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1.
Ecol Lett ; 27(5): e14415, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38712683

RESUMO

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.


Assuntos
Folhas de Planta , Ciclo do Carbono , Carbono/metabolismo
2.
Am Nat ; 204(1): 96-104, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38857342

RESUMO

AbstractMany Neotropical beetles present coloration patterns mimicking red-eyed flies, which are presumably evasive mimicry models. However, the role of predators in selecting for evasive mimics in nature remains untested. In a field experiment, we used nontoxic plasticine replicas of a specialized fly-mimicking beetle species, which we placed on the host plants of the beetles. We show that replicas painted with reddish patches simulating the eyes of flesh flies experienced a much lower predation rate than control replicas. We found that beak marks were the most frequent signs of attack on plasticine replicas, underlining the potential selective pressure exerted by birds. Replicas that matched the size of the beetles suffered higher predation than smaller or larger replicas. The predation rate was also higher for beetle replicas exposed during the warm and wet season, when adult beetles occur. Our results support predator-mediated selection of mimic beetles, highlighting that reddish spots resembling flies' eyes comprise an important trait in reducing attack by avian predators.


Assuntos
Mimetismo Biológico , Besouros , Comportamento Predatório , Animais , Besouros/fisiologia , Aves/fisiologia , Dípteros/fisiologia , Pigmentação
3.
Ann Bot ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38722218

RESUMO

BACKGROUND AND AIMS: The majority of the earth's land area is currently occupied by humans. Measuring how terrestrial plants reproduce in these pervasive environments is essential for understanding their long-term viability and their ability to adapt to changing environments. METHODS: We conducted hierarchical and phylogenetically-independent meta-analyses to assess the overall effects of anthropogenic land-use changes on pollination, and male and female fitness in terrestrial plants. KEY RESULTS: We found negative global effects of land use change (i.e., mainly habitat loss and fragmentation) on pollination and on female and male fitness of terrestrial flowering plants. Negative effects were stronger in plants with self-incompatibility (SI) systems and pollinated by invertebrates, regardless of life form and sexual expression. Pollination and female fitness of pollination generalist and specialist plants were similarly negatively affected by land-use change, whereas male fitness of specialist plants showed no effects. CONCLUSIONS: Our findings indicate that angiosperm populations remaining in fragmented habitats negatively affect pollination, and female and male fitness, which will likely decrease the recruitment, survival, and long-term viability of plant populations remaining in fragmented landscapes. We underline the main current gaps of knowledge for future research agendas and call out not only for a decrease in the current rates of land-use changes across the world but also to embark on active restoration efforts to increase the area and connectivity of remaining natural habitats.

4.
Proc Natl Acad Sci U S A ; 118(49)2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34845017

RESUMO

One-third of all Neotropical forests are secondary forests that regrow naturally after agricultural use through secondary succession. We need to understand better how and why succession varies across environmental gradients and broad geographic scales. Here, we analyze functional recovery using community data on seven plant characteristics (traits) of 1,016 forest plots from 30 chronosequence sites across the Neotropics. By analyzing communities in terms of their traits, we enhance understanding of the mechanisms of succession, assess ecosystem recovery, and use these insights to propose successful forest restoration strategies. Wet and dry forests diverged markedly for several traits that increase growth rate in wet forests but come at the expense of reduced drought tolerance, delay, or avoidance, which is important in seasonally dry forests. Dry and wet forests showed different successional pathways for several traits. In dry forests, species turnover is driven by drought tolerance traits that are important early in succession and in wet forests by shade tolerance traits that are important later in succession. In both forests, deciduous and compound-leaved trees decreased with forest age, probably because microclimatic conditions became less hot and dry. Our results suggest that climatic water availability drives functional recovery by influencing the start and trajectory of succession, resulting in a convergence of community trait values with forest age when vegetation cover builds up. Within plots, the range in functional trait values increased with age. Based on the observed successional trait changes, we indicate the consequences for carbon and nutrient cycling and propose an ecologically sound strategy to improve forest restoration success.


