Dynamics of phosphorus and phytate-utilizing bacteria during aerobic degradation of dairy cattle dung

During organic wastes degradation, P is transformed which may affect its availability. In this study, the dynamics of P and the occurrence of phytate-utilizing bacteria (PUB) were evaluated during aerobic degradation of dairy cattle dung in laboratory-scale reactors for 105 d. The results showed an increase of water-soluble inorganic P (Pi) (from 570 to 1890 mg kg(-1)) and biomass P (from 390 to 870 mg kg(-1)) during the initial 40 d. After this period, water-soluble Pi remained constant (around 1500 mg kg(-1)) and biomass P decreased (around 220 mg kg(-1)) probably due to the decrease of easily available C in dung. Under the acidic conditions in the first 20 d there was an increase in concentration of Al (25 mg kg(-1)) and Fe (27 mg kg(-1)) ions. These ions were no longer detectable in the alkaline conditions occurring after 40 d. In the same period, the Ca concentration increased (from 1170 to 2370 mg kg(-1)) and chemical speciation revealed permanent association of Ca ions with Pi. Sequential P fractionation showed a decrease of organic P in NaHCO(3), NaOH and HCl fractions and an increase of residual P (25-52% with respect to total P). Analysis by (31)P NMR also showed a decrease (from 14% to 1.6%) of phytic acid content during final experimental period (60 and 105 d). The bacteriological analysis revealed various PUB involved in degradation of the dung. Two morphotypes, genetically characterized as Enterobacter and Rahnella, which were dominant under higher content of residual P, showed strong utilization of phytate in vitro.     

Metal bioaccumulation in the greater white-toothed shrew, Crocidura russula, inhabiting an abandoned pyrite mine site

Hepatic and renal concentrations of iron, magnesium, zinc, lead, copper, manganese, mercury, cadmium, molybdenum, chromium, and nickel were quantified in shrews (Crocidura russula) inhabiting a pyrite mine site in Portugal. Several morphological parameters (body weight, residual index, and relative weights) were also examined to clarify the physiological effects of pollution. Shrews from the mine showed increased bioavailability of Fe, Pb, Hg, Cd, Mo, and Ni in comparison with reference specimens. Adult shrews had the highest Cd levels while Cr and Ni concentrations diminished. Intersexual differences were found for Mo and Ni. As a consequence of metal pollution, the relative hepatic weight was higher in shrews from the mine site when compared with reference specimens. These data indicate that C. russula is a good bioindicator of metal pollution. We also evaluated the toxic effects of Pb, Hg, Cd, and Ni, because several shrews from the polluted site showed high concentrations of these metals. To approximate at the real biological impact of abandoned mines, after this first step it is necessary to associate the bioaccumulation levels and morphological effects with other physiological, ecological and genetical biomarkers.     

Primary colonization and breakdown of igneous rocks by endemic, succulent elephant trees (Pachycormus discolor) of the deserts in Baja California, Mexico

Trees growing in rocks without soil are uncommon. In two arid regions in Baja California, Mexico, field surveys found large numbers of rock-colonizing elephant trees (Pachycormus discolor (Benth.) Coville ex Standl. (Mexican name: copalquin) growing in igneous rocks (granite and basalt) as primary colonizers without the benefit of soil or with a very small amount of soil generated by their own growth. Many adult trees broke large granite boulders and were capable of wedging, growing in, and colonizing rocks and cliffs made of ancient lava flows. This is the first record of a tree species, apart from the previously recorded cacti, capable of primary colonization of rocks and rock rubble in hot deserts.     

A pilot study of pesticides and PCBs in the breast milk of women residing in urban and agricultural communities of California

Currently, there is no nationally representative human milk biomonitoring program in the United States (U.S.) and no studies have reported non-persistent pesticides in the milk of U.S. women. In this pilot study we developed a multiresidue laboratory method to measure non-persistent and persistent pesticides and polychlorinated biphenyl (PCB) congeners in human milk samples from women residing in the agricultural region of Salinas, CA (n = 13) and the urban San Francisco Bay Area, CA (n = 21). Samples were collected from 2002-2007. Median concentrations in pg g(-1) milk among urban and agricultural women, respectively were reported for: chlorpyrifos (24.5 and 28.0), cis-permethrin (81.9 and 103), trans-permethrin (93.1 and 176), hexachlorobenzene (191 and 223), β-hexachlorocyclohexane (220 and 443), o,p'-DDT (36.6 and 62.4), p,p'-DDT,(107 and 102), o,p'-DDE (5.65 and 5.17), p,p'-DDE (3170 and 3490), dacthal (2.79 and 3.43), PCB 118 (92.8 and 17.0), PCB 138 (183 and 38.2), PCB 153 (242 and 43.6) and PCB 180 (239 and 683). Among urban women, median concentrations were 4.02 and 4.32 pg g(-1) milk for chlorpyrifos-methyl and propoxur, respectively. These results suggest that neonates and young children may be exposed to persistent and non-persistent pesticides and PCBs via breast milk.     

