[Assessing Convalescent Plasma Efficacy in Moderate COVID-19 Hospitalizations: A Bicentric Retrospective Study]. / Uso de plasma de convalecientes de COVID-19 en pacientes hospitalizados por SARS-CoV-2 de moderada grave-dad en la Región de Los Ríos, Chile.

INTRODUCTION: COVID-19 claimed millions of lives, mainly in the pre-vaccine era. Preliminary studies showed promising efficacy of convalescent plasma against SARS-CoV-2 (CP). OBJECTIVE: To evaluate the efficacy of CP in patients hospitalized for COVID-19 with moderate severity. METHODS: Retrospective, bicentric study including adults hospitalized for moderate (non-critical) COVID-19 who required oxygen therapy. CP donated by survivors of mild cases (600 cc) were searched for IgG anti-SARS-CoV-2. Its impact on mortality, hospital stay (days), and need for mechanical ventilation (IMV) was evaluated. RESULTS: Of the 119 patients included, 58% were men (median age 60 years), 88% had comorbidity, and 43% had a high-risk CALL score. Forty-three patients (36%) received CP, only 15 (12.6%) early (< 7 days). Twenty-two patients had to be transferred to the intensive care unit; 18 received IMV, and 15 died (12.6%). The use of CP was not associated with changes in mortality (p = 0.16), need for IMV (p = 0.79), or hospital stay (p = 0.24). Its early administration (< 7 days of symptoms) did not show a significant association either. The presence of heart disease and subsequently requiring IMV were independent factors of mortality. CONCLUSIONS: The use of CP in patients hospitalized for moderately severe COVID-19 was not associated with lower mortality, hospital stay, or the need for IMV.

Use of medical services in Chile: How sensitive are the results to different econometric models?

BACKGROUND: We compared different econometric specifications to model the use of medical services in Chile, focussing on visits to general practitioners and specialist physicians. METHODS: The evaluated models are the Poisson, Negative Binomial, Zero Inflated Poisson and Negative Binomial, two-step Hurdle model, sample-selection Poisson, and Latent Class model. These models were estimated using Chilean data for the years 2009 and 2015, separated by gender. RESULTS: Unlike previous literature that supported the use of the latent class model, our results show that the latent class model is not always the model with the best goodness of fit. Furthermore, the model with the best fit is not necessarily the model with the best predictive power. For instance, depending on the year and medical services, either the latent class model or the sample-selection Poisson model performs better than the other models. The results also show that the selection of the econometric model may have implications for the estimated influence that variables such as age, income, or affiliation to the public versus private sector have on the use of medical services. CONCLUSION: Using Chilean data, we have tested that the selection of an econometric method to model the use of medical services is not a problem with a unique answer. We recommend performing a sensitivity analysis of goodness of fit and predictive power between gender, healthcare services, or different years of datasets in future applications to be sure about the best model specification in each context.

[Inequality and inequity in the use of medical services in Chile, by age group, 2000-2011]. / Desigualdad e inequidad en la utilización de servicios médicos según grupos etarios en Chile, 2000-2011.

OBJECTIVE: To calculate indices of inequality and inequity in the use of medical services for children, adults, and older adults in Chile from 2000 to 2011. METHODS: Based on the CASEN survey (2000-2011), the concentration index (CI) was calculated to measure inequality and the horizontal inequity index (HI) was calculated to measure inequity in the use of medical services. Four groups were studied: children under 5, children aged 6-18 years, adults, and older adults. RESULTS: The results indicate higher levels of inequality in the use of specialized physician services in the child groups, and higher levels of inequity in the adult group. In the use of dental services, the greatest inequality and inequity is found among older adults. For visits to emergency services in the last two years for which data are available (2009 and 2011), the adult group shows a higher level of inequality. CONCUSIONS: In terms of levels of inequity and inequality, there are differences among children, adults, and older adults over the years in at least three of the six variables studied.

Chitosan microparticles mitigate nitrogen deficiency in tomato plants.

