Range contractions and reduced body mass predicted for endemic skinks of the Cameroon Volcanic Line with future warming

Aim

The vulnerability of montane species to environmental change has been increasingly recognized in recent years. However, most of these species are regionally endemic with restricted distributions, limiting dispersal necessary for avoiding extinction. The outcome of threats posed for montane lizards is further complicated in species exhibiting mass–temperature relationships where body size increases with cooling temperatures, and thus with altitude, causing intraspecific physiological and behavioural differences. We aimed to identify areas suitable for montane endemic skinks of the Cameroon Volcanic Line (CVL) under current and future climates to reveal patterns of persistence and vulnerability based on an intersection of climate and body mass.

Location

Cameroon Volcanic Line

Methods

We recorded occurrences and measured body mass in the field for two CVL-endemic skink species. We supplemented occurrences with online repository records. We projected current and future habitat suitability in the region by implementing bioclimatic species distribution models-based on occurrences. We tested for elevational variations in body mass, and integrated both occurrence and body mass information in a trait-based model to estimate current and future body mass.

Results

Projected currently suitable habitat for both species was limited to higher elevation regions, which are inhabited by numerous other threatened herpetofauna. We additionally detected Bergmann clines in body mass for both species. Given this variation in body mass, trait model projections covered slightly larger geographical ranges than bioclimatic estimates. Under future warming, both models project substantial contractions in suitable areas, potentially constraining species to mountain tops. Through the trait-based approach, we further detected potential warming-induced body mass reductions in projected suitable areas.

Main Conclusions

We demonstrate how combining occurrence records with species trait information in ecological modelling can reveal complementary trends for comprehensive warming impact assessments. Overall, challenges toward the persistence of CVL-endemic skinks should prompt urgent responses in national conservation management and local community engagement.     

In silico structure-based discovery of a SARS-CoV-2 main protease inhibitor

The Coronavirus Disease 2019 (COVID-19) pandemic caused by the novel lineage B betacoroanvirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in significant mortality, morbidity, and socioeconomic disruptions worldwide. Effective antivirals are urgently needed for COVID-19. The main protease (M^pro) of SARS-CoV-2 is an attractive antiviral target because of its essential role in the cleavage of the viral polypeptide. In this study, we performed an in silico structure-based screening of a large chemical library to identify potential SARS-CoV-2 M^pro inhibitors. Among 8,820 compounds in the library, our screening identified trichostatin A, a histone deacetylase inhibitor and an antifungal compound, as an inhibitor of SARS-CoV-2 M^pro activity and replication. The half maximal effective concentration of trichostatin A against SARS-CoV-2 replication was 1.5 to 2.7µM, which was markedly below its 50% effective cytotoxic concentration (75.7µM) and peak serum concentration (132µM). Further drug compound optimization to develop more stable analogues with longer half-lives should be performed. This structure-based drug discovery platform should facilitate the identification of additional enzyme inhibitors of SARS-CoV-2.     

Aspiration biopsy cytology of metastatic extraskeletal myxoid chondrosarcoma and its cytologic differential diagnosis

Transabdominal fine needle aspiration biopsy of a metastatic myxoid chondrosarcoma in retroperitoneal spaces revealed amorphous mucoid material containing clusters of chondroblasts with round hyperchromatic nuclei and scanty cytoplasm, pleomorphic mesenchymal cells with round nuclei and vacuolated cytoplasm and groups of immature cartilaginous cells with single or double nuclei and fibrillar or filmy cytoplasm. The cytologic differential diagnosis between myxoid chondrosarcoma and other myxomatous tumors of bone and soft tissue is discussed.     

Pf1 virus particle dynamics

The overall dynamics of the Pf1 filamentous bacteriophage particle in solution are characterized by nmr experiments. The chemical-shift anisotropy powder-pattern lineshapes from both DNA and protein backbone sites of the virus are motionally averaged in the same way, indicating that the entire particle undergoes rapid (< 10⁴ Hz) reorientation about the long axis of the filament when the virus is in solution at high pH. In contrast, the virus particles in samples at low pH are immobile on this time scale.     

Nod1 promotes colorectal carcinogenesis by regulating the immunosuppressive functions of tumor-infiltrating myeloid cells

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Unweaving hippolytoid systematics (Crustacea,Decapoda, Hippolytidae): resurrection of several families

The Hippolytidae is the fourth largest family within the Caridea, currently containing over 330 described species in 37 genera, and the classification of this family has been rather controversial. In this study, sequences of two nuclear protein‐coding genes, enolase and sodium‐potassium ATPase α‐subunit, and the mitochondrial 16S rRNA gene (totalling 1405 bp) from 29 hippolytid species in 20 genera plus 17 species from eight other caridean families were used to examine the phylogenetic status of Hippolytidae sensu lato. Our results clearly reject the monophyly of Hippolytidae and support the recognition of the Lysmatidae Dana, 1852, Thoridae Kingsley, 1879, Bythocarididae Christoffersen 1987 and Merguiidae Christoffersen 1990 .     

Apoptosis and cell cycle arrest of hepatocellular carcinoma spheroids treated by an alternating electric field

Most of the current cancer therapies may induce serious side effects and affect patient quality of life. Recently, a novel treatment using an alternating low-intensity and intermediate-frequency electric field was proposed and found to be a noninvasive and minimally toxic approach. However, additional fundamental studies and scientific evidence are required to further support the development of this treatment into a standard cancer therapy. In the current work, an in-house fabricated culture plate was developed to study the responses of hepatocellular carcinoma spheroids to treatment with an alternating electric field. From the results of the viability study, the electric field was confirmed to influence the dividing cells in the spheroids. Fluorescent staining of live and dead cells revealed that a fraction of the cells were damaged in the field-treated spheroids. Moreover, flow cytometry analyses were conducted and showed that a fraction of the cells in the spheroids underwent apoptosis and cell cycle arrest. Additionally, the apoptosis pathway (Bax/caspase) and cell cycle arrest pathway (p53/p21) were found to be activated after exposure to the electric field. In summary, the results further elucidated the cellular and molecular mechanism inducing apoptosis and cell cycle arrest in the field-treated hepatocellular carcinoma spheroids. This study provides more evidence to support the efficacy of electric-field-based cancer therapy.