Additions of landscape metrics improve predictions of occurrence of species distribution models

Species distribution models are used to aid our understanding of the processes driving the spatial patterns of species’ habitats. This approach has received criticism, however, largely because it neglects landscape metrics. We examined the relative impacts of landscape predictors on the accuracy of habitat models by constructing distribution models at regional scales incorporating environmental variables (climate, topography, vegetation, and soil types) and secondary species occurrence data, and using them to predict the occurrence of 36 species in 15 forest fragments where we conducted rapid surveys. We then selected six landscape predictors at the landscape scale and ran general linear models of species presence/absence with either a single scale predictor (the probabilities of occurrence of the distribution models or landscape variables) or multiple scale predictors (distribution models + one landscape variable). Our results indicated that distribution models alone had poor predictive abilities but were improved when landscape predictors were added; the species responses were not, however, similar to the multiple scale predictors. Our study thus highlights the importance of considering landscape metrics to generate more accurate habitat suitability models.

Partitioning between primary and secondary metabolism of carbon allocated to roots in four maize genotypes under water deficit and its effects on productivity

Plants may respond to drought by altering biomass allocation to shoots and roots or by changing the metabolic activities in these organs. To determine how drought changes the partitioning of carbon allocated to growth and secondary metabolism in maize roots and how it affects photosynthesis(A) and productivity in maize, we evaluated leaf gas exchange, yield componentes, root morphology, and primary and secondary metabolites including total soluble sugars(TSS), starch(S), phenolics(PHE), and lignin(LIG). Data were collected from pot-grown plants of four maize genotypes: BRS 1010 and 2B710(sensitive genotypes) and DKB390 and BRS1055(tolerant genotypes) under two soil water tensions: field capacity(FC,-18 kP a) and water deficit(WD,-138 kP a). WD was applied at the pre-flowering stage for 12 days and then the water supply was restored and maintained at optimum levels until the end of the cycle. For genotype BRS 1055 under FC, the greatest A did not result in greater grain biomass(DGB) because the accumulated photoassimilates had already filled the cells, and thus the excessive TSS synthesized in leaves was allocated to roots in large amounts. However, the sharp decrease in A caused by WD imposition in this genotype did not affect the influx pressure of leaf TSS, which was due largely to conversion of primary metabolites to PHE compounds to increase the length of fine roots. In leaves of DKB390 under WD, both S and TSS were reduced, whereas PHE were increased to prevent excessive water loss and xylem cavitation. Under WD, both BRS1010 and2B710 genotypes displayed reduced allocation of biomass to shoots and roots and LIG content in leaves, as well as lower A and DGB values. In BRS1010 this response was coupled to S decrease in leaves and TSS increase in roots, whereas in 2B710 there was a concomitant S increase in roots.

Controlled Reduction of Iron Content in Zirconiun Ore:A Case Study in Polyphase Mineralization,Pocs de Caldas Alkaline Plateau

In PCAC(Po?os de Caldas Alkaline Complex),in southeastern Brazil,it is observed a polyphase mineralization related to Zr-,U-,Th-,Mo-,and REE-enrichment due to hydromethermal processes which affected alkaline primary rock.Primary Zr-minerals were leached and concentrated as“caldasite”,a rock composed mainly by zircon and baddeleyite in different proportions.Several techniques of mineralogical characterization were applied and results indicated zircon,baddeleyite,magnetite and iron-oxyhydroxides,mainly.Magnetic separation by WHIMS(Wet High-Intensity Magnetic Separation)was performed in order to indicate the efficiency for Fe-concentration removal for potential application in refractory industry.

High aluminum concentration and initial establishment of Handroanthus impetiginosus : clues about an Al non-resistant species in Brazilian Cerrado

Cerrado soils are acidic and nutrient-poor,with high content of solubilized Al 3+.Plants growing in these conditions may display adaptations to cope with high aluminum concentrations especially during early developmental stages.We investigated leaf nutritional status,and photosynthetic and growth characteristics during the initial establishment of Handroanthus impetiginosus(Mart.Ex Dc.)Mattos,a secondary tree species distributed in the Brazilian Cerrado.Our goal was to understand leaf-level traits related to diff erent aluminum concentrations.H.impetiginosus plants were cultivated in four diff erent aluminum sulfate concentrations:0,1,2,and 4 mM Al,for 40 days.We performed analyses of growth,leaf gas exchange,chloroplast pigment content,and leaf mineral nutrients.We observed a linear increase of Al leaf content as a function of Al concentration in the nutrient solution.Plants grown in 1 mM Al showed a remarkable increase of K leaf content,net photosynthesis,stomatal conductance,and transpiration,while in 4 mM Al there were reductions of N,P,and K contents,gas exchange characteristics,and height.H.impetiginosus did not have mechanisms of avoidance,compartmentalization,or resistance to high Al concentrations.Indeed,this species showed a hormetic response,with low Al concentrations stimulating and high Al concentrations inhibiting plant responses.

