Hawaii's Pelagic Fisheries

Hawaii's diverse pelagic fisheries supply the bulk of the State's total catch. The largest Hawaii fishery is the recently expanded longline fishery, which now lands about 4,400 metric tons (t) of broadbill swordfish, Xiphias gladius; 1,500 t of bigeye tuna, Thunnus obesus, and 3,000 t of other pelagic species annually. The increased catch of these other species has raised concerns regarding the continued availability of yellowfin tuna, T. albacares; blue marlin, Makaira mazara; and mahimahi, Coryphaena hippurus, in the small-vessel troll and handline fisheries which target those species. Analysis of catch per unit effort (CPUE) statistics from Hawaii's fisheries did not provide strong evidence of recent declines in availability related to local fishery expansion. A more influential factor was variation in Pacific-wide CPUE, representing overall population abundance and catchability. Exogenous factors, including Pacific-wide fishing pressure, may overwhelm the influence of local fishing pressure on fish availability

Three problems of interdisciplinarity

Interdisciplinarity is widely promulgated as beneficial to science and society. However, there are three quite serious problems which can limit the success of any interdisciplinary research collaboration. The first problem is expertise (it takes years of effort to cultivate a deep knowledge of even one discipline). The second problem is comprehensibility (experts in different disciplines do not reliably understand each other). The third problem is service (in a given interdisciplinary endeavour, it often occurs that one discipline benefits and the other discipline does not benefit). This essay is an elaboration of these three problems. Parallels are drawn between translation between languages and translation between disciplines

Reciprocity and reputation: a review of direct and indirect social information gathering

Direct reciprocity, indirect reciprocity, and reputation are important interrelated topics in the evolution of sociality. This non-mathematical review is a summary of each. Direct reciprocity (the positive kind) has a straightforward structure (e.g., “A rewards B, then B rewards A”) but the allocation might differ from the process that enabled it (e.g., whether it is true reciprocity or some form of mutualism). Indirect reciprocity (the positive kind) occurs when person (B) is rewarded by a third party (A) after doing a good deed towards somebody else (C) — with the structure “A observes B help C, therefore A helps B.” Here too, the allocation differs from the process: if there is underlying cognition, then indirect reciprocity is based on some ability to keep track of the reputations of others (to remember that “B helped C”). Reputation is a kind of social impression based on typicality, derived from three channels of experience (direct encounters, bystander observation, and gossip). Although non-human animals cannot gossip verbally, they can eavesdrop on third parties and learn vicariously. This paper ends with a proposal to investigate the topic of social expertise as a model for understanding how animals understand and utilise observed information within their social groups

Measuring the mode volume of plasmonic nanocavities using coupled optical emitters

Metallic optical systems can confine light to deep sub-wavelength dimensions, but verifying the level of confinement at these length scales typically requires specialized techniques and equipment for probing the near-field of the structure. We experimentally measured the confinement of a metal-based optical cavity by using the cavity modes themselves as a sensitive probe of the cavity characteristics. By perturbing the cavity modes with conformal dielectric layers of sub-nm thickness using atomic layer deposition, we find the exponential decay length of the modes to be less than 5% of the free-space wavelength (\lambda) and the mode volume to be of order \lambda^3/1000. These results provide experimental confirmation of the deep sub-wavelength confinement capabilities of metal-based optical cavities.Comment: 11 pages, 4 figure

The Integration of Positron Emission Tomography With Magnetic Resonance Imaging

A number of laboratories and companies are currently exploring the development of integrated imaging systems for magnetic resonance imaging (MRI) and positron emission tomography (PET). Scanners for both preclinical and human research applications are being pursued. In contrast to the widely distributed and now quite mature PET/computed tomography technology, most PET/MRI designs allow for simultaneous rather than sequential acquisition of PET and MRI data. While this offers the possibility of novel imaging strategies, it also creates considerable challenges for acquiring artifact-free images from both modalities. This paper discusses the motivation for developing combined PET/MRI technology, outlines the obstacles in realizing such an integrated instrument, and presents recent progress in the development of both the instrumentation and of novel imaging agents for combined PET/MRI studies. The performance of the first-generation PET/MRI systems is described. Finally, a range of possible biomedical applications for PET/MRI are outlined

A supersonic crowdion in mica: Ultradiscrete kinks with energy between 40^{40}K recoil and transmission sputtering

In this chapter we analyze in detail the behaviour and properties of the kinks found in an one dimensional model for the close packed rows of potassium ions in mica muscovite. The model includes realistic potentials obtained from the physics of the problem, ion bombardment experiments and molecular dynamics fitted to experiments. These kinks are supersonic and have an unique velocity and energy. They are ultradiscrete involving the translation of an interstitial ion, which is the reason they are called 'crowdions'. Their energy is below the most probable source of energy, the decay of the $^{40}$K isotope and above the energy needed to eject an atom from the mineral, a phenomenon that has been observed experimentallyComment: 28 pages, 15 figure

An observational study of race and gender homophily in nursery children

Homophily (the preference for similar others) is a commonplace feature of social life. In this observational study, we recorded association patterns (based on spatial proximity or verbal or physical interaction) among children aged 3-4 years old during unstructured playtime in a university nursery. A basic social network analysis and a quadratic assignment procedure revealed gender and race to be significant predictive factors of social interaction, with girls seemingly displaying more racial homophily than boys. Age, parent occupation and number of siblings did not predict interaction patterns

Age and gender differences in smiling and laughter: the power asymmetry hypothesis retested

The power asymmetry hypothesis puts smiling and laughter into the context of relationships, in particular the inequalities between people within interactions. As a means of appeasement, junior members are expected to display higher than usual rates of deliberately affiliative gestures towards senior (dominant) counterparts (compared to rates towards non-senior counterparts). Previous researchers found these effects for males but not females. In a new observational study, we compared rates of smiling and laughter within male-male and female-female dyads in bars and restaurants in London UK. Age was used as a proxy for social status (older presumed dominant). Individuals within these focal dyads were classified in two ways: sex, and estimated age (binary category using age thirty-five as a dividing line). Instances of smiling and laughter were classified as either deliberate or spontaneous. In total, 150 dyads were observed. Some power asymmetry effects were found for male-male but not female-female dyads. Younger males displayed higher rates of deliberate laughs towards older males and older males displayed more deliberate smiles towards other older males. Females displayed more affiliative behaviors when interacting with peers compared to older counterparts. These results partly replicate earlier studies and provide support for power symmetry effects amongst males only