394 research outputs found
Enumeration and characterization of arsenic-tolerant diazotrophic bacteria in a long-term heavy-metal-contaminated soil
The abundance of arsenic-tolerant diazotrophic
bacteria was compared in a long-term contaminated
soil versus a non-contaminated one. In addition, the
characterization of tolerant diazotrophic bacteria was
carried out. Differences in the number of heterotrophic
N2 fixers were found between soils. Contaminated soil
showed a decrease in the microbial population size of
about 80%, confirming the great sensitivity of this
group of soil bacteria to metals. However, quantitative
analysis of the response to increased doses of arsenic
reveals that the proportion of the culturable diazotrophic
community tolerant to arsenic was identical for both
soils (contaminated and non-contaminated). Twentytwo
arsenic-tolerant diazotrophic isolates were obtained
and further characterized. 16S ribosomal DNA sequence
analysis revealed that these bacterial isolates
were distributed among four taxons (Actinobacteria,
Firmicutes, γ-Proteobacteria, and β-Proteobacteria).
Most genera recovered from the contaminated soil were
also found in the uncontaminated soi
Soil Chemical Attributes Of A Dystroferric Red Latosol (oxisol) Treated With An Alkaline Effluent From A Pharmaceutical Industry
Effluents from different industrial supply conglomerates are often discarded in the environment without proper treatment. The concern for an economically viable industrial production line, which is both environmentally sound and socially acceptable, is increasing. Some of these effluents are alkaline in nature and may be used as an alternative to chemical conditioners for acidic soils in agricultural systems. This research aimed to evaluate changes in the chemical attributes of a Dystroferric Red Latosol (Oxisol) after application of an effluent from a pharmaceutical industry. The experiment was conducted in a greenhouse using PVC tubes of 1-m length and a 0.2-m diameter filled with soil and different doses of the effluent. After 3 days, 100 mm of water was applied to each treatment. The PVC tubes were incubated for 30 days; thereafter, the tubes disassembled, and soil chemical analysis were made at different soil depths: 0-0.2, 0.2-0.4, 0.4-0.6, 0.6-0.8, and 0.8-1.0 m. The effluent applications significantly altered the soil elements in the 0-0.2 m layer, increasing the concentrations of K+, P, Mn2+, Na+, Cu2+, H+, Ca2+, Al3+ and the soil pH. In the subsurface layers, the concentration of the elements Zn2+, Cu2+, K+, and Na+ also changed significantly. In general, the application of pharmaceutical industry residue improved soil chemical attributes.3753037304
Meat quality of lambs fed different saltbush hay (Atriplex nummularia) levels
Climate changes have increased soil and water salinity, compromising animal produc- tion especially in dry areas where scientists have become more interested in halophyte plants, like saltbush. The effects of saltbush hay levels (30, 40, 50 and 60%) were evaluated based on physical-chemical, nutritional and sensory parameters of Santa Ine^s lamb meat. Thirty-two 8-month-old castrated Santa Ine^s lambs, with initial weights of 22±1.97 kg were used; they were slaughtered after 60 days in the feedlot. The pH, colour, moisture, protein and cholesterol contents did not differ among treatments. Panelists observed a greater inten- sity of lamb smell and flavour (P=0.0035) in the meat of animals that received more con- centrate in the diet. An increase in the inclu- sion of saltbush increased ash percentage (P=0.0232), total saturated (P=0.0035) and polyunsaturated (P=0.0287) fatty acids and reduced the lipids (P=0.0055) and the n-6:n-3 ratio (P=0.0058) of the meat. Therefore, salt- bush hay can be used as a feeding resource in regions with problems of water and soil salini- ty because it does not impair the physical- chemical, nutritional and sensory quality of sheep meat
Quantum Griffiths effects and smeared phase transitions in metals: theory and experiment
In this paper, we review theoretical and experimental research on rare region
effects at quantum phase transitions in disordered itinerant electron systems.
