Can zebrafish be used as a model to study the neurodevelopmental causes of autism?

The zebrafish has proven to be an excellent model for analyzing issues of vertebrate development. In this review we ask whether the zebrafish is a viable model for analyzing the neurodevelopmental causes of autism. In developing an answer to this question three topics are considered. First, the general attributes of zebrafish as a model are discussed, including low cost maintenance, rapid life cycle and the multitude of techniques available. These techniques include large-scale genetic screens, targeted loss and gain of function methods, and embryological assays. Second, we consider the conservation of zebrafish and mammalian brain development, structure and function. Third, we discuss the impressive use of zebrafish as a model for human disease, and suggest several strategies by which zebrafish could be used to dissect the genetic basis for autism. We conclude that the zebrafish system could be used to make important contributions to understanding autistic disorders.     

Can MTT be used to quantify the antioxidant activity of plant extracts?

Antioxidant properties of three different medicinal plant extracts from northern Nigeria were evaluated using the traditional qualitative 2,2, diphenyl-picrylhydrazyl (DPPH) method and a new 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) microdilution method described here. The results were in agreement. It is a simple, rapid and inexpensive method compared with many other methods for determining quantitative antioxidant activity of plant extracts.     

Can model species be used to advance the field of invasion ecology?

Hypotheses for explaining plant invasions have focused on a variety of factors that may influence invasion success, including propagule pressure, interactions of the introduced species with the biotic, abiotic, or disturbance properties of the new ecosystem, or the genetic characteristics of the invader itself. Evaluating the relative importance of these factors has been difficult because for most invaders key information about the introduced population or the introduction event is not available. We propose that natural experiments using model species is an important tool to test multiple invasion hypotheses at the same time, providing a complementary approach to meta-analysis and literature review. By focusing on a single candidate species, Pinus contorta, we explore several attributes that we propose constitute a good model, including: (a) intentional and relatively well documented introduction into a wide range of environments and countries across the world during the past century, where invasion success or failure has already occurred, (b) conspicuous growth form that simplifies assessment of growth rates, and comparisons across native and introduced ecosystems around the world, and, (c) documented and replicated variability of introduction intensity, genetic characteristics of the introduced populations, contrasting biotic communities present at sites of introduction, and abiotic conditions within and across introduced ecosystems. We propose that identifying model species with these characteristics will provide opportunities to disentangle the relative importance of different mechanisms hypothesized to influence invasion success, and thereby advance the field of invasion ecology.     

Can Wolbachia be used to control malaria?

Malaria is a mosquito-borne infectious disease caused by Plasmodium parasites transmitted by the infectious bite of Anopheles mosquitoes. Vector control of malaria has predominantly focused on targeting the adult mosquito through insecticides and bed nets. However, current vector control methods are often not sustainable for long periods so alternative methods are needed. A novel biocontrol approach for mosquito-borne diseases has recently been proposed, it uses maternally inherited endosymbiotic Wolbachia bacteria transinfected into mosquitoes in order to interfere with pathogen transmission. Transinfected Wolbachia strains in Aedes aegypti mosquitoes, the primary vector of dengue fever, directly inhibit pathogen replication, including Plasmodium gallinaceum, and also affect mosquito reproduction to allow Wolbachia to spread through mosquito populations. In addition, transient Wolbachia infections in Anopheles gambiae significantly reduce Plasmodium levels. Here we review the prospects of using a Wolbachia-based approach to reduce human malaria transmission through transinfection of Anopheles mosquitoes.     

Can periods of static loading be used to enhance the resistance of the spine to cumulative compression?

Results of in vitro studies conducted on isolated bone specimens have indicated a higher tolerance to static load than exists when exposed to cyclic loading, when controlled for creep rate. If this difference in load tolerance exists, it may be exploited to extend the life of vertebral bone exposed to repetitive compression, and potentially alter the development of spinal injury. However, little work has been conducted on functional spinal units to determine if bone displays this characteristic within an intact joint. Additionally, static loading may result in load redistribution within the intervertebral disc forcing more of the compressive load towards the periphery of the endplate away from the nucleus. In order to examine these potential mechanisms, 218 osteoligamentous porcine functional spinal units were assigned to one of 15 loading scenarios. This involved one of three normalized peak load magnitudes (50%, 70% and 90% of estimated compressive tolerance) and one of five normalized static load applications (0%, 50%, 100%, 200% and 1000% of the total dynamic work duration). Load magnitude significantly altered the resistance to cumulative compression with decreased peak magnitudes corresponding to both increased cumulative load tolerance and increased height loss. Static load periods did not alter the resistance of the spinal unit to cumulative compression or impact the number of cycles tolerated to failure. The insertion of static load periods impacted the total survival time to failure, but only for the 1000% static load group, an exposure unlikely to occur for most in vivo exposures. The insertion of static load periods decreased the amount of height loss during testing which may play a protective role by allowing load redistribution within the vertebral bone and intervertebral disc.     

