Controls on the quality of Miocene reservoirs, southern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Gutiérrez Paredes, Hilda Clarisa; Catuneanu, Octavian; Hernández Romano, Ulises

2018-01-01

An investigation was conducted to determine the main controls on the reservoir quality of the middle and upper Miocene sandstones in the southern Gulf of Mexico based on core descriptions, thin section petrography and petrophysical data; as well as to explore the possible link between the sequence stratigraphic framework, depositional facies and diagenetic alterations. The Miocene deep marine sandstones are attributed to the falling-stage, lowstand, and transgressive systems tracts. The middle Miocene falling-stage systems tract includes medium-to very fine-grained, and structureless sandstones deposited in channels and frontal splays, and muddy sandstones, deposited in lobes of debrites. The lowstand and transgressive systems tracts consist of medium-to very fine-grained massive and normally graded sandstones deposited in channel systems within frontal splay complexes. The upper Miocene falling-stage systems tract includes medium-to coarse-grained, structureless sandstones deposited in channel systems and frontal splay, as well as lobes of debrites formed by grain flows and hybrid-flow deposits. The lowstand and transgressive systems tracts include fine-grained sandstones deposited in overbank deposits. The results reveal that the depositional elements with the best reservoir quality are the frontal splays deposited during the falling-stage system tracts. The reservoir quality of the Miocene sandstones was controlled by a combination of depositional facies, sand composition and diagenetic factors (mainly compaction and calcite cementation). Sandstone texture, controlled primarily by depositional facies appears more important than sandstone composition in determining reservoir quality; and compaction was more important than cementation in porosity destruction. Compaction was stopped, when complete calcite cementation occurred.

Higher-order geodesic deviation for charged particles and resonance induced by gravitational waves

NASA Astrophysics Data System (ADS)

Heydari-Fard, M.; Hasani, S. N.

We generalize the higher-order geodesic deviation for the structure-less test particles to the higher-order geodesic deviation equations of the charged particles [R. Kerner, J. W. van Holten and R. Colistete Jr., Class. Quantum Grav. 18 (2001) 4725]. By solving these equations for charged particles moving in a constant magnetic field in the spacetime of a gravitational wave, we show for both cases when the gravitational wave is parallel and perpendicular to the constant magnetic field, a magnetic resonance appears at wg = Ω. This feature might be useful to detect the gravitational wave with high frequencies.

Stratigraphy and depositional environment of unnamed (lower Miocene) submarine-fan sandstone unit in Sierra Madre and San Rafael Mountains, northeastern Santa Barbara County, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, G.D.; Fritsche, A.E.; Condon, M.W.

1988-03-01

A relatively thick and extensive, previously unnamed, lower Miocene sandstone unit occurs in the central Sierra Madre and in the Hurricane Deck area of the San Rafael Mountains of northeastern Santa Barbara County, California. It is underlain conformably and interfingers with a dark mudstone that correlates with the Soda Lake Shale Member of the Vaqueros Formation; it is overlain conformably and interfingers with a brown shale that correlates with the Saltos Member of the Monterey Shale. Northeastern exposures along the north flank of the Sierra Madre are almost exclusively medium to coarse-grained, structureless sandstone with scattered pebbly conglomerate beds. Thicknessmore » ranges from zero in the southeastern part of the Sierra Madre to 70 m in the northeast, 75 m in the northwest, and 600 m in the central part of the range. Toward the southwest in the Hurricane Deck area of the San Rafael Mountains, the unit becomes thicker and more extensively interbedded with mudstone. Lithology of the unit consists of 0.3-3.5 m thick beds of medium to coarse-grained, structureless to vaguely graded sandstone with scoured contacts at the base. Sandstone beds 0.3-3.0 m thick, which are more distinctly graded from coarse to very fine are also present. The interbedded mudstone commonly is bioturbated, so bedding is indistinct. Thickness ranges from 1020 m in the central part of the area to 750 m toward the southwest and 92 m toward the northwest. The unit most likely represents deposition in a submarine-canyon and fan complex that had its channel head in the northeast and spread southwestward into a thick sequence of submarine-fan sandstone lobes, which were confined in a narrow west-trending trough.« less

A program for performing exact quantum dynamics calculations using cylindrical polar coordinates: A nanotube application

NASA Astrophysics Data System (ADS)

Skouteris, Dimitris; Gervasi, Osvaldo; Laganà, Antonio

2009-03-01

A program that uses the time-dependent wavepacket method to study the motion of structureless particles in a force field of quasi-cylindrical symmetry is presented here. The program utilises cylindrical polar coordinates to express the wavepacket, which is subsequently propagated using a Chebyshev expansion of the Schrödinger propagator. Time-dependent exit flux as well as energy-dependent S matrix elements can be obtained for all states of the particle (describing its angular momentum component along the nanotube axis and the excitation of the radial degree of freedom in the cylinder). The program has been used to study the motion of an H atom across a carbon nanotube. Program summaryProgram title: CYLWAVE Catalogue identifier: AECL_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECL_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 3673 No. of bytes in distributed program, including test data, etc.: 35 237 Distribution format: tar.gz Programming language: Fortran 77 Computer: RISC workstations Operating system: UNIX RAM: 120 MBytes Classification: 16.7, 16.10 External routines: SUNSOFT performance library (not essential) TFFT2D.F (Temperton Fast Fourier Transform), BESSJ.F (from Numerical Recipes, for the calculation of Bessel functions) (included in the distribution file). Nature of problem: Time evolution of the state of a structureless particle in a quasicylindrical potential. Solution method: Time dependent wavepacket propagation. Running time: 50000 secs. The test run supplied with the distribution takes about 10 minutes to complete.

Vibronic singlet and triplet steady-state interplay emissions in phenazine-based 1,2,3-triazole films

NASA Astrophysics Data System (ADS)

Costa, Bárbara B. A.; Souza, Paula D. C.; Gontijo, Rafael N.; Jardim, Guilherme A. M.; Moreira, Roberto L.; da Silva, Eufrânio N.; Cury, Luiz A.

2018-03-01

Photoluminescence and phosphorescence emissions of solid-state phenazine films were investigated in steady-state experimental conditions. Important discrepancies were observed for blended films where a host optically inert matrix was introduced to disperse the probe molecules. A vibronic spin-orbit phosphorescent emission clearly appeared, while for the films solely composed by the probe molecules, the phosphorescence broadened and presented a structureless shape, shifted to longer wavelengths. Further Arrhenius behavior analysis on the photoluminescent and phosphorescent emissions on temperature, corroborated the direct and reverse intersystem crossing interplay between singlet and triplet states. Molecular aggregation is responsible for the deterioration of non-blended triazole films phosphorescence.

Unsung Heroes

ERIC Educational Resources Information Center

Finkel, Ed

2012-01-01

Guidance counselors, sometimes underappreciated in difficult budgetary times, are feeling more respect in their quest to combat bullying. During the past decade, school counselors have become much more active in educating students, faculty, and staff about bullying and taking active steps to prevent it. The primary shift toward active prevention…

Exploring Universality: Does the World Really Use the Same Numbers?

ERIC Educational Resources Information Center

Klemm, Rebecca; Wallace, Rachel

2017-01-01

Arguably one of the most under-appreciated, yet ubiquitous and frequently utilized aspects of modern, globalized society, our number system exemplifies how we are inextricably interconnected. Indeed, without a universal number system, there would be no global collaboration and no global solutions.

Rising CO2, Climate Change, and Public Health: Exploring the Links to Plant Biology

PubMed Central

Ziska, Lewis H.; Epstein, Paul R.; Schlesinger, William H.

2009-01-01

Background Although the issue of anthropogenic climate forcing and public health is widely recognized, one fundamental aspect has remained underappreciated: the impact of climatic change on plant biology and the well-being of human systems. Objectives We aimed to critically evaluate the extant and probable links between plant function and human health, drawing on the pertinent literature. Discussion Here we provide a number of critical examples that range over various health concerns related to plant biology and climate change, including aerobiology, contact dermatitis, pharmacology, toxicology, and pesticide use. Conclusions There are a number of clear links among climate change, plant biology, and public health that remain underappreciated by both plant scientists and health care providers. We demonstrate the importance of such links in our understanding of climate change impacts and provide a list of key questions that will help to integrate plant biology into the current paradigm regarding climate change and human health. PMID:19270781

Underappreciated Factors to Consider in Revision Anterior Cruciate Ligament Reconstruction: A Current Concepts Review

PubMed Central

Southam, Brendan R.; Colosimo, Angelo J.; Grawe, Brian

2018-01-01

Primary anterior cruciate ligament (ACL) reconstructions (ACLRs) are being performed with increasing frequency. While many of these will have successful outcomes, failures will occur in a subset of patients who will require revision ACLRs. As such, the number of revision procedures will continue to rise as well. While many reviews have focused on factors that commonly contribute to failure of primary ACLR, including graft choice, patient factors, early return to sport, and technical errors, this review focused on several factors that have received less attention in the literature. These include posterior tibial slope, varus malalignment, injury to the anterolateral ligament, and meniscal injury or deficiency. This review also appraised several emerging techniques that may be useful in the context of revision ACL surgery. While outcomes of revision ACLR are generally inferior to those of primary procedures, identifying these potentially underappreciated contributing factors preoperatively will allow the surgeon to address them at the time of revision, ideally improving patient outcomes and preventing recurrent ACL failure. PMID:29399591

Women's Leadership: A Study of African American Female Principal Experiences

ERIC Educational Resources Information Center

Williams, Curtis

2013-01-01

Traditionally, women's leadership has been overlooked and underappreciated by researchers and policymakers although this leadership has been vital to America's ultimate success and infrastructure. Simply stated, contributions of female leadership have been overshadowed by a system that primarily values patriarchal forms of leadership and oppresses…

Fluid Aspects of Solar Wind Disturbances Driven by Coronal Mass Ejections. Appendix 3

NASA Technical Reports Server (NTRS)

Gosling, J. T.; Riley, Pete

2001-01-01

Transient disturbances in the solar wind initiated by coronal eruptions have been modeled for many years, beginning with the self-similar analytical models of Parker and Simon and Axford. The first numerical computer code (one-dimensional, gas dynamic) to study disturbance propagation in the solar wind was developed in the late 1960s, and a variety of other codes ranging from simple one-dimensional gas dynamic codes through three-dimensional gas dynamic and magnetohydrodynamic codes have been developed in subsequent years. For the most part, these codes have been applied to the problem of disturbances driven by fast CMEs propagating into a structureless solar wind. Pizzo provided an excellent summary of the level of understanding achieved from such simulation studies through about 1984, and other reviews have subsequently become available. More recently, some attention has been focused on disturbances generated by slow CMEs, on disturbances driven by CMEs having high internal pressures, and disturbance propagation effects associated with a structured ambient solar wind. Our purpose here is to provide a brief tutorial on fluid aspects of solar wind disturbances derived from numerical gas dynamic simulations. For the most part we illustrate disturbance evolution by propagating idealized perturbations, mimicking different types of CMEs, into a structureless solar wind using a simple one-dimensional, adiabatic (except at shocks), gas dynamic code. The simulations begin outside the critical point where the solar wind becomes supersonic and thus do not address questions of how the CMEs themselves are initiated. Limited to one dimension (the radial direction), the simulation code predicts too strong an interaction between newly ejected solar material and the ambient wind because it neglects azimuthal and meridional motions of the plasma that help relieve pressure stresses. Moreover, the code ignores magnetic forces and thus also underestimates the speed with which pressure disturbances propagate in the wind.

A fluorescence-based method for direct measurement of submicrosecond intramolecular contact formation in biopolymers: an exploratory study with polypeptides.

PubMed

Hudgins, Robert R; Huang, Fang; Gramlich, Gabriela; Nau, Werner M

2002-01-30

A fluorescent amino acid derivative (Fmoc-DBO) has been synthesized, which contains 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) as a small, hydrophilic fluorophore with an extremely long fluorescence lifetime (325 ns in H2O and 505 ns in D2O under air). Polypeptides containing both the DBO residue and an efficient fluorescence quencher allow the measurement of rate constants for intramolecular end-to-end contact formation. Bimolecular quenching experiments indicated that Trp, Cys, Met, and Tyr are efficient quenchers of DBO (k(q) = 20, 5.1, 4.5, and 3.6 x 10(8) M(-1) x s(-1) in D2O), while the other amino acids are inefficient. The quenching by Trp, which was selected as an intrinsic quencher, is presumed to involve exciplex-induced deactivation. Flexible, structureless polypeptides, Trp-(Gly-Ser)n-DBO-NH2, were prepared by standard solid-phase synthesis, and the rates of contact formation were measured through the intramolecular fluorescence quenching of DBO by Trp with time-correlated single-photon counting, laser flash photolysis, and steady-state fluorometry. Rate constants of 4.1, 6.8, 4.9, 3.1, 2.0, and 1.1 x 10(7) s(-1) for n = 0, 1, 2, 4, 6, and 10 were obtained. Noteworthy was the relatively slow quenching for the shortest peptide (n = 0). The kinetic data are in agreement with recent transient absorption studies of triplet probes for related peptides, but the rate constants are significantly larger. In contrast to the flexible structureless Gly-Ser polypeptides, the polyproline Trp-Pro4-DBO-NH2 showed insignificant fluorescence quenching, suggesting that a high polypeptide flexibility and the possibility of probe-quencher contact is essential to induce quenching. Advantages of the new fluorescence-based method for measuring contact formation rates in biopolymers include high accuracy, fast time range (100 ps-1 micros), and the possibility to perform measurements in water under air.

Reviewing Reviews of Research in Educational Leadership: An Empirical Assessment

ERIC Educational Resources Information Center

Hallinger, Philip

2014-01-01

Purpose: Reviews of research play a critical but underappreciated role in knowledge production and accumulation. Yet, until relatively recently, limited attention has been given to the "methodology" of conducting reviews of research. This observation also applies in educational leadership and management where reviews of research have…

Towards Equity in Service Provision for Gay Men and Other Men Who Have Sex with Men in Repressive Contexts.

PubMed

Beyrer, Chris; Makofane, Keletso; Orazulike, Ifeanyi; Diouf, Daouda; Baral, Stefan D

2016-10-01

Chris Beyrer and colleagues reflect on an underappreciated trend in multiple African, Asian, and Caribbean settings, in which the provision of HIV and other essential health services for sexual and gender minorities is expanding despite challenging legal and social environments.

Disturbance ecology in the Northern Rockies: One perspective

Treesearch

Al Harvey; Penny Morgan

2001-01-01

Since early 1900s forestry, ecology and related professions have been aware that external disturbances had important effects on the development of vegetation. However, the integral part they play in ecosystem development and sustainability across time and space was largely underappreciated. Failure to provide appropriate disturbances can place stable and productive...

Notable Government Documents 2007: Blogs, Battles, & Bees

ERIC Educational Resources Information Center

Church, Jim

2008-01-01

The world of government information mirrors the headlines. The resources in this list of Notable Government Documents from the American Library Association's Government Documents Round Table reflect the diversity of the profession, with topics ranging from "underappreciated fish" in Alaska to the Colonial papers of Sir William Johnson;…

SOURCES AND ESTIMATED LOAD OF BIOAVAILABLE NITROGEN ATTRIBUTED TO CHRONIC NITROGEN EXPOSURE AND CHANGED ECOSYSTEM STRUCTURE AND FUNCTION

EPA Science Inventory

Bioavailable nitrogen is a limiting nutrient throughout the Eastern United States. Research demonstrates that exposure to large doses of nitrogen leads to deleterious environmental impacts. However, effects of chronic exposure to lower doses of nitrogen are under-appreciated. ...

School Social Work: Increasing the Legitimacy of the Profession

ERIC Educational Resources Information Center

Altshuler, Sandra J.; Webb, Jennifer Reid

2009-01-01

School social workers often face challenges of having to legitimize their presence as a school professional, especially as compared to school psychologists and school counselors. Why are school social workers more often vulnerable to being underappreciated and not understood by school personnel than other mental health-based school professionals?…

Adolescent Childbearing, Poverty, and Siblings: Taking New Direction from the New Literature.

ERIC Educational Resources Information Center

East, Patricia L.; Jacobson, Leanne J.

2000-01-01

Article critically appraises the sibling-comparison method by discussing its limitations: it assumes within-family homogeneity; it neglects naturally occurring heterogeneity across siblings; it overlooks unique effects of a teen's childbearing for her family and siblings; it underappreciates the selectivity of sisters of teenage mothers who delay…

Invasive plant architecture alters trophic interactions by changing predator abundance and behavior

Treesearch

Dean E. Pearson

2009-01-01

As primary producers, plants are known to influence higher trophic interactions by initiating food chains. However, as architects, plants may bypass consumers to directly affect predators with important but underappreciated trophic ramifications. Invasion of western North American grasslands by the perennial forb, spotted knapweed (Centaurea maculosa...

Descriptive Social Norms as Underappreciated Sources of Social Control

ERIC Educational Resources Information Center

Cialdini, Robert B.

2007-01-01

Bockenholt and van der Heijden's results regarding compliance with insurance regulations--that the enforcement activities of a regulatory agency were relatively unpredictive of compliance--are consistent with findings from other domains (e.g., tax adherence), where personal factors and informal social controls have been shown to play a more…

Mood instability: significance, definition and measurement.

PubMed

Broome, M R; Saunders, K E A; Harrison, P J; Marwaha, S

2015-10-01

Mood instability is common, and an important feature of several psychiatric disorders. We discuss the definition and measurement of mood instability, and review its prevalence, characteristics, neurobiological correlates and clinical implications. We suggest that mood instability has underappreciated transdiagnostic potential as an investigational and therapeutic target. © The Royal College of Psychiatrists 2015.

Catastrophic Icefall Hazard Assessment, Avoidance Procedures & Mitigations Strategies, Phase II Site-Specific Studies

DOT National Transportation Integrated Search

2018-02-01

The incidence of icefall is one of the most underrepresented and likely underappreciated of all the natural hazards. Falling pieces of ice are subject to melting and sublimation, and evidence of such events may be gone in a matter of days or even hou...

Resonant two-photon ionization and laser induced fluorescence spectroscopy of jet-cooled adenine

NASA Astrophysics Data System (ADS)

Kim, Nam Joon; Jeong, Gawoon; Kim, Yung Sam; Sung, Jiha; Keun Kim, Seong; Park, Young Dong

2000-12-01

Electronic spectra of the jet-cooled DNA base adenine were obtained by the resonant two-photon ionization (R2PI) and the laser induced fluorescence (LIF) techniques. The 0-0 band to the lowest electronically excited state was found to be located at 35 503 cm-1. Well-resolved vibronic structures were observed up to 1100 cm-1 above the 0-0 level, followed by a slow rise of broad structureless absorption. The lowest electronic state was proposed to be of nπ* character, which lies ˜600 cm-1 below the onset of the ππ* state. The broad absorption was attributed to the extensive vibronic mixing between the nπ* state and the high-lying ππ* state.

Enriching the Brain: How to Maximize Every Learner's Potential

ERIC Educational Resources Information Center

Jensen, Eric

2006-01-01

Eric Jensen, a leading expert in the translation of brain research into education, argues that students' achievement capacity is greatly underappreciated. Drawing from a wide range of neuroscience research as well as related studies, the author reveals that the human brain is far more dynamic and malleable than earlier believed. He offers a…

Exploring the Landscape of Modern Academic Psychology: Finding and Filling the Holes

ERIC Educational Resources Information Center

Rozin, Paul

2007-01-01

Like any other domain of human activity, psychology has its fads and fashions. One consequence of fads is an overconcentration of resources on specific problems or approaches, which leaves other important problems or approaches (holes) underappreciated and understudied. This article is primarily about different factors (such as negativity bias,…

Evaluating Retirement Income Security for Illinois Public School Teachers. Public Pension Project Report

ERIC Educational Resources Information Center

Johnson, Richard W.; Southgate, Benjamin G.

2014-01-01

The financial problems afflicting the Illinois teacher pension plan have grabbed headlines. An equally important problem, though underappreciated, is that relatively few teachers benefit much from the plan. This report evaluates the pension benefits provided to Illinois public school teachers. The researchers project annual and lifetime pension…

Improving School Accountability Measures. NBER Working Paper Series.

ERIC Educational Resources Information Center

Kane, Thomas J.; Staiger, Douglas O.

A growing number of states are using annual school-level test scores as part of their school accountability systems. This paper highlights an under-appreciated weakness of that approach, the imprecision of school-level test score means, and proposes a method for discerning signal from noise in annual school report cards. Using methods developed in…

Algorithmic Puzzles: History, Taxonomies, and Applications in Human Problem Solving

ERIC Educational Resources Information Center

Levitin, Anany

2017-01-01

The paper concerns an important but underappreciated genre of algorithmic puzzles, explaining what these puzzles are, reviewing milestones in their long history, and giving two different ways to classify them. Also covered are major applications of algorithmic puzzles in cognitive science research, with an emphasis on insight problem solving, and…

Education: A Complex and Empowering Social Work Intervention at the End of Life

ERIC Educational Resources Information Center

Cagle, John G.; Kovacs, Pamela J.

2009-01-01

Education is a frequently used social work intervention. Yet it seems to be an underappreciated and a deceptively complex intervention that social workers may not be adequately prepared to use. Reliable, accessible information is essential as it helps prevent unnecessary crises, facilitates coping, and promotes self-determination. This article…

Robert Frost: Democracy, Teaching, and Teacher Education

ERIC Educational Resources Information Center

Frank, Jeffery M.

2010-01-01

The goal of this dissertation is to develop a connection between poetry and teacher education. I am motivated to undertake this project because poetry is an underappreciated resource, one that has a good deal to teach teachers. Specifically, I believe that poetry can teach teachers about how to creatively and democratically respond to problems of…

Causal criteria and counterfactuals; nothing more (or less) than scientific common sense.

PubMed

Phillips, Carl V; Goodman, Karen J

2006-05-26

Two persistent myths in epidemiology are that we can use a list of "causal criteria" to provide an algorithmic approach to inferring causation and that a modern "counterfactual model" can assist in the same endeavor. We argue that these are neither criteria nor a model, but that lists of causal considerations and formalizations of the counterfactual definition of causation are nevertheless useful tools for promoting scientific thinking. They set us on the path to the common sense of scientific inquiry, including testing hypotheses (really putting them to a test, not just calculating simplistic statistics), responding to the Duhem-Quine problem, and avoiding many common errors. Austin Bradford Hill's famous considerations are thus both over-interpreted by those who would use them as criteria and under-appreciated by those who dismiss them as flawed. Similarly, formalizations of counterfactuals are under-appreciated as lessons in basic scientific thinking. The need for lessons in scientific common sense is great in epidemiology, which is taught largely as an engineering discipline and practiced largely as technical tasks, making attention to core principles of scientific inquiry woefully rare.

Change in the frequency and intensity of the spectral lines of a hydrogen-like atom in the field of a point charge

NASA Astrophysics Data System (ADS)

Ovsyannikov, V. D.; Kamenskii, A. A.

2002-03-01

The changes in the wave functions and the energies of a hydrogen-like atom in the static field of a structureless charged particle are calculated in the asymptotic approximation. The corrections to the energy of states, as well as to the dipole matrix elements of radiative transitions caused by the interaction of the atom with the point charge at long range are calculated using the perturbation theory and the Sturm series for a reduced Coulomb Green’s function in parabolic coordinates. The analytical expressions are derived and tables of numerical values of the coefficients of asymptotic series that determine the corrections to the matrix elements and the intensities of transitions of the Lyman and Balmer series are presented.

Defining Equivalence in Medical Education Evaluation and Research: Does a Distribution-Based Approach Work?

ERIC Educational Resources Information Center

Rusticus, Shayna A.; Eva, Kevin W.

2016-01-01

Educators often seek to demonstrate the equivalence of groups, such as whether or not students achieve comparable success regardless of the site at which they trained. A methodological consideration that is often underappreciated is how to operationalize equivalence. This study examined whether a distribution-based approach, based on effect size,…

Close Cousins or Distant Relatives? The Relationship between Terrorism and Hate Crime

ERIC Educational Resources Information Center

Deloughery, Kathleen; King, Ryan D.; Asal, Victor

2012-01-01

Prior research has frequently drawn parallels between the study of hate crimes and the study of terrorism. Yet, key differences between the two behaviors may be underappreciated in extant work. Terrorism is often an "upward crime," involving a perpetrator of lower social standing than the targeted group. By contrast, hate crimes are…

Community Colleges and Underappreciated Assets: Using Institutional Data to Promote Success in Online Learning

ERIC Educational Resources Information Center

Hachey, Alyse; Conway, Katherine; Wladis, Claire

2013-01-01

Adapting to the 21st century, community colleges are not adding brick and mortar to meet enrollment demands. Instead, they are expanding services through online learning, with at least 61% of all community college students taking online courses today (Pearson, 2011). As online learning is affording alternate pathways to education for students, it…

Sport for Development (S4D) as "Core University Business"? Modelling University Participation in Sport-Based Social Development

ERIC Educational Resources Information Center

Rosso, Edoardo G. F.; McGrath, Richard; Immink, Maarten A.; May, Esther

2016-01-01

Among the recognised strengths of the "Sport for Development" (S4D) framework there is the capacity of sport to contribute to positive community networks, education and community participation. However, its relevance to tertiary education institutions is often under-appreciated. In this framework, the Football United® program was…

On-road emissions of ammonia: An underappreciated source of atmospheric nitrogen deposition

Treesearch

Mark E. Fenn; Andrzej Bytnerowicz; Susan L. Schilling; Dena M. Vallano; Erika S. Zavaleta; Stuart B. Weiss; Connor Morozumi; Linda H. Geiser; Kenneth Hanks

2018-01-01

We provide updated spatial distribution and inventory data for on-road NH3 emissions for the continental United States (U.S.) On-road NH3 emissions were determined from on-road CO2 emissions data and empirical NH3:CO2 vehicle emissions ratios. Emissions of...

Unifying Concepts in Stimulus-Secretion Coupling in Endocrine Cells and Some Implications for Therapeutics

ERIC Educational Resources Information Center

Misler, Stanley

2009-01-01

Stimulus-secretion coupling (SSC) in endocrine cells remains underappreciated as a subject for the study/teaching of general physiology. In the present article, we review key new electrophysiological, electrochemical, and fluorescence optical techniques for the study of exocytosis in single cells that have made this a fertile area for recent…

Are hospital floors an underappreciated reservoir for transmission of health care-associated pathogens?

PubMed

Deshpande, Abhishek; Cadnum, Jennifer L; Fertelli, Dennis; Sitzlar, Brett; Thota, Priyaleela; Mana, Thriveen S; Jencson, Annette; Alhmidi, Heba; Koganti, Sreelatha; Donskey, Curtis J

2017-03-01

In a survey of 5 hospitals, we found that floors in patient rooms were frequently contaminated with pathogens and high-touch objects such as blood pressure cuffs and call buttons were often in contact with the floor. Contact with objects on floors frequently resulted in transfer of pathogens to hands. Published by Elsevier Inc.

How Pensions Contribute to the Premium Paid to Experienced Public School Teachers

ERIC Educational Resources Information Center

McGee, Joshua B.; Winters, Marcus A.

2017-01-01

Many argue that public school systems should stop linking teachers' salaries so closely to their years of experience. However, the effect of deferred retirement compensation on the premium paid to experienced teachers has, to date, been underappreciated. To shed more light on this issue, we calculate the total compensation earned by teachers in…

Adolescent Exposure to and Perceptions of Environmental Tobacco Smoke

ERIC Educational Resources Information Center

Jordan, Timothy R.; Price, James H.; Dake, Joseph A.; Shah, Sapna

2005-01-01

Environmental tobacco smoke (ETS) poses an underappreciated risk to adolescent health. This study examined perceptions of adolescents (n = 574) regarding ETS. About one half (54%) were exposed to ETS the previous week, and one third (30%) were exposed to 3 or more hours of ETS the past week. Concurrently, 29% believed that breathing someone else's…

Adventures in Advising: Strategies, Solutions, and Situations to Student Problems in the Criminology and Criminal Justice Field

ERIC Educational Resources Information Center

Mier, Carrie

2018-01-01

Teaching and research are often the most focused upon aspects of working within academia in criminology and criminal justice (Sitren & Applegate, 2012; Jonson & Moon, 2014; Pratt, 2014), but an overlooked and underappreciated part of an undergraduate's overall higher education success is academic advising (Light, 2001). There has been…

Glacial loess or shoreface sands: a re-interpretation of the Upper Ordovician (Ashgillian) glacial Ammar Formation, Southern Jordan

NASA Astrophysics Data System (ADS)

Turner, B. R.; Makhlouf, I. M.; Armstrong, H. A.

2003-04-01

Upper Ordovician (Ashgillian) glacial deposits of the Ammar Formation, Southern Jordan, comprise locally deformed, structureless fine sandstone, incised by glacial channels filled by braided outwash plain sandstones and transgressive marine mudstones. The structureless sandstones, previously interpreted as a glacial rock flour or loessite derived from the underlying undisturbed sandstones, differ significantly from typical loessite and contain hitherto unrecognised sedimentary structures, including hummocky cross-stratification. The sandstones, which grade laterally and vertically into stratigraphically equivalent undeformed marginal marine sandstones, are interpreted as a deformed facies of the underlying sandstones, deposited in a similar high energy shoreface environment. Although deformation of the shoreface sandstones was post-depositional, the origin of the deformation, and its confinement to the Jebel Ammar area is unknown. Deformation due to the weight of the overlying ice is unlikely as the glaciofluvial channels are now thought to have been cut by tunnel valley activity not ice. A more likely mechanism is post-glacial crustal tectonics. Melting of ice caps is commonly associated with intraplate seismicity and the development of an extensional crustal stress regime around the perimeter of ice caps; the interior is largely aseismic because the weight of the ice supresses seismic activity and faulting. Since southern Jordan lay close to the ice cap in Saudi Arabia it may have been subjected to postglacial seismicity and crustal stress, which induced ground shaking, reduced overburden pressure, increased hydrostatic pressure and possibly reactivation of existing tectonic faults. This resulted in liquefaction and extensive deformation of the sediments, which show many characteristics of seismites, generated by earthquake shocks. Since the glaciation was a very short-lived event (0.2-1 Ma), deglaciation and associated tectonism triggering deformation, lasted not more than a few hundred thousand years. Deglaciation and crustal unloading commonly lead to seismically-induced reactivation of tectonic faults. This relationship provides a possible explanation for the localisation of the deformation to the Jebel Ammar area which lies on the footwall of the Hutayya graben. The fault may also have acted as a conduit for post-seismic fluid movement along the fault plane under high pressure, thereby enhancing permeability and promoting fluid migration.

Disability and Sunshine: Can Hedonic Predictions Be Improved by Drawing Attention to Focusing Illusions or Emotional Adaptation?

ERIC Educational Resources Information Center

Ubel, Peter A.; Loewenstein, George; Jepson, Christopher

2005-01-01

People frequently mispredict the long-term emotional impact of circumstances. The authors examine 2 causes of such mispredictions--a focusing illusion and underappreciation of adaptation. In Experiment 1, the authors found, in 852 adults, that quality of life estimates (for living with disability) were not increased by reducing focusing illusions.…

Using Student Test Scores to Measure Teacher Performance: Some Problems in the Design and Implementation of Evaluation Systems

ERIC Educational Resources Information Center

Ballou, Dale; Springer, Matthew G.

2015-01-01

Our aim in this article is to draw attention to some underappreciated problems in the design and implementation of evaluation systems that incorporate value-added measures. We focus on four: (1) taking into account measurement error in teacher assessments, (2) revising teachers' scores as more information becomes available about their students,…

Designing and Adapting Tasks in Lesson Planning: A Critical Process of Lesson Study

ERIC Educational Resources Information Center

Fujii, Toshiakira

2016-01-01

There is no doubt that a lesson plan is a necessary product of Lesson Study. However, the collaborative work among teachers that goes into creating that lesson plan is largely under-appreciated by non-Japanese adopters of Lesson Study, possibly because the effort involved is invisible to outsiders, with our attention going to its most visible…

Why Community Investment Is Good for Nonprofit Anchor Institutions: Understanding Costs, Benefits, and the Range of Strategic Options

ERIC Educational Resources Information Center

Webber, Henry S.; Karlstrom, Mikael

2009-01-01

This report was written out of a recognition that there has been little effort to systematically examine the value to anchor institutions of engaging in significant community investment. In the absence of such research, the authors believe that institutions tend to overestimate the costs and risks and underappreciate the potential benefits. In…

Prevalence of cryptic species in morphologically uniform taxa - fast speciation and evolutionary radiation in Asian toads.

PubMed

Liu, Zuyao; Chen, Guoling; Zhu, Tianqi; Zeng, Zhaochi; Lyu, Zhitong; Wang, Jian; Messenger, Kevin; Greenberg, Anthony J; Guo, Zixiao; Yang, Ziheng; Shi, Suhua; Wang, Yingyong

2018-06-16

Diversity and distributions of cryptic species have long been a vexing issue. Identification of species boundaries is made difficult by the lack of obvious morphological differences. Here, we investigate the cryptic diversity and evolutionary history of an underappreciated group of Asian frog species (Megophrys) to explore the pattern and dynamic of amphibian cryptic species. We sequenced four mitochondrial genes and five nuclear genes and delineated species using multiple approaches, combining DNA and mating-call data. A Bayesian species tree was generated to estimate divergence times and to reconstruct ancestral ranges. Macroevolutionary analyses and hybridization tests were conducted to explore the evolutionary dynamics of this cryptic group. Our phylogenies support the current subgenera. We revealed 43 cryptic species, 158% higher than previously thought. The species-delimitation results were further confirmed by mating-call data and morphological divergence. We found that these Asian frogss entered China from the Sunda Shelf 48 Mya, followed by an ancient radiation event during middle Miocene. We confirmed the efficiency of the multispecies coalescent model for delimitation of species with low morphological diversity. Species diversity of Megophrys is severely underappreciated, and species distributions have been misestimated as a result. Copyright © 2018. Published by Elsevier Inc.

Developing Probabilistic Safety Performance Margins for Unknown and Underappreciated Risks

NASA Technical Reports Server (NTRS)

Benjamin, Allan; Dezfuli, Homayoon; Everett, Chris

2015-01-01

Probabilistic safety requirements currently formulated or proposed for space systems, nuclear reactor systems, nuclear weapon systems, and other types of systems that have a low-probability potential for high-consequence accidents depend on showing that the probability of such accidents is below a specified safety threshold or goal. Verification of compliance depends heavily upon synthetic modeling techniques such as PRA. To determine whether or not a system meets its probabilistic requirements, it is necessary to consider whether there are significant risks that are not fully considered in the PRA either because they are not known at the time or because their importance is not fully understood. The ultimate objective is to establish a reasonable margin to account for the difference between known risks and actual risks in attempting to validate compliance with a probabilistic safety threshold or goal. In this paper, we examine data accumulated over the past 60 years from the space program, from nuclear reactor experience, from aircraft systems, and from human reliability experience to formulate guidelines for estimating probabilistic margins to account for risks that are initially unknown or underappreciated. The formulation includes a review of the safety literature to identify the principal causes of such risks.

Perceptions and observations of off-shift nursing.

PubMed

de Cordova, Pamela B; Phibbs, Ciaran S; Stone, Patricia W

2013-03-01

The purpose of this paper is to qualitatively explore registered nurse perceptions of off-shift (e.g. nights and weekends) nursing care and quality compared with regular hours. Patients admitted to hospitals on off-shifts have worse outcomes than patients admitted on more regular hours. The underlying mechanism for this association is not well understood. In-depth semi-structured interviews of 23 registered nurses and four observer-as-participant observations were conducted on both medical-surgical and intensive care units in two large (>850 beds) tertiary hospitals. Content analysis was used to identify themes. Six themes emerged: (1) collaboration among self-reliant night nurses; (2) completing tasks; (3) taking a breather on weekend day shift; (4) new nurse requirement to work at night; (5) mixture of registered nurse personnel; and (6) night nurse perception of under-appreciation. Although nurses collaborate, complete more tasks and work with other types of registered nurses, the decreased resources available on off-shifts may affect quality care delivered in hospitals. These findings support the importance of management to provide sufficient resources in terms of ancillary personnel and balance less experienced staff. Facilitating communication between night and day nurses may help allay night nurses' feelings of under-appreciation. © 2012 Blackwell Publishing Ltd.

Evidence for a 17-d periodicity from Cyg X-3

NASA Technical Reports Server (NTRS)

Holt, S. S.; Boldt, E. A.; Serlemitsos, P. J.; Kaluzienski, L. J.; Pravdo, S. H.; Peacock, A.; Elvis, M.; Watson, M. G.; Pounds, K. A.

1976-01-01

Data are presented from the Ariel-V All-Sky Monitor which indicate a 17-day periodicity of the X-ray spectra from Cyg X-3 (3U2030+40). The data are consistent with data from the Ariel V Sky Survey Experiment. Assuming that the high intensity state of Cyg X-3 is well fitted by a structureless black body (Serlemitsos et al., 1975), and that the 17-day maxima correspond to increased electron scattering in the source, it is suggested that the 17-day effect is analogous to the 35-day variation in Her X-1. The possible explanation of this phenomenon as a result of the 17-day orbital period of the binary system containing Cyg X-3 is severely constrained by the stability of the well-known 4.8-hour variation.

Research on slow electron collision processes in gases. Final report, September 15, 1970--December 31, 1972

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baldwin, G C

1974-04-30

Research on low energy electron collisions in gases by the time-of- flight velocity selection technique included, as a preliminary to total cross section measurements, investigations of the statistical and systematic errors inherent in the technique. In particular, thermal transpiration and instrumental fluctuation errors in manometry were investigated, and the results embodied in computer programs for data reduction. The instrumental system was improved to permit extended periods of data accumulation without manual attention. Total cross section measurements in helium, made prior to, and in molecular nitrogen, made after the supporting work was completed, are reported. The total cross sec tion ofmore » helium is found to be higher than reported in previous beam determinations. That of nitrogen is found to be structureless at low energies. (auth)« less

Vibration-translation energy transfer in anharmonic diatomic molecules. 2: The vibrational quantum number dependence

NASA Technical Reports Server (NTRS)

Mckenzie, R. L.

1975-01-01

A semiclassical model of the inelastic collision between a vibrationally excited anharmonic oscillator and a structureless atom was used to predict the variation of thermally averaged vibration-translation rate coefficients with temperature and initial-state quantum number. Multiple oscillator states were included in a numerical solution for collinear encounters. The results are compared with CO-He experimental values for both ground and excited initial states using several simplified forms of the interaction potential. The numerical model was also used as a basis for evaluating several less complete but analytic models. Two computationally simple analytic approximations were found that successfully reproduced the numerical rate coefficients for a wide range of molecular properties and collision partners. Their limitations were also identified. The relative rates of multiple-quantum transitions from excited states were evaluated for several molecular types.

Structural arrest in an ideal gas.

PubMed

van Ketel, Willem; Das, Chinmay; Frenkel, Daan

2005-04-08

We report a molecular dynamics study of a simple model system that has the static properties of an ideal gas, yet exhibits nontrivial "glassy" dynamics behavior at high densities. The constituent molecules of this system are constructs of three infinitely thin hard rods of length L, rigidly joined at their midpoints. The crosses have random but fixed orientation. The static properties of this system are those of an ideal gas, and its collision frequency can be computed analytically. For number densities NL(3)/V>1, the single-particle diffusivity goes to zero. As the system is completely structureless, standard mode-coupling theory cannot describe the observed structural arrest. Nevertheless, the system exhibits many dynamical features that appear to be mode-coupling-like. All high-density incoherent intermediate scattering functions collapse onto master curves that depend only on the wave vector.

Gordon Wilson Lecture: Infectious Disease Causes of Cancer: Opportunities for Prevention and Treatment.

PubMed

Howley, Peter M

2015-01-01

The role of infectious agents in cancer is generally underappreciated. However, approximately 20% of human cancers are caused by infectious agents and as such they rank second only to tobacco as a potentially preventable cause in humans. Specific viruses, parasites, and bacteria have been linked to specific human cancers. The infectious etiology for these specific cancers provides opportunities for prevention and treatment.

The Facial Platysma and Its Underappreciated Role in Lower Face Dynamics and Contour.

PubMed

de Almeida, Ada R T; Romiti, Alessandra; Carruthers, Jean D A

2017-08-01

The platysma is a superficial muscle involved in important features of the aging neck. Vertical bands, horizontal lines, and loss of lower face contour are effectively treated with botulinum toxin A (BoNT-A). However, its pars facialis, mandibularis, and modiolaris have been underappreciated. To demonstrate the role of BoNT-A treatment of the upper platysma and its impact on lower face dynamics and contour. Retrospective analysis of cases treated by an injection pattern encompassing the facial platysma components, aiming to block the lower face as a whole complex. It consisted of 2 intramuscular injections into the mentalis muscle and 2 horizontal lines of BoNT-A injections superficially performed above and below the mandible (total dose, 16 onabotulinumtoxinA U/side). Photographs were taken at rest and during motion (frontal and oblique views), before and after treatment. A total of 161 patients have been treated in the last 2 years with the following results: frontal and lateral enhancement of lower facial contour, relaxation of high horizontal lines located just below the lateral mandibular border, and lower deep vertical smile lines present lateral to the oral commissures and melomental folds. The upper platysma muscle plays a relevant role in the functional anatomy of the lower face that can be modulated safely with neuromodulators.

Marijuana: a decade and a half later, still a crude drug with underappreciated toxicity.

PubMed

Schwartz, Richard H

2002-02-01

In 1984, I published in this journal a review entitled "Marijuana: A Crude Drug With a Spectrum of Underappreciated Toxicity." In the introduction to that article, I disclosed that our son Keith, who was 15 years old at the time, was in a long-term, modified outpatient adolescent drug and alcohol rehabilitation program because he had become dependent on marijuana with its associated behavioral, interpersonal, scholastic, and antisocial problems. Keith and most of his friends had experimented several times with LSD, beer, and several other drugs but never used injection drugs. Marijuana was clearly Keith's drug of choice and the only drug he used with regularity. Approximately 1 year later, Keith graduated from the treatment program. He completed the early aftercare component, relapsed several times, and completed a 4-month refresher drug rehabilitation program in another state. Nine years after admission to the first rehabilitation program, Keith finally attained some adult goals. Now 34 years old, he has been drug-free for 10 years. He is the president and owner of a successful discount cellular phone business that he started. More important, a decade ago, he reestablished an excellent and close relationship with his parents. As far as I can tell, Keith remains drug-free except for an occasional beer.

Carbonate-shelf depositional environments of the Ordovician Viola formation in South-Central Kansas

USGS Publications Warehouse

Newell, K.D.

2000-01-01

The Upper Ordovician Viola Formation, an important petroleum reservoir in the Midcontinent, is a carbonate unit present over much of the subsurface in Kansas. The Viola is composed of two fining-upward sedimentary packages that are separated from each other by a minor karstic surface representing a brief period of exposure. Each package represents a third-order sedimentary cycle and consists of an echinoderm-rich packstone overlain by a thicker lime mudstone. The echinoderm-rich packstone was deposited nearshore in agitated waters, but subsequently was bioturbated. The overlying lime mudstone was deposited in deeper, quiet waters, and locally contains storm-deposited carbonate sands. Subtle growth of the Central Kansas Arch and Pratt Anticline (structures transecting the depositional shelf) is indicated by packstones and grainstones being thicker over these arches, whereas finer grained lithologies dominate in basinal areas on the arch flanks. Structureless lime mudstones, probably intensely bioturbated, grade into laminated lime mudstones farther basinward.

Demixing, surface nematization, and competing adsorption in binary mixtures of hard rods and hard spheres under confinement

NASA Astrophysics Data System (ADS)

Wu, Liang; Malijevský, Alexandr; Avendaño, Carlos; Müller, Erich A.; Jackson, George

2018-04-01

A molecular simulation study of binary mixtures of hard spherocylinders (HSCs) and hard spheres (HSs) confined between two structureless hard walls is presented. The principal aim of the work is to understand the effect of the presence of hard spheres on the entropically driven surface nematization of hard rod-like particles at surfaces. The mixtures are studied using a constant normal-pressure Monte Carlo algorithm. The surface adsorption at different compositions is examined in detail. At moderate hard-sphere concentrations, preferential adsorption of the spheres at the wall is found. However, at moderate to high pressure (density), we observe a crossover in the adsorption behavior with nematic layers of the rods forming at the walls leading to local demixing of the system. The presence of the spherical particles is seen to destabilize the surface nematization of the rods, and the degree of demixing increases on increasing the hard-sphere concentration.

The Effect of Predators on Cholera Biofilms: If it Lyses, We Can Smash It

NASA Astrophysics Data System (ADS)

Kalziqi, Arben; Bernardy, Eryn; Thomas, Jacob; Ratcliff, Will; Hammer, Brian; Yunker, Peter

Many microbes form biofilms--dense clumps of cells and proteins--on surfaces. Biofilms are complex communities that facilitate the study of biological competition (e.g., two types of microbes may compete to form a biofilm in the same location) and interesting physics (e.g., the source of a biofilm's rigidity). Vibrio cholerae can produce biofilms which have a network-like structure--however, cholera can be genetically engineered to kill other cholera with different genotypes, which leaves behind a structureless ``slime'' rather than such a biofilm. Through mechanical creep testing of both predator-prey and non-predator populations, we found that the predator-prey population responds viscously and decreases in height with repeated compression, whereas the non-predator population responds elastically and maintains its original height. The current work suggests that cell lysis after killing disrupts biofilm formation, preventing microbial colonies from forming rigid networks.

Automatic Detection of Blue-White Veil and Related Structures in Dermoscopy Images

PubMed Central

Celebi, M. Emre; Iyatomi, Hitoshi; Stoecker, William V.; Moss, Randy H.; Rabinovitz, Harold S.; Argenziano, Giuseppe; Soyer, H. Peter

2011-01-01

Dermoscopy is a non-invasive skin imaging technique, which permits visualization of features of pigmented melanocytic neoplasms that are not discernable by examination with the naked eye. One of the most important features for the diagnosis of melanoma in dermoscopy images is the blue-white veil (irregular, structureless areas of confluent blue pigmentation with an overlying white “ground-glass” film). In this article, we present a machine learning approach to the detection of blue-white veil and related structures in dermoscopy images. The method involves contextual pixel classification using a decision tree classifier. The percentage of blue-white areas detected in a lesion combined with a simple shape descriptor yielded a sensitivity of 69.35% and a specificity of 89.97% on a set of 545 dermoscopy images. The sensitivity rises to 78.20% for detection of blue veil in those cases where it is a primary feature for melanoma recognition. PMID:18804955

A transform from absorption to Raman excitation profile. A time-dependent approach

NASA Astrophysics Data System (ADS)

Lee, Soo-Y.; Yeo, Robert C. K.

1994-04-01

An alternative time-frame approach, which is canonically conjugate to the energy-frame approach, for implementing the transform relations for calculating Raman excitation profiles directly from the optical absorption spectrum is presented. Practical and efficient fast Fourier transformation in the time frame replaces the widely used Chan and Page algorithm for evaluating the Hilbert transform in the energy frame. The time-frame approach is applied to: (a) a two-mode model which illustrates the missing mode effect in both absorption and Raman excitation profiles, (b) carotene, in which both the absorption spectrum and the Raman excitation profile show vibrational structure and (c) hexamethylbenzene: TCNE electron donor—acceptor complex where the same spectra are structureless and the Raman excitation profile for the 168 cm -1 mode poses a problem for the energy-frame approach. A similar time-frame approach can be used for the inverse transform from the Raman excitation profile to the optical absorption spectrum.

Molecular mechanisms of decomposition of hydrated Na+Cl- ion pairs under planar nanopore conditions

NASA Astrophysics Data System (ADS)

Shevkunov, S. V.

2017-02-01

The decomposition of Na+Cl- ion pairs under the conditions of a nanoscopic planar pore with structureless walls in a material contact with water vapor at 298 K is simulated by Monte Carlo method. The transition from the state of a contact ion pair (CIP) to the state of solvent-separated ion pair (SSIP) is shown to occur as a result of an increase in the vapor pressure over a pore after exceeding the threshold number of molecules in a hydrate shell. It is found that the planar form of a molecular cluster under the conditions of a narrow pore does not level an abrupt structural transition and the formation of hydrogen bonds in the hydrate shell starts after three molecules are added. The hydrogen bond length under pore conditions is found to be resistant to variations in the hydrate shell size and coincides with that in water under normal conditions.

Morphological instability of a thermophoretically growing deposit

NASA Technical Reports Server (NTRS)

Castillo, Jose L.; Garcia-Ybarra, Pedro L.; Rosner, Daniel E.

1992-01-01

The stability of the planar interface of a structureless solid growing from a depositing component dilute in a carrier fluid is studied when the main solute transport mechanism is thermal (Soret) diffusion. A linear stability analysis, carried out in the limit of low growth Peclet number, leads to a dispersion relation which shows that the planar front is unstable either when the thermal diffusion factor of the condensing component is positive and the latent heat release is small or when the thermal diffusion factor is negative and the solid grows over a thermally-insulating substrate. Furthermore, the influence of interfacial energy effects and constitutional supersaturation in the vicinity of the moving interface is analyzed in the limit of very small Schmidt numbers (small solute Fickian diffusion). The analysis is relevant to physical vapor deposition of very massive species on cold surfaces, as in recent experiments of organic solid film growth under microgravity conditions.

Demixing, surface nematization, and competing adsorption in binary mixtures of hard rods and hard spheres under confinement.

PubMed

Wu, Liang; Malijevský, Alexandr; Avendaño, Carlos; Müller, Erich A; Jackson, George

2018-04-28

A molecular simulation study of binary mixtures of hard spherocylinders (HSCs) and hard spheres (HSs) confined between two structureless hard walls is presented. The principal aim of the work is to understand the effect of the presence of hard spheres on the entropically driven surface nematization of hard rod-like particles at surfaces. The mixtures are studied using a constant normal-pressure Monte Carlo algorithm. The surface adsorption at different compositions is examined in detail. At moderate hard-sphere concentrations, preferential adsorption of the spheres at the wall is found. However, at moderate to high pressure (density), we observe a crossover in the adsorption behavior with nematic layers of the rods forming at the walls leading to local demixing of the system. The presence of the spherical particles is seen to destabilize the surface nematization of the rods, and the degree of demixing increases on increasing the hard-sphere concentration.

Marketing-Stimulated Word-of-Mouth: A Channel for Growing Demand.

PubMed

Gombeski, William R; Martin, Becky; Britt, Jason

2015-01-01

Marketing-stimulated word-of-mouth (WOM) marketing has been poorly understood in health care, leading to it being underappreciated and underutilized by marketers. A study of new patients to a new runner's clinic was conducted to understand how they chose the program. The importance of marketing-stimulated WOM, both individual and organizational, is documented. Marketing-stimulated WOM is an often overlooked and rarely measured channel for increasing the impact of marketing programs.

Accountability: The Most Underappreciated Aspect of Command

DTIC Science & Technology

2012-02-15

1994). Webster, John. "Air Force Hush Job Skips Accountability." The Spokesman-Review. May 25, 1995. http://www.spokesman.com/stories/1995/may/25...air-force- hush -job-skips- accountability/ (accessed December 9, 2011). Wynne, Michael W., Secretary of the Air Force. "Resignation Letter." June 6...used against you in a trial by court-martial except…for perjury, false swearing, or for a false official statement.” 79 John Webster, “Air Force Hush

Warts and All: HPV in Primary Immunodeficiencies

PubMed Central

Leiding, Jennifer W.; Holland, Steven M.

2012-01-01

Infection with human papilloma virus (HPV) is almost universal and eventually asymptomatic, but pathologic infection with HPV is severe, recurrent, and recalcitrant to therapy. It is also an underappreciated manifestation of primary immunodeficiency. Mutations in EVER1, EVER2, GATA2, CXCR4, and DOCK8 are typically associated with extensive HPV infections, whereas several other primary immune defects have severe HPV much less frequently. We review immunodeficiencies with severe HPV infections and the mechanisms underlying them. PMID:23036745

EDITORIAL Neuroglia as a Central Element of Neurological Diseases: An Underappreciated Target for Therapeutic Intervention

PubMed Central

Peng, Liang; Parpura, Vladimir; Verkhratsky, Alexei

2014-01-01

Neuroglia of the central nervous system (CNS), represented by cells of neural (astrocytes, oligodendrocytes and NG2 glial cells) and myeloid (microglia) origins are fundamental for homeostasis of the nervous tissue. Astrocytes are critical for the development of the CNS, they are indispensable for synaptogenesis, and they define structural organisation of the nervous tissue, as well as the generation and maintenance of CNS-blood and cerebrospinal fluid-blood barriers. Astroglial cells control homeostasis of ions and neurotransmitters and provide neurones with metabolic support. Oligodendrocytes, through the process of myelination, as well as by homoeostatic support of axons provide for interneuronal connectivity. The NG2 cells receive direct synaptic inputs, and might be important elements of adult remyelination. Microglial cells, which originate from foetal macrophages invading the brain early in embryogenesis, shape the synaptic connections through removing of redundant synapses and phagocyting apoptotic neurones. Neuroglia also form the defensive system of the CNS through complex and context-specific programmes of activation, known as reactive gliosis. Many neurological diseases are associated with neurogliopathologies represented by asthenic and atrophic changes in glial cells that, through the loss or diminution of their homeostatic and defensive functions, assist evolution of pathology. Conceptually, neurological and psychiatric disorders can be regarded as failures of neuroglial homeostatic/ defensive responses, and, hence, glia represent a (much underappreciated) target for therapeutic intervention. PMID:25342938

Whooping cough in adults: an update on a reemerging infection.

PubMed

Paisley, Robert D; Blaylock, Jason; Hartzell, Joshua D

2012-02-01

Pertussis, or whooping cough, which is commonly thought of as a pediatric illness, is an underappreciated adult pathogen. Recent outbreaks highlight the significance of pertussis in adults and the risk of transmission to at-risk infants who are most susceptible to complications, including death. This article describes the recent epidemiologic shifts and reviews the clinical presentation, diagnosis, and treatment of pertussis. New vaccination recommendations by the Advisory Committee on Immunization Practices in response to recent outbreaks and infant deaths are highlighted. Published by Elsevier Inc.

Hidden Dragon, Crouching Lion: How China’s Advance in Africa is Underestimated and Africa’s Potential Underappreciated

DTIC Science & Technology

2012-09-01

revenues in ways that invest in development instead of being squandered by elites. Beijing is filling an important gap in Western aid—and doing...for yield .49 While this point about the cost of corruption is partly valid, most of the statistical evidence supports the optimists’ view that...foreign invest- ments in Africa have yielded , on average, the highest rates of return on investment of any region—returns that are accruing

Diamictite from Nimrod Glacier area, Antarctica: Possible Proterozoic glaciation on the seventh continent

NASA Astrophysics Data System (ADS)

Stump, Edmund; Miller, Julia M. G.; Korsch, Russell J.; Edgerton, David G.

1988-03-01

Late Proterozoic glacial deposits have been found on all continents except Antarctica. Here we describe four units of Late Proterozoic diamictite, with a total thickness of about 10m, from Panorama Point, Nimrod Glacier area, Antarctica, which have characteristics compatible with glaciogenic origin. The diamictite occurs within the Goldie Formation, a sequence of marine turbidites, and is associated with a unit of mafic pillow lavas. The diamictite is commonly structureless and in places laminated. Coarse clasts occur as scattered pebbles and cobbles and as pebbly pods and beds. No striated or faceted clasts were found. A few pebbles may pierce the laminae, but a drop-stone origin is uncertain. Deformation and metamorphism have obscured subtleties of original sedimentary structure. Outsize clasts in laminated sandy siltstone (now schistose) suggest a glaciogenic origin for these diamictites, but deposition by mass-flow processes cannot be ruled out. The discovery in Antarctica of possible Late Proterozoic glaciogenic deposits extends their geographic distribution to all of the major continental masses.

Optical constants of solid methane and ethane from 10,000 to 450/cm. [in outer planets atmospheres

NASA Technical Reports Server (NTRS)

Pearl, J.; Ngoh, M.; Ospina, M.; Khanna, R.

1991-01-01

Near- and mid-IR spectra of thin films of crystalling phase I and phase II C2H6 are presented using a combined least squares and Kramers-Kronig analysis. Complex refractive indices derived from these data are also presented. To obtain material in phase I, samples are annealed at 33 K for about 30 min; phase II is obtained by recooling below the transition temperature of 20.4 K. The derived optical parameters are shown. The infrared spectrum of phase I CH4 exhibits broad structureless absorptions at about 1300 and 2600/cm. On cooling the sample below 20.4 K (phase II), the absorptions are sharpened, and each band develops fine structure. The present results and those of Roux et al. (1979) are compared. The agreement with the real parts is found to be excellent; given the difference in resolution, the agreement with the imaginary parts is also good.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Chandan K.; Singh, Jayant K., E-mail: jayantks@iitk.ac.in

Three-stage pseudo-supercritical transformation path and multiple-histogram reweighting technique are employed for the determination of solid-liquid coexistence of the Lennard-Jones (12-6) fluid, in a structureless cylindrical pore of radius, R, ranging from 4 to 20 molecular diameters. The Gibbs free energy difference is evaluated using thermodynamic integration method by connecting solid and liquid phases under confinement via one or more intermediate states without any first order phase transition among them. The thermodynamic melting temperature, T{sub m}, is found to oscillate for pore size, R < 8, which is in agreement with the behavior observed for the melting temperature in slit pores.more » However, T{sub m} for almost all pore sizes is less than the bulk case, which is contrary to the behavior seen for the slit pore. The oscillation in T{sub m} decays at around pore radius R = 8, and beyond that shift in the melting temperature with respect to the bulk case is in line with the prediction of the Gibbs-Thomson equation.« less

Structure of spherical electric double layers with fully asymmetric electrolytes: a systematic study by Monte Carlo simulations and density functional theory.

PubMed

Patra, Chandra N

2014-11-14

A systematic investigation of the spherical electric double layers with the electrolytes having size as well as charge asymmetry is carried out using density functional theory and Monte Carlo simulations. The system is considered within the primitive model, where the macroion is a structureless hard spherical colloid, the small ions as charged hard spheres of different size, and the solvent is represented as a dielectric continuum. The present theory approximates the hard sphere part of the one particle correlation function using a weighted density approach whereas a perturbation expansion around the uniform fluid is applied to evaluate the ionic contribution. The theory is in quantitative agreement with Monte Carlo simulation for the density and the mean electrostatic potential profiles over a wide range of electrolyte concentrations, surface charge densities, valence of small ions, and macroion sizes. The theory provides distinctive evidence of charge and size correlations within the electrode-electrolyte interface in spherical geometry.

Emergent mechanics, quantum and un-quantum

NASA Astrophysics Data System (ADS)

Ralston, John P.

2013-10-01

There is great interest in quantum mechanics as an "emergent" phenomenon. The program holds that nonobvious patterns and laws can emerge from complicated physical systems operating by more fundamental rules. We find a new approach where quantum mechanics itself should be viewed as an information management tool not derived from physics nor depending on physics. The main accomplishment of quantum-style theory comes in expanding the notion of probability. We construct a map from macroscopic information as data" to quantum probability. The map allows a hidden variable description for quantum states, and efficient use of the helpful tools of quantum mechanics in unlimited circumstances. Quantum dynamics via the time-dependent Shroedinger equation or operator methods actually represents a restricted class of classical Hamiltonian or Lagrangian dynamics, albeit with different numbers of degrees of freedom. We show that under wide circumstances such dynamics emerges from structureless dynamical systems. The uses of the quantum information management tools are illustrated by numerical experiments and practical applications

In vitro energy transfer in Renilla bioluminescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, W.W.; Cormier, M.J.

1976-09-23

A quantitative study of in vitro energy transfer in a natural biological system is reported. The in vitro bioluminescent oxidation of Renilla (sea pansy) luciferin by luciferase produces a broad, structureless emission, peaking in the blue at 490 nm. In contrast, the live animal produces a structured emission peaking in the green at 509 nm. This difference in emission characteristics is due to the presence, in Renilla, of a green fluorescent protein (GFP). Addition of GFP in vitro sensitizes the oxyluciferin product excited state, resulting in the narrow, structured green emission characteristic of GFP fluorescence (lambda/sub max/ 509 nm). Undermore » conditions of efficient in vitro energy transfer (2.7 x 10/sup -6/ M GFP) the radiative quantum yield (with respect to luciferin) increases 5.7-fold from 5.3% (blue pathway) to 30% (green pathway). The fluorescence quantum yield of the Renilla GFP has been measured as 30%; thus, within the precision of our measurements (15% coefficient of variation) the in vitro energy transfer efficiency is a surprising 100%.« less

Mean force potential of interaction between Na+ and Cl- ions in planar nanopores in contact with water under pressure

NASA Astrophysics Data System (ADS)

Shevkunov, S. V.

2017-11-01

The mean force potential (MFP) of interaction between counterions Na+ and Cl- in a planar nanopore with structureless hydrophobic walls is calculated via computer simulation under the condition that the nanopore is in contact with water at an external pressure that exceeds the saturation pressure but remains insufficient to fill the nanopore with water. For a nanopore with a liquid phase, the MFP dependence on the interionic distance indicates the dissociation of an ion pair into two hydrated ions in a nanopore that is not completely filled with water. Fluctuations in the number of water molecules drawn into the interionic space decisively influence the dissociation. The attraction between counterions, averaged over thermal fluctuations, depends largely on the pore width and grows as the shielding of the ions' electric field by water molecules in a narrow pore diminishes. The contributions from energy and entropy to the free energy of hydration are analyzed.

Random catalytic reaction networks

NASA Astrophysics Data System (ADS)

Stadler, Peter F.; Fontana, Walter; Miller, John H.

1993-03-01

We study networks that are a generalization of replicator (or Lotka-Volterra) equations. They model the dynamics of a population of object types whose binary interactions determine the specific type of interaction product. Such a system always reduces its dimension to a subset that contains production pathways for all of its members. The network equation can be rewritten at a level of collectives in terms of two basic interaction patterns: replicator sets and cyclic transformation pathways among sets. Although the system contains well-known cases that exhibit very complicated dynamics, the generic behavior of randomly generated systems is found (numerically) to be extremely robust: convergence to a globally stable rest point. It is easy to tailor networks that display replicator interactions where the replicators are entire self-sustaining subsystems, rather than structureless units. A numerical scan of random systems highlights the special properties of elementary replicators: they reduce the effective interconnectedness of the system, resulting in enhanced competition, and strong correlations between the concentrations.

Fine Structure of Plasmaspheric Hiss

NASA Astrophysics Data System (ADS)

Summers, D.; Omura, Y.; Nakamura, S.; Kletzing, C.

2014-12-01

Plasmaspheric hiss plays a key role in controlling the structure and dynamics of Earth's radiation belts.The quiet time slot region between the inner and outer belts can be explained as a steady-state balance between earthward radial diffusion and pitch-angle scattering loss of energetic electrons to the atmosphere induced by plasmaspheric hiss. Plasmaspheric hiss can also induce gradual precipitation loss of MeV electrons from the outer radiation belt. Plasmaspheric hiss has been widely regarded as a broadband,structureless,incoherent emission. Here, by examining burst-mode vector waveform data from the EMFISIS instrument on the Van Allen Probes mission,we show that plasmaspheric hiss is a coherent emission with complex fine structure. Specifically, plasmaspheric hiss appears as discrete rising tone and falling tone elements. By means of waveform analysis we identify typical amplitudes,phase profiles,and sweep rates of the rising and falling tone elements. The new observations reported here can be expected to fuel a re-examination of the properties of plasmaspheric hiss, including a further re-analysis of the generation mechanism for hiss.

Distance distributions of short polypeptides recovered by fluorescence resonance energy transfer in the 10 A domain.

PubMed

Sahoo, Harekrushna; Roccatano, Danilo; Zacharias, Martin; Nau, Werner M

2006-06-28

Fluorescence resonance energy transfer (FRET) between tryptophan (Trp) as donor and 2,3-diazabicyclo[2.2.2]oct-2-ene (Dbo) as acceptor was studied by steady-state and time-resolved fluorescence spectroscopy. The unique feature of this FRET pair is its exceptionally short Förster radius (10 A), which allows one to recover distance distributions in very short structureless peptides. The technique was applied to Trp-(GlySer)n-Dbo-NH2 peptides with n = 0-10, for which the average probe/quencher distance ranged between 8.7 and 13.7 A experimentally (in propylene glycol, analysis according to wormlike chain model) and 8.6-10.2 A theoretically (for n = 0-6, GROMOS96 molecular dynamics simulations). The larger FRET efficiency in steady-state compared to time-resolved fluorescence experiments was attributed to a static quenching component, suggesting that a small but significant part (ca. 10%) of the conformations are already in van der Waals contact when excitation occurs.

Role of Passive Diffusion, Transporters, and Membrane Trafficking-Mediated Processes in Cellular Drug Transport.

PubMed

Cocucci, E; Kim, J Y; Bai, Y; Pabla, N

2017-01-01

Intracellular drug accumulation is thought to be dictated by two major processes, passive diffusion through the lipid membrane or membrane transporters. The relative role played by these distinct processes remains actively debated. Moreover, the role of membrane-trafficking in drug transport remains underappreciated and unexplored. Here we discuss the distinct processes involved in cellular drug distribution and propose that better experimental models are required to elucidate the differential contributions of various processes in intracellular drug accumulation. © 2016 American Society for Clinical Pharmacology and Therapeutics.

Role of short-acting nitroglycerin in the management of ischemic heart disease.

PubMed

Boden, William E; Padala, Santosh K; Cabral, Katherine P; Buschmann, Ivo R; Sidhu, Mandeep S

2015-01-01

Nitroglycerin is the oldest and most commonly prescribed short-acting anti-anginal agent; however, despite its long history of therapeutic usage, patient and health care provider education regarding the clinical benefits of the short-acting formulations in patients with angina remains under-appreciated. Nitrates predominantly induce vasodilation in large capacitance blood vessels, increase epicardial coronary arterial diameter and coronary collateral blood flow, and impair platelet aggregation. The potential for the prophylactic effect of short-acting nitrates remains an under-appreciated part of optimal medical therapy to reduce angina and decrease myocardial ischemia, thereby enhancing the quality of life. Short-acting nitroglycerin, administered either as a sublingual tablet or spray, can complement anti-anginal therapy as part of optimal medical therapy in patients with refractory and recurrent angina either with or without myocardial revascularization, and is most commonly used to provide rapid therapeutic relief of acute recurrent angina attacks. When administered prophylactically, both formulations increase angina-free walking time on treadmill testing, abolish or delay ST segment depression, and increase exercise tolerance. The sublingual spray formulation provides several clinical advantages compared to tablet formulations, including a lower incidence of headache and superiority to the sublingual tablet in terms of therapeutic action and time to onset, while the magnitude and duration of vasodilatory action appears to be comparable. Furthermore, the sublingual spray formulation may be advantageous to tablet preparations in patients with dry mouth. This review discusses the efficacy and utility of short-acting nitroglycerin (sublingual spray and tablet) therapy for both preventing and aborting an acute angina attack, thereby leading to an improved quality of life.

