Effects of Nitrogen Deposition on the Abundance and Metabolism of Lichens: A Meta-analysis

Lichens are the key to nutrient cycling and trophic networks in many terrestrial ecosystems and are good bioindicators of air pollution, including nitrogen (N) deposition. Experimental studies have shown that N deposition can reduce the abundance of lichens and alter their thallus chemistry and metabolism, but we currently lack information about how widespread this effect is and what are the environmental factors modulating the response of lichens to N. We carried out a meta-analysis of the literature about the effects of experimental N fertilization on lichen abundance and metabolism. We found thirty-nine articles from thirty-one experimental sites that met our search criteria. These studies showed that the addition of N accelerates lichen metabolism in the short term and decreases their abundance in the medium–long term. Early senescence of lichens is proposed as a possible mechanism linking the two observed responses. Chlorolichens from regions with high precipitation (> 1000 mm) and with a background N deposition of mixed origin (agricultural and industrial) were the most affected by N, in terms of both abundance and metabolism. Structural equation modelling showed that the rate of N addition was the main factor in modulating the response of lichens to N in terms of metabolism, whereas isothermality played a very important role in modulating the lichen response to N in terms of abundance. Our meta-analysis identified that excess N deposition reduces lichen abundance and increases the metabolism of sensitive species, especially across European ecosystems; lichens from more climatically benign regions (that is, greater precipitation and isothermality) are the most affectedROH initiated this study being funded by a Juan de la Cierva-Incorporación Fellowship (JCI-2014-21252) from MINECO and finished it with the support of a Ramón y Cajal Fellowship (RYC-2017-22032) from MICIU. All data used in this study can be accessed from Ochoa-Hueso and Gutierrez-Larruga (2019)

Current and historical factors drive variation of reproductive traits in unisexual mosses in Europe: A case study

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, los autores pertenecientes a la UAM y el nombre del grupo de colaboración, si lo hubiereUnisexual bryophytes provide excellent models to study the mechanisms that regulate the frequency of sexual versus asexual reproduction in plants, and their ecological and evolutionary implications. Here, we determined sex expression, phenotypic sex ratio, and individual shoot traits in 242 populations of the cosmopolitan moss Pseudoscleropodium purum spanning its whole distributional range. We tested whether niche differentiation, sex‐specific differences in shoot size, and biogeographical history explained the spatial variation of reproductive traits. We observed high levels of sex expression and predominantly female‐biased populations, although both traits showed high intraspecific variation among populations. Sex expression and sex ratio were partly explained by current macroscale environmental variation, with male shoots being less frequent at the higher end of the environmental gradients defined by the current distribution of the species. Female bias in population sex ratio was significantly lower in areas recolonized after the last glacial maximum (recent populations) than in glacial refugia (long‐term persistent populations). We demonstrated that reproductive trait variation in perennial unisexual mosses is partially driven by macroscale and historical environmental variation. Based on our results, we hypothesize that sexual dimorphism in environmental tolerance and vegetative growth contribute to sex ratio bias over time, constraining the chances of sexual reproduction, especially in long‐term persistent populations. Further studies combining genetic analyses and population monitoring should improve our understanding of the implications of the intraspecific variation in the frequency of sexual versus asexual reproduction in bryophyte population fitness and eco‐evolutionary dynamic

Copper content and resistance mechanisms in the terrestrial moss ptychostomum capillare: A case study in an abandoned Copper Mine in Central Spain

We present a case study on the tissue absorption of copper of a widely distributed moss species, Ptychostomum capillare in the polluted soil of an abandoned copper mine in central Spain. We studied the soil properties in a copper soil pollution gradient and sampled the moss tufts growing on them in four plots with contrasted soil copper levels. We determined the copper content in the soil and in the moss tissues. On these moss samples, we also performed histochemical tests and X-ray dispersive spectrometry coupled with scanning electron microscopy (SEM-EDX), both in untreated shoots and in samples where surface waxes were removed. We checked the behavior of this species using a metallophillous moss, Scopelophila cataractae, for comparative purposes. Copper contents in P. capillare seem to depend more on available, rather than total soil copper contents. Our results indicate that this moss is able to concentrate 12-fold the available soil copper in soil with low available copper content, whereas in the most polluted soil the concentration of Cu in the moss was only half those levels. Both histochemical and SEM-EDX tests show no surface copper in the mosses from the least polluted plot, whereas in samples from the soil with highest copper content, the removal of surface waxes also reduces or removes copper from the moss shoots. Our observations point at a mixed strategy in P. capillare in this copper mine, with metal accumulation behavior in the lowest Cu plot, and an exclusion mechanism involving wax-like substances acting as a barrier in the most polluted plots. These distortions impede the estimation of environmental levels and thus compromise the value of this moss in biomonitoring. We highlight the need of extending these studies to other moss species, especially those used in biomonitoring program

