Contact zone dynamics and the evolution of reproductive isolation in a North American treefrog, the spring peeper (Pseudacris crucifer)

Despite over seven decades of speciation research and 25 years of phylogeographic studies, a comprehensive understanding of mechanisms that generate biological species remains elusive. In temperate zones, the pervasiveness of range fragmentation and subsequent range expansions suggests that secondary contact between diverging lineages may be important in the evolution of species. Thus, such contact zones provide compelling opportunities to investigate evolutionary processes, particularly the roles of geographical isolation in initiating, and indirect selection against hybrids in completing (reinforcement), the evolution of reproductive isolation and speciation. The spring peeper (Pseudacris crucifer) has six well-supported mitochondrial lineages many of which are now in secondary contact. Here I investigate the evolutionary consequences of secondary contact of two such lineages (Eastern and Interior) in Southwestern Ontario using genetic, morphological, acoustical, experimental, and behavioural evidence to show accentuated divergence of the mate recognition system in sympatry. Mitochondrial and microsatellite data distinguish these two lineages but also show ongoing hybridization. Bayesian assignment tests and cline analysis imply asymmetrical introgression of Eastern lineage nuclear markers into Interior populations. Male calls are divergent between Eastern and Interior allopatric populations and show asymmetrical reproductive character displacement in sympatry. Female preference of pure lineage individuals is also exaggerated in sympatry, with hybrids showing intermediate traits and preference. I suggest that these patterns are most consistent with secondary reinforcement. I assessed levels of post-zygotic isolation between the Eastern and Interior lineages using a laboratory hybridization experiment. Hybrid tadpoles showed equal to or greater fitness than their pure lineage counterparts, but this may be countered through competition. More deformities and developmental anomalies in hybrid tadpoles further suggest post-zygotic isolation. Despite evidence for pre-mating isolation between the two lineages, isolation appears incomplete (i.e. hybridization is ongoing). I hypothesize that potentially less attractive hybrids may circumvent female choice by adopting satellite behaviour. Although mating tactics are related to body size, genetic status may play a role. I show that pure Eastern males almost always engage in calling, while hybrids adopt a satellite tactic. An absence of assortative mating, despite evidence of female preference, suggests successful satellite interception possibly facilitating introgression.

Factores explicativos de las actitudes hacia el castigo juvenil. Evidencias de un diseño factorial

El rol desempeñado por la opinión pública en el desarrollo de la política criminal actual justifica el incremento de investigaciones destinadas a evaluar las actitudes de los ciudadanos hacia el castigo. No obstante, los avances en este ámbito han sido limitados debido a la utilización de rudimentarios instrumentos de medida. Por ello, el presente trabajo tiene como propósito explorar el efecto que generan en la opinión ciudadana ciertas variables referidas al hecho delictivo y al infractor, precisando su contribución relativa y la interacción existente entre ellas. Para satisfacer este objetivo se recurrió a un diseño factorial de la encuesta, creando una población de 256 casos-escenario fruto de la combinación de cuatro factores: la edad del joven, su historial delictivo, el grado de implicación en el hecho y el tipo de delito cometido. Los mismos fueron distribuidos en grupos de ocho casos ordenados aleatoriamente y fueron suministrados a 32 sujetos. Posteriormente se aplicaron análisis de regresión logística binaria. Los resultados obtenidos revelan que la naturaleza violenta de los hechos, la implicación activa de los jóvenes y el historial delictivo son predictores importantes de las condenas punitivas. Sin embargo la edad, una variable fundamental en la configuración de la justicia juvenil, no resulta significativa. De este modo, el trabajo muestra el potencial explicativo de este conjunto de factores y debate sus implicaciones teóricas y metodológicas para la investigación futura en este terreno.

Exploration of the Kuiper Belt by High-Precision Photometric Stellar Occultations: First Results

We report here the first detection of hectometer-size objects by the method of serendipitous stellar occultation. This method consists of recording the diffraction shadow created when an object crosses the observer's line of sight and occults the disk of a background star. One of our detections is most consistent with an object between Saturn and Uranus. The two other diffraction patterns detected are caused by Kuiper Belt objects beyond 100 AU from the Sun and hence are the farthest known objects in the solar system. These detections show that the Kuiper Belt is much more extended than previously believed and that the outer part of the disk could be composed of smaller objects than the inner part. This gives critical clues to understanding the problem of the formation of the outer planets of the solar system.

Teacher attitudes and best practices with ICT faculty Adult Continuing Education in Andalusia

The present paper reports the results of a study aiming to describe the attitudes of teachers in adult continuous education in the Autonomous Community of Andalusia (Spain) towards the use and integration of information and communication technologies (ITC) in the educational centres they work in, while identifying those factors that favour the development of good practice. It is a mixed methods descriptive research, and information collection techniques include a questionnaire and in-depth interviews. A total number of 172 teachers were surveyed, as well as 18 head teachers and coordinators, in adult education. For questionnaire validation the expert judgment technique was used, as they were selected by the «expert competence coefficient» or «K coefficient» procedure. To improve its psychometric properties, construct validity was determined by means of Varimax factor analysis and maximum likelihood extraction (two factors were extracted). Confidence was set by Cronbach's alpha (0.88). The interview guide was also validated by this group of experts. Results point out, on one hand, that teachers hold positive attitudes towards ICT regarding both ICT's role in professional development and their ease of use and access. On the other hand, among the most important factors for ICT-supported good educational practices lies in ICT's capacity to favour personalized work.