Role of short-acting nitroglycerin in the management of ischemic heart disease

PubMed Central

Boden, William E; Padala, Santosh K; Cabral, Katherine P; Buschmann, Ivo R; Sidhu, Mandeep S

2015-01-01

Nitroglycerin is the oldest and most commonly prescribed short-acting anti-anginal agent; however, despite its long history of therapeutic usage, patient and health care provider education regarding the clinical benefits of the short-acting formulations in patients with angina remains under-appreciated. Nitrates predominantly induce vasodilation in large capacitance blood vessels, increase epicardial coronary arterial diameter and coronary collateral blood flow, and impair platelet aggregation. The potential for the prophylactic effect of short-acting nitrates remains an under-appreciated part of optimal medical therapy to reduce angina and decrease myocardial ischemia, thereby enhancing the quality of life. Short-acting nitroglycerin, administered either as a sublingual tablet or spray, can complement anti-anginal therapy as part of optimal medical therapy in patients with refractory and recurrent angina either with or without myocardial revascularization, and is most commonly used to provide rapid therapeutic relief of acute recurrent angina attacks. When administered prophylactically, both formulations increase angina-free walking time on treadmill testing, abolish or delay ST segment depression, and increase exercise tolerance. The sublingual spray formulation provides several clinical advantages compared to tablet formulations, including a lower incidence of headache and superiority to the sublingual tablet in terms of therapeutic action and time to onset, while the magnitude and duration of vasodilatory action appears to be comparable. Furthermore, the sublingual spray formulation may be advantageous to tablet preparations in patients with dry mouth. This review discusses the efficacy and utility of short-acting nitroglycerin (sublingual spray and tablet) therapy for both preventing and aborting an acute angina attack, thereby leading to an improved quality of life. PMID:26316714

Efficient electrochemical degradation of multiwall carbon nanotubes.

PubMed

Reipa, Vytas; Hanna, Shannon K; Urbas, Aaron; Sander, Lane; Elliott, John; Conny, Joseph; Petersen, Elijah J

2018-07-15

As the production mass of multiwall carbon nanotubes (MWCNT) increases, the potential for human and environmental exposure to MWCNTs may also increase. We have shown that exposing an aqueous suspension of pristine MWCNTs to an intense oxidative treatment in an electrochemical reactor, equipped with an efficient hydroxyl radical generating Boron Doped Diamond (BDD) anode, leads to their almost complete mineralization. Thermal optical transmittance analysis showed a total carbon mass loss of over two orders of magnitude due to the electrochemical treatment, a result consistent with measurements of the degraded MWCNT suspensions using UV-vis absorbance. Liquid chromatography data excludes substantial accumulation of the low molecular weight reaction products. Therefore, up to 99% of the initially suspended MWCNT mass is completely mineralized into gaseous products such as CO 2 and volatile organic carbon. Scanning electron microscopy (SEM) images show sporadic opaque carbon clusters suggesting the remaining nanotubes are transformed into structure-less carbon during their electrochemical mineralization. Environmental toxicity of pristine and degraded MWCNTs was assessed using Caenorhabditis elegans nematodes and revealed a major reduction in the MWCNT toxicity after treatment in the electrochemical flow-by reactor. Published by Elsevier B.V.

Stochastic fluctuations and the detectability limit of network communities.

PubMed

Floretta, Lucio; Liechti, Jonas; Flammini, Alessandro; De Los Rios, Paolo

2013-12-01

We have analyzed the detectability limits of network communities in the framework of the popular Girvan and Newman benchmark. By carefully taking into account the inevitable stochastic fluctuations that affect the construction of each and every instance of the benchmark, we come to the conclusion that the native, putative partition of the network is completely lost even before the in-degree/out-degree ratio becomes equal to that of a structureless Erdös-Rényi network. We develop a simple iterative scheme, analytically well described by an infinite branching process, to provide an estimate of the true detectability limit. Using various algorithms based on modularity optimization, we show that all of them behave (semiquantitatively) in the same way, with the same functional form of the detectability threshold as a function of the network parameters. Because the same behavior has also been found by further modularity-optimization methods and for methods based on different heuristics implementations, we conclude that indeed a correct definition of the detectability limit must take into account the stochastic fluctuations of the network construction.

Prize for a Faculty Member for Research in and Undergraduate Institution: Higher order corrections to positronium energies

NASA Astrophysics Data System (ADS)

Adkins, Gregory

2016-03-01

Positronium spectroscopy is of continuing interest as a high-precision test of our understanding of binding in QED. Positronium-the electron-positron bound state-represents the purest example of binding in QFT as the constituents are structureless and their interactions are dominated by QED with only negligible contributions from strong or weak effects. Positronium differs from other Coulombic bound systems such as hydrogen or muonium in having maximal recoil (the constituent mass ratio m / M is one) and being subject to real and virtual annihilation into photons. Positronium spectroscopy (n = 1 hyperfine splitting, n = 2 fine structure, and the 2 S - 1 S interval) has reached a precision of order 1MHz , and ongoing experimental efforts may lead to improved results. Theoretical calculations of positronium energies at order mα6 ~ 18 . 7MHz are complete, but only partial results are known at order mα7 ~ 0 . 14MHz . I will report on the status of the positronium energy calculations and present new results for order mα7 contributions. Support provided by the NSF through Grant No. PHY-1404268.

Calculating constants of the rates of the reactions of excitation, ionization, and atomic exchange: A model of a shock oscillator with a change of the Hamiltonian of the system

NASA Astrophysics Data System (ADS)

Tsyganov, D. L.

2017-11-01

A new model for calculating the rates of reactions of excitation, ionization, and atomic exchange is proposed. Diatomic molecule AB is an unstructured particle M upon the exchange of elastic-vibrational (VT) energy, i.e., a model of a shock forceful oscillator with a change in Hamiltonian (SFOH). The SFOH model is based on the quantum theory of strong perturbations. The SFOH model allows generalization in simulating the rates of the reactions of excitation, ionization, and atomic exchange in the vibrational-vibrational (VV) energy exchange of diatomic molecules, and the exchange of VV- and VT-energy of polyatomic molecules. The rate constants of the excitation of metastables A 3Σ u +, B 3Π g , W 3Δ u , B'3Σ u -, a'3Σ u -, and the ionization of a nitrogen molecules from ground state X2Σ g + upon a collision with a heavy structureless particle (a nitrogen molecule), are found as examples.

Transient Dissipation and Structural Costs of Physical Information Transduction

NASA Astrophysics Data System (ADS)

Boyd, Alexander B.; Mandal, Dibyendu; Riechers, Paul M.; Crutchfield, James P.

2017-06-01

A central result that arose in applying information theory to the stochastic thermodynamics of nonlinear dynamical systems is the information-processing second law (IPSL): the physical entropy of the Universe can decrease if compensated by the Shannon-Kolmogorov-Sinai entropy change of appropriate information-carrying degrees of freedom. In particular, the asymptotic-rate IPSL precisely delineates the thermodynamic functioning of autonomous Maxwellian demons and information engines. How do these systems begin to function as engines, Landauer erasers, and error correctors? We identify a minimal, and thus inescapable, transient dissipation of physical information processing, which is not captured by asymptotic rates, but is critical to adaptive thermodynamic processes such as those found in biological systems. A component of transient dissipation, we also identify an implementation-dependent cost that varies from one physical substrate to another for the same information processing task. Applying these results to producing structured patterns from a structureless information reservoir, we show that "retrodictive" generators achieve the minimal costs. The results establish the thermodynamic toll imposed by a physical system's structure as it comes to optimally transduce information.

Towards a physical classification of early-type galaxies. Profile of a key programme.

NASA Astrophysics Data System (ADS)

Bender, R.; Capaccioli, M.; Macchetto, F.; Nieto, J.-L.

1989-03-01

Hubble was the first who succeeded in classifying galaxies within a scheme of some physical meaning. Although it soon became clear that Hubble's tuning fork does not represent an evolutionary sequence, this essential diagram has proven to be a powerful tool especially for the understanding of late-type galaxies. On the other hand, the "early-type" sequence of elliptical (E) and SO galaxies is less satisfying, because it does not seem to reflect a unique sequence of physical properties. The SO class, although conceived to bridge the gap between disk- and disk-Iess galaxies, has often been abused to host ellipticals exhibiting peculiarities incompatible with their definition as structureless objects. For the elliptical galaxies themselves, "ellipticity" has been found to be essentially meaningless with regard to their angular momentum properties, and shows Iittle, if any, correlation with other global parameters. This fact became apparent after the first stellar kinematical measurements of luminous ellipticals (Bertola and Capaccioli 1975, IIlingworth 1977); E galaxies are not necessarily f1attened by rotation and may have anisotropie velocity dispersions (Binney 1978).

Coherent vorticity extraction in resistive drift-wave turbulence: Comparison of orthogonal wavelets versus proper orthogonal decomposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Futatani, S.; Bos, W.J.T.; Del-Castillo-Negrete, Diego B

2011-01-01

We assess two techniques for extracting coherent vortices out of turbulent flows: the wavelet based Coherent Vorticity Extraction (CVE) and the Proper Orthogonal Decomposition (POD). The former decomposes the flow field into an orthogonal wavelet representation and subsequent thresholding of the coefficients allows one to split the flow into organized coherent vortices with non-Gaussian statistics and an incoherent random part which is structureless. POD is based on the singular value decomposition and decomposes the flow into basis functions which are optimal with respect to the retained energy for the ensemble average. Both techniques are applied to direct numerical simulation datamore » of two-dimensional drift-wave turbulence governed by Hasegawa Wakatani equation, considering two limit cases: the quasi-hydrodynamic and the quasi-adiabatic regimes. The results are compared in terms of compression rate, retained energy, retained enstrophy and retained radial flux, together with the enstrophy spectrum and higher order statistics. (c) 2010 Published by Elsevier Masson SAS on behalf of Academie des sciences.« less

Registered nurse buddies: Educators by proxy?

PubMed

Rebeiro, Geraldine; Evans, Alicia; Edward, Karen-Leigh; Chapman, Rose

2017-08-01

The informal clinical teaching role of the buddy nurse seems to be a uniquely Australian title, with little consistency in terminology for informal nurse educator roles internationally. Not all registered nurses are professionally developed for the informal role of facilitating the clinical learning of students in clinical settings, yet these roles are expected by nursing professional bodies. In Australia the registered nurses (RN) experience of being a buddy nurse has been reported as lacking clarity, being unsupported and structureless. Whist there is a plethora of literature published about formal RN educator roles, little is available on the informal buddy nurse role. A view of the buddy nurse role in reference to the limited but available literature in the Australian context is offered in this paper. International perspectives are also gathered describing informal clinical education RN's roles with similar responsibilities to the Australian buddy nurse. The significance of this dialogue is to ignite debate about the role, potentially informing policy for the improved support of the role within the Australian nursing landscape. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solvation of carbonaceous molecules by para-H2 and ortho-D2 clusters. II. Fullerenes.

PubMed

Calvo, F; Yurtsever, E

2016-08-28

The coating of various fullerenes by para-hydrogen and ortho-deuterium molecules has been computationally studied as a function of the solvent amount. Rotationally averaged interaction potentials for structureless hydrogen molecules are employed to model their interaction with neutral or charged carbonaceous dopants containing between 20 and 240 atoms, occasionally comparing different fullerenes having the same size but different shapes. The solvation energy and the size of the first solvation shell obtained from path-integral molecular dynamics simulations at 2 K show only minor influence on the dopant charge and on the possible deuteration of the solvent, although the shell size is largest for ortho-D2 coating cationic fullerenes. Nontrivial finite size effects have been found with the shell size varying non-monotonically close to its completion limit. For fullerenes embedded in large hydrogen clusters, the shell size and solvation energy both follow linear scaling with the fullerene size. The shell sizes obtained for C60 (+) and C70 (+) are close to 49 and 51, respectively, and agree with mass spectrometry experiments.

Solvation of carbonaceous molecules by para-H2 and ortho-D2 clusters. II. Fullerenes

NASA Astrophysics Data System (ADS)

Calvo, F.; Yurtsever, E.

2016-08-01

The coating of various fullerenes by para-hydrogen and ortho-deuterium molecules has been computationally studied as a function of the solvent amount. Rotationally averaged interaction potentials for structureless hydrogen molecules are employed to model their interaction with neutral or charged carbonaceous dopants containing between 20 and 240 atoms, occasionally comparing different fullerenes having the same size but different shapes. The solvation energy and the size of the first solvation shell obtained from path-integral molecular dynamics simulations at 2 K show only minor influence on the dopant charge and on the possible deuteration of the solvent, although the shell size is largest for ortho-D2 coating cationic fullerenes. Nontrivial finite size effects have been found with the shell size varying non-monotonically close to its completion limit. For fullerenes embedded in large hydrogen clusters, the shell size and solvation energy both follow linear scaling with the fullerene size. The shell sizes obtained for C 60+ and C 70+ are close to 49 and 51, respectively, and agree with mass spectrometry experiments.

Transition metal atomic multiplets in the ligand K-edge x-ray absorption spectra and multiple oxidation states in the L2,3 emission of strongly correlated compounds

NASA Astrophysics Data System (ADS)

Jiménez-Mier, J.; Olalde-Velasco, P.; Yang, W.-L.; Denlinger, J.

2014-07-01

We present results that show that atomic multiplet ligand field calculations are in very good agreement with experimental x-ray absorption spectra at the L2,3 edge of transition metal (TM) di-fluorides (MF2, MCrCu). For chromium more than one TM oxidation state is needed to achieve such an agreement. We also show that signature of the TM atomic multiplet can be found at the pre-edge of the fluorine K-edge x-ray absorption spectra. TM atomic multiplet ligand field calculations with a structureless core hole show good agreement with the observed pre-edges in the experimental fluorine absorption spectra. Preliminary results for the comparison between calculated and experimental resonant x-ray emission spectra for nominal CrF2 with more than one oxidation state indicate the presence of three chromium oxidation states in the bulk.

Preparation of nonconducting infrared-absorbing thin films

NASA Astrophysics Data System (ADS)

Gradhand, Martin; Breitenstein, Otwin

2005-05-01

A simple procedure for preparing colloidal "black" bismuth films is introduced, which leaves the target cold and does not pollute the recipient. The Bi evaporation occurs in a closed box in the evaporation chamber with an internal radiation shield. The bismuth is evaporated from a tantalum boat at a residual air pressure of 2×102Pa. The resulting films with a thickness of about 10μm are structureless down to a spatial resolution of 5.6μm, they become electrically insulating after 48h storage time in air, and they show an IR absorbance of above 70% in the 3-5μm wavelength range. The films are easily removable in an ultrasonic water bath. Thus, these films are ideally appropriate to increase the IR emissivity of microelectronic structures in microthermal infrared failure analysis investigations such as lock-in thermography, as is demonstrated in an application example. The application of this film may improve the thermographic detection limit of heat sources below metallized areas by up to a factor of 10, leading to a saving in acquisition time by a factor of 100.

Progradational sequences in Miocene shoreline deposits, southeastern Caliente Range, California

USGS Publications Warehouse

Clifton, H. Edward

1981-01-01

An exceptionally well exposed marine-nonmarine transition in middle Miocene strata exists in the southeastern Caliente Range, California. About 50 individual progradational sequences form a succession that ranges in thickness from approximately 1000 m (where predominantly nonmarine) to more than 2500 m (where predominantly marine). Paleogreographic evidence in basalt flows near the top of the succession and in overlying fluvial deposists indicates that these middle Miocene strata were deposited across a north-northwest trending shoreline.A complete progradational sequence typically is several meters to a few tens of meters thick and includes strata that represent three intertonguing stratigraphic units. Individual sequences generally rest on a thin gravel deposit interpreted as a transgressive lag on an erosional surface. The gravel is overlain by structureless siltstone or fine-grained sandstone deposited at water depths where the rate of faunal mixing exceeded that of production of structures by physical processes. These rocks grade upward into bedded fine sandstone deposited closer to shore where physical processes exceeded bioturbation. Crossbedded lenses of coarse sand or fine gravel in the upper part of this facies suggest the presence of failry long-period surface waves. The bedded fine sandstone is sharply overlain by a crossbedded coarse sandstone facies that is interpreted as a combined offshore bar-rip channel-surf zone assemblage. Cross-strata dip dominantly offshore, suggesting substantial deposition from rip currents. A secondary, shore=parallel mode of cross-strata direction suggests longshore currents produced by surface waves from the northwest. The crossbedded coarse-grained sandstone grades upward into planar-bedded medium-grained sandstone that is interpreted as a beach foreshore. This facies grades upward through structureless medium-grained sandstone into nonmarine or lagoonal red and green mudstone of the Caliente Formation.The middle Miocene succession was deposited in a subsiding basin that was otherwise remarkably stable tectonically; the position of the strand line differed no more than a few kilometers through a period of 1 to 3 m.y. The average duration of the transgressive-regressive cycles, a few tens of thousands of years, together with their distribution in groups of three or four in the lower two-thirds of the succession, is consistent with the pattern of long-term climatic cycles produced by periodicity of the earth's solar orbit and may be related to eustatic sea level changes attendant to the development of the Antarctic ice cap. Changes in the pattern of progradation in the upper part of the succession and nearby basaltic eruptions may hav been precursors to the onset of movement along the San Andreas fault in this area 12-14 m.y. ago.

Categorizing vitric lithofacies on seamounts: implications for recognizing deep-marine pyroclastic deposits

NASA Astrophysics Data System (ADS)

Portner, R. A.; Clague, D. A.

2011-12-01

Glassy fragmental deposits commonly found capping seamounts have been variably interpreted as the products of quench-fragmentation (hyaloclastite), suppressed steam expansion, and/or explosive fire-fountains (pyroclastite). To better understand these vitriclastic deposits we use a multidisciplinary approach that outlines six lithofacies based on textures, sedimentary structures, geochemical diversity, and associations with seamount landforms. All seamounts studied yield MORB compositions and formed on or near mid-ocean ridge axes of the northeast Pacific Ocean. Consolidated deposits were sampled from the Taney (~29 Ma), President Jackson (~3 Ma), and Vance (~2 Ma) seamounts using ROV manipulator arms and dredge hauls. Unconsolidated deposits from the currently active Axial Seamount of the Juan de Fuca Ridge were sampled using ROV push core and vacuum techniques. Lithofacies occur with talus breccias and pillow basalt on steeply dipping outer flanks and caldera walls, and with pillow and sheet flows on subhorizontal rims and nested caldera floors of the seamounts. Vitric lithofacies within or near steeply dipping regions have very angular textures, coarse grain-sizes and abundant crystalline basalt fragments. Jig-saw fit texture is common in units with monomict geochemistry and closely associated with adjacent pillow basalt, suggesting in-situ fragmentation akin to pillow breccia. Similar units bearing polymodal geochemistry are generally associated with talus breccias along caldera walls and basal slopes, and are interpreted as fault-scarp derived debrites. Laterally these lithofacies abruptly grade into bottom-current reworked lithofacies on flat caldera floors. Reworked lithofacies have >40% muddy matrix with abundant angular mineral fragments, biogenic grains and minor devitrified glass shards. They typically exhibit well-defined planar lamination and locally show sinusoidal ripple forms. Horizontal burrows including Planolites are common. Locally this lithofacies has a structureless to 'swirled' habit and interdigitating bedding contacts where it is host to matrix-supported subround vitric lapilli with low-vesicularity. These rare globules have mud-filled embayments, bubbles and quench-cracks, jig-saw fit texture, and fluidal morphologies suggesting a pepperitic origin. Laterally, bottom current reworked lithofacies grade into fine-to medium-grained ash lithofacies proximal to volcanic-constructional landforms. These landforms have broad morphologies with subdued slopes and are interpreted as source vents. Lithofacies generated from these vents invariably contain an abundance of low-vesicular limu-o-Pele'- or highly-vesicular round lapilli. Units are coarse-tail reverse to normal graded and crudely planar laminated or structureless. Locally, basal contacts are erosive. This facies is interpreted as fall-out from particle lofting or high-density gravity flows generated by explosive eruptions. By combining high-resolution bathymetric mapping and sampling with post-cruise geochemical and petrographic examination, we outline a previously unrecognized diversity to seamount-capping vitriclastic deposits. This approach will be useful for studies focused on deciphering explosive origins of deep-marine volcaniclastic deposits.

The Converged Experience of Risk and Disease

PubMed Central

Aronowitz, Robert A

2009-01-01

Context: One underappreciated consequence of modern clinical and public health practices is that the experience of being at risk for disease has been converging with the experience of disease itself. This is especially true for certain chronic diseases, in which early diagnosis and aggressive treatment have led to symptom-less and sign-less disease and in which treatments have largely been aimed at altering the disease's future course. Methods: This article reviews the historical scholarship and medical literature pertinent to transformations in the chronic disease and risk experiences. Findings: The experience of chronic disease increasingly resembles or has become indistinguishable from risk because of (1) new clinical interventions that have directly changed the natural history of disease; (2) increased biological, clinical, and epidemiological knowledge about the risk of chronic disease; (3) the recruitment of larger numbers into chronic disease diagnoses via new screening and diagnostic technology and disease definitions; (4) new ways of conceptualizing efficacy; and (5) intense diagnostic testing and medical interventions. Conclusions: The converged experience of risk and disease has led to some unsettling and generally underappreciated consequences that might be subjected to more clinical and policy reflection and response: (1) some puzzling trends in medical decision making, such as the steep and uniform increase in the numbers of women across a broad spectrum of risk/disease in breast cancer who have opted for prophylactic mastectomies; (2) a larger and highly mobilized disease/risk population, resulting in an expanded market for interventions and greater clout for disease advocates; (3) shifts in the perceived severity of the disease, with ripple effects on how people experience and understand their illness and risk of disease; and (4) interventions that promise both to reduce the risk of disease and to treat its symptoms. PMID:19523124

Compared with what? An analysis of control-group types in Cochrane and Campbell reviews of psychosocial treatment efficacy with substance use disorders.

PubMed

Karlsson, Patrik; Bergmark, Anders

2015-03-01

A crucial, but under-appreciated, aspect in experimental research on psychosocial treatments of substance use disorders concerns what kinds of control groups are used. This paper examines how the distinction between different control-group designs have been handled by the Cochrane and the Campbell Collaborations in their systematic reviews of psychosocial treatments of substance abuse disorders. We assessed Cochrane and Campbell reviews (n = 8) that were devoted to psychosocial treatments of substance use disorders. We noted what control groups were considered and analysed the extent to which the reviews provided a rationale for chosen comparison conditions. We also analysed whether type of control group in the primary studies influenced how the reviews framed the effects discussed and whether this was related to conclusions drawn. The reviews covered studies involving widely different control conditions. Overall, little attention was paid to the use of different control groups (e.g. head-to-head comparisons versus untreated controls) and what this implies when interpreting effect sizes. Seven of eight reviews did not provide a rationale for the choice of comparison conditions. Cochrane and Campbell reviews of the efficacy of psychosocial interventions with substance use disorders seem to underappreciate that the use of different control-group types yields different effect estimates. Most reviews have not distinguished between different control-group designs and therefore have provided a confused picture regarding absolute and relative treatment efficacy. A systematic approach to treating different control-group designs in research reviews is necessary for meaningful estimates of treatment efficacy. © 2014 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.

The Evolution of the Human Genome

PubMed Central

Simonti, Corinne N.; Capra, John A.

2015-01-01

Human genomes hold a record of the evolutionary forces that have shaped our species. Advances in DNA sequencing, functional genomics, and population genetic modeling have deepened our understanding of human demographic history, natural selection, and many other long-studied topics. These advances have also revealed many previously underappreciated factors that influence the evolution of the human genome, including functional modifications to DNA and histones, conserved 3D topological chromatin domains, structural variation, and heterogeneous mutation patterns along the genome. Using evolutionary theory as a lens to study these phenomena will lead to significant breakthroughs in understanding what makes us human and why we get sick. PMID:26338498

Earthquakes in Hawai‘i—an underappreciated but serious hazard

USGS Publications Warehouse

Okubo, Paul G.; Nakata, Jennifer S.

2011-01-01

The State of Hawaii has a history of damaging earthquakes. Earthquakes in the State are primarily the result of active volcanism and related geologic processes. It is not a question of "if" a devastating quake will strike Hawai‘i but rather "when." Tsunamis generated by both distant and local quakes are also an associated threat and have caused many deaths in the State. The U.S. Geological Survey (USGS) and its cooperators monitor seismic activity in the State and are providing crucial information needed to help better prepare emergency managers and residents of Hawai‘i for the quakes that are certain to strike in the future.

Ion-dipole interactions and their functions in proteins.

PubMed

Sippel, Katherine H; Quiocho, Florante A

2015-07-01

Ion-dipole interactions in biological macromolecules are formed between atomic or molecular ions and neutral protein dipolar groups through either hydrogen bond or coordination. Since their discovery 30 years ago, these interactions have proven to be a frequent occurrence in protein structures, appearing in everything from transporters and ion channels to enzyme active sites to protein-protein interfaces. However, their significance and roles in protein functions are largely underappreciated. We performed PDB data mining to identify a sampling of proteins that possess these interactions. In this review, we will define the ion-dipole interaction and discuss several prominent examples of their functional roles in nature. © 2015 The Protein Society.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kadoura, Ahmad, E-mail: ahmad.kadoura@kaust.edu.sa, E-mail: adil.siripatana@kaust.edu.sa, E-mail: shuyu.sun@kaust.edu.sa, E-mail: omar.knio@kaust.edu.sa; Sun, Shuyu, E-mail: ahmad.kadoura@kaust.edu.sa, E-mail: adil.siripatana@kaust.edu.sa, E-mail: shuyu.sun@kaust.edu.sa, E-mail: omar.knio@kaust.edu.sa; Siripatana, Adil, E-mail: ahmad.kadoura@kaust.edu.sa, E-mail: adil.siripatana@kaust.edu.sa, E-mail: shuyu.sun@kaust.edu.sa, E-mail: omar.knio@kaust.edu.sa

In this work, two Polynomial Chaos (PC) surrogates were generated to reproduce Monte Carlo (MC) molecular simulation results of the canonical (single-phase) and the NVT-Gibbs (two-phase) ensembles for a system of normalized structureless Lennard-Jones (LJ) particles. The main advantage of such surrogates, once generated, is the capability of accurately computing the needed thermodynamic quantities in a few seconds, thus efficiently replacing the computationally expensive MC molecular simulations. Benefiting from the tremendous computational time reduction, the PC surrogates were used to conduct large-scale optimization in order to propose single-site LJ models for several simple molecules. Experimental data, a set of supercriticalmore » isotherms, and part of the two-phase envelope, of several pure components were used for tuning the LJ parameters (ε, σ). Based on the conducted optimization, excellent fit was obtained for different noble gases (Ar, Kr, and Xe) and other small molecules (CH{sub 4}, N{sub 2}, and CO). On the other hand, due to the simplicity of the LJ model used, dramatic deviations between simulation and experimental data were observed, especially in the two-phase region, for more complex molecules such as CO{sub 2} and C{sub 2} H{sub 6}.« less

Evolutionary pulsational mode dynamics in nonthermal turbulent viscous astrofluids

NASA Astrophysics Data System (ADS)

Karmakar, Pralay Kumar; Dutta, Pranamika

2017-11-01

The pulsational mode of gravitational collapse in a partially ionized self-gravitating inhomogeneous viscous nonthermal nonextensive astrofluid in the presence of turbulence pressure is illustratively analyzed. The constitutive thermal species, lighter electrons and ions, are thermostatistically treated with the nonthermal κ-distribution laws. The inertial species, such as identical heavier neutral and charged dust microspheres, are modelled in the turbulent fluid framework. All the possible linear processes responsible for dust-dust collisions are accounted. The Larson logatropic equations of state relating the dust thermal (linear) and turbulence (nonlinear) pressures with dust densities are included. A regular linear normal perturbation analysis (local) over the complex astrocloud ensues in a generalized quartic dispersion relation with unique nature of plasma-dependent multi-parametric coefficients. A numerical standpoint is provided to showcase the basic mode features in a judicious astronomical paradigm. It is shown that both the kinematic viscosity of the dust fluids and nonthermality parameter (kappa, the power-law tail index) of the thermal species act as stabilizing (damping) agent against the gravity; and so forth. The underlying evolutionary microphysics is explored. The significance of redistributing astrofluid material via waveinduced accretion in dynamic nonhomologic structureless cloud collapse leading to hierarchical astrostructure formation is actualized.

Dermoscopic nevus patterns in skin of colour: a prospective, cross-sectional, morphological study in individuals with skin type V and VI.

PubMed

Lallas, A; Reggiani, C; Argenziano, G; Kyrgidis, A; Bakos, R; Masiero, N C M S; Scheibe, A B; Cabo, H; Ozdemir, F; Sortino-Rachou, A M; Turk, B Gerceker; Moscarella, E; Longo, C; Zalaudek, I

2014-11-01

Most of the knowledge on the prevailing dermoscopic patterns of acquired melanocytic nevi (AMV) is based on studies in Caucasians, while little research focuses on the dermoscopic variability in nevi in skin of colour. To analyse the prevalent dermoscopic nevus patterns in subjects with a skin type (ST) V and VI. Prospective, cross-sectional, morphological study was conducted in six clinics with enrolment of consecutive individuals with a ST V or VI. Digital dermoscopic images of selected representative AMN were assessed for dermoscopic colours, morphological patterns and pigment distribution. Analysis of 300 nevi from subjects with ST V and VI revealed significant differences in the nevus pattern between these two groups. The majority of nevi in ST V revealed a reticular pattern, whereas persons with ST VI more frequently exhibited a structureless pattern. Black, blue and grey were more frequent in ST VI, whereas the vast majority of nevi in ST V individuals showed dark brown colour. Our study provides new insights into the nevus pattern in individuals with a dark pigmentary trait, which may aid the diagnosis and management of nevi in this patients group. © 2013 European Academy of Dermatology and Venereology.

Using positron 2D-ACAR as a probe of point defects in GaAs: The As vacancy as a case study

NASA Astrophysics Data System (ADS)

Ambigapathy, R.; Corbel, C.; Hautojärvi, P.; Manuel, A. A.; Saarinen, K.

1996-06-01

Two-Dimensional Angular Correlation of positron Annihilation Radiation (2D-ACAR) experiments have been performed on n-type GaAs. By combining these results with those from positron lifetime experiments, the momentum distribution of the arsenic vacancy in its neutral ( V {aAs/0}) and negative ( V {As/-}) charge states have been extracted. These distributions were all normalized to the respective positron lifetime that characterizes them. The first thing to be noticed is that the momentum distributions of the vacancies, as seen by the positron, are fairly isotropic and structureless. The distribution for V {As/0} is more peaked than that of V {As/-} while the latter is more intense in the large momentum regions of the spectra. From this, it can be inferred that VA. has a smaller open volume than V {As/0} A closer look at the momentum distribution of the vacancies reveals that they are not entirely isotropic, but, in fact, have a bulk-like component. Finally, the experimental results for bulk GaAs and V {As/-} compare well in a qualitative manner with the momentum distributions that result from an ab-initio molecular dynamics calculation.

Visual graph query formulation and exploration: a new perspective on information retrieval at the edge

NASA Astrophysics Data System (ADS)

Kase, Sue E.; Vanni, Michelle; Knight, Joanne A.; Su, Yu; Yan, Xifeng

2016-05-01

Within operational environments decisions must be made quickly based on the information available. Identifying an appropriate knowledge base and accurately formulating a search query are critical tasks for decision-making effectiveness in dynamic situations. The spreading of graph data management tools to access large graph databases is a rapidly emerging research area of potential benefit to the intelligence community. A graph representation provides a natural way of modeling data in a wide variety of domains. Graph structures use nodes, edges, and properties to represent and store data. This research investigates the advantages of information search by graph query initiated by the analyst and interactively refined within the contextual dimensions of the answer space toward a solution. The paper introduces SLQ, a user-friendly graph querying system enabling the visual formulation of schemaless and structureless graph queries. SLQ is demonstrated with an intelligence analyst information search scenario focused on identifying individuals responsible for manufacturing a mosquito-hosted deadly virus. The scenario highlights the interactive construction of graph queries without prior training in complex query languages or graph databases, intuitive navigation through the problem space, and visualization of results in graphical format.

Ultrafast exciton relaxation in monolayer transition metal dichalcogenides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thilagam, A., E-mail: thilaphys@gmail.com

2016-04-28

We examine a mechanism by which excitons undergo ultrafast relaxation in common monolayer transition metal dichalcogenides. It is shown that at densities ≈1 × 10{sup 11 }cm{sup −2} and temperatures ≤60 K, excitons in well known monolayers (MoS{sub 2}, MoSe{sub 2}, WS{sub 2}, and WSe{sub 2}) exist as point-like structureless electron-hole quasi-particles. We evaluate the average rate of exciton energy relaxation due to acoustic phonons via the deformation potential and the piezoelectric coupling mechanisms and examine the effect of spreading of the excitonic wavefunction into the region perpendicular to the monolayer plane. Our results show that the exciton relaxation rate is enhanced with increasemore » in the exciton temperature, while it is decreased with increase in the lattice temperature. Good agreements with available experimental data are obtained when the calculations are extrapolated to room temperatures. A unified approach taking into account the deformation potential and piezoelectric coupling mechanisms shows that exciton relaxation induced by phonons is as significant as defect assisted scattering and trapping of excitons by surface states in monolayer transition metal dichalcogenides.« less

S. Burt Wolbach, Rocky Mountain spotted fever, and blood-sucking arthropods: triumph of an early investigative pathologist.

PubMed

Musser, James M

2013-02-01

In a series of four articles published between 1916 and 1919 in The Journal of Medical Research, precursor to The American Journal of Pathology, the investigative pathologist S. Burt Wolbach unambiguously showed that Rocky Mountain spotted fever has a tick-borne mode of transmission, the causative agent replicates intracellularly, and the disease is fundamentally a vasculitis. Although underappreciated, Wolbach's tour-de-force work epitomized investigative pathology. These four articles should be mandatory reading for young investigators and are recommended also to seasoned investigators who seek reinvigoration in the beauty in their craft. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Global Health Warning: Definitions Wield Power

PubMed Central

Marten, Robert

2016-01-01

Gorik Ooms recently made a strong case for considering the centrality of normative premises to analyzing and understanding the underappreciated importance of the nexus of politics, power and process in global health. This critical commentary raises serious questions for the practice and study of global health and global health governance. First and foremost, this commentary underlines the importance of the question of what is global health, and why as well as how does this definition matter? This refocuses discussion on the importance of definitions and how they wield power. It also re-affirms the necessity of a deeper analysis and understanding of power and how it affects and shapes the practice of global health. PMID:26927595

X-Phi and Carnapian Explication.

PubMed

Shepherd, Joshua; Justus, James

2015-04-01

The rise of experimental philosophy (x-phi) has placed metaphilosophical questions, particularly those concerning concepts, at the center of philosophical attention. X-phi offers empirically rigorous methods for identifying conceptual content, but what exactly it contributes towards evaluating conceptual content remains unclear. We show how x-phi complements Rudolf Carnap's underappreciated methodology for concept determination, explication. This clarifies and extends x-phi's positive philosophical import, and also exhibits explication's broad appeal. But there is a potential problem: Carnap's account of explication was limited to empirical and logical concepts, but many concepts of interest to philosophers (experimental and otherwise) are essentially normative. With formal epistemology as a case study, we show how x-phi assisted explication can apply to normative domains.

Cystic neutrophilic granulomatous mastitis: an underappreciated pattern strongly associated with gram-positive bacilli.

PubMed

Renshaw, Andrew A; Derhagopian, Robert P; Gould, Edwin W

2011-09-01

Although granulomatous lobular mastitis is associated with gram-positive bacilli such as Corynebacterium, this association is not well known. We report 3 cases of mastitis caused by gram-positive bacilli. All 3 abscesses were suppurative with distinct enlarged cystic spaces in which rare gram-positive bacilli were identified. Two cases were also granulomatous. Cultures in all 3 cases were negative. All 3 patients recovered after biopsy and tetracycline-based therapy. Infection in the breast by gram-positive bacilli is associated with a distinct histologic pattern, including cystic spaces in the setting of neutrophilic/granulomatous inflammation that can be recognized and should prompt careful search for the organism within enlarged vacuoles.

High histologic grade and increased relative content of tryptophan in breast cancer using ratios from fingerprint fluorescence spectral peaks

NASA Astrophysics Data System (ADS)

Sordillo, Laura A.; Sordillo, Peter P.; Budansky, Yury; Pu, Yang; Alfano, R. R.

2015-03-01

Histologic grade is a very important, but underappreciated, parameter of breast cancer aggressiveness. Despite its importance, it has historically not been included as one of the criteria for staging of this cancer. In this study, spectral fluorescence profiles from patients with breast carcinoma were acquired. Ratios of emission peaks at 340 over 440,460 nm from biomolecules in malignant and normal samples were calculated. Cancerous over normal ratios (double ratio (DR) method) were evaluated with respect to tumor characteristics. Increased tryptophan content in breast cancer tissues correlates strongly with high grade, but not with lymph node metastases, estrogen receptor, progesterone receptor or Her-2-Neu receptor status.

Updated Physician’s Guide to the Off-label Uses of Oral Isotretinoin

PubMed Central

Peterson, Nathan; Peterson, Michael

2014-01-01

While oral isotretinoin is renowned for its ability to treat acne vulgaris, many of its off-label uses continue to go underappreciated. Since the last review on the unapproved indications of isotretinoin, relevant publications have surfaced with new recommendations. This article attempts to provide physicians with the latest information regarding successful and unsuccessful use of isotretinoin as an effective treatment for dermatological conditions, such as rosacea, psoriasis, pityriasis rubra pilaris, condyloma acuminatum, granuloma annulare, Darier’s disease, systemic cutaneous lupus erythematosus, nonmelanoma skin cancer, and hidradenitis suppurativa. Variations in dosage regimens and isotretinoin viability as an alternative to other standard treatments are also discussed in relation to these conditions. PMID:24765227

John Adams's Montesquieuean Moment: Enlightened Historicism in the Discourses on Davila.

PubMed

Green, Jonathan

2016-01-01

At the outset of the French Revolution John Adams penned a series of Discourses of Davila, philosophical ruminations on the sixteenth-century French Wars of Religion. Recent historians have read these Discourses in terms of Adams's Machiavellianism-his conviction that men's passions lead to violence, if unrestrained. But this reading overlooks the extent to which Adams intended his Discourses as a particular investigation into the French nation's character, and into whether the revolutionaries could lay claim to a native, French tradition of mixed constitutional government. Situating the Discourses vis-à-vis Adams's contemporaneous reading of Montesquieu, this article argues for an underappreciated historicist dimension to his thought.

Magnetically multiplexed heating of single domain nanoparticles

NASA Astrophysics Data System (ADS)

Christiansen, M. G.; Senko, A. W.; Chen, R.; Romero, G.; Anikeeva, P.

2014-05-01

Selective hysteretic heating of multiple collocated types of single domain magnetic nanoparticles (SDMNPs) by alternating magnetic fields (AMFs) may offer a useful tool for biomedical applications. The possibility of "magnetothermal multiplexing" has not yet been realized, in part due to prevalent use of linear response theory to model SDMNP heating in AMFs. Dynamic hysteresis modeling suggests that specific driving conditions play an underappreciated role in determining optimal material selection strategies for high heat dissipation. Motivated by this observation, magnetothermal multiplexing is theoretically predicted and empirically demonstrated by selecting SDMNPs with properties that suggest optimal hysteretic heat dissipation at dissimilar AMF driving conditions. This form of multiplexing could effectively offer multiple channels for minimally invasive biological signaling applications.

Sense and sensibility: flagellum-mediated gene regulation

PubMed Central

Anderson, Jennifer K.; Smith, Todd G.; Hoover, Timothy R.

2009-01-01

The flagellum, a rotary engine required for motility in many bacteria, plays key roles in gene expression. It has been known for some time that flagellar substructures serve as checkpoints that coordinate flagellar gene expression with assembly. Less well understood, however, are other more global effects on gene expression. For instance, the flagellum acts as a ‘wetness’ sensor in Salmonella typhimurium and as a mechanosensor in other bacteria. Additionally, it has been implicated in a variety of bacterial processes, including biofilm formation, pathogenesis and symbiosis. Although for many of these processes it may be simply that motility is required, for other cases it seems that the flagellum plays an underappreciated role in regulating gene expression. PMID:19942438

Functions of tissue-resident eosinophils.

PubMed

Weller, Peter F; Spencer, Lisa A

2017-12-01

Eosinophils are a prominent cell type in particular host responses such as the response to helminth infection and allergic disease. Their effector functions have been attributed to their capacity to release cationic proteins stored in cytoplasmic granules by degranulation. However, eosinophils are now being recognized for more varied functions in previously underappreciated diverse tissue sites, based on the ability of eosinophils to release cytokines (often preformed) that mediate a broad range of activities into the local environment. In this Review, we consider evolving insights into the tissue distribution of eosinophils and their functional immunobiology, which enable eosinophils to secrete in a selective manner cytokines and other mediators that have diverse, 'non-effector' functions in health and disease.

Profound metabolic acidosis from pyroglutamic acidemia: an underappreciated cause of high anion gap metabolic acidosis.

PubMed

Green, Thomas J; Bijlsma, Jan Jaap; Sweet, David D

2010-09-01

The workup of the emergency patient with a raised anion gap metabolic acidosis includes assessment of the components of “MUDPILES” (methanol; uremia; diabetic ketoacidosis; paraldehyde; isoniazid, iron or inborn errors of metabolism; lactic acid; ethylene glycol; salicylates). This approach is usually sufficient for the majority of cases in the emergency department; however, there are many other etiologies not addressed in this mnemonic. Organic acids including 5-oxoproline (pyroglutamic acid) are rare but important causes of anion gap metabolic acidosis. We present the case of a patient with profound metabolic acidosis with raised anion gap, due to pyroglutamic acid in the setting of malnutrition and chronic ingestion of acetaminophen.

Sense and sensibility: flagellum-mediated gene regulation.

PubMed

Anderson, Jennifer K; Smith, Todd G; Hoover, Timothy R

2010-01-01

The flagellum, a rotary engine required for motility in many bacteria, plays key roles in gene expression. It has been known for some time that flagellar substructures serve as checkpoints that coordinate flagellar gene expression with assembly. Less well understood, however, are other more global effects on gene expression. For instance, the flagellum acts as a 'wetness' sensor in Salmonella typhimurium, and as a mechanosensor in other bacteria. Additionally, it has been implicated in a variety of bacterial processes, including biofilm formation, pathogenesis and symbiosis. Although for many of these processes it might be simply that motility is required, in other cases it seems that the flagellum plays an underappreciated role in regulating gene expression.

Computational study of interfacial charge transfer complexes of 2-anthroic acid adsorbed on a titania nanocluster for direct injection solar cells

NASA Astrophysics Data System (ADS)

Manzhos, Sergei; Kotsis, Konstantinos

2016-09-01

Adsorption and light absorption properties of interfacial charge transfer complexes of 2-anthroic acid and titania, promising for direct-injection solar cells, are studied ab initio. The formation of interfacial charge transfer bands is observed. The intensity of visible absorption is relatively low, highlighting a key challenge facing direct injection cells. We show that the popular strategy of using a lower level of theory for geometry optimization followed by single point calculations of adsorption or optical properties introduces significant errors which have been underappreciated: by up to 3 eV in adsorption energies, by up to 5 times in light absorption intensity.

Sickle cell in Latin America and the United States [corrected].

PubMed

Huttle, Alexandra; Maestre, Gladys E; Lantigua, Rafael; Green, Nancy S

2015-07-01

Latin Americans are an underappreciated population affected by sickle cell disease (SCD). Sickle trait and SCD exist throughout Latin America and U.S. Latino communities. We describe the epidemiology and genetic heterogeneity of SCD among Latin Americans, and fetal hemoglobin expression. National population-based newborn screening for SCD is limited to Brazil, Costa Rica, and the U.S. Available and extrapolated data suggest that over 6,000 annual births and 100,000-150,000 Latin Americans are affected by SCD. This comprehensive review highlights the substantial numbers and population distribution of SCD and sickle trait in Latin America, and where national newborn screening programs for SCD exist. © 2015 Wiley Periodicals, Inc.

Physical and chemical properties of young soils of the Icelandic highlands

NASA Astrophysics Data System (ADS)

Gísladóttir, Guðrún; Mankasingh, Utra

2015-04-01

Most of the Icelandic soils are of volcanic origin, classified as andisols (carbon content 1-12%), many of which are strongly affected by erosion and so, formation of new soils is of great interest. The effect of land cover type on the weathering patterns and the formation of new soils are of interest. The southern Icelandic highlands are characterised by harsh climate, shallow soils and limited vegetation cover. We hypothesise that in the highland regions of Iceland the progression of land cover from unvegetated to vegetated sites will impact soil development. This study describes the physical and chemical properties of highland soils in Iceland. Soil samples were collected from 12 sites in September 2013, nine sites were fully vegetated and three unvegetated: grassland (G1-G8), with moss, Carex Bigelowii and dwarf shrubs, sandy fluvial wetland (S) and unvegetated gravels (M1-M3). All soils with vegetative cover were characterized by weak or structureless soil ranging in texture from loamy sand to silty clay loam, while at unvegetated sites soil texture was structureless and sandy. On average, the bulk density of soils (range 0.53 - 1.16 g cm-3) were lower at vegetated sites than unvegetated sites. The soil depth is greater in the vegetated sites, indicating greater soil development. The average % carbon (%C), % nitrogen (%N), overall % soil organic matter (%SOM), of vegetated sites were higher than for unvegetated sites, indicating the difference in soil development: vegetated sites (mean), 1.60%C, 0.10%N, 4.9%SOM; unvegetated sites (mean), 0.27%C, 0.02%N, 1.81%SOM. All soils had significant amounts of amorphous clay minerals such as allophone, imogolite, ferrihydrite or aluminium-humus complexes and also high aluminium and iron percentages, and high phosphate retention. All of which are characteristic for andisols. There were strong associations between Fe and Al and the soil C, which are indicative of Al and Fe complexed with humus or allophane and ferrihydrite clays. The allophane and ferrihydrite content was 3.5-7.7% and 2.4-5.3%, respectively. The soils in the study had a high clay content, generally greater than 10% for all soil types. However, selective dissolutions with oxalate and with pyrophosphate indicate that more organic carbon was associated with the Fe and Al of vegetated sites than observed for the vegetated sites. These results also indicate more organic associations in sites with vascular plants and mosses vs mosses only. The %C, %SOM, Fe/Al associations, soil structure and soil depth all indicate that there is gradient of increasing soil genesis form unvegetated to vegetated sites, with evidence of greater organic associations in sites with vascular plants. Even though the soils at the vegetated sites are andisols, they are still immature , while the less developed soils at the unvegetated sites are vitrisols (

T-lymphocyte homing: an underappreciated yet critical hurdle for successful cancer immunotherapy.

PubMed

Sackstein, Robert; Schatton, Tobias; Barthel, Steven R

2017-06-01

Advances in cancer immunotherapy have offered new hope for patients with metastatic disease. This unfolding success story has been exemplified by a growing arsenal of novel immunotherapeutics, including blocking antibodies targeting immune checkpoint pathways, cancer vaccines, and adoptive cell therapy (ACT). Nonetheless, clinical benefit remains highly variable and patient-specific, in part, because all immunotherapeutic regimens vitally hinge on the capacity of endogenous and/or adoptively transferred T-effector (T eff ) cells, including chimeric antigen receptor (CAR) T cells, to home efficiently into tumor target tissue. Thus, defects intrinsic to the multi-step T-cell homing cascade have become an obvious, though significantly underappreciated contributor to immunotherapy resistance. Conspicuous have been low intralesional frequencies of tumor-infiltrating T-lymphocytes (TILs) below clinically beneficial threshold levels, and peripheral rather than deep lesional TIL infiltration. Therefore, a T eff cell 'homing deficit' may arguably represent a dominant factor responsible for ineffective immunotherapeutic outcomes, as tumors resistant to immune-targeted killing thrive in such permissive, immune-vacuous microenvironments. Fortunately, emerging data is shedding light into the diverse mechanisms of immune escape by which tumors restrict T eff cell trafficking and lesional penetrance. In this review, we scrutinize evolving knowledge on the molecular determinants of T eff cell navigation into tumors. By integrating recently described, though sporadic information of pivotal adhesive and chemokine homing signatures within the tumor microenvironment with better established paradigms of T-cell trafficking under homeostatic or infectious disease scenarios, we seek to refine currently incomplete models of T eff cell entry into tumor tissue. We further summarize how cancers thwart homing to escape immune-mediated destruction and raise awareness of the potential impact of immune checkpoint blockers on T eff cell homing. Finally, we speculate on innovative therapeutic opportunities for augmenting T eff cell homing capabilities to improve immunotherapy-based tumor eradication in cancer patients, with special focus on malignant melanoma.

T-Lymphocyte Homing: An Underappreciated yet Critical Hurdle for Successful Cancer Immunotherapy

PubMed Central

Sackstein, Robert; Schatton, Tobias; Barthel, Steven R.

2017-01-01

Advances in cancer immunotherapy have offered new hope for patients with metastatic disease. This unfolding success story has been exemplified by a growing arsenal of novel immunotherapeutics, including blocking antibodies targeting immune checkpoint pathways, cancer vaccines, and adoptive cell therapy (ACT). Nonetheless, clinical benefit remains highly variable and patient-specific, in part, because all immunotherapeutic regimens vitally hinge on the capacity of endogenous and/or adoptively-transferred T effector (Teff) cells, including chimeric antigen receptor (CAR) T cells, to home efficiently into tumor target tissue. Thus, defects intrinsic to the multi-step T cell homing cascade have become an obvious, though significantly underappreciated contributor to immunotherapy resistance. Conspicuous have been low intralesional frequencies of tumor-infiltrating T-lymphocytes (TILs) below clinically beneficial threshold levels, and peripheral rather than deep lesional TIL infiltration. Therefore, a Teff cell ‘homing deficit’ may arguably represent a dominant factor responsible for ineffective immunotherapeutic outcomes, as tumors resistant to immune-targeted killing thrive in such permissive, immune-vacuous microenvironments. Fortunately, emerging data is shedding light into the diverse mechanisms of immune escape by which tumors restrict Teff cell trafficking and lesional penetrance. In this review, we scrutinize evolving knowledge on the molecular determinants of Teff cell navigation into tumors. By integrating recently described, though sporadic information of pivotal adhesive and chemokine homing signatures within the tumor microenvironment with better established paradigms of T cell trafficking under homeostatic or infectious disease scenarios, we seek to refine currently incomplete models of Teff cell entry into tumor tissue. We further summarize how cancers thwart homing to escape immune-mediated destruction and raise awareness of the potential impact of immune checkpoint blockers on Teff cell homing. Finally, we speculate on innovative therapeutic opportunities for augmenting Teff cell homing capabilities to improve immunotherapy-based tumor eradication in cancer patients, with special focus on malignant melanoma. PMID:28346400

What's Tramadol Got to Do with It? A Case Report of Rebound Hypoglycemia, a Reappraisal and Review of Potential Mechanisms.

PubMed

Odonkor, Charles A; Chhatre, Akhil

2016-01-01

Tramadol has gained traction as an analgesic of choice among pain practicing physicians. However some concerns regarding a previously unlabeled adverse reaction - hypoglycemia - have cast it in a dim light. Prior reports have noted an associated risk of hospitalization for hypoglycemia after tramadol use, but whether tramadol is the main causal agent is poorly understood and the underlying mechanisms are not well delineated. We present a unique case of rebound hypoglycemia as a variation of the theme of tramadol's adverse effect profile in a patient with type 1 diabetes mellitus, and reappraise potential mechanisms underlying this underappreciated phenomenon. A 71-year-old woman presented with right buttock pain and right lateral leg discomfort of 9-month duration. Her physical exam suggested sacroiliac joint (SIJ) etiology, confirmed by magnetic resonance imaging (MRI). She was scheduled for an SIJ-diagnostic and therapeutic block and started on tramadol 50 mg 3 times daily on as needed basis. The patient subsequently developed severe hypoglycemia initially resistant to euglycemia restorative interventions with a rebound episode. Hypoglycemia resolved with oral ingestion of high levels of glucose and the patient was taken off tramadol. Fortunately, she did not require hospitalization. The clinical scenario described is a case of rebound hypoglycemia after tramadol use in a patient with type-1 diabetes naïve to opioid analgesics. The episodes of hypoglycemia aligned perfectly with the anticipated pharmacodynamic and pharmacokinetic properties of tramadol. The specificity and temporality of events after tramadol use in this patient fulfilled causality criteria. Tramadol may cause rebound hypoglycemia in patients via interference of the intrinsic euglycemia-restoration pathways and a blunted autonomic counter-regulatory response to antecedent hypoglycemia. Its use must be tempered by this underappreciated adverse effect profile.Key words: Tramadol, hypoglycemia, sacroiliac joint arthritis, type 1 diabetes mellitus, serotonin uptake inhibitors, glutamate receptor 4.

Podiatry services for patients with arthritis: an unmet need.

PubMed

Rome, Keith; Chapman, Jonathan; Williams, Anita E; Gow, Peter; Dalbeth, Nicola

2010-03-05

Foot problems are extremely common in patients with rheumatoid arthritis (RA). There is ample evidence that foot pain, either alone or as a comorbidity, contributes significantly to disability. Despite the high prevalence of foot disease in RA, this problem is often trivialised or underappreciated. The inequity in foot health provision for patients with rheumatic disorders in New Zealand has recently been highlighted. Expertise in dealing with foot problems is often limited among healthcare professionals, and it has been argued that better integration of podiatric services into rheumatology services would be beneficial. The aim of this paper is to highlight the major issues related to foot care for patients with arthritis and provide key recommendations that should implemented to improve access to podiatric services in New Zealand.

Multifocal synchronous ipsilateral Warthin tumors: case report and review of the literature.

PubMed

Hall, Joseph E; Statham, Melissa McCarty; Sheridan, Rachel M; Wilson, Keith M

2010-09-01

We report a case of a 73-year-old woman who presented with an enlarging superficial parotid mass, a concomitant ipsilateral deep-lobe parotid mass, and associated upper jugular lymphadenopathy. The clinical presentation and radiographic imaging were suggestive of malignancy, and the patient was treated with total parotidectomy with upper jugular lymph node sampling. Pathologic examination revealed two distinct masses, one in the superficial lobe and one in the deep lobe of the parotid gland, both consistent with synchronous Warthin tumors. Analysis of the upper jugular lymph nodes was consistent with reactive lymphoid hyperplasia. Although the true incidence of multicentricity in ipsilateral Warthin tumors may be underappreciated and underreported, this entity should remain in the differential diagnosis for unilateral parotid masses.

Violence and aggression in the emergency department is under-reported and under-appreciated.

PubMed

Richardson, Sandra K; Grainger, Paula C; Ardagh, Michael W; Morrison, Russell

2018-06-08

To examine levels of reporting of violence and aggression within a tertiary level emergency department in New Zealand, and to explore staff attitudes to violence and reporting. A one-month intensive, prospective audit of the emergency department's violence and aggression reporting was undertaken and compared with previously reported data. There was a significant mismatch between the number of events identified during the campaign month and previously reported instances of violence and aggression. The findings identified that failure to report acts of violence was common. Reports of violence and aggression in the emergency department underestimate the true incidence. Failure to report has potential impacts on organisational recognition of risk and the ability to develop appropriate policy responses.

Stable Causal Relationships Are Better Causal Relationships.

PubMed

Vasilyeva, Nadya; Blanchard, Thomas; Lombrozo, Tania

2018-05-01

We report three experiments investigating whether people's judgments about causal relationships are sensitive to the robustness or stability of such relationships across a range of background circumstances. In Experiment 1, we demonstrate that people are more willing to endorse causal and explanatory claims based on stable (as opposed to unstable) relationships, even when the overall causal strength of the relationship is held constant. In Experiment 2, we show that this effect is not driven by a causal generalization's actual scope of application. In Experiment 3, we offer evidence that stable causal relationships may be seen as better guides to action. Collectively, these experiments document a previously underappreciated factor that shapes people's causal reasoning: the stability of the causal relationship. Copyright © 2018 Cognitive Science Society, Inc.

Presidential address: The origins and evolution of the Mayo Clinic from 1864 to 1939: a Minnesota family practice becomes an international "medical Mecca".

PubMed

Fye, W Bruce

2010-01-01

This paper describes the origins and international impact of the Mayo Clinic through 1939. Multispecialty group practice was invented at the clinic a century ago. A visiting Canadian physician wrote in 1906, "Specialization and cooperation, with the best that can be had in each department, is here the motto. Cannot these principles be tried elsewhere?" Mayo Clinic's major (and underappreciated) role in the development of rigorous postgraduate (specialty) training is addressed. Unlike traditional academic medical centers that emphasize research, Mayo's main mission has always been patient care. This activity has been undertaken in an environment enriched by extensive programs devoted to specialty training and clinical research.

A DsbA-Deficient Periplasm Enables Functional Display of a Protein with Redox-Sensitive Folding on M13 Phage.

PubMed

Chen, Minyong; Samuelson, James C

2016-06-14

The requirements for target protein folding in M13 phage display are largely underappreciated. Here we chose Fbs1, a carbohydrate binding protein, as a model to address this issue. Importantly, folding of Fbs1 is impaired in an oxidative environment. Fbs1 can be displayed on M13 phage using the SRP or Sec pathway. However, the displayed Fbs1 protein is properly folded only when Fbs1 is translocated via the SRP pathway and displayed using Escherichia coli cells with a DsbA-negative periplasm. This study indicates M13 phage display may be improved using a system specifically designed according to the folding requirements of each target protein.

Driving-induced population trapping and linewidth narrowing via the quantum Zeno effect

NASA Astrophysics Data System (ADS)

Christensen, Charles N.; Iles-Smith, Jake; Petersen, Torkil S.; Mørk, Jesper; McCutcheon, Dara P. S.

2018-06-01

We investigate the suppression of spontaneous emission from a driven three-level system embedded in an optical cavity via a manifestation of the quantum Zeno effect. Strong resonant coupling of the lower two levels to an external optical field results in a decrease of the decay rate of the third upper level. We show that this effect has observable consequences in the form of emission spectra with subnatural linewidths, which should be measurable using, for example, quantum dot-cavity systems in currently obtainable parameter regimes, and may find use in applications requiring the control of single-photon arrival times and wave-packet extent. These results suggest an underappreciated link between the Zeno effect, dressed states, and Purcell enhancement.

Coxiella burnetii: host and bacterial responses to infection.

PubMed

Waag, David M

2007-10-16

Designation as a Category B biothreat agent has propelled Coxiella burnetii from a relatively obscure, underappreciated, "niche" microorganism on the periphery of bacteriology, to one of possibly great consequence if actually used in acts of bioterrorism. Advances in the study of this microorganism proceeded slowly, primarily because of the difficulty in studying this obligate intracellular pathogen that must be manipulated under biosafety level-3 conditions. The dogged determination of past and current C. burnetii researchers and the application of modern immunological and molecular techniques have more clearly defined the host and bacterial response to infection. This review is intended to provide a basic introduction to C. burnetii and Q fever, while emphasizing immunomodulatory properties, both positive and negative, of Q fever vaccines and C. burnetii infections.

Scared and less noisy: glucocorticoids are associated with alarm call entropy

PubMed Central

Blumstein, Daniel T.; Chi, Yvonne Y.

2012-01-01

The nonlinearity and arousal hypothesis predicts that highly aroused mammals will produce nonlinear, noisy vocalizations. We tested this prediction by measuring faecal glucocorticoid metabolites (GCMs) in adult yellow-bellied marmots (Marmota flaviventris), and asking if variation in GCMs was positively correlated with Wiener entropy—a measure of noise. Contrary to our prediction, we found a significant negative relationship: marmots with more faecal GCMs produced calls with less noise than those with lower levels of GCMs. A previous study suggested that glucocorticoids modulate the probability that a marmot will emit a call. This study suggests that, like some other species, calls emitted from highly aroused individuals are less noisy. Glucocorticoids thus play an important, yet underappreciated role, in alarm call production. PMID:21976625

Scared and less noisy: glucocorticoids are associated with alarm call entropy.

PubMed

Blumstein, Daniel T; Chi, Yvonne Y

2012-04-23

The nonlinearity and arousal hypothesis predicts that highly aroused mammals will produce nonlinear, noisy vocalizations. We tested this prediction by measuring faecal glucocorticoid metabolites (GCMs) in adult yellow-bellied marmots (Marmota flaviventris), and asking if variation in GCMs was positively correlated with Wiener entropy-a measure of noise. Contrary to our prediction, we found a significant negative relationship: marmots with more faecal GCMs produced calls with less noise than those with lower levels of GCMs. A previous study suggested that glucocorticoids modulate the probability that a marmot will emit a call. This study suggests that, like some other species, calls emitted from highly aroused individuals are less noisy. Glucocorticoids thus play an important, yet underappreciated role, in alarm call production.

Artemisinins from folklore to modern medicine--transforming an herbal extract to life-saving drugs.

PubMed

Weina, P J

2008-06-01

The history of the artemisinins from Ge Hong in China during the 4th century, to the re-discovery of the qing hao derivatives in the 1970s, to the explosion of artemisinin derivatives and combinations throughout the world today is a fascinating story. The central and underappreciated role of the United States Army's 'drug company' known as the Division of Experimental Therapeutics at the Walter Reed Army Institute of Research is a story worth relating. From being the first group outside China to extract the active component of qing hao, to leading the work on neurotoxicity of the class in animals, to bringing a Good Manufacturing Practices intravenous formulation to the worldwide market is traced.

Epilepsy and secondary perceived stigma in a social setting: A night at the theater.

PubMed

Kaufman, Kenneth R

2016-08-01

Stigma impacts >50% of persons with epilepsy (PWE) and is a key factory in quality of life. Stigma can be both enacted (external factors) and felt (internal factors). In this article, felt/perceived stigma is more broadly defined as a combination of internal factors and perceptions of external factors. Secondary perceived stigma is felt/perceived stigma by a third party. A key, but often underappreciated, consideration in felt/perceived stigma may occur when a seemingly innocuous statement by a speaker is perceived as stigmatizing by the PWE and/or even by an unintended third party. This autobiographic short report addresses secondary perceived stigma in a social setting, the theater. Copyright © 2016 Elsevier Inc. All rights reserved.

X-Phi and Carnapian Explication

PubMed Central

Shepherd, Joshua; Justus, James

2015-01-01

The rise of experimental philosophy (x-phi) has placed metaphilosophical questions, particularly those concerning concepts, at the center of philosophical attention. X-phi offers empirically rigorous methods for identifying conceptual content, but what exactly it contributes towards evaluating conceptual content remains unclear. We show how x-phi complements Rudolf Carnap’s underappreciated methodology for concept determination, explication. This clarifies and extends x-phi’s positive philosophical import, and also exhibits explication’s broad appeal. But there is a potential problem: Carnap’s account of explication was limited to empirical and logical concepts, but many concepts of interest to philosophers (experimental and otherwise) are essentially normative. With formal epistemology as a case study, we show how x-phi assisted explication can apply to normative domains. PMID:26345713

Genomic basis for natural product biosynthetic diversity in the actinomycetes†

PubMed Central

Nett, Markus; Ikeda, Haruo; Moore, Bradley S.

2010-01-01

The phylum Actinobacteria hosts diverse high G + C, Gram-positive bacteria that have evolved a complex chemical language of natural product chemistry to help navigate their fascinatingly varied lifestyles. To date, 71 Actinobacteria genomes have been completed and annotated, with the vast majority representing the Actinomycetales, which are the source of numerous antibiotics and other drugs from genera such as Streptomyces, Saccharopolyspora and Salinispora. These genomic analyses have illuminated the secondary metabolic proficiency of these microbes – underappreciated for years based on conventional isolation programs – and have helped set the foundation for a new natural product discovery paradigm based on genome mining. Trends in the secondary metabolomes of natural product-rich actinomycetes are highlighted in this review article, which contains 199 references. PMID:19844637

Entropy and the driving force for the filling of carbon nanotubes with water.

PubMed

Pascal, Tod A; Goddard, William A; Jung, Yousung

2011-07-19

The spontaneous filling of hydrophobic carbon nanotubes (CNTs) by water observed both experimentally and from simulations is counterintuitive because confinement is generally expected to decrease both entropy and bonding, and remains largely unexplained. Here we report the entropy, enthalpy, and free energy extracted from molecular dynamics simulations of water confined in CNTs from 0.8 to 2.7-nm diameters. We find for all sizes that water inside the CNTs is more stable than in the bulk, but the nature of the favorable confinement of water changes dramatically with CNT diameter. Thus we find (i) an entropy (both rotational and translational) stabilized, vapor-like phase of water for small CNTs (0.8-1.0 nm), (ii) an enthalpy stabilized, ice-like phase for medium-sized CNTs (1.1-1.2 nm), and (iii) a bulk-like liquid phase for tubes larger than 1.4 nm, stabilized by the increased translational entropy as the waters sample a larger configurational space. Simulations with structureless coarse-grained water models further reveal that the observed free energies and sequence of transitions arise from the tetrahedral structure of liquid water. These results offer a broad theoretical basis for understanding water transport through CNTs and other nanostructures important in nanofluidics, nanofiltrations, and desalination.

Vibration-translation energy transfer in vibrationally excited diatomic molecules. Ph.D. Thesis - York Univ., Toronto

NASA Technical Reports Server (NTRS)

Mckenzie, R. L.

