4,389 research outputs found
Representation of non-semibounded quadratic forms and orthogonal additivity
In this article we give a representation theorem for non-semibounded
Hermitean quadratic forms in terms of a (non-semibounded) self-adjoint
operator. The main assumptions are closability of the Hermitean quadratic form,
the direct integral structure of the underlying Hilbert space and orthogonal
additivity. We apply this result to several examples, including the position
operator in quantum mechanics and quadratic forms invariant under a unitary
representation of a separable locally compact group. The case of invariance
under a compact group is also discussed in detail
Computing Optimal Distances to Pareto Sets of Multi-Objective Optimization Problems in Asymmetric Normed Lattices
[EN] Given a finite dimensional asymmetric normed lattice, we provide explicit formulae for the optimization of the associated (non-Hausdorff) asymmetric distance among a subset and a point. Our analysis has its roots and finds its applications in the current development of effective algorithms for multi-objective optimization programs. We are interested in providing the fundamental theoretical results for the associated convex analysis, fixing in this way the framework for this new optimization tool. The fact that the associated topology is not Hausdorff forces us to define a new setting and to use a new point of view for this analysis. Existence and uniqueness theorems for this optimization are shown. Our main result is the translation of the original abstract optimal distance problem to a clear optimization scheme. Actually, this justifies the algorithms and shows new aspects of the numerical and computational methods that have been already used in visualization of multi-objective optimization problems.This work was supported by the Ministerio de Economia y Competitividad (Spain) under grants DPI2015-71443-R and MTM2016-77054-C2-1-P.Blasco, X.; Reynoso-Meza, G.; Sánchez Pérez, EA.; Sánchez Pérez, JV. (2019). Computing Optimal Distances to Pareto Sets of Multi-Objective Optimization Problems in Asymmetric Normed Lattices. Acta Applicandae Mathematicae. 159(1):75-93. https://doi.org/10.1007/s10440-018-0184-z7593159
Influência do músculo pterigóideo lateral no crescimento cartilagem condilar na mandíbula
At the end of the last century, a model to explain clinical observations related to the mandibular growth was developed. According to it, the lateral pterigoid muscle (LPM) was one of the main modulators of the differentiation of mesenquimal cells inside the condyle to condroblasts or osteoblasts, and therefore of the growth of the mandibular condilar cartilage (CCM). The main components of the model were the humoral and the mechanical. Nowadays, the humoral would include growth factors such as IGF-I, FGF-2 and VEGF, which seem to be involved in mandibular growth. Since skeletal muscle can secrete these growth factors, there is a possibility that LPM modulates the growth of CCM by a paracrine or endocrine mechanism. The mechanical component derived from the observations that both the blood flow inside the temporomandibular joint (ATM) and the action of the retrodiscal pad on the growth of the CCM, depend, in part, on the contractile activity of the LPM. Despite the fact that there are some results suggesting hat LPM is activated under conditions of mandibular protrusion, there is no full agreement on whether this can stimulate the growth of CCM. In this review, the contributions and limitations of the works related to mandibular growth are discussed and a model which integrates the available information to explain the role of the LPM in the growth of the CCM is proposed.A finales del siglo pasado se desarrolló un modelo para explicar observaciones clínicas relacionadas con el crecimiento mandibular, según el cual el músculo pterigoideo lateral (LPM) era uno de los principales moduladores de la diferenciación de las células mesenquimales del cóndilo mandibular a condroblastos u osteoblastos y por lo tanto del crecimiento del cartílago condilar mandibular (CCM). Dos grandes componentes eran los pilares fundamentales del modelo: el humoral y el mecánico. En la actualidad, el componente humoral estaría dado por factores de crecimiento como el IGF-I, el FGF-2 y el VEGF, los cuales parecen estar involucrados en el crecimiento mandibular. Debido a que el músculo esquelético tiene un papel como órgano secretor de ellos, se abre la posibilidad de que el LPM regule el crecimiento del CCM por un mecanismo paracrino o endocrino mediado por estos factores. El componente mecánico nació de las observaciones de que tanto el flujo sanguíneo dentro de la articulación temporomandibular como la cción de la almohadilla retrodiscal en el crecimiento del CCM depende, en parte, de la actividad contráctil del LPM. A pesar de que hay evidencia de que el LPM se activa en situaciones de adelantamiento mandibular, no hay consenso sobre si esto estimula el crecimiento del CCM. En esta revisión se discuten los aportes y limitaciones de los trabajos relacionados con el crecimiento mandibular y se propone un modelo que integra la información disponible para explicar