Splitting one species into 22: an unusual tripling of molecular, morphological, and geographical differentiation in the fern family Didymochlaenaceae (Polypodiales)

The pantropical fern genus Didymochlaena (Didymochlaenaceae) has long been considered to contain one species only. Recent studies have resolved this genus/family as either sister to the rest of eupolypods I or as the second branching lineage of eupolypods I, and have shown that this genus is not monospecific, but the exact species diversity is unknown. In this study, a new phylogeny is reconstructed based on an expanded taxon sampling and six molecular markers. Our major results include: (i) Didymochlaena is moderately or weakly supported as sister to the rest of eupolypods I, highlighting the difficulty in resolving the relationships of this important fern lineage in the polypods; (ii) species in Didymochlaena are resolved into a New World clade and an Old World clade, and the latter further into an African clade and an Asian-Pacific clade; (iii) an unusual tripling of molecular, morphological and geographical differentiation in Didymochlaena is detected, suggesting single vicariance or dispersal events in individual regions and no evidence for reversals at all, followed by allopatric speciation at more or less homogeneous rates; (iv) evolution of 18 morphological characters is inferred and two morphological synapomorphies defining the family are recognized-the elliptical sori and fewer than 10 sori per pinnule, the latter never having been suggested before; (v) based on morphological and molecular variation, 22 species in the genus are recognized contrasting with earlier estimates of between one and a few; and (vi) our biogeographical analysis suggests an origin for Didymochlaena in the latest Jurassic-earliest Cretaceous and the initial diversification of the extant lineages in the Miocene-all but one species diverged from their sisters within the last 27 Myr, in most cases associated with allopatric speciation owing to geologic and climatic events, or dispersal.

The genus Deschampsia and the epithet " alpina"

The epithet "alpina" has been recurrently used in the genus Deschampsia to name plants located in northern regions of Europe, Asia and North America, as a species (Deschampsiaalpina (L.) Roem. & Schult.), but also in infraspecific categories (Deschampsiacespitosasubsp.alpina Tzvel. and Deschampsiacespitosavar.alpina Schur.). The morphological and molecular available evidence suggests the existence of a single species, Deschampsiacespitosa (L.) P. Beauv., in which individuals belonging to the same morphological gradient have received different names in different taxonomic categories throughout its wide distribution range. An evaluation of the available names indicates that all uses of the epithet "alpina" are illegitimate. A new combination is proposed at the infraspecific level as Deschampsiacespitosasubsp.neoalpina Chiapella, Xue & Greimler.

[Evaluation of the effect of the water-saving irrigation project on Oncomelania hupensis control in hilly regions of Yixing City, Jiangsu Province]

OBJECTIVE

To evaluate the effect of the water-saving irrigation project on Oncomelania hupensis snail control in hilly regions of Yixing City, Jiangsu Province.

METHODS

A retrospective survey combined with cross-sectional investigation was employed. The implementation of the water-saving irrigation development project in Yixing City from 2005 to 2007 was retrospectively collected, and the snail status was collected in regions where the water-saving irrigation project was located and the project-affected regions from 2003 to 2018, to examine the effect of the project on snail control. In addition, a cross-sectional survey was performed to investigate the destruction of the water-saving irrigation project in 2018.

RESULTS

A total of 22 water-saving irrigation projects were implemented in 5 townships in hilly regions of Yixing City from 2005 to 2007, where snail habitats were treated covering 266.97 hm². Before the implementation of the project from 2003 to 2006, cumulative 47.87 hm² snail habitats were detected in regions where the project was located, and no snails were found in regions where the project was located from the implementation of the project in 2006 to 2018. However, a few snails were found in the project-affected regions in 2017 and 2018. In addition, there were problems found in the later-stage maintenance and management of the project.

CONCLUSIONS

The water-saving irrigation projects shows a high efficiency on snail control in hilly regions of Yixing City. The later-stage maintenance of the project and monitoring of snails remain to be intensified to enhance the snail control efficiency of the water-saving irrigation project.

[Surveillance of echinococcosis in Yixing City from 2011 to 2018]

OBJECTIVE

To analyze the results of echinococcosis surveillance in Yixing City from 2011 to 2018, so as to provide insights into echinococcosis control in the city.