1976-01-01

A semiclassical collision model is applied to the study of energy transfer rates between a vibrationally excited diatomic molecule and a structureless atom. The molecule is modeled as an anharmonic oscillator with a multitude of dynamically coupled vibrational states. Three main aspects in the prediction of vibrational energy transfer rates are considered. The applicability of the semiclassical model to an anharmonic oscillator is first evaluated for collinear encounters. Second, the collinear semiclassical model is applied to obtain numerical predictions of the vibrational energy transfer rate dependence on the initial vibrational state quantum number. Thermally averaged vibration-translation rate coefficients are predicted and compared with CO-He experimental values for both ground and excited initial states. The numerical model is also used as a basis for evaluating several less complete but analytic models. Third, the role of rational motion in the dynamics of vibrational energy transfer is examined. A three-dimensional semiclassical collision model is constructed with coupled rotational motion included. Energy transfer within the molecule is shown to be dominated by vibration-rotation transitions with small changes in angular momentum. The rates of vibrational energy transfer in molecules with rational frequencies that are very small in comparison to their vibrational frequency are shown to be adequately treated by the preceding collinear models.

Non-Markovian dynamics in chiral quantum networks with spins and photons

NASA Astrophysics Data System (ADS)

Ramos, Tomás; Vermersch, Benoît; Hauke, Philipp; Pichler, Hannes; Zoller, Peter

2016-06-01

We study the dynamics of chiral quantum networks consisting of nodes coupled by unidirectional or asymmetric bidirectional quantum channels. In contrast to familiar photonic networks where driven two-level atoms exchange photons via 1D photonic nanostructures, we propose and study a setup where interactions between the atoms are mediated by spin excitations (magnons) in 1D X X spin chains representing spin waveguides. While Markovian quantum network theory eliminates quantum channels as structureless reservoirs in a Born-Markov approximation to obtain a master equation for the nodes, we are interested in non-Markovian dynamics. This arises from the nonlinear character of the dispersion with band-edge effects, and from finite spin propagation velocities leading to time delays in interactions. To account for the non-Markovian dynamics we treat the quantum degrees of freedom of the nodes and connecting channel as a composite spin system with the surrounding of the quantum network as a Markovian bath, allowing for an efficient solution with time-dependent density matrix renormalization-group techniques. We illustrate our approach showing non-Markovian effects in the driven-dissipative formation of quantum dimers, and we present examples for quantum information protocols involving quantum state transfer with engineered elements as basic building blocks of quantum spintronic circuits.

Entropy and the driving force for the filling of carbon nanotubes with water

PubMed Central

Pascal, Tod A.; Goddard, William A.; Jung, Yousung

2011-01-01

The spontaneous filling of hydrophobic carbon nanotubes (CNTs) by water observed both experimentally and from simulations is counterintuitive because confinement is generally expected to decrease both entropy and bonding, and remains largely unexplained. Here we report the entropy, enthalpy, and free energy extracted from molecular dynamics simulations of water confined in CNTs from 0.8 to 2.7-nm diameters. We find for all sizes that water inside the CNTs is more stable than in the bulk, but the nature of the favorable confinement of water changes dramatically with CNT diameter. Thus we find (i) an entropy (both rotational and translational) stabilized, vapor-like phase of water for small CNTs (0.8–1.0 nm), (ii) an enthalpy stabilized, ice-like phase for medium-sized CNTs (1.1–1.2 nm), and (iii) a bulk-like liquid phase for tubes larger than 1.4 nm, stabilized by the increased translational entropy as the waters sample a larger configurational space. Simulations with structureless coarse-grained water models further reveal that the observed free energies and sequence of transitions arise from the tetrahedral structure of liquid water. These results offer a broad theoretical basis for understanding water transport through CNTs and other nanostructures important in nanofluidics, nanofiltrations, and desalination. PMID:21709268

Petrology and geochemistry of komatiites and tholeiites from Gorgona Island, Colombia

NASA Astrophysics Data System (ADS)

Aitken, Bruce G.; Echeverría, Lina M.

1984-04-01

Komatiitic rocks from Gorgona Island, Colombia, in contrast to their Archaean counterparts, occur as rather structureless flows. In addition, textural and mineralogical features indicate that the Gorgona komatiites may have crystallized from superheated liquids. Komatiitic rocks have MgO contents which range from 24 to 11 wt.% and plot on well-defined olivine (Fo90) control lines. Calculations show that potential evolved liquids (MgO<11 wt%) will be SiO2-poor. Komatiites, in this case, cannot be regarded as parental to the associated tholeiitic basalt sequence. On the basis of REE concentrations and Sr, Nd isotopic compositions, the associated basalts are found to be of two types. One type (K-tholeiite) is characterized by noticeably fractionated REE patterns and relatively primitive isotopic compositions similar to those of the komatiites. K-tholeiites, together with komatiites, are regarded as comprising a distinctive komatiitic suite. REE patterns within this suite show progressive depletion in the LREE from K-tholeiites to komatiites, and represent increasingly higher degrees of melting of the same mantle source region. The other type (T-tholeiite), representative of the bulk of the exposed basalt sequence, has flat REE patterns and relatively evolved isotopic compositions. This tholeiitic suite is clearly genetically unrelated to the komatiitic suite.

Cryostratigraphy and the Sublimation Unconformity in Permafrost from an Ultraxerous Environment, University Valley, McMurdo Dry Valleys of Antarctica

NASA Technical Reports Server (NTRS)

Lapalme, Caitlin M.; Fortier, Daniel; Pollard, Wayne; Lacelle, Denis; Davila, Alfonso; McKay, Christopher P.

2017-01-01

The cryostratigraphy of permafrost in ultraxerous environments is poorly known. In this study, icy permafrost cores from University Valley (McMurdo Dry Valleys, Antarctica) were analyzed for sediment properties, ground-ice content, types and distribution of cryostructures, and presence of unconformities. No active layer exists in the valley, but the ice table, a sublimation unconformity, ranges from 0 to 60 cm depth. The sediments are characterized as a medium sand, which classifies them as low to non-frost susceptible. Computed tomography (CT) scan images of the icy permafrost cores revealed composite cryostructures that included the structureless, porous visible, suspended and crustal types. These cryostructures were observed irrespective of ground-ice origin (vapour deposited and freezing of snow meltwater), suggesting that the type and distribution of cryostructures could not be used as a proxy to infer the mode of emplacement of ground ice. Volumetric ice content derived from the CT scan images underestimated measured volumetric ice content, but approached measured excess ice content. A palaeo-sublimation unconformity could not be detected from a change in cryostructures, but could be inferred from an increase in ice content at the maximum predicted ice table depth. This study highlights some of the unique ground-ice processes and cryostructures in ultraxerous environments.

Classifying distinct basal cell carcinoma subtype by means of dermatoscopy and reflectance confocal microscopy.

PubMed

Longo, Caterina; Lallas, Aimilios; Kyrgidis, Athanassios; Rabinovitz, Harold; Moscarella, Elvira; Ciardo, Silvana; Zalaudek, Iris; Oliviero, Margaret; Losi, Amanda; Gonzalez, Salvador; Guitera, Pascale; Piana, Simonetta; Argenziano, Giuseppe; Pellacani, Giovanni

2014-10-01

The current guidelines for the management of basal cell carcinoma (BCC) suggest a different therapeutic approach according to histopathologic subtype. Although dermatoscopic and confocal criteria of BCC have been investigated, no specific studies were performed to evaluate the distinct reflectance confocal microscopy (RCM) aspects of BCC subtypes. To define the specific dermatoscopic and confocal criteria for delineating different BCC subtypes. Dermatoscopic and confocal images of histopathologically confirmed BCCs were retrospectively evaluated for the presence of predefined criteria. Frequencies of dermatoscopic and confocal parameters are provided. Univariate and adjusted odds ratios were calculated. Discriminant analyses were performed to define the independent confocal criteria for distinct BCC subtypes. Eighty-eight BCCs were included. Dermatoscopically, superficial BCCs (n=44) were primarily typified by the presence of fine telangiectasia, multiple erosions, leaf-like structures, and revealed cords connected to the epidermis and epidermal streaming upon RCM. Nodular BCCs (n=22) featured the classic dermatoscopic features and well outlined large basaloid islands upon RCM. Infiltrative BCCs (n=22) featured structureless, shiny red areas, fine telangiectasia, and arborizing vessels on dermatoscopy and dark silhouettes upon RCM. The retrospective design. Dermatoscopy and confocal microscopy can reliably classify different BCC subtypes. Copyright © 2014 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Brownian dynamics simulations of simplified cytochrome c molecules in the presence of a charged surface

NASA Astrophysics Data System (ADS)

Gorba, C.; Geyer, T.; Helms, V.

2004-07-01

Simulations were performed for up to 150 simplified spherical horse heart cytochrome c molecules in the presence of a charged surface, which serves as an approximate model for a lipid membrane. Screened electrostatic and short-ranged attractive as well as repulsive van der Waals forces for interparticle and particle-membrane interactions are utilized in the simulations. At a distance from the membrane, where particle-membrane interactions are negligible, the simulation is coupled to a noninteraction continuum analogous to a heat bath [Geyer et al., J. Chem. Phys. 120, 4573 (2004)]. From the particles' density profiles perpendicular to the planar surface binding isotherms are derived and compared to experimental results [Heimburg et al. (1999)]. Using a negatively charged structureless membrane surface a saturation effect was found for relatively large particle concentrations. Since biological membranes often contain membrane proteins, we also studied the influence of additional charges on our model membrane mimicking bacterial reaction centers. We find that the onset of the saturation occurs for much lower concentrations and is sensitive to the detailed implementation. Therefore we suggest that local distortion of membrane planarity (undulation), or lipid demixing, or the presence of charged integral membrane proteins create preferential binding sites on the membrane. Only then do we observe saturation at physiological concentrations.

Condylomata lata on the ankle: an unusual location.

PubMed

Ikeda, Eri; Goto, Akane; Suzaki, Reiko; Sawada, Mizuki; Dekio, Itaru; Ishizaki, Sumiko; Fujibayashi, Mariko; Takahashi, Hayato; Tanaka, Masaru

2016-04-01

A 43-year-old Japanese man presented with reddish nodules on the ankle. The nodules had a yellowish crust and eroded surface. Dermoscopy revealed red to milky-red globules at the periphery and some glomerular vessels in the center and a whitish-pink network, which corresponded to capillary dilatation in the papillary dermis and prominent acanthosis, respectively. These structures were surrounded by a yellowish peripheral structureless area and multiple white, small, round structures in the center, corresponding to the macerated horny layer and keratin plugs. Blood samples were positive for rapid plasma reagin (1:64), Treponema pallidum hemagglutination assay (1:20480), and fluorescent treponemal antibody-absorption (1:1280). A lesional skin biopsy specimen showed irregular acanthosis and papillomatosis. The Warthin-Starry and anti-Treponema pallidum antibody stains on the biopsy specimen revealed many spirochetes in the lower epidermis and the papillary dermis. A diagnosis of secondary syphilis with condylomata lata was made. After one week of treatment with oral benzylpenicillin benzathine hydrate (Bicillin(®) G granules 400,000 units; Banyu Pharmaceutical Co., Ltd, Tokyo, Japan), 1.6 million units (U) daily, the ankle lesions had resolved with a small ulcer and pigmentation. Although syphilis is a relatively common disease, this case study reports an unusual presentation as well as dermoscopy findings.

The promise of discovering population-specific disease-associated genes in South Asia.

PubMed

Nakatsuka, Nathan; Moorjani, Priya; Rai, Niraj; Sarkar, Biswanath; Tandon, Arti; Patterson, Nick; Bhavani, Gandham SriLakshmi; Girisha, Katta Mohan; Mustak, Mohammed S; Srinivasan, Sudha; Kaushik, Amit; Vahab, Saadi Abdul; Jagadeesh, Sujatha M; Satyamoorthy, Kapaettu; Singh, Lalji; Reich, David; Thangaraj, Kumarasamy

2017-09-01

The more than 1.5 billion people who live in South Asia are correctly viewed not as a single large population but as many small endogamous groups. We assembled genome-wide data from over 2,800 individuals from over 260 distinct South Asian groups. We identified 81 unique groups, 14 of which had estimated census sizes of more than 1 million, that descend from founder events more extreme than those in Ashkenazi Jews and Finns, both of which have high rates of recessive disease due to founder events. We identified multiple examples of recessive diseases in South Asia that are the result of such founder events. This study highlights an underappreciated opportunity for decreasing disease burden among South Asians through discovery of and testing for recessive disease-associated genes.

Transposable elements in cancer.

PubMed

Burns, Kathleen H

2017-07-01

Transposable elements give rise to interspersed repeats, sequences that comprise most of our genomes. These mobile DNAs have been historically underappreciated - both because they have been presumed to be unimportant, and because their high copy number and variability pose unique technical challenges. Neither impediment now seems steadfast. Interest in the human mobilome has never been greater, and methods enabling its study are maturing at a fast pace. This Review describes the activity of transposable elements in human cancers, particularly long interspersed element-1 (LINE-1). LINE-1 sequences are self-propagating, protein-coding retrotransposons, and their activity results in somatically acquired insertions in cancer genomes. Altered expression of transposable elements and animation of genomic LINE-1 sequences appear to be hallmarks of cancer, and can be responsible for driving mutations in tumorigenesis.

Comparison of expression of secondary metabolite biosynthesis cluster genes in Aspergillus flavus, A. parasiticus, and A. oryzae.

PubMed

Ehrlich, Kenneth C; Mack, Brian M

2014-06-23

Fifty six secondary metabolite biosynthesis gene clusters are predicted to be in the Aspergillus flavus genome. In spite of this, the biosyntheses of only seven metabolites, including the aflatoxins, kojic acid, cyclopiazonic acid and aflatrem, have been assigned to a particular gene cluster. We used RNA-seq to compare expression of secondary metabolite genes in gene clusters for the closely related fungi A. parasiticus, A. oryzae, and A. flavus S and L sclerotial morphotypes. The data help to refine the identification of probable functional gene clusters within these species. Our results suggest that A. flavus, a prevalent contaminant of maize, cottonseed, peanuts and tree nuts, is capable of producing metabolites which, besides aflatoxin, could be an underappreciated contributor to its toxicity.

Comparison of Expression of Secondary Metabolite Biosynthesis Cluster Genes in Aspergillus flavus, A. parasiticus, and A. oryzae

PubMed Central

Ehrlich, Kenneth C.; Mack, Brian M.

2014-01-01

Fifty six secondary metabolite biosynthesis gene clusters are predicted to be in the Aspergillus flavus genome. In spite of this, the biosyntheses of only seven metabolites, including the aflatoxins, kojic acid, cyclopiazonic acid and aflatrem, have been assigned to a particular gene cluster. We used RNA-seq to compare expression of secondary metabolite genes in gene clusters for the closely related fungi A. parasiticus, A. oryzae, and A. flavus S and L sclerotial morphotypes. The data help to refine the identification of probable functional gene clusters within these species. Our results suggest that A. flavus, a prevalent contaminant of maize, cottonseed, peanuts and tree nuts, is capable of producing metabolites which, besides aflatoxin, could be an underappreciated contributor to its toxicity. PMID:24960201

Epigenetics in the Vascular Endothelium: Looking From a Different Perspective in the Epigenomics Era.

PubMed

Yan, Matthew S; Marsden, Philip A

2015-11-01

Cardiovascular diseases are commonly thought to be complex, non-Mendelian diseases that are influenced by genetic and environmental factors. A growing body of evidence suggests that epigenetic pathways play a key role in vascular biology and might be involved in defining and transducing cardiovascular disease inheritability. In this review, we argue the importance of epigenetics in vascular biology, especially from the perspective of endothelial cell phenotype. We highlight and discuss the role of epigenetic modifications across the transcriptional unit of protein-coding genes, especially the role of intragenic chromatin modifications, which are underappreciated and not well characterized in the current era of genome-wide studies. Importantly, we describe the practical application of epigenetics in cardiovascular disease therapeutics. © 2015 American Heart Association, Inc.

Thromboembolism during neoadjuvant therapy for gastrointestinal cancer.

PubMed

Smart, Philip J; Burbury, Kate L; Lynch, A Craig; Mackay, John R; Heriot, Alexander G

2014-12-01

Thromboembolism a common, costly, and morbid complication that is also associated with decreased survival in cancer patients. The risk of thromboembolism in cancer patients is underappreciated. In addition to symptomatic deep venous thrombosis and pulmonary embolism, asymptomatic and arterial thromboembolic events are important consideration in ambulatory cancer patients receiving neoadjuvant chemoradiotherapy (nCRT). No specific randomized trial examining thromboprophylaxis (TP) during nCRT for gastrointestinal cancer has been performed, and none is accruing. Most guidelines currently recommend against TP in ambulatory cancer patients due to a lack of data rather than proof of harm or lack of efficacy. It is clear that robust data are urgently required, and that treatment with nCRT in patients with gastrointestinal malignancy is not an indication for routine pharmacological TP at the present time.

Long-Wavelength X-Ray Diffraction and Its Applications in Macromolecular Crystallography.

PubMed

Weiss, Manfred S

2017-01-01

For many years, diffraction experiments in macromolecular crystallography at X-ray wavelengths longer than that of Cu-K α (1.54 Å) have been largely underappreciated. Effects caused by increased X-ray absorption result in the fact that these experiments are more difficult than the standard diffraction experiments at short wavelengths. However, due to the also increased anomalous scattering of many biologically relevant atoms, important additional structural information can be obtained. This information, in turn, can be used for phase determination, for substructure identification, in molecular replacement approaches, as well as in structure refinement. This chapter reviews the possibilities and the difficulties associated with such experiments, and it provides a short description of two macromolecular crystallography synchrotron beam lines dedicated to long-wavelength X-ray diffraction experiments.

A foundation for public health ethics at Tuskegee University in the 21st century.

PubMed

Warren, Rueben C; Tarver, Will L

2010-08-01

This commentary is a reflection on Tuskegee University's National Center for Bioethics in Research and Health Care on the health and ethical challenges of the 21st century. The Center has dedicated the last 10 years to addressing the unresolved biomedicine and public health issues and/or the ethical dilemmas that plague the nation's health. The authors believe that health disparities continue to worsen because the approach under-appreciates the ethical dilemma that plagues health policy and health disparities. The authors discuss synergies and the paradigmatic differences between science and medicine, religion, spirituality, and faith. They also discuss the importance of considering these relationships if improvements in the health of people of African descent are expected. The concept of Optimal Health is explored.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kervin, Karina E.; Cook, Robert B.; Michener, William K.

Conventional wisdom makes the suggestion that there are benefits to the creation of shared repositories of scientific data. Funding agencies require that the data from sponsored projects be shared publicly, but individual researchers often see little personal benefit to offset the work of creating easily sharable data. These conflicting forces have led to the emergence of a new role to support researchers: data managers. This paper identifies key differences between the socio-technical context of data managers and other "human infrastructure" roles articulated previously in Computer Supported Cooperative Work (CSCW) literature and summarizes the challenges that data managers face when acceptingmore » data for archival and reuse. Finally, while data managers' work is critical for advancing science and science policy, their work is often invisible and under-appreciated since it takes place behind the scenes.« less

The promise of disease gene discovery in South Asia

PubMed Central

Nakatsuka, Nathan; Moorjani, Priya; Rai, Niraj; Sarkar, Biswanath; Tandon, Arti; Patterson, Nick; Bhavani, Gandham SriLakshmi; Girisha, Katta Mohan; Mustak, Mohammed S; Srinivasan, Sudha; Kaushik, Amit; Vahab, Saadi Abdul; Jagadeesh, Sujatha M.; Satyamoorthy, Kapaettu; Singh, Lalji; Reich, David; Thangaraj, Kumarasamy

2017-01-01

The more than 1.5 billion people who live in South Asia are correctly viewed not as a single large population, but as many small endogamous groups. We assembled genome-wide data from over 2,800 individuals from over 260 distinct South Asian groups. We identify 81 unique groups, of which 14 have estimated census sizes of more than a million, that descend from founder events more extreme than those in Ashkenazi Jews and Finns, both of which have high rates of recessive disease due to founder events. We identify multiple examples of recessive diseases in South Asia that are the result of such founder events. This study highlights an under-appreciated opportunity for reducing disease burden among South Asians through the discovery of and testing for recessive disease genes. PMID:28714977

Rotationally and vibrationally inelastic scattering in the rotational IOS approximation. Ultrasimple calculation of total (differential, integral, and transport) cross sections for nonspherical molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, G.A.; Pack, R.T

1978-02-15

A simple, direct derivation of the rotational infinite order sudden (IOS) approximation in molecular scattering theory is given. Connections between simple scattering amplitude formulas, choice of average partial wave parameter, and magnetic transitions are reviewed. Simple procedures for calculating cross sections for specific transitions are discussed and many older model formulas are given clear derivations. Total (summed over rotation) differential, integral, and transport cross sections, useful in the analysis of many experiments involving nonspherical molecules, are shown to be exceedingly simple: They are just averages over the potential angle of cross sections calculated using simple structureless spherical particle formulas andmore » programs. In the case of vibrationally inelastic scattering, the IOSA, without further approximation, provides a well-defined way to get fully three dimensional cross sections from calculations no more difficult than collinear calculations. Integral, differential, viscosity, and diffusion cross sections for He-CO/sub 2/ obtained from the IOSA and a realistic intermolecular potential are calculated as an example and compared with experiment. Agreement is good for the complete potential but poor when only its spherical part is used, so that one should never attempt to treat this system with a spherical model. The simplicity and accuracy of the IOSA make it a viable method for routine analysis of experiments involving collisions of nonspherical molecules.« less

Attribute of trace fossils of Laisong flysch sediments, Manipur, India

NASA Astrophysics Data System (ADS)

Khaidem, Kumar S.; Rajkumar, Hemanta S.; Soibam, Ibotombi

2015-07-01

The depositional basin in which the Late Eocene-Early Oligocene Laisong flysch sediments Barail Group, Manipur region (Indo-Myanmar ranges) have been deposited is generally considered to be of deep marine environment. However, field observation indicates the presence of many shallow environment signature characteristics of marginal to sublittoral marine settings, in addition to the general occurrence of deep marine turbidites. To address this aspect, ichnological analyses of the Laisong Formation has been attempted for elucidating palaeoenvironmental setting prevalent during the deposition of these sediments. Presence of 36 ichnospecies belonging to 33 ichnogenera has so far been identified. The ichnospecies may be grouped into different ichnofacies such as Skolithos-Cruziana mixed ichnofacies, Cruziana ichnofacies, Skolithos ichnofacies, Zoophycos ichnofacies, Nereites ichnofacies and Teredolites ichnofacies which decrease in abundance in this order of sequence with Skolithos-Cruziana mixed ichnofacies being the most dominant. The above-mentioned ichnofacies are found associated with sedimentary structures such as large sole marks, parallel laminations, massive and structureless beds, rip-up clasts, etc., which are characteristics of submarine fan deposits below the storm wave base and current ripples, herringbone structures, hummocky cross stratifications, pot casts, rain prints, etc., that marked shallow marginal marine setting such as tidal flats, deltas and shoreface. With such observations it is very likely that the Laisong sediments were formed in a tectonically active basin with varied bathymetric ranges indicating alternate transgressive and regressive nature.

Highstand shelf fans: The role of buoyancy reversal in the deposition of a new type of shelf sand body

USGS Publications Warehouse

Steel, Elisabeth; Simms, Alexander R.; Warrick, Jonathan; Yokoyama, Yusuke

2016-01-01

Although sea-level highstands are typically associated with sediment-starved continental shelves, high sea level does not hinder major river floods. Turbidity currents generated by plunging of sediment-laden rivers at the fluvial-marine interface, known as hyperpycnal flows, allow for cross-shelf transport of suspended sand beyond the coastline. Hyperpycnal flows in southern California have deposited six subaqueous fans on the shelf of the northern Santa Barbara Channel in the Holocene. Using eight cores and nine grab samples, we describe the deposits, age, and stratigraphic architecture of two fans in the Santa Barbara Channel. Fan lobes have up to 3 m of relief and are composed of multiple hyperpycnite beds ∼5 cm to 40 cm thick. Deposit architecture and geometry suggest the hyperpycnal flows became positively buoyant and lifted off the seabed, resulting in well-sorted, structureless, elongate sand lobes. Contrary to conventional sequence stratigraphic models, the presence of these features on the continental shelf suggests that active-margin shelves may locally develop high-quality reservoir sand bodies during sea-level highstands, and that such shelves need not be solely the site of sediment bypass. These deposits may provide a Quaternary analogue to many well-sorted sand bodies in the rock record that are interpreted as turbidites but lack typical Bouma-type features.

Mapping CTTS dynamics of Na- in tetrahydrofurane with ultrafast multichannel pump-probe spectroscopy.

PubMed

Shoshana, O; Pérez Lustres, J L; Ernsting, N P; Ruhman, S

2006-06-14

Using multichannel femtosecond spectroscopy we have followed Na- charge transfer to solvent (CTTS) dynamics in THF solution. Absorption of the primary photoproducts in the visible, resolved here for the first time, consists of an asymmetric triplet centered at 595 nm, which we assign to a metastable incompletely solvated neutral atomic sodium species. Decay of this feature within approximately 1 ps to a broad and structureless solvated neutral is accompanied by broadening and loss of spectral detail. Kinetic analysis shows that both the spectral structure and the decay of this band are independent of the excitation photon frequency in the range 400-800 nm. With different pump-probe polarizations the anisotropy in transient transmission has been charted and its variation with excitation wavelength surveyed. The anisotropies are assigned to the reactant bleach, indicating that due to solvent-induced symmetry breaking, the CTTS absorption band of Na- is made up of discreet orthogonally polarized sub bands. None of the anisotropy in transient absorption could be associated with the photoproduct triplet band even at the earliest measurable time delays. Along with the documented differences in the spatial distribution of ejected electrons across the tested excitation wavelength range, these results lead us to conclude that photoejection is extremely rapid, and that loss of correlations between the departing electron and its neutral core is faster than our time resolution of approximately 60 fs.

Conceptual shifts needed to understand the dynamic interactions of genes, environment, epigenetics, social processes, and behavioral choices.

PubMed

Jackson, Fatimah L C; Niculescu, Mihai D; Jackson, Robert T

2013-10-01

Social and behavioral research in public health is often intimately tied to profound, but frequently neglected, biological influences from underlying genetic, environmental, and epigenetic events. The dynamic interplay between the life, social, and behavioral sciences often remains underappreciated and underutilized in addressing complex diseases and disorders and in developing effective remediation strategies. Using a case-study format, we present examples as to how the inclusion of genetic, environmental, and epigenetic data can augment social and behavioral health research by expanding the parameters of such studies, adding specificity to phenotypic assessments, and providing additional internal control in comparative studies. We highlight the important roles of gene-environment interactions and epigenetics as sources of phenotypic change and as a bridge between the life and social and behavioral sciences in the development of robust interdisciplinary analyses.

Forensic aspects of DNA-based human identity testing.

PubMed

Roper, Stephen M; Tatum, Owatha L

2008-01-01

The forensic applications of DNA-based human identity laboratory testing are often underappreciated. Molecular biology has seen an exponential improvement in the accuracy and statistical power provided by identity testing in the past decade. This technology, dependent upon an individual's unique DNA sequence, has cemented the use of DNA technology in the forensic laboratory. This paper will discuss the state of modern DNA-based identity testing, describe the technology used to perform this testing, and describe its use as it relates to forensic applications. We will also compare individual technologies, including polymerase chain reaction (PCR) and Southern Blotting, that are used to detect the molecular differences that make all individuals unique. An increasing reliance on DNA-based identity testing dictates that healthcare providers develop an understanding of the background, techniques, and guiding principles of this important forensic tool.

A Checklist for Successful Quantitative Live Cell Imaging in Systems Biology

PubMed Central

Sung, Myong-Hee

2013-01-01

Mathematical modeling of signaling and gene regulatory networks has provided unique insights about systems behaviors for many cell biological problems of medical importance. Quantitative single cell monitoring has a crucial role in advancing systems modeling of molecular networks. However, due to the multidisciplinary techniques that are necessary for adaptation of such systems biology approaches, dissemination to a wide research community has been relatively slow. In this essay, I focus on some technical aspects that are often under-appreciated, yet critical in harnessing live cell imaging methods to achieve single-cell-level understanding and quantitative modeling of molecular networks. The importance of these technical considerations will be elaborated with examples of successes and shortcomings. Future efforts will benefit by avoiding some pitfalls and by utilizing the lessons collectively learned from recent applications of imaging in systems biology. PMID:24709701

Epistemic companions: shared reality development in close relationships.

PubMed

Rossignac-Milon, Maya; Higgins, E Tory

2018-01-11

We propose a framework outlining the development of shared reality in close relationships. In this framework, we attempt to integrate disparate close relationship phenomena under the conceptual umbrella of shared reality. We argue that jointly satisfying epistemic needs-making sense of the world together-plays an important but under-appreciated role in establishing and maintaining close relationships. Specifically, we propose that dyads progress through four cumulative phases in which new forms of shared reality emerge. Relationships are often initiated when people discover Shared Feelings, which then facilitate the co-construction of dyad-specific Shared Practices. Partners then form an interdependent web of Shared Coordination and ultimately develop a Shared Identity. Each emergent form of shared reality continues to evolve throughout subsequent phases, and, if neglected, can engender relationship dissolution. Copyright © 2018 Elsevier Ltd. All rights reserved.

Clinical empathy and narrative competence: the relevance of reading talmudic legends as literary fiction.

PubMed

Davidson, John H

2015-04-01

The "curative potential" in almost any clinical setting depends on a caregiver establishing and maintaining an empathic connection with patients so as to achieve "narrative competence" in discerning and acting in accord with their preferences and best interests. The "narrative medicine" model of shared "close reading of literature and reflective writing" among clinicians as a means of fostering a capacity for clinical empathy has gained validation with recent empirical studies demonstrating the enhancement of theory of mind (ToM), broadly conceived as empathy, in readers of literary fiction. Talmudic legends, like that of Rabbi Judah's death, are under-appreciated, relevant sources of literary fiction for these efforts. The limitations of narrative medicine are readily counterbalanced by simultaneously practiced attention to traditional bioethical principles, including-especially-beneficence, non-maleficence, and autonomy.

Global Health Warning: Definitions Wield Power Comment on "Navigating Between Stealth Advocacy and Unconscious Dogmatism: The Challenge of Researching the Norms, Politics and Power of Global Health".

PubMed

Marten, Robert

2015-12-25

Gorik Ooms recently made a strong case for considering the centrality of normative premises to analyzing and understanding the underappreciated importance of the nexus of politics, power and process in global health. This critical commentary raises serious questions for the practice and study of global health and global health governance. First and foremost, this commentary underlines the importance of the question of what is global health, and why as well as how does this definition matter? This refocuses discussion on the importance of definitions and how they wield power. It also re-affirms the necessity of a deeper analysis and understanding of power and how it affects and shapes the practice of global health. © 2016 by Kerman University of Medical Sciences.

Tinea genitalis: a new entity of sexually transmitted infection? Case series and review of the literature

PubMed Central

Luchsinger, Isabelle; Bosshard, Philipp Peter; Kasper, Romano Silvio; Reinhardt, Dominic; Lautenschlager, Stephan

2015-01-01

Objective Investigation on recent cases of tinea genitalis after travelling to South East Asia. Methods Patients with tinea in the genital region, which emerged after sex in South East Asia, underwent further assessment including microscopy, cultures and DNA analyses. Results The case series includes seven patients. In six patients, Trichophyton interdigitale (former Trichophyton mentagrophytes) was detected. Three patients suffered from a severe inflammatory reaction of the soft tissue and two of them needed hospitalisation due to severe pain. In four patients, cicatrising healing was noticed. Five patients were declared incapacitated for work. Conclusions Sexual activity should be considered as a potentially important and previously underappreciated means of transmission of T. interdigitale. To avoid irreversible scarring alopecia, prompt initiation of antifungal treatment is essential and adequate isolation and identification of the pathogen is mandatory. PMID:26071391

Host manipulation by cancer cells: Expectations, facts, and therapeutic implications.

PubMed

Tissot, Tazzio; Arnal, Audrey; Jacqueline, Camille; Poulin, Robert; Lefèvre, Thierry; Mery, Frédéric; Renaud, François; Roche, Benjamin; Massol, François; Salzet, Michel; Ewald, Paul; Tasiemski, Aurélie; Ujvari, Beata; Thomas, Frédéric

2016-03-01

Similar to parasites, cancer cells depend on their hosts for sustenance, proliferation and reproduction, exploiting the hosts for energy and resources, and thereby impairing their health and fitness. Because of this lifestyle similarity, it is predicted that cancer cells could, like numerous parasitic organisms, evolve the capacity to manipulate the phenotype of their hosts to increase their own fitness. We claim that the extent of this phenomenon and its therapeutic implications are, however, underappreciated. Here, we review and discuss what can be regarded as cases of host manipulation in the context of cancer development and progression. We elaborate on how acknowledging the applicability of these principles can offer novel therapeutic and preventive strategies. The manipulation of host phenotype by cancer cells is one more reason to adopt a Darwinian approach in cancer research. © 2016 WILEY Periodicals, Inc.

Condition-dependent sex: who does it, when and why?

PubMed Central

2016-01-01

We review the phenomenon of condition-dependent sex—where individuals' condition affects the likelihood that they will reproduce sexually rather than asexually. In recent years, condition-dependent sex has been studied both theoretically and empirically. Empirical results in microbes, fungi and plants support the theoretical prediction that negative condition-dependent sex, in which individuals in poor condition are more likely to reproduce sexually, can be evolutionarily advantageous under a wide range of settings. Here, we review the evidence for condition-dependent sex and its potential implications for the long-term survival and adaptability of populations. We conclude by asking why condition-dependent sex is not more commonly observed, and by considering generalizations of condition-dependent sex that might apply even for obligate sexuals. This article is part of the themed issue ‘Weird sex: the underappreciated diversity of sexual reproduction’. PMID:27619702

Dry mouth: Xerostomia and salivary gland hypofunction.

PubMed

Frydrych, Agnieszka M

2016-07-01

Mouth dryness may present as salivary gland hypofunction (SGH), xerostomia or both. It is considered one of the most underappreciated, underdiagnosed and undermanaged oral health conditions. Despite its common presentation and adverse impact on life quality, it is also generally poorly understood. Increased awareness of the condition is important in addressing these problems. This article discusses SGH and xerostomia, and the associated intra-oral and extra-oral implications. It also summarises currently available management approaches and the evidence behind them. SGH and xerostomia are complex problems. None of the currently available management approaches are entirely satisfactory. Addressing the causative or contributing factors is therefore paramount. While oral health complaints are generally left up to the dental professional to manage, the nature of mouth dryness necessitates increased dialogue between the dental and 
medical professions to ensure optimal patient care.

Education: a complex and empowering social work intervention at the end of life.

PubMed

Cagle, John G; Kovacs, Pamela J

2009-02-01

Education is a frequently used social work intervention. Yet it seems to be an underappreciated and a deceptively complex intervention that social workers may not be adequately prepared to use. Reliable, accessible information is essential as it helps prevent unnecessary crises, facilitates coping, and promotes self-determination. This article conceptualizes education as a fundamental social work intervention and discusses the role social workers play in providing information that is both empowering and culturally sensitive. In particular, this article focuses on social workers working with patients and families facing life-threatening situations, including those in hospice and other end-of-life care settings. After reviewing the relevant literature and theory and exploring the inherent complexities of educational interventions, the authors recommend strategies for more effectively helping patients and families access the information they need.

Time-reversed wave mixing in nonlinear optics

PubMed Central

Zheng, Yuanlin; Ren, Huaijin; Wan, Wenjie; Chen, Xianfeng

2013-01-01

Time-reversal symmetry is important to optics. Optical processes can run in a forward or backward direction through time when such symmetry is preserved. In linear optics, a time-reversed process of laser emission can enable total absorption of coherent light fields inside an optical cavity of loss by time-reversing the original gain medium. Nonlinearity, however, can often destroy such symmetry in nonlinear optics, making it difficult to study time-reversal symmetry with nonlinear optical wave mixings. Here we demonstrate time-reversed wave mixings for optical second harmonic generation (SHG) and optical parametric amplification (OPA) by exploring this well-known but underappreciated symmetry in nonlinear optics. This allows us to observe the annihilation of coherent beams. Our study offers new avenues for flexible control in nonlinear optics and has potential applications in efficient wavelength conversion, all-optical computing. PMID:24247906

Serological anthrax surveillance in wild boar (Sus scrofa) in Ukraine.

PubMed

Bagamian, Karoun H; Skrypnyk, Artem; Rodina, Yana; Bezymennyi, Maksym; Nevolko, Oleg; Skrypnyk, Valeriy; Blackburn, Jason K

2014-08-01

Anthrax, caused by Bacillus anthracis, is an acute disease affecting wildlife, livestock, and humans worldwide, although its impact on these populations is underappreciated. In Ukraine, surveillance is passive, and anthrax is often detected in livestock. However, wildlife is not subject to surveillance, although anthrax deaths (such as in wild boar, Sus scrofa) have been documented. The wild boar is a plentiful and widespread species in Ukraine and is frequently hunted. We initiated a screening study testing Ukrainian wild boar blood samples for antibodies to B. anthracis. We mapped results relative to known livestock anthrax hotspots. We discovered evidence of exposure in wild boar up to 35 km from livestock anthrax hotspots and over 400 km from previous anthrax reports in boars. We make recommendations about using wildlife species as biosentinels for anthrax in Ukraine.

The laboratory domestication of Caenorhabditis elegans.

PubMed

Sterken, Mark G; Snoek, L Basten; Kammenga, Jan E; Andersen, Erik C

2015-05-01

Model organisms are of great importance to our understanding of basic biology and to making advances in biomedical research. However, the influence of laboratory cultivation on these organisms is underappreciated, and especially how that environment can affect research outcomes. Recent experiments led to insights into how the widely used laboratory reference strain of the nematode Caenorhabditis elegans compares with natural strains. Here we describe potential selective pressures that led to the fixation of laboratory-derived alleles for the genes npr-1, glb-5, and nath-10. These alleles influence a large number of traits, resulting in behaviors that affect experimental interpretations. Furthermore, strong phenotypic effects caused by these laboratory-derived alleles hinder the discovery of natural alleles. We highlight strategies to reduce the influence of laboratory-derived alleles and to harness the full power of C. elegans. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ants and termites increase crop yield in a dry climate.

PubMed

Evans, Theodore A; Dawes, Tracy Z; Ward, Philip R; Lo, Nathan

2011-03-29

Agricultural intensification has increased crop yields, but at high economic and environmental cost. Harnessing ecosystem services of naturally occurring organisms is a cheaper but under-appreciated approach, because the functional roles of organisms are not linked to crop yields, especially outside the northern temperate zone. Ecosystem services in soil come from earthworms in these cooler and wetter latitudes; what may fulfill their functional role in agriculture in warmer and drier habitats, where they are absent, is unproven. Here we show in a field experiment that ants and termites increase wheat yield by 36% from increased soil water infiltration due to their tunnels and improved soil nitrogen. Our results suggest that ants and termites have similar functional roles to earthworms, and that they may provide valuable ecosystem services in dryland agriculture, which may become increasingly important for agricultural sustainability in arid climates.

Communicating climate sciences in academia and beyond

NASA Astrophysics Data System (ADS)

Dupigny-Giroux, L. L.

2008-12-01

Climate change has catapulted climate and atmospheric sciences onto center stage in a way that eclipses the challenges of acid rain deposition in the late 1990s. However, there are subtle differences in the non- scientists' understanding of climate dynamics, processes, feedbacks etc.. Even among non-atmospheric scientists, there is sometimes an under-appreciation of the nuances of the land-atmosphere-ocean system. Many agencies are poised to play pivotal roles in helping to move this understanding forward, either due to their scientific missions or outreach components. Among these are the American Association of State Climatologists, the American Meteorological Society, American Geophysical Union, UCAR, NOAA, NASA and Association of American Geographers to name a few. This presentation will suggest directions in communicating climate science that come out a State Climatologist's perspective as well as liberal arts academic setting.

Evaluation and treatment of failed shoulder instability procedures.

PubMed

Ho, Anthony G; Gowda, Ashok L; Michael Wiater, J

2016-09-01

Management of the unstable shoulder after a failed stabilization procedure can be difficult and challenging. Detailed understanding of the native shoulder anatomy, including its static and dynamic restraints, is necessary for determining the patient's primary pathology. In addition, evaluation of the patient's history, physical exam, and imaging is important for identifying the cause for failure after the initial procedure. Common mistakes include under-appreciation of bony defects, failure to recognize capsular laxity, technical errors, and missed associated pathology. Many potential treatment options exist for revision surgery, including open or arthroscopic Bankart repair, bony augmentation procedures, and management of Hill Sachs defects. The aim of this narrative review is to discuss in-depth the common risk factors for post-surgical failure, components for appropriate evaluation, and the different surgical options available for revision stabilization. Level of evidence Level V.

Clinical Empathy and Narrative Competence: The Relevance of Reading Talmudic Legends as Literary Fiction

PubMed Central

Davidson, John H.

2015-01-01

The “curative potential” in almost any clinical setting depends on a caregiver establishing and maintaining an empathic connection with patients so as to achieve “narrative competence” in discerning and acting in accord with their preferences and best interests. The “narrative medicine” model of shared “close reading of literature and reflective writing” among clinicians as a means of fostering a capacity for clinical empathy has gained validation with recent empirical studies demonstrating the enhancement of theory of mind (ToM), broadly conceived as empathy, in readers of literary fiction. Talmudic legends, like that of Rabbi Judah’s death, are under-appreciated, relevant sources of literary fiction for these efforts. The limitations of narrative medicine are readily counterbalanced by simultaneously practiced attention to traditional bioethical principles, including—especially—beneficence, non-maleficence, and autonomy. PMID:25973266

Rational use of oral contraceptives in the perimenopausal woman.

PubMed

Connell, E B

1993-12-01

Oral contraceptives have undergone extensive revision in their labeling over the past 10 years to remove warnings about cardiovascular and other risks and to highlight their noncontraceptive benefits. While these changes are becoming better known, the potential bone-sparing effects of oral contraceptives in the premenopausal and perimenopausal woman remain under-appreciated. Osteoporosis is a major health care problem worldwide in terms of both its associated morbidity and mortality and its economic impact. Although the benefits of postmenopausal hormone replacement therapy for the prevention and treatment of osteoporosis are generally recognized, little attention has been paid to strategies that might be used to maintain bone mass up to the time of menopause, at which time bone loss accelerates. An additional noncontraceptive benefit of oral contraceptives may be to maintain and build bone mass up to the time of menopause.

Noncirrhotic portal hypertension.

PubMed

Da, Ben L; Koh, Christopher; Heller, Theo

2018-05-01

Noncirrhotic portal hypertension represents a heterogeneous group of liver disorders that is characterized by portal hypertension in the absence of cirrhosis. The purpose of this review is to serve as a guide on how to approach a patient with noncirrhotic portal hypertension with a focus on recent developments. Recent studies pertaining to noncirrhotic portal hypertension have investigated aetiological causes, mechanisms of disease, noninvasive diagnostic modalities, clinical characteristics in the paediatric population and novel treatment targets. Noncirrhotic portal hypertension is an underappreciated clinical entity that can be difficult to diagnosis without a healthy suspicion. Diagnosis then relies on a comprehensive understanding of the causes and clinical manifestations of this disease, as well as a careful interpretation of the liver biopsy. Noninvasive approaches to diagnosis may play a significant role moving forward in this disease. Treatment in NCPH remains largely targeted at the individual sequalae of portal hypertension.

Genetic Information, the Principle of Rescue, and Special Obligations.

PubMed

Liao, S Matthew; Mackenzie, Jordan

2018-05-01

In "Genetic Privacy, Disease Prevention, and the Principle of Rescue," Madison Kilbride argues that patients have a duty to warn biological family members about clinically actionable adverse genetic findings. The duty does not stem from the special obligations that we may have to family members, she argues, but rather follows from the principle of rescue, which she understands as the idea that one ought to prevent, reduce, or mitigate the risk of harm to another person when the expected harm is serious and the cost or risk to oneself is sufficiently moderate. We doubt, however, whether the principle of rescue can ground a duty to warn in the cases Kilbride envisages, and we suggest that Kilbride may have underappreciated the role that special obligations could play in generating a duty to warn family members. © 2018 The Hastings Center.

Stereotypic movement disorder after acquired brain injury.

PubMed

McGrath, Cynthia M; Kennedy, Richard E; Hoye, Wayne; Yablon, Stuart A

2002-05-01

Stereotypic movement disorder (SMD) consists of repetitive, non-functional motor behaviour that interferes with daily living or causes injury to the person. It is most often described in patients with mental retardation. However, recent evidence indicates that this condition is common among otherwise normal individuals. This case study describes a patient with new-onset SMD occurring after subdural haematoma and brain injury. SMD has rarely been reported after acquired brain injury, and none have documented successful treatment. The current psychiatric literature regarding neurochemistry, neuroanatomy, and treatment of SMD are reviewed with particular application to one patient. Treatment options include serotonin re-uptake inhibitors, opioid antagonists and dopamine antagonists. SMD has been under-appreciated in intellectually normal individuals, and may also be unrecognized after brain injury. Further investigation is needed in this area, which may benefit other individuals with SMD as well.

Publication trends in cachexia and sarcopenia in elderly heart failure patients.

PubMed

Springer, Jochen; Anker, Stefan D

2016-12-01

The loss of skeletal mass - sarcopenia and cachexia - is considered to be a major contributor to morbidity and mortality in chronic heart failure (CHF). Unfortunately, sarcopenia is generally considered to be a geriatric syndrome, but not necessarily seen as a comorbidity in CHF, even though it has a wide range of adverse health outcomes. While there were 15,574 publication with the title word "heart failure" in PubMed in the 5‑year period from 1 June 2011 to 31 May 2016, only 22 or 71 publications were found with the search combination "sarcopenia" or "cachexia" (title word) and "heart failure" (all fields), respectively. This shows very clearly that loss of muscle quality and function due to heart failure is still an underappreciated problem in the medical field.

Role of the Undergraduate Student Research Assistant in the New Millennium

PubMed Central

2004-01-01

In this study, we analyze the contribution of the undergraduate student who participates in the process of generating scientific data and developing a research project using Brazilian research as an example. Historically, undergraduate students have performed the critical role of research assistants in developing countries. This aspect has been underappreciated as a means of generating scientific data in Brazilian research facilities. Brazilian educational institutions are facing major age-related generational changes among the science faculty within the next 5–10 yr. A lack of adequate support for graduate students leads to a concern that undergraduates will not be interested in choosing research assistant programs and, subsequently, academic research careers. To remedy this situation it is important to focus on ways to encourage new research careers and enhance university–industry collaborations. PMID:15592596

A Machine Learning Approach to Evaluating Illness-Induced Religious Struggle

PubMed Central

Glauser, Joshua; Connolly, Brian; Nash, Paul; Grossoehme, Daniel H

2017-01-01

Religious or spiritual struggles are clinically important to health care chaplains because they are related to poorer health outcomes, involving both mental and physical health problems. Identifying persons experiencing religious struggle poses a challenge for chaplains. One potentially underappreciated means of triaging chaplaincy effort are prayers written in chapel notebooks. We show that religious struggle can be identified in these notebooks through instances of negative religious coping, such as feeling anger or abandonment toward God. We built a data set of entries in chapel notebooks and classified them as showing religious struggle, or not. We show that natural language processing techniques can be used to automatically classify the entries with respect to whether or not they reflect religious struggle with as much accuracy as humans. The work has potential applications to triaging chapel notebook entries for further attention from pastoral care staff. PMID:28469429

A systematic review on the impact of diabetes mellitus on the ocular surface

PubMed Central

Shih, K Co; Lam, K S-L; Tong, L

2017-01-01

Diabetes mellitus is associated with extensive morbidity and mortality in any human community. It is well understood that the burden of diabetes is attributed to chronic progressive damage in major end-organs, but it is underappreciated that the most superficial and transparent organ affected by diabetes is the cornea. Different corneal components (epithelium, nerves, immune cells and endothelium) underpin specific systemic complications of diabetes. Just as diabetic retinopathy is a marker of more generalized microvascular disease, corneal nerve changes can predict peripheral and autonomic neuropathy, providing a window of opportunity for early treatment. In addition, alterations of immune cells in corneas suggest an inflammatory component in diabetic complications. Furthermore, impaired corneal epithelial wound healing may also imply more widespread disease. The non-invasiveness and improvement in imaging technology facilitates the emergence of new screening tools. Systemic control of diabetes can improve ocular surface health, possibly aided by anti-inflammatory and vasoprotective agents. PMID:28319106

Factors that Influence the Formation and Stability of Thin, Cryo-EM Specimens

DOE PAGES

Glaeser, Robert M.; Han, Bong-Gyoon; Csencsits, Roseann; ...

2015-09-17

Poor consistency of the ice thickness from one area of a cryo-electron microscope (cryo-EM) specimen grid to another, from one grid to the next, and from one type of specimen to another, motivates a reconsideration of how to best prepare suitably thin specimens. We first review the three related topics of wetting, thinning, and stability against dewetting of aqueous films spread over a hydrophilic substrate. Furthermore, we then suggest that the importance of there being a surfactant monolayer at the air-water interface of thin, cryo-EM specimens has been largely underappreciated. In fact, a surfactant layer (of uncontrolled composition and surfacemore » pressure) can hardly be avoided during standard cryo-EM specimen preparation. Thus it is suggested that better control over the composition and properties of the surfactant layer may result in more reliable production of cryo-EM specimens with the desired thickness.« less

Dietary fatty acids linking postprandial metabolic response and chronic diseases.

PubMed

Ortega, Almudena; Varela, Lourdes M; Bermudez, Beatriz; Lopez, Sergio; Abia, Rocio; Muriana, Francisco J G

2012-01-01

Chronic diseases are by far one of the main causes of mortality in the world. One of the current global recommendations to counteract disability and premature death resulting from chronic diseases is to decrease the consumption of energy-dense high-fat diets, particularly those rich in saturated fatty acids (SFA). The most effective replacement for SFA in terms of risk factor outcomes for chronic disease are polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA). The biochemical basis for healthy benefits of such a dietary pattern has been widely evaluated under fasting conditions. However, the increasing amount of data available from multiple studies suggest that the postprandial state, i.e., "the period that comprises and follows a meal", plays an important, yet underappreciated, role in the genesis of numerous pathological conditions. In this review, the potential of MUFA, PUFA, and SFA to postprandially affect selected metabolic abnormalities related to chronic diseases is discussed.

Wild-derived mouse stocks: an underappreciated tool for aging research

PubMed Central

2008-01-01

Virtually all biomedical research makes use of a relatively small pool of laboratory-adapted, inbred, isogenic stocks of mice. Although the advantages of these models are many, there are a number of disadvantages as well. When studying a multifaceted process such as aging, the problems associated with using laboratory stocks are greatly inflated. On the other hand, wild-derived mouse stocks, loosely defined here as either wild-caught individuals or the recent progeny of wild-caught individuals, have much to offer to biogerontology research. Hence, the aims of this review are threefold: (1) to (re)acquaint readers with the pros and cons of using a typical inbred laboratory mouse model for aging research; (2) to reintroduce the notion of using wild-derived mouse stocks in aging research as championed by Austad, Miller and others for more than a decade, and (3) to provide an overview of recent advances in biogerontology using wild-derived mouse stocks. PMID:19424863

Purinoceptors exert negative inotropic effects on the heart in all major groups of reptiles.

PubMed

Joyce, William; Gesser, Hans; Wang, Tobias

2014-05-01

The few and fragmentary studies on purinergic regulation of the reptile heart have reached equivocal conclusions. Indeed, unlike fish, amphibians, and mammals, it has been suggested that the turtle heart lacks purinoceptors. Here, we study the effect of adenosine and ATP on isolated heart strips from three species of reptiles: the red-eared slider (Trachemys scripta), the ball python (Python regius) and the spectacled caiman (Caiman crocodilus). Both adenosine and ATP markedly decreased contractility in atria from all three species. This was attenuated by theophylline, suggesting that the response is mediated by P1 receptors. Ventricles were less sensitive, although high concentrations of the adenyl compounds evoked decreases in contractility. Our study suggests that cardiac purinoceptors are ubiquitous across reptiles, and may play an important and underappreciated role in reptile cardiovascular physiology. Copyright © 2014 Elsevier Inc. All rights reserved.

Religious and spiritual aspects of family assessment.

PubMed

Moncher, Frank J; Josephson, Allan M

2004-01-01

Childhood emotional and behavioral problems have increased over the past several decades, and the consequences of these behaviors have an impact on the entire family. The role of the family in these problems is clearly an important consideration for the child psychiatrist. A specific understanding of how the family's spiritual worldview or religious convictions impact clinical problems has been underappreciated. The religious orientation or spirituality of parents influences various aspects of family life, from ideals about marriage and family to specifics regarding child rearing. This article reviews the goals of assessment of family religious or spiritual worldview, which include empathically engaging the family of a child in treatment, developing a formulation of how these spiritual factors impact general family functioning, and determining whether the family's religion and spirituality are a resource for treatment or a contributor to disorder. The spiritual and religious assessment of the family facilitates the development of a treatment plan.

Cecal Perforation Associated with Clostridium difficile Infection: A Case Report.

PubMed

Luthe, Sarah Kyuragi; Sato, Ryota

2017-04-01

Various complications are reported with Clostridium difficile infection (CDI), including fulminant CDI. Fulminant CDI is an underappreciated life-threatening condition associated with complications such as toxic megacolon and bowel perforation. A 79-year-old woman presented to the Emergency Department with altered mental status. She was admitted and conservatively treated for a left thalamic hemorrhage. While hospitalized, she developed watery diarrhea due to Clostridium difficile. Although metronidazole was initiated, she developed altered mental status and septic shock. Abdominal x-ray study and computed tomography revealed a significantly dilatated colon and a massive pneumoperitoneum. She underwent subtotal colectomy with a 14-day course of intravenous meropenem. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case suggests that we must be aware of the complications that CDI may present and adequately consider surgical management because early diagnosis and surgical treatment is critical to reduce the mortality of fulminant CDI. Copyright © 2016 Elsevier Inc. All rights reserved.

Sexually selected females in the monogamous Western Australian seahorse.

PubMed

Kvarnemo, Charlotta; Moore, Glenn I; Jones, Adam G

2007-02-22

Studies of sexual selection in monogamous species have hitherto focused on sexual selection among males. Here, we provide empirical documentation that sexual selection can also act strongly on females in a natural population with a monogamous mating system. In our field-based genetic study of the monogamous Western Australian seahorse, Hippocampus subelongatus, sexual selection differentials and gradients show that females are under stronger sexual selection than males: mated females are larger than unmated ones, whereas mated and unmated males do not differ in size. In addition, the opportunity for sexual selection (variance in mating success divided by its mean squared) for females is almost three times that for males. These results, which seem to be generated by a combination of a male preference for larger females and a female-biased adult sex ratio, indicate that substantial sexual selection on females is a potentially important but under-appreciated evolutionary phenomenon in monogamous species.

Nonpharmacologic approach to fatigue in patients with cancer.

PubMed

Pachman, Deirdre R; Price, Katharine A; Carey, Elise C

2014-01-01

Cancer-related fatigue is a common yet underappreciated problem with a significant impact on functional ability and quality of life. Practice guidelines mandate that all cancer patients and survivors be screened for cancer-related fatigue (CRF) at regular intervals. Comorbidities that could contribute to fatigue should be treated, and patients with moderate to severe fatigue should undergo a comprehensive evaluation. Nonpharmacologic interventions are important tools to combat CRF and should be incorporated into routine practice. Physical activity, educational interventions, and cognitive-behavioral therapy have the most supportive data and can be recommended to patients with confidence. From a practical standpoint, general education on CRF is something that most care providers can readily offer patients as part of routine care. Other interventions that appear promising but are as yet lacking convincing evidence include mindfulness-based stress reduction, yoga, and acupuncture. Reiki, Qigong, hypnosis, and music therapy may be worthy of further investigation.

Condition-dependent sex: who does it, when and why?

PubMed

Ram, Yoav; Hadany, Lilach

2016-10-19

We review the phenomenon of condition-dependent sex-where individuals' condition affects the likelihood that they will reproduce sexually rather than asexually. In recent years, condition-dependent sex has been studied both theoretically and empirically. Empirical results in microbes, fungi and plants support the theoretical prediction that negative condition-dependent sex, in which individuals in poor condition are more likely to reproduce sexually, can be evolutionarily advantageous under a wide range of settings. Here, we review the evidence for condition-dependent sex and its potential implications for the long-term survival and adaptability of populations. We conclude by asking why condition-dependent sex is not more commonly observed, and by considering generalizations of condition-dependent sex that might apply even for obligate sexuals.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'. © 2016 The Author(s).

Scoring the importance of tropical forest landscapes with local people: patterns and insights.

PubMed

Sheil, Douglas; Liswanti, Nining

2006-07-01

Good natural resource management is scarce in many remote tropical regions. Improved management requires better local consultation, but accessing and understanding the preferences and concerns of stakeholders can be difficult. Scoring, where items are numerically rated in relation to each other, is simple and seems applicable even in situations where capacity and funds are limited, but managers rarely use such methods. Here we investigate scoring with seven indigenous communities threatened by forest loss in Kalimantan, Indonesia. We aimed to clarify the forest's multifaceted importance, using replication, cross-check exercises, and interviews. Results are sometimes surprising, but generally explained by additional investigation that sometimes provides new insights. The consistency of scoring results increases in line with community literacy and wealth. Various benefits and pitfalls are identified and examined. Aside from revealing and clarifying local preferences, scoring has unexplored potential as a quantitative technique. Scoring is an underappreciated management tool with wide potential.

Comments on "cyclical swings" by Professor Hannah Decker: The underappreciated "solid center" of psychiatry.

PubMed

Pies, Ronald W

2016-02-01

The history of psychiatry is characterized by some deep ideological and conceptual divisions, as adumbrated in Professor Hannah Decker's essay. However, the schism between "biological" and "psychosocial" models of mental illness and its treatment represents extreme positions among some psychiatrists-not the model propounded by academic psychiatry or its affiliated professional organizations. Indeed, the "biopsycho-social model" (BPSM) developed by Dr. George L. Engel has been, and remains, the foundational model for academic psychiatry, notwithstanding malign market forces that have undermined the BPSM's use in clinical practice. The BPSM is integrally related to "centralizing" and integrative trends in American psychiatry that may be traced to Franz Alexander, Karl Jaspers, and Engel himself, among others. This "Alexandrian-Jaspersian-Engelian" tradition is explored in relation to Professor Decker's "cyclical swing" model of psychiatry's history. (c) 2016 APA, all rights reserved).

Callisto: A World in its Own Right

NASA Technical Reports Server (NTRS)

Moore, Jeffrey M.; Schenk, Paul M.

2003-01-01

Callisto, once unknown and then disregarded after Voyager, has emerged in the post-Galileo era worthy of the same intense scientific scrutiny that is lavished upon her sisters, playing an essential role in our understanding of the evolution of icy moons, and in a larger sense, the grand tapestry of solar system history. Along with the discovery of Callisto s con- ducting, probably fluid sub-surface layer, major Gulileo discoveries about Callisto include the complete absence of cryo-volcanic resurfacing, the relatively undifferentiated interior, and the presence of massive landform erosion from sublimation processes. Callisto s landscape at decameter scales is unique among the Galilean satellites, and might be most akin to that of cometary nuclei. The process of sublimation degradation, previously underappreciated, is now recognized as a major surface modification process on Callisto. Its role in mass wasting and landslide initiation was elemental in creating the bizarre and astonishing scenery imaged by Galileo.

Public health and primary care: struggling to "win friends and influence people".

PubMed

Mayes, Rick; McKenna, Sean

2011-01-01

Why are the goals of public health and primary care less politically popular and financially supported than those of curative medicine? A major part of the answer to this question lies in the fact that humans often worry wrongly by assessing risk poorly. This reality is a significant obstacle to the adequate promotion of and investment in public health, primary care, and prevention. Also, public health's tendency to infringe on personal privacy-as well as to call for difficult behavioral change-often sparks intense controversy and interest group opposition that discourage broader political support. Finally, in contrast to curative medicine, both the cost-benefit structure of public health (costs now, benefits later) and the way in which the profession operates make it largely invisible to and, thus, underappreciated by the general public. When curative medicine works well, most everybody notices. When public health and primary care work well, virtually nobody notices.

Cooperativity in Monomeric Enzymes with Single Ligand-Binding Sites

PubMed Central

Porter, Carol M.

2011-01-01

Cooperativity is widespread in biology. It empowers a variety of regulatory mechanisms and impacts both the kinetic and thermodynamic properties of macromolecular systems. Traditionally, cooperativity is viewed as requiring the participation of multiple, spatially distinct binding sites that communicate via ligand-induced structural rearrangements; however, cooperativity requires neither multiple ligand binding events nor multimeric assemblies. An underappreciated manifestation of cooperativity has been observed in the non-Michaelis-Menten kinetic response of certain monomeric enzymes that possess only a single ligand-binding site. In this review, we present an overview of kinetic cooperativity in monomeric enzymes. We discuss the primary mechanisms postulated to give rise to monomeric cooperativity and highlight modern experimental methods that could offer new insights into the nature of this phenomenon. We conclude with an updated list of single subunit enzymes that are suspected of displaying cooperativity, and a discussion of the biological significance of this unique kinetic response. PMID:22137502

Blood Pressure Regulation: Every Adaptation is an Integration?

PubMed Central

Joyner, Michael J.; Limberg, Jacqueline K.

2013-01-01

This focused review serves to explore relevant issues in regard to blood pressure regulation and by doing so, provides the initial stimulus paper for the Thematic Review series “Blood Pressure Regulation” to be published in the European Journal of Applied Physiology over the coming months. In this introduction, we highlight how variable normal blood pressure can be and challenge the reader to take another look at some key concepts related to blood pressure regulation. We point out that there is frequently an underappreciated balance between peripheral vasodilation and systemic blood pressure regulation and ask the question: Are changes in blood pressure, in effect, reasonable and integrated adaptations to the physiological challenge at hand? We conclude with the idea that blood pressure regulatory systems are both flexible and redundant; ensuring a wide variety of activities associated with life can be accompanied by a perfusion pressure that can serve multiple masters. PMID:23558925

Women in surgery: a survey in Switzerland.

PubMed

Kaderli, Reto; Guller, Ulrich; Muff, Brigitte; Stefenelli, Ulrich; Businger, Adrian

2010-11-01

An increasing proportion of women work in medicine; however, only few choose surgical specialties. The objective of this study was to analyze the current situation of female surgeons and surgical residents in Switzerland concerning their personal and professional fulfillment. Of 318 female surgeons and surgical residents included in our study, 189 (59.4%) returned the anonymous questionnaire. Mentor-mentee relationships were mentioned by 110 (58.2%) of the 189 respondents. On the basis of a 7-point Likert scale, these women responded that they were moderately satisfied with their professional (mean score [SD], 2.7 [1.3]) and personal (mean score [SD], 3.0 [1.7]) lives. Of the 189 respondents, 113 (59.8%) mentioned that they felt underappreciated. The most important ways suggested for increasing the attractiveness of a surgical career for women were a reduction in workload (49 respondents [25.9%]), more flexible working hours (38 respondents [20.1%]), and better structured residency programs (23 respondents [12.2%]).

Vaccines against invasive Salmonella disease

PubMed Central

MacLennan, Calman A; Martin, Laura B; Micoli, Francesca

2014-01-01

Though primarily enteric pathogens, Salmonellae are responsible for a considerable yet under-appreciated global burden of invasive disease. In South and South-East Asia, this manifests as enteric fever caused by serovars Typhi and Paratyphi A. In sub-Saharan Africa, a similar disease burden results from invasive nontyphoidal Salmonellae, principally serovars Typhimurium and Enteritidis. The existing Ty21a live-attenuated and Vi capsular polysaccharide vaccines target S. Typhi and are not effective in young children where the burden of invasive Salmonella disease is highest. After years of lack of investment in new Salmonella vaccines, recent times have seen increased interest in the area led by emerging-market manufacturers, global health vaccine institutes and academic partners. New glycoconjugate vaccines against S. Typhi are becoming available with similar vaccines against other invasive serovars in development. With other new vaccines under investigation, including live-attenuated, protein-based and GMMA vaccines, now is an exciting time for the Salmonella vaccine field. PMID:24804797

Testing and Validation of Computational Methods for Mass Spectrometry.

PubMed

Gatto, Laurent; Hansen, Kasper D; Hoopmann, Michael R; Hermjakob, Henning; Kohlbacher, Oliver; Beyer, Andreas

2016-03-04

High-throughput methods based on mass spectrometry (proteomics, metabolomics, lipidomics, etc.) produce a wealth of data that cannot be analyzed without computational methods. The impact of the choice of method on the overall result of a biological study is often underappreciated, but different methods can result in very different biological findings. It is thus essential to evaluate and compare the correctness and relative performance of computational methods. The volume of the data as well as the complexity of the algorithms render unbiased comparisons challenging. This paper discusses some problems and challenges in testing and validation of computational methods. We discuss the different types of data (simulated and experimental validation data) as well as different metrics to compare methods. We also introduce a new public repository for mass spectrometric reference data sets ( http://compms.org/RefData ) that contains a collection of publicly available data sets for performance evaluation for a wide range of different methods.

Sexually selected females in the monogamous Western Australian seahorse

PubMed Central

Kvarnemo, Charlotta; Moore, Glenn I; Jones, Adam G

2006-01-01

Studies of sexual selection in monogamous species have hitherto focused on sexual selection among males. Here, we provide empirical documentation that sexual selection can also act strongly on females in a natural population with a monogamous mating system. In our field-based genetic study of the monogamous Western Australian seahorse, Hippocampus subelongatus, sexual selection differentials and gradients show that females are under stronger sexual selection than males: mated females are larger than unmated ones, whereas mated and unmated males do not differ in size. In addition, the opportunity for sexual selection (variance in mating success divided by its mean squared) for females is almost three times that for males. These results, which seem to be generated by a combination of a male preference for larger females and a female-biased adult sex ratio, indicate that substantial sexual selection on females is a potentially important but under-appreciated evolutionary phenomenon in monogamous species. PMID:17476772

Fluorescent Protein Approaches in Alpha Herpesvirus Research

PubMed Central

Hogue, Ian B.; Bosse, Jens B.; Engel, Esteban A.; Scherer, Julian; Hu, Jiun-Ruey; del Rio, Tony; Enquist, Lynn W.

