(63)Cu NQR Evidence for Spatial Variation of Hole Concentration in La(2-x)Sr(x)CuO(4)

We report experimental evidence for the spatial variation of hole concentration x_(hole) in the high Tc superconductor La(2-x)Sr(x)CuO(4) (0.04 <= x <= 0.16) by using (63)Cu NQR for (63)Cu isotope enriched samples. We demonstrate that the extent of the spatial variation of the local hole concentration D(x)_(hole) is reflected on (63)1/T1 and deduce the temperature dependence. D(x)_(hole) increases below 500 - 600K, and reaches values as large as D(x)_(hole)/x ~ 0.5 below ~ 150K. We estimate the length scale of the spatial variation in x_(hole) to be R_(hole) >~ 3nm from analysis of the NQR spectrum.Comment: Accepted for publication in Physical Review Letter

Developing physical capability standards that are predictive of success on special forces selection courses

Free to read This study aimed to develop minimum standards for physical capability assessments (vertical jump, sit and reach, push-ups, seven-stage sit-ups, heaves, agility, 20-m shuttle run, loaded 5-km pack march, and 400-m swim) that candidates must pass before they can commence Australian Army Special Forces (SF) selection courses. Soldiers (Part A: n = 104; Part B: n = 92) completed the physical capability assessments before commencing a SF selection course. At the beginning of these selection courses, participants attempted two barrier assessments (3.2-km battle run and 20-km march). Statistical analysis revealed several physical capability assessments were associated with performance on the barrier assessments and selection course outcome (Part A); however, these statistical models were unable to correctly classify all candidates as likely to pass or fail the selection course. Alternatively, manual analysis identified a combination of physical capability standards that correctly classified 14% to 18% of candidates likely to fail, without excluding any candidates able to pass (Part A). The standards were applied and refined through Part B and included completing the 5-km pack march in ≤45:45 minutes : seconds, achieving ≥level five on the sit-up test, or completing ≥66 push-ups. Implementation of these standards may reduce attrition rates and enhance the efficiency of the SF recruitment process

The Genome and Methylome of a Subsocial Small Carpenter Bee, Ceratina calcarata

Understanding the evolution of animal societies, considered to be a major transition in evolution, is a key topic in evolutionary biology. Recently, new gateways for understanding social evolution have opened up due to advances in genomics, allowing for unprecedented opportunities in studying social behavior on a molecular level. In particular, highly eusocial insect species (caste-containing societies with nonreproductives that care for siblings) have taken center stage in studies of the molecular evolution of sociality. Despite advances in genomic studies of both solitary and eusocial insects, we still lack genomic resources for early insect societies. To study the genetic basis of social traits requires comparison of genomes from a diversity of organisms ranging from solitary to complex social forms. Here we present the genome of a subsocial bee, Ceratina calcarata. This study begins to address the types of genomic changes associated with the earliest origins of simple sociality using the small carpenter bee. Genes associated with lipid transport and DNA recombination have undergone positive selection in C. calcarata relative to other bee lineages. Furthermore, we provide the first methylome of a noneusocial bee. Ceratina calcarata contains the complete enzymatic toolkit for DNA methylation. As in the honey bee and many other holometabolous insects, DNA methylation is targeted to exons. The addition of this genome allows for new lines of research into the genetic and epigenetic precursors to complex social behaviors

Pose, posture, formation and contortion in kinematic systems

The concepts of pose, posture, formation and contortion are defined for serial, parallel and hybrid kinematic systems. Workspace and jointspace structure is examined in terms of these concepts. The inter-relationships of pose, posture, formation and contortion are explored for a range of robot workspace and jointspace types

Incidence of bullying and victimisation among adolescents in New Zealand

It has been established that bullying and victimisation have negative outcomes for those involved. However, this problem has received little research attention in New Zealand samples, particularly with longitudinal designs. The incidence of four types bullying was assessed in a large adolescent New Zealand sample including; traditional bullying inside the school, bullying outside the school, bullying via text message and bullying via the internet. The same categorisation of victimisation was also assessed. The overall rates of bullying and victimisation appeared elevated relative to international samples but traditional school-based bullying was more frequent than text or internet bullying. No gender differences were found. Differences for ethnic group differences were found only for specific types of bullying with Māori students reporting more traditional school and text bullying, and more text-based victimisation than other ethnic groups

Collisions with ice-volatile objects: Geological implications

The collision of the Earth with extra-terrestrial ice-volatile bodies is proposed as a mechanism to produce rapid changes in the geologic record. These bodies would be analogs of the ice satellites found for the Jovian planets and suspected for comets and certain low density bodies in the Asteroid belt. Five generic end-members are postulated: (1) water ice; (2) dry ice: carbon-carbon dioxide rich, (3) oceanic (chloride) ice; (4) sulfur-rich ice; (5) ammonia hydrate-rich ice; and (6) clathrate: methane-rich ice. Due to the volatile nature of these bodies, evidence for their impact with the Earth would be subtle and probably best reflected geochemically or in the fossil record. Actual boloids impacting the Earth may have a variable composition, generally some admixture with water ice. However for discussion purposes, only the effects of a dominant component will be treated. The general geological effects of such collisions, as a function of the dominant component would be: (1) rapid sea level rise unrelated to deglaciation, (2) decreased oceanic pH and rapid climatic warming or deglaciation; (3) increased paleosalinities; (4) increased acid rain; (5) increased oceanic pH and rapid carbonate deposition; and (6) rapid climatic warming or deglaciation

Effects of vertical vibration on hopper flows of granular material

The discharge of granular material from a hopper subject to vertical sinusoidal oscillations was investigated using experiments and discrete element computer simulations. With the hopper exit closed, side-wall convection cells are observed, oriented such that particles move up along the inclined walls of the hopper and down at the center line. The convection cells are a result of the granular bed dilation during free fall and the subsequent interaction with the hopper walls. The mass discharge rate for a vibrating hopper scaled by the discharge rate without vibration reaches a maximum value at a dimensionless velocity amplitude just greater than 1. Further increases in the velocity decrease the discharge rate. The decrease occurs due to a decrease in the bulk density of the discharging material when vibration is applied

The Impact of Source Credibility on Scientific Skepticism of Climate Change and Genetically Modified Foods: Findings from the General Social Survey

The current study explores the role of source credibility in continued public concern over climate change and GM foods, suggesting that this skepticism is more likely driven by perceptions of scientists as knowledgeable, trustworthy, and unbiased- the three primary constructs of source credibility (McCrosky & Teven, 1999; Teven 2008). We analyze data from the 2006 GSS survey to empirically measure the components of source credibility, comparing their influence and relationship to political ideology in perceptions of CC impacts and willingness to consume GM foods