Interspecific and intraspecific variability of water use traits in macrolichen species in a fragmented landscape along a climatic ecotone area.

Water use traits in lichens are important attributes that determine the duration of hydration and metabolically active periods. In this study, the water holding capacity (WHC) and specific thallus mass (STM) were measured for seven macrolichen species (Parmelia sulcata, Parmelina tiliacea, Evernia prunastri, Ramalina farinacea, Lobaria pulmonaria, Lobarina scrobiculata and Nephroma resupinatum) from a Temperate-Mediterranean fragmented landscape. Twenty Quercus forests with different environmental conditions were selected to gather therein five lichen samples of each species in order to analyse their interspecific and intraspecific variation in WHC and STM. The type of photobiont was mainly responsible for differences in the WHC and the water content per biomass among species. Lichens with cyanobacteria as the main or secondary photobiont showed the highest value for both parameters. However, particular features of species were more important in modulating STM, while growth form had a minor explanatory importance. At the intraspecific level, variation in WHC relied on climatic, microclimatic and forest structure factors, while STM variability was only dependent on the two last predictors. Future research should be focused on other drivers at the microscale to unveil the environmental conditions that shape WHC and STM in lichens.

Functional diversity regulates the effects of habitat degradation on biocrust phylogenetic and taxonomic diversities.

Biocrusts are major contributors to dryland diversity, functioning, and services. However, little is known about how habitat degradation will impact multiple facets of biocrust diversity and measurable functional traits. We evaluated changes in taxonomic, functional, and phylogenetic diversity of biocrust-forming lichens along a habitat degradation gradient related to the presence of linear infrastructure (i.e., a road) and a profound agricultural driven transformation. To do so, we selected 50 remnants of a Mediterranean shrubland. We considered several surrogates of habitat quality and causal disturbance on the various diversity facets of biocrusts by using structural equation modeling, hypothesizing that habitat degradation primarily affects functional diversity, which in turn regulates changes in taxonomic and phylogenetic diversities, and also that taxonomic and phylogenetic diversities are coupled. Fragment connectivity, distance to linear infrastructure (i.e., a road) and, particularly, soil fertility (i.e., soil P concentration), had mostly negative effects on biocrust functional diversity, which in turn affected both taxonomic and phylogenetic diversities. However, we found no direct effects of habitat degradation variables on the taxonomic and phylogenetic diversities. We also found that increases in phylogenetic diversity had a positive effect on taxonomic diversity along the habitat degradation gradient. Our results indicate that functional diversity of biocrusts is strongly affected by habitat degradation, which may profoundly alter their contribution to ecosystem functioning and services. Furthermore, functional diversity regulates the response of biocrust taxonomic and phylogenetic diversity to habitat degradation. These findings indicate that habitat degradation alters and simplifies the diversity of functional traits of biocrust-forming lichens, leading to biodiversity loss, with important consequences for the conservation of global drylands biodiversity.

Functional Traits in Lichen Ecology: A Review of Challenge and Opportunity.

Community ecology has experienced a major transition, from a focus on patterns in taxonomic composition, to revealing the processes underlying community assembly through the analysis of species functional traits. The power of the functional trait approach is its generality, predictive capacity such as with respect to environmental change, and, through linkage of response and effect traits, the synthesis of community assembly with ecosystem function and services. Lichens are a potentially rich source of information about how traits govern community structure and function, thereby creating opportunity to better integrate lichens into 'mainstream' ecological studies, while lichen ecology and conservation can also benefit from using the trait approach as an investigative tool. This paper brings together a range of author perspectives to review the use of traits in lichenology, particularly with respect to European ecosystems from the Mediterranean to the Arctic-Alpine. It emphasizes the types of traits that lichenologists have used in their studies, both response and effect, the bundling of traits towards the evolution of life-history strategies, and the critical importance of scale (both spatial and temporal) in functional trait ecology.

Contrasting Environmental Drivers Determine Biodiversity Patterns in Epiphytic Lichen Communities along a European Gradient.

