_Limusaurus_ and bird digit identity

_Limusaurus_ is a remarkable herbivorous ceratosaur unique among theropods in having digits II, III and IV, with only a small metacarpal vestige of digit I. This raises interesting questions regarding the controversial identity of avian wing digits. The early tetanuran ancestors of birds had tridactyl hands with digital morphologies corresponding to digits I, II & III of other dinosaurs. In bird embryos, however, the pattern of cartilage formation indicates that their digits develop from positions that become digits II, III, & IV in other amniotes. _Limusaurus_ has been argued to provide evidence that the digits of tetanurans, currently considered to be I, II and III, may actually be digits II, III, & IV, thus explaining the embryological position of bird wing digits. However, morphology and gene expression of the anterior bird wing digit specifically resemble digit I, not II, of other amniotes. We argue that digit I loss in _Limusaurus_ is derived and thus irrelevant to understanding the development of the bird wing

Factores que determinan la producción en brócoli (Brassica oleracea L. var Itálica) en cultivos a cielo abierto

Teniendo como origen citogenético la región mediterránea, comprendida entre Europal, Asia Occidental y Africa. El brócoli se ha desarrollándo de manera importante en México, por lo que se han obteniendo ingresos considerables, donde Según la SIAP (Servicio de Información Agroalimentaria y Pesquera) arroja que en el 2012 se obtuvo a nivel nacional una superficie sembrada de 24001.74 ha y 23,598.74 ha de superficie cosechada teniendo una producción total de 334,550.99 toneladas con un rendimiento promedio por hectárea de 14.18 toneladas. El brócoli es una masa de inflorescencias de color verde grisáceo o morado; el grado de compactación de las pellas o inflorescencias es menor comparado con el de la coliflor. Las hojas suelen ser de color verde obscuro más rizadas, con ligeras espículas, presentando un limbo hendido, las hojas pueden ser más pecioladas que las de la coliflor. Cada una de las etapas del cultivo es de gran importancia ya que en cada una se ve influenciada de distintos factores (fertilización, preparación de suelo, agua, plagas, enfermedades, fisiopatías, condiciones edafoclimaticas, entre otros que limitan o favorecen el desarrollo del cultivo), sin embargo se tienen mermas significativas por un mal manejo en cada una de estas. Debido a lo anterior, es necesario hacer un uso racional de los recursos naturales, económicos y humanos para conservar y aumentar la superficie y así beneficiando a productores de manera significativa con paquetes tecnológicos que favorezcan la obtención de buenos rendimientos con excelente calidad

Population ecology of Indo-Pacific bottlenose dolphins along the south-east coast of South Africa

In this study, the genetic population structure of the Indo-Pacific bottlenose dolphin (Tursiops aduncus) was assessed across the Agulhas and Natal Bioregions of South Africa. At the same time, the abundance, distribution and habitat use of T. aduncus was investigated using boat-based surveys along 145 km of coastline from Goukamma Marine Protected Area (MPA) to Tsitsikamma MPA along the south-east coast of South Africa (Agulhas Bioregion). Tursiops aduncus habitat preferences were assessed based on locations of sightings and recorded behaviour, and compared with those of the sympatric Indian Ocean humpback dolphins (Sousa plumbea). Strong patterns of differentiation between two sub-populations of T. aduncus were identified using double digest Restriction Site Associated DNA sequencing (ddRADseq). Pairwise FST were significant (p < 0.05) between individuals from the Agulhas and Natal Bioregions and yielded values of 0.033 for all the loci. Resource requirements, specialization and differences in habitat use possibly provided sufficient isolation allowing differentiation between sub-populations of the two ecologically distinct bioregions, despite the lack of any prominent boundary to gene flow. The two identified sub-populations should each be managed as a distinct conservation unit. The abundance estimate of T. aduncus for the study area according to an open population model (POPAN) was 2,295 individuals (95% CI: 1,157 - 4,553). Although closed models were considered inappropriate, such a model was applied for the Plettenberg Bay part of the study area in isolation, to allow for comparison with a previous estimate. The comparison showed a 72.3% decrease in abundance between the two periods: from 6,997 (95% CI: 5,230 - 9,492) in 2002 - 2003 to 1,940 (95% CI: 1,448 - 2,600) in 2014 - 2016. The mean group size also declined from 120 (range: 1 - 500) to 26 (range: 1 - 100). The results highlight the importance of assessing abundance changes at other sites to inform the revision of T. aduncus conservation status in South Africa. Tursiops aduncus were encountered throughout the area. The lowest encounter rate was along rocky and exposed shorelines. These areas were, however, associated with relatively larger group sizes and greater likelihood of travelling behaviour, whereas sandy bottomed areas, where encounter rates were highest (e.g. parts of Plettenberg Bay and the Goukamma MPA), were more likely to be associated with other behaviours (e.g. foraging, socialising). There was a relatively low association of encounters with MPAs, possibly due to the fact that two of the three MPAs in the area (Tsitsikamma and Robberg) were characterised by non-preferred habitat, namely rocky shorelines. Comparison with Sousa plumbea showed similarity in habitat preferences between the species, though S. plumbea also showed an affinity for estuarine habitats. Two areas that were highly utilised by both species were located along Goukamma MPA and the north-east section in Plettenberg Bay including the Keurbooms Estuary. The latter is unprotected and a management measure could be to create a controlled-use zone to reduce disturbance to dolphins there