The use of the fluorescente for the study of the water quality

We present a work proposal now in course that is based on the study of the fluorescence in cyanobacteria and toxicity, and the possibility of detecting their presence in freshwater environment, with a direct application in water assessment. The proposal is a consequence of a previous study about the fluorescence generated by hydrocarbon residue on the sea surface. In the first part of this work we present a review of results obtained from the analysis of hydrocarbon samples from the “prestige” oil spill accident and other referential hydrocarbons. In the second part we show the capability of this technique for the development of probes to explore the water quality

Dysregulated cell homeostasis and miRNAs in human iPSC-derived cardiomyocytes from a propionic acidemia patient with cardiomyopathy

Propionic acidemia (PA) disorder shows major involvement of the heart, among other alterations. A significant number of PA patients develop cardiac complications, and available evidence suggests that this cardiac dysfunction is driven mainly by the accumulation of toxic metabolites. To contribute to the elucidation of the mechanistic basis underlying this dysfunction, we have successfully generated cardiomyocytes through the differentiation of induced pluripotent stem cells (iPSCs) from a PCCB patient and its isogenic control. In this human cellular model, we aimed to examine microRNAs (miRNAs) profiles and analyze several cellular pathways to determine miRNAs activity patterns associated with PA cardiac phenotypes. We have identified a series of upregulated cardiac-enriched miRNAs and alterations in some of their regulated signaling pathways, including an increase in the expression of cardiac damage markers and cardiac channels, an increase in oxidative stress, a decrease in mitochondrial respiration and autophagy; and lipid accumulation. Our findings indicate that miRNA activity patterns from PA iPSC-derived cardiomyocytes are biologically informative and advance the understanding of the molecular mechanisms of this rare disease, providing a basis for identifying new therapeutic targets for intervention strategie

Moss establishment success is determined by the interaction between propagule size and species identity

Colonization of new habitat patches is a key aspect of metacommunity dynamics, particularly for sessile organisms. Mosses can establish in new patches through fragmentation, with different vegetative structures acting as propagules. Despite the importance of these propagules for successful colonization the specific aspects that favour moss colonization by vegetative propagules remain poorly understood, including the effect of propagule size. We examine the intra- and interspecific variation of establishment and colonization success in culture of propagules of different sizes in six widespread soil moss species of contrasting growth form (Dicranum scoparium, Homalothecium aureum, Hypnum cupressiforme, Ptychostomum capillare, Syntrichia ruralis and Tortella squarrosa). We obtained three different size classes of propagules from artificially fragmented vegetative material, and assessed their establishment under controlled light and temperature conditions. We characterize the size, shape, apparent viability, morphological type and size changes due to hydration states of the propagules, all of them traits with potentially significant influence in their dispersal pattern and establishment. Then we assess the effect of these traits on moss establishment, using indicators of surface establishment (number of established shoots and colonized surface) and biomass production (viable biomass) as proxies of colonization success. The establishment indicators related to colonization surface and biomass production differ among species and propagule sizes. The magnitude of the interspecific differences of all indicators of establishment success was larger at the smaller propagule size class. T. squarrosa was the most successful species, and D. scoparium showed the lowest performance. We also found interspecific differences in the hydration dynamics of the propagules. The process of establishment by vegetative fragments operates differently among moss species. Besides, differences between hydration states in propagules of some species could be part of syndromes for both dispersal and establishment. This study unveils several functional traits relevant for moss colonization, such as wet versus dry area and length of fragments, which may improve our understanding of their spatial dynamic

Method for assessing the breaking starting strength of meniscal horns from suture retention tests.

Surgical repair of a detached meniscal root is performed via a transtibial or in situ technique, using sutures to fix the meniscus to restore knee biomechanics. A critical aspect to prevent repair failure is the capacity of the tissue to hold the sutures subjected to forces throughout surgery and the postoperative period. Previously, visual inspection of video-monitored suture retention tests of meniscal horns and other soft tissues, allowed the identification of a breaking starting point that initiates tissue damage, better representing its suture retention capacity than the final failure. In this scenario, it is key to quantifying the Breaking Starting Strength (BSS). Some studies have analyzed horn resistance at the tissue-suture interface, but a robust methodology for computing the BSS has not been described. This work proposes a method to identify the BSS directly from the load curves of suture retention tests. The methodology has been validated using meniscal horns in human and porcine models.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. UMA20-FEDERJA-11

n-Alkan-2-ones in peat-forming plants from the Roñanzas ombrotrophic bog (Asturias, northern Spain)