Assessing the ecological impacts of environmental change on biological communities requires knowledge of the factors driving the spatial patterns of the three diversity facets along extensive environmental gradients. We quantified the taxonomic (TD), functional (FD), and phylogenetic diversity (PD) of lichen epiphytic communities in 23 beech forests along Europe to examine their response to environmental variation (climate, habitat quality, spatial predictors) at a continental geographic scale. We selected six traits related to the climatic conditions in forest ecosystems, the water-use strategy and the nutrient uptake, and we built a phylogenetic tree based on four molecular markers. FD and climate determined TD and PD, with spatial variables also affecting PD. The three diversity facets were primarily shaped by distinct critical predictors, with the temperature diurnal range affecting FD and PD, and precipitation of the wettest month determining TD. Our results emphasize the value of FD for explaining part of TD and PD variation in lichen communities at a broad geographic scale, while highlighting that these diversity facets provide complementary information about the communities' response under changing environmental conditions. Furthermore, traits such as growth form, photobiont type, and reproductive strategy mediated the response of lichen communities to abiotic factors emerging as useful indicators of macroclimatic variations.

Intraspecific variability drives functional changes in lichen epiphytic communities across Europe.

Traditional approaches in trait-based community ecology typically expect that trait filtering across broad environmental gradients is largely due to replacement of species, rather than intraspecific trait adjustments. Recently, the role of intraspecific trait variability has been largely highlighted as an important contributor mediating the ability of communities to persist under changing conditions and determining the community-level trait variation, particularly across limited environmental gradients. Unfortunately, few studies quantify the relative importance of species turnover versus intraspecific variability mediating the response of communities different from vascular plants. Here, we studied the functional changes in epiphytic lichen communities within 23 beech forests across large latitudinal (ca. 3,000 km) and environmental gradients in Europe to quantify the relative contribution of species turnover and intraspecific variability and the role of climate controlling community-level trait changes. For 58 lichen species, we focused on a set of 10 quantitative functional traits potentially affected by climatic conditions and related to photosynthetic performance (n = 1,184 thalli), water use strategy (n = 1,018 thalli), and nutrient uptake (n = 1,179 thalli). Our results showed that intraspecific trait variability explained most of the functional changes in lichen communities in response to the latitudinal gradient. Further, such functional changes were determined by the covariation between intraspecific trait variability and species turnover, which varied in sign depending on the trait considered. Finally, different climatic predictors explained functional variation due to both intraspecific trait variability and species turnover. We propose that lichen communities cope with contrasting climatic conditions by adjusting the functional trait values of the most abundant species within the communities rather than by the replacement of the species. Consequently, intraspecific variability should be explicitly incorporated to understand the effect of environmental changes on lichen communities, even over large environmental variations, better. Our results challenge the universality of the hypothesis that species turnover chiefly drives functional trait changes across large environmental gradients and call for a wider test of such important assumptions in trait ecology in different organism types and ecosystems.

How much matching there is in functional, phylogenetic and taxonomic optima of epiphytic macrolichen communities along a European climatic gradient?

Adopting an integrative approach that explicitly includes the different facets of biodiversity is crucial to assess the response of biological communities to changing environments. The identification of the optimal climatic conditions where communities maximize their functional, phylogenetic and taxonomic diversity is useful to compare whether the optima of the different facets of biodiversity match. Using a wide climatic gradient across Europe, we quantified the functional, phylogenetic and taxonomic diversity of epiphytic macrolichen communities, which are valuable early-warning ecological indicators. We ordinated 22 environmental variables and simultaneously illustrated non-parametric regressions of the diversity metrics against the climatic space using the 'hilltop plot' method to detect the climatic conditions in which the different diversity facets peaked and to compare the match between them. Functional diversity predicted at least part of the peaks of phylogenetic and taxonomic diversity, but phylogenetic and taxonomic hotspots did not overlap. Epiphytic macrolichen communities maximized their functional and phylogenetic diversity in the southernmost forests, with the Mediterranean region appearing as a biodiversity hotspot. Regarding the studied traits, photobiont type and growth form showed clearly defined optima while the quantitative physiological traits and families' optima did not show this pattern in response to climate. The different facets of biodiversity were not surrogates of each other highlighting the need for an integrative approach to assess the effect of environmental changes on communities and to establish conservation priorities. As functional traits mediated the response of lichen communities to climate, preserving high functional diversity might indirectly preserve high phylogenetic and taxonomic diversity. Relevant ecological indicators useful to develop rapid assessment methods to evaluate the effects of climatic changes include the photobiont type and growth form. The lack of relation between quantitative traits and climate call for further research to unveil their role as ecological indicators of small-scale variables or as effect traits.

