown in a phosphorus-deficient calcareous soil 总被引:3,自引:0,他引:3
A greenhouse experiment was carried out to study the severity of phosphorus (P) deficiency symptoms on leaves, shoot dry matter
production, and shoot concentration and content (the total amount per shoot) of P in 39 bread wheat (Triticum aestivum L.) and 34 durum wheat (Triticum durum L.) genotypes grown in a severely P-deficient calcareous soil with low (20mgPkg−1 soil) and adequate (80mgPkg−1 soil) P supply for 39 days. As the seed P concentration or content can affect plant performance under P-deficient conditions,
the seeds of the genotypes used in the present study were also analyzed for P concentration. Phosphorus efficiency (relative
shoot growth) of genotypes, calculated by the ratio of shoot dry matter production under low P to that under adequate P supply,
significantly differed among the genotypes, and varied between 46.7% and 78.6%. Phosphorus efficiency ranged from 51% to 71%
with an average of 61% for bread and from 47% to 79% with an average of 66% for durum wheat genotypes. There was no correlation
between P efficiency ratio and P concentration of plants (R
2=0.0001), but P efficiency of all bread and durum wheat genotypes showed a very significant correlation with the P content
(the total amount of P per shoot) (R
2=0.333***). The relationship between the P efficiency and total amount of P per shoot was much more significant in bread (R
2=0.341***) than in durum wheat (R
2=0.135*). Like shoot P concentrations, also severity of visible leaf symptoms of P deficiency on older leaves, including leaf chlorosis
and necrosis, did not correlate with P efficiency. In most cases, genotypes showing higher P efficiency had higher absolute
shoot dry weight under P deficient conditions. Under P deficient conditions, the absolute shoot dry weight very significantly
correlated with shoot P content (R
2=0.665***), but the correlation between the absolute shoot dry weight and shoot P concentration tended to be negative. There was also
variation in native seed P reserve of the genotypes, but this variation had no influence on the P efficiency. The results
indicate that the total amount of P per shoot and shoot dry matter production at low P supply are most reliable parameters
in ranking genotypes for P efficiency at early growth stage. In wheat germplasm tested in the present study, several wheat
genotypes are available showing both very high P efficiency and very high shoot content and concentration of P suggesting
that P acquisition ability should be most important mechanism for high P efficiency in such genotypes. On the other hand,
there are also genotypes in the germplasm having more or less same P concentration or P content in shoot but differing substantially
in P efficiency, indicating importance of P utilization at cellular level in P efficiency. All these results suggest that
P efficiency mechanisms can be different from one genotype to other within a given plant species. 相似文献
83.
Genotypic variation in common bean in response to zinc deficiency in calcareous soil 总被引:2,自引:0,他引:2
Hacisalihoglu Gökhan Ozturk Levent Cakmak Ismail Welch Ross M. Kochian Leon 《Plant and Soil》2004,259(1-2):71-83
Plant and Soil - Greenhouse experiments have been carried out to study the genotypic variation among 35 bean (Phaseolus vulgaris&;nbsp;L.) genotypes with regards to tolerance to zinc (Zn)... 相似文献
84.
Koç A Kaymak AO Karaer K Ergün MA Aksu T Perçin EF 《Genetic counseling (Geneva, Switzerland)》2008,19(2):193-198
Congenital radio-ulnar synostosis may be an isolated abnormality or additional abnormalities may accompany it. It may also be found as a part of well-known syndromes. We present a case with bilateral congenital radio-ulnar synostosis, speech delay, dimple on shoulders, café au lait spot and characteristic facial appearance. The proband has a brother with similar clinical findings with the exception of congenital radio-ulnar synostosis. We discuss the possible relationship between our case and previously described syndromes with congenital radio-ulnar synostosis, and distinct phenotypic features of the presented case. 相似文献
85.
Iron (Fe) deficiency is increasingly being observed in cropping systems with frequent glyphosate applications. A likely reason for this is that glyphosate interferes with root uptake of Fe by inhibiting ferric reductase in roots required for Fe acquisition by dicot and nongrass species. This study investigated the role of drift rates of glyphosate (0.32, 0.95 or 1.89 mm glyphosate corresponding to 1, 3 and 6% of the recommended herbicidal dose, respectively) on ferric reductase activity of sunflower (Helianthus annuus) roots grown under Fe deficiency conditions. Application of 1.89 mm glyphosate resulted in almost 50% inhibition of ferric reductase within 6 h and complete inhibition 24 h after the treatment. Even at lower rates of glyphosate (e.g. 0.32 mm and 0.95 mm), ferric reductase was inhibited. Soluble sugar concentration and the NAD(P)H oxidizing capacity of apical roots were not decreased by the glyphosate applications. To our knowledge, this is the first study reporting the effects of glyphosate on ferric reductase activity. The nature of the inhibitory effect of glyphosate on ferric reductase could not be identified. Impaired ferric reductase could be a major reason for the increasingly observed Fe deficiency in cropping systems associated with widespread glyphosate usage. 相似文献
86.
