Diatoms as Endophytes of Marine Macroalgae: Diversity and Relationships with Basiphyte

Ciliate grazing on bacteria, flagellates, and microalgae in a temperate zone sandy tidal flat: ingestion rates and food niche partitioning

<p indent=0mm>The study of social networks is widely applied, which is mainly focused on the change of the social network structure of node and link, and the research angle is relatively single. Group collaboration is common in social networks. To better explore the evolution of group-level network structure in the process of group collaboration, this paper first adds group-level tasks to the task classification for graphic visualization. A task taxonomy suitable for group collaboration relationship analysis is set up according to the characteristics of collaborative relationship networks and tasks to be completed for group collaboration are set up according to this task taxonomy. Then, relevant visual views are designed to display the features and evolution patterns of collaborative relationships among and within groups in a more intuitive way. Finally, a specific case analysis was carried out on the academic collaboration literature data set. Through user evaluation experiments, the Likert scale was used to analyze the questionnaire to verify the effectiveness and practicability of the design visualization view, so as to provide a visual analysis method of group collaboration for social network relationship analysts, facilitating further exploration and application of group collaboration network relationships.

Intimate partner violence (IPV) is prevalent among young gay and bisexual men (YGBM) and is associated with physical and mental health problems, as well as deleterious psychosocial conditions. Most previous studies of IPV among YGBM have been quantitative in nature and have not examined the numerous subtypes of IPV, the chronicity of IPV experiences, and how is IPV manifested in the context of these same-sex relationships. Thus, a qualitative approach may be useful in exploring these multidimensional and understudied experiences. The present qualitative study sought to (a) explore dimensions of IPV victimization, perpetration, and bidirectional IPV among a sample of (n = 26) YGBM living in New York City and (b) explore the chronicity of IPV experiences among these YGBM. Participants were recruited from an ongoing cohort study of YGBM. Participants completed semistructured interviews that included questions about IPV victimization, perpetration, and bidirectional IPV. A modified version of the consensual qualitative research method was used to analyze the data. The YGBM in this study reported numerous forms of physical, psychological, sexual, and financial IPV victimization and perpetration. Bidirectional experiences of IPV were common. The various subtypes of IPV victimization and perpetration are explored in detail in this manuscript. In addition, many participants reported multiple experiences of abuse within the same relationship, and some participants experienced a pattern of abusive relationships over time. This study corroborates findings from quantitative studies, which indicate that IPV is a prevalent and significant health problem among YGBM, and one that warrants additional attention from researchers, practitioners, and policy-makers. Furthermore, this study adds rich qualitative data to the existing literature-data that can be used to help develop and refine future measures of IPV that are tailored for use with YGBM.

In the present work, we assessed the contents of rare earth elements (REEs), including yttrium and scandium, in rhizomes and leaves of the widespread seagrass Zostera noltei Hornemann 1832 and in the nearby sediments from the Black Sea coast. The total REE content in the sediments was found to be much higher than in Z. noltei. The order of decrease in the major REE contents in the sediments and the seagrass rhizomes was identical, except for La and Y. La was the most abundant in the sediments, and Y in the rhizomes. The contents of all REEs in rhizomes of Z. noltei were 1.5–10 times higher than in the leaves. The highest difference in the REE contents was found for the minor elements (Sm–Lu). The translocation factors for Sc and the minor elements (excluding Tb) from the sediments to the rhizomes and from the rhizomes to the leaves turned out to be pairwise equal, which indicates the similarity of the REE translocation mechanisms. Comparing our results with the literature data, it is possible to conclude that the seagrass Z. noltei does not have an advantage in the REE accumulation over marine macroalgae. At the same time, large coastal deposits of this seagrass after storms allow us to consider it as a possible source of REEs in the future.

New Combinations and Type Analysis of<i>Chamaepinnularia</i>Species (Bacillariophyceae) from Aerial Habitats

In mine pit lake Bistrik, which is located near Kakanj Municipality, a diatom species from the genus Stauroneis has been recorded and identified. In addition to the analysis of the composition of cyanobacteria and algae, the basic physical and chemical parameters of water were also measured. By comparing the morphometric characteristics of the valve of Stauroneis neofossilis, a similarity with the literature data was determined. The paper also presents LM and SEM micrographs of S. neofossilis and a list of identified species of the genus Stauroneis in Bosnia and Herzegovina. To obtain a more complete picture of morphometric characteristics, distribution and ecology, a detailed investigation of this genus from freshwater habitats in Bosnia and Herzegovina is necessary.

