For more information visit: https://bese.kaust.edu.sa/

Collections in this community

Recent Submissions

  • Electropolymerization of robust conjugated microporous polymer membranes for rapid solvent transport and narrow molecular sieving

    Zhou, Zongyao; Li, Xiang; Guo, Dong; Shinde, Digambar; Lu, Dongwei; Chen, Long; Liu, Xiaowei; Cao, Li; Aboalsaud, Ammar M.; Hu, Yunxia; Lai, Zhiping (Nature Communications, Springer Science and Business Media LLC, 2020-10-21) [Article]
    Abstract Pore size uniformity is one of the most critical parameters in determining membrane separation performance. Recently, a novel type of conjugated microporous polymers (CMPs) has shown uniform pore size and high porosity. However, their brittle nature has prevented them from preparing robust membranes. Inspired by the skin-core architecture of spider silk that offers both high strength and high ductility, herein we report an electropolymerization process to prepare a CMP membrane from a rigid carbazole monomer, 2,2’,7,7’-tetra(carbazol-9-yl)-9,9’-spirobifluorene, inside a robust carbon nanotube scaffold. The obtained membranes showed superior mechanical strength and ductility, high surface area, and uniform pore size of approximately 1 nm. The superfast solvent transport and excellent molecular sieving well surpass the performance of most reported polymer membranes. Our method makes it possible to use rigid CMPs membranes in pressure-driven membrane processes, providing potential applications for this important category of polymer materials.
  • Electrification at water–hydrophobe interfaces

    Nauruzbayeva, Jamilya; Sun, Zhonghao; Gallo Junior, Adair; Ibrahim, Mahmoud; Santamarina, Carlos; Mishra, Himanshu (Nature Communications, Springer Science and Business Media LLC, 2020-10-20) [Article]
    Abstract The mechanisms leading to the electrification of water when it comes in contact with hydrophobic surfaces remains a research frontier in chemical science. A clear understanding of these mechanisms could, for instance, aid the rational design of triboelectric generators and micro- and nano-fluidic devices. Here, we investigate the origins of the excess positive charges incurred on water droplets that are dispensed from capillaries made of polypropylene, perfluorodecyltrichlorosilane-coated glass, and polytetrafluoroethylene. Results demonstrate that the magnitude and sign of electrical charges vary depending on: the hydrophobicity/hydrophilicity of the capillary; the presence/absence of a water reservoir inside the capillary; the chemical and physical properties of aqueous solutions such as pH, ionic strength, dielectric constant and dissolved CO2 content; and environmental conditions such as relative humidity. Based on these results, we deduce that common hydrophobic materials possess surface-bound negative charge. Thus, when these surfaces are submerged in water, hydrated cations form an electrical double layer. Furthermore, we demonstrate that the primary role of hydrophobicity is to facilitate water-substrate separation without leaving a significant amount of liquid behind. These results advance the fundamental understanding of water-hydrophobe interfaces and should translate into superior materials and technologies for energy transduction, electrowetting, and separation processes, among others.
  • Enrichment of salt-tolerant CO2-fixing communities in microbial electrosynthesis systems using porous ceramic hollow tube wrapped with carbon cloth as cathode and for CO2 supply.

