• Chapter 14: Automated Mining of Disease-Specific Protein Interaction Networks Based on Biomedical Literature

      Chowdhary, Rajesh; Jankovic, Boris R.; Stankowski, Rachel V.; Archer, John A.C.; Zhang, Xiangliang; Gao, Xin; Bajic, Vladimir B. (WORLD SCIENTIFIC, 2013-12-17)
    • Virus-Mediated Genome Editing in Plants Using the CRISPR/Cas9 System

      Mahas, Ahmed; Ali, Zahir; Tashkandi, Manal; Mahfouz, Magdy M. (Springer New York, 2019-01-04)
      Targeted modification of plant genomes is a powerful strategy for investigating and engineering cellular systems, paving the way for the discovery and development of important, novel agricultural traits. Cas9, an RNA-guided DNA endonuclease from the type II adaptive immune CRISPR system of the prokaryote Streptococcus pyogenes, has gained widespread popularity as a genome-editing tool for use in a wide array of cells and organisms, including model and crop plants. Effective genome engineering requires the delivery of the Cas9 protein and guide RNAs into target cells. However, in planta genome modification faces many hurdles, including the difficulty in efficiently delivering genome engineering reagents to the desired tissues. We recently developed a Tobacco rattle virus (TRV)-mediated genome engineering system for Nicotiana benthamiana. Using this platform, genome engineering reagents can be delivered into all plant parts in a simple, efficient manner, facilitating the recovery of progeny plants with the desired genomic modifications, thus bypassing the need for transformation and tissue culture. This platform expands the utility of the CRISPR/Cas9 system for in planta, targeted genome modification. Here, we provide a detailed protocol explaining the methodologies used to develop and implement TRV-mediated genome engineering in N. benthamiana. The protocol described here can be extended to any other plant species susceptible to systemic infection by TRV. However, this approach is not limited to vectors derived from TRV, as other RNA viruses could be used to develop similar delivery platforms.
    • Crustal and Upper-Mantle Structure Beneath Saudi Arabia from Receiver Functions and Surface Wave Analysis

      Mai, Paul Martin; Julià, Jordi; Tang, Zheng (Springer International Publishing, 2018-12-05)
      Using receiver-functions and surface-wave dispersion curves, we study the crustal and upper-mantle structure of Saudi Arabia. Our results reveal first-order differences in crustal thickness between the Arabian Shield in the west and the Arabian Platform in the east. Moho depths generally increase eastward, while crustal thickness varies strongly in the west over the volcanic regions and near the Red Sea. Localized zones of increased P-wave speed in the west may indicate solidified magmatic intrusions within the area of recent volcanism. Our receiver-function analysis for deep converted phases reveals that the transition zone thickness between the 410 km and the 660 km discontinuities is not anomalously thinned, refuting the hypothesis of a small localized mantle plume as the origin for the volcanic activity in western Saudi Arabia. Our results suggest that the volcanism in western Arabia may be due to the lithospheric mantle being heated from below by lateral flow from the Afar and (possibly) Jordan plumes. This triggers localized melts that ascend adiabatically through the lithosphere as magma diapirs. Recent xenolith measurements that provide information on temperatures and depths of melting are overall consistent with this hypothesis. However, further dedicated localized tomographic studies are needed to decipher the details of the origin of the volcanism and its relation to the overall geodynamics of the region.
    • Physicochemical Dynamics, Microbial Community Patterns, and Reef Growth in Coral Reefs of the Central Red Sea

