Selective inhibition of interleukin 6 receptor decreased inflammatory cytokines and increased proteases in an experimental model of critical calvarial defect.

Considering the lack of consensus related to the impact of selective IL-6 receptor inhibition on bone remodeling and the scarcity of reports, especially on large bone defects, this study proposed to evaluate the biological impact of the selective inhibitor of interleukin-6 receptor (tocilizumab) in an experimental model of critical calvarial defect in rats. In this preclinical and in vivo study, 24 male Wistar rats were randomly divided into two groups (n=12/group): defect treated with collagen sponge (CG) and defect treated with collagen sponge associated with 2 mg/kg tocilizumab (TCZ). The defect in the parietal bone was created using an 8-mm diameter trephine drill. After 90 days, the animals were euthanized, and tissue samples (skull caps) were evaluated through micro-CT, histological, immunohistochemistry, cytokines, and RT-qPCR analyses. Tocilizumab reduced mononuclear inflammatory infiltration (P<0.05) and tumor necrosis factor (TNF)-α levels (P<0.01) and down-regulated tissue gene expression of BMP-2 (P<0.001), RUNX-2 (P<0.05), and interleukin (IL)-6 (P<0.05). Moreover, it promoted a stronger immunostaining of cathepsin and RANKL (P<0.05). Micro-CT and histological analyses revealed no impact on general bone formation (P>0.05). The bone cells (osteoblasts, osteoclasts, and osteocytes) in the defect area were similar in both groups (P>0.05). Tocilizumab reduced inflammatory cytokines, decreased osteogenic protein, and increased proteases in a critical bone defect in rats. Ninety days after the local application of tocilizumab in the cranial defect, we did not find a significant formation of bone tissue compared with a collagen sponge.

Selective inhibition of interleukin 6 receptor decreased inflammatory cytokines and increased proteases in an experimental model of critical calvarial defect

Considering the lack of consensus related to the impact of selective IL-6 receptor inhibition on bone remodeling and the scarcity of reports, especially on large bone defects, this study proposed to evaluate the biological impact of the selective inhibitor of interleukin-6 receptor (tocilizumab) in an experimental model of critical calvarial defect in rats. In this preclinical and in vivo study, 24 male Wistar rats were randomly divided into two groups (n=12/group): defect treated with collagen sponge (CG) and defect treated with collagen sponge associated with 2 mg/kg tocilizumab (TCZ). The defect in the parietal bone was created using an 8-mm diameter trephine drill. After 90 days, the animals were euthanized, and tissue samples (skull caps) were evaluated through micro-CT, histological, immunohistochemistry, cytokines, and RT-qPCR analyses. Tocilizumab reduced mononuclear inflammatory infiltration (P<0.05) and tumor necrosis factor (TNF)-α levels (P<0.01) and down-regulated tissue gene expression of BMP-2 (P<0.001), RUNX-2 (P<0.05), and interleukin (IL)-6 (P<0.05). Moreover, it promoted a stronger immunostaining of cathepsin and RANKL (P<0.05). Micro-CT and histological analyses revealed no impact on general bone formation (P>0.05). The bone cells (osteoblasts, osteoclasts, and osteocytes) in the defect area were similar in both groups (P>0.05). Tocilizumab reduced inflammatory cytokines, decreased osteogenic protein, and increased proteases in a critical bone defect in rats. Ninety days after the local application of tocilizumab in the cranial defect, we did not find a significant formation of bone tissue compared with a collagen sponge.

In vitro effects of lapachol and ß-lapachone against Leishmania amazonensis.

Leishmaniasis is a neglected disease that affects millions of people worldwide, and special attention should be given to treatment because the available drugs have limitations, which can lead to low therapeutic adherence and parasitic resistance. This study evaluated the activity of the bioactive naphthoquinones, lapachol and ß-lapachone, against Leishmania amazonensis. The cell alterations were evaluated in vitro on promastigote and amastigote forms. The lethal dose (LD50) at 24, 48, and 72 h on the promastigote's forms using lapachol was 75.60, 72.82, and 58.85 µg/mL and for ß-lapachone was 0.65, 1.24, and 0.71 µg/mL, respectively. The naphthoquinones significantly inhibited the survival rate of L. amazonensis amastigotes at 83.11, 57.59, and 34.95% for lapachol (82.28, 41.14, and 20.57 µg/mL), and 78.49, 83.25, and 80.22% for ß-lapachone (3.26, 1.63, and 0.815 µg/mL). The compounds on the promastigote's forms led to the loss of mitochondrial membrane potential, induced changes in the integrity of the membrane, caused damage to cells suggestive of the apoptotic process, and showed inhibition of tumor necrosis factor (TNF)-α and interleukin (IL)-6 production. The results showed that these naphthoquinones are promising candidates for research on new drugs with anti-Leishmania activity derived from natural products.

