505 research outputs found
Surface mucous as a source of genomic DNA from Atlantic billfishes (Istiophoridae) and swordfish (Xiphiidae)
Procedures for sampling genomic DNA from live billfishes
involve manual restraint and tissue excision that can be difficult to carry out and may produce stresses that affect fish survival. We examined the collection of surface mucous as a less invasive alternative method for sourcing genomic DNA by comparing it to autologous muscle tissue samples
from Atlantic blue marlin (Makaira nigricans), white marlin (Tetrapturus albidus), sailfish (Istiophorus platypterus), and swordfish (Xiphias gladius). Purified DNA from mucous
was comparable to muscle and was suitable for conventional polymerase chain reaction, random amplified polymorphic
DNA analysis, and mitochondrial and nuclear locus sequencing. The nondestructive and less invasive
characteristics of surface mucous collection may promote increased survival of released specimens and may be advantageous for other marine fish genetic studies, particularly those involving large live specimens destined
for release
Large amplitude variability from the persistent ultracompact X-ray binary in NGC 1851
Using archival RXTE data, we show that the ultracompact X-ray binary in NGC
1851 exhibits large amplitude X-ray flux varations of more than a factor of 10
on timescales of days to weeks and undergoes sustained periods of months where
the time-averaged luminosty varies by factors of two. Variations of this
magnitude and timescale have not been reported previously in other ultracompact
X-ray binaries. Mass transfer in ultracompact binaries is thought to be driven
by gravitational radiation and the predicted transfer rates are so high that
the disks of ultracompact binaries with orbits as short as that of this object
should not be susceptible to ionization instabilities. Therefore the
variability characteristics we observe were unexpected, and need to be
understood. We briefly discuss a few alternatives for producing the observed
variations in light of the fact that the viscous timescale of the disk is of
order a week, comparable to the shorter time scale variation that is observed
but much less than the longer term variation. We also discuss the implications
for interpretation of observations of extragalactic binaries if the type of
variability seen in the source in NGC 1851 is typical.Comment: 7 pages, 5 figures, accepted for publication in MNRA
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Aligning Practice to Policies: Changing the Culture to Recognize and Reward Teaching at Research Universities
Recent calls for improvement in undergraduate education within STEM (science, technology, engineering, and mathematics) disciplines are hampered by the methods used to evaluate teaching effectiveness. Faculty members at research universities are commonly assessed and promoted mainly on the basis of research success. To improve the quality of undergraduate teaching across all disciplines, not only STEM fields, requires creating an environment wherein continuous improvement of teaching is valued, assessed, and rewarded at various stages of a faculty member’s career. This requires consistent application of policies that reflect well-established best practices for evaluating teaching at the department, college, and university levels. Evidence shows most teaching evaluation practices do not reflect stated policies, even when the policies specifically espouse teaching as a value. Thus, alignment of practice to policy is a major barrier to establishing a culture in which teaching is valued. Situated in the context of current national efforts to improve undergraduate STEM education, including the Association of American Universities Undergraduate STEM Education Initiative, this essay discusses four guiding principles for aligning practice with stated priorities in formal policies: 1) enhancing the role of deans and chairs; 2) effectively using the hiring process; 3) improving communication; and 4) improving the understanding of teaching as a scholarly activity. In addition, three specific examples of efforts to improve the practice of evaluating teaching are presented as examples: 1) Three Bucket Model of merit review at the University of California, Irvine; (2) Evaluation of Teaching Rubric, University of Kansas; and (3) Teaching Quality Framework, University of Colorado, Boulder. These examples provide flexible criteria to holistically evaluate and improve the quality of teaching across the diverse institutions comprising modern higher education
Identification of Giardia lamblia DHHC Proteins and the Role of Protein S-palmitoylation in the Encystation Process
Protein S-palmitoylation, a hydrophobic post-translational modification, is performed by protein acyltransferases that have a common DHHC Cys-rich domain (DHHC proteins), and provides a regulatory switch for protein membrane association. In this work, we analyzed the presence of DHHC proteins in the protozoa parasite Giardia lamblia and the function of the reversible S-palmitoylation of proteins during parasite differentiation into cyst. Two specific events were observed: encysting cells displayed a larger amount of palmitoylated proteins, and parasites treated with palmitoylation inhibitors produced a reduced number of mature cysts. With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome. These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades. Although all Giardia DHHC proteins were found to be present in trophozoites and encysting cells, these proteins showed a different intracellular localization in trophozoites and seemed to be differently involved in the encystation process when they were overexpressed. dhhc transgenic parasites showed a different pattern of cyst wall protein expression and yielded different amounts of mature cysts when they were induced to encyst. Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation.Fil: Merino, Maria Cecilia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y MartÃn Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y MartÃn Ferreyra; ArgentinaFil: Zamponi, Nahuel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y MartÃn Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y MartÃn Ferreyra; ArgentinaFil: Vranych, Cecilia Verónica. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y MartÃn Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y MartÃn Ferreyra; ArgentinaFil: Touz, Maria Carolina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y MartÃn Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y MartÃn Ferreyra; ArgentinaFil: Ropolo, Andrea Silvana. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y MartÃn Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y MartÃn Ferreyra; Argentin