      Roik, Anna Krystyna; Ziegler, Maren; Voolstra, Christian R. (Springer International Publishing, 2018-12-06)
      Coral reefs in the Red Sea belong to the most diverse and productive reef ecosystems worldwide, although they are exposed to strong seasonal variability, high temperature, and high salinity. These factors are considered stressful for coral reef biota and challenge reef growth in other oceans, but coral reefs in the Red Sea thrive despite these challenges. In the central Red Sea high temperatures, high salinities, and low dissolved oxygen on the one hand reflect conditions that are predicted for ‘future oceans’ under global warming. On the other hand, alkalinity and other carbonate chemistry parameters are considered favourable for coral growth. In coral reefs of the central Red Sea, temperature and salinity follow a seasonal cycle, while chlorophyll and inorganic nutrients mostly vary spatially, and dissolved oxygen and pH fluctuate on the scale of hours to days. Within these strong environmental gradients micro- and macroscopic reef communities are dynamic and demonstrate plasticity and acclimatisation potential. Epilithic biofilm communities of bacteria and algae, crucial for the recruitment of reef-builders, undergo seasonal community shifts that are mainly driven by changes in temperature, salinity, and dissolved oxygen. These variables are predicted to change with the progression of global environmental change and suggest an immediate effect of climate change on the microbial community composition of biofilms. Corals are so-called holobionts and associate with a variety of microbial organisms that fulfill important functions in coral health and productivity. For instance, coral-associated bacterial communities are more specific and less diverse than those of marine biofilms, and in many coral species in the central Red Sea they are dominated by bacteria from the genus Endozoicomonas. Generally, coral microbiomes align with ecological differences between reef sites. They are similar at sites where these corals are abundant and successful. Coral microbiomes reveal a measurable footprint of anthropogenic influence at polluted sites. Coral-associated communities of endosymbiotic dinoflagellates in central Red Sea corals are dominated by Symbiodinium from clade C. Some corals harbour the same specific symbiont with a high physiological plasticity throughout their distribution range, while others maintain a more flexible association with varying symbionts of high physiological specificity over depths, seasons, or reef locations. The coral-Symbiodinium endosymbiosis drives calcification of the coral skeleton, which is a key process that provides maintenance and formation of the reef framework. Calcification rates and reef growth are not higher than in other coral reef regions, despite the beneficial carbonate chemistry in the central Red Sea. This may be related to the comparatively high temperatures, as indicated by reduced summer calcification and long-term slowing of growth rates that correlate with ocean warming trends. Indeed, thermal limits of abundant coral species in the central Red Sea may have been exceeded, as evidenced by repeated mass bleaching events during previous years. Recent comprehensive baseline data from central Red Sea reefs allow for insight into coral reef functioning and for quantification of the impacts of environmental change in the region.
    • Seagrass Distribution, Composition and Abundance Along the Saudi Arabian Coast of Red Sea

      Qurban, Mohammad Ali B.; Karuppasamy, Manikandan; Krishnakumar, Periyadan K.; Garcias Bonet, Neus; Duarte, Carlos M. (Springer International Publishing, 2018-12-06)
      Seagrasses rank among the most productive ecosystems with important implications in climate change mitigation. Tropical and subtropical seas hold the largest seagrass species richness. A total of 12 different seagrass species have been reported from the Red Sea. However, there is little information on seagrass diversity and distribution along the Saudi Arabian coast of the Red Sea. This study aims to capture: (i) the distribution and composition of seagrasses from 18°N to 28°N latitudes on a broader scale, and (ii) the species composition, distribution and abundance of seagrasses by detailed investigations at three locations along the Saudi Arabian coast: Sharma, Umluj and Jazan, representing the northern, central and southern Red Sea. The most commonly observed seagrass species along the Red Sea were Halodule uninervis (17 observations), Thalassia hemprichii (13 observations) and Halophila stipulacea (11 observations). Halophila stipulacea was the most dominant species at each of the three locations studied in more detail. Syringodium isoetifolium and Thalassodendron ciliatum were found only at Umluj, while H. ovalis and T. hemprichii were found only at Jazan. H. uninervis was observed at both Umluj and Jazan. Shoot lengths of H. stipulacea and H. uninervis showed significant differences among the three locations. The average above-ground biomass of seagrasses differed significantly among locations (analysis <0.05; multiple tests), with the highest biomass for Halophila stipulacea recorded at Jazan (81 ± 24 gDW m−2) and an average biomass for T. ciliatum of 74 ± 16 gDW m−2 at Umluj. The species T. ciliatum was the only taxa that exhibited significant differences (p < 0.05) in the abundance of seagrasses among the three locations. This work contributes further to our understanding of the distribution and diversity of seagrasses in the Red Sea, confirming a high seagrass richness with at least ten different species along the Saudi Arabian coast of the Red Sea.
    • Metrological Qualification of the Kinect V2™ Time-of-Flight Camera