    AlQahtani, Manal Faisal; Bajracharya, Suman; Katuri, Krishna; Ali, Muhammad; Xu, Jiajie; Alarawi, Mohammed S; Saikaly, Pascal (The Science of the total environment, Elsevier BV, 2020-10-20) [Article]
    Microbial inocula from marine origins are less explored for CO2 reduction in microbial electrosynthesis (MES) system, although effective CO2-fixing communities in marine environments are well-documented. We explored natural saline habitats, mainly salt marsh (SM) and mangrove (M) sediments, as potential inoculum sources for enriching salt-tolerant CO2 reducing community using two enrichment strategies: H2:CO2 (80:20) enrichment in serum vials and enrichment in cathode chamber of MES reactors operated at -1.0 V vs. Ag/AgCl. Porous ceramic hollow tube wrapped with carbon cloth was used as cathode and for direct CO2 delivery to CO2 reducing communities growing on the cathode surface. Methanogenesis was dominant in both the M- and SM-seeded MES and the methanogenic Archaea Methanococcus was the most dominant genus. Methane production was slightly higher in the SM-seeded MES (4.9 ± 1.7 mmol) compared to the M-seeded MES (3.8 ± 1.1 mmol). In contrast, acetate production was almost two times higher in the M-seeded MES (3.1 ± 0.9 mmol) than SM-seeded MES (1.5 ± 1.3 mmol). The high relative abundance of the genus Acetobacterium in the M-seeded serum vials correlates with the high acetate production obtained. The different enrichment strategies affected the community composition, though the communities in MES reactors and serum vials were performing similar functions (methanogenesis and acetogenesis). Despite similar operating conditions, the microbial community composition of M-seeded serum vials and MES reactors differed from the SM-seeded serum vials and MES reactors, supporting the importance of inoculum source in the evolution of CO2-reducing microbial communities.
  • Impact of osmotic and thermal isolation barrier on concentration and temperature polarization and energy efficiency in a novel FO-MD integrated module

    Son, Hyuk Soo; Kim, Youngjin; Nawaz, Muhammad Saqib; Al-Hajji, Mohammed Ali; Abu-Ghdaib, Muhannad; Soukane, Sofiane; Ghaffour, NorEddine (Journal of Membrane Science, Elsevier BV, 2020-10-18) [Article]
    In this study, a novel integrated forward osmosis - membrane distillation (FO-MD) module equipped with an isolation barrier carefully placed between the FO and MD membranes is experimentally investigated, and its performance is compared with a conventional hybrid module. The function of the isolation barrier is to osmotically and thermally separate the FO draw solution (DS) and MD feed channels. A systematic approach is adopted to compare the flux through both modules under (i) different and similar hydrodynamic conditions, (ii) different DS concentrations and temperatures, and (iii) different feed solution concentrations. All experiments were performed for 9 h each in batch mode using a custom-made compact module. New FO and MD membrane sheets were mounted for each experiment to ensure similarity in operating conditions. The proposed module design increased the flux by 22.1% using the same module dimensions but different hydrodynamic conditions. The flux increased by 16.6% using the same hydrodynamic conditions but different module dimensions. The FO/MD energy ratio reduced from 0.89 to 0.64 for the novel module, indicating better utilization of energy (primarily from MD). The gain output ratio (GOR) increased on average by 15.8% for the novel module compared to the conventional module, with a maximum increment of 20.7%. The temperature and concentration polarization coefficients in the MD operations showed improvements of 17.4% and 2.6%, respectively. The presence of the isolation barrier inside the integrated module indicated promising improvements of the flux and internal heat recovery, and further significant enhancements are expected for larger scale modules. Additionally, the novel module design offers unprecedented process integration opportunities for FO-MD as well as other membrane hybrid systems.
  • High summer temperatures amplify functional differences between coral- and algae-dominated reef communities

