A Stochastic Dynamic Methodology (StDM) to simulate the effects of fire on vegetation and bird communities in Pinus pinaster stands

Worldwide forests have been impacted by broad-scale anthropogenic pressures, such as fire and logging, leading to the disruption of the structure and functioning of these systems. The present paper examined the applicability of a holistic Stochastic Dynamic Methodology (StDM) in predicting the tendencies of passerine bird communities in maritime pine (Pinus pinaster) stands as a response to the changes induced by fire occurrence. The StDM is a sequential modelling process developed in order to predict the ecological status of changed ecosystems, from which management strategies can be designed. The case of the pine stands of central Portugal was used to test the StDM performance in the scope of the wildfire problems. The datasets used in the dynamic model construction included the main gradients of environmental and biological characteristics of the studied maritime pine stands over space and time. The ecological integrity of the pine stands can be partly assessed by the observation of the occurrence of passerine indicators. The dynamic model developed was preceded by a conventional multivariate statistical procedure performed to discriminate the significant relationships between conceptually isolated key-components of the studied ecosystems. The final model provided some basis to analyse the responses of selected passerine indicators to fire scenarios that characterize the region. In this context, the simulation results are encouraging since they seem to demonstrate the StDM reliability in capturing the passerine community dynamics by predicting the behavioural pattern of indicators roughly associated with their structural and functional composition and habitat main characteristics.     

Length‐weight relationships of 29 fish species from the Tucuruí Reservoir (Tocantins/Araguaia Basin,Brazil)

The length‐weight relationships (LWRs) are described for 29 fish species in the region of the Tucuruí Reservoir, located in the Tocantins/Araguaia Basin, northern Brazil. Fishes in fourteen sites were sampled seasonally for 10 years, from 2001 to 2010. Significant differences between sexes were found for two species, while 27 species had similar LWRs for males and females. The relationship of standard length and total length is presented for all species as well as the minimum and average size of reproductive females and seasonality of occurrence. No information on LWRs of these 29 species was heretofore available in FishBase.     

Macrophage signaling by glycosylphosphatidylinositol-anchored mucin-like glycoproteins derived from Trypanosoma cruzi trypomastigotes

Activation of cells from the innate immune system has an important role in host resistance to early infection with the intracellular protozoan parasite, Trypanosoma cruzi. Here we review the studies that have identified and structurally characterized the glycosylphosphatidylinositol (GPI) anchors, as parasite molecules responsible for the activation of cells from the macrophage lineage. We also cover the studies that have identified the receptor, signaling pathways as well as the array of genes expressed in macrophages that are activated by these glycoconjugates. We discuss the possible implications of such response on the host resistance to T. cruzi infection and the pathogenesis of Chagas disease.     

Quaranfil,Johnston Atoll,and Lake Chad Viruses Are Novel Members of the Family Orthomyxoviridae

Arboviral infections are an important cause of emerging infections due to the movements of humans, animals, and hematophagous arthropods. Quaranfil virus (QRFV) is an unclassified arbovirus originally isolated from children with mild febrile illness in Quaranfil, Egypt, in 1953. It has subsequently been isolated in multiple geographic areas from ticks and birds. We used high-throughput sequencing to classify QRFV as a novel orthomyxovirus. The genome of this virus is comprised of multiple RNA segments; five were completely sequenced. Proteins with limited amino acid similarity to conserved domains in polymerase (PA, PB1, and PB2) and hemagglutinin (HA) genes from known orthomyxoviruses were predicted to be present in four of the segments. The fifth sequenced segment shared no detectable similarity to any protein and is of uncertain function. The end-terminal sequences of QRFV are conserved between segments and are different from those of the known orthomyxovirus genera. QRFV is known to cross-react serologically with two other unclassified viruses, Johnston Atoll virus (JAV) and Lake Chad virus (LKCV). The complete open reading frames of PB1 and HA were sequenced for JAV, while a fragment of PB1 of LKCV was identified by mass sequencing. QRFV and JAV PB1 and HA shared 80% and 70% amino acid identity to each other, respectively; the LKCV PB1 fragment shared 83% amino acid identity with the corresponding region of QRFV PB1. Based on phylogenetic analyses, virion ultrastructural features, and the unique end-terminal sequences identified, we propose that QRFV, JAV, and LKCV comprise a novel genus of the family Orthomyxoviridae.Arboviral infections are an important and emerging cause of human illness. Recent epidemics of West Nile, chikungunya, dengue, and yellow fever illustrate the importance of understanding the basic virology of arboviruses. Quaranfil virus (QRFV) is a heretofore-unclassified arbovirus isolated in 1953 from ticks (Argas [Persicargus] arboreus) collected near Cairo, Egypt, and subsequently passaged in mice and Vero cells. This tick-derived isolate was determined by serologic methods to be related to a virus previously cultured from the blood of two children with mild febrile illnesses in Quaranfil, Egypt (32). Human serologic studies performed in the 1960s in Egypt revealed that approximately 8% of the local population had neutralizing antibodies to this virus, demonstrating that human infection occurs and raising the question of whether QRFV might represent an unrecognized cause of viral illness in humans (32). The extent to which this virus may cause clinical illness in people is currently unknown; however, multiple strains of QRFV have been isolated from ticks and seabirds in Egypt, South Africa, Afghanistan, Nigeria, Kuwait, Iraq, Yemen, and Iran (1, 12, 20, 29, 30). QRFV is lethal after intracerebral (i.c.) inoculation of newborn mice (32). One study reported that experimental QRFV infection of laboratory mice causes a lethal respiratory disease and meningoencephalitis (4).Johnston Atoll virus (JAV) was originally isolated from ticks (Ornithodoros capensis) collected in 1964 from a Noddy Tern (Anous stolidus) nest, Sand Island, Johnston Atoll in the central Pacific (11). Multiple strains have subsequently been isolated from eastern Australia, New Zealand, and Hawaii (3). No human disease has been associated with JAV, but it is lethal to newborn and weanling mice after i.c. injection and to 1- to 2-day-old chicks after subcutaneous inoculation. (11). Lake Chad virus (LKCV), strain Ib An 38918, was isolated from a masked weaver bird, Ploceus vitellinus, collected at Lake Chad, Nigeria, in 1969. LKCV is lethal to newborn mice after i.c. inoculation, and it was shown to be antigenically related to QRFV (R. E. Shope, personnel communication).To date, conventional approaches to characterize QRFV, JAV, and LKCV have not resulted in a definitive classification of these viruses. QRFV and JAV are enveloped RNA viruses, and electron microscopic and serologic studies tentatively suggested a classification in the arenavirus family based on morphological and morphogenetic features of the viruses (38). In this study, we utilized high-throughput sequencing to identify genomic sequences from QRFV, JAV, and LKCV. Based on analysis of the complete sequences of five of these segments from QRFV and partial sequences from JAV and LKCV, ultrastructural analysis of infected cell cultures, and serologic testing, we propose that these viruses define a novel genus in the family Orthomyxoviridae.     

