Multiple Signaling Functions Of Song In A Polymorphic Species With Alternative Reproductive Strategies

Vocal traits can be sexually selected to reflect male quality, but may also evolve to serve additional signaling functions. We used a long-term dataset to examine the signaling potential of song in dimorphic white-throated sparrows (Zonotrichia albicollis). We investigated whether song conveys multifaceted information about the vocalizing individual, including fitness, species identity, individual identity, and morph. We also evaluated whether song traits correlate differently with fitness in the two morphs, as the more promiscuous strategy of white, relative to tan, morph males might impose stronger sexual selection. Males with high song rates achieved higher lifetime reproductive success, and this pattern was driven by white morph males. In addition, males that sang songs with many notes survived longer, but this pattern was less robust. Thus, song traits reflect differences in fitness and may more strongly affect fitness in the white morph. Song frequency was unrelated to fitness, body size, or morph, but was individual specific and could signal individual identity. Songs of the two morphs displayed similar frequency ratios and bandwidths. However, tan morph males sang songs with longer first notes, fewer notes, and higher variability. Thus, song could be used in morph discrimination. Variation in frequency ratios between notes was low and could function in conspecific recognition, but pitch change dynamics did differ between four different song types observed. Our results support a multiple messages model for white-throated sparrow song, in which different song traits communicate discrete information about the vocalizing individual

Actuarial Senescence In A Dimorphic Bird: Different Rates Of Ageing In Morphs With Discrete Reproductive Strategies

It is often hypothesized that intra-sexual competition accelerates actuarial senescence, or the increase in mortality rates with age. However, an alternative hypothesis is that parental investment is more important to determining senescence rates. We used a unique model system, the white-throated sparrow (Zonotrichia albicollis), to study variation in actuarial senescence. In this species, genetically determined morphs display discrete mating strategies and disassortative pairing, providing an excellent opportunity to test the predictions of the above hypotheses. Compared to tan-striped males, white-striped males are more polygynous and aggressive, and less parental. Tan-striped females receive less parental support, and invest more into parental care than white-striped females, which are also more aggressive. Thus, higher senescence rates in males and white-striped birds would support the intra-sexual competition hypothesis, whereas higher senescence rates in females and tan-striped birds would support the parental investment hypothesis. White-striped males showed the lowest rate of actuarial senescence. Tan-striped females had the highest senescence rate, and tan-striped males and white-striped females showed intermediate, relatively equal rates. Thus, results were inconsistent with sexual selection and competitive strategies increasing senescence rates, and instead indicate that senescence may be accelerated by female-biased parental care, and lessened by sharing of parental duties

Athena MIMOS II Mossbauer spectrometer investigation

Mössbauer spectroscopy is a powerful tool for quantitative mineralogical analysis of Fe-bearing materials. The miniature Mössbauer spectrometer MIMOS II is a component of the Athena science payload launched to Mars in 2003 on both Mars Exploration Rover missions. The instrument has two major components: (1) a rover-based electronics board that contains power supplies, a dedicated central processing unit, memory, and associated support electronics and (2) a sensor head that is mounted at the end of the instrument deployment device (IDD) for placement of the instrument in physical contact with soil and rock. The velocity transducer operates at a nominal frequency of 25 Hz and is equipped with two 57Co/Rh Mössbauer sources. The reference source (5 mCi landed intensity), reference target (alpha-Fe2O3 plus alpha-Fe0), and PIN-diode detector are configured in transmission geometry and are internal to the instrument and used for its calibration. The analysis Mössbauer source (150 mCi landed intensity) irradiates Martian surface materials with a beam diameter of 1.4 cm. The backscatter radiation is measured by four PIN-diode detectors. Physical contact with surface materials is sensed with a switch-activated contact plate. The contact plate and reference target are instrumented with temperature sensors. Assuming 18% Fe for Martian surface materials, experiment time is 6–12 hours during the night for quality spectra (i.e., good counting statistics); 1–2 hours is sufficient to identify and quantify the most abundant Fe-bearing phases. Data stored internal to the instrument for selectable return to Earth include Mössbauer and pulse-height analysis spectra (512 and 256 channels, respectively) for each of the five detectors in up to 13 temperature intervals (65 Mössbauer spectra), engineering data for the velocity transducer, and temperature measurements. The total data volume is 150 kB. The mass and power consumption are 500 g (400 g for the sensor head) and 2 W, respectively. The scientific measurement objectives of the Mössbauer investigation are to obtain for rock, soil, and dust (1) the mineralogical identification of iron-bearing phases (e.g., oxides, silicates, sulfides, sulfates, and carbonates), (2) the quantitative measurement of the distribution of iron among these iron-bearing phases (e.g., the relative proportions of iron in olivine, pyroxenes, ilmenite, and magnetite in a basalt), (3) the quantitative measurement of the distribution of iron among its oxidation states (e.g., Fe2+, Fe3+, and Fe6+), and (4) the characterization of the size distribution of magnetic particles. Special geologic targets of the Mössbauer investigation are dust collected by the Athena magnets and interior rock and soil surfaces exposed by the Athena Rock Abrasion Tool and by trenching with rover wheels