Assuntos
Conservação dos Recursos Naturais , Florestas , Modelos Biológicos , Clima Tropical
5.
Environ Monit Assess ; 196(6): 531, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38724710

RESUMO

The Samarco/Vale/BHP mine tailing dam breach that took place in Minas Gerais, southeastern Brazil, in 2015, deposited high concentrations of metals and metalloids in the Rio Doce basin, severely impacting freshwater and riverine forest ecosystems. To assess developmental instability of caddisflies in response to the environmental impacts of the dam breach, we investigated the fluctuating asymmetry (FA) in the species Smicridea (Rhyacophylax) coronata (Trichoptera: Hydropsychidae). FA was assessed at individual and populational scales using geometric morphometric methods in the cephalic capsule and mandibles of larvae and also on the forewings of adults, both collected under the impacted condition, and under the least disturbed condition. The levels of FA increased in response to stressors on the forewings at the populational scale, and on the mandibles, at individual scale. These morphological variations in the larval and adult stages may lead to detrimental effects and result in high mortality rates as well as lower adult fitness. Trichoptera forewings are revealed as suitable traits for assessing FA, holding potential for applications in biomonitoring programs. Directional asymmetry levels were higher than FA levels for all traits, and this correlation could be explained by a transition from fluctuating to directional asymmetry in the presence of heightened disturbance. Our results validate the relationship between the impacts from the dam breach and increased developmental instability in this species with likely cascade effects on the insect community.


Assuntos
Monitoramento Ambiental , Larva , Mineração , Animais , Larva/crescimento & desenvolvimento , Insetos , Brasil , Poluentes Químicos da Água
6.
Morphologie ; 108(361): 100757, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38134867

RESUMO

Voice disorders are common among teachers and, in particular, anatomy teachers are exposed to a potential enemy for dysphonia, irritating chemicals, that is, formaldehyde. We seek to verify the association between: (1) teaching time, (2) type of cadaveric conservation to which the teacher is exposed and (3) hours of exposure to cadaveric preservative related to the different categories of voice disorders screening (ITDV). The sample consisted of 111 teachers who answered to 02 data collection instruments: I - Sociodemographic Data; II - ITDV. Among participating teachers there were 71 male and 40 female, with an average age of 43 years and 11 months and an average teaching time of 16 years and 5 months. Association tests between teaching time and ITDV demonstrate a significant result in the relationship between voice failure and teaching time (p<0.05). All 111 teachers use their voices in laboratory classes and use cadaveric material. From those, 107 teachers are exposed to formaldehyde as cadaveric parts' conservative solution. There was a significant association (p<0.05) between voice failure and the type of cadaveric conservative solution but non-significant relationship (p>0.05) between ITDV and the time of exposure to formaldehyde preservative. Teachers' ITDV showed vocal signs and symptoms. In particular, voice loss due to time of teaching in anatomy, and voice failure, due to exposure to formaldehyde and combinations used in anatomical parts and cadavers, were significant.


Assuntos
Anatomia , Cadáver , Formaldeído , Humanos , Formaldeído/efeitos adversos , Feminino , Masculino , Adulto , Anatomia/educação , Pessoa de Meia-Idade , Distúrbios da Voz/diagnóstico , Distúrbios da Voz/etiologia , Distúrbios da Voz/induzido quimicamente , Doenças Profissionais/diagnóstico , Doenças Profissionais/etiologia , Doenças Profissionais/epidemiologia , Exposição Ocupacional/efeitos adversos , Fatores de Tempo , Fixadores/efeitos adversos , Docentes/estatística & dados numéricos
7.
An Acad Bras Cienc ; 94(1): e20200665, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35043851

