On the genus Mesopontonia Bruce, 1967 (Crustacea: Decapoda: Palaemonidae) in Korea, with the description of a new species
Mesopontonia verrucimanus and Mesopontonia kimwoni sp. nov. are recorded from high-latitude temperate waters in Munseom Islet, Jejudo Island, Republic of Korea, with both species collected on gorgonians and sponges by trimix diving between 50 and 75 m depth. Mesopontonia kimwoni sp. nov. is morphologically allied to M. brevicarpus, but can be distinguished by the cutting edges of the fingers of the first chela being entire. Significant morphological variation in the rostrum as well as the second pereiopods is documented in M. verrucimanus, although cytochrome c oxidase subunit I (COI) barcode analysis proves this to be infra-specific variation. A key to species of the genus Mesopontonia is provided.
Park et al. (2020) On the genus Mesopontonia Bruce, 1967 (Crustacea: Decapoda: Palaemonidae) in Korea, with the description of a new species. PeerJ 8:e10190 https://doi.org/10.7717/peerj.10190
The past century of coral bleaching in the Saudi Arabian central Red Sea
Accurate knowledge of the spatial and temporal patterns of coral bleaching is essential both for understanding how coral reef ecosystems are changing today and forecasting their future states. Yet, in many regions of the world, the history of bleaching is poorly known, especially prior to the late 20th century. Here, I use the information preserved within skeleton cores of long-lived Porites corals to reconstruct the past century of bleaching events in the Saudi Arabian central Red Sea. In these cores, skeletal “stress bands”—indicative of past bleaching—captured known bleaching events that occurred in 1998 and 2010, but also revealed evidence of previously unknown bleaching events in 1931, 1978, and 1982. However, these earlier events affected a significantly lesser proportion of corals than 1998 and 2010. Therefore, coral bleaching may have occurred in the central Red Sea earlier than previously recognized, but the frequency and severity of bleaching events since 1998 on nearshore reefs is unprecedented over the past century. Conversely, corals living on mid- to outer-shelf reefs have not been equally susceptible to bleaching as their nearshore counterparts, which was evident in that stress bands were five times more prevalent nearshore. Whether this pattern of susceptible nearshore reefs and resistant outer-shelf reefs continues in the future remains a key question in forecasting coral reef futures in this region.
DeCarlo (2020) The past century of coral bleaching in the Saudi Arabian central Red Sea. PeerJ 8:e10200 https://doi.org/10.7717/peerj.10200
Flower structure and development in Vietnamese Sciaphila (Triuridaceae: Pandanales): refined knowledge of the morphological misfit family and implications for taxonomy
The monocot family Triuridaceae is a morphological misfit with respect to several traits of floral morphology, including the uniformly apocarpous polymerous gynoecium and the famous inside-out flowers of Lacandonia. Although Triuridaceae are crucially important for understanding the floral evolution of Pandanales and angiosperms in general, significant knowledge gaps exist which hamper adequate morphological analysis of flowers in this family. The scarcity of morphological data is also reflected in numerous taxonomic inconsistencies. Here we provide a comprehensive study of reproductive organs of four species of Sciaphila occurring in Vietnam (S. arfakiana, S. densiflora, S. nana and S. stellata) including the first investigation of early floral development and gynoecium phyllotaxis. Our observations are mainly based on SEM images. We confirm the perianth (studied in male flowers) to be two-whorled and report a rare sequence of initiation of perianth parts: the outer tepals show a late congenital fusion, as their free lobes appear before the common perianth tube, whereas the inner tepals show an early congenital fusion, with their free lobes initiating on the tube rim. We interpret the stamen appendages as basal adaxial outgrowths of the stamen filaments. We discuss the number of thecae and locules in anthers of Sciaphila, and conclude that 3- and 4-, but not 2-locular anthers are characteristic of this genus. We describe the carpels as consisting of both ascidiate and plicate zones, the former being extremely short and completely obscured by anthesis. The single ovule is attached in the cross-zone. The style is non-plicate. We analyze gynoecium phyllotaxis by estimating its contact parastichies, and by investigating the number and arrangement of the outermost carpels. The carpel arrangement in a given gynoecium is a result of the balance between whorled and irregular (but not spiral) phyllotaxis. We recognize the following figures of gynoecium merism: 6, 9, 10, 10.5, 11 and 12, with the prevalence of those divisible by three. We discuss our results in the light of general diversity of floral structure of monocots. Our data allow to clarify several issues in taxonomy of Asian Sciaphila and indicate directions of further studies. We report a significant range extension for S. densiflora, which is newly recorded for the flora of Vietnam. We describe for the first time staminodes in female flowers of this species. We reveal two distinct morphs of S. nana in Vietnam. We highlight the need of a thorough revision of S. secundiflora species complex in order to verify the species boundaries and, in particular, to test the identity of the Vietnamese S. stellata.
