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1.
World J Microbiol Biotechnol ; 34(7): 87, 2018 Jun 09.
Article in English | MEDLINE | ID: mdl-29886562

ABSTRACT

Drought is one of the environmental factors that most affects peanut cultivation in semi-arid regions, resulting in economic losses to growers. However, growth promoting bacteria are able to reduce water deficit damage in some plant species. In this context, this study aimed to evaluate the interaction of Bradyrhizobium strains reducing water stress effects on peanut genotypes by antioxidant enzymes activities, leaf gas exchanges and vegetative growth, as well as to determine the taxonomic positioning of strain ESA 123. The 16S rRNA gene of ESA 123 was amplified by PCR and sequenced by dideoxy Sanger sequencing method. An experiment was performed in greenhouse with three peanut genotypes (BRS Havana, CNPA 76 AM and 2012-4), two Bradyrhizobium strains (SEMIA 6144 and ESA 123), a mineral source of N and an absolute control (without N) under two water regimes (with and without irrigation). Seeds of peanut were sown and the plants were grown until 30 days after emergence. On the 20th day, the water deficit plants group had their irrigation suspended for 10 days. At in silico analyzes, ESA 123 presented 98.97% similarity with the type strain of B. kavangense. Leaf gas exchange was affected by water deficit; as well as alteration of antioxidant activities and reduction of vegetative growth variables. However, some plants inoculated with SEMIA 6144 and ESA 123 strains presented lower reductions and increment of some evaluated variables, mainly the ones inoculated with the ESA 123 strain, Bradyrhizobium sp. from the semi-arid region of Northeast Brazil. This data suggests beneficial effects of the peanut-Bradyrhizobium interaction in a water stress condition, specially with the ESA 123 strain.


Subject(s)
Arachis/microbiology , Arachis/physiology , Bradyrhizobium/physiology , Droughts , Antioxidants , Arachis/growth & development , Bradyrhizobium/classification , Bradyrhizobium/genetics , Bradyrhizobium/isolation & purification , Brazil , Phylogeny , Plant Leaves/physiology , Plant Roots/microbiology , Plant Shoots/microbiology , RNA, Ribosomal, 16S/genetics , Seeds , Soil Microbiology , Stress, Physiological , Symbiosis , Water
2.
Braz J Biol ; 73(3): 593-604, 2013 Aug.
Article in English | MEDLINE | ID: mdl-24212700

ABSTRACT

Length-weight equations were determined for the main microcrustacean species of Três Marias and Furnas reservoirs (state of Minas Gerais, Brazil), and evaluated the fluctuations of their biomass. We examined the following species: Thermocyclops minutus, Bosminopsis deitersi, Bosmina hagmanni, Ceriodaphnia cornuta, and Moina minuta (Três Marias Reservoir), and Notodiaptomus henseni, Daphnia ambigua, Ceriodaphnia silvestrii, Diaphanosoma spinulosum, D. fluviatile, and Bosmina freyi (Furnas Reservoir). Dry weight was obtained in a microbalance for each size class (Cladocera) or developmental stage (Copepoda). Microcrustacean mean biomass varied from 5.76 mg DW.m(-3) and 20.36 mg DW.m(-3) (Furnas Reservoir) and from 3.75 mg DW.m(-3) and 18.14 mg DW.m(-3) (Três Marias Reservoir). Significant differences (p < 0.000) between seasons were registered with higher biomass during the rainy seasons. Thermocyclops minutus was the most important species in Três Marias, whereas in Furnas, N. henseni contributed in equal proportion. In Furnas, the higher cladoceran biomass was explained by the contribution of larger-sized species, such as D. ambigua, C. silvestrii, D. spinulosum, and D. fluviatile. Even though both reservoirs are considered oligotrophic, there were significant differences in the estimated microcrustacean biomass, which reinforces the importance of this parameter for the description of the real contribution of each species in the community.


