Captive Rearing Experiments Confirm Song Development without Learning in a Tracheophone Suboscine Bird

The origin of vocal learning in animals has long been the subject of debate, but progress has been limited by uncertainty regarding the distribution of learning mechanisms across the tree of life, even for model systems such as birdsong. In particular, the importance of learning is well known in oscine songbirds, but disputed in suboscines. Members of this diverse group (∼1150 species) are generally assumed not to learn their songs, but empirical evidence is scarce, with previous studies restricted to the bronchophone (non-tracheophone) clade. Here, we conduct the first experimental study of song development in a tracheophone suboscine bird by rearing spotted antbird (Hylophylax naevioides) chicks in soundproofed aviaries. Individuals were raised either in silence with no tutor or exposed to standardized playback of a heterospecific tutor. All individuals surviving to maturity took a minimum of 79 days to produce a crystallized version of adult song, which in all cases was indistinguishable from wild song types of their own species. These first insights into song development in tracheophone suboscines suggest that adult songs are innate rather than learnt. Given that empirical evidence for song learning in suboscines is restricted to polygamous and lek-mating species, whereas tracheophone suboscines are mainly monogamous with long-term social bonds, our results are consistent with the view that sexual selection promotes song learning in birds

Spin- and angle-resolved photoemission studies of the electronic structure of Si(110)"16x2" surfaces

The electronic structure of Si(110)"16 x 2" double-domain, single-domain and 1 x 1 surfaces have been investigated using spin- and angle-resolved photoemission at sample temperatures of 77 K and 300 K. Angle-resolved photoemission was conducted using horizontally- and vertically-polarised 60 eV and 80 eV photons. Band-dispersion maps revealed four surface states ($S_1$ to $S_4$) which were assigned to silicon dangling bonds on the basis of measured binding energies and photoemission intensity changes between horizontal and vertical light polarisations. Three surface states ($S_1$, $S_2$ and $S_4$), observed in the Si(110)"16 x 2" reconstruction, were assigned to Si adatoms and Si atoms present at the edges of the corrugated terrace structure. Only one of the four surface states, $S_3$, was observed in both the Si(110)"16 x 2" and 1 x 1 band maps and consequently attributed to the pervasive Si zigzag chains that are components of both the Si(110)"16 x 2" and 1 x 1 surfaces. A state in the bulk-band region was attributed to an in-plane bond. All data were consistent with the adatom-buckling model of the Si(110)"16 x 2" surface. Whilst room temperature measurements of $P_y$ and $P_z$ were statistically compatible with zero, $P_x$ measurements of the enantiomorphic A-type and B-type Si(110)"16 x 2" surfaces gave small average polarisations of around 1.5\% that were opposite in sign. Further measurements at 77 K on A-type Si(110)"16 x 2" surface gave a smaller value of +0.3\%. An upper limit of $\sim1\%$ may thus be taken for the longitudinal polarisation.Comment: Main paper: 12 pages and 11 figures. Supplemental information: 5 pages and 2 figure

Engineering swollen cubosomes using cholesterol and anionic lipids

Dispersions of non-lamellar lipid membrane assemblies are gaining increasing interest for drug delivery and protein therapeutic application. A key bottleneck has been the lack of rational design rules for these systems linking different lipid species and conditions to defined lattice parameters and structures. We have developed robust methods to form cubosomes (nanoparticles with a porous internal structure) with water channel diameters of up to 171 Å which are over 4 times larger than archetypal cubosome structures. The water channel diameter can be tuned via the incorporation of cholesterol and the charged lipids DOPA, DOPG or DOPS. We have found that large molecules can be incorporated into the porous cubosome structure and these molecules can interact with the internal cubosome membrane. This offers huge potential for accessible encapsulation and protection of biomolecules, and development of confined interfacial reaction environments

Ultrathin epitaxial Fe films in vicinal GaAs(001): A study by spin-resolved photoelectron spectroscopy

Thin epitaxial Fe films have been grown on vicinal GaAs(001) substrates and their remanent magnetic properties and the degree of substrate atom diffusion investigated using synchrotron-based photoelectron spectroscopy. The vicinal Fe films, though exhibiting greater As diffusion than their singular homologues, displayed better film quality both from the structural and the magnetic points of view. The spin-resolved valence spectra of the vicinal films resemble those for crystalline bulk Fe at lower film thicknesses than for singular films