In vitro effects of lapachol and β-lapachone against Leishmania amazonensis

Leishmaniasis is a neglected disease that affects millions of people worldwide, and special attention should be given to treatment because the available drugs have limitations, which can lead to low therapeutic adherence and parasitic resistance. This study evaluated the activity of the bioactive naphthoquinones, lapachol and β-lapachone, against Leishmania amazonensis. The cell alterations were evaluated in vitro on promastigote and amastigote forms. The lethal dose (LD50) at 24, 48, and 72 h on the promastigote's forms using lapachol was 75.60, 72.82, and 58.85 μg/mL and for β-lapachone was 0.65, 1.24, and 0.71 μg/mL, respectively. The naphthoquinones significantly inhibited the survival rate of L. amazonensis amastigotes at 83.11, 57.59, and 34.95% for lapachol (82.28, 41.14, and 20.57 µg/mL), and 78.49, 83.25, and 80.22% for β-lapachone (3.26, 1.63, and 0.815 µg/mL). The compounds on the promastigote's forms led to the loss of mitochondrial membrane potential, induced changes in the integrity of the membrane, caused damage to cells suggestive of the apoptotic process, and showed inhibition of tumor necrosis factor (TNF)-α and interleukin (IL)-6 production. The results showed that these naphthoquinones are promising candidates for research on new drugs with anti-Leishmania activity derived from natural products.

Mefenoxam and pyraclostrobin: toxicity and in vitro inhibitory activity against Pythium insidiosum.

The objective of this study is to verify in vitro susceptibility of Pythium insidiosum against the agricultural fungicides mefenoxam and pyraclostrobin and evaluate the toxicity of both compounds. Twenty-one P. insidiosum isolates were tested against mefenoxam and pyraclostrobin using the broth microdilution method. Minimum inhibitory and oomicidal concentrations for both compounds were established. Additionally, scanning electron microscopy was performed on P. insidiosum hyphae treated with the sublethal concentration of each fungicide. The toxicity of the compounds was evaluated in vivo Caenorhabditis elegans model. The concentration to inhibit 100% of P. insidiosum growth ranged from 0·625 to 10 µg ml-1 for mefenoxam and from 0·019 to 5 µg ml-1 for pyraclostrobin. The SEM analysis revealed changes on the surface of the hyphae treated with the fungicides, suggesting possible damage caused by these compounds. There was no evidence of toxicity in vivo models. Mefenoxam and pyraclostrobin did not show toxicity at the doses evaluated and have inhibitory effects on the pathogenic oomycete P. insidiosum. However, further evaluations of their pharmacokinetics and toxicity in different animal species and possible pharmacological interactions are necessary to infer a possible use in the clinical management of pythiosis.

The prognostic significance of immunophenotypes in canine malignant mammary tumors / [Significância prognóstica dos imunofenótipos em tumores mamários malignos caninos]

Canine malignant mammary neoplasms (CMMN) exhibit behavioral variability with the patient survival time depending on several prognostic factors. In the present study, 134 CMMN were selected and different immunophenotypes and their associations with clinical and pathological parameters were identified. The tumors were classified as follows: 46% of luminal B HER2-, 34% of luminal A, 13% of triple-negative, and 7% of luminal B HER2+. Shorter specific survival time were associated with larger tumor sizes (>3.0 cm, HR=1.94; P=0.0209), lymph node metastasis or distant metastasis (HR= 2.82; P <.0001), more aggressive histological types (HR= 7.15, P<0.0001), higher histological grades (HR= 12.97 P=0.011), angiolymphatic invasion (HR=4.68, P<0.0001) and luminal B HER2 - (HR= 3.27, P<0.0001) and luminal B HER2 + (HR= 7.14 P<0.0001) immunophenotypes. In patients with lymph nodal metastasis, shorter survival times were associated with luminal immunophenotype B HER2 + (P=0.003). However, in patients without metastasis, an increased risk of death was associated with the aggressive histological type. In conclusion, the classification in our study allowed us to identify subtypes with different prognoses in canine malignant mammary tumors. Factors such as clinical stage, histological type, luminal B HER2+ subtype, and angiolymphatic invasion were the most important prognostic factors.