Nuraliev et al. (2020) Flower structure and development in Vietnamese Sciaphila (Triuridaceae: Pandanales): refined knowledge of the morphological misfit family and implications for taxonomy. PeerJ 8:e10205 https://doi.org/10.7717/peerj.10205
Computerized monitoring of COVID-19 trials, studies and registries in ClinicalTrials.gov registry
Clinical trial registries can provide important information about relevant studies for a given condition to other researchers and the public. We developed a computerized informatics based approach to provide an overview and analysis of COVID-19 studies registered on ClinicalTrials.gov registry. Using the perspective of analyzing active or completed COVID-19 studies, we identified 401 interventional clinical trials, 287 observational studies and 64 registries. We analyzed features of each study type separately such as location, design, interventions and update history. Our results show that the United States had the most COVID-19 interventional trials, France had the most COVID-19 observational studies and France and the United States tied for the most COVID-19 registries on ClinicalTrials.gov. The majority of studies in all three study types had a single study site. For update history “Study Status” is the most updated information and we found that studies located in Canada (2.70 updates per study) and the United States (1.76 updates per study) update their studies more often than studies in any other country. Using normalization and mapping techniques, we identified Hydroxychloroquine (92 studies) as the most common drug intervention, while convalescent plasma (20 studies) is the most common biological intervention. The primary purpose of most interventional trials is for treatment with 298 studies (74.3%). For COVID-19 registries we found the most common proposed follow-up time is 1 year (15 studies). Of specific importance and interest is COVID-19 vaccine trials, of which 12 were identified. Our informatics based approach allows for constant monitoring and updating as well as multiple applications to other conditions and interests.
Mayer et al. (2020) Computerized monitoring of COVID-19 trials, studies and registries in ClinicalTrials.gov registry. PeerJ 8:e10261 https://doi.org/10.7717/peerj.10261
Gene flow relates to evolutionary divergence among populations at the range margin
Background Morphological differentiation between populations resulting from local adaptations to environmental conditions is likely to be more pronounced in populations with increasing genetic isolation. In a previous study a positive clinal variation in body size was observed in isolated Roesel’s bush-cricket, Metrioptera roeselii, populations, but were absent from populations within a continuous distribution at the same latitudinal range. This observational study inferred that there was a phenotypic effect of gene flow on climate-induced selection in this species. Methods To disentangle genetic versus environmental drivers of population differences in morphology, we measured the size of four different body traits in wild-caught individuals from the two most distinct latitudinally-matched pairs of populations occurring at about 60°N latitude in northern Europe, characterised by either restricted or continuous gene flow, and corresponding individuals raised under laboratory conditions. Results Individuals that originated from the genetically isolated populations were always bigger (femur, pronotum and genital appendages) when compared to individuals from latitudinally-matched areas characterised by continuous gene flow between populations. The magnitude of this effect was similar for wild-caught and laboratory-reared individuals. We found that previously observed size cline variation in both male and female crickets was likely to be the result of local genetic adaptation rather than phenotypic plasticity. Conclusions This strongly suggests that restricted gene flow is of major importance for frequencies of alleles that participate in climate-induced selection acting to favour larger phenotypes in isolated populations towards colder latitudes.
