Management strategy evaluation: a powerful tool for conservation?

The poor management of natural resources has led in many cases to the decline and extirpation of populations. Recent advances in fisheries science could revolutionize management of harvested stocks by evaluating management scenarios in a virtual world by including stakeholders and by assessing its robustness to uncertainty. These advances have been synthesized into a framework, management strategy evaluation (MSE), which has hitherto not been used in terrestrial conservation. We review the potential of MSE to transform terrestrial conservation, emphasizing that the behavior of individual harvesters must be included because harvester compliance with management rules has been a major challenge in conservation. Incorporating resource user decision-making required to make MSEs relevant to terrestrial conservation will also advance fisheries science.     

Biomass: Is it a useful tool in paleocommunity reconstruction?

In general, more of the biomass of the community is preserved than is its numerical abundance. Thus, the paleontologist, on the average, works with more of the community when biomass is used. Community characteristics such as taxon dominance and habitat proportions are at least as accurately derived from biomass as numerical abundance. The use of biomass is clearly more appropriate in describing energy flow and trophic proportions. Whenever possible, biomass should be used as a complement to numerical abundance in future paleoecologic reconstructions.     

Teleology in biology: Is it a cause for concern?

Evolutionary biology is distinctively forward looking or 'teleological' in its way of thought. In this, it distinguishes itself from the physical sciences. One can ask for the purpose or function of the stegoseaur's fins. One would never ask for the function of a planet. Many, including biologists, worry that such teleology is an unhappy legacy of a Christian past. Although teleology does have its roots in pre-evolutionary thought, there are good reasons why it has persisted, and there are equally good reasons why it should be cherished.     

CRISPR–Cas system: a powerful tool for genome engineering

Targeted gene regulation on a genome-wide scale is a powerful strategy for interrogating, perturbing, and engineering cellular systems. Recent advances with the RNA-mediated Cas9 endonuclease derived from clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) systems have dramatically transformed our ability to specifically modify intact genomes of diverse cells and organisms. The CRISPR–Cas system has been adapted as an efficient, facile, and robust gene-targeting technology with the potential for high-throughput and multiplexed genome engineering. Exciting breakthroughs in understanding the mechanisms of the CRISPR–Cas system and its enormous potential for applications across basic science, agricultural and biotechnology.     

Cortical plasticity: Is it time for a change?

Classical studies of plasticity in the visual cortex have been interpreted in terms of heterosynaptic competition between inputs. But an alternative type of 'homosynaptic' plasticity can explain many recent observations and has recently received experimental support. Perhaps both types of plasticity are important.     

Stimulating secondary compound accumulation by elicitation: Is it a realistic tool in medicinal plants in vivo?

Phytochemistry Reviews - Stimulating the production of secondary metabolites by elicitation seems to be an accepted tool in several in vitro cultures. In vivo application of chemical elicitation...     

Is amino acid racemization a useful tool for screening for ancient DNA in bone?

Many rare and valuable ancient specimens now carry the scars of ancient DNA research, as questions of population genetics and phylogeography require larger sample sets. This fuels the demand for reliable techniques to screen for DNA preservation prior to destructive sampling. Only one such technique has been widely adopted: the extent of aspartic acid racemization (AAR). The kinetics of AAR are believed to be similar to the rate of DNA depurination and therefore a good measure of the likelihood of DNA survival. Moreover, AAR analysis is only minimally destructive. We report the first comprehensive test of AAR using 91 bone and teeth samples from temperate and high-latitude sites that were analysed for DNA. While the AAR range of all specimens was low (0.02–0.17), no correlation was found between the extent of AAR and DNA amplification success. Additional heating experiments and surveys of the literature indicated that d/l Asx is low in bones until almost all the collagen is lost. This is because aspartic acid is retained in the bone within the constrained environment of the collagen triple helix, where it cannot racemize for steric reasons. Only if the helix denatures to soluble gelatin can Asx racemize readily, but this soluble gelatine is readily lost in most burial environments. We conclude that Asx d/l is not a useful screening technique for ancient DNA from bone.     