Neoplasias mamárias malignas caninas (CMMN) apresentam variável comportamento biológico e o tempo de sobrevida depende de diversos fatores prognósticos. Neste estudo, foram selecionadas 134 CMMN, bem como identificados diferentes imunofenótipos e suas associações com parâmetros clínicos e patológicos. Os tumores foram classificados em: 46% luminal B HER2-, 34% luminal A, 13% triplo negativo e 7% luminal B HER2+. Menores taxas de sobrevida específica foram associadas a tamanhos de tumor maiores (> 3,0cm; HR = 1,94; P = 0,0209), metástases em nodais ou a distância (HR = 2,82; P <0,0001), tipos histológicos mais agressivos (HR = 7,15; P <0,0001), graus histológicos mais elevados (HR = 12,97; P = 0,011), invasão angiolinfática (HR = 4,68; P <0,0001) e aos imunofenótipos luminal B HER2- (HR = 3,27; P <0,0001) e luminal B HER2+ ( HR = 7,14; P <0,0001). Em pacientes com estágio avançado, menor sobrevida específica foi associada ao imunofenótipo luminal B HER2+ (P = 0,003). Entretanto, em estágio inicial, um risco aumentado de óbito foi associado a tipos histológicos agressivos. Em conclusão, a classificação utilizada no presente estudo permitiu identificar subtipos com diferentes prognósticos em CMMN. Estágio clínico, tipo histológico, subtipo luminal B HER2+ e invasão angiolinfática foram os fatores prognósticos mais importantes.

Stromal IL2 is related to the neutrophil/lymphocyte ratio in epithelial ovarian cancer.

INTRODUCTION: There is a need for the development of new biomarkers for diagnosis and prognosis of ovarian cancer, which can ideally serve as targets for new therapeutic modalities and individualization of treatment. The objectives of this study were to determine the prognostic significance of the neutrophil/lymphocyte ratio in the peripheral blood of patients with ovarian cancer and tumor staging, and to associate this marker with the immune expression of a panel of cytokines. METHODS: The study included 24 patients with malignant ovarian neoplasia treated at the Pelvic Mass Outpatient Clinic of the Clinical Hospital of the Federal University of Triângulo Mineiro. The neutrophil/lymphocyte ratio was calculated as the absolute number of neutrophils divided by the absolute number of lymphocytes. Expression of the cytokines was evaluated by the immunohistochemistry method (IL2, IL5, IL6, IL8, IL10 and TNF-R1). Fisher's statistical test was used for the comparisons of immunohistochemical expression with the neutrophil/lymphocyte ratio, and the unpaired T-Test was used in the analysis of the association of this ratio with tumor staging. RESULTS: A neutrophil/lymphocyte ratio > 2.6 was significantly higher in the more advanced stages (II-IV) of malignant ovarian neoplasia (p = 0.0098). In addition, this ratio > 2.6 was associated with IL2 stromal immunostaining (1-3) (p = 0.0472). CONCLUSION: Stromal IL-2 is associated with higher a neutrophil/lymphocyte ratio, suggesting a worse prognosis in ovarian cancer and its role in tumor immunology; a neutrophil/lymphocyte ratio > 2.6 is associated with more advanced stages of malignant ovarian neoplasia.

Concentration of collagen fibers in the musculature of broiler chickens fed with cupuacu seed by-product / Concentração de fibras colágenas na musculatura de frangos alimentados com farinha de cupuaçu

In this essay, we quantify the concentration of collagen fibers in broiler chickens exposed to increasing concentrations of cupuacu seed by-product. Collection of material was carried out in five chickens per treatment at 70 days old in the groups: control, 5% and 10% inclusion of cupuacu seed by-product. Fragments of Thoracic Pectoralis (PT) and Iliotibial lateralis (ITL) muscles were prepared for light and electronic microscopy. The amount of collagen fibers in the muscle groups was 1.08±0.61% in the PTC group; 6.24±2.58% in PT5% and 7.30±2.75% in PT10%. In the Iliotibial Lateralis groups, the results were 6.96±3.14% in the ITLC; 7.43±4.22% in the ITL5% and 8.66±2.35% in ITL10%. The amount of collagen fibers in the ITL5% and ITL10% groups showed no significant statistical difference. However, when compared to the ILTC group, there was a significant statistical difference. The PT muscle responds to standard nutritional changes, unlike the ILT muscle, which requires a high-nutrient formulation. The use of 5% cupuacu seed by-product has proven to be a viable alternative source of animal feed, as it promotes an increase in the concentrations of collagen fibers in the musculature of broiler chickens and is possibly the determining factor in meat texture.(AU)