RESUMO

Ecological knowledge plays a significant role in ensuring efficient ecological restoration. We conducted a systematic review to assess if sufficient ecological knowledge has been accumulated to aid restoration practices for the Cerrado, a Brazilian biome dominated by savanna ecosystems and threatened by anthropogenic disturbances. Most Cerrado restoration studies were performed by few research groups and focused primarily on two vegetation types: cerrado sensu stricto (typical savanna) and riparian forest. We also found that defining reference ecosystems and selecting plant species for restoration programs is neglected, mostly disregarding their original occurrence and proportion of plant growth forms. Furthermore, studies lacked standardized and systematic evaluation of restoration outcomes. Hence, we argue that current ecological knowledge is insufficient to guarantee the success of large-scale ecological restoration of the Cerrado. We strengthen the need to explicitly define the reference ecosystem for each Cerrado ecosystem and use its structure and composition as guidance for ecological restoration research, which should be based on a scientific approach. We encourage investigations into ecological dynamics and natural regeneration of the different vegetation types of the Cerrado and highlight the importance of integrating such knowledge with environmental laws, societal engagement and cost-effective techniques to advance Cerrado ecological restoration.


Assuntos
Biodiversidade , Ecossistema , Efeitos Antropogênicos , Brasil , Florestas , Plantas
8.
Chem Biodivers ; 19(4): e202100842, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35285139

RESUMO

Zika virus (ZIKV) infection is a global threat associated to neurological disorders in adults and microcephaly in children born to infected mothers. No vaccine or drug is available against ZIKV. We herein report the anti-ZIKV activity of 36 plant extracts containing polyphenols and/or triterpenes. ZIKV-infected Vero CCL-81 cells were treated with samples at non-cytotoxic concentrations, determined by MTT and LDH assays. One third of the extracts elicited concentration-dependent anti-ZIKV effect, with viral loads reduction from 0.4 to 3.8 log units. The 12 active extracts were tested on ZIKV-infected SH-SY5Y cells and significant reductions of viral loads (in log units) were induced by Maytenus ilicifolia (4.5 log), Terminalia phaeocarpa (3.7 log), Maytenus rigida (1.7 log) and Echinodorus grandiflorus (1.7 log) extracts. Median cytotoxic concentration (CC50 ) of these extracts in Vero cells were higher than in SH-SY5Y lineage. M. ilicifolia (IC50 =16.8±10.3 µg/mL, SI=3.4) and T. phaeocarpa (IC50 =22.0±6.8 µg/mL, SI=4.8) were the most active extracts. UPLC-ESI-MS/MS analysis of M. ilicifolia extract led to the identification of 7 triterpenes, of which lupeol and a mixture of friedelin/friedelinol showed no activity against ZIKV. The composition of T. phaeocarpa extract comprises phenolic acids, ellagitannins and flavonoids, as recently reported by us. In conclusion, the anti-ZIKV activity of 12 plant extracts is here described for the first time and polyphenols and triterpenes were identified as the probable bioactive constituents of T. phaeocarpa and M. ilicifolia, respectively.


Assuntos
Neuroblastoma , Triterpenos , Infecção por Zika virus , Zika virus , Animais , Criança , Chlorocebus aethiops , Humanos , Neuroblastoma/tratamento farmacológico , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Polifenóis/farmacologia , Espectrometria de Massas em Tandem , Triterpenos/farmacologia , Células Vero , Infecção por Zika virus/tratamento farmacológico
9.
Can J Microbiol ; 67(4): 290-300, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33031708

RESUMO

Global climatic changes can have drastic impacts on plant species, including severe consequences for the agricultural species productivity. Many of these species present important mutualisms with endophytic fungi that positively influence their performance. The present study evaluated whether the increases in CO2 and temperature predicted for the year 2100 may cause changes in foliar carbon (C) and nitrogen (N) concentrations in soybean (Glycine max) and, consequently, the interactions with its endophytic fungi. The effects of elevated CO2 and temperature were evaluated in four treatments in open-top chambers: (i) control, (ii) increased temperature, (iii) increased CO2, and (iv) increased CO2 and temperature. Increased atmospheric CO2 resulted in decreased foliar N concentration, while increased temperature increased it. A total of 16 taxa of endophytic fungi were identified based on sequencing internal transcribed spacer regions of rRNA subunits. Increased atmospheric CO2 and temperature were observed to potentially modify the endophytic mycobiota of soybean plants. The results suggest that the fungi species substitution is a consequence of changes in foliar N concentration and C/N ratio. Predicted climatic changes shall affect the relationships between plant and endophytes, which in turn, will affect the performance and resistance of soybean, one of the most important crops in the world.