Kaňuch et al. (2020) Gene flow relates to evolutionary divergence among populations at the range margin. PeerJ 8:e10036 https://doi.org/10.7717/peerj.10036
The role of geomorphic zonation in long-term changes in coral-community structure on a Caribbean fringing reef
Ecological processes on coral reefs commonly have limited spatial and temporal scales and may not be recorded in their long-term geological history. The widespread degradation of Caribbean coral reefs over the last 40 years therefore provides an opportunity to assess the impact of more significant ecological changes on the geological and geomorphic structure of reefs. Here, we document the changing ecology of communities in a coral reef seascape within the context of its geomorphic zonation. By comparing basic ecological indices between historical and modern data we show that in 35 years the reef-front zone was transformed from a complex coral assemblage with a three-dimensional structure, to a size-homogenized and flattened one that is quasi indistinguishable from the adjacent non-accretional coral-ground zone. Today coral assemblages at Punta Maroma are characterized by the dominance of opportunistic species which are either tolerant to adverse environmental conditions, including sedimentation, or are known to be the first scleractinian species to recruit on disturbed reefs, implying they reflect a post-hurricane stage of adjustment. Despite an increase in similarity in ecological indices, the reef-front and coral-ground geomorphic zones still retain significant differences in coral assemblages and benthic habitat and are not homogeneous. The partial convergence of coral assemblages certainly has important consequences for the ecology and geological viability of the reef and its role in coastal protection, but environmental physical drivers continue to exert a fundamental role in the character and zonation of benthic communities of this reef seascape.
Medina-Valmaseda et al. (2020) The role of geomorphic zonation in long-term changes in coral-community structure on a Caribbean fringing reef. PeerJ 8:e10103 https://doi.org/10.7717/peerj.10103
Constitution of a comprehensive phytochemical profile and network pharmacology based investigation to decipher molecular mechanisms of Teucrium polium L. in the treatment of type 2 diabetes mellitus
Background Type 2 diabetes mellitus (T2DM) is a metabolic disease affecting a huge population worldwide. Teucrium polium L. has been used as a folk medicine for the treatment of T2DM in Anatolia, Turkey. The antihyperglycemic effect of the plant was reported previously. However, there was no detailed study on the underlying molecular mechanisms. In this study, we generated a research plan to clarify the active constituents of the extract and uncover the molecular mechanisms using network pharmacology analysis. Methods For this purpose, we composed a dataset of 126 compounds for the phytochemical profile of the aerial parts of T. polium. Drug-likeness of the compounds was evaluated, and 52 compounds were selected for further investigation. A total of 252 T2DM related targets hit by selected compounds were subjected to DAVID database. Results The KEGG pathway analysis showed enrichment for the TNF signaling pathway, insulin resistance, the HIF-1 signaling pathway, apoptosis, the PI3K-AKT signaling pathway, the FOXO signaling pathway, the insulin signaling pathway, and type 2 diabetes mellitus which are related to T2DM . AKT1, IL6, STAT3, TP53, INS, and VEGFA were found to be key targets in protein-protein interaction. Besides these key targets, with this study the role of GSK3β, GLUT4, and PDX1 were also discussed through literature and considered as important targets in the antidiabetic effect of T. polium. Various compounds of T. polium were shown to interact with the key targets activating PI3K-AKT and insulin signaling pathways. Conclusions According to these findings, mainly phenolic compounds were identified as the active components and IRS1/PI3K/AKT signaling and insulin resistance were identified as the main pathways regulated by T. polium. This study reveals the relationship of the compounds in T. polium with the targets of T2DM in human. Our findings suggested the use of T. polium as an effective herbal drug in the treatment of T2DM and provides new insights for further research on the antidiabetic effect of T. polium.
Kutluay et al. (2020) Constitution of a comprehensive phytochemical profile and network pharmacology based investigation to decipher molecular mechanisms of Teucrium polium L. in the treatment of type 2 diabetes mellitus. PeerJ 8:e10111 https://doi.org/10.7717/peerj.10111
Pseudodiaptomus marinus Sato, 1913 in the Black Sea: morphology, genetic analysis, and variability in seasonal and interannual abundance
Calanoid copepod Peudodiaptomus marinus Sato, 1913 was first recorded in Sevastopol Bay in the northern Black Sea in September 2016. We performed regular observations of this new invasive species between October 2016 and December 2018. We conducted bi-weekly plankton sampling at three stations located within or adjacent to Sevastopol Bay. This is the first paper to combine (i) a detailed morphological study, (ii) molecular genetic analysis, and (iii) an investigation of P. marinus seasonal dynamics and interannual abundance variability in the coastal Black Sea. Our morphological research showed similarities between Pseudodiaptomus specimens and existing P. marinus illustrations and descriptions. Our morphological analysis results were confirmed using molecular genetic studies. Based on the genetic variability of ITS2 and cytb, we found that all investigated specimens from Sevastopol Bay belonged to P. marinus. Investigations of P. marinus seasonal and interannual abundance variability showed the same seasonal patterns throughout the studied period, with a higher seasonal abundance from October to November and one pronounced density peak in autumn. The highest abundances (2,000 ind m–3 at the mouth of the bay and more than 5,000 ind m–3at its centre) were recorded in November 2018. In the samples, we found adults of both sexes, including ovigerous females, copepodites I–V, and nauplii, suggesting that the species reproduce in Sevastopol Bay. Our research indicated that P. marinus is a new non-indigenous species (NIS) in the Black Sea, and we will discuss a possible vector of its introduction into this basin.