Neste estudo, foram quantificadas as concentrações de fibras colágenas de frangos expostos a crescentes concentrações de farinha de cupuaçu. A coleta de material foi realizada em cinco animais por tratamento, aos 70 dias de idade, nos grupos: controle, inclusão de 5% e de 10% de farinha de cupuaçu. Fragmentos dos músculos peitoral torácico (PT) e iliotibial lateral (ITL) foram preparados para microscopia de luz e eletrônica. A quantidade de fibras colágenas nos grupos foi: 1,08±0,61% no grupo PTC; 6,24±2,58% em PT5% e 7,30±2,75% em PT10%. Nos grupos iliotibial lateral, os resultados foram: 6,96±3,14% no ITLC; 7,43±4,22% no ITL5% e 8,66±2,35% em ITL10%. A quantidade de fibras colágenas nos grupos ITL5% e ITL10% não apresentou diferença estatística significativa. No entanto, quando comparados ao grupo ILTC, houve diferença estatística significativa. O músculo PT responde a mudanças nutricionais padrão, ao contrário do músculo ILT, que requer alta formulação nutricional. O uso de 5% de farinha de cupuaçu provou ser uma fonte alternativa viável de alimentação animal, pois promove um aumento nas concentrações de fibras de colágeno na musculatura de frangos de corte e é possivelmente um fator determinante na textura da carne.(AU)

Concentration of collagen fibers in the musculature of broiler chickens fed with cupuacu seed by-product / Concentração de fibras colágenas na musculatura de frangos alimentados com farinha de cupuaçu

In this essay, we quantify the concentration of collagen fibers in broiler chickens exposed to increasing concentrations of cupuacu seed by-product. Collection of material was carried out in five chickens per treatment at 70 days old in the groups: control, 5% and 10% inclusion of cupuacu seed by-product. Fragments of Thoracic Pectoralis (PT) and Iliotibial lateralis (ITL) muscles were prepared for light and electronic microscopy. The amount of collagen fibers in the muscle groups was 1.08±0.61% in the PTC group; 6.24±2.58% in PT5% and 7.30±2.75% in PT10%. In the Iliotibial Lateralis groups, the results were 6.96±3.14% in the ITLC; 7.43±4.22% in the ITL5% and 8.66±2.35% in ITL10%. The amount of collagen fibers in the ITL5% and ITL10% groups showed no significant statistical difference. However, when compared to the ILTC group, there was a significant statistical difference. The PT muscle responds to standard nutritional changes, unlike the ILT muscle, which requires a high-nutrient formulation. The use of 5% cupuacu seed by-product has proven to be a viable alternative source of animal feed, as it promotes an increase in the concentrations of collagen fibers in the musculature of broiler chickens and is possibly the determining factor in meat texture.(AU)

Neste estudo, foram quantificadas as concentrações de fibras colágenas de frangos expostos a crescentes concentrações de farinha de cupuaçu. A coleta de material foi realizada em cinco animais por tratamento, aos 70 dias de idade, nos grupos: controle, inclusão de 5% e de 10% de farinha de cupuaçu. Fragmentos dos músculos peitoral torácico (PT) e iliotibial lateral (ITL) foram preparados para microscopia de luz e eletrônica. A quantidade de fibras colágenas nos grupos foi: 1,08±0,61% no grupo PTC; 6,24±2,58% em PT5% e 7,30±2,75% em PT10%. Nos grupos iliotibial lateral, os resultados foram: 6,96±3,14% no ITLC; 7,43±4,22% no ITL5% e 8,66±2,35% em ITL10%. A quantidade de fibras colágenas nos grupos ITL5% e ITL10% não apresentou diferença estatística significativa. No entanto, quando comparados ao grupo ILTC, houve diferença estatística significativa. O músculo PT responde a mudanças nutricionais padrão, ao contrário do músculo ILT, que requer alta formulação nutricional. O uso de 5% de farinha de cupuaçu provou ser uma fonte alternativa viável de alimentação animal, pois promove um aumento nas concentrações de fibras de colágeno na musculatura de frangos de corte e é possivelmente um fator determinante na textura da carne.(AU)

Bothrops alternatus snake venom induces apoptosis of skeletal muscle cells in a rabbit model / O veneno da serpente Bothrops alternatus induz apoptose nas células musculares de coelhos