    Roth, Florian; Rädecker, Nils; Carvalho, Susana; Duarte, Carlos M.; Saderne, Vincent; Anton Gamazo, Andrea; Silva, Luis; Calleja Cortes, Maria de Lluch; Moran, Xose Anxelu G.; Voolstra, Christian R.; Kürten, Benjamin; Jones, Burton; Wild, Christian (Ecology, Wiley, 2020-10-17) [Article]
    Shifts from coral to algal dominance are expected to increase in tropical coral reefs as a result of anthropogenic disturbances. The consequences for key ecosystem functions such as primary productivity, calcification, and nutrient recycling are poorly understood, particularly under changing environmental conditions. We used a novel in situ incubation approach to compare functions of coral- and algae-dominated communities in the central Red Sea bi-monthly over an entire year. In situ gross and net community primary productivity, calcification, dissolved organic carbon fluxes, dissolved inorganic nitrogen fluxes, and their respective activation energies were quantified to describe the effects of seasonal changes. Overall, coral-dominated communities exhibited 30% lower net productivity and 10 times higher calcification than algae-dominated communities. Estimated activation energies indicated a higher thermal sensitivity of coral-dominated communities. In these communities, net productivity and calcification were negatively correlated with temperature (>40% and >65% reduction, respectively, with +5°C increase from winter to summer), while carbon losses via respiration and dissolved organic carbon release were more than doubled at higher temperatures. In contrast, algae-dominated communities doubled net productivity in summer, while calcification and dissolved organic carbon fluxes were unaffected. These results suggest pronounced changes in community functioning associated with phase shifts. Algae-dominated communities may outcompete coral-dominated communities due to their higher productivity and carbon retention to support fast biomass accumulation while compromising the formation of important reef framework structures. Higher temperatures likely amplify these functional differences, indicating a high vulnerability of ecosystem functions of coral-dominated communities to temperatures even below coral bleaching thresholds. Our results suggest that ocean warming may not only cause but also amplify coral-algal phase shifts in coral reefs.
  • Diatom modulation of select bacteria through use of two unique secondary metabolites

    Shibl, Ahmed A.; Isaac, Ashley; Ochsenkühn, Michael A.; Cardenas, Anny; Fei, Cong; Behringer, Gregory; Arnoux, Marc; Drou, Nizar; Santos, Miraflor P.; Gunsalus, Kristin C.; Voolstra, Christian R.; Amin, Shady A. (Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, 2020-10-17) [Article]
    Unicellular eukaryotic phytoplankton, such as diatoms, rely on microbial communities for survival despite lacking specialized compartments to house microbiomes (e.g., animal gut). Microbial communities have been widely shown to benefit from diatom excretions that accumulate within the microenvironment surrounding phytoplankton cells, known as the phycosphere. However, mechanisms that enable diatoms and other unicellular eukaryotes to nurture specific microbiomes by fostering beneficial bacteria and repelling harmful ones are mostly unknown. We hypothesized that diatom exudates may tune microbial communities and employed an integrated multiomics approach using the ubiquitous diatom Asterionellopsis glacialis to reveal how it modulates its naturally associated bacteria. We show that A. glacialis reprograms its transcriptional and metabolic profiles in response to bacteria to secrete a suite of central metabolites and two unusual secondary metabolites, rosmarinic acid and azelaic acid. While central metabolites are utilized by potential bacterial symbionts and opportunists alike, rosmarinic acid promotes attachment of beneficial bacteria to the diatom and simultaneously suppresses the attachment of opportunists. Similarly, azelaic acid enhances growth of beneficial bacteria while simultaneously inhibiting growth of opportunistic ones. We further show that the bacterial response to azelaic acid is numerically rare but globally distributed in the world’s oceans and taxonomically restricted to a handful of bacterial genera. Our results demonstrate the innate ability of an important unicellular eukaryotic group to modulate select bacteria in their microbial consortia, similar to higher eukaryotes, using unique secondary metabolites that regulate bacterial growth and behavior inversely across different bacterial populations.
  • How many alien species will there be in 2050?

    Anton Gamazo, Andrea (Global Change Biology, Wiley, 2020-10-17) [Article]
    The introduction of non-native species into new regions is on the rise due to humanity's increasing global connectivity (Seebens et al., 2017). Many studies have identified the widespread ecological, economic, and social damage that these alien species can cause (Doherty et al., 2016; Hoffmann & Broadhurst, 2016). Advanced statistical analysis has recently been employed to predict ecological patterns of alien species, such as how alien species may be globally distributed in the future. Previous studies that have attempted to answer this question have been restricted to single species, taxa, or regions (Seebens et al., 2015, 2016).
  • Pan-regional marine benthic cryptobiome biodiversity patterns revealed by metabarcoding Autonomous Reef Monitoring Structures.