Nitrogen (N) deficiency is one of the most prevalent nutrient deficiencies in plants, and has a significant impact on crop yields. In this work we aimed to develop and evaluate innovative strategies to mitigate N deficiency. We studied the effect of supplementing tomato plants grown under suboptimal N nutrition with chitosan microparticles (CS-MPs) during short- and long-term periods. We observed that the supplementation with CS-MPs prevented the reduction of aerial biomass and the elongation of lateral roots (LR) triggered by N deficiency in tomato plantlets. In addition, levels of nitrates, amino acids and chlorophyll, which decreased drastically upon N deficiency, were either partial or totally restored upon CS-MPs addition to N deficient media. Finally, we showed that CS-MPs treatments increased nitric oxide (NO) levels in root tips and caused the up-regulation of genes involved in N metabolism. Altogether, we suggest that CS-MPs enhance the growth and development of tomato plants under N deficiency through the induction of biochemical and transcriptional responses that lead to increased N metabolism. We propose treatments with CS-MPs as an efficient practice focused to mitigate the nutritional deficiencies in N impoverished soils.

[Prevalence of Gilbert syndrome and its genetic determinants in Chile]. / Prevalencia de síndrome de Gilbert y sus determinantes genéticas en población chilena.

BACKGROUND: In Europeans the TATA box TA7 repeat promoter variant in the UGT1A1 gene (UGT1A1*28) is the major determinant of bilirubin levels. AIM: To study the prevalence of Gilbert Syndrome (GS) and its genetic determinants in Chile. MATERIAL AND METHODS: Three different studies were conducted. The prevalence of GS in Chile was assessed in 991 subjects with normal liver tests (ALT and GGT) from the 2nd National Health Survey. We defined GS as a total bilirubin (TB) between 1.4-5mg/dL. The second study assessed the genotype prevalence of SNP rs6742078 (in LD with UGT1A1*28) and rs4149056 in 500 DNA samples of non-related Hispanics. Finally, a case-control study was designed to assess the phenotype-genotype correlation. UGT1A1*28 and rs4149056 variants were determined by direct sequencing and allelic discrimination assays (TaqMan), respectively. RESULTS: Prevalence of GS in the general Chilean population was 2.6% (4.5% in males and 0.5% in female). No correlation with age, educational level or home location was found. Genotypes for UGT1A1*28 (TA6/6 50.5%, TA6/7 37.8%, TA7/7 11.7%) and rs4149056 (TT 74.1%, CT 22.8%, and CC 3.1%) variants were similar to Europeans. In the case-control study, most patients with GS were homozygotes for UGT1A1*28 (TA7/7, 74%). Of note, 44% of patients with intermediate TB levels were also TA7/7, compared to 7% in normal subjects. SLCO1B1 genotype was not correlated with TB levels. CONCLUSIONS: While the prevalence of GS was lower in Chile compared to Europeans (~5%), the prevalence of UGT1A1*28 homozygotes was similar (~12%). In Chilean Hispanics, the UGT1A1*28 variant explain 75% of GS phenotype.

[Main virulence factors of Listeria monocytogenes and its regulation]. / Principales factores de virulencia de Listeria monocytogenesy su regulación.

Listeria monocytogenesis a facultative intracellular pathogen, ubiquitous and aetiological agent of listeriosis. The main way of acquisition is the consumption of contaminated food and can cause serious medical conditions such as septicemia, meningitis and gastroenteritis, especially in children, immunocompromised individuals and seniors and abortions in pregnant women. An increase in cases of listeriosis worldwide has been reported and it is estimated that its prevalence in developed countries is in the range of 2 to 15 cases per one million population. This microorganism is characterized for the transition from the environment into the eukaryotic cell. Several virulence factors have been involved in the intracellular cycle that are regulated, primarily, by the PrfA protein, which in turn is regulated by different mechanisms operating at the transcriptional, translational and post-translational levels. Additionally, other regulatory mechanisms have been described as sigma factor, system VirR/S and antisense RNA, but PrfA is the most important control mechanism and is required for the expression of essential virulence factors for the intracellular cycle.

The impact of social violence on HIV risk for women in Colombia: A concurrent mixed methods study.