Este estudo objetiva reportar a ocorrência de apoptose in vivo induzida pelo veneno da serpente Bothrops alternatus em células musculares esqueléticas. Cinco coelhos machos, adultos, receberam 150µg/kg de veneno no músculo vasto lateral, enquanto outros cinco animais receberam 0,1% de BSA diluído em PBS no mesmo local. Após 12 horas, os animais foram eutanasiados, e amostras do local de inoculação foram coletadas para análise histopatológica. Foram evidenciadas necrose e hemorragia nas células musculares. Além disso, a análise imuno-histoquímica para identificação de caspase-3 ativada revelou marcações granulares e agregadas no citoplasma das células musculares, compatíveis com o processo de apoptose. Este é o primeiro relato que confirma o veneno de B. alternatus como causador de apoptose in vivo em células musculares esqueléticas.(AU)

Mechanisms involved in anti-aging effects of guarana (Paullinia cupana) in Caenorhabditis elegans.

Guarana (Paullinia cupana) is habitually ingested by people in the Amazon region and is a key ingredient in various energy drinks consumed worldwide. Extension in longevity and low prevalence of chronic age-related diseases have been associated to habitual intake of guarana. Anti-aging potential of guarana was also demonstrated in Caenorhabditis elegans; however, the mechanisms involved in its effects are not clear. Herein, we investigated the putative pathways that regulate the effects of guarana ethanolic extract (GEE) on lifespan using C. elegans. The major known longevity pathways were analyzed through mutant worms and RT-qPCR assay (DAF-2, DAF-16, SKN-1, SIR-2.1, HSF-1). The possible involvement of purinergic signaling was also investigated. This study demonstrated that GEE acts through antioxidant activity, DAF-16, HSF-1, and SKN-1 pathways, and human adenosine receptor ortholog (ADOR-1) to extend lifespan. GEE also downregulated skn-1, daf-16, sir-2.1 and hsp-16.2 in 9-day-old C. elegans, which might reflect less need to activate these protective genes due to direct antioxidant effects. Our results contribute to the comprehension of guarana effects in vivo, which might be helpful to prevent or treat aging-associated disorders, and also suggest purinergic signaling as a plausible therapeutic target for longevity studies.

Predominance of Nyssomyia neivai (Pinto) on the Islands of the Paraná River, Southern Brazil.

Leishmaniasis is a vector-borne disease caused by the protozoan Leishmania and it is one of the six most important infectious diseases in the world. The aim of this study was to conduct a research on the fauna and most frequented ecotopes by sandflies on islands of the Paraná River. The sandflies were collected with Falcão light traps in 10 islands in the municipalities of São Pedro do Paraná, Porto Rico, and Querência do Norte, in Paraná State, Brazil, from November 2012 to November 2014. In total, 76,145 specimens of Nyssomyia neivai, the only species found, were collected, of which 63,015 were female and 13,130, male. The largest number of sandflies was collected mainly in domiciles and peridomiciles. The islands of the Paraná River showed predominance of Ny. neivai, which is largely involved in the transmission of Leishmania and a risk of human leishmaniasis to the island inhabitants and tourists.

Calophyllum brasiliense Modulates the Immune Response and Promotes Leishmania amazonensis Intracellular Death.

Calophyllum brasiliense is a plant from the Brazilian rain forests and has been used in folk medicine for the treatment of various diseases, including leishmaniasis. This infectious disease depends on the Leishmania sp. and the host immune response. C. brasiliense antileishmanial activity is well known, but the effects on immune response remain to be investigated. This study showed the leishmanicidal and immunomodulatory effects of a 30 µg/mL of hydroalcoholic extract of C. brasiliense in murine macrophages before and after Leishmania (Leishmania) amazonensis infection. The semiquantitative cytokine RNA expression was determined by RT-PCR and the anti-Leishmania activity was measured by infection index (IF). Hydroalcoholic extract of C. brasiliense reduced more than 95% of IF when used before and after Leishmania infection, with 3 and 24 h of treatment (p < 0.05). C. brasiliense inhibited or reduced significantly (p < 0.05) the TNF-α, IL-1ß, IL-18, and IL-10 mRNA expression. The antileishmanial and anti-inflammatory effects showed the potential of C. brasiliense as an alternative therapy for leishmaniasis and it must be investigated.

Two new species of Neanuridae (Collembola: Poduromorpha) from littoral of Rio de Janeiro, Brazil.

