Activation of innate immunity selectively compromises mitochondrial complex I, proline oxidation, and flight activity in the major arbovirus vector Aedes aegypti.

Aedes aegypti females are natural vectors of important arboviruses such as dengue, zika, and yellow fever. Mosquitoes activate innate immune response signaling pathways upon infection, as a resistance mechanism to fight pathogens and limit their propagation. Despite the beneficial effects of immune activation for insect vectors, phenotypic costs ultimately affect their fitness. However, the underlying mechanisms that mediate these fitness costs remain poorly understood. Given the high energy required to mount a proper immune response, we hypothesized that systemic activation of innate immunity would impair flight muscle mitochondrial function, compromising tissue energy demand and flight activity. Here, we investigated the dynamic effects of activation of innate immunity by intra-thoracic zymosan injection on A. aegypti flight muscle mitochondrial metabolism. Zymosan injection significantly increased defensin A expression in fat bodies in a time-dependent manner that compromised flight activity. Although oxidant levels in flight muscle were hardly altered, ATP-linked respiratory rates driven by mitochondrial pyruvate+proline oxidation were significantly reduced at 24 h upon zymosan injection. Oxidative phosphorylation coupling was preserved regardless of innate immune response activation along 24 h. Importantly, rotenone-sensitive respiration and complex I-III activity were specifically reduced 24 h upon zymosan injection. Also, loss of complex I activity compromised ATP-linked and maximal respiratory rates mediated by mitochondrial proline oxidation. Finally, the magnitude of innate immune response activation negatively correlated with respiratory rates, regardless of the metabolic states. Collectively, we demonstrate that activation of innate immunity is strongly associated with reduced flight muscle complex I activity with direct consequences to mitochondrial proline oxidation and flight activity. Remarkably, our results indicate a trade-off between dispersal and immunity exists in an insect vector, underscoring the potential consequences of disrupted flight muscle mitochondrial energy metabolism to arbovirus transmission.

Export of heme by the feline leukemia virus C receptor regulates mitochondrial biogenesis and redox balance in the hematophagous insect Rhodnius prolixus.

Heme is a prosthetic group of proteins involved in vital physiological processes. It participates, for example, in redox reactions crucial for cell metabolism due to the variable oxidation state of its central iron atom. However, excessive heme can be cytotoxic due to its prooxidant properties. Therefore, the control of intracellular heme levels ensures the survival of organisms, especially those that deal with high concentrations of heme during their lives, such as hematophagous insects. The export of heme initially attributed to the feline leukemia virus C receptor (FLVCR) has recently been called into question, following the discovery of choline uptake by the same receptor in mammals. Here, we found that RpFLVCR is a heme exporter in the midgut of the hematophagous insect Rhodnius prolixus, a vector for Chagas disease. Silencing RpFLVCR decreased hemolymphatic heme levels and increased the levels of intracellular dicysteinyl-biliverdin, indicating heme retention inside midgut cells. FLVCR silencing led to increased expression of heme oxygenase (HO), ferritin, and mitoferrin mRNAs while downregulating the iron importers Malvolio 1 and 2. In contrast, HO gene silencing increased FLVCR and Malvolio expression and downregulated ferritin, revealing crosstalk between heme degradation/export and iron transport/storage pathways. Furthermore, RpFLVCR silencing strongly increased oxidant production and lipid peroxidation, reduced cytochrome c oxidase activity, and activated mitochondrial biogenesis, effects not observed in RpHO-silenced insects. These data support FLVCR function as a heme exporter, playing a pivotal role in heme/iron metabolism and maintenance of redox balance, especially in an organism adapted to face extremely high concentrations of heme.

Reduction of host cell mitochondrial activity as Mycobacterium leprae's strategy to evade host innate immunity.