Shift in phenotypic variation coupled with rapid loss of genetic diversity in captive populations of Eristalis tenax (Diptera: Syrphidae): consequences for rearing and potential commercial use.

Because of its importance as a pollinator and its potential economic usefulness for the biodegradation of organic animal waste, the genetic and phenotypic diversity of the drone fly, Eristalis tenax L. (Diptera: Syrphidae), was studied in both wild and captive populations from southeastern Europe. Wild specimens from a natural protected habitat (with low human impact), field crop habitat (semisynanthropic condition), and intensive pig farming habitat (synanthropic condition) were compared with a laboratory colony reared on artificial media An integrative approach was applied based on allozyme loci, cytochrome c oxidase I mitochondrial DNA, wing traits (size and shape), and abdominal color patterns. Our results indicate that the fourth and eighth generations of the laboratory colony show a severe lack of genetic diversity compared with natural populations. Reduced genetic diversity in subsequent generations (F4 and F8) of the laboratory colony was found to be linked with phenotypic divergence. Loss of genetic variability associated with phenotypic differentiation in laboratory samples suggests a founder effect, followed by stochastic genetic processes and inbreeding. Hence, our results have implications for captive bred Eristalis flies, which have been used in crop pollination and biodegradation of organic waste under synanthropic conditions.

SEM studies on immature stages of the drone flies (diptera, syrphidae): Eristalis similis (Fallen, 1817) and Eristalis tenax (Linnaeus, 1758).

Adult drone flies (Syrphidae: Eristalis spp.) resemble male honeybees in appearance. Their immature stages are commonly known as rat-tailed maggots due to the presence of a very long anal segment and a telescopic breathing tube. The larvae are associated with decaying organic material in liquid or semi-liquid media, as in the case of other saprophagous eristalines. Biological and morphological data were obtained from both laboratory cultures and sampling in the field. Drone flies are important pollinators for wild flowers and crops. In fact, mass rearing protocols of Eristalis species are being developed to be used as efficient alternative pollinators. However, deeper knowledge of larval morphology and biology is required to improve artificial rearing. The production quality control of artificial rearing must manage the consistency and reliability of the production output avoiding, for example contamination with similar species. This article presents the first description of the larva and puparium of E. similis, including a comparative morphological study of preimaginal stages of the anthropophilic and ubiquitous European hoverfly species E. tenax. Scanning electron microscopy has been used for the first time to describe larvae and puparia of both species. Moreover, the preimaginal morphology of E. similis has been compared with all known descriptions of the genus Eristalis. The main diagnostic characters of the preimaginal stages of E. similis are the morphology of the anterior spiracles (shape of clear area and arrangement of facets) and pupal spiracles (length, shape, and arrangement of tubercles).

Absorption-mode Fourier transform mass spectrometry: the effects of apodization and phasing on modified protein spectra.

The method of phasing broadband Fourier transform ion cyclotron resonance (FT-ICR) spectra allows plotting the spectra in the absorption-mode; this new approach significantly improves the quality of the data at no extra cost. Herein, an internal calibration method for calculating the phase function has been developed and successfully applied to the top-down spectra of modified proteins, where the peak intensities vary by 100×. The result shows that the use of absorption-mode spectra allows more peaks to be discerned within the recorded data, and this can reveal much greater information about the protein and modifications under investigation. In addition, noise and harmonic peaks can be assigned immediately in the absorption-mode.

