No Evidence of Habitat Loss Affecting the Orchid Bees Eulaema nigrita Lepeletier and Eufriesea auriceps Friese (Apidae: Euglossini) in the Brazilian Cerrado Savanna

Habitat loss, landscape fragmentation, and agriculture intensification constitute the main threats to bees. As the organisms responsible for almost one third of the food produced worldwide, there are growing concerns on bees’ response to human-related disturbances. Among all bee groups, orchid bees (Apidae: Euglossini) compose an interesting group to test landscape-related hypotheses. In here, we tested the effect of landscape features (amount of anthropic areas and isolation) on the probability of occurrence and the abundances of both Eulaema nigrita Lepeletier and Eufriesea auriceps Friese in the Cerrado savanna. In general, we did not observe any effect of landscape features on the probability of occurrence and abundances of both species in our sampling sites. Given their potential high dispersal abilities, these bee species may be less sensitive to fragmented landscapes or even positively affected by the increase of anthropic habitats. Since we sampled many E. nigrita specimens in highly preserved Cerrado savanna areas, we believe that at least for this biome, this species may not be a good indicator of landscape disturbance.     

Biological activity in Cerrado soils: evaluation of vegetation,fire and seasonality effects using the “bait-lamina test”

Aims

The Cerrado, a South American savanna, is considered a priority for conservation. In this case study, we assessed soil feeding activity as a way to improve understanding of the ecosystem functioning, in order to support and refine conservation strategies.

Methods

Soil feeding activity was assessed using the bait-lamina method under different environmental conditions: in the dry and rainy seasons, in burned and unburned areas, and under native and invasive grasses.

Results

Feeding activity was significantly reduced after fire, but recovered to pre-fire levels with the rains. Activity increased significantly during the rainy season in both areas, being more pronounced in the unburned area. The highest feeding activity was observed under the invasive grass (Melinis minutiflora). Feeding activity declined with soil depth and was affected by season and fire.

Conclusions

Seasonality was the most important factor affecting the feeding activity of soil organisms, followed by the fire history and the extant vegetation. Although this method does not allow distinguishing between feeding activity of different organisms, it can provide valuable insights into differences in soil functioning due to changes in environmental conditions.     

Barnacle Goose (Branta leucopsis) feeding ecology and trophic relationships on Kolguev Island: The usage patterns of nutritional resources in tundra and seashore habitats

Insight into colonization of new areas by invasive species and their relationships with aboriginal species is a major challenge in ecology, allowing for prediction of the outcome of biological invasions. In this context, the current expansion of the Barnacle Goose (Branta leucopsis) is of great interest. The seasonal dynamics of Barnacle Goose feeding and the structure of its diet on Kolguev Island during the nesting and postnesting periods (May 27–July 29) have been examined. The diet structures of the invasive Barnacle Goose and the aboriginal species White-fronted goose (Anser albifrons) and Bean goose (A. fabalis) have been compared. The probability of interspecific competition and the ecological advantages in the diet patterns of these species have been estimated. If the Barnacle Goose population on Kolguev Island continues to increase, this may led to a decline in the population of aboriginal species of geese on the island.     

Permeability of isolated rat hepatocyte plasma membranes for molecules of dimethyl sulfoxide

We have studied permeability of isolated rat hepatocyte membranes for molecules of dimethyl sulfoxide (DMSO) at different hypertonicity of a cryoprotective medium. The permeability coefficient of hepatocyte membranes k ₁ for DMSO molecules was shown to be the differential function of osmotic pressure between a cell and an extracellular medium. Ten-fold augmentation of DMSO concentration in the cryoprotective medium causes the decrease of permeability coefficients k ₁ probably associated with the increased viscosity in membrane-adjacent liquid layers as well as partial limitations appeared as a result of change in cell membrane shape after hepatocyte dehydration. We have found out that in aqueous solutions of NaCl (2246 mOsm/L) and DMSO (2250 mOsm/L) the filtration coefficient L _p in the presence of a penetrating cryoprotectant (L _pDMSO = (4.45 ± 0.04) · 10^?14 m³/Ns) is 3 orders lower compared to the case with electrolyte (L _pNaCl = (2.25 ± 0.25) · 10^?11 m³/Ns). This phenomenon is stipulated by the cross impact of flows of a cryoprotectant and water at the stage of cell dehydration. Pronounced lipophilicity of DMSO, geometric parameters of its molecule as well as the presence of large aqueous pores in rat hepatocyte membranes allow of suggesting the availability of two ways of penetrating this cryoprotectant into the cells by non-specific diffusion through membrane lipid areas and hydrophilic channels.     