Leprosy is a much-feared incapacitating infectious disease caused by Mycobacterium leprae or M lepromatosis, annually affecting roughly 200,000 people worldwide. During host-pathogen interaction, M leprae subverts the immune response, leading to development of disease. Throughout the last few decades, the impact of energy metabolism on the control of intracellular pathogens and leukocytic differentiation has become more evident. Mitochondria play a key role in regulating newly-discovered immune signaling pathways by controlling redox metabolism and the flow of energy besides activating inflammasome, xenophagy, and apoptosis. Likewise, this organelle, whose origin is probably an alphaproteobacterium, directly controls the intracellular pathogens attempting to invade its niche, a feature conquered at the expense of billions of years of coevolution. In the present review, we discuss the role of reduced host cell mitochondrial activity during M leprae infection and the consequential fates of M leprae and host innate immunity. Conceivably, inhibition of mitochondrial energy metabolism emerges as an overlooked and novel mechanism developed by M leprae to evade xenophagy and the host immune response.

Boosting life sciences research in Brazil: building a case for a local Drosophila stock center.

Drosophila melanogaster is undoubtedly one of the most useful model organisms in biology. Initially used in solidifying the principles of heredity, and establishing the basic concepts of population genetics and of the synthetic theory of evolution, it can currently offer scientists much more: the possibility of investigating a plethora of cellular and biological mechanisms, from development and function of the immune system to animal neurogenesis, tumorigenesis and beyond. Extensive resources are available for the community of Drosophila researchers worldwide, including an ever-growing number of mutant, transgenic and genomically-edited lines currently carried by stock centers in North America, Europe and Asia. Here, we provide evidence for the importance of stock centers in sustaining the substantial increase in the output of Drosophila research worldwide in recent decades. We also discuss the challenges that Brazilian Drosophila scientists face to keep their research projects internationally competitive, and argue that difficulties in importing fly lines from international stock centers have significantly stalled the progression of all Drosophila research areas in the country. Establishing a local stock center might be the first step towards building a strong local Drosophila community that will likely contribute to all areas of life sciences research.

Performance, body development and ingestive behavior of Nelore and crossbred heifers finished in a grazing system.

The aim of this experiment was to evaluate growth, body development and ingestive behavior of Nelore and crossbred heifers. Twenty-two contemporary heifers (eight Nelore, seven Nelore × Angus (½ Angus) and seven Nelore × Pantaneiro (½ Pantaneiro) crosses) were evaluated. The variables evaluated were weight, subcutaneous fat thickness [assessed by ultrasound in the longissimus dorsi (SFT) and biceps femoris (SFTP8)] morphometric measures and ingestive behavior (determined between 7 am and 5 pm). The daily gain differed between the breeds (P < 0.05), being greater for the ½ Pantaneiro than Nelore and equal to ½ Angus at the end of the study. The ½ Angus heifers differed (P < 0.01) from the other breeds for SFT (4.36 mm), with no difference between Nelore (2.77 mm) and ½ Pantaneiro (3.38 mm). The SFTP8 was greater (P < 0.01) (5.36 mm) in ½ Angus heifers than t others crossbreed, and greater in ½ Pantaneiro than in Nelore (4.28 vs 3.29 mm). The heart girth and rump width between the ilia were larger (P < 0.01) for the ½ Angus than ½ Pantaneiro and Nelore (169 cm; 41.6 cm, respectively). Substernal height was greatest (P < 0.01) for the Nelore (69.1 cm), reflecting the greater anterior and posterior height. The ½ Angus spent the longest time (P < 0.05) walking and less time grazing. Idleness also differed (P < 0.05) throughout the day. Crossbred heifers exhibited better performance and development than Nelore. The grazing pattern of ½ Pantaneiro heifers was identical to Nelore, but walked less, gained more weight, and exhibited better carcass finishing.

Neurotoxicity and the Global Worst Pollutants: Astroglial Involvement in Arsenic, Lead, and Mercury Intoxication.