Transient micro heat transfer in a gas confined between parallel plates due to a sudden increase of the wall temperature

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.The transient heat transfer problem through a rarefied gas confined between parallel plates maintained at different temperatures is investigated. The theoretical formulation is based on the linear BGK kinetic model subject to Maxwell diffuse reflection. The governing time dependent equation is solved by using the discrete velocity method. Results are presented for the number density, macroscopic velocity, heat flux and temperature distributions in the whole range of the Knudsen number. The results are compared with direct Monte Carlo simulations and good agreement is found for small temperature variations.This study is funded from the European Community's Seventh Framework Programme (ITN - FP7/2007-2013) under grant agreement n° 215504

Entropy, pressure, ground states and calibrated sub-actions for linear dynamics

Denote by $X$ a Banach space and by $T : X \to X$ a bounded linear operator with non-trivial kernel satisfying suitable conditions. We consider the concepts of entropy - for $T$-invariant probability measures - and pressure for H\"older continuous potentials. We also prove the existence of ground states (the limit when temperature goes to zero) associated with such class of potentials when the Banach space $X$ is equipped with a Schauder basis. We produce an example concerning weighted shift operators defined on the Banach spaces $c_0(\mathbb{R})$ and $l^p(\mathbb{R})$, $1 \leq p < +\infty$, where our results do apply. In addition, we prove the existence of calibrated sub-actions when the potential satisfies certain regularity conditions using properties of the so-called Ma\~n\'e potential. We also exhibit examples of selection at zero temperature and explicit sub-actions in the class of H\"older continuous potentials

The Ruelle operator for symmetric β\beta-shifts

Consider $m \in \mathbb{N}$ and $\beta \in (1, m + 1]$. Assume that $a\in \mathbb{R}$ can be represented in base $\beta$ using a development in series $a = \sum^{\infty}_{n = 1}x(n)\beta^{-n}$ where the sequence $x = (x(n))_{n \in \mathbb{N}}$ take values in the alphabet $\mathcal{A}_m := \{0, \ldots, m\}$. The above expression is called the $\beta$-expansion of $a$ and it is not necessarily unique. We are interested in sequences $x = (x(n))_{n \in \mathbb{N}} \in \mathcal{A}_m^\mathbb{N}$ which are associated to all possible values $a$ which have a unique expansion. We denote the set of such $x$ (with some more technical restrictions) by $X_{m,\beta} \subset\mathcal{A}_m^\mathbb{N}$. The space $X_{m, \beta}$ is called the symmetric $\beta$-shift associated to the pair $(m, \beta)$. It is invariant by the shift map but in general it is not a subshift of finite type. Given a H\"older continuous potential $A:X_{m, \beta} \to\mathbb{R}$, we consider the Ruelle operator $\mathcal{L}_A$ and we show the existence of a positive eigenfunction $\psi_A$ and an eigenmeasure $\rho_A$ for some appropriated values of $m$ and $\beta$. We also consider a variational principle of pressure. Moreover, we prove that the family of entropies $h(\mu_{tA})_{t>1}$ converges, when $t \to\infty$, to the maximal value among the set of all possible values of entropy of all $A$-maximizing probabilities

Experimental phase functions of mm-sized cosmic dust grains

We present experimental phase functions of three types of millimeter-sized dust grains consisting of enstatite, quartz and volcanic material from Mount Etna, respectively. The three grains present similar sizes but different absorbing properties. The measurements are performed at 527 nm covering the scattering angle range from 3 to 170 degrees. The measured phase functions show two well defined regions i) soft forward peaks and ii) a continuous increase with the scattering angle at side- and back-scattering regions. This behavior at side- and back-scattering regions are in agreement with the observed phase functions for the Fomalhaut and HR 4796A dust rings. Further computations and measurements (including polarization) for millimeter sized-grains are needed to draw some conclusions about the fluffy or compact structure of the dust grains