Assuntos
Dióxido de Carbono/análise , Endófitos/isolamento & purificação , Fungos/isolamento & purificação , Glycine max/microbiologia , Temperatura , Carbono/metabolismo , Produtos Agrícolas/metabolismo , Produtos Agrícolas/microbiologia , Endófitos/classificação , Endófitos/genética , Fungos/classificação , Fungos/genética , Micobioma , Nitrogênio/metabolismo , Folhas de Planta/metabolismo , Glycine max/metabolismo
10.
Dev Psychobiol ; 63(7): e22201, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34674234

RESUMO

Fetuses are able to process olfactory stimuli present in the womb and continue to show a preference for these odors for months after birth. Despite the accumulated knowledge about their early ability to perceive odors, there is a lack of validated scales for odor response in newborns. The evaluation of reactions of the olfactory system to environmental stimuli in infants has been defined by methodological theoretical approaches of experimental and clinical assessment tools. These approaches are mainly based on psychophysical approaches and predominantly use behavioral and physiological measures. Examples can be found in studies describing early abilities of newborn babies for behaviors or heart rate variability showing memory of maternal food preferences or mother's breast milk. This systematic review aimed to determine whether validated odor assessment tools can be feasibly used in studies. Particularly in light of the current COVID-19 pandemic and evidence of associated olfactory impairment resulting from SARS-COV-2 infection, the study is also motivated by the need for tools to assess olfactory function in neonates.


Assuntos
Recém-Nascido/fisiologia , Olfato , Anosmia/diagnóstico , COVID-19/diagnóstico , COVID-19/fisiopatologia , Humanos , Doenças do Recém-Nascido/diagnóstico , Odorantes , Olfato/fisiologia
11.
An Acad Bras Cienc ; 93(suppl 3): e20210431, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34378637

RESUMO

A second deadlier wave of COVID-19 and the causes of the recent public health collapse of Manaus are compared with the Spanish flu events in that city, and Brazil. Historic sanitarian problems, and its hub position in the Brazilian airway network are combined drivers of deadly events related to COVID-19. These drivers were amplified by misleading governance, highly transmissible variants, and relaxation of social distancing. Several of these same factors may also have contributed to the dramatically severe outbreak of H1N1 in 1918, which caused the death of 10% of the population in seven months. We modelled Manaus parameters for the present pandemic and confirmed that lack of a proper social distancing might select the most transmissible variants. We succeeded to reproduce a first severe wave followed by a second stronger wave. The model also predicted that outbreaks may last for up to five and half years, slowing down gradually before the disease disappear. We validated the model by adjusting it to the Spanish Flu data for the city, and confirmed the pattern experienced by that time, of a first stronger wave in October-November 1918, followed by a second less intense wave in February-March 1919.


Assuntos
COVID-19 , Vírus da Influenza A Subtipo H1N1 , Influenza Pandêmica, 1918-1919 , Brasil , História do Século XX , Humanos , Floresta Úmida , SARS-CoV-2 , Sindemia
12.
An Acad Bras Cienc ; 93(2): e20200119, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34133536

RESUMO

The native flora of the Brazilian rupestrian grassland (campos rupestres) is threatened by the spread of invasive grasses. In this study, we evaluated the effect of habitat on the functional traits and CSR ecological strategies of three invasive alien grasses occurring both in the ironstone (IRG) and quartzitic (QRG) rupestrian grassland habitats. Although in both habitats the invasive species predominantly showed a stress-tolerant strategy, they exhibited distinct degrees of stress-tolerance and slightly differences in functional traits values in the IRG compared to the QRG. Habitat type distinctly influenced invasive grasses functional traits and ecological strategies, revealing a species-specific pattern.