Samples collected in "restinga" areas of two conservation units in Rio de Janeiro state revealed the presence of two new species of Neanuridae family. The first, Pseudachorutes solaris sp. nov., from Parque Estadual da Costa do Sol and from Parque Nacional da Restinga de Jurubatiba, differs from other species for having 34-50 vesicles in the postantennal organ, and the second, Friesea jurubatiba sp. nov. from Parque Nacional da Restinga de Jurubatiba, differs from other species for having 8 clavate chaetae in the abdominal segment VI.

Mechanisms involved in anti-aging effects of guarana (Paullinia cupana) in Caenorhabditis elegans

Guarana (Paullinia cupana) is habitually ingested by people in the Amazon region and is a key ingredient in various energy drinks consumed worldwide. Extension in longevity and low prevalence of chronic age-related diseases have been associated to habitual intake of guarana. Anti-aging potential of guarana was also demonstrated in Caenorhabditis elegans; however, the mechanisms involved in its effects are not clear. Herein, we investigated the putative pathways that regulate the effects of guarana ethanolic extract (GEE) on lifespan using C. elegans. The major known longevity pathways were analyzed through mutant worms and RT-qPCR assay (DAF-2, DAF-16, SKN-1, SIR-2.1, HSF-1). The possible involvement of purinergic signaling was also investigated. This study demonstrated that GEE acts through antioxidant activity, DAF-16, HSF-1, and SKN-1 pathways, and human adenosine receptor ortholog (ADOR-1) to extend lifespan. GEE also downregulated skn-1, daf-16, sir-2.1 and hsp-16.2 in 9-day-old C. elegans, which might reflect less need to activate these protective genes due to direct antioxidant effects. Our results contribute to the comprehension of guarana effects in vivo, which might be helpful to prevent or treat aging-associated disorders, and also suggest purinergic signaling as a plausible therapeutic target for longevity studies.

Modeling habitat suitability of the invasive clam Corbicula fluminea in a Neotropical shallow lagoon, southern Brazil / Modelagem da adequabilidade de habitat do bivalve invasor Corbicula fluminea em uma lagoa rasa Neotropical

This study aimed to model the habitat suitability for an invasive clam Corbicula fluminea in a coastal shallow lagoon in the southern Neotropical region (30.22, 50.55). The lagoon (19km2, maximum deep 2.5m) was sampled with an Ekman dredge in an orthogonal matrix comprising 84 points. At each sampling point, were obtained environmental descriptors as depth, organic matter content (OMC), average granulometry (Avgran), and the percentage of sand (Pcsand). Prediction performance of Generalized Linear Models (GLM), Generalized Additive Models (GAM) and Boosted Regression Tree (BRT) were compared. Also, niche overlapping with other native clam species (Castalia martensi, Neocorbicula limosa and Anodontites trapesialis) was examined. A BRT model with 1400 trees was selected as the best model, with cross-validated correlation of 0.82. The relative contributions of predictors were Pcsand-42.6%, OMC-35.8%, Avgran-10.9% and Depth-10.8%. Were identified that C. fluminea occur mainly in sandy sediments with few organic matter, in shallow areas nor by the shore. The PCA showed a wide niche overlap with the native clam species C. martensi, N. limosa and A. trapesialis.(AU)

O objetivo de deste estudo foi modelar a adequabilidade de habitat do bivalve invasor Corbicula fluminea em uma lagoa costeira na região Neotropical (30.22, 50.55). A lagoa (19km2, 2,5 m de profundidade máxima) foi amostrada com uma draga Ekman em uma matriz ortogonal compreendendo 84 pontos. Em cada ponto de amostragem foram obtidos descritores ambientais como a profundidade, teor de matéria orgânica (OMC), granulometria média (Avgran), e a percentagem de areia (Pcsand). O poder preditivo dos métodos Modelos Lineares Generalizados (GLM), Modelos Aditivos Generalizados (GAM) e Boosted Regression Trees (BRT) foram comparados. Além disso, a sobreposição de nicho com espécies de moluscos nativos (Castalia martensi, Neocorbicula limosa e Anodontites trapesialis) foi examinada. Um modelo BRT com 1.400 árvores foi selecionado como o melhor modelo, com correlação da validação cruzada de 0,82. As contribuições relativas dos preditores foram Pcsand-42,6%, OMC-35,8%, Avgran-10,9% e profundidade-10,8%. Foi demonstrado que C. fluminea está associada a sedimentos arenosos com pouca matéria orgânica, em áreas rasas próximo às margens. A PCA mostrou uma ampla sobreposição de nicho com as espécies de moluscos nativos C. martensi, N. limosa e A. trapesialis.(AU)