2015-01-01

In the nearly two decades since the popularization of green fluorescent protein (GFP), fluorescent protein-based methodologies have revolutionized molecular and cell biology, allowing us to literally see biological processes as never before. Naturally, this revolution has extended to virology in general, and to the study of alpha herpesviruses in particular. In this review, we provide a compendium of reported fluorescent protein fusions to herpes simplex virus 1 (HSV-1) and pseudorabies virus (PRV) structural proteins, discuss the underappreciated challenges of fluorescent protein-based approaches in the context of a replicating virus, and describe general strategies and best practices for creating new fluorescent fusions. We compare fluorescent protein methods to alternative approaches, and review two instructive examples of the caveats associated with fluorescent protein fusions, including describing several improved fluorescent capsid fusions in PRV. Finally, we present our future perspectives on the types of powerful experiments these tools now offer. PMID:26610544

New generation adjuvants--from empiricism to rational design.

PubMed

O'Hagan, Derek T; Fox, Christopher B

2015-06-08

Adjuvants are an essential component of modern vaccine development. Despite many decades of development, only a few types of adjuvants are currently included in vaccines approved for human use. In order to better understand the reasons that development of some adjuvants succeeded while many others failed, we discuss some of the common attributes of successful first generation adjuvants. Next, we evaluate current trends in the development of second generation adjuvants, including the potential advantages of rationally designed synthetic immune potentiators appropriately formulated. Finally, we discuss desirable attributes of next generation adjuvants. Throughout, we emphasize that the importance of formulation and analytical characterization in all aspects of vaccine adjuvant development is often underappreciated. We highlight the formulation factors that must be evaluated in order to optimize interactions between vaccine antigens, immune potentiators, and particulate formulations, and the resulting effects on safety, biological activity, manufacturability, and stability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sleep: A Health Imperative

PubMed Central

Luyster, Faith S.; Strollo, Patrick J.; Zee, Phyllis C.; Walsh, James K.

2012-01-01

Chronic sleep deficiency, defined as a state of inadequate or mistimed sleep, is a growing and underappreciated determinant of health status. Sleep deprivation contributes to a number of molecular, immune, and neural changes that play a role in disease development, independent of primary sleep disorders. These changes in biological processes in response to chronic sleep deficiency may serve as etiological factors for the development and exacerbation of cardiovascular and metabolic diseases and, ultimately, a shortened lifespan. Sleep deprivation also results in significant impairments in cognitive and motor performance which increase the risk of motor vehicle crashes and work-related injuries and fatal accidents. The American Academy of Sleep Medicine and the Sleep Research Society have developed this statement to communicate to national health stakeholders the current knowledge which ties sufficient sleep and circadian alignment in adults to health. Citation: Luyster FS; Strollo PJ; Zee PC; Walsh JK. Sleep: a health imperative. SLEEP 2012;35(6):727-734. PMID:22654183

COEXISTENCE OF CONSTIPATION AND INCONTINENCE IN CHILDREN AND ADULTS

PubMed Central

Nurko, S; Scott, SM

2011-01-01

The coexistence of constipation and fecal incontinence has long been recognized in pediatric and geriatric populations, but is grossly underappreciated in the rest of the adult population. In children, functional fecal incontinence is usually associated with constipation, stool retention and incomplete evacuation, and is frequently allied to urinary incontinence. Pathophysiology of the incontinence is incompletely understood, although both in children and adults, it is thought to be secondary to overflow, while in adults it may also be related to pelvic floor dysfunction and denervation. Incontinence has an important impact on quality of life and daily functioning, and in children may be associated with behavior problems. The treatment of underlying constipation usually results in improvement in incontinence. This review broadly addresses the epidemiology and pathophysiology of coexistent constipation and incontinence in both children and adults, and also reviews clinical presentation and treatment response in pediatrics. PMID:21382577

Mechanosensitive subcellular rheostasis drives emergent single-cell mechanical homeostasis

NASA Astrophysics Data System (ADS)

Weng, Shinuo; Shao, Yue; Chen, Weiqiang; Fu, Jianping

2016-09-01

Mechanical homeostasis--a fundamental process by which cells maintain stable states under environmental perturbations--is regulated by two subcellular mechanotransducers: cytoskeleton tension and integrin-mediated focal adhesions (FAs). Here, we show that single-cell mechanical homeostasis is collectively driven by the distinct, graduated dynamics (rheostasis) of subcellular cytoskeleton tension and FAs. Such rheostasis involves a mechanosensitive pattern wherein ground states of cytoskeleton tension and FA determine their distinct reactive paths through either relaxation or reinforcement. Pharmacological perturbations of the cytoskeleton and molecularly modulated integrin catch-slip bonds biased the rheostasis and induced non-homeostasis of FAs, but not of cytoskeleton tension, suggesting a unique sensitivity of FAs in regulating homeostasis. Theoretical modelling revealed myosin-mediated cytoskeleton contractility and catch-slip-bond-like behaviours in FAs and the cytoskeleton as sufficient and necessary mechanisms for quantitatively recapitulating mechanosensitive rheostasis. Our findings highlight the previously underappreciated physical nature of the mechanical homeostasis of cells.

Newly rare or newly common: evolutionary feedbacks through changes in population density and relative species abundance, and their management implications

PubMed Central

Lankau, Richard A; Strauss, Sharon Y

2011-01-01

Environmental management typically seeks to increase or maintain the population sizes of desirable species and to decrease population sizes of undesirable pests, pathogens, or invaders. With changes in population size come long-recognized changes in ecological processes that act in a density-dependent fashion. While the ecological effects of density dependence have been well studied, the evolutionary effects of changes in population size, via changes in ecological interactions with community members, are underappreciated. Here, we provide examples of changing selective pressures on, or evolution in, species as a result of changes in either density of conspecifics or changes in the frequency of heterospecific versus conspecific interactions. We also discuss the management implications of such evolutionary responses in species that have experienced rapid increases or decreases in density caused by human actions. PMID:25567977

Breast, milk and microbes: a complex relationship that does not end with lactation.

PubMed

Urbaniak, Camilla; Burton, Jeremy P; Reid, Gregor

2012-07-01

Until relatively recently, the extent of microbiota presence in the human breast was under-appreciated. A high-throughput sequencing study and culture-based studies have demonstrated the extensive presence of microbes in human milk, with their origin believed to be from the skin, oral cavity and via gut translocation. Since formula milk substitutes do not contain these bacteria, what benefits are denied to these infants? The addition of probiotic bacteria to some infant formula is meant to provide some benefits, but these only contain one species and the dose is relatively high compared with breast milk. Many questions of importance to women's health arise from these findings. When, how and what types of microbes colonize the breast at different stages of a woman's life, including postlactation, and what effect do they have on the host in the short and long term? This article discusses some aspects of these questions.

Divergence of Drosophila melanogaster repeatomes in response to a sharp microclimate contrast in Evolution Canyon, Israel

PubMed Central

Kim, Young Bun; Oh, Jung Hun; McIver, Lauren J.; Rashkovetsky, Eugenia; Michalak, Katarzyna; Garner, Harold R.; Kang, Lin; Nevo, Eviatar; Korol, Abraham B.; Michalak, Pawel

2014-01-01

Repeat sequences, especially mobile elements, make up large portions of most eukaryotic genomes and provide enormous, albeit commonly underappreciated, evolutionary potential. We analyzed repeatomes of Drosophila melanogaster that have been diverging in response to a microclimate contrast in Evolution Canyon (Mount Carmel, Israel), a natural evolutionary laboratory with two abutting slopes at an average distance of only 200 m, which pose a constant ecological challenge to their local biotas. Flies inhabiting the colder and more humid north-facing slope carried about 6% more transposable elements than those from the hot and dry south-facing slope, in parallel to a suite of other genetic and phenotypic differences between the two populations. Nearly 50% of all mobile element insertions were slope unique, with many of them disrupting coding sequences of genes critical for cognition, olfaction, and thermotolerance, consistent with the observed patterns of thermotolerance differences and assortative mating. PMID:25006263

Divergence of Drosophila melanogaster repeatomes in response to a sharp microclimate contrast in Evolution Canyon, Israel.

PubMed

Kim, Young Bun; Oh, Jung Hun; McIver, Lauren J; Rashkovetsky, Eugenia; Michalak, Katarzyna; Garner, Harold R; Kang, Lin; Nevo, Eviatar; Korol, Abraham B; Michalak, Pawel

2014-07-22

Repeat sequences, especially mobile elements, make up large portions of most eukaryotic genomes and provide enormous, albeit commonly underappreciated, evolutionary potential. We analyzed repeatomes of Drosophila melanogaster that have been diverging in response to a microclimate contrast in Evolution Canyon (Mount Carmel, Israel), a natural evolutionary laboratory with two abutting slopes at an average distance of only 200 m, which pose a constant ecological challenge to their local biotas. Flies inhabiting the colder and more humid north-facing slope carried about 6% more transposable elements than those from the hot and dry south-facing slope, in parallel to a suite of other genetic and phenotypic differences between the two populations. Nearly 50% of all mobile element insertions were slope unique, with many of them disrupting coding sequences of genes critical for cognition, olfaction, and thermotolerance, consistent with the observed patterns of thermotolerance differences and assortative mating.

Colonoscopy-associated pneumothorax: a case of tension pneumothorax and review of the literature.

PubMed

Zeno, Brian R; Sahn, Steven A

2006-09-01

A 64-year-old woman presented with severe abdominal pain and was found to have a large fecolith in the sigmoid colon with resulting bowel obstruction. During a therapeutic colonoscopy, she developed severe shortness of breath and hypoxia, and was found to have a tension pneumothorax. We review the potential mechanisms by which pneumothorax may occur following colonoscopy. In addition, the eight previously published cases are reviewed. Pneumothorax, with or without pneumomediastinum, can occur through a variety of mechanisms following colonoscopy. Although rarely reported, this may represent an underappreciated complication and should be fully investigated in the appropriate setting. Colonoscopy, an exceedingly common procedure, will continue to increase with the aging population. As a result, tension pneumothorax can have a profound effect on the patient outcome and therefore physicians, both gastroenterologists and pulmonologists, should be aware of all the potential problems with this procedure.

Factors that Influence the Formation and Stability of Thin, Cryo-EM Specimens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glaeser, Robert M.; Han, Bong-Gyoon; Csencsits, Roseann

Poor consistency of the ice thickness from one area of a cryo-electron microscope (cryo-EM) specimen grid to another, from one grid to the next, and from one type of specimen to another, motivates a reconsideration of how to best prepare suitably thin specimens. We first review the three related topics of wetting, thinning, and stability against dewetting of aqueous films spread over a hydrophilic substrate. Furthermore, we then suggest that the importance of there being a surfactant monolayer at the air-water interface of thin, cryo-EM specimens has been largely underappreciated. In fact, a surfactant layer (of uncontrolled composition and surfacemore » pressure) can hardly be avoided during standard cryo-EM specimen preparation. Thus it is suggested that better control over the composition and properties of the surfactant layer may result in more reliable production of cryo-EM specimens with the desired thickness.« less

The underappreciated potential of peatlands in global climate change mitigation strategies.

PubMed

Leifeld, J; Menichetti, L

2018-03-14

Soil carbon sequestration and avoidable emissions through peatland restoration are both strategies to tackle climate change. Here we compare their potential and environmental costs regarding nitrogen and land demand. In the event that no further areas are exploited, drained peatlands will cumulatively release 80.8 Gt carbon and 2.3 Gt nitrogen. This corresponds to a contemporary annual greenhouse gas emission of 1.91 (0.31-3.38) Gt CO 2 -eq. that could be saved with peatland restoration. Soil carbon sequestration on all agricultural land has comparable mitigation potential. However, additional nitrogen is needed to build up a similar carbon pool in organic matter of mineral soils, equivalent to 30-80% of the global fertilizer nitrogen application annually. Restoring peatlands is 3.4 times less nitrogen costly and involves a much smaller land area demand than mineral soil carbon sequestration, calling for a stronger consideration of peatland rehabilitation as a mitigation measure.

Human Epidermal Langerhans Cells Maintain Immune Homeostasis in Skin by Activating Skin Resident Regulatory T Cells

PubMed Central

Seneschal, Julien; Clark, Rachael A.; Gehad, Ahmed; Baecher-Allan, Clare M.; Kupper, Thomas S.

2013-01-01

Recent discoveries indicate that the skin of a normal individual contains 10-20 billion resident memory T cells ( which include various T helper, T cytotoxic, and T regulatory subsets, that are poised to respond to environmental antigens. Using only autologous human tissues, we report that both in vitro and in vivo, resting epidermal Langerhan cells (LC) selectively and specifically induced the activation and proliferation of skin resident regulatory T cells (Treg), a minor subset of skin resident memory T cells. In the presence of foreign pathogen, however, the same LC activated and induced proliferation of effector memory T (Tem) cells and limited Treg cells activation. These underappreciated properties of LC: namely maintenance of tolerance in normal skin, and activation of protective skin resident memory T cells upon infectious challenge, help clarify the role of LC in skin. PMID:22560445

Herbal medicine research and global health: an ethical analysis.

PubMed

Tilburt, Jon C; Kaptchuk, Ted J

2008-08-01

Governments, international agencies and corporations are increasingly investing in traditional herbal medicine research. Yet little literature addresses ethical challenges in this research. In this paper, we apply concepts in a comprehensive ethical framework for clinical research to international traditional herbal medicine research. We examine in detail three key, underappreciated dimensions of the ethical framework in which particularly difficult questions arise for international herbal medicine research: social value, scientific validity and favourable risk-benefit ratio. Significant challenges exist in determining shared concepts of social value, scientific validity and favourable risk-benefit ratio across international research collaborations. However, we argue that collaborative partnership, including democratic deliberation, offers the context and process by which many of the ethical challenges in international herbal medicine research can, and should be, resolved. By "cross-training" investigators, and investing in safety-monitoring infrastructure, the issues identified by this comprehensive framework can promote ethically sound international herbal medicine research that contributes to global health.

Ants and termites increase crop yield in a dry climate

PubMed Central

Evans, Theodore A.; Dawes, Tracy Z.; Ward, Philip R.; Lo, Nathan

2011-01-01

Agricultural intensification has increased crop yields, but at high economic and environmental cost. Harnessing ecosystem services of naturally occurring organisms is a cheaper but under-appreciated approach, because the functional roles of organisms are not linked to crop yields, especially outside the northern temperate zone. Ecosystem services in soil come from earthworms in these cooler and wetter latitudes; what may fulfill their functional role in agriculture in warmer and drier habitats, where they are absent, is unproven. Here we show in a field experiment that ants and termites increase wheat yield by 36% from increased soil water infiltration due to their tunnels and improved soil nitrogen. Our results suggest that ants and termites have similar functional roles to earthworms, and that they may provide valuable ecosystem services in dryland agriculture, which may become increasingly important for agricultural sustainability in arid climates. PMID:21448161

Condensins: universal organizers of chromosomes with diverse functions

PubMed Central

Hirano, Tatsuya

2012-01-01

Condensins are multisubunit protein complexes that play a fundamental role in the structural and functional organization of chromosomes in the three domains of life. Most eukaryotic species have two different types of condensin complexes, known as condensins I and II, that fulfill nonoverlapping functions and are subjected to differential regulation during mitosis and meiosis. Recent studies revealed that the two complexes contribute to a wide variety of interphase chromosome functions, such as gene regulation, recombination, and repair. Also emerging are their cell type- and tissue-specific functions and relevance to human disease. Biochemical and structural analyses of eukaryotic and bacterial condensins steadily uncover the mechanisms of action of this class of highly sophisticated molecular machines. Future studies on condensins will not only enhance our understanding of chromosome architecture and dynamics, but also help address a previously underappreciated yet profound set of questions in chromosome biology. PMID:22855829

Stillbirths: economic and psychosocial consequences.

PubMed

Heazell, Alexander E P; Siassakos, Dimitrios; Blencowe, Hannah; Burden, Christy; Bhutta, Zulfiqar A; Cacciatore, Joanne; Dang, Nghia; Das, Jai; Flenady, Vicki; Gold, Katherine J; Mensah, Olivia K; Millum, Joseph; Nuzum, Daniel; O'Donoghue, Keelin; Redshaw, Maggie; Rizvi, Arjumand; Roberts, Tracy; Toyin Saraki, H E; Storey, Claire; Wojcieszek, Aleena M; Downe, Soo

2016-02-06

Despite the frequency of stillbirths, the subsequent implications are overlooked and underappreciated. We present findings from comprehensive, systematic literature reviews, and new analyses of published and unpublished data, to establish the effect of stillbirth on parents, families, health-care providers, and societies worldwide. Data for direct costs of this event are sparse but suggest that a stillbirth needs more resources than a livebirth, both in the perinatal period and in additional surveillance during subsequent pregnancies. Indirect and intangible costs of stillbirth are extensive and are usually met by families alone. This issue is particularly onerous for those with few resources. Negative effects, particularly on parental mental health, might be moderated by empathic attitudes of care providers and tailored interventions. The value of the baby, as well as the associated costs for parents, families, care providers, communities, and society, should be considered to prevent stillbirths and reduce associated morbidity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physical parameters of Fluvisols on flooded and non-flooded terraces

NASA Astrophysics Data System (ADS)

Kercheva, Milena; Sokołowska, Zofia; Hajnos, Mieczysław; Skic, Kamil; Shishkov, Toma

2017-01-01

The heterogeneity of soil physical properties of Fluvisols, lack of large pristine areas, and different moisture regimes on non-flooded and flooded terraces impede the possibility to find a soil profile which can serve as a baseline for estimating the impact of natural or anthropogenic factors on soil evolution. The aim of this study is to compare the pore size distribution of pristine Fluvisols on flooded and non-flooded terraces using the method of the soil water retention curve, mercury intrusion porosimetry, nitrogen adsorption isotherms, and water vapour sorption. The pore size distribution of humic horizons of pristine Fluvisols on the non-flooded terrace differs from pore size distribution of Fluvisols on the flooded terrace. The peaks of textural and structural pores are higher in the humic horizons under more humid conditions. The structural characteristics of subsoil horizons depend on soil texture and evolution stage. The peaks of textural pores at about 1 mm diminish with lowering of the soil organic content. Structureless horizons are characterized by uni-modal pore size distribution. Although the content of structural pores of the subsoil horizons of Fluvisols on the non-flooded terrace is low, these pores are represented by biopores, as the coefficient of filtration is moderately high. The difference between non-flooded and flooded profiles is well expressed by the available water storage, volume and mean radius of pores, obtained by mercury intrusion porosimetry and water desorption, which are higher in the surface horizons of frequently flooded Fluvisols.

Palynostratigraphy, palynofacies and palaeoenvironment of deposition of Selandian to Aquitanian sediments, southeastern Nigeria

NASA Astrophysics Data System (ADS)

Okeke, Kingsley K.; Umeji, Obianuju P.

2016-08-01

Investigation of outcrop sections along the Onitsha-Awka transect in the Niger Delta Basin southeastern Nigeria was undertaken to assess the palynological composition, palynofacies and palaeoenvironment of deposition. Stratigraphic ranges of palynomorphs suggest an age of Selandian to Aquitanian. The palynological composition is marked by abundance of dinoflagellate cysts in the Imo Formation (Selandian to Thanetian), dominance of spores and pollen over dinoflagellate cysts in the Nanka Formation (Ypresian to Bartonian), and overwhelming amounts of spore and pollen in the Ogwashi Formation (Pariabonian to Aquitanian). Palynofacies content shows dominance of structureless organic matter in the Imo Formation, few phytoclasts in the Nanka Formation and maximum phytoclast amounts in the Ogwashi Formation. Thanetian to Ypresian boundary was marked by the mixing of older Palaeocene and younger Eocene microfossils, decrease of microflora towards the end of Palaeocene and the evolution of abundant and more diverse Eocene taxa. The Imo Formation was deposited in middle to outer neritic zone based on abundance of gonyaulacacean cysts. However, peridiniacean and terrestrial microflora extend the deposition range to shallow waters of inner neritic and coastal zone. Increase in diversity and abundance of terrestrial palynomorphs over marine palynomorphs assemblages in the overlying Nanka Formation suggest deposition under alternating coastal and inner neritic conditions while the Ogwashi Formation records oscillating coastal plain and brackish water depositional conditions. The palaeoenvironments illustrate that general retrogradation was followed by progradation of the delta during the Cenozoic.

Mapping a protein recognition centre with chiral photoactive ligands. An integrated approach combining photophysics, reactivity, proteomics and molecular dynamics simulation studies.

PubMed

Limones-Herrero, Daniel; Pérez-Ruiz, Raúl; Lence, Emilio; González-Bello, Concepción; Miranda, Miguel A; Jiménez, M Consuelo

2017-04-01

A multidisciplinary strategy to obtain structural information on the intraprotein region is described here. As probe ligands, ( S )- and ( R )- CPFMe (the methyl esters of the chiral drug carprofen) have been selected, while bovine α 1 -acid glycoprotein (BAAG) has been chosen as a biological host. The procedure involves the separate irradiation of the BAAG/( S )- CPFMe and BAAG/( R )- CPFMe complexes, coupled with fluorescence spectroscopy, laser flash photolysis, proteomic analysis, docking and molecular dynamics simulations. Thus, irradiation of the BAAG/ CPFMe complexes at λ = 320 nm was followed by fluorescence spectroscopy. The intensity of the emission band obtained after irradiation indicated photodehalogenation, whereas its structureless shape suggested covalent binding of the resulting radical CBZMe˙ to the biopolymer. After gel filtration chromatography, the spectra still displayed emission, in agreement with covalent attachment of CBZMe˙ to BAAG. Stereodifferentiation was observed in this process. After trypsin digestion and ESI-MS/MS, the incorporation of CBZMe was detected at Phe68. Docking and molecular dynamics simulation studies, which were carried out using a homology model of BAAG, reveal that the closer proximity of the aromatic moiety of the ( S )-enantiomer to the phenyl group of Phe68 would be responsible for the experimentally observed, more effective chemical modification of the protein. The proposed tridimensional structure of BAAG covalently modified by the two enantiomers is also provided. In principle, this approach can be extended to a variety of protein/ligand complexes.

Variance of the Quantum Dwell Time for a Nonrelativistic Particle

NASA Technical Reports Server (NTRS)

Hahne, Gerhard

2012-01-01

Munoz, Seidel, and Muga [Phys. Rev. A 79, 012108 (2009)], following an earlier proposal by Pollak and Miller [Phys. Rev. Lett. 53, 115 (1984)] in the context of a theory of a collinear chemical reaction, showed that suitable moments of a two-flux correlation function could be manipulated to yield expressions for the mean quantum dwell time and mean square quantum dwell time for a structureless particle scattering from a time-independent potential energy field between two parallel lines in a two-dimensional spacetime. The present work proposes a generalization to a charged, nonrelativistic particle scattering from a transient, spatially confined electromagnetic vector potential in four-dimensional spacetime. The geometry of the spacetime domain is that of the slab between a pair of parallel planes, in particular those defined by constant values of the third (z) spatial coordinate. The mean Nth power, N = 1, 2, 3, . . ., of the quantum dwell time in the slab is given by an expression involving an N-flux-correlation function. All these means are shown to be nonnegative. The N = 1 formula reduces to an S-matrix result published previously [G. E. Hahne, J. Phys. A 36, 7149 (2003)]; an explicit formula for N = 2, and of the variance of the dwell time in terms of the S-matrix, is worked out. A formula representing an incommensurability principle between variances of the output-minus-input flux of a pair of dynamical variables (such as the particle s time flux and others) is derived.

Heavy mineral sorting and distributions within massive sandstone divisions (Bouma A divisions) of Brushy Canyon Formation turbidites

NASA Astrophysics Data System (ADS)

Motanated, K.; Tice, M. M.

2009-12-01

KANNIPA MOTANATED and MICHAEL M. TICE Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843-3115, USA Sediment sorting data are commonly used for interpreting depositional environments, analyzing mechanisms of deposition and transportation, and inferring relative transport distance of sediments. Typically, sorting in sandstones is estimated by point-counting thin sections which is a time consuming procedure and requires cutting sections of rock samples. We demonstrate a new technique for quantifying sediment sorting using element distribution maps obtained by x-ray fluorescence microscopy. We show that hydraulic sorting of Zr- and Ti- bearing grains (probably zircon and rutile, respectively) results in characteristic vertical profiles of Zr and Ti abundances within the Bouma A divisions of turbidites of the Brushy Canyon Formation, Delaware Basin, southern New Mexico. Zr- and Ti- bearing grains decrease in abundance and diameter from bases to tops of A divisions in every sample examined in this study. These results contrast with previous observations which suggest that grading in Brushy Canyon Formation structureless sandstones is absent or rare. The data support turbiditic interpretations of these rocks against traction current interpretations which rely on the lack of textural grading. Grading is reflected in vertical profiles of Ti/Al, Zr/Al and Zr/Ti ratios, which each decrease upward. These compositional variations could potentially be used as geochemical proxies for physical sorting, and might be useful for inferring depositional processes and relative transport distances.

Time as an Observable in Nonrelativistic Quantum Mechanics

NASA Technical Reports Server (NTRS)

Hahne, G. E.

2003-01-01

The argument follows from the viewpoint that quantum mechanics is taken not in the usual form involving vectors and linear operators in Hilbert spaces, but as a boundary value problem for a special class of partial differential equations-in the present work, the nonrelativistic Schrodinger equation for motion of a structureless particle in four- dimensional space-time in the presence of a potential energy distribution that can be time-as well as space-dependent. The domain of interest is taken to be one of two semi-infinite boxes, one bounded by two t=constant planes and the other by two t=constant planes. Each gives rise to a characteristic boundary value problem: one in which the initial, input values on one t=constant wall are given, with zero asymptotic wavefunction values in all spatial directions, the output being the values on the second t=constant wall; the second with certain input values given on both z=constant walls, with zero asymptotic values in all directions involving time and the other spatial coordinates, the output being the complementary values on the z=constant walls. The first problem corresponds to ordinary quantum mechanics; the second, to a fully time-dependent version of a problem normally considered only for the steady state (time-independent Schrodinger equation). The second problem is formulated in detail. A conserved indefinite metric is associated with space-like propagation, where the sign of the norm of a unidirectional state corresponds to its spatial direction of travel.

THE DYNAMICS OF HYDROGEN ATOM ABSTRACTION FROM POLYATOMIC MOLECULES.

DOE Office of Scientific and Technical Information (OSTI.GOV)

LIU,X.; SUITS,A.G.

2002-11-21

The hydrogen atom abstraction reaction is an important fundamental process that is extensively involved in atmospheric and combustion chemistry. The practical significance of this type of reaction with polyatomic hydrocarbons is manifest, which has led to many kinetics studies. The detailed understanding of these reactions requires corresponding dynamics studies. However, in comparison to the A + HX {radical} AH + X reactions, the study of the dynamics of A + HR {yields} AH + R reactions is much more difficult, both experimentally and theoretically (here and in the following, A stands for an atom, X stands for a halogen atom,more » and R stands for a polyatomic hydrocarbon radical). The complication stems from the structured R, in contrast to the structureless X. First of all, there are many internal degrees of freedom in R that can participate in the reaction. In addition, there are different carbon sites from which an H atom can be abstracted, and the dynamics are correspondingly different; there are also multiple identical carbon sites in HR and in the picture of a local reaction, there exist competitions between neighboring H atoms, and so on. Despite this complexity, there have been continuing efforts to obtain insight into the dynamics of these reactions. In this chapter, some examples are presented, including the reactions of ground state H, Cl, and O atoms, with particular focus on our recent work using imaging to obtain the differential cross sections for these reactions.« less

The distribution of actin immunoreactivity in rhabdomeres of tipulid flies in relation to extracellular membrane shedding.

PubMed

Blest, A D; Stowe, S; Clausen, J A; Carter, M

1991-09-01

Rhabdomeres of tipulid flies lose membrane during turnover from a 'shedding zone' composed of microvillar tips. These distal domains lack intramicrovillar cytoskeletons and appear to be empty sacs of membrane. Recent concerns about the role of ninaC mechano-enzymes in the architecture of dipteran rhabdomeral microvilli and the dynamic role that they may play in the creation of shedding zones demand an examination of the distribution of actin in tipulid rhabdomeres. We compared rhabdomeres from tipulid retinae incubated before fixation for immunocytochemistry in a buffer without additives and a stabilising buffer that contained a cocktail of cysteine protease inhibitors; both were challenged by an anti-actin antibody for immunogold labelling after embedding in LR White Resin. Shedding zones thus processed collapse to structureless detritus. Stabilised and unstabilized shedding zones were immunonegative to anti-actin. To ensure that the negative results were not consequent upon conformational changes generated by the processing protocol, we examined microvilli of degenerating rhabdomeres of the Drosophila light-dependent retinal degeneration mutant rdgBKS222 (which separate and collapse without creating a shedding zone) and found the detritus they generate to be immunopositive to anti-actin. Stabilised and unstabilized regions of basal regions of tipulid rhabdomeres were equally immunopositive. We infer that (a) actin is absent from shedding zones; (b) actin is not degraded by microvillar cysteine proteases. The implications of these conclusions are discussed in relation to some functional models of arthropod photoreceptor microvilli.

Free energy simulations of amylin I26P mutation in a lipid bilayer.

PubMed

Jalili, Seifollah; Maleki, Afsaneh; Akhavan, Mojdeh; Najafi, Bijan; Schofield, Jeremy

2015-02-01

The amylin peptide in a dioleoylphosphatidylcholine (DOPC) bilayer is studied using united atom molecular dynamics (MD) simulations. Dynamics and transport properties of the peptide and the phospholipid bilayer are investigated. The lateral diffusion of DOPC is in the order of 10(-8) cm(2) s(-1), which is in agreement with the experimental results. The order parameter and density profile for phospholipid molecules in the bilayer are calculated. The secondary structure of amylin peptide shows that the amino acids in two terminals are structureless and two α-helical segments in the peptide are connected through an unstructured link. This structure is similar to the experimental structure in the membrane-mimicking media. Free energy calculations of the Ile26 → Pro mutation in the amylin peptide are performed in the bilayer and in aqueous solution using molecular dynamics simulations and a thermodynamic cycle. It is shown that in the mutated peptide in aqueous solution, the α-helix structure changes to a 5-helix, whereas this configuration is preserved in the bilayer environment. It is interesting that the accessible surface area increases for hydrophobic residues in the bilayer and for hydrophilic residues in aqueous solution as the coupling parameter changes from 0 to 1. These results are significant to understanding the aggregation mechanism of human amylin monomers in membranes to the dimers, trimers, oligomers, and fibrils associated with the type 2 diabetes at the atomic level.

Effects of light at night on laboratory animals and research outcomes.

PubMed

Emmer, Kathryn M; Russart, Kathryn L G; Walker, William H; Nelson, Randy J; DeVries, A Courtney

2018-06-28

Light has substantial influences on the physiology and behavior of most laboratory animals. As such, lighting conditions within animal rooms are potentially significant and often underappreciated variables within experiments. Disruption of the light/dark cycle, primarily by exposing animals to light at night (LAN), disturbs biological rhythms and has widespread physiological consequences because of mechanisms such as melatonin suppression, sympathetic stimulation, and altered circadian clock gene expression. Thus, attention to the lighting environment of laboratory animals and maintaining consistency of a light/dark cycle is imperative for study reproducibility. Light intensity, as well as wavelength, photoperiod, and timing, are all important variables. Although modern rodent facilities are designed to facilitate appropriate light cycling, there are simple ways to modify rooms to prevent extraneous light exposure during the dark period. Attention to lighting conditions of laboratory animals by both researchers and research care staff ensures best practices for maintaining animal welfare, as well as reproducibility of research results. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Variable charge transfer state energies at nanostructured pentacene/C60 interfaces

NASA Astrophysics Data System (ADS)

Lin, YunHui L.; Zhang, Fengyu; Kerner, Ross A.; Yang, Terry Chien-Jen; Kahn, Antoine; Rand, Barry P.

2018-05-01

While it has recently been recognized that organic donor-acceptor charge transfer (CT) state energies can vary substantially under different interfacial morphologies, this behavior is under-appreciated in the context of organic singlet fission solar cells where a specific alignment between the triplet state of the fission material and the CT state of the donor-acceptor interface is necessary to the function of the device. In this work, we demonstrate that the CT state energy of a prototypical pentacene-C60 singlet fission system is around 1 eV in most systems, but can vary over 300 meV depending on the composition and morphology of the interface. Moreover, we show that the inclusion of a poly(3-hexylthiophene-2,5-diyl) underlayer, which commonly serves as a triplet blocker and hole collector in pentacene/C60 solar cells, helps promote active layer morphologies with stabilized, low energy CT states. These trends in the interfacial energetics are correlated with structural characterization of the films by atomic force microscopy and x-ray diffraction.

Quantifying the Sources of Intermodel Spread in Equilibrium Climate Sensitivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caldwell, Peter M.; Zelinka, Mark D.; Taylor, Karl E.

This paper clarifies the causes of intermodel differences in the global-average temperature response to doubled CO 2, commonly known as equilibrium climate sensitivity (ECS). The authors begin by noting several issues with the standard approach for decomposing ECS into a sum of forcing and feedback terms. This leads to a derivation of an alternative method based on linearizing the effect of the net feedback. Consistent with previous studies, the new method identifies shortwave cloud feedback as the dominant source of intermodel spread in ECS. This new approach also reveals that covariances between cloud feedback and forcing, between lapse rate andmore » longwave cloud feedbacks, and between albedo and shortwave cloud feedbacks play an important and previously underappreciated role in determining model differences in ECS. Finally, defining feedbacks based on fixed relative rather than specific humidity (as suggested by Held and Shell) reduces the covariances between processes and leads to more straightforward interpretations of results.« less

Evidence that Speciation of Oxovanadium Complexes does not Solely Account for Inhibition of Leishmania Acid Phosphatases

NASA Astrophysics Data System (ADS)

Dorsey, Benjamin M.; McLauchlan, Craig C.; Jones, Marjorie A.

2018-04-01

Leishmaniasis is an endemic disease affecting a diverse spectra of populations, with 1.6 million new cases reported each year. Current treatment options are costly and have harsh side effects. New therapeutic options that have been previously identified, but still underappreciated as potential pharmaceutical targets, are Leishmania secreted acid phosphatases (SAP). These acid phosphatases, which are reported to play a role in the survival of the parasite in the sand fly vector, and in homing to the host macrophage, are inhibited by orthovanadate and decavanadate. Here, we use L. tarentolae to further evaluate these inhibitors. Using enzyme assays, and UV-visible spectroscopy, we investigate which oxovanadium starting material (orthovanadate or decavanadate) is a better inhibitor of L. tarentolae secreted acid phosphatase activity in vitro at the same total moles of vanadium. Considering speciation and total vanadium concentration, decavanadate is a consistently better inhibitor of SAP in our conditions, especially at low substrate:inhibitor ratios.

A new Miocene baleen whale from the Peruvian desert

NASA Astrophysics Data System (ADS)

Marx, Felix G.; Kohno, Naoki

2016-10-01

The Pisco-Ica and Sacaco basins of southern Peru are renowned for their abundance of exceptionally preserved fossil cetaceans, several of which retain traces of soft tissue and occasionally even stomach contents. Previous work has mostly focused on odontocetes, with baleen whales currently being restricted to just three described taxa. Here, we report a new Late Miocene rorqual (family Balaenopteridae), Incakujira anillodefuego gen. et sp. nov., based on two exceptionally preserved specimens from the Pisco Formation exposed at Aguada de Lomas, Sacaco Basin, southern Peru. Incakujira overall closely resembles modern balaenopterids, but stands out for its unusually gracile ascending process of the maxilla, as well as a markedly twisted postglenoid process of the squamosal. The latter likely impeded lateral (omega) rotation of the mandible, in stark contrast with the highly flexible craniomandibular joint of extant lunge-feeding rorquals. Overall, Incakujira expands the still meagre Miocene record of balaenopterids and reveals a previously underappreciated degree of complexity in the evolution of their iconic lunge-feeding strategy.

Quantifying the Sources of Intermodel Spread in Equilibrium Climate Sensitivity

DOE PAGES

Caldwell, Peter M.; Zelinka, Mark D.; Taylor, Karl E.; ...

2016-01-07

This paper clarifies the causes of intermodel differences in the global-average temperature response to doubled CO 2, commonly known as equilibrium climate sensitivity (ECS). The authors begin by noting several issues with the standard approach for decomposing ECS into a sum of forcing and feedback terms. This leads to a derivation of an alternative method based on linearizing the effect of the net feedback. Consistent with previous studies, the new method identifies shortwave cloud feedback as the dominant source of intermodel spread in ECS. This new approach also reveals that covariances between cloud feedback and forcing, between lapse rate andmore » longwave cloud feedbacks, and between albedo and shortwave cloud feedbacks play an important and previously underappreciated role in determining model differences in ECS. Finally, defining feedbacks based on fixed relative rather than specific humidity (as suggested by Held and Shell) reduces the covariances between processes and leads to more straightforward interpretations of results.« less

Role of cognitive parameters in dengue hemorrhagic fever and dengue shock syndrome

PubMed Central

2013-01-01

Dengue is becoming recognized as one of the most important vector-borne human diseases. It is predominant in tropical and subtropical zones but its geographical distribution is progressively expanding, making it an escalating global health problem of today. Dengue presents with spectrum of clinical manifestations, ranging from asymptomatic, undifferentiated mild fever, dengue fever (DF), to dengue hemorrhagic fever (DHF) with or without shock (DSS), a life-threatening illness characterized by plasma leakage due to increased vascular permeability. Currently, there are no antiviral modalities or vaccines available to treat and prevent dengue. Supportive care with close monitoring is the standard clinical practice. The mechanisms leading to DHF/DSS remains poorly understood. Multiple factors have been attributed to the pathological mechanism, but only a couple of these hypotheses are popular in scientific circles. The current discussion focuses on underappreciated factors, temperature, natural IgM, and endotoxin, which may be critical components playing roles in dengue pathogenesis. PMID:24305068

Early-onset seizures due to mosaic exonic deletions of CDKL5 in a male and two females.

PubMed

Bartnik, Magdalena; Derwińska, Katarzyna; Gos, Monika; Obersztyn, Ewa; Kołodziejska, Katarzyna E; Erez, Ayelet; Szpecht-Potocka, Agnieszka; Fang, Ping; Terczyńska, Iwona; Mierzewska, Hanna; Lohr, Naomi J; Bellus, Gary A; Reimschisel, Tyler; Bocian, Ewa; Mazurczak, Tadeusz; Cheung, Sau Wai; Stankiewicz, Paweł

2011-05-01

Mutations in the CDKL5 gene have been associated with an X-linked dominant early infantile epileptic encephalopathy-2. The clinical presentation is usually of severe encephalopathy with refractory seizures and Rett syndrome (RTT)-like phenotype. We attempted to assess the role of mosaic intragenic copy number variation in CDKL5. We have used comparative genomic hybridization with a custom-designed clinical oligonucleotide array targeting exons of selected disease and candidate genes, including CDKL5. We have identified mosaic exonic deletions of CDKL5 in one male and two females with developmental delay and medically intractable seizures. These three mosaic changes represent 60% of all deletions detected in 12,000 patients analyzed by array comparative genomic hybridization and involving the exonic portion of CDKL5. We report the first case of an exonic deletion of CDKL5 in a male and emphasize the importance of underappreciated mosaic exonic copy number variation in patients with early-onset seizures and RTT-like features of both genders.

Parasites in bloom: flowers aid dispersal and transmission of pollinator parasites within and between bee species.

PubMed

Graystock, Peter; Goulson, Dave; Hughes, William O H

2015-08-22

The dispersal of parasites is critical for epidemiology, and the interspecific vectoring of parasites when species share resources may play an underappreciated role in parasite dispersal. One of the best examples of such a situation is the shared use of flowers by pollinators, but the importance of flowers and interspecific vectoring in the dispersal of pollinator parasites is poorly understood and frequently overlooked. Here, we use an experimental approach to show that during even short foraging periods of 3 h, three bumblebee parasites and two honeybee parasites were dispersed effectively onto flowers by their hosts, and then vectored readily between flowers by non-host pollinator species. The results suggest that flowers are likely to be hotspots for the transmission of pollinator parasites and that considering potential vector, as well as host, species will be of general importance for understanding the distribution and transmission of parasites in the environment and between pollinators. © 2015 The Author(s).

A Chemical-Genomic Screen of Neglected Antibiotics Reveals Illicit Transport of Kasugamycin and Blasticidin S

DOE PAGES

Shiver, Anthony L.; Osadnik, Hendrik; Kritikos, George; ...

2016-06-29

Fighting antibiotic resistance requires a deeper understanding of the genetic factors that determine the antibiotic susceptibility of bacteria. Here we describe a chemical-genomic screen in Escherichia coli K-12 that was designed to discover new aspects of antibiotic resistance by focusing on a set of 26 antibiotics and other stresses with poorly characterized mode-of-action and determinants of resistance. We show that the screen identifies new resistance determinants for these antibiotics including a common signature from two antimicrobials, kasugamycin and blasticidin S, used to treat crop diseases like rice blast and fire blight. Following this signature, we further investigated the mechanistic basismore » for susceptibility to kasugamycin and blasticidin S in E. coli using both genetic and biochemical approaches. We provide evidence that these compounds hijack an overlapping set of peptide ABC-importers to enter the bacterial cell. As a result, the loss of uptake may be an underappreciated mechanism for the development of kasugamycin resistance in bacterial plant pathogens.« less

Homosexuality via canalized sexual development: a testing protocol for a new epigenetic model.

PubMed

Rice, William R; Friberg, Urban; Gavrilets, Sergey

2013-09-01

We recently synthesized and reinterpreted published studies to advance an epigenetic model for the development of homosexuality (HS). The model is based on epigenetic marks laid down in response to the XX vs. XY karyotype in embryonic stem cells. These marks boost sensitivity to testosterone in XY fetuses and lower it in XX fetuses, thereby canalizing sexual development. Our model predicts that a subset of these canalizing epigenetic marks stochastically carry over across generations and lead to mosaicism for sexual development in opposite-sex offspring--the homosexual phenotype being one such outcome. Here, we begin by outlining why HS has been under-appreciated as a commonplace phenomenon in nature, and how this trend is currently being reversed in the field of neurobiology. We next briefly describe our epigenetic model of HS, develop a set of predictions, and describe how epigenetic profiles of human stem cells can provide for a strong test of the model. © 2013 The Authors. Bioessays published by WILEY Periodicals, Inc.

Homosexuality via canalized sexual development: A testing protocol for a new epigenetic model

PubMed Central

Rice, William R; Friberg, Urban; Gavrilets, Sergey

2013-01-01

We recently synthesized and reinterpreted published studies to advance an epigenetic model for the development of homosexuality (HS). The model is based on epigenetic marks laid down in response to the XX vs. XY karyotype in embryonic stem cells. These marks boost sensitivity to testosterone in XY fetuses and lower it in XX fetuses, thereby canalizing sexual development. Our model predicts that a subset of these canalizing epigenetic marks stochastically carry over across generations and lead to mosaicism for sexual development in opposite-sex offspring – the homosexual phenotype being one such outcome. Here, we begin by outlining why HS has been under-appreciated as a commonplace phenomenon in nature, and how this trend is currently being reversed in the field of neurobiology. We next briefly describe our epigenetic model of HS, develop a set of predictions, and describe how epigenetic profiles of human stem cells can provide for a strong test of the model. PMID:23868698

Old wine in new bottles: decanting systemic family process research in the era of evidence-based practice.

PubMed

Rohrbaugh, Michael J

2014-09-01

Social cybernetic (systemic) ideas from the early Family Process era, though emanating from qualitative clinical observation, have underappreciated heuristic potential for guiding quantitative empirical research on problem maintenance and change. The old conceptual wines we have attempted to repackage in new, science-friendly bottles include ironic processes (when "solutions" maintain problems), symptom-system fit (when problems stabilize relationships), and communal coping (when we-ness helps people change). Both self-report and observational quantitative methods have been useful in tracking these phenomena, and together the three constructs inform a team-based family consultation approach to working with difficult health and behavior problems. In addition, a large-scale, quantitatively focused effectiveness trial of family therapy for adolescent drug abuse highlights the importance of treatment fidelity and qualitative approaches to examining it. In this sense, echoing the history of family therapy research, our experience with juxtaposing quantitative and qualitative methods has gone full circle-from qualitative to quantitative observation and back again. © 2014 FPI, Inc.

Common pitfalls in preclinical cancer target validation.

PubMed

Kaelin, William G

2017-07-01

An alarming number of papers from laboratories nominating new cancer drug targets contain findings that cannot be reproduced by others or are simply not robust enough to justify drug discovery efforts. This problem probably has many causes, including an underappreciation of the danger of being misled by off-target effects when using pharmacological or genetic perturbants in complex biological assays. This danger is particularly acute when, as is often the case in cancer pharmacology, the biological phenotype being measured is a 'down' readout (such as decreased proliferation, decreased viability or decreased tumour growth) that could simply reflect a nonspecific loss of cellular fitness. These problems are compounded by multiple hypothesis testing, such as when candidate targets emerge from high-throughput screens that interrogate multiple targets in parallel, and by a publication and promotion system that preferentially rewards positive findings. In this Perspective, I outline some of the common pitfalls in preclinical cancer target identification and some potential approaches to mitigate them.

Old Wine in New Bottles: Decanting Systemic Family Process Research in the Era of Evidence-Based Practice†

PubMed Central

Rohrbaugh, Michael J.

2015-01-01

Social cybernetic (systemic) ideas from the early Family Process era, though emanating from qualitative clinical observation, have underappreciated heuristic potential for guiding quantitative empirical research on problem maintenance and change. The old conceptual wines we have attempted to repackage in new, science-friendly bottles include ironic processes (when “solutions” maintain problems), symptom-system fit (when problems stabilize relationships), and communal coping (when we-ness helps people change). Both self-report and observational quantitative methods have been useful in tracking these phenomena, and together the three constructs inform a team-based family consultation (FAMCON) approach to working with difficult health and behavior problems. In addition, a large-scale, quantitatively focused effectiveness trial of family therapy for adolescent drug abuse highlights the importance of treatment fidelity and qualitative approaches to examining it. In this sense, echoing the history of family therapy research, our experience with juxtaposing quantitative and qualitative methods has gone full circle – from qualitative to quantitative observation and back again. PMID:24905101

Hořava-Lifshitz gravity: Detailed balance revisited

NASA Astrophysics Data System (ADS)

Vernieri, Daniele; Sotiriou, Thomas P.

2012-03-01

We attempt a critical reconsideration of “detailed balance” as a principle that can be used to restrict the proliferation of couplings in Hořava-Lifshitz gravity. We reexamine the shortcomings that have been usually associated with it in the literature and we argue that easy remedies can be found for all of them within the framework of detailed balance, and that the most persistent of them are actually related to projectability. We show that, once projectability is abandoned, detailed balance reduces the number of independent couplings by roughly an order of magnitude and imposes only one restriction that constitutes a phenomenological concern: the size of the (bare) cosmological constant is unacceptably large. Remarkably, this restriction (which is present in the projectable version as well) has been so far underappreciated in the literature. Optimists might prefer to interpret it as a potential blessing in disguise, as it allows one to entertain the idea of a miraculous cancellation between the bare cosmological constant and the (still poorly understood) vacuum energy contribution.

Ongoing resolution of duplicate gene functions shapes the diversification of a metabolic network

PubMed Central

Kuang, Meihua Christina; Hutchins, Paul D; Russell, Jason D; Coon, Joshua J; Hittinger, Chris Todd

2016-01-01

The evolutionary mechanisms leading to duplicate gene retention are well understood, but the long-term impacts of paralog differentiation on the regulation of metabolism remain underappreciated. Here we experimentally dissect the functions of two pairs of ancient paralogs of the GALactose sugar utilization network in two yeast species. We show that the Saccharomyces uvarum network is more active, even as over-induction is prevented by a second co-repressor that the model yeast Saccharomyces cerevisiae lacks. Surprisingly, removal of this repression system leads to a strong growth arrest, likely due to overly rapid galactose catabolism and metabolic overload. Alternative sugars, such as fructose, circumvent metabolic control systems and exacerbate this phenotype. We further show that S. cerevisiae experiences homologous metabolic constraints that are subtler due to how the paralogs have diversified. These results show how the functional differentiation of paralogs continues to shape regulatory network architectures and metabolic strategies long after initial preservation. DOI: http://dx.doi.org/10.7554/eLife.19027.001 PMID:27690225

Geriatric trauma.

PubMed

Adams, Sasha D; Holcomb, John B

2015-12-01

The landscape of trauma is changing due to an aging population. Geriatric patients represent an increasing number and proportion of trauma admissions and deaths. This review explores recent literature on geriatric trauma, including triage criteria, assessment of frailty, fall-related injury, treatment of head injury complicated by coagulopathy, goals of care, and the need for ongoing education of all surgeons in the care of the elderly. Early identification of high-risk geriatric patients is imperative to initiate early resuscitative efforts. Geriatric patients are typically undertriaged because of their baseline frailty being underappreciated; however, centers that see more geriatric patients do better. Rapid reversal of anticoagulation is important in preventing progression of brain injury. Anticipation of difficult disposition necessitates early involvement of physical therapy for rehabilitation and case management for appropriate placement. Optimal care of geriatric trauma patients will be based on the well established tenets of trauma resuscitation and injury repair, but with distinct elements that address the physiological and anatomical challenges presented by geriatric patients.

Hybridization Associated with Cycles of Ecological Succession in a Passerine Bird.

PubMed

Duckworth, Renée A; Semenov, Georgy A

2017-10-01

Identifying the diversity of contexts that can lead to hybridization is important for understanding its prevalence and dynamics in natural populations. Despite the potential of ecological succession to dramatically alter species co-occurrence and abundances, it is unknown whether it directly promotes hybridization and, if so, has long-lasting consequences. Here, we summarize 30 years of survey data across 10 populations to show that in western and mountain bluebirds, heterospecific pairing occurs during repeatable and transient colonization events at the early stages of species turnover. Despite mixed pairing occurring only during early succession, genetic data showed presence of hybrids at both early and late successional stages. Moreover, hybrids showed novel patterns of variation in morphology and behavior, emphasizing that even ephemeral contexts for hybridization can have important evolutionary consequences. Our results suggest that because ecological succession often brings together closely related competitors in disparate numbers but lasts for only a brief period of time, it may be a widespread but underappreciated context for hybridization.

Regulatory variation: an emerging vantage point for cancer biology.

PubMed

Li, Luolan; Lorzadeh, Alireza; Hirst, Martin

2014-01-01

Transcriptional regulation involves complex and interdependent interactions of noncoding and coding regions of the genome with proteins that interact and modify them. Genetic variation/mutation in coding and noncoding regions of the genome can drive aberrant transcription and disease. In spite of accounting for nearly 98% of the genome comparatively little is known about the contribution of noncoding DNA elements to disease. Genome-wide association studies of complex human diseases including cancer have revealed enrichment for variants in the noncoding genome. A striking finding of recent cancer genome re-sequencing efforts has been the previously underappreciated frequency of mutations in epigenetic modifiers across a wide range of cancer types. Taken together these results point to the importance of dysregulation in transcriptional regulatory control in genesis of cancer. Powered by recent technological advancements in functional genomic profiling, exploration of normal and transformed regulatory networks will provide novel insight into the initiation and progression of cancer and open new windows to future prognostic and diagnostic tools. © 2013 Wiley Periodicals, Inc.

The origin of pre-neoplastic metaplasia in the stomach: Chief cells emerge from the Mist

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldenring, James R., E-mail: jim.goldenring@vanderbilt.edu; Departments of Surgery and Cell and Developmental Biology, Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN; Nam, Ki Taek

2011-11-15

The digestive-enzyme secreting, gastric epithelial chief (zymogenic) cell is remarkable and underappreciated. Here, we discuss how all available evidence suggests that mature chief cells in the adult, mammalian stomach are postmitotic, slowly turning over cells that arise via a relatively long-lived progenitor, the mucous neck cell, The differentiation of chief cells from neck cells does not involve cell division, and the neck cell has its own distinct pattern of gene expression and putative physiological function. Thus, the ontogeny of the normal chief cell lineage exemplifies transdifferentiation. Furthermore, under pathophysiogical loss of acid-secreting parietal cell, the chief cell lineage can itselfmore » trasndifferentiate into a mucous cell metaplasia designated Spasmolytic Polypeptide Expressing Metaplasia (SPEM). Especially in the presence of inflammation, this metaplastic lineage can regain proliferative capacity and, in humans may also further differentiate into intestinal metaplasia. The results indicate that gastric fundic lineages display remarkable plasticity in both physiological ontogeny and pathophysiological pre-neoplastic metaplasia.« less

Affordability Engineering: Bridging the Gap Between Design and Cost

NASA Technical Reports Server (NTRS)

Reeves, J. D.; DePasquale, Dominic; Lim, Evan

2010-01-01

Affordability is a commonly used term that takes on numerous meanings depending on the context used. Within conceptual design of complex systems, the term generally implies comparisons between expected costs and expected resources. This characterization is largely correct, but does not convey the many nuances and considerations that are frequently misunderstood and underappreciated. In the most fundamental sense, affordability and cost directly relate to engineering and programmatic decisions made throughout development programs. Systems engineering texts point out that there is a temporal aspect to this relationship, for decisions made earlier in a program dictate design implications much more so than those made during latter phases. This paper explores affordability engineering and its many sub-disciplines by discussing how it can be considered an additional engineering discipline to be balanced throughout the systems engineering and systems analysis processes. Example methods of multidisciplinary design analysis with affordability as a key driver will be discussed, as will example methods of data visualization, probabilistic analysis, and other ways of relating design decisions to affordability results.

Anoxic photochemical oxidation of siderite generates molecular hydrogen and iron oxides

PubMed Central

Kim, J. Dongun; Yee, Nathan; Nanda, Vikas; Falkowski, Paul G.

2013-01-01

Photochemical reactions of minerals are underappreciated processes that can make or break chemical bonds. We report the photooxidation of siderite (FeCO3) by UV radiation to produce hydrogen gas and iron oxides via a two-photon reaction. The calculated quantum yield for the reaction suggests photooxidation of siderite would have been a significant source of molecular hydrogen for the first half of Earth’s history. Further, experimental results indicate this abiotic, photochemical process may have led to the formation of iron oxides under anoxic conditions. The reaction would have continued through the Archean to at least the early phases of the Great Oxidation Event, and provided a mechanism for oxidizing the atmosphere through the loss of hydrogen to space, while simultaneously providing a key reductant for microbial metabolism. We propose that the photochemistry of Earth-abundant minerals with wide band gaps would have potentially played a critical role in shaping the biogeochemical evolution of early Earth. PMID:23733945

Development of an internet based system for modeling biotin metabolism using Bayesian networks.

PubMed

Zhou, Jinglei; Wang, Dong; Schlegel, Vicki; Zempleni, Janos

2011-11-01

Biotin is an essential water-soluble vitamin crucial for maintaining normal body functions. The importance of biotin for human health has been under-appreciated but there is plenty of opportunity for future research with great importance for human health. Currently, carrying out predictions of biotin metabolism involves tedious manual manipulations. In this paper, we report the development of BiotinNet, an internet based program that uses Bayesian networks to integrate published data on various aspects of biotin metabolism. Users can provide a combination of values on the levels of biotin related metabolites to obtain the predictions on other metabolites that are not specified. As an inherent feature of Bayesian networks, the uncertainty of the prediction is also quantified and reported to the user. This program enables convenient in silico experiments regarding biotin metabolism, which can help researchers design future experiments while new data can be continuously incorporated. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Biphasic targeting and cleavage furrow ingression directed by the tail of a myosin II

PubMed Central

Fang, Xiaodong; Luo, Jianying; Nishihama, Ryuichi; Wloka, Carsten; Dravis, Christopher; Travaglia, Mirko; Iwase, Masayuki; Vallen, Elizabeth A.

2010-01-01

Cytokinesis in animal and fungal cells utilizes a contractile actomyosin ring (AMR). However, how myosin II is targeted to the division site and promotes AMR assembly, and how the AMR coordinates with membrane trafficking during cytokinesis, remains poorly understood. Here we show that Myo1 is a two-headed myosin II in Saccharomyces cerevisiae, and that Myo1 localizes to the division site via two distinct targeting signals in its tail that act sequentially during the cell cycle. Before cytokinesis, Myo1 localization depends on the septin-binding protein Bni5. During cytokinesis, Myo1 localization depends on the IQGAP Iqg1. We also show that the Myo1 tail is sufficient for promoting the assembly of a “headless” AMR, which guides membrane deposition and extracellular matrix remodeling at the division site. Our study establishes a biphasic targeting mechanism for myosin II and highlights an underappreciated role of the AMR in cytokinesis beyond force generation. PMID:21173112

From Brain Maps to Cognitive Ontologies: Informatics and the Search for Mental Structure.

PubMed

Poldrack, Russell A; Yarkoni, Tal

2016-01-01

A major goal of cognitive neuroscience is to delineate how brain systems give rise to mental function. Here we review the increasingly large role informatics-driven approaches are playing in such efforts. We begin by reviewing a number of challenges conventional neuroimaging approaches face in trying to delineate brain-cognition mappings--for example, the difficulty in establishing the specificity of postulated associations. Next, we demonstrate how these limitations can potentially be overcome using complementary approaches that emphasize large-scale analysis--including meta-analytic methods that synthesize hundreds or thousands of studies at a time; latent-variable approaches that seek to extract structure from data in a bottom-up manner; and predictive modeling approaches capable of quantitatively inferring mental states from patterns of brain activity. We highlight the underappreciated but critical role for formal cognitive ontologies in helping to clarify, refine, and test theories of brain and cognitive function. Finally, we conclude with a speculative discussion of what future informatics developments may hold for cognitive neuroscience.

From brain maps to cognitive ontologies: informatics and the search for mental structure

PubMed Central

Poldrack, Russell A.; Yarkoni, Tal

2015-01-01

A major goal of cognitive neuroscience is to delineate how brain systems give rise to mental function. Here we review the increasingly large role informatics-driven approaches are playing in such efforts. We begin by reviewing a number of challenges conventional neuroimaging approaches face in trying to delineate brain-cognition mappings—for example, the difficulty in establishing the specificity of postulated associations. Next, we demonstrate how these limitations can potentially be overcome using complementary approaches that emphasize large-scale analysis—including meta-analytic methods that synthesize hundreds or thousands of studies at a time; latent-variable approaches that seek to extract structure from data in a bottom-up manner; and predictive modeling approaches capable of quantitatively inferring mental states from patterns of brain activity. We highlight the underappreciated but critical role for formal cognitive ontologies in helping to clarify, refine, and test theories of brain and cognitive function. Finally, we conclude with a speculative discussion of what future informatics developments may hold for cognitive neuroscience. PMID:26393866

Dispersal and neutral sampling mediate contingent effects of disturbance on plant beta-diversity: a meta-analysis.

PubMed

Catano, Christopher P; Dickson, Timothy L; Myers, Jonathan A

2017-03-01

A major challenge in ecology, conservation and global-change biology is to understand why biodiversity responds differently to similar environmental changes. Contingent biodiversity responses may depend on how disturbance and dispersal interact to alter variation in community composition (β-diversity) and assembly mechanisms. However, quantitative syntheses of these patterns and processes across studies are lacking. Using null-models and meta-analyses of 22 factorial experiments in herbaceous plant communities across Europe and North America, we show that disturbance diversifies communities when dispersal is limited, but homogenises communities when combined with increased immigration from the species pool. In contrast to the hypothesis that disturbance and dispersal mediate the strength of niche assembly, both processes altered β-diversity through neutral-sampling effects on numbers of individuals and species in communities. Our synthesis suggests that stochastic effects of disturbance and dispersal on community assembly play an important, but underappreciated, role in mediating biotic homogenisation and biodiversity responses to environmental change. © 2017 John Wiley & Sons Ltd/CNRS.

Polycystic ovary syndrome: a major unrecognized cardiovascular risk factor in women.

PubMed

Alexander, Carolyn J; Tangchitnob, Edward P; Lepor, Norman E

2009-01-01

The prevalence of polycystic ovary syndrome (PCOS) is estimated to be nearly 10% among reproductive-age women. PCOS may represent the largest underappreciated segment of the female population at risk of cardiovascular disease. Clinicians providing care to women of childbearing age must recognize the presenting clues, including irregular menses, hirsutism, alopecia, hyperandrogenemia, and obesity. The pathophysiology of PCOS is complex, involving the hypothalamus-pituitary-ovarian axis, ovarian theca cell hyperplasia, hyperinsulinemia, and a multitude of other cytokine- and adipocyte-driven factors. Cardiac risk factors associated with PCOS have public health implications and should drive early screening and intervention measures. There are no consensus guidelines regarding screening for cardiovascular disease in patients with PCOS. Fasting lipid profiles and glucose examinations should be performed regularly. Carotid intimal medial thickness examinations should begin at age 30 years, and coronary calcium screening should begin at age 45 years. Treatment of the associated cardiovascular risk factors, including insulin resistance, hypertension, and dyslipidemia, should be incorporated into the routine PCOS patient wellness care program.

Polycystic ovary syndrome: a major unrecognized cardiovascular risk factor in women.

PubMed

Alexander, Carolyn J; Tangchitnob, Edward P; Lepor, Norman E

2009-01-01

The prevalence of polycystic ovary syndrome (PCOS) is estimated to be nearly 10% among reproductive age women. PCOS may represent the largest underappreciated segment of the female population at risk of cardiovascular disease. Clinicians providing care to women of childbearing age must recognize the presenting clues, including irregular menses, hirsutism, alopecia, hyperandrogenemia, and obesity. The pathophysiology of PCOS is complex, involving the hypothalamus-pituitary-ovarian axis, ovarian theca cell hyperplasia, hyperinsulinemia, and a multitude of other cytokine- and adipocyte-driven factors. Cardiac risk factors associated with PCOS have public health implications and should drive early screening and intervention measures. There are no consensus guidelines regarding screening for cardiovascular disease in patients with PCOS. Fasting lipid profiles and glucose examinations should be performed regularly. Carotid intimal medial thickness examinations should begin at age 30 years, and coronary calcium screening should begin at age 45 years. Treatment of the associated cardiovascular risk factors, including insulin resistance, hypertension, and dyslipidemia, should be incorporated into the routine PCOS patient wellness care program.

Occupational asthma and contact dermatitis in a spray painter after introduction of an aziridine cross-linker.

PubMed Central

Leffler, C T; Milton, D K

1999-01-01

A 23-year-old spray painter developed contact dermatitis and respiratory difficulty characterized by small airways obstruction shortly after the polyfunctional aziridine cross-linker CX-100 began to be used in his workplace as a paint activator. The symptoms resolved after he was removed from the workplace and was treated with inhaled and topical steroids. Painters may have an increased risk of asthma due to exposure to a variety of agents, such as isocyanates, alkyd resins, and chromates. This case illustrates the importance of using appropriate work practices and personal protective equipment to minimize exposure. Occupational asthma is diagnosed by a history of work-related symptoms and exposure to known causative agents. The diagnosis is confirmed by serial pulmonary function testing or inhalational challenge testing. The risk of asthma attributable to occupational exposures is probably underappreciated due to underreporting and to inappropriate use of narrow definitions of exposure in epidemiologic studies of attributable risk. Images Figure 1 PMID:10379008

Evidence That Speciation of Oxovanadium Complexes Does Not Solely Account for Inhibition of Leishmania Acid Phosphatases

PubMed Central

Dorsey, Benjamin M.; McLauchlan, Craig C.; Jones, Marjorie A.

2018-01-01

Leishmaniasis is an endemic disease affecting a diverse spectra of populations, with 1.6 million new cases reported each year. Current treatment options are costly and have harsh side effects. New therapeutic options that have been previously identified, but still underappreciated as potential pharmaceutical targets, are Leishmania secreted acid phosphatases (SAP). These acid phosphatases, which are reported to play a role in the survival of the parasite in the sand fly vector, and in homing to the host macrophage, are inhibited by orthovanadate and decavanadate. Here, we use L. tarentolae to further evaluate these inhibitors. Using enzyme assays, and UV-visible spectroscopy, we investigate which oxovanadium starting material (orthovanadate or decavanadate) is a better inhibitor of L. tarentolae secreted acid phosphatase activity in vitro at the same total moles of vanadium. Considering speciation and total vanadium concentration, decavanadate is a consistently better inhibitor of SAP in our conditions, especially at low substrate:inhibitor ratios. PMID:29707535

Tinea genitalis: a new entity of sexually transmitted infection? Case series and review of the literature.

PubMed

Luchsinger, Isabelle; Bosshard, Philipp Peter; Kasper, Romano Silvio; Reinhardt, Dominic; Lautenschlager, Stephan

2015-11-01

Investigation on recent cases of tinea genitalis after travelling to South East Asia. Patients with tinea in the genital region, which emerged after sex in South East Asia, underwent further assessment including microscopy, cultures and DNA analyses. The case series includes seven patients. In six patients, Trichophyton interdigitale (former Trichophyton mentagrophytes) was detected. Three patients suffered from a severe inflammatory reaction of the soft tissue and two of them needed hospitalisation due to severe pain. In four patients, cicatrising healing was noticed. Five patients were declared incapacitated for work. Sexual activity should be considered as a potentially important and previously underappreciated means of transmission of T. interdigitale. To avoid irreversible scarring alopecia, prompt initiation of antifungal treatment is essential and adequate isolation and identification of the pathogen is mandatory. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Lessons From Biodiversity—The Value of Nontraditional Species to Advance Reproductive Science, Conservation, and Human Health

PubMed Central

WILDT, DAVID E.; COMIZZOLI, PIERRE; PUKAZHENTHI, BUDHAN; SONGSASEN, NUCHARIN

2014-01-01

SUMMARY Reproduction is quintessential to species survival. But what is underappreciated for this discipline is the wondrous array of reproductive mechanisms among species—variations as diverse as the morphology of the species themselves (more than 55,000 vertebrate and 1.1 million invertebrate types). We have investigated only a tiny fraction of these species in reproductive science. Besides the need to fill enormous gaps in a scholarly database, this knowledge has value for recovering and genetically managing rare species as well as addressing certain reproductive issues in humans. This article provides examples, first to advise against oversimplifying reproduction and then to show how such knowledge can have practical use for managing whole animals, populations, or even saving an entire species. We also address the expected challenges and opportunities that could lead to creative shifts in philosophy and effective actions to benefit more species as well as a future generation of reproductive scientists. PMID:19967718

Bone marrow fat: linking adipocyte-induced inflammation with skeletal metastases

PubMed Central

Hardaway, Aimalie L.; Herroon, Mackenzie K.; Rajagurubandara, Erandi

2014-01-01

Adipocytes are important but underappreciated components of bone marrow microenvironment, and their numbers greatly increase with age, obesity, and associated metabolic pathologies. Age and obesity are also significant risk factors for development of metastatic prostate cancer. Adipocytes are metabolically active cells that secrete adipokines, growth factors, and inflammatory mediators; influence behavior and function of neighboring cells; and have a potential to disturb local milleu and dysregulate normal bone homeostasis. Increased marrow adiposity has been linked to bone marrow inflammation and osteoporosis of the bone, but its effects on growth and progression of prostate tumors that have metastasized to the skeleton are currently not known. This review focuses on fat-bone relationship in a context of normal bone homeostasis and metastatic tumor growth in bone. We discuss effects of marrow fat cells on bone metabolism, hematopoiesis, and inflammation. Special attention is given to CCL2- and COX-2-driven pathways and their potential as therapeutic targets for bone metastatic disease. PMID:24398857

Ongoing resolution of duplicate gene functions shapes the diversification of a metabolic network

DOE PAGES

Kuang, Meihua Christina; Hutchins, Paul D.; Russell, Jason D.; ...