el papel del LPM en el crecimiento del CCM.No fim do século passado desenhou-se um modelo para esclarecer as observações clínicas envolvidas no crescimento da mandíbula, no qual o músculo pterigoideo lateral (LPM) foi um dois moduladores principais da diferenciação das células messenquimais do côndilo mandibular em condroblastos ou osteoblastos e porém do crescimento da cartilagem condilar mandibular (CCM). Dois componentes principais possui o modelo: o humoral e o mecânico. Na atualidade, há evidência que o componente humoral é dado pelos fatores de crescimento IGF-1, IGF2 e VEGF que estimulam diretamente o crescimento mandibular. Devido a que o músculo esquelético pode desempenhar uma função endócrina fica aberta a possibilidade que o LPM regule o crescimento do CCM por mecanismos paracrinos ou autocrinos, mediante a secreção desses fatores de crescimento que estimulam diretamente o crescimiento mandibular. O componente mecânico é derivado das observações do que tanto o fluxo sanguíneo na articulação tempo-mandibular quanto a ação da almofadinha retro-discal no crescimento do CCM, dependem parcialmente da atividade contrátil do LPM. Embora, há evidências que o LPM é ativado pelo adiantamento mandibular, ainda não há consenso sob seu possível papel na estimulação do crescimento do CCM. Esta revisão tem o objetivo de discutir as evidencias e limitações de trabalhos relativos ao crescimento mandibular e propõe-se um modelo que integra a informação disponível para explicar a função do IPM no crescimento do CCM
Nutrición parenteral e identificación de subpoblaciones con necesidades nutricionales similares
[email protected] disponibilidad de formulaciones parenterales normalizadas
en relación a los aportes de nutrientes, plantea
la problemática de su idoneidad en relación a las necesidades
nutritivas de los pacientes. El objetivo de este
trabajo es identificar subpoblaciones de pacientes con
necesidades calórico-proteicas similares y valorar su
adecuación a formulaciones normalizadas. Con este fin,
se evaluaron, de forma prospectiva las necesidades calórico-
proteicas de 100 pacientes adultos metabólicamente
estables en tratamiento con nutrición parenteral total.
Los aportes calóricos se estudiaron por Harris-Benedict
(con corrección de Long) y los aportes proteicos se calcularon
en función del grado de estrés. Las necesidades
calórico-proteicas se analizaron mediante un análisis de
cluster mediante el algoritmo de partición alrededor de
los mediodes. Se consideró que cuando la formulación
de nutrición parenteral contenía aportes equivalentes a
± 20% de las necesidades medias de cada subpoblación
era adecuada para satisfacer los requerimientos calórico-
proteicos de los pacientes. El porcentaje de pacientes,
en función del número de subpoblaciones identificadas,
que recibirían aportes adecuados a sus requerimientos
se tomó como variable de estudio comparativo.
En el caso de dos subpoblaciones, para la subpoblación
1 (N = 35), las necesidades de glucosa, lípidos y aminoácidos
son: 275 (IC 95%: 265-285) g, 83 (IC 95%: 78-
88) g y 89 (IC 95%: 86-92) y para la subpoblación 2 (N =
65), 195 (IC 95%: 187-203) g, 58 (IC 95%: 56-61) g y 74
(IC 95%: 72-77) g, respectivamente. En el caso de tres subpoblaciones,
estas mismas necesidades de nutrientes
son para la subpoblación 1 (N = 19): 295 (IC 95%: 283-
306) g, 91 (IC 95%: 84-97) g y 91 (IC 95%: 86-95); para
la subpoblación 2 (N = 45), 234 (IC 95%: 227-240) g, 67
(IC 95%: 64-70) g, y 84 (IC 95%: 82-86) g; y para la
subpoblación 3 (N = 36): 172 (IC 95%: 165-179) g, 55
(IC 95%: 52-57) g y 68 (IC 95%: 64-71) g, respectivamente.
La utilización de una, dos o tres formulaciones,
que contengan aportes equivalentes a ± 20% de las necesidades
medias de cada subpoblación, satisfacen los requerimientos
de glucosa, lípidos y proteínas en el 45%
(IC 95%: 36% a 55%), 74% (IC 95%: 65% a 83) y 82%
(IC 95%: 74% a 89%) de los pacientes, respectivamente.
En suma, el desarrollo de tres formulaciones normalizadas
de nutrición parenteral permite satisfacer las necesidades
nutricionales de al menos el 74% de los
pacientes adultos metabólicamente estables subsidiarios
de nutrición parenteral total.The aim of this study is to identify patients subpopulations
with similar caloric and proteic needs (CPN) and
developing and assessing the utility of standarized formulations
of total parenteral nutrition (TPN) with equivalents
supplies to the average patients needs of each
identified subpopulation. CPN of one hundred metabolically
stables adults patients in treatment with TPN were
evaluated consecutively. Caloric supplies were calculated
with the Harris-Benedict equation, with the Long corrections
and proteics supplies were evaluated according
to stress level. The identification of patients
subpopulation according to the CPN was made through
the cluster analysis with partitioning around mediods
algorithm. We considered the formulation with equivalent
supplies to the average needs of each subpopulation
was adequated to the patients caloric-proteic requirements
when their difference was lower than 20%. The
percentage of patients who received adequated supplies
were compared between the subpopulations identified.
