Systematic screening of bryophytes for antitumor agents

References are made to cytotoxic and/or antitumor compounds that have been isolated - ansamitocin P-3 from Claopodium crispifolium (Hook.) Ren. & Card. and Anomodon attenuatus Hueb., or an associated actinomycete, and ohioensins and pallidisetums from Polytrichum spp. Several hundred collections, which have been obtained from temperate regions of North America during 1990 and 1991, are currently being screened in new bioassays; active sesquiterpene lactones have been recently isolated from species of Porella. The methodologies of collecting and screening bryophyte samples are discussed with consideration to costs based on expected number of samples that might be collected in a day, the diversity in the collections as related to phytogeography and vegetation types, and the bryophyte cover that is vanishing in many forest regions of the United States. The difficulties in obtaining large collections for isolation of active agents are also discussed by examplerecollection of Claopodium crispifolium

Tomography of atomic number and density of materials using dual-energy imaging and the Alvarez and Macovski attenuation model

Dual-energy computed tomography and the Alvarez and Macovski [Phys. Med. Biol. 21, 733 (1976)] transmitted intensity (AMTI) model were used in this study to estimate the maps of density (ρ) and atomic number (Z) of mineralogical samples. In this method, the attenuation coefficients are represented [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)] in the form of the two most important interactions of X-rays with atoms that is, photoelectric absorption (PE) and Compton scattering (CS). This enables material discrimination as PE and CS are, respectively, dependent on the atomic number (Z) and density (ρ) of materials [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)]. Dual-energy imaging is able to identify sample materials even if the materials have similar attenuation coefficients at single-energy spectrum. We use the full model rather than applying one of several applied simplified forms [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976); Siddiqui et al., SPE Annual Technical Conference and Exhibition (Society of Petroleum Engineers, 2004); Derzhi, U.S. patent application 13/527,660 (2012); Heismann et al., J. Appl. Phys. 94, 2073–2079 (2003); Park and Kim, J. Korean Phys. Soc. 59, 2709 (2011); Abudurexiti et al., Radiol. Phys. Technol. 3, 127–135 (2010); and Kaewkhao et al., J. Quant. Spectrosc. Radiat. Transfer 109, 1260–1265 (2008)]. This paper describes the tomographic reconstruction of ρ and Z maps of mineralogical samples using the AMTI model. The full model requires precise knowledge of the X-ray energy spectra and calibration of PE and CS constants and exponents of atomic number and energy that were estimated based on fits to simulations and calibration measurements. The estimated ρ and Z images of the samples used in this paper yield average relative errors of 2.62% and 1.19% and maximum relative errors of 2.64% and 7.85%, respectively. Furthermore, we demonstrate that the method accounts for the beam hardening effect in density (ρ) and atomic number (Z) reconstructions to a significant extent.S.J.L., G.R.M., and A.M.K. acknowledge funding through the DigiCore consortium and the support of a linkage grant (LP150101040) from the Australian Research Council and FEI Company

The Legacy of the Glacier Priest : Bernard R. Hubbard, S.J.

One of the most colorful and controversial individuals to bring notoriety to Santa Clara University in the past 150 years was Father Bernard R. Hubbard, S.J.(1888-1962). Known as the Glacier Priest, for his mountaineering prowess , Father Hubbard gained public prominence in the 1930s for his highly publicized and photographed expeditions to the then little known territory of Alaska. In an era without television and the internet, the public\u27s imagination was captured through public lectures and newsreels. In spite of his larger than life public persona Father Hubbard\u27s relationship with his professional colleagues and the Society of Jesus was sometimes less than ideal when it came to scholarly and educational goals. Perhaps this is best underscored by the fact that following his death in 1962 an exhibit on the Santa Clara University campus on his Alaskan expeditions was closed and dismantled. As the readers of this volume will find, the scholars of the 1960s and 1970s continued to see his documentaries as little more than newsreel filler. Now, as we enter a new century, a new generation of scholars and descendants are finding Hubbard\u27s film and photographic legacy to be the only documentation of a way of life that ceased to exist a half a century ago

Representing fine-wire EMG with surface EMG in three thigh muscles during high knee flexion movements