Modeling habitat suitability of the invasive clam Corbicula fluminea in a Neotropical shallow lagoon, southern Brazil / Modelagem da adequabilidade de habitat do bivalve invasor Corbicula fluminea em uma lagoa rasa Neotropical

Abstract This study aimed to model the habitat suitability for an invasive clam Corbicula fluminea in a coastal shallow lagoon in the southern Neotropical region (–30.22, –50.55). The lagoon (19km2, maximum deep 2.5m) was sampled with an Ekman dredge in an orthogonal matrix comprising 84 points. At each sampling point, were obtained environmental descriptors as depth, organic matter content (OMC), average granulometry (Avgran), and the percentage of sand (Pcsand). Prediction performance of Generalized Linear Models (GLM), Generalized Additive Models (GAM) and Boosted Regression Tree (BRT) were compared. Also, niche overlapping with other native clam species (Castalia martensi, Neocorbicula limosa and Anodontites trapesialis) was examined. A BRT model with 1400 trees was selected as the best model, with cross-validated correlation of 0.82. The relative contributions of predictors were Pcsand-42.6%, OMC-35.8%, Avgran-10.9% and Depth-10.8%. Were identified that C. fluminea occur mainly in sandy sediments with few organic matter, in shallow areas nor by the shore. The PCA showed a wide niche overlap with the native clam species C. martensi, N. limosa and A. trapesialis.

Resumo O objetivo de deste estudo foi modelar a adequabilidade de habitat do bivalve invasor Corbicula fluminea em uma lagoa costeira na região Neotropical (–30.22, –50.55). A lagoa (19km2, 2,5 m de profundidade máxima) foi amostrada com uma draga Ekman em uma matriz ortogonal compreendendo 84 pontos. Em cada ponto de amostragem foram obtidos descritores ambientais como a profundidade, teor de matéria orgânica (OMC), granulometria média (Avgran), e a percentagem de areia (Pcsand). O poder preditivo dos métodos Modelos Lineares Generalizados (GLM), Modelos Aditivos Generalizados (GAM) e Boosted Regression Trees (BRT) foram comparados. Além disso, a sobreposição de nicho com espécies de moluscos nativos (Castalia martensi, Neocorbicula limosa e Anodontites trapesialis) foi examinada. Um modelo BRT com 1.400 árvores foi selecionado como o melhor modelo, com correlação da validação cruzada de 0,82. As contribuições relativas dos preditores foram Pcsand-42,6%, OMC-35,8%, Avgran-10,9% e profundidade-10,8%. Foi demonstrado que C. fluminea está associada a sedimentos arenosos com pouca matéria orgânica, em áreas rasas próximo às margens. A PCA mostrou uma ampla sobreposição de nicho com as espécies de moluscos nativos C. martensi, N. limosa e A. trapesialis.

Modeling habitat suitability of the invasive clam Corbicula fluminea in a Neotropical shallow lagoon, southern Brazil.

This study aimed to model the habitat suitability for an invasive clam Corbicula fluminea in a coastal shallow lagoon in the southern Neotropical region (-30.22, -50.55). The lagoon (19km2, maximum deep 2.5m) was sampled with an Ekman dredge in an orthogonal matrix comprising 84 points. At each sampling point, were obtained environmental descriptors as depth, organic matter content (OMC), average granulometry (Avgran), and the percentage of sand (Pcsand). Prediction performance of Generalized Linear Models (GLM), Generalized Additive Models (GAM) and Boosted Regression Tree (BRT) were compared. Also, niche overlapping with other native clam species (Castalia martensi, Neocorbicula limosa and Anodontites trapesialis) was examined. A BRT model with 1400 trees was selected as the best model, with cross-validated correlation of 0.82. The relative contributions of predictors were Pcsand-42.6%, OMC-35.8%, Avgran-10.9% and Depth-10.8%. Were identified that C. fluminea occur mainly in sandy sediments with few organic matter, in shallow areas nor by the shore. The PCA showed a wide niche overlap with the native clam species C. martensi, N. limosa and A. trapesialis.

Dairy goat kids fed liquid diets in substitution of goat milk and slaughtered at different ages: an economic viability analysis using Monte Carlo techniques.