      Giancola, Silvio; Valenti, Matteo; Sala, Remo (Springer International Publishing, 2018-06-19)
      The Kinect V2™ is a Time-of-Flight (TOF) camera device with state-of-the-art performances. Including the first version of the device, Microsoft sold tens of million of Kinects, proposing appealing low-cost Three-dimension (3D) cameras below 200€. The main specifications of the Microsoft Kinect V2™ are summarized in Table 4.1. Bamji et al. (2015) released a full description of the 512 × 424 CMOS IR TOF sensor included in the Kinect V2™. The Kinect V2™ also incorporates a full HD RGB camera, calibrated with the aforementioned depth sensor, and provide colored depth maps and point clouds at roughly 30 Hz. In this chapter, we investigate the performances of the Kinect V2™ as a depth camera, focusing on uncertainty characterization according to the Guide to the Expression of Uncertainty in Measurement (GUM) (BIPM et al.2008). First of all, the TOF signal transmitted by the Kinect V2™ is evaluated. Then, stability is discussed as well as distribution normality. Range measurement uncertainty is studied at pixel and sensor scales. Last, qualitative results are provided in simple scenarios.
    • Interpreting and Predicting Experimental Responses of Micro- and Nano-Devices via Dynamical Integrity

      Ruzziconi, Laura; Lenci, Stefano; Younis, Mohammad I. (Springer International Publishing, 2018-09-24)
      The present chapter highlights the importance of the dynamical integrity theory for micro and nanoapplications. Three case-studies of devices at different scales are presented (a capacitive accelerometer, a microbeam-based micro-electromechanical system, and a single-walled slacked carbon nanotube) and different issues commonly addressed in the engineering design are examined via dynamical integrity concepts. The iso-integrity curves are observed to follow exactly the experimental data. They are able to detect the parameter range where each attractor can be reliably observed in practice and where, instead, becomes vulnerable. Also, they may be used to simulate and predict the expected dynamics under different (smaller or larger) experimental disturbances. While referring to particular case-studies, we show the relevance of the dynamical integrity analysis for the engineering design of a mechanical system, in order to operate it in safe conditions, according to the desired outcome and depending on the expected disturbances.
    • Conclusion

      Giancola, Silvio; Valenti, Matteo; Sala, Remo (Springer International Publishing, 2018-06-19)
      This manuscript presents the technology on which are based Three-dimension (3D) cameras. We provide a comparison of the main 3D camera available on the mass market, as well as a deep analysis of the uncertainty in the depth measurement for each technology.
    • Polyhomologation and ATRP: A Perfect Partnership toward Unique Polyethylene-Based Architectures

      Wang, De; Zhang, Zhen; Zhang, Hefeng; Gnanou, Yves; Hadjichristidis, Nikolaos (American Chemical Society, 2018-08-13)
      The recent developments in organoborane initiated C1 polymerization (chain grows by one atom at a time) of ylides opens unique horizons towards well-defined/perfectly linear polymethylenes (equivalent to polyethylenes, PE). On the other hand, atom transfer radical polymerization (ATRP) is an excellent and powerful controlled/living polymerization for polar monomers such as (meth)acrylates and styrenes. In this Chapter the partnership of these two living polymerizations towards the synthesis of well-defined PE (perfectly linear)-based block copolymers, with unprecedented macromolecular architectures, is presented. Some ideas about new ylide monomers are also discussed.
    • Synthesis of Transition Metal Dichalcogenides