Gender, violence, and migration structurally impact health. The Venezuelan humanitarian crisis comprises the largest transnational migration in the history of the Americas. Colombia, a post-conflict country, is the primary recipient of Venezuelans. The Colombian context imposes high levels of violence on women across migration phases. There is little information on the relationship between violence and HIV risk in the region and how it impacts these groups. Evidence on how to approach the HIV response related to Venezuela's humanitarian crisis is lacking. Our study seeks to 1) understand how violence is associated with newly reported HIV/AIDS case rates for women in Colombian municipalities; and 2) describe how social violence impacts HIV risk, treatment, and prevention for Venezuelan migrant and refugee women undergoing transnational migration and resettlement in Colombia. We conducted a concurrent mixed-methods design. We used negative binomial models to explore associations between social violence proxied by Homicide Rates (HR) at the municipality level (n = 84). The also conducted 54 semi-structured interviews with Venezuelan migrant and refugee women and key informants in two Colombian cities to expand and describe contextual vulnerabilities to HIV risk, prevention and care related to violence. We found that newly reported HIV cases in women were 25% higher for every increase of 18 homicides per 100,000, after adjusting for covariates. Upon resettlement, participants cited armed actors' control, lack of government accountability, gender-based violence and stigmatization of HIV as sources of increased HIV risk for VMRW. These factors impose barriers to testing, treatment and care. Social violence in Colombian municipalities is associated with an increase in newly reported HIV/AIDS case rates in women. Violence hinders Venezuelan migrant and refugee women's access and engagement in available HIV prevention and treatment interventions.

Barriers and facilitators to HIV prevention and care for Venezuelan migrant/refugee women and girls in Colombia.

Venezuelan migrant and refugee women and girls (VMRWG) face risks of exposure to and infection from HIV and threats of multiple forms of violence (including GBV) during and after migration. Yet, there is a lack of evidence on barriers and facilitators to VMRWGs' access to HIV prevention and care services this population at all stages of their migration. We addressed this evidence gap by conducting a qualitative study composed of fifty-four semi-structured interviews with practitioners (n = 24) and VMRWG (n = 30) in the two largest receiving cities of migrants in Colombia. We sought to identify perceived barriers and facilitators to HIV prevention and care to inform policies and programmatic efforts. Analysis followed a theory-informed approach using the Socioecological Model. Findings describe multi-level barriers to access to HIV prevention and care related to discrimination, gender-based violence, rigid gender norms, lack of information and system fragmentation. Policies that integrate community-based networks and support intersectoral work are pivotal to breach the gaps between services and communities and develop a gender-sensitive approach that tackles the relationship between gender-based violence and HIV risk.

Ingestion of marine debris by juvenile Magellanic penguins (Spheniscus magellanicus) in wintering grounds of coastal Argentina.

The occurrence of marine debris in the stomach contents of young male and female Spheniscus magellanicus stranded along the Atlantic coast of northern Argentina during its post-breeding exodus is reported for the first time. Marine debris was found in 15.5 % of 148 dead penguins, with a higher proportion of debris found in females when compared to males. A total of 81 debris items was recorded; plastic and paper each contributed with an equal number of debris whereas rubber contributed with a single item. Chemical identification performed using FTIR/ATR revealed that plastic items were largely LDPE and PA; other polymers included HDPE, PP and PS. The average length of fragmented plastic debris are in line with those reported from penguins stranded along the southern Brazilian coasts. Our study indicates that loads of ingested marine debris were roughly five times lower when compared to the estimates for the species in Brazilian beaches.

Rubella vaccination of unknowingly pregnant women during 2006 mass campaign in Argentina.

We report a prospective study of 56 pregnant women inadvertently vaccinated with rubella vaccine during the 2006 campaign performed in Argentina. Of these patients, 48 (87%) were immune, whereas the remaining 9 (16%) were susceptible. In the latter group, 7 presented with a primary reaction to the vaccine confirmed through immunoglobulin (Ig) G antibody avidity testing or seroconversion of IgG titers. During the clinical and laboratory follow-up, newborns did not present evidence of infection or malformations compatible with congenital rubella syndrome.

Development and Characterization of Antimicrobial Textiles from Chitosan-Based Compounds: Possible Biomaterials Against SARS-CoV-2 Viruses.