The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.jelekin.2018.08.006 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/Activation waveforms of vastus intermedius, adductor magnus, and semimembranosus have not been reported for high knee flexion activities such as kneeling or squatting, likely due to the invasive procedures required for their measurement. Their relatively large physiological cross sectional areas would suggest their contributions to knee joint loading could be considerable. Therefore, the purpose of this study was to quantify the activities of these muscles using fine-wire EMG and to assess easy to measure surface sites (vastus lateralis, rectus femoris, vastus medialis, semitendinosus, and biceps femoris) for their potential as proxy measures using 0.85 R2 as criteria for successful representation of deep muscle activity by that measured at a surface site. Overall, no surface and fine-wire site pair met both criteria for these movements. When fine-wire measurement of muscle activity is infeasible or impractical, the waveforms presented in supplementary material could be used as a guide for the activity of these deep muscles. Although select muscles for some participants satisfied our criteria, inter-participant variability was considerable. Therefore, future muscle models may benefit from fine-wire measurement of these muscles, but researchers should be cautious of electrode site specificity.Natural Sciences and Engineering Research Council of Canada [#418647]University of OttawaUniversity of WaterlooOntario Graduate Scholarshi

Cuticle surfaces of fossil plants as a potential proxy for volcanic SO₂ emissions: observations from the Triassic–Jurassic transition of East Greenland

Flood basalt volcanism has been implicated in several episodes of mass extinctions and environmental degradation in the geological past, including at the Triassic–Jurassic (Tr–J) transition, through global warming caused by massive outgassing of carbon dioxide. However, the patterns of biodiversity loss observed are complicated and sometimes difficult to reconcile with the effects of global warming alone. Recently, attention has turned to additional volcanic products as potential aggravating factors, in particular sulphur dioxide (SO₂). SO₂ acts both directly as a noxious environmental pollutant and indirectly through forming aerosols in the atmosphere, which may cause transient global dimming and cooling. Here, we present a range of morphological changes to fossil plant leaf cuticle surfaces of hundreds of Ginkgoales and Bennettitales specimens across the Tr–J boundary of East Greenland. Our results indicate that morphological structures of distorted cuticles near the Tr–J boundary are consistent with modern cuticle SO₂-caused damage and supported by recent leaf-shape SO₂ proxy results, thus identifying cuticle surface morphology as a potentially powerful proxy for SO₂. Recording the timing and duration of SO₂ emissions in the past may help distinguish between the driving agents responsible for mass extinction events and thus improve our understanding of the Earth System

Electronic transport anisotropy of 2D carriers in biaxial compressive strained germanium

The anisotropic nature of carrier mobility in simple cubic crystalline semiconductors, such as technologically important silicon and germanium, is well understood as a consequence of effective mass anisotropy arising from a change in band structure along non-identical surface crystal directions. In contrast to this, we show experimentally that this type of anisotropy is not the dominant contribution. Recent advances in epitaxial growth of high quality germanium enabled the appearance of high mobility 2D carriers suitable for such an experiment. A strong anisotropy of 2D carrier mobility, effective mass, quantum, and transport lifetime has been observed, through measurements of quantum phenomena at low temperatures, between the ⟨110⟩ and ⟨100⟩ in-plane crystallographic directions. These results have important consequences for electronic devices and sensor designs and suggest similar effects could be observed in technologically relevant and emerging materials such as SiGe, SiC, GeSn, GeSnSi, and C (Diamond)

Adult family violence coming out of the shadows

© [2023, Emerald Publishing Limited]. This AAM is provided for your own personal use only. It may not be used for resale, reprinting, systematic distribution, emailing, or for any other commercial purpose without the permission of the publisher.We consider what is known regarding the characteristics and context of adult family violence; and what practitioners and organisations in the United Kingdom might learn from the literature. Approach - We review literature on adult family violence and parricide and include illustrative cases from a study of domestic homicide review reports involving older adults. Findings - Adult family violence most often involves mothers killed by their adult sons. Mental health issues, alcohol/ substance misuse, and criminality are common themes for perpetrators. Caregiving responsibilities is a theme for both victims and perpetrators. Our research identified two main categories of adult family homicide: perpetrators with major psychotic illness, and victims-perpetrators in complex relational contexts. Practical implications - We consider how practitioners respond to situations of adult family violence and learning for policy-makers, agencies and practitioners. Originality - This paper summarises what is known, argues that more research is needed, and suggests practical ways forward for policy-makers, relevant agencies and practitioners