253 research outputs found
Effect of the temperature and relative humidity in stored sotol (Dasylirion cedrosanum Trel.) seeds on fungi biodiversity
The objective of the research was to identify the fungi in sotol seeds at different conditions of temperature and relative humidity. Seeds were collected at Buñuelos, municipality, and taken to the Laboratory of the Center for Training and Development in Seed Technology (CCDTS) at Universidad Autonoma Agraria Antonio Narro. The seed was stored for a period of 90 days, whit conditions of 60, 75, 80 and 85% of relative humidity kept at 5, 15 and 25 °C. Fungi identifying by morphological criteria. A completely randomized experiment using R software, with factorial arrangement whit two replications. Pathogens identified were: Aspergillus glaucus, Aspergillus niger, Fusarium sp., Penicillium sp., Aspergillus candidus, Cladosporiun sp., Alternaria sp. and Aspergillus chraceus, the results showed that the higher the humidity, temperature and storage time, the incidence of fungi tends to be higher. Fungi with a higher presence in sotol seeds were: Aspergillus glaucus and Penicillium sp. Safe storage environments for sotol seeds reported in this work are 5 °C and a relative humidity of 60-75%. Sotol seeds tolerates conditions of 15 °C and a relative humidity up to 75%. 
Osmotic stress tolerance in forage oat varieties (Avena Sativa L.) based on osmotic potential trials
Received: April 1st, 2022 ; Accepted: December 12th, 2022 ; Published: February 7th, 2023 ; Correspondence: [email protected]; [email protected] oats (Avena sativa L.) are globally important for milk and meat production,
and, to a lesser extent, for the human diet. In Mexico, oats are a strategic crop, occupying the
fourth place in cultivated area, only after maize for grain, bean, and sorghum for grain. Droughts
are the main problem for oat production in Mexico. This study evaluated the germination and
seedling growth of several oat varieties in response to drought stress simulated by PEG-6000
treatments of different osmotic pressure in order to identify drought-resistant genotypes. The
Teporaca genotype was the most outstanding in the three levels of OP compared to its control
with 0.0 of Osmotic Potential (OP). The Teporaca genotype showed the largest root length and
the lowest diminishment of root length under osmotic stress conditions. This genotype also had
the largest shoot length in the three osmotic stress levels. Regarding root fresh weight, Babicora
stands out with 98.5% and Teporaca with 43% in the most severe level. Teporaca, Menonita, and
Babicora showed the outstanding root dry weights of 346.5%, 327.2%, and 251.2%, respectively.
These varieties had higher root dry weight than their own controls in water in the most severe
level of OP. In conclusion, the Teporaca, Menonita, and Karma genotypes showed the highest
osmotic stress tolerance and could be used as sources of favorable alleles to improve oat drought
tolerance
Three-dimensional effects on extended states in disordered models of polymers
We study electronic transport properties of disordered polymers in the
presence of both uncorrelated and short-range correlated impurities. In our
procedure, the actual physical potential acting upon the electrons is replaced
by a set of nonlocal separable potentials, leading to a Schr\"odinger equation
that is exactly solvable in the momentum representation. We then show that the
reflection coefficient of a pair of impurities placed at neighboring sites
(dimer defect) vanishes for a particular resonant energy. When there is a
finite number of such defects randomly distributed over the whole lattice, we
find that the transmission coefficient is almost unity for states close to the
resonant energy, and that those states present a very large localization
length. Multifractal analysis techniques applied to very long systems
demonstrate that these states are truly extended in the thermodynamic limit.