Use of high resolution mass spectrometry for analysis of polymeric excipients in drug delivery formulations.

Two polymeric excipients, typically used in enabling drug delivery approaches, are Gelucire 44/14 (a product of Gattefosse s.a, St Priest, France) and polysorbate 80; these are known to improve solubility of poorly water-soluble drugs and, hence, increase their effective bioavailability. In addition to the use of Gelucire 44/14 and polysorbate 80 as excipients in drugs, they are also widely used as cosmetic and food additives. In general, complex structures and compositions of drug excipients impact performance of the formulation in vivo and consequently affect drug absorption. Therefore, a comparison between excipients from different suppliers and batches to batch would provide an indication of the impact on drug product performance and also the study of the effectiveness of the system and any problems associated with the formulation. In this study, high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) is used to compare two different batches of Gelucire 44/14 and polysorbate 80. With the high resolving power of FTICR MS, it was possible to differentiate between batches of excipients from differences in the identified components. The improved resolution offered by FTICR MS allowed assignment of four polymeric series differences in the two batches of polysorbate 80 and the presence of one compound and three polymeric series differences in the two batches of Gelucire 44/14. The increase in the number of components assigned in the excipients batch using FTICR-MS, compared to the numbers previously assigned by lower resolution TOF MS, underlines the importance of high resolution techniques in analysis of highly complex mixtures.

Differentiation of isomeric amino acid residues in proteins and peptides using mass spectrometry.

Characterization and differentiation of isomers in biological macromolecules using mass spectrometry is one of the most significant challenges facing scientists in the field. The capability of high-resolution MS instruments along with the development of new fragmentation methods now provides the ability to indirectly differentiate between some isomers. This ability has enabled mass spectrometry to evolve into a multidisciplinary technique incorporating areas such as pharmaceutical research, proteomics, polymer science, medicine, environmental chemistry, and recently archeology. This article aims to review recent developments in mass spectrometry methodologies in the identification of structural and spatial isomers in biological macromolecules, such as aspartic acid and isoaspartic acid (Asp/IsoAsp), leucine and isoleucine (Leu/Ile), glutamic acid and γ-glutamic acid, and D/L enantiomers.

Deamidation of collagen.

Collagen is the major component of skin, tendons, ligaments, teeth, and bones, it provides the framework that holds most multicellular animals together, and collagen type I constitutes the major fibrillar collagen of bone. Because of the complexity of collagen's structure, the study of post-translational modifications such as deamidation for this protein is challenging. Although there is no evidence of this protein being used for age assessment, it has been shown that deamidation of collagen is remarkably increased in old bones from mammals. Nonspectrometric methodologies have been used for the determination of the extent of deamidation as a measure of the amount of amide nitrogen released in ammonia as well as constant rates for deamidation of asparagine in collagen. In general, these methodologies required more sample and separation processes. To understand if collagen plays a significant role in the aging process of fossil materials, a simpler and more accurate method is needed to determine the extent of deamidation at the whole protein level. The present work shows a method to determine the extent of deamidation in collagen using Fourier transform ion cyclotron resonance-mass spectrometry (FTICR-MS) along with collisionally activated dissociation (CAD) and electron capture dissociation (ECD). The measured deamidation half-life for three different tryptic peptides from collagen (I) ranged from 2000 to 6000 s under high temperature conditions (∼62 °C) and pH 7.5.

Variation of the Fourier transform mass spectra phase function with experimental parameters.

