290 research outputs found
D'atri spaces of type k and related classes of geometries concerning jacobi operators
In this article we continue the study of the geometry of -D'Atri spaces,
( denotes the dimension of the manifold) began by
the second author. It is known that -D'Atri spaces, are related
to properties of Jacobi operators along geodesics, since she has shown
that , are invariant
under the geodesic flow for any unit tangent vector . Here, assuming that
the Riemannian manifold is a D'Atri space, we prove in our main result that
is also invariant under the geodesic flow if . In addition, other properties of Jacobi operators related to the
Ledger conditions are obtained and they are used to give applications to
Iwasawa type spaces. In the class of D'Atri spaces of Iwasawa type, we show two
different characterizations of the symmetric spaces of noncompact type: they
are exactly the -spaces and on the other hand they are -D'Atri
spaces for some In the last case, they are -D'Atri for all
as well. In particular, Damek-Ricci spaces that are -D'Atri
for some are symmetric.
Finally, we characterize -D'Atri spaces for all as the -spaces (geodesic symmetries preserve the principal curvatures of
small geodesic spheres). Moreover, applying this result in the case of 4%
-dimensional homogeneous spaces we prove that the properties of being a D'Atri
(1-D'Atri) space, or a 3-D'Atri space, are equivalent to the property of being
a -D'Atri space for all .Comment: 19 pages. This paper substitute the previous one where one Theorem
has been deleted and one section has been adde
Autoridad y sentido del humor en la educación familiar
Desde la perspectiva antropológica suscrita en esta monografía el sentido del humor es
un soporte emocional para la felicidad y una disposición afectiva para la alegría, y por lo
tanto expresión natural de dicha virtud. Esto lo hace dependiente la buena orientación
de la inteligencia y la voluntad. En la educación familiar dicha orientación se traduce -
en buena parte- en la adecuada armonización entre afecto y autoridad, un reto que
puede ser facilitado a través del sentido del humor. Como mecanismo natural de
liberación no traumática de las emociones negativas, permite autorregular la propia
dinámica afectiva, promoviendo así competencias emocionales parentales en cuanto a
flexibilidad, mantenimiento de la serenidad, asertividad en la comunicación. Todo lo cual
contribuye a un equilibrado ejercicio de la autoridad parental.From the anthropological perspective endorsed in this monograph sense of humour acts
as an emotional foundation for happiness and is a mood disposition for joy that naturally
expresses the latter. This makes it dependant on the correct exercise of intelligence and
willpower. In the context of family education this ability requires, among others, an
adequate adjustment between parental authority and affection, a challenge that can be
eased by sense of humour. Since it is a natural mechanism of non-traumatic release
from negative emotions, it allows to self-regulate one’s psychological dynamics through
enhancing the emotional competences necessary to maintain serenity, to communicate
more assertively and to behave with more flexibility. All of which contributes to a
balanced exercise of parental authority
Evaluation of soil salinity indexes based on bulk electrical conductivity
[SPA] Los sensores del suelo que miden conductividad eléctrica (CE) y humedad desempeñan un papel esencial en el control de la salinidad del suelo. Sin embargo, la interpretación precisa de la salinidad del suelo depende del desarrollo de Índices de Salinidad (IS) adecuados. Este trabajo se enfoca en el estudio del potencial de varios IS basados en la CE del medio (ECb), utilizando análisis de regresión para conocer cómo estos IS representan la salinidad del suelo. Los resultados indican que el ECb es un IS eficiente siempre que se mida a humedad constante. Además, la precisión de esta medida aumenta con la humedad del sustrato. La pendiente del ajuste de regresión lineal humedad-ECb se propone como un IS nuevo y fiable.
[ENG] Soil sensors that measure electrical conductivity (EC) and moisture play an essential role in monitoring soil salinity. However, the accurate understanding of salinity depends on the development of suitable sensor-based Salinity Indices (SI). This work studied the potential of several SIs based on bulk EC (ECb), which is the only EC directly measured by sensors. Regression studies were performed to know how these SIs describe soil salinity. The results indicate that ECb is an efficient SI as long as humidity is constant. Moreover, its accuracy increases with substrate moisture. The slope of the linear regression fit moisture-ECb is proposed as a novel and reliable SIEsta investigación ha sido financiada por el Ministerio de Ciencia, Innovación y Universidades de España, el Fondo Europeo de Desarrollo Regional, subvención número RTI2018-093997-B-I00, y por la AEI española (subvención número PCI 2019-103608) bajo el programa PRIMA en el marco del proyecto PRECIMED
Sulfadiazine, sulfamethazine and sulfachloropyridazine removal using three different porous materials: Pine bark, “oak ash” and mussel shell
This work focuses on studying the efficacy of three different by-products to adsorb three antibiotics (sulfadiazine, SDZ; sulfamethazine, SMT; sulfachloropyridazine, SCP). These antibiotics can be considered pollutants of the environment when they reach water, as well as in cases where they are spread on soils through irrigation or contained in sewage sludge or livestock manure. In this study, batch-type adsorption/desorption experiments were performed for each of the three sulfonamides, adding 7 different concentrations of the antibiotics, going from 1 to 50 μmol L−1, and with contact time of 24 h. The results indicate that pine bark is the most efficient bioadsorbent among those studied, as it adsorbs up to 95% of the antibiotics added, while desorption is always less than 11%. However, for “oak ash” and mussel shell the adsorption is always lower than 45 and 15%, respectively, and desorption is high, reaching up to 49% from “oak ash” and up to 81% from mussel shell. Adsorption data showed good fitting to the Linear and Freundlich models, with R2 values between 0.98 and 1.00 in both cases. Kd and KF adsorption parameters showed similar values