Organic matter characteristics and nutrient content in eroded soils

Twenty-one severely eroded soils of SE Spain (Torriorthent xeric soils) were studied. These soils form a fragile system characterized by soils with a low density of plant cover (<5%), are loamy and occur in a semiarid climate. The soils formerly were used for agricultural purposes but were abandoned at least 15 years ago. These eroded soils had a low total organic carbon content, and their humic substances, humic acid carbon, and carbohydrates were lower compared with soils that had never been cultivated (natural soils). The variables in which the effects of erosion were particularly noted were those related with the active organic matter (respiration and water-soluble organic matter). Those eroded soils with higher salt content showed lower organic matter and carbohydrate contents. Only total nitrogen was correlated with the carbon fractions in the eroded soils.     

High overlap between traditional ecological knowledge and forest conservation found in the Bolivian Amazon

It has been suggested that traditional ecological knowledge (TEK) may play a key role in forest conservation. However, empirical studies assessing to what extent TEK is associated with forest conservation compared with other variables are rare. Furthermore, to our knowledge, the spatial overlap of TEK and forest conservation has not been evaluated at fine scales. In this paper, we address both issues through a case study with Tsimane’ Amerindians in the Bolivian Amazon. We sampled 624 households across 59 villages to estimate TEK and used remote sensing data to assess forest conservation. We ran statistical and spatial analyses to evaluate whether TEK was associated and spatially overlapped with forest conservation at the village level. We find that Tsimane’ TEK is significantly and positively associated with forest conservation although acculturation variables bear stronger and negative associations with forest conservation. We also find a very significant spatial overlap between levels of Tsimane’ TEK and forest conservation. We discuss the potential reasons underpinning our results, which provide insights that may be useful for informing policies in the realms of development, conservation, and climate. We posit that the protection of indigenous cultural systems is vital and urgent to create more effective policies in such realms.     

RNAi-mediated silencing of vitellogenin gene function turns honeybee (Apis mellifera) workers into extremely precocious foragers

The switch from within-hive activities to foraging behavior is a major transition in the life cycle of a honeybee (Apis mellifera) worker. A prominent regulatory role in this switch has long been attributed to juvenile hormone (JH), but recent evidence also points to the yolk precursor protein vitellogenin as a major player in behavioral development. In the present study, we injected vitellogenin double-stranded RNA (dsVg) into newly emerged worker bees of Africanized genetic origin and introduced them together with controls into observation hives to record flight behavior. RNA interference-mediated silencing of vitellogenin gene function shifted the onset of long-duration flights (>10 min) to earlier in life (by 3–4 days) when compared with sham and untreated control bees. In fact, dsVg bees were observed conducting such flights extremely precociously, when only 3 days old. Short-duration flights (<10 min), which bees usually perform for orientation and cleaning, were not affected. Additionally, we found that the JH titer in dsVg bees collected after 7 days was not significantly different from the controls. The finding that depletion of the vitellogenin titer can drive young bees to become extremely precocious foragers could imply that vitellogenin is the primary switch signal. At this young age, downregulation of vitellogenin gene activity apparently had little effect on the JH titer. As this unexpected finding stands in contrast with previous results on the vitellogenin/JH interaction at a later age, when bees normally become foragers, we propose a three-step sequence in the constellation of physiological parameters underlying behavioral development. David Santos Marco Antonio and Karina Rosa Guidugli-Lazzarini contributed equally to the present study.     

Accumulation fatty acids of in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoA carboxylase,temperature, and co-immobilization with Azospirillum brasilense

The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae.     

Spatial distribution and sources of trace elements in sediments affected by old mining activities

The distribution of trace elements throughout mining areas is an important issue because abandoned tailings could be a major source of environmental pollution. In order to analyze the spatial variation of trace elements in a zone where mining activities took place and to identify pollution sources in the study area, a three-step study was carried out at a regional, at a local, and a detailed scale. In addition, a conceptual model of trace elements dispersion was established and confirmed by a geographic information system. The results obtained allowed to establish points affected by primary, secondary, and tertiary contamination, according to their proximity to contamination sources and as a function of attenuation processes which could take place in the studied area.     

The solitary median maxillary central incisor (SMMCI) syndrome: Associations,prenatal diagnosis,and outcomes

Solitary median maxillary central incisor (SMMCI) syndrome is a complex disorder consisting of multiple, developmental defects involving midline structures of the head, which includes the cranial bones, the maxilla, and its container dentition (specifically the central incisor tooth germ), together with other midline structures of the body. SMMCI may appear as an isolated trait or in association with other midline developmental anomalies. We describe the case of a patient with SMMCI. He presented with a solitary median maxillary incisor, short stature, corpus callosum anomalies and a microform of holoprosencephaly (HPE), diabetes insipidus, and neurodevelopmental delay. The diagnosis was performed postnatally based on clinical features, radiological imaging, and a comprehensive genetic study. SMMCI can be diagnosed during the prenatal or neonatal periods or during infancy. Evaluation of the superior maxillary bone is important for prenatal diagnosis. Direct evaluation through bidimensional ultrasound or the use of multiplanar ultrasound or tridimensional reconstruction should be performed in cases of brain or face malformations. Early diagnosis can contribute to improved prenatal assessment and postnatal management.