It has been known for almost 40 years that phase correction of Fourier transform ion cyclotron resonance (FTICR) data can generate an absorption-mode spectrum with much improved peak shape compared to the conventional magnitude-mode. However, research on phasing has been slow due to the complexity of the phase-wrapping problem. Recently, the method for phasing a broadband FTICR spectrum has been solved in the MS community which will surely resurrect this old topic. This paper provides a discussion on the data processing procedure of phase correction and features of the phase function based on both a mathematical treatment and experimental data. Finally, it is shown that the same phase function can be optimized by adding correction factors and can be applied from one experiment to another with different instrument parameters, regardless of the sample measured. Thus, in the vast majority of cases, the phase function needs to be calculated just once, whenever the instrument is calibrated.

Estudio de la histología y la histopatología como modelo integrador en el proceso de enseñanza-aprendizaje / Study of histology and histopathology as a model integrating the teaching-learning process

Las ciencias de la salud están en la búsqueda de nuevas estrategias para el proceso de enseñanza-aprendizaje, incluyendo cambios notables en sus programas. En la Universidad Central de Venezuela (UCV) y en la Facultad de Medicina se están implementando propuestas innovadoras para los estudios de pregrado y posgrado. De esta búsqueda se origina el modelo propuesto que permite integrar varias disciplinas como anatomía, fisiología, histología, fisiopatología y clínica de los síndromes clásicos infecciosos. La modalidad incluye dos fases con tres modelos: i. sistema gastrointestinal; ii. sistema renal y iii. sistema cardiorrespiratorio. La primera fase corresponde al proceso de enseñanza-aprendizaje y actividades docentes de la asignatura microbiología. La segunda fase, consistirá en la aplicación y evaluación del modelo

The teaching-learning process in health sciences is undergoing changes in the search for new strategies. At the "Universidad Central de Venezuela" in its Faculty of Medicine curricular changes are taking place and proposals are being made for improving the undergrade and postgraduate courses. The proposed model is product of this search intending to integrate several disciplines such as anatomy, physiology, histology, physiopathology and the classic infectious syndromes. The model includes two phases and three models, gastrointestinal, renal and cardio-respiratory. The first instance includes its application in the microbiology course and the second moment the evaluation of the results

Aquatic toxicity of sertraline to Pimephales promelas at environmentally relevant surface water pH.

Researchers recognize that ionization state may influence the biological activity of weak acids and bases. Dissociation in aqueous solutions is controlled by the pKa of a compound and the pH of the matrix. Because many pharmaceuticals are implicitly designed as ionizable compounds, site-specific variability in pH of receiving waters may introduce uncertainty to ecological risk assessments. The present study employed 48-h and 7-d toxicity tests with Pimephales promelas exposed to the model weak base pharmaceutical sertraline over a gradient of environmentally relevant surface water pHs. The 48-h experiments were completed in triplicate, and the average lethal concentration values were 647, 205, and 72 microL sertraline at pH 6.5, 7.5, and 8.5, respectively. Survivorship, growth, and feeding rate (a nontraditional endpoint linked by other researchers to sertraline's specific mode of action) were monitored during the 7-d experiment. Adverse effects were more pronounced when individuals were exposed to sertraline at pH 8.5 compared to pH 7.5 and 6.5. The pH-dependent toxicological relationships from these studies were related to in-stream pH data for two streams in the Brazos River basin of central Texas, USA. This predictive approach was taken because of the scarcity of environmental analytical data for sertraline. The results of this study emphasized temporal variability associated with in-stream pH linked to seasonal differences within and between these spatially related systems. Relating site-specific pH variability of surface waters to ionization state may allow researchers to reduce uncertainty during ecological risk assessment of pharmaceuticals by improving estimates of biological effects associated with exposure.

Occurrence of pharmaceuticals and personal care products in fish: results of a national pilot study in the United States.