Novel antiviral cotton fabrics impregnated with different formulations based on Chitosan (CH), citric acid (CA), and Copper (Cu) were developed. CA was selected as a CH crosslinker agent and Cu salts as enhancers of the polymer antimicrobial activity. The characterization of the polymeric-inorganic formulations was assessed by using atomic absorption spectroscopy, X-ray diffraction, Fourier transform infrared and UV-Vis spectroscopy, as well as thermogravimetric analysis. The achieved data revealed that CuO nanoparticles were formed by means of chitosan and citric acid in the reaction media. The antiviral activity of CH-based formulations against bovine alphaherpesvirus and bovine betacoronavirus was analyzed. Cotton fabrics were impregnated with the selected formulations and the antiviral properties of such textiles were examined before and after 5 to 10 washing cycles. Herpes simplex virus type 1 was selected to analyze the antiviral activities of the functionalized cotton fabrics. The resulting impregnated textiles exhibited integrated properties of good adhesion without substantially modifying their appearance and antiviral efficacy (~ 100%), which enabling to serve as a scalable biocidal layer in protective equipment's by providing contact killing against pathogens. Thus, the results revealed a viable contribution to the design of functional-active materials based on a natural polymer such as chitosan. This proposal may be considered as a potential tool to inhibit the propagation and dissemination of enveloped viruses, including SARS-CoV-2. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10904-021-02192-x.

Novel Phenobarbital-Loaded Nanostructured Lipid Carriers for Epilepsy Treatment: From QbD to In Vivo Evaluation.

Pharmacological treatments of central nervous system diseases are always challenging due to the restrictions imposed by the blood-brain barrier: while some drugs can effectively cross it, many others, some antiepileptic drugs among them, display permeability issues to reach the site of action and exert their pharmacological effects. The development of last-generation therapeutic nanosystems capable of enhancing drug biodistribution has gained ground in the past few years. Lipid-based nanoparticles are promising systems aimed to improve or facilitate the passage of drugs through biological barriers, which have demonstrated their effectiveness in various therapeutic fields, without signs of associated toxicity. In the present work, nanostructured lipid carriers (NLCs) containing the antiepileptic drug phenobarbital were designed and optimized by a quality by design approach (QbD). The optimized formulation was characterized by its entrapment efficiency, particle size, polydispersity index, and Z potential. Thermal properties were analyzed by DSC and TGA, and morphology and crystal properties were analyzed by AFM, TEM, and XRD. Drug localization and possible interactions between the drug and the formulation components were evaluated using FTIR. In vitro release kinetic, cytotoxicity on non-tumoral mouse fibroblasts L929, and in vivo anticonvulsant activity in an animal model of acute seizures were studied as well. The optimized formulation resulted in spherical particles with a mean size of ca. 178 nm and 98.2% of entrapment efficiency, physically stable for more than a month. Results obtained from the physicochemical and in vitro release characterization suggested that the drug was incorporated into the lipid matrix losing its crystalline structure after the synthesis process and was then released following a slower kinetic in comparison with the conventional immediate-release formulation. The NLC was non-toxic against the selected cell line and capable of delivering the drug to the site of action in an adequate amount and time for therapeutic effects, with no appreciable neurotoxicity. Therefore, the developed system represents a promising alternative for the treatment of one of the most prevalent neurological diseases, epilepsy.

The Dairy Cow Slurry Composition Used as Organic Fertilizer Is Influenced by the Level and Origin of the Dietary Protein.

Less than 30% of dairy cattle's nitrogen ingested is retained in milk. Therefore, large amounts of nitrogen can be excreted in manure and urine with a potential environmental impact. In addition, some legume forages can be more susceptible to proteolysis during the silage process than grasses, and dairy cows fed these legume silages would excrete a larger quantity of nitrogen in slurry. The objectives of this work were to evaluate the amount of nitrogen excretion in dairy cows fed different protein levels and legume silages with a view to improve the slurry quality as a co-product that can be used as fertilizer. Two double 3 × 3 Latin square trials were carried out in order to study three different protein levels (high, medium, and low) and three different silages (grass, faba bean, and field pea). Dry matter intake, milk production, and composition were not affected by treatments. The excretion of ammonia-N in the urine was almost four times lower in the diet with the lowest protein level. The ammonia-N in the urine was twice as high with the pea silage than faba bean and grass silages. In conclusion, the diet containing 13% of protein meets the protein requirement for lactating cows producing 31 kg daily, with low nitrogen excretion in the urine, and the main pathway for the excretion of surplus nitrogen from legume silages is through urine and the metabolization of pea silage protein goes toward ammonia-N.

Historical trends of the ecotoxicological pesticide risk from the main grain crops in Rolling Pampa (Argentina).