METHODS

All echinococcosis cases reported in Yixing City since 2007 that were captured from the China National Notifiable Infectious Disease Reporting Information System of Chinese Center for Disease Control and Prevention received a case study, and serological test and transabdominal B-mode ultrasound screening were performed among permanent residents and mutton market workers in Fangdong and Fangzhuang villages of Yixing City from 2011 to 2018. The cyst, mass and tubercle were detected in the liver and lung of the sheep from the mutton markets, and the Echinococcus coproantigen was detected in the canine stool samples from Fangdong and Fangzhuang villages. In addition, the awareness of echinococcosis prevention and control knowledge was investigated in the two villages using a questionnaire survey from 2011 to 2018.

RESULTS

A total of 7 cases with echinococcosis had been reported in Yixing City since 2007, with prevalence of 0.56/100 000, and all cases were E. granulosus-infected patients, including 2 cases with a history to travel to echinococcosis-endemic areas and 5 cases with a history of working in local mutton markets or dog contacts. From 2011 to 2018, a total of 1 861 residents received serological tests, with 0.54% seropositivity, and no seropositives were detected since 2016. Among the 1 807 individuals receiving transabdominal B-mode ultrasound screening, suspected cysts were found in 143 individuals (7.91%), and 1.40% (2/143) seropositivity was detected in these individuals. The mean positive rate of the Echinococcus coproantigen was 0.67% (3 /446) in the canine stool samples. Among the 4 010 sheep liver and lung specimens sampled from the mutton markets, 7 specimens (0.17%) were detected with cysts or tubercles. In addition, the mean awareness rate of echinococcosis prevention and control knowledge was 76.95% among the 538 subjects receiving questionnaire surveys from 2011 to 2018, and the overall awareness appeared a tendency towards a rise year after year.

CONCLUSIONS

Although the prevalence of echinococcosis and the seropositivity of anti-Echinococcus antibodies are low, there is still a risk of transmission of echinococcosis in Yixing City. The surveillance of echinococcosis should continue to be intensified and related control interventions are required.

The Plastid Genome of Deschampsia cespitosa (Poaceae)

Plastid genome analysis of non-model organisms provides valuable information for basic research e.g., molecular evolutionary genomics, phylogeny and phylogeography. Deschampsia cespitosa is the most widespread species of the genus and it is a common grass that is found across Eurasia and North America. Scattered populations in regions of appropriate ecological conditions are also found in Australia, New Zealand and southern South America, where it is sympatric with D. antarctica. We analyzed the plastid genome of a sample of Deschampsia cespitosa of the Austrian Alps using high-throughput sequencing. The plastid (cp) genome shows the typical quadripartite structure with a length of 135,340 bp, comprising a large single-copy (LSC) region of 79,992 bp, a small single-copy (SSC) region of 12,572 bp and two inverted repeats (IR) regions of 21,388 bp each. It contains 115 genes, including 85 protein-coding genes, four ribosomal RNA genes and 30 transfer RNA genes. The GC content (%), number of repeats and microsatellites, RNA editing sites and codon usage were highly similar to those of D. antarctica. The results of this present study highlight the extremely conserved nature of the cp genome in this group, since the comparison involved individuals separated by about 13,000 km, from the Alps to Antarctica.

[Analysis of tissue-specific differentially methylated genes with differential gene expression in non-small cell lung cancer]

Adenocarcinoma (ADC) and squamous cell carcinomas (SCC) are two subtypes of non-small cell lung carcinomas which are regarded as the leading cause of cancer-related malignancy worldwide. The aim of this study is to detect the differentially methylated loci (DMLs) and differentially methylated genes (DMGs) of these two tumor sets, and then to illustrate the different expression level of specific methylated genes. Using TCGA database and Illumina HumanMethylation 27 arrays, we first screened the DMGs and DMLs in tumor samples. Then, we explored the BiologicalProcess terms of hypermethylated and hypomethylated genes using Functional Gene Ontology (GO) catalogues. Hypermethylation intensively occurred in CpG-island, whereas hypomethylation was located in non-CpG-island. Most SCC and ADC hypermethylated genes involved GO function of DNA dependenit regulation of transcription, and hypomethylated genes mainly 'enriched in the term of immune responses. Additionally, the expression level of specific differentially methylated genesis distinctbetween ADC and SCC. It is concluded that ADC and SCC have different methylated status that might play an important role in carcinogenesis.

Positive electron affinity of fullerenes: Its effect and origin

The universal variation pattern of the total energy of various fullerenes including single-walled carbon nanotubes with respect to their extra charge is revealed by the density-functional-theory calculations. The parabolic energy-charge curve with its lowest energy value corresponding to a negatively charged fullerene indicates that these carbon materials have positive electron affinity and are not in the most stable state. The positive electron affinity seems to originate from the pi-electrons and is found to be related to the aggregation property of fullerenes.