Subject(s)
Cladocera/anatomy & histology , Copepoda/anatomy & histology , Rotifera/anatomy & histology , Animals , Biomass , Brazil , Cladocera/classification , Copepoda/classification , Fresh Water , Population Density , Rotifera/classification , Seasons
3.
Braz J Biol ; 70(3 Suppl): 795-802, 2010 Oct.
Article in English | MEDLINE | ID: mdl-21085784

ABSTRACT

In order to verify changes in physical, chemical and biological features of Dom Helvécio Lake (South-East Brazil), this study compares previous and recent data obtained from limnological investigations over three decades. Plankton species composition and density together with environmental data from 1978, 1983, and during 1999 to 2006 showed changes driven by seasonal climatic forces or by anthropogenic causes. Changes in diversity are shown as a consequence of alternation of rainy and dry periods and introduction of exotic fish species. Finally, suggestions are made for improving conservation efforts in the area, through planned actions and monitoring programmes.


Subject(s)
Biodiversity , Fishes , Fresh Water/analysis , Introduced Species , Phytoplankton/classification , Zooplankton/classification , Animals , Brazil , Climate , Conservation of Natural Resources , Population Density , Population Dynamics , Seasons
4.
J Phys Condens Matter ; 22(49): 496003, 2010 Dec 15.
Article in English | MEDLINE | ID: mdl-21406789

ABSTRACT

Ni-doped SnO2 nanoparticles prepared by a polymer precursor method have been characterized structurally and magnetically. Ni doping (up to 10 mol%) does not significantly affect the crystalline structure of SnO2, but stabilizes smaller particles as the Ni content is increased. A notable solid solution regime up to ∼ 3 mol% of Ni, and a Ni surface enrichment for the higher Ni contents are found. The room temperature ferromagnetism with saturation magnetization (MS) ∼ 1.2 × 10 (- 3) emu g (- 1) and coercive field (HC) ∼ 40 Oe is determined for the undoped sample, which is associated with the exchange coupling of the spins of electrons trapped in oxygen vacancies, mainly located on the surface of the particles. This ferromagnetism is enhanced as the Ni content increases up to ∼ 3 mol%, where the Ni ions are distributed in a solid solution. Above this Ni content, the ferromagnetism rapidly decays and a paramagnetic behavior is observed. This finding is assigned to the increasing segregation of Ni ions (likely formed by interstitials Ni ions and nearby substitutional sites) on the particle surface, which modifies the magnetic behavior by reducing the available oxygen vacancies and/or the free electrons and favoring paramagnetic behavior.

5.
Rev Hosp Clin Fac Med Sao Paulo ; 52(6): 295-301, 1997.
Article in Portuguese | MEDLINE | ID: mdl-9629738

ABSTRACT

The object of this research was to establish the prevalence of fecal incontinence in those diabetics attended as outpatients at the Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Individual verbal interviewing was the an adopted method. The classification of diabetes mellitus of World Health Organization was employed (1985). Data was aggregated relative sex, age, color, type of diabetes mellitus, fecal incontinence, duration of diabetes mellitus, peripheral neuropathy, intestinal habits (normal, constipation and diarrhea), urgency to evacuate, sensation of incomplete evacuation, urinary incontinence, vaginal deliveries and its characteristics. The study involved 258 diabetics, 167 of female sex having an average age of 56.2 years (17 to 78 years of age) and 91 of the male sex having average age of 55.8 years (10 to 74 years of age). With relation to color, 57% were white, 28.7% mullato, 11.2% black and 3.1% yellow. Fecal incontinence was prevalent in 18.6% of the cases studied. It occurred also in types I and II diabetics with predominance in the male sex. It also occurred in diabetics having an average history of 10.8 years to onset of illness. Peripheral neuropathy was observed in 8.5% of the diabetics investigated however no association was observed between the peripheral neuropathy and fecal incontinence. Constipation occurred in 29.5% of the patients and diarrhea in 21.3%. Incomplete evacuation was apparent in 15.1% of diabetics and urgency to evacuate in 12.8%. A relationship was identified between fecal incontinence with diarrhea and incomplete evacuation in the group investigated. Total vaginal deliveries was 458 with 70 episiotomies and 25 by forceps. There was no statistical evidence of association between the average number of vaginal deliveries, episiotomies and forceps in diabetics demonstrating or not demonstrating fecal incontinence. Urinary incontinence was more prevalent that fecal incontinence. No relationship was determined between urinary and fecal incontinence for the purpose of the present study.


Subject(s)
Diabetes Complications , Fecal Incontinence/complications , Fecal Incontinence/epidemiology , Adolescent , Adult , Aged , Ambulatory Care , Brazil , Child , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 2/complications , Female , Humans , Male , Middle Aged , Prevalence
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