The prevalence of nonadherence in difficult asthma

Rationale: With the advent of new and expensive therapies for severe refractory asthma, targeting the appropriate patients is important. An important issue is identifying nonadherence with current therapies. The extent of nonadherence in a population with difficult asthma has not been previously reported.

Objectives: To examine the prevalence of nonadherence to corticosteroid medication in a population with difficult asthma referred to a Specialist Clinic and to examine the relationship of poor adherence to asthma outcome.

Methods: General practitioner prescription refill records for the previous 6 months for inhaled combination therapy and short-acting ß-agonists were compared with initial prescriptions and expressed as a percentage. Blood plasma prednisolone and cortisol assay levels were used to examine the utility of these measures in assessing adherence to oral prednisolone. Patient demographics, hospital admissions, lung function, oral prednisolone courses, and quality of life data were analyzed to indentify the variables associated with reduced medication adherence.

Measurements and Main Results: A total of 182 patients were assessed. Sixty-three patients (35%) filled 50% or fewer inhaled medication prescriptions; 88% admitted poor adherence with inhaled therapy after initial denial. Twenty-one percent of patients filled more than 100% of presciptions, and 45% of subjects filled between 51 and 100% of prescriptions. Twenty-three of 51 patients (45%) prescribed oral steroids were found to be nonadherent.

Conclusions: A significant proportion of patients with difficult-to-control asthma remained nonadherent to corticosteroid therapy. Objective surrogate and direct measures of adherence should be performed as part of a difficult asthma assessment and are important before prescibing expensive novel biological therapies.

Quality factor of E-plane periodically loaded waveguide resonators and filter applications

The quality factor of microwave resonators miniaturised by virtue of periodic loading is assessed. Five X-band resonators in E-plane technology with different miniaturisation factors have been designed to resonate at approximately the same frequency. The loaded quality factor is extracted from the fractional bandwidth and subsequently employed to estimate the unloaded quality factor. The study reveals that the unloaded quality factor drops approximately linearly with the miniaturisation. Subsequently design guidelines for E-plane filters with periodically loaded resonators are provided by means of an example involving a fifth-order filter. Full-wave simulated and experimental results are presented to validate the study.

A 330-360 GHz spectral survey of G34.3+0.15 - III. The outer halo

We have undertaken a 330-360 GHz molecular line survey of the halo gas surrounding the hot core associated with G34.26+0.15. In contrast to our molecular line survey of the hot core itself, where 338 lines from at least 38 species were detected, only 18 lines from 9 species were detected in the halo. The lines are mainly single transitions of simple di atomic and triatomic molecules. Lower limits to their column densities have been evaluated by an LTE method. In the case of methanol, where four transitions were detected, the rotation temperature and column density have been evaluated by the rotation diagram technique. We have modified the previous depth-dependent chemical model developed in Paper II to calculate the column densities observed along a general line of sight drawn through the model cloud. The model is also extended to produce beam-averaged column densities for better comparison with those observed. We compare the model column densities with those observed and make recommendations for future depth-dependent chemical modelling of hot cores.

Surgical optimisation and characterisation of a minimally invasive aortic banding procedure to induce cardiac hypertrophy in mice

Left ventricular pressure overload in response to aortic banding is an invaluable model for studying progression of cardiac hypertrophy and transition to heart failure. Traditional aortic banding has recently been superceded by minimally invasive transverse aortic banding (MTAB) which does not require ventilation so is less technically challenging. Although the MTAB procedure is superior, few laboratories have documented success and minimal information on the model is available. The aim of this study was to optimise conditions for MTAB and to characterise the development and progression of cardiac hypertrophy. Isofluorane proved the most suitable anaesthetic for MTAB surgery in mice and one week after surgery MTAB animals showed significant increases in systolic blood pressure (110±6 v's 78±3(mmHg), MTAB v's sham, n=7,p

A Corpus-Based Approach to Speech Enhancement from Nonstationary Noise

Temporal dynamics and speaker characteristics are two important features of speech that distinguish speech from noise. In this paper, we propose a method to maximally extract these two features of speech for speech enhancement. We demonstrate that this can reduce the requirement for prior information about the noise, which can be difficult to estimate for fast-varying noise. Given noisy speech, the new approach estimates clean speech by recognizing long segments of the clean speech as whole units. In the recognition, clean speech sentences, taken from a speech corpus, are used as examples. Matching segments are identified between the noisy sentence and the corpus sentences. The estimate is formed by using the longest matching segments found in the corpus sentences. Longer speech segments as whole units contain more distinct dynamics and richer speaker characteristics, and can be identified more accurately from noise than shorter speech segments. Therefore, estimation based on the longest recognized segments increases the noise immunity and hence the estimation accuracy. The new approach consists of a statistical model to represent up to sentence-long temporal dynamics in the corpus speech, and an algorithm to identify the longest matching segments between the noisy sentence and the corpus sentences. The algorithm is made more robust to noise uncertainty by introducing missing-feature based noise compensation into the corpus sentences. Experiments have been conducted on the TIMIT database for speech enhancement from various types of nonstationary noise including song, music, and crosstalk speech. The new approach has shown improved performance over conventional enhancement algorithms in both objective and subjective evaluations.