Induced pseudoscalar coupling of the proton weak interaction

The induced pseudoscalar coupling $g_p$ is the least well known of the weak coupling constants of the proton's charged--current interaction. Its size is dictated by chiral symmetry arguments, and its measurement represents an important test of quantum chromodynamics at low energies. During the past decade a large body of new data relevant to the coupling $g_p$ has been accumulated. This data includes measurements of radiative and non radiative muon capture on targets ranging from hydrogen and few--nucleon systems to complex nuclei. Herein the authors review the theoretical underpinnings of $g_p$, the experimental studies of $g_p$, and the procedures and uncertainties in extracting the coupling from data. Current puzzles are highlighted and future opportunities are discussed.Comment: 58 pages, Latex, Revtex4, prepared for Reviews of Modern Physic

Sexual Plasticity and Self-Fertilization in the Sea Anemone Aiptasia diaphana

Traits that influence reproductive success and contribute to reproductive isolation in animal and plant populations are a central focus of evolutionary biology. In the present study we used an experimental approach to demonstrate the occurrence of environmental effects on sexual and asexual reproduction, and provide evidence for sexual plasticity and inter-clonal fertilization in laboratory-cultured lines of the sea anemone Aiptasia diaphana. We showed that in A. diaphana, both asexual reproduction by pedal laceration, and sexual reproduction have seasonal components. The rate of pedal laceration was ten-fold higher under summer photoperiod and water temperature conditions than under winter conditions. The onset of gametogenesis coincided with the rising water temperatures occurring in spring, and spawning occurred under parameters that emulated summer photoperiod and temperature conditions. In addition, we showed that under laboratory conditions, asexually produced clones derived from a single founder individual exhibit sexual plasticity, resulting in the development of both male and female individuals. Moreover, a single female founder produced not only males and females but also hermaphrodite individuals. We further demonstrated that A. diaphana can fertilize within and between clone lines, producing swimming planula larvae. These diverse reproductive strategies may explain the species success as invader of artificial marine substrates. We suggest that these diverse reproductive strategies, together with their unique evolutionary position, make Aiptasia diaphana an excellent model for studying the evolution of sex

Odontoclasts in the Chinook salmon differ from mammalian odontoclasts by exhibiting a great proportion of cells with high nuclei number

Odontoclasts resorbing teeth are multinucleated cells. Previously, the authors have investigated the distribution of number of nuclei per human odontoclast and showed that the mean number of nuclei per cell is 5.3, the median is 4, and 93.8% of cells have 10 or fewer nuclei. Teleost odontoclasts have features similar to those of mammals; however, the distribution of number of nuclei per cell remains unknown. The present study aimed to examine the distribution of number of nuclei per odontoclast in a teleost fish, Chinook salmon, Oncorhynchus tshawytscha (Walbaum), and to clarify the difference of number of nuclei in odontoclasts between Chinook salmon and humans. The maxillae and mandibles of Chinook salmon were fixed, decalcified, and embedded in Epon 812. Specimens were serially sectioned into 0.5- m semithin sections and examined by light microscopy. Cells possessing a brush border adjacent to a resorptive lacuna were identified as odontoclasts, and 246 odontoclasts were investigated to determine the distribution of nuclei per cell. The mean number of nuclei per cell was 21.8 and the median was 17; only 24.4% of odontoclasts had 10 or fewer nuclei, and 95.5% had 50 or fewer nuclei. These results suggest that the range for the number of nuclei per odontoclast in Chinook salmon is greater than that in humans

Features of the clear zone of odontoclasts in the Chinook salmon (Oncorhynchus tshawytscha)

This study aims to clarify the features of the clear zone of odontoclasts on shedding teeth of a teleost fish, Chinook salmon, Oncorhynchus tshawytscha (Walbaum), using a light microscope to determine the orientation between a cell body and a resorptive lacuna, followed by transmission electron microscopy. Ultrathin sections of LR White embedded material were incubated in rabbit anti-actin polyclonal antibody and then were incubated with 15 nm gold-conjugated goat anti-rabbit IgG. The clear zones of odontoclasts showed a variable structure with electron-dense structures on sections, but distinct clear zones were not always seen on odontoclasts. In odontoclasts sectioned in the direction perpendicularly to the surface of a resorptive lacuna, some cells showed a wide clear zone, but two types of clear zones were usually observed: a part composed of some cytoplasmic processes and one composed of several complicatedly interwoven processes. Gold particles were localized on the clear zones, especially in electron-dense structures; very few gold particles were detected in ruffled borders. These results show that the clear zone of odontoclasts in Chinook salmon contains actin. Our results suggest that the clear zone of an odontoclast in Chinook salmon is not always a wide annular structure

Subpleural fibrotic interstitial lung abnormalities are implicated in non-small cell lung cancer radiotherapy outcomes

The relationship between interstitial lung abnormalities (ILAs) and the outcomes of lung cancer radiotherapy is unclear. This study investigated whether specific ILA subtypes are risk factors for radiation pneumonitis (RP)