for the same sorbent materials but were much higher for pine bark than for the other two bioadsorbents. The Freundlich's n parameter showed values in the range 0.81–1.28. The highest KF values (and therefore the highest adsorption capacities) were obtained for the antibiotic SCP in pine bark. Pine bark showed the highest capacity to adsorb each of the antibiotics, increasing as a function of the concentration added. When the concentration of sulfonamide added was 50 μM, the amounts adsorbed were 780 μmol kg−1 for SDZ, 890 μmol kg−1 for SMT, and 870 μmol kg−1 for SCP. “Oak ash” and mussel shell have low adsorption capacity for all three sulfonamides, showing values always lower than 150 μmol kg−1 (oak ash) and 20 μmol kg−1 (mussel shell) when a concentration of 50 μmol L−1 of antibiotic is added. The results of this study could aid to make an appropriate management of the by-products studied, in order to facilitate their valorization and recycling in the treatment of environmental compartments polluted with sulfonamide antibiotics.Agencia Estatal de Investigación | Ref. RTI2018-099574-B-C21Agencia Estatal de Investigación | Ref. RTI2018-099574-B-C2
Dust destruction and survival in the Cassiopeia A reverse shock
Stars and planetary system
A pharmacogenetic intervention for the improvement of the safety profile of antipsychotic treatments
Antipsychotic drugs fail to achieve adequate response in 30-50% of treated patients and about 50% of them develop severe and lasting side effects. Treatment failure results in poorer prognosis with devastating repercussions for the patients, carers and broader society. Our study evaluated the clinical benefits of a pharmacogenetic intervention for the personalisation of antipsychotic treatment. Pharmacogenetic information in key CYP polymorphisms was used to adjust clinical doses in a group of patients who started or switched treatment with antipsychotic drugs (PharmG+, N = 123), and their results were compared with those of a group of patients treated following existing clinical guides (PharmG−, N = 167). There was no evidence of significant differences in side effects between the two arms. Although patients who had their antipsychotic dose adjusted according to CYPs polymorphisms (PharmG+) had a bigger reduction in side effects than those treated as usual (PharmG−), the difference was not statistically significant (p > 0.05 for all comparisons). However, PharmG+ patients treated with CYP2D6 substrates that were carriers of CYP2D6 UMs or PMs variants showed a significantly higher improvement in global, psychic and other UKU side effects than PharmG− patients (p = 0.02, p = 0.05 and p = 0.01, respectively). PharmG+ clozapine treated patients with CYP1A2 or CYP2C19 UM and PMs variants also showed higher reductions in UKU scores than PharmG− clozapine patients in general. However, those differences were not statistically significant. Pharmacogenetic interventions may improve the safety of antipsychotic treatments by reducing associated side effects. This intervention may be particularly useful when considering treatment with antipsychotics with one major metabolic pathway, and therefore more susceptible to be affected by functional variants of CYP enzymes
Dietary Fat Patterns and Outcomes in Acute Pancreatitis in Spain
Background/Objective: Evidence from basic and clinical studies suggests that unsaturated fatty acids (UFAs) might be relevant mediators of the development of complications in acute pancreatitis (AP). Objective: The aim of this study was to analyze outcomes in patients with AP from regions in Spain with different patterns of dietary fat intake.
Materials and Methods: A retrospective analysis was performed with data from 1,655 patients with AP from a Spanish prospective cohort study and regional nutritional data from a Spanish cross-sectional study. Nutritional data considered in the study concern the total lipid consumption, detailing total saturated fatty acids, UFAs and monounsaturated fatty acids (MUFAs) consumption derived from regional data and not from the patient prospective cohort. Two multivariable analysis models were used: (1) a model with the Charlson comorbidity index, sex, alcoholic etiology, and recurrent AP; (2) a model that included these variables plus obesity.
Results: In multivariable analysis, patients from regions with high UFA intake had a significantly increased frequency of local complications, persistent organ failure (POF), mortality, and moderate-to-severe disease in the model without obesity and a higher frequency of POF in the model with obesity. Patients from regions with high MUFA intake had significantly more local complications and moderate-to-severe disease; this significance remained for moderate-to-severe disease when obesity was added to the model.
Conclusions: Differences in dietary fat patterns could be associated with different outcomes in AP, and dietary fat patterns may be a pre-morbid factor that determines the severity of AP. UFAs, and particulary MUFAs, may influence the pathogenesis of the severity of AP
Targeting Alzheimer’s disease with multimodal polypeptide-based nanoconjugates
Alzheimer’s disease (AD), the most prevalent form of dementia, remains incurable mainly due to our failings in the search for effective pharmacological strategies. Here, we describe the development of targeted multimodal polypeptide-based nanoconjugates as potential AD treatments. Treatment with polypeptide nanoconjugates bearing propargylamine moieties and bisdemethoxycurcumin or genistein afforded neuroprotection and displayed neurotrophic effects, as evidenced by an increase in dendritic density of pyramidal neurons in organotypic hippocampal culture. The additional conjugation of the Angiopep-2 targeting moiety enhanced nanoconjugate passage through the blood-brain barrier and modulated brain distribution with nanoconjugate accumulation in neurogenic areas, including the olfactory bulb. Nanoconjugate treatment effectively reduced neurotoxic amyloid aggregate levels and rescued impairments to olfactory memory and object recognition in APP/PS1 transgenic AD model mice. Overall, this study provides a description of a targeted multimodal polyglutamate-based nanoconjugate with neuroprotective and neurotrophic potential for AD treatment. Copyrigh
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