Faruk Ozkutlu Levent Ozturk Halil Erdem Mike McLaughlin Ismail Cakmak 《Plant and Soil》2007,290(1-2):323-331
Cadmium (Cd) accumulation in durum wheat grain is a growing concern. Among the factors affecting Cd accumulation in plants,
soil chloride (Cl) concentration plays a critical role. The effect of leaf NaCl application on grain Cd was studied in greenhouse-grown
durum wheat (Triticum turgidum L. durum, cv. Balcali-2000) by immersing (10 s) intact flag leaves into Cd and/or NaCl-containing solutions for 14 times during heading
and dough stages. Immersing flag leaves in solutions containing increasing amount of Cd resulted in substantial increases
in grain Cd concentration. Adding NaCl alone or in combination with the Cd-containing immersion solution promoted accumulation
of Cd in the grains, by up to 41%. In contrast, Zn concentrations of grains were not affected or even decreased by the NaCl
treatments. This is likely due to the effect of Cl complexing Cd and reducing positive charge on the metal ion, an effect
that is much smaller for Zn. Charge reduction or removal (CdCl20 species) would increase the diffusivity/lipophilicity of Cd and enhance its capability to penetrate the leaf epidermis and
across membranes. Of even more significance to human health was the ability of Cl alone to penetrate leaf tissue and mobilize
and enhance shoot Cd transfer to grains, yet reducing or not affecting Zn transfer. 相似文献
87.
An adaptive neuro-fuzzy inference technique has been adopted to estimate light levels in a reservoir. The data were collected
randomly from Doğanci Dam Reservoir over a number of years. The input data set is a matrix with vectors of time, depth, sampling
location, and incident solar radiation. The output data set is a vector representing light measured at various depths. Randomization
and logarithmic transformations have been applied as preprocessing. One-half of the data have been utilized for training;
testing and validation steps utilized one-fourth each. An adaptive neuro-fuzzy inference system (ANFIS) has been built as
a prediction model for light penetration. Very high correlation values between predictions and real values on light measurements
with relatively low root mean square error values have been obtained for training, test, and validation data sets. Elimination
of the overtraining problem was ensured by satisfying close root mean square error values for all sets. 相似文献
88.
Expression of high zinc efficiency of Aegilops tauschii and Triticum monococcum in synthetic hexaploid wheats 总被引:4,自引:0,他引:4
The effect of varied zinc (Zn) supply on shoot and root dry matter production, severity of Zn deficiency symptoms and Zn tissue
concentrations was studied in two Triticum turgidum (BBAA) genotypes and three synthetic hexaploid wheat genotypes by growing
plants in a Zn-deficient calcareous soil under greenhouse conditions with (+Zn=5 mg kg-1 soil) and without (−Zn) Zn supply. Two synthetic wheats (BBAADD) were derived from two different Aegilops tauschii (DD) accessions
using same Triticum turgidum (BBAA), while one synthetic wheat (BBAAAA) was derived from Triticum turgidum (BBAA) and Triticum
monococcum (AA). Visible symptoms of Zn deficiency, such as occurrence of necrotic patches on leaves and reduction in shoot
elongation developed more rapidly and severely in tetraploid wheats than in synthetic hexaploid wheats. Correspondingly, decreases
in shoot and root dry matter production due to Zn deficiency were higher in tetraploid wheats than in synthetic hexaploid
wheats. Transfer of the DD genome from Aegilops tauschii or the AA genome from Triticum monococcum to tetraploid wheat greatly
improved root and particularly shoot growth under Zn-deficient, but not under Zn-sufficient conditions. Better growth and
lesser Zn deficiency symptoms in synthetic hexaploid wheats than in tetraploid wheats were not accompanied by increases in
Zn concentration per unit dry weight, but related more to the total amount of Zn per shoot, especially in the case of synthetic
wheats derived from Aegilops tauschii. This result indicates higher Zn uptake capacity of synthetic wheats. The results demonstrated
that the genes for high Zn efficiency from Aegilops tauschii (DD) and Triticum monococcum (AA) are expressed in the synthetic
hexaploid wheats. These wheat relatives can be used as valuable sources of genes for improvement of Zn efficiency in wheat.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
89.
Yazici M. Atilla Asif Muhammad Tutus Yusuf Ortas Ibrahim Ozturk Levent Lambers Hans Cakmak Ismail 《Plant and Soil》2021,459(1-2):19-21
Plant and Soil - Grass pea is a legume species with recognized resistance to several diseases and thus important for the improvement of related major legume crops. It is infected by the soil-borne... 相似文献
90.
Effect of nitrogen on uptake, remobilization and partitioning of zinc and iron throughout the development of durum wheat 总被引:4,自引:0,他引:4
Deficiencies of zinc (Zn) and iron (Fe) are global nutritional problems and caused most often by their limited dietary intake. Increasing Zn and Fe concentrations of staple food crops such as wheat is therefore an important global challenge. This study investigated the effects of varied nitrogen (N) and Zn supply on the total uptake, remobilization and partitioning of Zn, Fe and N in durum wheat throughout its ontogenesis. Plants were grown under greenhouse conditions with high or low supply of N and Zn, and harvested at 8 different developmental stages for analysis of Zn, Fe and N in leaves, stems, husks and grains. The results obtained showed that the Zn and Fe uptake per plant was enhanced up to 4-fold by high N supply while the increases in plant growth by high N supply were much less. When both the Zn and N supplies were high, approximately 50% of grain Zn and 80% of grain Fe were provided by post-anthesis shoot uptake, indicating that the contribution of remobilization to grain accumulation was higher for Zn than for Fe. At the high N and Zn application, about 60% of Zn, but only 40% of Fe initially stored in vegetative parts were retranslocated to grains, and nearly 80% of total shoot Zn and 60% of total shoot Fe were harvested with grains. All these values were significantly lower at the low N treatment. Results indicate that N nutrition is a critical factor in both the acquisition and grain allocation of Zn and Fe in wheat. 相似文献