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Awareness that our planet is a self-supporting biosphere with sunlight as its major source of energy for life has resulted in a long-term historical fascination with the workings of self-supporting ecological systems. However, the studies of such systems have never entered the canon of ecological or evolutionary tools and instead, have led a fringe existence connected to life support system engineering and space travel. We here introduce a framework for a renaissance in biospherics based on the study of matter-closed, energy-open ecosystems at a microbial level (microbial biospherics). Recent progress in genomics, robotics, and sensor technology makes the study of closed systems now much more tractable than in the past, and we argue that the time has come to emancipate the study of closed systems from this fringe context and bring them into a mainstream approach for studying ecosystem processes. By permitting highly replicated long-term studies, especially on predetermined and simplified systems, microbial biospheres offer the opportunity to test and develop strong hypotheses about ecosystem function and the ecological and evolutionary determinants of long-term system failure or persistence. Unlike many sciences, ecosystem ecology has never fully embraced a reductionist approach and has remained focused on the natural world in all its complexity. We argue that a reductionist approach to ecosystem ecology, using microbial biospheres, based on a combination of theory and the replicated study of much simpler self-enclosed microsystems could pay huge dividends.

A closed‐loop system that can mini‐invasively track blood glucose and intelligently treat diabetes is in great demand for modern medicine, yet it remains challenging to realize. Microneedles technologies have recently emerged as powerful tools for transdermal applications with inherent painlessness and biosafety. In this work, for the first time to the authors' knowledge, a fully integrated wearable closed‐loop system (IWCS) based on mini‐invasive microneedle platform is developed for in situ diabetic sensing and treatment. The IWCS consists of three connected modules: 1) a mesoporous microneedle‐reverse iontophoretic glucose sensor; 2) a flexible printed circuit board as integrated and control; and 3) a microneedle‐iontophoretic insulin delivery component. As the key component, mesoporous microneedles enable the painless penetration of stratum corneum, implementing subcutaneous substance exchange. The coupling with iontophoresis significantly enhances glucose extraction and insulin delivery and enables electrical control. This IWCS is demonstrated to accurately monitor glucose fluctuations, and responsively deliver insulin to regulate hyperglycemia in diabetic rat model. The painless microneedles and wearable design endows this IWCS as a highly promising platform to improve the therapies of diabetic patients. A fully integrated wearable closed‐loop system (IWCS) based on microneedle‐iontophoresis platform is developed for in situ diabetic sensing and treatment. This IWCS is demonstrated to accurately monitor glucose fluctuations and responsively deliver insulin to regulate hyperglycemia. The painless microneedles and wearable design endow this IWCS as a highly promising platform to improve the therapies of diabetic patients.

Transcranial focused ultrasound stimulation (tFUS) is an effective noninvasive treatment modality for brain disorders with high clinical potential. However, the therapeutic effects of ultrasound neuromodulation are not widely explored due to limitations in preclinical systems. The current preclinical studies are head‐fixed, anesthesia‐dependent, and acute, limiting clinical translatability. Here, this work reports a general‐purpose ultrasound neuromodulation system for chronic, closed‐loop preclinical studies in freely behaving rodents. This work uses microelectromechanical systems (MEMS) technology to design and fabricate a small and lightweight transducer capable of artifact‐free stimulation and simultaneous neural recording. Using the general‐purpose system, it can be observed that state‐dependent ultrasound neuromodulation of the prefrontal cortex increases rapid eye movement (REM) sleep and protects spatial working memory to REM sleep deprivation. The system will allow explorative studies in brain disease therapeutics and neuromodulation using ultrasound stimulation for widespread clinical adoption. This work demonstrates a chronic, artifact‐free, and closed‐loop ultrasound stimulation system based on a capacitive micromachined ultrasound transducer for neuromodulation of the medial prefrontal cortex in mice. Stimulation during non‐rapid eye movement (NREM) sleep modulates REM sleep characteristics and short‐term spatial working memory. Neuroprotective effects of REM sleep are observed, which negates the adverse effects of REM sleep deprivation in spatial working memory.