After summarizing a few basic concepts about phase transitions in the presence
of quenched randomness, we introduce the idea of rare regions and discuss their
importance. We then analyze in detail the different phenomena that can arise at
magnetic quantum phase transitions in disordered metals, including quantum
Griffiths singularities, smeared phase transitions, and cluster-glass
formation. For each scenario, we discuss the resulting phase diagram and
summarize the behavior of various observables. We then review several recent
experiments that provide examples of these rare region phenomena. We conclude
by discussing limitations of current approaches and open questions.Comment: 31 pages, 7 eps figures included, v2: discussion of the dissipative
Ising chain fixed, references added, v3: final version as publishe
Principles of crop modeling and simulation: I. uses of mathematical models in agricultural science
Major discrepancy between clinical diagnosis of death and anatomopathological findings in adolescents with chronic diseases during 18-years
Objectives: To evaluate the inconsistency between clinical diagnosis of death and autopsy findings in adolescents with chronic diseases.
Methods: A cross-sectional study including a sample of adolescents’ autopsies who died in a pediatric and adolescent tertiary hospital over 18 consecutive years. During this period, there were n = 2912 deaths, and n = 581/2912(20%) occurred in adolescents. Of these, n = 85/581(15%) underwent autopsies and were analyzed. Further results were divided into two groups: Goldman classes I or II (high disagreement between main clinical diagnosis of death and anatomopathological findings, n = 26) and Goldman classes III, IV or V (low or no disagreement between these two parameters, n = 59).
Results: Median age at death (13.5 [10‒19] vs. 13 [10‒19] years, p = 0.495) and disease duration (22 [0‒164] vs. 20 [0‒200] months, p = 0.931), and frequencies for males (58% vs. 44%, p = 0.247) were similar between class I/II vs. class III/IV/V. The frequency of pneumonia (73% vs. 48%, p = 0.029), pulmonary abscess (12% vs. 0%, p = 0.026), as well as isolation of yeast (27% vs. 5%, p = 0.008), and virus (15% vs. 2%, p = 0.029) identified in the autopsy, were significantly higher in adolescents with Goldman class I/II compared to those with Goldman class III/IV/V. In contrast, cerebral edema was significantly lower in adolescents of the first group (4% vs. 25%, p = 0.018).
Conclusion: This study showed that 30% of the adolescents with chronic diseases had major discrepancies between clinical diagnosis of death and autopsy findings. Pneumonia, pulmonary abscess, as well as isolation of yeast and virus were more frequently identified at autopsy findings in the groups with major discrepancies
Comparative study of the sedative and antinociceptive effects of levomepromazine, azaperone and midazolam in laboratory animals
Local fluctuations in quantum critical metals
We show that spatially local, yet low-energy, fluctuations can play an
essential role in the physics of strongly correlated electron systems tuned to
a quantum critical point. A detailed microscopic analysis of the Kondo lattice
model is carried out within an extended dynamical mean-field approach. The
correlation functions for the lattice model are calculated through a
self-consistent Bose-Fermi Kondo problem, in which a local moment is coupled
both to a fermionic bath and to a bosonic bath (a fluctuating magnetic field).
A renormalization-group treatment of this impurity problem--perturbative in
, where is an exponent characterizing the spectrum
of the bosonic bath--shows that competition between the two couplings can drive
the local-moment fluctuations critical. As a result, two distinct types of
quantum critical point emerge in the Kondo lattice, one being of the usual
spin-density-wave type, the other ``locally critical.'' Near the locally
critical point, the dynamical spin susceptibility exhibits scaling
with a fractional exponent. While the spin-density-wave critical point is
Gaussian, the locally critical point is an interacting fixed point at which
long-wavelength and spatially local critical modes coexist. A Ginzburg-Landau
description for the locally critical point is discussed. It is argued that
these results are robust, that local criticality provides a natural description
of the quantum critical behavior seen in a number of heavy-fermion metals, and
that this picture may also be relevant to other strongly correlated metals.Comment: 20 pages, 12 figures; typos in figure 3 and in the main text
corrected, version as publishe
Correlation between specific IgM levels and percentage IgG-class antibody avidity to Toxoplasma gondii
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