We showed the results of the first long-term analysis (1987-2019) of pesticide (herbicides, fungicides and insecticides) impact in the Rolling Pampa, one of the main agricultural areas of Argentina. Using a clear and meaningful tool, based not only on acute toxicity but also on scaling up the results to total sown area, we identified time trends for both pesticide impact and the ecoefficiency of modal pesticide profiles. By the end of the time series, soybean showed a pesticide impact four times greater than maize crop in the studied area. However, the time trend in the subperiod (2012-2019) showed a sustainable pattern of pesticide use in soybean crop, with an improvement in its ecoefficiency. Oppositely, maize showed a relatively constant ecoefficiency value during most of the time series, suggesting a possible path towards an unsustainable cropping system. Findings from this study suggest that some efforts have to be made to improve the pest management decisions towards a more efficient pesticide profiles in maize crop and to keep improving the ecotoxicity pesticide profile in soybean crops because of its large sown area in the studied area.

Mycosinthetized Ag, CuO and ZnO nanoparticles from a promising Trichoderma harzianum strain and their antifungal potential against important phytopathogens.

Fungal green biosynthesis of nanoparticles (NPs) is a promising eco-friendly method for mass-scale production. In the present study Ag, CuO and ZnO nanoparticles were biogenically synthetized using a cell filtrate of a strain of Trichoderma harzianum as a reducer and stabilizer agent. The structure, morphology and physicochemical properties of the NPs were characterized through transmission electron microscopy, dynamic light scattering, wide angle X-ray scattering and thermogravimetric analysis. Since nanotechnology could offer promising applications in agricultural area, we evaluated the ability of the NPs to reduce the growth of important fungal phytopathogens as Alternaria alternata, Pyricularia oryzae and Sclerotinia sclerotiorum. Silver and CuO NPs reduced significantly the mycelial growth of A. alternata and P. oryzae in a dose dependent manner. This is the first report of a multiple extracellular biosynthesis of NPs from T. harzianum and the first time that CuO and ZnO NPs were obtained from this fungus. In addition, we highlighted the rapid production of NPs, as well as, the potential of Ag and CuO for the control of phytopathogens. On the other hand, the three types of NPs could be easily and sustainably produced on a large scale with the chance of having multiple applications in biotechnological processes.

Chitosan microparticles improve tomato seedling biomass and modulate hormonal, redox and defense pathways.

Agrobiotechnology challenges involve the generation of new sustainable bioactives with emerging properties as plant biostimulants with reduced environment impact. We analyzed the potential use of recently developed chitosan microparticles (CS-MP) as growth promoters of tomato which constitutes one of the most consumed vegetable crops worldwide. Treatments of tomato seeds with CS-MP improved germination and vigor index. In addition, CS-MP sustained application triggered an improvement in root and shoot biomass reinforcing tomato performance before transplanting. The level of reactive oxygen species (ROS), antioxidant enzyme activities and defense protein markers were modulated by CS-MP treatment in tomato plantlets. Analyses of ARR5:GUS and DR5:GUS transgenic reporter tomato lines highlighted the participation of cytokinin and auxin signaling pathways during tomato root promotion mediated by CS-MP. Our findings claim a high commercial potential of CS-MP to be incorporated as a sustainable input for tomato production.

Enhanced Properties of Chitosan Microparticles over Bulk Chitosan on the Modulation of the Auxin Signaling Pathway with Beneficial Impacts on Root Architecture in Plants.

Improving the root system architecture (RSA) under adverse environmental conditions by using biostimulants is emerging as a new way to boost crop productivity. Recently, we have reported the characterization of novel chitosan-based microparticles (CS-MPs) with promising biological properties as rooting agents in lettuce. In this work, we demonstrated that in contrast to bulk chitosan (CS), which exerts root growth inhibition, CS-MPs promoted root growth and development from 1 to 10 µg mL-1 without cytotoxicity effects at higher doses in Arabidopsis and lettuce seedlings. In addition, we studied the mechanistic mode of action of CS-MPs in the development of early RSA in the Arabidopsis model. CS-MPs unchained accurate and sustained spatio-temporal activation of the nuclear auxin signaling pathway. Our findings validated a promising scenario for the application of CS-MPs in the modulation of RSA to respond to changing soil environments and improve crop performance.