      Shi, Yumeng; Li, Lain-Jong (Cambridge University Press, 2017-06-21)
      Novel properties and new phenomena that arise from two-dimensional (2D) materials have stimulated huge research interest recently. Among the 2D material family, semiconducting transition metal dichalcogenides (TMDCs) with an intrinsic band gap are complementary to the gapless graphene [1, 2]. Hence, both single-layer and multi-layer TMDCs are promising candidates for high-performance electronic [3-7] and optoelectronic [8-14] applications. The thickness uniformity and the lateral size of a single domain are important concerns for the exploration of the properties, function, and fabrication of electronic devices. Considerable efforts have been made in the synthesis of 2D semiconducting TMDCs, and the main theme focuses on large-scale growth of single crystalline monolayers and their heterostructures. Various methods have been developed for the large-scale production of monolayer and few-layer TMDC nanosheets, including the top-down layer exfoliation from bulk crystals [15-19] and the bottom-up chemical synthesis. Among all the approaches, the liquid phase exfoliation of TMDC layers from their bulk crystals generates a range of well-dispersed TMDC monolayers with a high yield [20]. This method has immense potential for solution-based printable and flexible electronics. However, the wet chemical method may unavoidably alter the lattice structure of thin TMDC layers and introduce extrinsic defects during the exfoliation process. It is essential to develop a synthetic technique that can produce wafer-scale TMDC materials that are also compatible with the current nanoelectronic fabrication processes. Considerable efforts have been made in developing controllable synthesis of 2D semiconducting TMDCs. Several synthetic routes, including thermolysis of thiosalts [21, 22], sulfurization (or selenization) of metal (or metal oxide) thin films [23], physical vapor phase transport [24], and chemical vapour deposition (CVD) [25], have been developed. Among all these methods, vapor phase deposition shows great promise towards high-quality TMDC production [1]. With this technique, monolayer TMDCs that have single domains with scalable size, controllable thickness, and excellent electronic properties can be obtained. In addition, the electro-dispersive properties and the semiconducting nature of TMDCs can be tailored by tuning the synthesis conditions. Remarkably, vapor phase deposition can also be employed to synthesize TMDC ternary alloys, in-plane heterostructures, and multilayer van der Waals stackings, which pave the way for exploring new devices and physics based on 2D materials.
    • Smolyak’s Algorithm: A Powerful Black Box for the Acceleration of Scientific Computations

      Tempone, Raul; Wolfers, Sören (Springer International Publishing, 2018-06-20)
      We provide a general discussion of Smolyak’s algorithm for the acceleration of scientific computations. The algorithm first appeared in Smolyak’s work on multidimensional integration and interpolation. Since then, it has been generalized in multiple directions and has been associated with the keywords: sparse grids, hyperbolic cross approximation, combination technique, and multilevel methods. Variants of Smolyak’s algorithm have been employed in the computation of high-dimensional integrals in finance, chemistry, and physics, in the numerical solution of partial and stochastic differential equations, and in uncertainty quantification. Motivated by this broad and ever-increasing range of applications, we describe a general framework that summarizes fundamental results and assumptions in a concise application-independent manner.
    • Applications of Emerging Nanomaterials for Oily Wastewater Treatment

      Goh, P.S.; Ong, Chi Siang; Ng, B.C.; Ismail, Ahmad Fauzi (Elsevier, 2018-11-23)
      The huge volume of oily wastewater produced from the industries has resulted in alarming environmental pollution and resource usage problems. A wide range of conventional and emerging approaches have been established to effectively reduce all these pollutants to an acceptable level to discharge the treated wastewater for reuse. Lately, nanomaterials have shown great potential to address this issue based on their unique and exceptionally properties such as high surface area, superhydrophilicity/hydrophobicity and surface functionalities. This chapter discusses the application of emerging nanomaterials for oily wastewater treatment. The characteristics of these nanomaterials and their hybrid or nanocomposites for oily water treatment are discussed. Finally, a brief future outlook and concluding remarks are presented.
    • Renewable Energy Storage and Its Application for Desalination

      Shahzad, Muhammad Wakil; Burhan, Muhammad; Ng, Kim Choon (Springer Singapore, 2018-11-09)
      The economic development has serious impact on the nexus between water, energy, and environment. This impact is even more severe in Non-Organization for Economic Cooperation and Development (non-OECD) countries due to improper resource management. It is predicted that energy demand will increase by more than 71% in non-OECD as compared to 18% in developed countries by 2040. In Gulf Cooperation Council countries, water and power sector consume almost half of primary energy produced. In the past, many studies were focused on renewable energies based on desalination processes to accommodate fivefold increase in demand by 2050 but they were not commercialized due to intermittent nature of renewable energy such as solar and wind. We proposed highly efficient energy storage material, magnesium oxide (MgO), system integrated with innovative hybrid desalination cycle for future sustainable water supplies. The condensation of Mg(OH)2 dehydration vapor during day operation with concentrated solar energy and exothermic hydration of MgO at night can produce 24 h thermal energy without any interruption. It was showed that Mg(OH)2 dehydration vapor condensation produces 120 °C and MgO hydration exothermic reaction produces 140 °C heat during day and night operation, respectively, corresponding to energy storage of 81 kJ/mol and 41 kJ/mol. The produced energy can be utilized to operate desalination cycle to reduce CO2 emission and to achieve COP21 goal. The proposed hybrid desalination cycle is successfully demonstrated by pilot experiments at KAUST. It was showed that MgO + MEDAD cycle can achieve performance over UPR = 200, one of the highest reported ever.
    • Combustion-Based Transportation in a Carbon-Constrained World—A Review

