Skin and poison glands in toads (Rhinella) and their role in defence and water balance

Toads are considered poisonous animals since they have a passive mode of defence relying on cutaneous poison glands, differently from venomous animals who can inject venom in predators/aggressors or prey. Toads of Rhinella marina group are generally large and have a broad distribution in South America, inhabiting a wide range of environments. In this paper, we studied the toads Rhinella icterica from the Atlantic rainforest, and Rhinella jimi from the Brazilian Semiarid Caatinga, analysing aspects of natural history and comparing their skin morphology, the presence of macroglands, their resistance to water loss and rates of water uptake. In periods of extreme drought, R. jimi uses rock cracks as refuges, exposing only the head and regions of accumulation of poison glands. The skin of R. jimi showed higher number of poison glands with hydrophilic content than R. icterica. R. jimi also had a thicker skin, which can be related to its superior resistance to water loss. It also showed high rates of rehydration in association with a peculiar behaviour using the limbs to spread water onto highly glandular skin areas, suggesting that poison glands may also act in water balance in addition to chemical defence.     

Occupancy of young-of-year Arctic grayling (Thymallus arcticus) in Barrenland streams

Hydrobiologia - Arctic grayling (Thymallus arcticus) is an iconic fish species that is present across the remote subarctic Barrenlands, yet our lack of understanding of their distributional...     

A noninvasive and integrative approach for improving density and abundance estimates of moose

Acquiring demographic data for moose (Alces alces) can be difficult because they are solitary in nature, they prefer densely vegetated and mountainous habitats, and they often occur at low density. Such data, however, are essential for long-term population monitoring, evaluating management practices, and effective conservation. Winter aerial surveys are the standard method for estimating moose population parameters, but they can be logistically challenging, expensive, and subject to sightability correction, which necessitates the capture of study animals for initial model development. Herein, we demonstrate a noninvasive alternative approach for estimating population parameters of moose in northern Yellowstone National Park, where aerial surveys were attempted but proved ineffective. We determined individual moose genotype and sex using microsatellite polymerase chain reaction amplification of DNA extracted from fecal pellets, integrated ancillary pellet sample data (i.e., metadata) in genotype analysis to aid in the identification of matching genotypes, and used spatially explicit capture-recapture (SECR) modeling to estimate sex-specific density and abundance. We collected 616 samples over 3 consecutive winters (Dec 2013–Apr 2016) and within 2 sampling occasions each winter. We recorded 514 captures of 142 individual moose (69 males, 73 females). Overall density ranged between 0.062 moose/km² and 0.076 moose/km² and averaged 0.034/km² for females and 0.033/km² for males. Abundance estimates were 150 moose in 2013 (female = 76, 95% CI = 55–105; male = 74, 95% CI = 54–103), 186 in 2014 (female = 95, 95% CI = 63–142; male = 91, 95% CI = 60–138), and 160 in 2015 (female = 79, 95% CI = 58–108; male = 81, 95% CI = 59–110). Average population sex ratio was 0.99 males/female. We demonstrate that SECR analysis of fecal DNA genotypes, using metadata in genotype analysis to help identify matching moose genotypes, is a promising alternative method for estimating sex-specific density and abundance of a low-density moose population in a mountainous and forested landscape.     

Correction to: Early detection monitoring for non-indigenous fishes; comparison of survey approaches during two species introductions in a Great Lakes port

Biological Invasions -     

Delimitation of the genus Schizachyrium (Poaceae,Andropogoneae) based on molecular and morphological data