Uso de plasma de convalecientes de COVID-19 en pacientes hospitalizados por SARS-CoV-2 de moderada grave-dad en la Región de Los Ríos, Chile

Introducción: COVID-19 cobró millones de vidas especialmente en la era pre-vacunas. Estudios preliminares mostraban eficacia promisoria del plasma de personas convalecientes anti SARS-CoV-2 (PPC). Objetivo: evaluar la eficacia del PPC en hospitalizados por COVID-19 de moderada gravedad. Material y Métodos: Estudio retrospectivo, bicéntrico, en adultos hospitalizados por COVID-19 moderado (no crítico) que requirieron oxigenoterapia. Al plasma donado por sobrevivientes de cuadros leves (600 cc) se les realizó búsqueda de IgG anti SARS-CoV-2. Se evaluó su impacto en mortalidad, estadía hospitalaria (días) y necesidad de ventilación mecánica (VMI). Resultados: De los 119 pacientes incluidos, 58% eran hombres (edad mediana 60 años), 88% poseía comorbilidad y 43% tenía "CALL score" de alto riesgo. 43 pacientes (36%) recibieron PPC, sólo 15 (12,6%) precozmente (< 7 días). 22 pacientes debieron trasladarse a unidad intensiva, 18 recibieron VMI y 15 fallecieron (12,6%). El uso de PPC no se asoció a cambios en la mortalidad (p = 0,16), necesidad de VMI (p = 0,79) ni en la estadía hospitalaria (p = 0,24). Su administración en forma precoz (< 7 días de síntomas) tampoco demostró asociación significativa. La presencia de cardiopatía y el requerir posteriormente VMI fueron factores independientes asociados a mortalidad. Conclusiones: El uso de PPC en pacientes hospitalizados por COVID-19 de moderada gravedad no se asoció a menor mortalidad, estadía hospitalaria ni necesidad de VMI.

Introduction: COVID-19 claimed millions of lives, mainly in the pre-vaccine era. Preliminary studies showed promising efficacy of convalescent plasma against SARS-CoV-2 (CP). Objective: To evaluate the efficacy of CP in patients hospitalized for COVID-19 with moderate severity. Methods: Retrospective, bicentric study including adults hospitalized for moderate (non-critical) COVID-19 who required oxygen therapy. CP donated by survivors of mild cases (600 cc) were searched for IgG anti-SARS-CoV-2. Its impact on mortality, hospital stay (days), and need for mechanical ventilation (IMV) was evaluated. Results: Of the 119 patients included, 58% were men (median age 60 years), 88% had comorbidity, and 43% had a high-risk CALL score. Forty-three patients (36%) received CP, only 15 (12.6%) early (< 7 days). Twenty-two patients had to be transferred to the intensive care unit; 18 received IMV, and 15 died (12.6%). The use of CP was not associated with changes in mortality (p = 0.16), need for IMV (p = 0.79), or hospital stay (p = 0.24). Its early administration (< 7 days of symptoms) did not show a significant association either. The presence of heart disease and subsequently requiring IMV were independent factors of mortality. Conclusions: The use of CP in patients hospitalized for moderately severe COVID-19 was not associated with lower mortality, hospital stay, or the need for IMV.

Salicylic acid loaded chitosan microparticles applied to lettuce seedlings: Recycling shrimp fishing industry waste.

Shrimp fishing industry wastes are still a main problem with high environmental impact worldwide. In this study, chitosan with ultra-high molecular weight and deacetylation degree ≥85% was obtained from shrimp fishing industry waste from Argentinean Patagonia. Chitosan based microparticles capable to entrap salicylic acid, a phytohormone known to play major role in the regulation of plant defense response against various pathogens, were prepared using TPP as crosslinker. Unloaded microparticles and microparticles loading several salicylic acid amount were fully characterized exhibiting a size between 1.57 µm and 2.45 µm. Furthermore, a good PDI, entrappment efficiencies from 59% to 98% and salicylic acid sustained release over 24 h were achieved. Chitosan based microparticles were non toxic in most of the doses applied in lettuce seedlings. Instead, microparticles can positively modulate plant growth and have the potential to improve plant defense responses. In particular salicylic acid loaded microparticles effect was very promising for its application as activators of salicylic acid dependent plant defense responses in lettuce as a model of horticultural plant species.