Melanin in the dimorphic fungal pathogen Paracoccidioides brasiliensis: effects on phagocytosis, intracellular resistance and drug susceptibility

The fungal pathogen Paracoccidioides brasiliensis produces a melanin-like pigment in the presence of l-DOPA in vitro. We investigated whether melanization affected yeast uptake by alveolar and peritoneal macrophages, the intracellular resistance of fungal cells and their susceptibility to antifungal drugs. The interactions of melanized and nonmelanized P. brasiliensis with murine primary macrophages and J774.16 and MH-S macrophage-like cell lines were investigated. Melanized yeast cells were poorly phagocytosed by the cells even in the presence of complement. Melanization caused significant interference with the binding of cell wall components to lectin receptors on macrophages. Melanized cells were also more resistant than nonmelanized cells to the antifungal activity of murine macrophages. No difference in the susceptibilities of melanized and nonmelanized P. brasiliensis to antifungal drugs was observed using the minimum inhibitory concentration (MIC) method. However killing assays showed that melanization significantly reduced fungal susceptibility to amphotericin B and also protected against ketoconazole, fluconazole, itraconazole and sulfamethoxazole. The present results indicate that fungal melanin protects P. brasiliensis from phagocytosis and increases its resistance to antifungal drugs.     

Assessing trophic interactions between pelagic predatory fish by gut content and stable isotopes analysis around Fernando de Noronha Archipelago (Brazil), Equatorial West Atlantic

The objective of this study was to analyse the feeding habits and trophic interactions between four oceanic predatory fish around the Fernando de Noronha Archipelago (FNA), Brazil, in the western equatorial Atlantic (3.86°S/32.42°W), internationally recognized as an environment of high economic and ecological value. For this purpose, biological samples of yellowfin tuna (Thunnus albacares), wahoo (Acanthocybium solandri), barracuda (Sphyraena barracuda) and dolphinfish (Coryphaena hippurus) were collected for stomach content and stable isotope analysis. Values of the index of relative importance revealed varied diets, with a strong presence of teleost fishes (Diodontidae and Exocoetidae) for all species, with yellowfin tuna having a greater diversity of food items. Despite being generalists/opportunists, the feeding strategy of these predators showed a tendency towards a specialized diet in the use of the available resources around the FNA. They presented a narrow trophic niche width (Levin's index, Bi < 0.6) and low overlap between species, except between barracuda and wahoo (MacArthur and Levin's, R₀ = 0.72). Isotopic compositions had broad values of δ¹³C and δ¹⁵N, and were significantly different between species. Our results provide information about the four species' trophic organization and suggest that the predators avoid competition by preying on different prey, thus allowing their coexistence.     

Historical trends in frog populations in New Zealand based on public perceptions

Surveys were distributed to New Zealand land users in 1998 and 2008 to acquire information about New Zealand frogs with the aim of compiling and mapping their distribution and inferred population trends without costly and time-consuming field surveys. The overall frog population trend was reported as declining, with possible causes reported as an increase in agriculture, an increase in the distribution of predatory fish and disease. The resultant maps could be used for four main purposes: 1) to identify regions where Litoria populations are known to occur, which can be eliminated when considering suitable regions for translocation of Leiopelma; 2) to identify growing or stable populations of Litoria species, which may assist future disease surveys, population monitoring and to identify sources of genetic material that may serve as an Ark for declining Australian populations; 3) to highlight populations that are in decline to enable effective targeting of detailed disease studies; and 4) to approximate the stability of amphibian populations in the absence of more accurate, but costly, scientific monitoring.     

α-Pinene isolated from Schinus terebinthifolius Raddi (Anacardiaceae) induces apoptosis and confers antimetastatic protection in a melanoma model

Malignant melanoma is one the most aggressive types of cancer and its incidence has gradually increased in the last years, accounting for about 75% of skin cancer deaths. This poor prognosis results from the tumor resistance to conventional drugs mainly by deregulation of apoptotic pathways. The aim of this work was to investigate the cell death mechanism induced by α-pinene and its therapeutic application. Our results demonstrated that α-pinene was able to induce apoptosis evidenced by early disruption of the mitochondrial potential, production of reactive oxygen species, increase in caspase-3 activity, heterochromatin aggregation, DNA fragmentation and exposure of phosphatidyl serine on the cell surface. Most importantly, this molecule was very effective in the treatment of experimental metastatic melanoma reducing the number of lung tumor nodules. This is the first report on the apoptotic and antimetastatic activity of isolated α-pinene.