You talkin’ to me? Interactive playback is a powerful yet underused tool in animal communication research

Over the years, playback experiments have helped further our understanding of the wonderful world of animal communication. They have provided fundamental insights into animal behaviour and the function of communicative signals in numerous taxa. As important as these experiments are, however, there is strong evidence to suggest that the information conveyed in a signal may only have value when presented interactively. By their very nature, signalling exchanges are interactive and therefore, an interactive playback design is a powerful tool for examining the function of such exchanges. While researchers working on frog and songbird vocal interactions have long championed interactive playback, it remains surprisingly underused across other taxa. The interactive playback approach is not limited to studies of acoustic signalling, but can be applied to other sensory modalities, including visual, chemical and electrical communication. Here, I discuss interactive playback as a potent yet underused technique in the field of animal behaviour. I present a concise review of studies that have used interactive playback thus far, describe how it can be applied, and discuss its limitations and challenges. My hope is that this review will result in more scientists applying this innovative technique to their own study subjects, as a means of furthering our understanding of the function of signalling interactions in animal communication systems.     

Is it a revolution?

Jablonka and Lamb's claim that evolutionary biology is undergoing a ‘revolution’ is queried. But the very concept of revolutionary change has uncertain application to a field organized in the manner of contemporary biology. The explanatory primacy of sequence properties is also discussed.

Is pulse oximetry a reliable tool for detection of aspiration?

This study was designed to determine whether significant differences in saturation levels existed among patients with aspiration and patients without and wether pulse oximetry can reliably detect aspiration in patients with dysphagia. We also examined the effects of gender and disease (neurologic versus non neurologic) on saturation levels. We studied 38 patients. They all underwent a videofluoroscopic study of swallowing (VFSS). Twenty patients aspirated on videofluoroscopic study of swallowing: ten patients were solid aspirators, ten patients were liquid aspirators. In each group (liquid aspirators, solid aspirators or non aspirators) we found no significant difference in saturation levels. We found however a significant difference in saturation levels between each group before, during and after videofluoroscopic study of swallowing. Both gender and disease had an effect on saturation levels. We conclude that pulse oximetry can not serve as a screening tool for detection of aspiration as saturation levels are dependent on many factors. Therefore one can not reliably predict aspiration with a single saturation screening.     

Is prescribed fire a suitable management tool to reduce shrub encroachment in palm savannas?

Shrub encroachment in grasslands is a worldwide problem that has many ecological consequences, transforming previously open environments into dense forests. Disruption of natural fire regimes is one of the main causes of shrub encroachment, and the use of prescribed fire is a common strategy used to restore these ecosystems. In this study, we provide information about how a palm tree savanna under a process of shrub encroachment responds to the reintroduction of fire. We describe the effects of a first fire event on vegetation composition and structure using an experimental approach. We examine a species‐specific response to the fire. After one prescribed fire event applied to four study areas of 16 ha each, we analyzed the change in vegetation physiognomy and composition in burned and control plots for 1 year. Low‐intensity prescribed fire decreased height and cover of most shrub species and increased herbaceous vegetation cover over time. We classified shrub and herbaceous species response to fire according to the time they became present and their phenological characteristics. Our results can help stakeholders to determine if prescribed fire is helpful at reducing shrub encroachment in short term in similar ecosystems, considering how plant community responds to the reintroduction of fire after decades of fire suppression.     

Hyponatremia: Is it related to the seasons?

BackgroundHyponatremia is a common electrolyte disorder in inpatients related to morbidity and mortality. In this study, we aimed to examine whether there is a relationship between the incidence of hyponatremia and the seasons among the patients hospitalized in our nephrology department.MethodsThe inpatients in our Nephrology Department between 2012 and 2015 were retrospectively analyzed. The patients with serum sodium levels below 135 mmol/L were included in the study. Hyponatremia incidence was calculated as the proportion of inpatients with low sodium levels in a season to the total number of inpatients in the same season.ResultsOut of 1950 inpatients in four years, 509 were found to have hyponatremia (26.1%). The mean serum sodium level of the patients was 129.7±4.7 mmol/L. Hyponatremia incidences in autumn, winter, spring, and summer were found to be 28.7%, 15.4%, 20.4%, and 36.6%, respectively. Upon comparing the incidence of hyponatremia in patients hospitalized in winter and summer seasons, there was a significantly higher incidence of hyponatremia in summer (p<0.001). We found a positive correlation between hyponatremia incidence and temperature (r=0.867, p=0.001). However, there was a negative correlation between hyponatremia incidence and relative humidity (r=-0.735, p=0.001).ConclusionsThe highest hyponatremia incidence was observed in summer in a four-year period. Loss of sodium by perspiration, along with increased temperature and/or excessive hypotonic fluid intake, might contribute to the development of hyponatremia.