Environmental pollution is a global threat and represents a strong risk factor for human health. It is estimated that pollution causes about 9 million premature deaths every year. Pollutants that can cross the blood-brain barrier and reach the central nervous system are of special concern, because of their potential to cause neurological and development disorders. Arsenic, lead and mercury are usually ranked as the top three in priority lists of regulatory agencies. Against xenobiotics, astrocytes are recognised as the first line of defence in the CNS, being involved in virtually all brain functions, contributing to homeostasis maintenance. Here, we discuss the current knowledge on the astroglial involvement in the neurotoxicity induced by these pollutants. Beginning by the main toxicokinetic characteristics, this review also highlights the several astrocytic mechanisms affected by these pollutants, involving redox system, neurotransmitter and glucose metabolism, and cytokine production/release, among others. Understanding how these alterations lead to neurological disturbances (including impaired memory, deficits in executive functions, and motor and visual disfunctions), by revisiting the current knowledge is essential for future research and development of therapies and prevention strategies.

Hair mercury is associated with dyslipidemia and cardiovascular risk: An anthropometric, biochemical and genetic cross-sectional study of Amazonian vulnerable populations.

This cross-sectional study evaluated the association between human exposure to mercury and cardiovascular risk using lipid profile (including apolipoproteins) and genetic analysis of Amazonian riverine population. Anthropometric data (gender, age, height, weight, blood pressure, and neck and waist circumferences) of the participants were recorded. Total mercury and methylmercury (MeHg) content were quantified in hair by ICP-MS and GC-pyro-AFS system. Polymorphisms rs662799, rs693, rs429358 and rs7412 (of genes of apolipoproteins A-V, B, and E at positions 112 and 158, respectively) were genotyped by real-time PCR. The population presented a dyslipidemia profile significantly correlated with high mercury levels. The apolipoprotein B/apolipoprotein A-I (ApoB/ApoA-I) index was also positively correlated with mercury, supporting a possible causal relationship. Allelic distributions were similar to those described in other populations, suggesting that genetic susceptibility may not have a significant role in the lipid alterations found in this work. This study demonstrated for the first time: i) the relationship between mercury exposure and cardiovascular risk-related apolipoproteins in humans, ii) the ApoB levels and the ApoB/ApoA-I index as the risk factors more strongly associated to the mercury-related dyslipidemia in humans, and iii) the prevalence of high/moderate risk of acute myocardial infarction in the vulnerable and chronically exposed-populations of the Amazon, in addition to the genotypic profile of the three most frequent polymorphisms in apolipoproteins of relevance for cardiovascular risk. This early detection of lipid alterations is essential to prevent the development of cardiovascular diseases (CVD), especially in chronically exposed populations such as those found in the Amazon. Therefore, in addition to provide data for the Minamata Convention implementation, our work is in line with the efforts joined by all members of the World Health Organization committed to reducing premature deaths originating from non-communicable diseases by 25% in 2025, including CVD.

Mercury in the Amazon: The danger of a single story.

Amazon conservation is essential for the global future. Mercury is currently among the worst global pollutants and most (78.5%) of the South-American emissions are from the Amazon. Current Brazilian legislation on mining activities and trade of gold, and economic interests in soy, beef and large-scale projects such as dams, are key influences in mercury mobilization and emissions in the Amazon with the potential to affect the global environment. However, banning mercury in mining, while desirable, is not an efficient strategy if no other action is taken. The interconnected issues, such as exports (soy, beef and gold) and energy generation, must be addressed together to provide effective protection for human health and the environment. Realistically, to improve mercury emissions in the Amazon, we must stop looking solely at "the single story" (a limited view of reality) of supposedly "artisanal and small-scale gold mining" in the region and understand the complex economic, social, political, and international aspects of this problem. We propose some recommendations for international agencies, governments, communities and the private sector.

Performance of Pantaneira breed cows in precision grazing system.