      Javed, Tamour; Ahmed, Ahfaz; Raman, Vallinayagam; Alquaity, Awad B. S.; Johansson, Bengt (Springer Singapore, 2018-11-01)
      The transportation sector accounts for around a quarter of global CO2 emissions and is powered predominantly by fossil-derived fuels. The regulatory framework is evolving globally to more stringent requirements for fuel efficiency and CO2 emissions, forcing the OEMs to adopt advanced powertrain technologies. Such changes are more evident in the light-duty road transportation sector compared to the heavy-duty road, marine and air transportation sectors. Here, a holistic review of the current and prospective regulations targeted at curbing transportation-based CO2 emissions is presented. For road transport, these include various government- and state-level policy initiatives such as the Corporate Average Fuel Economy (CAFE) and CO2 emission standards and the zero emission mandates. For marine and aviation sectors, these include the International Maritime Organization (IMO) and the International Civil Aviation Organization (ICAO) regulations and aspirations targeted at reducing the CO2 footprint. The compliance options for these regulations are evaluated using a combination of fuels, engines, and hybridization in each transportation sector. Furthermore, a brief overview of how OEMs are working toward achieving these targets is presented. An overview of several advanced spark and compression ignition engine technologies with the potential to improve the fuel economy and CO2 emissions is presented. Finally, an overview of major disruptions that are changing the road-based transportation is presented and a balanced life cycle based policy approach is advocated.
    • Concentrated Photovoltaic (CPV) for Rooftop—Compact System Approach

      Burhan, Muhammad; Shahzad, Muhammad Wakil; Ng, Kim Choon (Springer Singapore, 2018-11-01)
      The single-junction-based conventional PV panels are dominating almost the entire photovoltaic market. In addition, they can only offer a limited solar conversion efficiency due to limitations of the band gap of their single pn-junction. On the other hand, third-generation multi-junction solar cell offers the highest solar energy conversion efficiency as their multiple pn-junctions can absorb a larger portion of solar spectrum. Despite such high potential, their share in current photovoltaic market is still negligible, even though, they have been used in form of concentrated photovoltaic (CPV) systems to reduce the use of expensive solar cell material. The main reason for such low market share is due to the gigantic design of commercial PV system which is only suitable to install in the open desert regions, thereby limiting its customers and application scope. In this chapter, a compact CPV system design is discussed with the motivation for its rooftop application and installation. Moreover, the long-term performance of CPV is also compared with conventional PV system in tropical conditions to highlight its potential in low solar energy areas.
    • Optimization Strategy of Sustainable Concentrated Photovoltaic Thermal (CPVT) System for Cooling

      Burhan, Muhammad; Shahzad, Muhammad Wakil; Ng, Kim Choon (Springer Singapore, 2018-11-09)
      Renewable energy resources are susceptible to intermittent power supply, and their standalone operation has prime importance for steady power supply. Solar energy resources have high global availability and potential among all energy sources. Most of areas with high solar energy potential have either dry hot or tropical climate. A major portion of primary energy supply for such area is utilized in their cooling energy needs. In this chapter, a sustainable approach for cooling needs has been proposed using solar energy-based highly efficient concentrated photovoltaic (CPV). A combined cooling system, based upon mechanical vapour compression (MVC), and adsorption chillers have been considered. The MVC chiller utilizes the produced electricity by the third -generation multi-junction solar cells (MJCs). However, adsorption chiller is operated with thermal energy recovered from the cooling of CPV system, which also increases the system efficiency as high as 71%. To handle intermittency, hydrogen production is used primary energy storage system, along with the hot water storage. The complete system configuration is then optimized for standalone operation with optimum components size and minimum cost, using micro-genetic algorithm according to proposed optimization strategy.
    • Chapter 17 - Carbon Geological Storage: Coupled Processes, Engineering and Monitoring