2016-09-30

The evolutionary mechanisms leading to duplicate gene retention are well understood, but the long-term impacts of paralog differentiation on the regulation of metabolism remain underappreciated. Here we experimentally dissect the functions of two pairs of ancient paralogs of theGALactose sugar utilization network in two yeast species. Here, we show that theSaccharomyces uvarumnetwork is more active, even as over-induction is prevented by a second co-repressor that the model yeastSaccharomyces cerevisiaelacks. Surprisingly, removal of this repression system leads to a strong growth arrest, likely due to overly rapid galactose catabolism and metabolic overload. Alternative sugars, such as fructose, circumvent metabolic control systemsmore » and exacerbate this phenotype. Furthermore, we show thatS. cerevisiaeexperiences homologous metabolic constraints that are subtler due to how the paralogs have diversified. Our results show how the functional differentiation of paralogs continues to shape regulatory network architectures and metabolic strategies long after initial preservation.« less

A Chemical-Genomic Screen of Neglected Antibiotics Reveals Illicit Transport of Kasugamycin and Blasticidin S

PubMed Central

Shiver, Anthony L.; Kritikos, George; Li, Bo; Krogan, Nevan; Typas, Athanasios

2016-01-01

Fighting antibiotic resistance requires a deeper understanding of the genetic factors that determine the antibiotic susceptibility of bacteria. Here we describe a chemical-genomic screen in Escherichia coli K-12 that was designed to discover new aspects of antibiotic resistance by focusing on a set of 26 antibiotics and other stresses with poorly characterized mode-of-action and determinants of resistance. We show that the screen identifies new resistance determinants for these antibiotics including a common signature from two antimicrobials, kasugamycin and blasticidin S, used to treat crop diseases like rice blast and fire blight. Following this signature, we further investigated the mechanistic basis for susceptibility to kasugamycin and blasticidin S in E. coli using both genetic and biochemical approaches. We provide evidence that these compounds hijack an overlapping set of peptide ABC-importers to enter the bacterial cell. Loss of uptake may be an underappreciated mechanism for the development of kasugamycin resistance in bacterial plant pathogens. PMID:27355376

Evolutionary mysteries in meiosis.

PubMed

Lenormand, Thomas; Engelstädter, Jan; Johnston, Susan E; Wijnker, Erik; Haag, Christoph R

2016-10-19

Meiosis is a key event of sexual life cycles in eukaryotes. Its mechanistic details have been uncovered in several model organisms, and most of its essential features have received various and often contradictory evolutionary interpretations. In this perspective, we present an overview of these often 'weird' features. We discuss the origin of meiosis (origin of ploidy reduction and recombination, two-step meiosis), its secondary modifications (in polyploids or asexuals, inverted meiosis), its importance in punctuating life cycles (meiotic arrests, epigenetic resetting, meiotic asymmetry, meiotic fairness) and features associated with recombination (disjunction constraints, heterochiasmy, crossover interference and hotspots). We present the various evolutionary scenarios and selective pressures that have been proposed to account for these features, and we highlight that their evolutionary significance often remains largely mysterious. Resolving these mysteries will likely provide decisive steps towards understanding why sex and recombination are found in the majority of eukaryotes.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'. © 2016 The Author(s).

Evolutionary mysteries in meiosis

PubMed Central

2016-01-01

Meiosis is a key event of sexual life cycles in eukaryotes. Its mechanistic details have been uncovered in several model organisms, and most of its essential features have received various and often contradictory evolutionary interpretations. In this perspective, we present an overview of these often ‘weird’ features. We discuss the origin of meiosis (origin of ploidy reduction and recombination, two-step meiosis), its secondary modifications (in polyploids or asexuals, inverted meiosis), its importance in punctuating life cycles (meiotic arrests, epigenetic resetting, meiotic asymmetry, meiotic fairness) and features associated with recombination (disjunction constraints, heterochiasmy, crossover interference and hotspots). We present the various evolutionary scenarios and selective pressures that have been proposed to account for these features, and we highlight that their evolutionary significance often remains largely mysterious. Resolving these mysteries will likely provide decisive steps towards understanding why sex and recombination are found in the majority of eukaryotes. This article is part of the themed issue ‘Weird sex: the underappreciated diversity of sexual reproduction’. PMID:27619705

The Quench Control of Water Estimates in Convergent Margin Magmas

NASA Astrophysics Data System (ADS)

Gavrilenko, M.; Krawczynski, M.; Ruprecht, P.

2017-12-01

Mineral-hosted glassy melt inclusions (MIs) have been used to quantify magma volatile contents for several decades. Despite the growing number of volatile studies utilizing MIs, it has not been tested whether there is a physical limit on how much dissolved volatiles a glassy MI can contain. We explored the limits of MIs as hydrous magma recorders in an experimental study, showing that there is a limit of dissolved H2O that glassy MIs cannot exceed. These results show there is potential bias in the glassy MI data set; they can only faithfully record pre-eruptive H2O contents in the upper-most part of the Earth's crust where H2O-solubility is low. The current MI database cannot be used to robustly estimate the full range of arc magmas and therefore assess volatile budgets in primitive or evolved compositions. Such magmas may contain much larger amounts of H2O than currently recognized and the diversity of magma evolutionary pathways in subduction zones is likely being significantly underappreciated.

Ubiquitin Ligases and Deubiquitinating Enzymes in CD4+ T Cell Effector Fate Choice and Function.

PubMed

Layman, Awo A K; Oliver, Paula M

2016-05-15

The human body is exposed to potentially pathogenic microorganisms at barrier sites such as the skin, lungs, and gastrointestinal tract. To mount an effective response against these pathogens, the immune system must recruit the right cells with effector responses that are appropriate for the task at hand. Several types of CD4(+) T cells can be recruited, including Th cells (Th1, Th2, and Th17), T follicular helper cells, and regulatory T cells. These cells help to maintain normal immune homeostasis in the face of constantly changing microbes in the environment. Because these cells differentiate from a common progenitor, the composition of their intracellular milieu of proteins changes to appropriately guide their effector function. One underappreciated process that impacts the levels and functions of effector fate-determining factors is ubiquitylation. This review details our current understanding of how ubiquitylation regulates CD4(+) T cell effector identity and function. Copyright © 2016 by The American Association of Immunologists, Inc.

Intrinsically disordered segments and the evolution of protein half-life

NASA Astrophysics Data System (ADS)

Babu, M.

2013-03-01

Precise turnover of proteins is essential for cellular homeostasis and is primarily mediated by the proteasome. Thus, a fundamental question is: What features make a protein an efficient substrate for degradation? Here I will present results that proteins with a long terminal disordered segment or internal disordered segments have a significantly shorter half-life in yeast. This relationship appears to be evolutionarily conserved in mouse and human. Furthermore, upon gene duplication, divergence in the length of terminal disorder or variation in the number of internal disordered segments results in significant alteration of the half-life of yeast paralogs. Many proteins that exhibit such changes participate in signaling, where altered protein half-life will likely influence their activity. We suggest that variation in the length and number of disordered segments could serve as a remarkably simple means to evolve protein half-life and may serve as an underappreciated source of genetic variation with important phenotypic consequences. MMB acknowledges the Medical Research Council for funding his research program.

Atopic dermatitis in diverse racial and ethnic groups-Variations in epidemiology, genetics, clinical presentation and treatment.

PubMed

Kaufman, Bridget P; Guttman-Yassky, Emma; Alexis, Andrew F

2018-04-01

Atopic dermatitis (AD) is a chronic inflammatory skin condition that affects diverse ethnic groups with varying prevalence. Despite a predominance of studies in individuals of European ancestry, AD has been found to occur more frequently in Asian and Black individuals than Whites. Therefore, an understanding of the unique clinical features of AD in diverse ethnic groups, as well as the differences in genetic polymorphisms that influence susceptibility to AD and response to current therapies, is paramount for management of an increasingly diverse patient population. In this article, we review key nuances in the epidemiology, pathophysiology, clinical presentation and treatment of AD in non-White ethnic groups, which are largely underappreciated in the literature. We highlight the need for studies evaluating the tissue molecular and cellular phenotypes of AD in non-White patients, as well as greater inclusion of minority groups in clinical trials, to develop targeted treatments for a multi-ethnic population. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Missed opportunities in educating Aboriginal Australians about bowel cancer screening: whose job is it anyway?

PubMed

Christou, Aliki; Thompson, Sandra C

2013-12-01

A culturally relevant educational flipchart targeting Aboriginal people was distributed across Western Australia to support education on bowel cancer screening and encourage participation in the National Bowel Cancer Screening Program. Respondents sampled from the flipchart distribution list were surveyed on the appropriateness, usefulness, and the extent to and manner in which they used the flipchart for educating Aboriginal clients. Despite praising the resource, few respondents used the flipchart as intended for various reasons, including the view that Aboriginal health education was the responsibility of Aboriginal health workers. Greater recognition by all health service providers is needed of their potential role in Aboriginal health education. Promoting a national health program of under-appreciated importance for a marginalised population is challenging. Effective utilisation of an educational tool is predicated on factors beyond its production quality and wide dissemination. Intended users require awareness of the underlying problem, and adequate time for and specific training in implementation of the tool.

Elevated moisture stimulates carbon loss from mineral soils by releasing protected organic matter.

PubMed

Huang, Wenjuan; Hall, Steven J

2017-11-24

Moisture response functions for soil microbial carbon (C) mineralization remain a critical uncertainty for predicting ecosystem-climate feedbacks. Theory and models posit that C mineralization declines under elevated moisture and associated anaerobic conditions, leading to soil C accumulation. Yet, iron (Fe) reduction potentially releases protected C, providing an under-appreciated mechanism for C destabilization under elevated moisture. Here we incubate Mollisols from ecosystems under C 3 /C 4 plant rotations at moisture levels at and above field capacity over 5 months. Increased moisture and anaerobiosis initially suppress soil C mineralization, consistent with theory. However, after 25 days, elevated moisture stimulates cumulative gaseous C-loss as CO 2 and CH 4 to >150% of the control. Stable C isotopes show that mineralization of older C 3 -derived C released following Fe reduction dominates C losses. Counter to theory, elevated moisture may significantly accelerate C losses from mineral soils over weeks to months-a critical mechanistic deficiency of current Earth system models.

Shortened Lifespan and Lethal Hemorrhage in a Hemophilia A Mouse Model.

PubMed

Staber, Janice M; Pollpeter, Molly J

2016-01-01

Hemophilia A animal models have helped advance our understanding of factor VIII deficiency. Previously, factor VIII deficient mouse models were reported to have a normal life span without spontaneous bleeds. However, the bleeding frequency and survival in these animals has not been thoroughly evaluated. To investigate the survival and lethal bleeding frequency in two strains of E-16 hemophilia A mice. We prospectively studied factor VIII deficient hemizygous affected males (n = 83) and homozygous affected females (n = 55) for survival and bleeding frequency. Animals were evaluated for presence and location of bleeds as potential cause of death. Hemophilia A mice had a median survival of 254 days, which is significantly shortened compared to wild type controls (p < 0.0001). In addition, the hemophilia A mice experienced hemorrhage in several tissues. This previously-underappreciated shortened survival in the hemophilia A murine model provides new outcomes for investigation of therapeutics and also reflects the shortened lifespan of patients if left untreated.

There is no fitness but fitness, and the lineage is its bearer

PubMed Central

2016-01-01

Inclusive fitness has been the cornerstone of social evolution theory for more than a half-century and has matured as a mathematical theory in the past 20 years. Yet surprisingly for a theory so central to an entire field, some of its connections to evolutionary theory more broadly remain contentious or underappreciated. In this paper, we aim to emphasize the connection between inclusive fitness and modern evolutionary theory through the following fact: inclusive fitness is simply classical Darwinian fitness, averaged over social, environmental and demographic states that members of a gene lineage experience. Therefore, inclusive fitness is neither a generalization of classical fitness, nor does it belong exclusively to the individual. Rather, the lineage perspective emphasizes that evolutionary success is determined by the effect of selection on all biological and environmental contexts that a lineage may experience. We argue that this understanding of inclusive fitness based on gene lineages provides the most illuminating and accurate picture and avoids pitfalls in interpretation and empirical applications of inclusive fitness theory. PMID:26729925

Environment and host as large-scale controls of ectomycorrhizal fungi.

PubMed

van der Linde, Sietse; Suz, Laura M; Orme, C David L; Cox, Filipa; Andreae, Henning; Asi, Endla; Atkinson, Bonnie; Benham, Sue; Carroll, Christopher; Cools, Nathalie; De Vos, Bruno; Dietrich, Hans-Peter; Eichhorn, Johannes; Gehrmann, Joachim; Grebenc, Tine; Gweon, Hyun S; Hansen, Karin; Jacob, Frank; Kristöfel, Ferdinand; Lech, Paweł; Manninger, Miklós; Martin, Jan; Meesenburg, Henning; Merilä, Päivi; Nicolas, Manuel; Pavlenda, Pavel; Rautio, Pasi; Schaub, Marcus; Schröck, Hans-Werner; Seidling, Walter; Šrámek, Vít; Thimonier, Anne; Thomsen, Iben Margrete; Titeux, Hugues; Vanguelova, Elena; Verstraeten, Arne; Vesterdal, Lars; Waldner, Peter; Wijk, Sture; Zhang, Yuxin; Žlindra, Daniel; Bidartondo, Martin I

2018-06-06

Explaining the large-scale diversity of soil organisms that drive biogeochemical processes-and their responses to environmental change-is critical. However, identifying consistent drivers of belowground diversity and abundance for some soil organisms at large spatial scales remains problematic. Here we investigate a major guild, the ectomycorrhizal fungi, across European forests at a spatial scale and resolution that is-to our knowledge-unprecedented, to explore key biotic and abiotic predictors of ectomycorrhizal diversity and to identify dominant responses and thresholds for change across complex environmental gradients. We show the effect of 38 host, environment, climate and geographical variables on ectomycorrhizal diversity, and define thresholds of community change for key variables. We quantify host specificity and reveal plasticity in functional traits involved in soil foraging across gradients. We conclude that environmental and host factors explain most of the variation in ectomycorrhizal diversity, that the environmental thresholds used as major ecosystem assessment tools need adjustment and that the importance of belowground specificity and plasticity has previously been underappreciated.

The use of mechanistic evidence in drug approval.

PubMed

Aronson, Jeffrey K; La Caze, Adam; Kelly, Michael P; Parkkinen, Veli-Pekka; Williamson, Jon

2018-06-11

The role of mechanistic evidence tends to be under-appreciated in current evidence-based medicine (EBM), which focusses on clinical studies, tending to restrict attention to randomized controlled studies (RCTs) when they are available. The EBM+ programme seeks to redress this imbalance, by suggesting methods for evaluating mechanistic studies alongside clinical studies. Drug approval is a problematic case for the view that mechanistic evidence should be taken into account, because RCTs are almost always available. Nevertheless, we argue that mechanistic evidence is central to all the key tasks in the drug approval process: in drug discovery and development; assessing pharmaceutical quality; devising dosage regimens; assessing efficacy, harms, external validity, and cost-effectiveness; evaluating adherence; and extending product licences. We recommend that, when preparing for meetings in which any aspect of drug approval is to be discussed, mechanistic evidence should be systematically analysed and presented to the committee members alongside analyses of clinical studies. © 2018 The Authors Journal of Evaluation in Clinical Practice Published by John Wiley & Sons Ltd.

Proximate causes of natal dispersal in female yellow-bellied marmots, Marmota flaviventris.

PubMed

Armitage, Kenneth B; Van Vuren, Dirk H; Ozgul, Arpat; Oli, Madan K

2011-01-01

We investigated factors influencing natal dispersal in 231 female yearling yellow-bellied marmots (Marmota flaviventris) using comprehensive analysis of 10 years (1983-1993) of radiotelemetry and 37 years (1963-1999) of capture-mark-recapture data. Only individuals whose dispersal status was verified, primarily by radiotelemetry, were considered. Univariate analyses revealed that six of the 24 variables we studied significantly influenced dispersal: dispersal was less likely when the mother was present, amicable behavior with the mother and play behavior were more frequent, and spatial overlap was greater with the mother, with matriline females, and with other yearling females. Using both univariate and multivariate analyses, we tested several hypotheses proposed as proximate causes of dispersal. We rejected inbreeding avoidance, population density, body size, social intolerance, and kin competition as factors influencing dispersal. Instead, our results indicate that kin cooperation, expressed via cohesive behaviors and with a focus on the mother, influenced dispersal by promoting philopatry. Kin cooperation may be an underappreciated factor influencing dispersal in both social and nonsocial species.

Soldier Health Habits and the Metabolically Optimized Brain.

PubMed

Friedl, Karl E; Breivik, Torbjorn J; Carter, Robert; Leyk, Dieter; Opstad, Per Kristian; Taverniers, John; Trousselard, Marion

2016-11-01

Human performance enhancement was the subject of a NATO workshop that considered the direct benefits of individual soldier health and fitness habits to brain health and performance. Some of the important health and fitness include physical activity and purposeful exercise, nutritional intake, sleep and rest behaviors, psychological outlook and mindfulness, and other physiologically based systemic challenges such as thermal exposure. These influences were considered in an integrated framework with insights contributed by each of five participating NATO member countries using representative research to highlight relevant interrelationships. Key conclusions are that (1) understanding the neurobiological bases and consequences of personal health behaviors is a priority for soldier performance research, and this also involves long-term brain health consequences to veterans and (2) health and fitness habits have been underappreciated as reliably effective performance enhancers and these should be preferred targets in the development of scientifically based recommendations for soldier brain health and performance. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Inferring Perspective Versus Getting Perspective: Underestimating the Value of Being in Another Person's Shoes.

PubMed

Zhou, Haotian; Majka, Elizabeth A; Epley, Nicholas

2017-04-01

People use at least two strategies to solve the challenge of understanding another person's mind: inferring that person's perspective by reading his or her behavior (theorization) and getting that person's perspective by experiencing his or her situation (simulation). The five experiments reported here demonstrate a strong tendency for people to underestimate the value of simulation. Predictors estimated a stranger's emotional reactions toward 50 pictures. They could either infer the stranger's perspective by reading his or her facial expressions or simulate the stranger's perspective by watching the pictures he or she viewed. Predictors were substantially more accurate when they got perspective through simulation, but overestimated the accuracy they had achieved by inferring perspective. Predictors' miscalibrated confidence stemmed from overestimating the information revealed through facial expressions and underestimating the similarity in people's reactions to a given situation. People seem to underappreciate a useful strategy for understanding the minds of others, even after they gain firsthand experience with both strategies.

Glial and Neuroimmune Mechanisms as Critical Modulators of Drug Use and Abuse.

PubMed

Lacagnina, Michael J; Rivera, Phillip D; Bilbo, Staci D

2017-01-01

Drugs of abuse cause persistent alterations in synaptic plasticity that may underlie addiction behaviors. Evidence suggests glial cells have an essential and underappreciated role in the development and maintenance of drug abuse by influencing neuronal and synaptic functions in multifaceted ways. Microglia and astrocytes perform critical functions in synapse formation and refinement in the developing brain, and there is growing evidence that disruptions in glial function may be implicated in numerous neurological disorders throughout the lifespan. Linking evidence of function in health and under pathological conditions, this review will outline the glial and neuroimmune mechanisms that may contribute to drug-abuse liability, exploring evidence from opioids, alcohol, and psychostimulants. Drugs of abuse can activate microglia and astrocytes through signaling at innate immune receptors, which in turn influence neuronal function not only through secretion of soluble factors (eg, cytokines and chemokines) but also potentially through direct remodeling of the synapses. In sum, this review will argue that neural-glial interactions represent an important avenue for advancing our understanding of substance abuse disorders.

Nonequilibrium Chemical Effects in Single-Molecule SERS Revealed by Ab Initio Molecular Dynamics Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, Sean A.; Aprà, Edoardo; Govind, Niranjan

2017-02-03

Recent developments in nanophotonics have paved the way for achieving significant advances in the realm of single molecule chemical detection, imaging, and dynamics. In particular, surface-enhanced Raman scattering (SERS) is a powerful analytical technique that is now routinely used to identify the chemical identity of single molecules. Understanding how nanoscale physical and chemical processes affect single molecule SERS spectra and selection rules is a challenging task, and is still actively debated. Herein, we explore underappreciated chemical phenomena in ultrasensitive SERS. We observe a fluctuating excited electronic state manifold, governed by the conformational dynamics of a molecule (4,4’-dimercaptostilbene, DMS) interacting withmore » a metallic cluster (Ag20). This affects our simulated single molecule SERS spectra; the time trajectories of a molecule interacting with its unique local environment dictates the relative intensities of the observable Raman-active vibrational states. Ab initio molecular dynamics of a model Ag20-DMS system are used to illustrate both concepts in light of recent experimental results.« less

Rapid instructed task learning: A new window into the human brain’s unique capacity for flexible cognitive control

PubMed Central

Cole, Michael W.; Laurent, Patryk; Stocco, Andrea

2012-01-01

The human ability to flexibly adapt to novel circumstances is extraordinary. Perhaps the most illustrative yet underappreciated form of this cognitive flexibility is rapid instructed task learning (RITL) – the ability to rapidly reconfigure our minds to perform new tasks from instruction. This ability is important for everyday life (e.g., learning to use new technologies), and is used to instruct participants in nearly every study of human cognition. We review the development of RITL as a circumscribed domain of cognitive neuroscience investigation, culminating in recent demonstrations that RITL is implemented via brain circuits centered on lateral prefrontal cortex. We then build on this and other insights to develop an integrative theory of cognitive flexibility and cognitive control, identifying theoretical principles and mechanisms that may make RITL possible in the human brain. Insights gained from this new theoretical account have important implications for further developments and applications of RITL research. PMID:23065743

Prevalence of noise-induced hearing loss among woodworkers in Nepal: a pilot study

PubMed Central

Robinson, Tim; Whittaker, Joshua; Acharya, Aanand; Singh, Devesh; Smith, Michael

2015-01-01

Background: The woodworking industry represents an important cause of occupational noise-induced hearing loss (NIHL), a significant yet underappreciated problem in many developing countries. Objectives: To describe the prevalence of occupational NIHL among woodworkers in Nepal and measure noise levels at workplaces. Methods: We conducted a cross-sectional study with 124 woodworkers (88 carpenters, 36 sawyers), recruited through convenience sampling from 26 workplaces. Pure-tone audiometry between the frequencies 0·5 and 8 kHz ascertained participants’ hearing status, and noise readings were taken at selected workplaces. Results: In all, 31% of carpenters and 44% of sawyers met criteria for NIHL, with 7 and 17% meeting World Health Organization (WHO) criteria for hearing impairment (HI), respectively. Noise levels at various workplaces ranged from 71·2 to 93·9 dBA. Conclusions: Woodworkers in Nepal are at risk of occupational NIHL. As the industry develops, this problem will likely become more extensive, highlighting the need for workplace interventions and additional research. PMID:25335826

The head and neck discomfort of autonomic failure: an unrecognized aetiology of headache

NASA Technical Reports Server (NTRS)

Robertson, D.; Kincaid, D. W.; Haile, V.; Robertson, R. M.

1994-01-01

Information concerning the frequency, severity, character, location, duration, diurnal pattern of headache and ancillary symptoms were obtained in 25 patients with autonomic failure and 44 control subjects. Precipitating and ameliorating factors were identified. Autonomic failure patients had more head and neck discomfort than controls. Their discomfort was much more likely to localize in the occiput, nape of the neck and shoulder, compared with controls. There was a greater tendency for the discomfort to occur in the morning and after meals. It was sometimes less than 5 min in duration and was often associated with dimming, blurring, or tunnelling of vision. It was provoked by upright posture and relieved by lying down. Patients with severe autonomic failure and orthostatic hypotension often present with a posture-dependent headache or neck pain. Because the relationship of these symptoms to posture is often not recognized, the fact that these findings may signal an underlying autonomic disorder is underappreciated, and the opportunity to consider this aetiology for the headache may be missed.

Bias against research on gender bias.

PubMed

Cislak, Aleksandra; Formanowicz, Magdalena; Saguy, Tamar

2018-01-01

The bias against women in academia is a documented phenomenon that has had detrimental consequences, not only for women, but also for the quality of science. First, gender bias in academia affects female scientists, resulting in their underrepresentation in academic institutions, particularly in higher ranks. The second type of gender bias in science relates to some findings applying only to male participants, which produces biased knowledge. Here, we identify a third potentially powerful source of gender bias in academia: the bias against research on gender bias. In a bibliometric investigation covering a broad range of social sciences, we analyzed published articles on gender bias and race bias and established that articles on gender bias are funded less often and published in journals with a lower Impact Factor than articles on comparable instances of social discrimination. This result suggests the possibility of an underappreciation of the phenomenon of gender bias and related research within the academic community. Addressing this meta-bias is crucial for the further examination of gender inequality, which severely affects many women across the world.

Cahokia's emergence and decline coincided with shifts of flood frequency on the Mississippi River

NASA Astrophysics Data System (ADS)

Munoz, Samuel E.; Gruley, Kristine E.; Massie, Ashtin; Fike, David A.; Schroeder, Sissel; Williams, John W.

2015-05-01

Here we establish the timing of major flood events of the central Mississippi River over the last 1,800 y, using floodwater sediments deposited in two floodplain lakes. Shifts in the frequency of high-magnitude floods are mediated by moisture availability over midcontinental North America and correspond to the emergence and decline of Cahokia-a major late prehistoric settlement in the Mississippi River floodplain. The absence of large floods from A.D. 600 to A.D. 1200 facilitated agricultural intensification, population growth, and settlement expansion across the floodplain that are associated with the emergence of Cahokia as a regional center around A.D. 1050. The return of large floods after A.D. 1200, driven by waning midcontinental aridity, marks the onset of sociopolitical reorganization and depopulation that culminate in the abandonment of Cahokia and the surrounding region by A.D. 1350. Shifts in the frequency and magnitude of flooding may be an underappreciated but critical factor in the formation and dissolution of social complexity in early agricultural societies.

Targeted gene flow for conservation.

PubMed

Kelly, Ella; Phillips, Ben L

2016-04-01

Anthropogenic threats often impose strong selection on affected populations, causing rapid evolutionary responses. Unfortunately, these adaptive responses are rarely harnessed for conservation. We suggest that conservation managers pay close attention to adaptive processes and geographic variation, with an eye to using them for conservation goals. Translocating pre-adapted individuals into recipient populations is currently considered a potentially important management tool in the face of climate change. Targeted gene flow, which involves moving individuals with favorable traits to areas where these traits would have a conservation benefit, could have a much broader application in conservation. Across a species' range there may be long-standing geographic variation in traits or variation may have rapidly developed in response to a threatening process. Targeted gene flow could be used to promote natural resistance to threats to increase species resilience. We suggest that targeted gene flow is a currently underappreciated strategy in conservation that has applications ranging from the management of invasive species and their impacts to controlling the impact and virulence of pathogens. © 2015 Society for Conservation Biology.

A Chemical-Genomic Screen of Neglected Antibiotics Reveals Illicit Transport of Kasugamycin and Blasticidin S

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiver, Anthony L.; Osadnik, Hendrik; Kritikos, George

Fighting antibiotic resistance requires a deeper understanding of the genetic factors that determine the antibiotic susceptibility of bacteria. Here we describe a chemical-genomic screen in Escherichia coli K-12 that was designed to discover new aspects of antibiotic resistance by focusing on a set of 26 antibiotics and other stresses with poorly characterized mode-of-action and determinants of resistance. We show that the screen identifies new resistance determinants for these antibiotics including a common signature from two antimicrobials, kasugamycin and blasticidin S, used to treat crop diseases like rice blast and fire blight. Following this signature, we further investigated the mechanistic basismore » for susceptibility to kasugamycin and blasticidin S in E. coli using both genetic and biochemical approaches. We provide evidence that these compounds hijack an overlapping set of peptide ABC-importers to enter the bacterial cell. As a result, the loss of uptake may be an underappreciated mechanism for the development of kasugamycin resistance in bacterial plant pathogens.« less

Advantages and pitfalls in the application of mixed-model association methods.

PubMed

Yang, Jian; Zaitlen, Noah A; Goddard, Michael E; Visscher, Peter M; Price, Alkes L

2014-02-01

Mixed linear models are emerging as a method of choice for conducting genetic association studies in humans and other organisms. The advantages of the mixed-linear-model association (MLMA) method include the prevention of false positive associations due to population or relatedness structure and an increase in power obtained through the application of a correction that is specific to this structure. An underappreciated point is that MLMA can also increase power in studies without sample structure by implicitly conditioning on associated loci other than the candidate locus. Numerous variations on the standard MLMA approach have recently been published, with a focus on reducing computational cost. These advances provide researchers applying MLMA methods with many options to choose from, but we caution that MLMA methods are still subject to potential pitfalls. Here we describe and quantify the advantages and pitfalls of MLMA methods as a function of study design and provide recommendations for the application of these methods in practical settings.

Less Is More: A Minimalist Approach to Endoscopy.

PubMed

Shaheen, Nicholas J; Fennerty, M Brian; Bergman, Jacques J

2018-05-01

A substantial literature documents inappropriate usage of gastrointestinal endoscopy in a variety of clinical settings. Overusage of endoscopy appears to be common, and 30% or more of procedures performed in some clinical settings have questionable indications. The potential reasons for overuse of endoscopy are multiple, and include cancer phobia, fear of medical malpractice litigation, profit motive, the investigation of "incidentalomas" found on other imaging, and underappreciation of the delayed harms of endoscopy, among other reasons. Clinical guidelines, which should limit overuse of endoscopy, may instead serve to promote it, if authors opt to be "conservative," recommending endoscopy in situations of unclear utility. Several strategies may decrease overuse of endoscopy, including careful attention to risk stratification when choosing patients to screen, adherence to guidelines for surveillance intervals for colonoscopy, the use of quality indicators to identify outliers in endoscopy utilization, and education on appropriate indications and the risks of overuse at the medical student, residency, and fellowship levels. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Effective signaling of surface boundaries by L-vertices reflect the consistency of their contrast in natural images.

PubMed

Vessel, Edward A; Biederman, Irving; Subramaniam, Suresh; Greene, Michelle R

2016-07-01

An L-vertex, the point at which two contours coterminate, provides highly reliable evidence that a surface terminates at that vertex, thus providing the strongest constraint on the extraction of shape from images (Guzman, 1968). Such vertices are pervasive in our visual world but the importance of a statistical regularity about them has been underappreciated: The contours defining the vertex are (almost) always of the same direction of contrast with respect to the background (i.e., both darker or both lighter). Here we show that when the two contours are of different directions of contrast, the capacity of the L-vertex to signal the termination of a surface, as reflected in object recognition, is markedly reduced. Although image statistics have been implicated in determining the connectivity in the earliest cortical visual stage (V1) and in grouping during visual search, this finding provides evidence that such statistics are involved in later stages where object representations are derived from two-dimensional images.

Factors controlling mud accumulation in the Heuksan mud belt off southwestern Korea

NASA Astrophysics Data System (ADS)

Chang, Tae Soo; Ha, Hun Jun; Chun, Seung Soo

2015-12-01

The Heuksan mud belt (hereafter HMB) is 20~50 km wide, ~200 km long, and ~50 m thick, having accumulated in the course of the Holocene transgression on the tide-dominated epicontinental shelf southwest of Korea. The internal architecture of the HMB is characterized by offshore prograding clinoforms. Of particular interest are the depositional processes responsible for this anomalously thick mud accumulation within a relatively short period of time. Tidal currents are important in the dispersal of mud in the HMB, although these alone cannot explain such an enormous mud deposit. In order to understand the formative processes of the HMB, a detailed sedimentary facies analysis, including high-resolution grain-size measurements, has been conducted on more than 30 short cores and three long drill cores recovered from the mud belt. Five major mud facies were identified. Of these, mud sequences showing a thickening-thinning trend of alternating silt and clay laminae suggestive of a tidal origin occur dominantly at inner to mid shelf locations. By contrast, internally structureless muds with sharp bases and no bioturbation, which are interpreted of representing fluid-mud deposits, are widespread at mid to outer shelf locations. Wave-generated mud ripples and storm beds on the inner shelf suggest that storm waves in winter resuspend previously deposited mud to form near-bed fluid-mud suspensions with resulting gravity-driven mud transport across the low-gradient outer shelf. This previously not recognized process is probably a major factor controlling depositional processes on the giant mud belt, enabling rapid accumulation and offshore progradation even during transgression, i.e., at times of sea-level rise.

Landau quantization in the spinning cosmic string spacetime

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muniz, C.R., E-mail: celiomuniz@yahoo.com; Bezerra, V.B.; Cunha, M.S.

2014-11-15

We analyze the quantum phenomenon arising from the interaction of a spinless charged particle with a rotating cosmic string, under the action of a static and uniform magnetic field parallel to the string. We calculate the energy levels of the particle in the non-relativistic approach, showing how these energies depend on the parameters involved in the problem. In order to do this, we solve the time independent Schrödinger equation in the geometry of the spinning cosmic string, taking into account that the coupling between the rotation of the spacetime and the angular momentum of the particle is very weak, suchmore » that makes sense to apply the Schrödinger equation in a curved background whose metric has an off diagonal term which involves time and space. It is also assumed that the particle orbits sufficiently far from the boundary of the region of closed timelike curves which exist around this topological defect. Finally, we find the Landau levels of the particle in the presence of a spinning cosmic string endowed with internal structure, i.e., having a finite width and uniformly filled with both material and vacuum energies. - Highlights: • Solution of the wave equation characterizing the problem. • Energy levels of the particle in spacetime of the structureless string. • Expression for an analogous of the quadratic Zeeman effect. • Energy levels of the particle in spacetime of the string with internal structure. • Evidence of the string structure by the internal existence of the vacuum energy.« less

Contribution of Anisotropy of Magnetic Susceptibility (AMS) to reconstruct flooding characteristics of a 4220 BP tsunami from a thick unconsolidated structureless deposit (Banda Aceh, Sumatra)

NASA Astrophysics Data System (ADS)

Wassmer, Patrick; Gomez, Christopher; Iskandasyah, T. Yan W. M.; Lavigne, Franck; Sartohadi, Junun

2015-07-01

One of the main concerns of deciphering tsunami sedimentary records along seashore is to link the emplaced layers with marine high energy events. Based on a combination of morphologic features, sedimentary figures, grain size characteristics, fossils content, microfossils assemblages, geochemical elements, heavy minerals presence; it is, in principle, possible to relate the sedimentary record to a tsunami event. However, experience shows that sometimes, in reason of a lack of any visible sedimentary features, it is hard to decide between a storm and a tsunami origin. To solve this issue, the authors have used the Anisotropy of Magnetic Susceptibility (AMS) to evidence the sediment fabric. The validity of the method for reconstructing flow direction has been proved when applied on sediments in the aftermath of a tsunami event, for which the behaviour was well documented (2004 IOT). We present herein an application of this method for a 56 cm thick paleo-deposit dated 4220 BP laying under the soil covered by the 2004 IOT, SE of Banda Aceh, North Sumatra. We analysed this homogenous deposit, lacking of any visible structure, using methods of classic sedimentology to confirm the occurrence of a high energy event. We then applied AMS technique that allowed the reconstruction of flow characteristics during sediment emplacement. We show that all the sequence was emplaced by uprush phases and that the local topography played a role on the re-orientation of a part of the uprush flow, creating strong reverse current. This particular behaviour was reported by eyewitnesses during the 2004 IOT event.

Early diagnosis of genital mucosal melanoma: how good are our dermoscopic criteria?

PubMed

Rogers, Tova; Pulitzer, Melissa; Marino, Maria L; Marghoob, Ashfaq A; Zivanovic, Oliver; Marchetti, Michael A

2016-10-01

There are limited studies on the dermoscopic features of mucosal melanoma, particularly early-stage lesions. Described criteria include the presence of blue, gray, or white colors, with a reported sensitivity of 100%. It is unclear if these features will aid in the detection of early mucosal melanoma or improve diagnostic accuracy compared to naked-eye examination alone. An Asian female in her fifties was referred for evaluation of an asymptomatic, irregularly pigmented patch of the clitoral hood and labia minora of unknown duration. Her past medical history was notable for Stage IV non-small cell lung cancer. She denied a personal or family history of skin cancer. Dermoscopic evaluation of the vulvar lesion revealed heterogeneous brown and black pigmentation mostly composed of thick lines. There were no other colors or structures present. As the differential diagnosis included vulvar melanosis and mucosal melanoma, the patient was recommended to undergo biopsy, which was delayed due to complications from her underlying lung cancer. Repeat dermoscopic imaging performed three months later revealed significant changes concerning for melanoma, including increase in size, asymmetric darkening, and the appearance of structureless areas and central blue and pink colors. Histopathological examination of a biopsy and subsequent resection confirmed the diagnosis of melanoma in situ. Previously described dermoscopic features for mucosal melanoma may not have high sensitivity for early melanomas. Additional studies are needed to define the dermoscopic characteristics of mucosal melanomas that aid in early detection. Health care providers should have a low threshold for biopsy of mucosal lesions that show any clinical or dermoscopic features of melanoma, especially in older women.

Quantum tunneling and scattering of a composite object

NASA Astrophysics Data System (ADS)

Ahsan, Naureen

Reaction physics involving composite objects with internal degrees of freedom is an important subject since it is encountered in the context of nuclear processes like fusion, fission, particle decay, as well as many other branches of science. Quantum tunneling and scattering of a composite object are explored in this work. A few model Hamiltonians are chosen as examples where a two-particle system interacts, in one dimension, with a target that poses a delta-potential or an infinite wall potential. It is assumed that only one of the two components interacts with the target. The study includes the harmonic oscillator and the infinite square well as examples of intrinsic Hamiltonians that do not allow the projectile to break up, and a finite square well and a delta-well as examples of Hamiltonians that do. The Projection Method and the Variable Phase Method are applied with the aim of an exact solution to the relevant scattering problems. These methods are discussed in the context of the pertinent convergence issues related thereto, and of their applicability. Virtual excitations of the projectile into the classically forbidden energy-domain are found to play a dominant and non-perturbative role in shaping reaction observables, giving rise to enhanced or reduced tunneling in various situations. Cusps and discontinuities are found to appear in observables as manifestations of unitarity and redistribution of flux at the thresholds. The intrinsic structure gives rise to resonancelike behavior in tunneling probabilities. It is also shown that there is charge asymmetry in the scattering of a composite object, unlike in the case of a structureless particle.

Silicic, high- to extremely high-grade ignimbrites and associated deposits from the Paraná Magmatic Province, southern Brazil

NASA Astrophysics Data System (ADS)

Luchetti, Ana Carolina F.; Nardy, Antonio J. R.; Madeira, José

2018-04-01

The Cretaceous trachydacites and dacites of Chapecó type (ATC) and dacites and rhyolites of Palmas type (ATP) make up 2.5% of the 800.000 km3 of volcanic pile in the Paraná Magmatic Province (PMP), emplaced at the onset of Gondwana breakup. Together they cover extensive areas in southern Brazil, overlapping volcanic sequences of tholeiitic basalts and andesites; occasional mafic units are also found within the silicic sequence. In the central region of the PMP silicic volcanism comprises porphyritic ATC-type, trachydacite high-grade ignimbrites (strongly welded) overlying aphyric ATP-type, rhyolite high- to extremely high-grade ignimbrites (strongly welded to lava-like). In the southwestern region strongly welded to lava-like high-grade ignimbrites overlie ATP lava domes, while in the southeast lava domes are found intercalated within the ignimbrite sequence. Characteristics of these ignimbrites are: widespread sheet-like deposits (tens to hundreds of km across); absence of basal breccias and basal fallout layers; ubiquitous horizontal to sub-horizontal sheet jointing; massive, structureless to horizontally banded-laminated rock bodies locally presenting flow folding; thoroughly homogeneous vitrophyres or with flow banding-lamination; phenocryst abundance presenting upward and lateral decrease; welded glass blobs in an 'eutaxitic'-like texture; negligible phenocryst breakage; vitroclastic texture locally preserved; scarcity of lithic fragments. These features, combined with high eruption temperatures (≥ 1000 °C), low water content (≤ 2%) and low viscosities (104-7 Pa s) suggest that the eruptions were characterized by low fountaining, little heat loss during collapse, and high mass fluxes producing extensive deposits.

Ion Counting from Explicit-Solvent Simulations and 3D-RISM

PubMed Central

Giambaşu, George M.; Luchko, Tyler; Herschlag, Daniel; York, Darrin M.; Case, David A.

2014-01-01

The ionic atmosphere around nucleic acids remains only partially understood at atomic-level detail. Ion counting (IC) experiments provide a quantitative measure of the ionic atmosphere around nucleic acids and, as such, are a natural route for testing quantitative theoretical approaches. In this article, we replicate IC experiments involving duplex DNA in NaCl(aq) using molecular dynamics (MD) simulation, the three-dimensional reference interaction site model (3D-RISM), and nonlinear Poisson-Boltzmann (NLPB) calculations and test against recent buffer-equilibration atomic emission spectroscopy measurements. Further, we outline the statistical mechanical basis for interpreting IC experiments and clarify the use of specific concentration scales. Near physiological concentrations, MD simulation and 3D-RISM estimates are close to experimental results, but at higher concentrations (>0.7 M), both methods underestimate the number of condensed cations and overestimate the number of excluded anions. The effect of DNA charge on ion and water atmosphere extends 20–25 Å from its surface, yielding layered density profiles. Overall, ion distributions from 3D-RISMs are relatively close to those from corresponding MD simulations, but with less Na+ binding in grooves and tighter binding to phosphates. NLPB calculations, on the other hand, systematically underestimate the number of condensed cations at almost all concentrations and yield nearly structureless ion distributions that are qualitatively distinct from those generated by both MD simulation and 3D-RISM. These results suggest that MD simulation and 3D-RISM may be further developed to provide quantitative insight into the characterization of the ion atmosphere around nucleic acids and their effect on structure and stability. PMID:24559991

The importance of excluded solvent volume effects in computing hydration free energies.

PubMed

Yang, Pei-Kun; Lim, Carmay

2008-11-27

Continuum dielectric methods such as the Born equation have been widely used to compute the electrostatic component of the solvation free energy, DeltaG(solv)(elec), because they do not need to include solvent molecules explicitly and are thus far less costly compared to molecular simulations. All of these methods can be derived from Gauss Law of Maxwell's equations, which yields an analytical solution for the solvation free energy, DeltaG(Born), when the solute is spherical. However, in Maxwell's equations, the solvent is assumed to be a structureless continuum, whereas in reality, the near-solute solvent molecules are highly structured unlike far-solute bulk solvent. Since we have recently reformulated Gauss Law of Maxwell's equations to incorporate the near-solute solvent structure by considering excluded solvent volume effects, we have used it in this work to derive an analytical solution for the hydration free energy of an ion. In contrast to continuum solvent models, which assume that the normalized induced solvent electric dipole density P(n) is constant, P(n) mimics that observed from simulations. The analytical formula for the ionic hydration free energy shows that the Born radius, which has been used as an adjustable parameter to fit experimental hydration free energies, is no longer ill defined but is related to the radius and polarizability of the water molecule, the hydration number, and the first peak position of the solute-solvent radial distribution function. The resulting DeltaG(solv)(elec) values are shown to be close to the respective experimental numbers.

The geology of the Florida land-pebble phosphate deposits

USGS Publications Warehouse

Cathcart, J.B.; Blade, L.V.; Davidson, D.F.; Ketner, K.B.

1952-01-01

The land-pebble phosphate district is on the Gulf Coastal Plain of Florida. The phosphate deposits are in the Bone Valley formation, dated Pliocene by most writers. These strata overlie the Miocene Hawthorn formation and are overlain by consolidated sands 3 to 20 feet thick. The minable phosphate deposits, called “matrix” in the district, range from a featheredge to about 50 feet in thickness and consist of phosphatic pellets and nodules, quartz sand, and montmorillonitic clay in about equal proportions. Locally the matrix displays cross-bedding and horizontal laminations, but elsewhere it is structureless. The phosphorite particles, composed largely of carbonate-fluorapatite, range in diameter from less than 0.1 mm to about 60 cm and in P2O5 content from 30 to 36 percent. Coarse-pebble deposits, containing 30 to 34 percent P2O5 are found mainly on basement highs; and fine-pebble deposits, containing 32 to 36 percent P2O5 are, are found in basement lows. Deposits in the northern part of the field contain more phosphate particles and their P2O5 content is higher than those in the southern part. The upper part of the phosphatic strata is leached to an advanced degree and consists of quartz sand and clay-sized particules of pseudowavellite and wavellite. The leached zone ranges in thickness from a featheredge to 60 feet. The origin of the land-pebble deposits is incompletely known. Possible modes of origin are a residuum of Miocene age, or a reworked residuum of Pliocene or Quaternary age.

α +d →6Li+γ astrophysical S factor and its implications for Big Bang nucleosynthesis

NASA Astrophysics Data System (ADS)

Grassi, A.; Mangano, G.; Marcucci, L. E.; Pisanti, O.

2017-10-01

The α +d →6Li +γ radiative capture is studied in order to predict the 6Li primordial abundance. Within a two-body framework, the α particle and the deuteron are considered the structureless constituents of 6Li. Five α +d potentials are used to solve the two-body problem: four of them are taken from the literature, only one having also a tensor component. A fifth model is here constructed in order to reproduce, besides the 6Li static properties as binding energy, magnetic dipole, and electric quadrupole moments, also the S -state asymptotic normalization coefficient (ANC). The two-body bound and scattering problem is solved with different techniques, in order to minimize the numerical uncertainty of the present results. The long-wavelength approximation is used, and therefore only the electric dipole and quadrupole operators are retained. The astrophysical S factor is found to be significantly sensitive to the ANC, but in all the cases in good agreement with the available experimental data. The theoretical uncertainty has been estimated of the order of few percent when the potentials which reproduce the ANC are considered, but increases up to ≃20 % when all five potential models are retained. The effect of this S -factor prediction on the 6Li primordial abundance is studied, using the public code PArthENoPE. For the five models considered here we find 6Li/H=(0.9 -1.8 ) ×10-14 , with the baryon density parameter in the 3-σ range of Planck 2015 analysis, Ωbh2=0.022 26 ±0.000 23 .

Photophysics of phenol and pentafluorophenol: The role of nonadiabaticity in the optical transition to the lowest bright 1ππ* state

NASA Astrophysics Data System (ADS)

Rajak, Karunamoy; Ghosh, Arpita; Mahapatra, S.

2018-02-01

We report multimode vibronic coupling of the energetically low-lying electronic states of phenol and pentafluorophenol in this article. First principles nuclear dynamics calculations are carried out to elucidate the optical absorption spectrum of both of the molecules. This is motivated by the recent experimental measurements [S. Karmakar et al., J. Chem. Phys. 142, 184303 (2015)] on these systems. Diabatic vibronic coupling models are developed with the aid of adiabatic electronic energies calculated ab initio by the equation of motion coupled cluster quantum chemistry method. A nuclear dynamics study on the constructed electronic states is carried out by both the time-independent and time-dependent quantum mechanical methods. It is found that the nature of low-energy πσ* transition changes, and in pentafluorophenol the energy of the first two 1πσ* states, is lowered by about half an eV (vertically, relative to those in phenol), and they become energetically close to the optically bright first excited 1ππ* (S1) state. This results in strong vibronic coupling and multiple multi-state conical intersections among the ππ* and πσ* electronic states of pentafluorophenol. The impact of associated nonadiabatic effects on the vibronic structure and dynamics of the 1ππ* state is examined at length. The structured vibronic band of phenol becomes structureless in pentafluorophenol. The theoretical results are found to be in good accord with the experimental finding at both high energy resolution and low energy resolution.

Energy of the ground and 2{sup +} excited states of {sub {lambda}}{sub {lambda}}{sup 10}Be: A partial ten-body model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shoeb, Mohammad; Sonika

2009-08-15

The energies of the ground and excited 2{sup +} states of {sub {lambda}}{sub {lambda}}{sup 10}Be have been calculated variationally in the Monte Carlo framework. The hypernucleus is treated as a partial ten-body problem in the {lambda}{lambda}+{alpha}{alpha} model where nucleonic degrees of freedom of {alpha}'s are taken into consideration ignoring the antisymmetrization between two {alpha}'s. The central two-body {lambda}N and {lambda}{lambda} and the three-body dispersive and two-pion exchange {lambda}NN forces, constrained by the {lambda}p scattering data and the observed ground state energies of {sub {lambda}}{sup 5}He and {sub {lambda}}{sub {lambda}}{sup 6}He, are employed. The product-type trial wave function predicts binding energymore » for the ground state considerably less than for the event reported by Danysz et al.; however, it is consistent with the value deduced assuming a {gamma} ray of 3.04 MeV must have escaped undetected in the decay of the product {sub {lambda}}{sup 9}Be* {yields} {sub {lambda}}{sup 9}Be+{gamma} of the emulsion event {sub {lambda}}{sub {lambda}}{sup 10}Be{yields} {pi}{sup -}+p+{sub {lambda}}{sup 9}Be* and for the excited 2{sup +} state closer to the value measured in the Demachi-Yanagi event. The hypernucleus {sub {lambda}}{sub {lambda}}{sup 10}Be has an oblate shape in the excited state. These results are consistent with the earlier four-body {alpha} cluster model approach where {alpha}'s are assumed to be structureless entities.« less

Lynch Syndrome: A Primer for Urologists and Panel Recommendations.

PubMed

Mork, Maureen; Hubosky, Scott G; Rouprêt, Morgan; Margulis, Vitaly; Raman, Jay; Lotan, Yair; O'Brien, Timothy; You, Nancy; Shariat, Shahrokh F; Matin, Surena F

2015-07-01

Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer, is a common genetic disease. The predisposition of patients with Lynch syndrome to urological cancer, particularly upper tract urothelial carcinoma, is underappreciated. Urologists may be involved in several aspects of care involving Lynch syndrome, including identifying undiagnosed patients, surveillance of those with established Lynch syndrome or screening family members, in addition to treating patients with Lynch syndrome in whom upper tract urothelial carcinoma develops. We sought to increase awareness in the urological community about Lynch syndrome and provide some guidance where little currently exists. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement we reviewed the available published literature and guidelines from 1998 to 2014 on Lynch syndrome and its association with upper tract urothelial carcinoma. Recommendations based on the literature and the consensus of expert opinion are provided. No randomized or prospective study has been done to evaluate Lynch syndrome in the setting of urological cancer. All data were based on retrospective studies. Lynch syndrome is an autosomal dominant genetic disease caused by germline mutations in 4 mismatch repair genes, leading to the accumulation of DNA errors in microsatellite regions. Upper tract urothelial carcinoma develops in up to 28% of patients with known Lynch syndrome. The diagnosis of Lynch syndrome is established by clinical criteria, tumor tissue testing and genetic evaluation. Urologists should suspect Lynch syndrome when a patient with upper tract urothelial carcinoma presents before age 60 years or meets the 3-2-1 rule. Screening patients with Lynch syndrome for upper tract urothelial carcinoma presents a particular challenge. While no ideal screening test exists, at a minimum routine urinalysis is recommended using the American Urological Association guideline of 3 or more red blood cells per high power field as a trigger for further assessment. Upper tract urothelial carcinoma associated with Lynch syndrome presents at a younger age than sporadic upper tract urothelial carcinoma. It shows a higher proportion of ureteral cancer with a female preponderance and a possible predisposition to bilaterality. Lynch syndrome is a common genetic disease that is an underappreciated cause of upper tract urothelial carcinoma and possibly other urological cancers. Optimal screening for upper tract urothelial carcinoma in this population is unclear. Further study is needed to identify the best screening test and interval of testing. Urologists should consider routine tissue testing of de novo upper tract urothelial carcinoma tissue in individuals at risk. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Volcanic Debris Flows of the Latest Paleozoic Arbasay Formation: Geomorphological Characters and Paleoenvironment Reconstruction of Northern Tian Shan, NW China

NASA Astrophysics Data System (ADS)

Yang, W.; Liu, D.; Guo, Z.

2015-12-01

Texturally well-preserved volcanic debris flows (also called lahars) are exposed in the Latest Paleozoic Arbasay Formation, Northern Tian Shan. LA-ICP-MS zircon dating of the intercalated fallout tuff sample provided an age of 314.4±3.4 Ma (MSWD=1.6), suggesting they were deposited at Latest Carboniferous. The lahars consist primarily of two lithofacies: massive, poorly lithified diamictites and stratified, moderately lithified gravelly sandstones. The diamictites can be generally divided into two subfacies, i.e., the matrix-supported and the clast-supported diamictites. Most diamictites are structureless and nongraded. They are thick in beds and contain large clasts up to 3 m in dimension. The gravelly sandstones display much finer particle size and have wedge or lenticular geometries. Large clasts are absent within them and the sorting characters are much better than the diamictites. Despite the different size grading, the matrix and the clasts of the two lithofacies appear to be homogeneous. The matrix is generally sandy mudstone. The clasts comprise rhyolites, dacites, andesites, andesitic basalts and basalts, same to the co-existing volcanic rocks, suggesting they originate from the cognate volcanics. The disorganized diamictites are supposed to deposit from a turbulent flood or pyroclastic surge. The gravelly sandstone lithofacies are interpreted as sand-rich flood flows or hyperconcentrated flood flows during the waning stage of a mass-flow event. The overall characteristics of the deposits suggest a mass-flow dominated alluvial fan environment. It's noteable that several syn- sedimentary normal faults occurred within these lahar deposits, indicating that the Southern Junggar Basin was in an extensional regime during the lahars' deposition. Structure is dominated by normal faulting, allowing the existence of relatively small, highly compartmentalized depocenters. This is also supported by geochemistry and detrital zircon studies.

Drying and wetting transitions of a Lennard-Jones fluid: Simulations and density functional theory

NASA Astrophysics Data System (ADS)

Evans, Robert; Stewart, Maria C.; Wilding, Nigel B.

2017-07-01

We report a theoretical and simulation study of the drying and wetting phase transitions of a truncated Lennard-Jones fluid at a flat structureless wall. Binding potential calculations predict that the nature of these transitions depends on whether the wall-fluid attraction has a long ranged (LR) power law decay or is instead truncated, rendering it short ranged (SR). Using grand canonical Monte Carlo simulation and classical density functional theory, we examine both cases in detail. We find that for the LR case wetting is first order, while drying is continuous (critical) and occurs exactly at zero attractive wall strength, i.e., in the limit of a hard wall. In the SR case, drying is also critical but the order of the wetting transition depends on the truncation range of the wall-fluid potential. We characterize the approach to critical drying and wetting in terms of the density and local compressibility profiles and via the finite-size scaling properties of the probability distribution of the overall density. For the LR case, where the drying point is known exactly, this analysis allows us to estimate the exponent ν∥, which controls the parallel correlation length, i.e., the extent of vapor bubbles at the wall. Surprisingly, the value we obtain is over twice that predicted by mean field and renormalization group calculations, despite the fact that our three dimensional system is at the upper critical dimension where mean field theory for critical exponents is expected to hold. Possible reasons for this discrepancy are discussed in the light of fresh insights into the nature of near critical finite-size effects.

Drying and wetting transitions of a Lennard-Jones fluid: Simulations and density functional theory.

PubMed

Evans, Robert; Stewart, Maria C; Wilding, Nigel B

2017-07-28

We report a theoretical and simulation study of the drying and wetting phase transitions of a truncated Lennard-Jones fluid at a flat structureless wall. Binding potential calculations predict that the nature of these transitions depends on whether the wall-fluid attraction has a long ranged (LR) power law decay or is instead truncated, rendering it short ranged (SR). Using grand canonical Monte Carlo simulation and classical density functional theory, we examine both cases in detail. We find that for the LR case wetting is first order, while drying is continuous (critical) and occurs exactly at zero attractive wall strength, i.e., in the limit of a hard wall. In the SR case, drying is also critical but the order of the wetting transition depends on the truncation range of the wall-fluid potential. We characterize the approach to critical drying and wetting in terms of the density and local compressibility profiles and via the finite-size scaling properties of the probability distribution of the overall density. For the LR case, where the drying point is known exactly, this analysis allows us to estimate the exponent ν ∥ , which controls the parallel correlation length, i.e., the extent of vapor bubbles at the wall. Surprisingly, the value we obtain is over twice that predicted by mean field and renormalization group calculations, despite the fact that our three dimensional system is at the upper critical dimension where mean field theory for critical exponents is expected to hold. Possible reasons for this discrepancy are discussed in the light of fresh insights into the nature of near critical finite-size effects.

Emplacement of the Cabezo María lamproite volcano (Miocene, SE Spain)

NASA Astrophysics Data System (ADS)

Gernon, Thomas M.; Spence, Samuel; Trueman, Clive N.; Taylor, Rex N.; Rohling, Eelco; J. Hatter, Stuart; Harding, Ian C.

2015-06-01

Lamproite volcanoes are uncommon in the geological record but are exceptionally well preserved in the Betic Cordilleras of SE Spain, where they erupted during the Late Miocene (Tortonian to Messinian stages). The parent melts are thought to have been channelled through major lithospheric faults to erupt at or near the faulted margins of Neogene sedimentary basins. Lamproite magmas are thought to be relatively CO2-poor (<1 wt %) and are typically characterised by an effusive eruption style and the development of lava lakes and scoria cones. Cabezo María is a relatively small (˜550 m diameter) lamproite volcano that was emplaced within the shallow-water marine-influenced Vera Basin. The lamproites are compositionally similar to those of the Roman Province and generally less potassic (K2O<5 wt%) than other (ultra-) potassic rocks in SE Spain (e.g. Cancarix, Fortuna). The initial eruption stages were dominated by explosive magma-water interactions and the formation of peperites. These are characterised by angular fragments of glassy lamproite lavas (and isolated lobes) incorporated in sediments, locally showing the effects of thermal metamorphism. Further, elutriation pipes and `jigsaw-fit' textures are observed in the peperites. The lavas and peperites are overlain by outward-dipping well-stratified scoria deposits defining part of a cinder cone, which is inferred to have emerged above sea level. Steep internal contacts with inward-dipping, structureless breccias likely represent the inner wall deposits of a central conduit. The deposits are cross-cut by late-stage dykes, which supplied fissure eruptions of geochemically similar lavas capping the scoria cone. The transition from explosive to effusive behaviour may reflect the decreased availability of water, possibly due to downward migration of the feeder conduit below the level of water-saturated sediments.

Identification of ribozymes within a ribozyme library that efficiently cleave a long substrate RNA.

PubMed Central

Campbell, T B; Cech, T R

1995-01-01

Positions 2-6 of the substrate-binding internal guide sequence (IGS) of the L-21 Sca I form of the Tetrahymena thermophila intron were mutagenized to produce a GN5 IGS library. Ribozymes within the GN5 library capable of efficient cleavage of an 818-nt human immunodeficiency virus type 1 vif-vpr RNA, at 37 degrees C, were identified by ribozyme-catalyzed guanosine addition to the 3' cleavage product. Three ribozymes (IGS = GGGGCU, GGCUCC, and GUGGCU) within the GN5 library that actively cleaved the long substrate were characterized kinetically and compared to the wild-type ribozyme (GGAGGG) and two control ribozymes (GGAGUC and GGAGAU). The two control ribozymes have specific sites within the long substrate, but were not identified during screening of the library. Under single-turnover conditions, ribozymes GGGGCU, GGCUCC, and GUGGCU cleaved the 818-nt substrate 4- to 200-fold faster than control ribozymes. Short cognate substrates, which should be structureless and therefore accessible to ribozyme binding, were cleaved at similar rates by all ribozymes except GGGGCU, which showed a fourfold rate enhancement. The rate of cleavage of long relative to short substrate under single-turnover conditions suggests that GGCUCC and GUGGCU were identified because of accessibility to their specific cleavage sites within the long substrate (substrate-specific effects), whereas GGGGCU was identified because of an enhanced rate of substrate binding despite a less accessible site in the long substrate. Even though screening was performed with 100-fold excess substrate (relative to total ribozyme), the rate of multiple-turnover catalysis did not contribute to identification of trans-cleaving ribozymes in the GN5 library. PMID:7489519

Case Report: Dermoscopic features of oral lichen planus - the evolution of mucoscopy.

PubMed

Sonthalia, Sidharth; Varma, Sangeeta; Jha, Abhijeet Kumar; Jakhar, Deepak; Kaliyadan, Feroze

2018-01-01

Dermoscopy, a non-invasive technique for cutaneous diagnosis is being increasingly studied in various disorders of the skin, nails and scalp. However, it has been under-utilized for the diagnosis and characterization of mucosal disorders. The dermoscopic characterization of cutaneous lichen planus and its variants has been well documented with Wickham's striae constituting the hallmark of the condition. However, the dermoscopic features of oral lichen planus with hand-held or videodermoscopy remain to be elucidated. We present the case of a young adult man who presented with asymptomatic white lacy lesions over a bluish-black background over the tongue, patchy hyperpigmentation of the buccal mucosae and gingivae, and longitudinal melanonychia involving some nails. History of intake of any drugs preceding the lesions, smoking, chewing of betel nut and dental implants was negative. Family history was non-contributory. There were no cutaneous lesions suggestive of lichen planus. Mucoscopy (dermoscopy of the mucosa, oral in this case) and onychoscopy were done followed by biopsy from the tongue that confirmed the diagnosis of lichen planus. Oral mucoscopy of the tongue revealed a tri-colored pattern with structureless veil-like grey-white areas (modified Wickham's striae), well-demarcated red glossy erosions, and violaceous-to-brown clods. Additionally, vascular pattern of dotted and linear to curved vessels along the borders of leukoplakia-like areas and erosions were observed. Onychoscopy confirmed lichen planus-associated melanonychia. Dermoscopy also proved useful in conveniently ruling out other disorders typified by mucosal and nail pigmentation such as Laugier Hunziker syndrome and drug-induced changes. Although direct oral microscopy has been used in defining features of oral lichen planus, to the best of our knowledge this case is the first report on mucoscopy or dermoscopy of oral lichen planus.

Excited states of aniline by photoabsorption spectroscopy in the 30,000-90,000 cm(-1) region using synchrotron radiation.

PubMed

Rajasekhar, B N; Veeraiah, A; Sunanda, K; Jagatap, B N

2013-08-14

The photoabsorption spectrum of aniline (C6H5NH2) in gas phase in the 30,000-90,000 cm(-1) (3.7-11.2 eV) region is recorded at resolution limit of 0.008 eV using synchrotron radiation source for the first time to comprehend the nature of the excited valence and Rydberg states. The first half of the energy interval constitutes the richly structured valence transitions from the ground to excited states up to the first ionization potential (IP) at 8.02 eV. The spectrum in the second half consists of vibrational features up to second IP (9.12 eV) and structureless broad continuum up to the third IP (10.78 eV). The electronic states are assigned mainly to the singlets belonging to π → π* transitions. A few weak initial members of Rydberg states arising from π → 4s, np or nd transitions are also identified. Observed vibrational features are assigned to transitions from the ground state A' to the excited states 1A", 3A', 5A", 6A', and 10A" in C(s) symmetry. Time dependent density functional theory (TDDFT) calculations at B3LYP level of theory are employed to obtain the vertical excitation energies and the symmetries of the excited states in equilibrium configuration. The computed values of the transition energies agree fairly well with the experimental data. Further the calculated oscillator strengths are used to substantiate the assignments of the bands. The work provides a comprehensive picture of the vacuum ultraviolet photoabsorption spectrum of aniline up to its third ionization limit.

Colloid transport in dual-permeability media

NASA Astrophysics Data System (ADS)

Leij, Feike J.; Bradford, Scott A.

2013-07-01

It has been widely reported that colloids can travel faster and over longer distances in natural structured porous media than in uniform structureless media used in laboratory studies. The presence of preferential pathways for colloids in the subsurface environment is of concern because of the increased risks for disease caused by microorganisms and colloid-associated contaminants. This study presents a model for colloid transport in dual-permeability media that includes reversible and irreversible retention of colloids and first-order exchange between the aqueous phases of the two regions. The model may also be used to describe transport of other reactive solutes in dual-permeability media. Analytical solutions for colloid concentrations in aqueous and solid phases were obtained using Laplace transformation and matrix decomposition. The solutions proved convenient to assess the effect of model parameters on the colloid distribution. The analytical model was used to describe effluent concentrations for a bromide tracer and 3.2- or 1-μm-colloids that were observed after transport through a composite 10-cm long porous medium made up of a cylindrical lens or core of sand and a surrounding matrix with sand of a different grain size. The tracer data were described very well and realistic estimates were obtained for the pore-water velocity in the two flow domains. An accurate description was also achieved for most colloid breakthrough curves. Dispersivity and retention parameters were typically greater for the larger 3.2-μm-colloids while both reversible and irreversible retention rates tended to be higher for the finer sands than the coarser sand. The relatively small sample size and the complex flow pattern in the composite medium made it difficult to reach definitive conclusions regarding transport parameters for colloid transport.