    Pearman, John K.; Chust, G; Aylagas, E; Villarino, E; Watson, J R; Chenuil, A; Borja, A; Cahill, A E; Carugati, L; Danovaro, R; David, R; Irigoien, X; Mendibil, I; Moncheva, S; Rodríguez-Ezpeleta, N; Uyarra, M C; Carvalho, Susana (Molecular ecology, Wiley, 2020-10-16) [Article]
    Autonomous Reef Monitoring Structures (ARMS) have been applied worldwide to characterize the critical yet frequently overlooked biodiversity patterns of marine benthic organisms. In order to disentangle the relevance of environmental factors in benthic patterns, here, through standardized metabarcoding protocols, we analyze sessile and mobile (
  • Total alkalinity production in a mangrove ecosystem reveals an overlooked Blue Carbon component

    Saderne, Vincent; Fusi, Marco; Thomson, Timothy; Dunne, Aislinn; Mahmud, Fatima; Roth, Florian; Carvalho, Susana; Duarte, Carlos M. (Limnology and Oceanography Letters, Wiley, 2020-10-16) [Article]
    Mangroves have the capacity to sequester organic carbon (Corg) in their sediments permanently. However, the carbon budget of mangroves is also affected by the total alkalinity (TA) budget. Principally, TA emitted from carbonate sediment dissolution is a perennial sink of atmospheric CO2. The assessment of the TA budget of mangrove carbonate sediments in the Red Sea revealed a large TA emission of 403 ± 17 mmol m−2 d−1, independent of light, seasons, or the presence of pneumatophores, compared to −36 ± 10 mmol m−2 d−1 in lagoon sediment. We estimate the TA emission from carbonate dissolution in Red Sea mangroves supported a CO2 uptake of 345 ± 15 gC m−2 yr−1, 23-fold the Corg burial rate of 15 gC m−2 yr−1. The focus on Corg burial in sediments may substantially underestimate the role of mangroves in CO2 removal. Quantifying the role of mangroves in climate change mitigation requires carbonate dissolution to be included in assessments.
  • Understanding High-Salt and Cold Adaptation of a Polyextremophilic Enzyme

    Karan, Ram; Mathew, Sam; Muhammad, Reyhan; Bautista, Didier B.; Vogler, Malvina M.; Eppinger, Jörg; Oliva, Romina; Cavallo, Luigi; Arold, Stefan T.; Rueping, Magnus (Microorganisms, MDPI AG, 2020-10-16) [Article]
    The haloarchaeon Halorubrum lacusprofundi is among the few polyextremophilic organisms capable of surviving in one of the most extreme aquatic environments on Earth, the Deep Lake of Antarctica (−18 °C to +11.5 °C and 21–28%, w/v salt content). Hence, H. lacusprofundi has been proposed as a model for biotechnology and astrobiology to investigate potential life beyond Earth. To understand the mechanisms that allow proteins to adapt to both salinity and cold, we structurally (including X-ray crystallography and molecular dynamics simulations) and functionally characterized the β-galactosidase from H. lacusprofundi (hla_bga). Recombinant hla_bga (produced in Haloferax volcanii) revealed exceptional stability, tolerating up to 4 M NaCl and up to 20% (v/v) of organic solvents. Despite being cold-adapted, hla_bga was also stable up to 60 °C. Structural analysis showed that hla_bga combined increased surface acidity (associated with halophily) with increased structural flexibility, fine-tuned on a residue level, for sustaining activity at low temperatures. The resulting blend enhanced structural flexibility at low temperatures but also limited protein movements at higher temperatures relative to mesophilic homologs. Collectively, these observations help in understanding the molecular basis of a dual psychrophilic and halophilic adaptation and suggest that such enzymes may be intrinsically stable and functional over an exceptionally large temperature range.
  • An Assistive Magnetic Skin System: Enabling Technology for Quadriplegics