Assuntos
Pradaria , Poaceae , Brasil , Ecossistema , Espécies Introduzidas
13.
An Acad Bras Cienc ; 93(2): e20201604, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33852672

RESUMO

The Program for Biodiversity Research (PPBio) is an innovative program designed to integrate all biodiversity research stakeholders. Operating since 2004, it has installed long-term ecological research sites throughout Brazil and its logic has been applied in some other southern-hemisphere countries. The program supports all aspects of research necessary to understand biodiversity and the processes that affect it. There are presently 161 sampling sites (see some of them at Supplementary Appendix), most of which use a standardized methodology that allows comparisons across biomes and through time. To date, there are about 1200 publications associated with PPBio that cover topics ranging from natural history to genetics and species distributions. Most of the field data and metadata are available through PPBio web sites or DataONE. Metadata is available for researchers that intend to explore the different faces of Brazilian biodiversity spatio-temporal variation, as well as for managers intending to improve conservation strategies. The Program also fostered, directly and indirectly, local technical capacity building, and supported the training of hundreds of undergraduate and graduate students. The main challenge is maintaining the long-term funding necessary to understand biodiversity patterns and processes under pressure from global environmental changes.


Assuntos
Biodiversidade , Ecossistema , Brasil , Conservação dos Recursos Naturais , Humanos , Conhecimento
14.
An Acad Bras Cienc ; 92(4): e20201139, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32965306

RESUMO

The spread of SARS-CoV-2 and the distribution of cases worldwide followed no clear biogeographic, climatic, or cultural trend. Conversely, the internationally busiest cities in all countries tended to be the hardest hit, suggesting a basic, mathematically neutral pattern of the new coronavirus early dissemination. We tested whether the number of flight passengers per time and the number of international frontiers could explain the number of cases of COVID-19 worldwide by a stepwise regression. Analysis were taken by 22 May 2020, a period when one would claim that early patterns of the pandemic establishment were still detectable, despite of community transmission in various places. The number of passengers arriving in a country and the number of international borders explained significantly 49% of the variance in the distribution of the number of cases of COVID-19, and number of passengers explained significantly 14.2% of data variance for cases per million inhabitants. Ecological neutral theory may explain a considerable part of the early distribution of SARS-CoV-2 and should be taken into consideration to define preventive international actions before a next pandemic.


Assuntos
Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/transmissão , Pneumonia Viral/epidemiologia , Pneumonia Viral/transmissão , Viagem , Aeronaves , Betacoronavirus , COVID-19 , Cidades , Humanos , Modelos Teóricos , Pandemias , SARS-CoV-2
15.
An Acad Bras Cienc ; 92(suppl 2): e20190058, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33146275

RESUMO

Elevation creates a variety of physical conditions in a relatively short distance, which makes mountains suitable for studying the effects of climate change on biodiversity. We investigated the importance of climate and vegetation for the distribution of butterflies from 800 to 1400 m elevation. We sampled butterflies, and woody and rosette plants and measured air temperature and humidity, wind speed and gust, and solar radiation. We partitioned diversity to assess the processes underlying community shifts across altitudes - species loss versus replacement. We assessed the strength of the association among butterfly, vegetation, and climate. Butterfly richness and abundance decreased with altitude, and species composition changed along the elevation. Changes in butterfly composition with altitude were mainly through species replacement and by abundance increases in some species being compensated by decreases in others. Since the floristic diversity decreased with altitude due to soil conditions, and butterflies are closely related to their host plants, this could explain species replacement with altitude. Overall, we found a stronger association of butterfly community with vegetation than climate, but plant community and climate were also strongly associated between them. Butterfly richness was more strongly associated with plant richness than with temperature, while the reverse was true for butterfly abundance, which was more strongly associated with temperature than with plant richness. We must consider the complementary roles of resource and conditions in species distribution.


