A common origin of complex life cycles in parasitic flatworms: evidence from the complete mitochondrial genome of Microcotyle sebastis (Monogenea: Platyhelminthes)

BACKGROUND: The parasitic Platyhelminthes (Neodermata) contains three parasitic groups of flatworms, each having a unique morphology, and life style: Monogenea (primarily ectoparasitic), Trematoda (endoparasitic flukes), and Cestoda (endoparasitic tapeworms). The evolutionary origin of complex life cyles (multiple obligate hosts, as found in Trematoda and Cestoda) and of endo-/ecto-parasitism in these groups is still under debate and these questions can be resolved, only if the phylogenetic position of the Monogenea within the Neodermata clade is correctly estimated. RESULTS: To test the interrelationships of the major parasitic flatworm groups, we estimated the phylogeny of the Neodermata using complete available mitochondrial genome sequences and a newly characterized sequence of a polyopisthocotylean monogenean Microcotyle sebastis. Comparisons of inferred amino acid sequences and gene arrangement patterns with other published flatworm mtDNAs indicate Monogenea are sister group to a clade of Trematoda+Cestoda. CONCLUSION: Results confirm that vertebrates were the first host for stem group neodermatans and that the addition of a second, invertebrate, host was a single event occurring in the Trematoda+Cestoda lineage. In other words, the move from direct life cycles with one host to complex life cycles with multiple hosts was a single evolutionary event. In association with the evolution of life cycle patterns, our result supports the hypothesis that the most recent common ancestor of the Neodermata giving rise to the Monogenea adopted vertebrate ectoparasitism as its initial life cycle pattern and that the intermediate hosts of the Trematoda (molluscs) and Cestoda (crustaceans) were subsequently added into the endoparasitic life cycles of the Trematoda+Cestoda clade after the common ancestor of these branched off from the monogenean lineage. Complex life cycles, involving one or more intermediate hosts, arose through the addition of intermediate hosts and not the addition of a vertebrate definitive host. Additional evidence is required from monopisthocotylean monogeneans in order to confirm the monophyly of the group

Association between lower urinary tract symptoms and cigarette smoking or alcohol drinking

Background: Although there have been several studies about the relationship between alcohol or smoking and lower urinary tracts symptoms (LUTS). This study aimed to investigate the association between alcohol or smoking and severity of LUTS in men, as alcohol intake and cigarette smoking is important modifiable lifestyle factors for LUTS. Methods: A cross-sectional analysis has been performed and a total of 86,707 participants in Korean Community Health Survey were included for final analysis. The adjusted odds ratio (OR) or coefficient with 95% confidence interval (CI) estimates were described to show the association between alcohol consumption or cigarette smoking and LUTS. Results: Among the total subjects, 77,398 (89.3%), 7,532 (8.7%), and 1,777 (2.0%) had mild, moderate, and severe symptoms, respectively, according to International Prostate Symptom Score (IPSS) grade. Those who drank alcohol at least once per month were significantly associated with decreased risk of having the worst IPSS grade (OR: 0.80, 95% CI: 0.68 to 0.93). Those who smoked in the past but currently quitted and those who were daily smokers showed significantly increased risk of having the worst IPSS grade (past smoker, OR: 1.26, 95% CI: 1.14 to 1.39; daily smoker, OR: 1.21, 95% CI: 1.10 to 1.34). For nocturia, daily smoking showed positive effect (OR: 0.79, 95% CI: 0.75 to 0.84) whereas heavy alcohol drinking showed negative effect (OR: 1.22, 95% CI: 1.14 to 1.32) Conclusions: Alcohol showed positive effect on LUTS except nocturia whereas cigarette smoking had negative effect on LUTS except nocturia. Daily smoking showed positive effect on nocturia whereas heavy alcohol drinking showed negative effect on nocturia

Combinatorial growth of Si nanoribbons

Silicon nanoribbons (Si NRs) with a thickness of about 30 nm and a width up to a few micrometers were synthesized. Systematic observations indicate that Si NRs evolve via the following sequences: the growth of basal nanowires assisted with a Pt catalyst by a vapor-liquid-solid (VLS) mechanism, followed by the formation of saw-like edges on the basal nanowires and the planar filling of those edges by a vapor-solid (VS) mechanism. Si NRs have twins along the longitudinal < 110 > growth of the basal nanowires that also extend in < 112 > direction to edge of NRs. These twins appear to drive the lateral growth by a reentrant twin mechanism. These twins also create a mirror-like crystallographic configuration in the anisotropic surface energy state and appear to further drive lateral saw-like edge growth in the < 112 > direction. These outcomes indicate that the Si NRs are grown by a combination of the two mechanisms of a Pt-catalyst-assisted VLS mechanism for longitudinal growth and a twin-assisted VS mechanism for lateral growth