    Almansouri, Abdullah S.; Upadhyaya, Lakshmeesha; Nunes, Suzana Pereira; Salama, Khaled N.; Kosel, Jürgen (Advanced Engineering Materials, Wiley, 2020-10-15) [Article]
    People with quadriplegia no longer have control over their legs, neither the hands and cannot continue living their life independently. On top of that, severely injured quadriplegics (i.e., C1 and C2 injuries) suffer from speaking difficulties and minimal head and neck movements. With the advancement in wearable artificial skins and the Internet of Things, realizing comfortable and practical solutions for quadriplegics is more tangible than ever. Here, a comprehensive assistive magnetic skin system is presented that allows quadriplegics, including the severely injured ones, to move around individually and control their surroundings with ease. The system tracks facial expressions by tracking the movement of magnetic tattoos attached to the face, using magnetic field sensors incorporated into eyeglasses. The magnetic tattoos are made of highly flexible, stretchable, breathable, and biocompatible magnetic skins. In combination with smart-glasses, smart-wheelchair, and smart-gadgets, the users can move around and control their environment with their facial expressions. The system is also designed to allow quadriplegics to perform outdoor activities effortlessly. It supports line-of-sight communication and does not require pre-tethering to the smart-gadgets, unlike the existing solutions. Thus, enabling the user to walk on pathways, activate pedestrian lights, control public elevators, and perform various outdoor activities independently.
  • Interleukin-26 activates macrophages and facilitates killing of Mycobacterium tuberculosis

    Hawerkamp, Heike C.; van Geelen, Lasse; Korte, Jan; Di Domizio, Jeremy; Swidergall, Marc; Momin, Afaque Ahmad Imtiyaz; Guzmán-Vega, Francisco J.; Arold, Stefan T.; Ernst, Joachim; Gilliet, Michel; Kalscheuer, Rainer; Homey, Bernhard; Meller, Stephan (Scientific Reports, Springer Science and Business Media LLC, 2020-10-14) [Article]
    Abstract Tuberculosis-causing Mycobacterium tuberculosis (Mtb) is transmitted via airborne droplets followed by a primary infection of macrophages and dendritic cells. During the activation of host defence mechanisms also neutrophils and T helper 1 (TH1) and TH17 cells are recruited to the site of infection. The TH17 cell-derived interleukin (IL)-17 in turn induces the cathelicidin LL37 which shows direct antimycobacterial effects. Here, we investigated the role of IL-26, a TH1- and TH17-associated cytokine that exhibits antimicrobial activity. We found that both IL-26 mRNA and protein are strongly increased in tuberculous lymph nodes. Furthermore, IL-26 is able to directly kill Mtb and decrease the infection rate in macrophages. Binding of IL-26 to lipoarabinomannan might be one important mechanism in extracellular killing of Mtb. Macrophages and dendritic cells respond to IL-26 with secretion of tumor necrosis factor (TNF)-α and chemokines such as CCL20, CXCL2 and CXCL8. In dendritic cells but not in macrophages cytokine induction by IL-26 is partly mediated via Toll like receptor (TLR) 2. Taken together, IL-26 strengthens the defense against Mtb in two ways: firstly, directly due to its antimycobacterial properties and secondly indirectly by activating innate immune mechanisms.
  • A Comprehensive Subcellular Atlas of the Toxoplasma Proteome via hyperLOPIT Provides Spatial Context for Protein Functions.

