36 research outputs found
Manual mapping of drumlins in synthetic landscapes to assess operator effectiveness
Mapped topographic features are important for understanding processes that sculpt the Earth's surface. This paper presents maps that are the primary product of an exercise that brought together 27 researchers with an interest in landform mapping wherein the efficacy and causes of variation in mapping were tested using novel synthetic DEMs containing drumlins. The variation between interpreters (e.g. mapping philosophy, experience) and across the study region (e.g. woodland prevalence) opens these factors up to assessment. A priori known answers in the synthetics increase the number and strength of conclusions that may be drawn with respect to a traditional comparative study. Initial results suggest that overall detection rates are relatively low (34–40%), but reliability of mapping is higher (72–86%). The maps form a reference dataset
CO2 bioremediation by microalgae in photobioreactors: impacts of biomass and CO2 concentrations, light, and temperature
Microalgae have the potential to recycle and bioremediate CO2 and also produce chemical energy in the form of biomass. The potential production of renewable energy and high value products (i.e. carotenoid, antioxidants and polyunsaturated fatty acids) makes large scale microalgal cultivation an attractive application. To achieve high productivity all microalgae cultures require CO2 addition. Various microalgae species have shown different capabilities to bioremediate CO2. This review article reports biomass concentrations, biomass productivities, and CO2 fixation rates of several microalgae and cyanobacteria species under different input CO2 concentrations. The effects of important factors such as type of photobioreactor, temperature, and light intensity on CO2 removal are also discussed
Data from: Context-dependent scaling of kinematics and energetics during contests and feeding in mantis shrimp
Measurements of energy use, and its scaling with size, are critical to understanding how organisms accomplish myriad tasks. For example, energy budgets are central to game theory models of assessment during contests and underlie patterns of feeding behavior. Clear tests connecting energy to behavioral theory require measurements of the energy use of single individuals for particular behaviors. Many species of mantis shrimp (Stomatopoda: Crustacea) use elastic energy storage to power high-speed strikes that they deliver to opponents during territorial contests and to hard-shelled prey while feeding. We compared the scaling of strike kinematics and energetics between feeding and contests in the mantis shrimp Neogonodactylus bredini. We filmed strikes with high-speed video, measured strike velocity, and used a mathematical model to calculate strike energy. During contests, strike velocity did not scale with body size but strike energy scaled positively with size. Conversely, while feeding, strike velocity decreased with increasing size and strike energy did not vary according to body size. Individuals most likely achieved this strike variation through differential compression of their exoskeletal spring prior to the strike. Post-hoc analyses found that N. bredini used greater velocity and energy when striking larger opponents, yet variation in prey size was not accompanied by varying strike velocity or energetics. Our estimates of energetics inform prior tests of contest and feeding behavior in this species. More broadly, our findings elucidate the role behavioral context plays in measurements of animal performance
CO2 environmental bioremediation by microalgae
Various microalgae species have shown a differential ability to bioremediate atmospheric CO2 . This chapter reports biomass concentration , biomass productivity , and CO2 fixation rates of several microalgae and cyanobacteria species under different CO2 concentrations and culture conditions. Research indicates that microalgal species of Scenedesmuss obliquss , Duniella tertiolecta , Chlorella vulgaris , Phormidium sp. , Amicroscopica negeli , and Chlorococcum littorale are able to bioremediate CO2 more effectively than other species. Furthermore, coccolithophorid microalgae such as Chrysotila carterae were also found to effectively bioremediate CO2 into organic biomass and generate inorganic CaCO3 as additional means of removing atmospheric CO2 . Important factors to increase the rate of CO2 bioremediation such as initial cell concentration , input CO2 concentration , and aeration rate are reviewed and discussed
Larval zebrafish rapidly sense the water flow of a predator's strike