The worldwide fossil fuel reserves are rapidly and continually being depleted as a result of the rapid increase in global population and rising energy sector needs. Fossil fuels should not be used carelessly since they produce greenhouse gases, air pollution, and global warming, which leads to ecological imbalance and health risks. The study aims to discuss the alternative renewable energy source that is necessary to meet the needs of the global energy industry in the future. Both microalgae and macroalgae have great potential for several industrial applications. Algae-based biofuels can surmount the inadequacies presented by conventional fuels, thereby reducing the ‘food versus fuel’ debate. Cultivation of algae can be performed in all three systems; closed, open, and hybrid frameworks from which algal biomass is harvested, treated and converted into the desired biofuels. Among these, closed photobioreactors are considered the most efficient system for the cultivation of algae. Different types of closed systems can be employed for the cultivation of algae such as stirred tank photobioreactor, flat panel photobioreactor, vertical column photobioreactor, bubble column photobioreactor, and horizontal tubular photobioreactor. The type of cultivation system along with various factors, such as light, temperature, nutrients, carbon dioxide, and pH affect the yield of algal biomass and hence the biofuel production. Algae-based biofuels present numerous benefits in terms of economic growth. Developing a biofuel industry based on algal cultivation can provide us with a lot of socio-economic advantages contributing to a publicly maintainable result. This article outlines the third-generation biofuels, how they are cultivated in different systems, different influencing factors, and the technologies for the conversion of biomass. The benefits provided by these new generation biofuels are also discussed. The development of algae-based biofuel would not only change environmental pollution control but also benefit producers' economic and social advancement.

An improved prescribed performance control using a backstepping technique and adaptive fuzzy is proposed for a strict feedback nonlinear dynamic system. A new virtual variable was defined to generate the virtual control that forces the tracking errors to fall within prescribed boundaries, and an adaptive fuzzy system was used to obtain required approximation performances. A strict feedback controller and adaptive laws for estimating the unknown non-linear function were designed to avoid a singularity problem and calculation of the explosive number of terms generated by the error transformations of conventional error constraint method and the recursive steps of traditional backstepping control. Lyapunov stability analysis confirmed the boundedness and convergence of the closed-loop system. The prescribed error constraint performance of the proposed control scheme was validated by applying it to control the position of a second-order non-linear system and a robot manipulator.

Environmental DNA metabarcoding has been widely touted as a powerful tool for monitoring biodiversity in marine ecosystems. However, this method still requires thorough validation and standardization before it can be widely applied for ecological monitoring. The potential utility of environmental DNA metabarcoding is greatest in systems with high levels of diversity, yet environmental DNA metabarcoding has typically been validated in closed systems with relatively low levels of diversity. Additionally, the use of a multiple marker approach has been minimally explored under controlled, closed systems in the literature. Using a pilot study, we assess the ability of eDNA metabarcoding to capture biodiversity in a highly diverse closed system at the Ripley's Aquarium of Canada in Toronto, Ontario. Our pilot study highlights several key knowledge gaps that must be addressed before metabarcoding can be employed for widespread use in ecological monitoring. We found that environmental DNA metabarcoding recovered just over 50% of target species and 80% of target genera within a closed marine system containing 107 species and 44 genera using previously published markers for COI, 12S, and 16S. Additionally, COI and 12S were found to identify fewer target species than 16S, with COI generating the most off‐target identifications, but maximum detection success was achievable by combining all three markers. We discuss numerous key limitations which currently present barriers to the application of eDNA metabarcoding for studying highly diverse marine systems. These include marker selection, data validation and confidence, and the complexity of abundant and diverse novel systems. This study highlights important, yet incompletely resolved, challenges of environmental DNA metabarcoding for the detection of marine fishes in a diverse closed system environment using a multiple marker approach. This case study assesses the ability of eDNA metabarcoding to capture biodiversity in a closed system containing 107 species of marine fishes using previously published COI, 12S, and 16S primers. In doing so we were able to recover just over 50% of target species and 80% of target genera known to be present in the system, with differing performance by marker tested. We discuss numerous key limitations which currently present barriers for the application of eDNA metabarcoding for studying highly diverse marine systems identified while conducting this case study, including marker selection, data validation and confidence, and the complexity of abundant and diverse novel systems.

