Deconstructing the eradication of new world screwworm in North America: retrospective analysis and climate warming effects.

Before its eradication from North America, the subtropical-tropical new world screwworm fly Cochliomyia hominivorax (Coquerel) invaded southwestern temperate areas of the U.S.A., where it caused myiasis in wildlife and livestock. Outbreaks of the fly occurred during years when adult migrants were carried northward on North American monsoon winds from the northern areas of Mexico and south Texas. We deconstruct, retrospectively, the biology and the effect of weather on the eradication of the fly in North America. Screwworm was found to be an ideal candidate for eradication using the sterile insect technique (SIT) because females mate only once, whereas males are polygynous, and, although it has a high reproductive potential, field population growth rates are low in tropical areas. In northern areas, eradication was enhanced by cool-cold weather, whereas eradication in tropical Mexico and Central America is explained by the SIT. Despite low average efficacy of SIT releases (approximately 1.7%), the added pressure of massive SIT releases reduced intrinsically low fly populations, leading to mate-limited extinction. Non-autochthonous cases of myiasis occur in North America and, if the fly reestablishes, climate warming by 2045-2055 will expand the area of favourability and increase the frequency and severity of outbreaks

Weighing the black holes in ultraluminous X-ray sources through timing

We describe a new method to estimate the mass of black holes in Ultraluminous X-ray Sources (ULXs). The method is based on the recently discovered ``variability plane'', populated by Galactic stellar-mass black-hole candidates (BHCs) and supermassive active galactic nuclei (AGNs), in the parameter space defined by the black-hole mass, accretion rate and characteristic frequency. We apply this method to the two ULXs from which low-frequency quasi-periodic oscillations have been discovered, M82 X-1 and NGC 5408 X-1. For both sources we obtain a black-hole mass in the range 100~1300 Msun, thus providing evidence for these two sources to host an intermediate-mass black hole.Comment: 5 pages, 2 figures, Accepted by MNRA

XMM-Newton study of the complex and variable spectrum of NGC 4051

We study the X-ray spectral variability of the Narrow Line Seyfert 1 galaxy NGC 4051 as observed during two XMM-Newton observations. The data show evidence for a neutral and constant reflection component and for constant emission from photoionized gas, which are included in all spectral models. The nuclear emission can be modelled both in terms of a ``standard model'' (pivoting power law plus a black body component for the soft excess) and of a two--component one (power law plus ionized reflection from the accretion disc). The standard model results indicate that the soft excess does not follow the standard black body law. Moreover, although the spectral slope is correlated with flux, which is consistent with spectral pivoting, the hardest photon indexes are so flat as to require rather unusual scenarios. These problems can be solved in terms of the two-component model in which the soft excess is not thermal, but due to the ionized reflection component. The variability of the reflection component from the inner disc closely follows the predictions of the light bending model, suggesting that most of the primary nuclear emission is produced in the very innermost regions, only a few gravitational radii from the central black hole. (abridged)Comment: accepted for publication in MNRA

A PDE-regularized smoothing method for space-time data over manifolds with application to medical data

We propose an innovative statistical-numerical method to model spatio- temporal data, observed over a generic two-dimensional Riemanian manifold. The proposed approach consists of a regression model completed with a regu- larizing term based on the heat equation. The model is discretized through a finite element scheme set on the manifold, and solved by resorting to a fixed point-based iterative algorithm. This choice leads to a procedure which is highly efficient when compared with a monolithic approach, and which allows us to deal with massive datasets. After a preliminary assessment on simulation study cases, we investigate the performance of the new estimation tool in prac- tical contexts, by dealing with neuroimaging and hemodynamic data

Shyness and Psychological Adjustment During Adolescence: The Moderating Role of Parenting Style

Although shyness constitutes a risk factor for maladjustment, parenting style may influence these developmental trajectories during childhood. Little is known about the role of parental style in the relationship between shyness and psychological adjustment during adolescence.Aims: To explore the relationship between shyness and parenting style and to analyse the moderating role of the quality of parenting in the relationship between shyness and internalizing difficulties during adolescence.Method: 787 11 to 19 year-old participants (divided in early and late adolescents) were recruited for this study. Participants completed Revised Cheek and Buss Shyness Scale, Parental Bonding Instrument and internalizing scale of Youth Self Report.Results: Shy adolescents perceived parents to be less warm and close, less encouraging of their autonomy and independence, and more overprotective and intrusive than did other participants. During early-adolescence participants who perceived their parents as supportive and not intrusive showed significantly fewer internalizing problems related to shynes

Sensation Seeking and Gambling Behavior in Adolescence: Can Externalizing Problems Moderate This Relationship?

Gambling is a widespread phenomenon during adolescence. Among different risk factors involved in the onset of adolescent gambling behaviors, one factor that is studied is the sensation seeking personality trait. However, the literature is heterogeneous and a direct relationship between sensation seeking and gaming behaviors has not always been highlighted. This suggests that the relationship can be influenced by other factors. In particular, we explored the moderating role of externalizing problems in this relationship. A total of 363 adolescents (232 males and 131 females) aged 14 to 20 (M = 16.35, SD = 1.36) completed a battery of questionnaires aimed to assess their gambling behaviors, as well as the levels of externalizing problems and sensation seeking. The results showed that sensation seeking was associated with gambling severity, but this relationship was significant when externalizing problems were high and medium. On the contrary, when externalizing problems were low, the relationship between sensation seeking and gambling severity was not significant. Overall, sensation seeking in adolescence can favor the implementation of risk behaviors, such as gambling, but only in association with the presence of externalizing problems. Limitations, strengths, and social and clinical implications of the present study are discussed

Biomonitoring of lake sediments using benthic macroinvertebrates

The Water Framework Directive (2000/60/EC) is an innovative piece of legislation aimed at protecting the quality of all continental and coastal waters in Europe through an ecological evaluation of the ecosystems. Since it is widely acknowledged that the greater the ecological realism the greater the difficulty of its definition, we describe the different uses of benthic organisms as a tool for assessing the quality of sediment in lakes. We review the responses from single species to the community. We focus on studies in the laboratory and in the field, and we also critically consider the use of predictive models for these evaluations. Our discussion of the information collected underlines the importance of the relation between sensitivity of single species and contaminants. Moreover, the recent approach in developing mechanistic models to predict the response of natural communities seems to be particularly powerful for community ecology, and we strongly recommend more effort along these lines

Virtual mechanical product disassembly sequences based on disassembly order graphs and time measurement units

Recently, the approach that defines the total life cycle assessment (LCA) and the end of life (EoL) in the early design phases is becoming even more promising. Literature evidences many advantages in terms of the saving of costs and time and in the fluent organization of the whole design process. Design for disassembly (DfD) offers the possibility of reducing the time and cost of disassembling a product and accounts for the reusing of parts and of the dismantling of parts, joints, and materials. The sequence of disassembly is the ordered way to extract parts from an assembly and is a focal item in DfD because it can deeply influence times and operations. In this paper, some disassembly sequences are evaluated, and among them, two methods for defining an optimal sequence are provided and tested on a case study of a mechanical assembly. A further sequence of disassembly is provided by the authors based on experience and personal knowledge. All three are analyzed by the disassembly order graph (DOG) approach and compared. The operations evaluated have been converted in time using time measurement units (TMUs). As result, the best sequence has been highlighted in order to define a structured and efficient disassembly