Clonal Characterization of Rat Muscle Satellite Cells: Proliferation, Metabolism and Differentiation Define an Intrinsic Heterogeneity
Satellite cells (SCs) represent a distinct lineage of myogenic progenitors responsible for the postnatal growth, repair and maintenance of skeletal muscle. Distinguished on the basis of their unique position in mature skeletal muscle, SCs were considered unipotent stem cells with the ability of generating a unique specialized phenotype. Subsequently, it was demonstrated in mice that opposite differentiation towards osteogenic and adipogenic pathways was also possible. Even though the pool of SCs is accepted as the major, and possibly the only, source of myonuclei in postnatal muscle, it is likely that SCs are not all multipotent stem cells and evidences for diversities within the myogenic compartment have been described both in vitro and in vivo. Here, by isolating single fibers from rat flexor digitorum brevis (FDB) muscle we were able to identify and clonally characterize two main subpopulations of SCs: the low proliferative clones (LPC) present in major proportion (∼75%) and the high proliferative clones (HPC), present instead in minor amount (∼25%). LPC spontaneously generate myotubes whilst HPC differentiate into adipocytes even though they may skip the adipogenic program if co-cultured with LPC. LPC and HPC differ also for mitochondrial membrane potential (ΔΨm), ATP balance and Reactive Oxygen Species (ROS) generation underlying diversities in metabolism that precede differentiation. Notably, SCs heterogeneity is retained in vivo. SCs may therefore be comprised of two distinct, though not irreversibly committed, populations of cells distinguishable for prominent differences in basal biological features such as proliferation, metabolism and differentiation. By these means, novel insights on SCs heterogeneity are provided and evidences for biological readouts potentially relevant for diagnostic purposes described
MFA15 (MFA 2015)
Catalogue of a culminating student exhibition held at the Mildred Lane Kemper Art Museum, May 1 - August 2, 2015 . Introduction / Heather Corcoran and Patricia Olynyk -- Diana Casanova / Emily J. Hanson -- Andrea M. Coates : in the operating theater / Stephanie Dering -- Margaux Crump -- Brandon Daniels -- Addoley Dzegede : do you prefer answers or truth? / Aaron Coleman -- Vita Eruhimovitz -- Carling Hale -- Amanda Helman -- Mike Helms / Ming Ying Hong -- Ming Ying Hong / Emily J. Hanson -- Sea A Joung / Ervin Malakaj -- Stephanie Kang / Jeremy Shipley -- Dayna Jean Kriz / Andrew Johnson -- Thomas Moore : you should move to the city / Nathaniel Rosenthalis -- Jacob Muldowney -- Laurel Panella / Garrett Clough -- Caitlin Penny -- On the bridge, between Juarez and El Paso / Eric Lyle Schultz -- Jeremy Shipley -- Emmeline Solomon -- Kellie Spano / Margaux Crump -- Michael Aaron Williams -- Austin R. Wolf : monumental labor / Adam Turl.https://openscholarship.wustl.edu/books/1015/thumbnail.jp
A canine model to evaluate the effect of exercise intensity and duration on olfactory detection limits: the running nose
Detection canines serve critical roles to support the military, homeland security and border protection. Some explosive detection tasks are physically demanding for dogs, and prior research suggests this can lead to a reduction in olfactory detection sensitivity. To further evaluate the effect of exercise intensity on olfactory sensitivity, we developed a novel olfactory paradigm that allowed us to measure olfactory detection thresholds while dogs exercised on a treadmill at two different exercise intensities. Dogs (n = 3) showed a decrement in olfactory detection for 1-bromooctane at 10−3 (v/v) dilutions and lower under greater exercise intensity. Dogs' hit rate for the lowest concentration dropped from 0.87 ± 0.04 when walking at low intensity to below 0.45 ± 0.06 when trotting at moderate intensity. This decline had an interaction with the duration of the session in moderate intensity exercise, whereby dogs performed near 100% detection in the first 10 min of the 8 km/h session, but showed 0% detection after 20 min. Hit rates for high odor concentrations (10−2) were relatively stable at both low (1 ± 0.00) and moderate (0.91 ± 0.04) exercise intensities. The paradigm and apparatus developed here may be useful to help further understand causes of operationally relevant olfactory detection threshold decline in dogs
Trait Rumination Influences Neural Correlates of the Anticipation but Not the Consumption Phase of Reward Processing
Cumulative evidence suggests that trait rumination can be defined as an abstract information processing mode, which leads people to constantly anticipate the likely impact of present events on future events and experiences. A previous study with remitted depressed patients suggested that enhanced rumination tendencies distort brain mechanisms of anticipatory processes associated with reward and loss cues. In the present study, we explored the impact of trait rumination on neural activity during reward and loss anticipation among never-depressed people. We analyzed the data of 37 healthy controls, who performed the monetary incentive delay (MID) task which was designed for the simultaneous measurement of the anticipation (motivational) and consumption (hedonic) phase of reward processing, during functional magnetic resonance imaging (fMRI). Our results show that rumination-after controlling for age, gender, and current mood-significantly influenced neural responses to reward (win) cues compared to loss cues. Blood-oxygenation-level-dependent (BOLD) activity in the left inferior frontal gyrus (IFG) triangularis, left anterior insula, and left rolandic operculum was positively related to Ruminative Response Scale (RRS) scores. We did not detect any significant rumination-related activations associated with win-neutral or loss-neutral cues and with reward or loss consumption. Our results highlight the influence of trait rumination on reward anticipation in a non-depressed sample. They also suggest that for never-depressed ruminators rewarding cues are more salient than loss cues. BOLD response during reward consumption did not relate to rumination, suggesting that rumination mainly relates to processing of the motivational (wanting) aspect of reward rather than the hedonic (liking) aspect, at least in the absence of pathological mood
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
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