Influence of bovine lactoferrin on the growth of selected probiotic bacteria under aerobic conditions

Bovine lactoferrin (bLf) is a natural glycoprotein, and it shows broad-spectrum antimicrobial activity. However, reports on the influences of bLf on probiotic bacteria have been mixed. We examined the effects of apo-bLf (between 0.25 and 128 mg/mL) on both aerobic and anaerobic cultures of probiotics. We found that bLf had similar effects on the growth of probiotics under aerobic or anaerobic conditions, and that it actively and significantly (at concentrations of >0.25 mg/mL) retarded the growth rate of Bifidobacterium bifidum (ATCC 29521), B. longum (ATCC 15707), B. lactis (BCRC 17394), B. infantis (ATCC 15697), Lactobacillus reuteri (ATCC 23272), L. rhamnosus (ATCC 53103), and L. coryniformis (ATCC 25602) in a dose-dependent manner. Otherwise, minimal inhibitory concentrations (MICs) were 128 or >128 mg/mL against B. bifidum, B. longum, B. lactis, L. reuteri, and L. rhamnosus (ATCC 53103). With regard to MICs, bLf showed at least four-fold lower inhibitory effect on probiotics than on pathogens. Intriguingly, bLf (>0.25 mg/mL) significantly enhanced the growth of Rhamnosus (ATCC 7469) and L. acidophilus (BCRC 14065) by approximately 40–200 %, during their late periods of growth. Supernatants produced from aerobic but not anaerobic cultures of L. acidophilus reduced the growth of Escherichia coli by about 20 %. Thus, bLf displayed a dose-dependent inhibitory effect on the growth of most probiotic strains under either aerobic or anaerobic conditions. An antibacterial supernatant prepared from the aerobic cultures may have significant practical use.     

Ticks (Acari: Ixodidae) in the Serra da Canastra National Park in Minas Gerais,Brazil: species,abundance, ecological and seasonal aspects with notes on rickettsial infection

The Cerrado Biome is the second largest in Brazil covering roughly 2 million km², with varying features throughout its area. The Biome is endangered but it is also source of animal species for rural, green urban and degraded rainforest areas. Ticks are among Cerrado species that establish at anthropogenic sites and although information about them is steadily increasing, several features are unknown. We herein report tick species, abundance and some ecological relationships within natural areas of the Cerrado at higher altitudes (800–1500 m) within and around Serra da Canastra National Park, in Minas Gerais State Brazil. In total of 1196 ticks were collected in the environment along 10 campaigns held in 3 years (2007–2009). Amblyomma sculptum was the most numerous species followed by Amblyomma dubitatum and Amblyomma brasiliense. Distribution of these species was very uneven and an established population of A. brasiliense in the Cerrado is reported for the first time. Other tick species (Amblyomma ovale, Amblyomma nodosum, Amblyomma parvum, Ixodes schulzei and Haemaphysalis leporispalustris) were found in lesser numbers. Domestic animals displayed tick infestations of both rural and urban origin as well as from natural areas (Rhipicephalus sanguineus sensu lato, Rhipicephalus microplus, Dermacentor nitens, A. sculptum, A. ovale, Amblyomma tigrinum, Argas miniatus). Amblyomma sculptum had the widest domestic host spectrum among all tick species. DNA of only one Rickettsia species, R. bellii, was found in an A. dubitatum tick. Several biological and ecological features of ticks of the studied areas are discussed.     