The aim of this study was to analyze the economic viability of producing dairy goat kids fed liquid diets in alternative of goat milk and slaughtered at two different ages. Forty-eight male newborn Saanen and Alpine kids were selected and allocated to four groups using a completely randomized factorial design: goat milk (GM), cow milk (CM), commercial milk replacer (CMR) and fermented cow colostrum (FC). Each group was then divided into two groups: slaughter at 60 and 90 days of age. The animals received Tifton hay and concentrate ad libitum. The values of total costs of liquid and solid feed plus labor, income and average gross margin were calculated. The data were then analyzed using the Monte Carlo techniques with the @Risk 5.5 software, with 1000 iterations of the variables being studied through the model. The kids fed GM and CMR generated negative profitability values when slaughtered at 60 days (US$ -16.4 and US$ -2.17, respectively) and also at 90 days (US$ -30.8 and US$ -0.18, respectively). The risk analysis showed that there is a 98% probability that profitability would be negative when GM is used. In this regard, CM and FC presented low risk when the kids were slaughtered at 60 days (8.5% and 21.2%, respectively) and an even lower risk when animals were slaughtered at 90 days (5.2% and 3.8%, respectively). The kids fed CM and slaughtered at 90 days presented the highest average gross income (US$ 67.88) and also average gross margin (US$ 18.43/animal). For the 60-day rearing regime to be economically viable, the CMR cost should not exceed 11.47% of the animal-selling price. This implies that the replacer cannot cost more than US$ 0.39 and 0.43/kg for the 60- and 90-day feeding regimes, respectively. The sensitivity analysis showed that the variables with the greatest impact on the final model's results were animal selling price, liquid diet cost, final weight at slaughter and labor. In conclusion, the production of male dairy goat kids can be economically viable when the kids diet consists mainly of either cow milk or fermented colostrum, especially when kids are slaughtered at 90 days of age.

Modeling habitat suitability of the invasive clam Corbicula fluminea in a Neotropical shallow lagoon, southern Brazil

Abstract This study aimed to model the habitat suitability for an invasive clam Corbicula fluminea in a coastal shallow lagoon in the southern Neotropical region (30.22, 50.55). The lagoon (19km2, maximum deep 2.5m) was sampled with an Ekman dredge in an orthogonal matrix comprising 84 points. At each sampling point, were obtained environmental descriptors as depth, organic matter content (OMC), average granulometry (Avgran), and the percentage of sand (Pcsand). Prediction performance of Generalized Linear Models (GLM), Generalized Additive Models (GAM) and Boosted Regression Tree (BRT) were compared. Also, niche overlapping with other native clam species (Castalia martensi, Neocorbicula limosa and Anodontites trapesialis) was examined. A BRT model with 1400 trees was selected as the best model, with cross-validated correlation of 0.82. The relative contributions of predictors were Pcsand-42.6%, OMC-35.8%, Avgran-10.9% and Depth-10.8%. Were identified that C. fluminea occur mainly in sandy sediments with few organic matter, in shallow areas nor by the shore. The PCA showed a wide niche overlap with the native clam species C. martensi, N. limosa and A. trapesialis.

Resumo O objetivo de deste estudo foi modelar a adequabilidade de habitat do bivalve invasor Corbicula fluminea em uma lagoa costeira na região Neotropical (30.22, 50.55). A lagoa (19km2, 2,5 m de profundidade máxima) foi amostrada com uma draga Ekman em uma matriz ortogonal compreendendo 84 pontos. Em cada ponto de amostragem foram obtidos descritores ambientais como a profundidade, teor de matéria orgânica (OMC), granulometria média (Avgran), e a percentagem de areia (Pcsand). O poder preditivo dos métodos Modelos Lineares Generalizados (GLM), Modelos Aditivos Generalizados (GAM) e Boosted Regression Trees (BRT) foram comparados. Além disso, a sobreposição de nicho com espécies de moluscos nativos (Castalia martensi, Neocorbicula limosa e Anodontites trapesialis) foi examinada. Um modelo BRT com 1.400 árvores foi selecionado como o melhor modelo, com correlação da validação cruzada de 0,82. As contribuições relativas dos preditores foram Pcsand-42,6%, OMC-35,8%, Avgran-10,9% e profundidade-10,8%. Foi demonstrado que C. fluminea está associada a sedimentos arenosos com pouca matéria orgânica, em áreas rasas próximo às margens. A PCA mostrou uma ampla sobreposição de nicho com as espécies de moluscos nativos C. martensi, N. limosa e A. trapesialis.