Gubanova et al. (2020) Pseudodiaptomus marinus Sato, 1913 in the Black Sea: morphology, genetic analysis, and variability in seasonal and interannual abundance. PeerJ 8:e10153 https://doi.org/10.7717/peerj.10153
Using ForeStereo and LIDAR data to assess fire and canopy structure-related risks in relict Abies pinsapo Boiss. forests
In this study we combine information from aerial LIDAR and hemispherical images taken in the field with ForeStereo—a forest inventory device—to assess the vulnerability and to design conservation strategies for endangered Mediterranean fir forests based on the mapping of fire risk and canopy structure spatial variability. We focused on the largest continuous remnant population of the endangered tree species Abies pinsapo Boiss. spanning 252 ha in Sierra de las Nieves National Park (South Andalusia, Spain). We established 49 sampling plots over the study area. Stand structure variables were derived from ForeStereo device, a proximal sensing technology for tree diameter, height and crown dimensions and stand crown cover and basal area retrieval from stereoscopic hemispherical images photogrammetry. With this information, we developed regression models with airborne LIDAR data (spatial resolution of 0.5 points∙m−2). Thereafter, six fuel models were fitted to the plots according to the UCO40 classification criteria, and then the entire area was classified using the Nearest Neighbor algorithm on Sentinel imagery (overall accuracy of 0.56 and a KIA-Kappa Coefficient of 0.46). FlamMap software was used for fire simulation scenarios based on fuel models, stand structure, and terrain data. Besides the fire simulation, we analyzed canopy structure to assess the status and vulnerability of this fir population. The assessment shows a secondary growth forest that has an increasing presence of fuel models with the potential for high fire spread rate fire and burn probability. Our methodological approach has the potential to be integrated as a support tool for the adaptive management and conservation of A. pinsapo across its whole distribution area (<4,000 ha), as well as for other endangered circum-Mediterranean fir forests, as A. numidica de Lannoy and A. pinsapo marocana Trab. in North Africa.
Cortés-Molino et al. (2020) Using ForeStereo and LIDAR data to assess fire and canopy structure-related risks in relict Abies pinsapo Boiss. forests. PeerJ 8:e10158 https://doi.org/10.7717/peerj.10158
Older adults at high risk of HIV infection in China: a systematic review and meta-analysis of observational studies
There is an increasing prevalence of human immunodeficiency virus (HIV) infection in older adults in China, but the findings across prevalence studies have been mixed. This is the first meta-analysis of the prevalence of HIV infection and its moderating factors in older adults in China. Two investigators systematically and independently searched both international (PubMed, PsycINFO, Web of Sciences and EMBASE) and Chinese (WanFang, CNKI, and CQVIP) databases. HIV infection rates in older adults were analyzed using the random-effects model. Altogether 46 studies were included in the analysis. The pooled prevalence of HIV infection in older adults was 2.1% (95% CI [1.9%–2.3%], I2 = 99.4%). Subgroup analyses revealed that men who have sex with men (MSM), hospital population samples, publications after 2014, studies conducted in the western region of China, and higher study quality were significantly associated with higher HIV infection rate. This meta-analysis found that the HIV infection prevalence in older adults is significantly higher than the general population in China. Attention should be given to this urgent public health issue, and effective HIV/AIDS preventive, screening and treatment measures are warranted in this population. PROSPERO: CRD42019124286.
Wang et al. (2020) Older adults at high risk of HIV infection in China: a systematic review and meta-analysis of observational studies. PeerJ 8:e9731 https://doi.org/10.7717/peerj.9731