    Barylyuk, Konstantin; Koreny, Ludek; Ke, Huiling; Butterworth, Simon; Crook, Oliver M; Lassadi, Imen; Gupta, Vipul; Tromer, Eelco; Mourier, Tobias; Stevens, Tim J; Breckels, Lisa M; Pain, Arnab; Lilley, Kathryn S; Waller, Ross F (Cell host & microbe, Elsevier BV, 2020-10-14) [Article]
    Apicomplexan parasites cause major human disease and food insecurity. They owe their considerable success to highly specialized cell compartments and structures. These adaptations drive their recognition, nondestructive penetration, and elaborate reengineering of the host's cells to promote their growth, dissemination, and the countering of host defenses. The evolution of unique apicomplexan cellular compartments is concomitant with vast proteomic novelty. Consequently, half of apicomplexan proteins are unique and uncharacterized. Here, we determine the steady-state subcellular location of thousands of proteins simultaneously within the globally prevalent apicomplexan parasite Toxoplasma gondii. This provides unprecedented comprehensive molecular definition of these unicellular eukaryotes and their specialized compartments, and these data reveal the spatial organizations of protein expression and function, adaptation to hosts, and the underlying evolutionary trajectories of these pathogens.
  • Organic carbon export and loss rates in the Red Sea

    Kheireddine, Malika; Dall'Olmo, Giorgio; Ouhssain, Mustapha; Krokos, Georgios; Claustre, Hervé; Schmechtig, Catherine; Poteau, Antoine; Zhan, Peng; Hoteit, Ibrahim; Jones, Burton (Global Biogeochemical Cycles, American Geophysical Union (AGU), 2020-10-14) [Article]
    The export and fate of organic carbon in the mesopelagic zone are still poorly understood and quantified due to lack of observations. We exploited data from a BGC-Argo float that was deployed in the Red Sea to study how a warm and hypoxic environment can affect the fate of the organic carbon in the ocean’s interior. We observed that only 10% of the particulate organic carbon (POC) exported survived at depth due to remineralization processes in the upper mesopelagic zone. We also found that POC exported was rapidly degraded in a first stage and slowly in a second one, which may be dependent on the palatability of the organic matter. We observed that AOU-based loss rates (a proxy of the remineralization of total organic matter) were significantly higher than the POC-based loss rates, likely because changes in AOU are mainly attributed to changes in dissolved organic carbon. Finally, we showed that POC- and AOU-based loss rates could be expressed as a function of temperature and oxygen concentration. These findings advance our understanding of the biological carbon pump and mesopelagic ecosystem.
  • Biofilm removal efficacy using direct electric current in cross-flow ultrafiltration processes for water treatment

    Kerdi, Sarah; Qamar, Adnan; Vrouwenvelder, Johannes S.; Ghaffour, NorEddine (Journal of Membrane Science, Elsevier BV, 2020-10-14) [Article]
    Biofouling of membranes in water treatment is considered as one of the major practical problems. A novel and an efficient approach for cleaning biofilm grown on the membrane surface is proposed by applying a direct electric current (124 mA, 90 s) through platinum electrodes inside a cross-flow ultrafiltration channel. Depending on the electrochemical reactions occurring at the electrodes, either chlorine or hydrogen-producing configuration is realized by interchanging the current polarity. Baseline determination of the amount of chlorine generated and change in pH is assessed as a function of current intensity, linear cross-flow velocity, and duration of applied current. The efficiency of the proposed method is determined by investigating electrically treated biofilm through bacterial inactivation using Confocal Laser Scanning Microscopy (CLSM), bacterial cell structure changes through Scanning Electron Microscopy (SEM), and by estimating the amount of biomass removal through Optical Coherence Tomography (OCT). When a chlorine-producing electrode is placed at the inlet of the flow cell, 68% of bacterial inactivation is achieved without any modification of bacterial cell shape. Furthermore, a high and near-complete biomass removal is achieved (99%) after a subsequent forward flush of the electrically treated biofilm. However, placing a hydrogen-producing electrode at the inlet reveals a slightly lower bacterial inactivation (65%) and lower biomass removal (77%). Additional systematic experiments using individually sodium hydroxide (NaOH), sodium hypochlorite (NaOCl), or gas microbubbles enabled to elucidate the cause of biofilm removal, synergic effect of caustic agent NaOH and microbubbles.
  • Unlocking the relationships among population structure, plant architecture, growing season, and environmental adaptation in Henan wheat cultivars.