Ionization and dissociation of molecular ion beams by intense ultrafast laser pulses

NASA Astrophysics Data System (ADS)

Ben-Itzhak, Itzik

2007-06-01

Laser-induced dissociation and ionization of a diatomic molecular-ion beam were simultaneously measured using coincidence 3D momentum imaging, with direct separation of the two processes even where the fragment kinetic energy is the same for both processes. We mainly focus on the fundamental H2^+ molecule in 7-135 fs laser pulses having 10^13-10^15 W/cm^2 peak intensity. At high intensities the kinetic energy release (KER) distribution following ionization of H2^+ was measured to be broad and structureless. Its centroid shifts toward higher energies as the laser intensity is increased indicating that ionization shifts to smaller internuclear distances. In contrast, a surprising structure is observed near the ionization threshold, which we call above threshold Coulomb explosion (ATCE) [1]. The angular distributions of the two H^+ fragments are strongly peaked along the laser polarization, and the angular distribution is described well by [cos^2θ]^n, where n is the number of photons predicted by our ATCE model [1]. Our data indicates that n varies with the laser wavelength as predicted by the model. The KER and angular distributions of H2^+ dissociation change dramatically with decreasing pulse width over the 7-135 fs range in contrast to the reported trend for longer pulses. Others contributing to this work: A.M. Sayler, P.Q. Wang, J. McKenna, B. Gaire, Nora G. Johnson, E. Parke, K.D. Carnes, and B.D. Esry. Thank are due to Professor Zenghu Chang for providing the intense laser beams and Dr. Charles Fehrenbach for his help with the ion beams. [1] B.D. Esry, A.M. Sayler, P.Q. Wang, K.D. Carnes, and I. Ben-Itzhak, Phys. Rev. Lett. 97, 013003 (2006).

Crevasse splay processes and deposits in an ancient distributive fluvial system: The lower Beaufort Group, South Africa

NASA Astrophysics Data System (ADS)

Gulliford, Alice R.; Flint, Stephen S.; Hodgson, David M.

2017-08-01

Up to 12% of the mud-prone, ephemeral distributive fluvial system stratigraphy in the Permo-Triassic lower Beaufort Group, South Africa, comprises tabular fine-grained sandstone to coarse-grained siltstone bodies, which are interpreted as proximal to distal crevasse splay deposits. Crevasse splay sandstones predominantly exhibit ripple to climbing ripple cross-lamination, with some structureless and planar laminated beds. A hierarchical architectural scheme is adopted, in which 1 m thick crevasse splay elements extend for tens to several hundreds of meters laterally, and stack with other splay elements to form crevasse splay sets up to 4 m thick and several kilometers in width and length. Paleosols and nodular horizons developed during periods, or in areas, of reduced overbank flooding are used to subdivide the stratigraphy, separating crevasse splay sets. Deposits from crevasse splays differ from frontal splays as their proximal deposits are much thinner and narrower, with paleocurrents oblique to the main paleochannel. In order for crevasse splay sets to develop, the parent channel belt and the location where crevasse splays form must stay relatively fixed during a period of multiple flood events. Beaufort Group splays have similar geometries to those of contemporary perennial rivers but exhibit more lateral variability in facies, which is interpreted to be the result of more extreme fluctuations in discharge regime. Sharp-based crevasse splay packages are associated with channel avulsion, but most are characterized by a gradual coarsening upward, interpreted to represent progradation. The dominance of progradational splays beneath channel belt deposits may be more characteristic of progradational stratigraphy in a distributive fluvial system rather than dominated by avulsion processes in a trunk river system. This stratigraphic motif may therefore be an additional criterion for recognition of distributive fluvial systems in the ancient record.

Detrital and oceanic dysoxia influence on OAE2 sediment geochemistry from Tarfaya, SW Morocco

NASA Astrophysics Data System (ADS)

Turgeon, S. C.; Kolonic, S.; Brumsack, H.-J.; Wagner, T.

2003-04-01

The Cretaceous "greenhouse" world's stratigraphic record is punctuated by several important organic-rich intervals representing quasi-global "Oceanic Anoxic Events" (OAEs). This study focuses on sediments from Tarfaya in SW Morocco deposited during the Cenomanian-Turonian Boundary Event (CTBE or OAE2 at 93.5 Ma). These sediments consist of distinctly laminated, carbonate-rich black shales alternating with lighter coloured structureless intervals and sporadic chert lenses. Sediments from three sites representing proximal to distal settings were studied. Samples were analysed for Ctot, Corg, Stot, as well as several major-, minor- and trace elements using XRF and ICP-MS. These sediments are characterised by high Corg, Stot, and CaCO3 contents and consist of a simple two component mixing system ("average shale"-CaCO3). Major element concentrations are low, except for Ca and P, owing in part to the carbonate dilution effect. Most elements plot along "average shale" lines. Elements such as Si, Ti, Fe, K, Rb, and Zr show positive relationships with Al2O3, pointing to homogeneous source area material. Several Al-normalised elements (As, Ba, Cr, Cu, Ni, Sr, U, V, Y, Zn), many of them redox-sensitive or sulphide-residing, are enriched in the sediments indicating an oxygen-depleted environment and potential availability of hydrogen sulfide in the water column at the time of deposition. High Zn concentrations suggest increased submarine volcanism and/or hydrothermal activity during this time interval. High Ba concentrations are possibly indicative of high regional paleoproductivity, which is further supported by the elevated P concentrations hinting at nutrient availability. Basinward trends in the geochemical distribution of some elements are apparent and probably reflect the decreasing influence of terrestrial sediments away from the shoreline.

Semiflexible polymers confined in a slit pore with attractive walls: two-dimensional liquid crystalline order versus capillary nematization.

PubMed

Milchev, Andrey; Egorov, Sergei A; Binder, Kurt

2017-03-01

Semiflexible polymers under good solvent conditions interacting with attractive planar surfaces are investigated by Molecular Dynamics (MD) simulations and classical Density Functional Theory (DFT). A bead-spring type potential complemented by a bending potential is used, allowing variation of chain stiffness from completely flexible coils to rod-like polymers whose persistence length by far exceeds their contour length. Solvent is only implicitly included, monomer-monomer interactions being purely repulsive, while two types of attractive wall-monomer interactions are considered: (i) a strongly attractive Mie-type potential, appropriate for a strictly structureless wall, and (ii) a corrugated wall formed by Lennard-Jones particles arranged on a square lattice. It is found that in dilute solutions the former case leads to the formation of a strongly adsorbed surface layer, and the profile of density and orientational order in the z-direction perpendicular to the wall is predicted by DFT in nice agreement with MD. While for very low bulk densities a Kosterlitz-Thouless type transition from the isotropic phase to a phase with power-law decay of nematic correlations is suggested to occur in the strongly adsorbed layer, for larger densities a smectic-C phase in the surface layer is detected. No "capillary nematization" effect at higher bulk densities is found in this system, unlike systems with repulsive walls. This finding is attributed to the reduction of the bulk density (in the center of the slit pore) due to polymer adsorption on the attractive wall, for a system studied in the canonical ensemble. Consequently in a system with two attractive walls nematic order in the slit pore can occur only at a higher density than for a bulk system.

Nonradiative Decay Route of Cinnamate Derivatives Studied by Frequency and Time Domain Laser Spectroscopy in the Gas Phase, Matrix Isolation FTIR Spectroscopy and Quantum Chemical Calculations

NASA Astrophysics Data System (ADS)

Ebata, Takayuki

2017-06-01

The nonraddiative dececy route involving trans → cis photo-isomerization from the S_1 (ππ*) state has been investigated for several trans-cinnamate derivatives, which are known as sunscreen reagents. We examined two types of substitution effects. One is structural isomer such as ortho-, meta-, and para-hydroxy-methylcinnmate (o-, m-, p-HMC). The S_1 lifetime of p-HMC is less than 8 ps at zero-point level, and it undergoes rapid S_1 → ^1nπ* → T_1 decay via multiple conical intersections. Finally, the trans → cis isomerization proceeds in the T_1 state. On the other hand, both o- and m-HMC show very slow decay. Their S_1 lifetimes are in the order of 100 ps even at the excess energy of 2000-3000 \\wn. The other is the effect of the complexity of ester group in para-subsitituted species, such as para-methoxy-methyl, -ethyl and -2ethylhexyl cinnamate (p-MMC, p-MEC, p-M2EHC). p-MMC and p-MEC show sharp S_0 → S_1 (ππ*) vibronic bands, while p-M2EHC shows only broad structureless feature even under the jet-cooled condition. In addition, we found that the S_0 → ^1nπ* absorption appears at 1000 \\wn below the S_0 → S_1 (ππ*) transition in p-MEC and p-M2EHC, but not in p-MMC. Thus, the complexity of the ester group is very important for the appearance of the ^1nπ* state.

Monte Carlo computer simulation of sedimentation of charged hard spherocylinders.

PubMed

Viveros-Méndez, P X; Gil-Villegas, Alejandro; Aranda-Espinoza, S

2014-07-28

In this article we present a NVT Monte Carlo computer simulation study of sedimentation of an electroneutral mixture of oppositely charged hard spherocylinders (CHSC) with aspect ratio L/σ = 5, where L and σ are the length and diameter of the cylinder and hemispherical caps, respectively, for each particle. This system is an extension of the restricted primitive model for spherical particles, where L/σ = 0, and it is assumed that the ions are immersed in an structureless solvent, i.e., a continuum with dielectric constant D. The system consisted of N = 2000 particles and the Wolf method was implemented to handle the coulombic interactions of the inhomogeneous system. Results are presented for different values of the strength ratio between the gravitational and electrostatic interactions, Γ = (mgσ)/(e(2)/Dσ), where m is the mass per particle, e is the electron's charge and g is the gravitational acceleration value. A semi-infinite simulation cell was used with dimensions Lx ≈ Ly and Lz = 5Lx, where Lx, Ly, and Lz are the box dimensions in Cartesian coordinates, and the gravitational force acts along the z-direction. Sedimentation effects were studied by looking at every layer formed by the CHSC along the gravitational field. By increasing Γ, particles tend to get more packed at each layer and to arrange in local domains with an orientational ordering along two perpendicular axis, a feature not observed in the uncharged system with the same hard-body geometry. This type of arrangement, known as tetratic phase, has been observed in two-dimensional systems of hard-rectangles and rounded hard-squares. In this way, the coupling of gravitational and electric interactions in the CHSC system induces the arrangement of particles in layers, with the formation of quasi-two dimensional tetratic phases near the surface.

Undersea landslides: Extent and significance in the Pacific Ocean, an update

USGS Publications Warehouse

Lee, H.J.

2005-01-01

Submarine landslides are known to occur disproportionately in a limited number of environments including fjords, deltas, canyons, volcanic islands and the open continental slope. An evaluation of the progress that has been made in understanding Pacific Ocean submarine landslides over the last 15 years shows that mapping technologies have improved greatly, allowing a better interpretation of landslide features. Some features previously identified as landslides are being reinterpreted by some as sediment waves. Previously underappreciated environments for landslides such as deep-sea trenches are being recognized and lava deltas are being found to be landslide prone. Landslides are also being recognized much more commonly as a potential source of tsunamis. Landslides that have produced tsunamis in the past are being mapped and in some cases modeled. The flow characteristics of turbidity currents produced by landslides in canyon heads have recently been monitored and the source of these failures has been identified using repeated multibeam mapping. Finally, some landslide deposits are being dated as part of assessing risk to coastal cities from landslide-tsunamis. European Geosciences Union ?? 2005 Author(s). This work is licensed under a Creative Commons License.

Animal scavenging and scattering and the implications for documenting the deaths of undocumented border crossers in the Sonoran Desert.

PubMed

Beck, Jess; Ostericher, Ian; Sollish, Gregory; De León, Jason

2015-01-01

Since 1998, over 5500 people have died while attempting to cross the U.S.-Mexico border without authorization. These deaths have primarily occurred in the Arizona desert. Despite the high volume of deaths, little experimental work has been conducted on Sonoran Desert taphonomy. In this study, pig carcasses were used as proxies for human remains and placed in different depositional contexts (i.e., direct sunlight and shade) that replicate typical sites of migrant death. Decomposition was documented through daily site visits, motion-sensitive cameras and GIS mapping, while skeletal preservation was investigated through the collection of the remains and subsequent faunal analysis. Our results suggest that vultures and domestic dogs are underappreciated members of the Sonoran scavenging guild and may disperse skeletal remains and migrant possessions over 25 m from the site of death. The impact of scavengers and the desert environment on the decomposition process has significant implications for estimating death rates and identifying human remains along the Arizona/Mexico border. © 2014 American Academy of Forensic Sciences.

Anthropology from a Kantian point of view: toward a cosmopolitan conception of human nature.

PubMed

Louden, Robert B

2008-12-01

Anthropology was a new field of study when Kant first began lecturing on it in 1772, and Kant himself was the first academic to teach regular courses in this area. As is well known, his own approach to anthropology is self-described as 'pragmatic', and Kant's pragmatic anthropology differs markedly from the anthropologies that other early contributors to the new discipline were advocating. In this essay I focus on a fundamental feature of Kant's anthropology that has been under-appreciated in previous discussions; namely, the particular conception of human nature that he believes anthropology, when pursued properly, leads to. I call this conception a cosmopolitan conception of human nature. In addition to establishing the central importance of this idea for Kant's project in anthropology, I also try in this essay to unravel some of its ambiguities and tensions as well as to highlight its underlying moral motives. The cosmopolitan conception of human nature that is central to Kant's anthropology is a further indication of the significance of his anthropology for ethics.

Ecosystem services and agriculture: tradeoffs and synergies

PubMed Central

Power, Alison G.

2010-01-01

Agricultural ecosystems provide humans with food, forage, bioenergy and pharmaceuticals and are essential to human wellbeing. These systems rely on ecosystem services provided by natural ecosystems, including pollination, biological pest control, maintenance of soil structure and fertility, nutrient cycling and hydrological services. Preliminary assessments indicate that the value of these ecosystem services to agriculture is enormous and often underappreciated. Agroecosystems also produce a variety of ecosystem services, such as regulation of soil and water quality, carbon sequestration, support for biodiversity and cultural services. Depending on management practices, agriculture can also be the source of numerous disservices, including loss of wildlife habitat, nutrient runoff, sedimentation of waterways, greenhouse gas emissions, and pesticide poisoning of humans and non-target species. The tradeoffs that may occur between provisioning services and other ecosystem services and disservices should be evaluated in terms of spatial scale, temporal scale and reversibility. As more effective methods for valuing ecosystem services become available, the potential for ‘win–win’ scenarios increases. Under all scenarios, appropriate agricultural management practices are critical to realizing the benefits of ecosystem services and reducing disservices from agricultural activities. PMID:20713396

Teaching Physics Through Comic Books

NASA Astrophysics Data System (ADS)

Thompson, Rebecca

2011-04-01

Comics have been around as a form of entertainment for decades. They are often as seen as one of the distracting vices of kids (and adults!), but comics and their more adult version, the graphic novel, are increasingly valued as a legitimate genre of literature. The APS Outreach Department has created three comic books, one featuring Nikola Tesla and his battles with the evil Thomas Edison, and two about laser super hero Spectra and her continuing battles with the nefarious Miss Alignment. These comics have struck a delicate balance between education and entertainment being well received by both the comic book and education communities. By creating a compelling comic story that has correct physics, it is possible to use this under-appreciated medium to excite middle-school students who might otherwise be turned off by traditional teaching methods. One lesson-learned is that It is very important to make sure first and foremost that the students enjoy the story and that they feel a connection to the characters. Students are thus hooked and once they are drawn in, the learning happens automatically.

Teaching Physics Through Comic Books

NASA Astrophysics Data System (ADS)

Thompson, Rebecca; Owen, Tassia

2011-03-01

Comics have been around as a form of entertainment for decades. They are often as seen as one of the distracting vices of kids (and adults!), but comics and their more adult version, the graphic novel, are increasingly valued as a legitimate genre of literature. The APS Outreach Department has created three comic books, one featuring Nikola Tesla and his battles with the evil Thomas Edison, and two about laser super hero Spectra and her continuing battles with the nefarious Miss Alignment. These comics have struck a delicate balance between education and entertainment being well received by both the comic book and education communities. By creating a compelling comic story that has correct physics, it is possible to use this under-appreciated medium to excite middle-school students who might otherwise be turned off by traditional teaching methods. One lesson-learned is that It is very important to make sure first and foremost that the students enjoy the story and that they feel a connection to the characters. Students are thus hooked and once they are drawn in, the learning happens automatically..

Redundant functions of I-BAR family members, IRSp53 and IRTKS, are essential for embryonic development

PubMed Central

Chou, Ai Mei; Sem, Kai Ping; Lam, Wei Jun; Ahmed, Sohail; Lim, Chin Yan

2017-01-01

The insulin receptor substrate of 53 kDa, IRSp53, is an adaptor protein that works with activated GTPases, Cdc42 and Rac, to modulate actin dynamics and generate membrane protrusions in response to cell signaling. Adult mice that lack IRSp53 fail to regulate synaptic plasticity and exhibit hippocampus-associated learning deficiencies. Here, we show that 60% of IRSp53 null embryos die at mid to late gestation, indicating a vital IRSp53 function in embryonic development. We find that IRSp53 KO embryos displayed pleiotropic phenotypes such as developmental delay, oligodactyly and subcutaneous edema, and died of severely impaired cardiac and placental development. We further show that double knockout of IRSp53 and its closest family member, IRTKS, resulted in exacerbated placental abnormalities, particularly in spongiotrophoblast differentiation and development, giving rise to complete embryonic lethality. Hence, our findings demonstrate a hitherto under-appreciated IRSp53 function in embryonic development, and further establish an essential genetic interaction between IRSp53 and IRTKS in placental formation. PMID:28067313

The gender gap in science: How long until women are equally represented?

PubMed Central

Stuart-Fox, Devi; Hauser, Cindy E.

2018-01-01

Women comprise a minority of the Science, Technology, Engineering, Mathematics, and Medicine (STEMM) workforce. Quantifying the gender gap may identify fields that will not reach parity without intervention, reveal underappreciated biases, and inform benchmarks for gender balance among conference speakers, editors, and hiring committees. Using the PubMed and arXiv databases, we estimated the gender of 36 million authors from >100 countries publishing in >6000 journals, covering most STEMM disciplines over the last 15 years, and made a web app allowing easy access to the data (https://lukeholman.github.io/genderGap/). Despite recent progress, the gender gap appears likely to persist for generations, particularly in surgery, computer science, physics, and maths. The gap is especially large in authorship positions associated with seniority, and prestigious journals have fewer women authors. Additionally, we estimate that men are invited by journals to submit papers at approximately double the rate of women. Wealthy countries, notably Japan, Germany, and Switzerland, had fewer women authors than poorer ones. We conclude that the STEMM gender gap will not close without further reforms in education, mentoring, and academic publishing. PMID:29672508

Terrestrial Micro Renewable Energy Applications of Space Technology

NASA Astrophysics Data System (ADS)

Komerath, N. M.; Komerath, P. P.

This paper explores the synergy between technologies intended for extraterrestrial in situ resource utilization and those for terrestrial mass-market micro renewable power generation systems. The case for a micro renewable energy architecture is presented. The obstacles hindering market success are summarized, along with opportunities from recent demonstrations suggesting that the public appetite for sophisticated technology worldwide may be underappreciated by technical researchers. Technical innovations from space research are summarized along with estimates of possible conversion efficiencies. It is argued that the cost-effectiveness of micro power generation must be viewed through the value of the first few watts of available power, rather than the marginal cost per kilowatt-hour of electric power from utility power grids. This leads to the finding that the actual target cost per unit power, and efficiency, are well within reach of space technology products. Hybrid systems integrating power extraction from multiple resources, and adaptable for multiple applications, can break through mass market price barriers. Recent work to develop learning resources and test beds as part of a Micro Renewable Energy Laboratory is summarized.

Equality and quality in education. A comparative study of 19 countries.

PubMed

Pfeffer, Fabian T

2015-05-01

This contribution assesses the performance of national education systems along two important dimensions: The degree to which they help individuals develop capabilities necessary for their successful social integration (educational quality) and the degree to which they confer equal opportunities for social advancement (educational equality). It advances a new conceptualization to measure quality and equality in education and then uses it to study the relationship between institutional differentiation and these outcomes. It relies on data on final educational credentials and literacy among adults that circumvent some of the under-appreciated conceptual challenges entailed in the widespread analysis of international student assessment data. The analyses reveal a positive relationship between educational quality and equality and show that education systems with a lower degree of institutional differentiation not only provide more educational equality but are also marked by higher levels of educational quality. While the latter association is partly driven by other institutional and macro-structural factors, I demonstrate that the higher levels of educational equality in less differentiated education systems do not entail an often-assumed trade-off for lower quality. Copyright © 2014 Elsevier Inc. All rights reserved.

Incidence of Low Body Mass Index in the Elderly in Forensic Cases-A Possible Marker for Frailty Syndrome?

PubMed

Byard, Roger W; Bellis, Maria

2016-05-01

Diagnosing frailty syndrome at autopsy may be difficult if no adequate clinical history is provided. As low body mass index (BMI) may be associated with frailty in the elderly, the following study was undertaken to determine the percentage of medicolegal cases with BMIs < 18.5 in decedents aged over 75 years. Review was undertaken over three time periods: January to December 1986, January to December 2006, and January to December 2012. In 1986, 16% (15 of 93) of individuals aged ≥75 years had BMIs < 18.5, in 2006, 15% (50 of 336), and in 2012, 13% (35 of 274). In no case was frailty syndrome mentioned. This study demonstrates that frailty syndrome appears to be an underappreciated diagnosis in forensic practice despite a significant percentage of elderly decedents (13-16% over a 27-year period) having low BMIs. Prospective assessment of this group is required to determine the incidence and contribution to mortality of frailty syndrome in a forensic context. © 2016 American Academy of Forensic Sciences.

Airplane tracking documents the fastest flight speeds recorded for bats.

PubMed

McCracken, Gary F; Safi, Kamran; Kunz, Thomas H; Dechmann, Dina K N; Swartz, Sharon M; Wikelski, Martin

2016-11-01

The performance capabilities of flying animals reflect the interplay of biomechanical and physiological constraints and evolutionary innovation. Of the two extant groups of vertebrates that are capable of powered flight, birds are thought to fly more efficiently and faster than bats. However, fast-flying bat species that are adapted for flight in open airspace are similar in wing shape and appear to be similar in flight dynamics to fast-flying birds that exploit the same aerial niche. Here, we investigate flight behaviour in seven free-flying Brazilian free-tailed bats ( Tadarida brasiliensis ) and report that the maximum ground speeds achieved exceed speeds previously documented for any bat. Regional wind modelling indicates that bats adjusted flight speeds in response to winds by flying more slowly as wind support increased and flying faster when confronted with crosswinds, as demonstrated for insects, birds and other bats. Increased frequency of pauses in wing beats at faster speeds suggests that flap-gliding assists the bats' rapid flight. Our results suggest that flight performance in bats has been underappreciated and that functional differences in the flight abilities of birds and bats require re-evaluation.

An Underappreciated Radiation Hazard from High Voltage Electrodes in Vacuum.

PubMed

West, Adam D; Lasner, Zack; DeMille, David; West, Elizabeth P; Panda, Cristian D; Doyle, John M; Gabrielse, Gerald; Kryskow, Adam; Mitchell, Corinne

2017-01-01

The use of high voltage (HV) electrodes in vacuum is commonplace in physics laboratories. In such systems, it has long been known that electron emission from an HV cathode can lead to bremsstrahlung x rays; indeed, this is the basic principle behind the operation of standard x-ray sources. However, in laboratory setups where x-ray production is not the goal and no electron source is deliberately introduced, field-emitted electrons accelerated by HV can produce x rays as an unintended hazardous byproduct. Both the level of hazard and the safe operating regimes for HV vacuum electrode systems are not widely appreciated, at least in university laboratories. A reinforced awareness of the radiation hazards associated with vacuum HV setups would be beneficial. The authors present a case study of a HV vacuum electrode device operated in a university atomic physics laboratory. They describe the characterization of the observed x-ray radiation, its relation to the observed leakage current in the device, the steps taken to contain and mitigate the radiation hazard, and suggested safety guidelines.

The gender gap in science: How long until women are equally represented?

PubMed

Holman, Luke; Stuart-Fox, Devi; Hauser, Cindy E

2018-04-01

Women comprise a minority of the Science, Technology, Engineering, Mathematics, and Medicine (STEMM) workforce. Quantifying the gender gap may identify fields that will not reach parity without intervention, reveal underappreciated biases, and inform benchmarks for gender balance among conference speakers, editors, and hiring committees. Using the PubMed and arXiv databases, we estimated the gender of 36 million authors from >100 countries publishing in >6000 journals, covering most STEMM disciplines over the last 15 years, and made a web app allowing easy access to the data (https://lukeholman.github.io/genderGap/). Despite recent progress, the gender gap appears likely to persist for generations, particularly in surgery, computer science, physics, and maths. The gap is especially large in authorship positions associated with seniority, and prestigious journals have fewer women authors. Additionally, we estimate that men are invited by journals to submit papers at approximately double the rate of women. Wealthy countries, notably Japan, Germany, and Switzerland, had fewer women authors than poorer ones. We conclude that the STEMM gender gap will not close without further reforms in education, mentoring, and academic publishing.

Native gold in Hawaiian alkalic magma

USGS Publications Warehouse

Sisson, T.W.

2003-01-01

Native gold found in fresh basanite glass from the early submarine phase of Kilauea volcano, Hawaii, may be the first documented case of the transport of gold as a distinct precious metal phase in a mantle-derived magma. The gold-bearing glass is a grain in bedded volcanic glass sandstone (Japan Marine Science and Technology Center (JAMSTEC) sample S508-R3) collected by the submersible Shinkai 6500 at 3879 m depth off Kilauea's south flank. Extensive outcrops there expose debris-flow breccias and sandstones containing submarine-erupted alkalic rock fragments and glasses from early Kilauea. Precipitation of an immiscible gold liquid resulted from resorption of magmatic sulfides during crystallization-differentiation, with consequent liberation of sulfide-hosted gold. Elevated whole-rock gold concentrations (to 36 ppb) for fresh lavas and clasts from early Kilauea further show that some magmas erupted at the beginning stages of Hawaiian shield volcanoes were distinctly gold rich, most likely owing to limited residual sulfide in their mantle source. Alkalic magmas at other ocean islands may also be gold rich, and oceanic hot-spot provinces may contain underappreciated gold resources.

Llewellyn Hilleth Thomas: An appraisal of an under-appreciated polymath

NASA Astrophysics Data System (ADS)

Jackson, John David

2010-02-01

Llewellyn Hilleth Thomas was born in 1903 and died in 1992 at the age of 88. His name is known by most for only two things, Thomas precession and the Thomas-Fermi atom. The many other facets of his career - astrophysics, atomic and molecular physics, nonlinear problems, accelerator physics, magnetohydrodynamics, computer design principles and software and hardware - are largely unknown or forgotten. I review his whole career - his early schooling, his time at Cambridge, then Copenhagen in 1925-26, and back to Cambridge, his move to the US as an assistant professor at Ohio State University in 1929, his wartime years at the Ballistic Research Laboratory, Aberdeen Proving Grounds, then in 1946 his new career as a unique resource at IBM's Watson Scientific Computing Laboratory and Columbia University until his first retirement in 1968, and his twilight years at North Carolina State University. Although the Thomas precession and the Thomas-Fermi atom may be the jewels in his crown, his many other accomplishments add to our appreciation of this consummate applied mathematician and physicist. )

Tuberculous otitis in infants: temporal bone histopathology and clinical extrapolation.

PubMed

Nicolau, Yamileth; Northrop, Clarinda; Eavey, Roland

2006-08-01

The study of infant temporal bones with tuberculosis (TB) of the middle ear and mastoid could provide information to assist with clinical diagnosis in this population. The TB pandemic has become a critical global public health problem. With the rising incidence of the disease, otolaryngologists might encounter an increased frequency of otologic TB. Pediatric temporal bone reports of TB are rare. Light microscopic examination was performed on both temporal bones from an infant who died as a result of miliary TB. The tympanic membranes were thickened with dilated blood vessels, yet were intact without perforations. Purulence, granulation tissue, and classic tubercles were observed in the middle ears and mastoids. Serous labyrinthitis and inflammatory cells surrounding the Cranial Nerve VIII in the internal auditory canal were observed in the inner ear. The histological findings suggest that a clinical presentation of infantile tuberculous otitis media and mastoiditis could be a patient with otoscopic findings consistent with common otitis media with an intact tympanic membrane, likely in conjunction with inner ear symptoms. Lacking the classic finding of multiple tympanic membrane perforations, tuberculous otitis might be underappreciated in this population.

Cahokia’s emergence and decline coincided with shifts of flood frequency on the Mississippi River

PubMed Central

Munoz, Samuel E.; Gruley, Kristine E.; Massie, Ashtin; Fike, David A.; Schroeder, Sissel; Williams, John W.

2015-01-01

Here we establish the timing of major flood events of the central Mississippi River over the last 1,800 y, using floodwater sediments deposited in two floodplain lakes. Shifts in the frequency of high-magnitude floods are mediated by moisture availability over midcontinental North America and correspond to the emergence and decline of Cahokia—a major late prehistoric settlement in the Mississippi River floodplain. The absence of large floods from A.D. 600 to A.D. 1200 facilitated agricultural intensification, population growth, and settlement expansion across the floodplain that are associated with the emergence of Cahokia as a regional center around A.D. 1050. The return of large floods after A.D. 1200, driven by waning midcontinental aridity, marks the onset of sociopolitical reorganization and depopulation that culminate in the abandonment of Cahokia and the surrounding region by A.D. 1350. Shifts in the frequency and magnitude of flooding may be an underappreciated but critical factor in the formation and dissolution of social complexity in early agricultural societies. PMID:25941363

A new "twist" on right heart failure with left ventricular assist systems.

PubMed

Houston, Brian A; Shah, Keyur B; Mehra, Mandeep R; Tedford, Ryan J

2017-07-01

Despite significant efforts to predict and prevent right heart failure, it remains a leading cause of morbidity and mortality after implantation of left ventricular assist systems (LVAS). In this Perspective, we review the underappreciated anatomic and physiologic principles that govern the relationship between left and right heart function and contribute to this phenomenon. This includes the importance of considering the right ventricle (RV) and pulmonary arterial circuit as a coupled system; the contribution of the left ventricle (LV) to RV contractile function and the potential negative impact of acutely unloading the LV; the influence of the pericardium and ventricular twist on septal function; the role of RV deformation in reduced mechanical efficiency after device placement; and the potential of ongoing stressors of an elevated right-sided preload. We believe an appreciation of these complex issues is required to fully understand the expression of the unique phenotypes of right heart failure after LVAS implantation and for developing better prognostic and therapeutic strategies. Copyright © 2017 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Ancient Diversification of Three-Finger Toxins in Micrurus Coral Snakes.

PubMed

Dashevsky, Daniel; Fry, Bryan G

2018-01-01

Coral snakes, most notably the genus Micrurus, are the only terrestrial elapid snakes in the Americas. Elapid venoms are generally known for their potent neurotoxicity which is usually caused by Three-Finger Toxin (3FTx) proteins. These toxins can have a wide array of functions that have been characterized from the venom of other elapids. We examined publicly available sequences from Micrurus 3FTx to show that they belong to 8 monophyletic clades that diverged as deep in the 3FTx phylogenetic tree as the other clades with characterized functions. Functional residues from previously characterized clades of 3FTx are not well conserved in most of the Micrurus toxin clades. We also analyzed the patterns of selection on these toxins and find that they have been diversifying at different rates, with some having undergone extreme diversifying selection. This suggests that Micrurus 3FTx may contain a previously underappreciated functional diversity that has implications for the clinical outcomes of bite victims, the evolution and ecology of the genus, as well as the potential for biodiscovery efforts focusing on these toxins.

Durable antitumor responses to CD47 blockade require adaptive immune stimulation

PubMed Central

Sockolosky, Jonathan T.; Dougan, Michael; Ingram, Jessica R.; Ho, Chia Chi M.; Kauke, Monique J.; Almo, Steven C.; Ploegh, Hidde L.; Garcia, K. Christopher

2016-01-01

Therapeutic antitumor antibodies treat cancer by mobilizing both innate and adaptive immunity. CD47 is an antiphagocytic ligand exploited by tumor cells to blunt antibody effector functions by transmitting an inhibitory signal through its receptor signal regulatory protein alpha (SIRPα). Interference with the CD47–SIRPα interaction synergizes with tumor-specific monoclonal antibodies to eliminate human tumor xenografts by enhancing macrophage-mediated antibody-dependent cellular phagocytosis (ADCP), but synergy between CD47 blockade and ADCP has yet to be demonstrated in immunocompetent hosts. Here, we show that CD47 blockade alone or in combination with a tumor-specific antibody fails to generate antitumor immunity against syngeneic B16F10 tumors in mice. Durable tumor immunity required programmed death-ligand 1 (PD-L1) blockade in combination with an antitumor antibody, with incorporation of CD47 antagonism substantially improving response rates. Our results highlight an underappreciated contribution of the adaptive immune system to anti-CD47 adjuvant therapy and suggest that targeting both innate and adaptive immune checkpoints can potentiate the vaccinal effect of antitumor antibody therapy. PMID:27091975

Changing tides: Adaptive monitoring, assessment, and management of pharmaceutical hazards in the environment through time.

PubMed

Gaw, Sally; Brooks, Bryan W

2016-04-01

Pharmaceuticals are ubiquitous contaminants in aquatic ecosystems. Adaptive monitoring, assessment, and management programs will be required to reduce the environmental hazards of pharmaceuticals of concern. Potentially underappreciated factors that drive the environmental dose of pharmaceuticals include regulatory approvals, marketing campaigns, pharmaceutical subsidies and reimbursement schemes, and societal acceptance. Sales data for 5 common antidepressants (duloxetine [Cymbalta], escitalopram [Lexapro], venlafaxine [Effexor], bupropion [Wellbutrin], and sertraline [Zoloft]) in the United States from 2004 to 2008 were modeled to explore how environmental hazards in aquatic ecosystems changed after patents were obtained or expired. Therapeutic hazard ratios for Effexor and Lexapro did not exceed 1; however, the therapeutic hazard ratio for Zoloft declined whereas the therapeutic hazard ratio for Cymbalta increased as a function of patent protection and sale patterns. These changes in therapeutic hazard ratios highlight the importance of considering current and future drivers of pharmaceutical use when prioritizing pharmaceuticals for water quality monitoring programs. When urban systems receiving discharges of environmental contaminants are examined, water quality efforts should identify, prioritize, and select target analytes presently in commerce for effluent monitoring and surveillance. © 2015 SETAC.

Donor-acquired fat embolism syndrome after lung transplantation.

PubMed

Jacob, Samuel; Courtwright, Andrew; El-Chemaly, Souheil; Racila, Emilian; Divo, Miguel; Burkett, Patrick; Fuhlbrigge, Anne; Goldberg, Hilary J; Rosas, Ivan O; Camp, Phillip

2016-05-01

Fat embolism is a known complication of severe trauma and closed chest cardiac resuscitation both of which are more common in the lung transplant donor population and can lead to donor-acquired fat embolism syndrome (DAFES). The objective was to review the diagnosis and management of DAFES in the lung transplantation literature and at our centre. We performed a literature review on DAFES using the Medline database. We then reviewed the transplant record of Brigham and Women's Hospital, a large academic hospital with an active lung transplant programme, for cases of DAFES. We identified 2 cases of DAFES in our centre, one of which required extracorporeal membrane oxygenation (ECMO) for successful management. In contrast to the broader literature on DAFES, which emphasizes unsuccessfully treated cases, both patients survived. DAFES is a rare but likely underappreciated early complication of lung transplant as it can mimic primary graft dysfunction. Aggressive interventions, including ECMO, may be necessary to achieve a good clinical outcome following DAFES. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Lossless Compression of Stromatolite Images: A Biogenicity Index?

NASA Astrophysics Data System (ADS)

Corsetti, Frank A.; Storrie-Lombardi, Michael C.

2003-12-01

It has been underappreciated that inorganic processes can produce stromatolites (laminated macroscopic constructions commonly attributed to microbiological activity), thus calling into question the long-standing use of stromatolites as de facto evidence for ancient life. Using lossless compression on unmagnified reflectance red-green-blue (RGB) images of matched stromatolite-sediment matrix pairs as a complexity metric, the compressibility index (δc, the log of the ratio of the compressibility of the matrix versus the target) of a putative abiotic test stromatolite is significantly less than the δc of a putative biotic test stromatolite. There is a clear separation in δc between the different stromatolites discernible at the outcrop scale. In terms of absolute compressibility, the sediment matrix between the stromatolite columns was low in both cases, the putative abiotic stromatolite was similar to the intracolumnar sediment, and the putative biotic stromatolite was much greater (again discernible at the outcrop scale). We propose that this metric would be useful for evaluating the biogenicity of images obtained by the camera systems available on every Mars surface probe launched to date including Viking, Pathfinder, Beagle, and the two Mars Exploration Rovers.

Lineage-specific genomics: Frequent birth and death in the human genome: The human genome contains many lineage-specific elements created by both sequence and functional turnover.

PubMed

Young, Robert S

2016-07-01

Frequent evolutionary birth and death events have created a large quantity of biologically important, lineage-specific DNA within mammalian genomes. The birth and death of DNA sequences is so frequent that the total number of these insertions and deletions in the human population remains unknown, although there are differences between these groups, e.g. transposable elements contribute predominantly to sequence insertion. Functional turnover - where the activity of a locus is specific to one lineage, but the underlying DNA remains conserved - can also drive birth and death. However, this does not appear to be a major driver of divergent transcriptional regulation. Both sequence and functional turnover have contributed to the birth and death of thousands of functional promoters in the human and mouse genomes. These findings reveal the pervasive nature of evolutionary birth and death and suggest that lineage-specific regions may play an important but previously underappreciated role in human biology and disease. © 2016 The Authors BioEssays Published by WILEY Periodicals, Inc.

Ice-sheet thinning and acceleration at Camp Century, Greenlan

NASA Astrophysics Data System (ADS)

Colgan, W. T.

2017-12-01

Camp Century, Greenland (77.18 °N, 61.12 °W, 1900 m), is located approximately 150 km inland from the ice-sheet margin in Northwest Greenland. In-situ and remotely-sensed measurements of ice-sheet elevation at Camp Century exhibit a thinning trend between 1964 and the present. A comparison of 1966 and 2017 firn density profiles indicates that a portion of this ice-sheet thinning is attributable to increased firn compaction rate. In-situ measurements of increasing ice surface velocity over the 1977-2017 period indicate that enhanced horizontal divergence of ice flux is also contributing to ice dynamic thinning at Camp Century. This apparent ice dynamic thinning could potentially result from a migrating local flow divide or decreasing effective ice viscosity. In a shorter-term context, observations of decadal-scale ice-sheet thinning and acceleration at Camp Century highlights underappreciated transience in inland ice form and flow during the satellite era. In a longer-term context, these multi-decadal observations contrast with inferences of millennial-scale ice-sheet thickening and deceleration at Camp Century.

Medical devices and diagnostics for cardiovascular diseases in low-resource settings.

PubMed

McGuire, Helen; Weigl, Bernhard H

2014-11-01

Noncommunicable diseases (NCDs), including cardiovascular diseases and diabetes, have emerged as an underappreciated health threat with enormous economic and public health implications for populations in low-resource settings. In order to address these diseases, devices that are to be used in low-resource settings have to conform to requirements that are generally more challenging than those developed for traditional markets. Characteristics and issues that must be considered when working in low- and middle-income countries (LMICs) include challenging environmental conditions, a complex supply chain, sometimes inadequate operator training, and cost. Somewhat counterintuitively, devices for low-resource setting (LRS) markets need to be of at least as high quality and reliability as those for developed countries to be setting-appropriate and achieve impact. Finally, the devices need to be designed and tested for the populations in which they are to be used in order to achieve the performance that is needed. In this review, we focus on technologies for primary and secondary health-care settings and group them according to the continuum of care from prevention to treatment.

Assay format as a critical success factor for identification of novel inhibitor chemotypes of tissue-nonspecific alkaline phosphatase from high-throughput screening.

PubMed

Chung, Thomas D Y; Sergienko, Eduard; Millán, José Luis

2010-04-27

The tissue-nonspecific alkaline phosphatase (TNAP) isozyme is centrally involved in the control of normal skeletal mineralization and pathophysiological abnormalities that lead to disease states such as hypophosphatasia, osteoarthritis, ankylosis and vascular calcification. TNAP acts in concert with the nucleoside triphosphate pyrophosphohydrolase-1 (NPP1) and the Ankylosis protein to regulate the extracellular concentrations of inorganic pyrophosphate (PP(i)), a potent inhibitor of mineralization. In this review we describe the serial development of two miniaturized high-throughput screens (HTS) for TNAP inhibitors that differ in both signal generation and detection formats, but more critically in the concentrations of a terminal alcohol acceptor used. These assay improvements allowed the rescue of the initially unsuccessful screening campaign against a large small molecule chemical library, but moreover enabled the discovery of several unique classes of molecules with distinct mechanisms of action and selectivity against the related placental (PLAP) and intestinal (IAP) alkaline phosphatase isozymes. This illustrates the underappreciated impact of the underlying fundamental assay configuration on screening success, beyond mere signal generation and detection formats.

Adverse effects of concentrated green tea extracts.

PubMed

Schönthal, Axel H

2011-06-01

A myriad of health claims are being made in favor of the consumption of green tea. However, mostly due to the easy availability and greater than ever popularity of highly concentrated green tea extracts, sometimes combined with an attitude of more-is-better, certain health risks of green tea consumption have begun to emerge. Among such risks are the possibility of liver damage, the potential to interact with prescription drugs to alter their therapeutic efficacy, and the chance to cause harm when combined with other highly popular herbal remedies. This review will summarize documented examples of adverse effects of green tea in humans, and will discuss risks of copious consumption of highly concentrated green tea extracts as indicated by studies in animals. While there is no intention to minimize any of the scientifically established benefits of the use of green tea, the purpose of this review is to focus primarily on the potential for adverse effects and raise awareness of the rare, yet under-appreciated risks. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New genes from old: asymmetric divergence of gene duplicates and the evolution of development.

PubMed

Holland, Peter W H; Marlétaz, Ferdinand; Maeso, Ignacio; Dunwell, Thomas L; Paps, Jordi

2017-02-05

Gene duplications and gene losses have been frequent events in the evolution of animal genomes, with the balance between these two dynamic processes contributing to major differences in gene number between species. After gene duplication, it is common for both daughter genes to accumulate sequence change at approximately equal rates. In some cases, however, the accumulation of sequence change is highly uneven with one copy radically diverging from its paralogue. Such 'asymmetric evolution' seems commoner after tandem gene duplication than after whole-genome duplication, and can generate substantially novel genes. We describe examples of asymmetric evolution in duplicated homeobox genes of moths, molluscs and mammals, in each case generating new homeobox genes that were recruited to novel developmental roles. The prevalence of asymmetric divergence of gene duplicates has been underappreciated, in part, because the origin of highly divergent genes can be difficult to resolve using standard phylogenetic methods.This article is part of the themed issue 'Evo-devo in the genomics era, and the origins of morphological diversity'. © 2016 The Author(s).

Equality and Quality in Education. A Comparative Study of 19 Countries

PubMed Central

Pfeffer, Fabian T.

2015-01-01

This contribution assesses the performance of national education systems along two important dimensions: The degree to which they help individuals develop capabilities necessary for their successful social integration (educational quality) and the degree to which they confer equal opportunities for social advancement (educational equality). It advances a new conceptualization to measure quality and equality in education and then uses it to study the relationship between institutional differentiation and these outcomes. It relies on data on final educational credentials and literacy among adults that circumvent some of the under-appreciated conceptual challenges entailed in the widespread analysis of international student assessment data. The analyses reveal a positive relationship between educational quality and equality and show that education systems with a lower degree of institutional differentiation not only provide more educational equality but are also marked by higher levels of educational quality. While the latter association is partly driven by other institutional and macro-structural factors, I demonstrate that the higher levels of educational equality in less differentiated education systems do not entail an often-assumed trade-off for lower quality. PMID:25769872

Advantages of Crystallographic Fragment Screening: Functional and Mechanistic Insights from a Powerful Platform for Efficient Drug Discovery

PubMed Central

Patel, Disha; Bauman, Joseph D.; Arnold, Eddy

2015-01-01

X-ray crystallography has been an under-appreciated screening tool for fragment-based drug discovery due to the perception of low throughput and technical difficulty. Investigators in industry and academia have overcome these challenges by taking advantage of key factors that contribute to a successful crystallographic screening campaign. Efficient cocktail design and soaking methodologies have evolved to maximize throughput while minimizing false positives/negatives. In addition, technical improvements at synchrotron beamlines have dramatically increased data collection rates thus enabling screening on a timescale comparable to other techniques. The combination of available resources and efficient experimental design has resulted in many successful crystallographic screening campaigns. The three-dimensional crystal structure of the bound fragment complexed to its target, a direct result of the screening effort, enables structure-based drug design while revealing insights regarding protein dynamics and function not readily obtained through other experimental approaches. Furthermore, this “chemical interrogation” of the target protein crystals can lead to the identification of useful reagents for improving diffraction resolution or compound solubility. PMID:25117499

Renal osteodystrophy, phosphate homeostasis, and vascular calcification.

PubMed

Hruska, Keith A; Saab, Georges; Mathew, Suresh; Lund, Richard

2007-01-01

New advances in the pathogenesis of renal osteodystrophy (ROD) change the perspective from which many of its features and treatment are viewed. Calcium, phosphate, parathyroid hormone (PTH), and vitamin D have been shown to be important determinants of survival associated with kidney diseases. Now ROD dependent and independent of these factors is linked to survival more than just skeletal frailty. This review focuses on recent discoveries that renal injury impairs skeletal anabolism decreasing the osteoblast compartment of the skeleton and consequent bone formation. This discovery and the discovery that PTH regulates the hematopoietic stem cell niche alters our view of secondary hyperparathyroidism in chronic kidney disease (CKD) from that of a disease to that of a necessary adaptation to renal injury that goes awry. Furthermore, ROD is shown to be an underappreciated factor in the level of the serum phosphorus in CKD. The discovery and the elucidation of the mechanism of hyperphosphatemia as a cardiovascular risk in CKD change the view of ROD. It is now recognized as more than a skeletal disorder, it is an important component of the mortality of CKD that can be treated.

Capturing microRNA targets using an RNA-induced silencing complex (RISC)-trap approach

PubMed Central

Cambronne, Xiaolu A.; Shen, Rongkun; Auer, Paul L.; Goodman, Richard H.

2012-01-01

Identifying targets is critical for understanding the biological effects of microRNA (miRNA) expression. The challenge lies in characterizing the cohort of targets for a specific miRNA, especially when targets are being actively down-regulated in miRNA– RNA-induced silencing complex (RISC)–messengerRNA (mRNA) complexes. We have developed a robust and versatile strategy called RISCtrap to stabilize and purify targets from this transient interaction. Its utility was demonstrated by determining specific high-confidence target datasets for miR-124, miR-132, and miR-181 that contained known and previously unknown transcripts. Two previously unknown miR-132 targets identified with RISCtrap, adaptor protein CT10 regulator of kinase 1 (CRK1) and tight junction-associated protein 1 (TJAP1), were shown to be endogenously regulated by miR-132 in adult mouse forebrain. The datasets, moreover, differed in the number of targets and in the types and frequency of microRNA recognition element (MRE) motifs, thus revealing a previously underappreciated level of specificity in the target sets regulated by individual miRNAs. PMID:23184980

Capturing microRNA targets using an RNA-induced silencing complex (RISC)-trap approach.

PubMed

Cambronne, Xiaolu A; Shen, Rongkun; Auer, Paul L; Goodman, Richard H

2012-12-11

Identifying targets is critical for understanding the biological effects of microRNA (miRNA) expression. The challenge lies in characterizing the cohort of targets for a specific miRNA, especially when targets are being actively down-regulated in miRNA- RNA-induced silencing complex (RISC)-messengerRNA (mRNA) complexes. We have developed a robust and versatile strategy called RISCtrap to stabilize and purify targets from this transient interaction. Its utility was demonstrated by determining specific high-confidence target datasets for miR-124, miR-132, and miR-181 that contained known and previously unknown transcripts. Two previously unknown miR-132 targets identified with RISCtrap, adaptor protein CT10 regulator of kinase 1 (CRK1) and tight junction-associated protein 1 (TJAP1), were shown to be endogenously regulated by miR-132 in adult mouse forebrain. The datasets, moreover, differed in the number of targets and in the types and frequency of microRNA recognition element (MRE) motifs, thus revealing a previously underappreciated level of specificity in the target sets regulated by individual miRNAs.

Variation across mitochondrial gene trees provides evidence for systematic error: How much gene tree variation is biological?

PubMed

Richards, Emilie J; Brown, Jeremy M; Barley, Anthony J; Chong, Rebecca A; Thomson, Robert C

2018-02-19

The use of large genomic datasets in phylogenetics has highlighted extensive topological variation across genes. Much of this discordance is assumed to result from biological processes. However, variation among gene trees can also be a consequence of systematic error driven by poor model fit, and the relative importance of biological versus methodological factors in explaining gene tree variation is a major unresolved question. Using mitochondrial genomes to control for biological causes of gene tree variation, we estimate the extent of gene tree discordance driven by systematic error and employ posterior prediction to highlight the role of model fit in producing this discordance. We find that the amount of discordance among mitochondrial gene trees is similar to the amount of discordance found in other studies that assume only biological causes of variation. This similarity suggests that the role of systematic error in generating gene tree variation is underappreciated and critical evaluation of fit between assumed models and the data used for inference is important for the resolution of unresolved phylogenetic questions.

Modular degradable dendrimers enable small RNAs to extend survival in an aggressive liver cancer model

PubMed Central

Zhou, Kejin; Nguyen, Liem H.; Miller, Jason B.; Yan, Yunfeng; Kos, Petra; Xiong, Hu; Li, Lin; Hao, Jing; Minnig, Jonathan T.; Siegwart, Daniel J.

2016-01-01

RNA-based cancer therapies are hindered by the lack of delivery vehicles that avoid cancer-induced organ dysfunction, which exacerbates carrier toxicity. We address this issue by reporting modular degradable dendrimers that achieve the required combination of high potency to tumors and low hepatotoxicity to provide a pronounced survival benefit in an aggressive genetic cancer model. More than 1,500 dendrimers were synthesized using sequential, orthogonal reactions where ester degradability was systematically integrated with chemically diversified cores, peripheries, and generations. A lead dendrimer, 5A2-SC8, provided a broad therapeutic window: identified as potent [EC50 < 0.02 mg/kg siRNA against FVII (siFVII)] in dose–response experiments, and well tolerated in separate toxicity studies in chronically ill mice bearing MYC-driven tumors (>75 mg/kg dendrimer repeated dosing). Delivery of let-7g microRNA (miRNA) mimic inhibited tumor growth and dramatically extended survival. Efficacy stemmed from a combination of a small RNA with the dendrimer’s own negligible toxicity, therefore illuminating an underappreciated complication in treating cancer with RNA-based drugs. PMID:26729861

An Accident Precursor Analysis Process Tailored for NASA Space Systems

NASA Technical Reports Server (NTRS)

Groen, Frank; Stamatelatos, Michael; Dezfuli, Homayoon; Maggio, Gaspare

2010-01-01

Accident Precursor Analysis (APA) serves as the bridge between existing risk modeling activities, which are often based on historical or generic failure statistics, and system anomalies, which provide crucial information about the failure mechanisms that are actually operative in the system and which may differ in frequency or type from those in the various models. These discrepancies between the models (perceived risk) and the system (actual risk) provide the leading indication of an underappreciated risk. This paper presents an APA process developed specifically for NASA Earth-to-Orbit space systems. The purpose of the process is to identify and characterize potential sources of system risk as evidenced by anomalous events which, although not necessarily presenting an immediate safety impact, may indicate that an unknown or insufficiently understood risk-significant condition exists in the system. Such anomalous events are considered accident precursors because they signal the potential for severe consequences that may occur in the future, due to causes that are discernible from their occurrence today. Their early identification allows them to be integrated into the overall system risk model used to intbrm decisions relating to safety.

Evolving Concepts in Atopic Dermatitis.

PubMed

Sidbury, Robert; Khorsand, Kate

2017-07-01

Tremendous advances have been made in the field of atopic dermatitis in the past 5 years. We will explore developments in burden of disease, co-morbidities, pathogenesis, prevention, and management. The tremendous burden moderate to severe atopic dermatitis (AD) places on families from a medical, psychosocial, and financial perspective has been characterized. Epidemiologic studies have identified intriguing new associations beyond the well-characterized "atopic march" of food allergies, asthma, and hay fever. Studies of primary prevention have gained traction including the remarkable impacts of early emollient therapy. Basic advances have simultaneously elucidated the nature of atopic inflammation, setting the stage for an explosion of new potential therapeutic targets. After a fallow period of nearly 15 years without a substantial therapeutic advance, this year has already seen two new FDA-approved treatments for AD. AD has a tremendous impact on quality of life with an underappreciated burden of disease; there are important newly described co-morbidities including ADHD and anemia; new insights into etio-pathogenesis have paved the way for novel topical therapies like crisaborole, and new systemic interventions like dupilumab.

Fundamental and functional aspects of mesoscopic architectures with examples in physics, cell biology, and chemistry.

PubMed

Kalay, Ziya

2011-08-01

How small can a macroscopic object be made without losing its intended function? Obviously, the smallest possible size is determined by the size of an atom, but it is not so obvious how many atoms are required to assemble an object so small, and yet that performs the same function as its macroscopic counterpart. In this review, we are concerned with objects of intermediate nature, lying between the microscopic and the macroscopic world. In physics and chemistry literature, this regime in-between is often called mesoscopic, and is known to bear interesting and counterintuitive features. After a brief introduction to the concept of mesoscopic systems from the perspective of physics, we discuss the functional aspects of mesoscopic architectures in cell biology, and supramolecular chemistry through many examples from the literature. We argue that the biochemistry of the cell is largely regulated by mesoscopic functional architectures; however, the significance of mesoscopic phenomena seems to be quite underappreciated in biological sciences. With this motivation, one of our main purposes here is to emphasize the critical role that mesoscopic structures play in cell biology and biochemistry.

Why disgust matters

PubMed Central

Curtis, Valerie

2011-01-01

The new synthesis about disgust is that it is a system that evolved to motivate infectious disease avoidance. There are vital practical and intellectual reasons why we need to understand disgust better. Practically, disgust can be harnessed to combat the behavioural causes of infectious and chronic disease such as diarrhoeal disease, pandemic flu and smoking. Disgust is also a source of much human suffering; it plays an underappreciated role in anxieties and phobias such as obsessive compulsive disorder, social phobia and post-traumatic stress syndromes; it is a hidden cost of many occupations such as caring for the sick and dealing with wastes, and self-directed disgust afflicts the lives of many, such as the obese and fistula patients. Disgust is used and abused in society, being both a force for social cohesion and a cause of prejudice and stigmatization of out-groups. This paper argues that a better understanding of disgust, using the new synthesis, offers practical lessons that can enhance human flourishing. Disgust also provides a model system for the study of emotion, one of the most important issues facing the brain and behavioural sciences today. PMID:22042923

Simulation of the M13 life cycle II: Investigation of the control mechanisms of M13 infection and establishment of the carrier state.

PubMed

Smeal, Steven W; Schmitt, Margaret A; Pereira, Ronnie Rodrigues; Prasad, Ashok; Fisk, John D

2017-01-01

Bacteriophage M13 is a true parasite of bacteria, able to co-opt the infected cell and control the production of progeny across many cellular generations. Here, our genetically-structured simulation of M13 is applied to quantitatively dissect the interplay between the host cellular environment and the controlling interactions governing the phage life cycle during the initial establishment of infection and across multiple cell generations. Multiple simulations suggest that phage-encoded feedback interactions constrain the utilization of host DNA polymerase, RNA polymerase and ribosomes. The simulation reveals the importance of p5 translational attenuation in controlling the production of phage double-stranded DNA and suggests an underappreciated role for p5 translational self-attenuation in resource allocation. The control elements active in a single generation are sufficient to reproduce the experimentally-observed multigenerational curing of the phage infection. Understanding the subtleties of regulation will be important for maximally exploiting M13 particles as scaffolds for nanoscale devices. Copyright © 2016 Elsevier Inc. All rights reserved.

The causes of variation in the presence of genetic covariance between sexual traits and preferences.

PubMed

Fowler-Finn, Kasey D; Rodríguez, Rafael L

2016-05-01

Mating traits and mate preferences often show patterns of tight correspondence across populations and species. These patterns of apparent coevolution may result from a genetic association between traits and preferences (i.e. trait-preference genetic covariance). We review the literature on trait-preference covariance to determine its prevalence and potential biological relevance. Of the 43 studies we identified, a surprising 63% detected covariance. We test multiple hypotheses for factors that may influence the likelihood of detecting this covariance. The main predictor was the presence of genetic variation in mate preferences, which is one of the three main conditions required for the establishment of covariance. In fact, 89% of the nine studies where heritability of preference was high detected covariance. Variables pertaining to the experimental methods and type of traits involved in different studies did not greatly influence the detection of trait-preference covariance. Trait-preference genetic covariance appears to be widespread and therefore represents an important and currently underappreciated factor in the coevolution of traits and preferences. © 2015 Cambridge Philosophical Society.

Computational modeling of psychiatric illnesses via well-defined neurophysiological and neurocognitive biomarkers.

PubMed

Siekmeier, Peter J

2015-10-01

A good deal of recent research has centered on the identification of biomarkers and endophenotypic measures of psychiatric illnesses using in vivo and in vitro studies. This is understandable, as these measures-as opposed to complex clinical phenotypes-may be more closely related to neurobiological and genetic vulnerabilities. However, instantiation of such biomarkers using computational models-in silico studies-has received less attention. This approach could become increasingly important, given the wealth of detailed information produced by recent basic neuroscience research, and increasing availability of high capacity computing platforms. The purpose of this review is to survey the current state of the art of research in this area. We discuss computational approaches to schizophrenia, bipolar disorder, Alzheimer's disease, fragile X syndrome and autism, and argue that it represents a promising and underappreciated research modality. In conclusion, we outline specific avenues for future research; also, potential uses of in silico models to conduct "virtual experiments" and to generate novel hypotheses, and as an aid in neuropsychiatric drug development are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Histone methylation and aging: Lessons learned from model systems

PubMed Central

McCauley, Brenna S.; Dang, Weiwei

2014-01-01

Aging induces myriad cellular and, ultimately, physiological changes that cause a decline in an organism's functional capabilities. Although the aging process and pathways that regulate it have been extensively studied, only in the last decade have we begun to appreciate that dynamic histone methylation may contribute to this process. In this review, we discuss recent work implicating histone methylation in aging. Loss of certain histone methyltransferases and demethylases changes lifespan in invertebrates, and alterations in histone methylation in aged organisms regulate lifespan and aging phenotypes, including oxidative stress-induced hormesis in yeast, insulin signaling in Caenorhabiditis elegans and mammals, and the senescence-associated secretory phenotype in mammals. In all cases where histone methylation has been shown to impact aging and aging phenotypes, it does so by regulating transcription, suggesting that this is a major mechanism of its action in this context. Histone methylation additionally regulates or is regulated by other cellular pathways that contribute to or combat aging. Given the numerous processes that regulate aging and histone methylation, and are in turn regulated by them, the role of histone methylation in aging is almost certainly underappreciated. PMID:24859460

Dormancy cues alter insect temperature-size relationships.

PubMed

Clemmensen, Sharon F; Hahn, Daniel A

2015-01-01

Developmental temperatures can have dramatic effects on body size in ectotherms. Thermal plasticity in body size is often viewed in the context of seasonality, but the role of seasonal dormancy responses in generating temperature-size relationships is underappreciated. We used the moth Helicoverpa zea (corn earworm) to examine how photoperiodic seasonal dormancy programming for pupal diapause affects the temperature-size relationship. Specifically, we partition out the contributions of somatic growth versus nutrient storage as fat to the thermal reaction norm for size. With increasing temperature from 16 °C to 20 °C, dormant pupae were both overall larger and progressively fatter than non-dormant pupae. This body mass response is likely driven by concurrent increases in food consumption and longer development times as temperatures increase. Our results demonstrate that seasonal photoperiodic cues can alter temperature-size relationships during pre-dormancy development. For biologists interested in seasonal effects on temperature-size relationships, our results suggest that the key to fully understanding these relationships may lie in integrating multiple seasonal cues and multiple aspects of body size and composition in a nutrient-allocation framework.

Lossless compression of stromatolite images: a biogenicity index?

PubMed

Corsetti, Frank A; Storrie-Lombardi, Michael C

2003-01-01

It has been underappreciated that inorganic processes can produce stromatolites (laminated macroscopic constructions commonly attreibuted to microbiological activity), thus calling into question the long-standing use of stromatolites as de facto evidence for ancient life. Using lossless compression on unmagnified reflectance red-green-blue (RGB) images of matched stromatolite-sediment matrix pairs as a complexity metric, the compressibility index (delta(c), the log ratio of the ratio of the compressibility of the matrix versus the target) of a putative abiotic test stromatolite is significantly less than the delta(c) of a putative biotic test stromatolite. There is a clear separation in delta(c) between the different stromatolites discernible at the outcrop scale. In terms of absolute compressibility, the sediment matrix between the stromatolite columns was low in both cases, the putative abiotic stromatolite was similar to the intracolumnar sediment, and the putative biotic stromatolite was much greater (again discernible at the outcrop scale). We propose tht this metric would be useful for evaluating the biogenicity of images obtained by the camera systems available on every Mars surface probe launched to date including Viking, Pathfinder, Beagle, and the two Mars Exploration Rovers.

Gut microbiota and graft-versus-host disease: broad-spectrum antibiotic use increases post-allogeneic hematopoietic stem cell transplant graft-versus-host disease-related mortality.

PubMed

Shono, Yusuke

2017-01-01

Intestinal bacteria can modulate the risk of infection and graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Allo-HSCT recipients often develop neutropenic fever, which is treated with antibiotics that may target anaerobic bacteria in the gut. We retrospectively examined 857 allo-HSCT recipients and found that treatment using broad-spectrum antibiotics was associated with increased GVHD-related mortality at 5 years. Analysis of stool specimens from allo-HSCT recipients showed that broad-spectrum antibiotic administration was associated with perturbation of gut microbial composition. Studies in mice also demonstrated aggravated GVHD mortality with broad-spectrum antibiotics use. Broad-spectrum antibiotics treatment of mice with GVHD led to a loss of the protective mucus lining of the colon, compromised intestinal barrier function, as well as increased a commensal bacterium with mucus-degrading capabilities, raising the possibility that mucus degradation may contribute to murine GVHD. We demonstrate an underappreciated risk of antibiotics in allo-HSCT recipients that may exacerbate GVHD in the colon.

Business or pleasure? Utilitarian versus hedonic considerations in emotion regulation.

PubMed

Tamir, Maya; Chiu, Chi-Yue; Gross, James J

2007-08-01

It is widely accepted that emotions have utilitarian as well as hedonic consequences. Nevertheless, it is typically assumed that individuals regulate emotions to obtain hedonic, rather than utilitarian, benefits. In this study, the authors tested whether individuals represent the utility of pleasant and unpleasant emotions and whether they would be motivated to experience unpleasant emotions if they believed they could be useful. First, findings revealed that participants explicitly viewed approach emotions (e.g., excitement) as useful for obtaining rewards, but viewed avoidance emotions (e.g., worry) as useful for avoiding threats. Second, this pattern was replicated in implicit representations of emotional utility, which were dissociated from explicit ones. Third, implicit, but not explicit, representations of emotional utility predicted motives for emotion regulation. When anticipating a threatening task, participants who viewed emotions such as worry and fear as useful for avoiding threats preferred to engage in activities that were likely to increase worry and fear (vs. excitement) before the task. These findings demonstrate that utilitarian considerations play an important, if underappreciated, role in emotion regulation. ((c) 2007 APA, all rights reserved).

Anosmia and Ageusia in Parkinson's Disease.

PubMed

Tarakad, Arjun; Jankovic, Joseph

2017-01-01

Anosmia, the loss of sense of smell, is a common nonmotor feature of Parkinson's disease (PD). Ageusia, the loss of sense of taste, is additionally an underappreciated nonmotor feature of PD. The olfactory tract is involved early in PD as indicated by frequent occurrence of hyposmia or anosmia years or decades before motor symptoms and by autopsy studies showing early synuclein pathology in the olfactory tract and anterior olfactory nucleus even in the early stages of PD. Testing for olfaction consists of evaluation of olfactory thresholds, smell identification and discrimination, and olfactory memory. Testing for gustation involves evaluating thresholds and discrimination of five basic tastes (salty, sweet, bitter, sour, and umami). The presence of a specific pattern of loss in both olfaction and gustation in PD has been proposed, but this has not yet been confirmed. Within PD, olfactory loss is strongly tied with cognitive status though links to other features of PD or a particular PD phenotype is debated. Hyposmia is more often present and typically more severe in PD patients than other parkinsonian syndromes, making it a potentially useful biomarker for the disease. © 2017 Elsevier Inc. All rights reserved.

Group living in squamate reptiles: a review of evidence for stable aggregations.

PubMed

Gardner, Michael G; Pearson, Sarah K; Johnston, Gregory R; Schwarz, Michael P

2016-11-01

How sociality evolves and is maintained remains a key question in evolutionary biology. Most studies to date have focused on insects, birds, and mammals but data from a wider range of taxonomic groups are essential to identify general patterns and processes. The extent of social behaviour among squamate reptiles is under-appreciated, yet they are a promising group for further studies. Living in aggregations is posited as an important step in the evolution of more complex sociality. We review data on aggregations among squamates and find evidence for some form of aggregations in 94 species across 22 families. Of these, 18 species across 7 families exhibited 'stable' aggregations that entail overlapping home ranges and stable membership in long-term (years) or seasonal aggregations. Phylogenetic analysis suggests that stable aggregations have evolved multiple times in squamates. We: (i) identify significant gaps in our understanding; (ii) outline key traits which should be the focus of future research; and (iii) outline the potential for utilising reproductive skew theory to provide insights into squamate sociality. © 2015 Cambridge Philosophical Society.