Entomopathogenic nematode distribution and edaphoclimatic conditions in the Cerrado of Minas Gerais,Brazil

Based on the high diversity of Brazilian fauna and flora, edaphoclimatic conditions in the Cerrado of Minas Gerais, and the situation of utilization of EPNs in Brazil, a survey was conducted in order to relate the presence of these organisms with the physical and chemical attributes of the soil, combined with precipitation. To this end, soil samples were collected in areas with diversified vegetation types in Monte Carmelo, MG, at Juliana Farm. The samples were obtained every 15 days for 6 months. From each spot, soil samples (about 500 g) were collected for soil moisture characterization, nematode isolation and determination of pH, organic matter, potassium (K), calcium (Ca), magnesium (Mg), phosphorus (P), potential acidity (H + Al) and precipitation data (mm). Three populations of entomopathogenic nematodes of the Heterorhabditis amazonensis species were isolated in Cerrado stricto sensu and Gallery forest areas. The occurrence H. amazonensis could not be considered restricted to specific soil condition, as organic matter, humidity, pH, Ca, K, Mg and H + Al, especially considering the organic matter and K values, which had variable levels between the places of collection. The p values of the positive soil samples were at a lower level than the mean of the Gallery forest and Cerrado, and at the same level as maize and pasture area. The soil moisture in the Cerrado area increased with the higher values of precipitation; however, in the Gallery forest area this association was not observed. Also, the nematodes were isolated when the temperature began to decrease.     

Oxytocin plasma concentrations in children and adolescents with autism spectrum disorder: correlation with autistic symptomatology

Findings from research in animal models and humans have shown a clear role for the neuropeptide oxytocin (OT) on complex social behaviors. This is also true in the context of autism spectrum disorder (ASD). Previous studies on peripheral OT concentrations in children and young adults have reported conflicting results with the initial studies presenting mainly decreased OT plasma levels in ASD compared to healthy controls. Our study therefore aimed to further investigate changes in peripheral OT concentrations as a potential surrogate for the effects observed in the central nervous system (CNS) in ASD. OT plasma concentrations were assessed in 19 male children and adolescents with ASD, all with an IQ > 70 (age 10.7 ± 3.8 years), 17 healthy male children (age 13.6 ± 2.1 years) and 19 young male patients with attention deficit hyperactivity disorder (ADHD) as a clinical control group (age 10.4 ± 1.9 years) using a validated radioimmunoassay. Analysis of covariance revealed significant group differences in OT plasma concentrations (F(2, 48) = 9.574, p < 0.001, η ² = 0.285; plasma concentrations ASD 19.61 ± 7.12 pg/ml, ADHD 8.05 ± 5.49 pg/ml, healthy controls 14.43 ± 9.64 pg/ml). Post hoc analyses showed significantly higher concentrations in children with ASD compared to ADHD (p < 0.001). After Bonferroni correction, there was no significant difference in ASD in comparison with healthy controls (p = 0.132). A significant strong correlation between plasma OT and autistic symptomatology, assessed by the Autism Diagnostic Observation Schedule, was observed in the ASD group (p = 0.013, r = 0.603). Patients with ADHD differed from healthy control children by significantly decreased OT concentrations (p = 0.014). No significant influences of the covariates age, IQ, medication and comorbidity could be seen. Our preliminary results point to a correlation of OT plasma concentrations with autistic symptom load in children with ASD and a modulation of the OT system also in the etiologically and phenotypically overlapping disorder ADHD. Further studies in humans and animal models are warranted to clarify the complex association of the OT system with social impairments as well as stress-related and depressive behavior and whether peripheral findings reflect primary changes of OT synthesis and/or release in relevant areas of the CNS.     

Parasitism ofPhthorimaea operculella [Lep.: Gelechiidae] larvae in Queensland

Parasitism ofPhthorimaea operculella (Zeller) larvae on potato foliage was examined intensively in the Lockyer Valley, south-eastern Queensland from 1975–78 and extensively from other hosts and areas of Queensland. The % parasitism in the Lockyer Valley exceeded 50% in 29 of the 36 collections. The parasite species were dominated by the introducedCopidosoma desantisi Annecke & Mynhardt (Encyrtidae) andOrgilus lepidus Muesebeck (Braconidae) which together accounted for 92.6% of parasite numbers recorded. In more northern areas of Queensland, the dominant parasite species found was the introducedApanteles subandinus Blanchard (Braconidae). Other hymenopterous parasites found wereMicrochelonus curvimaculatus Cameron (Braconidae), Elasmus funereus Riek (Elasmidae) andTemelucha minuta (Morley) (Ichneumonidae).     

