18 research outputs found

    Larval growth and allometry in the cabbage butterfly Pieris brassicae (Lepidoptera: Pieridae)

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    By adopting a longitudinal study design and through geometric morphometrics methods, we investigated individual and ontogenetic variation in size, shape and timing during larval development of the cabbage butterfly Pieris brassicae under laboratory conditions. We found that ontogenetic size progression departs modestly, but significantly, from growth at a constant rate and that size at hatching contributes considerably to determine the size of the individual at all subsequent stages. As for the shape, ontogenetic allometry is much more conspicuous than static allometry, the latter in many cases being close to isometry. Analysis of developmental timing revealed a stage of apparently more effective developmental control at stage 3, supported by both the relatively small variance in cumulative developmental time up to stage 3 and by the pattern of correlation between duration of single stages. While presenting detailed quantitative aspects of growth in P.\ua0brassicae, in particular with respect to individual variation, this study and the associated dataset can provide a basis for further explorations of the post-embryonic development in this insect and contribute to the ongoing investigations on growth regulation and control in insects

    Size and shape regulation during larval growth in the lepidopteran Pieris brassicae

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    By adopting a longitudinal study design and through geometric morphometrics methods, we investigated size and shape regulation in the head capsule during the larval development of the cabbage butterfly Pieris brassicae under laboratory conditions. We found evidence of size regulation by compensatory growth, although not equally effective in all larval stages. Size compensation is not attained through the regulation of developmental timing, but rather through the modulation of per-time growth rate. As for the shape, neither the variance of the symmetric component of shape, nor the level of fluctuating asymmetry show any evidence of increase across stages, either at the population or individual level, which is interpreted as a mark of ontogenetic shape regulation. In addition, also the geometry of individual asymmetry is basically conserved across stages. While providing specific documentation on the ontogeny of size and shape variation in this insect, this study may contribute to a more general understanding of developmental regulation and its influence on phenotypic evolution

    CT-guided transthoracic needle aspiration of solitary lung lesions. Personal experience in 118 cases

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    Fast-scan CT is widely and frequently used to guide fine-needle aspiration biopsy (FNAB) of questionable lung nodules. To investigate technical problems, complications, diagnostic accuracy and indications of this technique, the findings were reviewed relative to 118 patients with negative transbronchial biopsy and sputum cytology who underwent CT-guided FNAB of solitary lung lesions. Over a 25-month period, 73 men and 45 women underwent CT-guided FNAB of lung lesions. The CT unit was a GE 9800; 22-gauge 7/9-cm spinal needles were used in most cases, while 22-G 15-cm Chiba needles were used in 6 cases. In 114 patients one FNAB was performed, 4 patients only requiring the maneuver to be repeated. Regarding the malignant nature of the lesions, there were 70 true positive, 36 true negative, 12 false negative and no false positive cytologic findings; sensitivity was 85.36%, specificity and positive predictive value were 100%, negative predictive value was 75% and diagnostic accuracy 89.83%. Only minor complications occurred: 5 cases of hemophtoe, 7 of peripheral bleeding, 4 of chest pain, 4 vagal reactions and 10 cases of pneumothorax, only one of them requiring drainage. In our experience, only one pass per patient is required and the presence of the cytopathologist is unnecessary, since in most of our cases (114/118) the diagnosis was made at the first FNAB performed by the radiologist. CT allowed the lesions to be approached easily and precisely, which is useful especially in small, peripheral or hilar, nodules missed or poorly defined by radiology. To conclude, CT-guided transthoracic FNAB can be suggested as the method of choice to diagnose lung lesions which are difficult to puncture endoscopically because of size or location, and in suspected metastases. Moreover, FNAB can be used as second-line method in the lesions where endoscopic biopsy cannot be performed or whose findings are negative
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