Use of a grazing system that takes into account the ingestive behavior of animals and the physiological characteristics of plants maximizes land use and promotes positive effects on the environment. In this sense, the objective of this study was to evaluate the performance of Pantaneira breed cows, kept in rotated grazing in Mombasa grass (Megathyrsus maximum), with different grazing times. Fifty animals were divided into two treatments: Continuous T1: 24 h and T2-Inverted: 12 h. The experiment lasted 98 days, being determined the production and nutritional quality of the forage, digestibility, intake, and performance of the animals. The design was randomized blocks at 5% probability, with the means compared by the F test. The design used was completely randomized at 5% probability by the T test. There was no significant difference for biomass production (P > 0.05). However, after grazing the Inverted group, the forage showed a lower percentage of leaves and an increase in neutral detergent fiber and acid contents and total carbohydrates, and a reduction in crude protein and ether extract values, as well as a higher digestibility (P < 0.05). The animals of the Continuous group intaked more forage (P < 0.05). The Inverted group had a higher average daily weight gain, in addition to a lower feed conversion (P < 0.001). The animals in the Control group spent more time eating (P < 0.0001) and sleeping (P < 0.0001), while the animals of the Inverted group spent more time in idleness (P < 0.0001) and interacting (P < 0.05). There was no difference in rumination time between treatments (P > 0.05). It was concluded that Inverted grazing improved the quality of Mombasa grass and the performance of cows.

Metabolomics detects clinically silent neuroinflammatory lesions earlier than neurofilament-light chain in a focal multiple sclerosis animal model.

BACKGROUND: Despite widespread searches, there are currently no validated biofluid markers for the detection of subclinical neuroinflammation in multiple sclerosis (MS). The dynamic nature of human metabolism in response to changes in homeostasis, as measured by metabolomics, may allow early identification of clinically silent neuroinflammation. Using the delayed-type hypersensitivity (DTH) MS rat model, we investigated the serum and cerebrospinal fluid (CSF) metabolomics profiles and neurofilament-light chain (NfL) levels, as a putative marker of neuroaxonal damage, arising from focal, clinically silent neuroinflammatory brain lesions and their discriminatory abilities to distinguish DTH animals from controls. METHODS: 1H nuclear magnetic resonance (NMR) spectroscopy metabolomics and NfL measurements were performed on serum and CSF at days 12, 28 and 60 after DTH lesion initiation. Supervised multivariate analyses were used to determine metabolomics differences between DTH animals and controls. Immunohistochemistry was used to assess the extent of neuroinflammation and tissue damage. RESULTS: Serum and CSF metabolomics perturbations were detectable in DTH animals (vs. controls) at all time points, with the greatest change occurring at the earliest time point (day 12) when the neuroinflammatory response was most intense (mean predictive accuracy [SD]-serum: 80.6 [10.7]%, p < 0.0001; CSF: 69.3 [13.5]%, p < 0.0001). The top discriminatory metabolites at day 12 (serum: allantoin, cytidine; CSF: glutamine, glucose) were all reduced in DTH animals compared to controls, and correlated with histological markers of neuroinflammation, particularly astrogliosis (Pearson coefficient, r-allantoin: r = - 0.562, p = 0.004; glutamine: r = - 0.528, p = 0.008). Serum and CSF NfL levels did not distinguish DTH animals from controls at day 12, rather, significant differences were observed at day 28 (mean [SEM]-serum: 38.5 [4.8] vs. 17.4 [2.6] pg/mL, p = 0.002; CSF: 1312.0 [379.1] vs. 475.8 [74.7] pg/mL, p = 0.027). Neither serum nor CSF NfL levels correlated with markers of neuroinflammation; serum NfL did, however, correlate strongly with axonal loss (r = 0.641, p = 0.001), but CSF NfL did not (p = 0.137). CONCLUSIONS: While NfL levels were elevated later in the pathogenesis of the DTH lesion, serum and CSF metabolomics were able to detect early, clinically silent neuroinflammation and are likely to present sensitive biomarkers for the assessment of subclinical disease activity in patients.

Blocking mitochondrial pyruvate import in brown adipocytes induces energy wasting via lipid cycling.

