Morphometric changes and sex steroid levels during the annual reproductive cycle of the Lusitanian toadfish, Halobatrachus didactylus

The Lusitanian toadfish has group synchronous oocytes, which grow from November until June–July when they are released probably as a single batch. Blood plasma levels of estradiol-17b (E2) and testosterone (T) increase during vitellogenesis and drop rapidly during final maturation and ovulation, when 17,20b, 21-trihydroxy-4-pregnen-3-one (17,20b,21-P) levels increase. The male reproductive apparatus is composed of paired testes and multichambered accessory glands, which secrete mucosubstances and are connected to the spermatic duct. Changes in the gonadosomatic index of males paralleled the females but started to drop slightly earlier. The swimbladder and accessory glands also underwent important seasonal changes in weight reaching a maximum at spawning. T, 11-ketotestosterone (11-KT) and 17,20a-dihydroxy-4-pregnen-3-one (17,20a-P) were generally low except for a sharp peak in June. 17,20b,21-P also peaked in June and then declined slowly. 17,20b-dihydroxy-4-pregnen-3-one (17,20a-P) was undetectable in males and females. As with other species of the family two types of males were identified: type I males with smaller testes (ca. 7-fold) and larger accessory glands (ca. 3-fold) and swimbladders than type II. Type I males also had significantly higher (ca. 6- fold) 11-KT levels than type II males. This suggests a role for 11-KT in the development of structures important for reproductive behaviour

The Hidden Quantum Groups Symmetry of Super-renormalizable Gravity

In this paper we consider the relation between the super-renormalizable theories of quantum gravity (SRQG) studied in [arXiv:1110.5249v2, arXiv:1202.0008] and an underlying non-commutativity of spacetime. For one particular super-renormalizable theory we show that at linear level (quadratic in the Lagrangian) the propagator of the theory is the same we obtain starting from a theory of gravity endowed with {\theta}-Poincar\'e quantum groups of symmetry. Such a theory is over the so called {\theta}-Minkowski non-commuative spacetime. We shed new light on this link and show that among the theories considered in [arXiv:1110.5249v2, arXiv:1202.0008], there exist only one non-local and Lorentz invariant super-renormalizable theory of quantum gravity that can be described in terms of a quantum group symmetry structure. We also emphasize contact with pre-existent works in the literature and discuss preservation of the equivalence principle in our framework.Comment: 10 page

Self-completeness and spontaneous dimensional reduction

A viable quantum theory of gravity is one of the biggest challenges facing physicists. We discuss the confluence of two highly expected features which might be instrumental in the quest of a finite and renormalizable quantum gravity -- spontaneous dimensional reduction and self-completeness. The former suggests the spacetime background at the Planck scale may be effectively two-dimensional, while the latter implies a condition of maximal compression of matter by the formation of an event horizon for Planckian scattering. We generalize such a result to an arbitrary number of dimensions, and show that gravity in higher than four dimensions remains self-complete, but in lower dimensions it is not. In such a way we established an "exclusive disjunction" or "exclusive or" (XOR) between the occurrence of self-completeness and dimensional reduction, with the goal of actually reducing the unknowns for the scenario of the physics at the Planck scale. Potential phenomenological implications of this result are considered by studying the case of a two-dimensional dilaton gravity model resulting from dimensional reduction of Einstein gravity.Comment: 12 pages, 3 figures; v3: final version in press on Eur. Phys. J. Plu

The swimbladder of the Lusitanian toadfish: sexual dimorphism and hormonal control

The members of the family Batrachoididae produce sounds associated with courtship and agonistic interactions. While long mating calls are only produced by nesting males, agonistic short duration grunts have been recorded from toadfishes and midshipmen in both males (nesting or not) and females. Sound production results from the contraction of paired sonic muscles attached to the walls of the swimbladder, which cause a rapid variation in swimbladder volume and internal pressure. Both sonic muscle growth and sonic fibre morphology have been shown to be androgen sensitive in batrachoidids

Hormonal control of swimbladder sonic muscle dimorphism in the Lusitanian toadfish, Halobatrachus didactylus

The swimbladder and associated sonic muscle of the Lusitanian toadfish Halobatrachus didactylus increase in size throughout life and are, respectively, 25% and 30% larger in type I (nest-holder) males than females, which may generate sexual differences in sound production. Sexual dimorphism in swimbladder is also evident in the morphological features of sonic muscle fibers. During the breeding season, type I males have smaller myofibril contracting zones surrounded by larger sarcoplasm areas compared with females, possibly an adaptation to speed and fatigue resistance for the production of long mating calls. Type II (floater) males show characteristics that are intermediate, but statistically not significantly different, between type I males and females. Six weeks after castration and androgen (testosterone and 11- ketotestosterone) replacement in type I and type II males there were no alterations either in swimbladder mass or fiber morphology. However, 17b-estradiol induced a significant decrease in swimbladder mass and sarcoplasm area/myofibril area ratio. Six months after castration there was a clear reduction in the seasonal swimbladder hypertrophy in males and induction of sonic fiber morphological characteristics that resemble those occurring in females (low sarcoplasm area/myofibril area ratio). These results suggest that testicular factors are required to initiate sonic muscle hypertrophy and type I sonic fiber phenotype in H. didactylus, but a specific involvement of androgens has not been completely clarified