Pharmaceuticals and personal care products are being increasingly reported in a variety of biological matrices, including fish tissue; however, screening studies have presently not encompassed broad geographical areas. A national pilot study was initiated in the United States to assess the accumulation of pharmaceuticals and personal care products in fish sampled from five effluent-dominated rivers that receive direct discharge from wastewater treatment facilities in Chicago, Illinois; Dallas, Texas; Orlando, Florida; Phoenix, Arizona; and West Chester, Pennsylvania, USA. Fish were also collected from the Gila River, New Mexico, USA, as a reference condition expected to be minimally impacted by anthropogenic influence. High performance liquid chromatography-tandem mass spectrometry analysis of pharmaceuticals revealed the presence of norfluoxetine, sertraline, diphenhydramine, diltiazem, and carbamazepine at nanogram-per-gram concentrations in fillet composites from effluent-dominated sampling locations; the additional presence of fluoxetine and gemfibrozil was confirmed in liver tissue. Sertraline was detected at concentrations as high as 19 and 545 ng/g in fillet and liver tissue, respectively. Gas chromatography-tandem mass spectrometry analysis of personal care products in fillet composites revealed the presence of galaxolide and tonalide at maximum concentrations of 2,100 and 290 ng/g, respectively, and trace levels of triclosan. In general, more pharmaceuticals were detected at higher concentrations and with greater frequency in liver than in fillet tissues. Higher lipid content in liver tissue could not account for this discrepancy as no significant positive correlations were found between accumulated pharmaceutical concentrations and lipid content for either tissue type from any sampling site. In contrast, accumulation of the personal care products galaxolide and tonalide was significantly related to lipid content. Results suggest that the detection of pharmaceuticals and personal care products was dependent on the degree of wastewater treatment employed.

Diseminación tisular de Cryptosporidium SPP en hospedadores murinos experimentalmente inmunosuprimidos / Tissue spread of Cryptosporidium spp in experimentally immunosuppressed murine hosts

Cryptosporidium spp. es un protozoario parásito perteneciente al Phylum Apicomplexa, el cual ha sido estudiado ampliamente a nivel humano y veterinario por ser el causante de la criptosporidiosis. En este trabajo estudiamos la diseminación tisular del parásito utilizando dos grupos de hospedadores murinos: uno constituido por ratones infectados y tratados con ciclofosfamida (CPA) por su efecto inmunosupresor y el segundo por animales infectados, no tratados. El análisis de las muestras del grupo parasitado y tratado presentó una amplia diseminación en el intestino, la tráquea, el pulmón, el bazo, en ganglios linfáticos, glándula tiroides, además del hígado, mientras que el grupo control mostró diseminación solamente en el intestino. Los resultados obtenidos en los roedores inmunosuprimidos sugieren resultados semejantes en cuanto a diseminación en el humano inmunodeficiente y la importancia de enfocarse hacia la prevención de la infección intestinal por este Coccidia en individuos con alteraciones del sistema inmune.

[Intestinal giardiasis. Mini-review]. / Giardiasis intestinal. Mini-Revisión.

Giardia intestinalis is a common parasite in our country and the rest of the world and is responsible for several clinical disturbances that include dysentery type diarrheas, recurrent abdominal pain, duodenitis, jejunitis, cholecystitis and in some cases toxemias and convulsions. In this paper we review recent concepts of intestinal giardiasis, considering the basic aspects of the biology and physiology of Giardia intestinalis, its morphology and its relationship the parasite pathogenicity. We detail the physiopathological mechanisms responsible for the different clinic manifestations of giardiasis, the specific laboratory and endoscopic methods of diagnosis and the most recent advances in the treatment and prophylaxis of this disease.

Intestinal giardiasis. Mini-review / Giardiasis intestinal. Mini-Revisión

Giardia intestinalis is a common parasite in our country and the rest of the world and is responsible for several clinical disturbances that include dysentery type diarrheas, recurrent abdominal pain, duodenitis, jejunitis, cholecystitis and in some cases toxemias and convulsions. In this paper we review recent concepts of intestinal giardiasis, considering the basic aspects of the biology and physiology of Giardia intestinalis, its morphology and its relationship the parasite pathogenicity. We detail the physiopathological mechanisms responsible for the different clinic manifestations of giardiasis, the specific laboratory and endoscopic methods of diagnosis and the most recent advances in the treatment and prophylaxis of this disease.