Combined fatty acid esterification and lipolysis, termed lipid cycling, is an ATP-consuming process that contributes to energy expenditure. Therefore, interventions that stimulate energy expenditure through lipid cycling are of great interest. Here we find that pharmacological and genetic inhibition of the mitochondrial pyruvate carrier (MPC) in brown adipocytes activates lipid cycling and energy expenditure, even in the absence of adrenergic stimulation. We show that the resulting increase in ATP demand elevates mitochondrial respiration coupled to ATP synthesis and fueled by lipid oxidation. We identify that glutamine consumption and the Malate-Aspartate Shuttle are required for the increase in Energy Expenditure induced by MPC inhibition in Brown Adipocytes (MAShEEBA). We thus demonstrate that energy expenditure through enhanced lipid cycling can be activated in brown adipocytes by decreasing mitochondrial pyruvate availability. We present a new mechanism to increase energy expenditure and fat oxidation in brown adipocytes, which does not require adrenergic stimulation of mitochondrial uncoupling.

Astroglial asthenia and loss of function, rather than reactivity, contribute to the ageing of the brain.

Astroglia represent a class of heterogeneous, in form and function, cells known as astrocytes, which provide for homoeostasis and defence of the central nervous system (CNS). Ageing is associated with morphological and functional remodelling of astrocytes with a prevalence of morphological atrophy and loss of function. In particular, ageing is associated with (i) decrease in astroglial synaptic coverage, (ii) deficits in glutamate and potassium clearance, (iii) reduced astroglial synthesis of synaptogenic factors such as cholesterol, (iv) decrease in aquaporin 4 channels in astroglial endfeet with subsequent decline in the glymphatic clearance, (v) decrease in astroglial metabolic support through the lactate shuttle, (vi) dwindling adult neurogenesis resulting from diminished proliferative capacity of radial stem astrocytes, (vii) decline in the astroglial-vascular coupling and deficient blood-brain barrier and (viii) decrease in astroglial ability to mount reactive astrogliosis. Decrease in reactive capabilities of astroglia are associated with rise of age-dependent neurodegenerative diseases. Astroglial morphology and function can be influenced and improved by lifestyle interventions such as intellectual engagement, social interactions, physical exercise, caloric restriction and healthy diet. These modifications of lifestyle are paramount for cognitive longevity.

Contrasting migratory journeys and changes in hippocampal astrocyte morphology in shorebirds.

Semipalmated sandpiper (Calidris pusilla) migration to the Southern Hemisphere includes a 5-day non-stop flight over the Atlantic Ocean, whereas semipalmated plover (Charadrius semipalmatus) migration, to the same area, is largely over land, with stopovers for feeding and rest. We compared the number and 3D morphology of hippocampal astrocytes of Ch. semipalmatus before and after autumnal migration with those of C. pusilla to test the hypothesis that the contrasting migratory flights of these species could differentially shape hippocampal astrocyte number and morphology. We captured individuals from both species in the Bay of Fundy (Canada) and in the coastal region of Bragança (Brazil) and processed their brains for selective GFAP immunolabeling of astrocytes. Hierarchical cluster analysis of astrocyte morphological features distinguished two families of morphological phenotypes, named type I and type II, which were differentially affected after migratory flights. Stereological counts of hippocampal astrocytes demonstrated that the number of astrocytes decreased significantly in C. pusilla, but did not change in Ch. semipalmatus. In addition, C. pusilla and Ch. semipalmatus hippocampal astrocyte morphological features were differentially affected after autumnal migration. We evaluated whether astrocyte morphometric variables were influenced by phylogenetic differences between C. pusilla and Ch. semipalmatus, using phylogenetically independent contrast approach, and phylogenetic trees generated by nuclear and mitochondrial markers. Our findings suggest that phylogenetic differences do not explain the results and that contrasting long-distance migratory flights shape plasticity of type I and type II astrocytes in different ways, which may imply distinct physiological roles for these cells.

Salivary biomarkers and neuropsychological outcomes: A non-invasive approach to investigate pollutants-associated neurotoxicity and its effects on cognition in vulnerable populations.