Possible Effects of Glyphosate on Mucorales Abundance in the Rumen of Dairy Cows in Germany

Glyphosate (N-phosphonomethyl glycine) is registered as a herbicide for many food and non-food crops, as well as non-crop areas where total vegetation control is desired. Glyphosate influences the soil mycobiota; however, the possible effect of glyphosate residues in animal feed (soybean, corn, etc.) on animal mycobiota is almost unknown. Accordingly, the present study was initiated to investigate the mycological characteristics of dairy cows in relationship to glyphosate concentrations in urine. A total of 258 dairy cows on 14 dairy farms in Germany were examined. Glyphosate was detected in urine using ELISA. The fungal profile was analyzed in rumen fluid samples using conventional microbiological culture techniques and differentiated by MALDI-TOF mass spectrometry. LPS-binding protein (LBP) and antibodies (IgG1, IgG2, IgA, and IgM) against fungi were determined in blood using ELISA. Different populations of Lichtheimia corymbifera, Lichtheimia ramosa, Mucor, and Rhizopus were detected. L. corymbifera and L. ramosa were significantly more abundant in animals containing high glyphosate (>40 ng/ml) concentrations in urine. There were no significant changes in IgG1 and IgG2 antibodies toward isolated fungi that were related to glyphosate concentration in urine; however, IgA antibodies against L. corymbifera and L. ramosa were significantly lower in the higher glyphosate groups. Moreover, a negative correlation between IgM antibodies against L. corymbifera, L. ramosa, and Rhizopus relative to glyphosate concentration in urine was observed. LBP also was significantly decreased in animals with higher concentrations of glyphosate in their urine. In conclusion, glyphosate appears to modulate the fungal community. The reduction of IgM antibodies and LBP indicates an influence on the innate immune system of animals.     

Index,Vol. 34, 1999

To investigate whether similar physiognomic areas support similar faunas, the richness, similarity, and community structure of the ant fauna attracted to baits in an area of the Brazilian Cerrado sensu stricto at the core of the domain and in two Cerrado 'islands' (one of sensu stricto and another of 'cerradão') were compared. In each locality, four collecting events were performed (two during the day and two at night) capturing ants attracted to 400 sardine baits (200 in soil, 200 in vegetation). Ants of six subfamilies, 33 genera, and 121 species were identified visiting baits in the three areas (180 species estimated). The most speciose genera were Camponotus (27 species), Pheidole (13), Solenopsis (11), and Crematogaster (8). The similarity values between pair sites can be considered medium in relation to other studies. The highest value was recorded for the core area and the 'island' of Cerrado sensu stricto (Morisita-Horn = 0.57). The two Cerrado 'islands' were found to be 0.44 similar and the core area and the 'cerradão' 0.41 similar. The ordination analysis (non-metric multidimensional scaling) revealed discontinuities in species distributions between areas of Cerrado sensu stricto and 'cerradão,' and distinctive ant faunas relative to the temporal (nocturnal and diurnal) and foraging niches (ground and vegetation). The ant fauna at ground level in the 'cerradão' and Cerrado sensu stricto showed the greatest dissimilarity. The data suggest that areas of Cerrado are characterized by relatively high local ant fauna richness, and that community structure is influenced by the distance between sites and the diversity of vegetation.     

Abnormalities of blood selenium and glutathione peroxidase activity in patients with acquired immunodeficiency syndrome and aids-related complex

Severe protein-calorie malnutrition is common in patients with AIDS and could contribute to the progressive deterioration characteristic of that disease. Selenium deficiency could also have a negative impact on immune function and other organ functions vital for recovery from infectious diseases. Therefore, to assess any role for selenium in AIDS, we determined plasma and erythrocyte selenium levels and glutathione peroxidase activity in 13 patients with AIDS compared to 8 patients with AIDS-related complex (ARC) and 14 healthy controls. Plasma selenium levels were significantly reduced in AIDS patients compared to controls (p<.0001) and to ARC (p<.02). Erythrocyte selenium levels in both AIDS and ARC were also reduced compared to controls (p<.02), but not to each other. Glutathione peroxidase activity in AIDS was 28.9±1.4 U/g Hb vs 38.4±6.9 in ARC (p=NS) and 52.3±1.7 in controls (p<.0001 vs AIDS;p<.02 vs ARC). When all groups were combined, there were significant correlations between total lymphocyte count and both plasma selenium (r=.53;p<.002) and erythrocyte glutathione peroxidase activity (r=.65;p<.0001). In addition, strong correlations were noted between plasma selenium and serum albumin (r=.68;p<.0001), plasma selenium and glutathione peroxidase (r=.77;p<.0001), and glutathione peroxidase and hematocrit (r=.66;p<.0001). In AIDS or ARC, no correlations between selenium with disease duration or weight loss were present. We conclude that, in comparison to normals, patients manifesting infection with human immunodeficiency virus have evidence of selenium deficiency as determined by diminished plasma and erythrocyte levels and glutathione peroxidase activity. These abnormalities are most marked in patients with AIDS, but are also present in patients with AIDS-related complex. Selenium deficiency has important implications for the progression and pathogenesis of clinical disease in AIDS.     