In case of two subpopulations, glucose, lipids and
amino acid needs are: 275 (CI 95%: 265-285) g, 83 (CI
95%: 78-88) g and 89 (CI 95%: 86-92) g in subpopulation
1 (N = 35), and 195 (CI 95%: 187-203) g, 58 (CI
95%: 56-61) g and 74 (CI 95%: 72-77) g in subpopulation
2 (N = 65), respectively. In case of three subpopulations,
in subpopulation 1 (N = 19), glucose, lipids and
amino acid needs are: 295 (CI 95%: 283-306) g, 91 (CI
95%: 84-97) g and 91 (CI 95%: 86-95); 234 (CI 95%:
227-240) g, 67 (CI 95%: 64-70) g and 84 (CI 95%: 82-86)
g to the subpopulation 2 (N = 45) and 172 (CI 95%: 165-
179) g, 55 (CI 95%: 52-57) g, and 68 (CI 95%: 64-71) g
to the subpopulation 3 (N = 36) respectively. In general,
caloric and proteic supplies are equal to the patients needs,
but there was a tendendy to overfeeding in patients
with lower CPN. The utilization of one, two or three formulations with equivalent supplies to the average needs
of each subpopulation was adequated to the patients in
the 45% (CI 95%: 36%-55%), 75% (CI 95%: 65%-
83%) and 82% (CI 95%: 74%-89%), respectively.
Therefore, the development of three normalized formulations
of total parenteral nutrition allows to satisfy the
patients nutritional needs at least the 74% of the patients
Form and function of the mantle edge in Protobranchia (Mollusca: Bivalvia)
We analyzed, by optical and transmission electron microscopy, the morphology and function of the mantle edge,
including the formation of the periostracum, of ten species of protobranchs. Five species from the order Nuculida,
four species from the order Nuculanida and one species from the order Solemyida were studied. A second outer
fold, which seems to function as a template for the internal marginal crenulations of the valves, is present in the
crenulated species of Nucula. The minute non-crenulated Ennucula aegeensis shows the glandular basal cells
displaced toward the periostracal groove, resembling a minute additional fold between the outer and middle
folds. Intense secretion of glycocalyx, together with active uptake of particles, have been observed in the inner
epithelium of the middle mantle fold and the whole epithelium of the inner mantle fold in all the studied species.
Contrary to the rest of the bivalves, all the protobranchs analyzed have two basal cells involved in the formation
of the external nanometric pellicle of the periostracum, a character that would support the monophyly of protobranchs.
A three-layered pattern is the general rule for the periostracum in protobranchs, like for other bivalves.
The presence of pouches of translucent layer inside the tanned dark layer under periostracal folds is
characteristic of the species with a folded periostracum; its function is unclear but could give flexibility to the
periostracum. The non-nacreous internal shell layer and the presence of translucent pouches under periostracal
folds in Sarepta speciosa resemble those found in nuculanids. However, the free periostracum is rather similar to
those of N. hanleyi and E. aegeensis, with a continuous vesicular layer. All the latter supports the inclusion of
Sarepta in the order Nuculanida but could indicate either a basal lineage or that the translucent vesicular layer is
an adaptive trait.Málaga/CBU
Efecto del medio y de la herencia sobre los pesos al nacer, destete y 16 meses de edad en la raza costeño con cuernos
Con el objetivo de estimar parámetros genéticos para los caracteres productivos, pesos al nacer, destete y 16 meses de edad, en la raza Costeño con Cuernos en la estación experimental de Turipaná, ubicada en el municipio de Cereté, norte de Colombia, fueron analizados 1303, 1108 y 841 datos, para los pesos al nacer (PD), al destete (PD) y peso a los 16 meses (P16M), respectivamente, en el periodo 1991 al año 2001. Las medias observadas y desvíos estándares para dichos caracteres fueron 29.03 ± 3.69Kg, 173.27± 23.71Kg y 228.36 ± 27.64Kg., respectivamente. Los valores estimados y los errores para los coeficientes de repetibilidad y de heredabilidad para los PN, PD y P16M fueron 0.05 ± 0.02; 0.08 ± 0.03; 0.082 ± 0.048; 0.26± 0.82 y 0.22 ± 0.089, respectivamente. Los coeficientes de correlación genética fueron 0.19 para PN x PD y 0.045 para PD x P16M
Brood desertion by female shorebirds: A test of the differential parental capacity hypothesis on Kentish plovers
The aim of this study was to examine whether the energetic costs of reproduction explain offspring desertion by female shorebirds, as is suggested by the differential parental capacity hypothesis. A prediction of the hypothesis is that, in species with biparental incubation in which females desert from brood care after hatching, the body condition of females should decline after laying to a point at which their body reserves are too low for continuing parental care. We tested this prediction on Kentish plovers (Charadrius alexandrinus) in which both sexes incubate but the females desert from brood care before the chicks fledge. We found no changes in either the body masses or body compositions of both individual male and female plovers from early incubation and throughout early chick rearing. Furthermore, the timing of brood desertion by females was not affected by their body condition. Neither did we find gender differences in the energetic costs of incubation. There were no differences in the timing of brood desertion between experimental and control females in an experiment in which we lengthened or shortened the duration of incubation by one week. These results indicate that energetic costs do not explain offspring desertion by female Kentish plovers and that the needs of chicks for parental care rather than cumulative investment by females is what determines the timing of brood desertion.Peer Reviewe
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