Potent Elastase Inhibitors from Cyanobacteria: Structural Basis and Mechanisms Mediating Cytoprotective and Anti-inflammatory Effects in Bronchial Epithelial Cells

PubMed Central

Salvador, Lilibeth A.; Taori, Kanchan; Biggs, Jason S.; Jakoncic, Jean; Ostrov, David A.; Paul, Valerie J.; Luesch, Hendrik

2013-01-01

We discovered new structural diversity to a prevalent, yet medicinally underappreciated, cyanobacterial protease inhibitor scaffold and undertook comprehensive protease profiling to reveal potent and selective elastase inhibition. SAR and X-ray cocrystal structure analysis allowed a detailed assessment of critical and tunable structural elements. To realize the therapeutic potential of these cyclodepsipeptides, we probed the cellular effects of a novel and representative family member, symplostatin 5 (1), which attenuated the downstream cellular effects of elastase in an epithelial lung airway model system, alleviating clinical hallmarks of chronic pulmonary diseases such as cell death, cell detachment and inflammation. This compound attenuated the effects of elastase on receptor activation, proteolytic processing of the adhesion protein ICAM-1, NF-κB activation and transcriptomic changes, including the expression of pro-inflammatory cytokines IL1A, IL1B and IL8. Compound 1 exhibited activity comparable to the clinically-approved elastase inhibitor sivelestat in short-term assays and demonstrated superior sustained activity in longer-term assays. PMID:23350733

Defensive repertoire of Drosophila larvae in response to toxic fungi.

PubMed

Trienens, Monika; Kraaijeveld, Ken; Wertheim, Bregje

2017-10-01

Chemical warfare including insecticidal secondary metabolites is a well-known strategy for environmental microbes to monopolize a food source. Insects in turn have evolved behavioural and physiological defences to eradicate or neutralize the harmful microorganisms. We studied the defensive repertoire of insects in this interference competition by combining behavioural and developmental assays with whole-transcriptome time-series analysis. Confrontation with the toxic filamentous fungus Aspergillus nidulans severely reduced the survival of Drosophila melanogaster larvae. Nonetheless, the larvae did not behaviourally avoid the fungus, but aggregated at it. Confrontation with fungi strongly affected larval gene expression, including many genes involved in detoxification (e.g., CYP, GST and UGT genes) and the formation of the insect cuticle (e.g., Tweedle genes). The most strongly upregulated genes were several members of the insect-specific gene family Osiris, and CHK-kinase-like domains were over-represented. Immune responses were not activated, reflecting the competitive rather than pathogenic nature of the antagonistic interaction. While internal microbes are widely acknowledged as important, our study emphasizes the underappreciated role of environmental microbes as fierce competitors. © 2017 John Wiley & Sons Ltd.

Advantages of crystallographic fragment screening: functional and mechanistic insights from a powerful platform for efficient drug discovery.

PubMed

Patel, Disha; Bauman, Joseph D; Arnold, Eddy

2014-01-01

X-ray crystallography has been an under-appreciated screening tool for fragment-based drug discovery due to the perception of low throughput and technical difficulty. Investigators in industry and academia have overcome these challenges by taking advantage of key factors that contribute to a successful crystallographic screening campaign. Efficient cocktail design and soaking methodologies have evolved to maximize throughput while minimizing false positives/negatives. In addition, technical improvements at synchrotron beamlines have dramatically increased data collection rates thus enabling screening on a timescale comparable to other techniques. The combination of available resources and efficient experimental design has resulted in many successful crystallographic screening campaigns. The three-dimensional crystal structure of the bound fragment complexed to its target, a direct result of the screening effort, enables structure-based drug design while revealing insights regarding protein dynamics and function not readily obtained through other experimental approaches. Furthermore, this "chemical interrogation" of the target protein crystals can lead to the identification of useful reagents for improving diffraction resolution or compound solubility. Copyright © 2014. Published by Elsevier Ltd.

How alkyl halide structure affects E2 and SN2 reaction barriers: E2 reactions are as sensitive as SN2 reactions.

PubMed

Rablen, Paul R; McLarney, Brett D; Karlow, Brandon J; Schneider, Jean E

2014-02-07

High-level electronic structure calculations, including a continuum treatment of solvent, are employed to elucidate and quantify the effects of alkyl halide structure on the barriers of SN2 and E2 reactions. In cases where such comparisons are available, the results of these calculations show close agreement with solution experimental data. Structural factors investigated include α- and β-methylation, adjacency to unsaturated functionality (allyl, benzyl, propargyl, α to carbonyl), ring size, and α-halogenation and cyanation. While the influence of these factors on SN2 reactivity is mostly well-known, the present study attempts to provide a broad comparison of both SN2 and E2 reactivity across many cases using a single methodology, so as to quantify relative reactivity trends. Despite the fact that most organic chemistry textbooks say far more about how structure affects SN2 reactions than about how it affects E2 reactions, the latter are just as sensitive to structural variation as are the former. This sensitivity of E2 reactions to structure is often underappreciated.

Myelination: an overlooked mechanism of synaptic plasticity?

PubMed

Fields, R Douglas

2005-12-01

Myelination of the brain continues through childhood into adolescence and early adulthood--the question is, Why? Two new articles provide intriguing evidence that myelination may be an underappreciated mechanism of activity-dependent nervous system plasticity: one study reported increased myelination associated with extensive piano playing, another indicated that rats have increased myelination of the corpus callosum when raised in environments providing increased social interaction and cognitive stimulation. These articles make it clear that activity-dependent effects on myelination cannot be considered strictly a developmental event. They raise the question of whether myelination is an overlooked mechanism of activity-dependent plasticity, extending in humans until at least age 30. It has been argued that regulating the speed of conduction across long fiber tracts would have a major influence on synaptic response, by coordinating the timing of afferent input to maximize temporal summation. The increase in synaptic amplitude could be as large as neurotransmitter-based mechanisms of plasticity, such as LTP. These new findings raise a larger question: How did the oligodendrocytes know they were practicing the piano or that their environment was socially complex?

Suicidality and antidepressants in the elderly

PubMed Central

2008-01-01

Suicide has reached epidemic proportions in the elderly, particularly in non-Hispanic white men. Unfortunately, the risk is underappreciated in this population. Known risk correlates for suicide in this population fall into three interrelated categories. Sociologic factors include such considerations as living alone and having few social interactions. Physical health factors include having more medical comorbidity and being a current smoker. The mental health risk factors include the presence of mood and anxiety disorders with a focus on the greater severity of symptoms, especially hypersomnia, hopelessness, and a history of suicide attempts. Suicide is a spectrum comprising ideation, intent, and plan. Clinical depression is never a normal part of aging and warrants aggressive treatment. Recent warnings linking antidepressants and suicide may have special relevance in the elderly. Based on preliminary studies with antipsychotic drugs, a subgroup of patients who experience akathisia may be particularly vulnerable to suicide. Upon initiation of antidepressants, it is recommended that adults be seen in follow-up three times within the first 12 weeks of treatment; if medically indicated, the first contact should be during the first week. PMID:18982077

The neurocognitive consequences of the wandering mind: a mechanistic account of sensory-motor decoupling

PubMed Central

Kam, Julia W. Y.; Handy, Todd C.

2013-01-01

A unique human characteristic is our ability to mind wander – a state in which we are free to engage in thoughts that are not directly tied to sensations and perceptions from our immediate physical environment. From a neurocognitive perspective, it has been proposed that during mind wandering, our executive resources are decoupled from the external environment and directed to these internal thoughts. In this review, we examine an underappreciated aspect of this phenomenon – attenuation of sensory-motor processing – from two perspectives. First, we describe the range of widespread sensory, cognitive and motor processes attenuated during mind wandering states, and how this impacts our neurocognitive processing of external events. We then consider sensory-motor attenuation in a class of clinical neurocognitive disorders that have ties to pathological patterns of decoupling, reviews suggesting that mind wandering and these clinical states may share a common mechanism of sensory-motor attenuation. Taken together, these observations suggest the sensory-motor consequences of decoupled thinking are integral to normal and pathological neurocognitive states. PMID:24133472

Paediatric and maternal schistosomiasis: shifting the paradigms.

PubMed

Bustinduy, Amaya L; Stothard, J Russell; Friedman, Jennifer F

2017-09-01

In endemic areas, schistosomiasis causes both overt and subclinical disease in young children and their mothers, as well as in returned travellers. Key recently published literature. An action plan for paediatric schistosomiasis and female genital schistosomiasis (FGS) is needed with expanded access to praziquantel (PZQ) treatment required. Schistosomiasis-related morbidity is underappreciated. Present and future demand for PZQ treatment is bottlenecked, imbalanced and inequitable. Current dosing, treatment algorithms and access plans are suboptimal with treatment stalled during pregnancy. Raised dosing of PZQ (>40 mg/kg) is being explored in young children. Surveillance of female genital schistosomiasis FGS is increasing. Use of PZQ in pregnancy is safe and preventive chemotherapy guidelines are being revised in morbidity- and transmission-control settings. Shifting focus of population-level control to individual-case management. Detection and prevention of FGS within general health services and integration of PZQ treatment for women and children in antenatal clinics. Feasibility studies assessing alternative and expanded access to PZQ treatment to at-risk children and mothers and pregnant women. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Blood money: Harvey's De motu cordis (1628) as an exercise in accounting.

PubMed

Neuss, Michael J

2018-04-13

William Harvey's famous quantitative argument from De motu cordis (1628) about the circulation of blood explained how a small amount of blood could recirculate and nourish the entire body, upending the Galenic conception of the blood's motion. This paper argues that the quantitative argument drew on the calculative and rhetorical skills of merchants, including Harvey's own brothers. Modern translations of De motu cordis obscure the language of accountancy that Harvey himself used. Like a merchant accounting for credits and debits, intake and output, goods and moneys, Harvey treated venous and arterial blood as essentially commensurate, quantifiable and fungible. For Harvey, the circulation (and recirculation) of blood was an arithmetical necessity. The development of Harvey's circulatory model followed shifts in the epistemic value of mercantile forms of knowledge, including accounting and arithmetic, also drawing on an Aristotelian language of reciprocity and balance that Harvey shared with mercantile advisers to the royal court. This paper places Harvey's calculations in a previously underappreciated context of economic crisis, whose debates focused largely on questions of circulation.

Economic contract theory tests models of mutualism.

PubMed

Weyl, E Glen; Frederickson, Megan E; Yu, Douglas W; Pierce, Naomi E

2010-09-07

Although mutualisms are common in all ecological communities and have played key roles in the diversification of life, our current understanding of the evolution of cooperation applies mostly to social behavior within a species. A central question is whether mutualisms persist because hosts have evolved costly punishment of cheaters. Here, we use the economic theory of employment contracts to formulate and distinguish between two mechanisms that have been proposed to prevent cheating in host-symbiont mutualisms, partner fidelity feedback (PFF) and host sanctions (HS). Under PFF, positive feedback between host fitness and symbiont fitness is sufficient to prevent cheating; in contrast, HS posits the necessity of costly punishment to maintain mutualism. A coevolutionary model of mutualism finds that HS are unlikely to evolve de novo, and published data on legume-rhizobia and yucca-moth mutualisms are consistent with PFF and not with HS. Thus, in systems considered to be textbook cases of HS, we find poor support for the theory that hosts have evolved to punish cheating symbionts; instead, we show that even horizontally transmitted mutualisms can be stabilized via PFF. PFF theory may place previously underappreciated constraints on the evolution of mutualism and explain why punishment is far from ubiquitous in nature.

Merging Literature, Visual Art and Physics: Teaching Through Comics

NASA Astrophysics Data System (ADS)

Thompson, R.

2012-12-01

Comics have been around as a form of entertainment for decades. They are often as seen as one of the distracting vices of kids (and adults!), but comics and their more adult version, the graphic novel, are increasingly valued as a legitimate genre of both literature and visual. The APS Outreach Department has teamed up with the APS graphics department to create a series of comics, one featuring Nikola Tesla and his battles with the evil Thomas Edison, and four about laser the APS original super hero Spectra and her continuing battles with such villains as nefarious Miss Alignment and bumbling General Relativity. These comics have struck a delicate balance between education and entertainment being well received by both the comic book and education communities. By creating a compelling comic story that has correct physics, it is possible to use this under-appreciated medium to excite middle-school students who might otherwise be turned off by traditional teaching methods. In merging physics with the art of comics it is crucial to make sure first and foremost that the students enjoy the story and that they feel a connection to the characters. Students are thus hooked and once they are drawn in, the learning happens automatically.

Hermann von Helmholtz's empirico-transcendentalism reconsidered: construction and constitution in Helmholtz's psychology of the object.

PubMed

De Kock, Liesbet

2014-12-01

This paper aims at contributing to the ongoing efforts to get a firmer grasp of the systematic significance of the entanglement of idealism and empiricism in Helmholtz's work. Contrary to existing analyses, however, the focal point of the present exposition is Helmholtz's attempt to articulate a psychological account of objectification. Helmholtz's motive, as well as his solution to the problem of the object are outlined, and interpreted against the background of his scientific practice on the one hand, and that of empiricist and (transcendental) idealist analyses of experience on the other. The specifically psychological angle taken, not only prompts us to consider figures who have hitherto been treated as having only minor import for Helmholtz interpretation (most importantly J.S. Mill and J.G. Fichte), it furthermore sheds new light on some central tenets of the latter's psychological stance that have hitherto remained underappreciated. For one thing, this analysis reveals an explicit voluntarist tendency in Helmholtz's psychological theory. In conclusion, it is argued that the systematic significance of Helmholtz's empirico-transcendentalism with respect to questions of the mind is best understood as an attempt to found his empirical theory of perception in a second order, normative account of epistemic subjectivity.

Petrobarter: oil, inequality, and the political imagination in and after the Cold War.

PubMed

Rogers, Douglas

2014-04-01

Petrobarter--the exchange of oil for goods and services without reference to monetary currency--has been a widespread and underappreciated practice among corporations, states, and state agencies over the past half century. Analyzing this practice with reference to anthropological theories of barter adds to our understandings of two significant and intertwined concerns in contemporary social science: (1) the production and reproduction of inequality at various scales, from subnational regions to the international system as a whole, and (2) the generation and fate of mobilizing political imaginaries that challenge the abstracted, universalizing imaginaries so often associated with monetized exchange, especially in capitalist contexts. Barter exchanges featuring oil are, therefore, as analytically significant as the much more commonly studied transactions of oil and money. Ethnographic and historical case studies of petrobarter are drawn from the Perm region of the Russian Urals in the post-Soviet period and the global oil trade in the early Cold War. This view from the perspective of the socialist and postsocialist world, it is argued, provides an instructive counterpoint to the many existing studies of oil and money, both in and beyond anthropology, that are situated in the European-American colonial and postcolonial periphery.

A case of choking phobia: towards a conceptual approach.

PubMed

Lopes, Rui; Melo, Raquel; Curral, Rosário; Coelho, Rui; Roma-Torres, António

2014-03-01

Choking phobia, also known as phagophobia or swallowing phobia is an uncommon clinical entity that has been underappreciated and is included in the new DSM-5 and upcoming ICD-11 diagnostic category of avoidant/restrictive food intake disorder. Phenomenologically distinct from other eating disorders, it is characterized by the phobic stimulus of swallowing that results in the avoidance of food or drinks, and ultimately to low weight, social withdrawal, anxiety and depression states. Its prevalence and long-term course on the general population still needs to be determined, probably reflecting years of indefiniteness regarding its nosology and by the absence of a clear set of diagnostic criteria. We present a clinical case of choking phobia in a 32-year-old male patient after an episode of choke when eating chicken. An early diagnosis and distinction from other eating disorders is important for proper treatment and fundamental for prognosis. We also make a thorough revision on literature in clinical features, differential diagnosis and treatment approaches, suggesting a conceptual approach for choking phobia as a clinical spectrum settled by different degrees of phobic subtypes, which may depend on a varied number of clinical variables.

Therapeutic effects of remediating autophagy failure in a mouse model of Alzheimer disease by enhancing lysosomal proteolysis.

PubMed

Yang, Dun-Sheng; Stavrides, Philip; Mohan, Panaiyur S; Kaushik, Susmita; Kumar, Asok; Ohno, Masuo; Schmidt, Stephen D; Wesson, Daniel W; Bandyopadhyay, Urmi; Jiang, Ying; Pawlik, Monika; Peterhoff, Corrinne M; Yang, Austin J; Wilson, Donald A; St George-Hyslop, Peter; Westaway, David; Mathews, Paul M; Levy, Efrat; Cuervo, Ana M; Nixon, Ralph A

2011-07-01

The extensive autophagic-lysosomal pathology in Alzheimer disease (AD) brain has revealed a major defect: in the proteolytic clearance of autophagy substrates. Autophagy failure contributes on several levels to AD pathogenesis and has become an important therapeutic target for AD and other neurodegenerative diseases. We recently observed broad therapeutic effects of stimulating autophagic-lysosomal proteolysis in the TgCRND8 mouse model of AD that exhibits defective proteolytic clearance of autophagic substrates, robust intralysosomal amyloid-β peptide (Aβ) accumulation, extracellular β-amyloid deposition and cognitive deficits. By genetically deleting the lysosomal cysteine protease inhibitor, cystatin B (CstB), to selectively restore depressed cathepsin activities, we substantially cleared Aβ, ubiquitinated proteins and other autophagic substrates from autolysosomes/lysosomes and rescued autophagic-lysosomal pathology, as well as reduced total Aβ40/42 levels and extracellular amyloid deposition, highlighting the underappreciated importance of the lysosomal system for Aβ clearance. Most importantly, lysosomal remediation prevented the marked learning and memory deficits in TgCRND8 mice. Our findings underscore the pathogenic significance of autophagic-lysosomal dysfunction in AD and demonstrate the value of reversing this dysfunction as an innovative therapeautic strategy for AD.

Incidence, Clinical Correlates and Treatment Effect of Rage in Anxious Children

PubMed Central

Salloum, Alison; De Nadai, Alessandro S.; McBride, Nicole; Crawford, Erika A.; Lewin, Adam B.; Storch, Eric A.

2015-01-01

Episodic rage represents an important and underappreciated clinical feature in pediatric anxiety. This study examined the incidence and clinical correlates of rage in children with anxiety disorders. Change in rage during treatment for anxiety was also examined. Participants consisted of 107 children diagnosed with an anxiety disorder and their parents. Participants completed structured clinical interviews and questionnaire measures to assess rage, anxiety, functional impairment, family accommodation and caregiver strain, as well as the quality of the child's relationship with family and peers. Rage was a common feature amongst children with anxiety disorders. Rage was associated with a more severe clinical profile, including increased anxiety severity, functional impairment, family accommodation and caregiver strain, as well as poorer relationships with parents, siblings, extended family and peers. Rage was more common in children with separation anxiety, comorbid anxiety, attention deficit/hyperactivity disorder and behavioral disorders, but not depressive symptoms. Rage predicted higher levels of functional impairment, beyond the effect of anxiety severity. Rage severity reduced over treatment in line with changes in anxiety symptoms. Findings suggest that rage is a marker of greater psychopathology in anxious youth. Standard cognitive behavioral treatment for anxiety appears to reduce rage without adjunctive treatment. PMID:26235476

Applying the dark diversity concept to nature conservation.

PubMed

Lewis, Rob J; de Bello, Francesco; Bennett, Jonathan A; Fibich, Pavel; Finerty, Genevieve E; Götzenberger, Lars; Hiiesalu, Inga; Kasari, Liis; Lepš, Jan; Májeková, Maria; Mudrák, Ondřej; Riibak, Kersti; Ronk, Argo; Rychtecká, Terezie; Vitová, Alena; Pärtel, Meelis

2017-02-01

Linking diversity to biological processes is central for developing informed and effective conservation decisions. Unfortunately, observable patterns provide only a proportion of the information necessary for fully understanding the mechanisms and processes acting on a particular population or community. We suggest conservation managers use the often overlooked information relative to species absences and pay particular attention to dark diversity (i.e., a set of species that are absent from a site but that could disperse to and establish there, in other words, the absent portion of a habitat-specific species pool). Together with existing ecological metrics, concepts, and conservation tools, dark diversity can be used to complement and further develop conservation prioritization and management decisions through an understanding of biodiversity relativized by its potential (i.e., its species pool). Furthermore, through a detailed understanding of the population, community, and functional dark diversity, the restoration potential of degraded habitats can be more rigorously assessed and so to the likelihood of successful species invasions. We suggest the application of the dark diversity concept is currently an underappreciated source of information that is valuable for conservation applications ranging from macroscale conservation prioritization to more locally scaled restoration ecology and the management of invasive species. © 2016 Society for Conservation Biology.

Pathogen Transmission from Humans to Great Apes is a Growing Threat to Primate Conservation.

PubMed

Dunay, Emily; Apakupakul, Kathleen; Leard, Stephen; Palmer, Jamie L; Deem, Sharon L

2018-01-23

All six great ape species are listed as endangered or critically endangered by the IUCN and experiencing decreasing population trends. One of the threats to these non-human primates is the transmission of pathogens from humans. We conducted a literature review on occurrences of pathogen transmission from humans to great apes to highlight this often underappreciated issue. In total, we found 33 individual occurrences of probable or confirmed pathogen transmission from humans to great apes: 23 involved both pathogen and disease transmission, 7 pathogen transmission only, 2 positive antibody titers to zoonotic pathogens, and 1 pathogen transmission with probable disease. Great ape populations were categorized into captive, semi-free-living, and free-living conditions. The majority of occurrences involved chimpanzees (Pan troglodytes) (n = 23) or mountain gorillas (Gorilla beringei beringei) (n = 8). These findings have implications for conservation efforts and management of endangered great ape populations. Future efforts should focus on monitoring and addressing zoonotic pathogen and disease transmission between humans, great ape species, and other taxa to ensure the health of humans, wild and domestic animals, and the ecosystems we share.

Nutrient-rich meat proteins in offsetting age-related muscle loss.

PubMed

Phillips, Stuart M

2012-11-01

From a health perspective, an underappreciated consequence of the normal aging process is the impacts that the gradual loss of skeletal muscle mass, termed sarcopenia, has on health beyond an effect on locomotion. Sarcopenia, refers to the loss of muscle mass, and associated muscle weakness, which occurs in aging and is thought to proceed at a rate of approximately 1% loss per year. However, periods of inactivity due to illness or recovery from orthopedic procedures such as hip or knee replacement are times of accelerated sarcopenic muscle loss from which it may be more difficult for older persons to recover. Some of the consequences of age-related sarcopenia are easy to appreciate such as weakness and, eventually, reduced mobility; however, other lesser recognized consequences include, due to the metabolic role the skeletal muscle plays, an increased risk for poor glucose control and a predisposition toward weight gain. What we currently know is that two stimuli can counter this age related muscle loss and these are physical activity, specifically resistance exercise (weightlifting), and nutrition. The focus of this paper is on the types of dietary protein that people might reasonably consume to offset sarcopenic muscle loss. Copyright © 2012 Elsevier Ltd. All rights reserved.

Estimating the ratio of multivariate recurrent event rates with application to a blood transfusion study.

PubMed

Ning, Jing; Rahbar, Mohammad H; Choi, Sangbum; Piao, Jin; Hong, Chuan; Del Junco, Deborah J; Rahbar, Elaheh; Fox, Erin E; Holcomb, John B; Wang, Mei-Cheng

2017-08-01

In comparative effectiveness studies of multicomponent, sequential interventions like blood product transfusion (plasma, platelets, red blood cells) for trauma and critical care patients, the timing and dynamics of treatment relative to the fragility of a patient's condition is often overlooked and underappreciated. While many hospitals have established massive transfusion protocols to ensure that physiologically optimal combinations of blood products are rapidly available, the period of time required to achieve a specified massive transfusion standard (e.g. a 1:1 or 1:2 ratio of plasma or platelets:red blood cells) has been ignored. To account for the time-varying characteristics of transfusions, we use semiparametric rate models for multivariate recurrent events to estimate blood product ratios. We use latent variables to account for multiple sources of informative censoring (early surgical or endovascular hemorrhage control procedures or death). The major advantage is that the distributions of latent variables and the dependence structure between the multivariate recurrent events and informative censoring need not be specified. Thus, our approach is robust to complex model assumptions. We establish asymptotic properties and evaluate finite sample performance through simulations, and apply the method to data from the PRospective Observational Multicenter Major Trauma Transfusion study.

Roadblocks en route to the clinical application of induced pluripotent stem cells.

PubMed

Lowry, William E; Quan, William L

2010-03-01

Since the first studies of human embryonic stem cells (hESCs) and, more recently, human induced pluripotent stem cells (hiPSCs), the stem-cell field has been abuzz with the promise that these pluripotent populations will one day be a powerful therapeutic tool. Although it has been proposed that hiPSCs will supersede hESCs with respect to their research and/or clinical potential because of the ease of their derivation and the ability to create immunologically matched iPSCs for each individual patient, recent evidence suggests that iPSCs in fact have several underappreciated characteristics that might mean they are less suitable for clinical application. Continuing research is revealing the similarities, differences and deficiencies of various pluripotent stem-cell populations, and suggests that many years will pass before the clinical utility of hESCs and hiPSCs is realized. There are a plethora of ethical, logistical and technical roadblocks on the route to the clinical application of pluripotent stem cells, particularly of iPSCs. In this Essay, we discuss what we believe are important issues that should be considered when attempting to bring hiPSC-based technology to the clinic.

Bioethical considerations in animal production.

PubMed

Reynnells, R D

2004-03-01

The Western Coordinating Committee-204 (WCC-204) on animal bioethics is a multistate research committee that was formed through the cooperation of several university and government personnel having diverse backgrounds. The WCC-204 is pleased to provide this symposium to Poultry Science Association (PSA) members and invite their participation in the committee. Generic objectives of the committee include facilitation of dialogue to improve our understanding of complex ethical issues related to animal production and utilization by humans, to encourage research and educational programs in this area, and to create a means for critical analysis of the animal sciences professions. The basis for philosophical discussions and religious implications of bioethical discussions that create profound differences of opinion between people is discussed. The various and often underappreciated contributions of society to the structure of our current food production system, and society's approach to change (taking marketplace responsibility for demands vs. regulations), are briefly discussed. Several factors that may contribute to the creation of conflicts and misunderstandings are listed. Speakers will discuss the WCC-204 organization, the need to define where there is agreement between opposing entities, education of students and others through contemporary issues classes, and global issues related to animal well-being.

Cancer across the tree of life: cooperation and cheating in multicellularity

PubMed Central

Aktipis, C. Athena; Boddy, Amy M.; Jansen, Gunther; Hibner, Urszula; Hochberg, Michael E.; Maley, Carlo C.; Wilkinson, Gerald S.

2015-01-01

Multicellularity is characterized by cooperation among cells for the development, maintenance and reproduction of the multicellular organism. Cancer can be viewed as cheating within this cooperative multicellular system. Complex multicellularity, and the cooperation underlying it, has evolved independently multiple times. We review the existing literature on cancer and cancer-like phenomena across life, not only focusing on complex multicellularity but also reviewing cancer-like phenomena across the tree of life more broadly. We find that cancer is characterized by a breakdown of the central features of cooperation that characterize multicellularity, including cheating in proliferation inhibition, cell death, division of labour, resource allocation and extracellular environment maintenance (which we term the five foundations of multicellularity). Cheating on division of labour, exhibited by a lack of differentiation and disorganized cell masses, has been observed in all forms of multicellularity. This suggests that deregulation of differentiation is a fundamental and universal aspect of carcinogenesis that may be underappreciated in cancer biology. Understanding cancer as a breakdown of multicellular cooperation provides novel insights into cancer hallmarks and suggests a set of assays and biomarkers that can be applied across species and characterize the fundamental requirements for generating a cancer. PMID:26056363

N-Acetylcysteine's Role in Sepsis and Potential Benefit in Patients With Microcirculatory Derangements.

PubMed

Chertoff, Jason

2018-02-01

To review the data surrounding the utility of N-acetylcysteine (NAC) in sepsis and identify areas needed for additional research. A review of articles describing the mechanisms of action and clinical use of NAC in sepsis. Despite many advances in critical care medicine, still as many as 50% of patients with septic shock die. Treatments thus far have focused on resuscitation and restoration of macrocirculatory targets in the early phases of sepsis, with less focus on microcirculatory dysfunction. N-acetylcysteine, due to its anti-inflammatory and antioxidative properties, has been readily investigated in sepsis and has yielded largely incongruous and disappointing results. In addition to its known anti-inflammatory and antioxidative roles, one underappreciated property of NAC is its ability to vasodilate the microcirculation and improve locoregional blood flow. Some investigators have sought to capitalize on this mechanism with promising results, as evidenced by microcirculatory vasodilation, improvements in regional blood flow and oxygen delivery, and reductions in lactic acidosis, organ failure, and mortality. In addition to its antioxidant and anti-inflammatory properties, N-acetylcysteine possesses vasodilatory properties that could benefit the microcirculation in sepsis. It is imperative that we investigate these properties to uncover NAC's full potential for benefit in sepsis.

Reverse transendothelial cell migration in inflammation: to help or to hinder?

PubMed

Burn, Thomas; Alvarez, Jorge Ivan

2017-05-01

The endothelium provides a strong barrier separating circulating blood from tissue. It also provides a significant challenge for immune cells in the bloodstream to access potential sites of infection. To mount an effective immune response, leukocytes traverse the endothelial layer in a process known as transendothelial migration. Decades of work have allowed dissection of the mechanisms through which immune cells gain access into peripheral tissues, and subsequently to inflammatory foci. However, an often under-appreciated or potentially ignored question is whether transmigrated leukocytes can leave these inflammatory sites, and perhaps even return across the endothelium and re-enter circulation. Although evidence has existed to support "reverse" transendothelial migration for a number of years, it is only recently that mechanisms associated with this process have been described. Here we review the evidence that supports both reverse transendothelial migration and reverse interstitial migration within tissues, with particular emphasis on some of the more recent studies that finally hint at potential mechanisms. Additionally, we postulate the biological significance of retrograde migration, and whether it serves as an additional mechanism to limit pathology, or provides a basis for the dissemination of systemic inflammation.

What can we infer about the origin of sex in early eukaryotes?

PubMed Central

2016-01-01

Current analysis shows that the last eukaryotic common ancestor (LECA) was capable of full meiotic sex. The original eukaryotic life cycle can probably be described as clonal, interrupted by episodic sex triggered by external or internal stressors. The cycle could have started in a highly flexible form, with the interruption of either diploid or haploid clonal growth determined by stress signals only. Eukaryotic sex most likely evolved in response to a high mutation rate, arising from the uptake of the endosymbiont, as this (proto) mitochondrion generated internal reactive oxygen species. This is consistent with the likely development of full meiotic sex from a diverse set of existing archaeal (the host of the endosymbiont) repair and signalling mechanisms. Meiotic sex could thus have been one of the fruits of symbiogenesis at the basis of eukaryotic origins: a product of the merger by which eukaryotic cells arose. Symbiogenesis also explains the large-scale migration of organellar DNA to the nucleus. I also discuss aspects of uniparental mitochondrial inheritance and mitonuclear interactions in the light of the previous analysis. This article is part of the themed issue ‘Weird sex: the underappreciated diversity of sexual reproduction’. PMID:27619694

What can we infer about the origin of sex in early eukaryotes?

PubMed

Speijer, Dave

2016-10-19

Current analysis shows that the last eukaryotic common ancestor (LECA) was capable of full meiotic sex. The original eukaryotic life cycle can probably be described as clonal, interrupted by episodic sex triggered by external or internal stressors. The cycle could have started in a highly flexible form, with the interruption of either diploid or haploid clonal growth determined by stress signals only. Eukaryotic sex most likely evolved in response to a high mutation rate, arising from the uptake of the endosymbiont, as this (proto) mitochondrion generated internal reactive oxygen species. This is consistent with the likely development of full meiotic sex from a diverse set of existing archaeal (the host of the endosymbiont) repair and signalling mechanisms. Meiotic sex could thus have been one of the fruits of symbiogenesis at the basis of eukaryotic origins: a product of the merger by which eukaryotic cells arose. Symbiogenesis also explains the large-scale migration of organellar DNA to the nucleus. I also discuss aspects of uniparental mitochondrial inheritance and mitonuclear interactions in the light of the previous analysis.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'. © 2016 The Author(s).

Population responses to environmental change in a tropical ant: the interaction of spatial and temporal dynamics.

PubMed

Jackson, Doug; Vandermeer, John; Perfecto, Ivette; Philpott, Stacy M

2014-01-01

Spatial structure can have a profound, but often underappreciated, effect on the temporal dynamics of ecosystems. Here we report on a counterintuitive increase in the population of a tree-nesting ant, Azteca sericeasur, in response to a drastic reduction in the number of potential nesting sites. This surprising result is comprehensible when viewed in the context of the self-organized spatial dynamics of the ants and their effect on the ants' dispersal-limited natural enemies. Approximately 30% of the trees in the study site, a coffee agroecosystem in southern Mexico, were pruned or felled over a two-year period, and yet the abundance of the ant nests more than doubled over the seven-year study. Throughout the transition, the spatial distribution of the ants maintained a power-law distribution - a signal of spatial self organization - but the local clustering of the nests was reduced post-pruning. A cellular automata model incorporating the changed spatial structure of the ants and the resulting partial escape from antagonists reproduced the observed increase in abundance, highlighting how self-organized spatial dynamics can profoundly influence the responses of ecosystems to perturbations.

Population Responses to Environmental Change in a Tropical Ant: The Interaction of Spatial and Temporal Dynamics

PubMed Central

Jackson, Doug; Vandermeer, John; Perfecto, Ivette; Philpott, Stacy M.

2014-01-01

Spatial structure can have a profound, but often underappreciated, effect on the temporal dynamics of ecosystems. Here we report on a counterintuitive increase in the population of a tree-nesting ant, Azteca sericeasur, in response to a drastic reduction in the number of potential nesting sites. This surprising result is comprehensible when viewed in the context of the self-organized spatial dynamics of the ants and their effect on the ants’ dispersal-limited natural enemies. Approximately 30% of the trees in the study site, a coffee agroecosystem in southern Mexico, were pruned or felled over a two-year period, and yet the abundance of the ant nests more than doubled over the seven-year study. Throughout the transition, the spatial distribution of the ants maintained a power-law distribution – a signal of spatial self organization – but the local clustering of the nests was reduced post-pruning. A cellular automata model incorporating the changed spatial structure of the ants and the resulting partial escape from antagonists reproduced the observed increase in abundance, highlighting how self-organized spatial dynamics can profoundly influence the responses of ecosystems to perturbations. PMID:24842117

Building a better foundation: improving root-trait measurements to understand and model plant and ecosystem processes

DOE PAGES

McCormack, M. Luke; Guo, Dali; Iversen, Colleen M.; ...

2017-03-13

Trait-based approaches provide a useful framework to investigate plant strategies for resource acquisition, growth, and competition, as well as plant impacts on ecosystem processes. Despite significant progress capturing trait variation within and among stems and leaves, identification of trait syndromes within fine-root systems and between fine roots and other plant organs is limited. Here we discuss three underappreciated areas where focused measurements of fine-root traits can make significant contributions to ecosystem science. These include assessment of spatiotemporal variation in fine-root traits, integration of mycorrhizal fungi into fine-root-trait frameworks, and the need for improved scaling of traits measured on individual rootsmore » to ecosystem-level processes. Progress in each of these areas is providing opportunities to revisit how below-ground processes are represented in terrestrial biosphere models. Targeted measurements of fine-root traits with clear linkages to ecosystem processes and plant responses to environmental change are strongly needed to reduce empirical and model uncertainties. Further identifying how and when suites of root and whole-plant traits are coordinated or decoupled will ultimately provide a powerful tool for modeling plant form and function at local and global scales.« less

Cerebral microhemorrhages due to traumatic brain injury and their effects on the aging human brain.

PubMed

Irimia, Andrei; Van Horn, John D; Vespa, Paul M

2018-06-01

Although cerebral microbleeds (CMBs) are frequently associated with traumatic brain injury (TBI), their effects on clinical outcome after TBI remain controversial and poorly understood, particularly in older adults. Here we (1) highlight major challenges and opportunities associated with studying the effects of TBI-mediated CMBs; (2) review the evidence on their potential effects on cognitive and neural outcome as a function of age at injury; and (3) suggest priorities for future research on understanding the clinical implications of CMBs. Although TBI-mediated CMBs are likely distinct from those due to cerebral amyloid angiopathy or other neurodegenerative diseases, the effects of these 2 CMB types on brain function may share common features. Furthermore, in older TBI victims, the incidence of TBI-mediated CMBs may approximate that of cerebral amyloid angiopathy-related CMBs, and thus warrants detailed study. Because the alterations effected by CMBs on brain structure and function are both unique and age-dependent, it seems likely that novel, age-tailored therapeutic approaches are necessary for the adequate clinical interpretation and treatment of these ubiquitous and underappreciated TBI sequelae. Copyright © 2018 Elsevier Inc. All rights reserved.

The social, economic, and environmental importance of inland fish and fisheries

USGS Publications Warehouse

Lynch, Abigail J.; Cooke, Steven J.; Deines, Andrew M.; Bower, Shannon D.; Bunnell, David B.; Cowx, Ian G.; Nguyen, Vivian M.; Nohner, Joel K.; Phouthavong, Kaviphone; Riley, Betsy; Rogers, Mark W.; Taylor, William W.; Woelmer, Whitney; Youn, So-Jung; Beard, T. Douglas

2016-01-01

Though reported capture fisheries are dominated by marine production, inland fish and fisheries make substantial contributions to meeting the challenges faced by individuals, society, and the environment in a changing global landscape. Inland capture fisheries and aquaculture contribute over 40% to the world’s reported finfish production from less than 0.01% of the total volume of water on earth. These fisheries provide food for billions and livelihoods for millions of people worldwide. Herein, using supporting evidence from the literature, we review 10 reasons why inland fish and fisheries are important to the individual (food security, economic security, empowerment), to society (cultural services, recreational services, human health and well-being, knowledge transfer and capacity building), and to the environment (ecosystem function and biodiversity, as aquatic “canaries”, the “green food” movement). However, the current limitations to valuing the services provided by inland fish and fisheries make comparison with other water resource users extremely difficult. This list can serve to demonstrate the importance of inland fish and fisheries, a necessary first step to better incorporating them into agriculture, land-use, and water resource planning, where they are currently often underappreciated or ignored.

Building a better foundation: improving root-trait measurements to understand and model plant and ecosystem processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCormack, M. Luke; Guo, Dali; Iversen, Colleen M.

Trait-based approaches provide a useful framework to investigate plant strategies for resource acquisition, growth, and competition, as well as plant impacts on ecosystem processes. Despite significant progress capturing trait variation within and among stems and leaves, identification of trait syndromes within fine-root systems and between fine roots and other plant organs is limited. Here we discuss three underappreciated areas where focused measurements of fine-root traits can make significant contributions to ecosystem science. These include assessment of spatiotemporal variation in fine-root traits, integration of mycorrhizal fungi into fine-root-trait frameworks, and the need for improved scaling of traits measured on individual rootsmore » to ecosystem-level processes. Progress in each of these areas is providing opportunities to revisit how below-ground processes are represented in terrestrial biosphere models. Targeted measurements of fine-root traits with clear linkages to ecosystem processes and plant responses to environmental change are strongly needed to reduce empirical and model uncertainties. Further identifying how and when suites of root and whole-plant traits are coordinated or decoupled will ultimately provide a powerful tool for modeling plant form and function at local and global scales.« less

Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host–parasite interactions

PubMed Central

Tao, Leiling; Gowler, Camden D.; Ahmad, Aamina; Hunter, Mark D.; de Roode, Jacobus C.

2015-01-01

Host–parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host–parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host–parasite systems. PMID:26468247

Predictors of summertime heat index levels in New York City apartments

PubMed Central

Quinn, Ashlinn; Kinney, Patrick; Shaman, Jeffrey

2018-01-01

Background During heat waves, fatal overexposure to heat most often occurs at home. It is not known how factors such as building size, floor level, and different types of air conditioning (AC) contribute to excess indoor heat. Methods We monitored indoor temperature and humidity in 36 apartments in New York City during summers 2014 and 2015, and used these values to calculate the indoor heat index (HI). We investigated the role of AC type and building-level factors on indoor HI using multilevel regression models. Results 34 of 36 homes had AC. Central and ductless AC types were associated with the coolest indoor conditions; homes with window and portable AC were significantly warmer. Apartments on the top floor of a building were significantly hotter during heat advisory periods than other apartments regardless of the presence of AC. High indoor HI levels persisted in some homes for approximately one day following the end of the two heat advisory periods. Conclusions We provide concrete evidence of higher heat levels in top floor apartments and in homes with certain types of AC. High heat levels that persist indoors after outdoor heat has subsided may present an underappreciated public health risk. PMID:28107558

How mangrove forests adjust to rising sea level

USGS Publications Warehouse

Krauss, Ken W.; McKee, Karen L.; Lovelock, Catherine E.; Cahoon, Donald R.; Saintilan, Neil; Reef, Ruth; Chen, Luzhen

2014-01-01

Mangroves are among the most well described and widely studied wetland communities in the world. The greatest threats to mangrove persistence are deforestation and other anthropogenic disturbances that can compromise habitat stability and resilience to sea-level rise. To persist, mangrove ecosystems must adjust to rising sea level by building vertically or become submerged. Mangroves may directly or indirectly influence soil accretion processes through the production and accumulation of organic matter, as well as the trapping and retention of mineral sediment. In this review, we provide a general overview of research on mangrove elevation dynamics, emphasizing the role of the vegetation in maintaining soil surface elevations (i.e. position of the soil surface in the vertical plane). We summarize the primary ways in which mangroves may influence sediment accretion and vertical land development, for example, through root contributions to soil volume and upward expansion of the soil surface. We also examine how hydrological, geomorphological and climatic processes may interact with plant processes to influence mangrove capacity to keep pace with rising sea level. We draw on a variety of studies to describe the important, and often under-appreciated, role that plants play in shaping the trajectory of an ecosystem undergoing change.

Refuge-mediated apparent competition in plant-consumer interactions.

PubMed

Orrock, John L; Holt, Robert D; Baskett, Marissa L

2010-01-01

At the intersection of consumer behaviour and plant competition is the concept of refuge-mediated apparent competition: an indirect interaction whereby plants provide a refuge for a shared consumer, subsequently increasing consumer pressure on another plant species. Here, we use a simple model and empirical examples to develop and illustrate the concept of refuge-mediated apparent competition. We find that the likelihood that an inferior competitor will succeed via refuge-mediated apparent competition is greater when competitors have similar resource requirements and when consumers exhibit a strong response to the refuge and high attack rates on the superior competitor. Refuge-mediated apparent competition may create an emergent Allee effect, such that a species invades only if it is sufficiently abundant to alter consumer impact on resident species. This indirect interaction may help explain unresolved patterns observed in biological invasion, such as the different physical structure of invasive exotic plants, the lag phase, and the failure of restoration efforts. Given the ubiquity of refuge-seeking behaviour by consumers and the ability of consumers to alter the outcome of direct competition among plants, refuge-mediated apparent competition may be an underappreciated mechanism affecting the composition and diversity of plant communities.

Florivory as an Opportunity Benefit of Aposematism.

PubMed

Higginson, Andrew D; Speed, Michael P; Ruxton, Graeme D

2015-12-01

Inconspicuous prey pay a cost of reduced feeding opportunities. Flowers are highly nutritious but are positioned where prey would be apparent to predators and often contain toxins to reduce consumption. However, many herbivores are specialized to subvert these defenses by retaining toxins for their own use. Here, we present a model of the growth and life history of a small herbivore that can feed on leaves or flowers during its development and can change its primary defense against visual predators between crypsis and warning coloration. When herbivores can retain plant toxins, their fitness is greatly increased when they are aposematic and can consume flowers. Thus, toxin sequestration leading to aposematism may enable a significant opportunity benefit for florivory. Florivory by cryptic herbivores is predicted when toxins are very potent but are at high concentration only in flowers and not in leaves. Herbivores should usually switch to eating flowers only when large and in most conditions should switch simultaneously from crypsis to aposematism. Our results suggest that florivory should be widespread in later instars of small aposematic herbivores and should be associated with ontogenic color change. Florivory is likely to play an underappreciated role in herbivorous insect life histories and host plant reproductive success.

Abuse potential and psychoactive effects of δ-9-tetrahydrocannabinol and cannabidiol oromucosal spray (Sativex), a new cannabinoid medicine.

PubMed

Robson, Philip

2011-09-01

There is a growing consensus that cannabis dependence is a substantial and underappreciated problem. The key component responsible for the euphoric effects of cannabis and its dependence potential is δ-9-tetrahydrocannabinol (THC). THC-containing cannabinoid medicines theoretically pose a risk of abuse and dependence. In order to evaluate the potential of Sativex to cause cannabis-like psychoactivity, abuse or dependence relevant data from all published papers have been reviewed along with the integrated safety analysis for Sativex use in multiple sclerosis (MS) patients on file at GW Pharmaceuticals. In clinical trials, intoxication scores have been low and euphoria reported by only 2.2% of patients. Tolerance has not occurred, abrupt withdrawal has not resulted in a formal withdrawal syndrome, and no cases of abuse or diversion have been reported to date. A formal abuse liability study of Sativex in experienced cannabis smokers showed some abuse potential in comparison with placebo at higher doses, but scores were consistently lower than equivalent doses of THC. Evidence to date suggests that abuse or dependence on Sativex is likely to occur in only a very small proportion of recipients.

Estimating the impact of alcohol consumption on survival for HIV+ individuals

PubMed Central

BRAITHWAITE, R. S.; CONIGLIARO, J.; ROBERTS, M. S.; SHECHTER, S.; SCHAEFER, A.; MCGINNIS, K.; RODRIGUEZ, M. C.; RABENECK, L.; BRYANT, K.; JUSTICE, A. C.

2012-01-01

Alcohol consumption is associated with decreased antiretroviral adherence, and decreased adherence results in poorer outcomes. However the magnitude of alcohol’s impact on survival is unknown. Our objective was to use a calibrated and validated simulation of HIV disease to estimate the impact of alcohol on survival. We incorporated clinical data describing the temporal and dose-response relationships between alcohol consumption and adherence in a large observational cohort (N = 2,702). Individuals were categorized as nondrinkers (no alcohol consumption), hazardous drinkers (consume ≥5 standard drinks on drinking days), and nonhazardous drinkers (consume <5 standard drinks on drinking days). Our results showed that nonhazardous alcohol consumption decreased survival by more than 1 year if the frequency of consumption was once per week or greater, and by 3.3 years (from 21.7 years to 18.4 years) with daily consumption. Hazardous alcohol consumption decreased overall survival by more than 3 years if frequency of consumption was once per week or greater, and by 6.4 years (From 16.1 years to 9.7 years) with daily consumption. Our results suggest that alcohol is an underappreciated yet modifiable risk factor for poor survival among individuals with HIV. PMID:17453583

Misplaced Paternalism and other Mistakes in the Debate over Kidney Sales.

PubMed

Semrau, Luke

2017-03-01

Erik Malmqvist defends the prohibition on kidney sales as a justifiable measure to protect individuals from harms they have not autonomously chosen. This appeal to 'group soft paternalism' requires that three conditions be met. It must be shown that some vendors will be harmed, that some will be subject to undue pressure to vend, and that we cannot feasibly distinguish between the autonomous and the non-autonomous. I argue that Malmqvist fails to demonstrate that any of these conditions are likely to obtain. His argument involves two common errors. First, he, like many, proceeds on a mistaken understanding of how to assess harm. What matters is not the balance of costs and benefits of vending, but a comparison of potential vendors' welfare across two possible courses of action. Second, Malmqvist's concerns about third-party pressure are predicated on an empirically unrealistic understanding of the operation of a regulated market. A widely underappreciated fact is that kidney sales will be relatively rare, and most who try to vend will be unable to. Because pressure on another to vend will not result in the desired outcome, few will exert it. © 2016 John Wiley & Sons Ltd.

The birth of the blues: how physics underlies music

NASA Astrophysics Data System (ADS)

Gibson, J. M.

2009-07-01

Art and science have intimate connections, although these are often underappreciated. Western music provides compelling examples. The sensation of harmony and related melodic development are rooted in physical principles that can be understood with simple mathematics. The focus of this review is not the better known acoustics of instruments, but the structure of music itself. The physical basis of the evolution of Western music in the last half millennium is discussed, culminating with the development of the 'blues'. The paper refers to a number of works which expand the connections, and introduces material specific to the development of the 'blues'. Several conclusions are made: (1) that music is axiomatic like mathematics and that to appreciate music fully listeners must learn the axioms; (2) that this learning does not require specific conscious study but relies on a linkage between the creative and quantitative brain and (3) that a key element of the musical 'blues' comes from recreating missing notes on the modern equal temperament scale. The latter is an example of 'art built on artifacts'. Finally, brief reference is made to the value of music as a tool for teaching physics, mathematics and engineering to non-scientists.

Multi-Omics Factor Analysis-a framework for unsupervised integration of multi-omics data sets.

PubMed

Argelaguet, Ricard; Velten, Britta; Arnol, Damien; Dietrich, Sascha; Zenz, Thorsten; Marioni, John C; Buettner, Florian; Huber, Wolfgang; Stegle, Oliver

2018-06-20

Multi-omics studies promise the improved characterization of biological processes across molecular layers. However, methods for the unsupervised integration of the resulting heterogeneous data sets are lacking. We present Multi-Omics Factor Analysis (MOFA), a computational method for discovering the principal sources of variation in multi-omics data sets. MOFA infers a set of (hidden) factors that capture biological and technical sources of variability. It disentangles axes of heterogeneity that are shared across multiple modalities and those specific to individual data modalities. The learnt factors enable a variety of downstream analyses, including identification of sample subgroups, data imputation and the detection of outlier samples. We applied MOFA to a cohort of 200 patient samples of chronic lymphocytic leukaemia, profiled for somatic mutations, RNA expression, DNA methylation and ex vivo drug responses. MOFA identified major dimensions of disease heterogeneity, including immunoglobulin heavy-chain variable region status, trisomy of chromosome 12 and previously underappreciated drivers, such as response to oxidative stress. In a second application, we used MOFA to analyse single-cell multi-omics data, identifying coordinated transcriptional and epigenetic changes along cell differentiation. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

Computer-based diagnostic expert systems in rheumatology: where do we stand in 2014?

PubMed

Alder, Hannes; Michel, Beat A; Marx, Christian; Tamborrini, Giorgio; Langenegger, Thomas; Bruehlmann, Pius; Steurer, Johann; Wildi, Lukas M

2014-01-01

Background. The early detection of rheumatic diseases and the treatment to target have become of utmost importance to control the disease and improve its prognosis. However, establishing a diagnosis in early stages is challenging as many diseases initially present with similar symptoms and signs. Expert systems are computer programs designed to support the human decision making and have been developed in almost every field of medicine. Methods. This review focuses on the developments in the field of rheumatology to give a comprehensive insight. Medline, Embase, and Cochrane Library were searched. Results. Reports of 25 expert systems with different design and field of application were found. The performance of 19 of the identified expert systems was evaluated. The proportion of correctly diagnosed cases was between 43.1 and 99.9%. Sensitivity and specificity ranged from 62 to 100 and 88 to 98%, respectively. Conclusions. Promising diagnostic expert systems with moderate to excellent performance were identified. The validation process was in general underappreciated. None of the systems, however, seemed to have succeeded in daily practice. This review identifies optimal characteristics to increase the survival rate of expert systems and may serve as valuable information for future developments in the field.

Binding cooperativity between a ligand carbonyl group and a hydrophobic side chain can be enhanced by additional H-bonds in a distance dependent manner: A case study with thrombin inhibitors.

PubMed

Said, Ahmed M; Hangauer, David G

2015-01-01

One of the underappreciated non-covalent binding factors, which can significantly affect ligand-protein binding affinity, is the cooperativity between ligand functional groups. Using four different series of thrombin inhibitors, we reveal a strong positive cooperativity between an H-bond accepting carbonyl functionality and the adjacent P3 hydrophobic side chain. Adding an H-bond donating amine adjacent to the P3 hydrophobic side chain further increases this positive cooperativity thereby improving the Ki by as much as 546-fold. In contrast, adding an amidine multiple H-bond/salt bridge group in the distal S1 pocket does not affect this cooperativity. An analysis of the crystallographic B-factors of the ligand groups inside the binding site indicates that the strong cooperativity is mainly due to a significant mutual reduction in the residual mobility of the hydrophobic side chain and the H-bonding functionalities that is absent when the separation distance is large. This type of cooperativity is important to encode in binding affinity prediction software, and to consider in SAR studies. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Melatonin: An Underappreciated Player in Retinal Physiology and Pathophysiology

PubMed Central

Tosini, Gianluca; Baba, Kenkichi; Hwang, Christopher K.; Iuvone, P. Michael

2012-01-01

In the vertebrate retina, melatonin is synthesized by the photoreceptors with high levels of melatonin at night and lower levels during the day. Melatonin exerts its influence by interacting with a family of G-protein-coupled receptors that are negatively coupled with adenylyl cyclase. Melatonin receptors belonging to the subtypes MT1 and MT2 have been identified in the mammalian retina. MT1 and MT2 receptors are found in all layers of the neural retina and in the retinal pigmented epithelium. Melatonin in the eye is believed to be involved in the modulation of many important retinal functions; it can modulate the electroretinogram (ERG), and administration of exogenous melatonin increases light-induced photoreceptor degeneration. Melatonin may also have protective effects on retinal pigment epithelial cells, photoreceptors and ganglion cells. A series of studies have implicated melatonin in the pathogenesis of age-related macular degeneration, and melatonin administration may represent a useful approach to prevent and treat glaucoma. Melatonin is used by millions of people around the world to retard aging, improve sleep performance, mitigate jet lag symptoms, and treat depression. Administration of exogenous melatonin at night may also be beneficial for ocular health, but additional investigation is needed to establish its potential. PMID:22960156

Climate variability has a stabilizing effect on the coexistence of prairie grasses

PubMed Central

Adler, Peter B.; HilleRisLambers, Janneke; Kyriakidis, Phaedon C.; Guan, Qingfeng; Levine, Jonathan M.

2006-01-01

How expected increases in climate variability will affect species diversity depends on the role of such variability in regulating the coexistence of competing species. Despite theory linking temporal environmental fluctuations with the maintenance of diversity, the importance of climate variability for stabilizing coexistence remains unknown because of a lack of appropriate long-term observations. Here, we analyze three decades of demographic data from a Kansas prairie to demonstrate that interannual climate variability promotes the coexistence of three common grass species. Specifically, we show that (i) the dynamics of the three species satisfy all requirements of “storage effect” theory based on recruitment variability with overlapping generations, (ii) climate variables are correlated with interannual variation in species performance, and (iii) temporal variability increases low-density growth rates, buffering these species against competitive exclusion. Given that environmental fluctuations are ubiquitous in natural systems, our results suggest that coexistence based on the storage effect may be underappreciated and could provide an important alternative to recent neutral theories of diversity. Field evidence for positive effects of variability on coexistence also emphasizes the need to consider changes in both climate means and variances when forecasting the effects of global change on species diversity. PMID:16908862

Biological basis and pathological relevance of microvascular thrombosis.

PubMed

Pfeiler, Susanne; Massberg, Steffen; Engelmann, Bernd

2014-05-01

Microvascular thrombosis indicates a pathological occlusion of microvessels by fibrin- and/or platelet-rich thrombi. It is observed during systemic infections, cancer, myocardial infarction, stroke, neurodegenerative diseases and in thrombotic microangiopathies. Microvessel thrombosis can cause greatly differing symptoms that range from limited changes in plasma coagulation markers to severe multi-organ failure. Because microvessel thrombi are difficult to detect and often occur only transiently, their importance for disease development and host biology is likely markedly under-appreciated. Recently, clear indications for a biological basis of microvascular thrombosis have been obtained. During systemic infections microvessel thrombosis can mediate an intravascular innate immune response (immunothrombosis). This biological form of thrombosis is based on the generation of fibrin inside blood vessels and is critically triggered by neutrophils and their interactions with platelets which result in the release of neutrophil extracellular traps (extracellular nucleosomes). Immunothrombosis is critically supported by neutrophil elastase and the activator molecules of blood coagulation tissue factor and factor XII. Identification of the biological driving forces of microvascular thrombosis should help to elucidate the mechanisms promoting pathological vessel occlusions in both microvessels and large vessels. Copyright © 2014 Elsevier Ltd. All rights reserved.

Short-duration respirometry underestimates metabolic rate for discontinuous breathers.

PubMed

Winwood-Smith, Hugh S; White, Craig R

2018-06-07

Metabolic rate is commonly estimated from rates of gas exchange. An underappreciated factor that can influence estimates is patterns of pulmonary respiration. Amphibians display discontinuous respiratory patterns, often including long apnoeas, in addition to cutaneous gas exchange. The contribution of cutaneous exchange increases at low temperatures when metabolic rate is low. Due to the relatively low permeability of skin, measurements that disproportionately capture cutaneous exchange can produce underestimates of metabolic rate. The permeability of amphibian skin to CO 2 is greater than O 2 , therefore calculating the ratio of whole-animal CO 2 emission to O 2 uptake (the respiratory exchange ratio, RER) can be used to avoid underestimates of metabolic rate by ensuring that observed values of RER fall within the normal physiological range (∼0.7 to 1). Using data for cane toads Rhinella marina we show that short-duration measurements lead to underestimates of metabolic rate and overestimates of RER. At low temperatures this problem is exacerbated, requiring over 12 hours for RER to fall within the normal physiological range. Many published values of metabolic rate in animals that utilise cutaneous exchange may be underestimates. © 2018. Published by The Company of Biologists Ltd.

Cortisol shifts financial risk preferences

PubMed Central

Kandasamy, Narayanan; Hardy, Ben; Page, Lionel; Schaffner, Markus; Graggaber, Johann; Powlson, Andrew S.; Fletcher, Paul C.; Gurnell, Mark; Coates, John

2014-01-01

Risk taking is central to human activity. Consequently, it lies at the focal point of behavioral sciences such as neuroscience, economics, and finance. Many influential models from these sciences assume that financial risk preferences form a stable trait. Is this assumption justified and, if not, what causes the appetite for risk to fluctuate? We have previously found that traders experience a sustained increase in the stress hormone cortisol when the amount of uncertainty, in the form of market volatility, increases. Here we ask whether these elevated cortisol levels shift risk preferences. Using a double-blind, placebo-controlled, cross-over protocol we raised cortisol levels in volunteers over 8 d to the same extent previously observed in traders. We then tested for the utility and probability weighting functions underlying their risk taking and found that participants became more risk-averse. We also observed that the weighting of probabilities became more distorted among men relative to women. These results suggest that risk preferences are highly dynamic. Specifically, the stress response calibrates risk taking to our circumstances, reducing it in times of prolonged uncertainty, such as a financial crisis. Physiology-induced shifts in risk preferences may thus be an underappreciated cause of market instability. PMID:24550472

Production of ultrasonic vocalizations by Peromyscus mice in the wild

PubMed Central

Kalcounis-Rueppell, Matina C; Metheny, Jackie D; Vonhof, Maarten J

2006-01-01

Background There has been considerable research on rodent ultrasound in the laboratory and these sounds have been well quantified and characterized. Despite the value of research on ultrasound produced by mice in the lab, it is unclear if, and when, these sounds are produced in the wild, and how they function in natural habitats. Results We have made the first recordings of ultrasonic vocalizations produced by two free-living species of mice in the genus Peromyscus (P. californicus and P. boylii) on long term study grids in California. Over 6 nights, we recorded 65 unique ultrasonic vocalization phrases from Peromyscus. The ultrasonic vocalizations we recorded represent 7 different motifs. Within each motif, there was considerable variation in the acoustic characteristics suggesting individual and contextual variation in the production of ultrasound by these species. Conclusion The discovery of the production of ultrasonic vocalizations by Peromyscus in the wild highlights an underappreciated component in the behavior of these model organisms. The ability to examine the production of ultrasonic vocalizations in the wild offers excellent opportunities to test hypotheses regarding the function of ultrasound produced by rodents in a natural context. PMID:16507093

Biological synthesis of nanoparticles in biofilms.

PubMed

Tanzil, Abid H; Sultana, Sujala T; Saunders, Steven R; Shi, Liang; Marsili, Enrico; Beyenal, Haluk

2016-12-01

The biological synthesis of nanoparticles (NPs) by bacteria and biofilms via extracellular redox reactions has received attention because of the minimization of harmful chemicals, low cost, and ease of culturing and downstream processing. Bioreduction mechanisms vary across bacteria and growth conditions, which leads to various sizes and shapes of biosynthesized NPs. NP synthesis in biofilms offers additional advantages, such as higher biomass concentrations and larger surface areas, which can lead to more efficient and scalable biosynthesis. Although biofilms have been used to produce NPs, the mechanistic details of NP formation are not well understood. In this review, we identify three critical areas of research and development needed to advance our understanding of NP production by biofilms: 1) synthesis, 2) mechanism and 3) stabilization. Advancement in these areas could result in the biosynthesis of NPs that are suitable for practical applications, especially in drug delivery and biocatalysis. Specifically, the current status of methods and mechanisms of nanoparticle synthesis and surface stabilization using planktonic bacteria and biofilms is discussed. We conclude that the use of biofilms to synthesize and stabilize NPs is underappreciated and could provide a new direction in biofilm-based NP production. Copyright © 2016 Elsevier Inc. All rights reserved.

Local GABAergic signaling within sensory ganglia controls peripheral nociceptive transmission

PubMed Central

Du, Xiaona; Hao, Han; Yang, Yuehui; Huang, Sha; Wang, Caixue; Gigout, Sylvain; Ramli, Rosmaliza; Li, Xinmeng; Jaworska, Ewa; Edwards, Ian; Yanagawa, Yuchio; Qi, Jinlong; Guan, Bingcai; Jaffe, David B.; Zhang, Hailin

2017-01-01

The integration of somatosensory information is generally assumed to be a function of the central nervous system (CNS). Here we describe fully functional GABAergic communication within rodent peripheral sensory ganglia and show that it can modulate transmission of pain-related signals from the peripheral sensory nerves to the CNS. We found that sensory neurons express major proteins necessary for GABA synthesis and release and that sensory neurons released GABA in response to depolarization. In vivo focal infusion of GABA or GABA reuptake inhibitor to sensory ganglia dramatically reduced acute peripherally induced nociception and alleviated neuropathic and inflammatory pain. In addition, focal application of GABA receptor antagonists to sensory ganglia triggered or exacerbated peripherally induced nociception. We also demonstrated that chemogenetic or optogenetic depolarization of GABAergic dorsal root ganglion neurons in vivo reduced acute and chronic peripherally induced nociception. Mechanistically, GABA depolarized the majority of sensory neuron somata, yet produced a net inhibitory effect on the nociceptive transmission due to the filtering effect at nociceptive fiber T-junctions. Our findings indicate that peripheral somatosensory ganglia represent a hitherto underappreciated site of somatosensory signal integration and offer a potential target for therapeutic intervention. PMID:28375159

Mental disorders, health inequalities and ethics: A global perspective

PubMed Central

NGUI, EMMANUEL M.; KHASAKHALA, LINCOLN; NDETEI, DAVID; ROBERTS, LAURA WEISS

2010-01-01

The global burden of neuropsychiatry diseases and related mental health conditions is enormous, underappreciated and under resourced, particularly in the developing nations. The absence of adequate and quality mental health infrastructure and workforce is increasingly recognized. The ethical implications of inequalities in mental health for people and nations are profound and must be addressed in efforts to fulfil key bioethics principles of medicine and public health: respect for individuals, justice, beneficence, and non-malfeasance. Stigma and discrimination against people living with mental disorders affects their education, employment, access to care and hampers their capacity to contribute to society. Mental health well-being is closely associated to several Millennium Development Goals and economic development sectors including education, labour force participation, and productivity. Limited access to mental health care increases patient and family suffering. Unmet mental health needs have a negative effect on poverty reduction initiatives and economic development. Untreated mental conditions contribute to economic loss because they increase school and work absenteeism and dropout rates, healthcare expenditure, and unemployment. Addressing unmet mental health needs will require development of better mental health infrastructure and workforce and overall integration of mental and physical health services with primary care, especially in the developing nations. PMID:20528652

Dinner rituals that correlate with child and adult BMI.

PubMed

Wansink, Brian; van Kleef, Ellen

2014-05-01

What predicts whether a child will be at risk for obesity? Whereas past research has focused on foods, eating habits, feeding styles, and family meal patterns, this study departs from a food-centric approach to examine how various dinner rituals might influence the BMIs of children and adults. In this study of 190 parents (BMI = 29.1 ± 7.2) and 148 children (BMI = 20.3 ± 4.4), the relationship between their BMIs and everyday family dinner rituals was examined using both correlation and regression analysis (controlled for educational level of parents). Families who frequently ate dinner in the kitchen or dining room had significantly lower BMIs for both adults (r = -0.31) and children (r = -0.24) compared to families who ate elsewhere. Additionally, helping cook dinner was associated with higher BMI for girls (r = 0.26), and remaining at the table until everyone is finished with eating was associated with lower BMI for boys (r = -0.31). Dinner tables may be one place where social support and family involvement meet-both of which relate to the BMI of children as well as parents. Family meals and their rituals might be an underappreciated battleground to fight obesity. Copyright © 2013 The Obesity Society.

Reliability of infarct volumetry: Its relevance and the improvement by a software-assisted approach.

PubMed

Friedländer, Felix; Bohmann, Ferdinand; Brunkhorst, Max; Chae, Ju-Hee; Devraj, Kavi; Köhler, Yvette; Kraft, Peter; Kuhn, Hannah; Lucaciu, Alexandra; Luger, Sebastian; Pfeilschifter, Waltraud; Sadler, Rebecca; Liesz, Arthur; Scholtyschik, Karolina; Stolz, Leonie; Vutukuri, Rajkumar; Brunkhorst, Robert

2017-08-01

Despite the efficacy of neuroprotective approaches in animal models of stroke, their translation has so far failed from bench to bedside. One reason is presumed to be a low quality of preclinical study design, leading to bias and a low a priori power. In this study, we propose that the key read-out of experimental stroke studies, the volume of the ischemic damage as commonly measured by free-handed planimetry of TTC-stained brain sections, is subject to an unrecognized low inter-rater and test-retest reliability with strong implications for statistical power and bias. As an alternative approach, we suggest a simple, open-source, software-assisted method, taking advantage of automatic-thresholding techniques. The validity and the improvement of reliability by an automated method to tMCAO infarct volumetry are demonstrated. In addition, we show the probable consequences of increased reliability for precision, p-values, effect inflation, and power calculation, exemplified by a systematic analysis of experimental stroke studies published in the year 2015. Our study reveals an underappreciated quality problem in translational stroke research and suggests that software-assisted infarct volumetry might help to improve reproducibility and therefore the robustness of bench to bedside translation.