Larval fishes have a remarkable ability to sense and evade the feeding strike of a predator fish with a rapid escape manoeuvre. Although the neuromuscular control of this behaviour is well studied, it is not clear what stimulus allows a larva to sense a predator. Here we show that this escape response is triggered by the water flow created during a predator's strike. Using a novel device, the impulse chamber, zebrafish (Danio rerio) larvae were exposed to this accelerating flow with high repeatability. Larvae responded to this stimulus with an escape response having a latency (mode=13–15 ms) that was fast enough to respond to predators. This flow was detected by the lateral line system, which includes mechanosensory hair cells within the skin. Pharmacologically ablating these cells caused the escape response to diminish, but then recover as the hair cells regenerated. These findings demonstrate that the lateral line system plays a role in predator evasion at this vulnerable stage of growth in fishes
Ototoxin-induced cellular damage in neuromasts disrupts lateral line function in larval zebrafish
The ototoxicity of a number of marketed drugs is well documented, and there is an absence of convenient techniques to identify and eliminate this unwanted effect at a pre-clinical stage. We have assessed the validity of the larval zebrafish, or more specifically its lateral line neuromast hair cells, as a microplate-scale in vivo surrogate model of mammalian inner ear hair cell responses to ototoxin exposure. Here we describe an investigation of the pathological and functional consequences of hair cell loss in lateral line neuromasts of larval zebrafish after exposure to a range of well known human and non-human mammalian ototoxins. Using a previously described histological assay, we show that hair cell damage occurs in a concentration-dependent fashion following exposure to representatives from a range of drug classes, including the aminoglycoside antibiotics, salicylates and platinum-based chemotherapeutics, as well as a heavy metal. Furthermore, we detail the optimisation of a semi-automated method to analyse the stereotypical startle response in larval zebrafish, and use this to assess the impact of hair cell damage on hearing function in these animals. Functional assessment revealed robust and significant attenuation of the innate startle, rheotactic and avoidance responses of 5 day old zebrafish larvae after treatment with a number of compounds previously shown to induce hair cell damage and loss. Interestingly, a startle reflex (albeit reduced) was still present even after the apparent complete loss of lateral line hair cell fluorescence, suggesting some involvement of the inner ear as well as the lateral line neuromast hair cells in this reflex response. Collectively, these data provide evidence to support the use of the zebrafish as a pre-clinical indicator of drug-induced histological and functional ototoxicity
Novel Cleft Susceptibility Genes in Chromosome 6q
Cleft lip/palate is a defect of craniofacial development. In previous reports, chromosome 6q has been suggested as a candidate region for cleft lip/palate. A multipoint posterior probability of linkage analysis of multiplex families from the Philippines attributed an 88% probability of harboring a cleft-susceptibility gene to a narrower region on bands 6q14.2-14.3. We genotyped 2732 individuals from families and unrelated individuals with and without clefts to investigate the existence of possible cleft-susceptibility genes in this region. We found association of PRSS35 and SNAP91 genes with cleft lip/palate in the case-control cohort and in Caucasian families. Haplotype analyses support the individual associations with PRSS35. We found Prss35 expression in the head and palate of mouse embryos at critical stages for palatogenesis, whereas Snap91 was expressed in the adult brain. We provide further evidence of the involvement of chromosome 6q in cleft lip/palate and suggest PRSS35 as a novel candidate gene
Manual mapping of drumlins in synthetic landscapes to assess operator effectiveness
Mapped topographic features are important for understanding processes that sculpt the Earth's surface. This paper presents maps that are the primary product of an exercise that brought together 27 researchers with an interest in landform mapping wherein the efficacy and causes of variation in mapping were tested using novel synthetic DEMs containing drumlins. The variation between interpreters (e.g. mapping philosophy, experience) and across the study region (e.g. woodland prevalence) opens these factors up to assessment. A priori known answers in the synthetics increase the number and strength of conclusions that may be drawn with respect to a traditional comparative study. Initial results suggest that overall detection rates are relatively low (34–40%), but reliability of mapping is higher (72–86%). The maps form a reference dataset