Fungi are one of the richest sources of bioactive metabolites, which can be used to produce innovative therapeutic agents. Pleosporales sp. including epiphytic, endophytic, or parasitic species can yield diverse secondary metabolites widely spread throughout many ecosystems. These metabolites are classified into polyketides, alkaloids, sesquiterpenoids, diterpenoids, steroids, and others depending on their unique structural characteristics. Secondary metabolites produced by Pleosporales sp. displayed outstanding biological activities such as cytotoxic, antibacterial, antifungal, and anti‐inflammatory properties. The goal of this review was to compile the most recent, comprehensive literature data on the secondary metabolite classes of Pleosporales sp., backed by its various bioactivity data, as a scientific record for the upcoming drug discovery endeavors.

The macromolecular composition of macroalgae influences nutrient flow and food quality in aquatic ecosystems and the value of macroalgae species for human consumption, aquaculture, biofuels, and other applications. We used literature data (125 publications, 1,117 observations) and a hierarchal Bayesian statistical model to estimate the average macromolecular composition, protein, lipid, and carbohydrate of macroalgae as a whole and at the phylum level. Our focus was on marine, noncalcified macroalgae sampled from wild-grown populations in the field. We found that the median macromolecular composition is 9.98% protein, 2.7% lipid, 48.5% carbohydrate, and 31.8% ash as percent dry weight. We compared the median macromolecular content of macroalgae to microalgae and herbaceous plants andtest for differences in macromolecular content across macroalgal phyla. Macroalgae were much more enriched in carbohydrate and minerals than the microalgae and lower in protein and lipid than many herbaceous plants. Rhodophyte macroalgae have significantly less lipid and more protein and the Ochrophyte macroalgae have significantly less protein than the average.

В статье рассмотрен вопрос использования уникальной группы диатомовых водорослей в диагностике условий среды. На примере литературных данных и собственных исследований представлены диагностические возможности диатомовых водорослей: маркировка почвообразовательных процессов, особенности процесса освоения первичных субстратов, географическое распределение диатомовых в почвах. В частности, уникальность таксономического состава диатомовых в болотных экосистемах, таежных и некоторых других. Показана возможность использования диатомовых водорослей в качестве биологических индикаторов современных условий и при реконструкции палеоэкологической обстановке. В том числе особое внимание уделено диагностике палеоэкологических условий через современных представителей Bacillariophyta. Тем не менее, остается еще огромное количество вопросов. Важно накапливать материал по экологическим спектрам видов диатомовых, особенно экологическому преферендуму каждого из них, чтобы надежно диагностировать условия современных систем и реконструировать палеоусловия древних почв. Какие фитоценотические показатели необходимо использовать для характеристики вида (встречаемость, активность, эколого-ценотическую значимость), используя уже известные расчетные формулы в почвенной альгологии. Насколько корректна такая экстраполяция? Пока что преобладают вопросы, но в перспективности этого направления исследования сомнений не остается.

For the first time, we have compiled a general list of diatoms for the Zarafshan River consisting of 428 species based on our own research and the literature data. Indicator species for nine water parameters were identified, making up more than 90% of the list. Bioindicators and statistical methods revealed that sections of the river around the city of Samarkand and further in the middle reaches reflect the complexity of the impact of the environment on diatom communities. The surveyed sections of the middle reaches of the river are divided into branches and the dynamics of water parameters and diatom communities are shown from the border with Tajikistan to the confluence of the Zarafshan with the Amu Darya. The indices of organic pollution, S, and toxic impact, WESI, were calculated. They show that there is an increase in salinity and turbidity and a decrease in organic pollution downriver. At the same time, the Navoi section is a source of water acidification. Nutrients and heavy metals, as well as phenol pollution, enter the river from various sources, mainly in the middle reaches of the river. The Zarafshan Nature Reserve in the catchment area of the upper section of the river within Uzbekistan is important for maintaining water quality. Bioindicators show an increase in self-purification, with an increase in the species richness and abundance of diatoms in the middle section of the Zarafshan River. The integrated index of river pollution, RPI, shows that most pollution comes from the northern canal of the river in the middle reaches. A general look at the Zarafshan River catchment basin and the dynamics of the identified water parameters and bioindicator species of diatoms shows that the river ecosystem successfully copes with incoming pollution, including transboundary impacts from Tajikistan. Such a conclusion could not be made based on chemical analysis of the water alone. This allowed us to recommend expanding state monitoring points to the lower section of Karakul while including biological indicators in the observations.