The birth of the blues : how physics underlies music.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gibson, J. M.

Art and science have intimate connections, although these are often underappreciated. Western music provides compelling examples. The sensation of harmony and related melodic development are rooted in physical principles that can be understood with simple mathematics. The focus of this review is not the better known acoustics of instruments, but the structure of music itself. The physical basis of the evolution of Western music in the last half millennium is discussed, culminating with the development of the 'blues'. The paper refers to a number of works which expand the connections, and introduces material specific to the development of the 'blues'.more » Several conclusions are made: (1) that music is axiomatic like mathematics and that to appreciate music fully listeners must learn the axioms; (2) that this learning does not require specific conscious study but relies on a linkage between the creative and quantitative brain and (3) that a key element of the musical 'blues' comes from recreating missing notes on the modern equal temperament scale. The latter is an example of 'art built on artifacts'. Finally, brief reference is made to the value of music as a tool for teaching physics, mathematics and engineering to non-scientists.« less

The mosaic of equestrian-related injuries in Greece.

PubMed

Petridou, Eleni; Kedikoglou, Simos; Belechri, Maria; Ntouvelis, Evangelos; Dessypris, Nick; Trichopoulos, Dimitrios

2004-03-01

This study aims to estimate the burden and describe the profile of equestrian injuries in Greece, where horses, donkeys, and mules are still used in agriculture and where horse riding is a popular leisure activity. Prospectively collected information on 140,823 injuries reported in the national Emergency Department Injury Surveillance System was examined and 244 equestrian-related injuries that occurred during farming, equestrian sports, or horse racing were analyzed. The estimated countrywide injury incidence for farming and equestrian sports combined was 21 per 100,000 person-years, but it was 160 times higher for horse-racing personnel. Men had higher rates of racing injuries and women had higher rates of equestrian sport injuries. Fractures accounted for 39.0% of injuries in horse racing and 30.5% in farming; head injuries accounted for approximately 50% of injuries among farmers. Farming injuries were more serious, with 25% requiring hospitalization. Analysis through the Barell matrix pointed to the role of spurs in the causation of ankle fractures and dislocations and the likely contribution of helmets in preventing traumatic brain injuries. Equestrian-related injuries are a serious but underappreciated health problem and merit targeted prevention efforts for each category affected.

Ancestry-Specific Methylation Patterns in Admixed Offspring from an Experimental Coyote and Gray Wolf Cross.

PubMed

vonHoldt, Bridgett; Heppenheimer, Elizabeth; Petrenko, Vladimir; Croonquist, Paula; Rutledge, Linda Y

2017-06-01

Reduced fitness of admixed individuals is typically attributed to genetic incompatibilities. Although mismatched genomes can lead to fitness changes, in some cases the reduction in hybrid fitness is subtle. The potential role of transcriptional regulation in admixed genomes could provide a mechanistic explanation for these discrepancies, but evidence is lacking for nonmodel organisms. Here, we explored the intersection of genetics and gene regulation in admixed genomes derived from an experimental cross between a western gray wolf and western coyote. We found a significant positive association between methylation and wolf ancestry, and identified outlier genes that have been previously implicated in inbreeding-related, or otherwise deleterious, phenotypes. We describe a pattern of site-specific, rather than genome-wide, methylation driven by inter-specific hybridization. Epigenetic variation is thus suggested to play a nontrivial role in both maintaining and combating mismatched genotypes through putative transcriptional mechanisms. We conclude that the regulation of gene expression is an underappreciated key component of hybrid genome functioning, but could also act as a potential source of novel and beneficial adaptive variation in hybrid offspring. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Cortisol shifts financial risk preferences.

PubMed

Kandasamy, Narayanan; Hardy, Ben; Page, Lionel; Schaffner, Markus; Graggaber, Johann; Powlson, Andrew S; Fletcher, Paul C; Gurnell, Mark; Coates, John

2014-03-04

Risk taking is central to human activity. Consequently, it lies at the focal point of behavioral sciences such as neuroscience, economics, and finance. Many influential models from these sciences assume that financial risk preferences form a stable trait. Is this assumption justified and, if not, what causes the appetite for risk to fluctuate? We have previously found that traders experience a sustained increase in the stress hormone cortisol when the amount of uncertainty, in the form of market volatility, increases. Here we ask whether these elevated cortisol levels shift risk preferences. Using a double-blind, placebo-controlled, cross-over protocol we raised cortisol levels in volunteers over 8 d to the same extent previously observed in traders. We then tested for the utility and probability weighting functions underlying their risk taking and found that participants became more risk-averse. We also observed that the weighting of probabilities became more distorted among men relative to women. These results suggest that risk preferences are highly dynamic. Specifically, the stress response calibrates risk taking to our circumstances, reducing it in times of prolonged uncertainty, such as a financial crisis. Physiology-induced shifts in risk preferences may thus be an underappreciated cause of market instability.

The pathogenesis and treatment of cardiac atrophy in cancer cachexia.

PubMed

Murphy, Kate T

2016-02-15

Cancer cachexia is a multifactorial syndrome characterized by a progressive loss of skeletal muscle mass associated with significant functional impairment. In addition to a loss of skeletal muscle mass and function, many patients with cancer cachexia also experience cardiac atrophy, remodeling, and dysfunction, which in the field of cancer cachexia is described as cardiac cachexia. The cardiac alterations may be due to underlying heart disease, the cancer itself, or problems initiated by the cancer treatment and, unfortunately, remains largely underappreciated by clinicians and basic scientists. Despite recent major advances in the treatment of cancer, little progress has been made in the treatment of cardiac cachexia in cancer, and much of this is due to lack of information regarding the mechanisms. This review focuses on the cardiac atrophy associated with cancer cachexia, describing some of the known mechanisms and discussing the current and future therapeutic strategies to treat this condition. Above all else, improved awareness of the condition and an increased focus on identification of mechanisms and therapeutic targets will facilitate the eventual development of an effective treatment for cardiac atrophy in cancer cachexia. Copyright © 2016 the American Physiological Society.

Separating the from the Imagined: Flight Research at the NACA and NASA, 1915-1998

NASA Technical Reports Server (NTRS)

Gorn, Michael H.

2000-01-01

One of the most important, but under-appreciated, aspects of the NACA/NASA mission is its aeronautical R&D efforts. Within a short time of the first flight of the Wright brothers in 1903, the United States government recognized the importance of fostering development in the new and critical field of aeronautics. NASA's predecessor, the National Advisory Committee for Aeronautics (NACA), was chartered by Congress in 1915 specifically "to supervise and direct the scientific study of the problems of flight, with a view to their practical solution. " This became an enormously important government research and development activity for the next half century, materially enhancing the development of aeronautics 'in America. The results of the NACA's research appeared in more than 16,000 research reports of one type or another, distributed widely for the benefit of all. Many of the reports documenting R&D conducted under NACA auspices are still being used today. Since the creation of NASA in 1958, the critical R&D function has continued but is not well known. This work documents the historical R&D program of the agency by focusing on flight research.

Pollination by nocturnal Lepidoptera, and the effects of light pollution: a review.

PubMed

MacGregor, Callum J; Pocock, Michael J O; Fox, Richard; Evans, Darren M

2015-06-01

1. Moths (Lepidoptera) are the major nocturnal pollinators of flowers. However, their importance and contribution to the provision of pollination ecosystem services may have been under-appreciated. Evidence was identified that moths are important pollinators of a diverse range of plant species in diverse ecosystems across the world. 2. Moth populations are known to be undergoing significant declines in several European countries. Among the potential drivers of this decline is increasing light pollution. The known and possible effects of artificial night lighting upon moths were reviewed, and suggest how artificial night lighting might in turn affect the provision of pollination by moths. The need for studies of the effects of artificial night lighting upon whole communities of moths was highlighted. 3. An ecological network approach is one valuable method to consider the effects of artificial night lighting upon the provision of pollination by moths, as it provides useful insights into ecosystem functioning and stability, and may help elucidate the indirect effects of artificial light upon communities of moths and the plants they pollinate. 4. It was concluded that nocturnal pollination is an ecosystem process that may potentially be disrupted by increasing light pollution, although the nature of this disruption remains to be tested.

The Ins and Outs of Meaning: Behavioral and Neuroanatomical Dissociation of Semantically-Driven Word Retrieval and Multimodal Semantic Recognition in Aphasia

PubMed Central

Mirman, Daniel; Zhang, Yongsheng; Wang, Ze; Coslett, H. Branch; Schwartz, Myrna F.

2015-01-01

Theories about the architecture of language processing differ with regard to whether verbal and nonverbal comprehension share a functional and neural substrate and how meaning extraction in comprehension relates to the ability to use meaning to drive verbal production. We (re-)evaluate data from 17 cognitive-linguistic performance measures of 99 participants with chronic aphasia using factor analysis to establish functional components and support vector regression-based lesion-symptom mapping to determine the neural correlates of deficits on these functional components. The results are highly consistent with our previous findings: production of semantic errors is behaviorally and neuroanatomically distinct from verbal and nonverbal comprehension. Semantic errors were most strongly associated with left ATL damage whereas deficits on tests of verbal and non-verbal semantic recognition were most strongly associated with damage to deep white matter underlying the frontal lobe at the confluence of multiple tracts, including the inferior fronto-occipital fasciculus, the uncinate fasciculus, and the anterior thalamic radiations. These results suggest that traditional views based on grey matter hub(s) for semantic processing are incomplete and that the role of white matter in semantic cognition has been underappreciated. PMID:25681739

Presence of Vaccine-Derived Newcastle Disease Viruses in Wild Birds

PubMed Central

Ayala, Andrea J.; Dimitrov, Kiril M.; Becker, Cassidy R.; Goraichuk, Iryna V.; Arns, Clarice W.; Bolotin, Vitaly I.; Ferreira, Helena L.; Gerilovych, Anton P.; Goujgoulova, Gabriela V.; Martini, Matheus C.; Muzyka, Denys V.; Orsi, Maria A.; Scagion, Guilherme P.; Silva, Renata K.; Solodiankin, Olexii S.; Stegniy, Boris T.; Miller, Patti J.; Afonso, Claudio L.

2016-01-01

Our study demonstrates the repeated isolation of vaccine-derived Newcastle disease viruses from different species of wild birds across four continents from 1997 through 2014. The data indicate that at least 17 species from ten avian orders occupying different habitats excrete vaccine-derived Newcastle disease viruses. The most frequently reported isolates were detected among individuals in the order Columbiformes (n = 23), followed in frequency by the order Anseriformes (n = 13). Samples were isolated from both free-ranging (n = 47) and wild birds kept in captivity (n = 7). The number of recovered vaccine-derived viruses corresponded with the most widely utilized vaccines, LaSota (n = 28) and Hitchner B1 (n = 19). Other detected vaccine-derived viruses resembled the PHY-LMV2 and V4 vaccines, with five and two cases, respectively. These results and the ubiquitous and synanthropic nature of wild pigeons highlight their potential role as indicator species for the presence of Newcastle disease virus of low virulence in the environment. The reverse spillover of live agents from domestic animals to wildlife as a result of the expansion of livestock industries employing massive amounts of live virus vaccines represent an underappreciated and poorly studied effect of human activity on wildlife. PMID:27626272

The differential expression of IL-4 and IL-13 and its impact on type-2 immunity.

PubMed

Bao, Katherine; Reinhardt, R Lee

2015-09-01

Allergic disease represents a significant global health burden, and disease incidence continues to rise in urban areas of the world. As such, a better understanding of the basic immune mechanisms underlying disease pathology are key to developing therapeutic interventions to both prevent disease onset as well as to ameliorate disease morbidity in those individuals already suffering from a disorder linked to type-2 inflammation. Two factors central to type-2 immunity are interleukin (IL)-4 and IL-13, which have been linked to virtually all major hallmarks associated with type-2 inflammation. Therefore, IL-4 and IL-13 and their regulatory pathways represent ideal targets to suppress disease. Despite sharing many common regulatory pathways and receptors, these cytokines perform very distinct functions during a type-2 immune response. This review summarizes the literature surrounding the function and expression of IL-4 and IL-13 in CD4+ T cells and innate immune cells. It highlights recent findings in vivo regarding the differential expression and non-canonical regulation of IL-4 and IL-13 in various immune cells, which likely play important and underappreciated roles in type-2 immunity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Detectability matters: conspicuous nestling mouth colours make prey transfer easier for parents in a cavity nesting bird.

PubMed

Dugas, Matthew B

2015-11-01

An often underappreciated function of signals is to notify receivers of the presence and position of senders. The colours that ornament the mouthparts of nestling birds, for example, have been hypothesized to evolve via selective pressure generated by parents' inability to efficiently detect and feed nestlings without such visually conspicuous targets. This proposed mechanism has primarily been evaluated with comparative studies and experimental tests for parental allocation bias, leaving untested the central assumption of this detectability hypothesis, that provisioning offspring is a visually challenging task for avian parents and conspicuous mouths help. To test this assumption, I manipulated the mouths of nestling house sparrows to appear minimally and maximally conspicuous, and quantified prey transfer difficulty as the total duration of a feeding event and the number of transfer attempts required. Prey transfer to inconspicuous nestlings was, as predicted, more difficult. While this suggests that detectability constraints could shape nestling mouth colour evolution, even minimally conspicuous nestlings were not prohibitively difficult for parents to feed, indicating that a more nuanced explanation for interspecific diversity in this trait is needed. © 2015 The Author(s).

Peroneal tendon disorders

PubMed Central

Davda, Kinner; Malhotra, Karan; O’Donnell, Paul; Singh, Dishan; Cullen, Nicholas

2017-01-01

Pathological abnormality of the peroneal tendons is an under-appreciated source of lateral hindfoot pain and dysfunction that can be difficult to distinguish from lateral ankle ligament injuries. Enclosed within the lateral compartment of the leg, the peroneal tendons are the primary evertors of the foot and function as lateral ankle stabilisers. Pathology of the tendons falls into three broad categories: tendinitis and tenosynovitis, tendon subluxation and dislocation, and tendon splits and tears. These can be associated with ankle instability, hindfoot deformity and anomalous anatomy such as a low lying peroneus brevis or peroneus quartus. A thorough clinical examination should include an assessment of foot type (cavus or planovalgus), palpation of the peronei in the retromalleolar groove on resisted ankle dorsiflexion and eversion as well as testing of lateral ankle ligaments. Imaging including radiographs, ultrasound and MRI will help determine the diagnosis. Treatment recommendations for these disorders are primarily based on case series and expert opinion. The aim of this review is to summarise the current understanding of the anatomy and diagnostic evaluation of the peroneal tendons, and to present both conservative and operative management options of peroneal tendon lesions. Cite this article: EFORT Open Rev 2017;2:281-292. DOI: 10.1302/2058-5241.2.160047 PMID:28736620

Peroneal tendon disorders.

PubMed

Davda, Kinner; Malhotra, Karan; O'Donnell, Paul; Singh, Dishan; Cullen, Nicholas

2017-06-01

Pathological abnormality of the peroneal tendons is an under-appreciated source of lateral hindfoot pain and dysfunction that can be difficult to distinguish from lateral ankle ligament injuries.Enclosed within the lateral compartment of the leg, the peroneal tendons are the primary evertors of the foot and function as lateral ankle stabilisers.Pathology of the tendons falls into three broad categories: tendinitis and tenosynovitis, tendon subluxation and dislocation, and tendon splits and tears. These can be associated with ankle instability, hindfoot deformity and anomalous anatomy such as a low lying peroneus brevis or peroneus quartus.A thorough clinical examination should include an assessment of foot type (cavus or planovalgus), palpation of the peronei in the retromalleolar groove on resisted ankle dorsiflexion and eversion as well as testing of lateral ankle ligaments.Imaging including radiographs, ultrasound and MRI will help determine the diagnosis. Treatment recommendations for these disorders are primarily based on case series and expert opinion.The aim of this review is to summarise the current understanding of the anatomy and diagnostic evaluation of the peroneal tendons, and to present both conservative and operative management options of peroneal tendon lesions. Cite this article: EFORT Open Rev 2017;2:281-292. DOI: 10.1302/2058-5241.2.160047.

Herpes simplex virus type 2 (Mollaret's) meningitis: a case report.

PubMed

Abu Khattab, Mohammed; Al Soub, Hussam; Al Maslamani, Mona; Al Khuwaiter, Jameela; El Deeb, Yasser

2009-11-01

Mollaret's meningitis is an unusual and under-appreciated syndrome of benign, recurrent aseptic meningitis. The available literature indicates that the causative agent is herpes simplex virus type 2 (HSV-2) in the majority of cases and much less frequently herpes simplex virus type 1 (HSV-1). We report the case of a 49-year-old Indian female who had four attacks of recurrent lymphocytic meningitis (Mollaret's meningitis) occurring over a 7-year period. The diagnosis of herpes simplex meningitis was made at the time of the fourth episode by a positive PCR for herpes simplex virus infection in the cerebrospinal fluid. During the first three episodes, the patient was treated with anti-tuberculous drugs and antibiotics for bacterial meningitis; however for the last episode, once the diagnosis of herpes simplex meningitis was confirmed, only symptomatic treatment was given. No long-term suppressive therapy was given and no recurrence has been experienced so far. Mollaret's meningitis should be suspected in all cases of recurrent lymphocytic meningitis. Early diagnosis may prevent prolonged hospital admissions, unnecessary investigations, and exposure to unnecessary medications, with the associated considerable costs. Treatment with acyclovir may be beneficial in decreasing the severity and duration of attacks and in preventing further episodes. [Au?1].

Perceptions of Tobacco Control Media Campaigns Among Smokers With Lower Socioeconomic Status.

PubMed

McCullough, Anna; Meernik, Clare; Baker, Hannah; Jarman, Kristen; Walsh, Barbara; Goldstein, Adam O

2017-11-01

People with low socioeconomic status (SES) in the United States have disparately high rates of smoking and experience disproportionately high burdens of smoking-related disease. Tobacco control media campaigns are a critical strategy for reducing tobacco use prevalence, but evidence is mixed about the optimal use of mass media to reach and promote tobacco use cessation among people with low SES. Improved understanding of the factors influencing how low-SES tobacco users evaluate tobacco control media campaigns may inform development of more effective messages and strategies. Focus groups with primarily low-SES smokers in Connecticut were conducted, finding that participants had seen many tobacco control television ads that used graphic imagery and testimonials, but participants voiced two main themes that limited ad effectiveness: (1) skepticism about the content of ads, the role of the tobacco industry and the government in sponsoring the ads, and the safety and efficacy of cessation supports; and (2) barriers to quitting such as stress, social contexts, and addiction that participants perceived as being underappreciated in the context of the ads. Tobacco control media campaigns targeting low-SES tobacco users may need additional messages, tools, or refinements to more optimally motivate this group to make quit attempts.

Down but Not Out: The Consequences of Pretangle Tau in the Locus Coeruleus

PubMed Central

Chalermpalanupap, Termpanit; Weinshenker, David

2017-01-01

Degeneration of locus coeruleus (LC) is an underappreciated hallmark of Alzheimer's disease (AD). The LC is the main source of norepinephrine (NE) in the forebrain, and its degeneration is highly correlated with cognitive impairment and amyloid-beta (Aβ) and tangle pathology. Hyperphosphorylated tau in the LC is among the first detectable AD-like neuropathology in the brain, and while the LC/NE system impacts multiple aspects of AD (e.g., cognition, neuropathology, and neuroinflammation), the functional consequences of hyperphosphorylated tau accrual on LC neurons are not known. Recent evidence suggests that LC neurons accumulate aberrant tau species for decades before frank LC cell body degeneration occurs in AD, suggesting that a therapeutic window exists. In this review, we combine the literature on how pathogenic tau affects forebrain neurons with the known properties and degeneration patterns of LC neurons to synthesize hypotheses on hyperphosphorylated tau-induced dysfunction of LC neurons and the prion-like spread of pretangle tau from the LC to the forebrain. We also propose novel experiments using both in vitro and in vivo models to address the many questions surrounding the impact of hyperphosphorylated tau on LC neurons in AD and its role in disease progression. PMID:29038736

Parental Moral Distress and Moral Schism in the Neonatal ICU.

PubMed

Foe, Gabriella; Hellmann, Jonathan; Greenberg, Rebecca A

2018-05-25

Ethical dilemmas in critical care may cause healthcare practitioners to experience moral distress: incoherence between what one believes to be best and what occurs. Given that paediatric decision-making typically involves parents, we propose that parents can also experience moral distress when faced with making value-laden decisions in the neonatal intensive care unit. We propose a new concept-that parents may experience "moral schism"-a genuine uncertainty regarding a value-based decision that is accompanied by emotional distress. Schism, unlike moral distress, is not caused by barriers to making and executing a decision that is deemed to be best by the decision-makers but rather an encounter of significant internal struggle. We explore factors that appear to contribute to both moral distress and "moral schism" for parents: the degree of available support, a sense of coherence of the situation, and a sense of responsibility. We propose that moral schism is an underappreciated concept that needs to be explicated and may be more prevalent than moral distress when exploring decision-making experiences for parents. We also suggest actions of healthcare providers that may help minimize parental "moral schism" and moral distress.

Economic contract theory tests models of mutualism

PubMed Central

Weyl, E. Glen; Frederickson, Megan E.; Yu, Douglas W.; Pierce, Naomi E.

2010-01-01

Although mutualisms are common in all ecological communities and have played key roles in the diversification of life, our current understanding of the evolution of cooperation applies mostly to social behavior within a species. A central question is whether mutualisms persist because hosts have evolved costly punishment of cheaters. Here, we use the economic theory of employment contracts to formulate and distinguish between two mechanisms that have been proposed to prevent cheating in host–symbiont mutualisms, partner fidelity feedback (PFF) and host sanctions (HS). Under PFF, positive feedback between host fitness and symbiont fitness is sufficient to prevent cheating; in contrast, HS posits the necessity of costly punishment to maintain mutualism. A coevolutionary model of mutualism finds that HS are unlikely to evolve de novo, and published data on legume–rhizobia and yucca–moth mutualisms are consistent with PFF and not with HS. Thus, in systems considered to be textbook cases of HS, we find poor support for the theory that hosts have evolved to punish cheating symbionts; instead, we show that even horizontally transmitted mutualisms can be stabilized via PFF. PFF theory may place previously underappreciated constraints on the evolution of mutualism and explain why punishment is far from ubiquitous in nature. PMID:20733067

Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host-parasite interactions.

PubMed

Tao, Leiling; Gowler, Camden D; Ahmad, Aamina; Hunter, Mark D; de Roode, Jacobus C

2015-10-22

Host-parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host-parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host-parasite systems. © 2015 The Author(s).

A protective role for IL-13 receptor α 1 in bleomycin-induced pulmonary injury and repair

PubMed Central

Karo-Atar, D; Bordowitz, A; Wand, O; Pasmanik-Chor, M; Fernandez, I E; Itan, M; Frenkel, R; Herbert, D R; Finkelman, F D; Eickelberg, O; Munitz, A

2016-01-01

Molecular mechanisms that regulate lung repair vs. progressive scarring in pulmonary fibrosis remain elusive. Interleukin (IL)-4 and IL-13 are pro-fibrotic cytokines that share common receptor chains including IL-13 receptor (R) α1 and are key pharmacological targets in fibrotic diseases. However, the roles of IL-13Rα1 in mediating lung injury/repair are unclear. We report dysregulated levels of IL-13 receptors in the lungs of bleomycin-treated mice and to some extent in idiopathic pulmonary fibrosis patients. Transcriptional profiling demonstrated an epithelial cell-associated gene signature that was homeostatically dependent on IL-13Rα1 expression. IL-13Rα1 regulated a striking array of genes in the lung following bleomycin administration and Il13ra1 deficiency resulted in exacerbated bleomycin-induced disease. Increased pathology in bleomycin-treated Il13ra1−/− mice was due to IL-13Rα1 expression in structural and hematopoietic cells but not due to increased responsiveness to IL-17, IL-4, IL-13, increased IL-13Rα2 or type 1 IL-4R signaling. These data highlight underappreciated protective roles for IL-13Rα1 in lung injury and homeostasis. PMID:26153764

Cellular stress and innate inflammation in organ-specific autoimmunity: lessons learned from vitiligo

PubMed Central

Harris, John E.

2015-01-01

Summary For decades, research in autoimmunity has focused primarily on immune contributions to disease. Yet recent studies report elevated levels of reactive oxygen species (ROS) and abnormal activation of the unfolded protein response (UPR) in cells targeted by autoimmunity, implicating cellular stress originating from the target tissue as a contributing factor. A better understanding of this contribution may help to answer important lingering questions in organ-specific autoimmunity, like what factors initiate disease, and what directs its tissue specificity. Vitiligo, an autoimmune disease of the skin, has been the focus of translational research for over 30 years, and both melanocyte stress and immune mechanisms have been thought to be mutually exclusive explanations for pathogenesis. Chemical-induced vitiligo is a unique clinical presentation that reflects the importance of environmental influences on autoimmunity, provides insight into a new paradigm linking cell stress to the immune response, and serves as a template for other autoimmune diseases. In this review I will discuss the evidence for cell stress contributions to a number of autoimmune diseases, the questions that remain, and how vitiligo, an underappreciated example of organ-specific autoimmunity, helps to answer them. PMID:26683142

Mental disorders, health inequalities and ethics: A global perspective.

PubMed

Ngui, Emmanuel M; Khasakhala, Lincoln; Ndetei, David; Roberts, Laura Weiss

2010-01-01

The global burden of neuropsychiatry diseases and related mental health conditions is enormous, underappreciated and under resourced, particularly in the developing nations. The absence of adequate and quality mental health infrastructure and workforce is increasingly recognized. The ethical implications of inequalities in mental health for people and nations are profound and must be addressed in efforts to fulfil key bioethics principles of medicine and public health: respect for individuals, justice, beneficence, and non-malfeasance. Stigma and discrimination against people living with mental disorders affects their education, employment, access to care and hampers their capacity to contribute to society. Mental health well-being is closely associated to several Millennium Development Goals and economic development sectors including education, labour force participation, and productivity. Limited access to mental health care increases patient and family suffering. Unmet mental health needs have a negative effect on poverty reduction initiatives and economic development. Untreated mental conditions contribute to economic loss because they increase school and work absenteeism and dropout rates, healthcare expenditure, and unemployment. Addressing unmet mental health needs will require development of better mental health infrastructure and workforce and overall integration of mental and physical health services with primary care, especially in the developing nations.

Autogynephilia: an underappreciated paraphilia.

PubMed

Lawrence, Anne A

2011-01-01

Autogynephilia is defined as a male's propensity to be sexually aroused by the thought of himself as a female. It is the paraphilia that is theorized to underlie transvestism and some forms of male-to-female (MtF) transsexualism. Autogynephilia encompasses sexual arousal with cross-dressing and cross-gender expression that does not involve women's clothing per se. The concept of autogynephilia defines a typology of MtF transsexualism and offers a theory of motivation for one type of MtF transsexualism. Autogynephilia resembles a sexual orientation in that it involves elements of idealization and attachment as well as erotic desire. Nearly 3% of men in Western countries may experience autogynephilia; its most severe manifestation, MtF transsexualism, is rare but increasing in prevalence. Some theorists and clinicians reject the transsexual typology and theory of motivation derived from autogynephilia; their objections suggest a need for additional research. The concept of autogynephilia can assist clinicians in understanding some otherwise puzzling manifestations of nonhomosexual MtF transsexualism. Autogynephilia exemplifies an unusual paraphilic category called 'erotic target identity inversions', in which men desire to impersonate or turn their bodies into facsimiles of the persons or things to which they are sexually attracted. Copyright © 2011 S. Karger AG, Basel.

State Support: A Prerequisite for Global Health Network Effectiveness

PubMed Central

Marten, Robert; Smith, Richard D.

2018-01-01

Shiffman recently summarized lessons for network effectiveness from an impressive collection of case-studies. However, in common with most global health governance analysis in recent years, Shiffman underplays the important role of states in these global networks. As the body which decides and signs international agreements, often provides the resourcing, and is responsible for implementing initiatives all contributing to the prioritization of certain issues over others, state recognition and support is a prerequisite to enabling and determining global health networks’ success. The role of states deserves greater attention, analysis and consideration. We reflect upon the underappreciated role of the state within the current discourse on global health. We present the tobacco case study to illustrate the decisive role of states in determining progress for global health networks, and highlight how states use a legitimacy loop to gain legitimacy from and provide legitimacy to global health networks. Moving forward in assessing global health networks’ effectiveness, further investigating state support as a determinant of success will be critical. Understanding how global health networks and states interact and evolve to shape and support their respective interests should be a focus for future research. PMID:29524958

Dermatoscopic features of cutaneous non-facial non-acral lentiginous growth pattern melanomas

PubMed Central

Keir, Jeff

2014-01-01

Background: The dermatoscopic features of facial lentigo maligna (LM), facial lentigo maligna melanoma (LMM) and acral lentiginous melanoma (ALM) have been well described. This is the first description of the dermatoscopic appearance of a clinical series of cutaneous non-facial non-acral lentiginous growth pattern melanomas. Objective: To describe the dermatoscopic features of a series of cutaneous non-facial non-acral lentiginous growth pattern melanomas in an Australian skin cancer practice. Method: Single observer retrospective analysis of dermatoscopic images of a one-year series of cutaneous non-facial, non-acral melanomas reported as having a lentiginous growth pattern detected in an open access primary care skin cancer clinic in Australia. Lesions were scored for presence of classical criteria for facial LM; modified pattern analysis (“Chaos and Clues”) criteria; and the presence of two novel criteria: a lentigo-like pigment pattern lacking a lentigo-like border, and large polygons. Results: 20 melanomas occurring in 14 female and 6 male patients were included. Average patient age was 64 years (range: 44–83). Lesion distribution was: trunk 35%; upper limb 40%; and lower limb 25%. The incidences of criteria identified were: asymmetry of color or pattern (100%); lentigo-like pigment pattern lacking a lentigo-like border (90%); asymmetrically pigmented follicular openings (APFO’s) (70%); grey blue structures (70%); large polygons (45%); eccentric structureless area (15%); bright white lines (5%). 20% of the lesions had only the novel criteria and/or APFO’s. Limitations: Single observer, single center retrospective study. Conclusions: Cutaneous non-facial non-acral melanomas with a lentiginous growth pattern may have none or very few traditional criteria for the diagnosis of melanoma. Criteria that are logically expected in lesions with a lentiginous growth pattern (lentigo-like pigment pattern lacking a lentigo-like border, APFO’s) and the novel criterion of large polygons may be useful in increasing sensitivity and specificity of diagnosis of these lesions. Further study is required to establish the significance of these observations. PMID:24520520

Dermatoscopic features of cutaneous non-facial non-acral lentiginous growth pattern melanomas.

PubMed

Keir, Jeff

2014-01-01

The dermatoscopic features of facial lentigo maligna (LM), facial lentigo maligna melanoma (LMM) and acral lentiginous melanoma (ALM) have been well described. This is the first description of the dermatoscopic appearance of a clinical series of cutaneous non-facial non-acral lentiginous growth pattern melanomas. To describe the dermatoscopic features of a series of cutaneous non-facial non-acral lentiginous growth pattern melanomas in an Australian skin cancer practice. Single observer retrospective analysis of dermatoscopic images of a one-year series of cutaneous non-facial, non-acral melanomas reported as having a lentiginous growth pattern detected in an open access primary care skin cancer clinic in Australia. Lesions were scored for presence of classical criteria for facial LM; modified pattern analysis ("Chaos and Clues") criteria; and the presence of two novel criteria: a lentigo-like pigment pattern lacking a lentigo-like border, and large polygons. 20 melanomas occurring in 14 female and 6 male patients were included. Average patient age was 64 years (range: 44-83). Lesion distribution was: trunk 35%; upper limb 40%; and lower limb 25%. The incidences of criteria identified were: asymmetry of color or pattern (100%); lentigo-like pigment pattern lacking a lentigo-like border (90%); asymmetrically pigmented follicular openings (APFO's) (70%); grey blue structures (70%); large polygons (45%); eccentric structureless area (15%); bright white lines (5%). 20% of the lesions had only the novel criteria and/or APFO's. Single observer, single center retrospective study. Cutaneous non-facial non-acral melanomas with a lentiginous growth pattern may have none or very few traditional criteria for the diagnosis of melanoma. Criteria that are logically expected in lesions with a lentiginous growth pattern (lentigo-like pigment pattern lacking a lentigo-like border, APFO's) and the novel criterion of large polygons may be useful in increasing sensitivity and specificity of diagnosis of these lesions. Further study is required to establish the significance of these observations.

Book Review:

NASA Astrophysics Data System (ADS)

McKane, Alan

2003-12-01

This is a book about the modelling of complex systems and, unlike many books on this subject, concentrates on the discussion of specific systems and gives practical methods for modelling and simulating them. This is not to say that the author does not devote space to the general philosophy and definition of complex systems and agent-based modelling, but the emphasis is definitely on the development of concrete methods for analysing them. This is, in my view, to be welcomed and I thoroughly recommend the book, especially to those with a theoretical physics background who will be very much at home with the language and techniques which are used. The author has developed a formalism for understanding complex systems which is based on the Langevin approach to the study of Brownian motion. This is a mesoscopic description; details of the interactions between the Brownian particle and the molecules of the surrounding fluid are replaced by a randomly fluctuating force. Thus all microscopic detail is replaced by a coarse-grained description which encapsulates the essence of the interactions at the finer level of description. In a similar way, the influences on Brownian agents in a multi-agent system are replaced by stochastic influences which sum up the effects of these interactions on a finer scale. Unlike Brownian particles, Brownian agents are not structureless particles, but instead have some internal states so that, for instance, they may react to changes in the environment or to the presence of other agents. Most of the book is concerned with developing the idea of Brownian agents using the techniques of statistical physics. This development parallels that for Brownian particles in physics, but the author then goes on to apply the technique to problems in biology, economics and the social sciences. This is a clear and well-written book which is a useful addition to the literature on complex systems. It will be interesting to see if the use of Brownian agents becomes a standard tool in the study of complex systems in the future.

Alluvial fan facies of the Yongchong Basin: Implications for tectonic and paleoclimatic changes during Late Cretaceous in SE China

NASA Astrophysics Data System (ADS)

Chen, Liuqin; Steel, Ronald J.; Guo, Fusheng; Olariu, Cornel; Gong, Chenglin

2017-02-01

Late Cretaceous continental redbeds, the Guifeng Group of the Yongchong Basin in SE China have been investigated to conduct detailed fan facies description and interpretation. Tectonic activities determined the alluvial fan development along the basin margin, but the alluvial facies was linked with paleoclimate changes. The Guifeng Group is divided into the Hekou, Tangbian and Lianhe formations in ascending order. The Hekou conglomerates are typically polymict, moderately sorted with erosional bases, cut-and-fill features, normal grading and sieve deposits, representing dominant stream-flows on alluvial fans during the initial opening stage of the basin infill. The Tangbian Formation, however, is characterized by structureless fine-grained sediments with dispersed coarse clasts, and couplets of conglomerate and sandstone or siltstone and mudstone, recording a change to a playa and ephemeral lake environments with occasional stream flooding, thus indicating a basin expanding stage. The hallmark of the Lianhe Formation is disorganized, poorly sorted conglomerates lack of erosional bases, and a wide particle-size range from clay to boulders together reflect mud-rich debris-flows accumulating on fans, likely related to reactivation of faulting along the northwestern mountain fronts during a post-rift stage. The depositional system changes from stream-flows up through playa with ephemeral streams to debris-flows during the accumulation of the three formations are thus attributed to different source rocks and climatic conditions. Therefore, the fluvial-dominated fans of the Hekou Formation recorded a subhumid paleoclimate (Coniacian-Santonian Age). The dominant semiarid climate during the Campanian Age produced abundant fine-grained sediments in the playa and ephemeral lake environments of the Tangbian Formation. A climatic change towards more humidity during the late stage of the Guifeng Group (Maastrichtian Age) probably yielded high deposition rate of coarse clasts in debris-flow dominated fans of the Lianhe Formation. Thus the Late Cretaceous climate changes are inferred to have influenced and preserved signals in the alluvial stratigraphy of the Yongchong Basin.

Impacts of flamingos on saline lake margin and shallow lacustrine sediments in the Kenya Rift Valley

NASA Astrophysics Data System (ADS)

Scott, Jennifer J.; Renaut, Robin W.; Owen, R. Bernhart

2012-11-01

Studies of modern, Holocene, and Pleistocene sediments around saline to hypersaline, alkaline Lake Bogoria and Lake Magadi show that evidence of flamingo activity in marginal areas of these lakes is nearly ubiquitous. Flamingos produce discrete structures such as webbed footprints (~ 9 cm long, ~ 11 cm wide) and nest mounds (~ 30 cm wide, ~ 20 cm high), and they also extensively rework sediments in delta front, delta plain, and shoreline areas. Large (~ 0.5-2 cm in diameter), pinched, 'bubble pores' and ped-like mud clumps are formed by the trampling and churning of wet clay-rich sediments in these settings. Flamingo nest mounds, although superficially similar to some thrombolite mounds, are typically internally structureless, unless formed on pre-existing sediments that preserve internal structures. The flamingo mounds consist of a dense, packed oval-shaped core, a surrounding 'body' of packed sediment, and an external layer with a ped-like texture of clumped mud. The nests may contain open holes from roots or feather shafts incorporated into the nest, and (or) burrows produced once the nests are abandoned. In areas with high densities of flamingos, lake margin sediments may be preferentially compacted, particularly at breeding sites, and become resistant to subaerial erosion and the effects of transgressive ravinement on time scales ranging from seasons to tens of thousands of years. The relatively well-compacted nest mounds and associated sediments also contribute to the stability of delta distributary channels during regressive-transgressive cycles, and can lead to the minor channelization of unconfined flows where currents are diverted around nest mounds. Pleistocene exhumed surfaces of relatively well-indurated lake margin sediments at Lake Bogoria and Lake Magadi that are interpreted as combined regressive and transgressive surfaces (flooding surface/sequence boundary) preserve evidence of flamingo activities, and are overlain by younger, porous lacustrine silts that preserve large bubble pores produced by flamingos.

Anatomy and dimensions of fluvial crevasse-splay deposits: Examples from the Cretaceous Castlegate Sandstone and Neslen Formation, Utah, U.S.A.

NASA Astrophysics Data System (ADS)

Burns, C. E.; Mountney, N. P.; Hodgson, D. M.; Colombera, L.

2017-04-01

Crevasse-splay deposits form a volumetrically significant component of many fluvial overbank successions (up to 90% in some successions).Yet the relationships between the morphological form of accumulated splay bodies and their internal facies composition remains poorly documented from ancient successions. This work quantifies lithofacies distributions and dimensions of exhumed crevasse-splay architectural elements in the Campanian Castlegate Sandstone and Neslen Formation, Mesaverde Group, Utah, USA, to develop a depositional model. Fluvial crevasse-splay bodies thin from 2.1 m (average) to 0.8 m (average) and fine from a coarsest recorded grain size of lower-fine sand to fine silt away from major trunk channel bodies. Internally, the preserved deposits of splays comprise laterally and vertically variable sandstone and siltstone facies associations: proximal parts are dominated by sharp and erosional-based sandstone-prone units, which may be structureless or may comprise primary current lineation on beds and erosional gutter casts; medial parts comprise sets of climbing-ripple strata and small scale deformed beds; distal parts comprise sets of lower-stage plane beds and complex styles of lateral grading into fine-grained floodbasin siltstones and coals. Lithofacies arrangements are used to establish the following: (i) recognition criteria for crevasse-splay elements; (ii) criteria for the differentiation between distal parts of crevasse-splay bodies and floodplain fines; and (iii) empirical relationships with which to establish the extent (ca. 500 m long by 1000 m wide) and overall semi-elliptical planform shape of crevasse-splay bodies. These relationships have been established by high-resolution stratigraphic correlation and palaeocurrent analysis to identify outcrop orientation with respect to splay orientation. This permits lateral changes in crevasse-splay facies architecture to be resolved. Facies models describing the sedimentology and architecture of crevasse-splay deposits preserved in floodplain successions serve as tools for determining both distance from and direction to major trunk channel sandbodies.

Massive units deposited by bedload transport in sheet flow mode

NASA Astrophysics Data System (ADS)

Viparelli, E.; Hernandez Moreira, R. R.; Jafarinik, S.; Sanders, S.; Huffman, B.; Parker, G.; Kendall, C.

2017-12-01

A sandy massive (structureless) unit overlying a basal erosional surface and underlying a parallel or cross-laminated unit often characterizes turbidity current and coastal storm deposits. The basal massive units are thought to be the result of relatively rapid deposition of suspended sediment. However, suspension-based models fail to explain how basal massive units can be emplaced for long distances, far away from the source and can contain gravel particles as floating clasts. Here we present experimental results that can significantly change the understanding of the processes forming turbidity current and coastal storm deposits. The experiments were performed in open channel flow mode in the Hydraulics Laboratory at the University of South Carolina. The sediment was a mixture of sand size particles with a geometric mean diameter of 0.95 mm and a geometric standard deviation of 1.65. Five experiments were performed with a flow rate of 30 l/s and sediment feed rates varying between 1.5 kg/min and 20 kg/min. Each experiment was characterized by two phases, 1) the equilibration phase, in which we waited for the system to reach equilibrium condition, and 2) the aggradation phase, in which we slowly raised the water surface base level to induce channel bed aggradation under the same transport conditions observed over the equilibrium bed. Our experiments show that sandy massive units can be the result of deposition from a thick bedload layer of colliding grains, the sheet flow layer. The presence of this sheet flow layer explains how a strong, sustained current can emplace extensive massive units containing gravel clasts. Although our experiments were conducted in open-channel mode, observations of bedload driven by density underflows suggest that our results are directly applicable to sheet flows driven by deep-sea turbidity currents. More specifically, we believe that this mechanism offers an explanation for massive turbidites that heretofore have been identified as the deposits of "high density" turbidity currents.

Event sedimentation in low-latitude deep-water carbonate basins, Anegada passage, northeast Caribbean

USGS Publications Warehouse

Chaytor, Jason D.; ten Brink, Uri S.

2015-01-01

The Virgin Islands and Whiting basins in the Northeast Caribbean are deep, structurally controlled depocentres partially bound by shallow-water carbonate platforms. Closed basins such as these are thought to document earthquake and hurricane events through the accumulation of event layers such as debris flow and turbidity current deposits and the internal deformation of deposited material. Event layers in the Virgin Islands and Whiting basins are predominantly thin and discontinuous, containing varying amounts of reef- and slope-derived material. Three turbidites/sandy intervals in the upper 2 m of sediment in the eastern Virgin Islands Basin were deposited between ca. 2000 and 13 600 years ago, but do not extend across the basin. In the central and western Virgin Islands Basin, a structureless clay-rich interval is interpreted to be a unifite. Within the Whiting Basin, several discontinuous turbidites and other sand-rich intervals are primarily deposited in base of slope fans. The youngest of these turbidites is ca. 2600 years old. Sediment accumulation in these basins is low (−1) for basin adjacent to carbonate platform, possibly due to limited sediment input during highstand sea-level conditions, sediment trapping and/or cohesive basin walls. We find no evidence of recent sediment transport (turbidites or debris flows) or sediment deformation that can be attributed to the ca. M7.2 1867 Virgin Islands earthquake whose epicentre was located on the north wall of the Virgin Islands Basin or to recent hurricanes that have impacted the region. The lack of significant appreciable pebble or greater size carbonate material in any of the available cores suggests that submarine landslide and basin-wide blocky debris flows have not been a significant mechanism of basin margin modification in the last several thousand years. Thus, basins such as those described here may be poor recorders of past natural hazards, but may provide a long-term record of past oceanographic conditions in ocean passages.

Phreatomagmatic eruptive and depositional processes during the 1949 eruption on La Palma (Canary Islands)

NASA Astrophysics Data System (ADS)

White, James D. L.; Schmincke, Hans-Ulrich

1999-12-01

In 1949, a 5-week-long magmatic and phreatomagmatic eruption took place along the active volcanic ridge of La Palma (Canary Islands). Two vents, Duraznero and Hoyo Negro, produced significant pyroclastic deposits. The eruption began from Duraznero vent, which produced a series of deposits with an upward decrease in accidental fragments and increase in fluidal ash and spatter, together inferred to indicate decreasing phreatomagmatic interaction. Hoyo Negro erupted over a 2-week period, producing a variety of pyroclastic density currents and ballistic blocks and bombs. Hoyo Negro erupted within and modified an older crater having high walls on the northern to southeastern edges. Southwestern to western margins of the crater lay 50 to 100 m lower. Strongly contrasting deposits in the different sectors (N-SE vs. SW-W) were formed as a result of interaction between topography, weak eruptive columns and stratified pyroclastic density currents. Tephra ring deposits are thicker and coarser-grained than upper rim deposits formed along the higher edges of the crater, and beyond the crater margin, valley-confined deposits are thicker than more thinly bedded mantling deposits on higher topography. These differences indicate that the impact zone for the bulk of the collapsing, tephra-laden column lay within the crater and that the high crater walls inhibited escape of pyroclastic density currents to the north and east. The impact zone lay outside the low SW-W rims, however, thus allowing stratified pyroclastic density currents to move freely away from the crater in those directions, depositing thin sections (<30 cm) of well-bedded ash (mantling deposits) on ridges and thicker sections (1-3 m) of structureless ash beds in valleys and small basins. Such segregation of dense pyroclastic currents from more dilute ones at the crater wall is likely to be common for small eruptions from pre-existing craters and is an important factor to be taken into account in volcanic hazards assessments.

Sedimentology of Hirnantian glaciomarine deposits in the Balkan Terrane, western Bulgaria: Fixing a piece of the north peri-Gondwana jigsaw puzzle

NASA Astrophysics Data System (ADS)

Chatalov, Athanas

2017-04-01

Glaciomarine deposits of late Hirnantian age in the western part of the Palaeozoic Balkan Terrane have persistent thickness ( 7 m) and lateral uniformity in rock colour, bedding pattern, lithology, and sedimentary structures. Four lithofacies are distinguished from base to top: lonestone-bearing diamictites, interbedded structureless mudstones, crudely laminated diamictites, and finely laminated mudstones. The diamictites are clast-poor to clast-rich comprising muddy to sandy varieties. Their compositional maturity is evidenced by the very high amount of detrital quartz compared to the paucity of feldspar and unstable lithic grains. Other textural components include extraclasts derived from the local Ordovician basement, mudstone intraclasts, and sediment aggregates. Turbate structures, grain lineations, and soft sediment deformation of the matrix below larger grains are locally observed. Sedimentological analysis reveals that deposition occurred in an ice-intermediate to ice-distal, poorly agitated shelf environment by material supplied from meltwater buoyant plumes and rain-out from ice-rafted debris. Remobilization by mass-flow processes (cohesive debris flows and slumps) was an important mechanism particularly for the formation of massive diamictites. The glaciomarine deposits represent a typical deglaciation sequence reflecting retreat of the ice front (grounded or floating ice sheet), relative sea-level rise and gradually reduced sedimentation rate with increasing contribution from suspension fallout. This sequence was deposited on the non-glaciated shelf of the intracratonic North Gondwana platform along the southern margin of the Rheic Ocean. The Hirnantian strata of the Balkan Terrane can be correlated with similar glaciomarine deposits known from peri-Gondwana terranes elsewhere in Europe showing clear 'Armorican affinity'. Several lines of evidence suggest that the provenance of siliciclastic material was associated mainly with sedimentary recycling of mature sands which had been deposited across North Gondwana in Cambrian and pre-glacial Ordovician times.

Broadening the interpretive framework of deepwater deposits: 3D characterization of outcrop scale bedforms within supercritical dominated slope deposits of the Fish Creek-Vallecito Basin, Late-Miocene Gulf of California

NASA Astrophysics Data System (ADS)

West, L. M.; Steel, R.; Olariu, C.

2017-12-01

Study of seafloor bathymetry, numerical and physical modeling, and direct observation of turbidity currents increasingly suggests that sediment gravity flows over moderately steep basin slopes commonly reach Froude supercritical states. However, interpretation of supercritical features in deepwater outcrops remains limited in both quantity and scope, leaving stratigraphic qualities of supercritical deposits poorly understood. Slope turbidites on along steep margins of the early Gulf of California are exposed in seismic scale outcrops of the Late Miocene Lycium Member in the Fish Creek-Vallecito Basin of south-central California where they build 100s m-thick slopes. Measured sections, bedding orientation, and facies descriptions collected both for strike- and dip-oriented sections are combined with photogrammetric to characterize selected bedforms in three-dimensions. Analysis shows upflow accreting stacks of 10s of beds into a variety of bedforms with wavelengths and widths tens to hundreds of meters in scale and heights of 5-15 m. Beds have low-angle sinusoidal to sigmoidal down dip geometries and lens or lobate strike geometries. Bedding facies are dominated by 5-50 cm thick, normally graded, laminated sandstones capped by 1-3 cm bioturbated muds. Sandstones transition into interbedded sandstones and silty mudstones or 1-2 m thick silty mudstones. In places, Present also are incisional, steeply dipping backsets of 0.5-3 m-thick boulder-rich, amalgamated, structureless sandtones with abundant soft sediment deformation. that can transition downflow into arching, thinning, normally-graded sandstones. These bedforms are interpreted here as large-scale, long-lived supercritical deposits that represent preserved antidune and possibly cyclic steps bedforms or as-yet undefined bedforms incorporating by not bound by hydraulic jumps. This characterization provides new understanding of the nature of supercritical deposits and an important framework criteria for recognizing similar deposits elsewhere.

Comparing observations and morphodynamic numerical modeling of upper-flow-regime bedforms in fjords and outcrop

NASA Astrophysics Data System (ADS)

Hubbard, Stephen; Kostic, Svetlana; Englert, Rebecca; Coutts, Daniel; Covault, Jacob

2017-04-01

Recent bathymetric observations of fjord prodeltas in British Columbia, Canada, reveal evidence for multi-phase channel erosion and deposition. These processes are interpreted to be related to the upstream migration of upper-flow-regime bedforms, namely cyclic steps. We integrate data from high-resolution bathymetric surveys and monitoring to inform morphodynamic numerical models of turbidity currents and associated bedforms in the Squamish prodelta. These models are applied to the interpretation of upper-flow-regime bedforms, including cyclic steps, antidunes, and/or transitional bedforms, in Late Cretaceous submarine conduit strata of the Nanaimo Group at Gabriola Island, British Columbia. In the Squamish prodelta, as bedforms migrate, >90% of the deposits are reworked, making morphology- and facies-based recognition challenging. Sedimentary bodies are 5-30 m long, 0.5-2 m thick and <30 m wide. The Nanaimo Group comprises scour fills of similar scale composed of structureless sandstone, with laminated siltstone locally overlying basal erosion surfaces. Backset stratification is locally observed; packages of 2-4 backset beds, each of which are up to 60 cm thick and up to 15 m long (along dip), commonly share composite basal erosion surfaces. Numerous scour fills are recognized over thin sections (<4 m), indicating limited aggradation and preservation of the bedforms. Preliminary morphodynamic numerical modeling indicates that Squamish and Nanaimo bedforms could be transitional upper-flow-regime bedforms between cyclic steps and antidunes. It is likely that cyclic steps and related upper-flow-regime bedforms are common in strata deposited on high gradient submarine slopes. Evidence for updip-migrating cyclic step and related deposits inform a revised interpretation of a high gradient setting dominated by supercritical flow, or alternating supercritical and subcritical flow in the Nanaimo Group. Integrating direct observations, morphodynamic numerical modeling, and outcrop characterization better constrains fundamental processes that operate in deep-water depositional systems; our analyses aims to further deduce the stratigraphy and preservation potential of upper flow-regime bedforms.

Inelastic losses in X-ray absorption theory

NASA Astrophysics Data System (ADS)

Campbell, Luke Whalin

There is a surprising lack of many body effects observed in XAS (X-ray Absorption Spectroscopy) experiments. While collective excitations and other satellite effects account for between 20% and 40% of the spectral weight of the core hole and photoelectron excitation spectrum, the only commonly observed many body effect is a relatively structureless amplitude reduction to the fine structure, typically no more than a 10% effect. As a result, many particle effects are typically neglected in the XAS codes used to predict and interpret modern experiments. To compensate, the amplitude reduction factor is simply fitted to experimental data. In this work, a quasi-boson model is developed to treat the case of XAS, when the system has both a photoelectron and a core hole. We find that there is a strong interference between the extrinsic and intrinsic losses. The interference reduces the excitation amplitudes at low energies where the core hole and photo electron induced excitations tend to cancel. At high energies, the interference vanishes, and the theory reduces to the sudden approximation. The x-ray absorption spectrum including many-body excitations is represented by a convolution of the one-electron absorption spectrum with an energy dependent spectral function. The latter has an asymmetric quasiparticle peak and broad satellite structure. The net result is a phasor sum, which yields the many body amplitude reduction and phase shift of the fine structure oscillations (EXAFS), and possibly additional satellite structure. Calculations for several cases of interest are found to be in reasonable agreement with experiment. Edge singularity effects and deviations from the final state rule arising from this theory are also discussed. The ab initio XAS code FEFF has been extended for calculations of the many body amplitude reduction and phase shift in x-ray spectroscopies. A new broadened plasmon pole self energy is added. The dipole matrix elements are modified to include a projection operator to calculate deviations from the final state rule and edge singularities.

Cardio-Oncology: Cancer Therapy-related Cardiovascular Complications in a Molecular Targeted Era: New Concepts and Perspectives.

PubMed

Hurtado-de-Mendoza, David; Loaiza-Bonilla, Arturo; Bonilla-Reyes, Paula A; Tinoco, Gabriel; Alcorta, Rodrigo

2017-05-18

Cardio-oncology is a medical discipline that identifies, prevents, and treats the cardiovascular complications related to cancer therapy. Due to the remarkable proliferation of new cancer therapies causing cardiovascular complications, such as hypertension, heart failure, vascular complications, and cardiac arrhythmia, we provide an extensive, comprehensive revision of the most up-to-date scientific information available on the cardiovascular complications associated with the use of newer, novel chemotherapeutic agents, including their reported incidence, suggested pathophysiology, clinical manifestations, potential treatment, and prevention. The authors consider this topic to be relevant for the clinicians since cardiovascular complications associated with the administration of recently approved drugs are relatively underappreciated. The purpose of this article is to provide a state-of-the-art review of cardiovascular complications associated with the use of newer, novel chemotherapeutic agents and targeted therapies, including their reported incidence, suggested pathophysiology, clinical manifestations, potential treatment, and prevention.  Ongoing efforts are needed to provide a better understanding of the frequency, mechanisms of disease, prevention, and treatment of cardiovascular complications induced by the newer, novel chemotherapeutic agents. Development of a cardio-oncology discipline is warranted in order to promote task forces aimed at the creation of oncology patient-centered guidelines for the detection, prevention, and treatment of potential cardiovascular side effects associated with newer cancer therapies.

Lutein, Zeaxanthin, and meso-Zeaxanthin: The Basic and Clinical Science Underlying Carotenoid-based Nutritional Interventions against Ocular Disease

PubMed Central

Bernstein, Paul S.; Li, Binxing; Vachali, Preejith P.; Gorusupudi, Aruna; Shyam, Rajalekshmy; Henriksen, Bradley S.; Nolan, John M.

2015-01-01

The human macula uniquely concentrates three carotenoids: lutein, zeaxanthin, and meso-zeaxanthin. Lutein and zeaxanthin must be obtained from dietary sources such as green leafy vegetables and orange and yellow fruits and vegetables, while meso-zeaxanthin is rarely found in diet and is believed to be formed at the macula by metabolic transformations of ingested carotenoids. Epidemiological studies and large-scale clinical trials such as AREDS2 have brought attention to the potential ocular health and functional benefits of these three xanthophyll carotenoids consumed through the diet or supplements, but the basic science and clinical research underlying recommendations for nutritional interventions against age-related macular degeneration and other eye diseases are underappreciated by clinicians and vision researchers alike. In this review article, we first examine the chemistry, biophysics, and physiology of these yellow pigments that are specifically concentrated in the macula lutea through the means of high-affinity binding proteins and specialized transport and metabolic proteins where they play important roles as short-wavelength (blue) light-absorbers and localized, efficient antioxidants in a region at high risk for light-induced oxidative stress. Next, we turn to clinical evidence supporting functional benefits of these carotenoids in normal eyes and for their potential protective actions against ocular disease from infancy to old age. PMID:26541886

Macroevolutionary patterns of glucosinolate defense and tests of defense-escalation and resource availability hypotheses.

PubMed

Cacho, N Ivalú; Kliebenstein, Daniel J; Strauss, Sharon Y

2015-11-01

We explored macroevolutionary patterns of plant chemical defense in Streptanthus (Brassicaceae), tested for evolutionary escalation of defense, as predicted by Ehrlich and Raven's plant-herbivore coevolutionary arms-race hypothesis, and tested whether species inhabiting low-resource or harsh environments invest more in defense, as predicted by the resource availability hypothesis (RAH). We conducted phylogenetically explicit analyses using glucosinolate profiles, soil nutrient analyses, and microhabitat bareness estimates across 30 species of Streptanthus inhabiting varied environments and soils. We found weak to moderate phylogenetic signal in glucosinolate classes and no signal in total glucosinolate production; a trend toward evolutionary de-escalation in the numbers and diversity of glucosinolates, accompanied by an evolutionary increase in the proportion of aliphatic glucosinolates; some support for the RAH relative to soil macronutrients, but not relative to serpentine soil use; and that the number of glucosinolates increases with microhabitat bareness, which is associated with increased herbivory and drought. Weak phylogenetic signal in chemical defense has been observed in other plant systems. A more holistic approach incorporating other forms of defense might be necessary to confidently reject escalation of defense. That defense increases with microhabitat bareness supports the hypothesis that habitat bareness is an underappreciated selective force on plants in harsh environments. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Bats prove to be rich reservoirs for emerging viruses

USGS Publications Warehouse

Calisher, Charles H.; Holmes, Kathryn V.; Dominguez, Samuel R.; Schountz, Tony; Cryan, Paul M.

2008-01-01

Emerging pathogens, many of them viruses, continue to surprise us, providing many newly recognized diseases to study and to try to control. Many of these emergent viruses are zoonotic, transmitted from reservoirs in wild or domestic animals to humans, either by insect vectors or by exposure to the droppings or tissues of such animals. One rich- but, until recently, underappreciated-source of emergent viruses is bats (Chiroptera, meaning "hand wing"). Accounting for 1,116, or nearly one fourth, of the 4,600 recognized species of mammals, bats are grouped into two suborders Megachiroptera, which contains a single family, Pteropodidae, consisting of 42 genera and 186 species, and Microchiroptera, which contains 17 families, 160 genera, and 930 species. Although bats are among the most abundant, diverse, and geographically dispersed orders of terrestrial mammals, research on these flying mammals historically focused more on their habits and outward characteristics than on their role in carrying microorganisms and transmitting pathogens to other species. Even in those cases where bats were known to carry particular pathogens, the microbiologists who studied those pathogens typically knew little about the bat hosts. Hence, investigators now are seeking to explain how variations of anatomy, physiology, ecology, and behavior influence the roles of bats as hosts for viral pathogens.

Metabolite damage and repair in metabolic engineering design.

PubMed

Sun, Jiayi; Jeffryes, James G; Henry, Christopher S; Bruner, Steven D; Hanson, Andrew D

2017-11-01

The necessarily sharp focus of metabolic engineering and metabolic synthetic biology on pathways and their fluxes has tended to divert attention from the damaging enzymatic and chemical side-reactions that pathway metabolites can undergo. Although historically overlooked and underappreciated, such metabolite damage reactions are now known to occur throughout metabolism and to generate (formerly enigmatic) peaks detected in metabolomics datasets. It is also now known that metabolite damage is often countered by dedicated repair enzymes that undo or prevent it. Metabolite damage and repair are highly relevant to engineered pathway design: metabolite damage reactions can reduce flux rates and product yields, and repair enzymes can provide robust, host-independent solutions. Herein, after introducing the core principles of metabolite damage and repair, we use case histories to document how damage and repair processes affect efficient operation of engineered pathways - particularly those that are heterologous, non-natural, or cell-free. We then review how metabolite damage reactions can be predicted, how repair reactions can be prospected, and how metabolite damage and repair can be built into genome-scale metabolic models. Lastly, we propose a versatile 'plug and play' set of well-characterized metabolite repair enzymes to solve metabolite damage problems known or likely to occur in metabolic engineering and synthetic biology projects. Copyright © 2017 International Metabolic Engineering Society. All rights reserved.

Ecological consequences of interactions between ants and honeydew-producing insects

PubMed Central

Styrsky, John D; Eubanks, Micky D

2006-01-01

Interactions between ants and honeydew-producing hemipteran insects are abundant and widespread in arthropod food webs, yet their ecological consequences are very poorly known. Ant–hemipteran interactions have potentially broad ecological effects, because the presence of honeydew-producing hemipterans dramatically alters the abundance and predatory behaviour of ants on plants. We review several studies that investigate the consequences of ant–hemipteran interactions as ‘keystone interactions’ on arthropod communities and their host plants. Ant–hemipteran interactions have mostly negative effects on the local abundance and species richness of several guilds of herbivores and predators. In contrast, out of the 30 studies that document the effects of ant–hemipteran interactions on plants, the majority (73%) shows that plants actually benefit indirectly from these interactions. In these studies, increased predation or harassment of other, more damaging, herbivores by hemipteran-tending ants resulted in decreased plant damage and/or increased plant growth and reproduction. The ecological consequences of mutualistic interactions between honeydew-producing hemipterans and invasive ants relative to native ants have rarely been studied, but they may be of particular importance owing to the greater abundance, aggressiveness and extreme omnivory of invasive ants. We argue that ant–hemipteran interactions are largely overlooked and underappreciated interspecific interactions that have strong and pervasive effects on the communities in which they are embedded. PMID:17148245

Host-pathogen evolutionary signatures reveal dynamics and future invasions of vampire bat rabies.

PubMed

Streicker, Daniel G; Winternitz, Jamie C; Satterfield, Dara A; Condori-Condori, Rene Edgar; Broos, Alice; Tello, Carlos; Recuenco, Sergio; Velasco-Villa, Andrés; Altizer, Sonia; Valderrama, William

2016-09-27

Anticipating how epidemics will spread across landscapes requires understanding host dispersal events that are notoriously difficult to measure. Here, we contrast host and virus genetic signatures to resolve the spatiotemporal dynamics underlying geographic expansions of vampire bat rabies virus (VBRV) in Peru. Phylogenetic analysis revealed recent viral spread between populations that, according to extreme geographic structure in maternally inherited host mitochondrial DNA, appeared completely isolated. In contrast, greater population connectivity in biparentally inherited nuclear microsatellites explained the historical limits of invasions, suggesting that dispersing male bats spread VBRV between genetically isolated female populations. Host nuclear DNA further indicated unanticipated gene flow through the Andes mountains connecting the VBRV-free Pacific coast to the VBRV-endemic Amazon rainforest. By combining Bayesian phylogeography with landscape resistance models, we projected invasion routes through northern Peru that were validated by real-time livestock rabies mortality data. The first outbreaks of VBRV on the Pacific coast of South America could occur by June 2020, which would have serious implications for agriculture, wildlife conservation, and human health. Our results show that combining host and pathogen genetic data can identify sex biases in pathogen spatial spread, which may be a widespread but underappreciated phenomenon, and demonstrate that genetic forecasting can aid preparedness for impending viral invasions.

Inland Sea Spray Aerosol Transport and Incomplete Chloride Depletion: Varying Degrees of Reactive Processing Observed during SOAS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bondy, Amy L.; Wang, Bingbing; Laskin, Alexander

Multiphase reactions involving sea spray aerosol (SSA) impact trace gases budgets in coastal regions by acting as a reservoir for oxidized nitrogen and sulfur species, as well as a source of halogen gases (HCl, ClNO2, etc.). While most studies of multiphase reactions on SSA have focused on marine environments, far less is known about SSA transported inland. Herein, single particle measurements of SSA are reported at a site > 320 km from the Gulf of Mexico, with transport times of 7-68 h. Samples were collected during the Southern Oxidant and Aerosol Study (SOAS) in June-July 2013 near Centreville, Alabama. SSAmore » was observed in 93% of 42 time periods analyzed. During two marine air mass periods, SSA represented significant number fractions of particles in the accumulation (0.2-1.0 μm, 11%) and coarse (1.0-10.0 μm, 35%) modes. Chloride content of SSA particles ranged from full to partial depletion, with 24% of SSA particles containing chloride (mole fraction of Cl/Na > 0.1, 90% chloride depletion). Both the frequent observation of SSA at an inland site and the range of chloride depletion observed, suggest that SSA may represent an underappreciated inland sink for NOx/SO2 and source of halogen gases.« less

An evidence-based approach to assessing surgical versus clinical diagnosis of symptomatic endometriosis.

PubMed

Taylor, Hugh S; Adamson, G David; Diamond, Michael P; Goldstein, Steven R; Horne, Andrew W; Missmer, Stacey A; Snabes, Michael C; Surrey, Eric; Taylor, Robert N

2018-05-05

Challenges intrinsic to the accurate diagnosis of endometriosis contribute to an extended delay between the onset of symptoms and clinical confirmation. Intraoperative visualization, preferably with histologic verification, is considered by many professional organizations to be the gold standard by which endometriosis is diagnosed. Clinical diagnosis of symptomatic endometriosis via patient history, physical examination, and noninvasive tests, though more easily executed, is generally viewed as less accurate than surgical diagnosis. Technological advances and increased understanding of the pathophysiology of endometriosis warrant continuing reevaluation of the standard method for diagnosing symptomatic disease. A review of the published literature was therefore performed with the goal of comparing the accuracy of clinical diagnostic measures with that of surgical diagnosis. The current body of evidence suggests that clinical diagnosis of symptomatic endometriosis is more reliable than previously recognized and that surgical diagnosis has limitations that could be underappreciated. Regardless of the methodology used, women with suspected symptomatic endometriosis would be well served by a diagnostic paradigm that is reliable, conveys minimal risk of under- or over-diagnosis, lessens the time from symptom development to diagnosis, and guides the appropriate use of medical and surgical management strategies. © 2018 The Authors. International Journal of Gynecology & Obstetrics published by John Wiley & Sons Ltd on behalf of International Federation of Gynecology and Obstetrics.