The occurrence of neurotoxicity caused by xenobiotics such as pesticides (dichlorodiphenyltrichloroethane, organophosphates, pyrethroids, etc.) or metals (mercury, lead, aluminum, arsenic, etc.) is a growing concern around the world, particularly in vulnerable populations with difficulties on both detection and symptoms treatment, due to low economic status, remote access, poor infrastructure, and low educational level, among others features. Despite the numerous molecular markers and questionnaires/clinical evaluations, studying neurotoxicity and its effects on cognition in these populations faces problems with samples collection and processing, and information accuracy. Assessing cognitive changes caused by neurotoxicity, especially those that are subtle in the initial stages, is fundamentally challenging. Finding accurate, non-invasive, and low-cost strategies to detect the first signals of brain injury has the potential to support an accelerated development of the research with these populations. Saliva emerges as an ideal pool of biomarkers (with interleukins and neural damage-related proteins, among others) and potential alternative diagnostic fluid to molecularly investigate neurotoxicity. As a source of numerous neurological biomarkers, saliva has several advantages compared to blood, such as easier storage, requires less manipulation, and the procedure is cheaper, safer and well accepted by patients compared with drawing blood. Regarding cognitive dysfunction, neuropsychological batteries represent, with their friendly interface, a feasible and accurate method to evaluate the eventual cognitive deficits associated with neurotoxicity in people from diverse cultural and educational backgrounds. The association of these two tools, saliva and neuropsychological batteries, to cover the molecular and cognitive aspects of neurotoxicity in vulnerable populations, could potentially increase the prevalence of early intervention and successful treatment.

Human neurotoxicity of mercury in the Amazon: A scoping review with insights and critical considerations.

Human exposure to mercury is a major public health concern, causing neurological outcomes such as motor and visual impairment and learning disabilities. Currently, human exposure in the Amazon is among the highest in the world. A recent systematic review (doi:10.1016/j.jtemb.2018.12.001), however, highlighted the lack of high-quality studies on mercury-associated neurotoxicity. There is, therefore, a need to improve research and much to still learn about how exposure correlates with disease. In this review, we discuss studies evaluating the associations between neurological disturbances and mercury body burden in Amazonian populations, to generate recommendations for future studies. A systematic search was performed during July 2020, in Pubmed/Medline, SCOPUS and SCIELO databases with the terms (mercury*) and (Amazon*). Four inclusion criteria were used: original article (1), with Amazonian populations (2), quantifying exposure (mercury levels) (3), and evaluating neurological outcomes (4). The extracted data included characteristics (as year or origin of authorship) and details of the research (as locations and type of participants or mercury levels and neurological assessments). Thirty-four studies, most concentrated within three main river basins (Tapajós, Tocantins, and Madeira) and related to environmental exposure, were found. Mercury body burden was two to ten times higher than recommended and main neurological findings were cognitive, vision, motor, somatosensory and emotional deficits. Important insights are described that support novel approaches to researching mercury exposure and intoxication, as well as prevention and intervention strategies. As a signatory country to the Minamata Convention, Brazil has the opportunity to play a central role in improving human health and leading the research on mercury intoxication.

Responsible Science Assessment: downplaying indexes, boosting quality.

Scientists are facing enormous pressures posed by growing scientific communities and stagnant/reduced funding. In this scenario, mechanisms of knowledge achievement and management, as well as how recruitment, progression and evaluation are carried out should be reevaluated. We argue here that knowledge has become a profitable commodity and, as a consequence, excessive academic quantification, individual output assessment problems and abusive editorial market strategies have reached unsustainable levels. We propose to reinforce existing guidelines and to establish new ones to overcome these issues. Our proposal, the Initiative for Responsible Scientific Assessment (IRSA), has the main goal to strengthen and expand previous movements in the scientific community to promote higher quality research assessment, focused on better Science.

Contributing to Understand the Crosstalk between Brain and Periphery in Methylmercury Intoxication: Neurotoxicity and Extracellular Vesicles.