Advances in technology and improvement of efficacy for many neuromodulation applications have been achieved without understanding the relationship between the stimulation parameters and the neural activity which is generated in the nervous system. It is the neural activity that ultimately drives the therapeutic benefit and the advent of evoked compound action potential recording allows this activity to be directly measured and quantified. Closed-loop control adjusts the stimulation parameters to maintain a predetermined level of neural recruitment and has been shown to provide improved pain relief in individuals with spinal cord stimulators. However, no mechanism that relates more consistent neural recruitment to patient outcomes has been proposed. The authors propose a hypothesis that may explain the difference in efficacy between open- and closed-loop operational modes by considering the relationship between measured neural recruitment with hypothetical dose and side effect response curves. This provides a rational basis for directing clinical research and improving therapeutic systems.

Microalgae are versatile sources of bioproducts, a solution for many environmental problems. However, and despite its importance, one of the main problems in large-scale cultures—the presence of contaminants—is rarely systematically approached. Contamination, or the presence of undesirable organisms in a culture, is deleterious for the culture and frequently leads to culture crashes. To avoid contamination, closed systems can be used; however, for very large-scale open systems, contamination is unavoidable and remediation procedures are necessary—ranging from physicochemical treatment to addition of biocidal substances. In all cases, early detection and culture monitoring are paramount. This article describes the biological contaminants, contamination mechanisms, and control systems used in open and closed cultures, discussing the latest advances and techniques in the area. It also discusses the complex interactions of algae with other microorganisms that can be expected in cultivation systems.

1. Given their vulnerability to local extinction, the reintroduction of megafauna species (often long-lived, ecologically influential and highly social) is an increasingly relevant conservation intervention. Studies that evaluate past megafauna reintroductions are both critical and rare. 2. Between 1981 and 1996, 12 cohorts of a total of 200 juvenile (<5 years old) African savannah elephants Loxodonta africana africana were reintroduced to Hluhluwe-iMfolozi Park (HiP), South Africa, after 100 years of absence. Here, we model the population's long-term growth. We also present data on the current (2016) age class distribution and social dynamics of the population based on a year of intensive vehicle-based monitoring of 16 collared adult females and their family groups. 3. Exponential population growth (7.1% annual increase) between 1996 and 2014 suggests reintroduction success but has created concerns about overpopulation (with contraception of females implemented since 2014 to suppress reproduction). The age class distribution has normalized as the juveniles have aged; reproductive females (>10 years old) composed 30% of the population in 2016. The population remains relatively young and forecasts suggest high potential for sustained growth over the next decade. 4. The first calf was born to a reintroduced female in 1990 and since then mothercalf units have gradually developed into semi-independent multi-generation families (7-15 individuals in size in 2016). The size of observed cow-calf groups was highly variable (mean = 21.4 individuals, range: 7-109), with repeat observation of individual collared females revealing fusion and fission among different family groups through time, as is typical of more natural elephant populations. 5. Synthesis and applications. From an unusual founder population of reintroduced juvenile elephants, we document rapid population growth and the development of normal sociality over 35 years. While this may be an encouragement for megaherbivore reintroductions in general, the potential for exponential population growth must be carefully considered when ecologically influential species are introduced to closed systems. Our study provides key long-term insights for elephant translocations, which are becoming increasingly necessary due to overpopulation in some areas and local extinction in others.