      Kim, Seunghee; Espinoza, D. Nicolas; Jung, Jongwon; Cha, Minsu; Santamarina, Carlos (Elsevier, 2018-09-14)
      Today’s energy concerns reflect the large anticipated increase in demand within the next generation, the current dependency on fossil fuels and climate implications, the geographic mismatch between resources and demand, and the disparity in associated time scales. The long-term geological storage of vast quantities of CO2 is a relatively new scientific and technological challenge, plagued with underlying coupled hydro-chemo-mechanical processes and potential emergent phenomena. Processes include: capillarity, density and viscous effects on flow; acidification, mineral dissolution, and ensuing changes in permeability; phase transformations (and CO2-CH4 exchange in hydrates); and stress changes. These processes are involved in the analysis of CO2 storage in saline aquifers, coal seams, depleted reservoirs, and in clathrates. Furthermore, the understanding of underlying processes guides monitoring (active: seismic and electromagnetic; passive: seismic, deformation, thermal) and may lead to improved efficiency and leakage-sealing strategies. Dimensionless ratios help identify the domain for the various dominant processes that govern CO2 geo-storage.
    • Theory of Rashba Torques

      Manchon, Aurelien; Zhang, S. (Oxford University Press, 2017-12-21)
      This chapter focuses on the theory of current-driven Rashba torque, a special type of spin-orbit mediated spin torque that requires broken spatial-inversion symmetry. This specific form of spin-orbit interaction enables the electrical generation of a non-equilibrium spin density that yields both damping-like and field-like torques on the local magnetic moments. We review the recent results obtained in (ferromagnetic and antiferromagnetic) two-dimensional electron gases, bulk magnetic semiconductors, and at the surface of topological insulators. We conclude by summarizing recent experimental results that support the emergence of Rashba torques in magnets lacking inversion symmetry.
    • For a World Without Boundaries: Connectivity Between Marine Tropical Ecosystems in Times of Change

      Earp, Hannah S.; Prinz, Natalie; Cziesielski, Maha J.; Andskog, Mona (Springer International Publishing, 2018-08-30)
      Tropical mangrove forests, seagrass beds, and coral reefs are among the most diverse and productive ecosystems on Earth. Their evolution in dynamic, and ever-changing environments means they have developed a capacity to withstand and recover (i.e., are resilient) from disturbances caused by anthropogenic activities and climatic perturbations. Their resilience can be attributed, in part, to a range of cross-ecosystem interactions whereby one ecosystem creates favorable conditions for the maintenance of its neighbors. However, in recent decades, expanding human populations have augmented anthropogenic activities and driven changes in global climate, resulting in increased frequencies and intensities of disturbances to these ecosystems. Many contemporary environments are failing to regenerate following these disturbances and consequently, large-scale degradation and losses of ecosystems on the tropical seascape are being observed. This chapter reviews the wealth of available literature focused on the tropical marine seascape to investigate the degree of connectivity between its ecosystems and how cross-ecosystem interactions may be impacted by ever-increasing anthropogenic activities and human-induced climate change. Furthermore, it investigates how disruption and/or loss of these cross-ecosystem interactions may impact the success of neighboring ecosystems and consequently, the highly-valued ecosystem services to which these ecosystems give rise. The findings from this review highlight the degree of connectivity between mangroves, seagrasses and coral reefs, and emphasizes the need for a holistic, seascape-wide research approach to successfully protect and preserve these critically important ecosystems and their associated services for future generations.
    • Reading the Book of Life – Omics as a Universal Tool Across Disciplines

      Brüwer, Jan David; Buck-Wiese, Hagen (Springer International Publishing, 2018-08-30)
      In the last centuries, new high-throughput technologies, including sequencing and mass-spectrometry, have emerged and are constantly refurbished in order to decipher the molecular code of life. In this review, we summarize the physiological background from genes via transcriptome to proteins and metabolites and discuss the variety of dimensions in which a biological entity may be studied. Herein, we emphasize regulatory processes which underlie the plasticity of molecular profiles on different ome layers. We discuss the four major fields of omic research, namely genomics, transcriptomics, proteomics, and metabolomics, by providing specific examples and case studies for (i) the assessment of functionality on molecular, organism, and community level; (ii) the possibility to use omic research for categorization and systematic efforts; and (iii) the evaluation of responses to environmental cues with a special focus on anthropogenic influences. Thereby, we exemplify the knowledge gains attributable to the integration of information from different omes and the enhanced precision in predicting the phenotype. Lastly, we highlight the advantages of combining multiple omics layers in assessing the complexity of natural systems as meta-communities and -organisms.