Schizachyrium (Poaceae, Andropogoneae) includes about 60 species distributed in tropical and subtropical regions of the world. In all recent molecular phylogenies of Andropogoneae, representatives of Schizachyrium appear closely related to Andropogon species. The objective of this study was to contribute to the delimitation of Schizachyrium. We performed a phylogenetic study including 38 taxa (>63%) of Schizachyrium, along with representatives of related genera, mainly of Andropogon, yielding a total of 49 taxa. This is the first phylogenetic analysis to include the type species of Schizachyrium, S. condensatum. DNA sequences of two plastid markers (ndhF and trnL-F) were analyzed under Bayesian methods. The results indicate that Schizachyrium is not monophyletic: 26 of the 38 Schizachyrium taxa analyzed are placed in a Schizachyrium s.s. clade that includes the type species of the genus, while 10 taxa are related to Andropogon species and two other species, S. delavayi (from China and India) and S. jeffreysii (from Africa), appear clearly separated. Additionally, 58 morphological characters (41 qualitative and 17 quantitative) were scored for the same 49 taxa and analyzed under the parsimony criterion. Character optimizations showed that (i) the reduced pedicellate spikelets, (ii) with lower glume less than or equal to 0.5 mm wide, (iii) awned, and (iv) without lemma and palea support the Schizachyrium s.s. clade. We propose these four characters as diagnostic features for the delimitation of Schizachyrium s.s.     

Updated geographic range maps for giraffe,Giraffa spp., throughout sub‐Saharan Africa,and implications of changing distributions for conservation

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The diversity and host interactions of Propionibacterium acnes bacteriophages on human skin

The viral population, including bacteriophages, is an important component of the human microbiota, yet is poorly understood. We aim to determine whether bacteriophages modulate the composition of the bacterial populations, thus potentially playing a role in health or disease. We investigated the diversity and host interactions of the bacteriophages of Propionibacterium acnes, a major human skin commensal implicated in acne pathogenesis. By sequencing 48 P. acnes phages isolated from acne patients and healthy individuals and by analyzing the P. acnes phage populations in healthy skin metagenomes, we revealed that P. acnes phage populations in the skin microbial community are often dominated by one strain. We also found phage strains shared among both related and unrelated individuals, suggesting that a pool of common phages exists in the human population and that transmission of phages may occur between individuals. To better understand the bacterium–phage interactions in the skin microbiota, we determined the outcomes of 74 genetically defined Propionibacterium strains challenged by 15 sequenced phages. Depending on the Propionibacterium lineage, phage infection can result in lysis, pseudolysogeny, or resistance. In type II P. acnes strains, we found that encoding matching clustered regularly interspaced short palindromic repeat spacers is insufficient to confer phage resistance. Overall, our findings suggest that the prey–predator relationship between bacteria and phages may have a role in modulating the composition of the microbiota. Our study also suggests that the microbiome structure of an individual may be an important factor in the design of phage-based therapy.     

Life cycle assessment of electricity generation: a review of the characteristics of existing literature

Purpose

The environmental impacts of electricity generation are a critical issue towards sustainability and thus an important research topic in several countries. The life cycle assessment methodology has been widely employed to assess electricity generation. However, there are still gaps in research to be explored within this theme. Therefore, this paper aims to conduct a systematic theoretical analysis of the state of the art of the scientific research on LCA of electricity generation systems in the world.

Methods

A critical review of 47 studies was conducted. The study is comprehensive in the analysis of the main aspects of the identified high impact studies as follows: authors, countries, universities, keywords, journals, number of citations, life cycle impact assessment methods, impact categories, software tools, and databases. The Methodi Ordinatio was applied to rank the studies in terms of impact factor and number of citations, pointing out high impact research.

Results and discussion

Wind and solar powers have two of the smallest impact indices in their generation in terms of global warming, compared to other sources. The ecoinvent database was the most used among the studies analyzed, providing data for potential environmental impacts. The most frequently used impact category in the assessments was climate change. The studies are not equally distributed but most of them are concentrated in European countries. In some countries, clean sources seem promising due to their capacity to generate electricity in places with high wind incidence and high capacity for sunlight capture.

Conclusions

The conclusions of this article summarize the characteristics of existing literature and provide suggestions for future work. The results of the study can also be used to promote development actions and foment changes in energy matrices in a global context. The main studies in this area point that in the future, the main sources for electricity generation will be renewable ones, since life cycle assessment of electricity generation systems has been seeking to generate knowledge to support informed decision-making.