Assuntos
Borboletas , Altitude , Animais , Biodiversidade , Mudança Climática , Ecossistema , Solo
16.
An Acad Bras Cienc ; 91(1): e20180162, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30916155

RESUMO

We compiled published Brazilian gall-inducing insect inventories aiming to understand trends and biases in this field research and to investigate the factors that potentially explain the diversity of gall-inducing insects among different sampling sites. A total of 51 studies with gall-inducing insect inventories were compiled for Brazil, which sampled 151 sites in 88 municipalities, 13 states and five regions. The number of papers published on gall-inducing insects per year has increased over the last 30 years, being Cecidomyiidae (Diptera) the main galling taxon, Fabaceae the main host-plant family and Protium heptaphyllum (Burseraceae) the most important super-host species in these inventories. We found a great bias in the geographical distribution of Brazilian inventories, with the majority of studies in the Southeast region, and Atlantic Forest and Cerrado biomes. The total richness of gall-inducing insects differed significantly among regions and biomes, with higher gall richnesses being recorded in the North region and Amazon biome. However, Brazilian regions and biomes did not vary in richness of gall-inducing insect morphotypes per plant species. According our results, sampling by cecidologists in less studied regions of Brazil is needed, particularly in the North and South regions and subsampled biomes such as the Amazon, Pampas and Pantanal.


Assuntos
Ecossistema , Florestas , Insetos/fisiologia , Plantas/parasitologia , Distribuição Animal , Animais , Biodiversidade , Brasil , Dilleniaceae/crescimento & desenvolvimento , Interações Hospedeiro-Parasita
17.
An Acad Bras Cienc ; 90(4): 3353-3361, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30184009

RESUMO

The theory of landscape ecology applied to the methods of spatial analysis helps to understand changes in the structure of forest remnants. In view of this theory, the objective of the present study was to analyze the structure of a fragmented area between the years 1979 and 2015 through calculation of landscape metrics for arboreal, shrubby and herbaceous vegetation classes. Vegetation classes were classified with visits to the field, interpretation of aerial photographs from 1979 and supervised classification of Landsat 8 from 2015. The metrics calculated for each class were area and total number of fragments, total edge and average connectivity among the fragments. The analysis of structure found that it changed negatively due to an increase in the number of small fragments, which increased the intensity of edge effects and reduced connectivity between fragments for all classes.


Assuntos
Monitoramento Ambiental/métodos , Florestas , Fotografação , Comunicações Via Satélite , Brasil , Análise Espacial
18.
Int J Exp Pathol ; 97(2): 114-24, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-27277193

RESUMO

This study investigated the pathological morphofunctional adaptations related to the imbalance of exercise tolerance triggered by paraquat (PQ) exposure in rats. The rats were randomized into four groups with eight animals each: (a) SAL (control): 0.5 ml of 0.9% NaCl solution; (b) PQ10: PQ 10 mg/kg; (c) PQ20: PQ 20 mg/kg; and (d) PQ30: PQ 30 mg/kg. Each group received a single injection of PQ. After 72 hours, the animals were subjected to an incremental aerobic running test until fatigue in order to determine exercise tolerance, blood glucose and lactate levels. After the next 24 h, lung, liver and skeletal muscle were collected for biometric, biochemical and morphological analyses. The animals exposed to PQ exhibited a significant anticipation of anaerobic metabolism during the incremental aerobic running test, a reduction in exercise tolerance and blood glucose levels as well as increased blood lactate levels during exercise compared to control animals. PQ exposure increased serum transaminase levels and reduced the glycogen contents in liver tissue and skeletal muscles. In the lung, the liver and the skeletal muscle, PQ exposure also increased the contents of malondialdehyde, protein carbonyl, 8-hydroxy-2'-deoxyguanosine, superoxide dismutase and catalase, as well as a structural remodelling compared to the control group. All these changes were dose-dependent. Reduced exercise tolerance after PQ exposure was potentially influenced by pathological remodelling of multiple organs, in which glycogen depletion in the liver and skeletal muscle and the imbalance of glucose metabolism coexist with the induction of lipid, protein and DNA oxidation, a destructive process not counteracted by the upregulation of endogenous antioxidant enzymes.