Spinning Loop Black Holes

In this paper we construct four Kerr-like spacetimes starting from the loop black hole Schwarzschild solutions (LBH) and applying the Newman-Janis transformation. In previous papers the Schwarzschild LBH was obtained replacing the Ashtekar connection with holonomies on a particular graph in a minisuperspace approximation which describes the black hole interior. Starting from this solution, we use a Newman-Janis transformation and we specialize to two different and natural complexifications inspired from the complexifications of the Schwarzschild and Reissner-Nordstrom metrics. We show explicitly that the space-times obtained in this way are singularity free and thus there are no naked singularities. We show that the transformation move, if any, the causality violating regions of the Kerr metric far from r=0. We study the space-time structure with particular attention to the horizons shape. We conclude the paper with a discussion on a regular Reissner-Nordstrom black hole derived from the Schwarzschild LBH and then applying again the Newmann-Janis transformation.Comment: 18 pages, 18 figure

Hawking emission from quantum gravity black holes

We address the issue of modelling quantum gravity effects in the evaporation of higher dimensional black holes in order to go beyond the usual semi-classical approximation. After reviewing the existing six families of quantum gravity corrected black hole geometries, we focus our work on non-commutative geometry inspired black holes, which encode model independent characteristics, are unaffected by the quantum back reaction and have an analytical form compact enough for numerical simulations. We consider the higher dimensional, spherically symmetric case and we proceed with a complete analysis of the brane/bulk emission for scalar fields. The key feature which makes the evaporation of non-commutative black holes so peculiar is the possibility of having a maximum temperature. Contrary to what happens with classical Schwarzschild black holes, the emission is dominated by low frequency field modes on the brane. This is a distinctive and potentially testable signature which might disclose further features about the nature of quantum gravity.Comment: 36 pages, 18 figures, v2: updated reference list, minor corrections, version matching that published on JHE

Atributos químicos de um argissolo após a aplicação do resíduo agroindustrial do processamento de goiabas.

Resumo: O Brasil é um grande produtor de goiabas. A fruta pode ser consumida in natura ou industrializada e, neste último caso, gera resíduos. Esse subproduto pode ser empregado na agricultura como adubo orgânico, pois, é rico em nutrientes. Entretanto, são necessárias pesquisas para empregar com critério técnico. Assim, objetivou-se avaliar a fertilidade do solo, após a aplicação do resíduo da indústria processadora de goiabas, em pomar comercial da própria fruta. Foram aplicadas as seguintes doses: zero; 9; 18; 27; 36 t ha-1 em um Argissolo. As aplicações foram superficiais, em pomar de goiabeiras adultas, anualmente a partir de 2006. No final de 2010, foram mensurados os atributos químicos do solo na camada de 0 - 0,20 m. O subproduto da indústria processadora de goiabas promoveu alterações na fertilidade do solo, com diminuição do pH e aumentos nas concentrações de fósforo e de nitrogênio inorgânico, sendo este último até a dose de 19 t ha-1

Uso fertilizante do subproduto da agroindústria processadora de goiabas em pomar comercial de goiabeiras.

Resumo: A utilização de resíduos orgânicos, urbanos ou industriais, em áreas agrícolas pode ser justificada pela necessidade de um destino apropriado para esses materiais visando a sua reciclagem, visto que a quantidade desses materiais tem aumentado rapidamente com o tempo. Assim, objetivou-se avaliar a fertilidade do solo, após a aplicação do resíduo da indústria processadora de goiabas, em pomar comercial da própria fruta. Foram aplicadas doses do subproduto da indústria processadora de goiabas (zero; 9; 18; 27; 36 t ha-1) em Argissolo. As aplicações foram realizadas superficialmente, em pomar de goiabeiras adultas, a partir de 2006. Antecedendo a aplicação de 2011, foram mensurados os atributos químicos do solo na camada de 0 - 0,20 m. O subproduto da indústria processadora de goiabas promoveu alterações na fertilidade do solo, com diminuição do pH e aumentos nas concentrações de fósforo e de nitrogênio, sendo este último até da dose de 19 t ha-1. [Fertilizer use of guava processing industry waste in orchard of guava trees]. Abstract: The use of organic waste, urban or industrial, in agricultural areas can be justified by the need for an appropriate target for such materials in order to recycle, since the amount of such wastes is increasing rapidly with time. The objective was to evaluate soil fertility, after applying the processing industry waste of guavas, commercial orchard in the fruit itself. Doses were applied by product processing industry guavas (zero, 9, 18, 27, 36 t ha-1) in Ultisol. The applications were made superficially in adult guava orchard from 2006. Prior to implementation of 2011, were measured soil chemical properties in the 0 - 0.20 m. The byproduct of the processing industry guavas promoted changes in soil fertility, decreased pH and increases in the concentrations of phosphorus and nitrogen, the latter to the dose of 19 t ha-1

Medida indireta da clorofila, estado nutricional em N e produção de frutos de goiabeiras adubadas com subproduto da indústria processadora de goiabas.

RESUMO ? O reaproveitamento de subprodutos é uma alternativa interessante para a reciclagem de nutrientes e melhoria do estado nutricional das plantas. A utilização de ferramentas que auxiliem na diagnose foliar pode contribuir para a tomada de decisão sobre a adubação. Assim, objetivaram-se avaliar o teor foliar de N, a medida indireta da clorofila, a produção de frutos e suas correlações, em um pomar de goiabeiras adultas cv. Paluma, por três safras consecutivas. Foram aplicadas as seguintes doses do subproduto da indústria processadora de goiabas: zero; 9; 18; 27; 36 t ha-1. O material foi aplicado superficialmente no pomar, sem incorporação uma vez por ano, entre 2006 e 2009, sendo avaliados em três safras consecutivas o teor de N, o índice SPAD, a produção de frutos, realizando-se a correlação entre as variáveis. A medida indireta da clorofila, o teor foliar de N e a produção de frutos apresentaram alta relação com as doses de subproduto da indústria processadora de goiabas. A leitura SPAD apresenta correlação linear e positiva com o teor foliar de nitrogênio, bem como com a produção de frutos de goiabeiras adultas