Expression profile of MAGI2 gene as a novel biomarker in combination with major deregulated genes in prostate cancer

Complex molecular changes that occur during prostate cancer (PCa) progression have been described recently. Whole genome sequencing of primary PCa samples has identified recurrent gene deletions and rearrangements in PCa. Specifically, these molecular events disrupt the gene loci of phosphatase and tensin homolog (PTEN) and membrane-associated guanylate kinase inverted-2 (MAGI2). In the present study, we analyzed the expression profile of MAGI2 gene in a cohort of clinical PCa (n = 45) and benign prostatic hyperplasia (BPH) samples (n = 36) as well as three PCa cell lines. We also studied the expression of PCa-related genes, including PTEN, NKX3.1, SPINK1, DD3, AMACR, ERG, and TMPRSS2-ERG fusion in the same samples. The expression of MAGI2 mRNA was significantly down-regulated in PC3, LNCaP and DU-145 PCa cell lines (p = 0.000), and also in clinical tumor samples (Relative expression = 0.307, p = 0.002, [95 % CI 0.002–12.08]). The expression of PTEN, NKX3.1, SPINK1, DD3, and AMACR genes was significantly deregulated in prostate tumor samples (p range 0.000–0.044). A significant correlation was observed between MAGI2 and NKX3.1 expression in tumor samples (p = 0.006). Furthermore, the inclusion of MAGI2 in the gene panel improved the accuracy for discrimination between PCa and BPH samples with the sensitivity and specificity of 0.88 [CI 0.76–0.95] and 0.83 [CI 0.68–0.92], respectively. The data presented here suggest that MAGI2 gene can be considered as a novel component of gene signatures for the detection of PCa.     

A comparison of type 2 diabetes risk allele load between African Americans and European Americans

The prevalence of type 2 diabetes (T2D) is greater in populations of African descent compared to European-descent populations. Genetic risk factors may underlie the disparity in disease prevalence. Genome-wide association studies (GWAS) have identified >60 common genetic variants that contribute to T2D risk in populations of European, Asian, African and Hispanic descent. These studies have not comprehensively examined population differences in cumulative risk allele load. To investigate the relationship between risk allele load and T2D risk, 46 T2D single nucleotide polymorphisms (SNPs) in 43 loci from GWAS in European, Asian, and African-derived populations were genotyped in 1,990 African Americans (n = 963 T2D cases, n = 1,027 controls) and 1,644 European Americans (n = 719 T2D cases, n = 925 controls) ascertained and recruited using a common protocol in the southeast United States. A genetic risk score (GRS) was constructed from the cumulative risk alleles for each individual. In African American subjects, risk allele frequencies ranged from 0.024 to 0.964. Risk alleles from 26 SNPs demonstrated directional consistency with previous studies, and 3 SNPs from ADAMTS9, TCF7L2, and ZFAND6 showed nominal evidence of association (p < 0.05). African American individuals carried 38–67 (53.7 ± 4.0, mean ± SD) risk alleles. In European American subjects, risk allele frequencies ranged from 0.084 to 0.996. Risk alleles from 36 SNPs demonstrated directional consistency, and 10 SNPs from BCL11A, PSMD6, ADAMTS9, ZFAND3, ANK1, CDKN2A/B, TCF7L2, PRC1, FTO, and BCAR1 showed evidence of association (p < 0.05). European American individuals carried 38–65 (50.9 ± 4.4) risk alleles. African Americans have a significantly greater burden of 2.8 risk alleles (p = 3.97 × 10^?89) compared to European Americans. However, GRS modeling showed that cumulative risk allele load was associated with risk of T2D in European Americans, but only marginally in African Americans. This result suggests that there are ethnic-specific differences in genetic architecture underlying T2D, and that these differences complicate our understanding of how risk allele load impacts disease susceptibility.