Human exposure to methylmercury (MeHg) is currently high in regions such as the Amazon. Understanding the molecular changes associated with MeHg-induced neurotoxicity and the crosstalk with the periphery is essential to support early diagnoses. This work aimed to evaluate cellular and molecular changes associated with behavioral alterations in MeHg acute exposure and the possible changes in extracellular vesicles (EVs) number and S100ß content. Adults male Wistar rats were orally treated with 5 mg/kg for four days. Behavioral performance, molecular and histological changes in the cerebellum, and plasma EVs were assessed. MeHg-intoxicated animals performed significantly worse in behavioral tests. MeHg increased the number of GFAP+ cells and GFAP and S100ß mRNA expression in the cerebellum but no change in NeuN+ or IBA-1+ cells number was detected. The number of exosomes isolated from plasma were decreased by the metal. S100B mRNA was detected in circulating plasma EVs cargo in MeHg exposure. Though preliminary, our results suggest astrocytic reactivity is displaying a protective role once there was no neuronal death. Interestingly, the reduction in exosomes number could be a new mechanism associated with MeHg-induced neurotoxicity and plasma EVs could represent a source of future biomarkers in MeHg intoxication.

Competition indices after reduced impact logging in the Brazilian Amazon.

Competition for resources can affect growth and increase mortality in forest stands. The effects of this process are little known, especially in areas subjected to forest management which show distinct growth dynamics when compared to unmanaged natural areas. This study aimed to estimate, evaluate and select the best fit competition indices (CI) for individual trees in a managed forest in the eastern Amazon. The data used originated from 18 permanent plots of 1 ha each, which were monitored for 12 years after Reduced Impact Logging (RIL). For the competition analysis, 23 indices were tested. CIs were evaluated based on graphical analyses and linear correlation coefficients(r)between each index and variables, basal area growth(ΔG), probability of mortality(Pm), and post-logging period (PLP). In addition, the partial F-test was applied to verify how well the calculated CIs explain the variations observed in ΔGandP(m). The distance-independent index for BAL (Basal Area Larger) performed the best. For the distance-dependent and semi-independent indices, the best interactions with the variables tested occurred in radii of 15 and 20 m away from the object tree. The largest trees presented higher values ofΔG. While P(m)was similar among the three tree classes, larger trees had a slightly higher P(m)due to thier low density of individuals. The results obtained in this study may help to include CIs in growth and production models at the individual tree level in tropical rainforests, especially in those managed in the Brazilian Amazon.

Ruminal degradation kinetics of diets with different lipid sources and its influence on intake and milk yield of early lactation crossbred Holstein × Gir cows.

The hypothesized that the dietary inclusion of different lipid sources does not alter diet quality, feed intake, and, consequently, milk yield of cows. Thus, this study aimed to evaluate the effects of supplemental lipid sources for early lactation crossbred cows on milk yield, intake, and diet quality through in vitro digestibility and fermentation kinetics, and to demonstrate which variables have the most impact on each diet using principal component analysis (PCA). Five early lactating crossbred ¾ Holstein × » Gir cows (35 ± 8 days in milk), with a mean body weight of 410 ± 7.15 kg of body weight, were randomly allotted to a 5 × 5 Latin square. The treatments consisted of five experimental diets: a control diet with no additional lipid source and four diets with different lipid sources: cottonseed (242.6 g/kg of dry matter (DM)), sunflower seed (243.0 g/kg of DM), whole soybeans (234.0 g/kg of DM), and soybean oil (42.0 g/kg of DM), which were included at a rate to provide 70 g/kg of lipid. Diets with no additional lipid source and containing whole soybeans had higher DM, OM, and CP digestibility than other treatments. The diet containing soybean oil had the highest EE digestibility. Gas production was highest in the diet containing soybean oil. The dietary treatments did not affect DM intake. Milk yield was lower in cows receiving diets containing cottonseed. Whole soybeans can be included in diets for lactating cows to increase the energy intake without impairing the feed intake and milk yield.