These results reinforce the possibility to verify experimentally theoretical
predictions about absence of localization in quasi-one-dimensional disordered
systems.Comment: 16 pages, REVTeX 3.0, 5 figures on request from FDA
([email protected]). Submitted to Phys. Rev. B. MA/UC3M/09/9
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Scaling up cancer care for children without medical insurance in developing countries: The case of Mexico
Background: In 2006, the Mexican government launched the Fund for Protection Against Catastrophic Expenditures (FPGC) to support financially healthcare of high cost illnesses. This study aimed at answering the question whether FPGC improved coverage for cancer care and to measure survival of FPGC affiliated children with cancer. Procedure A retrospective cohort study (2006–2009) was conducted in 47 public hospitals. Information of children and adolescents with cancer was analyzed. The coverage was estimated in accordance with expected number of incident cases and those registered at FPGC. The survival was analyzed by using Kaplan–Meier survival curves and Cox proportional hazards regression modeling. Results: The study included 3,821 patients. From 2006 to 2009, coverage of new cancer cases increased from 3.3% to 55.3%. Principal diagnoses were acute lymphoblastic leukemia (ALL, 46.4%), central nervous system (CNS) tumors (8.2%), and acute myeloid leukemia (AML, 7.4%). The survival rates at 36 months were ALL (50%), AML (30.5%), Hodgkin lymphoma (74.5%), Non-Hodgkin lymphoma (40.1%), CNS tumors (32.8%), renal tumors (58.4%), bone tumors (33.4%), retinoblastoma (59.2%), and other solid tumors (52.6%). The 3-year overall survival rates varied among the regions; children between the east and south-southeast had the higher risks (hazard ratio 3.0; 95% CI: 2.3–3.9) and 2.4; 95% CI: 2.0–2.8) of death from disease when compared with those from the central region. Conclusion: FPGC has increased coverage of cancer cases. Survival rates were different throughout the country. It is necessary to evaluate the effectiveness of this policy to increase access and identify opportunities to reduce the differences in survival
Magnetic susceptibility studies of the spin-glass and Verwey transitions in magnetite nanoparticles
Magnetite nanostructured powder samples were synthesized by aging chemical method. Phase, structural, and magnetic properties were characterized. X-ray diffraction patterns showed cubic magnetite pure phase, with average crystallite size, , equal to 40 nm. Susceptibility measurements showed the well-known Verwey transition at a temperature of 90 K. The decrease of Verwey transition temperature, with respect to the one reported in literature (125 K) was attributed to the low average crystallite size. Moreover, the spin-glass like transition was observed at 35 K. Activation energy calculated from susceptibility curves, with values ranging from 6.26 to 6.93 meV, showed a dependence of spin-glass transition on frequency. Finally, hysteresis loops showed that there is not an effect of Verwey transition on magnetic properties. On the other hand, a large increase of coercivity and remanent magnetization at a temperature between 5 and 50 K confirmed the presence of a magnetic transition at low temperatures
Análisis de la matriz energética de Guatemala, y el comportamiento del precio de los combustibles en función de los precios internacionales.
Desde el inicio del siglo XXI hasta la actualidad, la matriz energética en Guatemala ha variado en precio, capacidad instalada, diversidad de fuentes de generación, tecnología en la transmisión de potencia, y otros factores. Desde el año 1996 cuando se abrió el mercado energético al capital privado, se amplió la variedad de plantas generadoras en el país. En esta situación se hizo necesario analizar variables del sistema como crecimiento anual de la demanda de energía eléctrica, variaciones de los precios del petróleo y sus derivados. Esto con la intención de poder tomar mejores decisiones a la hora de diseñar un plan de expansión del sistema eléctrico para el futuro crecimiento del país. En base a estos datos se pueden encontrar, por medio de métodos estocásticos, relaciones entre los precios de los derivados del petróleo con el precio del petróleo mismo que permiten entender mejor como impactan en la vida cotidiana de los guatemaltecos y guatemaltecas
Infestation assessment with Haematobia irritans in grazing cattle and stress behaviors in tropical regions
The objective was to evaluate the infestation with flies in grazing cattle, and its relationship with some behaviors (tail butting, head butting, kicking and rubbing) that alter animal welfare, through direct observation and use of photographs. At two times (7:00 and 14:00 h) the variables were measured on thirty naturally infested cows and randomly distributed in two treatments: TS: control without deworming and TD: chemically dewormed. The fly infestation were higher (P<0.001) in TS cows (483.7 flies/animal), they also, expressed with greater intensity (P<0.001) and frequency of upset behaviors: tail-tapping (10.84 movements/min), head-butting (1.66), kicking (0.51) and rubbing (0.33) in order to drive away the annoying contact and aggression of the ectoparasite. It is concluded that the greater the fly infestation, the movements that alter the welfare of the animals increase; however, more research is required to know the physiological welfare consequences that the infestation of this parasite implies.Objective: To evaluate the infestation with flies in grazing cattle, and its relationship with some behaviors (tail butting, head butting, kicking and rubbing) that alter animal welfare, through direct observation and use of photographs.