Growth of compound single- and multi-walled carbon nanotubes

Single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) are complement to each other in many of their physical properties. We report the synthesis of carbon nanotube cables-a form of compound single- and multi-walled carbon nanotubes which could have the superior properties of both the SWCNTs and MWCNTs. This compound form of carbon nanotubes consists of a bundle of SWCNTs formed into a MWCNT, and the diameter of the inner most shell of the MWCNT ranges from a few to tens nanometers. The growth of these compound carbon nanotubes cannot be explained readily via existing modes of carbon nanotube growth, but promises a new way for improving and controlling the physical properties of either single- or multi-walled carbon nanotubes.

Stability of carbon nanotubes: how small can they be?

Experimental evidence has been found for the existence of small single wall carbon nanotubes with diameters of 0.5 and 0.33 nm by high resolution transmission electron microscopy, and their mechanical stability was investigated using tight-binding molecular dynamics simulations. It is shown that, while the carbon tubes with diameters smaller than 0.4 nm are energetically less favorable than a graphene sheet, some of them are indeed mechanically stable at temperatures as high as 1100 degrees C. The 0.33 nm carbon tube observed is likely a (4, 0) tube and is indeed part of a compound nanotube system that forms perhaps the smallest metal-semiconductor-metal tubular junction yet synthesized.

Reversible, nanometer-scale conductance transitions in an organic complex

Reversible conductance transitions are demonstrated on the molecular scale in a complex of 3-nitrobenzal malononitrile and 1, 4-phenylenediamine, by application of local electric field pulses. Both macroscopic and local current-voltage (I/V) measurements show similar electrical bistability behavior. The mechanism of the electrical bistability is discussed.

[Bilateral primary breast cancer. An analysis of 64 cases]

64 cases of bilateral primary breast cancer were confirmed pathologically and treated in our hospital from 1973 to 1990. There were seven synchronous cases and 57 cases of sequential type. The patients were treated by surgery, radiotherapy and chemotherapy, separately or in combination. 2-, 5-, and 10-year survival rate were 81%, 46.7% and 20%, respectively. The incidence, diagnosis, clinical features, and therapeutic indications for bilateral breast cancer were discussed.

[Primary gastrointestinal malignant lymphoma. An analysis of 63 cases]

Sixty-three patients with primary gastrointestinal malignant lymphoma confirmed by pathology and treated in our hospital from 1973 to 1989 were reported. There were 30 males and 33 females, four suffering hodgkin's diseases and 59 non-hodgkin's lymphoma, with 17 at stage I, 17 at stage II, 9 at stage III, and 20 at stage IV. Patients were treated by surgery, radiotherapy and chemotherapy separately or combined. Forty-seven patients underwent tumor extirpation. Five-year's postoperative survival at stage I, II, and III were 84.6%, 33.3%, and 14.2%, respectively. Surgery combined with postoperative radiotherapy and/or chemotherapy gave better results. The incidence, diagnosis, clinical staging and the therapeutic indications were discussed with a review of literature.

[Primary gastric malignant lymphoma--analysis of 32 cases]

Thirty-two patients with primary gastric malignant lymphoma confirmed by pathology and treated in our hospital from 1973 to 1986 are reported. There were 10 males and 22 females (3 Hodgkin's diseases and 29 non-Hodgkin's lymphoma). There were 12 Stage I, 6 Stage II, and 14 Stage IV lesions. The patients were treated by surgery, radiotherapy and chemotherapy separately or combined. Twenty-three patients underwent surgery. Surgery combined with postoperative radiotherapy and/or chemotherapy gave better results. The incidence, diagnosis, clinical staging and the therapeutic indications are discussed with a review of literature.

[Multifactorial analysis of survival in breast cancer]

Eleven clinical and pathological factors were eligible for study in relation to the survival of 617 female patients with breast cancer treated by radical mastectomy. All the patients have been followed for more than five years. The data were analyzed by the Cox's proportional hazards regression model. A final set of five independent significant prognostic factors was obtained. In order of importance, they were clinical stage, age at diagnosis, axillary lymph node status, histologic type and size of the primary. To test the time-dependency of these factors using Cox's model, all except age reduced their prognostic impact significantly after five years, however, age was a powerful prognostic factor for long-term survival. A prognostic index based on the regression coefficients was constructed. This index can give a better prediction for our patients' survival and be taken as reference when formulating treatment protocols for breast cancer.