Although many studies have examined the algae associated with various habitats in tree trunks, the diatoms in these environments are still poorly studied. Studies of corticolous algae mainly focus on green algae and cyanobacteria, which are usually immediately visible, while diatoms are mostly overlooked or not reported. During the research, 143 species of diatoms were identified, including two new representatives of the genus Luticola: L.bryophilasp. nov. with relatively large central area and short distal raphe endings and L.confusasp. nov. characterized by the presence of small depressions on central raphe endings. Both are described herein based on light and scanning electron microscopy observations and compared to similar taxa based on literature data. Basic morphological data for almost all the diatom taxa are noted, and their habitat requirements, and photographic documentation are also presented. The present research showed that the occurrence of diatom assemblages on tree trunks is influenced by various factors like host tree species, the area where the host tree grows, and the availability of suitable microhabitats within the trunk. However, the species composition of this assemblages depends mainly on the tree species.

Species sensitivity distributions (SSDs) are an important predictive tool in risk assessment. Usually, literature data are used to build SSDs that are mostly based on planktonic species. But, to get adequate protective thresholds for environmental communities, one could argue that SSD should be built on ecotoxicological data obtained from species found in the ecosystem that should be protected. This is particularly true when benthic algae are of concern. Due to the lack of literature data, building SSD on benthic microalgae is difficult. This paper aims in comparing SSDs, and thus protective thresholds (hazardous concentration that affects 5% of the species of a community, HC5), built on ecotoxicological data obtained (1) from literature and (2) with specific bioassays on benthic diatoms from a lake. Thresholds were derived for protection against four herbicides separately and for a mixture of them. Sensitivity data obtained from literature were statistically lower than the specific data for all herbicides: Species tested in the literature were usually more sensitive (mainly chlorophytes), leading to more protective lower HC5. The HC5 thresholds (literature or specific) derived for protection against the mixture were also compared to the observed sensitivity of an assemblage of benthic diatom species exposed to an increasing range of herbicide mixture concentrations. We observed that one species within the assemblage (Fragilaria rumpens) was affected at a concentration below both the literature and the specific HC5 thresholds.

The article presents the detailed analysis results considering bottom sediments from the Chukchi Sea. Two core samples, b16 and НС–8 were taken from the northern Herald Canyon 150 km northeast from NE Wrangel Island. Core b16 has been studied in more detail. According to the 210 Pb measurements, the recent sedimentation rate amounts to 0.9 mm/y – 1 at the sampling point. In the bottom layer of the core sample, the minimum concentrations of biogenic components (SiO 2bio , C org , N tot , and Br) and the increased concentrations of cold-water diatom species Thalassiosira antarctica may result from low biological productivity during the Maunder Minimum. A correlation with recent global warming (11–22 years) is shown by the increased concentrations of SiO 2bio , C org , N tot , and Br and the decreased values of magnetic susceptibility and X-ray density in the top layer (1–2 cm) of the same core sample. The results of our geochemical and diatom analysis support the available literature data and confirm that the Late Holocene sedimentation in the Chukchi Sea takes place in the zone wherein the water transits from the Pacific to the Arctic Ocean.

This paper focuses on study of benthic diatoms of the sand beach of Kruglaya (Omega) Bay of the Black Sea. For the first time, diatom algae of epipsammon were studied in an electron scanning microscope. 14 Bacillariophyta taxa representing 8 genera were found, of which 6 species of the genus Cocconeis Ehrenberg (C. guttata, C. pinnata, C. placentula, C. pseudodebesii, C. scutellum, Cocconeis sp.) prevailed. Of the diatoms, 6 species, Anorthoneis arthus-bertrandi, A. dulcis, Cocconeis guttata, Coscinodiscus concinnus, Diplomenora cocconeiformis and Pseudostaurosira medliniae were found in Black Sea coastal waters for the first time. Original and literature data on species morphology, variability of shell and shell size, occurrence, ecology and geography of distribution in different areas of the World Ocean are presented. 55 SEM-microphotographs of all diatom species from different angles are presented.

Bottom sediments and near-bottom currents in the Southwestern Atlantic