    Yang, Jian; Zhou, Yanjie; Hu, Weiguo; Zhang, Yu'e; Zhou, Yong; Chen, Yongxing; Wang, Xicheng; Zhao, Hong; Cao, Tingjie; Liu, Zhiyong (BMC plant biology, Springer Science and Business Media LLC, 2020-10-13) [Article]
    BACKGROUND:Ecological environments shape plant architecture and alter the growing season, which provides the basis for wheat genetic improvement. Therefore, understanding the genetic basis of grain yield and yield-related traits in specific ecological environments is important. RESULTS:A structured panel of 96 elite wheat cultivars grown in the High-yield zone of Henan province in China was genotyped using an Illumina iSelect 90 K SNP assay. Selection pressure derived from ecological environments of mountain front and plain region provided the initial impetus for population divergence. This determined the dominant traits in two subpopulations (spike number and spike percentage were dominance in subpopulation 2:1; thousand-kernel weight, grain filling rate (GFR), maturity date (MD), and fertility period (FP) were dominance in subpopulation 2:2), which was also consistent with their inheritance from the donor parents. Genome wide association studies identified 107 significant SNPs for 12 yield-related traits and 10 regions were pleiotropic to multiple traits. Especially, GY was co-located with MD/FP, GFR and HD at QTL-ple5A, QTL-ple7A.1 and QTL-ple7B.1 region. Further selective sweep analysis revealled that regions under selection were around QTLs for these traits. Especially, grain yield (GY) is positively correlated with MD/FP and they were co-located at the VRN-1A locus. Besides, a selective sweep signal was detected at VRN-1B locus which was only significance to MD/FP. CONCLUSIONS:The results indicated that extensive differential in allele frequency driven by ecological selection has shaped plant architecture and growing season during yield improvement. The QTLs for yield and yield components detected in this study probably be selectively applied in molecular breeding.
  • Evolution and biogeography of the Zanclea-Scleractinia symbiosis

    Maggioni, Davide; Arrigoni, Roberto; Seveso, Davide; Galli, Paolo; Berumen, Michael L.; Denis, Vianney; Hoeksema, Bert W.; Huang, Danwei; Manca, Federica; Pica, Daniela; Puce, Stefania; Reimer, James D.; Montano, Simone (Coral Reefs, Springer Science and Business Media LLC, 2020-10-12) [Article]
    Abstract Scleractinian corals provide habitats for a broad variety of cryptofauna, which in turn may contribute to the overall functioning of coral symbiomes. Among these invertebrates, hydrozoans belonging to the genus Zanclea represent an increasingly known and ecologically important group of coral symbionts. In this study, we analysed 321 Zanclea colonies associated with 31 coral genera collected from 11 localities across the Indo-Pacific and Caribbean regions, and used a multi-disciplinary approach to shed light on the evolution and biogeography of the group. Overall, we found high genetic diversity of hydrozoans that spans nine clades corresponding to cryptic or pseudo-cryptic species. All but two clades are associated with one or two coral genera belonging to the Complex clade, whereas the remaining ones are generalists associated with both Complex and Robust corals. Despite the observed specificity patterns, no congruence between Zanclea and coral phylogenies was observed, suggesting a lack of coevolutionary events. Most Zanclea clades have a wide distribution across the Indo-Pacific, including a generalist group extending also into the Caribbean, while two host-specific clades are possibly found exclusively in the Red Sea, confirming the importance of this peripheral region as an endemicity hotspot. Ancestral state reconstruction suggests that the most recent common ancestor of all extant coral-associated Zanclea was a specialist species with a perisarc, occurring in what is now known as the Indo-Pacific. Ultimately, a mixture of geography- and host-related diversification processes is likely responsible for the observed enigmatic phylogenetic structure of coral-associated Zanclea.
  • MYC as a driver of stochastic chromatin networks: implications for the fitness of cancer cells

