Bioaerosols and atmospheric ice nuclei in a Mediterranean dryland: community changes related to rainfall

Certain biological particles are highly efficient ice nuclei (IN), but the actual contribution of bioparticles to the pool of atmospheric IN and their relation to precipitation are not well characterized. We investigated the composition of bioaerosols, ice nucleation activity, and the effect of rainfall by metagenomic sequencing and freezing experiments of aerosol samples collected during the INUIT 2016 campaign in a rural dryland on the eastern Mediterranean island of Cyprus. Taxonomic analysis showed community changes related to rainfall. For the rain-affected samples, we found higher read proportions of fungi, particularly of Agaricomycetes, which are a class of fungi that actively discharge their spores into the atmosphere in response to humidity changes. In contrast, the read proportions of bacteria were reduced, indicating an effective removal of bacteria by precipitation. Freezing experiments showed that the IN population in the investigated samples was influenced by both rainfall and dust events. For example, filtration and heat treatment of the samples collected during and immediately after rainfall yielded enhanced fractions of heat-sensitive IN in the size ranges larger than 5 µm and smaller than 0.1 µm, which were likely of biological origin (entire bioparticles and soluble macromolecular bio-IN). In contrast, samples collected in periods with dust events were dominated by heat-resistant IN active at lower temperatures, most likely mineral dust. The DNA analysis revealed low numbers of reads related to microorganisms that are known to be IN-active. This may reflect unknown sources of atmospheric bio-IN as well as the presence of cell-free IN macromolecules that do not contain DNA, in particular for sizes < 0.1 µm. The observed effects of rainfall on the composition of atmospheric bioaerosols and IN may influence the hydrological cycle (bioprecipitation cycle) as well as the health effects of air particulate matter (pathogens, allergens).

Michael Harmel (1915-1974): A South African Communist and His Discourse

<p>This thesis explores the life and work of a South African journalist, editor, and activist Michael Alan Harmel (1915–1974), a political mentor and friend of Nelson Mandela. A resolute believer in racial equality and Marxism-Leninism, Harmel devoted his life to fighting, with “the pen” as well as “the sword”, segregation and apartheid, and promoting an alliance of communists with the African National Congress as a stepping stone to socialism in South Africa. Part 1, after tracing his Jewish-Lithuanian and Irish family roots, follows Harmel from his birth to 1940 when, having joined the Communist Party of South Africa, he got married and was elected secretary of the District Committee in Johannesburg. The focus is on factors germane to the formation of his political identity. The narrative section is accompanied by an analytical sketch. This, using tools of close literary interpretation, catalogues Harmel’s core beliefs as they inscribed themselves in his journalism, histories, a sci-fi novel, party memoranda, and private correspondence. The objective is to delineate his ideological outlook, put to the test the assessment of Harmel—undeniably a skilled publicist—as a “creative thinker” and “theorist”, and determine his actual contribution to the liberation discourse.</p>

Michael Harmel (1915-1974): A South African Communist and His Discourse

<p>This thesis explores the life and work of a South African journalist, editor, and activist Michael Alan Harmel (1915–1974), a political mentor and friend of Nelson Mandela. A resolute believer in racial equality and Marxism-Leninism, Harmel devoted his life to fighting, with “the pen” as well as “the sword”, segregation and apartheid, and promoting an alliance of communists with the African National Congress as a stepping stone to socialism in South Africa. Part 1, after tracing his Jewish-Lithuanian and Irish family roots, follows Harmel from his birth to 1940 when, having joined the Communist Party of South Africa, he got married and was elected secretary of the District Committee in Johannesburg. The focus is on factors germane to the formation of his political identity. The narrative section is accompanied by an analytical sketch. This, using tools of close literary interpretation, catalogues Harmel’s core beliefs as they inscribed themselves in his journalism, histories, a sci-fi novel, party memoranda, and private correspondence. The objective is to delineate his ideological outlook, put to the test the assessment of Harmel—undeniably a skilled publicist—as a “creative thinker” and “theorist”, and determine his actual contribution to the liberation discourse.</p>

Infiltration under Ponded Conditions

Ponded infiltration processes occur in agricultural lands irrigated by flooding of their soil surface or under insufficient drainage conditions. The existing equations describing the phenomenon of vertical infiltration under ponded conditions have not considered the actual contribution of the pressure head gradient to the flow. In this study, simple equations are proposed to describe the horizontal and vertical infiltration under various ponding heads incorporating the actual contribution of the pressure head gradient to the flow. Six soils with known hydraulic properties, covering a wide range of soil textures, were used. Horizontal and vertical infiltration data are obtained by numerical simulation for all soils studied using the Hydrus-1D code. To validate the accuracy of the proposed equations, the solutions of horizontal and vertical infiltrations provided by the proposed equations were compared with numerically simulated ones provided by the Hydrus 1-D. The analysis of the results showed a very good agreement in all soils studied. The proposed vertical infiltration equation was also compared to a simple and accurate equation which does not incorporate the actual contribution of the pressure head gradient to the flow and differences between them were observed in all soils studied.