We determined the distribution of lipids (n-alkanes and n-alkan-2-ones) in present-day peat-formingplants in the RoñanzasBog in northernSpain. Consistent with the observation of others, most Sphagnum (moss) species alkanes maximized at C23, whereas the other plants maximized at higher molecular weight (C27 to C31). We show for the first time that plants other than seagrass and Sphagnum moss contain n-alkan-2-ones. Almost all the species analysed showed an n-alkan-2-one distribution between C21 and C31 with an odd/even predominance, maximizing at C27 or C29, except ferns, which maximized at lower molecular weight (C21–C23). We also observed that microbial degradation can be a major contributor to the n-alkan-2-one distribution in sediments as opposed to a direct input of ketones from plant

Survival of Moss Reproductive Structures under Simulated Martian Environmental Conditions and Extreme Thermal Stress: Vibrational Spectroscopic Study and Astrobiological Implications

The principal goal of astrobiology is the search for extraterrestrial life forms. A key aspect is the study of the ability of different kinds of terrestrial organisms to support simulated extraterrestrial environmental conditions. Mosses are multicellular green plants, poorly studied from an astrobiological perspective. In this paper, we report experimental results obtained using two species of moss, which demonstrate that both the spores of the moss Funaria hygrometrica as well as the desiccated vegetative gametophyte shoots of the moss Tortella squarrosa (=Pleurochaete squarrosa) were capable of resisting Simulated Martian Environmental Conditions (SMEC): Mars simulated atmospheric composition 99.9% CO2, and 0.6% H2O with a pressure of 7 mbars, -73 ºC and UV irradiation of 30 mW cm-2 in a wavelength range of 200-400 nm under a limited short time of exposition of 2 hours. After being exposed to SMEC and then transferred to an appropriate growth medium, the F. hygrometrica spores germinated, producing typical gametophyte protonemal cells and leafy shoots. Likewise, detached leaves from SMEC-exposed gametophyte shoots of T. squarrosa retained the ability to produce new protonemata and shoots under suitable growth conditions. Furthermore, we studied the tolerance of these moss structures to a thermal stress of 100 °C for 1 h; in both cases the spores and shoots were capable of resisting this heat treatment. Our study using FT-Raman and FT-IR vibrational spectroscopy demonstrated that neither spores nor shoots apparently suffered significant damage in their biomolecular makeup after being subject to these stress treatments. The implications of these findings for the search of life on Mars are discussed

Improved tibiofemoral contact restoration after transtibial reinsertion of the anterior root of the lateral meniscus compared to in situ repair: a biomechanical study

Purpose: To compare biomechanical behaviour of the anterior root of the lateral meniscus (ARLM) after a transtibial repair (TTR) and after an in situ repair (ISR), discussing the reasons for the efficacy of the more advantageous technique. Methods: Eight cadaveric human knees were tested at flexion angles from 0° to 90° in four conditions of their ARLM: intact, detached, reinserted using TTR, and reinserted using ISR. Specimens were subjected to 1000 N of compression, and the contact area (CA), mean pressure (MP), and peak pressure (PP) on the tibial cartilage were computed. For the TTR, traction force on the sutures was registered. Results: ARLM detachment significantly altered contact biomechanics, mainly at shallow flexion. After ISR, differences compared to the healthy group persisted (extension, CA 22% smaller (p = 0.012); at 30°, CA 30% smaller (p = 0.012), MP 21%, and PP 32% higher (both p = 0.017); at 60°, CA 28% smaller (p = 0.012), MP 32%, and PP 49% higher (both p = 0.025). With TTR, alterations significantly decreased compared to the injured group, with no statistical differences from the intact ones observed, except for CA at extension (15% decrease, p = 0.012) and at 30° (12% decrease, p = 0.017). The suture tension after TTR, given as mean(SD), was 36.46(11.75)N, 44.32(11.71)N, 40.38(14.93)N, and 43.18(14.89)N for the four tested flexion angles. Conclusions: Alterations caused by ARLM detachment were partially restored with both ISR and TTR, with TTR showing better results on recovering CA, MP, and PP in the immediate postoperative period. The tensile force was far below the value reported to cause meniscal cut-out in porcine models.Funding for open access charge: Universidad de Málaga / CBUA. Funding for open access publishing: Universidad Málaga/CBUA This work was supported by the Ministerio de Ciencia, Inno vación y Universidades (Spain) under grant agreement RTI2018-094339-B-100 and the Consejería de Economia, Conocimiento, Empresas y Universidades de Andalucia, (Spain) under grant agree ment P20-00294