Assuntos
Tolerância ao Exercício/efeitos dos fármacos , Herbicidas/administração & dosagem , Insuficiência de Múltiplos Órgãos/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacos , Paraquat/administração & dosagem , Animais , Antioxidantes/metabolismo , Glicemia/metabolismo , Relação Dose-Resposta a Droga , Tolerância ao Exercício/fisiologia , Herbicidas/toxicidade , Ácido Láctico/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Insuficiência de Múltiplos Órgãos/fisiopatologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Estresse Oxidativo/fisiologia , Paraquat/toxicidade , Distribuição Aleatória , Ratos Wistar
19.
Int J Exp Pathol ; 96(4): 261-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26175225

RESUMO

Simvastatin can modulate lipid and bone metabolism. However, information related to the interaction between diet and simvastatin on bone structure and biomechanics is scarce. Thus, this study evaluated the effects of simvastatin on femoral biomechanics and cortical/trabecular bone structure in wild-type mice nourished with a hyperlipidic diet. Three-month-old male wild-type mice (C57BL6 strain) were divided into four groups: (1) group W, nourished with a standard diet; (2) group WH, fed a hyperlipidic diet; (3) group WS, nourished with a standard diet plus oral simvastatin (20 mg/kg/day); and (4) group WHS, fed a hyperlipidic diet plus oral simvastatin (20 mg/kg/day). All animals received only their specific diet and water for 60 days. Blood samples were collected for the analysis of calcium, triglycerides, total cholesterol (TC) and fraction serum levels. Diet manipulation was able to induce a dyslipidaemic status in mice, characterized by triglyceride and TC rise in WH animals. Simvastatin prevented hypercholesterolaemia and reduced TC and LDL serum levels, but did not prevent hypertriglyceridaemia and HDL serum levels in the WHS group. In the WH mice the hyperlipidaemia was associated with reduction in trabecular bone thickness, femur structural and material property alterations. Simvastatin prevented these morphological alterations and minimized femur biomechanical changes in WHS mice. Taken together, the results indicated that the hyperlipidic diet intake acts as a risk factor for bone integrity, generating bones with reduced resistance and more susceptible to fractures, an effect attenuated by simvastatin that is potentially related to the modulatory action of this drug on lipid and bone metabolism.


Assuntos
Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Dieta Hiperlipídica/efeitos adversos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Sinvastatina/farmacologia , Animais , Fenômenos Biomecânicos , Modelos Animais de Doenças , Hiperlipidemias/complicações , Masculino , Camundongos , Camundongos Endogâmicos C57BL
20.
Sci Rep ; 14(1): 4559, 2024 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-38402243

RESUMO

Simulating future land use changes can be an important tool to support decision-making, especially in areas that are experiencing rapid anthropogenic pressure, such as the Cerrado-Brazilian savanna. Here we used a spatially-explicit model to identify the main drivers of native vegetation loss in the Cerrado and then extrapolate this loss for 2050 and 2070. We also analyzed the role of property size in complex Brazilian environmental laws in determining different outcomes of these projections. Our results show that distance to rivers, roads, and cities, agricultural potential, permanent and annual crop agriculture, and cattle led to observed/historical loss of vegetation, while protected areas prevented such loss. Assuming full adoption of the current Forest Code, the Cerrado may lose 26.5 million ha (± 11.8 95% C.I.) of native vegetation by 2050 and 30.6 million ha (± 12.8 95% C.I.) by 2070, and this loss shall occur mainly within large properties. In terms of reconciling conservation and agricultural production, we recommend that public policies focus primarily on large farms, such as protecting 30% of the area of properties larger than 2500 ha, which would avoid a loss of more than 4.1 million hectares of native vegetation, corresponding to 13% of the predicted loss by 2070.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Animais , Bovinos , Brasil , Florestas , Agricultura , Ecossistema
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