Evaluation of physicochemical properties as supporting information on quality control of raw materials and veterinary pharmaceutical formulations

This study aimed to show that the physicochemical proprieties obtained by Fourier transform infrared spectroscopy （FTIR）, thermogravimetry （TG）, and scanning electronic microscopy （SEM） can be useful tools for evaluating the quality of active pharmaceutical ingredients （APIs） and pharmaceutical products. In addition, a simple, sensitive, and efficient method employing HPLC-DAD was developed for simulta- neous determination of lidocaine （LID）, ciprofloxacin （CFX） and enrofloxacin （EFX） in raw materials and in veterinary pharmaceutical formulations. Compounds were separated using a Gemini Cm （250 mm×4.6 mm, 5μm） Phenomenex column, at a temperature of 25℃, with a mobile phase containing 10 mM of phosphoric acid （pH 3.29）： acetonitrile （85.7：14.3, v/v） and a flow rate of 1.5 mL/min. Physicochemical characterization by TG, FTIR, and SEM of raw materials of LID, CFX, and EFX provided information useful for the evaluation, differentiation, and qualification of raw materials. Finally, the HPLC method was proved to be useful for evaluation of raw material and finished products, besides satisfying the need for an analytical method that allows simultaneous determination of EFX, CFX, and LID, which can also be extended to other matrices and applications.

Analysis of Radium Isotopes in Surface Waters nearby a Phosphate Mining with NORM at Santa Quiteria,Brazil

The radium isotopes 226Ra and 228Ra were analyzed in surface water at six points in the neighborhood of a mine of phosphate, associated with uranium, in the region of Santa Quitéria, state of Ceará, Brazil. Water samples were collected during twenty months, filtered and the concentrations of activity determined in the soluble and particulate phases. The results were analyzed using the Principal Component Analysis (PCA) for ordination of environmental data, and also by ANOVA, Tukey and Z tests to compare sets of data considering the radionuclides, the two analyzed phases and the six collecting points. The PCA identified four groups that included all collecting points, using aggregation features such as radionuclide and analyzed phase. The first group is composed by the samples of 226Ra in the soluble phase;the second group by samples of 226Ra in the particulate phase;the third one by 228Ra in the soluble phase, and finally, the fourth group by 228Ra in the particulate phase. This last group has two discrepant points (01 and 06). Statistical analysis identified differences between the concentrations of activity of radionuclides (228Ra higher than 226Ra) and in analyzed phases (soluble phase higher than the particulate one) but showed no differences between sampled points.

Release of Uranium by an Ore Treatment Unit at Caldas,MG,Brazil

This study aims to assess the behavior of the release of Unat (i.e. uranium isotopes in natural relative abundance) from the release of water treated by the Ore Treatment Unit (UTM) in Caldas, state of Minas Gerais, Brazil, during the years 1999 to 2009. During this period, the unit showed no industrial activity, except between 2004 and 2005, when UTM operated 400 tons of monazite in a process to obtain rare earths. Unat was analyzed by spectrophotometry once per week in the effluent waters at sampling point 014. Two fractions were considered for analysis: the soluble one (that passes through a 0.45 μm filter) and the particulate one (retained on a 0.45 μm filter). Statistical analyses were performed: the “Z” test and Pearson’s r2 correlation index. The values for the soluble fraction were consistently lower than those of the particulate fraction and no statistically significant correlation was observed between the soluble and particulate fractions. However, the particulate and the total fractions (the sum of soluble and particulate) strongly correlated.

Convergent pathways of the gut microbiota–brain axis and neurodegenerative disorders

Recent research has been uncovering the role of the gut microbiota for brain health and disease.These studies highlight the role of gut microbiota on regulating brain function and behavior through immune,metabolic,and neuronal pathways.In this review we provide an overview of the gut microbiota axis pathways to lay the groundwork for upcoming sessions on the links between the gut microbiota and neurogenerative disorders.We also discuss how the gut microbiota may act as an intermediate factor between the host and the environment to mediate disease onset and neuropathology.Based on the current literature,we further examine the potential for different microbiota-based therapeutic strategies to prevent,to modify,or to halt the progress of neurodegeneration.

Host preference of the bean weevil Zabrotes subfasciatus

It is largely known that the range of an insect diet is mostly determined by oviposition behavior, mainly in species with endophytic larvae such as Zabrotes subfasciatus. However, the proximate factors determining host choice and the subsequent steps leading to the expansion or reduction of the host number and occasional host shifts are largely unknown. We analyzed various factors determining host preference of Z. subfasciatus through the evaluation of： （i） oviposition preference of a wild population of Z. subfasciatus on the usual host （bean） and unusual hosts （lentil, chickpea and soy）, and the performance of the offspring; （ii） artificial selection for increasing preference for hosts initially less frequently chosen; （iii） comparison of oviposition behavior between two different populations （reared for -30 generations in beans or chickpeas, respectively）; （iv） oviposition timing on usual and unusual hosts; and （v） identification of preference hierarchies. We found that when using unusual hosts, there is no correlation between performance and preference and that the preference hierarchy changes only slightly when the population passes through several generations on the less frequently accepted host. We also found a positive response to artificial selection for increasing oviposition on the less preferred host; however, when the host-choice experiment involved two varieties of the usual host, the response was faster than when the choice involved usual and unusual hosts. Finally, beetles reared on an unusual host （chickpea） for 26 generations showed similar good fitness on both usual and unusual hosts, indicating that the use of a new host does not necessarily result in the loss of performance on the original host. Nevertheless, this population showed lower fitness on the usual host than that of the original population, suggesting an underlying partial trade-off phenomenon which may contribute to a broadening of diet of this insect species.