Pelagodictyon Clarke,a newly recorded nanodiatom genus for China

Marine nanoplanktonic diatoms have been frequently either underestimated or overlooked in phytoplankton investigations due to their small size （2-20μm）, which allows most of them to pass through a regular phytoplankton net of 70μm pore size. For nanoplanktonic diatom classification, water samples （each 2000 mL） were collected from several representative sea areas of Chinese coast from May 2002 to May 2006. Pelagodictyon Clarke was identified as a newly recorded nanodiatom genus for China under transmission electron microscope （TEM）. This genus is characterized by the delicate structure of the valve face. The striae are seen to be formed by ribs with cross-ribs （frets） and the intervening spaces are occupied by polygonal cribra situated much close to the exterior face of the valve. Just one species was found, i.e., P. tenue Clarke. Detailed description of the taxonomic characteristics with TEM photographs of this species and its ecological habitat and distribution are given in this paper. Morphological characteristics comparisons among several resembling genera were discussed.

First report of Protokeelia spinifera and Rhopalodia iriomotensis from China,with comments on their systematic positions

Protokeelia is described as a new and rare pennate diatom genus in China. Its valve includes two parts： ventral valve and dorsal valve. The ventral valve is more or less convex or concave. The raphe runs in a distinct elevated and thickened siliceous ridge. In the internal valve, beneath the raphe are fibulae or fibulae clusters which connect the ventral and dorsal valves. One species, P. spinifera Round ＆ Basson, is observed in the water samples from a mangrove forest in Sai Kung, Hong Kong, China. Its main morphological features are described in this paper along with electron microscope （EM） photos. Morphological comparisons are also made among several allied species. In addition, a newly recorded species for China, Rhopalodia iriomotensis Kobayasi, Nagumo ＆ Tanaka, is discussed here. Because several key features observed in this species resemble those of some Protokeelia species, we suggest that it may actually represent a Protokeelia species.

COVID-19–Related Insomnia Populations Research and Management Strategies:A Review

Coronavirus disease 2019(COVID-19)has affected the quality of sleep for various populations,causing anxiety and depression world-wide.COVID-19–related insomnia(COVIDRI)appears to be more common in certain populations,including females,urban residents and other individuals who reside in high-risk COVID-19–related areas,lack higher socioeconomic and educational levels,have a history of underlying mental illness,have no access to social support and work,or have been mandated for isolation.Among vulnerable pop-ulations,pregnant women,adolescents and children are more likely to suffer from anxiety and depression,which leads to irregular sleep-wake cycles and significantly poor sleep quality.Insomnia in COVID-19 patients is associated with decreased immune levels,ex-cessive psychological stress and severe anxiety.The COVIDRI incidence and severity among frontline healthcare workers is high,espe-cially among females and those working in isolation wards and intensive care units.The factors related to COVIDRI for college students during home study are stress from upcoming graduation,disharmonious family relationships and inadaptability to online education.For military personnel,anxiety and depression are the main causes of poor sleep quality.Based on the characteristics of different popula-tions,active Chinese and Western medications,non-drug therapy,psychological counseling and suitable sleep management are vital measures to strengthen immunity,alleviate insomnia and limit recurrence.

Endophytic Colletotrichum species from Bletilla ochracea (Orchidaceae), with descriptions of seven new speices

Thirty-six strains of endophytic Colletotrichum species were isolated from leaves of Bletilla ochracea Schltr.(Orchidaceae)collected from 5 sites in Guizhou,China.Seventeen different species,including 7 new species(namely C.bletillum,C.caudasporum,C.duyunensis,C.endophytum,C.excelsum-altitudum and C.guizhouensis and C.ochracea),8 previously described species(C.boninense,C.cereale,C.destructivum,C.karstii,C.liriopes,C.miscanthi,C.parsonsiae and C.tofieldiae)and 2 sterile mycelia were identified.All of the taxa were identified based on morphology and phylogeny inferred from multi-locus sequences,including the nuclear ribosomal internal transcribed spacer(ITS)region,partial genes ofβ-tubulin(TUB2),actin(ACT)and glyceraldehyde-3-phosphate dehydrogenase(GAPDH).Comprehensive morphological descriptions and illustrations are provided for new species.Our investigation indicates a high diversity of Colletotrichum species in B.ochracea.