Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Full inactivation of human influenza virus by high hydrostatic pressure preserves virus structure and membrane fusion while conferring protection to mice against infection.

Whole inactivated vaccines (WIVs) possess greater immunogenicity than split or subunit vaccines, and recent studies have demonstrated that WIVs with preserved fusogenic activity are more protective than non-fusogenic WIVs. In this work, we describe the inactivation of human influenza virus X-31 by high hydrostatic pressure (HHP) and analyze the effects on the structure by spectroscopic measurements, light scattering, and electron microscopy. We also investigated the effects of HHP on the glycoprotein activity and fusogenic activity of the viral particles. The electron microscopy data showed pore formation on the viral envelope, but the general morphology was preserved, and small variations were seen in the particle structure. The activity of hemagglutinin (HA) during the process of binding and fusion was affected in a time-dependent manner, but neuraminidase (NA) activity was not affected. Infectious activity ceased after 3 hours of pressurization, and mice were protected from infection after being vaccinated. Our results revealed full viral inactivation with overall preservation of viral structure and maintenance of fusogenic activity, thereby conferring protection against infection. A strong response consisting of serum immunoglobulin IgG1, IgG2a, and serum and mucosal IgA was also detected after vaccination. Thus, our data strongly suggest that applying hydrostatic pressure may be an effective method for developing new vaccines against influenza A as well as other viruses

Viral proteins structure is slightly affected by HHP treatment.

<p>(A) The changes in spectral center of mass (●) and light scattering (○) were followed as a function of the pressure at 289.6 MPa over 6 h. For tryptophan fluorescence emission, the sample was excited at 280 nm, and the emission was measured at 300 to 420 nm. (B) The influenza virus was pre-incubated for 10 min with 15 mM of bis-ANS probe and then exposed to 289.6 MPa for 3 h, and the intensity of the probe was measured every 10 min.</p

HHP treatment preserves viral fusogenic activity.

<p>Virus samples were pressurized for 3, 6, or 12 h at 289.6 MPa. (A) Viruses were incubated with DiD and monitored for their fusogenic properties. Mock (cells incubated with PBS), control (influenza viruses kept for 12 h at 25°C), and pressurized influenza virus. (B) Fusogenic activity relative to the control. The asterisks (***) mark a significant difference (***p<0.0001 by Tukey´s post-test).</p

Viral glycoproteins remain functional after pressurization.

<p>(A) Hemagglutination assay titer of viruses pressurized at pH 7.4 for 3, 6, or 12 h at 289.6 MPa. Hemagglutination units were given by the reciprocal of the highest dilution where total hemagglutination was observed. (B) X-31 NA activity. Virus particles were pressurized at pH 7.4 for 3 h at 289.6 MPa. Enzymatic activity was determined with the MUNANA substrate, as described in the Materials and Methods. The NA activity was calculated by normalizing the NA activity of the pressurized virus to the NA activity of the native virus. </p

Intranasal Immunization with Pressure Inactivated Avian Influenza Elicits Cellular and Humoral Responses in Mice

<div><p>Influenza viruses pose a serious global health threat, particularly in light of newly emerging strains, such as the avian influenza H5N1 and H7N9 viruses. Vaccination remains the primary method for preventing acquiring influenza or for avoiding developing serious complications related to the disease. Vaccinations based on inactivated split virus vaccines or on chemically inactivated whole virus have some important drawbacks, including changes in the immunogenic properties of the virus. To induce a greater mucosal immune response, intranasally administered vaccines are highly desired as they not only prevent disease but can also block the infection at its primary site. To avoid these drawbacks, hydrostatic pressure has been used as a potential method for viral inactivation and vaccine production. In this study, we show that hydrostatic pressure inactivates the avian influenza A H3N8 virus, while still maintaining hemagglutinin and neuraminidase functionalities. Challenged vaccinated animals showed no disease signs (ruffled fur, lethargy, weight loss, and huddling). Similarly, these animals showed less Evans Blue dye leakage and lower cell counts in their bronchoalveolar lavage fluid compared with the challenged non-vaccinated group. We found that the whole inactivated particles were capable of generating a neutralizing antibody response in serum, and IgA was also found in nasal mucosa and feces. After the vaccination and challenge we observed Th1/Th2 cytokine secretion with a prevalence of IFN-γ. Our data indicate that the animals present a satisfactory immune response after vaccination and are protected against infection. Our results may pave the way for the development of a novel pressure-based vaccine against influenza virus.</p></div

Analysis of residual virus infectivity after pressure-induced inactivation^a.

<p>^a The residual infectivity of the pressurized virus samples (282.7 MPa for 12 h at 25°C) was assayed for three sequential serial passages in embryonated hens eggs and in MDCK cell monolayers. For each blind passage, the samples revealed the absence of infectivity by a hemagglutination assay or a TCID₅₀.</p><p>^b No residual infectivity was detected in MDCK cells.</p><p>Analysis of residual virus infectivity after pressure-induced inactivation<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128785#t001fn001" target="_blank">^a</a>.</p

Virus titer measured in lung homogenates after challenge^a.

<p>^a BALB/c mice were vaccinated with pressurized virus and challenged intranasally with native virus.</p><p>^b The results are expressed as the means of six animals.</p><p>^c No infectivity was detected in MDCK cells.</p><p>Virus titer measured in lung homogenates after challenge<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128785#t003fn001" target="_blank">^a</a>.</p