Can the dual-functional capability of CIK cells be used to improve antitumor effects?

Cytokine-induced killer (CIK) cells, which display both potent anti-tumor ability of T lymphocytes and non-major histocompatibility complex (MHC) restricted killing tumor cells capacity of natural killer (NK) cells are capable of recognizing and lysing a broad array of tumor targets. They have begun to be used in clinical care with good prospects for treatment success. CIK cells are a heterogeneous cell population that contain CD3⁺CD56⁺ cells, CD3⁻CD56⁺ natural killer (NK) cells and CD3⁺CD56⁻ T cells on which much attention has been focused. This review will summarize the connections and differences among CD3⁺CD56⁺CIK cells, CD3⁻CD56⁺ NK cells and CD3⁺CD56⁻ T cells in the following aspects: the main cell surface molecule, killing mechanism, and clinical applications so that treatment with CIK cells can be optimized and further to enhance the antitumor effect.     

Can transposable elements be used to drive disease refractoriness genes into vector populations?

A number of biological procedures are currently being considered as alternatives to insecticide-based methods for the control of insect vectors of disease. Among these are the adaptation of various genetic mechanisms to drive genes of interest, such as refractoriness to malaria in mosquitoes, into natural populations, for vector control purposes. Here, Margaret Kidwell and Jose Ribeiro develop a rationale for the possible use of transposable genetic elements, one of these potential drive mechanisms, and some of the problems being faced in seeking to determine the feasibility of such a strategy are described.     

Can yeast be used to study mitochondrial diseases? Biolistic tRNA mutants for the analysis of mechanisms and suppressors

Base substitutions equivalent to those causing human pathologies have been introduced in yeast mitochondrial tRNA genes. These mutants can be utilized as flexible tools to investigate the molecular aspects of mitochondrial diseases and identify correcting genes. We show that for all studied tRNA mutations (including an homoplasmic one in tRNA^Val) the severity of phenotypes follows the same trend in four different nuclear backgrounds. Correcting genes include TUF1 and genes encoding aminoacyl-tRNA synthetase. The effect of suppressors was analyzed by Northern blot. Mutated leucyl-tRNA synthetase with highly reduced catalytic activity maintains full suppressing effect, thus suggesting a chaperone-like and/or stabilizing function.     

Can ultrasound be used to stimulate nerve tissue?

Background  

The stimulation of nerve or cortical tissue by magnetic induction is a relatively new tool for the non-invasive study of the brain and nervous system. Transcranial magnetic stimulation (TMS), for example, has been used for the functional mapping of the motor cortex and may have potential for treating a variety of brain disorders.     

Can the narrow red bands of dragonflies be used to perceive wing interference patterns?

Despite numerous studies of selection on position and number of spectral vision bands, explanations to the function of narrow spectral bands are lacking. We investigate dragonflies (Odonata), which have the narrowest spectral bands reported, in order to investigate what features these narrow spectral bands may be used to perceive. We address whether it is likely that narrow red bands can be used to identify conspecifics by the optical signature from wing interference patterns (WIPs). We investigate the optical signatures of Odonata wings using hyperspectral imaging, laser profiling, ellipsometry, polarimetric modulation spectroscopy, and laser radar experiments. Based on results, we estimate the prospects for Odonata perception of WIPs to identify conspecifics in the spectral, spatial, intensity, polarization, angular, and temporal domains. We find six lines of evidence consistent with an ability to perceive WIPs. First, the wing membrane thickness of the studied Odonata is 2.3 μm, coinciding with the maximal thickness perceivable by the reported bandwidth. Second, flat wings imply that WIPs persist from whole wings, which can be seen at a distance. Third, WIPs constitute a major brightness in the visual environment only second after the solar disk. Fourth, WIPs exhibit high degree of polarization and polarization vision coincides with frontal narrow red bands in Odonata. Fifth, the angular light incidence on the Odonata composite eye provides all prerequisites for direct assessment of the refractive index which is associated with age. Sixth, WIPs from conspecifics in flight make a significant contribution even to the fundamental wingbeat frequency within the flicker fusion bandwidth of Odonata vision. We conclude that it is likely that WIPs can be perceived by the narrow red bands found in some Odonata species and propose future behavioral and electrophysiological tests of this hypothesis.     

Can neuroscience be integrated into the DSM-V?

To date, the diagnosis of mental disorders has been based on clinical observation, specifically: the identification of symptoms that tend to cluster together, the timing of the symptoms' appearance, and their tendency to resolve, recur or become chronic. The Diagnostic and Statistical Manual of Mental Disorders and the International Classification of Disease, the manuals that specify these diagnoses and the criteria for making them, are currently undergoing revision. It is thus timely to ask whether neuroscience has progressed to the point that the next editions of these manuals can usefully incorporate information about brain structure and function.     

Can observation of climatic variables be used to predict the flight dispersal rates of Prostephanus truncatus?