Ultrasound and Microbubbles Enhance Uptake of Doxorubicin in Murine Kidneys

The use of ultrasound and microbubble-enhanced drug delivery, commonly referred to as sonoporation, has reached numerous clinical trials and has shown favourable results. Nevertheless, the microbubbles and acoustic path also pass through healthy tissues. To date, the majority of studies have focused on the impact to diseased tissues and rarely evaluated the impact on healthy and collateral tissue. The aim of this study was to test the effect and feasibility of low-intensity sonoporation on healthy kidneys in a mouse model. In our work here, we used a clinical diagnostic ultrasound system (GE Vivid E9) with a C1-5 ultrasound transducer combined with a software modification for 20-µs-long pulses to induce the ultrasound-guided drug delivery of doxorubicin (DOX) in mice kidneys in combination with SonoVue® and Sonazoid™ microbubbles. The acoustic output settings were within the commonly used diagnostic ranges. Sonoporation with SonoVue® resulted in a significant decrease in weight vs. DOX alone (p = 0.0004) in the first nine days, whilst all other comparisons were not significant. Ultrasound alone resulted in a 381% increase in DOX uptake vs. DOX alone (p = 0.0004), whilst SonoVue® (p = 0.0001) and Sonazoid™ (p < 0.0001) further increased the uptake nine days after treatment (419% and 493%, respectively). No long-standing damage was observed in the kidneys via histology. In future sonoporation and drug uptake studies, we therefore suggest including an “ultrasound alone” group to verify the actual contribution of the individual components of the procedure on the drug uptake and to perform collateral damage studies to ensure there is no negative impact of low-intensity sonoporation on healthy tissues.

Intraluminal Behavior of Various Transporter Substrates in the Rat Gastrointestinal Tract

Purpose: The aim of this study was to evaluate the intraluminal behavior of various transporter substrates in different regions of the gastrointestinal (GI) tract. Methods: Drug solutions containing non-absorbable FITC-dextran 4000 (FD-4), were orally administered to rats. Residual water was sampled from the GI regions to measure the luminal drug concentration. Results: Cephalexin (CEX), a substrate of the proton-coupled oligopeptide transporter, was absorbed rapidly, and no drug was detected in the lower small intestine. Saquinavir (SQV) was primarily absorbed in the upper region. However, unlike CEX, SQV was detected even in the lower segment probably due to the efflux of SQV via P-glycoprotein (P-gp). The concentration of methotrexate (MTX) showed a similar pattern to that of non-absorbable FD-4. The low absorption of MTX was probably due to efflux via several efflux transporters, and the limited expression of proton-coupled folate transporter, an absorptive transporter for MTX, in the upper region. Conclusion: This study revealed that the luminal concentration pattern of each drug differed considerably depending on the site because of the different absorption properties and luminal volumes. Although further investigation using a specific transporter inhibitor or transporter-knockout animals are necessary to clarify the actual contribution of each transporter to the drug absorption, this information will be valuable in evaluating transporter-mediated drug absorption in in vitro transport studies for ensuring optimal drug concentrations.

Kir4.1 Dysfunction in the Pathophysiology of Depression: A Systematic Reviews

A serotonergic dysfunction has been largely postulated as the main cause of depression, mainly due to its effective response to drugs that increase the serotonergic tone, still currently the first therapeutic line in this mood disorder. However, other dysfunctional pathomechanisms are likely involved in the disorder, and this may in part explain why some individuals with depression are resistant to serotonergic therapies. Among these, emerging evidence suggests a role for the astrocytic inward rectifier potassium channel 4.1 (Kir4.1) as an important modulator of neuronal excitability and glutamate metabolism. To discuss the relationship between Kir4.1 dysfunction and depression, a systematic review was performed according to the PRISMA statement. Searches were conducted across PubMed, Scopus, and Web of Science by two independent reviewers. Twelve studies met the inclusion criteria, analyzing Kir4.1 relationships with depression, through in vitro, in vivo, and post-mortem investigations. Increasing, yet not conclusive, evidence suggests a potential pathogenic role for Kir4.1 upregulation in depression. However, the actual contribution in the diverse subtypes of the disorder and in the comorbid conditions, for example, the epilepsy-depression comorbidity, remain elusive. Further studies are needed to better define the clinical phenotype associated with Kir4.1 dysfunction in humans and the molecular mechanisms by which it contributes to depression and implications for future treatments.

