The nature of 1WGA J1958.2+3232: a new intermediate polar

We present low and intermediate resolution spectroscopy of the optical counterpart to the recently discovered pulsating X-ray source 1WGA J1958.2+3232. The presence of strong HI , HeI and HeII emission lines together with the absence of absorption features rules out the possibility that the object is a massive star, as had recently been suggested. The observed X-ray and optical characteristics are consistent with the object being an intermediate polar. The double-peaked structure of the emission lines indicates that an accretion disc is present

Sobre la posición sistemática del género Placogyropsis Alloiteau, 1957. (Scleractinia cretácica)

Utilizando varios topotipos de la especie tipo, se estudia el género Placogyropsis Alloiteau, 1957, inscrito por el propio Alloiteau en la familia Dendrogyriidae Alloiteau, 1952. Se sugiere que no pertenece a esta familia, sino a la familia Latomeandriidae y se propone una diagnosis del género

A 0535+26: Back in business

In May/June 2005, after 10 years of inactivity, the Be/X-ray binary system A 0535+26 underwent a major X-ray outburst. In this paper data are presented from 10 years of optical, IR and X-ray monitoring showing the behaviour of the system during the quiescent epoch and the lead up to the new outburst. The results show the system going through a period when the Be star in the system had a minimal circumstellar disk and then a dramatic disk recovery leading, presumably, to the latest flare up of X-ray emission. The data are interpreted in terms of the state of the disk and its interaction with the neutron star companion.Comment: Accepted for publication in MNRA

The SMC X-ray transient XTE J0111.2-7317 : a Be/X-ray binary in a SNR?

We report observations which confirm the identity of the optical/IR counterpart to the Rossi X-ray Timing Explorer transient source XTE J0111.2-7317. The counterpart is suggested to be a B0-B2 star (luminosity class III--V) showing an IR excess and strong Balmer emission lines. The distance derived from reddening and systemic velocity measurements puts the source in the SMC. Unusually, the source exhibits an extended asymetric H alpha structure.Comment: 5 pages, 3 figs, accepted by MNRA

Calculating shadow wages for family labour in agriculture : An analysis for Spanish citrus fruit farms

This paper deals with the calculation of shadow wages for family labour in agriculture. Using the existence of a duality between input distance and cost functions, we use the former to derive individual labour shadow prices for a sample of Spanish citrus fruit producers. Our results show that the average shadow price representing the opportunity cost of family labour employed onfarm, is lower than the average market wage rate paid for hired labour. We relate this finding to a strategy of outsourcing of many growing tasks that is currently pursued by farmers to overcome the problems posed by a suboptimal farm size.shadow prices, duality, distance functions, on-farm labour opportunity cost, outsourcing

Actualización en el tratamiento de la cadera degenerativa en el adulto joven

El tratamiento de la patología degenerativa de la cadera en el adulto joven es un desafío para el cirujano ortopeda dadas las expectativas de función y calidad de vida que solicitan estos pacientes. En la última década se ha experimentado un cambio hacia la implantación de técnicas quirúrgicas de preservación de la articulación. La selección adecuada de los pacientes candidatos a estas técnicas nos permitirá obtener excelentes resultados y retrasar la necesidad de la cirugía protésica. La prótesis total de cadera sigue siendo la técnica de elección en los pacientes jóvenes con enfermedad degenerativa moderada o severa, aunque es necesario una mejora en los biomateriales y pares de fricción para aumentar la supervivencia del implante y la percepción de calidad de vida por parte del pacienteThe orthopaedic treatment of young patients with hip osteoarthritis is a challenge for the orthopaedic surgeon, as young patients have higher expectation for function and quality of life. Surgical treatment has evolved to joint preservation surgery in the past decade. The proper selection of patients for these techniques allows us to obtain excellent results and delay the need for prosthetic surgery. Total hip replacement is the technique of choice in young patients with moderate or severe hip osteoarthritis. Improvement in biomaterials and bearing surfaces are required to improve the prosthesis survival rates and the quality of life of these patient

Multiwavelength observations of the Be/X-ray binary 4U1145-619

We report optical and infrared observations of the massive X-ray binary system 4U1145-619 (V801 Cen) which show that the circumstellar disc of the Be star component is in decline. Infrared J,H,K,L magnitudes of V801Cen have been monitored from 1993 March to 1996 April. H alpha spectra have been obtained throughout the same period. We find that both the infrared excess and the Balmer emission have been in decline throughout the period of observations. A 13 year optical and X-ray history of the source has been collated, revealing a possible correlation between the optical and X-ray activity. In addition, we have used u,v,b,y,beta indices, corrected for both circumstellar and interstellar effects, to calculate the physical parameters of the underlying B star.Comment: 8 pages postscript. Accepted by MNRA

Bound-state dark matter with Majorana neutrinos

We propose a simple scenario in which dark matter (DM) emerges as a stable neutral hadronic thermal relics, its stability following from an exact $\operatorname{U}(1)_D$ symmetry. Neutrinos pick up radiatively induced Majorana masses from the exchange of colored DM constituents. There is a common origin for both dark matter and neutrino mass, with a lower bound for neutrinoless double beta decay. Direct DM searches at nuclear recoil experiments will test the proposal, which may also lead to other phenomenological signals at future hadron collider and lepton flavour violation experiments.Comment: 9 pages, 4 figures. arXiv admin note: text overlap with arXiv:1803.0852