Abstract 1 Attack by Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) on the maize and cassava stored by small‐holder farmers in Africa is sporadic, varying considerably within and between years. The risk that food in store will become infested is related to the number of beetles dispersing by flight. A means of predicting years with high dispersal rates is needed to warn farmers when to be vigilant. 2 The relationship between climatic variables and pheromone trap catches was observed in a forest‐savannah transition zone in Ghana. These observations were used to devise a model using a mix of biological and empirical rules that operate on temperature and humidity data. The predicted and actual trap catch deviated by only +5% to ?1% in years when there were high dispersal rates. 3 The first part of the model estimates the numbers of beetles with potential for dispersal. The second part predicts the proportion likely to disperse. This is based on the apparent effect that those P. truncatus developing under low temperature conditions (about 24 °C) have a lowered propensity for flight, a response previously observed in a related species. 4 The model was validated using climate data and trap catches from a woodland–savannah zone and a short grass steppe zone. With minor adjustment, the model worked well for these two habitats.     

Can sugarcoated fingerprints be used to identify lurking viruses?

Comparative proteomics is increasingly used to detect biomarkers and therapeutic targets that differ between healthy and diseased populations; however, differences in posttranslational modifications have received less attention. In this issue, Yang et al. (Proteomics 2016, 16, 1872–1880) present data indicating that a glycoproteomics approach can detect N‐glycosylated membrane protein differences between non‐HIV‐infected and latently infected human CD4⁺ T‐cell lines, identifying 172 proteins differentially expressed by these cells. Latently infected CD4⁺ T cells are thought to represent the major barrier to eventual HIV cure, but do not express detectable levels of viral protein and have not been shown to express biomarkers that can distinguish them from the vastly more abundant uninfected CD4⁺ T‐cell population. The findings of Yang et al. suggest that glycoproteomic analyses may have untapped potential to identify novel biomarkers and therapeutic targets in cell populations not readily distinguishable be standard proteomic analyses.     

Can ecological theory be used to improve water quality?

The role of ecology in environmental management has been more to warn of the dangers of pollution than to propose technical solutions for environmental problems, this being mostly left to chemists and engineers. Only limited aspects of the broad and diverse theory of ecology have been applied in the present bottom-up-control approach to water management (nutrient reduction). Another aspect of ecological theory which has recently become applicable is the top-down-control approach known as biomanipulation (promoting efficient herbivores). Both approaches are likely to be reinforced in the future by further application of ecological theory to water management. Of the multiple possibilities of applying ecological theory to environmental problems, one is the use of our knowledge on chemical communication in aquatic habitats, the phenomena by which prey detect the presence of their predators. I postulate that the phytoplankton standing crop might be reduced by chemical regulation of the physiology and life cycles of algae and cyanobacteria, as well as by chemical regulation of the behaviour and life histories of planktonic herbivores and their predators. At present planktivorous fish seem to be the most logical target for such chemical manipulation. A desirable effect, i.e. a reduction in algal standing crop, could be achieved by scaring fish from the lake pelagial thus releasing predation pressure on the offshore herbivorous zooplankton.     

Can ribozymes be used to regulate procaryote gene expression?

The in vivo activity of ribozymes designed against mRNA coding for E. coli beta-galactosidase was tested both in intramolecular and in intermolecular conditions. When recombinant M13 phage DNA carrying on the same molecule the information for both the ribozyme and the target was transfected into bacterial cells, ribozyme activity was observed. Conversely, a ribozyme coded by a recombinant M13 vector, but targeted against an mRNA transcribed from the F episome including the remaining part of the beta-galactosidase gene, was inefficient.     

Can treadmill walking be used to assess propulsion generation?

Instrumented treadmills offer significant advantages for analysis of human locomotion, including recording consecutive steady-state gait cycles, precisely controlling walking speed, and avoiding force plate targeting. However, some studies of hemiparetic walking on a treadmill have suggested that the moving treadmill belt may fundamentally alter propulsion mechanics. Any differences in propulsion mechanics during treadmill walking would be problematic since recent studies assessing propulsion have provided fundamental insight into hemiparetic walking. The purpose of this study was to test the hypothesis that there would be no difference in the generation of anterior/posterior (A/P) propulsion by performing a carefully controlled comparison of the A/P ground reaction forces (GRFs) and impulses in healthy adults during treadmill and overground walking. Gait data were collected from eight subjects walking overground and on a treadmill with speed and cadence controlled. Peak negative and positive horizontal GRFs in early and late stance, respectively, were reduced by less than 5% of body weight (p<0.05) during treadmill walking compared to overground walking. The magnitude of the braking impulse was similarly lower (p<0.05) during treadmill walking, but no significant difference was found between propulsion impulses. While there were some subtle differences in A/P GRFs between overground and treadmill walking, these results suggest there is no fundamental difference in propulsion mechanics. We conclude that treadmill walking can be used to investigate propulsion generation in healthy and by implication clinical populations.