EXPLORING THE IMPACT OF COVID-19 ON TOURISM INDUSTRY OF BANGLADESH: AN EMPIRICAL STUDY

The tourism industry is one of the fastest-growing service industries in Bangladesh. This industry observed consistent economic growth for the last five years and contributed significantly to the GDP of Bangladesh. The outbreak of the Covid-19 pandemic impacted the tourism industry notedly. This paper aims to explore the impact on the tourism industry of Bangladesh, considering the economic and environmental aspects. The study found a catastrophic impact on the tourism industry's economic growth, which also affects the country’s total GDP growth. The tourism industry is expected to contribute 1309.27 billion Taka, which would be 3.20% of the total GDP of Bangladesh, but the actual contribution is 539.60 billion Taka which is 1.70% of total GDP. The pandemic also negatively affected employment opportunities, tourists’ arrival rate, hotel occupancy rate, and total tourism expenditures. On the other hand, despite some negative issues, Covid-19 impacted positively on the natural environment. The air quality improved, water pollution, noise pollution, consumption of natural resources, emission of greenhouse gas reduced notably. Considering the positive impacts on the environment, this study also formulated some possible recovery strategies to regain the economic losses through sustainable tourism development.

Rethinking symbiotic metabolism: trophic strategies in the microbiomes of different sponge species

In this study we describe the major lithoheterotrophic and autotrophic processes in 21 microbial sponge-associated phyla using novel and existing genomic and transcriptomic datasets. We show that a single gene family, molybdenum-binding subunit of dehydrogenase (coxL), likely evolved to benefit both lithoheterotrophic and organoheterotrophic symbionts, through adaptation to different inorganic and organic substrates. We show the main microbial carbon fixation pathways in sponges are restricted to specialized symbiotic lineages within five phyla. We also propose that sponge symbionts, in particular Acidobacteria, are capable of assimilating carbon through anaplerotic processes. However, the presence of symbionts genomically capable of autotrophy does not inform on their actual contribution to light and dark carbon fixation. Using radioisotope assays we identified variability in the relative contributions of chemosynthesis to total carbon fixation in different sponge species. Furthermore, the symbiosis of sponges with two closely related Cyanobacteria results in outcomes that are not predictable by analysis of -omics data alone: Candidatus Synechococcus spongiarum contributes to the holobiont carbon budget by transfer of photosynthates, while Candidatus Synechococcus feldmannii does not. Our results highlight the importance of combining sequencing data with physiology to gain a broader understanding of carbon metabolism within holobionts characterized by highly diverse microbiomes.

Community Support or Funding Amount: Actual Contribution of Reward-Based Crowdfunding to Market Success of Video Game Projects on Kickstarter

The research provides empirical evidence differentiating between market success and funding success in reward-based crowdfunding campaigns of video games and hypothesizes that the actual contribution of crowdfunding is more stemming from community support and feedback rather than funding amount. The paper uses publicly available data by combining three different sources. Project data from Kickstarter, a large crowdfunding website, in the video game category are extracted and matched with market success variables of ratings and revenues from two other public sources namely Metacritic and Steamspy. Regression results indicate that once the project is successfully funded, the funding amount does not have a significant effect on market success variables. On the other hand, the number of backers as a community support variable is a significant determinant of market success in terms of higher revenues and ratings for a project. Whether the project was successfully funded or not moderates some of the relationships. Prior literature is predominantly focused on crowdfunding success in terms of financing. Yet, this study empirically demonstrates that funding does not necessarily indicate that projects will be successful in the market and further shows the actual contribution of crowdfunding to the market success of video game projects is the community engagement, not the funding amount. This study contributes to the rapidly emerging crowdfunding literature by extending its boundaries from the crowdfunding platforms themselves to the differentiated effects of crowdfunding on market success, which has not been studied thoroughly. This paper provides a new avenue of research by suggesting not solely focusing on funding outcomes but understanding, defining and explaining the dynamics of the community aspect in crowdfunding platforms with their repercussions on market success. Future work can also highlight potential differences in these effects between product groups, as well as more holistically assess market success and capture interactions within the community on crowdfunding platforms.