    Sumida, Noriyuki; Sifakis, Emmanouil G; Kiani, Narsis A; Ronnegren, Anna Lewandowska; Scholz, Barbara A; Vestlund, Johanna; Gomez-Cabrero, David; Tegner, Jesper; Göndör, Anita; Ohlsson, Rolf (Nucleic Acids Research, Oxford University Press (OUP), 2020-10-11) [Article]
    Abstract The relationship between stochastic transcriptional bursts and dynamic 3D chromatin states is not well understood. Using an innovated, ultra-sensitive technique, we address here enigmatic features underlying the communications between MYC and its enhancers in relation to the transcriptional process. MYC thus interacts with its flanking enhancers in a mutually exclusive manner documenting that enhancer hubs impinging on MYC detected in large cell populations likely do not exist in single cells. Dynamic encounters with pathologically activated enhancers responsive to a range of environmental cues, involved <10% of active MYC alleles at any given time in colon cancer cells. Being the most central node of the chromatin network, MYC itself likely drives its communications with flanking enhancers, rather than vice versa. We submit that these features underlie an acquired ability of MYC to become dynamically activated in response to a diverse range of environmental cues encountered by the cell during the neoplastic process.
  • Innovative concentrated photovoltaic thermal (CPV/T) system with combined hydrogen and MgO based storage

    Burhan, Muhammad; Chen, Qian; Shahzad, Muhammad Wakil; Ybyraiymkul, Doskhan; Akhtar, Faheem; Ng, Kim Choon (International Journal of Hydrogen Energy, Elsevier BV, 2020-10-10) [Article]
    The intermittency of renewable energy resources which only have localized availability with low energy density, is the main reasons for our reliance on conventional fossil fuels. If steady supply and high energy quality can be achieved then solar energy potential is enough to meet the global energy demand. Heat and electricity both are equally important forms of derived energies. In this paper, an innovative configuration of solar energy system for simultaneous need of electricity and high grade thermal energy, is presented and discussed along with the long term energy storage solution. The proposed CPV/T system, with hydrogen based electrical and MgO based thermal storage, can produce electricity and high-temperature thermal energies at efficiency of 30% and 70% respectively. The CPV-Hydrogen configuration achieved Solar to Hydrogen efficiency of 19%. On the other hand, the MgO based TES system obtained 80% material storage efficiency at 400 °C which can be easily achieved with the concentrated thermal energy density of 240 Suns.
  • Optimising sample sizes for animal distribution analysis using tracking data

    Shimada, Takahiro; Thums, Michele; Hamann, Mark; Limpus, Colin J.; Hays, Graeme C.; FitzSimmons, Nancy; Wildermann, Natalie E.; Duarte, Carlos M.; Meekan, Mark G. (Methods in Ecology and Evolution, Wiley, 2020-10-09) [Article]
    1. Knowledge of the spatial distribution of populations is fundamental to management plans for any species. When tracking data are used to describe distributions, it is sometimes assumed that the reported locations of individuals delineate the spatial extent of areas used by the target population. 2. Here, we examine existing approaches to validate this assumption, highlight caveats, and propose a new method for a more informative assessment of the number of tracked animals (i.e. sample size) necessary to identify distribution patterns. We show how this assessment can be achieved by considering the heterogeneous use of habitats by a target species using the probabilistic property of a utilisation distribution. Our methods are compiled in the R package SDLfilter. 3. We illustrate and compare the protocols underlying existing and new methods using conceptual models and demonstrate an application of our approach using a large satellite tracking data-set of flatback turtles, Natator depressus, tagged with accurate Fastloc-GPS tags (n = 69). 4. Our approach has applicability for the post-hoc validation of sample sizes required for the robust estimation of distribution patterns across a wide range of taxa, populations and life history stages of animals.

View more