Song evolution, speciation, and vocal learning in passerine birds

Phenotypic divergence can promote reproductive isolation and speciation, suggesting a possible link between rates of phenotypic evolution and the tempo of speciation at multiple evolutionary scales. To date, most macroevolutionary studies of diversification have focused on morphological traits, whereas behavioral traits─including vocal signals─are rarely considered. Thus, although behavioral traits often mediate mate choice and gene flow, we have a limited understanding of how behavioral evolution contributes to diversification. Furthermore, the developmental mode by which behavioral traits are acquired may affect rates of behavioral evolution, although this hypothesis is seldom tested in a phylogenetic framework. Here, we examine evidence for rate shifts in vocal evolution and speciation across two major radiations of codistributed passerines: one oscine clade with learned songs (Thraupidae) and one suboscine clade with innate songs (Furnariidae). We find that evolutionary bursts in rates of speciation and song evolution are coincident in both thraupids and furnariids. Further, overall rates of vocal evolution are higher among taxa with learned rather than innate songs. Taken together, these findings suggest an association between macroevolutionary bursts in speciation and vocal evolution, and that the tempo of behavioral evolution can be influenced by variation in developmental modes among lineages

Microfluidic generation of droplet interface bilayer networks incorporating real-time size sorting in linear and non-linear configurations

In this study, a novel droplet based microfluidic method for the generation of different sized droplet interface bilayers is reported. A microfluidic platform was designed, which allows the generation and packing of picoliter lipid coated water droplets. Droplets were generated by hydrodynamic focusing coupled with selective transport along grooves according to their size. A trapping structure at the end of the groove and a fine control of the flow pressures allowed for the droplets to be successfully trapped and aligned on demand. This technology facilitates the fine control of droplet size production as well as the generation of extended networks from a variety of lipids including 1,2-diphytanoyl-sn-glycero-3-phosphocholine and 1,2-dioleoyl-sn-glycero-3-phosphocholine in linear and non-linear configurations, which is vital to the application of Droplet Interface Bilayers to biological network construction on-chip

Tuberculous meningitis in children: reducing the burden of death and disability

Tuberculous meningitis disproportionately affects young children. As the most devastating form of tuberculosis, it is associated with unacceptably high rates of mortality and morbidity even if treated. Challenging to diagnose and treat, tuberculous meningitis commonly causes long-term neurodisability in those who do survive. There remains an urgent need for strengthened surveillance, improved rapid diagnostics technology, optimised anti-tuberculosis drug therapy, investigation of new host-directed therapy, and further research on long-term functional and neurodevelopmental outcomes to allow targeted intervention. This review focuses on the neglected field of paediatric tuberculous meningitis and bridges current clinical gaps with research questions to improve outcomes from this crippling disease

Measuring Health and Broader Well-Being Benefits in the Context of Opiate Dependence: The Psychometric Performance of the ICECAP-A and the EQ-5D-5L

BACKGROUND: Measuring outcomes in economic evaluations of social care interventions is challenging because both health and well-being benefits are evident. The ICEpop CAPability instrument for adults (ICECAP-A) and the five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) are measures potentially suitable for the economic evaluation of treatments for substance use disorders. Evidence for their validity in this context is, however, lacking. OBJECTIVES: To assess the construct validity of the ICECAP-A and the EQ-5D-5L in terms of convergent and discriminative validity and sensitivity to change on the basis of standard clinical measures (Clinical Outcomes in Routine Evaluation-Outcome Measure, Treatment Outcomes Profile, Interpersonal Support Evaluation List, Leeds Dependence Questionnaire, and Social Satisfaction Questionnaire). METHODS: A secondary analysis of pilot trial data for heroin users in opiate substitution treatment was conducted. Baseline convergence with clinical measures was assessed using the Pearson correlation coefficient. Discriminative validity was assessed using one-way analysis of variance and stepwise regressions. Sensitivity to changes in clinical indicators was assessed at 3 and 12 months using the standardized response mean statistic and parametric and nonparametric testing. RESULTS: Both measures had the same level of construct validity, except for clinical indicators of well-being, for which the ICECAP-A performed better. The ICECAP-A was sensitive to changes in both health and well-being indicators. The EQ-5D-5L had lower levels of sensitivity to change, and a ceiling effect (27%), particularly evident in the dimensions of self-care (89%), mobility (75%), and usual activities (72%). CONCLUSIONS: The findings support the construct validity of both measures, but the ICECAP-A gives more attention to broader impacts and is more sensitive to change. The ICECAP-A shows promise in evaluating treatments for substance use disorders for which recovery is the desired outcome