Decommissioning normal: COVID‐19 as a disruptor of school norms for young people with learning disabilities

To slow the spread of COVID-19, on 20 March 2020, nurseries, schools and colleges across England were closed to all learners, apart from those who were children of key workers or were considered “vulnerable.” As young people with learning disabilities, families, professionals and schools become acquainted with the Erfahrung of the new horizon brought about by COVID-19, the negativity of altered social inclusion is becoming the “new normal.” Capturing this transitory moment in time, this paper reflexively analyses the curiously productive variables of altered ecological pathways to social inclusion for people with learning disabilities. Taking a hermeneutic stance, this paper draws on Gadamer's construction of the nature of new experiences. Focussed on the experience of social inclusion during the COVID-19 pandemic, semi-structured interviews were conducted with six key stakeholders. As the phenomenon in question was new, an inductive approach to thematic analysis was applied. The critical tenet of this paper is that the Erfahrung of COVID-19 has created the conditions for a “new normal” which have afforded children with learning disabilities altered opportunities for social inclusion, whether that be through increased power/agency for them and their families and/or new modes of connectedness leading to enhanced relationships. Whilst the impact of COVID-19 has been a negative one for many aspects of society, application of Simplican and Gadamer's theories on social inclusion and the nature of new experiences has permitted the surfacing of new possibilities for the social inclusion of children with learning disabilities.N/

Microsatellite mutations and inferences about human demography.

Microsatellites have been widely used as tools for population studies. However, inference about population processes relies on the specification of mutation parameters that are largely unknown and likely to differ across loci. Here, we use data on somatic mutations to investigate the mutation process at 14 tetranucleotide repeats and carry out an advanced multilocus analysis of different demographic scenarios on worldwide population samples. We use a method based on less restrictive assumptions about the mutation process, which is more powerful to detect departures from the null hypothesis of constant population size than other methods previously applied to similar data sets. We detect a signal of population expansion in all samples examined, except for one African sample. As part of this analysis, we identify an "anomalous" locus whose extreme pattern of variation cannot be explained by variability in mutation size. Exaggerated mutation rate is proposed as a possible cause for its unusual variation pattern. We evaluate the effect of using it to infer population histories and show that inferences about demographic histories are markedly affected by its inclusion. In fact, exclusion of the anomalous locus reduces interlocus variability of statistics summarizing population variation and strengthens the evidence in favor of demographic growth

Removal of plutonium from uranium by molten metal extraction

The extraction of plutonium from molten uranium with immiscible molten metals, silver, lanthanum and cerium, has been investigated. A facility is described in which these experiments on uranium containing 0. 2% plutonium were conducted safely. The distribution coefficients and efficiency of removal from uranium were determined for silver and lanthanum at several temperatures in the range 1175-1375° C and for cerium at 1225o C.</p

Spin States of Divalent Iron in Anhydrohemoglobin

Mössbauer spectra of anhydrohemoglobin establish the existence of two ferrous iron spin states in anhydrohemoglobin. Magnetic susceptibility measurements show that anhydrohemoglobin is paramagnetic and has an effective magnetic moment per iron atom of 3.5 ± 0.1 μ(B) at low temperatures. In conjunction with the susceptibility results, the Mössbauer spectra indicate that the iron in anhydrohemoglobin is distributed between high and low spin states in roughly equal amounts