Design/Methodology/Approach: At two times (7:00 and 14:00 h) the variables were measured on thirty naturally infested cows and randomly distributed in two treatments: TS: control without deworming and TD: chemically dewormed.
Results: The fly infestation were higher (p < 0.001) in TS cows (483.7 flies/animal), they also, expressed with greater intensity (p < 0.001) and frequency of upset behaviors: tail-tapping (10.84 movements min-1), head-butting (1.66), kicking (0.51) and rubbing (0.33) in order to drive away the annoying contact and aggression of the ectoparasite.
Limitations: More in deep research is needed in order to assess the physiological disorders that this parasite could cause by altering well-being of grazing cattle in the tropics.
Findings/Conclusions: It is concluded that the greater the fly infestation, the movements that alter the welfare of the animals’ increase; however, more research is required to know the physiological welfare consequences that the infestation of this parasite implies
Molecular Epidemiology of Multidrug-Resistant Uropathogenic Escherichia coli O25b Strains Associated with Complicated Urinary Tract Infection in Children.
BACKGROUND: Uropathogenic Escherichia coli (UPEC) has increased the incidence of urinary tract infection (UTI). It is the cause of more than 80% of community-acquired cystitis cases and more than 70% of uncomplicated acute pyelonephritis cases. AIM: The present study describes the molecular epidemiology of UPEC O25b clinical strains based on their resistance profiles, virulence genes, and genetic diversity. METHODS: Resistance profiles were identified using the Kirby-Bauer method, including the phenotypic production of extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs). The UPEC serogroups, phylogenetic groups, virulence genes, and integrons were determined via multiplex PCR. Genetic diversity was established using pulsed-field gel electrophoresis (PFGE), and sequence type (ST) was determined via multilocus sequence typing (MLST). RESULTS: UPEC strains (n = 126) from hospitalized children with complicated UTIs (cUTIs) were identified as O25b, of which 41.27% were multidrug resistant (MDR) and 15.87% were extensively drug resistant (XDR). The O25b strains harbored the fimH (95.23%), csgA (91.26%), papGII (80.95%), chuA (95.23%), iutD (88.09%), satA (84.92%), and intl1 (47.61%) genes. Moreover, 64.28% were producers of ESBLs and had high genetic diversity. ST131 (63.63%) was associated primarily with phylogenetic group B2, and ST69 (100%) was associated primarily with phylogenetic group D. CONCLUSION: UPEC O25b/ST131 harbors a wide genetic diversity of virulence and resistance genes, which contribute to cUTIs in pediatrics
First Measurement of Coherent Elastic Neutrino-Nucleus Scattering on Argon
We report the first measurement of coherent elastic neutrino-nucleus
scattering (\cevns) on argon using a liquid argon detector at the Oak Ridge
National Laboratory Spallation Neutron Source. Two independent analyses prefer
\cevns over the background-only null hypothesis with greater than
significance. The measured cross section, averaged over the incident neutrino
flux, is (2.2 0.7) 10 cm -- consistent with the
standard model prediction. The neutron-number dependence of this result,
together with that from our previous measurement on CsI, confirms the existence
of the \cevns process and provides improved constraints on non-standard
neutrino interactions.Comment: 8 pages, 5 figures with 2 pages, 6 figures supplementary material V3:
fixes to figs 3,4 V4: fix typo in table 1, V5: replaced missing appendix, V6:
fix Eq 1, new fig 3, V7 final version, updated with final revision
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