scholarly journals Phenotypic Flexibility during Migration: Optimization of Organ Size Contingent on the Risks and Rewards of Fueling and Flight?

1998 ◽  
Vol 29 (4) ◽  
pp. 511 ◽  
Author(s):  
Theunis Piersma
2019 ◽  
Vol 69 (3) ◽  
pp. 365-376 ◽  
Author(s):  
Li Zhao ◽  
Chun Lan Mai ◽  
Guo Hou Liu ◽  
Wen Bo Liao

Abstract Phenotypic flexibility of morphological and physiological traits within species is a common phenomenon across animal taxa. Hesse’s rule predicts that the size of an organ should exhibit an increase with increasing altitude along environmental gradients due to changes in oxygen supply and energy demands. Here, we test the prediction of Hesse’s rule by investigating geographical variation in the relative size of organs (i.e., heart, lungs, liver, and kidneys) across ten populations of Bufo andrewsi along an environmental gradient. We found that the relative size of these four specific organs did not increase with altitude or latitude across all populations. We also did not find that the relative size of the organs increased with increasing altitude among six populations located at a similar latitude and longitude, which is inconsistent with Hesse’s rule. Our findings suggest that oxygen supply and energy demands do not necessarily affect variation in organ size among populations.


Author(s):  
Emanuele Trovalusci ◽  
Marco Gasparella ◽  
Cristina Pizzato ◽  
Paola Midrio

AbstractThe laparoscopic splenectomy in pediatric patients is performed worldwide but often the disproportion between size of patients and size of organs requires an extra laparotomic access for spleen removal. The aim of the present study was to evaluate the safety and effectiveness of the Alexis® system to retrieve the spleen without additional laparotomic access. The charts of all patients who underwent splenectomy at our center during the last 5 years were retrieved. In all the cases the Alexis® system was placed in the umbilicus, thru which a 10 mm camera was inserted. Three additional 5 mm standard trocars were inserted. Seven patients, affected by spherocytosis (3), epidermoid cyst (2), idiopathic thrombocytopenic purpura (2) and thalassemia (1), underwent laparoscopic splenectomy at a median age of 10 years (range: 8–17). Median patients’ weight was 32.5 kg (range: 25–71) and spleen size 15 cm (11–18). In all the cases, upon removal of the camera, the retrieval bag was inserted thru the umbilicus under direct view, the spleen retrieved, morcellated, and removed. No conversion nor enlargement of one of the ports nor an extra laparotomic access were required. The patients were discharged on the fifth post-operative day and the cosmetic results were excellent. Removal of the spleen can be safely performed without any additional laparotomy thru the Alexis® system placed in the umbilicus. This system is effective also in case of major patient/organ size disproportion and the final cosmetic aspect is excellent.


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