7 research outputs found
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Subspecies limits based on morphometry and mitochondrial DNA genomics in a polytypic species, the common grackle, Quiscalus quiscula
Nearctic migratory songbirds have demonstrated low levels of genetic differentiation and weak phylogeographical structure in mitochondrial DNA lineages compared with resident species. The common grackle, Quiscalus quiscula, is a widespread, partially migratory, North American icterid composed of three currently recognized subspecies. In this study, mensural characters (external and skeletal measurements) and the complete mitochondrial genome together with two mitochondrial genes, Cytb and ND2, were used to investigate subspecific differentiation and demographic history of the common grackle. The results showed substantial variation in body size among subspecies, mostly distributed between the ‘Florida grackle’, Quiscalus quiscula quiscula, and the two other subspecies. Analysis of mitochondrial DNA indicated low levels of genetic variation, but we found distinct haplotypes in Florida that form a clade in the phylogenetic tree. This suggests that the nominate subspecies in Florida is a distinct evolutionary unit. The sharing of haplotypes among the other subspecies (Quiscalus quiscula versicolor and Quiscalus quiscula stonei) in the north suggests high levels of gene flow, making the status of these two subspecies equivocal. Gene f low between nominate Q. q. quiscula, Q. q. versicolor and putative Q. q. stonei is probably attributable to historical changes in distribution and abundance following climate change events. We therefore recognize only two subspecies in the common grackle complex
Correlation of renal B-mode ultrasonographic findings with diabetic nephropathy stage [Renal B-mod ultrasonografi· bulgularinin di·abetik nefropati· evresi· i·le i·li·şki·si·]
Aim: We aimed to investigate the renal morphological features detected by B-mode ultrasonography (US) in various clinical stages of diabetic nephropathy by means of a control group. Methods: As control group, 20 healthy person were selected. As study group, 69 patients with type-2 diabetes were included. All cases in both groups were evaluated with B-mode US in terms of renal length, parenchymal thickness and echogenicity. Diabetic patients were divided into 3 groups according to 24-hour urinary albumin excretion ratios (AER) (Group-1: AER300 mg/ day); and mean renal parenchymal thickness and length were measured. By SPSS programme, mean values were compared between groups. Results: When mean renal length was compared between the control and study groups, a significant difference was noticed; but when mean renal parenchymal thickness was compared, no significant difference was demonstrated between the two groups. When study groups were compared, no statistically significant difference was seen. Cortical hyperechogenicity ratios; mean serum BUN and creatinine clearance rates, were correlated with nephropathy stage. Conclusion: With the progression of nephropathy in diabetic patients,renal parenchymal thickness does not significantly differ; but hyperechogenicity and a decrease in renal dimensions (control versus the study group) are observed
Intramedullary lipoma of the cervico-thoracic spinal cord
Most of the spinal cord lipomas reported in the literature are intradural extramedullary, and true intramedullary lipomas are very rare. We present a case of intramedullary spinal cord lipoma of the cervico-thoracic region with extensions over many spinal segments. Magnetic resonance (MR) examination showed an intramedullary lipoma of the cervico-thoracic spinal cord of both high T1 and T2-weighted signal intensity and suppression on fat saturation sequence. MR imaging assessment is critical in the detection of intramedullary lipomas which may present without any neurological deficit at an early stage. Early diagnosis may lead to prevention of the irreversible deterioration of neurological functions
The global spread of misinformation on spiders
In the internet era, the digital architecture that keeps us connected and informed may also amplify the spread of misinformation. This problem is gaining global attention, as evidence accumulates that misinformation may interfere with democratic processes and undermine collective responses to environmental and health crises1,2. In an increasingly polluted information ecosystem, understanding the factors underlying the generation and spread of misinformation is becoming a pressing scientific and societal challenge3. Here, we studied the global spread of (mis-)information on spiders using a high-resolution global database of online newspaper articles on spider-human interactions, covering stories of spider-human encounters and biting events published from 2010-20204. We found that 47% of articles contained errors and 43% were sensationalist. Moreover, we show that the flow of spider-related news occurs within a highly interconnected global network and provide evidence that sensationalism is a key factor underlying the spread of misinformation